HEAT PUMP

• US 20170248349A1
• Filed: 01/08/2016
• Published: 08/31/2017
• Est. Priority Date: 01/09/2015
• Status: Active Grant

• Current Assignee: Trane International Inc. (Trane Technologies plc)
• Original Assignee: Trane International Inc. (Trane Technologies plc)
• Inventors: KUJAK, Stephen A., SCHULTZ, Kenneth J., COSBY, II, Ronald Maurice
• Granted Patent: US 10,443,900 B2
• Time in Patent Office: Days
• CPC Class Codes: F24H 4/02 Water heaters
• CPC Class Codes: F25B 13/00 Compression machines, plants or systems, with reversible cycle defrosting cycles F25B47/02
• CPC Class Codes: F25B 2313/0252 with bypasses
• CPC Class Codes: F25B 2313/0253 in parallel arrangements
• CPC Class Codes: F25B 2339/047 Water-cooled condensers
• CPC Class Codes: F25B 2400/0403 for the condenser
• CPC Class Codes: F25B 2500/31 Low ambient temperatures
• CPC Class Codes: F25B 2600/2501 Bypass valves
• CPC Class Codes: F25B 45/00 Arrangements for charging or discharging refrigerant
• CPC Class Codes: F25B 5/04 arranged in series
• CPC Class Codes: F25B 7/00 Compression machines, plants or systems, with cascade operation, i.e. with two or more circuits, the heat from the condenser of one circuit being absorbed by the evaporator of the next circuit F25B9/00 takes precedence
• CPC Class Codes: F25B 9/002 characterised by the refrigerant
• CPC Class Codes: F25B 9/008 the refrigerant being carbon dioxide
• CPC Class Codes: F25B 9/10 with several cooling stages

Abstract

Embodiments as disclosed herein are directed to a heat pump that employs at least two different refrigerants, each of which is optimized for either a cooling operation mode or a heating operation mode. The embodiments as disclosed herein can help increase the capacity and/or efficiency of a heat pump in both the cooling operation mode and the heating operation mode. In addition, the embodiments as disclosed herein may also eliminate the need for a ground source in a relatively low ambient temperature environment.

Claims

1. A heat pump system, comprising:

a first refrigeration circuit having a first refrigerant, the first refrigeration circuit including a compressor, a flow reversing device in fluid communication with the compressor, a first heat exchanger in fluid communication with the flow reversing device in a heating operation mode, an expansion device in fluid communication with the first heat exchanger in the heating operation mode, a second heat exchanger in communication with the expansion device in the heating operation mode, the second heat exchanger is in fluid communication with the flow reversing device in the heating operation mode to return the first refrigerant to the compressor,

the second heat exchanger is in fluid communication with the flow reversing device in an operation mode different from the heating operation mode, the expansion device is in fluid communication with the second heat exchanger in the operation mode, the first heat exchanger is in fluid communication with the expansion device in the operation mode, the first heat exchanger is in fluid communication with the flow reversing device to return the first refrigerant to the compressor;

a second refrigeration circuit having a second refrigerant, the second refrigerant circuit including a compressor, a first heat exchanger in fluid communication with the compressor, an expansion device in fluid communication with the first heat exchanger, a second heat exchanger in fluid communication with the expansion device and in fluid communication with the compressor to return the second refrigerant to the compressor; and

a capacity boost circuit that forms a heat exchange relationship between the first refrigerant and the second refrigerant, the capacity boost circuit is formed by a first flow regulating device in fluid communication with the second heat exchanger of the first refrigeration circuit, and which is in fluid communication with the first heat exchanger of the second refrigeration circuit, and a second flow regulating device in fluid communication with the first heat exchanger of the second refrigeration circuit, wherein, in the capacity boost circuit, the first refrigerant forms a heat exchange relationship with the second refrigerant through the first heat exchanger of the second refrigeration circuit to provide a capacity boost to the first refrigeration circuit through the heat exchange relationship of the first refrigerant and the second refrigerant.

2. The heat pump system of claim 1, wherein, in the capacity boost circuit, the first heat exchanger of the second refrigeration circuit is configured to receive at least a portion of the second refrigerant, the first heat exchanger of the second refrigeration circuit is configured to receive at least a portion of the first refrigerant, and the portion of the first refrigerant and the portion of the second refrigerant form the heat exchange relationship in the first heat exchanger of the second refrigeration circuit,

the portion of the first refrigerant is either expanded or compressed refrigerant, and the portion of the second refrigerant is either compressed or expanded refrigerant.

3. The heat pump system of claim 1, further comprising a hot water heat exchanger in fluid communication with the first heat exchanger of the second refrigeration circuit, the hot water heat exchanger is configured to receive at least a portion of the second refrigerant compressed by the compressor of the second refrigeration circuit, to transfer heat from the second refrigerant to a fluid directed into the hot water heat exchanger, and to direct the portion of the second refrigerant to the first heat exchanger of the second refrigeration circuit.

4. The heat pump system of claim 3, further comprising a bypass valve in fluid communication with the compressor of the second refrigeration circuit and the hot water heat exchanger.

5. The heat pump system of claim 1, further comprising a thermal storage circuit in fluid communication with the second heat exchanger of the first refrigeration circuit and in fluid communication with the first heat exchanger of the first refrigeration circuit, the thermal storage circuit is configured to receive a portion of the first refrigerant from the capacity boost circuit, where, in the capacity boost circuit, the portion of the first refrigerant is in heat exchange relationship with a portion of expanded refrigerant of the second refrigerant.

6. The heat pump system of claim 5, wherein the second refrigeration circuit includes a flow reversing device.

7. The heat pump system of claim 1, wherein the first refrigerant is a HFC or HFC/HFO blend with a low global warming potential.

8. The heat pump system of claim 1, wherein the second refrigerant is R744 or other refrigerant that has a higher critical temperature than the first refrigerant.

9. The heat pump system of claim 1, wherein the first heat exchanger of the first refrigeration circuit is an indoor heat exchanger, and the second heat exchanger of the first refrigeration circuit is an outdoor heat exchanger.

10. The heat pump system of claim 1, wherein the capacity boost circuit boosts the capacity of the first refrigerant in the heating operation mode of the first refrigeration circuit.

11. The heat pump system of claim 3, wherein the first and second flow regulating devices of the capacity boost circuit are closed in a cooling operation mode of the first refrigeration circuit.

12. (canceled)

13. (canceled)

14. A method of boosting capacity of a main refrigeration circuit, comprising:

replacing a refrigerant in a first refrigeration circuit with a first refrigerant; and

coupling the first refrigeration circuit to a second refrigeration circuit, the second refrigeration circuit has a second refrigerant different from the first refrigerant;

the coupling includes fluidly communicating the first refrigeration circuit with a capacity boost circuit having a heat exchanger, and fluidly communicating the second refrigeration circuit with the capacity boost circuit, forming a heat exchange relationship between the first refrigerant and the second refrigerant through the heat exchanger of the capacity boost circuit,

wherein the second refrigerant is to boost the capacity of the first refrigerant during operation of the first refrigeration circuit.