Research On The Electro-hydraulic Proportional Pressure Control Technique Of The Simulating Platform For Deep-sea Extreme Environment

By research and culturing of the sampled deep-sea microorganisms in laboratory, we can not only know the species of deep-sea microorganisms, but also observe the effect of pressure and temperature on deep-sea microorganisms. And it is also the basis of development and utilization of deep-sea microorganism resources. In this thesis, based on present status about studies and culturing of deep-sea microorganisms, a simulating platform for deep-sea extreme environment including high temperature and pressure reactors and circular flow devices is designed and developed, which is closed-loop controlled by computer entirely. It can simulate and control different living environments of deep-sea microorganisms, and will be used to exploit and research of deep-sea microorganism genetic engineering.The thesis discuss the design principle of the simulating platform for deep-sea extreme environment from the reasoning of project, design of hydraulic system and electronic control system,study of contol strategy and realization of software etc. Against the high hydrostatic pressure and microflow features of deep-sea exteme environment,based on present research and application status for seawater hydraulic elements, a relief valve with micrometeor and extreme high pressure is designed and the electro-hydraulilc proportional pressure control system of the simulating platform is accomplished. Meanwhile the analysis and experimental research of system pressure control strategy are done. Finally, on the basis of three relevant national research projects, the experimental research on the simulating platform is finished.The field experiment proved that the control performance reaches the requirements and the simulating platform is one of the most advanced systems in the are of culturing microbes in the country and abroad.The thesis includes seven chapters.The first chapter introduces the present research background of submarine hydrothermal activities and extreme ecological systems from country to abroad. And the present status of relevant sustaining technique in the area is discussed from the simulating and control technique for deep-sea extreme environment. The research and application status of proportional pressure control technique for micrometeor seawater hydraulic system is also analyzed. At the end of this chapter the research purpose, contents, key technique and meaning are put forward.The second chapter expounds the overall design principle of the simulatingplatform for deep-sea extreme environment. According to the structure components, the realizing scheme and operating principle for circular culturing system and control system are introduced detailedly. Meanwhile, the design project of other correlative modules is also given. And based on the analysis of the key technic difficulties ,the feasible solving methods are brought out.In chapter 3, based on the analysis of advantages and disadvantages of seawater or freshwater medium, against the technical requirements for simulating and control platform for deep-sea extreme environment, the corresponding solving measures are given on basis of material, design and machining technology. The proportional relief valve with extreme high pressure which is fit for microflow seawater hydraulic system is developed.The fourth chapter introduces the design principle and overall realizing method of pressure control system for the simulating platform detailedly. The theoretical analysis and research of the electro-hydraulic proportional pressure control system is discussed. The precious mathematics model about single reactor system is proposed. And with the aid of control tools of Matlab6.5, the control performance of system is analyzed.The fifth chapter discusses the PID control strategy for the electro-hydraulic proportional pressure control system. According to functional requirements of the simulating platform, the structure of system software is introduced, especially the software realization of PID control algorithms is presented.In chapter 6, based on the foregoing analysis, the experimental research on the serial and parallel culturing reaction apparatuses is executed. First, the testing experiment of the multiple stepped serial and parallel system is finished, and then two field example experiment research—culturing microorganisms and reaction between seawater and rock, The system control performance and practicability are further checked.The seventh chapter gives a brief generalization about all the research work this thesis concerns with,and a prospect about further research is given.