RU2429036C1 - Method of fire protection and extinguishing fires of oil product reservoirs - Google Patents

Abstract

FIELD: fire safety. ^ SUBSTANCE: according to the method, a liquid coolant is supplied into the lower part of a reservoir together with an oil product and/or via nozzles installed on the reservoir's bottom, the liquid coolant is supplied to the oil product surface via floating nozzles, and in the upper part of the reservoir the coolant is supplied via a nozzle installed in the reservoir roof. Sequence and duration of coolant feed into various areas of the reservoir are determined depending on oil product parameters and oil-gas-air mixture concentration above its surface. The coolant is fed into the upper zone of the reservoir in gaseous or liquid form. The coolant may be, in particular, carbon dioxide, nitrogen or a mixture of inert gases. ^ EFFECT: reduced evaporation of oil products as a result of their temperature reduction as coolant is supplied into various zones of the reservoir and reduced concentration of oil-gas-air mixture under the reservoir cover as a result of considerable difference of coolant and specified mixture density. ^ 6 cl, 1 dwg

Description

The invention relates to the field of fire safety, and in particular to the prevention and suppression of fires at special facilities, in particular tanks for storing combustible liquids.

There is a method of extinguishing combustible liquids in a tank, according to which a fire extinguishing agent is supplied to the liquid surface from the center of the tank to its walls with jets located at least three levels above the liquid surface (USSR author's certificate No. 1597201, IPC А62С 3/06). However, in this way it is impossible to provide fire protection of the tank and it is difficult to ensure effective spraying of the extinguishing agent onto the surface of the burning product.

There is also known a method of fire protection of tanks with petroleum products, including the supply of a fire extinguishing agent from generators placed stationary at the bottom of the tank and the delivery of additional generators from the bottom of the tank after a fire on a floating platform (RF patent No. 2320385, IPC А62С 3/06). In this way, it is also impossible to provide effective fire protection of the tank, and the excessive complexity of delivering additional generators with a fire extinguishing agent to the ignition zone significantly reduces the reliability and efficiency of fire fighting.

The closest set of essential features to the claimed invention is a method of extinguishing flammable liquids in a tank, the essence of which is to supply liquid carbon dioxide under a liquid layer (USSR author's certificate No. 1299599, IPC A52C 3/12). However, this method does not provide effective prevention of fire and extinguishing fires in tanks with petroleum products. As you know, to effectively prevent and extinguish oil products in tanks, it is necessary not only to lower the temperature of the surface layer of the liquid below the flash point, but also to reduce the concentration of light fractions above the surface of the liquid.

The objective of the present invention is to increase the reliability and effectiveness of preventing fire and fire extinguishing of petroleum products in tanks.

The problem is solved by the fact that in the method of fire protection and extinguishing fires of reservoirs with petroleum products, including supplying liquid refrigerant under a layer of oil product, in contrast to the prototype, liquid refrigerant is supplied to the lower part of the tank together with the oil product and / or through nozzles installed at the bottom of the tank, liquid refrigerant is supplied to the surface of the oil product through floating nozzles, and refrigerant is fed to the upper part of the tank through the nozzle installed in the tank roof. The sequence and duration of refrigerant supply to different zones of the tank is determined depending on the parameters of the oil product (temperature, density, etc.) and the concentration of the oil and gas mixture above its surface. In the upper zone of the tank, the supply of refrigerant is carried out in a gaseous or liquid state. As the refrigerant, for example, carbon dioxide, nitrogen or a mixture of inert gases can be used.

The technical result achieved by the implementation of the claimed invention is to reduce the evaporation of petroleum products by lowering their temperature when applying refrigerant to various zones of the tank and reducing the concentration of the oil and gas mixture under the tank cover due to the significant difference in the density of the refrigerant and the specified mixture.

The implementation of the proposed method is illustrated in the drawing and is as follows.

Filling the tank 1 with oil or oil through the pipeline 2 is carried out simultaneously with the supply through the same pipeline from the isothermal tank 3 of liquid refrigerant, for example, carbon dioxide, or nitrogen, or a mixture of inert gases. The temperature of the product to be poured and the concentration of the oil and gas mixture above its surface are monitored by sensors 4, 5 installed in the tank. Liquid refrigerant can also be supplied to the lower zone of the tank through nozzles 6. The liquid refrigerant is supplied from the tank 3 to the surface of the oil product (oil) through floating nozzles 7.

In case of exceeding the permissible concentration of the oil and gas mixture above the surface of the product, the refrigerant is supplied in a gaseous state through the nozzle 8 located in the roof of the tank 1.

When a fire is detected, liquid refrigerant is supplied simultaneously through nozzles 6, 7, 8.

The proposed method allows for filling (emptying) of tanks, when there is the highest intensity of oil and gas formation and, therefore, there is the greatest probability of fire, to significantly reduce the concentration of oil and gas mixture and thereby reduce the likelihood of a fire.

When storing oil and oil products due to exposure to refrigerant at different points in the tank, evaporation and the appearance of an oil and gas mixture are significantly reduced, which leads to a reduction in technological losses and the likelihood of fire.

Improving the efficiency of fire fighting during the implementation of this method is achieved by suppressing oxygen in the fire.

Claims (6)

1. A method of fire protection and extinguishing fires of reservoirs with oil products, comprising supplying liquid refrigerant under a layer of oil product, characterized in that the liquid refrigerant is supplied to the bottom of the tank together with the oil product and / or through nozzles installed at the bottom of the tank, and liquid refrigerant is supplied to the surface of the oil product through the floating nozzles, and to the upper part of the tank the refrigerant is fed through the nozzle installed in the roof of the tank, with the sequence and duration of the refrigerant different zones of the tank are determined depending on the parameters of the oil product and the concentration of the oil and gas mixture above its surface. 2. The method according to claim 1, characterized in that in the upper zone of the tank the refrigerant is supplied in a gaseous state. 3. The method according to claim 1, characterized in that in the upper zone of the tank the refrigerant is supplied in a liquid state. 4. The method according to claim 1, characterized in that carbon dioxide is used as the refrigerant. 5. The method according to claim 1, characterized in that nitrogen is used as the refrigerant. 6. The method according to claim 1, characterized in that a mixture of inert gases is used as the refrigerant.

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