water injected twin screw compressor, mechanical vapor compression, p-V diagram, efficiency, design guidances
The mechanical vapor compression (MVC) system is a promising way for energy saving among energy intensive industries such as desalination, food and beverage, chemistry and waste water concentration etc. In practical its application is limited by the vapor compressor technology which is demanded to have high pressure ratio for large saturation temperature difference and low discharge steam temperature. Due to the ability of wet compression, twin screw compressor can overcome the technical limitation above by the injection of liquid water into the working chamber. In this paper a test rig of a MVC system with water injected twin screw compressor has been designed and built. Compressor performance of flow rate, power consumption and discharge temperature was measured. Moreover, operation characteristics of the water injected twin screw compressor were studied by the measurement of its working process p-V diagram. Volumetric efficiency and adiabatic efficiency of the compressor variation under different operation conditions were calculated. The mass flow rate and temperature of injected water was also measured and adjusted for optimization. The results of the experiment study can provide some design guidances of water injected twin screw compressor for mechanical vapor compression system.