Abstract: The inner flow and performance of vacuum pump and compressor conditions of 2BE liquid-ring pump were analyzed by using numerical simulation and experimental method. Analysis results show that the volume flow rate of compressor is less than that of the vacuum pump under the same pressure ratio, and the ratio of volume flow rate and efficiency decrease with the increasing of pressure ratio. The distribution of phase, velocity and pressure field are basically the same under the conditions of vacuum pump and compressor. The secondary flow in the exhaust zone and the transition zone of the compressor are obviously stronger than those in the vacuum pump condition. Under the same variation of pressure ratio, the pressure in the exhaust area of the compressor increases significantly. The frequency characteristics of pressure for the pump casing shows obviously partition characteristics along the circumferential direction. The main frequency characteristic of vacuum pump is the same as that of compressor. Under different pressure ratios condition, the pressure fluctuation amplitude of the inner wall of the pump housing in compressor condition is larger than that of the vacuum pump. With the increase of the pressure ratio, the pressure fluctuation amplitude for the compressor exhaust zone and transition zone increases obviously.

Key words: liquid ring pump, compressor, vacuum pump, pressure ratio