考虑系统可靠性分析的柔性换热网络综合

Optimization of flexible heat exchanger network embedded with system level reliability analysis

基于虚拟温-焓图法与遗传/模拟退火算法,提出了一种考虑系统可靠性水平的柔性换热器网络综合方法。为简化求解问题的复杂度,首先通过虚拟温-焓图法得到了柔性网络匹配,对于得到的网络结构,通过网络结构的连接矩阵分析网络之中的连接状况,搜索出换热网络中存在关联的换热器单元,以关联的换热器作为主线识别出网络之中不相关的子系统,根据包含换热器单元个数最多的不相关的子系统含有换热器的数量,计算出换热网络系统的可靠性。对于未能满足网络系统可靠性要求的网络结构,通过去掉与其它换热器相关联总数最多的换热器,进行网络解耦,改变换热网络的关联状况,提高了系统的可靠性。换热网络结构改变后,采用遗传/模拟退火算法对热负荷回路中相关换热器的热量分配和换热面积进行计算,得出满足系统可靠性需求,并且总费用最为节约的网络结构。本文所提出的方法可以将需要改善系统可靠性的网络结构系统可靠性提高至设计的容许范围,适用于包含系统可靠性分析的柔性换热网络综合。计算实例表明了所提方法的实用性与可行性。

On the basis of pseudo-temperature enthalpy diagram and genetic/simulated annealing algorithms（GA/SA）,an optimization method with system level reliability analysis was presented for flexible heat exchanger network（HEN）.Flexible arrangements of HEN were obtained via pseudo-temperature enthalpy diagram scheme,the connections of heat exchangers and independent subsystems in the HEN were analyzed by the connection matrix,then the system level reliability was measured by the independent subsystem that included maximum quantity of heat exchangers in the HEN.As for the HEN that didn’t meet system level reliability,the heat exchanger（HEX） connected most extensively with other HEX was deleted to decouple the HEN,and the independent subsystems in the HEN were changed,therefore system level reliability was increased.Heat duty redistribution based on the relevant elements of the heat load loops and HEX areas were then calculated in genetic/simulated annealing algorithms（GA/SA）.Then the favorable network configurations which matched economical measurement were located.The proposed method can promote the system level reliability to reach the design tolerance,thus can be suitable for flexible HEN synthesis that includes system level reliability.Computational examples proved the effectiveness and feasibility of the proposed method.