RU2607147C2 - Method of engine actuation (versions) and engine system - Google Patents

Abstract

FIELD: engines.

SUBSTANCE: invention can be used in supercharged internal combustion engines. Engine actuation method comprises first charge provision with air having barometric pressure or below it into engine cylinder (14) through first inlet channel (30) and provision of second air charge subjected to supercharging, into same cylinder (14) through second, separate, inlet channel (31). Second air charge is subjected to supercharging by means of inlet compressor (52), driven by exhaust turbine (54). Invention discloses version of engine actuation method and engine system.

EFFECT: technical result consists in reduction of compressor and turbine dimensions.

19 cl, 9 dwg

Description

Cross reference to related applications

This application is a partial continuation of application No. 12 / 878,838 for the grant of a US patent entitled "Method and system for turbocharging an engine", filed September 9, 2010, the contents of which are incorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to a method for improving the thermal efficiency of a turbocharged engine. The method may be particularly useful for providing EGR (exhaust gas recirculation) in a turbocharged engine.

State of the art

The engine cylinders can be made with one or more inlets for receiving air charge. One or more inlets may extend from a common inlet or may have separate inlet ducts. In addition, one or more inlets can receive fresh air or can recirculate exhaust gases.

One example of a cylinder with a separate intake system is shown by Duret in US patent 6,135,088. There, in low-load modes, the first inlet of the cylinder is configured to receive recirculated exhaust gases, while the second inlet is configured to receive the air-fuel mixture that was pressurized, following the channel through the compressor.

However, the authors in the materials of this application have identified potential problems with such a system. As one example, the addition of an exhaust turbine to drive a compressor may render the system functions unsuitable. More specifically, if the turbine was included in a common outlet, the high pressure exhaust would be drawn into the inlet at a lower pressure (i.e., naturally aspirated), leading to EGR control problems. As another example, it may be difficult to provide higher pressure EGR (HP-EGR) to further improve engine performance during certain modes.

Disclosure of invention

In one example, some of the above problems can be at least partially solved by a method of driving the engine, including providing a first charge of air at or below barometric pressure into the engine cylinder through the first inlet channel and providing a second boosted air charge to the cylinder through a second, separate inlet channel, wherein the second air charge is boosted by an inlet compressor driven by an exhaust turbine. Thus, the inlet compressor can be driven by an exhaust turbine to deliver a pressurized inlet air charge to the cylinder through the inlet channel, while a naturally aspirated inlet air charge is supplied to the cylinder in parallel through a separate inlet channel. Different charges of air can then be mixed with each other and the fuel in the cylinder before burning.

In one example, the first inlet channel may be connected to the first outlet channel through a second, separate inlet channel connected to the second, separate outlet channel. A turbocharger compressor connected only to the second inlet channel can be driven by a turbocharger turbine connected only to the second outlet channel, thereby providing a boosted charge of air in the second inlet channel. In one example, fresh air at or below barometric pressure (BP) may be supplied to the cylinder through a first inlet valve in communication with the first inlet, while fresh air is supplied under compressor pressure (i.e., pressurized air) into the cylinder through a second inlet valve in communication with the second inlet channel. Thus, at least a portion of the fresh intake air can be provided by naturally aspirated suction while the other part is compressed. By reducing a portion of the intake air requiring compression, the compressor return can be increased, and the control delay can be reduced. In addition, the required boost can be provided by a smaller compressor and turbine without compromising the performance of the boost.

In an alternative example, one or both of the first and second charges of air may include at least some fresh air and at least some recycled exhaust gas. For example, at least a certain amount of lower pressure EGR (LP-EGR) recycled from the first outlet to the first inlet can be mixed with fresh air at or below BP in the first inlet to form a first air charge. In addition, at least some of the higher pressure EGR (HP-EGR) recycled from the second outlet to the second inlet can be mixed with pressurized fresh air in the second inlet to form a second air charge. The first and second charges of air can be mixed with each other and directly injected fuel in the cylinder before combustion. The setting of the distribution phases of the opening of the individual intake valves connected to the individual intake channels may vary relative to each other so as to supply different charges of air at different moments of the engine intake stroke. The settings of the intake valve distribution phases can be further coordinated with the opening of individual exhaust valves connected to separate exhaust channels.

Thus, by flowing only part of the exhaust gas through the turbine, along with the naturally aspirated suction of the remaining part of the exhaust gas into the cylinder, the heat recovered from the exhaust gas is increased, and the thermodynamic efficiency of the turbine is improved. By naturally aspirating a certain amount of fresh air into the engine cylinder along with boosting the remaining part, the compressor can be reduced, thereby improving the efficiency of the compressor. In addition, the boost control delay can be reduced. By delivering an air charge with varying ratios of recirculated exhaust gas and fresh air at different pressures into the engine cylinder through separate intake ports, the benefits of EGR can be expanded and the benefits of a turbocharger can be improved, even using a smaller turbocharger. Essentially, the efficiency and performance of the engine can be improved.

Thus, according to one aspect, there is provided a method of driving an engine, comprising: providing a first air charge at or below barometric pressure into an engine cylinder through a first inlet channel and providing a second air charge to the cylinder through a second, separate inlet channel, this second charge of air is subjected to pressurization by means of an inlet compressor driven by an exhaust turbine.

The first inlet channel is preferably connected to the first exhaust channel, the second inlet channel is connected to the second exhaust channel, the inlet compressor is included in the second inlet channel, and the exhaust turbine is included in the second exhaust channel.

The method preferably further includes mixing the first and second charges of air with fuel in the cylinder and burning the mixture in the cylinder.

Providing at least some charge of air under or below barometric pressure preferably includes opening a first intake valve in a first intake passage with a first setting of the distribution phases of the intake valve, and providing at least some boosted charge of air includes opening a second intake valve in a second intake channel with a second, excellent setting of the intake valve distribution phases, in the same engine cycle.

The first setting of the intake valve distribution phases is preferably adjusted relative to the second setting of the intake valve distribution phases based on the engine operation mode.

The method preferably further includes actuating an inlet valve actuator coupled to the first and second inlet valves with a phase difference to open the first valve with the first distribution phase setting and open the second valve with the second distribution phase setting.

The first charge of air preferably includes a first amount of fresh intake air at or below barometric pressure, wherein the second charge of air includes a second amount of fresh intake air at boost pressure.

The first charge of air preferably includes a mixture of a first amount of fresh intake air with a first amount of recirculated exhaust gas at or below barometric pressure, and the second charge of air includes a mixture of a second amount of fresh intake air with a second amount of recirculated exhaust gas under boost pressure.

The second inlet channel is preferably parallel to the first inlet channel, with the second outlet channel parallel to the first outlet channel.

According to another aspect, there is provided a method of driving an engine, comprising supplying a first charge of air, including a first amount of recirculated exhaust gases and a first amount of fresh intake air below barometric pressure, to a cylinder of a engine through a first inlet channel, and supplying a second charge of air including a second amount of recirculated exhaust gas and a second amount of fresh intake air under compressor pressure into the engine cylinder through a second, separate channel-final year.

The method preferably further includes directly injecting fuel into the cylinder, mixing the first air charge with the second air charge and the injected fuel in the cylinder, and burning the mixture in the cylinder.

The supply of the first charge of air preferably includes opening the first intake valve of the first intake channel with the first setting of the intake valve distribution phases, and the supply of the second charge of air includes opening the second intake valve of the second intake channel with the second installation of the intake valve distribution phases.

The supply of the first air charge preferably further includes opening the first EGR valve for recirculating the first amount of exhaust gas from the first exhaust channel to the first inlet channel, and the supply of the second air charge further includes opening the second EGR valve for recirculating the second amount of exhaust gas from the second, separate exhaust channel into second inlet channel.

The supply of a second charge of air under the pressure of the compressor preferably further includes driving a compressor included in the second inlet channel and driven by a turbine included in the second exhaust channel, the second amount of exhaust gas being recycled from a place upstream of the turbine to a place below downstream of the compressor.

The first inlet valve and the second inlet valve are preferably connected to the valve actuator, the method further comprising adjusting the valve phase of the valve actuator to open the first valve with the first setting of the intake valve distribution phases, and the second valve with the second setting of the intake valve distribution phases, the first setting the intake valve distribution phases is earlier in the intake cycle of the engine cycle than the second setting of the intake valve distribution phases valve.

The supply of the first charge of air preferably further includes opening the first exhaust valve of the first exhaust channel with the first setting of the distribution phases and opening the second exhaust valve of the second exhaust channel with the second, earlier setting of the distribution phases.

According to yet another aspect, there is provided an engine system comprising an engine cylinder, a first inlet channel that transfers uncompressed air charge to the engine cylinder through a first inlet valve, a second inlet channel that transfers compressed air charge to the cylinder through a second inlet valve, a turbocharger compressor connected to the first inlet a channel configured to compress a charge of air supplied to the cylinder, an actuator for opening the first inlet valve and the second inlet valve, and a control system with machine-readable commands to adjust the phase of the valve actuator to open the first inlet valve with the first installation of the distribution phases, and the second valve, with the second, excellent installation of the distribution phases.

The uncompressed charge of air preferably includes at least some fresh air and at least some EGR under or below barometric pressure, wherein the compressed air charge includes at least some fresh air and at least some EGR under compressor pressure.

The first inlet channel is preferably parallel and separate with respect to the second inlet channel, the system further comprising a first and second outlet channels, the first outlet channel being parallel and separated with respect to the second outlet channel, and a turbocharger turbine connected to the second outlet channel, wherein the turbine is configured to drive a compressor.

The system preferably further comprises a first EGR channel communicatingly connecting the first exhaust channel to the first inlet channel, wherein the first EGR channel includes a first EGR cooler and a first EGR valve, and a second EGR channel communicatingly connecting the second exhaust channel to the second inlet channel, moreover, the second EGR channel includes a second EGR cooler and a second EGR valve, while the control system includes additional commands for opening the first EGR valve for supplying at least some the amount of EGR at or below atmospheric pressure into the first inlet channel and opening a second EGR valve to supply at least a certain amount of EGR under compressor pressure from the second outlet channel, upstream of the turbine, to the second inlet channel, downstream of the compressor.

It should be understood that the disclosure of the invention above is presented to familiarize yourself with a simplified form of a selection of concepts that are further described in the detailed description. It is not intended to identify key or essential features of the claimed subject matter, the scope of which is uniquely defined by the claims that accompany the detailed description. Moreover, the claimed subject matter is not limited to implementations that solve any of the disadvantages noted above or in any part of this description.

Brief Description of the Drawings

FIG. 1 is a schematic view of an engine including a separate intake manifold and a separate exhaust manifold, and associated exhaust gas recirculation systems.

FIG. 2 is an exemplary embodiment of the engine cylinder of FIG. 1 connected to the first and second inlet channels, as well as the first and second outlet channels.

FIG. 3 is a local view of an engine.

FIG. 4 is a high-level flowchart illustrating a procedure that can be implemented to control the engine cylinder of FIG. 2, according to the present invention.

FIG. 5 is exemplary settings of the distribution phases of the intake valves and exhaust valves of the cylinder of FIG. 2.

FIG. 6 is a mixture of charges of air that can be provided into the cylinder of FIG. 2 through the first and second inlet channels during different operating modes.

FIG. 7 is a high-level flowchart illustrating a procedure that can be implemented to coordinate the operation of the intake air damper with the operation of a turbocharger during an event of an increase in engine load at constant speeds.

FIG. 8 is a graph illustrating an example of adjustments of the intake air damper and the EGR valve during an increase in engine load at constant speeds.

FIG. 9 is a high-level flowchart illustrating a procedure for adjusting the operation of an EGR cooler based on an engine operating mode.

