CN108266289B

CN108266289B - High-pressure gas double-wall pipe

Info

Publication number: CN108266289B
Application number: CN201710004855.5A
Authority: CN
Inventors: 刘汉军; 马杰; 蔡乾亚; 陈乐�; 王占捷; 徐鹏飞; 陈云飞
Original assignee: Jiangnan Shipyard Group Co Ltd
Current assignee: Jiangnan Shipyard Group Co Ltd
Priority date: 2017-01-04
Filing date: 2017-01-04
Publication date: 2020-03-31
Anticipated expiration: 2037-01-04
Also published as: CN108266289A

Abstract

The invention provides a high-pressure gas double-wall pipe, which comprises an outer pipe and an inner pipe coaxially arranged with the outer pipe, wherein the outer pipe and the inner pipe are formed by welding a plurality of pipe sections; arranging an outer pipe elbow on the outer pipe at intervals as a compensating piece; an elastic support is arranged in an annular space between the outer pipe and the inner pipe, and the inner pipe is supported on the inner wall of the outer pipe through the elastic support; the outer pipe is also provided with a fixed bracket for fixing the inner pipe; an observation cock is arranged on the elbow of the outer pipe. The inner pipe can meet the design requirements that the pressure is up to dozens of MPa, the temperature is as low as minus dozens of degrees, and the double-wall pipe is in low-frequency vibration for a long time when a ship runs. And the ventilation performance is good, the stress, the vibration and the thermal expansion displacement can be effectively absorbed, and the service life is long.

Description

High-pressure gas double-wall pipe

Technical Field

The invention relates to the technical field of double-wall pipes, in particular to a high-pressure gas double-wall pipe applied to a gas fuel supply pipe system of a ship engine.

Background

With the known rapid consumption of oil reserves, the enhancement of environmental protection awareness and the continuous tightening of emission limits, gas fuels (methane, ethane, etc.) will certainly become the main marine fuel source for the fastest development in the world in the future due to the advantages of green, environmental protection and high efficiency. The advent of dual fuel engines has also enabled the use of gaseous fuels in ships and ocean platforms, and new ship fuel supply systems have emerged. Because the gas fuel (methane, ethane and the like) of the dual-fuel engine is flammable and explosive gas, intrinsic safety must be ensured in the engine room, and the dual-fuel engine requires that the engine room area must adopt a double-wall pipe type gas supply mode according to IGC (international liquefied gas ship structure and equipment for bulk transportation) and SOLAS (international maritime life safety) specifications when the dual-fuel engine is applied to a ship so as to ensure the normal operation and personnel safety of the ship.

When the inner pipe of the engine supply system conveys high-pressure low-temperature gas and the annular gap between the inner pipe and the outer pipe is connected with the atmosphere, the gas pressure of the inner pipe is up to dozens of MPa, the temperature is as low as minus dozens of degrees, the double-wall pipe is in low-frequency vibration for a long time when a ship runs, the running condition of the gas pipe is quite severe, the safety performance of the common single-wall pipe and the double-layer pipe is poor, the stress cannot be effectively absorbed, the thermal expansion displacement cannot be released, the severe running condition cannot be overcome, the service life is short, the requirement of long-term service of the ship cannot be met, and the safe running.

Disclosure of Invention

In view of the above-mentioned drawbacks of the prior art, the present invention provides a high-pressure gas double-wall pipe with a long service life, which can effectively absorb the stress and release the thermal expansion displacement, so as to overcome the above-mentioned drawbacks of the prior art.

In order to solve the technical problem, the invention provides a high-pressure gas double-wall pipe which comprises an outer pipe and an inner pipe coaxially arranged with the outer pipe, wherein the outer pipe and the inner pipe are formed by welding a plurality of pipe sections;

arranging an outer pipe elbow on the outer pipe at intervals as a compensating piece;

an elastic support is arranged in an annular space between the outer pipe and the inner pipe, and the inner pipe is supported on the inner wall of the outer pipe through the elastic support;

the outer pipe is also provided with a fixed bracket for fixing the inner pipe;

an observation cock is arranged on the elbow of the outer pipe.

Preferably, the elastic support comprises two support bodies which are symmetrically arranged along the circumference; the support comprises an outer tube and two support bodies, wherein the outer tube is provided with an inner tube, the inner tube is provided with an outer tube, the outer tube is provided with an inner tube, the outer tube is provided with an outer tube, the outer tube is provided with an inner tube, the inner tube is provided with a fixing part, the two support bodies are arranged on the inner tube, one end of each support body is provided with a.

