Experimental investigation and analysis of composite silica-gel coated fin-tube heat exchangers

Desiccant coated heat exchanger provides a promising option for desiccant cooling system, since it can handle sensible load and latent load simultaneously within one component. It is fabricated by coating desiccant material on the surface of conventional fin-tube heat exchanger. In order to enhance the performance of conventional silica gel coated heat exchanger (SGCHE), a novel composite silica gel coated heat exchanger (CCHE) is proposed and fabricated. An experimental setup is built to test and compare the dynamic performance of SGCHE and CCHE. Influences of main operation parameters including water temperatures and inlet air conditions on system performance are analyzed in terms of average dehumidification capacity (Davg) and thermal coefficient of performance (COPth). Optimization of cycle switch modes is also discussed. Experimental results show that CCHE has better dehumidification performance compared with SGCHE. In addition, pre-cooling before dehumidification process is found to be advantageous to both Davg and COPth.