Abstract
In recent years, inter-plant heat integration has been widely studied. Direct Heat Integration using process streams and Indirect Heat Integration using intermediate fluid are both researched. Up to now, for large scale problem, most of published work concentrated on Indirect Heat Integration through steam system. Due to complexity of large scale problem, very few works have been done to consider Direct Heat Integration. However, the twice heat transfer nature of Indirect Heat Integration limits energy saving potential. In order to solve the bottleneck of heat integration in interplant heat integration, Direct Heat Integration should be considered. Moreover, applying Direct Heat Integration can provide more cascade utilization opportunities of energy. To overcome the complex problem in solving large scale interplant heat integration, in this paper, a new targeting approach is proposed to determine the maximum energy recovery and optimal match between plants. The approach is based on Particle Swarm Optimization (PSO) and Multi-Verse Optimizer (MVO) to randomly match all the plants. Pinch Approach is used to determine the energy target for each pair of plants, and then the total energy target can be found. The optimal match of plants with maximum energy recovery can be found when the terminal condition for PSO is met. A case study is used to illustrate the capacity of solving large scale problem of the proposed methodology, and significant energy recovery can be obtained compared with Indirect Heat Integration.
