CN210532064U

CN210532064U - LNG loading and unloading ship pipeline system capable of preventing damage caused by transient liquid attack

Info

Publication number: CN210532064U
Application number: CN201921286318.5U
Authority: CN
Inventors: 刘禹岑; 贾保印; 刘佳; 刘以荣
Original assignee: China Huanqiu Contracting and Engineering Corp
Current assignee: China National Petroleum Corp; China Huanqiu Contracting and Engineering Corp
Priority date: 2019-08-08
Filing date: 2019-08-08
Publication date: 2020-05-15
Anticipated expiration: 2029-08-08

Abstract

The utility model provides a can protect LNG loading and unloading ship pipe-line system of transient state liquid attack damage, include the branch road of unloading ship that is connected to the loading and unloading house steward with LNG loading and unloading arm, install first cut-off valve and check valve on the branch road of unloading ship, first cut-off valve is compared the check valve and is more close to LNG loading and unloading arm. Under the working condition of ship unloading operation, the check valve allows LNG to be conveyed to the ship unloading header pipe direction by the LNG loading and unloading arm; at the moment, if the wharf has accident conditions, the first cut-off valve needs to be turned off in an emergency, and due to the fact that the check valve has the backflow preventing function, the liquid impact of cut-off bridging formed by the rear pipe section of the first cut-off valve after the first cut-off valve is turned off in an emergency can be relieved.

Description

LNG loading and unloading ship pipeline system capable of preventing damage caused by transient liquid attack

Technical Field

The utility model relates to a LNG loading and unloading ship pipe-line system can protect transient state liquid and hit the damage.

Background

The LNG receiving station is an engineering facility for receiving, unloading, storing, gasifying, transporting or loading the LNG. The receiving station loading and unloading ship pipeline system is used as an important system device for unloading, loading and unloading ships and has the characteristics of complex process flow, various operating conditions, large pipeline size, more flange interfaces and large volume flow.

In a traditional LNG receiving station loading and unloading ship pipeline system (as shown in figure 1), a loading function area and an unloading function area are separated and independent from each other, a loading main pipe 11 is connected with an LNG loading arm 15 through a loading branch pipe 13, an unloading main pipe 12 is connected with the LNG loading arm 15 through an unloading branch pipe 14, functional system control cannot interfere with each other, and operation is relatively simple. But the problems of high project investment, large occupied area, low wharf space utilization rate and the like are caused by increasing the quantity of process facilities such as equipment, pipelines and the like.

In addition, in the conventional LNG receiving station loading and unloading ship pipeline system, research on the protection theory of the transient liquid impact phenomenon is limited, and the installation mode of the pipeline of the system is designed according to experience, for example, on the unloading ship branch pipe 14, the check valve 16 is installed at one end closer to the LNG loading and unloading arm 15 than the cut-off valve 17, which increases the risk of damage to the pipeline system caused by the transient liquid impact to a certain extent.

After numerical simulation calculation analysis (by using PIPETET software) is carried out on a traditional LNG receiving station loading and unloading ship pipeline system under extreme working conditions, the fact that the system can generate serious cutoff closing liquid impact phenomena (as shown in figures 2 and 3) after an emergency shut-off valve is turned off can be known, the generated instantaneous liquid impact pressure obviously exceeds the design pressure of the system, then a pipeline is damaged, and the safe operation of the whole system is seriously damaged.

At present, the configuration of a traditional LNG receiving station loading and unloading ship pipeline system is lack of integrity and correctness, great system safety hidden dangers exist, and irreparable social hazards can be caused if the pipeline system is not eliminated and corrected in time.

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing a can protect LNG loading and unloading ship pipe-line system of transient state liquid attack damage, through simple and easy configuration optimization, solve the above-mentioned technical problem that prior art exists.

