Research On Simulating And Control Techniques For Deep-sea High-temperature And High-pressure Extreme Environment

The discovery of deep-sea extreme microorganism is one of the major discoveries in the marine system in the end of twentieth century. It plays a great role on the global carbon cycle, and the geochemical cycle of other living matter, and the course of submarine mineralization. The discovery of microorganism promises to provide new information about the origin of life and its evolution. The study of deep-sea microorganisms and biogeochemistry is gradually becoming a newly promising complex subject. To develop the study, truth-preserving sampling of microorganisms from ocean floor is necessary, and furthermore, it is more significant and difficult to culture the deep-sea microorganisms under the condition of field anti-pollution and detectability. But the present culturing equipments and technique at home block the scientific research. Based on the development of the multiple-stepped simulating platform for deep-sea extreme environment, the profound research on the simulating and control technique of deep-sea extreme environment is the main contents.Some pertinent research on principle design and control scheme of the circular culturing system and control system is done. The detailed analysis and statement of some key elements are made. Based on a self-developed backpressure proportional relief valve, the pressure control technique for micro-flux seawater fluid system is demonstrated in detail. The control structure and algorithm for heating control system of dominant delay are well researched. The analysis and research of the multiple-stepped simulating control system for deep-sea extreme environment are also executed. The simulating platform for deep-sea extreme environment is developed successfully. It would lay strong foundation for the study of deep-sea microorganisms and biogeochemistryThe thesis includes six chapters.Chapterl introduces the development actuality of like equipment and technique and the existent problem. In this chapter, the main research content, and key technique, and overall research program are also put forward.In chapter2, according to project requirements, supercritical sea-water hydraulic control technique is analyzed based on electro-hydraulic control principle. The structure design and characteristic of key elements are researched. At the end of this chapter, the mathematics model is built and simulation study is also done.In the third chapter, based on the theoretical research of heating control system of dominant delay, the temperature control system of the simulating platform is built. The smith-predictor-based PID control algorithm and improvement are researched in detail. The simulation and experimental studies are executed.Chapter 4 discusses the characteristic of multiple-stepped simulating system based on the principle of hydraulic circuit network. The control performance of serial and parallel structure is analyzed. The coupling relation between steps and other disturbing actors are put forward. The control software of hydraulic control system is designed.In chapter 6, based on the foregoing analysis and research, the experimental research on the multiple-stepped simulating platform is expounded in detail. The control performance and practicability of the system are further checked.