Optimal synthesis of integrated refrigeration systems—I: Mixed-integer programming model

Abstract This paper deals with the problem of synthesizing minimum-cost refrigeration systems that are integrated with heat-recovery networks. An efficient network representation is proposed for embedding multistage cycle configurations that operate over a discrete set of potential temperature levels, and which account for the heat integration of a set of hot and cold process streams. Based on this network representation, the prediction of a lower bound for the utility costs is formulated as a linear programming problem. The synthesis of integrated refrigeration systems that minimize both capital and utility costs is formulated as a mixed-integer linear programming problem. The application of this method is illustrated with a test problem.