Experimental Investigation On Oil- Refrigerant R410A Mixture Leakage In A Rolling Piston Type Rotary Compressor

China is the largest country who is manufacturing and consuming air conditioning equipment. This is good for the development of peoples' living standard, but can also cause environmental concerns and big energy consumption. In order to protect our environment, China is accelerating HCFCs refrigeration replacement, this will promote the consumption of HFCs. R410 A belongs to HFCs, its development and research will be meaningful. The rolling piston type rotary compressor almost occupies the whole domestic air conditioning units market. The internal leakage in a rolling piston type rotary compressor can cause around 33.2% of the overall mass flow loss, which has been the key factor affecting the compressor volumetric efficiency.Experimental investigation on internal leakage in a rolling piston type rotary compressor was proceeded. Firstly, a physical model of foam flow leakage was established to evaluate the oil-refrigerant R410 A mixture leakage through radial leakage channel and piston faces leakage channel. In order to make sure specified pressure, temperature and dissolve rate of the oilrefrigerant R410 A mixture leak through radial and piston face leakage channel, a unique test bench was designed and set up. Then, experiments were carried out to verify how the drive pressure, the geometry of leakage channel, viscosity of fluid and the liquid film length would affect the refrigerant leakage mass flow rate. Finally, an empirical modified formula which was derived from Navier-Stokes equation was fitted on the base of experimental data. The empirical modified formula shows that when the two phase mixture flows through micron-size channel, the influence of the geometry of flow channel, the drive pressure and the viscosity of fluid can be different from ordinary macro flow. By applying the empirical modified formula in a working rolling piston type compressor, the liquid film length effect on the volumetric efficiency can be derived.The results can provide reference to the study on micro clearance leakage flow in rotary piston type compressor and could give good advice on the design, processing and assembling of rolling piston type compressor.