FI125390B - Procedure for operating an ottoman engine and an ottoman engine - Google Patents

Description

A method of operating an internal combustion engine machine and an internal combustion engine

The invention relates to a method for operating an internal combustion engine machine according to the preamble of claim 1. The invention further relates to an internal combustion engine machine according to the preamble of claim 8.

The combustion engine engine formed as a high gas engine has a plurality of cylinders for burning a mixture of fuel, namely gas and combustion air. Such a high-gas engine typically has an exhaust gas compressor comprising a turbine and an air press, wherein the exhaust gas compressor hot exhaust gas pressure is lowered in the exhaust gas turbine to purify the exhaust gas compressor air and thereby supply combustion air to the cylinders of the combustion engine. In addition, the high-gas engine has fuel control valves fitted to the cylinders of the internal combustion engine, whereby fuel can be mixed with the compressed combustion air to make the combustible mixture of fuel and combustion air for use in the cylinders. In high-gas engines, the gas produced as gas is added to the combustion air after being compressed, because compressing a combustible mixture of fuel and combustion air in high-gas engines is considered too dangerous. In addition, it is known in the art to open or close fuel control valves fitted to the cylinders of an internal combustion engine and which operate to mix fuel with compressed combustion air, control or control valves such that fuel control valves can be operated / or RPM. This regulator or control, which operates to control the fuel control valves to operate the internal combustion engine at a predetermined reference power and / or reference RPM, is also referred to as a RPM.

However, to ensure safe and trouble-free operation of an internal combustion engine, in particular a high gas engine, it is not only necessary that the combustion engine is operated at a predetermined reference power and / or reference RPM; However, prior art methods for adjusting the defined composition of the fuel and combustion air supply to the lambda control or to the cylinders have the disadvantage that they respond slowly to changing operating conditions and only detect load increases and load decreases. Load coupling and load offsets for lambda control are known to be very inadequate in methods known in the art. As a result, a mixture of fuel and combustion air that is too thin or too fat is placed on the cylinders of the internal combustion engine so that the operation of the internal combustion engine can result in unwanted knocking, excessive exhaust emissions and a reduced efficiency of the internal combustion engine.

EP 0 259 382 B1 and EP 1 158 149 B1 each disclose known methods for controlling a mixture of combustion air and fuel fed to a gas engine, which may be introduced in gas engines in which the combustion air and gas are blended before the air press, whereby the fuel and the combustible mixture of combustion air is fed to the air press. These methods are unsuitable for use in an internal combustion engine, where fuel is only mixed downstream of the compressed combustion air compressor. Henceforth, the present invention is based on the problem of creating a novel method of operating an internal combustion engine and a novel internal combustion engine with improved lambda control. This problem is solved by a method according to claim 1, characterized in that the first control or control device provides a control signal for use with the fuel control valves to a second control or control device that generates a control signal for the exhaust gas compressor depending on this control signal a mixture for operating a combustion engine machine with a predetermined lambda value, the second control or control device correcting the control signal provided by the first control or control device for use with the fuel control valves by the control offset value, and the second control or control device and that the control offset value for the fuel control valves occurs to adjust the control signal set to be determined by the second control or control device, depending on the pressure difference between the pressure of the compressed combustion air and the fuel pressure and / or depending on the ignition time of the combustion engine and / or depending on depending on the methane number or octane number of the fuel and / or depending on the knock integrator value.

The method of the invention enables improved lambda control in an internal combustion engine machine in which the fuel is only mixed downstream of the compressed combustion air air press. The method can react rapidly to changing operating conditions such as load increases and load decreases, especially load switching and load loss. The use of an internal combustion engine can avoid unwanted knocking and excessive exhaust emissions. The internal combustion engine can be operated with good efficiency.

An internal combustion engine machine according to the invention is defined in claim 8.

