EXPERIMENTAL ANALYSIS OF A COOLING SYSTEM BY USING DOMESTIC LIQUEFIED PETROLIUM GAS (LPG) CYLINDER WITH OUT ELECTRICITY

Abstract

Preservation of some medicine and food are impossible in remote areas, mines and deserts due to lack of electricity. So instead of electricity a liquefied petroleum gas (LPG) can be used for refrigeration. In this cooling system domestic LPG can be used because of its low boiling point temperature and high pressure. Liquid petroleum is under high pressure in the cylinder therefore there is no need of compressor and condenser for this cooling system. The principle in this present LPG cooling system is isenthalpic expansion of high pressure LP gas by passing through capillary tube. Smaller internal diameter of capillary tube provides high pressure drop there by phase change of liquid petroleum from liquid to gas due to this temperature of the LPG decreases. Then this low temperature LPG is passed through the evaporator for cooling. This LPG gas can be sent for heating the water by gas geyser or burner for cooking or etc .In this present work experimental analysis of the LPG cooling system is carried out by changing the different diameters of capillary (sizes 36, 44, 55 or 0.036, 0.044, 0.055 inches) and also changing the length of each capillary. The experiment is carried out and test results are compared for each diameter and lengths of the capillary tubes by measuring the pressures at inlet and outlet of capillary tube, temperatures at inside of the evaporator and time required to bring down evaporator temperature from atmospheric temperature to required low temperature. By comparing the above measured values 0.036 diameters, 18 feet length of capillary can reduce evaporator temperature less than 50C within half an hour.