Energy conservation studies on room air conditioning units using loop heat pipes

Abstract

With the rapid development of the economics and the consequent improvement on the living standards of common man in developing countries, the usage of air conditioning equipment has been increasing faster in the recent years. The effect of air conditioning demand makes the energy consumption increasing quicker and also the energy cost. Around 15% of global energy utilization is towards air conditioning and refrigeration. Energy efficient compressors, condensers and fan coil units of high effectiveness and refrigerants of superior thermo physical properties are some of the measures towards making the conventional Compression Refrigeration System (CRS) more efficient. Pre cooling the room return air is an effective way to reduce the thermal load on the compressor of the air conditioning system. Incorporation of Loop Heat Pipes (LHPs) in domestic airconditioning system is one of the techniques to make the system energy efficient and affordable. The current research work focused on incorporation of Loop Heat Pipes (LHP) in the conventional window and split Air conditioning (AC) units, which not only reduces the energy consumption significantly but also enable the AC units more suitable for handling outside air in high humid locations. The objectives of this research were also to investigate the effects of LHPs in energy recovery capability, energy saving potential, Sensible Heat Factor (SHF) reduction rate and dehumidification enhancement while employed in the conventional AC unit. This research thesis presents theoretical and experimental performance investigations on incorporation of loop heat pipes in small capacity window and split type conventional air conditioning units. Loop Heat Pipes were designed for this specific working temperature range of 5°C-30°C with working medium as Ethanol, R134a having desirable thermo physical properties. Copper was chosen as material for heat pipes and sintered Nickel as primary wick with desired permeability and porosity. The fill ratio of working medium was 51.3vol%. newline