Passage arrangement optimization of multi-stream plate-fin heat exchangers

•A passage arrangement method by minimizing cumulative heat load is presented.•Mean square error of cumulative heat load is reduced by 2.9% than previous research.•A further improvement scheme is proposed based on heat transfer simulation.•Outlet temperature distribution becomes more uniform after improvement.

Passage arrangement quality is of great significance for the heat transfer performance of multi-stream plate-fin heat exchangers. In the present paper, a passage arrangement method is presented on the basis of minimizing the cumulative heat load to bring convenience for passage arrangements and to improve the heat transfer performance. The passage arrangement results are compared with that of the previous research, indicating 2.9% reduction of the mean square error of the cumulative heat load. For further improvement of the passage arrangement quality, the temperature profiles of the heat exchangers are obtained by applying the distributed-parameter model, based on which a further scheme for optimization is proposed. By carrying out the optimization, the outlet temperature inhomogeneity of the air stream, the waste nitrogen stream and the nitrogen stream are reduced by 7.8%, 4.1% and 82.0% respectively, indicating better heat transfer performance.