JP2013068138A - Waste heat utilization device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high-performance waste heat utilization device.SOLUTION: The waste heat utilization device includes a motor 33 and a rankine cycle 3 for use in a driving system 1. The driving system 1 includes an engine 5 and a turbocharger 7 supplying compressed air for the engine 5. The rankine cycle 3 includes a first pump P1, a second pump P2, a boiler 21, an expander 23, and a condenser 25, and a hydraulic fluid circulates between them. The first pump P1 and the second pump P2 are arranged in parallel across the motor 33. The first and second pumps P1, P2 and the motor 33 are connected, respectively, via driving shafts 35, 37, driven shafts 39, 41, and torque limiters 43, 45. The torque limiters 43, 45 disconnect the transmission of power from the motor 33 to either the first pump P1 or the second pump P2, when torque between either the first pump P1 or the second pump P2 and the motor 33 exceeds a threshold.

Description

  The present invention relates to a waste heat utilization apparatus.

  Patent Document 1 discloses a conventional waste heat utilization device. This waste heat utilization device is used in a drive system having an internal combustion engine and includes a Rankine cycle for circulating a working fluid. The Rankine cycle includes a single pump that circulates a working fluid along a pipe, a boiler, an expander, a motor generator, and a condenser. In the boiler, the cooling water and the working fluid for the internal combustion engine exchange heat. The motor generator converts the power generated by the expander into electric power.

  In such a waste heat utilization apparatus, the working fluid is heated by heat exchange in the boiler, and power is generated in the expander by pressure energy when the working fluid is expanded and depressurized. The motor generator converts the power of the expander, that is, pressure energy into electric power and recovers it. Furthermore, in this waste heat utilization apparatus, it is also possible to improve the output of the internal combustion engine by cooling the cooling water by heat exchange in the boiler.

  Moreover, in such a waste heat utilization apparatus, it becomes impossible for a Rankine cycle to circulate a working fluid because a pump fails. In this case, there is a problem that the cooling water cannot be cooled in the boiler and the output of the internal combustion engine is reduced. For this reason, in the above waste heat utilization apparatus, the motor generator can supply power (electric power) to the expander.

  In this way, in this waste heat utilization device, since the expander operated by the motor generator can circulate the working fluid, the heat exchange with the cooling water is continued even if the pump fails. It is possible to suppress a decrease in the output of the internal combustion engine.

JP 2010-174848 A

  However, in the above-described conventional waste heat utilization apparatus, when the pump fails, the expander functions as a pump, and therefore, the Rankine cycle cannot recover the pressure energy of the working fluid. For this reason, the above-mentioned waste heat utilization apparatus has insufficient performance.

  This invention is made | formed in view of the said conventional situation, Comprising: It is set as the problem which should be solved to provide a high-performance waste heat utilization apparatus.

The waste heat utilization apparatus of the present invention is used in a drive system having an internal combustion engine, and in a waste heat utilization apparatus having a Rankine cycle for circulating a working fluid,
The Rankine cycle has a plurality of pumps that circulate the working fluid along piping.
All the pumps are connected to the driving source through driving force transmission means,
The drive force transmission means is capable of cutting off the transmission of power from the drive source when the torque exceeds the threshold with the drive source (Claim 1).

  The waste heat utilization apparatus of the present invention includes a Rankine cycle. This Rankine cycle is used for a drive system, and circulates a working fluid. Thereby, in the Rankine cycle, it is possible to collect pressure energy when the working fluid is expanded and depressurized. In particular, this Rankine cycle has a plurality of pumps for circulating a working fluid along a pipe. For this reason, in this waste heat utilization device, even if one pump fails, the working fluid can be circulated by another pump, so it is possible to continuously recover energy in the Rankine cycle. It is.

  Further, in this waste heat utilization apparatus, all the pumps are connected to the drive source via the driving force transmission means, and the torque transmitted from the driving source to the pump exceeds the threshold value. In some cases, transmission of power from the power source can be cut off. As a result, for example, when the performance of one pump is reduced or the pump fails, the torque transmitted from the driving source to the pump via the driving force transmitting means increases. For this reason, in this waste heat utilization apparatus, when the torque transmitted from the drive source to the pump exceeds a threshold value, the transmission of power from the drive source to the pump is cut off. This reduces the load on the drive source and ensures transmission of power to other pumps. For this reason, in this waste heat utilization apparatus, the recovery | restoration of the energy by Rankine cycle can be performed continuously.

