Minimization of Thermal Oil Flow Rate for Indirect Integration of Multiple Plants

Energy integration of multiple plants may be carried out indirectly through thermal oil. Flow rate of thermal oil is related to the heat to be transferred, and it affects the capacity and power requirement of the pumps and the piping size. In this paper, a linear programming formulation is proposed to minimize the flow rate of thermal oil. The proposed formulation considers the minimum total utilities requirement for indirectly integrated multiple plants as a constraint. For the special case of two plants integration, a graphical methodology, based on the principles of Pinch Analysis, is also developed. The proposed methodologies are illustrated with examples, and possible heat exchanger networks are developed.