VRF, Performance Evaluation, Compressor Curve Method, Volumetric Efficiency
This paper deals with the simple performance evaluation method of variable refrigerant flow (hereafter VRF) system using volumetric efficiency of compressor. Generally, it is very difficult to evaluate the actual performance of VRF system, and it is a matter of urgency to establish the performance evaluation method on the actual condition. Especially, the simple method which can be used by user is essential to sound development of the air conditioning system. The refrigerant mass flow and the capacity are calculated by the mechanical formula of the compressor. Since only volumetric efficiency is an unknown parameter of this formula, we calculated the volumetric efficiency using the refrigerant flow meter in the several static conditions and analyzed the change of the volumetric efficiency. The results show that the volumetric efficiency is about 90% in all condition. Therefore, we calculated the capacity using the fixed volumetric efficiency as the simple method. The relative error between this method and the capacity based on the refrigerant flow meter is less than 9%.