CONTROL METHOD AND APPARATUS FOR COMPRESSION SYSTEM, AND AIR ENERGY HEAT PUMP WATER HEATER

The present disclosure relates to the technical field of water heaters, and provides a control method and apparatus for a compression system, and an air energy heat pump water heater. The compression system comprises a compressor provided between an outdoor first heat exchanger and a second heat exchanger of a water tank, a first electronic expansion valve provided between the second heat exchanger and a flash evaporator, and a second electronic expansion valve provided between the flash evaporator and the first heat exchanger. The method comprises: executing a first control step at least once, executing the first control step every time comprising: determining a first target step number of the first electronic expansion valve; after the first electronic expansion valve is controlled to operate for a first time period according to the first target step number, determining a temperature difference between the current exhaust temperature of the compressor and the current highest water temperature of the water tank; when the temperature difference is less than a first preset value, decreasing the first target step number by a first correction step number, the first preset value being greater than 0 degree Celsius, and the first correction step number being greater than 0 step; and controlling the first electronic expansion valve to operate according to the decreased first target step number.