Experimental study on the parallel-flow heat pipe heat exchanger for energy saving in air conditioning

Energy saving significantly and positively affects energy conservation and releases less carbon dioxide. This study aims to investigate the energy-saving characteristics of a novel parallel-flow heat pipe heat exchanger (PFHP-HE) in air conditioning. It merged the characteristics of high axial heat transfer performance of heat pipe with high external heat transfer performance of parallel-flow heat exchanger (PF-HE). The test rig for the PFHP-HE was built on the basis of the heat transfer wind tunnel in this work. The heat transfer performance of parallel-flow heat pipe heat exchanger charged with R600A as the working fluid was experimentally studied. The filling rate of the heat pipe was 26%, and its thermal behavior was analyzed. The evaporation section of the PFHP-HE was heated by heating belt. The experiment was conducted with heating power of 500W. The experiments were performed with cooling air flow rates ranging from 63.36 m3/h to 118.08 m3/h. The results indicate that when the airflow rate was 118.08 m3/h, the minimum thermal resistance of the PFHP-HE was 0.06 K/W, and the heat transfer efficiency was up to 98% in the experiments. As the pulsation phenomenon was caused by its small diameter, the temperature distribution in condenser had stratified phenomenon in PFHP-HE. The PFHP-HE has excellent heat transfer performance and working stability. The PFHP-HE is a promising heat exchanger for energy-saving in air conditioning. Its superior heat transfer performance and working stability make it an attractive alternative to conventional heat pipe heat exchangers.