Refining device buried main pipe structure and laying method thereof

Abstract

The invention provides a buried main pipe structure of a refining device and a laying method of the buried main pipe structure, and relates to the technical field of buried main pipes, the buried main pipe structure comprises at least two sub-pipes, the axis of each sub-pipe is bent into an n shape, and the adjacent sub-pipes are coaxially connected through a first straight pipe part and a second straight pipe part; the axes of all the first straight pipe parts and the second straight pipe parts of the at least two sub-pipes are located on a set laying straight line; the length of the closed end of the U-shaped pipe part is L1, the sum of the lengths of the straight pipe part and the second straight pipe part which are coaxially connected is L2, the ratio of L1 to L2 is 0.8-1.2, the closed end of the U-shaped pipe part is at least partially parallel to a set laying straight line, the distance between the part, parallel to the set laying straight line, of the closed end of the U-shaped pipe part and the set laying straight line is L3, and the ratio of L1 to L3 is 6-16; the problems that in the prior art, the thermal expansion deformation, capable of being absorbed by an existing pi-shaped compensator, of a buried pipeline is quite limited, and the pi-shaped compensator and flexible filler often need to be used together are solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of buried main pipes, and more specifically, relates to a buried main pipe structure of a refining device and a laying method thereof. Background Art

[0002] The buried pipelines of refining and chemical plants are usually buried directly or in trenches with sand filling. If a leak occurs in the buried pipeline, it is easy to cause the accumulation of combustible media and thus cause explosions, and it is also easy to cause groundwater pollution. The pipe system has the characteristics of high calculation temperature, limited buried space, slope gravity flow, and frequent operations on the main pipe branches. More importantly, the pipeline is affected by soil friction and extrusion in the soil, and stress often exceeds the standard in the lateral deformation zone, that is, the elbow, making stress calculation difficult.

[0003] For long-distance buried pipelines that transport media similar to those of refineries, anchor piers and flexible fillers are often used to solve the problem of excessive pipeline stress because of the lower temperature, long transportation distance and few branches on the main pipe. For municipal hot water pipelines with a transportation temperature close to that of refineries, preheating installation, flexible fillers, π-type compensators, anchor piers and other methods are often used to solve the problem of excessive pipeline stress. Among these methods, the anchor pier and preheating installation methods have high construction costs, and flexible fillers are prone to reduce the rebound rate at high temperatures. The existing π-type compensator setting method is based on the experience of overhead laying. Figure 1 As shown in FIG. 1 , the length l3 between the π bends of the π-type compensator 101 is much larger than the width l2 of the π bends. At the same time, the protruding length l1 of the π bend on one side of the set laying straight line is also much larger than the width l2 of the π bends. When the buried pipeline expands due to heat, Figure 2 As shown, the deformation at the two elbows 102 close to the set laying straight line is significantly greater than the deformation at the two elbows 102 away from the set laying straight line, resulting in uneven deformation. The amount of thermal expansion deformation that can be absorbed is also very limited, and the π-type compensator 101 is often required to be used together with a flexible filler, which is relatively costly. Summary of the invention

[0004] The purpose of the present invention is to provide a buried main pipe structure of a refining device and a laying method thereof in view of the deficiencies in the prior art, so as to solve the problem that the thermal expansion deformation of the buried pipeline that can be absorbed by the existing π-type compensator in the prior art is very limited, and the π-type compensator is often required to be used together with a flexible filler, resulting in high cost.

[0005] In order to achieve the above-mentioned object, the present invention provides an underground main pipe structure of a refinery, comprising:

[0006] At least two sub-tubes, the axis of each sub-tube is bent into a "X" shape, each sub-tube comprises a first straight tube portion, a U-shaped tube portion and a second straight tube portion connected in sequence, adjacent sub-tubes are coaxially connected through one first straight tube portion and one second straight tube portion, and the axes of all the first straight tube portions and the second straight tube portions of at least two sub-tubes are on a set laying straight line;

[0007] The length of the closed end of the U-shaped tube portion is L1, the sum of the lengths of the coaxially connected first straight tube portion and the second straight tube portion is L2, the ratio of L1 to L2 is 0.8-1.2, the closed end of the U-shaped tube portion is at least partially parallel to the set laying straight line, and the distance between the part of the closed end of the U-shaped tube portion parallel to the set laying straight line and the set laying straight line is L3, and the ratio of L1 to L3 is 6-16.