DETAILED DESCRIPTION OF THE INVENTION

The following description relates to systems and methods for controlling an engine, such as the engine system of FIG. 1-3, by providing an air charge of different pressure and / or different composition (for example, different ratios of fresh air to EGR) to the engine cylinder through separate inlet channels at different times in the engine cycle. More specifically, an air inlet charge at or below barometric pressure may be provided to the cylinder separately from the air inlet charge under compressor pressure. Similarly, an air inlet charge including recirculated exhaust gases may be provided to the cylinder separately from the air inlet charge containing fresh air. In addition, other combinations may be possible, as specified in FIG. 6. The engine controller may be configured to perform a control procedure, such as the procedure of FIG. 4, for opening the first cylinder inlet valve with an earlier set of distribution phases than the second cylinder inlet valve (FIG. 5), thereby providing a first air charge of the first composition at a different time in the engine cycle than the second air charge of the second composition. The settings of the intake valve distribution phases are further coordinated with the corresponding settings of the exhaust valve distribution phases (FIG. 5). The position of one or more air inlet flaps and EGR valves connected to different inlet channels can be adjusted and coordinated to compensate for transients, as specified in FIG. 7-8. In addition, various EGR valves can be adjusted to allow the air intake of each inlet to be heated or cooled by respective EGR coolers, as specified in FIG. 9. Thus, the amount of compression work of the turbocharger spent on drawing the EGR can be reduced, thereby increasing the average pressure of the inlet and / or exhaust gases supplied to and from the turbocharger, which improves the return of the turbocharger. Additionally, by keeping the EGR-based air charge separate from the charge-based air charge until they mix in the cylinder, delays in both EGR control and boost control can be reduced. In general, the benefits of both EGR and boost can be extended, thereby improving engine performance and fuel economy.

FIG. 1 shows a schematic illustration of an example turbocharged engine system 100 including a multi-cylinder internal combustion engine 10 and a turbocharger 50. As a non-limiting example, the engine system 100 may be included as part of a propulsion system for a passenger vehicle. The engine 10 may include a plurality of cylinders 14. In the illustrated example, the engine 10 includes three cylinders arranged in an in-line configuration. However, in alternative examples, the engine 10 may include two or more cylinders, for example 4, 5, 8, 10 or more cylinders, arranged in alternative configurations, such as a V-shaped, box-shaped, etc. Each cylinder 14 can be configured by fuel nozzle 166. In the illustrated example, fuel nozzle 166 is a direct in-cylinder nozzle. However, in other examples, the fuel injector 166 may be configured as a windowed fuel injector. Further details of the single cylinder 14 are described below in FIG. 2-3.

Each cylinder 14 of the engine 10 is configured to receive an air intake charge (including fresh air and / or recirculated exhaust gases) from the first inlet channel 42 as well as the second inlet channel 44. Essentially, the second inlet channel 44 may be separate from, but parallel to the first inlet channel 42. The first inlet channel 42 may include an air inlet damper 62 downstream of the air filter 60. The position of the damper 62 may be controlled by the control system 15 by means of an actuator a coil (not shown) connected in contact with the controller 12. By modulating the shutter 62, a certain amount of fresh air can be introduced from the atmosphere into the engine 10 and supplied to the engine cylinders at or below barometric (or atmospheric) pressure through the first inlet channel 42. The first the inlet channel 42 can be divided into multiple inlet pipes 43a-43c downstream of the valve 62. Each inlet pipe 43a-43c can be connected to a separate engine cylinder and can be made with ozhnostyu flow of the intake charge air inlet duct 42 into the corresponding cylinder.

The second inlet 44 may include an air inlet damper 64 downstream of the charge cooler 56 and the turbocharger compressor 52. More specifically, the compressor 52 of the turbocharger 50 can be included in and attached to the second inlet 44, but not to the first inlet 42. The position of the shutter 64 can be controlled by the control system 15 by means of a shutter actuator (not shown) connected in contact with the controller 12 By modulating the air intake shutter 64, along with controlling the compressor 52, some fresh air can be introduced from the atmosphere into the engine 10 and supplied to the engine cylinders under by compressing the compressor (or increased pressure) through the second inlet channel 44. The second inlet channel 44 can be divided into multiple inlet pipes 45a-45c downstream of the shutter 64. Each inlet pipe 45a-45c can be connected to a separate cylinder and can be made with the possibility of feeding part of the intake air charge of the intake channel 44 into the corresponding cylinder.

Exhaust gases generated during combustion events in the cylinder may be discharged from each cylinder 14 through a first exhaust channel 46 and a second exhaust channel 48. The exhaust channel 46 may be divided into multiple exhaust pipes 47a-47c. More specifically, each exhaust pipe 47a-47c may be coupled to a separate cylinder and may be configured to supply a portion of the exhaust gases discharged from the corresponding cylinder to the exhaust channel 46. The exhaust gases flowing through the first exhaust channel 46 may be treated with one or more exhaust aftertreatment devices, such as catalytic converters 70 and 72, before being released to the atmosphere through exhaust pipe 35.

In the same way, the second exhaust channel 48 can be divided into multiple exhaust pipelines 49a-49c. Each exhaust pipe may be connected to a separate cylinder and may be configured to supply a portion of the exhaust gases discharged from the corresponding cylinder to the exhaust channel 48. The turbine 54 of the turbocharger 50 may be included in and connected to the second exhaust channel 48, but not to the first the exhaust channel 46. Thus, combustion products that are discharged through the exhaust channel 48 can be guided through the turbine 54 to provide mechanical work to the compressor 52 through a shaft (not shown). In some examples, the turbine 54 may be configured as a variable geometry turbine, wherein the controller 12 may adjust the position of the blades (or blades) of the turbine impeller to change the level of energy that is obtained from the exhaust gas stream and communicated to the compressor 52. B alternatively, the exhaust turbine 54 may be configured as a turbine with an adjustable nozzle, while the controller 12 may adjust the position of the turbine nozzle to change the level of energy that is received from exhaust gas stream 52 and communicated to the compressor.

The exhaust gases flowing through the second exhaust channel 48 may be treated with one or more exhaust after-treatment devices, such as a catalytic converter 72, before being exhausted into the atmosphere through the exhaust pipe 35. In the illustrated example, the exhaust gases from the second exhaust channel 48 are combined with the exhaust gases from the first exhaust channel 46 downstream of the turbine 54 and the catalytic converter 70, but higher because of the catalytic converter 72, and are discharged into the atmosphere through the exhaust pipe 35. However, in alternative embodiments, the exhaust channel 46 and 48 may not be re-combined and may exhaust the gases through separate exhaust pipes. The exhaust channels 46 and 48 may also include one or more exhaust gas sensors, as is further specified in FIG. 3.

The engine 10 may further include one or more exhaust gas recirculation (EGR) channels for recirculating at least a portion of the exhaust gas from the first and second exhaust channels 46 and 48 to the first and second inlet channels 42 and 44, respectively. More specifically, the first exhaust channel 46 may be communicably connected to the first inlet 42 through a first EGR channel 80 including a first EGR cooler 82 and a first EGR valve 84. The engine controller may be configured to open the first EGR valve 84 to recirculate a certain amount of exhaust gas at or below atmospheric pressure to the first inlet channel 42. Thus, low pressure EGR (LP-EGR) can be withdrawn from the first outlet channel to the first inlet channel .

Similarly, the second exhaust channel 48 may be communicatively coupled to the second inlet 44 through a second EGR channel 90 including a second EGR cooler 92 and a second EGR valve 94. The engine controller may be configured to open a second EGR valve 94 to recycle a certain amount of exhaust gas, under compressor pressure, from upstream of turbine 54 of second inlet 44, downstream of compressor 52. Thus, high pressure EGR ( HP-EGR) may be provided to the engine through a second intake duct and exhaust ducts. By issuing LP-EGR through the first EGR channel, along with issuing HP-EGR via the second, separate EGR channel, both HP-EGR and LP-EGR can be simultaneously provided, thereby expanding the benefits of EGR.

EGR coolers 82 and 92 can be configured to lower the temperature of the exhaust gases flowing through the respective EGR channels before recirculating to the engine inlet. In an alternative embodiment, EGR coolers 82 and 92 may be located at the junction of the EGR channel and the corresponding inlet channel. In this position, as specified in the materials of the present application with reference to FIG. 9, under certain conditions, EGR cooler (s) can advantageously be used to heat the intake charge of air supplied to the cylinder. More specifically, an EGR cooler can be used to deliver a heated charge of air (e.g., heated fresh air or a mixture of heated exhaust and fresh air) to the engine cylinder during some mode, along with the delivery of a cooled charge of air (e.g., cooled EGR) to the engine cylinder during another mode. In one example, during the cooling mode, the air charge supplied to the cylinder through the second inlet can be heated before entering the compressor to avoid droplets of water hitting the compressor.

In addition to yet other embodiments, the conduit may link EGR channels. A pipe could connect the second EGR channel 90, from a position located between the EGR valve 94 and the EGR cooler 94 to the first EGR channel 80, in a position located between the EGR valve 84 and the EGR cooler 82. Here, during some modes, higher pressure exhaust gases discharged into the second exhaust channel through the second exhaust valve can be cooled in the EGR cooler 92, and heat can be transferred to the coolant. Cooled exhaust gas can be recycled to the engine inlet through the first lower pressure inlet channel. Alternatively, cooled exhaust gases may be discharged into the atmosphere through the first exhaust passage 46 and exhaust pipe 35. Thus, a greater amount of work can be extracted from the exhaust gases.

The engine system 100 may further include a valve actuator 96 for adjusting the operation of the valve of the cylinder 14. More specifically, the valve actuator 96 may be configured to open the first inlet and / or exhaust valve of the cylinder 14 with a first setting of the distribution phases along with opening the second inlet and / or exhaust valve of the cylinder 14 with the second installation of the distribution phases. Thus, the first charge of air of the first composition under or below barometric pressure can provide get into the engine cylinder with the first installation of the distribution phases, while the second air charge of a second, excellent composition under the compressor pressure can be provided into the engine cylinder with the second, excellent installation of the distribution phases. By way of non-limiting example, as shown in FIG. 2-3, the valve actuator 96 may be configured as a cam actuator, wherein the inlet and / or exhaust valves of each cylinder 14 are connected to respective cams. The controller may be configured to adjust the phase (or cam profile) of the valve actuator 96 (or cam actuator) based on an engine operating mode for opening the first intake valve with a first setting of the distribution phases to supply a first air charge, along with opening the second intake valves with a second setting of the distribution phases to supply a second charge of air. For example, as specified in the materials of the present application in FIG. 5, the settings of the intake valve distribution phases may be biased to introduce a portion of the intake air charge through the compressor along with a naturally aspirated suction of another portion of the intake air charge.

The controller must additionally be configured to adjust the valve phase to open the first exhaust valve with the first installation of the distribution phases, along with opening the second exhaust valve with the second, excellent installation of the distribution phases to exhaust the exhaust gases with different pressures, while at different positions in the engine cycle. For example, as specified in the materials of the present application in FIG. 5, the settings of the exhaust valve distribution phases can be biased to separate the exhaust gas discharge (for example, expanding exhaust gas in the cylinder until the time when the cylinder piston reaches the bottom dead center of the expansion stroke) from the exhaust residual gas discharge (for example, gases that remain in cylinder after reset). In one example, by coordinating the installation of the distribution phases of the first intake valve with the installation of the distribution phases of the first exhaust valve, and, similarly, the installation of the distribution phases of the second intake valve with the installation of the distribution phases of the second exhaust valve, exhaust energy can be transmitted from the exhaust gas through the turbine a turbocharger in a second exhaust channel for activating a turbocharger compressor in a second inlet to provide boost advantages. Essentially at the same time, residual gases can be removed from the first exhaust channel to the first inlet channel to provide EGR benefits. Thus, the required dilution of EGR can be achieved without spending additional energy on pumping exhaust gases from the exhaust manifold to the intake manifold through an EGR cooler, even at higher loads.

