US-20260126199-A1 - SYSTEMS AND METHODS FOR DEFROSTING AN OUTDOOR HEAT EXCHANGER OF A HEAT PUMP

US20260126199A1US 20260126199 A1US20260126199 A1US 20260126199A1US-20260126199-A1

Abstract

An embodiment of a thermal storage module installable on a climate control system. The thermal storage module is an independent device that can be mountable between an outdoor unit and an indoor unit of the climate control system. The thermal storage module may include a fluid tank, a fluid pump, a heat exchanger for exchanging thermal energy between the working fluid and a refrigerant flow within the refrigerant circuit, an expansion valve and a solenoid valve, and a controller. The fluid pump is activated when the climate control system is operating in a heating mode and a defrost mode and is deactivated when the climate control system is operating in a cooling mode. The operation of the expansion valve and solenoid valve depends on the operation mode (cooling/heating/defrosting) of the main climate control system.

Inventors

Min CHE
Wayne N. Kraft
Behrooz Karimi

Assignees

TRANE INTERNATIONAL INC.

Dates

Publication Date: 20260507
Application Date: 20251230

Claims (20)

1 . A thermal storage module in fluid communication with an outdoor unit and an indoor unit of a climate control system, the climate control system comprising a refrigerant circuit for directing a refrigerant flowing between the indoor unit and the outdoor unit, the outdoor unit comprising a compressor, wherein the thermal storage module comprises: a fluid tank containing a thermal energy storage fluid; a fluid pump configured to circulate a working fluid through the fluid tank, the working fluid exchanging thermal energy with the thermal energy storage fluid; a heat exchanger fluidly coupled to the refrigerant circuit between the outdoor unit and the indoor unit, the heat exchanger configured to exchange thermal energy between the working fluid and a refrigerant flow within the refrigerant circuit; an expansion valve coupled to the refrigerant circuit between the heat exchanger and the outdoor unit; and a controller configured to control the fluid pump based on an operation mode of the climate control system, wherein the fluid pump is configured to be activated when the climate control system is operating in a heating mode or in a defrosting mode, and the fluid pump is configured to be deactivated when the climate control system is operating in a cooling mode; and wherein the thermal storage module is separate from the indoor unit and the outdoor unit and located along the refrigerant circuit therebetween.
2 . The thermal storage module of claim 1 , wherein: the controller is configured to activate or deactivate the fluid pump based on mode of operation signals received from the climate control system; and the thermal energy storage fluid is a phase-change material.
3 . The thermal storage module of claim 1 , further comprising a solenoid valve coupled to the refrigerant circuit between the heat exchanger and the indoor unit, the solenoid valve configured to bypass the refrigerant such that the refrigerant is prevented from flowing into the indoor unit when the climate control system is in a defrost mode.
4 . The thermal storage module of claim 3 , wherein the controller is configured to open or close the expansion valve and the solenoid valve based on an operation mode of the control system, the operation mode selected from heating mode, cooling mode, and defrost mode, such that: upon receiving a control signal from the climate control system that the climate control system is operating in heating mode, the controller is configured to open the expansion valve and close the solenoid valve; upon receiving a control signal from the climate control system that the climate control system is operating in cooling mode, the controller is configured to open the expansion valve and close the solenoid valve; and upon receiving a control signal from the climate control system that the climate control system is operating in defrost mode, the controller is configured to open the expansion valve and open the solenoid valve.
5 . The thermal storage module of claim 3 , wherein, when the climate control system is in a heating mode: the expansion valve is opened and the solenoid valve is closed; the refrigerant is directed from the compressor along the refrigerant circuit to the indoor coil of the indoor unit, the heat exchanger of the thermal storage module, the outdoor coil of the outdoor unit, and back to the compressor; the fluid pump is activated to facilitate heat transfer from the refrigerant to fluid stored in the fluid tank via the heat exchanger; and the fluid pump is deactivated to stop the heat transfer from the refrigerant to the thermal energy storage fluid stored in the fluid tank via the heat exchanger, when a predetermined amount of heat has been stored in the tank.
6 . The thermal storage module of claim 1 , wherein, when the climate control system is in a defrost mode; both the expansion valve and the solenoid valve are opened; and the refrigerant is directed from the compressor along the refrigerant circuit to an outdoor coil of the outdoor unit, to the heat exchanger, and back to the compressor via the solenoid valve so as to bypass the indoor unit.
7 . The thermal storage module of claim 6 , wherein, when the climate control system is in a defrost mode: the fluid pump is activated to facilitate heat transfer from the fluid in the fluid tank to the refrigerant via the heat exchanger; and the heat exchanger operates as an evaporator to heat the refrigerant for defrosting the outdoor coil of the outdoor unit.