[0008] Optionally, the U-shaped tube portion includes two third straight tube portions and one fourth straight tube portion, one end of the two third straight tube portions are respectively connected to the two ends of the fourth straight tube portion through an elbow, and the other end of the two third straight tube portions are respectively connected to the first straight tube portion and the second straight tube portion through an elbow.

[0009] Optionally, the axis of the third straight tube portion is perpendicular to the axis of the fourth straight tube portion, and the distance between the two third straight tube portions is L1.

[0010] Optionally, the distance between a third straight tube portion and a fourth straight tube portion that are close to each other of adjacent U-shaped tube portions is L2.

[0011] Optionally, the fourth straight pipe portion is parallel to the set laying straight line, and the distance between the fourth straight pipe portion and the set laying straight line is L3.

[0012] Optionally, the nominal diameter of the sub-pipe is D, and the bending radius of the elbow is 3D-6D.

[0013] Optionally, the turning angle of the elbow is 75°-125°.

[0014] Optionally, the U-shaped tube portions of all the sub-tubes are on one side of the set laying straight line, or the U-shaped tube portions of a part of the sub-tubes are on one side of the set laying straight line, and the U-shaped tube portions of another part of the sub-tubes are on the other side of the set laying straight line.

[0015] Optionally, when adjacent sub-pipes are coaxially connected via a first straight pipe portion and a second straight pipe portion, a connecting pipe portion is further connected between a first straight pipe portion and a second straight pipe portion.

[0016] The present invention also provides a method for laying an underground main pipe structure of a refinery, based on the above-mentioned buried main pipe structure of the refinery, comprising:

[0017] Obtain at least two sub-tubes, wherein the axis of each sub-tube is bent into a "X" shape, and each sub-tube comprises a first straight tube portion, a U-shaped tube portion, and a second straight tube portion connected in sequence;

[0018] Set the laying line and the laying plane;

[0019] Placing at least two of the sub-pipes on a set laying plane;

[0020] The adjacent sub-pipes are coaxially connected through a first straight pipe portion and a second straight pipe portion, so that the axes of all the first straight pipe portions and the second straight pipe portions are on the set laying straight line, and the length of the closed end of the U-shaped pipe portion is L1, the sum of the lengths of the coaxially connected first straight pipe portion and the second straight pipe portion is L2, the ratio of L1 to L2 is 0.8-1.2, the closed end of the U-shaped pipe portion is at least partially parallel to the set laying straight line, and the distance between the part of the closed end of the U-shaped pipe portion parallel to the set laying straight line and the set laying straight line is L3, and the ratio of L1 to L3 is 6-16.

[0021] The present invention provides a buried main pipe structure of a refinery and a laying method thereof, and the beneficial effects thereof are as follows: the buried main pipe structure of the refinery has at least two sub-pipes whose axes are bent into a "X" shape, and at least two sub-pipes are laid along a set laying straight line. Compared with the π-type compensator provided in the prior art, the length l3 between the π bends is much larger than the width l2 of the π bends, and the extended length l1 of the π bends on one side of the set laying straight line is also much larger than the width l2 of the π bends. The length of the closed end of the U-shaped pipe portion of the sub-pipe of the buried main pipe structure of the refinery is L1, the sum of the lengths of a coaxially connected straight pipe portion and a second straight pipe portion is L2, the ratio of L1 to L2 is 0.8-1.2, and the U-shaped pipe portion is L1. The closed end of the pipe is at least partially parallel to the set laying straight line, and the distance between the part of the closed end of the U-shaped pipe that is parallel to the set laying straight line and the set laying straight line is L3, and the ratio of L1 to L3 is 6-16; obviously, compared with the prior art in which a π-type compensator is set in the buried main pipe structure, the lengths of L1 and L3 of the sub-pipe are closer, and L3 is significantly smaller than L2. Such a setting can make the deformation of the four bending positions of the "J"-shaped sub-pipe more uniform when subjected to thermal expansion deformation, thereby improving its ability to absorb thermal expansion deformation. At the same time, the buried main pipe structure of the refining device can be directly buried underground without the need to be used together with flexible fillers, and the cost is relatively low.

