关键词: 纳米制冷剂, 流动沸腾, 传热系数, 干度

Abstract: The boiling heat transfer characteristics of nano-refrigerant CuO/R141b flowing in a horizontal tube was studied experimentally. In order to verify the reliability of the experiment, the experimental results of boiling heat transfer of flowing pure HCFC141b were compared with Chenmin formula. The absolute average error was 7.4% when compared the calculated value with experimental results, which is satisfactory. The experimental condition was: mass flow rate 100—350 kg·m^-2·s^-1,vapor quality 0.3—0.8,the total length of copper tube 1.4 m and its inside diameter 10 mm. The heat transfer was investigated at different mass fractions of nanoparticles, different vapor quality and different mass flow rates. The boiling heat transfer is enhanced by adding nanoparticles, and the improvement is related to the mass flow rate, vapor quality and nanoparticle concentration. At the mass flow rate of 120 kg·m^-2·s^-1 and mass fractions of CuO nanoparticles of 0.1%,0.2% and 0.3%,the heat transfer coefficient increases 7%,10.4%,and 16.6%,respectively.

Key words: nano-refrigerant, boiling heat transfer, heat transfer coefficient, vapor quality