# US 2014/0190189 A1 · Unitary heat pump air conditioner having a compressed vapor diversion loop

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- Number: US 2014/0190189 A1
- Document ID: US20140190189A1
- Status: Published application
- Kind: A1
- Application number: 14/203,903
- Filed: 2014-03-11
- Published: 2014-07-10
- Earliest claimed: 2011-02-17
- Assignees: Delphi Technologies, Inc.
- Applicants: Delphi Technologies, Inc.
- Inventors: CARRIE M. KOWSKY; PRASAD S. KADLE; FREDERICK V. ODDI; LINDSEY L. LEITZEL
- Web page: https://patentgrep.com/patent/US20140190189A1

## CPC

- F25B 30/02: of the compression type
- B60H 1/00342: {of the liquid-liquid type}
- 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)}
- B60H 1/32284: {comprising two or more secondary circuits, e.g. at evaporator and condenser side}
- B60H 1/3229: {characterised by constructional features, e.g. housings, mountings, conversion systems (B60H1/3227, B60H1/3233 take precedence)}
- F25B 25/005: {using primary and secondary systems}
- F25B 47/022: {hot gas defrosting}
- F25D 21/12: by hot-fluid circulating system separate from the refrigerant system
- F28D 9/005: {the plates having openings therein for both heat-exchange media}
- F28D 9/0093: {Multi-circuit heat-exchangers, e.g. integrating different heat exchange sections in the same unit or heat-exchangers for more than two fluids}
- B60H 2001/00928: {comprising a secondary circuit}
- B60H 2001/00961: {comprising means for defrosting outside heat exchangers}
- F25B 2339/047: Water-cooled condensers
- F25B 2400/0403: for condensers
- F25B 2400/0411: for expansion valves or capillary tubes
- F25B: REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- B60H: ARRANGEMENTS OF HEATING, COOLING, VENTILATING OR OTHER AIR-TREATING DEVICES SPECIALLY ADAPTED FOR PASSENGER OR GOODS SPACES OF VEHICLES
- F25D: REFRIGERATORS; COLD ROOMS; ICE-BOXES; COOLING OR FREEZING APPARATUS NOT OTHERWISE PROVIDED FOR (refrigerated showcases A47F3/04; thermally-insulated vessels for domestic use A47J41/00; refrigerated vehicles, see the appropriate subclasses of classes B60 - B64; containers with thermal insulation in general B65D81/38; heat-transfer, heat-exchange or heat-storage materials, e.g. refrigerants, or materials for the production of heat or cold by chemical reactions other than by combustion C09K5/00; thermally-insulated vessels for liquefied or solidified gases F17C; air-conditioning or air-humidification F24F; refrigeration machines, plants, or systems F25B; cooling of instruments or comparable apparatus without refrigeration G12B)
- F28D: HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT (fluid heaters having heat generating means and heat transferring means F24H; furnaces F27; details of heat-exchange apparatus of general)

## Abstract

Disclosed is a unitary heat pump air conditioner (HPAC) system having a refrigerant diversion loop configured to supply sufficient heat to defrost an external heat exchanger while not materially affecting the supply of heat to the passenger compartment of a vehicle. The HPAC system includes a refrigerant loop configured to pump heat from a cold coolant loop that scavenges heat from the external heat exchanger to a hot coolant loop that supplies heat to the passenger compartment. The refrigerant loop includes a condenser in thermal communication with the hot coolant loop, evaporator in thermal communication with the cold coolant loop, and a compressor to cycle the refrigerant through the refrigerant loop. The refrigerant loop further includes means to selectively divert at least a portion of the hot compressed refrigerant exiting the compressor directly to the evaporator to heat the cold coolant loop sufficient to defrost the external heat exchanger.

## Claims

### Claim 1

A unitary heat pump air conditioner (HPAC) system, comprising:
a refrigerant loop including:
a condenser configured to condense a hot compressed refrigerant into a liquid refrigerant,
an expansion device configured to receive and partially expand the liquid refrigerant from said condenser into a vapor-liquid phase refrigerant,
an evaporator downstream of said expansion device configured to evaporate the vapor-liquid phase refrigerant into a cold vapor refrigerant and is in thermal communication with a cold coolant loop having an external heat exchanger, and
a compressor configured to receive and compress the cold vapor refrigerant from said evaporator into the hot compressed refrigerant to said condenser,
wherein said refrigerant loop includes means to selectively divert at least a portion of said hot compressed refrigerant exiting from said compressor to said evaporator.

### Claim 2 (depends on 1)

The unitary HPAC system of claim 1, wherein said means to selectively divert at least a portion of said hot compressed refrigerant includes a proportioning valve in said refrigerant loop between said compressor and said condenser, wherein said proportioning valve is operative to divert between zero to 100 percent of said hot compressed refrigerant exiting from said compressor to said evaporator.