[0022] Other features and advantages of the present invention will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The above and other objects, features and advantages of the present invention will become more apparent through a more detailed description of exemplary embodiments of the present invention in conjunction with the accompanying drawings, wherein like reference numerals generally represent like components throughout the exemplary embodiments of the present invention.

[0024] Figure 1 A schematic diagram of an underground main pipe structure of a refinery in the prior art is shown.

[0025] Figure 2 A schematic diagram of the stress deformation of an underground main pipe structure of a refinery in the prior art is shown.

[0026] Figure 3 A schematic diagram of an underground main pipe structure of a refinery according to an embodiment of the present invention is shown.

[0027] Figure 4 A schematic diagram of the stress deformation of an underground main pipe structure of a refinery according to an embodiment of the present invention is shown.

[0028] Figure 5 A schematic diagram of an underground main pipe structure of a refinery according to another embodiment of the present invention is shown.

[0029] Figure 6 A schematic diagram comparing an underground main pipe structure of a refinery according to an embodiment of the present invention and an underground main pipe structure of a refinery using two π-type compensators and three π-type compensators in the prior art is shown.

[0030] Figure 7 A flow chart of a method for laying an underground main pipe structure of a refinery according to an embodiment of the present invention is shown.

[0031] Description of reference numerals:

[0032] exist Figure 1 and Figure 2 middle:

[0033] 101. π-type compensator; 102. elbow;

[0034] exist Figures 3 to 6 middle:

[0035] 1. The first straight pipe section; 2. The second straight pipe section; 3. The third straight pipe section; 4. The fourth straight pipe section; 5. The elbow. DETAILED DESCRIPTION

[0036] The preferred embodiments of the present invention will be described in more detail below. Although the preferred embodiments of the present invention are described below, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to make the present invention more thorough and complete, and to fully convey the scope of the present invention to those skilled in the art.

[0037] like Figure 3 As shown, the present invention provides an underground main pipe structure of a refinery, comprising:

[0038] At least two sub-tubes, the axis of each sub-tube is bent into a "X" shape, each sub-tube comprises a first straight tube portion 1, a U-shaped tube portion and a second straight tube portion 2 connected in sequence, adjacent sub-tubes are coaxially connected through a first straight tube portion 1 and a second straight tube portion 2, and the axes of all the first straight tube portions 1 and the second straight tube portions 2 of at least two sub-tubes are on a set laying straight line;

[0039] The length of the closed end of the U-shaped tube portion is L1, the sum of the lengths of a first straight tube portion 1 and a second straight tube portion 2 coaxially connected is L2, the ratio of L1 to L2 is 0.8-1.2, the closed end of the U-shaped tube portion is at least partially parallel to the set laying straight line, and the distance between the part of the closed end of the U-shaped tube portion parallel to the set laying straight line and the set laying straight line is L3, and the ratio of L1 to L3 is 6-16.

[0040] Specifically, in order to solve the problem that the amount of thermal expansion deformation of buried pipelines that can be absorbed by the existing π-type compensators in the prior art is very limited, and the π-type compensators are often required to be used together with flexible fillers, which is costly; the buried main pipe structure of the refining device provided by the present invention has at least two sub-pipes with axes bent into a "X" shape, and at least two sub-pipes are laid along a set laying straight line. Compared with the π-type compensators provided in the prior art, the length l3 between the π bends is much larger than the width l2 of the π bends, and at the same time, the protruding length l1 of the π bends on one side of the set laying straight line is close to the width l2 of the π bends. The length of the closed end of the U-shaped tube portion of the sub-pipe of the buried main pipe structure is L1, the sum of the lengths of a coaxially connected straight tube portion and a second straight tube portion 2 is L2, the ratio of L1 to L2 is 0.8-1.2, the closed end of the U-shaped tube portion is at least partially parallel to the set laying straight line, and the distance between the part of the closed end of the U-shaped tube portion parallel to the set laying straight line and the set laying straight line is L3, and the ratio of L1 to L3 is 6-16; obviously, compared with the prior art in which a π-type compensator is arranged in the buried main pipe structure, the lengths of L1 and L2 of the sub-pipe are closer, and L3 is significantly smaller than L2; Figure 4As shown, such an arrangement can make the deformation of the four bending positions of the "X"-shaped sub-pipe more uniform when subjected to thermal expansion deformation, fully utilize the parts of the soil that are more easily deformed and compressed, and thus improve its ability to absorb thermal expansion deformation. At the same time, the buried main pipe structure of the refining device can be buried directly underground without the need to be used together with flexible fillers, and the cost is relatively low.

