Cause analysis and investigation of the hottest oi

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With the rapid development of national economy, oil and petroleum products are more and more widely used in production and life, and all kinds of oil depots and gas stations are increasing. Oil tanks are the most important equipment for storing bulk oil, and oil tank storage is the most commonly used way of oil storage at present. All kinds of oil products stored in oil tanks are generally volatile, easy to lose, easy to burn, easy to explode and other properties. Once a fire occurs, it will cause significant losses. Studying the fire causes and investigation methods of oil tanks is of great significance to eliminate fire hazards, formulate practical safety measures and management systems, so that the impacted surface of 10 samples should be consistent, and improve the technical level of fire personnel

I. risk and overview of fire

(I) the oil in the tank is mainly composed of hydrocarbons, and there is a risk of combustion when heated, exposed to fire and in contact with oxidants. The lower the flash point and natural point of oil products, the greater the risk of combustion. When the mixing ratio of steam and air of petroleum products reaches the lower explosion limit concentration, it can explode in case of sparks

(II) the resistivity of petroleum products is about 1012 Ω • cm, which is most likely to accumulate slowly in the process of loading and unloading, canning, 1. GB 10006 (1) 988 plastic film and sheet friction coefficient measurement method, pumping and other operations, resulting in static charges, resulting in oil tank combustion and explosion

(III) the oil with low viscosity has strong flow and diffusion, and will quickly flow around if there is leakage. The Expansion Department of oil products will verify it regularly every year. The dispersion and mobility are the risk factors leading to fire

(IV) steam pressure and volume expansion of petroleum products after heating. If the container is too full or stored in a closed container, the oil tank will expand, even explode and cause fire

(V) when heavy or moisture containing oil products in the oil tank are burned, some of the burned oil products overflow in large quantities, and some are violently ejected from the tank to form a huge fire column up to meters. The downwind spray distance of the fire column can reach about 120 meters, which is easy to burn directly to the adjacent oil tank and expand the disaster area

the investigation results of domestic refineries show that in all tank fires, crude oil tanks account for 40%, gasoline tanks account for 32%, diesel tanks account for 8%, and heavy oil tanks account for 20%. It can be seen that the oil products with flash point lower than 28 ℃ account for 72% of all tank fires. The top cover of the vertical steel oil tank is completely lifted, accounting for 40%, and in most cases, part of the top cover of the oil tank is lifted, causing a certain danger

II. Main causes of oil tank fires

in this paper, the causes of oil tank fires are mainly divided into the following seven categories from the perspective of fire source:

(I) open fire ignition, ignition of sparks in the flue near the oil tank, sparks from vehicles, flying fires of firecrackers and paper burning, illegal smoking in the reservoir area, open fire, electric welding operations, etc., which are very easy to ignite oil leaked on the ground or ignite oil vapor diffused in the air. At 4:32 a.m. in September, 2001, Shenyang, located at No. 140, Shenyang new road, compared with the current aluminum chassis city DALONGYANG Oil Co., Ltd., due to the gasoline overflow in the oil tank during the oil pouring process, a large amount of volatile gas flowed into the garage 160 meters away. When the driver started the car, the fire ignited the gasoline volatile gas, resulting in a vicious explosion and fire in eight storage tanks in the buildings in the northeast of the irrigation area. If the oil leaks and the oil vapor diffuses into the boiler room, stove room, power distribution station and other places, it is very easy to cause combustion or explosion. If the oil tank is not equipped with a flame arrester, the hydraulic safety valve is short of oil or the sealing ports are not tight, it is easy to introduce external fire into the tank, causing combustion or explosion

(II) explosion caused by static spark

liquids with resistivity of about 1012 Ω• cm are most likely to generate accumulated static electricity. The resistivity of most oil products is greater than 1012 Ω • cm. They are electrostatic substances, which are easy to generate and accumulate electrostatic charges, and dissipate slowly. Electrostatic accumulation often occurs as follows:

1. Oil flows in the pipeline

2. Filtration of splashed oil

3. top of tank car and oil tank

4. rapid evaporation and leakage of oil products

5. oil passes through the pump

6. After the oil tank is washed, the water settles from a certain volume of oil products

7. shaking and oscillation of sampling or transportation

8. Static electricity carried by human body

9. wear chemical fiber clothes

10. oil products in plastic barrels

due to the excessive grounding resistance of the oil tank (greater than 100 Ω), or the failure of the device to eliminate static electricity, or the poor contact between the isolated conductor (such as the floating roof) and the oil tank, it is easy to accumulate static charges. Once discharged, sparks are formed, which are enough to ignite or detonate the diffuse oil vapor

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