Liquefied natural gas (LNG) leakage collection flow guide ditch

Abstract

The utility model provides an LNG (Liquefied Natural Gas) leakage collection flow guide ditch. The LNG leakage collection flow guide ditch consists of a concrete ditch wall, a ditch top, a ditch bottom and a steel grating plate, an isosceles trapezoid longitudinal section with a wide upper part and a narrow lower part is adopted, the inner side of a concrete ditch wall is a gradually-deformed slope, and the section can provide different vaporization surface areas and different conveying flows according to the LNG leakage volume. The collection flow guide ditch has the advantages of simple structure, high practicability, easiness in implementation, wide application range and the like, can be suitable for working situations with different LNG leakage volumes, has two important functions of reducing the gasification surface area and shortening the residence time of leaked LNG in the ditch due to the design of the isosceles trapezoid longitudinal section with the wide upper part and the narrow lower part, can effectively improve the LNG leakage collection efficiency, and is suitable for popularization and application. And explosion and fire risks are reduced.

Description

Technical Field

[0001] The utility model belongs to the field of chemical industry and relates to an LNG technology, in particular to an LNG leakage collection and diversion ditch. Background Art

[0002] LNG is a liquefied storage product with a temperature as low as -160℃. After leakage, it will cause dangers such as hypothermia, suffocation, flammability, explosion, and fire. How to collect and effectively control possible LNG leakage and prevent leakage accidents from expanding is crucial to ensure the safe operation of the factory. Therefore, an LNG leakage collection system is usually designed in LNG stations to collect accidentally leaked LNG in an accident state to a designated area and conduct safe and centralized treatment to avoid low-temperature damage caused by the spread of low-temperature LNG and the risk of fire and explosion caused by the flammable and explosive vapor cloud formed after gasification.

[0003] In the existing domestic design, the diversion ditch is an important facility for collecting LNG liquid leaked to the ground. The diversion ditch can quickly divert the leaked LNG liquid to the liquid collection pool to avoid the formation of a steam cloud flow layer on the ground and reduce the risk of fire or explosion. The diversion ditch in the LNG station is usually designed as a concrete square ditch with a rectangular longitudinal section, and its evaporation surface area is a fixed value. Patent CN218119403U discloses that when the volume of LNG leakage is small, the surface area of ​​LNG liquid free flow provided by the diversion ditch designed according to the maximum leakage is relatively large, which will accelerate the volatilization of LNG and increase the risk of forming a steam cloud. It proposes a diversion ditch with the ability to inhibit LNG gasification. The longitudinal section of the diversion ditch is an inverted convex shape, which mainly includes a top ditch, a bottom ditch, and a stainless steel woven mesh covering the upper edge of the bottom ditch. The bottom area of ​​the top ditch is larger than the top area of ​​the bottom ditch, that is, the diversion ditch is arranged in a stepped manner. This utility model can limit the LNG with a smaller leakage volume to a smaller range, reduce the gasification surface area of ​​LNG, and slow down the evaporation rate of LNG. However, this approach still has the following disadvantages and shortcomings: 1. The inverted convex longitudinal cross-section design can only provide two gasification surface areas, the bottom ditch and the top ditch. When the LNG leakage is large, the LNG liquid overflows the upper surface of the bottom ditch, and its gasification surface area is still the larger gasification surface area provided by the top ditch. Therefore, it cannot effectively reduce the gasification surface area when the leakage is large; 2. When the LNG leakage is large, the LNG liquid will first fill the bottom ditch with a smaller cross-section, and the excess part will be located in the lower half of the top ditch. Due to the small cross-section of the bottom ditch, the delivery flow of the leaked LNG to the liquid collection pool will be greatly reduced; 3. Its stainless steel woven mesh covers the upper edge of the bottom ditch, while the top ditch is completely open, which is not conducive to the passage of personnel, and it is easy for debris to accumulate in the ditch, making it inconvenient to clean. Summary of the invention

[0004] In order to solve the above problems existing in the prior art, the utility model provides an LNG leakage collection and diversion ditch.

[0005] The utility model provides an LNG leakage collection and diversion ditch, which comprises a concrete ditch wall, a ditch top, a ditch bottom and a steel grating plate; the diversion ditch adopts an isosceles trapezoidal longitudinal section that is wide at the top and narrow at the bottom, a slope is provided at the ditch bottom, a steel grating plate is provided at the ditch top, the inner side of the concrete ditch wall is a gradually deformed slope, and the isosceles trapezoidal longitudinal section that is wide at the top and narrow at the bottom can provide different vaporization surface areas and different conveying flow rates according to the amount of LNG leakage volume.

[0006] When the LNG leakage volume is small, the LNG liquid occupies the lower part of the diversion ditch. At this time, the LNG vaporization surface area and diversion flow rate in the diversion ditch are both small, and the risk of LNG vaporization forming a steam cloud is low; when the LNG leakage volume is large, the LNG liquid will occupy the middle and lower part of the diversion ditch. At this time, the LNG vaporization surface area in the diversion ditch is large, but because its longitudinal cross-sectional area increases, the diversion flow rate is also large, and the residence time of the leaked LNG in the diversion ditch will be greatly reduced, which also reduces the risk of LNG vaporization forming a steam cloud. Therefore, the LNG leakage collection diversion ditch can take into account the two important functions of reducing the vaporization surface area and shortening the residence time of the leaked LNG in the ditch.