It should be understood that, despite the fact that the engine system 100 is shown recirculating the exhaust gas at or below barometric pressure through the first inlet channel, in addition to still further embodiments, such as where the first inlet channel is connected to an engine fuel vapor recovery system, the first inlet channel may be configured to recirculate one or more of the purge vapors, crankcase vapors and gases or vaporized fuel vapors into the cylinder below or below the barometric pressure about pressure.

The engine system 100 may be controlled, at least in part, by a control system 15 including a controller 12 and input signals from a vehicle driver through an input device (as shown in FIG. 3). The control system 15 is shown receiving information from a plurality of sensors 16 (various examples of which are described in the materials of the present application) and sending control signals to a plurality of actuators 81. As one example, the sensors 16 may include pressure sensors and intake air temperatures, MAP sensors (absolute pressure in the intake manifold) and MAT sensors (absolute temperature in the intake manifold) in one or both inlet ducts. Other sensors may include a damper inlet pressure sensor (TIP) for estimating the damper inlet pressure (TIP) and / or a damper inlet temperature sensor for evaluating the damper air temperature (TCT) attached downstream of the damper in each inlet. In other examples, one or more EGR channels may include pressure, temperature, and fuel-air ratio sensors to determine EGR flow characteristics. Additional sensors and actuators of the system are specified with reference to FIG. 3. As another example, actuators 81 may include fuel injectors 166, EGR valves 84 and 94, valve actuators 96, and dampers 62 and 64. Other actuators, such as a variety of additional valves and dampers, may be attached to various locations in the engine system 100. The controller 12 may receive input from various sensors, process the input, and actuate actuators in response to the processed input, based on a command or code programmed therein, corresponding to one or more procedures. Exemplary control procedures are described herein with respect to FIG. 4, 7 and 9.

Next, with reference to FIG. 2-3, a single cylinder of an internal combustion engine 10 is shown. As such, the components introduced previously in FIG. 1 are represented by the same reference numbers and are not resubmitted. FIG. 2 shows a first view 200 of a cylinder 14. Here, a cylinder 14 is shown with four openings, including two inlet openings 17 and 18 and two exhaust openings 19 and 20. More specifically, the first inlet 17 of the cylinder 14 can receive a first charge of air under or lower than atmospheric pressure through the first inlet channel 30 from the first inlet pipe 43a connected to the first inlet channel 42. The first air charge may include fresh air, recycled lower pressure exhaust gases (LP-EGR), or a mixture of fresh air and LP-EGR introduced into the cylinder at or below atmospheric pressure. The second inlet 18 of the cylinder 14 may receive a second charge of air under compressor pressure through the second inlet valve 31 from the second inlet pipe 45a connected to the second inlet 44. The second charge of air may include fresh air, higher pressure recirculated exhaust gases (HP-EGR ) or a mixture of fresh air and HP-EGR introduced into the cylinder under increased pressure after compression by the compressor 52.

Part of the combustion products in the cylinder can be discharged from the first outlet 19 of the cylinder 14 through the first exhaust valve 32 into the first exhaust pipe 47a connected to the first exhaust channel 46. Another part of the combustion products in the cylinder can be discharged from the second outlet 20 of the cylinder 14 through the second outlet a valve 33 in a second exhaust pipe 49a connected to the second exhaust channel 48. Exhaust gases can subsequently be exhausted into the atmosphere through the exhaust pipe 35. More specifically, the first and The second exhaust ducts can be re-combined downstream of the turbine and upstream of the exhaust gas toxicity reduction device 72, allowing the exhaust gas discharged to the first exhaust duct to be treated with the exhaust gas toxicity reduction devices 70 and 72 before being discharged, along with providing the exhaust the gases discharged into the second exhaust channel of the opportunity to be processed by the device 72 before exhaustion through the exhaust pipe 35. Additionally or optionally, part of the exhaust gas It can also be recycled from the first exhaust pipe 47a to the first inlet channel 43a via the first EGR passage 80, along with the fact that part of the exhaust gases may be recirculated from the second discharge pipe 49a into the first inlet conduit 45a through the second passage 90 EGR. In addition to yet other embodiments, the second exhaust channel may be configured to discharge exhaust gases to the first or second intake channel, and the first exhaust channel may be configured to discharge exhaust gases to any of the first or second intake channel.

In the illustrated example, the first intake valve 30 and the second intake valve 31 can each be actuated by respective cams of the intake valve (FIG. 3). The position of the intake cams, and thereby the setting of the distribution phases of the intake valves, can be determined by the intake cam actuator 97 through the camshaft stem 101. Similarly, the first exhaust valve 32 and the second exhaust valve 33 can each be actuated by respective exhaust cams (FIG. 3), the position of the exhaust cams is determined by the exhaust cam actuator 98 through the camshaft 102. However, in alternative embodiments, each inlet valve and each exhaust valve may have independent valve actuators. In addition, the first intake valve and the first exhaust valve can be connected to the (common) valve actuator, while the second intake valve and the second exhaust valve are connected to another valve actuator. The controller 12 may be configured to adjust the phase of the intake valve actuator 97 based on the engine operating mode to open the first intake valve 30 with a first setting of the intake valve distribution phases and open the second intake valve 31 with a second, excellent setting of the intake valve distribution phases. For example, the first distribution phase setting can be tuned relative to the second distribution phase setting so as to deliver a first air intake, including fresh air and / or recirculated exhaust gases, to the cylinder 14 under the first, lower pressure, earlier in the engine cycle (e.g. in the earlier part of the intake stroke), along with the issuance of a second air intake charge, including fresh air and / or recirculated exhaust gases, into the cylinder 14 under a second, higher pressure, later in the cycle A (e.g., in the later part of the same intake stroke in the same engine cycle).

In the same way, the controller 12 may be configured to adjust the phase of the exhaust valve actuator 98 based on the engine operating mode to open the first exhaust valve 32 and the second exhaust valve 33 with predetermined distribution phase settings. In one example, the phase of the exhaust valve actuator 97 may be adjusted relative to the phase of the valve actuator 98, so that the opening and / or closing of the intake valves 30 and 31 are coordinated with (or based on) opening and / or closing of the respective exhaust valves 32 and 33. For example, a first exhaust valve may open to selectively discharge (or recirculate) the residual exhaust gas, while a second exhaust valve may open to selectively discharge exhaust gas through a turbine to drive an attached compressor. Exemplary settings for the distribution phases of the first and second intake and exhaust valves are illustrated in FIG. 5.

With reference to FIG. 3, it shows an alternate view 300 of an internal combustion engine 10. The engine 10 is shown with a combustion chamber 14, a coolant pipe 118 and cylinder walls 136 with a piston 138 located therein and connected to the crankshaft 140. The combustion chamber 14 is shown communicating with the inlet channel 146 and the exhaust channel 148 through the respective inlet valves 150 and exhaust valves 156. As specified previously in FIG. 1-2, each cylinder 14 of the engine 10 can receive an air intake charge through two inlet pipes and can discharge combustion products through two exhaust pipes. In the depicted view 300, the inlet channel 146 and the outlet channel 148 represent the first inlet pipe and the first exhaust pipe leading to / from the cylinder (such as the pipes 43a and 47a of FIG. 2) while the second inlet and second outlet pipes, leading to / from the cylinder are invisible in this view. As also specified earlier in FIG. 2, each cylinder of the engine 10 may include two (or more) inlet valves and two (or more) exhaust valves connected to respective inlet and outlet pipes. In the depicted view 300, at least one of the intake valves is shown as an inlet poppet valve 150, and at least one of the exhaust valves is shown as an exhaust poppet valve 156 located in the upper region of the cylinder 14.

The inlet valve 150 and the exhaust valve 156 can be controlled by the controller 12 using respective cam actuator systems including one or more cams. Cam actuator systems may use one or more of a cam profile changeover (CPS), cam cam (VCT), cam valve (VVT) and / or cam valve lift (VVL) to vary valve performance. In the illustrated example, each inlet valve 150 is driven by the inlet cam 151, and each exhaust valve is driven by the exhaust cam 153. The position of the inlet valve 150 and the exhaust valve 156 can be detected by the valve position sensors 155 and 157, respectively. In alternative embodiments, the intake and / or exhaust valve may be controlled by means of a solenoid valve. For example, cylinder 14, alternatively, may include an inlet valve controlled through an electromagnetic valve actuator and an exhaust valve controlled through a cam drive including CPS and / or VCT systems. And in addition to still other embodiments, the intake and exhaust valves can be controlled by a spool drive or distributor system or a drive or distributor system with variable valve timing.

In one example, intake cam 151 includes separate and different cam projections that provide different valve profiles (e.g., valve phase distribution, valve lift height, duration, etc.) for each of the two inlet valves of combustion chamber 14 . Similarly, exhaust cam 151 may include separate and different cam projections that provide different valve profiles (e.g., setting valve distribution phases, valve lift height, duration, etc.) for each of the two exhaust valves of the combustion chamber 14. Alternatively, exhaust cam 153 may include a common working protrusion or similar working protrusions that provide a substantially similar valve profile for each of the two exhaust valves.

For example, the first cam profile of the first intake valve of the combustion chamber 14 may have a first lift height value and a first distribution phase setting and opening duration. The second cam profile of the second intake valve of the combustion chamber 14 may have a second lift height value and a second distribution phase setting and opening duration. In one example, the first lift height may be less than the second lift height, the first setting of the opening distribution phases may be earlier (or advanced) than the second setting of the opening distribution phases, and / or the first opening duration may be more shorter than the second opening duration. In addition, in some examples, the phase of the first and second cam profiles may be individually adjusted relative to the phase of the crankshaft of the engine. Thus, the first inlet cam may be positioned to open the inlet valve near the TDC of the intake stroke of the combustion chamber 14, so that the first inlet valve can open at the top of the TDC and close at the BDC of the intake stroke. Alternatively, a second intake cam profile may open a second intake valve near the BDC of the intake stroke. Thus, setting the distribution phases of the first inlet valve and the second inlet valve can separate the first air intake received through the first inlet from the second air intake received through the second, different inlet.

In the same way, different cam profiles for different exhaust valves can be used to separate the exhaust gases discharged under pressure in the cylinder from the exhaust gases discharged under discharge pressure. For example, a first exhaust cam profile may open a first exhaust valve after a BDC of an expansion stroke. Alternatively, a second exhaust cam profile may be positioned to open the second exhaust valve on the BDC of the expansion stroke so that the second exhaust valve can open and close before the BDC of the expansion stroke. In addition, the second cam profile can be adjusted in response to the engine speed to adjust the opening and closing of the exhaust valve in order to selectively discharge the exhaust gas of the combustion chamber. Thus, setting the distribution phases of the first exhaust valve and the second exhaust valve can isolate the cylinder exhaust gases from the residual gases. Although, in the above example, the first setting of the exhaust valve distribution phases is later in the engine cycle than the second setting of the exhaust valve distribution phases, it will be appreciated that, in an alternative example, the first setting of the exhaust valve distribution phases may be earlier in the engine cycle than the second installation of the exhaust valve distribution phases. For example, during a purge mode, the second exhaust valve may open after opening the first exhaust valve.

