Wide speed range high-efficiency cold climate heat pump

Patent metadata

Field	Value
Publication number	US-2016290683-A1
Application number	US-201615086500-A
Country	US
Kind code	A1
Filing date	Mar 31, 2016
Priority date	Apr 2, 2015
Publication date	Oct 6, 2016
Grant date	—

Abstract

A heat pump system includes a refrigerant circuit, at least one variable speed compressor operating with a maximum pressure ratio of at least 5.0 and a variable speed range of at least three times (3×), a heat absorption heat exchanger, a heat rejection heat exchanger, an ejector disposed on the refrigerant circuit upstream of the compressor to extend a pressure ratio range and a volumetric flow range of the compressor in the cold climates, a separator disposed downstream of the ejector and upstream of the heat absorption heat exchanger, and at least one variable speed fan configured to move air through the heat rejection heat exchanger to provide a predefined an air discharge temperature greater than 90° F. A two-phase refrigerant is provided to an inlet of the heat absorption heat exchanger with a quality of less than or equal to 0.05.

First claim

1 . A heat pump system for cold climates comprising:
a refrigerant circuit; at least one variable speed compressor operating with a maximum pressure ratio of at least 5.0 and a variable speed range of at least three times (3×); a heat absorption heat exchanger; a heat rejection heat exchanger; an ejector disposed on the refrigerant circuit upstream of the compressor to extend a pressure ratio range and a volumetric flow range of the compressor in the cold climates; a separator disposed downstream of the ejector and upstream of the heat absorption heat exchanger; and at least one variable speed fan configured to move air through the heat rejection heat exchanger to provide a predefined air discharge temperature greater than 90° F., wherein the at least one variable speed compressor, the ejector, and the at least one variable speed fan are configured to provide a two-phase refrigerant to an inlet of the heat absorption heat exchanger with a quality of less than or equal to 0.05.

2 . The heat pump system of claim 1 , further comprising at least one of a sub-critical refrigerant utilized in the refrigerant circuit, and wherein work recovery is only active in a heating mode of the heat pump system.

3 . The heat pump system of claim 1 , further comprising a sub-critical refrigerant utilized in the refrigerant circuit, and wherein work recovery is only active in a heating mode of the heat pump system.

4 . The heat pump system of claim 1 , wherein the at least one compressor is operated at a four times (4×) speed range.

5 . The heat pump system of claim 1 , further comprising a heat transfer loop thermally coupled to the heat rejection heat exchanger, wherein the heat transfer loop circulates a heat exchange medium to a building for thermal conditioning thereof.

6 . The heat pump system of claim 1 , wherein the refrigerant circuit includes a refrigerant with a predefined temperature glide configured to elevate a discharge of the compressor.

7 . The heat pump system of claim 1 , further comprising a super-hydrophobic coating disposed on the heat absorption heat exchanger, the super-hydrophobic coating configured to reduce frost formation thereon.

8 . The heat pump system of claim 1 , wherein the at least one variable speed fan is configured to move air through the heat rejection heat exchanger to provide an air discharge temperature greater than 95° F.

9 . A method of assembling a heat pump system for cold climates, the method comprising:
providing a refrigerant circuit having a heat rejection heat exchanger thermally coupled to a serviced space for heating thereof; coupling at least one variable speed compressor to the refrigerant circuit, the at least one variable speed compressor operating with a maximum pressure ratio of at least 5.0 and a variable speed range of at least three times (3×); coupling a heat absorption heat exchanger to the refrigerant circuit; coupling an ejector to the refrigerant circuit upstream of the compressor to extend a pressure ratio range and a volumetric flow range of the compressor in the cold climates; and providing at least one variable speed fan configured to move air through the heat rejection heat exchanger to provide an air discharge temperature greater than 90° F., wherein the at least one variable speed compressor, the ejector, and the at least one variable speed fan are configured to provide a two-phase refrigerant to an inlet of the heat absorption heat exchanger with a quality of less than or equal to 0.05.

10 . The method of claim 9 , further comprising at least one of:
providing a sub-critical refrigerant in the refrigerant circuit; and operating in a work recovery mode only during a heating mode of the heat pump system.

11 . The method of claim 9 , further comprising:
providing a sub-critical refrigerant in the refrigerant circuit; and operating in a work recovery mode only during a heating mode of the heat pump system.

12 . The method of claim 9 , further comprising:
determining a predefined temperature glide for a refrigerant of the refrigerant circuit; and setting the temperature glide of the refrigerant to the predefined temperature glide.

13 . The method of claim 9 , further comprising disposing a super-hydrophobic coating on the heat absorption heat exchanger, the super-hydrophobic coating configured to reduce frost formation thereon.

14 . The method of claim 9 , wherein the at least one variable speed fan is configured to move air through the heat rejection heat exchanger to provide an air discharge temperature greater than 97° F.

Assignees

• Carrier Corp

Inventors

• Mahmoud Ahmad M
• Verma Parmesh
• Radcliff Thomas D
• Lord Richard G
• Nieter Jeffrey J

Classifications

• F25B2341/0014

  Ejectors with a high pressure hot primary flow from a compressor discharge · CPC title

• F25B2341/0012

  Ejectors with the cooled primary flow at high pressure · CPC title

• F25B2400/23

  Separators · CPC title

• F25B43/00

  Arrangements for separating or purifying gases or liquids (in analysers or rectifiers F25B33/00); Arrangements for vaporising the residuum of liquid refrigerant, e.g. by heat (F25B40/00 takes precedence) · CPC title

• F25B13/00 Primary

  Compression machines, plants or systems, with reversible cycle (defrosting cycles F25B47/02) · CPC title