US-12624874-B2 - Heat pump system and control method thereof

Abstract

The heat pump system comprises an indoor unit and an outdoor unit communicated through a refrigerant pipeline. The outdoor unit comprises a compressor, a first heat exchanger, a first throttling device, and a change-over valve. The indoor unit comprises a second heat exchanger. A heat storage unit is arranged on the refrigerant gas-phase pipeline between the indoor unit and the outdoor unit, the heat storage unit comprising a first branch and a second branch arranged in parallel. The first branch is provided with a heat storage heat exchanger and a second throttling device, and the second branch is provided with a control valve device capable of cutting off refrigerant flowing through the second branch in a controlled manner. The heat pump system can operate in a cooling mode, a heating mode, a heat storage and heating mode, and a defrosting mode.

Inventors

• Guangyu SHEN
• Guang Zhang
• Hui Zhai

Assignees

• CARRIER CORPORATION

Dates

Publication Date

20260512

Application Date

20231004

Priority Date

20230922

Claims (18)

1. 1 . A heat pump system, comprising: an outdoor unit comprising a compressor, a first heat exchanger, a first throttling device, and a change-over valve; an indoor unit comprising a second heat exchanger; a refrigerant pipeline comprising a refrigerant gas-phase pipeline and a refrigerant liquid-phase pipeline; a heat storage unit comprising a first branch and a second branch, wherein the first branch is provided with a heat storage heat exchanger and a second throttling device, and the second branch is provided with a control valve device capable of cutting off refrigerant flowing through the second branch in a controlled manner; and wherein, the heat pump system is capable of operating in a heating mode, wherein in the heating mode, the second throttling device is turned on with an opening, and the control valve device is turned on to allow the refrigerant to flow from the change-over valve of the outdoor unit to the second heat exchanger of the indoor unit through the second branch.
2. 2 . The heat pump system according to claim 1 , wherein the heat storage unit is arranged on the refrigerant gas-phase pipeline.
3. 3 . The heat pump system according to claim 1 , wherein the first branch and the second branch are arranged in parallel.
4. 4 . The heat pump system according to claim 1 , wherein the heat pump system is capable of further operating in a cooling mode, a heat storage and heating mode, and/or a defrosting mode.
5. 5 . The heat pump system according to claim 1 , wherein the control valve device comprises a solenoid valve or an electric ball valve.
6. 6 . The heat pump system according to claim 1 , wherein the heat storage heat exchanger is a phase change heat exchanger.
7. 7 . A heat pump system, comprising: an outdoor unit comprising a compressor, a first heat exchanger, a first throttling device, and a change-over valve; an indoor unit comprising a second heat exchanger; a refrigerant pipeline comprising a refrigerant gas-phase pipeline and a refrigerant liquid-phase pipeline; a heat storage unit comprising a first branch and a second branch, wherein the first branch is provided with a heat storage heat exchanger and a second throttling device, and the second branch is provided with a control valve device capable of cutting off refrigerant flowing through the second branch in a controlled manner; and wherein, the heat pump system is capable of operating in a heat storage and heating mode, wherein in the heat storage and heating mode, the second throttling device is fully turned on with the first throttling device playing a throttling role to store heat in the heat storage heat exchanger, and the control valve device is turned off, so that no refrigerant passes through the second branch.
8. 8 . The heat pump system according to claim 7 , wherein, the heat pump system is capable of further operating in a heating mode, a cooling mode, and/or a defrosting mode.
9. 9 . The heat pump system according to claim 7 , wherein the heat storage unit is arranged on the refrigerant gas-phase pipeline.
10. 10 . The heat pump system according to claim 7 , wherein the first branch and the second branch are arranged in parallel.
11. 11 . The heat pump system according to claim 7 , wherein the control valve device comprises a solenoid valve or an electric ball valve.
12. 12 . The heat pump system according to claim 7 , wherein the heat storage heat exchanger is a phase change heat exchanger.
13. 13 . A heat pump system, comprising: an outdoor unit comprising a compressor, a first heat exchanger, a first throttling device, and a change-over valve; an indoor unit comprising a second heat exchanger; a refrigerant pipeline comprising a refrigerant gas-phase pipeline and a refrigerant liquid-phase pipeline; a heat storage unit comprising a first branch and a second branch, wherein the first branch is provided with a heat storage heat exchanger and a second throttling device, and the second branch is provided with a control valve device capable of cutting off refrigerant flowing through the second branch in a controlled manner; and wherein, the heat pump system is capable of operating in a heat storage and heating mode, wherein in the heat storage and heating mode, the second throttling device is partially turned on to allow at least a portion of the refrigerant to flow through the heat storage heat exchanger, and the control valve device is turned on to allow most of the refrigerant to pass through the second branch.
14. 14 . The heat pump system according to claim 13 , wherein, the heat pump system is capable of further operating in a heating mode, a cooling mode, and/or a defrosting mode.
15. 15 . The heat pump system according to claim 13 , wherein the heat storage unit is arranged on the refrigerant gas-phase pipeline.
16. 16 . The heat pump system according to claim 13 , wherein the first branch and the second branch are arranged in parallel.
17. 17 . The heat pump system according to claim 13 , wherein the control valve device comprises a solenoid valve or an electric ball valve.
18. 18 . The heat pump system according to claim 13 , wherein the heat storage heat exchanger is a phase change heat exchanger.