By flowing part of the exhaust gas (e.g., higher pressure exhaust) through a turbine and higher pressure outlet, along with the remaining part of the exhaust gas (e.g., lower pressure exhaust) flowing through the catalytic devices and the lower pressure outlet, heat recovered from Exhaust emissions may increase along with improved turbine performance. By coordinating the setting of the distribution phases of the exhaust valves and the setting of the distribution phases of the intake valves, a part of the residual exhaust gas can be supplied to provide EGR, while the other part drives the turbocharger compressor. More specifically, in one embodiment, the engine can be separated into a low pressure supercharged part and a higher pressure supercharged part, giving various synergistic advantages of EGR and supercharging. In addition, this configuration allows the engine to control the engine with a smaller turbine and compressor along with a lower turbocharger delay.

In addition, in other embodiments, both exhaust valves may open simultaneously to provide a similar boost control action. Similarly, both inlet valves can open simultaneously to provide a compressor-like bypass valve action. As such, the benefits provided by the split intake manifold can be used even in the absence of a split exhaust manifold. In addition, benefits can be provided even in the absence of EGR channels. For example, an action similar to a boost pressure regulator and an action similar to a compressor bypass valve can be achieved if there are one or more EGR channels or not a single EGR channel between the split inlet and the split outlet.

An exhaust gas sensor 128 is shown attached to an exhaust channel 148. A sensor 128 may be located upstream of one or more exhaust gas emission reduction devices, such as devices 70 and 72 of FIG. 1-2. The sensor 128 may be selected from among various suitable sensors for providing an indication of the air / fuel ratio in the exhaust gas, such as, for example, a linear oxygen sensor or a UEGO (universal or wide range exhaust gas oxygen sensor), a dual-mode oxygen sensor, or an EGO sensor (which pictured), HEGO (heated EGO), NOx, HC, or CO. Downstream exhaust gas emission control devices may include a three-way catalytic converter (TWC), NOx trap, various other exhaust gas emission control devices, or combinations thereof.

The temperature of the exhaust gas can be estimated by one or more temperature sensors (not shown) located in the exhaust pipe 48. Alternatively, the temperature of the exhaust gas can be displayed based on engine operating conditions, such as speed, load, air to fuel ratio ( AFR), spark delay, etc.

The cylinder 14 may have a compression ratio, which is the ratio of the volumes of when the piston 138 is at bottom dead center to when at top dead center. Traditionally, the compression ratio is in the range from 9: 1 to 10: 1. However, in some examples where another fuel is used, the compression ratio may be increased. This, for example, can occur when a higher octane fuel or a fuel with a higher latent heat content of evaporation is used. The compression ratio can also be increased if direct injection is used, due to its effect on engine operation with detonation.

In some embodiments, implementation, each cylinder of the engine 10 may include a spark plug 192 to initiate combustion. The ignition system 190 can provide an ignition spark to the combustion chamber 14 through the spark plug 192 in response to the ignition timing signal SA from the controller 12, at selected operating modes. However, in some embodiments, the spark plug 192 may be omitted, such as where the engine 10 may initiate self-ignition or fuel injection combustion, as may be the case with some diesel engines.

In some embodiments, implementation, each cylinder of the engine 10 may be configured with one or more fuel nozzles for supplying fuel to it. As a non-limiting example, a cylinder 14 including one fuel injector 166 is shown. A fuel injector 166 is shown connected directly to the cylinder 14 for injecting fuel directly into it in proportion to the pulse width of the FPW signal received from the controller 12 via an electronic driver 168. Thus, the fuel injector 166 provides what is known as direct injection (hereinafter, also referred to as "DI") of fuel into the combustion cylinder 14. Although FIG. 3 shows the nozzle 166 as a side nozzle, it can also be located upstream of the piston, for example, near the position of the spark plug 192. This situation can improve the mixing and combustion during operation of the engine with alcohol-containing fuel due to the low volatility of some alcohol-containing fuel. Alternatively, the nozzle may be located above and near the inlet valve to improve mixing. In an alternative embodiment, the nozzle 166 may be a channel nozzle that delivers fuel into the inlet channel upstream of the cylinder 14.

Fuel can be supplied to the fuel injector 166 from the high pressure fuel system 8, including fuel tanks, fuel pumps, and a fuel rail. Alternatively, the fuel may be delivered by a single stage low pressure fuel pump, in which case the timing of the direct fuel injection may be more limited during the compression stroke than if a high pressure fuel system is used. Furthermore, although not shown, the fuel tanks may have a pressure transducer providing a signal to the controller 12. The fuel tanks in the fuel system 8 can store fuel with different fuel qualities, such as different fuel compositions. These differences may include different alcohol contents, different octane numbers, different heat of vaporization, different fuel mixtures and / or combinations thereof, etc. In some embodiments, the fuel system 8 may be coupled to a fuel vapor recovery system including a tank for accumulating refueling and daily fuel vapor. Fuel vapors may be blown from the reservoir into the engine cylinders during engine operation, when purge conditions are satisfied. For example, purge vapors can be aspirated naturally into the cylinder through a first inlet channel at or below barometric pressure.

Controller 12 is shown in FIG. 3 as a microcomputer including a microprocessor unit 106, input / output ports 108, an electronic storage medium for executable programs and calibration values, shown as a read-only memory chip 110 in this particular example, random access memory 112, non-volatile memory 114 and a data bus . The read only memory 110 may be programmed with machine-readable data representing instructions executed by the processor 106 to perform the methods and procedures described below, as well as options that are anticipated but not specifically listed. The controller 12 may receive various signals from sensors connected to the engine 10, in addition to those signals previously discussed, including measuring the mass flow rate of the introduced air (MAF) from the mass flow rate sensor 122; engine coolant temperature (ECT) from a temperature sensor 116 connected to the cooling pipe 118; a profile ignition read (PIP) signal from a Hall sensor (or other type) 120 connected to the crankshaft 140; throttle position (TP) with throttle position sensor; the manifold absolute pressure signal (MAP) from the 124 sensor, AFR in the cylinder from the 128 EGO sensor and abnormal combustion from the knock sensor and the crankshaft acceleration sensor. The engine speed signal, RPM, may be generated by the controller 12 from the PIP signal. The manifold pressure signal, MAP, from the manifold pressure sensor can be used to indicate a vacuum or pressure in the intake manifold.

Based on input from one or more of the above sensors, the controller 12 may adjust one or more actuators, such as a fuel injector 166, a shutter 162, a spark plug 192, intake / exhaust valves and cams, etc. The controller can receive input from various sensors, process the input, and actuate actuators in response to the processed input, based on a command or control program programmed in it, corresponding to one or more procedures. An exemplary control procedure is described herein with respect to FIG. four.

Next, referring to FIG. 4, an exemplary procedure 400 for supplying a first air charge to an engine cylinder through a first intake channel is shown along with supplying a second air charge to an engine cylinder through a second, parallel but separate inlet channel. The first and second charges of air can have different compositions (for example, different ratios of fresh air to recycled exhaust gases), different pressures (for example, one charge of air at a higher boost pressure, while another charge of air at a lower sub-barometric pressure), different temperatures (for example, one charge of air heated to a higher temperature, while another charge of air is cooled to a lower temperature), etc. In addition, different charges of air may

fed with different settings of the distribution phases in order to bias their flow during a given intake stroke.

At 402, engine operating modes may be evaluated and / or measured. For example, they can include ambient temperature and pressure, engine temperature, engine speed, engine speed, transmission speed, battery status, fuel available, percentage of alcohol in the fuel, catalytic converter temperature required by the driver moment, etc.

At 404, based on the estimated engine operating mode, the required (total) air charge can be determined. This may include determining the amount of fresh intake air, the amount of exhaust gas recirculation (EGR), and boost values. In addition, the proportion of fresh intake air, which must be supplied at or below barometric pressure (BP), relative to fresh intake air, which must be supplied under boost pressure, can be determined. Similarly, the proportion of EGR supplied at higher pressure (HP-EGR) relative to EGR supplied at lower pressure (LP-EGR) can be determined.

In one example, in response to a higher torque requirement, the required (total) air charge may include a higher amount of fresh intake air and a lower amount of EGR. In addition, the charge of air may include a higher amount of boosted fresh intake air and a lower amount of fresh air below or below BP. In yet another example, during a medium-high engine load mode, when the engine is warming up, the required (total) air charge may include a higher amount of EGR and a lower amount of fresh intake air. In addition, the air charge may include a higher amount of LP-EGR and a lower amount of HP-EGR.

Based on the required total air charge, the procedure can additionally determine the first air charge that must be supplied to the engine cylinder through the first inlet channel under the first, lower pressure (such as below or below barometric pressure), as well as the second air charge that must be supplied into the cylinder through a second, separate inlet channel under a second, higher pressure (such as boost pressure). More specifically, the first and second charges of air can be mixed in a cylinder to provide the desired total charge of air. The first charge of air supplied through the first inlet may include fresh air, recycled exhaust gases (LP-EGR), or a combination of the two, supplied at or below barometric pressure. Similarly, the second charge of air supplied through the second inlet may include fresh air, recirculated exhaust gases (HP-EGR), or a combination of the two, supplied under boost pressure or compressor pressure. Various combinations of the first and second charges of air that can be supplied to the cylinder through the first and second inlet channels are further specified in the materials of the present application with reference to FIG. 6.

At 406, settings for the first and second EGR valves may be determined based on the required air charge. For example, based on the required air charge, the first EGR valve in the first EGR channel may open by an amount for recirculating the first amount of exhaust gas from the first exhaust channel to the first inlet channel. Here, the first amount of exhaust gas may be under a first, lower pressure (such as, below or below barometric pressure), thereby providing LP-EGR. As another example, based on the required air charge, the second EGR valve in the second, separate EGR channel may open by an amount for recirculating the second amount of exhaust gas from the second, separate exhaust channel to the second, separate inlet channel. As specified previously, the second exhaust channel can be arranged parallel to the first exhaust channel, the second inlet channel can be arranged parallel to the first inlet channel, and the second EGR channel can be arranged parallel to the first EGR channel, even if all channels can be separate from each other. Here, the second amount of exhaust gas may be under a second, higher pressure (such as under boost pressure or compressor) to thereby provide LP-EGR. More specifically, a second EGR valve may open to supply a second amount of exhaust gas from upstream of a turbocharger turbine connected to the second exhaust channel to a downstream of a turbocharger compressor connected to the second inlet.

At 408, based on the required air charge, the first setting of the intake valve distribution phases for supplying the first air charge to the cylinder through the first intake valve connected to the first intake channel and the second setting of the intake valve distribution phases for supplying the second air charge to the cylinder through a second inlet valve connected to the second inlet channel. In one example, in cases where the first intake valve and the second intake valve are connected to the intake valve actuator, the valve phase of the intake valve actuator can be adjusted to open the first intake valve with the first setting of the distribution phases of the intake valve and the second intake valve with the second setting of the intake valve distribution phases. The first setting of the intake valve distribution phases may be adjusted relative to the second setting of the intake valve distribution phases based on the engine operation mode. More specifically, the first setting of the distribution phases can be adjusted to be earlier in the engine cycle than the second setting of the distribution phases. For example, as specified in FIG. 5, the first setting of the intake valve distribution phases may be earlier in the intake stroke (i.e., closer to TDC (top dead center, TDC) of the intake stroke) while the second setting of the distribution phases may be later in the same intake stroke (i.e., farther from TDC intake stroke).

In addition to the first and second settings of the intake valve distribution phases, the valve lift height as well as the opening duration of the intake valve can be determined for each intake valve. The valve phase of the intake valve actuator can be adjusted accordingly. In one example, the first inlet valve may open with a first valve lift amount while the second inlet valve opens with a second, excellent valve lift amount. For example, as specified in FIG. 5, the first valve height of the first intake valve may be smaller than the second valve height of the second intake valve. In yet another example, the first intake valve may open for a first duration while the second intake valve opens for a second, excellent duration. For example, as specified in FIG. 5, the first inlet valve may open for a shorter duration than the second inlet valve.