  Therefore, the waste heat utilization apparatus of the present invention has high performance.

  As the internal combustion engine, various types of engines can be employed in addition to a gasoline engine, a diesel engine, and the like. These engines may be hybrid engines combining motors. Furthermore, these engines may be air-cooled or water-cooled. There may be a plurality of internal combustion engines.

  As the drive source, for example, a motor can be employed. An internal combustion engine can also be employed as a drive source.

  As the driving force transmission means, a torque limiter, an electromagnetic clutch, or the like can be employed. In particular, the driving force transmission means preferably has a torque limiter (claim 2). In this case, when the torque transmitted from the drive source to the pump exceeds the threshold value, the torque limiter operates, and the transmission of power from the drive source to the pump is cut off. Here, if the torque limiter is used, the torque generated between the driven shaft of each pump and the drive shaft of the drive source can be detected by itself and the transmission of power to the driven shaft of the pump can be cut off. It is possible to simplify the configuration of the utilization device. Thereby, the mounting property of the waste heat utilization apparatus with respect to a vehicle etc. improves.

  When an electromagnetic clutch is employed, the electromagnetic clutch is provided between the driven shaft of the pump and the drive shaft of the drive source. Then, the torque generated between the driven shaft of the pump and the drive shaft of the drive source is detected, and if the torque exceeds the above threshold value, the electromagnetic clutch is operated and the driven shaft and the drive shaft exceeding the threshold value are operated. The connection can be broken. Further, the fluid pressure of the working fluid circulating in the pipe is detected, and the torque generated between the driven shaft of the pump and the drive shaft of the drive source is calculated based on the fluid pressure, and the torque exceeds the above threshold. It can also be determined whether or not.

  The number of pumps provided in the Rankine cycle of the waste heat utilization apparatus of the present invention is not limited as long as it is two or more. Moreover, each pump may be provided in series with each other, and may be provided in parallel with each other. However, when the pumps are provided in series, it is not preferable to provide the pumps in series if the malfunctioning pump functions as a kind of dam for the working fluid.

  For this reason, the pump can be a first pump and a second pump provided in parallel with each other. And it is preferable that the 1st check valve is provided in the piping downstream of the 1st pump, and the 2nd check valve is provided in the piping downstream of the 2nd pump.

  In this case, since the first pump and the second pump are provided in parallel with each other in the Rankine cycle, for example, even when the first pump fails, the working fluid is not blocked by the first pump. The second pump continues to circulate.

  Then, the first check valve provided in the pipe downstream of the first pump prevents the working fluid discharged by the second pump from flowing back from the downstream of the first pump to the first pump. Similarly, the second check valve provided in the pipe downstream of the second pump prevents the working fluid discharged by the first pump from flowing back from the downstream of the second pump to the second pump. As a result, in the Rankine cycle, the working fluid circulates suitably along the piping. For this reason, it becomes possible to collect | recover energy suitably in a Rankine cycle.

  Moreover, it is preferable that the first pump and the second pump are arranged symmetrically with a motor as a drive source interposed therebetween. In this case, in the Rankine cycle, the first pump and the second pump can be disposed close to each other. Thereby, it becomes possible to make it difficult to cause loss of power transmitted from the motor to the first pump and the second pump, respectively. In addition, the waste heat utilization device can be reduced in size. Furthermore, it becomes easy to arrange the torque limiter as described above in the driving force transmission means.

  In the waste heat utilization apparatus of the present invention, the drive system includes a supercharger that supplies pressurized air to the internal combustion engine, and an exhaust gas recirculation passage that recirculates a part of the exhaust gas generated in the internal combustion engine to the internal combustion engine as recirculation exhaust gas. A heat source that is at least one of the following. And it is preferable that the Rankine cycle has a boiler which performs heat exchange between the heat of the heat source and the working fluid.

