Abstract: For the life cycle of the heat exchanger network (HEN)，the heat exchanger performance steps down and energy consumption steps up because of network equipment aging and other factors.And this problem is not resolved effectively by the present margin design for the HEN.A margin optimal design method of the HEN with bypasses based on life cycle energy saving was presented.Through bypass adjustment，effective margin area was released gradually，achieving the purpose of saving energy in the life cycle.The HEN life cycle operation accumulative total cost was considered as the objective function，and at the same time the effect of fouling of heat exchangers and bypass adjustment was included to solve the best margin while satisfying the operation conditions.Lastly sustaining energy conservation was realized.The HEN of a given crude distillation unit in a refinery was treated as the specific research object，illustrating the effectiveness and application prospect of the presented method.

Key words: heat exchanger network, margin design, bypass, life cycle, energy saving

摘要： 换热网络全周期运行期间，由于设备老化等因素，换热性能逐步下降，能耗逐步提高。而当前工业换热网络的裕量设计并没有有效地解决此问题。因此提出了一种基于有旁路换热网络全周期节能优化的裕量优化设计方法，通过旁路调节，逐步释放有效面积裕量，达到全周期节能的目的。该优化方法以换热网络运行全周期内总累积费用为目标函数，同时考虑结垢热阻对换热器换热效果的影响以及旁路对换热网络的调节作用，在满足工艺条件的基础上求解换热网络的最优裕量，最终实现换热网络的持续节能。最后，以某炼油厂的常减压脱盐前换热网络为具体的研究对象，说明所提方法的有效性和使用前景。

关键词: 换热网络, 裕量设计, 旁路, 全周期, 节能