In the same way, the first setting of the outlet valve distribution phases for the first exhaust valve connected to the first exhaust channel and the second setting of the exhaust valve distribution phases for the second exhaust valve connected to the second exhaust channel can be determined. In one example, in cases where the first exhaust valve and the second exhaust valve are connected to the exhaust valve actuator, the valve phase of the exhaust valve actuator can be adjusted to open the first exhaust valve with the first setting of the distribution phases of the exhaust valve, and the second exhaust valve with the second setting of the phases of the distribution of the exhaust valve. The first setting of the intake valve distribution phases and the second setting of the intake valve distribution phases may be selected based on an engine operation mode. In one example, as specified in FIG. 5, the first and second exhaust valves may open with a common setting of the distribution phases of the exhaust valves. Alternatively, they may be biased.

The valve phase of the intake and exhaust valve actuators can also be adjusted to coordinate the setting of the distribution phases of the events of the exhaust valves with the setting of the phases of the distribution of events of the intake valves. More specifically, the first setting of the intake valve distribution phases of the first intake valve may be based on the first setting of the exhaust valve distribution phases (for example, the first setting of the intake valve distribution phases may be delayed from the first setting of the exhaust valve distribution phases by a predetermined amount), while that the second installation of the intake valve distribution phases may be based on the second installation of the exhaust valve distribution phases of the second exhaust valve (e.g., second I installation phase distribution may be delayed from the second outlet valve installation phase distribution by a predetermined amount).

At 410, based on the required air charge and engine operating mode, the settings for the air inlet flaps connected to each inlet can be determined. In addition, the settings of the fuel injectors can be determined (for example, setting the distribution phases, injection amount, opening time, etc.), as well as the settings of the turbocharger. For example, the compressor setting for a turbocharger connected to the second inlet can be determined based on a desired boost amount (for example, based on a desired amount of boosted air charge).

At 412, based on certain EGR valve settings, the first and second EGR valves may open. More specifically, the procedure includes opening the first EGR valve in the first EGR channel to recirculate the first amount of exhaust gas, at or below barometric pressure, from the first exhaust channel to the first inlet channel. The procedure further includes opening the second EGR valve in the second EGR channel to recirculate the second amount of exhaust gas, under compressor pressure (i.e., boost pressure), from the second exhaust channel, upstream of the turbocharger turbine, into the second inlet channel, downstream of turbocharger compressor.

At 414, the procedure includes opening the first inlet valve of the first inlet channel with first setting the distribution phases of the inlet valve to supply a first (not pressurized) air charge below or below the barometric pressure into the cylinder. At 416, the procedure includes opening the second inlet valve of the second inlet channel with a second setting of the phases of the distribution of the inlet valve to supply a second (pressurized) air charge under pressure from the compressor to the cylinder. Essentially, delivering a second boosted air charge involves activating a turbocharger compressor connected to the second inlet (and not connected to the first inlet) according to the determined boost settings.

As further specified with reference to FIG. 6, the first and second charges of air may include various combinations of fresh air and recycled exhaust gases under varying pressures. For example, the first charge of air being supplied to the cylinder may include a first amount of fresh intake air and a first amount of recirculated exhaust gas (LP-EGR) at or below barometric pressure, while the second charge of air, being supplied to the cylinder, may include a second amount of fresh intake air and a second amount of recirculated exhaust gas (HP-EGR) under boost pressure.

At 418, the procedure involves directly injecting a certain amount of fuel into the cylinder and mixing the first charge of air with the second charge of air and the injected fuel in the cylinder. The mixture of injected fuel and the first and second charges of air can then be burned in a cylinder. In one example, where the first air inlet charge includes only recirculated exhaust gases and the second air inlet charge includes only fresh air, fresh air and EGR can be separately supplied to the cylinder through separate inlet channels, and then, the air charge can, for the first time mixed in the cylinder. The mixed charge of air can then be further mixed with the injected fuel and burned in the cylinder. In another example, where the first air inlet charge includes only LP-EGR and the second air inlet charge includes only HP-EGR, the recirculated exhaust gases of different pressures can be separately supplied to the cylinder through separate inlet channels and then mixed for the first time in the cylinder. Similarly, in an example where the first intake air charge includes fresh intake air at or below atmospheric pressure and the second intake air charge includes boosted fresh intake air, fresh air of different pressures can be separately supplied to the cylinder through separate intake channels, and then, for the first time, mix in a cylinder.

In yet another example, where each of the first air charge and the second air charge includes at least some fresh air and at least some exhaust gas, the first amount of LP-EGR may be mixed with the first amount of fresh intake air below or below the barometric pressure pressure in the first intake valve to form the first charge of air, while the second amount of HP-EGR can be mixed with the second amount of boosted fresh intake air by d pressure of the compressor in the second inlet channel to form a second air charge. Each charge of air can then be separately supplied to the engine cylinder and rather mixed for the first time in the cylinder than before in the intake valve. The mixture of charges of air can then be further mixed with the injected fuel and burned in the cylinder.

Thus, different charges of air can be supplied separately, but completely mixed in the cylinder to provide a homogenized charge of air of the cylinder. By allowing air charge homogenization to occur in the cylinder, engine performance and EGR benefits can be increased. By adjusting the first setting of the distribution phases of the first intake valve with respect to the second setting of the distribution phases of the second intake valve and setting the distribution phases of the first and second exhaust valves, different air charges can be supplied at different times, but can be mixed in the cylinder to provide a homogenized final charge of air in the cylinder .

Next, referring to FIG. 5, the multi-dimensional characteristic 500 of the engine depicts an example of the settings of the intake valve distribution phases and the exhaust valve distribution phase settings, with respect to the piston position, for the engine cylinder configured to receive the first intake air charge from the first intake passage through the first intake valve, to receive the second intake charge air from a second, separate inlet channel through a second, different inlet valve, and exhausting combustion products of the engine into each of the first exhaust channel through first exhaust valve, and a second, different exhaust path via the second exhaust valve. By adjusting the first setting of the distribution phases of the first intake valve with respect to the second setting of the distribution phases of the second intake valve and setting the distribution phases of the first and second exhaust valves, different air charges can be supplied at different times to provide some layering, but can be mixed in the cylinder to provide a homogenized final air charge in the cylinder.

The multidimensional engine characteristic 500 illustrates the position of the engine along the x axis in degrees of the crankshaft angle of rotation (CAD). Curve 502 depicts the position of the piston (along the y axis), with reference to their location from top dead center (TDC) and / or bottom dead center (BDC), and in addition, with reference to their location within four cycles (intake, compression , working and release) engine cycle.

During engine operation, each cylinder typically undergoes a four-stroke cycle including an intake stroke, a compression stroke, an expansion stroke, and an exhaust stroke. During the intake stroke, usually the exhaust valves are closed and the intake valves are open. Air is drawn into the cylinder through the corresponding inlet channel, and the piston of the cylinder moves to the bottom of the cylinder so as to increase the volume inside the cylinder. The position in which the piston is near the bottom of the cylinder and at the end of its stroke (for example, when the combustion chamber is at its largest volume) is typically indicated by those skilled in the art by reference as bottom dead center (BDC). During the compression stroke, the intake valves and exhaust valves are closed. The piston moves towards the cylinder head in order to compress the air inside the combustion chamber. The point at which the piston is at the end of its stroke and closest to the cylinder head (for example, when the combustion chamber is at its smallest volume) is typically indicated by those skilled in the art as top dead center (TDC). In the process, in the materials of this application referred to as an injection, fuel is introduced into the combustion chamber. In the process, herein referenced as ignition, the injected fuel is ignited by a known ignition means, such as a spark plug, resulting in combustion. During the expansion stroke, expanding gases push the piston back to the BDC. The crankshaft converts this movement of the piston into the torque of the rotating shaft. During the exhaust stroke, the exhaust valves are open to release the remaining combusted air-fuel mixture into the corresponding exhaust channels, and the piston returns to the TDC.

Curve 504 depicts a first set of intake valve distribution phases, lift height and duration for a first intake valve (Int_1) connected to a first engine cylinder inlet, along with 506 showing a second set of intake valve distribution phases, lift height and duration for a second an inlet valve (Int_2) connected to the second inlet channel of the engine cylinder. Curves 508a and 508b depict exemplary second settings of exhaust valve distribution phases, lift heights, and durations for a second exhaust valve (Exh_2) connected to a second exhaust channel of the engine cylinder, while curves 510a and 510b depict example settings of exhaust valve distribution phases, lift heights and durations for the first exhaust valve (Exh_1) attached to the first exhaust valve of the engine cylinder. As specified earlier, the first and second inlet channels may be separate from, but arranged parallel to each other. Similarly, the first and second outlet channels may be separate from, but arranged in parallel to each other. In addition, the first inlet valve may be message-connected to the first exhaust channel through the first EGR channel, while the second inlet channel may be message-connected to the second exhaust channel through the second EGR channel.

In the illustrated example, the first intake valve opens with the first setting of the distribution phases (curve 502), which is earlier in the engine cycle than the second setting of the distribution phases (curve 504), with which the second intake valve opens. More specifically, the first setting of the distribution phases for the first intake valve is closer to the TDC of the intake stroke, immediately in front of CAD2 (for example, in or directly in front of the TDC of the intake stroke). In comparison, the second setting of the distribution phases for the second intake valve is delayed from the TDC of the intake stroke, after CAD2, but before CAD3. Thus, the first intake valve can open at or before the start of the intake stroke and can close before the intake stroke ends, while the second intake valve can open after the start of the intake stroke and can remain open at least until until the next compression cycle is started.

Additionally, the first intake valve can open with a first setting of the distribution phases with a first, lower valve lift height L1, while the second intake valve can open with a second setting of the distribution phases with a second, higher valve lift height L2. In addition, the first intake valve can open with the first setting of the distribution phases to the first, shorter duration D1, while the second intake valve can open with the second setting of the distribution phases to the second, longer duration D2.

In one example, in cases where the first and second intake valves are connected to the intake valve actuator, the valve phase of the actuator can be adjusted to open the first intake valve with the first setting of the distribution phases along with opening the second intake valve with the second setting of the distribution phases. The valve phase of the actuator can also be adjusted to allow the first inlet valve to open with the first valve lift for the first duration, along with opening the second inlet valve with a second, excellent valve lift for the second duration. Although the illustrated example illustrates different settings of the distribution phases, lift heights and durations for different inlet valves, it should be understood that, in alternative embodiments, the inlet valves may have the same valve lift and / or the same opening time along with opening with biased distribution phase settings.

Further, referring to the exhaust valves, curves 508a and 510a depict the first example of setting the distribution phases of the exhaust valves, wherein both the first and second exhaust valves (Exh_1, Exh_2) open with a common installation of the distribution phases, starting essentially from the BDC of the exhaust stroke, at or near CAD1, and ending essentially at the TDC of a release cycle at or near CAD2. More specifically, in this example, the first and second exhaust valves may be actuated within the exhaust stroke. Additionally, in this example, both the first and second exhaust valves open with the same lift height L3 and the same duration D3. In the illustrated example, the lift height L3 may have a value less than the lift height L2, but greater than the lift height L1 of the intake valves. In one example, the lift height L3 may have a value equal to the average value or the average value of the lift heights L1 and L2.

