Multistream heat exchanger (MHEX) has attracted attention in the process intensification field with its compact structure

high efficiency and low heat loss. However

the potential advantages of its process and equipment are still worth discussing. An improved State-space superstructure based on MHEXs process operator (PO) was proposed to convert the network synthesis into a super-exchanger design. Hierarchy matching MHEXs PO was constructed

and the strict heat transfer calculation among multiple streams was implemented through temperature coordinated effect between adjacent streams. Arbitrary splitting and mixing of any stream was achieved by corresponding mixers and splitters in distribution network (DN). The objective function was ameliorated by taking heat loss into consideration. Through introducing the cost of heat loss and thermal insulation material

the external surface envelope advantage of MHEX was presented clearly owing to coverage between adjacent heat-transfer surfaces. Then

a corresponding nonlinear programming (NLP) mathematical model was formulated for generating the optimal design of MHEXs network while synthesizing the utilities

equipment investment

heat loss and thermal insulation material simultaneously. At last

four case studies were performed to verify the feasibility and superiority of the methodology.