JP5910531B2 - Rankine cycle system abnormality judgment device - Google Patents

Description

  The present invention relates to an abnormality determination device for a Rankine cycle system.

  Conventionally, the Rankine cycle system that vaporizes the refrigerant of the internal combustion engine by the waste heat of the internal combustion engine, operates the waste heat recovery machine by the vaporized refrigerant, and guides the refrigerant that passed through the waste heat recovery machine to the condenser by the refrigerant passage It has been known. As such a Rankine cycle system, for example, Patent Document 1 discloses a waste heat recovery machine having a turbine that is operated by a refrigerant vaporized by heat (waste heat) of exhaust gas from an internal combustion engine, and the waste heat recovery machine. A Rankine cycle system including a refrigerant passage that guides the refrigerant to a condenser is disclosed. Patent Document 1 also discloses a technique for detecting whether there is an abnormality in the waste heat recovery machine based on the rotational speed of the turbine of the waste heat recovery machine.

JP 2012-172528 A

  However, in the Rankine cycle system according to Patent Document 1, it is difficult to determine whether there is an abnormality in the waste heat recovery machine or in the refrigerant passage that guides the refrigerant that has passed through the waste heat recovery machine to the condenser. It was.

  The present invention provides an abnormality determination device for a Rankine cycle system that can determine whether there is an abnormality in a waste heat recovery machine or an abnormality in a refrigerant passage that guides the refrigerant that has passed through the waste heat recovery machine to a condenser. For the purpose.

  In the Rankine cycle system abnormality determination device according to the present invention, the refrigerant of the Rankine cycle system having a refrigerant passage that guides the refrigerant to the condenser via the waste heat recovery machine that is operated by the refrigerant vaporized by the waste heat of the internal combustion engine. When the pressure of the passage is out of a predetermined reference range, it is determined that the refrigerant passage is abnormal, the pressure is included in the reference range, and the output of the waste heat recovery machine is less than a predetermined value In addition, an abnormality determining unit that determines that the waste heat recovery machine has an abnormality is provided.

  According to the Rankine cycle system abnormality determination device according to the present invention, it is possible to determine whether there is an abnormality in the waste heat recovery machine or whether there is an abnormality in the refrigerant passage that guides the refrigerant that has passed through the waste heat recovery machine to the condenser. it can.

  In the above configuration, between the case where the abnormality determination unit determines that there is an abnormality in the refrigerant passage and the case where the abnormality determination unit determines that there is an abnormality in the waste heat recovery machine, You may further provide the control part which changes the control content. According to this configuration, the Rankine cycle system can be appropriately controlled according to the abnormality content of the Rankine cycle system.

  In the above-described configuration, the Rankine cycle system includes a tank that stores the refrigerant that has passed through the condenser, and the abnormality determination unit further includes the refrigerant that is stored in the tank when the temperature of the refrigerant is higher than a predetermined value. When the pressure of the passage is included in the reference range, it may be determined that the condenser is abnormal. According to this configuration, it is possible to accurately determine whether the condenser is abnormal.

  According to the present invention, there is provided an abnormality determination device for a Rankine cycle system capable of determining whether there is an abnormality in a waste heat recovery machine or an abnormality in a refrigerant passage that guides a refrigerant that has passed through the waste heat recovery machine to a condenser. Can be provided.

FIG. 1 is a schematic diagram showing the overall configuration of the Rankine cycle system. FIG. 2 is a schematic cross-sectional view showing the internal structure of the vane pump. FIG. 3 is a flowchart of the abnormality determination control. FIG. 4 is a flowchart showing a subroutine of abnormality determination processing of the waste heat recovery machine. FIG. 5 is an example of a flowchart showing a subroutine of abnormality determination processing for the first electromagnetic valve. FIG. 6 is a flowchart showing a subroutine of the vane pump abnormality determination process. FIG. 7 is a flowchart showing a subroutine for condenser abnormality determination processing.

  Hereinafter, modes for carrying out the present invention will be described.

  An abnormality determination device for a Rankine cycle system according to an embodiment of the present invention will be described. First, the overall configuration of the Rankine cycle system 300 to which the abnormality determination device according to the present embodiment is applied will be described, and then the details of the abnormality determination device will be described. FIG. 1 is a schematic diagram showing the overall configuration of the Rankine cycle system 300. The Rankine cycle system 300 according to the present embodiment is mounted on a vehicle. The Rankine cycle system 300 includes an ECU (Electronic Control Unit) 200. The ECU 200 has a function as an abnormality determination device of the Rankine cycle system 300. That is, the abnormality determination device according to the present embodiment is realized by the ECU 200. The ECU 200 according to the present embodiment also serves as a control device that controls the Rankine cycle system 300 in an integrated manner.

  The ECU 200 is a computer including a CPU (Central Processing Unit) 201, a ROM (Read Only Memory) 202, and a RAM (Random Access Memory) 203. The CPU 201 executes each step of each flowchart described later. The CPU 201 has a function as an abnormality determination unit that determines whether each member of the Rankine cycle system 300 has an abnormality. The CPU 201 also has a function as a control unit that controls the Rankine cycle system 300. The ROM 202 and the RAM 203 have a function as a storage device that stores various information necessary for the operation of the CPU 201.

  The Rankine cycle system 300 uses a refrigerant for cooling the internal combustion engine 2 as a working fluid. The Rankine cycle system 300 includes a refrigerant passage 3 through which a refrigerant passes. The Rankine cycle system 300 includes an internal combustion engine 2, a gas-liquid separator 5, a superheater 7, a waste heat recovery machine 4, a condenser 8, and a condensation header tank 15 in order from the upstream side in the refrigerant flow direction. A condensation tank 9, a vane pump 10, a thermostat 19, and a water pump 12.

  The main body 20 of the internal combustion engine 2 includes a cylinder block 20a and a cylinder head 20b disposed on the upper portion of the cylinder block 20a. A block-side water jacket 21a is formed on the cylinder block 20a, and a head-side water jacket 21b is formed on the cylinder head 20b. In the main body 20, the refrigerant flows into the head side water jacket 21b after passing through the block side water jacket 21a. The refrigerant receives heat from the cylinder block 20a and the cylinder head 20b when passing through the main body 20. Thereby, the temperature of the refrigerant rises. As a result, a part of the refrigerant is vaporized.

  The refrigerant passing through the main body 20 passes through the refrigerant passage 3 and flows into the gas-liquid separator 5. The gas-liquid separator 5 is a device that separates the refrigerant into a gas-phase refrigerant (vapor) and a liquid-phase refrigerant. The superheater 7 is a device that superheats the refrigerant by the waste heat of the internal combustion engine 2. Specifically, the superheater 7 according to the present embodiment superheats the refrigerant by using the heat (that is, waste heat) of the exhaust gas that passes through the exhaust pipe 18 of the internal combustion engine 2. The superheater 7 according to the present embodiment includes an evaporation unit 7a that converts the refrigerant supplied from the gas-liquid separator 5 into vapor by the heat of exhaust gas, and an overheating unit 7b that superheats the vaporized refrigerant to further increase the temperature. It has.

