Constrained Optimization Technology Based on Synthesis Concepts for Solving Complex Heat Recovery Problems

Abstract

Simulation of complex heat recovery systems such as crude preheat trains using computer tools is now widely practiced. ChemDesign, Inc. has developed a computer tool which can perform this calculation but is also capable of synthesizing an optimum exchanger flow scheme based on stream rates and enthalpies, and other constraints input by the user. The tool further provides guidelines for integrating new exchangers into an existing preheat train and will perform a rigorous simulation of the modified heat recovery system. In addition, the tool can alter the surface area of the added exchangers and calculate the heat recovery after each step change, and thus ultimately determine an economic optimum exchanger surface area addition based on payout or rate-of-return criteria. This tool has been used by ChemDesign, Inc. to redesign and optimize crude unit preheat trains and main fractionator heat recovery systems on catalytic cracking units. This service, marketed by ChemDesign, Inc. is called HOTS (sm) .