### Claim 3 (depends on 2)

The unitary HPAC system of claim 2, wherein said means to selectively divert at least a portion of said hot compressed refrigerant includes a refrigerant diversion loop hydraulically connecting said proportioning valve to an inlet of said evaporator.

### Claim 4 (depends on 2)

The unitary HPAC system of claim 2, wherein:
said external heat exchanger is susceptible to frosting, and
said proportioning valve is operative to divert at least a portion of said hot compressed refrigerant to said evaporator to sufficiently provide heat to said cold coolant loop to defrost said external heat exchanger.

### Claim 5 (depends on 3)

The unitary HPAC system of claim 3, wherein said refrigerant loop includes a bypass valve positioned downstream of said condenser and upstream of said expansion device.

### Claim 6 (depends on 5)

The unitary HPAC system of claim 5, wherein said bypass valve is operative to bypass the liquid refrigerant exiting said condenser directly to said evaporator.

### Claim 7 (depends on 5)

The unitary HPAC system of claim 5, wherein said bypass valve is operative to bypass the liquid refrigerant exiting said condenser to said diversion loop when said proportioning valve is diverting less than 100 percent of hot compressed refrigerant from said compressor.

### Claim 8 (depends on 1)

The unitary HPAC system of claim 1, wherein:
said external heat exchanger is susceptible to frosting, and
said means to selectively divert at least a portion of said hot compressed refrigerant exiting from said compressor directly to said evaporator is operative to provide sufficient heat energy to said cold coolant loop to defrost said external heat exchanger.

### Claim 9 (depends on 1)

The unitary HPAC system of claim 1, wherein said means to selectively divert at least a portion of said hot compressed refrigerant includes:
a proportioning valve configured to selectively divert at least a portion of the hot compressed refrigerant exiting from said compressor to said evaporator,
a refrigerant diversion loop hydraulically connecting said proportioning valve to inlet of said evaporator; and
a bypass valve operative to bypass the liquid refrigerant exiting said condenser to said refrigerant diversion loop when said proportioning valve is diverting less than 100 percent of hot compressed refrigerant from said compressor.

### Claim 10

A method for defrosting an external heat exchanger of a unitary heat pump air conditioner (HPAC) system, comprising the steps of:
providing a refrigerant loop having:
a condenser configured to condense a hot compressed refrigerant into a liquid refrigerant,
an expansion device configured to receive and partially expand the liquid refrigerant from said condenser into a vapor-liquid phase refrigerant,
an evaporator downstream of said expansion device configured to evaporate the vapor-liquid phase refrigerant into a cold vapor refrigerant, and
a compressor configured to receive and compress the cold vapor refrigerant from said evaporator into the hot compressed refrigerant for said condenser;
providing a cold coolant loop in thermal communication with said evaporator and said external heat exchanger;
diverting at least a portion of said hot compressed refrigerant exiting from said compressor to said evaporator to transfer sufficient heat from said hot compressed refrigerant to said cold coolant loop to defrost said external heat exchanger.

### Claim 11 (depends on 10)

A method for defrosting an external heat exchanger of a unitary heat pump air conditioner (HPAC) system of claim 10, further comprising the steps of:
providing a refrigerant diversion loop hydraulically connecting the exit of the compressor to the inlet of the evaporator;
providing a refrigerant proportion valve configured to selectively divert at least a portion of said hot compressed refrigerant exiting from said compressor to said inlet of said evaporator;
detecting said frosting of said external heat exchanger; and
diverting a sufficient portion of aid hot compressed refrigerant to said evaporator to provide sufficient heat to defrost said external heat exchanger.

### Claim 12

A unitary heat pump air conditioner (Unitary HPAC), comprising:
a refrigerant loop having a condenser for condensing a high pressure vapor,
an evaporator downstream of said condenser for evaporating a low pressure liquid refrigerant, and
a compressor for receiving a low pressure vapor refrigerant from said evaporator and discharging a high pressure vapor refrigerant to said condenser;
a cold side heat exchanger configured to hydraulically connect to a cold side coolant loop, wherein said cold side heat exchanger is in thermal communication with said evaporator;
a hot heat exchanger configured to hydraulically connect to a hot side coolant loop, wherein said hot heat exchanger is in thermal communication with said condenser; and
a refrigerant diversion loop hydraulically connecting the hot compressed refrigerant exiting from said compressor to said evaporator.

### Claim 13 (depends on 12)

The unitary heat pump air conditioner (Unitary HPAC) of claim 12, wherein said refrigerant diversion loop includes a proportioning valve configured to selectively divert at least a portion of the hot compressed refrigerant exiting from said compressor to said evaporator.

### Claim 14 (depends on 12)

The unitary heat pump air conditioner (Unitary HPAC) of claim 12, wherein said refrigerant loop includes a bypass valve operative to bypass the liquid refrigerant exiting said condenser to said diversion loop when said proportioning valve is diverting less than 100 percent of hot compressed refrigerant from said compressor to said condenser.