Rotating cylinder, Triangular cylinder, Laminar flow, Numerical solution, Free stream

In this paper, the principles of constructal theory is utilized for modeling and designing of three stream tubular heat exchangers. The target is improvement of thermal performance of this kind of heat exchangers using constructal theory especially dendritic systems. In this regard, the differential equations of a threes stream heat exchanger are extracted and its solution is achieved. A consecutive division ratio is obtained using constructal theory and Lagrange method for three stream tubular heat exchangers. this ratio reduce remarkably the design and optimization procedures of a tree-shaped three stream heat exchanger which is actually a complicated and cumbersome task. Finally, the design algorithm of a three stream dendritic heat exchanger is extracted using geometric and thermal modeling. In order to evaluate the presented algorithm, a case study is used and the results will be shown. The results shows remarkable reduction of pressure drop and heat transfer area in tree-shaped heat exchanger rather than the typical tubular heat exchangers.