A device for detecting and cleaning hydrate blockage in long-distance natural gas pipelines

Abstract

The present invention provides a natural gas long-distance pipeline hydrate blockage detection and cleaning device, including a device body and a controller. The device body is provided with a positioning element, a speed sensor, a liquid collector and a plurality of groups of telescopic mechanical arms. The adjustable telescopic device drives the motion device to telescopically move along the long-distance pipeline radially. The motion box is provided with a temperature control device corresponding to the extension direction of the telescopic mechanical arm. The natural gas long-distance pipeline hydrate blockage detection and cleaning device provided by the present invention has a reasonable structural design, uses a heating method to generate heat by friction with a mechanical device, effectively cleans the hydrate in the pipeline, prevents pipeline blockage, reduces the use cost, has high feasibility, high cleaning efficiency and good cleaning effect, and does not pollute the environment.

Description

Technical Field

[0001] The invention relates to the technical field of oil and gas storage and transportation engineering, and in particular to a hydrate blockage detection and cleaning device for a natural gas long-distance pipeline. Background Art

[0002] Hydrates are cage-shaped crystal inclusions formed by water and gas under low temperature and high pressure, and cage-shaped crystals are formed by hydrogen bonds. In the field of oil and gas storage and transportation, especially in long-distance pipelines, the formation of hydrates will adhere to the inner wall of the metal pipeline, reducing the area of ​​natural gas circulation in the pipeline, causing pipeline blockage, affecting pipeline transportation, and in serious cases even affecting pipeline transportation safety, resulting in safety accidents.

[0003] At present, the solutions to the hydrate blockage problem in pipeline transportation are mainly divided into adding inhibitors, reducing pressure and heating.

[0004] In order to inhibit the formation of hydrates, traditional methods usually use alcohols such as methanol and ethylene glycol or electrolytes to change the hydrate equilibrium conditions. However, this method requires a large amount of addition, generally up to 40%, and sometimes even up to 50% by weight. The cost of preventing hydrate formation is high and it is also harmful to the environment. The use of low-dose new inhibitors is expensive.

[0005] Pressure reduction is to reduce the pressure in the pipeline to below the hydrate formation pressure, so as to promote the decomposition of hydrates. Pressure reduction can be carried out by reducing pressure at one end or at both ends. However, in natural gas transportation, the pressure reduction operation needs to be coordinated by multiple structures during pipeline operation, which is not easy to achieve in pipeline transportation and still has defects in practicality. Summary of the invention

[0006] The technical problem to be solved by the present invention is: in order to overcome the shortcomings of the prior art, the present invention provides a hydrate blockage detection and cleaning device for a long-distance natural gas pipeline, which can conveniently, quickly and effectively remove hydrate blockages in pipeline transportation, avoid the problem that hydrates are difficult to clean and easy to be repeatedly generated, thereby causing pipeline blockages and even safety accidents.

[0007] The technical solution adopted by the present invention to solve its technical problems is: a natural gas long-distance pipeline hydrate blockage detection and cleaning device, including a device body and a controller, the device body is provided with a positioning element, a speed sensor, a liquid collector and a plurality of groups of telescopic mechanical arms, the positioning element and the speed sensor are connected with the controller signal, the telescopic mechanical arm is controlled to be telescopic by the controller, and the motion device is controlled by the controller; the telescopic mechanical arm includes a rod body, an adjustable telescopic device and a motion device, one end of the rod body is fixed to the device body, and the other end is connected to the motion device through the telescopic adjustment device, and the adjustable telescopic device drives the motion device to telescopically move along the long-distance pipeline; the motion device includes a motion box body, the motion box body is fixed to the telescopic adjustment device, a rotating shaft controlled to rotate by a motor is provided in the motion box body, both ends of the rotating shaft extend out of the motion box body and track wheels are fixed to the ends respectively; the motion box body is provided with a temperature control device corresponding to the extension direction of the telescopic mechanical arm.

