Modelling Heat Exchanger Of Automobile Air Conditioning System

Since entering 21 centuries, accompanied with automobile popularization, the automobile industry has been developing rapidly. The Automobile Air Conditioner(AAC) is concerned by more and more people ,and the modernization of the designs method on the Air Conditioner become a focus among the international refrigeration academia through the world.The primary point of the designs method is the matching of different parts of Air Conditioner system on dynamic characteristic. To reach this target, the work should employ not only the Information Technique ,but also the thermodynamics theory .Same thing applies to condenser and evaporator which affect directly the behavior of the refrigerant System as the main heat exchange equipments in the refrigerant system.Condenser and Evaporator are the main equipments in the refrigerant system. To modeling a heat exchanger to acquaint and grip the working performance of different refrigerant in a AAC system can accelerate the equipments choice matching. Furthermore which has the important practical meaning for the modernization of AAC designs .This thesis, emphasizing on theoretical research of dynamic simulation and optimization of AAC system, make use of the computer simulation opinion and thermodynamics theory to establish a subsection model for the heat-exchanger. The special principle of mass-heat transfer is also handled to erect the model by analyzing the characteristics of the heat exchanger structure.According the characteristics of heat exchanger, the number of flow phases and the flow structure in the heat exchanger vary when heat transfer area, heat transfer coefficient or pressure change. Subsection models was founded respectively, and that the simulation model has been set up through Advanced Continuous Simulation Language (ACSL) correspondingly.The subsection heat exchanger model is not limited to special equipment structure and a particular refrigerant, so it can work in different refrigerant and different heat exchanger. Examinations of steady status and analysis of dynamic experiments have been conducted on Band-Tube evaporator and Parallel-Flow condenser using R134a refrigerant. The steady examination show that the model error was under the allowable error, The inlet mass and enthalpy disturb experiments indicate that the subsection model ,be good at reflecting the change of parameters of the heat exchanger, accord with the basic principle of thermodynamics theory and the actual work status. Hence, the subsection simulation model research has important benefits both on theory and engineering application.