System reliability can produce a strong influence on the performance of the heat exchanger network (HEN). In this paper

an optimization method with system reliability analysis for flexible HEN by genetic/simulated annealing algorithms (GA/SA) is presented. Initial flexible arrangements of HEN is received by pseudo-temperature enthalpy diagram. For determining system reliability of HEN

the connections of heat exchangers(HEXs) and independent subsystems in the HEN are analyzed by the connection sequence matrix(CSM)

and the system reliability is measured by the independent subsystem including maximum number of HEXs in the HEN. As for the HEN that did not meet system reliability

HEN decoupling is applied and the independent subsystems in the HEN are changed by removing decoupling HEX

and thus the system reliability is elevated. After that

heat duty redistribution based on the relevant elements of the heat load loops and HEX areas are optimized in GA/SA. Then

the favorable network configuration

which matches both the most economical cost and system reliability criterion

is located. Moreover

particular features belonging to suitable decoupling HEX are extracted from calculations. Corresponding numerical example is presented to verify that the proposed strategy is effective to formulate optimal flexible HEN with system reliability measurement.