This paper analyses the function of heat exchanger networks(HEN) is a process system

and states the essence of energy evolvement and diversification in the process system The paper indicates that the optimal objective function of all of the previous methods expressed by the sum of cold utility and hot utility for the energy cost is not rational Actually

from the exergy analysis point

it is the exergy dissipation that drives the process of heat transfer The energy cost and its objective function should be expressed based on exergy analysis and exergy economics So

this paper presents the exergy economic objective function of HEN synthesis from exergy analysis and exergy economics

which contains the flow exergy dissipation of HEN Moreover

this paper proposes the optimal mathematical model and the procedure of HEN optimal synthesis

shows that the exergy economic objective function of HEN can be decomposed into the sum of overall cost of each match unit . The strategy of decomposition and coordination is proposed based on the resolvability of HENs exergy economic objective function

which is between optimization of network and optimization of match units The cost of flow exergy dissipation of HEN is considered simultaneously for HEN synthesis The method proposed in this paper can obtain not only the optimal structure of HEN but also the optimal operation parameters of each match unit Finally

a case study demonstrates the potential application of this method