The fixing part is flat, and the middle part of the fixing part is provided with an arc-shaped groove which is attached to the outer wall of the inner pipe.

The supporting part is further fixed with a self-lubricating lining plate, and the supporting part is in contact with the inner wall of the outer pipe through the self-lubricating lining plate.

Preferably, the fixing bracket comprises a three-way joint, an upper bracket and a lower bracket; the tee joint comprises a first interface, a second interface and a third interface, wherein the first interface and the second interface are arranged along an axis, the third interface is perpendicular to the axis, the inner pipe penetrates through the first interface and the second interface along the axis, the upper bracket and the lower bracket are respectively clamped on the inner pipe from the upper side and the lower side and are fixed on the inner wall of the third interface, the first interface and the second interface are in butt joint with the outer pipe, and a sealing cover plate is arranged on the third interface.

Preferably, the lower bracket comprises two parallel support legs, an arc-shaped support plate connected to the upper ends of the two support legs and a bottom plate vertically connected to the lower ends of the two support legs, the arc-shaped support plate is in contact with the outer wall of the inner pipe, and the bottom plate is fixed on the inner wall of the third connector.

Preferably, the upper bracket is in an inverted U shape, the upper end of the upper bracket is an arc part and is in contact with the outer wall of the inner pipe, the lower end of the upper bracket is provided with two sections of screw rods, and the two sections of screw rods penetrate through the through hole in the bottom plate of the lower bracket and are locked by nuts.

Preferably, the viewing cock is disposed at a 45 ° angle to the end face of the outer pipe elbow.

Preferably, the viewing tap, the fixing bracket, and the inner and outer tubes are of the same material.

Preferably, the weld seam on the outer tube is offset from the weld seam on the inner tube.

As described above, the high-pressure gas double-wall pipe of the present invention has the following beneficial effects:

the high-pressure gas double-wall pipe inner pipe can meet the design requirements that the pressure is up to dozens of MPa, the temperature is as low as minus dozens of degrees, and the double-wall pipe is in low-frequency vibration for a long time when a ship runs. The invention has good ventilation performance, can effectively absorb stress, can effectively release thermal expansion displacement, can effectively absorb vibration and has long service life.

Drawings

Fig. 1 is a schematic sectional view of a high-pressure gas double-wall pipe according to the present invention.

Fig. 2 is a front view schematically showing the elastic support of the high-pressure gas double-wall pipe of the present invention.

Fig. 3 is a front sectional view of the fixing bracket of the high pressure gas double wall pipe according to the present invention.

Description of the element reference numerals

100 outer pipe 200 inner pipe

300 outer tube elbow 400 elastic support

410 bracket body 411 fixing part

411a arc slot 412 support

420 fastener 430 self-lubricating liner

500 fixed bolster 510 three way connection

520 upper bracket 530 lower bracket

540 sealing cover plate 550 nut

600 observation cock

Detailed Description

The following description of the embodiments of the present invention is provided for illustrative purposes, and other advantages and effects of the present invention will become apparent to those skilled in the art from the present disclosure.

Please refer to fig. 1 to 3. It should be understood that the structures, ratios, sizes, and the like shown in the drawings and described in the specification are only used for matching with the disclosure of the specification, so as to be understood and read by those skilled in the art, and are not used to limit the conditions under which the present invention can be implemented, so that the present invention has no technical significance, and any structural modification, ratio relationship change, or size adjustment should still fall within the scope of the present invention without affecting the efficacy and the achievable purpose of the present invention. In addition, the terms "upper", "lower", "left", "right", "middle" and "one" used in the present specification are for clarity of description, and are not intended to limit the scope of the present invention, and the relative relationship between the terms and the terms is not to be construed as a scope of the present invention.

As shown in fig. 1, the high-pressure gas double-wall pipe comprises an outer pipe 100 and an inner pipe 200 coaxially arranged with the outer pipe, wherein the outer pipe 100 and the inner pipe 200 are formed by welding a plurality of pipe sections. The coaxial arrangement of outer tube 100, inner tube 200 to satisfy the concentricity requirement when the butt weld links to each other between the follow-up section, wherein the annular space between outer tube 100, inner tube 200 is big, and ventilation performance is good, and realizes taking a breath in real time, can ensure that the gas can not reveal in the gas supply line to the marine engine room, controls the possibility of gas explosion to zero.

