Research on fluid heat transfer characteristics of heat pipe radiator directly driven by heat pump

The heat pipe radiator directly driven by heat pump heating system has the ad-vantages of fast heat transfer and high energy efficiency. Based on the empirical heat transfer formula, the heat and mass transfer process in the heat pipe radiator was studied. The key parameters in the empirical heat transfer formula were de-rived by combining with the experimental data. The distribution of the thickness of the condensate film and the heat transfer coefficient in the height direction of the heat pipe radiator was analyzed. The influence of the working fluid condensate mass and vapour mass in the heat pipe radiator was investigated. The results showed that the thickness of the liquid film changes from the bottom of 0.1110 mm to the top of 0.0594 mm along the height of the heat pipe. The minimum charge of working fluid is 1.78 kg to 1.81 kg and the heating COP of the system still reach to 3.14 even at the outdoor temperature of -12.6?C.