Advantageous further developments of the invention will be apparent from the dependent claims and the following description. Exemplary embodiments of the invention will be described in more detail without reference to the drawing. The drawing shows a pattern strongly diagrammatic one ignition internal combustion engine, the description, Fig ignition internal combustion engine of the detail of Figure 2, 1 is a block diagram for operating an internal combustion engine illustrating the method according to the invention, Figure 3 is a diagram of the use of ignition internal combustion engine illustrating the method according to the invention, Figure 4 further diagram of the ignition internal combustion engine for use to illustrate the method according to the invention, Figure 5 is an additional diagram of the ignition internal combustion engine for practicing the invention Fig. 6 is a further diagram illustrating the method of the invention, Fig. 7 is a further diagram illustrating a method of the invention, Fig. 7 is a further diagram illustrating a method of the invention, Fig. 8 is a further diagram illustrating the method of Fig. 9, for operating an internal combustion engine to illustrate the method of the invention, Fig. 10 is a further diagram of using an internal combustion engine to illustrate the method of the invention and Fig. 11 is a further diagram for using an internal combustion engine to illustrate the method of the invention.

The invention relates to a process for combustion of a gaseous fuel by a combustion engine machine, preferably a combustion gas engine formed as a high gas engine. Although the invention will be described with reference to a preferred use of a large gas engine, the invention is not limited to this use. On the contrary, the invention can also be used in internal combustion engine engines which burn liquid fuel.

Fig. 1 shows a schematic block diagram of a high-combustion internal combustion engine machine comprising cylinders 10. A mixture 11 of fuel 12, namely gas and combustion air 13, is fed to the cylinders 10 to combust the mixture 11, thereby mixing the fuel 12 and combustion air 13.

In the case of combustion air 13 which is mixed with fuel 12, it is compressed combustion air 13 which is compressed by means of the exhaust gas compressor 16. The exhaust compressor 16 has an air press 17 where the non-compressed combustion air 18 is compressed into a compressed combustion air 13, wherein the exhaust press 17 of the exhaust gas compressor 16 is operated by its turbine 19, whereby the pressure of the combustion engine exhaust 20 is reduced.

As already mentioned, the fuel 12 is mixed with the compressed combustion air 13 for which at least one fuel control valve 15 is fitted to each cylinder 10 of the combustion engine. A defined mixture of.

The combustion engine of Fig. 1, constructed as a high gas engine, has two control or control means 21 and 22, namely a first control or control device 21, preferably formed as a speed control, and a second independent or independent control or control device 22, preferably a motor control device.

The first control or control device 21 functions inter alia to make the control signal 23 operable for the fuel control valves 15, wherein the first control or control device 21 defines the control signals 23 for the fuel control valves 15 such that depending on the control signal 23, the is used at a predetermined reference speed and / or at a predetermined reference power. In the case of the fuel control valves 15, these are electromagnetically controlled fuel control valves 15. The first control or control device 21 sets the control signals 23 for the fuel control valves 15 to be used specifically for their flow-through time.

It is now an object of the present invention that the first control or control device 21 does not make the control signals 23 produced for the fuel control valves 15 to be used only for the fuel control valves 15 but vice versa the second control or control device 22, the second control or control device 22 an exhaust supercharger 16 such that a defined mixture of fuel 12 and combustion air 14 is provided to the cylinders 10 to operate the internal combustion engine at a predetermined lambda value and thereby adjust the lambda control for the internal combustion engine. The control signal 24 for the exhaust compressor 16 is then preferably generated in such a way that the pressure p13 of the compressed combustion air 13 compressed by the exhaust gas compressor 16 is dimensioned such that the mixture 11 has the desired composition and thus the combustion engine is operated at a predetermined lambda value.

Regardless of the type of exhaust supercharger 16 used, the control variable 24 for the exhaust supercharger 16 is defined as either a control variable for the turbine adjustable turbine blades 19 of the turbocharger 16 or a control variable for the adjustable bypass of the exhaust compressor 16 not shown in FIG. Accordingly, it is an object of the present invention to provide a composition control, and thus a lambda control, of the fuel 12 and combustion air 13 mixture, preferably utilizing a flow signal 23 for the fuel control valves 15, preferably independent of to influence or adjust the pressure p13.

