Research On Monitoring Large Storage Tank With Optical Fiber Sensing Technology

In the oil depot of petroleum and petrochemical enterprises, there are a large variety ofenormous storage tanks are established. The production of enterprise and managementdepartment need to grasp the liquid level of tank storage medium, temperature, pressure, andother important data everyday, the accuracy and timely of date and the safety of tank are mustensured to prevent the occurrence of an accident.Due to the specific national conditions of our country, artificial are mainly relied on forthe management of Oil tank in a long time, a true "monitoring system" is not formed. In orderto prevent the explosion of tank, storage area without electric detection need to be conducted,while the storage area without electric detection can be realized by optical fiber sensingtechnique to ensure the safety of storage tanks, the measurement results are more accurate atthe same time. The optical fiber sensing technique are used to monitor the liquid level of tank,temperature, pressure and other parameter. In this paper, storage tank of50000cubic meters isconsidered as the research object, on the base of a large number of documents are referred to,the job of the following respects are conducted.1,According to the design information of East oil depot50000cubic meters of storagetank,50000meters of physical and mathematical model of storage tank are builded withFluent software preprocessor. Simulation model is arranged with corresponding boundaryconditions, floating roof is arranged into a dynamic grid at the same time to simulate thefluctuation of liquid level.2,The temperature field, pressure field of storage tank are numerically simulated throughthe Fluent software. The temperature field and pressure field of tank before and after the oilout are researched respectively in two under extreme conditions of summer and winter. Thetemperature field, pressure field, and the corresponding velocity after simulation areprocessed through the processor Tecplot. The internal temperature field of storage tank isanalyzed at last, changing regularities of the temperature field and pressure field are obtainedbefore and after oil out of tank, thus the theoretical basis are provided for monitoring largestorage tank using the technology of optical fiber sensing.3, A set of monitoring system of optical fiber sensing technique for monitoring of largestorage tank are established. The arrangement of optic fiber sensor of tank farm ininformation collection, transmission cable, and fiber Bragg grating analyzer of signalprocessing of acquisition zone transmission are included. The liquid level, temperature andpressure in the tank can be monitored by this set of monitoring system to ensure the safeoperation of large storage tank.The distribution rule of temperature field before and after the oil out of tank is obtainedthrough the study. Theoretical basis is provided for reasonable arrangement of the optical fiber sensor, accordingly optical fiber sensing technique for monitoring of large storage tankmonitoring system is established.