Exit mechanism, entry mechanism, exit method and entry method

Abstract

The invention relates to the field of pipeline robots, and particularly discloses an exit mechanism, an entry mechanism, an exit method and an entry method.The exit mechanism comprises a transfer pipeline, an exit mechanism, an exit mechanism and an entry method.One end of the transfer pipeline communicates with a natural gas pipeline, and the other end communicates with the outside; the multiple switches are arranged at intervals in the axial direction of the transfer pipeline, and each switch can open or close circulation of the transfer pipeline; when the pipeline robot walks in the natural gas pipeline, all the switches are turned off; when the pipeline robot retreats from the natural gas pipeline to the outside, enters the transfer pipeline, and moves along the upstream of the transfer pipeline to the downstream, when the pipeline robot is close to the switch on the most upstream, the switch on the most upstream is turned on, and after the pipeline robot passes through the switch on the most upstream, the switch on the most upstream is turned off; when the pipeline robot continues to travel to the downstream of the transfer pipeline, the switch is turned on every time the pipeline robot is close to the switch. The effect of ensuring that the pipeline robot safely exits from the high-pressure natural gas pipeline to the outside is achieved.

Description

Technical Field

[0001] The present invention relates to the field of pipeline robots, and in particular to an exit mechanism, an entry mechanism, an exit method and an entry method. Background Art

[0002] Railway transportation, road transportation, water transportation, air transportation and pipeline transportation, as the five major modes of transportation in the national economy, play an important role in economic production. Currently, the safety inspection of oil and natural gas pipelines has attracted widespread attention from more and more scientific researchers.

[0003] In the related technology, pipeline robots are needed for the safety inspection inside the natural gas pipeline. In the actual operation process, the natural gas pipeline is usually a high-pressure environment. When the pipeline robot inside the pipeline needs to withdraw from the pipeline, a set of physical transfer mechanism is required to ensure that the pipeline robot can safely withdraw from the high-pressure natural gas pipeline to the outside world.

[0004] To this end, we propose an exit mechanism, an entry mechanism, an exit method and an entry method to solve the above problems. Summary of the invention

[0005] The purpose of the present invention is to provide an exit mechanism, an entry mechanism, an exit method and an entry method to ensure that a pipeline robot can safely exit from a high-pressure natural gas pipeline to the outside world.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] In the first aspect, the present application proposes a physical delivery mechanism, which includes a delivery pipeline, one end of which is connected to a natural gas pipeline, and the other end is connected to the outside world; a plurality of switches, wherein the plurality of switches are arranged at intervals along the axial direction of the delivery pipeline, and each of the switches can open or close the flow of the delivery pipeline; when the pipeline robot walks in the natural gas pipeline, all switches are closed; when the pipeline robot exits the natural gas pipeline to the outside world and enters the delivery pipeline, during the process of the pipeline robot moving from upstream to downstream along the delivery pipeline, when the pipeline robot approaches the switch most upstream, the switch most upstream is opened, and after the pipeline robot passes the switch most upstream, the switch is closed; when the pipeline robot continues to move downstream of the delivery pipeline, the switch is opened each time it approaches a switch.

[0008] By adopting the above technical solution, when the pipeline robot is driving normally in the natural gas pipeline, all switches are closed to prevent natural gas from leaking from the transmission pipeline. When the pipeline robot needs to exit from the natural gas pipeline to the outside world, the pipeline robot enters the transmission pipeline, and the pipeline robot walks from upstream to downstream of the transmission pipeline. When the pipeline robot approaches the first switch, the first switch is opened, and the pipeline robot continues to walk. After the pipeline robot passes the first switch, the first switch is closed. At this time, the pressure between the first switch and the second switch is the same as the pressure in the natural gas pipeline. Then the pipeline robot continues to walk, and when it approaches the second switch, the second switch is opened. At this time, the space for accommodating natural gas in the transmission pipeline changes from the space between the first switch and the second switch to the space between the first switch and the third switch, and the pressure of natural gas in the transmission pipeline decreases. The pipeline robot continues to walk, and when it approaches the third switch, the third switch is opened. By analogy, the downstream switches are opened in sequence, so that the gas pressure of the natural gas in the transmission pipeline gradually decreases until it decreases to a suitable pressure. The last switch is opened, and the pipeline robot exits from the transmission pipeline to the outside world, thereby ensuring that the pipeline robot can exit to the outside world safely.