8 . A climate control system, comprising: an indoor unit; an outdoor unit; a refrigerant circuit for directing a refrigerant flowing between the indoor unit and the outdoor unit, the outdoor unit comprising a compressor; a thermal storage device in fluid communication with the outdoor unit and the indoor unit, the thermal storage device comprising: a fluid pump; a fluid tank coupled to the fluid pump and storing a fluid; a heat exchanger fluidly coupled to the refrigerant circuit between an outdoor coil of the outdoor unit and an indoor coil of the indoor unit; an expansion valve coupled to the refrigerant circuit between an inlet of the heat exchanger and the outdoor unit; a solenoid valve coupled to the refrigerant circuit between an outlet of the heat exchanger and an indoor coil of the indoor unit; and a controller configured to control the fluid pump based on an operation mode of the climate control system, wherein the fluid pump is configured to be activated when the climate control system is operating in a heating mode or in a defrosting mode, and the fluid pump is configured to be deactivated when the climate control system is operating in a cooling mode; and wherein the thermal storage module is separate from the indoor unit and the outdoor unit and located along the refrigerant circuit therebetween.
9 . The climate control system of claim 8 , wherein the fluid is a thermal energy storage fluid or a phase-change material.
10 . The climate control system of claim 8 , wherein the expansion valve is coupled to the outdoor unit and the indoor unit via a liquid line along the refrigerant circuit and the solenoid valve is coupled to the outdoor unit and the indoor unit via a gas line along the refrigerant circuit.
11 . The climate control system of claim 8 , wherein when the climate control system is in a heating mode, the expansion valve is opened and the solenoid valve is closed, the refrigerant is directed from the compressor along the refrigerant circuit to the indoor coil of the indoor unit, the heat exchanger of the thermal storage module, the outdoor coil of the outdoor unit, and back to the compressor, the fluid pump is activated to facilitate heat from the refrigerant to fluid stored in the fluid tank via the heat exchanger, and the fluid pump is deactivated to stop the heat transfer from the refrigerant to fluid stored in the fluid tank via the heat exchanger when a predetermined amount of heat is stored in the tank.
12 . The climate control system of claim 8 , wherein, when the climate control system is in a defrost mode, both the expansion valve and the solenoid valve are opened, and the refrigerant is directed from the compressor along the refrigerant circuit to an outdoor coil of the outdoor unit, to the heat exchanger, and back to the compressor via the solenoid valve so as to bypass the indoor unit.
13 . The climate control system of claim 12 , wherein, wherein the climate control system is in a defrost mode, the fluid pump is activated to facilitate heat transfer from the fluid in the fluid tank to the refrigerant via the heat exchanger, and the heat exchanger operates as an evaporator to heat the refrigerant for defrosting the outdoor coil of the outdoor unit.
14 . A method of operating a defrost mode for a climate control system, the climate control system comprising a refrigerant circuit for directing a refrigerant flowing between an indoor unit and an outdoor unit, the outdoor unit comprising a compressor, and a thermal storage module located between the indoor unit and the outdoor unit, the method comprising: activating or deactivating the thermal storage module based on one or more mode of operation signals received from the climate control system; and directing, when the climate control system is in a defrost mode, the refrigerant from the compressor along the refrigerant circuit to an outdoor coil of the outdoor unit, to the thermal storage module, and back to the compressor via the solenoid valve so as to bypass the indoor unit.
15 . The method of claim 14 , wherein the thermal storage module comprises: a fluid pump; a fluid tank coupled to the fluid pump and storing a fluid; a heat exchanger fluidly coupled to the refrigerant circuit between an outdoor coil of the outdoor unit and an indoor coil of the indoor unit; an expansion valve coupled to the refrigerant circuit between an inlet of the heat exchanger and the outdoor unit; a solenoid valve coupled to the refrigerant circuit between an outlet of the heat exchanger and an indoor coil of the indoor unit; and a controller configured to control the fluid pump based on an operation mode of the climate control system, wherein the expansion valve is coupled to the outdoor unit and the indoor unit via a liquid line along the refrigerant circuit and the solenoid valve is coupled to the outdoor unit and the indoor unit via a gas line along the refrigerant circuit.
16 . The method of claim 15 , further comprising, when the climate control system is in the defrosting mode: opening both the expansion valve and the solenoid valve; activating the fluid pump to facilitate heat transfer from the fluid in the fluid tank to the refrigerant via the heat exchanger, and operating the heat exchanger as an evaporator to heat the refrigerant for defrosting the outdoor coil of the outdoor unit.
17 . The method of claim 14 , further comprising: installing the thermal storage module along the refrigerant circuit between the indoor unit and the outdoor unit, wherein the thermal storage module is separate unit from the indoor unit and the outdoor unit.
18 . The method of claim 14 , further comprising, when the climate control system is in a heating mode: opening the expansion valve and closing the solenoid valve; directing the refrigerant from the compressor of the outdoor unit along the refrigerant circuit to the indoor coil of the indoor unit, to the heat exchanger of the thermal storage module, to the outdoor coil of the outdoor unit, and back to the compressor of the outdoor unit; and activating the fluid pump of the thermal storage module to facilitate heat transfer from the refrigerant to fluid stored in the fluid tank via the heat exchanger.
