换热器螺旋细通道结构参数对流体流动、传热及综合性能的影响

Effects of structural parameters in helical mini-channels of heat exchanger on fluid flow,heat transfer and overall performance

为了探究换热器结构参数对流体流动、传热和综合性能的影响,设计了不同扇形半径和凹穴间距的螺旋细通道,采用数值模拟方法研究其在不同雷诺数Re下的流动、传热和综合性能.研究结果表明,扇形凹穴显著地影响螺旋细通道内流体的流动性能:Re在168～2016范围内,扇形凹穴半径越大,流阻增量越大;当Re>336时,流阻随凹穴间距的减小而增大,而当Re<336时反之.凹穴结构参数的变化不能明显地影响传热性能,也不能明显地提高螺旋细通道的综合性能,凹穴螺旋细通道比较适用于低Re范围.

In order to investigate effects of structural parameters of heat exchanger on fluid flow,heat transfer and overall performance in helical mini-channels with fan cavities,the helical mini-channels with different radiuses and pitches of fan cavities were designed in present work. The fluid flow,heat transfer and overall performance characteristics in these mini-channels under different Re were studied using numerical simulation.The results showed that the fan cavities had obvious influences on the fluid flow performance in the helical mini-channel. At the range of 168〈 Re 〈 2016,the flow resistance increased with the increase in the radius of fan cavity. The flow resistance descreased with the rise in the pitch of fan cavity when Re 〉 336. But this trend was inversed when Re 〈 336. The variations for structural parameters of fan cavity had no significant influence on heat transfer performance. Also these variations can＇t improved obviously the overall performance in helical mini-channel. The helical mini-channels with fan cavities were suitable for the low ranges of Re.