印刷电路板式换热器热应力与机械应力的耦合分析

Coupling Analysis of Mechanical Stress and Thermal Stress of Printed Circuit Heat Exchanger

印刷电路板式换热器(Printed circuit heat exchanger,PCHE)因其结构紧凑、换热高效及耐高温高压等优势,在各工业领域具有广阔的发展潜力。采用有限元方法对PCHE芯体冷热通道的机械应力、热应力与总应力进行分析,研究了板片厚度、通道肋宽与尖角圆弧半径等几何结构参数对PCHE应力分布的影响。结果表明,PCHE冷热通道壁上的总应力水平高于机械应力,为保证结构分析的可靠性,结构分析时需同时考虑压力载荷与温度载荷;通道圆弧尖角处的应力发生应力集中现象,通道半圆弧中点处由于温度梯度较高产生较大的热应力;随着板片厚度与通道肋宽的增加,圆弧尖角处的热应力增大,机械应力则减小,总体可以降低圆弧尖角处的总应力;增加尖角圆弧半径可有效缓解圆弧尖角处的应力集中现象。

Printed circuit heat exchanger(PCHE)have broad development potential in various industrial fields due to its compact structure,high efficiency,and high temperature and pressure resistance.The finite element method was used to analyze the mechanical stress,thermal stress,and total stress of the cold and hot channels for PCHE core.The effects of geometric structural parameters such as plate thickness,ridge thickness,and rounded tip radius on the stress distribution of PCHE were studied.The results indicate that the total stress level on the wall of the cold and hot channel is higher than the mechanical stress.To ensure the reliability of structural analysis,both pressure load and temperature load need to be considered during structural analysis.As the thickness of the plate and the ridge thickness increase,the thermal stress in the rounded tip increases,while the mechanical stress and total stress decreases.Increasing the rounded tip radiu can effectively alleviate the stress concentration phenomenon in the rounded tip.