CN214037841U

CN214037841U - LNG unloading arm sweeps replacement system

Info

Publication number: CN214037841U
Application number: CN202023163562.8U
Authority: CN
Inventors: 杨亮; 宋坤; 毕晓星; 陈海平; 范嘉堃; 许佳伟; 邱灶杨; 周树辉; 张彧
Original assignee: CNOOC Gas and Power Group Co Ltd
Current assignee: CNOOC Gas and Power Group Co Ltd
Priority date: 2020-12-24
Filing date: 2020-12-24
Publication date: 2021-08-24
Anticipated expiration: 2030-12-24

Abstract

The utility model relates to a LNG unloading arm sweeps replacement system, including unloading arm body and sweeping replacement device, unloading arm body mainly comprises stand, rotary mechanism, balanced drive mechanism, outer arm supporting, main line, rotary joint, emergent disengaging gear and quick connector, sweeps replacement device and includes the gas pressure storage tank, pulse solenoid valve, sweeps the pipeline, once expands the pressure section, annular section, water conservancy diversion section and the secondary section of expanding that connects in order, and is provided with the water conservancy diversion awl in the water conservancy diversion section, sweeps the secondary section of expanding pressure of replacement device and the quick connector sealing connection of unloading arm body; the annular overflows the section and is constituted for the passageway that overflows of a plurality of annular cavities by the cross section, is provided with 3 at least blades along circumference in the outside of water conservancy diversion awl to produce when making the air current pass through the blade and rotate. The utility model discloses can overcome the inside inhomogeneous defect of replacement effect that sweeps of prior art discharge arm pipeline, and then guarantee the safety and stability operation after the discharge arm is put into operation.

Description

LNG unloading arm sweeps replacement system

Technical Field

The utility model relates to a LNG unloads the arm, specifically is about a LNG unloads arm and sweeps replacement system.

Background

The LNG receiving terminal may be divided into a terrestrial LNG receiving terminal and an offshore LNG receiving terminal: terrestrial LNG receiving terminals are currently in wide use worldwide and are still rapidly developing with increasing demand for natural gas; the offshore LNG receiving terminal is a new receiving terminal type proposed in recent years, and engineering examples are now available in the world. The offshore LNG receiving terminal may be further divided into a floating receiving terminal and a fixed receiving terminal, wherein the fixed receiving terminal is similar to the terrestrial LNG receiving terminal. According to different LNG receiving terminal forms, the adopted LNG unloading modes are different.

The LNG unloading arm is an articulated pipe system for unloading which is installed on a dock (or a floating terminal), and when an LNG carrier arrives at a dock dedicated for a receiving station, LNG is fed into a storage tank of the receiving station through a liquid-phase unloading arm and an unloading pipeline by using a cryogenic pump on the ship, and BOG gas in the storage tank is returned to the LNG carrier through a gas return pipeline and a gas return arm. The liquid phase discharging arm and the gas phase gas returning arm have the same structure, and the main structure comprises a three-dimensional rotating joint, an outer arm, an inner arm, a top end rotating joint, a base vertical pipe, a rotating joint for connecting the inner arm and the base vertical pipe, and other process pipelines, supporting structures and accessories thereof. The main difficulties of the design, manufacture and inspection of the LNG discharging arm are in the aspects of material cryogenic treatment, rotary joint design and low-temperature dynamic test, design and reliability of an emergency separation device, reliability of a quick connection joint and the like. In the LNG unloading arm operation process, the end part of the unloading arm is guided to be interconnected with the receiving end of the LNG transport ship through the traction line, so that the unloading arm can be accurately butted under the condition of ensuring relative motion, and a hydraulic system of the LNG unloading arm is controlled to enable the unloading arm to bear the influence of the speed and the acceleration caused by the motion of a ship body.