Curves 508b and 510b depict a second example of setting the distribution phases of the exhaust valves, while setting the distribution phases of the first and second exhaust valves are biased. More specifically, the second exhaust valve opens closer to (or in) the BDC of the operating cycle (or expansion), on or immediately before CAD1 (for example, on or immediately in front of the BDC of the working cycle), while the distribution phases of the second exhaust valve are delayed from BDC working cycle, after CAD1, but to CAD2. Thus, the second exhaust valve may open at or before the start of the exhaust stroke, as soon as the piston reaches the lowest point at the end of the operating stroke, and may close before the exhaust stroke ends. In comparison, the first exhaust valve may open after the start of the exhaust stroke and may remain open at least before the subsequent intake stroke is started. Additionally, the second exhaust valve may open with a second lower valve lift height L4, while the first exhaust valve opens with a first, higher valve lift height L5. In addition, the second exhaust valve can open for a second, shorter duration D4, while the first exhaust valve can open for a first, longer duration D5. In the illustrated example, the first setting of the exhaust valve distribution phases is later in the engine cycle than the second setting of the exhaust valve distribution phases. However, in an alternative embodiment, such as during a pulse load mode, the first setting of the exhaust valve distribution phases may be earlier in the engine cycle than the second setting of the exhaust valve distribution phases. In addition to other examples, both exhaust valves can open simultaneously to provide a pressure-like boost control action. Similarly, both inlet valves can open simultaneously to provide a compressor-like bypass valve action.

In one example, the cam profile of the second exhaust valve can be adjusted to open and close the second exhaust valve in the BDC of the expansion stroke and selectively exhaust the cylinder exhaust gas into the second exhaust channel. On the other hand, the cam profile of the first exhaust valve can be adjusted to open the exhaust valve after the BDC of the expansion stroke and selectively release the remaining residual gas of the cylinder into the first exhaust channel.

In one example, in cases where the first and second exhaust valves are connected to the exhaust valve actuator, the valve phase of the actuator can be adjusted to open the first exhaust valve with the first setting of the distribution phases along with opening the second exhaust valve from the second (same or excellent) setting the distribution phases. The valve phase of the actuator can also be adjusted to allow the first exhaust valve to open with the first valve lift and for the first duration, along with opening the second intake valve with the second (same or different) valve lift and (same or different) ) the second duration. For example, the valve phase of the intake valve actuator may be adjusted based on the valve phase of the exhaust valve actuator to allow the biased setting of the intake valve distribution phases (as shown in curves 504, 506) to coordinate with the biased setting of the exhaust valve distribution phases (as shown in the curves 508b, 510b). Additionally, the amount of overlap between the intake valve distribution phase setting and the exhaust valve distribution phase setting can be adjusted to control the amount of EGR discharged into the cylinder. In addition to other examples, both exhaust valves can open simultaneously to provide a pressure-like boost control action. Similarly, both inlet valves can open simultaneously to provide a compressor-like bypass valve action. In the same way, the amount of valve overlap between the exhaust valves can be adjusted based on the desired boost pressure control, and the valve overlap between the inlet valves can be adjusted based on the desired compressor bypass.

Thus, using different settings of the exhaust valve distribution phases, the engine efficiency can be increased while the engine emissions are reduced by separating the exhaust gases discharged under higher pressure (for example, expanding exhaust gas in the cylinder until time when the cylinder piston reaches the bottom dead center of the expansion stroke) from exhaust gases released at a lower pressure (for example, exhaust gases that remain tsya cylinder after a reset), according to various outlet channels. In particular, exhaust energy can be transferred from the exhaust gases to one or two exhaust channels for activating a turbocharger turbine (which, in turn, drives a turbocharger compressor), or for delivering EGR at a higher pressure. Essentially at the same time, the residual gases can be directed to another outlet from two exhaust channels to heat the catalytic converter, thereby reducing engine emissions, or to deliver EGR at a lower pressure. Thus, the exhaust gases can be used more efficiently than simply directing all the exhaust gases of the cylinder through a single common outlet to the turbocharger turbine. Essentially, several advantages can be achieved. For example, the average pressure of the exhaust gas supplied to the turbocharger may increase to improve the return of the turbocharger. Additionally, fuel economy can be improved, and particulate emissions can be reduced by reducing engine warm-up time. In addition, the method can reduce engine emissions, since at least a portion of the cylinder exhaust gas is sent directly from the cylinder to the catalytic converter.

Various examples of air inlet charges supplied to the cylinder through the first and second inlet channels are further elaborated with reference to FIG. 6. More specifically, table 600 lists exemplary combinations of the first charge of air that is supplied to the cylinder through the first inlet channel through the first intake valve with the first, earlier setting of the phases of distribution of the intake valve, and the second charge of air that is supplied to the cylinder through a second, separate the inlet channel, through a second, separate inlet valve, with a second, later setting of the phases of distribution of the inlet valve. Essentially, the first and second charges of air can be supplied separately, and then mixed (for the first time) in the cylinder with each other and with the directly injected fuel before burning the mixture.

In one example, during the first mode (Cond_1), the first air inlet charge supplied through the first inlet channel may include fresh intake air, which is naturally aspirated at or below barometric pressure. At the same time, the second air inlet charge may include freshly aspirated freshly aspirated air which is supplied under compressor pressure through the second inlet channel. Here, by supplying naturally aspirated fresh intake air and freshly aspirated freshly aspirated air through separate inlet channels to the engine cylinder, the naturally aspirated portion of the air intake charge can be introduced without putting in compression work (turbocharger), while only the air-charged portion of the intake air charge needs to be compressed. . In this way, a gain in thermal efficiency is advantageously achieved.

In yet another example, during the second mode (Cond_2), the first air inlet charge discharged through the first inlet channel may include at least some recirculated exhaust gas at or below barometric pressure. That is, the low pressure EGR may be recycled from the first exhaust passage to the first intake passage. At the same time, the second air inlet charge may include freshly aspirated freshly aspirated air which is supplied under compressor pressure through the second inlet channel.

Here, by dispensing low pressure EGR and freshly aspirated intake air through separate inlets, the LP-EGR can remain outside the compressed air path. This has numerous benefits. Firstly, the compression work of a turbocharger is not wasted on supplying EGR. As a result, the compression efficiency of the turbocharger is improved. Secondly, by keeping the LP-EGR away from the turbocharger compressor, problems related to clogging and pollution of the compressor from the EGR are reduced. Thirdly, since a freshly charged intake air charge is not diluted with EGR, a temperature gain is achieved because the charge air cooler does not need to be activated to lower the temperature of the intake air charge. Fourth, by separating the pressurized intake air charge from the EGR-based intake air charge, both delays, boost control and EGR control can be reduced, giving synergistic advantages. In conclusion, by dividing the total charge of air into a part supplied through a naturally aspirated inlet channel (i.e., a part that is not pressurized) and a part which is supplied through a compressor, the required compressor compression work is reduced, giving the advantage of thermodynamic efficiency. Essentially, this can give the same compression the ability to be provided by a smaller turbocharger (having a smaller compressor and / or turbine) without compromising on boost efficiency and at the same time reducing the delay of the turbocharger.

As another example, during the third mode (Cond_3), the first air inlet charge supplied through the first inlet channel may include a mixture of recirculated exhaust gases and fresh intake air that is aspirated at or below barometric pressure. Thus, the first amount of LP-EGR can be mixed with the first amount of fresh intake air below or below the BP and supplied to the cylinder through the first inlet. At the same time, the second intake air charge may include fresh intake air under compressor pressure. Here, as with the previous example (during Cond_2), by dispensing at least some EGR through an inlet channel that is separate from the inlet channel including the compressor, clogging of the compressor can be reduced, control delays of the turbocharger and EGR can be reduced, efficiency can be improved turbocharger, and the benefits of boost and EGR can extend to a wider engine operating range.

In yet another example, during the fourth mode (Cond_4), the first air inlet charge supplied through the first inlet channel may include at least some recirculated exhaust gas at or below barometric pressure. At the same time, the second air intake charge may include at least some recirculated exhaust gas under compressor pressure. That is, LP-EGR may be provided through the first inlet, while HP-EGR is provided through the second inlet. Here, by dispensing LP-EGR and HP-EGR through separate inlets to the engine cylinder, the benefits of exhaust gas recirculation can extend to a wider range of engine speed / load modes. Additionally, HP-EGR and LP-EGR can be independently controlled.

In another example, during the fifth mode (Cond_5), the first air inlet charge supplied through the first inlet channel may include fresh intake air, which is aspirated at or below barometric pressure. At the same time, the second air intake charge may include at least some recirculated exhaust gas under compressor pressure. That is, high-pressure EGR (HP-EGR) can be recycled from a second exhaust channel, upstream of the turbocharger turbine, to a second inlet channel, downstream of the turbocharger compressor. Here, by supplying naturally aspirated fresh intake air and pressurized EGR through separate inlets to the engine cylinder, dilution of intake air from EGR can be reduced.

In yet another example, during the sixth mode (Cond_6), the first inlet air charge supplied through the first inlet may include a mixture of recirculated exhaust gases and fresh intake air that is aspirated at or below barometric pressure. At the same time, the second air intake charge may include at least some recirculated exhaust gas under compressor pressure. Thus, a first amount of LP-EGR can be mixed with a first amount of fresh intake air below or below BP and supplied to the cylinder through the first inlet, while HP-EGR is supplied to the cylinder through the second inlet. Here, as with the previous example (Cond_4), by dispensing LP-EGR and HP-EGR through separate inlets, the benefits of exhaust gas recirculation can extend to a wider range of engine speed / load modes.

As an additional example, during the seventh mode (Cond_7), the first air inlet charge supplied through the first inlet channel may include at least some recirculated exhaust gas at or below barometric pressure. At the same time, the second intake air charge may include a mixture of recirculated exhaust gases and fresh intake air under compressor pressure. Thus, the second amount of HP-EGR can be mixed with the second amount of fresh intake air under compressor pressure and supplied to the cylinder through the second inlet, while LP-EGR is supplied to the cylinder through the first inlet. Here, as with the previous examples (Cond_4, and Cond_6), by delivering HP-EGR and LP-EGR through separate inlets, the benefits of exhaust gas recirculation can extend to a wider range of engine speed / load modes.

As another other example, during the eighth mode (Cond_8), the first air inlet charge supplied through the first inlet channel may include a mixture of recirculated exhaust gases and fresh air that is aspirated at or below barometric pressure. At the same time, the second intake air charge may include a mixture of recirculated exhaust gases and fresh intake air under compressor pressure. Thus, the first amount of LP-EGR can be mixed with the first amount of fresh intake air below or below BP and supplied to the cylinder through the first inlet, while the second amount of HP-EGR can be mixed with the second amount of fresh intake air under compressor pressure and supplied into the cylinder through the second inlet channel. Here, by issuing a first charge of air under the first, lower pressure into the cylinder separately from the second charge of air under the second, higher pressure into the cylinder through separate inlet channels, EGR and pressurization can be used on a wide range of operating modes, while allowing each to be better controlled .

As another example, during the ninth mode (Cond_9), the first air inlet charge supplied through the first inlet channel may include fresh intake air that is aspirated at or below barometric pressure. At the same time, the second intake air charge may include a mixture of recirculated exhaust gases and at least some fresh intake air under compressor pressure. Thus, the second amount of HP-EGR can be mixed with the second amount of fresh intake air under compressor pressure and supplied to the cylinder through the second inlet channel, while the naturally aspirated fresh intake is supplied to the cylinder through the first inlet channel. Here, by delivering a pressurized intake air charge and a naturally aspirated intake air charge through the separate intake channels, the naturally aspirated intake air charge can be introduced without investing the compression work along with spending the compression work of the turbocharger only on the pressurized intake air charge.

Next, referring to FIG. 7, an exemplary procedure 700 is described for reducing the delay of a turbocharger. More specifically, the procedure depicts the coordination of the operation of the inlet air damper of the first inlet channel with the operation of the turbocharger in the second inlet channel during the event of an increase in engine load at constant speeds to reduce the delay of the turbocharger. By reducing the turbocharger lag, the turbocharger output can be increased, and engine performance can be improved. FIG. 8 illustrates an exemplary adjustment of an EGR throttle valve during an increase in engine load at constant speeds, as for the procedure of FIG. 7, as a multi-dimensional characteristic of an 800 engine.