[0008] In the above scheme, by setting up the retractable mechanical arm, the pressure between the track wheel and the inner wall of the long-distance pipeline can be effectively adjusted through the control of the controller. When no hydrate is generated on the inner wall of the pipeline, the track wheel normally drives the main body of the device to move along the inner wall of the pipeline. When there is a trace amount of hydrate on the inner wall of the pipeline, the track wheel moves to this position, and the retractable mechanical arm applies pressure, and the friction between the track wheel and the inner wall of the pipeline is increased, and the hydrate is decomposed by frictional heat. When there is a large amount of hydrate on the inner wall of the pipeline, and the friction force caused by the pressure of the retractable mechanical arm is greater than the forward power of the track wheel to drive the main body of the device, the controller controls the motor to stop, and uses the temperature control device to increase the temperature, so as to decompose a large amount of hydrate and collect it through the liquid collector.

[0009] Preferably, the device body has protruding rods evenly distributed in the circumference corresponding to the number of telescopic mechanical arms, the rod body is fixed with the protruding rods by a clamping device, and a connecting rod is protruded on the outer wall of the movement device, and the connecting rod is fixed with the adjustable telescopic device by a clamping device. Through the cooperation of the protruding rod and the connecting rod with the clamping device, the connection between the device body, the telescopic mechanical arm and the movement device can be effectively realized.

[0010] Preferably, the liquid collector comprises a reservoir, a straw, a soft structure and a suction port, wherein the reservoir is arranged in the device body, one end of the straw is connected to the reservoir pipeline, and the other end is connected to the suction port through the soft structure.

[0011] The above-mentioned natural gas long-distance pipeline hydrate blockage detection and cleaning device has the following pipeline cleaning method:

[0012] a. After the device body enters the long-distance pipeline, the motor controls the track wheel to drive the device body to run smoothly and at a uniform speed along the long-distance pipeline;

[0013] b. Maintain the motor power. When the speed sensor detects an abnormal speed signal, the signal is transmitted to the controller. The controller controls the retractable mechanical arm to extend so that the track wheel is pressed against the inner wall of the pipe. The friction between the track wheel and the inner wall of the pipe is increased, and the friction between the track wheel and the inner wall of the pipe generates heat.

[0014] c. The retractable mechanical arm is extended until the track wheel presses the inner wall of the pipeline until the track wheel can no longer rotate relative to the inner wall of the pipeline. The track wheel stops, the controller controls the motor to stop, the device body is stationary relative to the pipeline, the controller controls the temperature control device to heat up, and controls the liquid collector to work until there is no liquid inlet signal from the liquid collector. The controller recovers the command and ends the pipe cleaning operation.

[0015] In step b, when the speed sensor detects a speed abnormality signal, the positioning element transmits a position signal to the controller.

[0016] In step c, the controller controls the motor to stop, and the positioning element transmits the position signal to the controller.

[0017] The beneficial effect of the present invention is that the device for detecting and cleaning hydrate blockage in a long-distance natural gas pipeline provided by the present invention has a reasonable structural design, and uses a heating method in conjunction with a mechanical device to effectively clean hydrates in the pipeline to prevent pipeline blockage. The main method uses a heating method, and combines the frictional heat generated by the mechanical device, which further reduces the cost of use, is highly feasible, and does not pollute the environment. At the same time, when dealing with serious problems of pipeline hydrate extrusion, the mechanical device and the pipeline are relatively stationary, and the cleaning efficiency is high and the cleaning effect is good. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0019] Figure 1 It is a structural schematic diagram of the best embodiment of the present invention.

[0020] Figure 2 It is a ladder diagram of the PLC control system of the controller in the optimal embodiment of the present invention.

[0021] In the figure, 1, a retractable mechanical arm 101, a rod body 102, an adjustable retractable device 103, a clamping device 104, a moving device 105, a track wheel 2, a speed sensor 3, a temperature control device 4, a positioning element 5, a controller 6, a liquid collector 601, a suction port 602, a suction tube 603, a software structure 7, a motor 701, a rotating shaft 8, and a device body. DETAILED DESCRIPTION

[0022] The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams that only illustrate the basic structure of the present invention in a schematic manner, and therefore only show the components related to the present invention, and directions and references (e.g., up, down, left, right, etc.) may only be used to help describe the features in the drawings. Therefore, the following specific embodiments are not to be taken in a limiting sense, and the scope of the subject matter claimed is limited only by the attached claims and their equivalents.

