Key Technology Reserarch Of Water Hydraulic Directional Valve Applied In Deep Sea

Water hydraulic transmission using seawater or fresh water has caught attention as a developing new technology of hydraulics in the world.Seawater hydraulic directional valve is one of the most important and basic control components in seawater hydraulic systems,which control the reliable action of actuating element(e.g.hydraulic motor and hydraulic cylinder)for seawater hydraulic systems.It can be widely used in underwater tools system,fire extinguishing,metallurgy,mining device,food processing and packaging,agricultural machinery,high-pressure water jet cleaners,nuclear industry,seawater reverse osmosis desalination systems and so on.The key techniques of seawater hydraulics are concentrated on the research on the seawater hydraulic directional valve,owing to the research based on the synthesizing application of water hydraulics,novel materials,tribology,mechanism,etc.Therefore,the research on the seawater hydraulic directional valve is meaningful.In this paper,the research object is water hydraulic directional valve applied in deep sea.Aiming at the key technical problems of hydraulic valve in marine environment,this study compared the friction and wear mechanism and electrochemical corrosion mechanism for the sealing materials of seawater hydraulic valve commonly,and made a quantitative analysis of the interactions between corrosion and wear of materials.Based on the wet electromagnet,a self balance technology for the seawater pressure is put forward to being applied in the sampling valve.The feasibility of full immersion electromagnet used in seawater hydraulic solenoid valve is discussed,and the experiments are carried out.A fractal model for the leakage of the sealing in hydraulic cone valve is established,and used to reveal the effect of sealing pressure on leakage of valve port.Meanwhile,based on the stress strength interference theory and considered the correlation between the multiple failure modes,the reliability of sealing spring in the hydraulic valve is analyzed.Taking the seawater hydraulic cartridge-type 4/3 directional valve as an example,the laboratory test and sea test method are further perfected.The concrete works in this dissertation are as follows.(1)The research progress of water hydraulic reversing valve at home and abroad is summarized and summarized,and the performance characteristics and development of water hydraulic directional valve at home and abroad are compared.The application prospect of the hydraulic cartridge-type 4/3 directional valve is emphasized.Then the research status of corrosive wear and sealing reliability of hydraulic valve port under seawater environment is summarized.At last,the key technical problems and main research contents of this paper are put forward.(2)The corrosion and wear mechanism of sea water environment to the sealingaccessory material of valve mouth is explained,and made a quantitative description of the mathematical relationship between the interaction of corrosion and wear.A comprehensive electrochemical test device for the seawater corrosive wear is built,and the tribological test and electrochemical corrosion test are measured,thus the important parameters of corrosion and wear of the valve port sealing are obtained.The interaction between corrosion and wear in corrosion wear is discussed in depth,and the negative interaction of corrosion and wear is compared and analyzed.(3)A deep sea sampling method driven by the hydrostatic pressure energy is introduced.And a pressure self balancing sampling valve technology based on wet electromagnet is proposed.Then the electromagnet is simulated and analyzed by the multi-physical field coupling theory,and the static and dynamic properties of the wet electromagnet are studied,on this basis,a 2/2 directional valve used in the deep-sea acquisition is designed and developed,and laboratory and deep-sea simulation experiments have been carried out.Through the comparison of simulation and test,it is proved that the sampler prototype can complete the collection of gas hydrate in the deep sea environment.(4)On the premise of considering the corrosion and wear of sea water,high pressure flow and high reliability,a design scheme of seawater cartridge valve based on full immersion electromagnet is proposed.The feasibility of the full immersion electromagnet used in the seawater electromagnetic valve is verified by the test.And the mathematical model of seawater hydraulic cartridge-type 4/3 directional valve is established,and using the single parameter analysis and multi parameter genetic algorithm analyzed the key structure parameters of the directional valve.By comparison and analysis,the key structural parameters that affect the dynamic performance of the directional valve are optimized,and the dynamic response time is improved.(5)For the leakage failure of hydraulic cone valve port sealing,a fractal model for the leakage of the cone valve port is established.The comprehensive and uniform corrosion test for the sealing materials of the valve port under the seawater pressure are carried out,and to be modified the material corrosion attenuation model under the seawater pressure.The reliability analysis method related to the seal failure of the hydraulic valve port is put forward,and based on the stress-strength interference model,the reliability of multiple failure modes for valve port sealing spring is analyzed,which provided the theoretical basis for the sealing reliability of the valve mouth of the hydraulic pressure reversing valve.(6)On the basis of the above research,a full immersion seawater hydraulic cartridge-type 4/3 directional valve prototype is developed.And the test system for hydraulic reversing valve of sea water is set up.The performance test method of seawater reversing valve is systematically studied.At last,the dynamic and staticperformance test in laboratory,the deep sea simulation test and the marine test research are completed.The test results show that rated pressure is 14 MPa,rated flow rate is 160 L/min,dynamic opening time is 109 ms,dynamic closing time is 128 ms,which satisfies the requirements of established technical indicators,and it is able to work normally in the deep sea environment.Finally,a summary of the the concrete works in this dissertation is proposed and the further research direction is suggested.