The Design And Research Of Swro Erd's 4/2 Water Hydraulic Directional Valve

Seawater reverse osmosis desalination technology has developed into an important desalination approach.Energy recovery device is one of the three key equipment for reverse osmosis desalination system;it is vital importance to substantially reduce the energy consumption of the system and the cost for water output.Energy recovery device is made up of three key parts:4/2 directional control valves,four-way rectifying valve and the hydraulic energy exchange cylinder.The reversing valve,used in sea water medium,need to be solved a series of problems,such as corrosion,crossing water,leakage,dynamic quality and so on.In the seawater desalination project,the flow of salt water and the sea water are so large that a hydraulic valve control system is required to have a good quick response.In the fast commutation process of reciprocating motion,the dynamic performance of the valve must be a significant impact on system performance,while the volatility shocks of pressure will affect the life of the reverse osmosis membrane and the quality of water output.The subject used the combination of structural design,theoretical analysis,experimental investigation and simulation comparison methods to carry out research on the valve,its main contents and conclusions of this paper are as follows:1.A comparative analysis of domestic and foreign several common water hydraulic valve structure and its advantages and disadvantages are carried out.And the applicable occasions of the valve with a variety of structural forms are explored.Finally a new kind of 4/2 directional control valves applied to high-pressure flow systems is proposed.It uses the structure of the cartridge valve,including normally open to the cartridge unit and normally closed cartridge unit.Each cartridge unit is made of main flow cavity,pilot control cavity and water discharge cavity.The opening and closing of the valve core are controlled by pilot control cavity pressure of the 3/2 pilot ball valve.2.We design the structure and parameters of 4/2 directional control valve and four-way rectifier valve.Meanwhile,in order to prevent the erosion of valve effectively,electrochemical corrosion of materials,leakage and other issues,we discussed the form of valve port,the seal structure and form,material selection and matching problems.3.The performance of the water hydraulic valve was tested on the testing platform after its processing and assembly.The testing result showed that the plug-in 4/2 valve we designed achieved a predetermined logical reversing function,and the static performance meets the design requirements.4.We studied the impact of the pilot damping,spool valve damping,the gap of the cushion header,Returnning spring,pressure,flow and other factors on the valve dynamic performance by experiment.The experimental result showed that:the pilot damping,Returning spring,spool valve damping,the gap of the cushion header have a significant impact on dynamic performance.We need to choose optimization parameters to improve dynamic performance in the future work.5.Based on AMESim simulation model of the electro-hydraulic water hydraulic valve was established,we studied the dynamic response of the valve from a systems perspective.Compared with the experimental results showed that:The simulation results were in good agreement with experimental results which verified the validity of the simulation model,and it can provide a basis to further optimize the design of the structure and parameters of valve.