Experimental investigation on closed-type heating tower using glycerol solution

Abstract

A heating tower is a key component of a heating tower heat pump. To figure out the heat and mass transfer characteristics of a cross-flow closed-type heating tower (CCHT) using a glycerol solution, an experimental investigation was conducted. The effects of fluids’ parameters on the performance of the CCHT were studied, which indicated that its performance could be improved by increasing the air flow rate, the solution flow rate, the secondary refrigerant flow rate, the inlet air temperature, and the inlet air humidity ratio, while decreased with the increase in the inlet temperature of the secondary refrigerant and remained constant with the variation of the inlet solution concentration. Based on the results, correlations of heat and mass transfer coefficients for the CCHT were developed. In addition, a quantitative performance comparison between the glycerol solution and the CaCl2 solution was also conducted, which indicated that compared with the performance of the CCHT when using the CaCl2 solution, the total heat transfer capacity when using the glycerol solution was 1.3–1.7 times higher, while the latent heat ratio was 1.9–3.3 times larger.