In order to achieve the above object, the utility model adopts the following technical scheme:

the utility model provides a can protect LNG loading and unloading ship pipe-line system of transient state liquid attack damage which characterized in that includes and is connected to the unloading ship branch road of unloading the ship house steward with LNG loading and unloading arm, installs first cut-off valve and check valve on the unloading ship branch road, and the check valve is more close to LNG loading and unloading arm is compared to first cut-off valve.

Can protect LNG loading and unloading ship pipe-line system of transient state liquid attack damage, wherein: the loading branch is used for connecting the unloading main pipe to the LNG loading arm, and two ends of the loading branch are bridged on the outer side parts of the first cut-off valve and the check valve of the unloading branch.

Can protect LNG loading and unloading ship pipe-line system of transient state liquid attack damage, wherein: a second shut-off valve and a manual control valve are installed on the loading branch, and the second shut-off valve is closer to the LNG loading arm than the manual control valve.

The utility model discloses a simple and easy configuration optimization can prevent effectively that transient state liquid from hitting and causing damage and destruction to LNG receiving station loading and unloading ship pipe-line system, and maintenance system normal operating also can provide reasonable economic optimization technical reference scheme to the engineering design of whole project.

The utility model discloses rationally dispose the loading and unloading ship pipe-line system to the LNG receiving station, satisfying under the prerequisite of all loading and unloading ship technology operation requirements, simplify the system operation, reduce system process facility scale to the realization is alleviated transient state liquid and is hit pressure, avoids the liquid to hit the destruction that causes, maintenance system safe operation.

The utility model discloses load onto ship functional area and unload ship functional area with LNG receiving station loading and unloading ship pipe-line system and integrate together, and adjust the control alarm interlock system to whole device, can satisfy all loading and unloading ship technology operation functions like this, again can the at utmost reduce system's equipment, process facilities quantity such as pipelines, improve pier space utilization, and regard as this to guide all valves in the loading and unloading ship pipe-line system, instrument and valve member carry out reasonable configuration, and then from the whole area that saves of project, investment cost is reduced.

Drawings

Fig. 1 is a schematic structural view of a conventional LNG receiving station loading and unloading ship piping system;

fig. 2 and 3 are schematic diagrams of the liquid impact cavity volume and the liquid impact pressure generated after a valve of a conventional LNG receiving station loading and unloading ship pipeline system is closed (a severe cut-off bridging liquid impact phenomenon is generated);

fig. 4 is a schematic structural diagram of an LNG loading/unloading ship pipeline system capable of protecting against damage due to transient liquid attack, provided by the present invention;

fig. 5 and fig. 6 are schematic diagrams of the liquid impact cavity volume and liquid impact pressure generated by the LNG loading and unloading ship pipeline system capable of protecting against transient liquid impact damage after the valve is closed.

Description of reference numerals: a loading main pipe 11; a main ship unloader 12; a ship-loading branch pipe 13; an offloading leg 14; an LNG loading arm 15; a check valve 16; a shut-off valve 17; an LNG loading arm 21; the main pipe 22 for unloading the ship; a ship unloading branch 23; a first shut-off valve 24; a check valve 25; a shipment branch 26; a second shut-off valve 27; a manual control valve 28; a cold retention recycle line 29.

Detailed Description

As shown in fig. 4, the utility model provides a can protect LNG loading and unloading ship pipe-line system of transient state liquid attack damage, LNG loading and unloading ship pipe-line system mainly includes the functional area of unloading a ship and the functional area of loading a ship, all the other parts, for example pier exhaust pipe line and valve instrument and Boil Off Gas (BOG) pipeline and valve instrument belong to prior art, do not give the repeated description here.