[0023] like Figure 1 The device for detecting and clearing hydrate blockage in a long-distance natural gas pipeline is the best embodiment of the present invention.

[0024] The device includes a device body and a controller 5. The device body is provided with a positioning element 4, a speed sensor 2, a liquid collector 6 and three groups of retractable mechanical arms 1. The positioning element 4 and the speed sensor 2 are connected to the controller 5 by signals, the retractable mechanical arm 1 is controlled by the controller 5, and the motion device 104 is controlled by the controller 5. The controller 5 is provided with a PLC control system, and the PLC control system can issue the following control commands: the mechanical arm is tensioned, the motor 7 stops rotating, the temperature control device 3 heats up, the liquid collector 6 starts working, and the positioning element 4 outputs position information. The PLC control system can also issue a retraction command to end the control work.

[0025] The controller 5 mentioned above needs to control the mechanical parts of the device body to complete the pipe cleaning operation. The telescopic mechanical arm 1 includes a rod body 101, an adjustable telescopic device 102 and a motion device 104. One end of the rod body 101 is fixed to the device body 8, and the other end is connected to the motion device 104 through a telescopic adjustment device. The adjustable telescopic device 102 drives the motion device 104 to move radially along the long-distance pipeline. The motion device 104 includes a motion box, which is fixed to the telescopic adjustment device. A rotating shaft 701 controlled by a motor 7 is provided in the motion box. Both ends of the rotating shaft 701 extend out of the motion box and track wheels 105 are fixed to the ends respectively; the motion box is provided with a temperature control device 3 corresponding to the extension direction of the telescopic mechanical arm 1. The temperature control device 3 can be heated by electric heating wire or other electric heating structures. In this embodiment, the temperature control device 3 is preferably arranged at the outer wall of the motion box.

[0026] The liquid collector 6 includes a storage container, a straw 602, a soft structure 603 and a suction port 601. The storage container is arranged in the device body 8. One end of the straw 602 is connected to the storage container pipeline, and the other end is connected to the suction port 601 through the soft structure 603. In actual use, the liquid collector 6 absorbs the water produced by the decomposition of hydrates through the suction port 601 under the action of the controller 5, and transports it to the storage container through the soft structure 603 and the straw 602 for storage, effectively cleaning the water produced by the cleaning pipe and avoiding the occurrence of hydrate blockage there again. On the one hand, the soft structure 603 can support the suction port 601 relative to the straw 602, and on the other hand, it has a certain adjustable performance. During the pipe cleaning operation, three sets of retractable robotic arms 1 support the inner circle of the pipe in three parts. The decomposed water will be gathered to the lowest point of the inner circle of the pipe in the height direction under the action of gravity. In order to effectively suck the decomposed water, the final direction of the suction pipe 602 and the suction port 601 also points to the lowest point of the inner circle of the pipe. The design of the soft structure 603 copes with the ups and downs of the long-distance pipeline, avoiding obstruction of the device's movement due to the ups and downs of the pipeline.

[0027] In this embodiment, the adjustable telescopic device 102 can select a telescopic structure such as an electric push rod according to actual needs, and the telescopic movement of the electric push rod is also controlled by the controller 5. The adjustable telescopic device 102 is actively extended or retracted through PLC circuit connection control or manual control, so as to complete the purpose of clamping the inner wall of the pipeline and adapting to pipelines of various diameters. The clamping device 103 can use structures such as a clamp, a flange, and a bolt to achieve the connection between the two device bodies. In this embodiment, the device body 8 is evenly distributed with convex rods in the axial direction, and the rod body 101 is fixed with the convex rod by bolts and nuts. A connecting rod is protruding from the outer wall of the motion box body, and the connecting rod is fixed to the adjustable telescopic device 102 by bolts and nuts.

