Design And Research Of High Resolution Gas Hydrate Geophysical Sensor

As a new type of unconventional energy source with broad development prospects,natural gas hydrate is called “the cleanest energy source in the 21 st century” because of its high energy density,large scale and wide distribution range.China’s natural gas hydrate resources are extremely rich.As an important strategic resource,natural gas hydrate development has broad prospects.Therefore,the design and research of high-resolution natural gas hydrate geophysical sensors is of great significance and value for the utilization of natural gas hydrates.Compared with other types of gas sensors,metal oxide semiconductor gas sensors have the advantages of high sensitivity,fast response-recovery time,simple preparation process and low manufacturing cost.The advantages of thick film gas sensors are more obvious.The high resolution gas hydrate geophysical sensor based on tin dioxide thick film is designed and studied in this paper.Aiming at the design and research of new gas hydrate geophysical sensor,the main work of this paper is as follows.Firstly,the mechanism of physical and chemical adsorption of tin dioxide gas-sensing materials is systematically summarized.The mechanism of different reactions of tin dioxide in oxidizing or reducing gases is used to explain the nature of the change of resistance value of tin dioxide.Secondly,the arrangement of electrodes is redesigned based on the theory of conductivity measurement to ensure that the calculated values of conductivity of tin dioxide formed by new electrodes and traditional interdigital electrodes are the same.Statics and CFD analysis are used to analyze the tin dioxide matrix formed by the new electrode and the interdigital electrode.In both cases,the performance of tin dioxide matrix under the new electrode is better than that under the interdigital electrode.Thirdly,based on the finite element method,ANSYS Workbench platform response surface optimization analysis tool is used to optimize the shell design of gas hydrate geophysical sensor head.The shell of gas hydrate geophysical sensor is designed and its compressive strength is analyzed.The simulation results meet the requirements of compressive strength.The working principle of thick film gas hydrate geophysical sensor is analyzed,the parametric model of gas hydrate geophysical sensor is established,and the overall structure and key components are analyzed.Finally,the design scheme of underwater methane gas on-line monitoring and calibration device is analyzed.The performance of gas sensor is tested by voltage detection method.The structure design of gas detection device is completed.The comprehensive performance experiment of gas hydrate geophysical sensor is carried out.The key performance parameters such as sensitivity,time characteristic,repeatability and long-term stability of the new thick film gas hydrate geophysical sensor are obtained.