导流板旋向对螺旋铜管换热器传热性能的影响

Effects of rotating direction of spiral deflector on heat transfer performance of helical copper tube heat exchanger

为获得具有更高综合传热性能的螺旋铜管(helical copper tube, HCT)换热设备,基于两种导流方案的换热器:螺旋导流板(spiral deflector, SD)、HCT同旋向换热器(记为:SSD-HCT换热器)和SD、HCT反旋向换热器(记为:OSD-HCT换热器),采用双向-流固耦合计算法,研究了SD旋向对HCT振动强化传热性能和换热器综合传热性能的影响。研究表明:对于SSD-HCT换热器,壳程流体纵掠HCT,场协同角接近90°,HCT传热性能不佳,壳程流体出口温度较低;对于OSD-HCT换热器,壳程流体横掠HCT,场协同角较小,HCT传热性能较佳,壳程流体出口温度较高;SD和HCT同旋向布置时,换热器内HCT的传热性能较差,但HCT振动强化传热的效果明显;SD和HCT反旋向布置时,换热器内HCT的传热性能较好,但HCT振动强化传热的效果不明显。换热器的综合振动强化传热能力随流速的增加而降低,SSD-HCT换热器的综合振动强化传热能力较高。

Here,to obtain helical copper tube(HCT)heat exchanger with higher comprehensive heat transfer performance,for heat exchangers based on two diversion schemes:heat exchanger with spiral deflector(SD)and HCT in the same spiral direction,i.e.,SSD-HCT heat exchanger and heat exchanger with SD and HCT in opposite spiral direction,i.e.,OSD-HCT heat exchanger,the two-way fluid-structure interaction calculation method was adopted to study effects of SD rotating direction on HCT vibration enhanced heat transfer performance and comprehensive heat transfer performance of heat exchanger.The study showed that for SSD-HCT heat exchanger,shell path fluid longitudinally sweeps over HCT with a field synergy angle close to 90°,HCT heat transfer performance is poorer,and outlet temperature of shell path fluid is lower;for OSD-HCT heat exchanger,shell path fluid transversely sweeps across HCT with a smaller field synergy angle,HCT heat transfer performance is better,and outlet temperature of shell path fluid is higher;when SD and HCT are arranged in the same rotating direction,HCT heat transfer performance in heat exchanger is poorer,but the effect of HCT vibration enhanced heat transfer is obvious;when SD and HCT are arranged in opposite rotating,HCT heat transfer performance in heat exchanger is good,but the effect of HCT vibration enhanced heat transfer is not obvious;in addition,comprehensive vibration enhanced heat transfer ability of heat exchanger decreases with increase in flow rate,and comprehensive vibration enhanced heat transfer ability of SSD-HCT heat exchanger is higher.