This paper describes recent advances in simulation of zero flow conditions based on work with Daimler using the Air Conditioning Library from Modelon. The Air Conditioning Library is based on the open standard modelling language Modelica. Simulating refrigerant loops at (near) zero flow for large vapor compression cycles is challenging, due to the fast dynamics in the model under those conditions that drastically reduce the step size of the solver. Findings on solver selection and pressure drop correlations are presented. An approach to improve zero flow simulation based on a systematic analysis of heat transfer coefficients is suggested and demonstrated to increase simulation robustness under (near) zero flow conditions.

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Ever increasing energy demand and the stringent emission norms have resulted in the need for developing more efficient automotive systems. Fuel economy and emission targets are the two important driving factors in the development of an automobile. Efficiency of a Mobile Air-Conditioning system (MAC) has a considerable impact on the fuel economy of an automobile. This study involves simulative comparison of MAC concepts for mechanical & electrical driven systems. System models are developed for MAC concepts using Dymola simulation tool. Drive cycles considered in this study correspond to the real time driving scenarios and ambient conditions. From this study the conclusions are drawn about the most efficient ways to reach the thermal comfort for the passenger cabin in an automobile.

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