Engine cooling configurations with waste heat recovery system
View Patent ↗A vehicle has a waste heat recovery (WHR) system and an engine. The WHR system includes a WHR working fluid circuit with a pump, a power turbine, and a condenser. An engine coolant circuit circulates coolant between the engine and an engine coolant heat exchanger/working fluid boiler in the WHR working fluid circuit. At least one exhaust gas heat exchanger/superheater in the WHR working fluid circuit receives waste heat from an exhaust circuit and/or from an exhaust gas recirculation circuit. A working fluid cooled charge air cooler in the WHR working fluid circuit receives waste heat from compressed charge air in a charge air intake circuit. A recuperator may transfer waste heat from working fluid passing from the power turbine to the condenser to working fluid passing from the working fluid cooled charge air cooler to the engine coolant heat exchanger/working fluid boiler.
1. A vehicle having a waste heat recovery (WHR) system, comprising:
an engine;
a WHR working fluid circuit having a working fluid pump, a power turbine, and a working fluid condenser;
an engine coolant circuit circulating engine coolant between the engine and an engine coolant heat exchanger or working fluid boiler, the engine coolant heat exchanger or working fluid boiler being arranged between the working fluid pump and the power turbine in the WHR working fluid circuit;
at least one exhaust gas heat exchanger or superheater arranged between the engine coolant heat exchanger or working fluid boiler and the power turbine in the WHR working fluid circuit, the at least one exhaust gas heat exchanger or superheater receiving exhaust gas from at least one of an exhaust circuit and an exhaust gas recirculation (EGR) circuit;
a charge air intake circuit conducting charge air from a turbocharger through a working fluid cooled charge air cooler to an engine charge air intake manifold, the working fluid cooled charge air cooler being arranged one of:
between the working fluid pump and the engine coolant heat exchanger or working fluid boiler in the WHR working fluid circuit; and
in parallel with the engine coolant heat exchanger or working fluid boiler in the WHR working fluid circuit; wherein
the working fluid cooled charge air cooler is arranged between the working fluid pump and the engine coolant heat exchanger or working fluid boiler in the WHR working fluid circuit; and
a recuperator is arranged in the WHR working fluid circuit between the working fluid cooled charge air cooler and the engine coolant heat exchanger or working fluid boiler and between the power turbine and the working fluid condenser, the recuperator being operable to transfer waste heat from working fluid passing from the power turbine to the working fluid condenser to working fluid passing from the working fluid cooled charge air cooler to the engine coolant heat exchanger or working fluid boiler.
2. The vehicle of claim 1 , further comprising:
at least one bypass circuit within the WHR working fluid circuit selectively bypassing at least one of:
at least one of the exhaust gas heat exchanger or superheaters; and the working fluid cooled charge air cooler.
3. The vehicle of claim 1 , wherein:
the at least one exhaust gas heat exchanger or superheater further comprises a first exhaust gas heat exchanger or superheater and a second exhaust gas heat exchanger or superheater;
the exhaust gas circuit including at least one exhaust aftertreatment device and the first exhaust gas heat exchanger or superheater, the first exhaust gas heat exchanger or superheater being arranged in the WHR working fluid circuit between the engine coolant heat exchanger or working fluid boiler and the second exhaust gas heat exchanger or superheater; and
the EGR circuit recirculating exhaust gas from an engine exhaust manifold to an engine charge air intake manifold by way of the second exhaust gas heat exchanger or superheater, the second exhaust gas heat exchanger or superheater being arranged in the WHR working fluid circuit between the first exhaust gas heat exchanger or superheater and the power turbine.
4. The vehicle of claim 1 , wherein at least one of:
the working fluid condenser is one of air cooled and liquid cooled;
the WHR working fluid circuit uses one of water and organic fluid;
the working fluid pump is one of variable speed and variable displacement;
the power turbine being one of mechanically connected to a driveline, used to power a generator, and used to power a vehicle subsystem or accessory; and
the WHR working fluid circuit includes at least one additional heat exchanger in communication with one of a vehicle cabin heater, a vehicle cabin air conditioner, and an auxiliary power unit (APU).
5. The vehicle of claim 1 , wherein:
the engine coolant circuit further includes an auxiliary engine coolant radiator circuit having an auxiliary engine coolant radiator, engine coolant flow through the auxiliary engine coolant radiator circuit being controlled by an auxiliary engine coolant radiator bypass valve.
6. A waste heat recovery (WHR) system, comprising:
a WHR working fluid circuit having a working fluid pump, a power turbine, and a working fluid condenser;
an engine coolant heat exchanger or working fluid boiler in fluid communication with an engine coolant circuit of an engine, the engine coolant heat exchanger or working fluid boiler being arranged between the working fluid pump and the power turbine in the WHR working fluid circuit;
at least one exhaust gas heat exchanger or superheater receiving exhaust gas from at least one of an exhaust circuit and an exhaust gas recirculation (EGR) circuit of the engine, the at least one exhaust gas heat exchanger or superheater being arranged between the engine coolant heat exchanger or working fluid boiler and the power turbine in the WHR working fluid circuit;
a working fluid cooled charge air cooler in fluid communication with a charge air intake circuit conducting charge air from a turbocharger to an engine charge air intake manifold of the engine, the working fluid cooled charge air cooler being arranged one of:
between the working fluid pump and the engine coolant heat exchanger or working fluid boiler in the WHR working fluid circuit; and
in parallel with the engine coolant heat exchanger or working fluid boiler in the WHR working fluid circuit, wherein;
the working fluid cooled charge air cooler is arranged between the working fluid pump and the engine coolant heat exchanger or working fluid boiler in the WHR working fluid circuit and a recuperator is arranged in the WHR working fluid circuit between the working fluid cooled charge air cooler and the engine coolant heat exchanger or working fluid boiler and between the power turbine and the working fluid condenser, the recuperator bring operable to transfer waste heat from working fluid passing from the power turbine to the working fluid condenser to working fluid passing from the working fluid cooled charge air cooler to the engine coolant heat exchanger or working fluid boiler.
