关键词: 传热, 转子组合, 相间排列, 综合评价因子PEC

Abstract: This paper researched on heat transfer enhancement and friction characteristics of tubes with alternatively arranged rotors with diameters 22mm and 19mm. Glycerin solution was used as tube-side working fluid and water was used as shell-side fluid. Experiment of smooth tube was carried out prior to the actual experiments，in order to ensure the reliability and accuracy of the experiment apparatus and methods. The experimental results revealed that：When rotors of diameters 22mm and 19mm were arranged at the ratio 1︰1，Nu and PEC were higher than when the ratio were at 2︰2 and 3︰3. The Nu value was 19.17%—34% higher than when the diameter was fixed at 19mm，and the PEC value was 1.78—2.37，indicating that the more frequent the two rotors were alternatively arranged，the better the effect of heat transfer enhancement was. The difference of resistance coefficients among the three scenarios was not significant compared to the situation when the diameter was 22mm，alternate arrangement of the large and small diameter rotors could be practical，considering saving materials and cost of industrial applications

Key words: heat transfer, assembled rotors, alternate arrangement, performance evaluation criteria（PEC）