A NOVEL COUPLING DISCRETIZATION METHOD FOR MODELLING MULTI-PHASE HEAT EXCHANGERS

This paper presents a novel coupling discretization method for modelling multi-phase heat exchangers. In the method, the moving boundary method is adopted as the solver to solve each of the finite volume control volume divided by the method of finite volume method. When all finite volume control volume are solved, the finite volume control volume boundary values are updated based on the relationships of finite volume control volume. The solving procedure is initiated when the starting values of hot source fluid and cold source fluid outlet of the heat exchanger are giv-en by the user and terminated when these values no longer change anymore. The experimental results of a plate heat exchanger with R245fa and Therminol 66 as cold source fluid and hot source fluid are adopted to validate the proposed model. Simulation results of 11 operating conditions show that the maximum deviation is within +/- 4% compared to the measured values. The model presented in this paper is appropriate for heat exchangers under operating conditions either with or without fluid phase change, such as the evaporator and condenser in the ORC system.