  Here, in the refrigerant passage 3, the portion where the gas-phase refrigerant of the gas-liquid separator 5 exists (specifically, the upper portion) and the evaporator 7 a of the superheater 7 communicate with each other is referred to as a passage 31. . The gas-phase refrigerant separated in the gas-liquid separator 5 passes through the passage 31 and is supplied to the evaporation section 7 a of the superheater 7. In the refrigerant passage 3, the portion where the liquid phase refrigerant of the gas-liquid separator 5 exists (specifically, the bottom portion) and the evaporation portion 7 a communicate with each other is referred to as a passage 32. The first electromagnetic valve 13 is disposed in the passage 32. The ECU 200 controls the first electromagnetic valve 13 to be opened when it is estimated that the liquid phase refrigerant in the superheater 7 is insufficient. As a result, the liquid-phase refrigerant separated by the gas-liquid separator 5 passes through the passage 32 and is supplied to the superheater 7.

  The refrigerant superheated by the superheater 7 passes through the refrigerant passage 3 and is supplied to the waste heat recovery machine 4. The waste heat recovery machine 4 is a device that recovers energy from the waste heat of the internal combustion engine 2 received by the refrigerant. Specifically, the waste heat recovery machine 4 according to the present embodiment includes a supersonic nozzle 41, a turbine 42, a generator 43, a shaft 45 connecting the turbine 42 and the generator 43, and a storage battery 44. ing. The refrigerant (steam) after passing through the superheater 7 passes through the supersonic nozzle 41 to become high-temperature and high-pressure steam and is sprayed onto the turbine 42. As a result, the turbine 42 rotates. When the turbine 42 rotates, the generator 43 connected to the turbine 42 via the shaft 45 also rotates. As a result, the generator 43 generates electricity. The electricity generated by the generator 43 is stored in the storage battery 44. In this manner, the waste heat recovery machine 4 recovers energy (electric energy in this embodiment) from the refrigerant vaporized by the waste heat of the internal combustion engine 2. However, the specific configuration of the waste heat recovery machine 4 is not limited to the configuration of FIG. 1 as long as energy can be recovered from the waste heat of the internal combustion engine 2.

  The refrigerant that has passed through the waste heat recovery machine 4 passes through the refrigerant passage 3 and is supplied to the condenser 8. The condenser 8 is a device that condenses the refrigerant that has passed through the waste heat recovery machine 4 to form a liquid-phase refrigerant. Here, a portion of the refrigerant passage 3 that connects the waste heat recovery machine 4 and the condenser 8 is referred to as a passage 33. That is, the passage 33 is a refrigerant passage that guides the refrigerant that has passed through the turbine 42 of the waste heat recovery machine 4 to the condenser 8. Although the specific configuration of the condenser 8 is not particularly limited, in the present embodiment, a radiator is used as an example. In this case, the radiator as the condenser 8 has a plurality of thin tubes through which the refrigerant passes. The refrigerant is condensed by being cooled by air when passing through the narrow tube, and becomes a liquid phase refrigerant. The Rankine cycle system 300 according to this embodiment includes a cooling fan 14 that blows air to the condenser 8. The cooling fan 14 operates in response to an instruction from the ECU 200. Since the Rankine cycle system 300 includes the cooling fan 14, the condensation efficiency of the condenser 8 is increased.

  The refrigerant that has passed through the condenser 8 flows into the condensation header tank 15. The refrigerant stored in the condensation header tank 15 then passes through the refrigerant passage 3 and is stored in the condensation tank 9. The condensation header tank 15 is a tank that temporarily stores the refrigerant that has passed through the condenser 8, and is a tank disposed on the upstream side of the condensation tank 9. The condensation header tank 15 according to the present embodiment is provided at the outlet of the condenser 8. When the vane pump 10 is operated, the refrigerant in the condensation tank 9 passes through the refrigerant passage 3 and is supplied to the vane pump 10.

  The vane pump 10 is a pump that transfers a fluid by rotating a rotor including the vanes. The specific configuration of the vane pump 10 according to the present embodiment is as follows. FIG. 2 is a schematic cross-sectional view showing the internal structure of the vane pump 10. The vane pump 10 operates in response to an instruction from the ECU 200. The roller 102 of the vane pump 10 is arranged in an eccentric state with respect to the circular cam ring 101. A vane 103 is incorporated in the rotor 102 so as to be buried. The vane 103 is pressed against the wall surface of the cam ring 101 by a spring 104. When the rotor 102 rotates in response to an instruction from the ECU 200, the vane 103 is pressed against the wall surface of the cam ring 101 by the centrifugal force and the force applied from the spring 104. As a result, the tip of the vane 103 moves in contact with the wall surface of the cam ring 101. Accordingly, the refrigerant is pushed into the vane pump 10 by being pushed by the vane 103 from the port 105 on the suction side. On the other hand, the refrigerant is pushed out by the vane 103 at the port 106 on the delivery side. As described above, the vane pump 10 transfers the refrigerant. The specific configuration of the vane pump 10 is not limited to the configuration illustrated in FIG.

  Referring to FIG. 1, the refrigerant passing through vane pump 10 passes through refrigerant passage 3 and is supplied to thermostat 19. A check valve 11 is disposed in the refrigerant passage 3 between the vane pump 10 and the thermostat 19. The check valve 11 allows the refrigerant to flow from the vane pump 10 to the thermostat 19, and prohibits the refrigerant from flowing from the thermostat 19 to the vane pump 10. Thus, the refrigerant is prevented from flowing back from the thermostat 19 side to the vane pump 10 side. The thermostat 19 and the bottom of the gas-liquid separator 5 are communicated with each other through the refrigerant passage 3. A portion of the refrigerant passage 3 that connects the thermostat 19 and the bottom of the gas-liquid separator 5 is referred to as a passage 34.

  The thermostat 19 is a device that changes the passage through which the refrigerant flows based on the temperature of the refrigerant. Specifically, when the temperature of the refrigerant is equal to or higher than a predetermined temperature, the thermostat 19 closes the passage 34 and opens the refrigerant passage 3 that connects the vane pump 10 and the thermostat 19. In this case, the refrigerant that has passed through the vane pump 10 is supplied to the main body 20 of the internal combustion engine 2 by the water pump 12. On the other hand, when the temperature of the refrigerant is lower than a predetermined temperature, the thermostat 19 closes the refrigerant passage 3 connecting the vane pump 10 and the thermostat 19 and opens the passage 34. In this case, the liquid-phase refrigerant of the gas-liquid separator 5 is supplied to the main body 20 of the internal combustion engine 2 by the water pump 12. The thermostat 19 and the water pump 12 according to this embodiment have a function as a refrigerant supply unit that supplies a refrigerant to the internal combustion engine 2 (specifically, the main body 20).

  The Rankine cycle system 300 according to this embodiment includes a bypass passage 16 and a second electromagnetic valve 17 disposed in the bypass passage 16. The bypass passage 16 is a passage that guides the refrigerant that has passed through the gas-liquid separator 5 to the condenser 8 by bypassing the superheater 7 and the waste heat recovery machine 4. The bypass passage 16 according to the present embodiment communicates the passage 31 of the passage 31 with the passage 33 of the passage 33. The second electromagnetic valve 17 operates in response to an instruction from the ECU 200. When the second electromagnetic valve 17 is opened, the gas-phase refrigerant separated by the gas-liquid separator 5 passes through the bypass passage 16 and is supplied to the passage 33 and then supplied to the condenser 8.

