COMPARATIVE STUDY ON ELECTRIC HEATER DEFROSTING OF GRAVITY FEEDING REFRIGERATION SYSTEM

摘要

The gravity feeding refrigeration system is based on the thermal siphon principle, rely on the height difference between the gas-liquid separator and the evaporator to realize super times feeding liquid for the evaporator. When the evaporator surface is covered with frost, increase the thermal resistance of the tube wall, impede air circulation, thus affecting the overall performance of the refrigerating unit. Therefore, studying defrosting of the evaporator is of great significance for the whole refrigeration system operation. The defrosting mathematical models of the evaporator are established. A test bench of the gravity feeding refrigeration system is established to study the defrosting effect of the evaporator with and without refrigerant. Experimental studies have shown that. The two defrosting modes each have advantages, for the evaporator without refrigerant, the defrosting time is shorter, but the range of temperature rise is slightly larger, the whole experiment process takes longer. Under the same condition, for the evaporator without refrigerant, the frost quantity is more than that of evaporator with refrigerant, but the defrosting time is shorter.