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 heightdifference between the gas-liquid separator and the evaporator to realize super times feeding liquid for theevaporator.When the evaporator surface is covered with frost, increase the thermal resistance of the tubewall,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 systemoperation.The defrosting mathematical models of the evaporator are established. A test bench of the gravityfeeding refrigeration system is established to study the defrosting effect of the evaporator with and withoutrefrigerant.Experimental studies have shown that,The two defrosting modes each have advantages, for theevaporator without refrigerant, the defrosting time is shorter, but the range of temperature rise is slightlylarger, the whole experiment process takes longer.Under the same condition, for the evaporator withoutrefrigerant, the frost quantity is more than that of evaporator with refrigerant, but the defrosting time isshorter.