Performance analysis of desiccant dehumidifier with different channel geometry using CFD. (December 2021) - Bhabhor, K.K.
Abstract: Traditional cooling systems based on vapor compression are ineffective in humid climates due to their inability to remove moisture below the dew point of the conditioned air, which necessitates additional effort in the form of electrical power supply to run vapor compressors. A solid desiccant cooling system reduces power usage while simultaneously providing fresh and clean air. It is important to examine and analyse the performance of desiccant dehumidifiers that will help to develop more efficient cooling system. A Computational Fluid Dynamic (CFD) simulation predicts the numerical performance of the solid desiccant wheel while dehumidifying moist room air during dehumidification. The aim of this study is to conduct performance study of different desiccant wheel channel geometries like triangular, square, hexagonal, sinusoidal-1 and sinusoidal-2 using simulation carried out with the help of CFD for various operating performance input parameters like supply air temperature, velocity, pressure and humidity of air. The CFD simulation technique evaluates all channel geometry shapes and identifies the most effective geometry among them that provide the most efficient dehumidification. During simulation, the operating parameters of supply process air were considered as 25°C temperature and 50 % (RH) in the case of a recirculation mode. Similarly, in the case of ventilation mode, for supply of process air, two transient climatic conditions have been selected for the city of Dahod, INDIA, as outdoor Condition-I 29°C with 83 % RH and outdoor condition II 35.8°C with 60.5 % RH for the supply of process air. The simulation results estimate the moisture removal capacity for different geometries under various operating conditions. It is found that the sinusoidal types of geometry provide substantial drop in the relative humidity up to 80.01 % with the average temperature raised by 38.98 % of supply air and provide the most effective dehumidification of the supply process air. As a result, CFD simulation techniques aid in the saving time which spent on rigorous experimentation and avoiding the cost of critical construction for various shapes of geometry. Highlights: To conduct performance of different channel geometries used in desiccant wheel with the help of CFD. Numerical simulation results define effective channel geometry which is suitable for desiccant wheel. Optimized channel geometry effectively removed moistures during dehumidification.