Study On Performance Attenuation Of Automotive Air Condition

Countries around the world are concerned about energy and environmental issues,improving the utilization of energy efficiency and reducing greenhouse gas emissionsare effective solution to these problems. Automotive air conditioning is one kind of themain source of refrigerant leakage and energy consumption. Its energy saving andemission reduction is to receive widespread attention. Basing on computer simulationtechnology, simulation models of automotive air conditioning system and componentsperformance analog and refrigerant leakage were established on software Visual Basic6.0. The validity of these models was verified by corresponding experiments. Theperformances of automotive air conditioning systems and components were simulatedof different kinds of conditions through these models and the impact of scaling,corrosion, refrigerant oil content, refrigerant leakage, and other factors on theautomotive air conditioning systems and components performance were predicted. Thework mainly includes the following aspects:①Thermodynamic parameter and status parameters simulation programs of R134aand air were built. The results of the calculation and analysis of the correspondingparameters showed that the calculation program was with a high calculation speed andhad a good accuracy, from which can provide effective support for the automotive airconditioning system simulation.②Laminated evaporator model and sub-cooling parallel flow condenser modelwere built from steady state distributed parameter model. In the program, the impact ofphase distribution and flow path on heat exchangers were comprehensive consideration.Models of a single working chamber rotary vane compressor, dual-chamber rotary vanecompressor, thermostatic expansion valve and cooling piping were established based onthe steady-state lumped parameter. The system model was a coupling of these modelsaccording to the energy and mass conservation.③Based on performance test methods and standards of automotive airconditioning, performance of compressors, evaporators and condensers were tested. Thetest results were found in good agreement with the result of the simulation program.Which indicated that program can simulate the performance of air conditioningcomponents well.④Prediction models of impact of scaling, corrosion, oil content of the refrigerant, the refrigerant leakage on the systems and components performance were establishedbased on the simulation programs of systems and components. The dynamic model ofrefrigerant leak was accomplished according to SAE J2727and SAE J2763. The resultsshowed that: the air conditioning refrigerant leakage of the sample car is32.042g.