Abstract

In present days, Refrigerators are cyclic devices working fluid in refrigerator is called Refrigerant. The performance of refrigerators is expressed in terms of coefficient of Performance. And the cooling capacity of a refrigerating system is expressed in terms of Tonne of Refrigeration. Frosting is an unavoidable phenomenon either in domestic refrigerator or in industrial installations. Different methods are available to remove the frost accumulation like water defrost, electric defrost and hot gas defrost methods. Very few techniques are available to reduce the frost accumulation in the evaporator. The main objective of the present work is to reduce the quantity of frost by using coating on the evaporator coil. The coating chosen is to be very smooth, sustain the low temperatures and non wettable . so that there is a chance of forming of frost layers in the evaporator. By doing so, water drips can roll off easily, the dust and other impurities deposited on the surface can be easily removed. Commercially available 662 S - SILICONE GREASE coating material is chosen as coating material. A domestic refrigerator of 165litres capacity working with refrigerant 134a was procured and its pull down characteristics was determined to analyse proper working condition of the refrigerator without coating on the evaporator walls the load was kept inside the refrigerator and the amount of frost deposited was measured for various time intervals. The above process was repeated for various loads. Then the evaporator was coated with 662 S-SILICONE GREASE. The amount of frost deposited on evaporator was measured with the same loads used for without coating for various time intervals. By comparing the experimental results the amount of frost deposited was found to be reduced when 662 S-SILICONE GREASE coating was used. Due to reduction of frost accumulation the power consumption also was found to be reduced.

Authors and Affiliations