The ship unloading function area comprises a ship unloading branch 23 connecting the LNG loading arm 21 to the ship unloading main pipe 22, a first cut-off valve 24 and a check valve 25 are installed on the ship unloading branch 23, and the first cut-off valve 24 is closer to the LNG loading arm 21 than the check valve 25;

the loading function area comprises a loading branch 26 which connects the unloading main 22 to the LNG loading arm 21, the two ends of the loading branch 26 are connected to the outer parts of a first cut-off valve 24 and a check valve 25 of the unloading branch 23 in a bridging mode, a second cut-off valve 27 and a manual control valve 28 are arranged on the loading branch 26, and the second cut-off valve 27 is closer to the LNG loading arm 21 than the manual control valve 28;

in the operating condition of the ship unloading, the second cut-off valve 27 and the manual control valve 28 on the ship loading branch 26 are both in a closed state, the first cut-off valve 24 on the ship unloading branch 23 is in an open state, and the check valve 25 allows the LNG to be conveyed from the LNG loading and unloading arm 21 to the ship unloading main pipe 22; at this moment, if the wharf has an accident condition, the first cut-off valve 24 needs to be closed urgently, and due to the fact that the check valve 25 has the function of preventing backflow, the liquid impact caused by cut-off bridging formed by the rear pipe section of the first cut-off valve 24 after the first cut-off valve 24 is closed urgently can be effectively relieved.

Under the working condition of the loading operation, the first cut-off valve 24 on the unloading branch 23 is in a closed state, the second cut-off valve 27 and the manual control valve 28 on the loading branch 26 are both in an open state, and LNG is conveyed from the unloading header 22 to the LNG loading and unloading arm 21; and when the working condition of the wharf accident occurs, the second stop valve 27 is closed emergently, so that the delivery of the logistics can be prevented. Because the main function of LNG receiving station is used for LNG to unload the ship, the shipment function is only as an auxiliary function, and the shipment flow is often very little, consequently the utility model discloses a structural design neither can arouse violent transient state liquid and hit the phenomenon under urgent operating condition, also can not influence normal shipment operation.

The utility model discloses an effect includes:

(1) the utility model discloses can promote to all relevant LNG receiving station cargo ship pipe-handling system, can satisfy all cargo ship technology operation functions on reducing process facilities quantity such as system's equipment, pipeline, instrument, improving pier space utilization's basis to save area, reduce economic cost in the whole investment of project.

(2) The optimized and adjusted LNG handling vessel instrument interlocking control system can efficiently switch the operating states of system equipment and pipelines according to system function requirements, realizes the optimization of operating resources on the premise of not influencing the stable operation of a handling vessel system, and improves the working efficiency of operators.

(3) Aiming at the phenomenon of liquid impact caused by flow cutoff and closing in the working condition of an emergency accident, the invention adopts a reasonable and effective liquid impact protection method, can reduce the pressure of liquid impact, solves the harm caused by the phenomenon of liquid impact, and maintains the operation stability of a device system.

The liquid impact relieving effect is as shown in fig. 5 and 6, after the arrangement design that the check valve is placed behind the shut-off valve is adopted, under the same emergency working condition, the PIPETET software is used for calculating and analyzing through numerical simulation, the liquid impact pressure is reduced from 2.7MPaG to 1.0MPaG, and the system design requirement is completely met.

The foregoing description is intended to be illustrative rather than limiting, and it will be appreciated by those skilled in the art that many modifications, variations or equivalents may be made without departing from the spirit and scope of the invention as defined in the appended claims.

Claims

1. The utility model provides a can protect LNG loading and unloading ship pipe-line system of transient state liquid attack damage which characterized in that includes and is connected to the unloading ship branch road of unloading the ship house steward with LNG loading and unloading arm, installs first cut-off valve and check valve on the unloading ship branch road, and the check valve is more close to LNG loading and unloading arm is compared to first cut-off valve.

2. An LNG tanker piping system protected against transient liquid attack damage according to claim 1, wherein: the loading branch is used for connecting the unloading main pipe to the LNG loading arm, and two ends of the loading branch are bridged on the outer side parts of the first cut-off valve and the check valve of the unloading branch.

3. An LNG tanker pipeline system protected against transient liquid attack damage according to claim 2, wherein: a second shut-off valve and a manual control valve are installed on the loading branch, and the second shut-off valve is closer to the LNG loading arm than the manual control valve.