2017, 32(9):40-44.
摘要:
For refrigerant R32 as popular alternative refrigerant of R22, the high discharge temperature influences seriously the reliability of long time operation for compressor. The wet compression method can reduce the discharge temperature of compressor, but it also can reduce the compressor efficiency. Through the experiments under the condition of variable frequency with constant pressure ratio and the condition of variable pressure ratio with constant frequency, the effects of different suction state on the efficiency of rolling rotary compressor were studied, and the relationship between isentropic compression efficiency and volume efficiency with different suction states was summarized. The experimental results show that: when suction refrigerant is superheated, compressor can maintain a high isentropic compression efficiency and volume efficiency. The superheat degree has little effect on compressor efficiency. However, the change in the efficiency of the compressor with vapor-liquid mixture suction is different as suction refrigerant is superheated. Compared to x = 1, with x = 0.9, the isentropic compression efficiency and volumetric efficiency decreases by about 7% and 5%, respectively; the overall reduction is very small. With constant frequency, the greater the pressure ratio is, the larger the reduction in compressor efficiency. With constant pressure ratio, the higher the frequency is, the smaller the decrease. The trends of the isentropic compression efficiency and the comprehensive efficiency coefficient are consistent.