[0009] In a further embodiment, after the pipeline robot passes through the switch most upstream, all remaining switches are closed after the pipeline robot passes through the switch.

[0010] By adopting the above technical solution, the pressure in the transmission pipeline can be reduced more quickly, which can reduce the number of switches used.

[0011] In a further embodiment, an air storage component is further included, wherein the air inlet end of the air storage component is located between the two switches at the most downstream and is connected to the transfer pipeline.

[0012] By adopting the above technical solution, the gas storage component can recover the natural gas in the transmission pipeline, thereby effectively avoiding the leakage of natural gas in the transmission pipeline, and can store the natural gas, thereby saving energy.

[0013] In a further embodiment, four switches are provided, and the four switches are respectively a first switch, a second switch, a third switch and a fourth switch along the upstream to downstream direction of the transmission pipeline; the space between the first switch and the second switch is a high-pressure chamber, the space between the second switch and the third switch is a medium-pressure chamber, and the space between the third switch and the fourth switch is a low-pressure chamber, and the air inlet end of the air storage assembly is connected to the low-pressure chamber.

[0014] By adopting the above technical solution, the transmission pipeline is divided into three chambers: high, medium and low. This can ensure that the pipeline robot can exit to the outside according to the three air pressure levels of high, medium and low, while ensuring that the number of switches in the transmission pipeline is appropriate.

[0015] In a further embodiment, the volumes of the high pressure chamber, the medium pressure chamber and the low pressure chamber are the same.

[0016] By adopting the above technical solution, the air pressure in each chamber can be reduced proportionally, which is more conducive to the pipeline robot adapting to changes in external air pressure.

[0017] In the second aspect, the present application also discloses an entry mechanism, which includes the exit mechanism described in the first aspect, and the air storage assembly also includes an air outlet end, the air inlet end of the air storage assembly is connected to the low-pressure chamber and the medium-pressure chamber, and the air outlet end is connected to the medium-pressure chamber and the high-pressure chamber; a first air inlet valve is arranged between the air inlet end and the low-pressure chamber, and a second air inlet valve is arranged between the air inlet end and the medium-pressure chamber; a first air outlet valve is arranged between the air outlet end and the medium-pressure chamber, and a second air outlet valve is arranged between the air outlet end and the high-pressure chamber.

[0018] By adopting the above technical solution, when the pipeline robot needs to enter the natural gas pipeline from the outside, first close the second switch, the third switch and the fourth switch, open the first switch, the natural gas in the natural gas pipeline enters the high-pressure chamber, and then close the first switch, the air pressure in the high-pressure chamber is the same as the air pressure of the natural gas pipeline. Then open the second switch, and then close the second switch, then the air pressure in the medium-pressure chamber is lower than the air pressure in the high-pressure chamber. Next, open the fourth switch, the pipeline robot enters the transfer pipeline, and then close the fourth switch. Then open the third switch, at this time the medium-pressure chamber and the low-pressure chamber are connected, and the air pressure in the medium-pressure chamber is reduced. After the pipeline robot passes the third switch, the third switch is closed and the pipeline robot stops. Then the first air inlet valve is opened, the first air outlet valve is opened, the natural gas in the low-pressure chamber is gradually pumped into the medium-pressure chamber, and the pressure of the medium-pressure chamber gradually returns to the previous pressure. Then the second switch is opened, the pipeline robot continues to move, and when the pipeline robot passes the second switch, the second switch is closed, and the pipeline robot stops. The second air inlet valve is opened, the second air outlet valve is opened, the gas storage assembly pumps the natural gas in the medium-pressure chamber into the high-pressure chamber, and the pressure of the high-pressure chamber gradually returns to the pressure in the natural gas pipeline. Finally, the first switch is turned on, and the pipeline robot continues to move into the natural gas pipeline.

