Heat pump system and control method thereof

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.

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.