印刷电路板式换热器换热流动特性数值分析

Nummerical Simulation on the Thermal-hydraulic Performance of Printed Circuit Heat Exchanger

印刷电路板式换热器不同通道型式的传热和流动特性存在明显的差异,本文基于兆瓦级超临界二氧化碳布雷顿循环发电应用条件,采用数值模拟方法计算印刷电路板式回热器直通道和Z通道的传热和流动特性,并且分析其存在差异的原因,获得了直通道和Z型通道换热器的传热特性、流动特性、速度场、温度场和热流密度分布,Z通道传热能力和流动压损均大于直通道,分析其原因是Z型通道的局部高流速、湍流效应和周期性扰动现象所致。

The heat transfer and flow characteristics of the different shaped channels for PCHE are obvious.In this paper,based on the application of megawatt supercritical carbon dioxide Brayton cycle power generation,numerical simulation analysis method is used to analyze the heat transfer characteristics and flow characteristics between the straight channel and Z channel of printed circuit plate reheater,and the reasons for the differences are analyzed.The heat transfer,pressure drop,velocity field,temperature field and heat flux are obtained.Compared with the Z-shaped channel,the heat effect of the straight channel is weaker,and pressure drop is smaller.The reasons are local high velocity,turbulence effect and periodic disturbance of Z channel.