[0019] On the third aspect, the present application also discloses an exit method, which includes the following steps: the pipeline robot enters the transfer pipeline and walks along the upstream to downstream direction of the transfer pipeline; when the pipeline robot approaches the switch at the most upstream, the switch at the most upstream is opened; the pipeline robot continues to walk, and after passing the switch at the most upstream, the switch is closed; the pipeline robot continues to walk, and each time it approaches a switch, the switch is opened; the switch at the most downstream is opened, and the pipeline robot exits from the transfer pipeline to the outside world.

[0020] In a further embodiment, the pipeline robot continues to move, and each time it approaches a switch, the switch is turned on and the following steps are further included: after the pipeline robot passes through the switch, the switch is closed.

[0021] In a further embodiment, a gas storage component is further provided between the two switches at the most downstream end. After the pipeline robot moves between the last two switches, the following steps are also included: closing the switch at the most upstream end and the switch at the most downstream end, and opening all switches between the two switches; the gas storage component performs air extraction to store the natural gas in the transfer pipeline in the gas storage component; the switch at the most downstream end is opened, and the pipeline robot exits from the transfer pipeline to the outside.

[0022] In a fourth aspect, the present application also discloses an entry method, which includes the following steps: close the second switch, the third switch and the fourth switch, and open the first switch; close the first switch; open the second switch, and then close the second switch; open the fourth switch, the pipeline robot enters the transfer pipeline, and closes the fourth switch; open the third switch, and the pipeline robot walks along the downstream to upstream direction of the transfer pipeline; when the pipeline robot passes the third switch, the third switch is closed and the pipeline robot stops; the first air inlet valve is opened, the first air outlet valve is opened, and the gas storage assembly draws the natural gas in the low-pressure chamber to the medium-pressure chamber; the second switch is opened, and the pipeline robot continues to walk; when the pipeline robot passes the second switch, the second switch is closed, and the pipeline robot stops; the second air inlet valve is opened, the second air outlet valve is opened, and the gas storage assembly draws the natural gas in the medium-pressure chamber to the high-pressure chamber; the first switch is opened, and the pipeline robot continues to walk into the natural gas pipeline.

[0023] Compared with the prior art, the beneficial effect of the present invention is that when the pipeline robot is normally traveling in the natural gas pipeline, all switches are closed to prevent natural gas from leaking from the transmission pipeline. When the pipeline robot needs to exit from the natural gas pipeline to the outside, the pipeline robot enters the transmission pipeline, and the pipeline robot walks from the upstream to the downstream of the transmission pipeline. When the pipeline robot approaches the first switch, the first switch is opened, and the pipeline robot continues to walk. After the pipeline robot passes the first switch, the first switch is closed. At this time, the pressure between the first switch and the second switch is the same as the pressure in the natural gas pipeline. Then the pipeline robot continues to walk, and when it approaches the second switch, the second switch is opened. At this time, the space for accommodating natural gas in the transmission pipeline changes from the space between the first switch and the second switch to the space between the first switch and the third switch, and the pressure of natural gas in the transmission pipeline is reduced. The pipeline robot continues to walk, and when it approaches the third switch, the third switch is opened. By analogy, the downstream switches are opened in sequence, so that the gas pressure of the natural gas in the transmission pipeline is gradually reduced until it is reduced to a suitable pressure. The last switch is opened, and the pipeline robot exits from the transmission pipeline to the outside, thereby ensuring that the pipeline robot can exit to the outside safely. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a schematic diagram of the exit structure in the embodiment of the present application;

[0025] Figure 2 This is a flowchart of the exit method in the embodiment of the present application;

[0026] Figure 3 This is a schematic diagram of the entry structure in the embodiment of the present application;

[0027] Figure 4 This is a flow chart of the method for entering the embodiment of the present application;

[0028] Figure 5 This is a schematic diagram of the gas path for the gas storage assembly in the embodiment of the present application to pump natural gas from the low-pressure chamber to the medium-pressure chamber;

[0029] Figure 6 This is a schematic diagram of the gas path for the gas storage assembly in the embodiment of the present application to pump natural gas from the medium-pressure chamber to the high-pressure chamber.