  The Rankine cycle system 300 includes a water temperature sensor 51, an exhaust temperature sensor 52, a liquid level sensor 53, a steam temperature sensor 54, a pressure sensor 55, a rotation speed sensor 56, a condensed water temperature sensor 57, and a header tank. A liquid level sensor 58 and a pressure sensor 59 are provided. These sensors transmit the detection result to the ECU 200. The water temperature sensor 51 is a sensor that detects the refrigerant temperature in the main body 20. The water temperature sensor 51 according to the present embodiment detects the temperature of the refrigerant in the head-side water jacket 21b. The exhaust temperature sensor 52 is a sensor that detects the exhaust temperature of the internal combustion engine 2. The exhaust temperature sensor 52 according to the present embodiment is a part of the exhaust pipe 18, specifically, a part in the vicinity of the cylinder head 20 b of the exhaust pipe 18 (this is a part upstream of the superheater 7 in the exhaust flow direction). The exhaust temperature is detected. The liquid level sensor 53 is a sensor that detects the liquid level of the liquid-phase refrigerant in the gas-liquid separator 5. The vapor temperature sensor 54 is a sensor that detects the temperature of the gas-phase refrigerant (vapor) in the superheater 7. Specifically, the steam temperature sensor 54 detects the internal temperature of the superheater 7 b of the superheater 7. The pressure sensor 55 is a sensor that detects the pressure of the refrigerant (vapor) between the superheater 7 and the supersonic nozzle 41.

  The rotation speed sensor 56 is a sensor that detects the rotation speed of the turbine 42. The rotational speed of the turbine 42 corresponds to the output of the waste heat recovery machine 4. That is, the rotation speed sensor 56 according to the present embodiment has a function as a sensor that detects the output of the waste heat recovery machine 4. The condensed water temperature sensor 57 is a sensor that detects the temperature of the refrigerant (that is, condensed water) after passing through the condenser 8. Specifically, the condensed water temperature sensor 57 according to the present embodiment detects the temperature of the refrigerant in the condensed header tank 15. The header tank liquid level sensor 58 is a sensor that detects the liquid level of the refrigerant in the condensation header tank 15. The pressure sensor 59 is a sensor that detects the pressure of the passage 33 (specifically, this is the pressure inside the piping that constitutes the passage 33 and also the pressure of the refrigerant that passes through the passage 33). Specifically, the pressure sensor 59 according to this embodiment detects the pressure of the upstream passage 33 in the refrigerant flow direction with respect to the portion of the passage 33 to which the bypass passage 16 is connected. The arrangement location of the pressure sensor 59 is not limited to the location illustrated in FIG. 1 as long as it is any portion of the passage 33.

  Next, details of the ECU 200 will be described. ECU 200 executes abnormality determination control for determining whether or not Rankine cycle system 300 is abnormal. The details of the abnormality determination control will be described with reference to a flowchart as follows. FIG. 3 is a flowchart of the abnormality determination control. The ECU 200 repeatedly executes the flowchart of FIG. 3 at a predetermined cycle. In step S1, the abnormality determination unit (CPU 201) of the ECU 200 determines whether or not the Rankine cycle system 300 is in operation. The abnormality determination unit according to this embodiment determines that the Rankine cycle system 300 is in operation when the refrigerant temperature in the main body 20 detected by the water temperature sensor 51 and the exhaust temperature detected by the exhaust temperature sensor 52 are within a predetermined range. to decide. When it is determined NO in step S1 (when Rankine cycle system 300 is not in operation), the abnormality determination unit ends the execution of the flowchart (END). On the other hand, when it determines with YES by step S1 (when Rankine cycle system 300 is operating), an abnormality determination part performs step S2.

  In step S2, the abnormality determination unit determines whether or not the refrigerant supply unit (specifically, the water pump 12 and the thermostat 19) of the internal combustion engine 2 is normal based on the temperature of the refrigerant present in the internal combustion engine 2. Here, when the water pump 12 breaks down, the refrigerant discharge amount (circulation amount) decreases, so the amount of refrigerant that can be cooled in the condenser 8 decreases. As a result, the temperature of the refrigerant in the main body 20 exceeds the appropriate temperature. Are expected to rise continuously. Therefore, when the refrigerant temperature in the main body 20 measured by the water temperature sensor 51 exceeds the appropriate temperature of the refrigerant and continues to rise abnormally, the abnormality determination unit has failed in the water pump 12 in step S3 (that is, the refrigerant supply unit). Is abnormal).

  Further, when the thermostat 19 fails in a state where the refrigerant from the vane pump 10 flows into the water pump 12, the refrigerant cooled in the condenser 8 is always supplied into the main body 20, and therefore the temperature measured by the water temperature sensor 51. Takes a value different from the normal value. Therefore, when the measured value of the water temperature sensor 51 does not increase or continuously decreases after a certain period of time has elapsed since the internal combustion engine 2 was started, the abnormality determination unit determines that the thermostat 19 is removed from the vane pump 10 in step S3. It is determined that the refrigerant is out of order (in other words, there is an abnormality in the cooling supply unit). On the other hand, when the thermostat 19 fails in a state where the refrigerant from the vane pump 10 is shut off, the refrigerant after passing through the condenser 8 is not supplied into the main body 20, so that the temperature of the refrigerant rises continuously. In this case, the temperature of the refrigerant is stably increased as compared to when the water pump 12 fails. Therefore, when the measured value of the water temperature sensor 51 continues to rise stably, the abnormality determination unit has a failure with the thermostat 19 closing the passage leading to the condenser 8 in step S3 (that is, the refrigerant supply unit has an abnormality). Is determined).

  When the abnormality determination unit determines in step S3 that the refrigerant supply unit of the internal combustion engine 2 is abnormal, the control unit (CPU 201) of the ECU 200 executes step S4. In step S4, the control unit executes the limited operation mode. The limited operation mode is an operation in which the output of the internal combustion engine 2 is limited more than when there is no abnormality in the refrigerant supply unit. Specifically, in step S4, the control unit controls the output of the internal combustion engine 2 so that the maximum output of the internal combustion engine 2 is lower than when the Rankine cycle system 300 has no abnormality. More specifically, the control unit changes the maximum value of the fuel injection amount of the internal combustion engine 2 to a lower value than when the Rankine cycle system 300 has no abnormality. As a result, the output of the internal combustion engine 2 becomes lower (that is, limited) than when there is no abnormality.

  In step S4, the control unit notifies the user of Rankine cycle system 300 that an abnormality has occurred in Rankine cycle system 300. Specifically, a warning lamp for notifying the user that an abnormality has occurred in the Rankine cycle system 300 is disposed in the driver's seat of the vehicle on which the Rankine cycle system 300 according to this embodiment is mounted. More specifically, a warning lamp indicating that a minor abnormality has occurred and a warning lamp indicating that a severe abnormality has occurred are arranged as warning lamps in the driver seat of the vehicle according to the present embodiment. ing. In step S4, the control unit turns on a warning lamp indicating that a minor abnormality has occurred. After step S4 is executed, the abnormality determination unit ends the execution of the flowchart (END).