[0041] Preferably, the ratio of L1 to L2 is 0.9-1.1.

[0042] Optionally, the U-shaped tube portion includes two third straight tube portions 3 and one fourth straight tube portion 4, one end of the two third straight tube portions 3 are connected to two ends of the fourth straight tube portion 4 through an elbow 5, and the other end of the two third straight tube portions 3 are connected to the first straight tube portion 1 and the second straight tube portion 2 through an elbow 5.

[0043] Specifically, the open end of each U-shaped tube portion is connected to the first straight tube portion 1 and the second straight tube portion 2 respectively through two elbows 5, and the closed end of each U-shaped tube portion is provided with a fourth straight tube portion 4 and two elbows 5, and the fourth straight tube portion 4 is parallel to the set laying straight line.

[0044] Optionally, the axis of the third straight tube portion 3 is perpendicular to the axis of the fourth straight tube portion 4 , and the distance between the two third straight tube portions 3 is L1 .

[0045] Specifically, Figure 4 As shown, such an arrangement enables a portion of the fourth straight tube portion 4, a third straight tube portion 3, and a portion of the second straight tube portion 2 on one side of the U-shaped tube portion to be connected through two elbows 5 to form a Z shape, and the third straight tube portion 3 is perpendicular to the fourth straight tube portion 4 and the second straight tube portion 2. In this way, the deformation amounts of the four bending positions of the "Z"-shaped sub-tube when subjected to thermal expansion deformation are approximately the same, thereby further improving its ability to absorb thermal expansion deformation.

[0046] Optionally, the distance between a third straight tube portion 3 and a fourth straight tube portion 4 that are close to each other of adjacent U-shaped tube portions is L2.

[0047] Optionally, the fourth straight pipe portion 4 is parallel to a set laying straight line, and a distance between the fourth straight pipe portion 4 and the set laying straight line is L3.

[0048] Specifically, Figure 3 As shown, L1 is the distance between two third straight tube portions 3 of a U-shaped tube portion, L2 is the distance between the third straight tube portions 3 of two adjacent U-shaped tube portions close to each other, and L1 is the distance that the U-shaped tube portion protrudes from the set laying straight line.

[0049] Optionally, the nominal diameter of the sub-pipe is D, and the bending radius of the elbow 5 is 3D-6D.

[0050] Specifically, the bending radius of the elbow 102 of the π-type compensator 101 in the prior art is usually 1.5D. The bending radius of the elbow 5 used in the sub-pipe in the present invention is significantly larger than the bending radius of the elbow 102 of the π-type compensator 101, which can increase the deformation that it can withstand when it absorbs thermal expansion deformation.

[0051] In this embodiment, the nominal diameter range of the buried main pipe structure of the refinery is DN80-DN400; preferably, the nominal diameter range of the buried main pipe structure of the refinery is DN100-DN250.

[0052] In this embodiment, the turning angle of the elbow 5 is 90°.

[0053] Optionally, the turning angle of the elbow 5 is 75°-125°.

[0054] Specifically, in other embodiments, the turning angle of the elbow 5 is 75°-125°. At this time, the two third straight pipe portions 3 are not perpendicular to the first straight pipe portion 1 and the fourth straight pipe portion 4. Then L1 is the total length of the two elbows 5 and one fourth straight pipe portion 4 along the axial direction of the fourth straight pipe portion 4 when the two elbows 5 are respectively connected to the two ends of a fourth straight pipe portion 4; L2 is the total length of the two elbows 5 and a first straight pipe portion 1 and a second straight pipe portion 2 coaxially connected along the axial direction of the first straight pipe portion 1; L3 is still the distance between the fourth straight pipe portion 4 and the set laying straight line.

