Research Of Indoor Tests And Digital Matching Of Vehicle Air-conditioning System

To fulfill the requirement of comfort, Air-Conditioning(AC) system has becomean indispensable part of modern Vehicle. Today people concern about the performanceof the AC than any time before as a result from the directly influences on the vehicle’ssafety and economy. Nowadays, the engineers design the AC system with a digitalmethod, however, when facing a case that how to choose specific components frommany sorts of them which have pass though the component indoor tests to assemble asystem, all the engineers could do is conducting system indoor tests experientially. Itcosts a large amount of money and time. Choosing the right parts to assemble anefficient AC system in a digital way is absolutely necessary. In this thesis, this kind ofapproach how to make up overall AC system numerically has been proposed, basedon the experiments of components separately. This method reduces the investmentsand the time spent on the AC system experiments and provides a way to obsolete thewrong configuration and to recommend how to get an excellent performance ACsystem.According to the component experiments, formulas have been raised to describethe characteristics of the component. Besides, the numerical models for main partshave been clarified. In this thesis, the heat transfer characteristics of evaporators andcondensers, the performance of compressor power and the mass flow feature ofthermal expansion valves(TEV) are involved. After the testing of components fromfour kinds of AC system and the analysis of relatively experimental data, we find outall kinds of characteristic equations and subsequently establish the models of everycomponent. Then the accuracy of each model has been tested. Results reveal that thedifferences between the calculation and the experiment always remain in5%relativeerror. So the entire AC system model was been built. Two sorts of AC system modelwere calculated to compare with respective experimental results. The model shows agood accuracy, which means not only the refrigerant capacity is closed to the actual data, but also both the evaporating and condensing pressure are closed to theexperimental results. After the accuracy of the model was proved, it was used toevaluate the influences of the components alternating on the performance of an ACsystem. Based on this numerical model, this paper illustrates the development ofrelevant software to analyze the performances and configuration of AC system onwindows operating system with C++language. The software was designed intographical interface to simplify the operation and possesses three main functions asfollowing: Database stage, analysis of working condition, evaluation of configuration.This software satisfies the matching work of AC system and makes it more easily.