Vapor compression type water chilling unit of energy storage battery

The steam compression type water chilling unit of the energy storage battery comprises a liquid supply pipeline, the liquid supply pipeline comprises a main pipeline and a branch pipeline, a heater, a water pump, a liquid temperature sensor and a liquid pressure sensor are arranged on the main pipeline, an expansion water tank is arranged on the branch pipeline, and a breather valve is installed in the expansion water tank; a compressor and a condenser which are connected in sequence are arranged on the refrigeration pipeline; the plate-type evaporator is connected with the liquid supply pipeline and the refrigeration pipeline, and the condensed gas in the refrigeration pipeline can transfer the cooling capacity to the cooling liquid in the liquid supply pipeline through the plate-type evaporator. The expansion water tank is used for replacing a traditional air bag, higher rigidity and strength are achieved, and therefore the service life is prolonged; when the hydraulic pressure in the liquid supply pipeline