  On the other hand, when it determines with the refrigerant | coolant supply part of the internal combustion engine 2 being normal in step S2 (in the case of YES), an abnormality determination part performs step S10. In step S10, the abnormality determination unit performs an abnormality determination process for the waste heat recovery machine 4. Details of step S10 will be described later. After executing step S10, the abnormality determination unit executes an abnormality determination process for the first electromagnetic valve 13 in step S20. Details of step S20 will be described later. After executing step S20, the abnormality determination unit executes abnormality determination processing for the vane pump 10 in step S30. Details of step S30 will be described later. After executing step S30, the abnormality determination unit executes abnormality determination processing for the condenser 8 in step S40. Details of step S40 will be described later. After step S40, the abnormality determination unit executes START (RETURN).

  Next, the abnormality determination process for the waste heat recovery machine 4 according to step S10 will be described. FIG. 4 is a flowchart showing a subroutine of abnormality determination processing of the waste heat recovery machine 4. In step S11, the abnormality determination unit of ECU 200 determines whether the output of Rankine cycle system 300 is stable. Until the output of the Rankine cycle system 300 is stabilized, it is difficult to determine whether the change in the measured value of the sensor is due to the abnormality of the device or the change of the Rankine cycle, so this processing is performed. The abnormality determination unit according to the present embodiment determines that the output of the Rankine cycle system 300 is stable when the response delay of the Rankine cycle system 300 is a predetermined value A or less. If the abnormality determination unit determines NO in step S11, the execution of the flowchart ends. If the abnormality determination unit determines YES in step S11, it executes step S12.

  In step S12, the abnormality determination unit acquires the rotation speed N of the turbine 42 at the normal time. The rotational speed N of the turbine 42 is calculated based on the amount of refrigerant vapor calculated from the operating conditions of the internal combustion engine 2 and the pressure of the steam introduced into the waste heat recovery machine 4. Specifically, in the storage device of the ECU 200, the rotation speed of the turbine 42 at the normal time (specifically, the rotation speed of the turbine 42 when there is no abnormality in the Rankine cycle system 300), the vapor amount of the refrigerant, and the waste heat are stored. A map defined in association with the pressure of the steam introduced into the recovery machine 4 is stored in advance. The abnormality determination unit determines the refrigerant vapor amount, the refrigerant temperature in the main body 20, the exhaust gas temperature of the internal combustion engine 2, the rotational speed of the crankshaft of the internal combustion engine 2, the load of the internal combustion engine 2, and other operating conditions of the internal combustion engine 2. It calculates based on the information shown. The abnormality determination unit acquires the pressure of the steam introduced into the waste heat recovery machine 4 based on the detection result of the pressure sensor 55. The abnormality determination unit extracts the rotation speed of the turbine 42 at a normal time corresponding to the calculated refrigerant vapor amount and the acquired pressure of the steam introduced into the waste heat recovery machine 4 from the map, and the extracted turbine 42 Is obtained as the rotational speed N of the turbine 42 according to step S12. Step S12 is thus executed. The abnormality determination unit executes step S13 after executing step S12.

  In step S13, the abnormality determination unit determines whether the steam pressure P at the outlet of the superheater 7 detected by the pressure sensor 55 is smaller than the product of the rotational speed N of the turbine 42 acquired in step S12 and a predetermined value B. Determine. Here, when the steam pressure P detected by the pressure sensor 55 is smaller than the value N × B acquired based on the rotation speed N acquired based on the map, the rotation estimated from the steam in the superheater 7 is increased. Since it is not obtained, it is considered that steam leakage has occurred. Therefore, when it is determined YES in step S13, the abnormality determination unit determines that there is an abnormality on the upstream side of the waste heat recovery machine 4 in step S14. Specifically, the abnormality determination unit determines in step S14 that the refrigerant is leaking upstream of the waste heat recovery machine 4. In this embodiment, the upstream side of the waste heat recovery machine 4 refers to the path from the gas-liquid separator 5 to the waste heat recovery machine 4, that is, the passage 31, the superheater 7, and the superheater 7 and the supersonic nozzle 41. Means a refrigerant passage 3 between them.

  After step S14 is executed, the control unit executes step S19a. In step S19a, the control unit executes a first abnormality handling process. The contents of the first abnormality handling process according to the present embodiment are as follows. First, the control unit notifies the user that an abnormality has occurred in the Rankine cycle system 300. Specifically, the control unit turns on a warning lamp indicating that a severe abnormality has occurred in the Rankine cycle system 300. This is due to the following reason. When the refrigerant leaks, the Rankine cycle system 300, particularly the internal combustion engine 2, may overheat and fail. Therefore, in step S19a, the control unit determines that the degree of abnormality of Rankine cycle system 300 is high (that is, severe), and notifies the user that a serious abnormality has occurred.

  In step S19a, the control unit opens the second electromagnetic valve 17. When the second electromagnetic valve 17 is opened, the gas-phase refrigerant (vapor) separated in the gas-liquid separator 5 passes through the bypass passage 16 and flows into the passage 33. Thereby, the approach of the vapor | steam to the superheater 7 and the waste heat recovery machine 4 is suppressed. Thereby, compared with the case where a vapor | steam enters the superheater 7 and the waste heat recovery machine 4, a refrigerant | coolant leakage can be suppressed. Further, the control unit closes the first electromagnetic valve 13. Thereby, the liquid phase refrigerant of the gas-liquid separator 5 is suppressed from flowing into the superheater 7.

  In step S19a, the control unit controls the maximum output of the internal combustion engine 2 to a predetermined value (referred to as an extremely low output) lower than that in step S19b described later. In the present embodiment, the maximum rotational speed of the internal combustion engine 2 is used as the maximum output of the internal combustion engine 2. The reason why the maximum output of the internal combustion engine 2 is kept lower in step S19a than in step S19b is that when step S19a is executed, the degree of abnormality of the Rankine cycle system 300 is higher than in step S19b. The reason why the output of the internal combustion engine 2 is not forced to zero in step S19a (that is, the internal combustion engine 2 is not forcibly stopped) is that the user can evacuate the vehicle. Thus, the control of the output of the internal combustion engine 2 according to step S19a is executed when step S19a has a higher degree of abnormality in the Rankine cycle system 300 than step S19b, so that the user can evacuate the vehicle. The maximum output of the internal combustion engine 2 is kept as low as possible while securing the output of 2. After step S19a is executed, the abnormality determination unit ends the execution of the flowchart.

  If the abnormality determination unit determines NO in step S13, it executes step S15. In step S15, the abnormality determination unit determines whether or not the pressure of the refrigerant passage (specifically, the passage 33) that guides the refrigerant that has passed through the waste heat recovery machine 4 to the condenser 8 is within the reference range. Specifically, the abnormality determination unit determines whether or not the pressure of the passage 33 detected by the pressure sensor 59 (this pressure is a negative pressure (a pressure lower than the atmospheric pressure) when normal) is within the reference range. To do. In step S15, when the pressure detected by the pressure sensor 59 is less than a predetermined value, the abnormality determination unit according to the present embodiment determines that the pressure detected by the pressure sensor 59 is within the reference range, and the pressure sensor When the pressure detected by 59 is equal to or greater than a predetermined value (that is, when the negative pressure in the passage 33 is insufficient), it is determined that the pressure detected by the pressure sensor 59 is outside the reference range. As the predetermined value used as the determination criterion in step S15, an appropriate value is obtained in advance by experiment, simulation, or the like, and stored in the storage device.

