不同类型翅片对印刷电路板式换热器性能的影响研究

Study on the Effect of Different Fin Types on the Performance of Printed Circuit Heat Exchangers

摘要: 随着印刷电路板式换热器(PCHE)在小型模块化反应堆系统中的日益广泛应用，其热工水力性能与结构可靠性已成为影响整个能量转换系统经济性与安全性的关键因素。目前，关于不同翅片结构对PCHE换热效率、流动阻力及力学性能综合影响的研究尚不充分。为此，本研究采用热–流–固多物理场耦合方法，系统分析了五种典型翅片构型在氦–氙混合工质作用下的综合特性。首先，本研究验证了数值模拟方法的准确性；其次，对比了五种类型翅片的换热能力与流动阻力，其中宽体翼型(NACA 0020)的换热效果最好，开槽纺锤型的流动阻力最小；最后，对比分析了五种翅片的结构强度。研究发现，总应力中换热器的机械应力占主要部分，芯体的热应力相对较小。对于相同外形的换热器，内部所有翅片顶面面积占比越大，翅尖平均机械应力越小。基于ASME规范的应力评估表明，所有构型均满足基本强度要求，但安全裕度差异显著，翅片面积占比最大的宽体翼型结构安全系数最高，而部分为追求低流阻或强化传热设计的新型翅片，因局部几何弱化导致安全系数接近工程下限。

Abstract: With the increasing application of printed circuit heat exchangers (PCHEs) in small modular reactor systems, their thermal-hydraulic performance and structural reliability have become key factors affecting the economy and safety of the entire energy conversion system. Currently, research on the comprehensive effects of different fin structures on the heat transfer efficiency, flow resistance, and mechanical performance of PCHEs remains insufficient. To address this, the present study employs a thermal-hydraulic-structural multi-physics coupling method to systematically analyze the comprehensive characteristics of five typical fin configurations under a helium-xenon mixture working fluid. First, the accuracy of the numerical simulation method was validated. Second, the heat transfer performance and flow resistance of the five fin types were compared. Among these, the wide-body airfoil (NACA 0020) exhibited the best heat transfer effect, while the slotted spindle type showed the lowest flow resistance. Finally, the structural strength of the five fin types was compared and analyzed. The study found that mechanical stress constitutes the main part of the total stress in the heat exchanger, while the thermal stress in the core is relatively small. For heat exchangers with the same external shape, a larger proportion of the top surface area of all internal fins correlates with a lower average mechanical stress at the fin tips. Stress evaluations based on the ASME code indicate that all configurations meet the basic strength requirements, but the safety margins vary significantly. The wide-body airfoil, with the largest fin area proportion, has the highest safety factor. In contrast, some novel fins designed for low flow resistance or enhanced heat transfer exhibit safety factors approaching the minimum engineering requirement due to localized geometric weaknesses.