增设旁路的换热网络运行优化

Optimal operation of heat exchanger network by design of bypass

通常情况下换热网络系统是按照特定的参数设计的,但实际工程实施中往往有很多因素影响运行工况偏离设定值,造成原网络结构无法满足出口温度或者使得运行费用大大增加,因此运用旁路控制是改善网络操作弹性、调节物流出口温度和节能降耗的有效方法,而如何确定旁路位置是人们关注较多的一个问题。提出以运行费用为优化目标,以所有潜在旁路开度为调节变量进行优化计算,从而确定旁路位置及数目的设计方法。实际算例说明,通过增设旁路优化不仅提高了换热网络自由度和可控性,其运行费用也平均降低了2.2%,说明所提出方法对改善网络操作弹性和节能降耗的有效性。

Under normal circumstances,the heat exchanger network system is designed according to specific parameters,but the actual implementation of the project there are many factors often make the operating conditions deviate from the set value,will result in the original network structure can not meet the outlet temperature or cause greatly increased operating costs. Therefore,the use of a bypass control to improve network operation flexibility,regulate outlet temperature and saving energy,and how to determine the location of the bypass is an issue of concern. The operating cost is considered as the optimization target and the degree of openness of the potential bypass is considered as the optimization variables,and then the location and the number of the bypass could be determined by the optimal calculations. The optimization not only improves the degree of freedom and control,its running costs are also reduced by an average of 2. 2%. A case study demonstrated the effectiveness of the method proposed in this paper.