Hybrid power plant with waste heat recovery system
View Patent ↗A hybrid power plant includes a waste heat recovery (WHR) system having an expander driven by waste heat from an internal combustion engine. The expander, which is rotary in one example, rotationally drives a first pump and alternator with which the expander may be packaged as a single unit. The first pump circulates a working fluid when the WHR system is in use to charge an electrical storage device. A second pump is employed to circulate the working fluid when the first pump is not in use, for example. The expander can be bypassed to divert the working fluid to a heater core used to heat engine coolant during cold start conditions, for example.
1. A hybrid power plant system comprising:
an engine including an exhaust system;
an exhaust cooler in fluid communication with the exhaust system;
a working fluid loop in fluid communication with the exhaust cooler and configured to receive heat from the exhaust system;
a rotary expander arranged in the working fluid loop downstream from the exhaust cooler;
an alternator and a pump configured to be rotationally driven by the rotary expander, the pump arranged in the working fluid loop and configured to pump working fluid therethrough in response to rotation from the rotary expander;
a heater core in fluid communication with the working. fluid loop and operable to transfer heat to the engine; and
a valve operable to bypass the rotary expander and the pump to direct the working fluid from the exhaust cooler to the heater core to supply heat to the engine.
2. The system according to claim 1 , wherein the rotary expander is one of a turbine and a sliding vane expander.
3. The system according to claim 1 , comprising a housing, the rotary expander, the alternator and the pump disposed within the housing providing an integrated unit.
4. The system according to claim 3 , comprising a shaft common to the rotary expander, the alternator and the pump, the shaft configured to be rotationally driven by the rotary expander.
5. The system according to claim 1 , comprising a cooling circuit in fluid communication with the working fluid loop and the alternator configured to cool the alternator with working fluid.
6. A hybrid power plant system comprising:
an engine including an exhaust system;
an exhaust cooler in fluid communication with the exhaust system;
a working fluid loop in fluid communication with the exhaust cooler and configured to receive heat from the exhaust system, and an expander arranged in the working fluid loop;
a first pump configured to be rotationally driven by the expander, the first pump arranged in the working fluid loop and configured to pump working fluid therethrough in response to rotation from the expander; and
a second pump arranged in the working fluid loop and configured to pump the working fluid therethrough in a bypass mode, the bypass mode causing the working fluid to bypass the expander and the first pump in response to an operating condition of the hybrid power plant system.
7. The system according to claim 6 , comprising an alternator coupled to the expander and configured to be rotationally driven by the expander in an operational state, the first and second pumps configured to circulate the working fluid through the expander in the operational state.
8. The system according to claim 7 , comprising a housing, the expander, the alternator and the first pump disposed within the housing providing an integrated unit.
9. The system according to claim 6 , wherein the operating condition is a cold start condition.
10. The system according to claim 9 , comprising a coolant loop in fluid communication with the engine, and a heater core in fluid communication with the coolant loop and the working fluid loop.
11. The system according to claim 10 , wherein the first pump is idled and the second pump is driven in response to the operating condition.
12. The system according to claim 11 , wherein the second pump circulates the working fluid through the heater core in response to the operating condition.
13. The system according to claim 10 , wherein the second pump circulates the working fluid through the heater core in response to the operating condition.
14. A hybrid power plant system comprising:
an engine including an exhaust system;
an exhaust cooler in fluid communication with the exhaust system;
a liquid coolant loop in fluid communication with the engine, the liquid cooling loop including a coolant bypass loop;
a working fluid loop in fluid communication with the exhaust cooler and configured to receive heat from the exhaust system, the working fluid loop including an expander bypass loop;
an expander arranged in the working fluid loop downstream from the exhaust cooler, the expander configured to drive an alternator;
a heater core in fluid communication with the coolant bypass loop and the expander bypass loop;
a bypass control system including at least one control valve arranged in the working fluid loop and configured to divert working fluid in the working fluid loop through the expander bypass loop around the expander and to the heater core in response to an operating condition of the hybrid power plant system; and
a pump arranged in the working fluid loop and driven by the expander in a charging mode, the at least one valve configured to divert working fluid in the working fluid loop through the expander bypass loop around the pump and to the heater core in response to the operating condition.
15. The system according to claim 14 , comprising an HVAC system in fluid communication with a vehicle cabin and configured to provide heat thereto, the HVAC system including the heater core.
16. The system according to claim 14 , comprising a condenser and a reservoir arranged in the working fluid loop and respectively arranged downstream from the expander.
17. The system according to claim 14 , comprising a radiator arranged in the coolant loop, the at least one valve configured to divert working fluid in the liquid coolant loop through the coolant bypass loop around the radiator and from the heater core to the engine in response to the operating condition.
18. The system according to claim 17 , comprising a coolant pump arranged in the coolant loop and configured to circulate coolant therethrough.
19. The system according to claim 14 , wherein the operating condition is a cold start condition.