[0007] Preferably, the inner side of the concrete ditch wall is a gradual slope.

[0008] Preferably, the width of the concrete trench top opening is greater than the trench bottom width.

[0009] Preferably, the concrete ditch bottom is provided with a slope towards the liquid collection tank.

[0010] Preferably, the steel grating is detachable and is provided with rectangular holes to allow leaked LNG to pass through quickly.

[0011] Preferably, the steel grating is nested in the concrete ditch top, and the top of the steel grating is flush with the concrete ditch top.

[0012] Preferably, the top of the concrete ditch is flush with the floor of the adjacent leakage collection area, and the floor slope of the collection area is directed toward the liquid guide ditch.

[0013] The utility model has the following beneficial effects:

[0014] (1) The LNG leak collection diversion ditch is suitable for working scenarios with different LNG leakage volumes. Its design of an isosceles trapezoidal longitudinal section that is wide at the top and narrow at the bottom can take into account two important functions: reducing the gasification surface area and shortening the residence time of the leaked LNG in the ditch. It can effectively improve the LNG leak collection efficiency and reduce the risk of explosion and fire.

[0015] (2) The LNG leak collection diversion ditch has a detachable steel grating plate on the top of the ditch, which allows people to pass through and can block larger debris, making it easy to clean.

[0016] (3) The LNG leakage collection and diversion ditch has the advantages of simple structure, strong practicality, easy implementation and wide application range. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the structure of the utility model;

[0018] Figure 2 This is the AA view of the utility model;

[0019] In the figure, 1-concrete ditch wall, 2-ditch top, 3-ditch bottom, 4-steel grating, 5-sloped floor. DETAILED DESCRIPTION

[0020] The implementation of the technical solution of the utility model is further described below in conjunction with the accompanying drawings.

[0021] like Figure 1 As shown, an LNG leakage collection and diversion ditch includes a concrete ditch wall 1, a ditch top 2, a ditch bottom 3 and a steel grating plate 4.

[0022] The longitudinal section of the LNG leakage collection and diversion ditch is an isosceles trapezoid that is wide at the top and narrow at the bottom. The inner side of the concrete ditch wall 1 is a gradual slope. The opening width of the concrete ditch top 2 is greater than the width of the ditch bottom 3. The concrete ditch bottom 3 is set with a slope toward the liquid collection tank. The steel grating plate 4 is detachable and has rectangular holes on it, which can allow the leaked LNG to pass quickly. The steel grating plate 4 is nested in the concrete ditch top 2. The top of the steel grating plate 4 is flush with the concrete ditch top 2. The concrete ditch top 2 is flush with the adjacent leakage collection area floor 5. The floor slope of the collection area is toward the liquid guide ditch.

[0023] The LNG leak collection and diversion ditch can be applied to working scenarios with different LNG leak volumes, effectively improve the LNG leak collection efficiency, and reduce the risk of explosion and fire. By setting a detachable steel grating plate on the top of the ditch, it can allow people to pass through, block larger debris, etc., and is easy to clean.

[0024] The above is only a typical example of the utility model, and does not impose any formal limitation on the utility model. Any technician familiar with the profession, without departing from the scope of the technical solution of the utility model, shall be regarded as an equivalent example of equivalent changes made by using the above technical content. Any equivalent changes made to the above examples based on the technical essence of the utility model without departing from the content of the technical solution of the utility model shall fall within the scope of the technical solution of the utility model.

Claims

1. An LNG leak collection and diversion ditch, characterized in that: The LNG leakage collection diversion ditch includes a concrete ditch wall, a ditch top, a ditch bottom, and a steel grating plate; the diversion ditch adopts an isosceles trapezoidal longitudinal section that is wide at the top and narrow at the bottom, a slope is provided at the ditch bottom, a steel grating plate is provided at the ditch top, the inner side of the concrete ditch wall is a gradually deformed slope, the inner side of the concrete ditch wall is a gradually changing slope, the opening width of the ditch top is greater than the width of the ditch bottom, and the concrete ditch bottom is provided with a slope toward the liquid collection tank.

2. The LNG leakage collection and diversion ditch according to claim 1 is characterized in that: The steel grating plate is detachable and is provided with rectangular holes to allow leaked LNG to pass through quickly.

3. The LNG leakage collection and diversion ditch according to claim 1 is characterized in that: The steel grating plate is nested in the top of the concrete ditch, and the top of the steel grating plate is flush with the top of the concrete ditch.

4. The LNG leakage collection and diversion ditch according to claim 1 is characterized in that: The top of the concrete ditch is flush with the floor of the adjacent leakage collection area, and the floor slope of the collection area is directed toward the liquid guide ditch.

Images