  When it is determined in step S15 that the pressure detected by the pressure sensor 59 is outside the reference range (in the case of NO), the abnormality determination unit executes step S16. In step S <b> 16, the abnormality determination unit determines that there is an abnormality in the negative pressure system of Rankine cycle system 300. Specifically, the abnormality determination unit determines that there is an abnormality in the passage 33 that is the negative pressure system of the Rankine cycle system 300. The abnormality of the passage 33 specifically means that a hole or a crack is generated in the passage 33 and an abnormality occurs in the negative pressure of the passage 33. More specifically, the abnormality is generated in the passage 33. This means that there is a possibility that the refrigerant is leaking from the hole or crack.

  After step S16 is executed, the control unit executes a first abnormality handling process according to step S19a. Since step S19a executed after step S16 is the same as step S19a executed after step S14 described above, detailed description thereof will be omitted. In addition, by opening the second electromagnetic valve 17 in step S19a executed after step S16, the gas-phase refrigerant separated in the gas-liquid separator 5 is supplied to the superheater 7 and the waste heat recovery machine 4. As a result of the supply being suppressed, the refrigerant leakage from the passage 33 can be suppressed as compared with the case where the refrigerant that has passed through the superheater 7 and the waste heat recovery machine 4 flows into the passage 33.

  If it is determined in step S15 that the pressure detected by the pressure sensor 59 is within the reference range (YES), the abnormality determination unit executes step S17. In step S17, the abnormality determination unit determines whether the output of the waste heat recovery machine 4 is less than a predetermined value. Specifically, the abnormality determination unit according to the present embodiment uses, as the output of the waste heat recovery machine 4, the rotational speed Nr (that is, actually measured value) of the turbine 42 detected by the rotational speed sensor 56. Further, as the predetermined value, the product of the rotational speed N acquired in step S12 and the predetermined value C is used. That is, in step S17, the abnormality determination unit according to the present embodiment determines whether the rotational speed Nr (actual value) of the turbine 42 is smaller than the product of the rotational speed N acquired in step S12 and the predetermined value C. ing. If the abnormality determination unit determines YES in step S17, it determines that there is an abnormality in the waste heat recovery machine 4 in step S18. For the predetermined value C, an appropriate value is obtained in advance and stored in the storage device. After step S18 is executed, the control unit executes step S19b.

  In step S19b, the control unit executes a second abnormality handling process. The content of the second abnormality handling process is different from the first abnormality handling process according to step S19a described above. In other words, the Rankine cycle between the case where the control unit according to the present embodiment determines that the passage 33 is abnormal (step S16) and the case where it is determined that the waste heat recovery machine 4 is abnormal (step S18). The control content of the system 300 is changed.

  The contents of the second abnormality handling process according to the present embodiment are as follows. First, the control unit notifies the user that a slight abnormality has occurred in the Rankine cycle system 300. Specifically, the control unit turns on a warning lamp indicating that a slight abnormality has occurred in the Rankine cycle system 300. The control unit opens the second electromagnetic valve 17. By opening the second electromagnetic valve 17, the gas-phase refrigerant (vapor) separated in the gas-liquid separator 5 passes through the bypass passage 16 and flows into the passage 33. Thereby, the approach of the steam to the superheater 7 and the waste heat recovery machine 4 in which an abnormality has occurred is suppressed. Further, the control unit closes the first electromagnetic valve 13. Further, the control unit controls the maximum output of the internal combustion engine 2 to a predetermined value lower than the normal maximum output (this is the maximum output when it is not determined that the Rankine cycle system 300 is abnormal) (that is, the maximum output). , Reduce the maximum output from the normal maximum output). Note that the predetermined value of the maximum output according to step S19b is higher than the extremely low output according to step S19a described above. Since step S19b is executed when the degree of abnormality is lower (that is, mild) than step S19a, the maximum output when step S19b is executed may be higher than that in step S19a. After step S19b is executed, the abnormality determination unit ends the execution of the flowchart.

  When it determines with NO in step S17, an abnormality determination part performs the abnormality determination process of the 1st solenoid valve which concerns on step S20. In step S20, the abnormality determination unit executes a flowchart of FIG. FIG. 5 is a flowchart showing a subroutine of abnormality determination processing for the first electromagnetic valve 13. In step S21, the abnormality determination unit obtains the liquid level Lw of the liquid phase refrigerant in the gas-liquid separator 5 detected by the liquid level sensor 53. Moreover, the abnormality determination part acquires the steam temperature Ts in the superheater 7 detected by the steam temperature sensor 54 in step S21. The abnormality determination unit executes step S22 after step S21.

  In step S22, the abnormality determination unit determines whether or not the liquid level Lw of the liquid refrigerant in the gas-liquid separator 5 is lower than the allowable minimum liquid level L1. When it is determined that the Rankine cycle system 300 is operating normally, the amount of liquid phase refrigerant in the gas-liquid separator 5 is within a predetermined range. The allowable minimum liquid level L1 is a liquid level indicated by the liquid level sensor 53 when the Rankine cycle system 300 is normal and the liquid phase refrigerant in the gas-liquid separator 5 has a minimum allowable amount. If the abnormality determination unit determines YES in step S22, it executes step S23. In step S23, the abnormality determination unit determines whether or not the steam temperature Ts in the superheater 7 is lower than the allowable minimum temperature T1. When it is determined that the Rankine cycle system 300 is operating normally, the temperature of the steam in the superheater 7 is in a predetermined range. The allowable minimum temperature T1 is the minimum allowable temperature of steam when the Rankine cycle system 300 is normal.

  Here, when it is determined YES in step S22 and step S23 (that is, when the amount of refrigerant in the liquid phase in the gas-liquid separator 5 is small and the temperature of the steam in the superheater 7 is also low), the first electromagnetic Although the valve 13 has to be closed, the first electromagnetic valve 13 malfunctions and is stuck in the open state, and the liquid-phase refrigerant is excessively transferred from the gas-liquid separator 5 to the superheater 7. It is thought that it is flowing out. Therefore, if the abnormality determination unit determines YES in step S23, it determines that the first electromagnetic valve 13 is malfunctioning in step S24, and records it in the storage device. The malfunction here has shown that the 1st solenoid valve 13 stuck in the valve opening state. One reason why the first electromagnetic valve 13 does not close is that dust is mixed in the refrigerant passage 3 and the dust is caught in the opening of the first electromagnetic valve 13 to prevent the valve from closing. After step S24 is executed, the control unit executes step S25.

