Apparatus for utilizing heat wasted from engine
Apparatus for utilizing heat wasted from an engine includes: a Rankine cycle ( 31 ); a transmission mechanism that couples an output shaft of an expansion device ( 37 ) to a rotary shaft of an engine via an electromagnetic clutch ( 32 ) that can be engaged and disengaged; a passage ( 65 ) through which refrigerant exiting a heat exchanger ( 36 ) flows so as to bypass the expansion device ( 37 ); and a bypass valve ( 66 ) interposed in the passage. To stop the expansion device ( 37 ), the electromagnetic clutch ( 32 ) is switched from an engaged state to a disengaged state after switching the bypass valve ( 66 ) from a closed state to an open state. If the bypass valve ( 66 ) becomes stuck in the closed state, expansion device front-rear differential pressure limiting processing in which a front-rear differential pressure of the expansion device is limited while maintaining the electromagnetic clutch ( 32 ) in the engaged state is performed.
1. An apparatus for utilizing heat wasted from an engine, comprising:
a Rankine cycle including:
a heat exchanger that recovers waste heat from the engine in a refrigerant;
an expansion device that generates power using the refrigerant at an outlet of the heat exchanger;
a condenser that condenses the refrigerant exiting the expansion device; and
a refrigerant pump that supplies the refrigerant exiting the condenser to the heat exchanger;
a transmission mechanism configured to couple an output shaft of the expansion device to a rotary shaft of the engine via an electromagnetic clutch, the electromagnetic clutch being configured to be engaged and disengaged;
a passage through which the refrigerant exiting the heat exchanger flows so as to bypass the expansion device;
a bypass valve interposed in the passage, and
a controller
wherein, the controller is programmed to:
switch the electromagnetic clutch from an engaged state to a disengaged state after switching the bypass valve from a closed state to an open state to stop the expansion device and
perform expansion device front-rear differential pressure limiting processing in which a front-rear differential pressure of the expansion device is limited while maintaining the electromagnetic clutch in the engaged state, in a case where the bypass valve becomes stuck in the closed state.
2. The apparatus for utilizing heat wasted from an engine as defined in claim 1 , wherein over-rotation of the expansion device is prevented by the front-rear differential pressure limiting processing while stopping the expansion device.
3. The apparatus for utilizing heat wasted from an engine as defined in claim 1 ,
wherein the expansion device front-rear differential pressure limiting processing is
expansion device front-rear differential pressure reducing processing
wherein the controller is programmed to:
reduce the expansion device front-rear differential pressure compared with a case where the bypass valve is not stuck in the closed state.
4. The apparatus for utilizing heat wasted from an engine as defined in claim 3 ,
wherein the expansion device front-rear differential pressure reducing processing is input heat amount reducing processing
wherein the controller is programmed to:
reduce an amount of heat recovered in the refrigerant by the heat exchanger compared with a case where the bypass valve is not stuck in the closed state.
5. The apparatus for utilizing heat wasted from an engine as defined in claim 3 ,
wherein the expansion device front-rear differential pressure reducing processing is heat released amount reducing processing
wherein the controller is programmed to:
reduce an amount of heat released from the refrigerant by the condenser compared with a case where the bypass valve is not stuck in the closed state.
6. The apparatus for utilizing heat wasted from an engine as defined in claim 5 ,
wherein the condenser is disposed parallel to a radiator for cooling engine cooling water so that the condenser is cooled by a radiator fan,
wherein the heat released amount reducing processing is radiator fan stopping processing in which the radiator fan is stopped, and
wherein the controller is programmed:
not to stop the radiator fan even in a case where the bypass valve is stuck in the closed state when a temperature of the engine cooling water equals or exceeds a predetermined value defined in advance.
7. The apparatus for utilizing heat wasted from an engine as defined in claim 3 ,
wherein the expansion device front-rear differential pressure reducing processing is expansion device workload reducing processing
wherein the controller is programmed to:
reduce a workload of the expansion device.
8. The apparatus for utilizing heat wasted from an engine as defined in claim 3 ,
wherein the condenser is a liquid-cooled condenser,
wherein the apparatus for utilizing heat wasted from an engine further comprises:
a cooling liquid passage for circulating second cooling liquid to the liquid-cooled condenser, the second cooling liquid being different from engine cooling water;
a cooling liquid pump interposed in the cooling liquid passage, the cooling liquid pump being configured to adjust a discharge amount of the second cooling liquid; and
a sub-radiator for cooling the second cooling liquid, and
wherein the expansion device front-rear differential pressure reducing processing is discharge amount reducing processing
wherein the controller is programmed to:
reduce a discharge amount of the cooling liquid pump compared with a case where the bypass valve is not stuck in the closed state.
9. The apparatus for utilizing heat wasted from an engine as defined in claim 8 ,
wherein the sub-radiator is disposed parallel to a radiator for cooling the engine cooling water so that the sub-radiator is cooled by a radiator fan,
wherein the controller is programmed:
not to stop the radiator fan even in a case where the bypass valve is stuck in the closed state when a second cooling liquid temperature at an outlet of the cooling liquid pump equals or exceeds a predetermined value.
10. The apparatus for utilizing heat wasted from an engine as defined in claim 3 ,
wherein the condenser is a liquid-cooled condenser,
wherein the apparatus for utilizing heat wasted from an engine further comprises:
a cooling liquid passage for circulating second cooling liquid to the liquid-cooled condenser, the second cooling liquid being different from engine cooling water;
a cooling liquid pump interposed in the cooling liquid passage, the cooling liquid pump being configured to adjust a discharge amount of the second cooling liquid; and
a sub-radiator for cooling the second cooling liquid, and
wherein the expansion device front-rear differential pressure reducing processing is heat released amount reducing processing
wherein the controller is programmed to:
reduce an amount of heat released from the second cooling liquid in the liquid-cooled condenser compared with a case where the bypass valve is not stuck it the closed state.
11. The apparatus for utilizing heat wasted from an engine as defined in claim 3 ,
wherein the condenser is a liquid-cooled condenser,
wherein the apparatus for utilizing heat wasted from an engine further comprises:
a cooling liquid passage for circulating second cooling liquid to the liquid-cooled condenser, the second cooling liquid being different from engine cooling water;
a cooling liquid pump interposed in the cooling liquid passage, the cooling liquid pump being configured to adjust a discharge amount of the second cooling liquid; and
a sub-radiator for cooling the second cooling liquid, and
wherein the expansion device front-rear differential pressure reducing processing is heat received amount reducing processing
wherein the controller is programmed to:
reduce an amount of heat received by the refrigerant in the liquid-cooled condenser compared with a case where the bypass valve is not stuck in the closed state.