Research Of The Key Technology For Gas-liquid Separation In Marine Environment

In the1970s, the discovery of hydrothermal vent biota lifted the curtain of theresearch and exploration on the deep fluid and its related areas, which became a hotspot of the international cutting-edge research quickly. With the hydrothermal sulfideminerals, gas hydrate minerals and authigenic carbonate precipitation phenomenonbeen discovered in succession, the scientists realized the deep fluid has both hugeeconomic value and potential global climate factors. For these reasons, much moreattention were paid to the deep fluid system.There are many approaches to study on deep fluid, but the conventionalapproaches including drag have some inevitable shortcomings. So the scientists paymore attention to the seafloor situ detection. Because dissolved methane and carbondioxide is rich in the deep fluid, the studies on the concentration and distribution ofthe two gases in deep fluid would be helpful to the researches in hydrothermalsolution, cold spring, oil and gas exploration in deep sea. For these reasons, theconcentration and distribution of methane and carbon dioxide become an importantindicator in the situ detection of deep fluid.However, the commonly used methods in detection require the two gases to beseparated from seawater. Under this situation, this paper presents a method usingvacuum degassing to separate the two gases from seawater. And a gas-liquidseparation system is designed which can meet the need of long-term continuousobservation of dissolved methane and carbon dioxide in deep sea. This design canintegrate spectra and electrochemical technology into underwater detection system,and can provide more accurate detection.The main contents of this paper are as follows: In the first part, it mainly introduces the present research status of dissolvedmethane and carbon dioxide in deep sea, and analyzes some sensors and detectionsystem used in this field. It analyzes the main causes and sources of the two gases,and expounds the significance of the study on the concentration and distribution of thetwo gases. At the end of this part, it introduces the existing degassing methods andtheir relative merits.In the second part, it introduces the two theories: the principle of vacuumdegassing and the infrared detection principle.In the third part, it minutely introduces the construction of the system, itsprimary structure and its working process. It introduces the operating principle andperformance index of each device, the construction of the hardware circuit andsoftware. At the end of this part, it tests some key module and analyzes theexperimental results.Through the preliminary experiment of the system and the analysis of theexperimental results, the paper comes to a conclusion that the system can reach thepurpose of design.