RU132158U1 - PROTECTIVE PROTECTION OF THE LIQUID NATURAL GAS STORAGE TANK - Google Patents

Abstract

A protective fence for the liquefied natural gas storage tank, containing screen partitions mounted on a foundation under the tank with a platform whose surface is inclined towards the pit located at the base of one of the screen partitions, characterized in that the protective device is additionally equipped with an evaporator tray and a unit tray control valves, while at the base of the screen partition installed between the evaporator tray and the platform for the tank with liquefied natural gas, and also a screen partition installed in front of the pit, drain windows are located.

Description

The utility model relates to the field of energy, in particular to a structure that provides a limitation of the area of a possible emergency spill of liquefied natural gas (LNG).

According to SNiP 21-01-97, SNiP23-05-95, SNiP 2.09.02-85, SNiP 2.01.02-85, SNiP 2.09.03-85, a natural barrier formed by the relief of the terrain or artificial, continuous perimeter structure, impermeable to LNG (pallet).

The height of the protective fence and the distance from its inner sole to the tank wall are determined by the project from the condition of exclusion of LNG transfusion outside the fence (including cases of leakage of LNG at its maximum design fill), but at the same time, the height of the protective fence must be at least 0, 3 m more than the height of the liquid level formed when the estimated volume of LNG is completely poured out of the storage. An annular protective fence is located in the immediate vicinity of the tank at a distance of no more than a radius from its side surface.

The closest known to the applicant is the design of the protective fence of the LNG storage tank, consisting of a foundation for the tank, screen partitions and a pit located at the base of one of the screen partitions. The foundation area is made with a slope of at least 1 ° from the tank towards the fence and with a total slope of at least 0.25 ° towards the pit (see PB 08-342-00). Safety rules for the production, storage and delivery of liquefied natural gas (LNG) at gas distribution stations of gas pipelines (gas distribution stations) and automobile gas-filling compressor stations (CNG filling stations). - M.: State Unitary Enterprise "Scientific and Technical Center for Safety in Industry of the Gosgortekhnadzor of Russia", 2001.).

The design of this protective fence is selected as a prototype.

The prototype and the claimed utility model have the following common features:

- screen partitions;

- screen partitions are installed on the foundation under the tank with the platform;

- the surface of the site is made with an inclination towards the pit;

- the pit is located at the base of one of the screen partitions.

The disadvantage of the protector of the LNG storage tank according to the prototype is that in the case of large emergency LNG spills, when it is impossible to stop access to the source of a fire, stagnant LNG zones are formed and its combustion is carried out on the foundation site under the LNG storage tank. In this case, significant damage is caused to the equipment (cryogenic tank, valves, evaporator) until its failure.

The utility model is based on the task of creating a protective fence for the liquefied natural gas storage tank, in which, by supplying it with an additional evaporator tray, valve control valve tray and drain windows, to limit the area of a possible emergency spill of the liquefied natural gas, to prevent the formation of stagnant zones, due to discharge spilled LNG from the foundation site under the LNG storage tank through the drain windows into the pit.

The problem is solved in the protective enclosure of the liquefied natural gas storage tank containing screen partitions mounted on a foundation under the tank with a platform whose surface is inclined towards the pit located at the base of one of the screen partitions, in that, unlike the prototype, the protective the device is additionally equipped with an evaporator tray and a valve control assembly tray, while at the base of the screen partition installed between the evaporator tray and the platform under a tank with liquefied natural gas, as well as a screen partition installed in front of the pit, drain windows are located.

The consequences of the LNG spill from the above-ground LNG storage tank within the protective enclosure are reduced by organizing directed LNG drains from the places of its potential leaks through the drain windows to drain into the pit located at the base of one of the screen partitions (fire barrier wall).

The dimensions of the pit are determined by the design project, based on the conditions for the reception of LNG effluents generated when there is a complete gap within the protective fence, the maximum (in diameter and pressure) pipeline for pumping LNG, for example, Dy40.

In addition, drain windows (windows for LNG drain) located at the bottom of the screen partition can prevent the formation of stagnant LNG zones when protecting equipment.

The protective fence of the liquefied natural gas storage tank is shown in the drawing, where:

figure 1 is a view of a protective fence;

figure 2 is a view of the protective fence with a storage tank for LNG, a boost evaporator and a control unit.

The proposed design of the protective fence (Fig. 1) consists of a foundation 1 with a platform for the LNG storage tank, screen partitions (fire-barrier walls) 2, the evaporator tray 3 and the valve control assembly 4 pallet.

At the base of the screen partition 2 installed between the evaporator tray 3 and the foundation 1 under the LNG storage tank, as well as the screen partition 2 installed in front of the pit 6, there are drain windows 5.

The foundation area 1 is made with a slope towards the pit 6.

To illustrate the principle of operation of the protective fence, Fig. 2 shows a boost evaporator 7 mounted on a pallet 3, an LNG storage tank 8 installed on a foundation 1, a valve control unit 9 located on a pallet 4.

The principle of operation of a protective fence is as follows. Liquefied natural gas when it is spilled from the LNG storage tank 8 enters the foundation area 1 and along the screen partitions 2, due to the existing slope, flows into the pit 6 through drain windows 5 located at the bottom of the screen partition 2 in its lower part from the pit side 6. B in the event of a valve malfunction or failure, the LNG spills into the sump of the valve control unit 4 and then flows through the drainage windows 5 into the pit 6. If there is a leak in the charge evaporator 7 or leaks, the LNG is drained into the sump of the evaporator 3. Dale 5 through the discharge window LNG flows onto the foundation platform 1 under the LNG storage tank 8, where gravity drained into the sump 6, is separated from the main equipment screen partition 2.

The presence of drain windows 5, as well as the evaporator tray 3 and the control unit tray 4, allows to save the cryogenic storage tank of LNG 8, pipelines and fittings, as well as the building structures of the tank supports 8, in case of fire spills.

The overall economic effect of reducing the cost of eliminating the consequences of the fire is estimated by the cost of the LNG storage system, which is from 5 to 7 million rubles. for freestanding tanks.

Claims (1)

A protective fence for the liquefied natural gas storage tank, containing screen partitions mounted on a foundation under the tank with a platform whose surface is inclined towards the pit located at the base of one of the screen partitions, characterized in that the protective device is additionally equipped with an evaporator tray and a unit tray control valves, while at the base of the screen partition installed between the evaporator tray and the platform for the tank with liquefied natural gas, and also a screen partition installed in front of the pit, drain windows are located.

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