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 operating 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.