螺旋折流板菱形翅片管换热器的传热与流阻性能

引　言近年来的研究1～ 6] 表明 ,螺旋折流板换热器的螺旋折流板使流体在壳侧呈连续柱塞状螺旋流动(即 plug流 ) ,不会出现传统折流板换热器内的流动“死区” ,并且由于旋流产生的涡与管束传热界面边界层相互作用 ,使湍流度大幅度增强 ,有利于提高壳侧传热膜系数 .PStehlik等2 ] 对螺旋折流板换热器进行研究得出 ,相同条件下与传统弓形折流板换热器相比 ,换热器的传热系数提高 1 8倍 ,流动阻力降低 2 5 % .陈世醒等6] 研究发现 ,对于水这样的低黏度流体 ,相同流量单位压降的壳程对流传热系数 ,螺旋折流板换热器约为普通弓形折流板换热器…

EXPERIMENTAL INVESTIGATION OF HEAT TRANSFER AND FLOW RESISTANCE PERFORMANCE ON HEAT EXCHANGER WITH LOZENGE FIN TUBES SUPPORTED BY HELICAL BAFFLES

Experimental investigation of heat transfer and flow resistance performance on heat exchanger with lozenge fin tubes supported by helical baffles was carried out. Under the experimental conditions，curves of relation between heat transfer film coefficient and flow velocity，relation between flow resistance coefficient and velocity were obtained，which provides references for industrial application of this type of heat exchanger. Experimental results indicated that within the range of diesel oil flow velocity 0.22—0.85 m·s^-1，heat transfer film coefficient in shell side of heat exchanger with lozenge fin tubes supported by helical baffles was 512—1378 W·m^-2·K^-1，which was 54%—108% higher than that of heat exchanger with smooth tubes supported by helical baffles，while flow resistance coefficient was lower by 5%—30%，which showed that heat exchanger with lozenge fin tubes supported by helical baffles had favorable heat transfer and flow resistance performance.