CN211925382U

CN211925382U - Novel gas dome of large-scale marine prismatic LNG storage tank

Info

Publication number: CN211925382U
Application number: CN202020412624.5U
Authority: CN
Inventors: 于世旭; 姜福茂; 马俊; 张义明; 嵇智勇; 吕岩; 何旭; 常立勇; 杜欣; 赵晓玲
Original assignee: Dalian Shipbuilding Industry Co Ltd
Current assignee: Dalian Shipbuilding Industry Co Ltd
Priority date: 2020-03-27
Filing date: 2020-03-27
Publication date: 2020-11-13
Anticipated expiration: 2030-03-27

Abstract

The utility model provides a novel gas vault in cabin is stored up to large-scale marine prism LNG has the prism LNG to store up the cabin, and LNG stores up cabin top central point and puts and be provided with the main line, stores up four corners in cabin top at LNG and stretches out there being the lateral, and four lateral extend along diagonal direction, and four lateral collect in main line department, the vertical setting of main line, main line pass the lateral and upwards extend, on the main line, lie in the lateral top and have the pressure release valve. The LNG storage tank meets the requirement that the LNG storage tank in the IGC/IGF specification reaches the filling limit and the pressure release valve of the LNG storage tank can still be kept in a steam state under the conditions that the ship is at a transverse inclination angle of 15 degrees and a longitudinal inclination angle of 0.015 times of the ship length, the LNG is prevented from flowing out of the pressure release valve and entering a gas pipeline, and the safety problem that the LNG flows back to the pressure release valve due to independent gas phase space is effectively solved.

Description

Novel gas dome of large-scale marine prismatic LNG storage tank

Technical Field

The invention relates to the field of construction and design of liquefied natural gas transport ships, in particular to a novel gas dome used for being matched with a liquefied natural gas storage cabin.

Background

Due to the extremely large size of the large-scale prismatic LNG storage tank for ships, the traditional design arranges a gas dome at the center of the top of the storage tank. When the ship moves to a certain degree of heeling or pitching and the filling rate of the storage tank is high and even reaches the filling limit, independent gas phase spaces are inevitably generated at the top corners of the storage tank, as shown in fig. 1.

After the formation of the isolated vapor space, the vapor pressure in the isolated vapor space may increase due to vessel motion, temperature increase, etc., and LNG may be discharged from a conventionally designed pressure relief valve at the gas dome into the gas pipeline. The requirement that the LNG storage tanks in the IGC/IGF specifications reach the filling limit and that their pressure relief valves remain in the vapor state when the vessel is at a trim of 15 ° and a trim of 0.015 times the length of the vessel creates a risk of use.

Therefore, there is a need for a new gas dome that can solve the safety problem of the independent gas phase space causing LNG to flow back to the pressure relief valve.

Disclosure of Invention

In order to solve the problems, the invention provides a novel gas dome of a prismatic LNG storage tank for a large ship, aiming at achieving the purpose of meeting the related regulation of the reloading limit of the LNG storage tank in IGC/IGF specification, and the adopted technical scheme is as follows:

the utility model provides a novel gas vault in cabin is stored up to large-scale marine prismatic LNG, has the prismatic LNG to store up the cabin, LNG stores up cabin top central point and puts and is provided with the main line LNG stores up four corners in cabin top and stretches out and has the lateral, four the lateral extends along diagonal direction, four the lateral is in main line department collects, the vertical setting of main line, the main line passes the lateral upwards extends, on the main line, be located the lateral top has the pressure release valve. The branch pipelines extend out from four corners at the top of the prismatic LNG storage tank. The four branch pipelines are gathered together and communicated with each other, and when the LNG steam forms an independent gas phase space at the top corner of the storage tank due to ship movement (such as rolling, pitching and the like), the branch pipelines are communicated to balance the LNG steam pressure. The branch pipeline is connected with one end of the main pipeline after being collected at the top of the prismatic LNG storage tank, the other end of the main pipeline is connected to external LNG vapor collection and treatment equipment, a pressure release valve is arranged on the main pipeline, the pressure release valve is far enough from the top of the storage tank so as to ensure that the LNG storage tank moves (such as heeling, rolling, pitching and the like) along with the ship, and the pressure release valve is in a vapor state.

According to the novel air dome of the prismatic LNG storage cabin for the large ship, furthermore, one end of the main pipeline is communicated with the four collecting positions of the branch pipelines, and the other end of the main pipeline is communicated to the external steam collecting equipment. The four branch pipelines are mutually communicated after being converged, so that the communicated branch pipelines can balance the LNG vapor pressure when an independent gas phase space is formed in the storage cabin. The collecting position of the branch pipelines is connected with the main pipeline, and the branch pipelines are also communicated with the main pipeline.

