基于场协同原理的换热网络性能评价因子

A performance evaluation factor of heat exchanger network based on field synergy

换热网络问题严重的非凸、非线性使从数学角度发现此类问题的全局最优解变得十分困难。鉴于此,本文以场协同理论为基础,建立了一种从温差场均匀性角度描述换热网络结构性能的评价因子,以期简化换热网络综合过程,获得高效的换热网络结构。首先以单体换热器的温差均匀性因子为基础,比拟出适用于换热网络的温差均匀性因子,称之为换热网络性能评价因子。继之,选择3个不同的算例,在固定结构和固定面积两个角度下分析了评价因子的有效性。最后,计算结果表明:提出的基于权重的换热网络温差均匀性因子与网络结构的总换热量之间能够形成明显的对应关系,可以准确地描述换热网络结构性能。简而言之,温差均匀性因子的值越小,对应换热网络结构的性能越好。

The global optimization of heat exchanger network（HEN）is significantly difficult resulting from the non-convexity and non-linearity of the model and constraints in the problem.A performance evaluation factor of heat exchanger network was established from the perspective of uniformity principle based on the field synergy theory to simplify the synthesis process of heat exchanger network and obtain efficient optimal HEN structure.Firstly,the performance evaluation factor of heat exchanger network namely was derived from the uniformity factor in a single heat exchanger to describe the uniformity of temperature difference field.Secondly,the efficiency of the performance evaluation factor of heat exchanger network was verified by three different cases,evaluating the performance of heat exchanger networks under the corresponding conditions of given network configuration and given area of heat exchangers,respectively.Finally,the results showed that the uniformity factor of temperature difference with weights,which has an obvious relation with the total heat load,could accurately describe the performance of heat exchanger networks.Generally,the performance of heat exchanger network configurations gets better under smaller value of uniformity factor.