  In step S25, the control unit opens the second electromagnetic valve 17. When the second electromagnetic valve 17 is opened, the gas-phase refrigerant separated in the gas-liquid separator 5 passes through the bypass passage 16 and flows into the passage 33. As a result, the operation of the waste heat recovery machine 4 is stopped, but the refrigerant can flow into the internal combustion engine 2 via the condenser 8, so that the internal combustion engine 2 is prevented from overheating. Next, in step S26, the control unit executes the limited operation mode. In addition, the control unit notifies the user that the operation has shifted to the limited operation mode, and notifies that an abnormality has occurred in the Rankine cycle system 300. Since the content of step S26 is the same as that of step S4 in FIG. 3, detailed description thereof is omitted. After step S26 is executed, the abnormality determination unit ends the execution of the flowchart.

  If the abnormality determination unit determines NO in step S22, it executes step S27. In step S27, the abnormality determination unit determines whether or not the liquid level Lw of the liquid phase refrigerant in the gas-liquid separator 5 is higher than the allowable maximum liquid level L2. The allowable maximum liquid level L2 is the highest liquid level allowed for the liquid refrigerant in the gas-liquid separator 5 when the Rankine cycle system 300 is normal. If the abnormality determination unit determines YES in step S27, it executes step S28. In step S28, the abnormality determination unit determines whether or not the steam temperature Ts in the superheater 7 is higher than the allowable maximum temperature T2. The allowable maximum temperature T2 is the maximum temperature allowed for steam when the Rankine cycle system 300 is normal. If the abnormality determination unit determines YES in step S28, it executes step S29.

  Here, when reaching step S29, in the gas-liquid separator 5, the temperature of the steam is excessively increased in the superheater 7 even though the liquid-phase refrigerant is excessively present. As this cause, it is considered that the liquid-phase refrigerant is not supplied from the gas-liquid separator 5 to the superheater 7. That is, it is conceivable that the refrigerant does not flow through the passage 32. It is conceivable that the refrigerant does not flow through the passage 32 because the first electromagnetic valve 13 is stuck in the closed state or the first electromagnetic valve 13 is clogged. Therefore, the abnormality determination unit determines that the first electromagnetic valve 13 is malfunctioning in step S29. The malfunction here indicates that the first electromagnetic valve 13 is stuck in the closed state or that the electric signal to the first electromagnetic valve 13 cannot be normally transmitted due to an abnormality in the electric system. Yes. After step S29 is executed, the control unit executes step S25.

  When it determines with NO in step S23, an abnormality determination part performs a of abnormality determination processing of the vane pump 10 which concerns on step S30. If the abnormality determination unit determines NO in step S28, the abnormality determination process b of the vane pump 10 according to step S30 is executed. If the abnormality determination unit determines NO in step S27, the abnormality determination process of the condenser 8 according to step S40 is executed.

  As described above, in the abnormality determination process of the first electromagnetic valve 13, the abnormality determination unit detects the amount of liquid-phase refrigerant in the gas-liquid separator 5 and the superheater when no abnormality is detected in the refrigerant supply unit of the internal combustion engine 2. The abnormality of the first electromagnetic valve 13 is determined based on the temperature of the gas-phase refrigerant in 7 (step S24). Further, when the abnormality of the first electromagnetic valve 13 is determined, the control unit suppresses the internal combustion engine 2 from overheating while stopping the operation of the waste heat recovery machine 4 by executing step S25.

  Next, the abnormality determination process for the vane pump 10 according to step S30 will be described. In step S30, the abnormality determination unit of the ECU 200 executes a flowchart of FIG. FIG. 6 is a flowchart showing a subroutine of the abnormality determination process of the vane pump 10. The abnormality determination unit proceeds to step S31 from the connector of FIG. In step S31, the abnormality determination unit acquires the amount Vw of the liquid phase refrigerant in the condensation header tank 15 based on the detection result of the header tank liquid level sensor 58, and the acquired amount Vw of the liquid phase refrigerant is the allowable maximum amount. It is determined whether or not there is more than V1. The allowable maximum amount V1 is the maximum value of the liquid phase refrigerant amount in the condensation header tank 15 when the Rankine cycle system 300 is operating normally. If the abnormality determination unit determines YES in step S31, it executes step S32.

  In step S32, the abnormality determination unit determines that the vane pump 10 is malfunctioning. The malfunction here is a case where the vane pump 10 is closed and stuck or a case where the operation is stopped. The closed fixing is an operation failure in which the rotor 102 becomes defective in rotation due to the sliding portion between the cam ring 101 and the vane 103 of the vane pump 10 being fixed for some reason, and the refrigerant cannot be pumped. The operation stop is a malfunction due to a failure of the drive mechanism that rotates the rotor 102. If the vane pump 10 is closed and stuck or stopped, the circulation of the refrigerant is stopped, so that the amount of the liquid phase refrigerant in the condensation header tank 15 increases. Further, the amount of liquid phase refrigerant supplied into the gas-liquid separator 5 is also reduced. Therefore, when reaching step S32, that is, when the amount of the liquid phase refrigerant in the gas-liquid separator 5 is small, the first electromagnetic valve 13 is not abnormal, and the amount of the liquid phase refrigerant in the condensation header tank 15 is In many cases, it can be determined that the vane pump 10 is closed or stuck. After step S32 is executed, the control unit executes step S33.

  In step S33, the control unit opens the second electromagnetic valve 17. When the second electromagnetic valve 17 is opened, the gas-phase refrigerant separated in the gas-liquid separator 5 passes through the bypass passage 16 and flows into the passage 33. Thereby, the refrigerant bypasses the superheater 7 and the waste heat recovery machine 4. By executing step S33, waste heat recovery by the waste heat recovery machine 4 is stopped, but overheating of the refrigerant by the superheater 7 is also stopped, so that the burden of cooling the refrigerant in the condenser 8 can be reduced. In addition, damage to the condenser 8 due to excessive refrigerant (vapor) flowing into the condenser 8 can be suppressed.

  After step S33, the control unit shifts to the limited operation mode in step S34. Thereby, the internal combustion engine 2 can be operated in an operable region, and can be safely stopped. In addition, the control unit notifies the user that the operation has shifted to the limited operation mode, and notifies the Rankine cycle system 300 that an abnormality has occurred. The content of step S34 is the same as that of step S4 in FIG. After step S34 is executed, the abnormality determination unit ends the execution of the flowchart.

  If the abnormality determination unit determines NO in step S31, it executes step S35. In step S35, the abnormality determination unit determines that the gas-liquid separator 5 is abnormal. Specifically, the abnormality determination unit determines that refrigerant leakage or breakage has occurred in the gas-liquid separator 5. In other words, the abnormality determination unit according to the present embodiment is such that the amount of the liquid-phase refrigerant in the gas-liquid separator 5 is less than a predetermined value (Step S22 in FIG. 5: Lw <L1), Is equal to or higher than a predetermined value (step S23 in FIG. 5: Ts ≧ T1), and the amount of liquid-phase refrigerant in the condensation header tank 15 is equal to or lower than a predetermined value (step S31 in FIG. 6: Vw ≦ V1). In step S35, it is determined that the gas-liquid separator 5 is abnormal. After step S35 is executed, the control unit executes step S33.

