In process industries, compressors or pumps are widely used to increase fluids’ pressure if necessary, and expanders are used to generate work for fluids with excess pressure. These fluid machinery forms a fluid machinery network if there are associations among these fluid machinery. Pumps and water turbines in a circulating water system is just such a fluid machinery network. Energy consumption could be reduced while the economic profit improved by means of setting fluid machinery appropriately. In this paper, aims at the fluid machinery network in a circulating water system, a superstructure of the network is built taking into account the main and auxiliary pumps system for delivering circulating water as well as the water turbines system for recovering pressure energy. Then based on the superstructure, an optimal mathematic model of the network is proposed with the annual total cost as the objective function. A case study is used to validate the applicability of the model finally.
