综合考虑传热、流动与投资的换热器性能优化

Performance Optimization for a Heat Exchanger with Overall Consideration of Heat Transfer, Fluid Flow and Investment

在给定换热器传热量下导出使投资费用最少的换热表面的最佳匹配准则和使流动传热过程火用损失率最小（即反映运行费用最省）的换热性能最佳配比准则，并利用两准则间的相关性对换热器进行综合性能优化，从而获得最佳的结构参数、性能参数和运行参数．为显示优化方法过程，以圆形肋片管换热器为例进行具体的性能优化。

An expression for optimal surface matching of a heat exchanger is derived based on the heat transfer equation and the investment equation under the condition of minimum investment cost per unit heat flow. Another expression for the optimal heat transfer coefficient ratio is obtained under the condition of minimum exergy loss rate of the heat transfer and fluid flow. Performance optimization of the heat exchanger can then be achieved with overall consideration of the heat transfer and flow characteristics as well as the primary investment. Relevant optimal parameters are obtained so as to give the lowest operating cost and least investment. A heat exchanger with circular finned tube is used to illustrate the optimization process, and the optimal parameters are calculated either by the iteration method or by numerical comparison.