Design Research And CFD Simulation Analysis Of MVC Desalination Compressor

Currently, the shortage of freshwater resources has been the obstacle to the sustainable development in many developing countries. It is also our country’s problem. Some Middle Eastern countries coincidentally make freshwater from sea water. The developing experience shows that the freshwater resources will be more and more important, and the desalination is the most effective way to produce freshwater. Mechanical pressure gas distillation(MVC) desalination technology can make the best quality water compared to other methods, and this method facilitates miniaturization and low power consumption. The steam compressor is the core component in the MVC system, and the centrifugal compressor is widely used.China’s own MVC desalination technology is not mature, and the core equipment is in low localization. Now, we studied the closed impeller centrifugal compressor knot steam and aerodynamic design combined with the actual conditions of using 100m3/d MVC desalination systems in steam compressor(low compression ratio, large volume flow). Firstly, the impeller geometry parameters were calculated. Secondly the compressor impeller and volute diffuser is designed and modeled by CFturbo. Finally, make a research of the compressor by using CFD. And study the centrifugal impeller to improve its efficiency and pressure ratio and expand its stable operating zone.The original design of impeller was improved through three aspects:(1)Improving the three-dimensional structure of leaf blades based on the optimal load distribution to improve the aerodynamic performance of the impeller;(2)In order to reduce flow separation phenomenon of the impeller at the exit, adjusting the width of the impeller at the exit in the form of the impeller optimal load distribution, further improving the work performance of the impeller;(3)By improving the position of the leading edge of the blade, changing the blade inlet area, expanding the scope of the impeller stable condition. After design improvement, the polytropic efficiency of the impeller rises by 2.95 percentage points, the pressure ratio also meet the design requirements, and the stable operating conditions area become significantly wider, the condition of flow separation of the flow field in the impeller channel has been improved.