  Since both the pressurized air and the reflux exhaust gas are high in temperature, the working fluid that has exchanged heat with these in the boiler is sufficiently heated to become high temperature. For this reason, the pressure energy when the working fluid is expanded and depressurized is increased, and the Rankine cycle can increase the amount of energy that can be recovered. In addition, the pressurized air and the reflux exhaust are cooled by heat exchange with the working fluid. Here, if the pressurized air is cooled, the density of the pressurized air can be increased, and more pressurized air can be supplied to the internal combustion engine. As a result, the output of the internal combustion engine can be improved. That is, the boiler functions as an intercooler by exchanging heat with the pressurized air. On the other hand, if the recirculated exhaust gas recirculated to the internal combustion engine is cooled, the pumping loss can be suppressed when the internal combustion engine is a gasoline engine, and when the internal combustion engine is a diesel engine, it is finally discharged into the atmosphere. It becomes possible to reduce the content of nitrogen oxides in the exhaust gas. For these reasons, even if some of the plurality of pumps fail, it is possible to continue cooling the pressurized air or the reflux exhaust, and the waste heat utilization device has higher performance.

  The waste heat utilization apparatus of the present invention has high performance.

It is a schematic structure figure which shows the waste heat utilization apparatus of an Example. It is a schematic structure figure which shows the state at the time of operation | movement concerning the waste heat utilization apparatus of an Example. It is a schematic structure figure which shows the operation state when it concerns on the waste heat utilization apparatus of an Example and a 1st pump fails.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments embodying the present invention will be described below with reference to the drawings.

(Example)
The waste heat utilization apparatus of the embodiment is mounted on a vehicle and is used in a drive system 1 of the vehicle as shown in FIG. The waste heat utilization device includes a Rankine cycle 3, a motor 33, and a control device 11. This motor 33 corresponds to a drive source.

  The drive system 1 includes an engine 5 as an internal combustion engine, a turbocharger 7 as a supercharger, and a radiator 9. The engine 5 is a known water-cooled gasoline engine. A water jacket (not shown) through which cooling water can flow is formed inside the engine 5. The engine 5 is formed with an outlet 5a and an inlet 5b communicating with the water jacket. Further, the engine 5 is formed with an exhaust port 5c for exhausting exhaust gas and an intake port 5d for sucking pressurized air described later.

  The turbocharger 7 and the radiator 9 are made of public goods. The turbocharger 7 is operated by exhaust generated from the engine 5 and supplies the engine 5 with pressurized air obtained by pressurizing air outside the vehicle. Further, the radiator 9 is formed with an inlet 9a for allowing cooling water to flow into the radiator 9 and an outlet 9b for allowing cooling water to flow out. The radiator 9 performs heat exchange between the cooling water flowing through the radiator 9 and the air outside the vehicle. Further, an electric fan 9 c is provided in the vicinity of the radiator 9. The electric fan 9 c is electrically connected to the control device 11.

  The engine 5 and the turbocharger 7 are connected by piping 13-15. Further, a boiler 21 described later is connected to the pipe 14 and the pipe 15. The pipe 13 is capable of circulating exhaust gas and is connected to the exhaust port 5 c of the engine 5 and the turbocharger 7. On the other hand, the compressed air can flow through the inside of the pipe 14 and the pipe 15. The pipe 14 is connected to the turbocharger 7 and the first inlet 21 a of the boiler 21. The pipe 15 is connected to the first outlet 21 b of the boiler 21 and the intake port 5 d of the engine 5.

  Further, the turbocharger 7 is connected to one end sides of the pipes 16 and 17. The other end side of the pipe 16 is connected to a muffler (not shown). The other end of the pipe 17 is open to an air intake of a vehicle (not shown). The pipe 16 communicates with the pipe 13 via the turbocharger 7. Similarly, the pipe 17 communicates with the pipe 14 via the turbocharger 7.

  On the other hand, the engine 5 and the radiator 9 are connected by pipes 18 and 19. The pipes 18 and 19 are capable of circulating cooling water inside. The pipe 18 is connected to the outlet 5 a of the engine 5 and the inlet 9 a of the radiator 9. The pipe 19 is connected to the outlet 9 b of the radiator 9 and the inlet 5 b of the engine 5. The piping 20 is provided with a cooling water pump P3. The cooling water pump P3 is electrically connected to the control device 11. The cooling water pump P3 may be provided in the pipe 18.

  The Rankine cycle 3 includes first and second pumps P1 and P2, a boiler 21, an expander 23, a condenser 25, and pipes 27 to 32. An HFC 134a as a working fluid can be circulated in the pipes 27 to 32.