An outer pipe elbow 300 is arranged on the outer pipe 100 at intervals as a compensation piece; the outer pipe bend 300 avoids stress concentrations so that thermal expansion displacements are released.

In the annular space between the outer tube 100 and the inner tube 200, an elastic support 400 is provided, and the inner tube 200 is supported on the inner wall of the outer tube 100 by the elastic support 400. As shown in fig. 2, the elastic stent 400 includes two stent bodies 410 arranged symmetrically along the circumference; the bracket body 410 is made of a stainless steel band through cold bending by a mold, one end of the bracket body is a fixing portion 411, the other end of the bracket body is an arc-shaped supporting portion 412, and the supporting portion 412 is elastically supported on the inner wall of the outer tube 100. The fixing portion 411 is flat, and an arc-shaped groove 411a attached to the outer wall of the inner tube 200 is formed in the middle of the fixing portion 411; the fixing portions 411 of the two bracket bodies 410 are clamped on the outer wall of the inner tube 200 and clamped by the fasteners 420. A self-lubricating liner plate 430 is further fixed on the supporting portion 412, and the supporting portion 412 is in contact with the inner wall of the outer pipe 100 through the self-lubricating liner plate 430. Because the flow direction of the fluid along the front straight pipe section of the outer pipe elbow 300 is the thermal expansion displacement direction, the arrangement of the elastic support 400 plays a role in damping; the bracket body 410 is made of a stainless steel band through cold bending of a die, and has enough high shear strength and hardness, and certain elasticity is ensured, so that huge stress and thermal expansion displacement caused by temperature difference, high pressure and vibration of the high-pressure gas double-wall pipe can be effectively absorbed, and a ship gas supply system can be safely operated for a long time.

On the outer tube 100, a fixing bracket 500 for fixing the inner tube 200 is further provided. As shown in fig. 3, the fixing bracket 500 includes a three-way joint 510, an upper bracket 520, and a lower bracket 530; three way connection 510 is including the first interface, the second interface that set up along the axis to and the third interface of perpendicular to axis, inner tube 200 passes first interface and second interface along the axis, go up bracket 520 and lower bracket 530 and press from both sides tight inner tube 200 and fix on the inner wall of third interface from upper and lower both sides respectively, first interface and second interface all dock with outer tube 100, be equipped with sealed apron 540 on the third interface. The lower bracket 530 comprises two parallel support legs, an arc-shaped support plate connected to the upper ends of the two support legs, and a bottom plate vertically connected to the lower ends of the two support legs, the arc-shaped support plate is in contact with the outer wall of the inner pipe, and the bottom plate is fixed on the inner wall of the third connector. The upper bracket 520 is in an inverted U shape, the upper end of the upper bracket is an arc portion and contacts with the outer wall of the inner tube 200, and the lower end of the upper bracket is provided with two sections of screws which pass through holes in the bottom plate of the lower bracket 530 and are locked by nuts 550.

The first and second joints of the three-way joint 510 and the respective adjacent outer pipes are welded together by a butt welding process, so that the top of the three-way joint 510 becomes a part of the outer pipe 100, and the fixing bracket 500 is welded on the hull structure to play a role in fixing and mainly used for controlling the thermal expansion displacement not to exceed the limit rebound offset of the elastic bracket 400 (the limit rebound offset is that the elastic bracket performs 10 times on the basis of the limit rebound offset⁷Can rebound to the original position or the maximum amplitude within a certain error range after sub-cycle loading), and can play a role of fixing the inner pipe 200 and the outer pipe 100 under the condition of not damaging the inner pipe 200 and the outer pipe 100, thereby ensuring that the inner pipe 200 and the outer pipe 100 are convenient to assemble, and have high safety performance and useThe service life is long.

As shown in fig. 1, the outer pipe elbows 300 are each welded with a viewing cock 600. The observation cock 600 is mainly used for inspecting the quality of the formation of the inner weld of the outer pipe 100 and the outer pipe bend 300 during the welding of the outer pipe 100. For ease of viewing, the viewing cock 600 is disposed at a 45 ° angle to the end face of the outer pipe elbow 300. The materials of the viewing cock 600, the fixing bracket 500, and the inner tube 200 and the outer tube 100 are the same or similar to avoid deformation during the assembly process. And the welding seam on the outer pipe 100 and the welding seam on the inner pipe 200 are staggered with each other, so that construction is facilitated.