Description

CROSS REFERENCE TO RELATED APPLICATIONS This application claims priority to European Patent Application No. 23199226.4 filed on Sep. 22, 2023, which is incorporated by reference herein in its entirety. FIELD OF THE INVENTION The present application relates to the field of heat pumps, and in particular to a heat pump system and a control method thereof. BACKGROUND OF THE INVENTION In order to improve the comfort of air conditioning systems, common air conditioning systems have a cooling mode. Air conditioning systems with cooling and heating modes are also known as heat pump systems. However, in the heating mode, the outdoor heat exchanger, when placed in a low-temperature and high-humidity environment, would easily get frosted. Generally, heat pump systems have a defrosting mode, where the high-temperature and overheated refrigerant at the compressor outlet is directly delivered to the outdoor heat exchanger to quickly melt the frost. In the defrosting mode, as the high-temperature refrigerant is delivered to the outdoor heat exchanger, this will cause the indoor heat exchanger not only to stop heating, but also to absorb heat from inside the room. In the prior art, heat storage heat exchangers are sometimes utilized to store heat in the heating mode and use the heat stored in the heat storage heat exchanger to defrost in the defrosting mode. This type of device usually includes two sets of change-over valves and several check valves. These devices are generally unable to provide indoor heating during the defrosting mode, or they can achieve continuous heating yet with significantly increased system costs, which makes it difficult to put on the market. In addition, heat storage heat exchangers are usually installed on the inner sides of the outdoor units of air conditioning systems, which increases the design difficulty of outdoor units. SUMMARY OF THE INVENTION According to a first aspect of the present invention, a heat pump system is provided, comprising: an indoor unit and an outdoor unit communicated through a refrigerant pipeline, wherein the outdoor unit comprises a compressor, a first heat exchanger, a first throttling device, and a change-over valve, and the indoor unit comprises a second heat exchanger, where the refrigerant pipeline has a refrigerant gas-phase pipeline and a refrigerant liquid-phase pipeline, wherein a heat storage unit is arranged on the refrigerant gas-phase pipeline between the indoor unit and the outdoor unit, the heat storage unit comprising a first branch and a second branch arranged in parallel, wherein the first branch is provided with a heat storage heat exchanger and a second throttling device, and the second branch is provided with a control valve device capable of cutting off refrigerant flowing through the second branch in a controlled manner, wherein, the heat pump system is capable of operating in a cooling mode, a heating mode, a heat storage and heating mode, and a defrosting mode, where,in the cooling mode, the second throttling device is turned off, so that no refrigerant passes through the heat storage heat exchanger, and the control valve device is turned on, so that the refrigerant flows from the second heat exchanger of the indoor unit to the change-over valve of the outdoor unit through the second branch, and then enters a suction port of the compressor;in the heating mode, the second throttling device is turned on with a tiny opening, where the tiny opening is an opening at which a small amount of refrigerant flows through the heat storage heat exchanger to maintain its flowing state, and the control valve device is turned on to allow the refrigerant to flow from the change-over valve of the outdoor unit to the second heat exchanger of the indoor unit through the second branch;in the heat storage and heating mode, the second throttling device is fully turned on with the first throttling device playing a throttling role to store heat in the heat storage heat exchanger, and the control valve device is turned off, so that no refrigerant passes through the second branch; or the second throttling device is partially turned on to allow at least a portion of the refrigerant to flow through the heat storage heat exchanger, and the control valve device is turned on to allow most of the refrigerant to pass through the second branch; andin the defrosting mode, the first throttling device is fully turned on with the second throttling device playing a throttling role to allow refrigerant to flow through the heat storage heat exchanger to absorb heat for evaporation, and the control valve device is turned off, so that no refrigerant passes through the second branch. Optionally, in an embodiment of the heat pump system, the heat storage unit is detachably installed on the refrigerant gas-phase pipeline between the indoor unit and the outdoor unit. Optionally, in an embodiment of the heat pump system, the heat storage unit is arranged on the refrigerant gas-phase pipelin