  By the above-described steps S31, S32, and S35, it is possible to determine whether the vane pump 10 is closed and the gas-liquid separator 5 is abnormal. Thereby, it is possible to determine whether the cause of the malfunction of the Rankine cycle system 300 is due to the closed fixation of the vane pump 10 or the abnormality of the gas-liquid separator 5.

  Next, processing from the connector b in the flowchart of FIG. 6 will be described. The abnormality determination unit proceeds to step S36 from the connector b. In step S36, the abnormality determination unit determines whether or not the amount of liquid-phase refrigerant Vw in the condensation header tank 15 is smaller than the allowable minimum amount V2. The allowable minimum amount V2 is the minimum value of the liquid phase refrigerant amount in the condensation header tank 15 when the Rankine cycle system 300 is operating normally. If the abnormality determination unit determines YES in step S36, it executes step S37.

  In step S37, the abnormality determination unit determines that the vane pump 10 is malfunctioning. The malfunction here is a malfunction in closing the vane pump 10 due to open fixation or dust biting. The open fixation is a malfunction in which the sealing performance of the vane pump 10 is lost and the refrigerant flows freely except during driving. Specifically, the loss of the sealing performance of the vane pump 10 means that the tip of the vane 103 of the vane pump 10 cannot be brought into good contact with the wall surface of the cam ring 101. This is considered to be due to the force that presses the vane 103 against the wall surface of the cam ring 101 due to the deterioration of the spring 104 and the like, and as a result, the tip of the vane 103 cannot contact the wall surface of the cam ring 101 well. In addition, the closing failure due to dust biting is an operation failure in which the refrigerant flows freely except during driving due to dust adhering to the tip side of the vane 103 and loss of sealing performance.

  When the vane pump 10 is stuck open or closed due to dust trapping, the refrigerant flows freely, so even if the vane pump 10 is stopped, the liquid refrigerant in the condensation header tank 15 flows out. . Since the flowing liquid phase refrigerant is supplied to the gas-liquid separator 5, the amount of the liquid-phase refrigerant in the gas-liquid separator 5 increases. Therefore, in the condition to reach step S37, that is, in the situation where the amount of liquid phase refrigerant in the gas-liquid separator 5 is large, the first electromagnetic valve 13 is not abnormal, and the amount of liquid phase refrigerant in the condensation header tank 15 In the case where there is little, in step S37, it can be determined that the closing failure due to the open fixation of the vane pump 10 or the biting of dust has occurred. After step S37 is executed, the control unit executes step S33.

  If the abnormality determination unit determines NO in step S36, it executes step S38 and proceeds to c of the abnormality determination control in FIG. That is, the abnormality determination part which concerns on a present Example determines with the refrigerant | coolant supply part having abnormality in step S3 of FIG. 3, when it determines with NO in step S36. This is because the level of the liquid phase refrigerant in the gas-liquid separator 5 is higher than the allowable maximum value even though there is no abnormality in the first solenoid valve 13 and the vane pump 10 (step S27 in FIG. 5). : Lw> L2), it is determined that there is an abnormality in the refrigerant supply unit.

  That is, the abnormality determination unit according to the present embodiment determines whether or not there is an abnormality in the refrigerant supply unit based on the temperature of the refrigerant existing inside the internal combustion engine 2 (in the case of NO in step S2 of FIG. 3). When step S3 is executed), the level of the liquid refrigerant in the gas-liquid separator 5 is higher than a predetermined value (step S27 in FIG. 5: Lw> L2), and the gas-phase refrigerant in the superheater 7 Even when the temperature (steam temperature) is equal to or lower than a predetermined value (step S28: Ts ≦ T2) and the amount of liquid-phase refrigerant in the condensation header tank 15 is equal to or higher than the predetermined value (step S36 in FIG. 6: Vw ≧ V2). ), It is determined that there is an abnormality in the refrigerant supply section of the internal combustion engine 2 (step S38 in FIG. 6 and step S3 in FIG. 3).

  By step S36, step S37, and step S38 described above, it is determined whether the cause of the malfunction of the Rankine cycle system 300 is due to the open fixing of the vane pump 10 or the abnormality of the refrigerant supply unit of the internal combustion engine 2. Can do.

  Next, the abnormality determination process for the condenser 8 according to step S40 in FIG. 3 will be described. In step S40, the abnormality determination unit of the ECU 200 executes a flowchart of FIG. FIG. 7 is a flowchart showing a subroutine of the abnormality determination process of the condenser 8. In step S41, the abnormality determination unit obtains the temperature Tw of the refrigerant stored in the condensation header tank 15 based on the detection result of the condensed water temperature sensor 57. Next, in step S42, the abnormality determination unit determines whether or not the refrigerant temperature Tw acquired in step S41 is greater than the condensate allowable temperature T3. The condensate allowable temperature T3 is the maximum temperature allowed for the refrigerant in the condensing header tank 15. If the abnormality determination unit determines NO in step S42, the abnormality determination unit returns to START in FIG.

  If the abnormality determination unit determines YES in step S42, in step S43, it is determined whether or not the pressure of the refrigerant passage (passage 33) that guides the refrigerant that has passed through the waste heat recovery machine 4 to the condenser 8 is within the reference range. judge. The specific contents of step S43 are the same as step S15 of FIG. That is, in step S43, when the pressure in the passage 33 detected by the pressure sensor 59 is less than a predetermined value, the abnormality determination unit determines that the pressure detected by the pressure sensor 59 is within the reference range (YES), When the pressure detected by the sensor 59 is equal to or greater than a predetermined value (that is, when the negative pressure in the passage 33 is insufficient), it is determined that the pressure detected by the pressure sensor 59 is outside the reference range (NO).

  When it determines with NO by step S43, an abnormality determination part determines with the abnormality in the negative pressure system of Rankine cycle system 300 in step S44. Step S44 is the same as step S16 of FIG. That is, in step S44, the abnormality determination unit determines that there is an abnormality in the passage 33 that is the negative pressure system of the Rankine cycle system 300.

  After step S44 is executed, the control unit executes the first abnormality handling process according to step S46a. Step S46a is the same as step S19a of FIG. Specifically, in step S46a, the control unit turns on a warning lamp indicating that a severe abnormality has occurred in the Rankine cycle system 300. The control unit opens the second electromagnetic valve 17. When the second electromagnetic valve 17 is opened, the gas-phase refrigerant separated in the gas-liquid separator 5 passes through the bypass passage 16 and flows into the passage 33. Thereby, the entrance of the refrigerant into the superheater 7 and the waste heat recovery machine 4 is suppressed. As a result, the refrigerant leakage from the passage 33 can be suppressed as compared with the case where the refrigerant enters the superheater 7 and the waste heat recovery machine 4. Further, the control unit closes the first electromagnetic valve 13. Thereby, the liquid phase refrigerant of the gas-liquid separator 5 is suppressed from flowing into the superheater 7. Further, the control unit controls the maximum output of the internal combustion engine 2 to a predetermined value (extremely low output) lower than in the case of step S46b. After step S46a is executed, the abnormality determination unit ends the execution of the flowchart.

