Simulation Algorithm for Multistream Plate Fin Heat Exchangers Including Axial Conduction, Heat Leakage, and Variable Fluid Property

The effect of axial conduction through heat exchanger matrix, heat exchange with the surroundings, and variable fluid properties are included in the simulation algorithm of multistream plate fin heat exchangers. The procedure involves partitioning of the exchanger in both axial and normal directions, writing conservation equations for each segment, and solving them using an iterative procedure. In the normal direction, the exchanger is divided into a stack of overlapping two-stream exchangers interacting through their common streams. In the axial direction, the exchanger is successively partitioned to $2k$ segments, the final value of $k$ being determined by the point where further partitioning has only marginal effect. The effects of axial conduction, heat leakage, and variable fluid properties are illustrated with the help of multistream heat exchanger examples solved by the above-mentioned technique.