The hot-state refrigerant constant-temperature defrosting method significantly reduces energy consumption while preventing frost buildup on the evaporator.

The principle is as follows: When the equipment is at a constant temperature, the liquid supply solenoid valve and the heating solenoid valve alternately operate to maintain the evaporator surface temperature at an optimal steady-state equilibrium, ensuring it neither cools nor heats. It operates without heating during cooling and vice versa. When hot refrigerant is injected into the evaporator, it instantly raises the temperature of the distribution copper pipe near the liquid inlet, and then instantly lowers it when liquid is supplied. This continuous cycle maintains a constant temperature, preventing frost buildup on the evaporator surface.