LNG unloads the arm before formal is put into operation, will carry out nitrogen gas to unloading arm transfer line and sweep the replacement to guarantee that LNG unloads the process safety that the arm carried LNG. The replacement system that sweeps now mainly adopts nitrogen pressure pipeline to link to each other with unloading arm pipeline, adopts the mode that the pulse sweeps to the inside jetting high-pressure nitrogen of unloading arm pipeline, realizes inert gas to the replacement of unloading arm pipeline inside air, because the jetting pipeline that the current technique of sweeping is through type pipeline, the replacement effect of jetting process is unsatisfactory, mainly has following problem:

the sweeping replacement effect is uneven: in the existing purging technology, during purging and replacement, a blowing pipeline is a straight-through pipeline, so that the direction of nitrogen airflow during blowing is opposite to the center of a conveying pipeline of a discharge arm, and the airflow energy of the blowing mode is inevitably more acted on the center position, so that the purging and replacement effects of the conveying pipeline of the discharge arm close to the center position and the edge position are greatly different, the position close to the center position bears larger airflow impact force, the purging force at the edge position is smaller, and the purging and replacement effects are uneven;

secondly, the purging and replacing efficiency is low: the existing purging technology mainly depends on experience to set working condition parameters of a nitrogen purging system, the purging gas consumption is large, the energy consumption is high, the operation duration is long, the purging and replacement efficiency is low, and a calculation model matched with the purging and replacement system needs to be established urgently to guide the optimization design of a scheme.

SUMMERY OF THE UTILITY MODEL

To the above problem, the utility model aims at providing a LNG unloads material arm and sweeps replacement system can sweep the inhomogeneous defect of replacement effect with overcoming the inside unloading arm transfer line that current technique exists that sweeps, and then guarantee the safety and stability operation after the unloading arm is put into operation.

In order to achieve the purpose, the utility model adopts the following technical proposal: an LNG discharging arm purging and replacing system comprises a discharging arm body and a purging and replacing device, wherein the discharging arm body mainly comprises an upright post, a rotating mechanism, a balance transmission mechanism, an outer arm support, a main pipeline, a rotating joint, an emergency separation device and a quick connection joint, the purging and replacing device comprises a gas pressure storage tank, a pulse electromagnetic valve, a purging pipeline, a primary diffusion section, an annular overflowing section, a flow guide section and a secondary diffusion section which are sequentially connected, a flow guide cone is arranged in the flow guide section, and the secondary diffusion section of the purging and replacing device is hermetically connected with the quick connection joint of the discharging arm body; the annular overflowing section is composed of overflowing channels with cross sections of a plurality of annular cavities, and at least 3 blades are arranged on the outer portion of the guide cone along the circumferential direction, so that airflow can rotate when passing through the blades.

The LNG unloading arm purging and replacing system is characterized in that preferably, the annular overflowing section is composed of an outer ring annular overflowing channel, a middle ring annular overflowing channel and an inner ring annular overflowing channel, the annular width of the outer ring annular overflowing channel is equal to the diameter of the inner ring annular overflowing channel, and the annular width of the middle ring annular overflowing channel is smaller than that of the outer ring annular overflowing channel and is also smaller than that of the inner ring annular overflowing channel.

Preferably, the included angle between the tip end of each blade and the section of the guide cone is 90 degrees, the included angle between the tail end of each blade and the section of the guide cone is 30-60 degrees, and the outer edge of each blade is connected with the inner wall of the guide section, so that the guide section, the guide cone and the blades jointly form a plurality of guide channels distributed in a turbine shape.

The LNG unloading arm purging and replacing system is characterized in that preferably, a flow stabilizer is arranged at the tail end of the secondary diffusion section, the flow stabilizer is of a hollow shuttle-shaped shell structure, and the included angle beta is 45-75 degrees.

The LNG unloading arm purging and replacing system is characterized in that preferably, the primary diffusion section is of a hollow circular truncated cone shell structure, and the secondary diffusion section is of a hollow circular truncated cone shell structure with an arc-shaped curved surface on the side surface.