19 . The method of claim 14 , further comprising deactivating the fluid pump of the thermal storage module when the climate control system is in a cooling mode.
20 . The method of claim 19 , further comprising: opening the expansion valve and closing the solenoid valve; and directing the refrigerant from the compressor of the outdoor unit to the outdoor coil of the outdoor unit, the heat exchanger of the thermal storage unit, an indoor coil of the indoor unit, and back to the compressor of the outdoor unit.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a Continuation-in-part Application of U.S. patent application Ser. No. 18/809,539 filed Aug. 20, 2024, and entitled “SYSTEMS AND METHODS FOR DEFROSTING AN OUTDOOR HEAT EXCHANGER OF A HEAT PUMP”, the entire contents of which is incorporated herein by reference. BACKGROUND A heat pump may be used to heat an interior space by circulating a refrigerant between a pair of heat exchangers. The interior space may be an interior space of a house, apartment, building, retail store, storage unit, office, refrigerator, freezer, vehicle, etc. Specifically, the refrigerant may be circulated between a first heat exchanger that is configured to transfer heat from an outdoor environment to the refrigerant and a second heat exchanger that is configured to transfer heat from the refrigerant to the interior space. BRIEF SUMMARY Some embodiments disclosed herein are directed to a heat pump for conditioning an interior space. In some embodiments, the heat pump includes an outdoor unit including an outdoor heat exchanger that is configured to exchange heat between a refrigerant and an outdoor environment, and an outdoor expansion device that is configured to expand the refrigerant flowing into the outdoor heat exchanger when the heat pump is operating in a heating mode. In addition, the heat pump includes an indoor unit including an indoor heat exchanger that is configured to exchange heat between the refrigerant and the interior space, and an indoor expansion device that is configured to expand the refrigerant flowing into the indoor heat exchanger when the heat pump is operating in a defrost mode. Further, the heat pump includes a thermal storage device in fluid communication between the outdoor expansion device and the indoor expansion device. Still further, the heat pump includes a reversing valve that is actuatable between: a first position during the heating mode to direct refrigerant through the indoor heat exchanger, the thermal storage device, the outdoor expansion device, and then the outdoor heat exchanger to heat the interior space and to transfer heat from the refrigerant to the thermal storage device; and a second position during the defrost mode to direct refrigerant through the outdoor heat exchanger and then the thermal storage device to transfer thermal energy to the outdoor heat exchanger from the thermal storage device. Some embodiments disclosed herein are directed to a method of operating a heat pump to condition an interior space, the heat pump including an outdoor heat exchanger to exchange heat between a refrigerant and an outdoor environment, an outdoor expansion device, an indoor heat exchanger to exchange heat between the refrigerant and the interior space, and an indoor expansion device. In some embodiments, the method includes routing the refrigerant through the indoor heat exchanger, a thermal storage device, the outdoor expansion device, and then an outdoor heat exchanger to heat the interior space via the indoor heat exchanger and to transfer heat from the refrigerant to the thermal storage device, the thermal storage device being in fluid communication between the indoor expansion device and the outdoor expansion device. In addition, the method includes routing the refrigerant through the outdoor heat exchanger and then the thermal storage device to transfer thermal energy to the outdoor heat exchanger from the thermal storage device. Some embodiments disclosed herein are directed to a heat pump for conditioning an interior space. In some embodiments, the heat pump includes an outdoor unit including an outdoor heat exchanger that is configured to exchange heat between a refrigerant and an outdoor environment. In addition, the heat pump includes an indoor unit including an indoor heat exchanger that is configured to exchange heat between the refrigerant and the interior space, an indoor expansion device that is configured to expand the refrigerant, and a thermal storage device that is configured to exchange heat between the refrigerant and a thermal storage medium. Further, the heat pump includes valving that is actuatable to operate the heat pump in: a heating mode in which refrigerant is flowed through the indoor heat exchanger and the thermal storage device in parallel and then is flowed to the outdoor unit to heat the interior space via the indoor heat exchanger and to transfer heat from the refrigerant to the thermal storage medium of the thermal storage device; and a defrost mode in which refrigerant is flowed through the outdoor heat exchanger and then is flowed through the thermal storage device in bypass of the indoor heat exchanger to transfer heat from the thermal storage medium of the thermal storage device to the outdoor heat exchanger. Some embodiments disclosed herein are directed to a thermal storage module. The thermal storage module may be in fluid communication with an outdoor unit and an indoor unit of a climate contro