  The boiler 21 is formed with a first inlet 21a and a first outlet 21b, and a second inlet 21c and a second outlet 21d. Further, in the boiler 21, a first passage 21e communicating with the first inflow port 21a and the first outflow port 21b respectively at both ends, and a second inflow port 21c and a second outflow port 21d respectively communicating with both ends. A second passage 21f is provided. In the boiler 21, the pressurized air is cooled and the working fluid is heated by exchanging heat between the pressurized air in the first passage 21e and the working fluid in the second passage 21f.

  The expander 23 is formed with an inflow port 23a through which the working fluid flows in and an outflow port 23b through which the working fluid flows out. In the expander 23, the working fluid heated through the boiler 21 is expanded to generate a rotational driving force. A known generator (not shown) is connected to the expander 23. The generator generates power with the driving force of the expander 23 and charges a battery (not shown) with electric power.

  The condenser 25 is formed with an inlet 25a through which the working fluid flows and an outlet 25b through which the working fluid flows out. The condenser 25 exchanges heat between the working fluid flowing through the inside of the condenser 25 and air outside the vehicle, and cools and liquefies the working fluid vaporized by the expansion in the expander 23. An electric fan 25 c is provided in the vicinity of the condenser 25. The electric fan 25 c is electrically connected to the control device 11.

  These boiler 21, expander 23, and condenser 25 are connected by pipes 27 to 32. Of these pipes 27 to 32, the pipe 28 and the pipe 29 are arranged in parallel to each other. The connection of the pipes 27 to 32 will be described in detail. One end side of the pipe 27 is connected to the outlet 25 b of the condenser 25. One end side of each of the pipe 28 and the pipe 29 is connected to the other end side of the pipe 27. One end side of the pipe 30 is connected to the other end side of the pipe 28 and the pipe 29. The other end of the pipe 30 is connected to the second inlet 21 c of the boiler 21. One end of a pipe 31 is connected to the second outlet 21 d of the boiler 21. The other end of the pipe 31 is connected to the inlet 23a of the expander 23. Then, one end side of the pipe 32 is connected to the outlet 23 b of the expander 23. The other end of the pipe 32 is connected to the inlet 25 a of the condenser 25.

  The first pump P1 is disposed in the pipe 28. The second pump P2 is disposed in the pipe 29. A motor 33 is disposed between the first and second pumps P1 and P2. As described above, since the pipe 28 and the pipe 29 are arranged in parallel with each other, the first and second pumps P1, P2 are arranged in parallel with each other, and these first, second pumps P1, P2 are arranged. Are arranged symmetrically across the motor 33.

  The motor 33 is provided with drive shafts 35 and 37 on both sides. The motor 33 is electrically connected to the control device 11. On the other hand, the first and second pumps P1 and P2 are provided with driven shafts 39 and 41, respectively. The drive shaft 35 of the motor 33 and the driven shaft 39 of the first pump P1 are connected via a torque limiter 43. Further, the drive shaft 37 of the motor 33 and the driven shaft 41 of the second pump P <b> 2 are connected via a torque limiter 45. These torque limiters 43 and 45 are both public goods. The torque limiters 43 and 45 are driven from the drive shaft 35 when the torque transmitted from the motor 33 to the first and second pumps P1 and P2 via the drive shafts 35 and 37 and the driven shafts 39 and 41 exceeds a threshold value. The transmission of power to the shaft 39 or the transmission of power from the drive shaft 37 to the driven shaft 41 is cut off. These drive shafts 35 and 37, driven shafts 39 and 41, and torque limiters 43 and 45 correspond to power transmission means.

  Further, the pipe 28 is provided with a first check valve 47 at a position downstream of the first pump P1 in the circulating direction of the working fluid. Similarly, the pipe 29 is provided with a second check valve 49 at a position downstream of the second pump P2 in the working fluid circulation direction.

  The control device 11 adjusts the amount of heat that the cooling water or the working fluid radiates to the outside air by controlling the operation of the electric fans 9c and 25c. In addition, the control device 11 performs output control of the motor 33.

  The waste heat utilization apparatus configured as described above operates as follows by driving the vehicle.

