Operation characteristics of air–air heat pipe inserted plate heat exchanger for heat recovery

Abstract

The heat pipe inserted plate (HPIP) type air–air heat exchanger was developed to recover energy from the exhaust air. The heat pipe was inserted through the waved plates, and the two streams with temperature difference flowing opposite along both sides of the plate. The prototype HPIP heat exchanger charging the different refrigerant in the heat pipes was analyzed experimentally, and the influences of the indoor and outdoor temperature difference and the type of refrigerant in the loop heat pipes on the temperature effectiveness, heat transfer rate, and energy efficiency ratio (EER) of the prototype were investigated. Results showed that the heat transfer rate and EER of the heat exchanger increased with the increase of indoor and outdoor temperature difference in winter and summer conditions. The maximum temperature effectiveness reached 62% in winter conditions and 70% in summer conditions. When the loop heat pipes working medium was R32, the heat exchange performance of the heat exchanger in winter and summer conditions was improved. The analysis and calculation of the average annual EER of the heat exchanger while running in Harbin, Beijing, Shanghai, and Guangzhou (China) were 12.72, 7.70, 5.75, and 3.67, respectively.