Experimental Study on Performance of Roots Steam Compressor

The compressor is the core equipment of a vapor compression system, which significantly affects the energy consumption and stability of the system. An experimental system was built for the vapor compression system driven by the roots compressor, in which the evaporation temperature, evaporation pressure, compressor pressure, and evaporation capacity were 80–100 °C, 46.60–101.64 kPa, 17.86–36.03 kPa and 125.72–424.85 kg/h, respecitvely. The suction flow rate, compression specific power, volumetric efficiency, and isentropic efficiency of the root water vapor compressor with varying evaporation temperatures were studied experimentally. The results show that the suction flow rate (7.10–11.74 m3/min) gradually increased, and the compression specific power (310.69–158.54 kJ/kg) gradually decreased with the increase in evaporation temperature. Both the volumetric efficiency (52.21%–71.54%) and isentropic efficiency (16.48%–36.15%) increased with the increase in evaporation temperature. Increasing the frequency can enhance the efficiency of the compressor, and the measured volumetric efficiency and compression specific power were consistent with the data in previous studies. There was a difference between the experimental and theoretical values of the volumetric efficiency and the isentropic efficiency of the compressor, but this difference decreased with an increase in the evaporation temperature, and the root water vapor compressor was more stable and highly efficient in the range of evaporation temperature of 90–100 °C.