As a measure of the amount of fuel burned in the cylinders 10, a control signal 23 for the fuel control valves 15, preferably realized during the flow duration, is accordingly taken, wherein the flow control time of the first control or control device 21 is determined by operating the internal combustion engine at the desired RPM. The longer the throughput time of the fuel control valves 15, the more fuel is burned in the cylinders 10 and the more power the internal combustion engine can deliver. By adjusting the pressure p13 of the compressed combustion air 13 by corresponding control of the exhaust gas compressor 16 via the control signal 24, the amount of combustion air 13 is matched to the amount of fuel 12 in the mixture 11 to provide the desired ratio of fuel 12 and combustion air 13 and thereby operate the combustion engine.

From Fig. 3, where the flow rate duration t-is shown as the control variable 23 for the fuel control valves 15 through the desired power output Lsoll of the internal combustion engine, it can be seen that with the increasing power output Lsoll the flow time h5 is increased for the fuel control valves 15.

With the increased throughput time ti5 of the fuel control valves 15, the control signal 24 for the exhaust compressor 16 is determined by adjusting the pressure p13 of the compressed combustion air 13 accordingly, as can be seen in the diagram of FIG.

Accordingly, Figures 3 and 4 immediately show that, with the increasing reference power Lsoll of the internal combustion engine, on the one hand the flow control time ti5 of the fuel control valves 15 is increased and on the other hand the control signal 24 for the exhaust compressor 16 is influenced.

In determining the control signal 24 for the exhaust compressor 16, depending on the control variable 23 of the fuel control valves 15, the second control or control device 22 proceeds in detail so that factors 26, 28 or quantities affecting lambda value are considered in the second control or control device 22.

According to a preferred further development, the second control or control device 22 corrects the control signal 23 provided by the first control or control device 21 for use with a control deviation value Δ23, the second control or control device 22 then generating an control deviation value Δ23 based on the control signal for. From Figure 2, it can be seen that another control or control device 22, depending on the corrected control signal 23 ', corrects the control signal 24' produced in the device 25 to set the control signal 24 for use with the exhaust compressor 16 by a control deviation value Δ24. The control deviation values Δ23 and Δ24 take into account factors 26, 28 or quantities that influence the lambda value.

2, the control offset value Δ23 for correcting the control signal 23 generated for the fuel control valve 15 is generated based on factors 26 in the device 27, wherein the control offset value Δ23 is determined depending on the pressure difference Δρ between the compressed combustion air 13 pressure p13 and the ignition time tz and / or the fuel temperature of the fuel 12 T12 and / or depending on the efficiency of the internal combustion engine and / or depending on the methane number of the fuel 12 (or octane number in the case of liquid fuel) and / or the knock integration value.

Figures 5, 6, and 7 each show diagrams for determining the control deviation value Δ23 in the second control or control device 22. Thus, the control deviation Δρ for the pressure difference Δρ between the compressed combustion air 13 and the fuel 12 pressure pi2 . This pressure difference Δρ must not change between the specified limits ΔρΜΐΝ and ΔρΜΑχ, so that when the pressure difference Δρ increases with the default value Δρεου., A negative control deviation value Δ23 is generated. On the other hand, a positive control deviation value Δ23 is generated in the case of a differential pressure difference Δρ compared to the reference pressure difference Apsoll ·

Fig. 6 is a diagram showing the generation of a control deviation value Δ23 depending on the ignition time tz of the internal combustion engine. The wider the ignition time tz relative to the corresponding reference value tz Soll in the direction ahead of the early ignition time, the more the crankshaft torque angle increases before the dead center, which in principle increases the efficiency of the internal combustion engine23 to generate a negative control value. On the other hand, if the setpoint tz for the start time of the internal combustion engine is set relative to soll in the direction of the delayed start time, a positive control deviation value Δ23 for the control signal is produced.

Figure 7 illustrates the generation of a control offset value Δ23 depending on the temperature T-12 of the fuel 12, where a positive control offset value Δ23 is generated when the temperature 12 of the fuel 12 increases relative to the reference TSoll, and while the temperature 12 of the fuel 12 to setpoint T12, soll lowers, a negative control deviation value Δ23 is generated.