At 702, the procedure includes acknowledging the event of an increase in engine load at constant speeds. In one example, the event of an increase in engine load at constant speeds can be confirmed in response to a push (or depression) of the accelerator pedal above a threshold position. In yet another example, an event of an increase in engine load at constant speeds can be confirmed in response to a driver demanding a torque that is higher than a threshold value.

Essentially, before the event of an increase in engine load at constant speeds, each cylinder of the engine can receive a certain amount of exhaust gas (more specifically, LP-EGR) through the first inlet channel along with the intake of fresh intake air through a second, separate but parallel inlet channel . The exhaust gas could be recycled at a lower pressure from the first exhaust channel, with the possibility of communication connected to the first inlet channel, downstream of the first air intake valve through the first EGR channel, including the first EGR valve. In response to the event of an increase in engine load at constant speeds, by 704, the procedure includes an increase in the amount of fresh intake air along with a decrease in the amount of recirculated exhaust gas supplied to the cylinder through the first inlet channel. More specifically, the procedure includes opening (or increasing the opening) of the first air inlet flap in the first inlet to increase the amount of fresh intake air introduced into the cylinder through the first inlet, along with closing (or decreasing the opening) of the first EGR valve in the first EGR channel, connected between the first inlet and the first outlet, to reduce the amount of exhaust gas recirculated through the first inlet.

Along with adjusting the air inlet damper and EGR valve in the first inlet, at 706, the procedure further includes activating a turbocharger compressor connected to the second inlet to increase the amount of freshly aspirated intake air supplied to the cylinder through the second inlet for the duration of the increase engine load at constant speed. More specifically, the engine controller may initiate the operation of the turbocharger compressor along with opening (or increasing opening) of the second air inlet flap connected in the second inlet channel downstream of the compressor to increase the amount of freshly aspirated intake air supplied to the cylinder. The controller may also close (or reduce opening) a second EGR valve included in a second EGR channel connected between the second inlet channel and the second outlet channel to reduce the amount of higher pressure exhaust gases recirculated through the second inlet channel. In one example, the first air intake valve may gradually open, and the first EGR valve may gradually close with a profile based on the compressor speed profile. The adjustments at the first and second air inlet flaps and the first and second EGR valves can continue for a duration corresponding to the duration until the compressor reaches the threshold speed. In one example, the threshold number of revolutions may correspond to the number of revolutions, above which the delay of the turbocharger may decrease, such as the number of revolutions at which the compressor outlet pressure is greater than atmospheric (or barometric) pressure for a given engine operation mode.

At 708, it can be confirmed whether the compressor speed has reached the threshold speed. Alternatively, it can be determined whether a predetermined duration corresponding to the duration has elapsed before the compressor reaches the threshold speed (for example, using a timer). If not, then, at 710, the procedure can keep the first intake air damper open and the first EGR valve closed while the compressor is running. In comparison, if the compressor speed has reached the threshold speed, or if the predetermined duration has elapsed, then, by 712, after the duration has elapsed, the procedure includes reducing the amount of fresh intake air along with increasing the amount of recirculated exhaust gas supplied to the cylinder through the first intake duct. More specifically, the procedure includes closing (or decreasing the opening) of the first air inlet flap in the first inlet to reduce the amount of fresh intake air introduced into the cylinder through the first inlet, along with opening (or increasing opening) of the first EGR valve in the first EGR channel, connected between the first inlet channel and the first outlet channel to increase the amount of exhaust gas recirculated through the first inlet channel. In one example, the first air intake valve may gradually close, and the first EGR valve may gradually open with a profile based on the engine speed profile.

In this way, the cylinder can be filled with fresh intake air through the first inlet valve, while the compressor accelerates in the second intake channel, so that by the time the compressor is at the required number of boost speeds, the cylinder can already be filled with fresh intake air. In other words, by the time the compressor is pressurized, boosted fresh intake air can be provided to the cylinder through the second intake valve, while additional fresh air is supplied to the cylinder through the first intake valve. Therefore, the delay in the turbocharger caused by the expectation that the compressor picks up speed before the cylinder is charged with fresh air can be introduced. Then, when the compressor has reached the desired speed, the EGR can be phased through the first and second inlet channels (more specifically, LP-EGR through the first inlet channel and HP-EGR through the second inlet channel) to provide EGR advantages in addition to the advantages of boost. By reducing the delay of the turbocharger, the efficiency of the turbocharger is improved and engine performance is increased. By jointly providing the benefits of boost and EGR, synergistic improvements in engine performance can be achieved.

The steps of FIG. 7 is further explained by the example of FIG. 8. The multi-dimensional characteristic 800 of the engine depicts the engine output torque on a graph 802 over the duration of the engine operation. Corresponding changes in the number of revolutions of a turbocharger compressor are shown on a graph 804. Changes in the position of the first air inlet damper and the first EGR valve connected to the first air inlet are shown in graphs 810 and 812, respectively, while changing the position of the second air intake damper and the second EGR valve, connected to the second stuffy inlet channel, shown in the graphs 806 and 808, respectively. Essentially, only the second inlet can include a turbocharger compressor. Changes in the composition of the first air charge (Air_Int_1) supplied to the cylinder through the first inlet channel, which are the result of adjustments at the first EGR valve and damper, are shown in graphs 818 and 820, while changes in the composition of the second air charge (Air_Int_2) supplied in the cylinder through the second inlet channel, which is the result of adjustments at the second EGR valve and damper, is shown in graphs 814 and 816. Changes in the total cylinder air charge (Cyl_aircharge) are shown in graphs 822 and 824, respectively. In each of the graphs 814-824, the solid line represents the fresh air component of the air charge, while the dashed line represents the EGR component of the air charge.

Until t1, based on the engine operating mode, lower torque may be required. Here, the total cylinder air charge corresponding to a lower output torque may include a relatively higher amount of EGR (dashed line in graph 824) and relatively less fresh air (solid line in graph 822). By using EGR during the low load mode, the advantages of fuel economy and reduced emissions can be achieved. The total cylinder air charge supplied to the cylinder up to t1 can be achieved by mixing the first air inlet charge supplied through the first inlet channel with the second air inlet charge supplied through the second inlet channel. More specifically, the first air inlet charge may include a higher amount of recirculated exhaust gas (plot 820) below or below barometric pressure (i.e., LP-EGR) and a lower amount of naturally aspirated fresh air (plot 818) supplied by opening the first EGR valve ( graph 812) and a second intake damper (graph 810) by the corresponding values. In comparison, the second intake air charge may include fresh intake air (solid line on schedule 814) and essentially not include EGR (dashed line on schedule 816) issued by opening the second intake valve (schedule 806) while closing the second EGR valve ( Chart 808).

At t1, an event of an increase in engine load at a constant speed may occur, leading to a higher torque requirement. For example, a higher output torque may be required in response to a driver pushing an accelerator pedal to a vehicle beyond a threshold position. In response to the event of an increase in engine load at constant revolutions, the compressor (schedule 804) can be used to issue a boosted intake air charge while the second intake shutter (schedule 806) opens (for example, fully opens) to enter freshly charged boost air into the cylinder. However, a boosted air charge may not be available until the compressor reaches the threshold speed, causing the turbocharger to delay. To reduce the delay of the turbocharger, while the compressor spins up in the second inlet channel, the first air inlet charge supplied through the first inlet channel can be temporarily adjusted to increase part of the fresh intake air along with decreasing part of the EGR (graphs 808-820). More specifically, the first EGR valve (graph 812) may close, while the first intake damper (graph 810) is fully open to increase the amount of naturally aspirated fresh air introduced into the cylinder while decreasing the amount of LP-EGR supplied to the cylinder.

At t2, when the compressor is at or above the required threshold speed, the boosted fresh air intake charge can be supplied to the cylinder via the second intake channel (graph 814). At this time, the amount of fresh air supplied through the first inlet can be reduced by gradually closing the first inlet damper (graph 810), while LP-EGR can gradually return to its previous state by opening the first EGR valve (graph 812). Thus, while the compressor is unwound in one inlet, fresh air can be introduced into the cylinder through another inlet to dilute any amount of EGR already present in the cylinder. Therefore, when the compressor has unwound, the fresh air introduced in the second inlet can be compressed to satisfy the requirement of a higher torque. In addition, when the compressor has unwound, the compressor can be used to inject freshly aspirated fresh air through one inlet, while the LP-EGR is simultaneously supplied to the engine cylinder through another inlet. Thus, the delay of the turbocharger can be reduced while providing the advantages of EGR in parallel with the advantages of boost.

It should be understood that, in addition to still other embodiments, the delay of the turbocharger can additionally or optionally be reduced by closing the EGR valves, shutting off the first exhaust valve and fully opening the second exhaust valve. Then, if EGR is required, one or more of the EGR valves may open to provide the desired EGR, as specified above at 808 and 812.

Next, referring to FIG. 9, an example procedure 900 is shown for adjusting the operation of an EGR cooler based on an engine operating mode. More specifically, the procedure allows the EGR cooler located at the junction of the EGR channel and the inlet channel (for example, at the junction of the first EGR channel and the first inlet valve) to be used to cool the intake charge of the air supplied to the cylinder (for example, through the first inlet channel) during certain modes, along with allowing the EGR cooler to heat the air intake charge during other modes.

At 902, engine operating modes may be evaluated and / or measured. For example, they can include ambient temperature and pressure, engine temperature, engine speed, engine speed, transmission speed, battery status, fuel available, percentage of alcohol in the fuel, catalytic converter temperature required by the driver moment, etc. At 904, it can be determined whether heating the intake air charge is required. In one example, heating the intake air charge may be required when the engine is not limited to detonation. For example, if no knock is expected, the intake air charge may heat up to reduce engine pumping and improve fuel economy.

If heating is required, then, at 906, the heating mode can be confirmed. More specifically, it can be determined whether all conditions are present for the ability to use an EGR cooler as a heater for heating an air intake charge. For example, in cases where the EGR cooler is a coolant-based cooler, it can be confirmed that the temperature of the coolant is higher than the temperature of the intake air. In addition, it can be confirmed that knock conditions are not present (that is, knocking does not occur and is not expected). If all the heating conditions are satisfied, then, at 908, the procedure involves closing the first EGR valve along with opening the first inlet flap in the first inlet channel to heat the inlet charge of air introduced into the cylinder through the first inlet channel using the first EGR cooler. Thus, the inlet air charge supplied through the first inlet channel can be heated before being introduced into the cylinder, thereby reducing engine pump losses and improving engine efficiency. Essentially, if any or all of the heating conditions are not satisfied, the controller may determine that the EGR cooler cannot be used as an air charge heater at this time, and the procedure may end.

If heating the air intake charge is not required at 904, then at 910 it can be determined whether cooling the air intake charge is required. In one example, cooling may be used to lower the temperature of the EGR supplied to the cylinder. Cooled EGR can reduce cylinder knocking, while also providing the benefits of fuel economy and reduced NOx. If no cooling is required, the procedure may end. If cooling is required, then, at 912, cooling conditions can be confirmed. More specifically, it can be determined whether all conditions are present for the ability to use an EGR cooler to cool the air intake charge. For example, it can be confirmed that cooling will not cause condensation in the compressor. If all cooling conditions are satisfied, then, at 914, the procedure involves opening the second EGR valve along with closing the second inlet damper in the second inlet channel to cool the EGR in the air intake charge introduced into the cylinder through the second inlet channel using a second EGR cooler. Additionally or optionally, the procedure may include opening the first EGR valve while closing the first inlet flap in the first inlet to cool the EGR in the air intake introduced into the cylinder through the first inlet using the first EGR cooler. Thus, the air intake charge can be cooled before being introduced into the cylinder, and EGR temperature control can be achieved. Essentially, if any or all of the cooling conditions are not satisfied, the controller may determine that the EGR cooler cannot be used as an air charge cooler at this time, and the procedure may end.

