丙烷旋转压缩机油池中矿物油和丙烷混合物的黏度测量与溶解度推算

Viscosity Measurement and Solubility Calculation of Mineral Oil and Propane (R290) Mixture in Oil Sump of R290 Rotary Compressor

丙烷(R290)在使用矿物油(MO)的高背压旋转压缩机油池中溶解度较大,影响其充注量及油池中MO-R290混合物的黏度,进而影响旋转压缩机滑动轴承的可靠性。本研究在压缩机性能试验台及空调器系统上对多个工况下压缩机油池内的MO-R290混合物黏度和温度进行了测量,并根据MO-R290混合物的物性推算出了R290的溶解度。结果表明,所研究的空调器压缩机油池中的混合物黏度足以满足轴承的润滑需求,但由于R290的排气温度或油池过热度较低,导致其在压缩机油池中溶解度较高,从而使得MO-R290混合物的黏度降低,影响旋转压缩机滑动轴承的可靠性。因此,R290空调器选用高黏度MO时,其吸气过热度需要高于现有空调的吸气过热度,从而提高排气温度,保证油池过热度及混合物黏度处于合理范围。

Propane （R290） has high solubility in mineral oil （MO） sump of rotary compressor with high back pressure which affects the charge quantity of R290 in the system and the MO/ R290 mixture viscosity in oil sump, and further influences the reliability of bearings in the rotary compressor. In this study, measurements of the temperature and mixture viscosity in the oil sump under different conditions were conducted on both compressor performance test platform and air conditioner test system. Based on the measurements and the mixture properties, R290 solubility in oil sump was calculated. Conclusions are drawn： 1） The mixture viscosity in oil sump of rotary compressor for domestic air conditioner is enough to lubricate the bearings; and 2） Because of the low discharge temperature, higher suction superheat than the suction superheat of conventional air conditioner is necessary to obtain adequate discharge superheat or oil sump superheat to make R290 solubility appropriate and mixture viscosity sufficient.