The generated offset values Δ23 for the control values 23 of the fuel control valves 15 are not actually used to match the control values 23 used to control the fuel control valves 15, on the contrary, This correction takes place, as already indicated with reference to the diagrams of Figures 5-7, for example depending on the pressure difference Δρ between the compressed combustion air 13 pressure pi3 and the fuel pressure pi2 and / or depending on the combustion engine ignition time tz and / or the fuel temperature T12.

Additionally or alternatively, the control offset value Δ23 may also be determined depending on the fuel value of the fuel 12 and / or depending on the efficiency of the internal combustion engine and / or the fuel methane number (or octane number for liquid fuel) and / or knock integrator value is not shown. The determination of the control deviation value Δ23 depending on the fuel value of fuel 12 is based on the knowledge that as the combustion value of fuel 12 increases at constant power of the internal combustion engine, the need for combustion air also increases. Gas analysis can then determine the calorific value of the gas in gas form, depending on the calorific value, to determine the control deviation value Δ23. Gas chromatography may be used to analyze the calorific value of gaseous fuel. The determination of the control deviation value Δ23 depending on the efficiency of the internal combustion engine is based on the knowledge that the effective efficiency may change during the service life. If, at the same constant efficiency of the internal combustion engine, the required fuel, which is defined by the flow-through time of the fuel control valves 15, changes, then the change in the efficiency of the internal combustion engine can be deduced. Depending on the new efficiency thus defined, the control deviation value Δ23 can be determined.

As can be seen in Figure 2, the second adjusting or controlling device 22, in addition to adjusting the control deviation value 23 for correcting the control variable 23, additionally determines the control deviation value Δ24 for correcting the control variable 24 'generated by the device 25 depending on the corrected control variable 23'.

In the case of the corrected control variable 23 ', this is the corrected flow-through time, based on which the control variable 24' for the exhaust supercharger 16 is determined such that the pressure p-13 of the compressed combustion air 13 matches the amount of fuel 12 mixed with the control valve 23. The control deviation value Δ24 takes into account factors 28 or quantities affecting the pressure p13 of the compressed combustion air 13 for determining the control variable 24 for the exhaust gas compressor 13.

Preferably, the control deviation value Δ24 for the control signal 24 'is determined depending on the temperature T-13 of the compressed combustion air 13 and / or depending on the methane number MZ (or octane number for liquid fuel 12) and / or

Figure 8 illustrates a procedure for determining the control offset value Δ24 depending on the start time of the internal combustion engine, wherein Figure 8 shows the change Δρΐ3 for the pressure of the compressed combustion air Δ As the ignition time tz rises relative to the corresponding setpoint tz, soll, the knocking tendency of the internal combustion engine also increases, so the control deviation value Δ24 is determined so that the positive Δρι3 is adjusted. Compared with the corresponding setpoint tz, soll, in the case of a delayed ignition time, the control deviation value Δ24 is determined by adjusting the negative value for Δρι3.

Fig. 9 illustrates a procedure for determining the control deviation value Δ24 depending on the temperature T-13 of the compressed combustion air 13, whereby when the temperature T-13 of the compressed combustion air 13 increases relative to the corresponding reference T13, soll, the control deviation value Δ24 is determined pi3 increases, which gives positive values for Δρι3. Conversely, if the temperature of the compressed combustion air 13 decreases relative to the corresponding reference value T13, soll, the control deviation value Δ24 is determined such that negative values are set for Δρι3 so that the pressure p3 of the compressed combustion air 13 is lowered.

Figure 10 illustrates the relationships in determining the control offset value Δ24 depending on the variable methane number of fuel 12, where Figure 10 shows that when the methane number MZ increases relative to the corresponding reference MZsoll, the control offset value Δ24 is determined such that Δρι3 so that the pressure pi3 of the compressed combustion air 13 is thus reduced. Conversely, if the methane number MZ of the fuel 12 is reduced relative to the reference MZsoll, the control deviation value Δ24 is determined such that positive values are set for Δρι3 so that the pressure p3 of the compressed combustion air 13 is increased. This is based on the knowledge that knock resistance decreases with the decreasing methane index.

