Measurement of refrigerant mass distribution within a R290 split air conditioner.
Abstract R-290 (propane) has been chosen as one of the most potential next generation working fluids of RACs because of its favourable environmental and thermo-physical properties. However, its use is hindered by its flammability and resulting concerns on safety. In addition, the charge mass is limited strictly by the standards which would impact RAC's heating performance. In this paper, refrigerant mass distributions within a R290 split type air conditioner were experimentally investigated at both static and dynamic state, in which the liquid nitrogen method (LNM) was used to determine the refrigerant mass inside the components of the circuit. The distribution of refrigerant that changes with temperatures and compressor speed were also measured and discussed. The results can assist with improving the design of the products (performance improvement, safety measures, etc.) and providing data for further theoretical study and simulation analyses.