The utility model discloses owing to take above technical scheme, it has following advantage: the utility model discloses a sweep replacement system adopts the special construction that once diffusion section-annular section-water conservancy diversion awl-blade-secondary diffusion section-current stabilizer are constituteed to realize sweeping the replacement to unloading arm conveying line with the mode of rotatory air current, can overcome the inside inhomogeneous defect of replacement effect that sweeps of prior art unloading arm conveying line, and then guarantee the safe and stable operation after unloading arm is put into operation. To sum up, the utility model discloses to present LNG unload arm conveying system exist sweep the replacement effect inhomogeneous, sweep a series of problems such as replacement inefficiency, the inventor relies on experience and practice that the relevant trade was engaged in for many years, provides a LNG unload arm and sweeps replacement system to overcome prior art's defect, the overall structure design optimization and the safety and stability operation of unloading the arm to large-scale LNG have guiding meaning.

Drawings

Fig. 1 is a schematic view of the overall structure of the LNG unloading arm purging and replacing system of the present invention;

FIG. 2 is an enlarged partial schematic view of FIG. 1;

FIG. 3 is a schematic cross-sectional view of the annular flow passage section of the present invention;

FIG. 4 is a schematic cross-sectional view of the flow guide section of the present invention;

FIG. 5 is a schematic cross-sectional view of a blade according to the present invention;

fig. 6 is a schematic structural diagram of the current regulator of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. It is to be understood that the embodiments described are only some of the embodiments of the present invention, and not all of them. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

In the description of the present invention, it should be noted that the terms "upper", "lower", "inner", "outer", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplification of description, but do not indicate or imply that the system or element referred to must have a specific orientation, be constructed in a specific orientation, and be operated, and thus should not be construed as limiting the present invention.

In the description of the present invention, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood in specific cases to those skilled in the art.

As shown in fig. 1 and fig. 2, the utility model provides a replacement system is swept to LNG unloading arm includes unloading arm body 100 and sweeps replacement device 200, unloading arm body 100 mainly comprises stand 11, rotary mechanism 12, balanced drive mechanism 13, outer arm supporting 14, main line 15, rotary joint 16, parts such as emergency release device 17 and quick connect coupling 18 constitute, sweep replacement device 200 including the gas pressure storage tank 21 that connects in order, pulse solenoid valve 22, sweep pipeline 23, once diffusion section 24, the annular section 25 that overflows, water conservancy diversion section 26 and secondary diffusion section 27 that expands, and be provided with water conservancy diversion awl 28 in water conservancy diversion section 26, sweep replacement device 200's secondary diffusion section 27 and unloading arm body 100's quick connect coupling 18 sealing connection.

As shown in FIG. 3, the annular flow passage section 25 is composed of flow passages with a plurality of annular cavities in cross section, the annular width of the outer annular flow passage 25-1 is equal to the diameter of the inner annular flow passage 25-3, the annular width of the middle annular flow passage 25-2 is smaller than the annular width of the outer annular flow passage 25-1 and the annular width of the inner annular flow passage 25-3, and the annular flow passage is designed to be matched with the downstream diversion cone 28 to ensure uniform air flow distribution, so that the air flow achieves the effects of rectification and pressure stabilization. As shown in fig. 4, at least 3 blades 29 are circumferentially provided on the outer portion of the guide cone 28 such that the airflow is rotated when passing through the blades 29.

In the above embodiment, preferably, as shown in fig. 5, the included angle between the tip of the blade 29 and the guide cone section is 90 °, the included angle between the tip of the blade 29 and the guide cone section is 30 ° to 60 °, and the outer edge of the blade 29 is connected to the inner wall of the guide section 26, so that the guide section 26, the guide cone 28 and the blade 29 together form a plurality of guide channels 30 distributed in a turbine shape, and thus the airflow enters the guide channels 30 in the axial direction and then flows out from the tip of the blade 29 at an angle, thereby generating acceleration and rotation.

In the above embodiment, as shown in fig. 1 and fig. 6, preferably, a flow stabilizer 31 is disposed inside the end of the secondary diffuser section 27, the flow stabilizer 31 is a hollow shuttle-shaped shell structure, and the included angle β is 45 ° to 75 °.

