Design Of Fire Alarm System For Oil Depot Of Petrochemical Enterprise Based On Fiber Sensor

With the development of economy,the demand for crude oil and the amount of crude oil reserves are increasing rapidly.It is also accompanied by frequent accidents of fire and explosion in oil tanks.When the oil tank fires,the fire is fierce,burning and spreading rapidly,with high flame temperature and strong radiation energy.The characteristics of the fires also indicate that the fire in oil tank area is easy to spread,the scope of fire is large,and it is difficult to extinguish.Once the fire accident happens,it will cause life hazards,pollution of the marine environment and air environment,huge economic losses,adverse social impact,etc..With the increasing attention of the state and people on the fire hazards of oil tanks,the fire alarm and fire extinguishing systems in petrochemical enterprises have become the most important tool to eliminate and reduce fire hazards.With The optical fiber sensor has great advantages like excellent geometry,electric transmission and sensing region of arbitrary location,strong anti-interference ability,excellent mechanical properties,corrosion resistance and anti-lightning.The optical fiber sensor is very suitable for wide application in petrochemical enterprises.Based on the theory of fiber optic sensor,the working principle of distributed vibrating optical fiber sensor based on Bragg grating theory and fiber-based Mach Zehnder interference theory is expounded.According to the above theory,in this paper we design a fire alarm system based on fiber optic sensor.The fire alarm system is divided into two parts: fire automatic alarm system part,based on fiber grating temperature sensor on the oil tank;intrusion alarm system,based on distributed vibration fiber optic sensor on the oil perimeter.The two sets of alarm systems integrate a set of complete fire alarm system with the programmable logic controller PLC.The design is divided into two parts: the engineering design part of the fire alarm system,including the selection of equipment,the design of the engineering scheme and the design of the interlocking logic.The program design part of the fire alarm system is based on the programmable logic controller Configuration and Operation of Machine Configuration Software.When the engineering design is completed,the experiments on the tank fiber grating temperature sensor and the distributed vibration fiber sensor are carried out respectively.The test results under different alarm temperatures have reached the design requirements.Finally,the author makes a summary of this paper,and puts forward some shortcomings and future development direction.