[0030] In the figure: 1. transfer pipeline; 11. high-pressure chamber; 12. medium-pressure chamber; 13. low-pressure chamber; 2. first switch; 3. second switch; 4. third switch; 5. fourth switch; 6. gas storage assembly; 61. vacuum pump; 62. gas storage box; 63. first air inlet valve; 64. second air inlet valve; 65. first air outlet valve; 66. second air outlet valve; 7. natural gas pipeline; 8. pipeline robot. DETAILED DESCRIPTION

[0031] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and the like are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", and the like may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0032] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood by specific circumstances.

[0033] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] See also Figure 1 The present application provides an embodiment of an exit mechanism, which includes a transmission pipeline 1 and a plurality of switches. One end of the transmission pipeline 1 is connected to the natural gas pipeline 7, and the other end is connected to the outside world. A plurality of switches are arranged in the transmission pipeline 1, and a plurality of switches are arranged at intervals along the axial direction of the transmission pipeline 1, and each switch can open or close the circulation of the transmission pipeline 1. When the pipeline robot 8 walks in the natural gas pipeline 7, all switches are closed. When the pipeline robot 8 exits from the natural gas pipeline 7 to the outside world, the pipeline robot 8 first enters the transmission pipeline 1. During the process of the pipeline robot 8 moving from the upstream to the downstream of the transmission pipeline 1, when the pipeline robot 8 approaches the most upstream switch, the most upstream switch is opened, and after the pipeline robot 8 passes the most upstream switch, the switch is closed. When the pipeline robot 8 continues to move downstream of the transmission pipeline 1, the switch is opened each time it approaches a switch.

[0035] When the pipeline robot 8 is moving normally in the natural gas pipeline 7, all switches are closed to prevent natural gas from leaking from the transmission pipeline 1. When the pipeline robot 8 needs to exit from the natural gas pipeline 7 to the outside, the pipeline robot 8 enters the transmission pipeline 1, and the pipeline robot 8 moves along the upstream to downstream of the transmission pipeline 1. When the pipeline robot 8 approaches the first switch, the first switch is opened, and the pipeline robot 8 continues to move. After the pipeline robot 8 passes the first switch, the first switch is closed. At this time, the pressure between the first switch and the second switch is the same as the pressure in the natural gas pipeline 7. Then the pipeline robot 8 continues to move, and when it approaches the second switch, the second switch is opened. At this time, the space for accommodating natural gas in the transmission pipeline 1 changes from the space between the first switch and the second switch to the space between the first switch and the third switch, and the pressure of the natural gas in the transmission pipeline 1 decreases. Taking the switches set at equal intervals as an example, the pressure in the space where the pipeline robot 8 is located changes from P to The pipeline robot 8 continues to move, and when it approaches the third switch, the third switch is turned on, and the pressure in the space where the pipeline robot 8 is located changes from Transformed into By analogy, the downstream switches are opened one by one, so that the pressure of the natural gas in the transmission pipeline 1 gradually decreases until it reaches a suitable pressure. The last switch is opened, and the pipeline robot 8 withdraws from the transmission pipeline 1 to the outside, thereby ensuring that the pipeline robot 8 can safely withdraw to the outside.

[0036] Furthermore, after the pipeline robot 8 passes the switch at the most upstream, all the remaining switches are closed after the pipeline robot 8 passes the switch. Still taking the switches arranged at equal intervals as an example, through such a control method, when the pipeline robot 8 approaches the second switch, the second switch is opened, and the pressure in the space where the pipeline robot 8 is located is changed from P to After the pipeline robot 8 passes the second switch, the second switch is closed. At this time, the pipeline robot 8 is located between the second switch and the third switch, and the pressure in the space where the pipeline robot 8 is located is still As the pipeline robot 8 continues to move forward, when the pipeline robot 8 approaches the third switch 4, the third switch 4 is turned on, and the pipeline robot 8 is located between the second switch 3 and the fourth switch 5. The space where the pipeline robot 8 is located doubles, and the pressure in the space is Transformed into It can be seen that through such a control method, the pressure in the space where the pipeline robot 8 is located can be reduced faster, the number of switches used can be reduced, and the pipeline robot 8 can exit to the outside world faster.

