| As a new resource rise in the 21 st century,submarine natural gas hydrate has shallow burial and large reserves.Submarine natural gas can replace oil,natural gas and other energy sources which has great development prospects.However,as our country deepens research for submarine natural gas,the disasters such as land subsidence and methane leakage often occur during the investigation.Therefore,it is crucial to strengthen the in-situ monitoring of submarine gas hydrate environment.In this paper,an in-situ monitoring system(also known as a deep-sea lander)is designed and implemented to monitor the gas hydrate area to simultaneously obtain long-term continuous environmental effect data parameters.The main contents include the following parts:(1)The selection of marine instruments and equipment are introduced and the overall scheme of in-situ monitoring system was designed according to the actual engineering application.The design system is divided into landing and release modules,rotary platform modules,microelectrode sensor mechanical packaging modules,and data acquisition modules.These four modules correspond to the system’s floating and seat bottom functions,in-situ multipoint detection function,multi-parameter acquisition function,overall control and data storage function respectively.(2)A carrier aircraft architecture design is created in the landing and releasing module.In addition,a software named ANSYS,is used to perform the statics simulation analysis to verify the rationality of the frame structure design.A balance calculation is also carried out to verify the overall balance of the system.As for the acoustic releaser,it is selected and built with solid buoyancy materials,which is a weight release device is designed to cooperate with it to better release the ballast weight so that the system can rise to the sea.(3)The rotating platform is composed of gear transmission mechanism,rolling wheel mechanism and penetration mechanism,and the transient dynamic simulation analysis was mainly performed for the gear transmission mechanism to verify the strength of the gear.(4)A protective shell,which has good pressure resistance and airtightness and an assembly method are applied to the design of the microelectrode sensor,and it is checked.At the same time,the assembly method is introduced in detail.(5)To complete the control of the system and store the data collected by the sensors,we have designed the hardware circuit,the lower computer control software and the upper computer operating software.(6)After the complete engine is assembled,various modules are tested on land,and combined tank test is completed.Finally,the "Zhang Jian" scientific research ship is launched for systematic offshore test in the South China Sea. |
