用渐近分析法研究蜂窝蓄热体温度分布

A Study of Temperature Distribution in a Honeycomb Heat Accumulator by Using an Asymptotic Analysis Method

提出一种求解逆流型蜂窝蓄热式热交换器非稳态传热问题的摄动半解析新方法。基于薄壁假设建立气固两相传热模型,推导了考虑沿通道轴向固体导热的无量纲传热偏微分方程。因传热方程的导热项系数为小参数,采用了摄动法求解;进行拉普拉斯变换后,用多重尺度法求出了热交换器弱导热时气固温度分布一阶渐近解。蓄热体温度分布摄动解析和实验及有限差分计算吻合。证实了摄动半解析提高蓄热式热交换器传热研究效率、经济性和准确性的可行性。

A new perturbation-analysis method is proposed to find a solution to a non-steady heat transfer problem concerning a counter-flow type of honeycomb heat-accumulation based heat exchanger. A gas-solid two-phase heat transfer model has been established based on a thin-wall assumption. A non-dimensional heat-transfer partial differential equation taking into account axial solid heat-conduction along channels has been derived. As the coefficient of the heat conduction term of the heat transfer equation is a small parameter, the perturbation method is adopted to find a solution. After a Laplace transformation, a first-order asymptotic solution to the gas-solid temperature distribution during the weak heat conduction of the heat exchanger was attained by using a multi-dimensional method. The perturbation analysis of the temperature distribution in the heat accumulator coincides with the results of experiments and finite difference calculations. The foregoing has demonstrated that by using the perturbation semi-analytic method it is feasible to enhance the efficiency, cost-effectiveness and accuracy of the heat transfer research for a heat-accumulation type heat exchanger.