VEHICLE HEAT PUMP SYSTEM AND METHOD UTILIZING INTERMEDIATE GAS RECOMPRESSION

• US 20140208775A1
• Filed: 01/25/2013
• Published: 07/31/2014
• 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: Styles, Bryan M., Nemesh, Mark D., Eustice, Harry E., Wankhede, Mukund S.
• Granted Patent: US 9,459,028 B2
• Time in Patent Office: Days
• US Class Current: 62/56
• CPC Class Codes: B60H 1/00278 for the battery arrangement of batteries B60R16/04
• CPC Class Codes: B60H 1/00921 where the flow direction of the refrigerant does not change and there is an extra subcondenser, e.g. in an air duct
• 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 2400/0403 for the condenser
• CPC Class Codes: F25B 2400/13 Economisers
• CPC Class Codes: F25B 29/003 of the compression type system
• CPC Class Codes: F25B 30/02 of the compression type
• CPC Class Codes: F25B 5/02 arranged in parallel
• CPC Class Codes: F25B 6/02 arranged in parallel

Abstract

A vehicular heat pump system utilizing intermediate gas recompression is provided. The heat pump system is for use in a vehicle having a battery and a passenger compartment. The heat pump system may include a heating circuit and a cooling circuit each including a compressor having a first inlet and a second inlet and a vapour-liquid separator configured to separate intermediate pressure refrigerant supplied by a first expansion device into refrigerant in a gaseous state flowing therethrough and refrigerant in a liquid state flowing therethrough. The vapor-liquid separator may be configured to selectively inject refrigerant in a gaseous state into the compressor at the second inlet to increase the mass flow rate of the refrigerant. This allows the heat pump system to operate effectively in cold ambient temperatures. A method of operating a heat pump system utilizing intermediate gas recompression is also provided.

Claims

1. A heat pump system for use in a vehicle having a battery and a passenger compartment, the heat pump system comprising:

a heating circuit configured to circulate refrigerant in a first operating mode, to heat the passenger compartment and cool the battery;

a cooling circuit configured to circulate refrigerant in a second operating mode, to condition air received by the passenger compartment and cool the battery;

a compressor having a first inlet and a second inlet, incorporated into each of the heating circuit and the cooling circuit, the compressor configured to compress refrigerant;

a vapor-liquid separator within each of the cooling circuit and the heating circuit configured to separate refrigerant in a gaseous state flowing therethrough from refrigerant in a liquid state flowing therethrough;

a first expansion device within each of the heating circuit and cooling circuit upstream of the vapor-liquid separator configured to supply the vapor-liquid separator with refrigerant in a gaseous state and refrigerant in a liquid state;

and wherein the vapor-liquid separator is configured to transmit and inject refrigerant in a gaseous state into the compressor at the second inlet to increase the mass flow rate of the refrigerant entering the compressor.

2. The heat pump system of claim 1 wherein the heating circuit further includes:

the compressor configured to receive refrigerant at the first inlet and second inlet and further configured to compress the refrigerant; and

a first condenser configured to receive refrigerant from the compressor and further configured to cool and condense the refrigerant.

3. The heat pump system of claim 2 wherein the first condenser is a refrigerant-to-air condenser in heat exchange relation with refrigerant flowing through the first condenser and air flowing across the first condenser.

4. The heat pump system of claim 3 wherein the vapor-liquid separator is an accumulator.

5. The heat pump system of claim 3 wherein the vapor-liquid separator is a combination receiver dryer and vapor-liquid separator.

6. The heat pump condenser of claim 2 wherein the first condenser is a refrigerant-to-coolant condenser having a refrigerant cavity and a coolant cavity, the refrigerant-to-coolant condenser in heat exchange relation with exchange refrigerant flowing through the refrigerant cavity and coolant flowing through the coolant cavity, the refrigerant-to-coolant heat exchanger configured to receive refrigerant from the compressor.

7. The heat pump system of claim 6 wherein the vapor-liquid separator is an accumulator.

8. The heat pump system of claim 6 wherein the vapor-liquid separator is a combination receiver dryer and vapor-liquid separator.

9. The heat pump system of claim 2 wherein the heating circuit further comprises:

a first flow control valve configured to receive refrigerant from the first condenser;

a receiver dryer configured to receive refrigerant from the first flow control valve and further configured to remove moisture from the refrigerant;

a first expansion device configured to allow the refrigerant to cool and expand, the first expansion device further configured to receive refrigerant from the receiver dryer and intermediate pressure refrigerant to the vapor-liquid separator;

wherein the vapor-liquid separator is configured to separate the gaseous refrigerant from the liquid refrigerant from the intermediate pressure refrigerant; and

wherein the vapor-liquid separator is configured to expel liquid refrigerant through the heating circuit.

