Abstract: In industrial practice, multi-tube heat exchangers,which involve both countercurrent and co-current flows are commonly used.Pinch technology is proposed for heat exchanger networks (HEN) with countercurrent flow, but cannot be applied to multi-tube HEN directly.Thus, it is necessary to analyze the relationship among minimum temperature difference, pinch characteristics and total cost quantitatively for multi-tube HEN.Considering the selection of tubes number and total cost of HEN, minimum temperature difference was optimized to minimize total annual cost.Then, it was used to synthesize multi-tube HENs based on pinch technology.Meanwhile, the correction factor for log mean temperature difference (LMTD) was calculated and the results were analyzed.Two case studies demonstrated the effectiveness and application prospect of the presented method.

Key words: heat exchanger network, multi-tube heat exchanger, synthesis, pinch technology, minimum temperature difference

摘要： 在实际生产过程中,多管程换热器广泛应用,其中既存在逆流换热也存在并流换热。针对多管程换热器网络中并流换热与逆流换热时换热温差对夹点特性尤其是换热网络综合的影响,定量分析最小温差的选择与夹点特性及其总费用的关系。兼顾管程数目的选择以及换热网络总费用两方面因素,以年度化总费用最低为目标,优化求解多管程换热器网络的最小温差。然后,将求得的最小温差作为夹点温差,遵循夹点设计原则综合换热网络。同时,计算得出多管程换热器网络的F_T修正因子,并对结果进行分析。最后,结合示例对比分析求解结果,证明方法的有效性。

关键词: 换热网络, 多管程换热器, 综合, 夹点技术, 最小温差