Heat pump air conditioning system and control method

A heat pump air conditioning system, comprising:

• a compressor;
• an indoor unit heat exchanger, an outdoor unit heat exchanger and a throttling device;
• a refrigerant circulation loop, connecting the compressor, the indoor unit heat exchanger, the outdoor unit heat exchanger and the throttling device in series;
• a heat storage module, disposed in the refrigerant circulation loop and configured to absorb heat from refrigerant in the refrigerant circulation loop;
• a pipeline between the outdoor unit heat exchanger and the throttling device is a first pipeline, and the heat storage module is connected to and arranged on the first pipeline between the outdoor unit heat exchanger and the throttling device;
• a first parallel pipeline is arranged at both ends of the heat storage module in parallel;
• one end of the first parallel pipeline is connected to a first position of the first pipeline, where one end of the heat storage module is located;
• another end of the first parallel pipeline is connected to a second position of the first pipe, where another end of the heat storage module is located;
• and
• a first control valve is further provided and configured to control one of the heat storage module and the first parallel pipeline to be open and control another to be closed.