Numerical study on heat and mass transfer characteristics of the counter-flow heat-source tower (CFHST)

The heat-source tower heat pump (HSTHP), as a novel energy-saving unit, extracts low-grade thermal energy from air that can be a promising alternative of boiler in Yangtze River basin, China. A numerical model for analysis of the heat and mass transfer characteristics of a counter-flow heat source tower (CFHST) operating in winter is developed and validated by using experimental results. In this proposed numerical model, the changeable Lewis number is considered, and the effects of various operating, environmental including inlet air dry bulb temperature, inlet air humidity ratio, inlet air flow rate, inlet solution temperature and inlet solution flow rate on the thermal behavior of the heat source tower are studied. Furthermore, the proposed model will also be used to analyze the impact of the porosity and spacing of packing on the heat exchange in the CFHST. Finally, the moisture transfer characteristics inside CFHST under various environmental conditions are also studied. This work can provide a theoretical foundation for performance evaluation and practical design of CFHST.