10. The heat pump system of claim 9 wherein the heating circuit further includes:

a second expansion device configured to receive refrigerant from the liquid-vapor separator;

an RESS chiller configured to act as a heat pump evaporator in heat exchange relation with air surrounding the vehicle battery and the refrigerant, the RESS chiller further configured to receive refrigerant from the second expansion device and expel refrigerant to the compressor;

a third expansion device configured to receive refrigerant from the liquid-vapor separator when dehumidification of the passenger compartment is required; and

a cabin evaporator in heat exchange relation with the refrigerant and the air received by the passenger compartment, the cabin evaporator configured to receive refrigerant from the third expansion device and expel refrigerant to the compressor.

11. The heat pump system of claim 5 wherein the heating circuit further comprises:

a first expansion device configured to receive refrigerant from the first condenser;

a first flow control valve configured to receive refrigerant from the first expansion device;

a combination receiver dryer vapor-liquid separator configured to receive refrigerant from the first flow control valve and further configured to remove moisture from the refrigerant;

wherein the combination receiver dryer vapor-liquid separator is configured to separate the gaseous refrigerant from the liquid refrigerant from the intermediate pressure refrigerant; and

wherein the combination receiver dryer vapor-liquid separator is configured to expel liquid refrigerant through the heating circuit.

12. The heat pump system of claim 11 wherein the heating circuit further includes:

a second expansion device configured to receive refrigerant from the liquid-vapor separator;

an RESS chiller configured to act as a heat pump evaporator in heat exchange relation with air surrounding the vehicle battery and the refrigerant, the RESS chiller further configured to receive refrigerant from the second expansion device and expel refrigerant to the compressor;

a third expansion device configured to receive refrigerant from the liquid-vapor separator when dehumidification of the passenger compartment is required; and

a cabin evaporator in heat exchange relation with the refrigerant and the air received by the passenger compartment, the cabin evaporator configured to receive refrigerant from the third expansion device and expel refrigerant to the compressor.

13. The heat pump system of claim 1 wherein the cooling circuit further includes:

the compressor configured to receive refrigerant at the first inlet and second inlet and further configured to compress the refrigerant;

a second condenser configured to receive refrigerant from the compressor and further configured to condition air received by the passenger compartment;

a first flow control valve configured to receive refrigerant from the second condenser;

a receiver dryer configured to receive refrigerant from the first flow control valve and further configured to remove moisture from the refrigerant;

a first expansion device configured to allow the refrigerant to cool and expand, the first expansion device further configured to receive refrigerant from the receiver dryer and intermediate pressure refrigerant to the vapor-liquid separator;

wherein the vapor-liquid separator is configured to separate the gaseous refrigerant from the liquid refrigerant from the intermediate pressure refrigerant; and

wherein the vapor-liquid separator is configured to expel liquid refrigerant through the cooling circuit.

14. The heat pump system of claim 13 wherein the cooling circuit further includes:

a second expansion device configured to receive refrigerant from the liquid-vapor separator; and

an RESS chiller configured to act as a heat pump evaporator in heat exchange relation with the air surrounding the vehicle battery and the refrigerant, the RESS chiller further configured to receive refrigerant from the second expansion device and expel refrigerant to the compressor.

a third expansion device configured to receive refrigerant from the liquid-vapor separator when dehumidification of the passenger compartment is required; and

a cabin evaporator in heat exchange relation with the refrigerant circulating through the refrigerant loop and the air received by the passenger compartment, the cabin evaporator configured to receive refrigerant from the third expansion device and expel refrigerant to the compressor.

15. The heat pump system of claim 6 further including a coolant loop, the coolant loop including the refrigerant-to-coolant first condenser and a coolant heater core in heat exchange relation with the coolant flowing through the coolant heater core and air flowing across the coolant heater core to the passenger compartment, the coolant heater core further configured to receive coolant from the refrigerant-to-coolant first condenser.

16. The heat pump system of claim 15 wherein the coolant circulating within the coolant loop is directed from the refrigerant-to-coolant first condenser to the coolant heater core and back to the refrigerant-to-coolant first condenser.

17. A method of operating a heat pump system comprising the steps of:

supplying intermediate pressure refrigerant to a vapor-liquid separator with one of a first flow control valve and a first expansion device;

separating the intermediate pressure refrigerant into gaseous refrigerant and liquid refrigerant with a vapor-liquid separator; and

evaluating the pressure of the refrigerant entering a compressor with a controller.

18. The method of claim 17 further comprising the step of:

injecting gaseous refrigerant from the vapor-liquid separator into a compressor to increase the mass flow rate of refrigerant entering the compressor when the refrigerant pressure entering the compressor reaches a minimum threshold value.

19. The method of claim 18 wherein the minimum threshold value ranges from about 0 kPaG to about 150 kPaG.

20. The method of claim 17 further comprising the step of:

metering the injection of gaseous refrigerant into the compressor with a second flow control valve, the second control valve controlled by the controller through an at least one electrical connection.