The manufacturing process of the high-pressure gas double-wall pipe comprises the following steps:

firstly, calculating the pipe diameters, the wall thicknesses and the materials of the inner pipe and the outer pipe under the designed pressure and temperature according to the classification society specification, and then selecting corresponding finished pipes of the inner pipe and the outer pipe.

Providing an outer pipe 100, cutting the outer pipe into a set length according to the size of a drawing, and reserving a groove to meet the welding requirement; providing an inner pipe 200, and cold-bending the corner of the inner pipe 200 into a specified angle by using a pipe bender.

The elastic support 400: firstly, manufacturing a bracket body 410, namely firstly providing a stainless steel band with a certain thickness, cutting the stainless steel band into a certain width by using a plate shearing machine, then removing burrs and chamfers, confirming that the stainless steel band has no burrs and is smooth, and then performing cold bending and pressing by using a mould to form the bracket body 410 shown in figure 2, so that the inner diameter of the inner wall of an arc-shaped groove 411a attached to the outer wall of an inner pipe 200 is equal to the outer diameter of the inner pipe 200, and 2 process holes for installing fasteners 420 are processed at two sides of the arc-shaped groove 411a on a fixing part 411; in addition, at least two screw fitting holes are processed on the supporting portion 412 for subsequent use in fixing the self-lubricating liner plate 430. Manufacturing a self-lubricating lining plate 430, providing a PEEK-HPV plate (PEEK is polyether-ether-ketone, the PEEK-HPV is a material formed by adding polytetrafluoroethylene, graphite and carbon fibers into polyether-ether-ketone, and the PEEK-HPV is bearing-grade plastic), enabling the width of the PEEK-HPV plate to be larger than that of the bracket body 410, milling a groove matched with the bracket body 410 by using a milling machine, enabling the depth of the groove to be approximate to the thickness of the bracket body 410, deburring the PEEK-HPV plate and enabling the surface to be smooth; the PEEK-HPV plate is then placed in a bending mold and bent to be plastically deformed so as to be closely fitted with the supporting portion 412 of the stent body 410. And then placing the bent PEEK-HPV plate into a mold for positioning, drilling a screw hole corresponding to the screw assembling hole of the supporting part 412 of the bracket body 410, and finally deburring and cleaning the PEEK-HPV plate to complete the manufacture of the self-lubricating lining plate 430. The bracket body 410 is formed by cold bending a stainless steel band, and the self-lubricating liner plate 430 is embedded in the supporting part 412, so that the elastic bracket 400 has sufficient shear strength and elasticity, excellent friction performance, good self-lubricating property, corrosion resistance, flame retardance and fatigue resistance to alternating stress.

Providing an outer pipe elbow 300 with the same diameter as the outer pipe 100, drilling a hole on the outer pipe elbow 300, and welding the observation cock 600 with the outer pipe elbow 300 so that the observation cock 600 and the end surface of the outer pipe elbow 300 form an included angle of 45 degrees.

When the installation is carried out, the outer pipe elbow 300 is arranged at the corner of the inner pipe 200, and then the fastener 420 of the elastic bracket 400 is screwed and fixed at the designated position of the inner pipe 200; the self-lubricating liner 430 is then coated with a lubricant and pushed into the outer tube 100, stopping when the outer tube 100 comes into contact with the outer tube bend 300, and finally welding the outer tube bend 300 and the outer tube 100 together.

During welding, the outer pipe elbow 300, the inner pipe 200, the outer pipe 100 and the fixing support 500 are fixed on the temporary support and centered; then filling 99.99% purity argon gas into the annular space of the inner pipe and the outer pipe, and sealing the position of the welding seam between the elbow 300 of the outer pipe and the outer pipe 100 by using aluminum foil adhesive tape to prevent the leakage of the argon gas; and (3) performing spot welding in sequence according to the symmetrical positions to avoid deformation of the pipe, removing dirt on the surface by using a grinding wheel before spot welding, rechecking the centering condition, fully welding and completely welding, and observing the forming quality of the welding line on the inner side of the outer pipe by using the observation cock 600 after welding is finished.

Finally, the gas supply pipe of the ship is formed by butt welding a plurality of high-pressure gas double-wall pipe sections as shown in fig. 1.

