Improvement in COP of Domestic Refrigeration ...

Improvement in COP of Domestic Refrigeration System with Water Mist Fan Cooled Condenser

Author Name : Anupam Mishra, Ajay Singh, Parag Mishra

ABSTRACT

In traditional vapour  compression refrigeration systems condenser looses heat to surroundings to condense the high pressure and high temperature refrigerant vapour, coming out of the compressor but the surrounding temperature plays an important role in the condensation of refrigerant vapour in condenser and hence in the performance of the refrigerator. Indian sub-continent is hot and dry in summer season when the atmospheric temperature ranges around 40 – 50 °C and 10 – 30 % relative humidity in northern parts of the country the heat dissipation capacity of condenser gets reduced and for condensation of refrigerant at condenser the condensing temperature and pressure must increase in order to maintain the temperature difference required for heat transfer and for that compressor needs to do more work and hence the COP drops drastically. To counter these problems we have used water mist with fan to provide the efficient cooling to the refrigerant vapour in condenser. The refrigeration effect also increased by 37.7% over conventional air cooled domestic refrigeration system. In our experimental set up we were able to achieve up to 32.6 % of COP improvement over conventional air cooled condenser system. In our experimental set up with water mist fan cooling system we improved the heat transfer rate at condenser and also managed to decrease the condenser outlet temperature from 42.6 °C to 19.9 °C that also lead to drop in compressor load. The drop in load across the compressor was 38% - 47% through our experimental set up. We have still managed to achieve a minimum temperature of -17.5 °C in the evaporator in 2 hrs operation with mist cooling, which was only -9 °C with simple air cooling. By this type of condenser cooling method refrigerators or air conditioners with smaller to larger cooling capacities could be built in a compact design.

Keywords: Domestic Refrigeration system, COP improvement, Condenser, Water mist fan, Evaporative cooling, VCRS cycle.