Air conditioning system modeling for car fuel economy simulation

Sammanfattning: The automotive air conditioning system is the greatest auxiliary load of a vehicle, having a considerable impact on its fuel consumption and CO2 emissions. For this reason, forecasting the influence that this sys-tem has on the fuel economy of a car is desired. The present work is dedicated to model the air conditioning system of a plug-in hybrid ve-hicle in order to predict its energy consumption. GT-SUITE was chosen as the simulation tool, where the air condi-tioner, which is a vapor-compression refrigeration system, was mod-eled by specifying its components: compressor, evaporator, thermal expansion valve and condenser. Moreover, additional sub-systems which influence the energy consumption were also considered, these are the vehicle’s cabin and the battery cooling loop. The simulated model shows good agreement with test data for impor-tant parameters such as the compressor power consumption and the air temperature after the evaporator. The percent difference between the test data and the simulation for the auxiliary power consumption (energy consumed by the A/C compressor and the charging load of the low voltage battery) is 6.25%.