[0028] The above device has the following cleaning method:

[0029] a. After the device body enters the long-distance pipeline, the motor 7 controls the track wheel 105 to drive the device body to run smoothly and at a uniform speed along the long-distance pipeline;

[0030] b. Maintaining the power of the motor 7, when the speed sensor 2 detects an abnormal speed signal, the abnormal speed signal is transmitted to the controller 5, and the controller 5 controls the retractable mechanical arm 1 to extend so that the track wheel 105 is pressed against the inner wall of the pipe, the friction between the track wheel 105 and the inner wall of the pipe is increased, and the track wheel 105 and the inner wall of the pipe generate heat by friction, and at the same time, the controller 5 also obtains the position signal of the device body from the positioning element 4;

[0031] c. The retractable mechanical arm 1 is extended until the track wheel 105 presses the inner wall of the pipeline until the track wheel 105 can no longer rotate relative to the inner wall of the pipeline, the track wheel 105 stops, the controller 5 controls the motor 7 to stop, the device body is stationary relative to the pipeline, the controller 5 obtains the position signal of the device body from the positioning element 4, the controller 5 controls the temperature control device 3 to heat up, controls the liquid collector 6 to work, until there is no liquid inlet signal from the liquid collector 6, the controller 5 recovers the instruction, and ends the current pipe cleaning operation.

[0032] like Figure 2 As shown, when the PLC control system of the controller 5 receives the abnormal speed signal X0, it simultaneously issues five control commands: the robot arm is tensioned, the motor 7 stops rotating, the temperature control device 3 heats up, the liquid collector 6 starts working, and the positioning element 4 outputs position information. When the signal X1 indicating that there is no liquid entering the suction port 601 is received, the control system withdraws the command and ends the control work.

[0033] During the operation of the device, the device relies on the motor 7 to drive the track wheel 105 to provide power. During the movement, the track wheel 105 is attached to the inner wall of the pipeline for transmission. When hydrate blockage is formed in the pipeline, the inner diameter of the pipeline becomes narrower due to the blockage, and the resistance increases. During operation, the power of the motor 7 remains unchanged, and the movement speed of the device slows down accordingly. At this time, the speed sensor 2 detects an abnormal speed signal and transmits the signal to the controller 5. The controller 5 issues an instruction to enable the positioning element 4 to determine the specific position of the device in the pipeline. The retractable mechanical arm 1 stretches and clamps with the inner wall of the pipeline, generating heat by increasing friction. When there is a trace amount of hydrate on the inner wall of the pipeline, the hydrate is decomposed by frictional heat. However, when there is a large amount of hydrate on the inner wall of the pipeline, the retractable mechanical arm 1 applies pressure to cause the friction force to be greater than the forward power of the track wheel 105 to drive the device body. The controller 5 controls the motor 7 to stop, and the device body 8 loses power and stops moving; at the same time, the controller 5 controls the temperature control device 3 to heat up, decompose the hydrate that causes the blockage, and decompose it into CH4 and water; the liquid collector 6 starts to work and absorbs the water generated by the decomposition. After a period of time, when no water enters the suction port 601 of the liquid collector 6, a signal is transmitted to the controller 5, and the above operation is stopped, the retractable mechanical arm 1 is retracted, the friction force is reduced, the motor 7 is operated, the temperature controller 5 stops heating, the liquid collector 6 stops working, and the device continues to operate normally. Repeat the above operation at the next hydrate blockage.

[0034] In this embodiment, the method for cleaning hydrates in pipeline transportation is a heating method, which is pollution-free to the environment. The heating method not only includes heating by using the temperature controller 5, but also combines the frictional heat generation of the mechanical device, so that the track wheel 105 originally used for the main body of the device to move in the pipeline also has a pipe cleaning effect. Before the temperature control device 3 heats up, it assists in raising the temperature in the pipe, and can clean part of the hydrates attached to the pipe wall during movement, further reducing the use cost of the device, and the feasibility is high. When dealing with the serious problem of pipeline hydrate extrusion, on the basis of frictional heat generation, the temperature control device 3 has an excellent heating effect, the mechanical device and the pipeline are relatively static, and the cleaning efficiency of the hydrates in the pipe is high and the cleaning effect is good.

