ANALYSIS OF ALTERNATIVE REFRIGERANT MIXTURES IN VAPOUR COMPRESSION REFRIGERATION SYSTEM

Abstract

Refrigeration is a process for maintaining a temperature below the surrounding temperature. Tetrafluroethane R134 is commonly used as a refrigerant in domestic refrigeration after 2000, before that we are using halogenated refrigerants R12 in refrigeration which is very much responsible for ozone layer depletion which act as preventing us from ultraviolet radiation. After when we came to know about ozone layer we start replacing the halogenated refrigerant and shifted to Tetrafluoroethane R134a. After shifted to R134a we came to know that it has zero ozone layer depletion (OLD) but higher rate of global warming potential (GWP) and after Kyoto protocol global warming is serious issue as it increases the overall temperature of our surroundings and then we are finding some alternate refrigerants that can be used in place of Tetrafluroethane in domestic refrigerator. Here we see that the mixture of propane and isobutane (R290 & R600a) which is a pure hydrocarbon refrigerants and available in market in name easily and have almost the same thermodynamic property properties as of Tetrafluoroethane. Here we are calculating the various parameter like coefficient of Performance, Refrigeration effect, Compressor work from Tetrafluoroethane (R134a), Propane (R290), Isobutane (R600a) and from mixture of propane and isobutane (R290+R600a) at three different condition. In first condition we fixed the compressor outlet temperature, condensing temperature and varying the evaporator temperature, In second case we use sub-cooling effect and in third case we fixed the evaporator temperature and condensing temperature and varying the compressor outlet temperature and calculate all the parameters and draw all the graph and make a conclusion whether the mixture can be used in domestic refrigerator or not.