[0037] In a preferred embodiment of the present application, each switch may adopt a PE ball valve or other passable valve body.

[0038] Further, see Figure 1 The exit mechanism also includes a gas storage component 6, the gas inlet end of which is located between the two switches at the most downstream and connected to the transmission pipeline 1. After the last switch is turned on, the natural gas in the transmission pipeline 1 will leak out. After the gas storage component 6 is set, the natural gas in the transmission pipeline 1 can be recovered, thereby effectively avoiding the leakage of the natural gas in the transmission pipeline 1, and the natural gas can be stored, thereby saving energy.

[0039] In a preferred embodiment of the present application, the gas storage assembly 6 includes an air pump 61 and an air storage box 62. The air inlet end of the air pump 61 is connected to the transmission pipeline 1, and the air storage box 62 is connected to the air outlet end of the air pump 61, and is used to store the natural gas extracted from the transmission pipeline 1 by the air pump 61. In other embodiments, the gas storage assembly 6 can also adopt other structures that can extract and store gas.

[0040] Further, see Figure 1 In the preferred embodiment of the present application, four switches are provided, and the four switches are the first switch 2, the second switch 3, the third switch 4 and the fourth switch 5 in the upstream to downstream direction of the transmission pipeline 1. The space between the first switch 2 and the second switch 3 is a high-pressure chamber 11, the space between the second switch 3 and the third switch 4 is a medium-pressure chamber 12, and the space between the third switch 4 and the fourth switch 5 is a low-pressure chamber 13. The air inlet end of the air storage component 6 is connected to the low-pressure chamber 13. Dividing the transmission pipeline 1 into three chambers of high, medium and low pressure can ensure that the pipeline robot 8 can exit to the outside according to the three air pressure levels of high, medium and low pressure, while ensuring that the number of switches in the transmission pipeline 1 is appropriate.

[0041] In order to make the pipeline robot 8 better adapt to the change of air pressure when walking from upstream to downstream, the volume of the high pressure chamber 11, the medium pressure chamber 12 and the low pressure chamber 13 are the same. Through such a setting, the air pressure in each chamber can be reduced in proportion, which is more conducive to the pipeline robot 8 to adapt to the change of external air pressure.

[0042] In other embodiments, the number of switches may be other numbers, such as 5, 6, etc. The number of switches is determined according to the actual air pressure.

[0043] Based on the above exit structure, refer to Figure 2 , the present application discloses an exit method, comprising the following steps:

[0044] S1. The pipeline robot 8 enters the transfer pipeline 1 and walks in the direction from upstream to downstream of the transfer pipeline 1;

[0045] S2. When the pipeline robot 8 is close to the most upstream switch, the most upstream switch is turned on;

[0046] S3. The pipeline robot 8 continues to move, and after passing the switch at the most upstream end, the switch is closed;

[0047] S4. The pipeline robot 8 continues to walk, and each time it approaches a switch, the switch is turned on;

[0048] S5. The switch at the most downstream is turned on, and the pipeline robot 8 withdraws from the transfer pipeline 1 to the outside.

[0049] In order to reduce the pressure of the space where the pipeline robot 8 is located more quickly, a step is further included between steps S4 and S5: S41. After the pipeline robot 8 passes through the switch, the switch is closed.

[0050] In order to recover the natural gas in the transmission pipeline 1, it can be known from the description of the withdrawal mechanism that the withdrawal mechanism also includes a gas storage component 6. After step S41, the following steps are also included:

[0051] S42. When the pipeline robot 8 moves between the two switches at the most downstream, the two switches at the most downstream are both closed.

[0052] S43. The gas storage assembly 6 is evacuated to store the natural gas in the transmission pipeline 1 in the gas storage assembly 6.

