Numerical Simulation Research On Automobile Air-conditioning System

With the development of technology and the standard of people’s life, the ride comfort has been made higher requirement, as well as air-conditioning system. How to make air-conditioning system work more effectively, cut down resource waste and optimize the structure of system have become one of the most important tasks in vehicle industry. The traditional method in designing air-conditioning system cannot keep the step of efficient design idea in modern societyin which background comes the method of computerized simulation. This paper focused on the application of simulation in design and optimization of air-conditioning system which had some value for reference.Using the large amounts of heat from phase changes, vehicle air-conditioning system helps heat exchange between the cabin and outside. Plenty of researches have been carried out in phase change. This paper concluded research results about phase change in micro-channels and air side which provided for or absorbed heat from phase change process from domestic and overseas scholars in recent years.Experiments have to be carried out in order to make sure that simulation has enough accuracy. Taking a commercial vehicle for instance, this paper built several experiments which matched the work conditions for the vehicle. Then a 1-D model for air-conditioning system had been built by KULI. After 1-D calculation and contrast with experiment, evaporator was been chosen as the main analysis target in 3-D simulation. Due to the limited source of computer,3-D evaporator model had to be simplified by some reasonable principles. In this 3-D model, User-defined Functions had been used for describe the progress of boiling. At last,1-D model had been modified based on 3-D results.1-D results with correction were more close to the experiments comparing to the original ones without correction which meant simulation combined 1-D and 3-D was feasible and more precise..Comparing to experiments, simulation takes less time and less money but with large achievement which can be used in design and optimizing the evaporator in order to save time and labor. After calculating the present evaporator, the paper came up with some improvement projects in geometry and put these projects in simulation and got best optimization by JF factor which combined the performance of flow and heat transfer. That optimization can be used in design and development in evaporator.