[0055] Preferably, the turning angle of the elbow 5 is 85°-110°.

[0056] Optionally, the U-shaped tube portions of all sub-tubes are on one side of the set laying straight line, or the U-shaped tube portions of a part of the sub-tubes are on one side of the set laying straight line, and the U-shaped tube portions of another part of the sub-tubes are on the other side of the set laying straight line.

[0057] Specifically, Figure 3 In this embodiment, the U-shaped tube portions of all sub-tubes are located on one side of the set laying straight line; Figure 5 As shown, in another embodiment, the U-shaped tube portions of a portion of the sub-tubes are located on one side of the set laying straight line, and the U-shaped tube portions of another portion of the sub-tubes are located on the other side of the set laying straight line.

[0058] Optionally, when adjacent sub-tubes are coaxially connected via a first straight tube portion 1 and a second straight tube portion 2 , a connecting tube portion is further connected between the first straight tube portion 1 and the second straight tube portion 2 .

[0059] Specifically, when adjacent sub-tubes are coaxially connected via a first straight tube portion 1 and a second straight tube portion 2, a first straight tube portion 1 and a second straight tube portion 2 may be directly connected or may be connected via a connecting tube portion.

[0060] like Figure 7 As shown, the present invention also provides a method for laying an underground main pipe structure of a refinery, based on the above-mentioned buried main pipe structure of the refinery, comprising:

[0061] Obtain at least two sub-tubes, wherein the axis of each sub-tube is bent into a "X" shape, and each sub-tube comprises a first straight tube portion 1, a U-shaped tube portion, and a second straight tube portion 2 connected in sequence;

[0062] Set the laying line and the laying plane;

[0063] Place at least two sub-pipes on the set laying plane;

[0064] Adjacent sub-tubes are coaxially connected through a first straight tube portion 1 and a second straight tube portion 2, so that the axes of all the first straight tube portions 1 and the second straight tube portions 2 are on the set laying straight line, and the length of the closed end of the U-shaped tube portion is L1, the sum of the lengths of a coaxially connected first straight tube portion 1 and a second straight tube portion 2 is L2, the ratio of L1 to L2 is 0.8-1.2, the closed end of the U-shaped tube portion is at least partially parallel to the set laying straight line, and the distance between the part of the closed end of the U-shaped tube portion parallel to the set laying straight line and the set laying straight line is L3, and the ratio of L1 to L3 is 6-16.

[0065] Specifically, the laying method of the buried main pipe structure of a refinery provided by the present invention is based on the buried main pipe structure of the refinery, and takes a laying as an example: the straight length of the buried main pipe is 200 meters, the pipe diameter is DN200, the wall thickness grade is Sch40, and the medium density in the pipeline is 1000kg / m 3 , the calculation temperature is 200℃, the calculation pressure is 0.1MPa, and the pipe material is A106-B. The traditional laying scheme uses the traditional π-type compensator 101 with a 1.5D elbow 102, and the elbow 5 used in the present invention is a 5D elbow. The calculation software is CAESAR II 2016, the calculation soil model is sand in CAESAR II BasicModel, the soil friction coefficient is 0.5, and the soil density is 1280kg / m 3 The buried depth of the pipeline is set to 1.2m, the internal friction angle of the soil is set to 27°, the compaction coefficient of the soil backfill is set to 1.01, the yield displacement coefficient is set to 0.015, and the other parameters are selected according to the system default values. Figure 6As shown, the scheme of double π type compensator 101, the scheme of triple π type compensator 101 and the buried main pipe structure scheme of two sub-pipes in the traditional laying scheme are calculated, and the calculation results are as follows: the scheme of the traditional double π type compensator 101, the scheme of the traditional triple π type compensator 101 and the buried main pipe structure scheme of two sub-pipes in the present invention, the calculation temperature is 200 ℃, the calculation results of the secondary stress of the pipeline are 130.8%, 81.9% and 85.9% respectively, and the total length of the pipeline is 220m, 230m and 212m respectively. It can be seen that under the same calculation conditions, the calculation result of the secondary stress of the buried main pipe structure scheme of the two sub-pipes of the present invention is 85.9%, which is much lower than the scheme of the traditional double type compensator 101, and is close to the calculation result of the scheme of the traditional triple π type compensator 101. At the same time, the buried main pipe structure scheme of the two sub-pipes of the present invention is shorter than the total length of the pipeline required by the traditional scheme in the prior art, which can save costs.