In the novel gas dome of the prismatic LNG storage tank for the large ship, furthermore, the branch pipeline is connected with the LNG storage tank through an independent gas dome or welding. The branch pipelines can be connected with the storage cabin in any mode, and are communicated with the interior of the storage cabin. Preferably, the branch pipeline is fixedly connected with the storage cabin by welding, and the welding connection enables the branch pipeline to be better fixed. The air storage cabin can also be connected with the air dome in an independent air dome mode, the safety of the independent air dome is high, and the connectivity between branch pipelines and between the branch pipelines and the air storage cabin is better.

According to the novel air dome of the prismatic LNG storage tank for the large ship, furthermore, the branch pipeline is communicated with the interior of the LNG storage tank. The branch pipeline is communicated with the interior of the LNG storage cabin and mutually ventilates, so that the LNG steam pressure in the storage cabin can be balanced when meteorological space is generated.

In the novel air dome of the prismatic LNG storage tank for the large ship, furthermore, a support is arranged below each of the four branch pipelines. Because the storage cabin is large and the branch pipelines are also long, a bracket is arranged below the branch pipelines to play a role in supporting the branch pipelines, and the structural stability of the invention is further ensured.

Above-mentioned novel gas vault in large-scale marine prismatic LNG storage tank, further, the support is "people" style of calligraphy, fixes LNG stores up cabin top, supports branch pipeline. The bracket can be any type of bracket, and is preferably in a shape like a Chinese character 'ren' to be safer and more stable.

The LNG storage tank meets the requirement that the LNG storage tank in the IGC/IGF specification reaches the filling limit and the pressure release valve of the LNG storage tank can still be kept in a steam state under the conditions that the ship is at a transverse inclination angle of 15 degrees and a longitudinal inclination angle of 0.015 times of the ship length, the LNG is prevented from flowing out of the pressure release valve and entering a gas pipeline, and the safety problem that the LNG flows back to the pressure release valve due to independent gas phase space is effectively solved.

Drawings

FIG. 1 is a schematic view of the meteorological space generated at the top of a storage tank;

FIG. 2 is a schematic structural view of the present invention;

wherein: 1-main pipeline, 2-branch pipeline, 3-pressure relief valve and 4-support.

Detailed Description

The invention is further explained by combining the attached drawings, and the novel air dome of the prismatic LNG storage tank for the large ship shown in the figure 2 is provided with the LNG storage tank, a main pipeline 1 is arranged at the center of the top of the storage tank, and the main pipeline is vertically arranged at the center of the top of the storage tank. The four corners at the top of the storage cabin extend out of the branch pipelines 2, the four branch pipelines extend in the diagonal direction and converge towards the main pipeline, the four branch pipelines are communicated with the main pipeline after converging, and the pressure release valves 4 are arranged on the main pipeline and at positions higher than the branch pipelines.

The branch pipelines are connected with the storage cabin through welding, and a bracket 4 is welded below each branch pipeline.

When the LNG steam pressure relief valve is used, steam pressure is designed in advance, the pressure relief valve is adjusted and set according to the designed steam pressure, and when the steam pressure rises to exceed the designed steam pressure, the pressure relief valve is opened to discharge LNG steam.

Claims

1. The utility model provides a novel gas vault of large-scale marine prismatic LNG storage tank which characterized in that: the LNG storage tank is prismatic, a main pipeline (1) is arranged in the center of the top of the LNG storage tank, branch pipelines (2) extend out of four corners of the top of the LNG storage tank, the four branch pipelines extend along the diagonal direction, the four branch pipelines are converged at the main pipeline, the main pipeline is vertically arranged, the main pipeline penetrates through the branch pipelines to extend upwards, and a pressure release valve (3) is arranged on the main pipeline and above the branch pipelines.

2. A novel gas dome for a prismatic LNG storage tank for a large ship according to claim 1, wherein: one end of the main pipeline is communicated with the four branch pipeline collecting positions, and the other end of the main pipeline is communicated to external steam collecting equipment.

3. A novel gas dome for a prismatic LNG storage tank for a large ship according to claim 1, wherein: the branch pipeline is connected with the LNG storage tank through an independent gas dome or welding.

4. A novel gas dome for a prismatic LNG storage tank for a large ship according to claim 1, wherein: the branch pipeline is communicated with the interior of the LNG storage cabin.

5. A novel gas dome for a prismatic LNG storage tank for a large ship according to claim 1, wherein: and a bracket (4) is arranged below each of the four branch pipelines.

6. A novel gas dome of a prismatic LNG storage tank for a large ship as claimed in claim 5, wherein: the support is in a shape of Chinese character 'ren', is fixed at the top of the LNG storage cabin and supports the branch pipelines.