Experimental study on heat transfer coefficient between air and liquid in the cross-flow heat-source tower

In order to prevent frosting in the outside surface of evaporators and utilize water chiller more efficiently and effectively in the heating season, a heat pump utilizing cooling tower as heat-source tower to absorb heat from ambient air is presented, and its advantages are discussed in detail. The effect of mass transfer ratio on heat transfer rate between cooling tower and heat-source tower is analyzed contrastively. A finite-volume model is developed to calculate the heat transfer coefficient between air and liquid, and the experimental test of cross-flow heat-source tower is built to study the relationship between air parameters and liquid parameters. According to the experimental results, the effects of air flow rate, air temperature, liquid flow rate, and liquid temperature on heat transfer coefficient are analyzed. It is concluded that both air flow rate and liquid flow rate have significant effect on heat transfer coefficient, but the influences of inlet air temperature and inlet liquid temperature on heat transfer coefficient are small. In addition, the correlation expression of heat transfer coefficient is developed by the regression method. The developed correlation expression is validated by comparing the experimental data with calculations.