[0053] After the above steps, when the step S5 is performed and the switch at the most downstream is turned on, no natural gas will leak out. Moreover, as the gas storage component 6 continuously extracts the natural gas in the space where the pipeline robot 8 is located, the pressure on the pipeline robot 8 gradually decreases to zero. When the switch at the most downstream is turned on, the pressure on the pipeline robot 8 does not change suddenly, further reducing the impact of the sudden pressure change on the pipeline robot 8.

[0054] After steps S42 and S43, natural gas still remains in the transmission pipeline 1. Therefore, in order to remove the remaining natural gas in the transmission pipeline 1, after step S5, the following steps are further included:

[0055] S6. Close the switch at the farthest downstream;

[0056] S7. Turn on all switches between the first and last switches;

[0057] S8. The gas storage assembly 6 extracts gas and stores the natural gas in the transmission pipeline 1 into the gas storage assembly 6.

[0058] After the above steps, the natural gas remaining in the transmission pipeline 1 is removed, thereby reducing the occurrence of hidden dangers.

[0059] Based on the above exit mechanism, the present application also discloses an embodiment of an entry mechanism, referring to Figure 3On the basis of the original exit mechanism, the gas storage assembly 6 also includes a gas outlet, the gas inlet of the gas storage assembly 6 is connected to the low-pressure chamber 13 and the medium-pressure chamber 12, and the gas outlet is connected to the medium-pressure chamber 12 and the high-pressure chamber 11. A first gas inlet valve 63 is provided between the gas inlet and the low-pressure chamber 13, and a second gas inlet valve 64 is provided between the gas inlet and the medium-pressure chamber 12. A first gas outlet valve 65 is provided between the gas outlet and the medium-pressure chamber 12, and a second gas outlet valve 66 is provided between the gas outlet and the high-pressure chamber 11.

[0060] In the preferred implementation of the embodiment of the present application, the first air inlet valve 63, the second air inlet valve 64, the first air outlet valve 65 and the second air outlet valve 66 can all adopt electromagnetic valves. Compared with the air storage assembly 6 mentioned in the exit mechanism, in the entry mechanism, the air storage assembly 6 includes two air pumps 61 and an air storage box 62, wherein the air pump end of one of the air pumps 61 is connected to the transfer pipeline 1, and the air outlet end is connected to the air storage box 62. The air pump end of the other air pump 61 is connected to the air outlet end, and the air outlet end is connected to the transfer pipeline 1.

[0061] Based on the above entry institutions, refer to Figure 4-Figure 6 The embodiment of the present application provides an entry method, comprising the following steps:

[0062] A1. Close the second switch 3, the third switch 4 and the fourth switch 5, and open the first switch 2;

[0063] A2. Turn off the first switch 2;

[0064] A3. Turn on the second switch 3, and then turn off the second switch 3;

[0065] A4. Turn on the fourth switch 5, the pipeline robot 8 enters the transfer pipeline 1, and turns off the fourth switch 5;

[0066] A5. Turn on the third switch 4, and the pipeline robot 8 walks along the downstream to upstream direction of the transfer pipeline 1;

[0067] A6. When the pipeline robot 8 passes through the third switch 4, the third switch 4 is closed and the pipeline robot 8 stops;

[0068] A7. The first air inlet valve 63 is opened, the first air outlet valve 65 is opened, and the gas storage assembly 6 draws the natural gas in the low-pressure chamber 13 to the medium-pressure chamber 12;

[0069] A8. The second switch 3 is turned on, and the pipeline robot 8 continues to move;

[0070] A9. When the pipeline robot 8 passes through the second switch 3, the second switch 3 is closed and the pipeline robot 8 stops;

[0071] A10. The second air inlet valve 64 is opened, the second air outlet valve 66 is opened, and the gas storage assembly 6 draws the natural gas in the medium-pressure chamber 12 to the high-pressure chamber 11;

[0072] A11. The first switch 2 is turned on, and the pipeline robot 8 continues to move into the natural gas pipeline 7.