In the above embodiment, as shown in fig. 2, preferably, the primary diffuser section 24 has a hollow circular truncated cone shell structure, and the secondary diffuser section 27 has a hollow circular truncated cone shell structure with an arc-shaped curved side surface.

The utility model provides a LNG unloading arm sweeps replacement system when using, its working process as follows:

when purging replacement is needed, the pulse electromagnetic valve 22 is opened, high-pressure nitrogen in the gas pressure storage tank 21 instantly enters the purging pipeline 23, the primary diffusion section 24 is firstly diffused, and then the high-pressure nitrogen enters the annular overflowing section 25; the air flow passing through the annular overflowing section 25 further obtains pressure stabilization and rectification, then is guided into the guide channel 30 distributed in a turbine shape by the guide cone 28, after the air flow is accelerated and rotated by the guide channel 30, the air flow enters the secondary diffusion section 27 for diffusion again, then enters the quick connection joint 18 of the discharging arm body 100 and the subsequent main pipeline 15 thereof after passing through the flow stabilizer 31 positioned at the tail end of the secondary diffusion section 27 in a rotary flowing mode, and the rotary air flow uniformly flows along the main pipeline 15 of the discharging arm body 100 to complete purging and replacement. Because high-pressure nitrogen gas adopts many times steady voltage and rectification to sweep the replacement to the main line 15 of unloading arm body 100 with rotatory air current's mode, consequently can avoid the current technique of sweeping to directly blow the inhomogeneous defect of replacement effect that the efflux leads to of blowing.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit and scope of the present invention in its corresponding aspects.

Claims

1. An LNG discharging arm purging and replacing system is characterized by comprising a discharging arm body (100) and a purging and replacing device (200), the discharging arm body (100) mainly comprises an upright post (11), a rotating mechanism (12), a balance transmission mechanism (13), an outer arm support (14), a main pipeline (15), a rotating joint (16), an emergency release device (17) and a quick connecting joint (18), the purging and replacing device (200) comprises a gas pressure storage tank (21), a pulse electromagnetic valve (22), a purging pipeline (23), a primary diffusion section (24), an annular overflow section (25), a flow guide section (26) and a secondary diffusion section (27) which are connected in sequence, a flow guide cone (28) is arranged in the flow guide section (26), and a secondary diffusion section (27) of the purging and replacing device (200) is hermetically connected with a quick connecting joint (18) of the discharging arm body (100);

the annular overflowing section (25) is composed of overflowing channels with a plurality of annular cavities in cross sections, and at least 3 blades (29) are arranged on the outer portion of the guide cone (28) along the circumferential direction, so that airflow can rotate when passing through the blades (29).

2. The LNG unloading arm purging and replacing system according to claim 1, wherein the annular overflowing section (25) is composed of an outer annular overflowing channel (25-1), an intermediate annular overflowing channel (25-2) and an inner annular overflowing channel (25-3), the annular width of the outer annular overflowing channel (25-1) is equal to the diameter of the inner annular overflowing channel (25-3), and the annular width of the intermediate annular overflowing channel (25-2) is smaller than the annular width of the outer annular overflowing channel (25-1) and smaller than the annular width of the inner annular overflowing channel (25-3).

3. The LNG discharge arm purging and replacing system as claimed in claim 1, wherein the included angle between the tip of the blade (29) and the guide cone section is 90 degrees, the included angle between the tail end of the blade (29) and the guide cone section is 30-60 degrees, and the outer edge of the blade (29) is connected with the inner wall of the guide section (26), so that the guide section (26), the guide cone (28) and the blade (29) form a plurality of guide channels (30) distributed in a turbine shape together.

4. An LNG discharge arm purging and replacing system as claimed in claim 1, characterized in that a flow stabilizer (31) is arranged inside the end of the secondary diffusion section (27), the flow stabilizer (31) is a hollow shuttle-shaped shell structure, and the included angle β is 45-75 °.

5. The LNG unloading arm purging and replacing system according to claim 1, wherein the primary diffuser section (24) is a hollow circular truncated cone shell structure, and the secondary diffuser section (27) is a hollow circular truncated cone shell structure with an arc-shaped curved side surface.