Defrosting performance and control strategy with hot gas bypass for a medical refrigerator

Frosting is a common phenomenon in refrigeration and frozen equipment, which degrades heat transfer performance and leads to more energy consumption. This paper investigates the application of hot gas bypass defrosting as an alternative to the electric heater defrosting method. The hot gas from the discharge port enters the evaporator to melt the frost layer on the surface of the evaporator. Experimental data indicate that more than 80% defrosting efficiency can be achieved. The defrosting efficiency increases with thicker frost layer and larger bypassed flow rate. In the end, a defrosting control strategy dedicated to medical refrigerator application is proposed.