In conclusion, the high-pressure gas double-wall pipe inner pipe can meet the design requirements that the pressure is up to dozens of MPa, the temperature is as low as minus dozens of degrees, and the double-wall pipe is in low-frequency vibration for a long time when a ship runs. The invention has good ventilation performance, can effectively absorb stress, can effectively release thermal expansion displacement, can effectively absorb vibration and has long service life. Therefore, the invention effectively overcomes various defects in the prior art and has high industrial utilization value.

The foregoing embodiments are merely illustrative of the principles and utilities of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or change the above-mentioned embodiments without departing from the spirit and scope of the present invention. Accordingly, it is intended that all equivalent modifications or changes which can be made by those skilled in the art without departing from the spirit and technical spirit of the present invention be covered by the claims of the present invention.

Claims

1. A high-pressure gas double-wall pipe comprises an outer pipe (100) and an inner pipe (200) which is coaxially arranged with the outer pipe, wherein the outer pipe (100) and the inner pipe (200) are formed by welding a plurality of pipe sections; it is characterized in that the preparation method is characterized in that,

arranging an outer pipe elbow (300) as a compensating piece on the outer pipe (100) at intervals;

an elastic support (400) is arranged in an annular space between the outer pipe (100) and the inner pipe (200), and the inner pipe (200) is supported on the inner wall of the outer pipe (100) through the elastic support (400);

the outer pipe (100) is further provided with a fixing support (500) for fixing the inner pipe (200), the fixing support (500) is welded on a ship structure, and the fixing support (500) comprises a three-way joint (510), an upper bracket (520) and a lower bracket (530); the three-way joint (510) comprises a first interface, a second interface and a third interface, wherein the first interface and the second interface are arranged along an axis, the third interface is perpendicular to the axis, the inner pipe (200) penetrates through the first interface and the second interface along the axis, the upper bracket (520) and the lower bracket (530) clamp the inner pipe (200) from the upper side and the lower side and are fixed on the inner wall of the third interface, the first interface and the second interface are in butt joint with the outer pipe (100), and a sealing cover plate (540) is arranged on the third interface;

an observation cock (600) is arranged on the outer pipe elbow (300).

2. The high pressure gas double wall tube of claim 1, wherein: the elastic support (400) comprises two support bodies (410) which are symmetrically arranged along the circumference; the support is characterized in that one end of each support body (410) is a fixing portion (411), the other end of each support body is an arc-shaped supporting portion (412), the supporting portions (412) are elastically supported on the inner wall of the outer pipe (100), and the fixing portions (411) of the two support bodies (410) are clamped on the outer wall of the inner pipe (200) and clamped through fasteners (420).

3. The high pressure gas double wall tube according to claim 2, wherein: the fixing part (411) is flat, and the middle part of the fixing part is provided with an arc-shaped groove (411a) attached to the outer wall of the inner pipe (200).

4. The high pressure gas double wall tube according to claim 2, wherein: a self-lubricating lining plate (430) is further fixed on the supporting portion (412), and the supporting portion (412) is in contact with the inner wall of the outer pipe (100) through the self-lubricating lining plate (430).

5. The high pressure gas double wall tube of claim 1, wherein: the lower bracket (530) comprises two parallel supporting legs, an arc-shaped supporting plate connected to the upper ends of the two supporting legs and a bottom plate vertically connected to the lower ends of the two supporting legs, the arc-shaped supporting plate is in contact with the outer wall of the inner pipe, and the bottom plate is fixed on the inner wall of the third interface.

6. The high pressure gas double wall tube of claim 5, wherein: the upper bracket (520) is in an inverted U shape, the upper end of the upper bracket is an arc part and is in contact with the outer wall of the inner pipe, the lower end of the upper bracket is provided with two sections of screw rods, and the two sections of screw rods penetrate through holes in the bottom plate of the lower bracket (530) and are locked by nuts (550).

7. A high-pressure gas double-walled tube according to any one of claims 1 to 3, characterized in that: the observation cock (600) is arranged at an included angle of 45 degrees with the end surface of the outer pipe elbow (300).

8. A high-pressure gas double-walled tube according to any one of claims 1 to 3, characterized in that: the observation tap (600), the fixing bracket (500), and the inner tube (200) and the outer tube (100) are the same material.

9. The high pressure gas double wall tube of claim 1, wherein: the welding seam on the outer pipe (100) and the welding seam on the inner pipe (200) are staggered.