管壳式换热器瞬态换热性能分析

通过理论分析，分别以壳程流体、管程流体、管内外壁为研究对象，建立了管壳式换热器瞬态换热数学模型．模型中很好地解决了顺流和逆流同时存在的问题．存此基础上借助于仿真手段对管壳式换热器的瞬态换热性能进行分析，为了减小线性化方法带来的误差以及提高计算的准确度，仿真计算时所采用的数学模型未进行线性化处理，而直接采用非线性化方程进行程序编写．仿真结果与换热器实际运行数据吻合很好，说明所建立的数学模型可用于同类换热器瞬态换热性能分析．通过对换热器瞬态换热性能的分析，町清楚地了解换热器的动态换热特性，为换热器设计及控制提供理论依据．

Analysis of the transient heat transfer performance of shell-and-tube heat exchangers

Mathematical models of transient heat transfer in shell-and-tube heat exchangers are established in this paper through theoretical analysis,with the shell side fluid,the tube side fluid,the outer walls,and the inner walls of the tube as research subjects respectively.Newly proposed mathematical models resolve problems involving simultaneous forward and backward flow.On that basis,the transient heat transfer performance of shell-and-tube heat exchangers was simulated.In order to reduce errors from a linearization approach and improve the accuracy of calculation,nonlinear equations were used.The results of numerical simulation agree well with operauing data from heat exchangers,suggesting that the mathematical model can be used on similar heat exchangers to analyze their transient heat transfer performance.The dynamic heat transfer performance of heat exchangers can be understood clearly through analysis of their transient heat transfer performance,thereby providing a theoretical foundation for design and control of heat exchangers.