A New Defrosting Method Using the Thermosyphon Principles

Finned coil air coolers in cold storage rooms need to be regularly defrosted to remove frost witch grows on the tubes and fins during operation and would otherwise lead to deterioration in heat transfer and blockage of air through the coolers. Common methods used in defrosting are use of hot discharge refrigerant gas from the compressor and insertion of electric heaters in the coolers. In Japan water spraying the coolers is very common. None of these methods are energy efficient. To improve energy conservation and efficiency of the cooling system we developed a defrosting method using the principles of the thermosiphon with CO2 the secondary refrigerant. CO2 within the cooler is heated with hot brine. The heated CO2 evaporates but since it is in contact with frost it condenses and while the CO2 condenses frost is melted.