[0073] Each step is described in detail below. The four switches are set at equal intervals. Assume that the natural gas pressure in the natural gas pipeline 7 is P. For A1, after the first switch 2 is turned on, the natural gas in the natural gas pipeline 7 enters between the first switch 2 and the second switch 3. The gas pressure between the first switch 2 and the second switch 3 is P. For A2, after the first switch 2 is turned off, the gas pressure between the first switch 2 and the second switch 3 is still P. In A3, the second switch 3 is turned on first, and the gas between the first switch 2 and the second switch 3 diffuses between the first switch 2 and the third switch 4. The gas pressure changes to After closing the second switch 3, a closed space is formed between the first switch 2 and the second switch 3, and the gas pressure is A closed space is formed between the second switch 3 and the third switch 4, and the gas pressure is

[0074] Next, in A4, the fourth switch 5 is first opened, the pipeline robot 8 enters the transfer pipeline 1, and then the fourth switch 5 is closed, so that a closed space is formed between the third switch 4 and the fourth switch 5. In A5, the third switch 4 is opened, and the gas between the second switch 3 and the third switch 4 diffuses to the space between the second switch 3 and the fourth switch 5, and the gas pressure is Changes to When the pipeline robot 8 initially bears the natural gas pressure, the pressure is relatively small and will not cause a large sudden change in pressure, thereby reducing the impact of the gas pressure on the pipeline robot 8.

[0075] For A6, when the third switch 4 is closed, the gas pressure of the second switch 3 and the third switch 4 is still

[0076] In A7, refer to Figure 5 The gas storage assembly 6 gradually draws the natural gas between the third switch 4 and the fourth switch 5 (the low pressure chamber 13) to between the second switch 3 and the third switch 4 (the medium pressure chamber 12), and the gas pressure between the second switch 3 and the third switch 4 is increased by Gradually increase to

[0077] In A8, since the natural gas pressure between the first switch 2 and the second switch 3 is The natural gas pressure between the second switch 3 and the third switch 4 is also Therefore, after the second switch 3 is opened, the pressure of the natural gas between the first switch 2 and the third switch 4 is still

[0078] In the next step A9, the second switch 3 is closed, and the pressure between the first switch 2 and the second switch 3 is still

[0079] Next, refer to Figure 6 In step A10, the gas storage assembly 6 gradually draws the natural gas between the second switch 3 and the third switch 4 (the medium pressure chamber 12) to between the first switch 2 and the second switch 3 (the high pressure chamber 11), and the gas pressure of the first switch 2 and the second switch 3 is increased by Gradually increases to P, at which time the pressure borne by the pipeline robot 8 is the same as the pressure in the natural gas pipeline 7.

[0080] Finally, in step A11, the first switch 2 is turned on, and the pressure on the pipeline robot 8 does not change suddenly, and the pipeline robot continues to move into the natural gas pipeline 7.

[0081] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

[0082] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A withdrawal mechanism, characterized in that: include: A transmission pipeline (1), one end of which is connected to a natural gas pipeline (7) and the other end of which is connected to the outside world; A plurality of switches, the plurality of switches being arranged at intervals along the axial direction of the transmission pipeline (1), each of the switches being capable of opening or closing the flow of the transmission pipeline (1); When the pipeline robot (8) walks in the natural gas pipeline (7), all switches are closed; When the pipeline robot (8) exits the natural gas pipeline (7) to the outside, it enters the transfer pipeline (1). During the process of the pipeline robot (8) moving from the upstream to the downstream of the transfer pipeline (1), when the pipeline robot (8) approaches the switch at the most upstream, the switch at the most upstream is opened. After the pipeline robot (8) passes the switch at the most upstream, the switch is closed. When the pipeline robot (8) continues to move downstream of the transfer pipeline (1), each time it approaches a switch, the switch is opened.

2. An exit mechanism according to claim 1, characterized in that: After the pipeline robot (8) passes through the switch at the most upstream, all the remaining switches are closed after the pipeline robot (8) passes through the switch.

3. An exit mechanism according to any one of claims 1-2, characterized in that: It also comprises an air storage component (6), wherein the air inlet end of the air storage component (6) is located between the two switches at the most downstream and is connected to the transmission pipeline (1).