In one example, heating the intake air charge may include heating only the EGR supplied to the cylinder. For example, when the EGR cooler is located within the recirculation channel (or EGR channel), as shown in FIG. 1-2, the EGR valve may open, and the EGR cooler can be used as a heater to heat the EGR and mix the heated EGR with cooler fresh intake air in the inlet channel before being fed into the cylinder. Alternatively, if the EGR cooler is located at the junction of the EGR duct and the intake duct, heating the air intake charge may include heating fresh intake air and / or EGR supplied to the cylinder. For example, the EGR valve may be closed while the EGR cooler is used as a heater to heat the fresh intake air before being fed into the cylinder. Alternatively, the EGR valve can be opened, and the EGR cooler can be used as a heater to heat fresh air and EGR, heated EGR and heated fresh air are mixed in the inlet before being fed into the cylinder.

In addition, in other examples, one of the EGR coolers can be used as a cooler, while the other EGR cooler is used as a heater. For example, during the first mode, the engine controller can control the first EGR cooler in the first inlet to heat the first amount of exhaust gas before recirculating the exhaust gases to the first inlet, and during the second mode, the controller can control the first EGR cooler in the first inlet for cooling the first amount of exhaust gas before recirculating the exhaust gas to the first inlet channel. At the same time, during the first mode, the engine controller can control the second EGR cooler in the second intake channel to cool the second amount of exhaust gas before recirculating the exhaust gas to the second intake channel, while during the second mode, the controller can control the second EGR cooler in a second inlet channel for heating a second amount of exhaust gas before exhaust gas recirculation to the second inlet channel. Essentially, a second EGR cooler can be used as a heater only when the compressor is not running and no boost is given out.

In addition, the operation of EGR coolers can be coordinated with the operation of an air charge cooler located downstream of a turbocharger compressor (such as air charge cooler 56 of FIGS. 1-2). For example, the first EGR cooler in the first intake duct can be used as a heater to deliver a heated intake air charge (including fresh intake air and / or LP-EGR) to the cylinder through the first intake duct. At the same time, the compressor in the second inlet channel can be used to deliver the pressurized inlet air charge while the charge cooler downstream of the compressor is used to cool the pressurized inlet air charge. Thus, heated naturally aspirated air (at or below atmospheric pressure) and cooled pressurized air can be provided into the cylinder at the same time. Heated and cooled air charges can then be mixed and burned in a cylinder. Here, by combining and burning heated and cooled air charges separately but simultaneously supplied to the cylinder, a substantially constant compression temperature can be achieved at varying loads, improving engine performance.

Thus, a separate engine inlet can be combined with a separate engine outlet for supplying different charges of air of different composition and pressure to a cylinder with different settings for the distribution phases. More specifically, a naturally aspirated charge may be introduced separately from the boosted air charge to reduce the amount of compression work required. By reducing the amount of work required by the compressor, engine boost efficiency can be increased, even with a smaller turbocharger. In yet another embodiment, EGR may be provided separately from the freshly charged fresh air intake. By holding EGR outside the compressor, clogging and fouling of the compressor can be reduced, while allowing EGR control delays and turbocharger control delays to be reduced. In yet another embodiment, HP-EGR and LP-EGR may be provided through separate channels. Here, overall EGR control can be improved along with giving EGR benefits the ability to expand over a wider range of modes. Additionally, excessive dilution of EGR air, in particular when switching from a high cylinder air charge to a low cylinder air charge, may be reduced by allowing the second path of undiluted air to be provided. In general, EGR and boost performance can be improved to improve engine performance.

Note that the exemplary management and evaluation procedures included in the materials of this application can be used with various system configurations. The specific procedures described herein may be one or more of any number of processing strategies, such as event-driven, interrupt-driven, multi-tasking, multi-threading, and the like. As such, the various acts, operations or functions illustrated can be performed in the illustrated sequence, in parallel, or in some cases skipped. Similarly, a processing order is not required to achieve the features and advantages of the exemplary embodiments described herein, but is provided to facilitate illustration and description. One or more of the illustrated actions, functions or operations may be performed repeatedly, depending on the particular strategy used. In addition, the described operations, functions, and / or actions may graphically represent a control program that must be programmed into a computer-readable storage medium in a control system.

In addition, it should be understood that the systems and methods disclosed in the materials of this application are exemplary in nature and that these specific embodiments or examples should not be construed in a limiting sense, since numerous variations are contemplated. Accordingly, the present invention includes the latest and non-obvious combinations of the various systems and methods disclosed in the materials of this application, as well as any and all their equivalents.

Claims (36)

1. A method of driving an engine, comprising: providing a first air charge at or below barometric pressure into the engine cylinder through the first inlet channel; at providing a second, pressurized, air charge into the same cylinder through a second, separate, inlet channel, wherein the second air charge is pressurized by an inlet compressor driven by an exhaust turbine. 2. The method according to claim 1, wherein providing a first charge of air at or below barometric pressure into the engine cylinder through the first inlet channel includes providing a first charge of air at or below barometric pressure into the cylinder through the first intake channel that is connected to the first exhaust channel, and providing a second, supercharged, air charge into the cylinder through a second, separate, inlet channel includes providing a second, supercharged, air charge into the cylinder through a second inlet a channel that is connected to the second exhaust channel, the inlet compressor being included in the second inlet channel, and the exhaust turbine included in the second exhaust channel. 3. The method according to p. 2, further comprising mixing the first and second charges of air with fuel in the cylinder and burning the mixture in the cylinder. 4. The method according to claim 1, wherein providing at least some charge of air under or below barometric pressure comprises opening a first intake valve in a first intake channel with first setting distribution phases of the intake valve, and providing at least some boosted charge of air includes opening a second intake valve in the second intake channel with a second, excellent setting of the phases of the distribution of the intake valve in the same engine cycle. 5. The method of claim 4, wherein opening the first intake valve in the first inlet with the first setting of the intake valve distribution phases includes opening the first inlet valve in the first inlet with the first setting of the intake valve distribution phases, which is adjusted relative to the second installation of the intake distribution phases valve based on engine operating mode. 6. The method according to claim 4, further comprising actuating the actuator of the intake valve connected to the first and second intake valves, with a phase difference for opening the first valve with the first setting of the distribution phases and opening the second valve with the second setting of the distribution phases. 7. The method of claim 1, wherein providing a first charge of air at or below barometric pressure into the engine cylinder through a first inlet channel includes providing a first charge of air that includes a first amount of fresh intake air at or below barometric pressure, and providing a second subjected to pressurization, the charge of air into the cylinder through a second, separate, inlet channel includes providing a second charge of air, which includes a second amount of fresh intake air under pressure boost it. 8. The method of claim 7, wherein providing a first charge of air under or below barometric pressure into the engine cylinder through a first inlet channel includes providing a first charge of air that comprises a mixture of a first amount of fresh intake air with a first amount of recirculated exhaust gas under barometric pressure or lower than it, and providing a second, boosted, charge of air into the cylinder through a second, separate, inlet channel includes providing a second charge of air, which Luciano mixture a second amount of fresh intake air with the second quantity of recycled exhaust gases under pressure supercharging. 9. The method according to p. 2, in which the provision of a second, boosted, air charge into the cylinder through a second, separate inlet channel, includes the provision of a second, boosted, air charge into the cylinder through a second inlet channel that is parallel to the first inlet channel, this second exhaust channel is parallel to the first exhaust channel. 10. A method of driving an engine, comprising: supplying a first charge of air, including a first amount of recirculated exhaust gas and a first amount of fresh intake air below a barometric pressure, to an engine cylinder through a first intake channel; and the supply of a second charge of air, including a second amount of recirculated exhaust gas and a second amount of fresh intake air under compressor pressure, into the engine cylinder through a second, separate, inlet channel. 11. The method according to p. 10, further comprising: direct injection of fuel into the cylinder; mixing the first charge of air with the second charge of air and injected fuel in the cylinder; and burning the mixture in a cylinder. 12. The method according to p. 10, in which the supply of the first charge of air includes opening the first intake valve of the first intake channel with the first setting of the phases of distribution of the intake valve, and the supply of the second charge of air includes opening the second intake valve of the second intake channel with the second setting of the phases of the distribution of the intake valve . 13. The method according to p. 12, in which the supply of the first charge of air further includes opening the first valve of the recirculated exhaust gas to recirculate the first amount of exhaust gas from the first exhaust channel to the first inlet channel, and the supply of the second charge of air further includes opening the second valve of the recirculated exhaust gas for recirculating a second amount of exhaust gas from a second, separate, exhaust channel to a second inlet channel. 14. The method according to p. 13, in which the second charge of air under pressure from the compressor further includes driving a compressor included in the second inlet channel and driven by a turbine included in the second exhaust channel, wherein the second amount of exhaust gas is recirculated from places upstream of the turbine to a place downstream of the compressor. 15. The method of claim 14, wherein the first inlet valve and the second inlet valve are connected to the valve actuator, the method further comprising adjusting the valve phase of the valve actuator to open the first valve with first setting the distribution phases of the intake valve and the second valve from the second setting the distribution phases of the intake valve, the first setting of the distribution phases of the intake valve being earlier in the intake stroke of the engine cycle than the second setting of the distribution phases final year at the valve. 16. The method according to p. 15, in which the supply of the first charge of air further includes opening the first exhaust valve of the first exhaust channel with the first setting of the distribution phases and opening the second exhaust valve of the second exhaust channel with the second, earlier, setting the distribution phases. 17. An engine system comprising: engine cylinder; a first inlet channel transmitting uncompressed air charge to the engine cylinder through the first inlet valve; a second inlet channel transmitting the compressed air charge to the cylinder through the second inlet valve; a turbocharger compressor connected to the first inlet channel, configured to compress a charge of air supplied to the cylinder; a valve actuator for opening a first intake valve and a second intake valve; and a control system with machine-readable instructions stored on a permanent machine-readable medium for: adjusting the phase of the valve actuator to open the first intake valve with the first setting of the distribution phases, and the second valve with the second, excellent setting of the distribution phases, while the uncompressed air charge includes at least some fresh air and at least some recirculated exhaust gases under or below barometric pressure, the compressed air charge comprising at least some fresh air and at least some Recycled exhaust gas under compressor pressure. 18. The system of claim 17, wherein the first inlet channel is parallel and separate with respect to the second inlet channel, the system further comprising a first and second outlet channels, wherein the first outlet channel is parallel and separated with respect to the second outlet channel, and a turbocharger turbine connected to the second exhaust channel, wherein the turbine is configured to drive a compressor. 19. The system of claim 18, further comprising: a first recirculated exhaust gas channel that connects the first exhaust passage to a first inlet channel, wherein the first recirculated exhaust gas channel includes a first recirculated exhaust gas cooler and a first recirculated exhaust gas valve; and a second recirculated exhaust gas channel connecting the second exhaust channel to the second inlet channel, the second recirculated exhaust gas channel including a second recirculated exhaust gas cooler and a second recirculated exhaust gas valve, the control system includes additional commands for opening the first recirculated exhaust gas valve to supply at least a certain amount of recirculated exhaust gas at or below atmospheric pressure to the first inlet channel and opening the second recirculated exhaust gas valve to supply at least some recirculated exhaust gas under the pressure of the compressor from the second outlet channel, upstream of the turbine, into the second inlet channel, lower downstream of the compressor.

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