Studies on falling film absorbers for R134a dmac based vapour absorption Refrigeration system

Abstract

In the recent years the refrigeration and air conditioning has become newlinean essential requirement in the daily life not only for human comfort but also for newlinevariety of applications such as food preservation refineries chemical newlineprocessing medical and surgical aids pharmaceutical electronic instruments newlineexpansion fittings liquefaction of gases and cryogenic jet engines etc These newlineindustries have a predominant role in improving the GDP gross domestic newlineproduction of the country Absorption systems have been extensively paid attention in recent newlineyears due to the potential for CFC and HCFC replacements in refrigeration newlineheating and cooling applications Due to the high cost of fossil fuels and the newlineenvironmental problems the particular features of the thermally activated newlinesystems have made it attractive for both residential and industrial applications newlineThermally activated absorption technology plays an important role in recovering newlinethe waste heat and generating the process heat One of the essential components of an absorption chiller heat pump is the absorber The heat and mass transfer performance of an absorber plays a newlinedominant role on overall performance of absorption machine Falling film heat newlinetransfer mode in absorbers provide relatively high heat transfer coefficient and is newlinestable during operation and is easy to manufacture In the previous works performed by the various researchers it was found that the working substances used are either water lithium bromide or ammonia water Ammonia has its own limitations due to its non compatibility newlinewith copper and high specific volume where as production of sub zero newlinetemperature and crystallization are the two main demerits associated with water newlineLithium bromide systems Besides these two working fluids require higher heat newlinesource temperature more than 100 C R134a DMAC working fluid pair is newlinehaving Zero Ozone Depletion Potential and lower Global Warming Potential newlinewith a comparatively lesser heat source temperature newline newline