On-line Monitoring Of Natural Gas Storage Tank Leakage Based On Fiber Optic Sensing Technology

In recent years,fire and explosion accidents caused by leakage of vertical liquefied natural gas storage tank occur frequently around the world.It not only seriously threatens life security,but also has negative effect on the surrounding environment.Therefore,the usage of optical fiber temperature sensor temperature measurement technology which monitors the outer wall temperature of the vertical liquefied natural gas storage tank timely can help to master the rule of the tank's external temperature change during the leaking process.As a result,it will offer the necessary technical guidance for safety control staff to timely prevent and control liquefied natural gas leakage and take remedial action,as well as ensure the enterprises to reduce security risks and achieve the production essential security.In order to study the variation in ambient temperature caused by the leakage and diffusion of vertical liquefied natural gas storage tank,Mathematical Model of Tempe rature Field Variation of Outer Wall of Vertical Liquefied Natural Gas Storage Tank in Leakage Period should be built,and then on the basis of distributed fiber temperatur e sensing technology positioning principle,reasonable analog fiber winding arrangemen t will be settled for a vertical gas storage tank.The vertical temperature field changes of the gas tank could be demonstrated through light and electrical singals.Then,ac cording to the temperature curve changes in the graph,the change law of the temper ature field of the outer wall of the tank is oconclused when the liquid natural gas lea ks in the storage tank.Based on the analysis,the corresponding conclusions are drawn: under the precondition and basic assumptions,the temperature curve of the tank's outer wall is obviously descended during leakage process which monitored by the temperature sensing fiber.And the closer to the leak area,the more severe the temperature drops,and the shorter time required;while the farther away from the leak port,the smaller the temperature drops,and the longer time required.The temperature of the relevant detection area also drops differently with various distance from the leak port.Since the outer wall of the tank temperature changes significantly only ascribed to gasification endothermic after liquefied natural gas leakage occurred,it can be concluded that the vertical liquefied natural gas storage tank has leaked and can be accurately found through the optical fiber temperature sensing positioning technology whichoffers technical advice for safety workers and guarantees safe operation of storage tanks.