[0035] Based on the above ideal embodiments of the present invention, the relevant staff can make various changes and modifications without departing from the technical concept of the present invention through the above description. The technical scope of the present invention is not limited to the contents of the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A natural gas long-distance pipeline hydrate blockage detection and cleaning device, characterized by: The device comprises a device body and a controller (5); the device body is provided with a positioning element (4), a speed sensor (2), a liquid collector (6) and a plurality of groups of retractable mechanical arms (1); the positioning element (4) and the speed sensor (2) are connected to the controller (5) by signals; and the retractable mechanical arms (1) are controlled to retract by the controller (5); The telescopic mechanical arm (1) comprises a rod body (101), an adjustable telescopic device (102) and a moving device (104); one end of the rod body (101) is fixed to the device body (8), and the other end is connected to the moving device (104) via the telescopic adjustable device; the adjustable telescopic device (102) drives the moving device (104) to move in a radial direction of the long-distance pipeline in a telescopic manner; and the movement of the moving device (104) is controlled by a controller (5); The movement device (104) comprises a movement box, the movement box is fixed to the telescopic adjustment device, a rotating shaft (701) controlled to rotate by a motor (7) is provided in the movement box, both ends of the rotating shaft (701) extend out of the movement box and track wheels (105) are respectively fixed to the ends; The moving box is provided with a temperature control device (3) corresponding to the extension direction of the telescopic mechanical arm (1); The liquid collector (6) comprises a reservoir, a straw (602), a soft structure (603) and a suction port (601); the reservoir is arranged in the device body (8); one end of the straw (602) is connected to the reservoir pipeline, and the other end is connected to the suction port (601) through the soft structure (603).

2. A natural gas long-distance pipeline hydrate blockage detection and cleaning device as claimed in claim 1, characterized in that: The device body (8) has protruding rods evenly distributed in the circumferential direction corresponding to the number of the retractable mechanical arms (1); the rod body (101) is fixed to the protruding rods by means of a clamping device (103); a connecting rod protrudes from the outer wall of the motion device (104); and the connecting rod is fixed to the adjustable retractable device (102) by means of the clamping device (103).

3. A natural gas long-distance pipeline hydrate blockage detection and cleaning device as claimed in claim 1, characterized in that: The following cleaning methods are available: a. After the main body of the device enters the long-distance pipeline, the motor (7) controls the track wheel (105) to drive the main body of the device to run smoothly and at a uniform speed along the long-distance pipeline; b. Maintaining the power of the motor (7), when the speed sensor (2) detects an abnormal speed signal, the signal is transmitted to the controller (5), and the controller (5) controls the retractable mechanical arm (1) to extend so that the track wheel (105) is pressed against the inner wall of the pipe, the friction between the track wheel (105) and the inner wall of the pipe is increased, and the track wheel (105) and the inner wall of the pipe generate heat by friction; c. The retractable mechanical arm (1) is extended until the track wheel (105) presses against the inner wall of the pipeline until the track wheel (105) can no longer rotate relative to the inner wall of the pipeline, the track wheel (105) stops rotating, the controller (5) controls the motor (7) to stop rotating, the device body is stationary relative to the pipeline, the controller (5) controls the temperature control device (3) to increase the temperature, and controls the liquid collector (6) to work until there is no liquid inlet signal from the liquid collector (6), and the controller (5) recovers the instruction, thus ending the cleaning operation.

4. A natural gas long-distance pipeline hydrate blockage detection and cleaning device as claimed in claim 3, characterized in that: In step b, when the speed sensor (2) detects a speed abnormality signal, the positioning element (4) transmits a position signal to the controller (5).

5. A natural gas long-distance pipeline hydrate blockage detection and cleaning device as claimed in claim 3, characterized in that: In step c, the controller (5) controls the motor (7) to stop, and the positioning element (4) transmits a position signal to the controller (5).

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