  When it determines with YES by step S43, an abnormality determination part performs step S45. In step S45, the abnormality determination unit determines that the condenser 8 is abnormal. That is, the abnormality determination unit determines that the temperature of the refrigerant stored in the condensation header tank 15 is higher than a predetermined value (step S42: Tw> T3) and the pressure in the passage 33 is included in the reference range (YES in step S43). In step S45, it is determined that the condenser 8 is abnormal. After step S45 is executed, the control unit executes a second abnormality handling process according to step S46b. Step S46b is a process different from step S46a. That is, the control unit according to the present embodiment performs a Rankine operation between the case where it is determined that the condenser 8 is abnormal in Step S45 of FIG. 7 and the case where it is determined that the passage 33 is abnormal in Step S44 of FIG. The control content of the cycle system 300 is changed.

  Specifically, the second abnormality handling process according to step S46b is the same as the second abnormality handling process according to step S19b of FIG. More specifically, in step S46b, the control unit turns on a warning lamp indicating that a slight abnormality has occurred in the Rankine cycle system 300. The control unit opens the second electromagnetic valve 17. By opening the second electromagnetic valve 17, the gas-phase refrigerant separated in the gas-liquid separator 5 passes through the bypass passage 16 and flows into the passage 33. Thereby, the approach of the refrigerant to the condenser 8 via the superheater 7 and the waste heat recovery machine 4 is suppressed. Further, the control unit closes the first electromagnetic valve 13. Further, the control unit controls the maximum output of the internal combustion engine 2 to a predetermined value lower than the normal maximum output (that is, reduces the maximum output from the normal maximum output). Note that the predetermined value of the maximum output according to step S46b is higher than the extremely low output according to step S46a. After step S46b is executed, the abnormality determination unit ends the execution of the flowchart.

  The operational effects of the Rankine cycle system abnormality determination device (ECU 200) according to the present embodiment are summarized as follows. First, the abnormality determination unit (CPU 201) of the abnormality determination device (ECU 200) according to the present embodiment uses the waste heat recovery machine 4 operated by the refrigerant vaporized by the waste heat of the internal combustion engine 2 as described in FIG. When the pressure of the refrigerant passage (specifically, the passage 33) for guiding the refrigerant passed through to the condenser 8 is out of the predetermined reference range, it is determined in step S16 that the passage 33 is abnormal, and the pressure is within the reference range. If the output of the waste heat recovery machine 4 is less than the predetermined value, it is determined in step S18 that the waste heat recovery machine 4 is abnormal. According to the abnormality determination device according to the present embodiment, it is possible to determine whether the waste heat recovery machine 4 has an abnormality or the passage 33 has an abnormality.

  Further, according to the abnormality determination device according to the present embodiment, as described in step S19a and step S19b in FIG. 4, the control unit (CPU 201) determines that the abnormality determination unit has an abnormality in the passage 33 (step The control content of the Rankine cycle system 300 is changed between the case of S16) and the case where the abnormality determination unit determines that there is an abnormality in the waste heat recovery machine 4 (in the case of Step S18) (Step S19a, Step S19b). Thereby, the Rankine cycle system 300 can be appropriately controlled according to the abnormality content of the Rankine cycle system 300. Specifically, it is possible to appropriately control the output of the Rankine cycle system 300, particularly the internal combustion engine 2, depending on whether there is an abnormality in the passage 33 of the Rankine cycle system 300 or an abnormality in the waste heat recovery machine 4. it can.

  Further, according to the abnormality determination device according to the present embodiment, as described in FIG. 7, the abnormality determination unit is further provided in the tank (specifically, the condensation header tank 15) that stores the refrigerant that has passed through the condenser 8. When the temperature of the stored refrigerant is higher than a predetermined value (in the case of YES in step S42) and the pressure of the passage 33 is included in the reference range (in the case of YES in step S43), in the condenser 8 in step S45. It is determined that there is an abnormality. According to this configuration, it is possible to determine whether the condenser 8 is abnormal or the passage 33 is abnormal. Thereby, the presence or absence of abnormality of the condenser 8 can be accurately determined.

  Moreover, according to the abnormality determination device according to the present embodiment, as described in step S46b and step S46a in FIG. 7, the control unit determines that the abnormality determination unit determines that the condenser 8 is abnormal in step S45. The control content of the Rankine cycle system 300 is changed between when the abnormality determination unit determines that there is an abnormality in the passage 33 in step S44 (step S46b, step S46a). Thereby, the Rankine cycle system 300 can be appropriately controlled according to the abnormality content of the Rankine cycle system 300. Specifically, the output of the Rankine cycle system 300, particularly the internal combustion engine 2, can be appropriately controlled depending on whether the condenser 8 of the Rankine cycle system 300 is abnormal or when the passage 33 is abnormal.

  Further, according to the abnormality determination device according to the present embodiment, as described in step S38 of FIG. 6 and the like, the abnormality determination unit has an abnormality in the refrigerant supply unit based on the temperature of the refrigerant existing in the internal combustion engine 2. It is determined whether or not (specifically, when step S3 is executed when NO in step S2 in FIG. 3), the level of the liquid phase refrigerant in the gas-liquid separator 5 is greater than a predetermined value. 5 (step S27 in FIG. 5: Lw> L2), the temperature of the gas-phase refrigerant in the superheater 7 is not more than a predetermined value (step S28: Ts ≦ T2), and the amount of the liquid-phase refrigerant in the condensation header tank 15 Is equal to or greater than the predetermined value (step S36 in FIG. 6: Vw ≧ V2), it is determined that the refrigerant supply unit of the internal combustion engine 2 is abnormal. According to this configuration, it is possible to accurately determine whether there is an abnormality in the refrigerant supply unit.

  Although the preferred embodiments of the present invention have been described in detail above, the present invention is not limited to such specific embodiments, and various modifications and changes can be made within the scope of the gist of the present invention described in the claims. It can be changed.

2 Internal combustion engine 3 Refrigerant passage 4 Waste heat recovery machine 5 Gas-liquid separator 7 Superheater 8 Condenser 10 Vane pump 13 First electromagnetic valve 15 Condensing header tank 16 Bypass passage 17 Second electromagnetic valve 33 passage 59 Pressure sensor 200 ECU
201 CPU
300 Rankine cycle system

Claims (3)

  When the pressure of the refrigerant passage of the Rankine cycle system having the refrigerant passage for guiding the refrigerant to the condenser via the waste heat recovery machine operated by the refrigerant vaporized by the waste heat of the internal combustion engine is out of a predetermined reference range And determining that the waste heat recovery machine is abnormal when the pressure is within the reference range and the output of the waste heat recovery machine is less than a predetermined value. An abnormality determination device for a Rankine cycle system, comprising:   The control content of the Rankine cycle system is changed between when the abnormality determination unit determines that the refrigerant passage is abnormal and when the abnormality determination unit determines that the waste heat recovery machine is abnormal. The abnormality determination apparatus for Rankine cycle system according to claim 1, further comprising a control unit that performs the operation. The Rankine cycle system includes a tank for storing the refrigerant that has passed through the condenser,
The abnormality determination unit further determines that the condenser is abnormal when the temperature of the refrigerant stored in the tank is higher than a predetermined value and the pressure of the refrigerant passage is included in the reference range. Item 3. The Rankine cycle system abnormality determination device according to Item 1 or 2.

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