Experimental investigation of the water–injected process-gas screw compressor

Abstract

The test rig for water-injected process-gas screw compressor is designed and established. The dry gas seal technology was adopted for the shaft seal of screw compressor and the test rig has the function of regulating and controlling the mass flow of injected water. The performance characteristics of process-gas screw compressor under different working conditions are investigated by experimental research. The effect of rotational speed, the injected water mass flow, and the discharge pressure on the performance of screw compressor including discharge temperature and power consumption were obtained. The experimental results show that the water injection could reduce the discharge temperature of compressor significantly and increase the capacity of screw compressor at the same time. There exists an optimum mass flow of injected water that could effectively reduce the discharge temperature and seal the clearance between the female and male rotor simultaneously. For the tested screw compressor prototype, the proper injected water-to-air mass ratio is about 2–3 L/m3. The additional power consumption caused by the injected water is small compared with the total shaft power. The established compressor test rig and the experimental results are helpful for the development and improvement on the performance of water-injected process-gas screw compressor.