Navid Kashani Nejad

A dynamic Simulation of Automobile Air Conditioning (AAC) systems with screw compressor coupled with cabin thermal environment is presented here.Two objectives have been followed in this research:first, presenting a computational model to simulate the performance of an Automotive vapour compression cycle specially in transient state in order to decrease vehicle fuel consumption and emissions across the nation.Second,by introducing a commercially available analytic software tool called SINDA/FLUINT [1],the results from transient simulation have been compared and good agreement was found.An innovation approach is implemented to obtain governing equations ,that is,high pressure and low pressure segments are divided into three control volumes ,including the refrigerant inside tube,the tube wall and the fluid outside the tube.Time dependant ordinary differential equations are obtained from the mass and energy balances for each control volume.Since the expansion valve and compressor both have very small thermal interia,the steady state models vere applied for these components.System simulation is finally carried out with predictor-corrector and adaptive integration step methods in MATLAB language[2].Based on the commercial software ,a computer simulation of the vehicle climate control system has been developed [3].The calculation data have good agreement with SINDA/FLUINT simulation ,which lead to conclusion that the model can be used as a tool for the product development..

vehicle climate control,car cooling ,vapour compression