Dynamic Distributed Modeling And Simulation Of Heat Exchangers In Automobile Air Conditioning System

The process of refrigeration combines heat and mass transfer, and it is a dynamic distributed-parameter system. Researching the dynamic properties of refrigeration system is a focus among the international refrigeration academia. The performance of automobile air conditioning system is a key factor of comfort of it. With the help of numeric simulation technique, we can analysis the system's steady-state and dynamic performance and the methods of optimization, thus are very important in theory and application fields.At now, the automobile air conditioning system is not as good as people wanted, and it must to be reformation. In this paper, an overview was made to the simulation technique of automobile air conditioning system. Aimed at the flaws of this field, this paper accomplished following issues.First, this paper constructs a general model of refrigerant thermodynamic properties calculation for simulation of refrigeration and air condition system based on the parametric equations of state of refrigerant. Compared with the data provided by the standard graphs and tables of refrigerant thermodynamic properties, the calculation results of this model have certain precision and meet the expectative requirements.Second, a general dynamic distributed model of heat exchangers (evaporator and condenser) in automobile air conditioning system is constructed. This model is described by Lagrange method. Base on the calculation method of tracing the little mass of liquid, a simulation model is set up. This model, is not only used to analysis the automobile air conditioning system's steady-state characteristic, but also can used to research the dynamic properties of it. The model, has good numerical robustness, settled the present key problems of the simulation, that models can not be used generalized. Hence, the genera] dynamic and distribute-parameter algorithm model research has important benefits both on theory and engineering application.At last, this paper used the general dynamic distributed model of automobile air conditioning system's heat exchangers to analysis the steady-state characteristic of automobile air conditioning system's evaporator and condenser. It also researched the dynamic characteristic of them. The results show that the model is reliable and can de used to predict the properties of evaporator and condenser precisely.