Vehicle heat pump system and method utilizing thermal storage

• US 9,327,577 B2
• Filed: 01/25/2013
• Issued: 05/03/2016
• Est. Priority Date: 01/25/2013
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations LLC (General Motors Company)
• Inventors: Lombardo, Paul S., Ziehr, Lawrence P., Lemon, Brian P., Nemesh, Mark D., Styles, Bryan M.
• Primary Examiner(s): Ciric, Ljiljana
• Assistant Examiner(s): OSWALD, KIRSTIN U
• Application Number:
  US13/750,421
• Publication Number:
  US 20140208789A1
• Time in Patent Office: 1,194 Days
• Field of Search: 165/64, 622/386, 622/381, 622/387, 624/30, 623/33
• US Class Current: 1/1
• CPC Class Codes: B60H 1/00007 Combined heating, ventilating, or cooling devices control systems or mechanisms B60H1/00642
• CPC Class Codes: B60H 1/00278 for the battery arrangement of batteries B60R16/04
• CPC Class Codes: B60H 1/00807 the input being a specific way of measuring or calculating an air or coolant temperature
• CPC Class Codes: B60H 1/00899 Controlling the flow of liquid in a heat pump system controlling the properties of the refrigerant liquid, e.g. pressure or temperature, B60H1/3204
• CPC Class Codes: B60H 2001/00307 Component temperature regulation using a liquid flow
• CPC Class Codes: B60H 2001/00949 comprising additional heating/cooling sources, e.g. second evaporator
• CPC Class Codes: F25B 2339/047 Water-cooled condensers
• CPC Class Codes: F25B 2400/24 Storage receiver heat
• CPC Class Codes: F25B 25/005 using primary and secondary systems
• CPC Class Codes: F25B 41/39 Dispositions with two or more expansion means arranged in series, i.e. multi-stage expansion, on a refrigerant line leading to the same evaporator
• CPC Class Codes: F25B 5/02 arranged in parallel
• CPC Class Codes: F25B 6/02 arranged in parallel

Abstract

A heat pump system, including a thermal storage medium, for use in a vehicle having a passenger compartment, and a corresponding method for providing heat to a vehicle passenger compartment. The vehicle may have an electric only vehicle mode wherein the vehicle may occupy one of an active electric drive state and an inactive state. The heat pump system may include a thermal storage medium configured to store heat produced during the inactive state. The thermal storage medium may be a device which has a thermal capacity exchangeable with a fluid medium such as an Rechargeable Energy Storage System (RESS) or a phase change material. The heat stored by the thermal storage medium during the vehicle charge event may be transmitted from the thermal storage medium to the passenger compartment via the heat pump system during the active electric drive state.

Claims

1. A heat pump system for use in a vehicle having a passenger compartment for receiving conditioned air, an engine, and a rechargeable vehicle battery, the system comprising:

a first coolant circuit configured to circulate a first coolant, the first coolant circuit including;

a heater configured to heat the first coolant;

a thermal storage medium positioned about and immediately surrounding the rechargeable vehicle battery, the thermal storage medium configured to receive and store heat produced by charging the rechargeable vehicle battery, such that the first coolant absorbs the heat stored in the thermal storage medium, wherein the thermal storage medium is a phase change material; and

a first heat exchanger having a first coolant cavity and a refrigerant cavity, such that the first coolant is configured to circulate through the first coolant cavity;

a refrigeration circuit in heat exchange relation with the first coolant circuit via the first heat exchanger, the refrigeration circuit further configured to circulate a refrigerant through the refrigerant cavity of the first heat exchanger, such that the refrigerant is configured to absorb stored heat from the first coolant circulating within the first coolant circuit and further configured to condition the air to be received by the passenger compartment;

a second coolant circuit configured to circulate a second coolant, the second coolant circuit in heat exchange relation with the refrigerant circuit via a second heat exchanger, wherein the second heat exchanger includes a refrigerant cavity and a coolant cavity, and the second heat exchanger is configured to exchange heat between the refrigerant flowing through the refrigerant cavity of the second heat exchanger and the second coolant flowing through the coolant cavity of the second heat exchanger, such that the heat absorbed by the refrigerant within the refrigeration circuit from the first coolant within the first coolant circuit is transferred to the second coolant within the second coolant circuit via the second heat exchanger; and

wherein the heat stored in the thermal storage medium is transferred to the conditioned air received by the passenger compartment via the first coolant circuit, the refrigeration circuit, and the second coolant circuit.

2. The heat pump system of claim 1 wherein the vehicle has one of an active drive state and an inactive state.

3. The heat pump system of claim 2 wherein the thermal storage medium is configured to receive and store heat produced by charging the rechargeable vehicle battery during the inactive state;

and wherein the heat stored in the thermal storage medium during the inactive state is transferred to the vehicle passenger compartment via the first coolant circuit, the refrigeration circuit, and the second coolant circuit during the active drive state.

4. The heat pump system of claim 1 wherein the phase change material has a thermal capacity exchangeable with a fluid medium.

5. The heat pump system of claim 1 wherein the phase change material is selected from a group consisting of an eutectic, salt hydrate, and organic material.