  As shown in FIG. 2, the engine 5 operates in the drive system 1 by driving the vehicle. As a result, the exhaust discharged from the exhaust port 5c is discharged from the muffler to the outside of the vehicle through the pipe 13, the turbocharger 7 and the pipe 16 (see the one-dot chain line arrow in the figure). At this time, the turbocharger 7 is operated depending on the exhaust. As a result, air outside the vehicle is sucked into the turbocharger 7 from the pipe 17 and compressed. This air is sucked as pressurized air into the engine 5 from the intake port 5d of the engine 5 through the pipe 14, the first passage 21e of the boiler 21 and the pipe 15 (see a two-dot chain arrow in the figure).

  Moreover, the control apparatus 11 operates the cooling water pump P3 and the electric fan 9c, respectively. As a result, in the drive system 1, the cooling water that has cooled the engine 5 flows out from the outlet 5 a and reaches the inside of the radiator 9 through the pipe 18 through the inlet 9 a of the radiator 9. And the cooling water inside the radiator 9 is heat-exchanged with the air around the radiator 9, that is, radiated and cooled. At this time, the control device 11 appropriately changes the operation amount of the electric fan 9c to suitably radiate the cooling water. The cooling water radiated and cooled flows out from the outlet 9b, flows into the engine 5 from the inlet 5b of the engine 5 through the pipe 19, and cools the engine 5 (see the broken line arrow in the figure).

  Furthermore, the control apparatus 11 operates the motor 33 and the electric fan 25c, respectively. When the motor 33 is operated, the first and second pumps P1 and P2 are operated. At this time, the control device controls the output of the motor 33 and adjusts the operation amounts of the first and second pumps P1 and P2. Thereby, in Rankine cycle 3, as shown by the solid line arrow of the figure, working fluid circulates along piping 27-32 at a fixed flow rate (circulation speed). Specifically, the working fluid discharged by the first and second pumps P1 and P2 reaches the second passage 21f from the second inlet 21c of the boiler 21 through the pipes 28 and 29 and the pipe 30. The working fluid exchanges heat with the pressurized air in the boiler 21. At this time, since the compressed air flowing through the first passage 21e has a heat of about 150 ° C. by being compressed by the turbocharger 7, the working fluid flowing through the second passage 21f is about Heated to about 150 ° C. On the other hand, the pressurized air flowing through the first passage 21e radiates heat to the working fluid flowing through the second passage 21f, and therefore reaches the engine 5 in a cooled state.

  Thus, the working fluid heated by the boiler 21 flows out from the second outlet 21d in a high temperature and high pressure state, and reaches the inside of the expander 23 from the inlet 23a of the expander 23 via the pipe 31. The high-temperature and high-pressure working fluid expands in the expander 23 and is depressurized. Due to the pressure energy at this time, the generator connected to the expander 23 generates power.

  The working fluid depressurized in the expander 23 flows out from the outlet 23 b and reaches the condenser 25 through the pipe 32 through the inlet 25 a of the condenser 25. The working fluid of the condenser 25 dissipates heat to the air around the condenser 25 and is cooled. At this time, the control device 11 appropriately changes the operating amount of the electric fan 25c to suitably dissipate the working fluid and liquefy it. The cooled working fluid flows out from the outlet 25b, passes through the pipes 28 and 29 and the pipe 30, and reaches the boiler 21 again.

  The Rankine cycle 3 of the waste heat utilization apparatus has first and second pumps P1 and P2. The first and second pumps P1 and P2 include drive shafts 35 and 37, driven shafts 39 and 41, and torque. The motor 33 is connected via limiters 43 and 45. The torque limiters 43 and 45 are connected to the drive shaft 35 and the driven shaft 39 or driven shaft 37 and the driven shaft by the torque exceeding the threshold between the first and second pumps P1 and P2 and the motor 33. 41 can be disconnected. For this reason, in this waste heat utilization apparatus, even if one of the first pump P1 or the second pump P2 breaks down, it is possible to continue the circulation of the working fluid by the other. Hereinafter, a case where the first pump P1 fails will be described as an example.

