Improved prediction of the temperature distribution in a HVAC module by coupling a CFD and a heat exchanger analysis program

摘要

The prediction of the temperature distribution inside HVAC units by employing computational fluid dynamics (CFD) requires a reliable simulation of heat transfer in the heater core and the evaporator. Heat transfer in these components depends on local fluiddynamical and thermodynamical phenomena on both fluid sides, the air side and the liquid side. Therefore the computational model used for the heat exchangers has to take account of the local heat and mass transfer mechanisms on both sides. Analysis programs for heat exchangers, which have been previously developed at Behr, fulfill these needs. These analysis programs have been implemented in the commercial CFD code STAR-CD used for the simulation of HVAC units.Analyses of different evaporators and heater cores have been performed. Comparison of the predicted thermal performance and air temperature downstream of the heat exchangers with experimental data shows good agreement. Analyses of a HVAC module simulating different operating modes have also been carried out.