Heat recovery technology and energy-saving effect analysis apply to cleanroom exhaust waste heat characteristics

Abstract

To investigate the efficient waste heat recovery (WHR) technology suitable for cleanrooms, the energy-saving effectiveness of three WHR technologies of heat pipe, liquid circulation, and solution absorption was compared and the comparison was conducted across four different climate regions: severe cold, cold, hot summer cold winter, and hot summer warm winter. The findings reveal that the energy efficiency ratio (EER) of the heat pipe WHR surpasses that of the other two technologies. Specifically, the EER values for the heat pipe WHR in the four climate regions are 21.0, 15.4, 14.1, and 7.3, respectively. Furthermore, a two-stage heat pipe WHR technology is proposed to enhance the heat recovery efficiency of the heat pipe WHR technology, and experimental research has been conducted. The results show that the average heat recovery efficiency reaches 61.64 % when the wind speed is 2 m/s and the new exhaust air temperature difference is 6–11 °C. Compared to the single-stage HPHE, the use of two-stage heat pipe WHR technology in the four climates regions resulted in 6.9 %, 12.8 %, 21.5 %, and 13.6 % higher net heat recovery, 7.1 %, 13.5 %, 16.6 %, and 40.2 % higher energy-efficiency ratios, and 8.2 %, 13.5 %, 12.2 %, and 37.3 % shorter static payback periods, respectively. The heat recovery solution shows a good application prospect in cleanroom WHR.