Finally, Fig. 11 illustrates a procedure for determining the control offset value Δ24, depending on the knock integrator value KIW, to adapt the lambda control to the corresponding control offset value Δ24 and reuse the internal combustion engine when there is already knock on the internal combustion engine. The knock indicator value is a measure of knock resistance (or knock frequency before firing cycles). The higher the knock integrator value KIW, the more powerful the knock motor is. The higher the knocker integrator value KIW, the more strongly the control deviation value Δ24 is adjusted so that Δρι3 becomes more positive, so that the pressure β3 of the compressed combustion air 13 increases with the increasing knocker integrator value KIW.

Claims (8)

A method for operating an internal combustion engine machine, in particular a combustion gas engine, comprising cylinders (10) for combusting a mixture of fuel and combustion air, compressing the combustion air supplied to the cylinders of the exhaust gas compressor (16), and adjusting the fuel (10) and an agitator (14) disposed between the exhaust gas compressor (16) for mixing the fuel and the combustion air wherein the first engine control or control device (21) for the combustion engine defines a control signal for the fuel control valves such that with the amount of fuel, the internal combustion engine is operated at a predetermined reference speed and / or at a predetermined reference power, characterized in that the first adjustment or a control means (21) for providing a control signal (23) for use with the fuel control valves to a second control or control device (22) generating, depending on this control signal (23), a control signal (24) for the exhaust gas compressor by providing the cylinders an internal combustion engine for operating the machine at a predetermined lambda value, the second control or control device (22) correcting the control signal (23) provided by the first control or control device (21) for use with the fuel control valves, and the second control or control device (22) depending on the control offset value (Δ23) of the corrected control signal (23 ') generates a control signal (24) for the exhaust gas compressor (16), and that the control offset value (Δ23) for the fuel control valve set control signal (23). is determined by a second control or control device (22) depending on the pressure difference between the pressure of the compressed combustion air and the fuel pressure and / or depending on the ignition time of the combustion engine and / or depending on the fuel temperature and / or on the fuel value and / or depending on the methane number or octane number of the fuel and / or depending on the knock integrator value. Method according to Claim 1, characterized in that the second control or control device (22), depending on the control signal (23) generated for the fuel control valves, generates the control signal (24) for the exhaust gas compressor (16) by compressing the exhaust gas compressor (24). the lamella air pressure is dimensioned such that the internal combustion engine is operated at a predetermined lambda value. Method according to claim 1 or 2, characterized in that the first control or control device (21) defines as a control signal (23) for the flow control duration of the fuel control valves. Method according to one or more of Claims 1 to 3, characterized in that the second control or control device (22) defines as a control signal (24) for the exhaust gas compressor (16) a variable turbine (19) of the turbocharger (16) for adjustable turbine blades. Method according to one or more of Claims 1 to 3, characterized in that the second control or control device (22) defines as a control signal (24) for the exhaust compressor (16) a variable amount of bypass of the exhaust gas compressor (16). A method according to claim 1, characterized in that, depending on the corrected control signal (23 '), the second control or control device (22) corrects the control signal (24) generated to adjust the control deviation value (Δ24) for the exhaust compressor (16). about. Method according to Claim 6, characterized in that the control deviation value (Δ24) depending on the corrected control signal (23 ') for the generated control signal (24') is determined depending on the combustion air temperature and / or the methane number or octane number of the fuel in the case of liquid fuel. knock integrator value and / or depending on the time of ignition of the combustion engine. 8. An internal combustion engine machine, in particular an exhaust gas engine, fitted with cylinders (10) for combustion of a mixture of fuel and combustion air, an exhaust gas compressor (16) for compressing the combustion air supplied to the cylinders and fuel control valves 10 ) with a first control or control device (21) for determining the control signal (23) for the fuel control valves (15) in such a way that, depending on this control signal, the amount of fuel mixed with the compressed combustion air is used with a predetermined reference speed and / or a predetermined reference power, characterized in that the first control or control device (21) sets a control signal (23) for the fuel control valves (15) to the second control or control device (22) which generates the control signal (24) for the exhaust gas compressor (15) for the purpose of one of the claims 1 to 7.