  When the first pump P1 fails, the torque transmitted from the motor 33 to the first pump P1 via the drive shaft 35 and the driven shaft 39 changes, and the torque increases. This torque change increases the load on the motor 33. For this reason, when the changed torque exceeds the threshold value, the torque limiter 43 operates to release the connection between the drive shaft 35 and the driven shaft 39. For this reason, the transmission of power from the motor 33 to the first pump P1 is cut off. As a result, the load on the motor 33 is reduced, and transmission of power from the motor 33 to the second motor P2 is ensured. As shown in FIG. 3, the working fluid is circulated only by the second pump P2. At this time, the first check valve 47 prevents the working fluid discharged by the second pump P2 from flowing into the first pump P1 via the pipe 28, that is, the working fluid is prevented from flowing back to the first pump P1. Therefore, the working fluid will preferably flow from the pipe 29 to the pipe 30. The control device 11 controls the output of the motor 33 and adjusts the flow rate (acceleration) of the working fluid when the working fluid is circulated only by the second pump P2.

  In this way, in the Rankine cycle 3, it is possible to continuously recover power even when the first pump P1 fails. The same applies when the second pump P2 fails. When the torque transmitted from the motor 33 to the second pump P2 exceeds the threshold value, the torque limiter 45 connects the drive shaft 37 and the driven shaft 41. To release. Thereby, the working fluid is circulated only by the first pump P1. At this time, the second check valve 49 prevents the working fluid discharged by the first pump P1 from flowing back to the second pump P2 via the pipe 29.

  Thus, in the Rankine cycle 3 in this waste heat utilization apparatus, it is possible to collect | recover the pressure energy at the time of expanding and pressure-reducing a working fluid as electric power. In particular, the drive system 1 has a turbocharger 7 that supplies pressurized air to the engine 5. In the boiler 21, heat exchange can be performed between the pressurized air and the working fluid. . In other words, since the working fluid is heated using this pressurized air as a heat source, the working fluid is sufficiently heated to a high temperature. For this reason, in this waste heat utilization apparatus, the pressure energy at the time of expanding and depressurizing the working fluid is increased, and the amount of electric power recovered in the Rankine cycle 3 is increased.

  In this waste heat utilization apparatus, the pressurized air is cooled by heat exchange in the boiler 21, that is, the boiler 21 also functions as an intercooler for the pressurized air. For this reason, the density of the pressurized air can be increased, and more pressurized air can be supplied to the engine 5. Thereby, in this waste heat utilization apparatus, it is possible to improve the output of the engine 5.

  Furthermore, Rankine cycle 3 in this waste heat utilization apparatus has 1st and 2nd pumps P1 and P2. For this reason, even if one of the first pump P1 or the second pump P2 fails, the working fluid is circulated by the other first pump P1 or second pump P2 that has not failed. It is possible. For this reason, in this waste heat utilization apparatus, even if one of the first pump P1 or the second pump P2 is out of order, the Rankine cycle 3 continuously recovers power and improves the output of the engine 5. It is possible.

  Therefore, this waste heat utilization apparatus has high performance.

  In particular, the drive shaft 35 and the driven shaft 39, and the drive shaft 37 and the driven shaft 41 are connected via torque limiters 43 and 45, respectively. The torque limiters 43 and 45 themselves detect the torque generated between the driven shafts 39 and 41 of the first and second pumps P1 and P2 and the drive shafts 35 and 37 of the motor 33, and the driven of the first pump P1. Transmission of power to the shaft 39 and the driven shaft 41 of the second pump P2 can be cut off. For this reason, it is possible to simplify the structure of a waste heat utilization apparatus, and the mountability with respect to a vehicle is improving in this waste heat utilization apparatus.

  Further, the first pump P1 and the second pump P2 are arranged in parallel with each other. For this reason, for example, even when the first pump P1 fails, the working fluid is not dammed up by the first pump P1 and is continuously circulated by the second pump P2. It will flow into the boiler 21 through the pipes 29 and 30. Similarly, when the second pump P2 fails, the working fluid continues to circulate.

  Furthermore, since the first pump P1 and the second pump P2 are arranged symmetrically across the motor, in the Rankine cycle 3, the first pump P1 and the second pump P1 can be arranged close to each other. ing. As a result, it is difficult for loss of power transmitted from the motor 33 to the first pump P1 and the second pump P2 to occur. It is also possible to reduce the size of the waste heat utilization device. Furthermore, torque limiters 43 and 45 are easily arranged between the drive shaft 35 and the driven shaft 39 and between the drive shaft 37 and the driven shaft 41, respectively.

  While the present invention has been described with reference to the embodiments, it is needless to say that the present invention is not limited to the above-described embodiments and can be appropriately modified and applied without departing from the spirit thereof.