[0066] The embodiments of the present invention have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A buried main pipe structure for a refinery, characterized in that: include: At least two sub-tubes, the axis of each sub-tube is bent into a "X" shape, each sub-tube comprises a first straight tube portion, a U-shaped tube portion and a second straight tube portion connected in sequence, adjacent sub-tubes are coaxially connected through one first straight tube portion and one second straight tube portion, and the axes of all the first straight tube portions and the second straight tube portions of at least two sub-tubes are on a set laying straight line; The length of the closed end of the U-shaped tube portion is L1, the sum of the lengths of the coaxially connected first straight tube portion and the second straight tube portion is L2, the ratio of L1 to L2 is 0.8-1.2, the closed end of the U-shaped tube portion is at least partially parallel to the set laying straight line, and the distance between the part of the closed end of the U-shaped tube portion parallel to the set laying straight line and the set laying straight line is L3, and the ratio of L1 to L3 is 6-16.

2. The buried main pipe structure of the refinery according to claim 1, characterized in that: The U-shaped tube portion includes two third straight tube portions and one fourth straight tube portion, one end of the two third straight tube portions are connected to the two ends of the fourth straight tube portion through an elbow respectively, and the other end of the two third straight tube portions are connected to the first straight tube portion and the second straight tube portion through an elbow respectively.

3. The buried main pipe structure of the refinery according to claim 2, characterized in that: The axis of the third straight tube portion is perpendicular to the axis of the fourth straight tube portion, and the distance between the two third straight tube portions is L1.

4. The buried main pipe structure of the refinery according to claim 3, characterized in that: The distance between a third straight tube portion and a fourth straight tube portion that are close to each other of adjacent U-shaped tube portions is L2.

5. The buried main pipe structure of the refinery according to claim 2, characterized in that: The fourth straight pipe portion is parallel to the set laying straight line, and the distance between the fourth straight pipe portion and the set laying straight line is L3.

6. The buried main pipe structure of a refinery according to claim 2, characterized in that: The nominal diameter of the sub-pipe is D, and the bending radius of the elbow is 3D-6D.

7. The buried main pipe structure of the refinery according to claim 6, characterized in that: The turning angle of the elbow is 75°-125°.

8. The buried main pipe structure of a refinery according to claim 1, characterized in that: The U-shaped tube portions of all the sub-tubes are on one side of the set laying straight line, or the U-shaped tube portions of a part of the sub-tubes are on one side of the set laying straight line and the U-shaped tube portions of another part of the sub-tubes are on the other side of the set laying straight line.

9. The buried main pipe structure of a refinery according to claim 1, characterized in that: When the adjacent sub-tubes are coaxially connected through one of the first straight tube portions and one of the second straight tube portions, a connecting tube portion is further connected between one of the first straight tube portions and one of the second straight tube portions.

10. A method for laying an underground main pipe structure of a refinery, based on the buried main pipe structure of a refinery according to any one of claims 1 to 9, characterized in that: include: Obtain at least two sub-tubes, wherein the axis of each sub-tube is bent into a "X" shape, and each sub-tube comprises a first straight tube portion, a U-shaped tube portion, and a second straight tube portion connected in sequence; Set the laying line and the laying plane; Placing at least two of the sub-pipes on a set laying plane; The adjacent sub-pipes are coaxially connected through a first straight pipe portion and a second straight pipe portion, so that the axes of all the first straight pipe portions and the second straight pipe portions are on the set laying straight line, and the length of the closed end of the U-shaped pipe portion is L1, the sum of the lengths of the coaxially connected first straight pipe portion and the second straight pipe portion is L2, the ratio of L1 to L2 is 0.8-1.2, the closed end of the U-shaped pipe portion is at least partially parallel to the set laying straight line, and the distance between the part of the closed end of the U-shaped pipe portion parallel to the set laying straight line and the set laying straight line is L3, and the ratio of L1 to L3 is 6-16.

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