7. The WHR system of claim 6 , further comprising:
at least one bypass circuit within the WHR working fluid circuit selectively bypassing at least one of:
at least one of the exhaust gas heat exchanger or superheaters; and the working fluid cooled charge air cooler.
8. The WHR system of claim 6 , wherein:
the at least one exhaust gas heat exchanger or superheater further comprises a first exhaust gas heat exchanger L or superheater and a second exhaust gas heat exchanger or superheater;
the first exhaust gas heat exchanger or superheater being in fluid communication with the exhaust circuit and being arranged in the WHR working fluid circuit between the engine coolant heat exchanger or working fluid boiler and the second exhaust gas heat exchanger or superheater; and
the second exhaust gas heat exchanger or superheater being in fluid communication with the EGR circuit and being arranged in the WHR working fluid circuit between the first exhaust gas heat exchanger or superheater and the power turbine.
9. The WHR system of claim 6 , wherein at least one of:
the working fluid condenser is one of air cooled and liquid cooled;
the WHR working fluid circuit uses one of water and organic fluid;
the working fluid pump is one of variable speed and variable displacement;
the power turbine being one of mechanically connected to a vehicle driveline, used to power a generator, and used to power a vehicle subsystem or accessory; and
the WHR working fluid circuit includes at least one additional heat exchanger in communication with one of a vehicle cabin heater, a vehicle cabin air conditioner, and an auxiliary power unit (APU).
10. The WHR system of claim 6 , wherein:
the engine coolant circuit further includes an auxiliary engine coolant radiator circuit having an auxiliary engine coolant radiator, engine coolant flow through the auxiliary engine coolant radiator circuit being controlled by an auxiliary engine coolant radiator bypass valve.
11. A method for recovering waste heat in a vehicle, comprising the steps of:
providing a WHR working fluid circuit having a working fluid pump, a power turbine, and a working fluid condenser;
arranging an engine coolant heat exchanger or working fluid boiler between the working fluid pump and the power turbine in the WHR working fluid circuit;
circulating engine coolant between an engine of the vehicle and the engine coolant heat exchanger or working fluid boiler;
arranging at least one exhaust gas heat exchanger or superheater between the engine coolant heat exchanger or working fluid boiler and the power turbine in the WHR working fluid circuit;
and routing exhaust gas from at least one of an exhaust circuit and an exhaust gas recirculation (EGR) circuit through the at least one exhaust gas heat exchanger or superheater;
arranging a working fluid cooled charge air cooler between the working fluid pump and the engine coolant heat exchanger or working fluid boiler in the WHR working fluid circuit and conducting charge air from a turbocharger through the working fluid cooled charge air cooler to an engine charge air intake manifold of the engine of the vehicle;
arranging a recuperator in the WHR working fluid circuit between the working fluid cooled charge air cooler and the engine coolant heat exchanger or working fluid boiler and between the power turbine and the working fluid condenser; and
transferring waste heat from working fluid passing from the power turbine to the working fluid condenser to working fluid passing from the working fluid cooled charge air cooler to the engine coolant heat exchanger or working fluid boiler.
12. The method of claim 11 , further comprising the steps of:
arranging at least one bypass circuit within the WHR working fluid circuit and selectively bypassing at least one of:
at least one of the exhaust gas heat exchanger or superheaters; and
the working fluid cooled charge air cooler.
13. The method of claim 11 , further comprising the steps of:
arranging a first exhaust gas heat exchanger or superheater and a second exhaust gas heat exchanger or superheater between the engine coolant heat exchanger or working fluid boiler and the power turbine in the WHR working fluid circuit;
routing exhaust gas from the engine through at least one exhaust aftertreatment device and through the first exhaust gas heat exchanger or superheater; and
routing recirculating exhaust gas from an engine exhaust manifold through the second exhaust gas heat exchanger or superheater to an engine charge air intake manifold.
14. The method of claim 11 , further comprising at least one of the steps of:
one of air cooling and liquid cooling the working fluid condenser;
circulating one of water and organic fluid in the WHR working fluid circuit;
configuring the working fluid pump as one of a variable speed working fluid pump and a variable displacement working fluid pump;
one of mechanically connecting the power turbine to a driveline of the vehicle, using the power turbine to power a generator, and using the power turbine to power a vehicle subsystem or accessory; and
including at least one additional heat exchanger in the WHR working fluid circuit and placing the at least one additional heat exchanger in communication with one of a vehicle cabin heater, a vehicle cabin air conditioner, and an auxiliary power unit (APU).