Author : Rajneesh Kaushal 1
Date of Publication :24th January 2018
Abstract: The continuously increasing energy demand in building space cooling and depleting conventional energy resources have provoked the need for generating renewable and sustainable energy technologies. Pre-eminent among the air conditioning technologies are absorption cooling that works on the low grade energy which is mostly delivered by solar energy. Liquid desiccant dehumidification technologies are the most optimistic option because of their lower regeneration temperature, higher coefficient of performance and ability to be used during night hours. But problems like desiccant carryover, process air pressure drop and incomplete wetted walls needs to be further investigations. The desiccant system investigated in the present study includes a flat plate energy exchanger for mass and heat transfer between process air and desiccant solution. It imparts high contact surface area and minimises the air pressure drop and carryover of desiccant droplets as there is a film contact between air and desiccant instead of direct intermixing which is associated with spray tower and packed bed dehumidifiers. It also provides a complete film over an entire surface of the flat plate which is the limitation of falling film absorbers. The diluted desiccant is heated into a heater tank consists of a heating coil and reactivated in the regenerator. The system comprises of an absorber, a regenerator, a solution heat exchanger to precool and preheat the solution and a cooling tower and a set of solution pumps. Calcium chloride was used as a desiccant material with 40 % by wt. concentration. Experiments were conducted by varying concentration of the desiccant solution and process air flow rates. Performance of the dehumidification system is represented in terms of dehumidification and regeneration effectiveness and moisture absorption rates.
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