Simultaneous optimization of integrated heat, mass and pressure exchange network using exergoeconomic method

Energy crisis becomes increasingly serious with the rapid industrial development. Apart from searching for the alternative energy sources, researchers are dedicated to increasing the efficiency of energy utilization in the industrial production process to alleviate the energy scarcity. The integration of heat, mass and pressure exchange networks is regarded as an effective way to reduce the energy consumption. This paper introduces exergoeconomic analysis to the integrated network optimization. The exergoeconomic analysis is performed by an overall analysis of energy and economic factors, which is very useful for industrial process design. The optimization turns out to be a mixed integer nonlinear programming (MINLP) problem due to the multi-objective and multi-constraint factors. A modified state space model is developed for the integrated network to handle all the parameters and possible network structures. Genetic algorithm is employed to get a globally optimal solution based on the developed state space model and MATLAB program. Case studies are carried out to demonstrate that exergoeconomic analysis is more suitable than the optimization of annual cost or raw material consumption. The results show that exergoeconomic analysis based on the proposed state space model performs well to solve the integrated network problems.