连续式跨超声速风洞热交换器设计技术初步研究

Investigation of heat exchanger design for continuous transonic and supersonic wind tunnel

以0.6m连续式跨超声速风洞为应用背景,通过工程计算得出椭圆翅片管式热交换器的初步结构,并利用数值模拟手段详细研究了结构参数、管束材料以及流动条件对热交换器性能的影响。结果显示:换热管束的排列方式和尺寸对热交换器性能影响很大;选用高导热率的材料制作翅片,会在基本不改变压损性能的情况下大幅提高热交换器的换热系数。建立了一组方便简洁的理论公式计算热交换器出口气流温度分布,且理论计算和数值模拟结果符合良好。发现通过合理布置冷却水的流动路线,可以使热交换器出口气流具有较好的温度均匀性。

The research work is focused on performance of finned elliptic tube heat exchanger used in wind tunnel.These jobs include engineering calculation and numerical simulation of air flow and heat transfer.The major influence factors,such as structural parameters,heat transfer tube material,flow condition,are discussed in detail by numerical simulation.The results indicate that structure parameters of heat transfer tube bundles have significant impact on heat exchanger performance.And heat exchanger performance will be improved greatly without increasing pressure drop by using metal with high thermoconductivity coefficient to produce heat transfer tube bundles.A group of theoretic formulae are established to calculate temperature distribution of airflow out from heat exchanger,and the results accord well with that of numerical simulation.It indicates that temperature grads augments along with the increase of tube row number,but the temperature uniformity will be improved greatly by designing the entrance of cooling water properly.