Experimental comparison and analysis on silica gel and polymer coated fin-tube heat exchangers

In this paper, two desiccant-coated heat exchangers, which are actually fin-tube heat exchanging devices coated with silica gel and polymer materials respectively, are investigated experimentally. Due to the hygroscopic properties of the desiccant materials, both the sensible heat and the latent heat of the process air can be handled by using this kind of heat exchanger. An experimental setup was designed and built to test the performance of this unit. It is found that this desiccant-coated fin-tube heat exchanger well overcomes the side effect of adsorption heat which occurs in desiccant dehumidification process, and achieves good dehumidification performance under given conditions. The silica gel coated heat exchanger behaves better than the polymer one. The influences of regeneration temperature, inlet air temperature and humidity on the system performance in terms of average moisture removal rate Davg and thermal coefficient of performance COPth were also analyzed.