低压降高效换热器复合强化传热试验研究

Compound Heat Transfer Enhancement Experimental Study of Low Pressure Drop and High Efficient Heat Exchanger

大小孔折流板与圆弧波纹管都是近几年提出的降低换热器壳程压降和提高传热效果的结构元件。针对大小孔折流板和圆弧波纹管的特点,提出了将两者相结合的低压降高效换热器,并试验研究该换热器的流动和传热性能。结果表明,换热器具有较低的壳程压降和良好综合传热能力。与光管的普通弓形折流板换热器相比,相同流量下,大孔直径为26 mm的圆弧切线波纹管与大小孔折流板复合结构换热器的壳程板间压降可降低64%,虽然孔径较大时壳程膜传热系数有所下降,但总传热系数有明显提高。若以单位压降的传热系数来评判,圆弧切线波纹管与大小孔折流板复合结构换热器的强化传热性能要远高于普通弓形折流板换热器,最高值可达普通弓形折流板换热器的2.87倍。

Large- and- small- hole （LASH） baffle and arc -tangent corrugated tube are the two com- ponents recently developed for decreasing pressure drop and enhancing heat transfer of heat exchangers. A new heat exchanger is constructed using LASH baffle and arc - tangent corrugated tube. Experiments were carried out to investigate the fluid flow and heat transfer properties of the heat exchanger. It was found this heat exchanger has a lower shell - side pressure drop and better comprehensive heat transfer ability. Com- pared with the conventional heat exchanger, the shell- side pressure drop could be reduced as much as 64% at the same shell - side flow rate. Although the shell - side heat transfer coefficient is decreased for large enlarged holes, the whole heat transfer coefficient is increased remarkably. Moreover, if comprehen- sively evaluated in terms of the shell - side heat transfer coefficient per unit pressure drop, the value could be as much as 2.87 times of that in the conventional heat exchanger.