对螺旋叶片和开槽螺旋叶片两种结构组合转子的综合传热性能进行了实验研究。与光管相比,两种转子都显著提高了换热管内的传热性能,装有螺旋叶片转子和开槽螺旋叶片转子换热管的努塞尔数分别比光管提高了1.06~1.26倍和1.03~1.15倍,引起的阻力系数分别比光管增加了60%~68%和36%~51%。螺旋叶片转子对管内传热性能的提升更为显著,但其引起的管内阻力系数也较大。综合考虑传热和阻力两方面因素,对两种转子结构的综合评价指标值进行比较,开槽螺旋叶片转子具有更好的综合传热性能。
The effects of rotor assembly with helical lobe and grooved helical lobe on heat transfer,flow friction and thermal performance characteristics in a round tube were experimentally investigated.The results showed that both heat transfer rate and friction factor associated with rotor assembly were consistently higher than those without rotor assembly.The Nusselt number with helical lobe rotor assembly and grooved helical lobe rotor assembly increased 1.06—1.26 and 1.03—1.15 times than that in the plain tube respectively.The friction factor with helical lobe rotor assembly and grooved helical lobe rotor assembly increased 60%—68% and 36%—51% than that in the plain tube respectively.Considering both heat transfer rate and friction factor,the performance evaluation criteria(PEC)of two kinds of rotors were compared,the result indicated that grooved helical lobe rotor assembly had a better thermal performance characteristic.