固定换热面积的回热器优化设计研究

为探究印刷电路板换热器（PCHE）Z型通道中超临界CO₂的换热特性，在换热面积固定的前提下指导回热器优化设计，采用数值模拟方法对CO₂-CO₂耦合换热的局部和整体特性进行了分析，通过CFD计算得到典型PCHE结构和典型工况下回热器的换热特性，与实验结果进行对比，验证计算模型。并利用此模型计算具有相同换热面积、不同通道结构的回热器的局部和整体换热性能，厘清结构参数对换热性能的影响规律。研究表明，计算结果与实验结果吻合，当通道夹角从110°增加至115°时换热系数出现最大幅度的下降，根据不同的设计需求，最佳的夹角范围为110°～120°。

Investigation into optimum design of recuperator at a confirmed heat transfer area

This study aims to investigate the heat transfer characteristics of supercritical CO₂ when flowing through the printed circuit heat exchanger with Z type channel, and further guide the optimum design of recuperator at confirmed heat transfer area. Numerical simulation is used to analyze the local and overall heat transfer characteristics between CO₂ at two pressures. The heat transfer characteristics of a recuperator with typical structure are calculated at a typical working condition, and compared to the experimental results to check the computation model. Then, the heat transfer characteristics of the recuperator with the same heat transfer area but different channel structure are calculated. The effect law of the structure on heat transfer is explored. The study shows that the calculation results have good agreement with the experimental results. The heat transfer coefficient decreases the most when the channel included angle increases from 110° to 115°and the advised range is 110°?120° for different design requirements.