6. The heat pump system of claim 1 wherein the rechargeable vehicle battery has an outermost perimeter, and wherein the phase change material is positioned about the outermost perimeter, such that the phase change material immediately surrounds the entirety of the outermost perimeter.

7. The heat pump system of claim 1 wherein the refrigeration circuit includes:

a compressor configured to compress the refrigerant; and

the second heat exchanger configured to exchange heat between the refrigerant flowing through the refrigerant cavity of the second heat exchanger and the second coolant flowing through the coolant cavity of the second heat exchanger.

8. The heat pump system of claim 7 wherein the refrigeration circuit further includes:

a first expansion device configured to receive refrigerant from the refrigerant cavity of the second heat exchanger and further configured to allow the refrigerant to cool and expand; and

the first heat exchanger configured to receive refrigerant from the first expansion device and expel refrigerant to the compressor, the first heat exchanger further configured to exchange heat between the refrigerant and the first coolant.

9. The heat pump system of claim 7 wherein the refrigeration circuit further includes:

a second expansion device configured to receive refrigerant from the refrigerant cavity of the second heat exchanger and further configured to allow the refrigerant to cool and expand; and

a third heat exchanger configured to receive refrigerant from the second expansion device and expel refrigerant to the compressor, the third heat exchanger further configured to exchange heat from the refrigerant to the air flowing across the third heat exchanger and to the passenger compartment to cool and dehumidify the passenger compartment.

10. The heat pump system of claim 1 wherein the second coolant circuit further includes:

a heater core configured to heat air flowing across the heater core and into the passenger compartment; and

a bypass valve configured to receive the second coolant from the coolant heater core and further configured to direct the second coolant to one of the second heat exchanger and the engine.

11. The heat pump system of claim 10 wherein the bypass valve directs refrigerant to the second heat exchanger to bypass the engine.

12. The heat pump system of claim 10 wherein the bypass valve directs the second coolant to the engine.

13. A method of heating a vehicle passenger compartment comprising the steps of:

providing a heat pump system for use in a vehicle having rechargeable vehicle battery, wherein the heat pump system includes;

a first coolant circuit configured to circulate a first coolant, the first coolant circuit including;

a heater configured to heat the first coolant;

a thermal storage medium positioned about and immediately surrounding the rechargeable vehicle battery, the thermal storage medium configured to receive and store heat produced by charging the rechargeable vehicle battery, such that the first coolant absorbs the heat stored in the thermal storage medium, wherein the thermal storage medium is a phase change material; and

a first heat exchanger having a first coolant cavity and a refrigerant cavity, such that the first coolant is configured to circulate through the first coolant cavity;

a refrigeration circuit in heat exchange relation with the first coolant circuit via the first heat exchanger, the refrigeration circuit further configured to circulate a refrigerant through the refrigerant cavity of the first heat exchanger; and

a second coolant circuit configured to circulate a second coolant, the second coolant circuit in heat exchange relation with the refrigerant circuit via a second heat exchanger, wherein the second heat exchanger includes a refrigerant cavity and a coolant cavity, and the second heat exchanger is configured to exchange heat between the refrigerant flowing through the refrigerant cavity of the second heat exchanger and the second coolant flowing through the coolant cavity of the second heat exchanger;

storing heat in the thermal storage medium during a vehicle charge event; and

transferring the heat stored in the thermal storage medium from the thermal storage medium to the vehicle passenger compartment to heat the vehicle passenger compartment via the first coolant circuit, the second coolant circuit, and the refrigeration circuit.

14. The method of claim 13 wherein transferring the heat stored in the thermal storage medium from the thermal storage medium to the vehicle passenger compartment via the first coolant circuit, the second coolant circuit, and the refrigeration circuit, includes the steps of:

absorbing the heat stored in the thermal storage medium with the first coolant circulating through the first coolant circuit;

exchanging heat between the first coolant and the refrigerant flowing through the refrigeration circuit with the first heat exchanger;

transferring heat from the refrigerant flowing through the refrigeration circuit to the second coolant flowing through the second coolant circuit with the second heat exchanger;

circulating the second coolant through a heater core; and

transferring heat from the second coolant and the heater core to the air flowing across the heater core and into the vehicle passenger compartment to heat the vehicle passenger compartment.

15. The method of claim 14 wherein the vehicle has an active electric drive state and an inactive electric charging state;

wherein the vehicle charge event occurs during the inactive electric charging state, such that heat is transferred to and stored in the thermal storage medium during the inactive electric charging state; and

wherein the heat stored in the thermal storage medium is transferred from the thermal storage medium to the vehicle passenger compartment via the first coolant circuit, the second coolant circuit, and the refrigeration circuit during the active electric drive state.

16. The method of claim 13 wherein the phase change material is selected from a group consisting of an eutectic, salt hydrate, and organic material.

17. The method of claim 13 wherein the rechargeable vehicle battery has an outermost perimeter, and wherein the phase change material is positioned about the outermost perimeter, such that the phase change material surrounds the entirety of the outermost perimeter.