Abstract: A general steady state and distributed parameter model of fin-and-tube heat exchanger is developed based on graph theory and traversal methods, in which the performance of fin-and-tube heat exchanger with the complex refrigerant circuitry can be predicted. With the help of the directed graph and graph-based traversal method (Breadth-first search and depth-first search), this model Canbe used to describe any flexible refrigerant circuit arrangement, and quantify the heat conduction through fins. The model is verified with the experimental results, and the average error of heat transfer and pressure drop are within ±5.0% and ±20.0%, respectively. It is concluded that the steady state model can be used as a tool to design and optimize the compact heat exchanger.

Key words: Graph theory, Heat exchanger, Steady state