4. The withdrawal mechanism according to claim 3, characterized in that: There are four switches, which are arranged in order from upstream to downstream of the transmission pipeline (1): a first switch (2), a second switch (3), a third switch (4) and a fourth switch (5); The space between the first switch (2) and the second switch (3) is a high-pressure chamber (11), the space between the second switch (3) and the third switch (4) is a medium-pressure chamber (12), the space between the third switch (4) and the fourth switch (5) is a low-pressure chamber (13), and the air inlet end of the air storage assembly (6) is connected to the low-pressure chamber (13).

5. The withdrawal mechanism according to claim 4, characterized in that: The volumes of the high-pressure chamber (11), the medium-pressure chamber (12) and the low-pressure chamber (13) are the same.

6. An entry mechanism, characterized in that: The gas storage component (6) further comprises a gas outlet, the gas inlet of the gas storage component (6) is connected to the low-pressure chamber (13) and the medium-pressure chamber (12), and the gas outlet is connected to the medium-pressure chamber (12) and the high-pressure chamber (11); A first air intake valve (63) is provided between the air intake end and the low-pressure chamber (13), and a second air intake valve (64) is provided between the air intake end and the medium-pressure chamber (12); A first air outlet valve (65) is provided between the air outlet end and the medium-pressure chamber (12), and a second air outlet valve (66) is provided between the air outlet end and the high-pressure chamber (11).

7. A withdrawal method based on the withdrawal mechanism according to claim 1, characterized in that: The following steps are involved: The pipeline robot (8) enters the transfer pipeline (1) and walks along the transfer pipeline (1) in a direction from upstream to downstream; When the pipeline robot (8) approaches the switch at the most upstream position, the switch at the most upstream position is opened; The pipeline robot (8) continues to move, and after passing the switch at the most upstream, the switch is closed; The pipeline robot (8) continues to move, and each time it approaches a switch, the switch is turned on; The switch at the most downstream is opened, and the pipeline robot (8) withdraws from the transfer pipeline (1) to the outside.

8. A withdrawal method according to claim 7, characterized in that: The pipeline robot (8) continues to move, and each time it approaches a switch, after the switch is turned on, it further comprises the following steps: After the pipeline robot (8) passes through the switch, the switch is closed.

9. A withdrawal method according to claim 8, characterized in that: A gas storage assembly (6) is also provided between the two switches at the most downstream. After the pipeline robot (8) moves between the last two switches, the following steps are also included: Close the switch farthest upstream and the switch farthest downstream, and open all switches between the two switches; The gas storage component (6) is used to extract gas, and the natural gas in the transmission pipeline (1) is stored in the gas storage component (6); The switch at the most downstream is opened, and the pipeline robot (8) withdraws from the transfer pipeline (1) to the outside.

10. An entry method based on the entry mechanism according to claim 6, characterized in that: The following steps are involved: The second switch (3), the third switch (4) and the fourth switch (5) are closed, and the first switch (2) is opened; Turning off the first switch (2); Turning on the second switch (3), and then turning off the second switch (3); The fourth switch (5) is turned on, the pipeline robot (8) enters the transfer pipeline (1), and the fourth switch (5) is turned off; The third switch (4) is turned on, and the pipeline robot (8) moves along the direction from downstream to upstream of the transfer pipeline (1); When the pipeline robot (8) passes through the third switch (4), the third switch (4) is closed and the pipeline robot (8) stops; The first air inlet valve (63) is opened, the first air outlet valve (65) is opened, and the gas storage component (6) draws the natural gas in the low-pressure chamber (13) into the medium-pressure chamber (12); The second switch (3) is turned on, and the pipeline robot (8) continues to move; When the pipeline robot (8) passes through the second switch (3), the second switch (3) is closed and the pipeline robot (8) stops; The second air inlet valve (64) is opened, the second air outlet valve (66) is opened, and the gas storage assembly (6) draws the natural gas in the medium-pressure chamber (12) into the high-pressure chamber (11); The first switch (2) is turned on, and the pipeline robot (8) continues to move into the natural gas pipeline (7).

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