Electricity Free Refrigeration using LPG

The most of the Refrigerators used in India work on electric energy and use traditional refrigerants such as Chlorofluorocarbons (CFC) and Hydrofluorocarbons (HFC). Such refrigerators consume too much running cost annually. Also even in current situation electricity is still not available in many remote areas and villages. It results in spoilage of food, meat and medicines. The traditional refrigerants like CFC and HFC have ozone depletion potential (ODP) and global warming potential (GWP). This paper investigates comparative study of domestic electric refrigerators and LPG refrigerators. In LPG refrigerators, refrigerant used is LPG. It is easily available and currently being used in India at both domestic and commercial level. LPG is a byproduct in fuel refinery and comprise of 24.4% propane, 56.4% butane and 17.2% isobutene which have very low boiling point (lower than 0 °C). The use of LPG for refrigeration purpose can be environment friendly since it has no ozone depletion potential (ODP). LPG is available in cylinders at high pressure. When this high pressure LPG is passed through the capillary tube of small internal diameter, the pressure of LPG is reduced due to expansion and phase change of LPG by isenthalpic process. Due to phase change from liquid to gas, latent heat is gained by the liquid refrigerant and the temperature drops. In this way LPG can generate refrigerating effect for a confined space. From experimental investigation, we have found that the COP of a refrigerator which uses LPG is higher than a domestic electric refrigerator.