  For example, in the drive system 1, an exhaust gas recirculation path that recirculates the exhaust gas generated in the engine 5 to the engine 5 as recirculated exhaust gas can be provided in place of the turbocharger 7 or together with the turbocharger 7. In this case, in the boiler 21, in addition to exchanging heat between the pressurized air and the working fluid, it is also possible to exchange heat between the reflux exhaust and the working fluid. Further, when the turbocharger 7 and the exhaust gas recirculation path are provided side by side, heat exchange is performed between the pressurized air and the working fluid in the boiler 21, and heat exchange between the recirculated exhaust gas and the working fluid is performed in another boiler. It is also possible. By these, it becomes possible to increase the quantity of the electric power which can be collect | recovered in Rankine cycle 3 by fully heating a working fluid.

  Moreover, you may provide the boiler which performs heat exchange between a cooling water and a working fluid, and the boiler which performs heat exchange between the exhaust_gas | exhaustion in the piping 13 or the piping 16, and a working fluid. This also makes it possible to heat the working fluid. In this case, since the cooling water can be cooled in the boiler, the engine 5 can be suitably cooled, and the output of the engine 5 can be improved. In this case, the radiator 9 can be reduced in size and the operation amount of the electric fan 9c can be reduced.

  Furthermore, the connection between the drive shaft 35 and the driven shaft 39 and the connection between the drive shaft 37 and the driven shaft 41 may be performed via an electromagnetic clutch. In this case, the torque between the drive shaft 35 and the driven shaft 39 and the torque between the drive shaft 37 and the driven shaft 41 are detected. For example, if the torque between the drive shaft 35 and the driven shaft 39 exceeds a threshold value, the electromagnetic clutch can be operated to disconnect the driven shaft 35 and the drive shaft 39 that have exceeded the threshold value.

  Further, when an electromagnetic clutch is employed, a pressure sensor capable of detecting the fluid pressure of the working fluid can be provided in the pipe 31 or the like, for example. As a result, the torque between the drive shaft 35 and the driven shaft 39 and the torque between the drive shaft 37 and the driven shaft 41 are calculated based on the fluid pressure of the working fluid flowing through the pipe 31, respectively. It can also be activated.

  Further, the pipe 32 may be provided with a known receiver. In this case, since the working fluid is suitably liquefied by the receiver, the working fluid that has passed through the condenser 25 is suitably discharged by the first and second pumps P1 and P2, and is preferably circulated through the pipes 27 to 32. Become.

  The present invention is applicable to vehicles and the like.

DESCRIPTION OF SYMBOLS 1 ... Drive system 3 ... Rankine cycle 5 ... Engine (internal combustion engine)
7 ... Turbocharger (supercharger)
21 ... Boiler 27-32 ... Piping 33 ... Motor (drive source)
35, 37 ... Drive shaft (power transmission means)
39, 41 ... driven shaft (power transmission means)
43, 45 ... Torque limiter (power transmission means)
47 ... 1st check valve 49 ... 2nd check valve P1 ... 1st pump P2 ... 2nd pump

Claims (5)

In a waste heat utilization apparatus provided with a Rankine cycle for circulating a working fluid, used in a drive system having an internal combustion engine,
The Rankine cycle has a plurality of pumps that circulate the working fluid along piping.
All the pumps are connected to the driving source through driving force transmission means,
The waste heat utilization device, wherein the driving force transmission means is capable of cutting off transmission of power from the driving source when the torque exceeds the threshold with the driving source.   The waste heat utilization apparatus according to claim 1, wherein the driving force transmission means includes a torque limiter. Each of the pumps is a first pump and a second pump provided in parallel with each other,
The waste heat according to claim 1 or 2, wherein the pipe downstream of the first pump is provided with a first check valve, and the pipe downstream of the second pump is provided with a second check valve. Use device.   The waste heat utilization apparatus according to claim 3, wherein the first pump and the second pump are arranged symmetrically with a motor as the drive source interposed therebetween. The drive system is at least one of a supercharger that supplies pressurized air to the internal combustion engine and an exhaust gas recirculation path that recirculates a part of the exhaust gas generated in the internal combustion engine to the internal combustion engine as recirculation exhaust gas. Have a heat source,
The waste heat utilization apparatus according to any one of claims 1 to 4, wherein the Rankine cycle includes a boiler that exchanges heat between heat of the heat source and the working fluid.

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