تجزیه و تحلیل عملکرد و شبیه سازی سیستم تهویه هوای خودرو

Performance analyses of separate components of an automobile air conditioning system have been carried out under various operating conditions. The air conditioning system consists of a laminated type evaporator, a swash plate type compressor, a parallel flow type condenser, a receiver drier and an externally equalized thermostatic expansion valve. A computer program for performance analysis of the laminated type evaporator has been developed on the basis of the overall heat transfer coefficient and pressure drop which were obtained experimentally. A computer program for performance analysis of the parallel flow type condenser, using an empirical equation for the heat transfer coefficient, has been developed, which demonstrates that the predicted condensing capacity agrees very well with the experimental data. Then, a model for combining the performance analysis programs of separate components of an automobile air conditioning system is proposed, which simulates very well the performance of the integrated automobile air conditioning system. Further, the effects of condenser size and refrigerant charge on the performance of the integrated automobile air conditioning system are discussed.

The overall heat transfer coefficient and pressure drop in a laminated type evaporator have been obtained experimentally, based on which the performance analysis program for the evaporator is developed. The performance analysis program for a parallel flow type condenser is developed by utilizing extant correlations, which demonstrates that the predicted condensing capacity agrees very well with the experimental data. Then a performance simulation program for the integrated automobile air conditioning system has been developed by combining the performance analysis programs of separate components constituting an automobile air conditioning system. The following conclusions have been drawn from the performance simulation of the integrated air conditioning system: 1. An overcharge of 10% proves to be most effective for various operating conditions. With an overcharge above this level, the COP rather tends to drop. 2. It is possible to select the most appropriate condenser size by executing the system performance simulation program for various operating conditions.