Experimental research on heat and mass transfer characteristics of cross-flow closed-type heat-source tower

A heat-source tower heat pump (HTHP) is a potential heating source for space heating due to frost-free characteristic. The heat and mass transfer between the antifreeze solution and air at low ambient temperatures is a key issue for performance enhancement. In this study, a test bench for evaluating the cross-flow closed-type heat-source tower (CCHT) is fabricated to investigate its performance under variable working conditions. Based on the experimental results, correlations of heat and mass transfer coefficients are developed, which can be used to predict the performance of the CCHT. As a result, the mass transfer coefficient between the solution and the air of the CCHT is 0.015-0.051 kg m−2 s−1, while that of the liquid desiccant dehumidifier is 0.0037-0.015 kg m−2 s−1. However, the latent heat ratio of the CCHT is 6-31%, while that of the liquid desiccant dehumidifier is 42-124%.