A system for recovering natural gas vented from a gas compressor station

Abstract

The present application relates to the technical field of natural gas recovery devices, and in particular to a system for recovering natural gas vented from a gas compressor station. It includes a station compressor, a primary recovery passage, and a secondary recovery passage; one end of the primary recovery passage is interconnected with the station compressor outlet, the other end of the primary recovery passage is interconnected with the station compressor inlet, a primary booster is provided on the primary recovery passage, and the primary booster is interconnected with the dry gas seal venting end of the natural gas long-distance pipeline; one end of the secondary recovery passage is interconnected with the station compressor outlet, the other end of the secondary recovery passage is interconnected with the station compressor inlet, and a reciprocating compressor, a high-pressure gas storage tank, and a secondary booster are sequentially provided on the secondary recovery passage in the direction close to the station compressor inlet, and the secondary booster is interconnected with the dry gas seal venting end of the natural gas long-distance pipeline. The present application has the effect of saving resources and protecting the environment.

Description

Technical Field

[0001] The present invention relates to the technical field of natural gas recovery devices, and in particular to a system for recovering natural gas vented from a gas compressor station. Background Art

[0002] During the service of a long-distance natural gas pipeline, it is usually necessary to regularly discharge the natural gas in the pipeline in order to maintain the pipeline.

[0003] At present, flaring is usually used to vent natural gas, but flaring not only wastes resources, but also easily pollutes the environment, produces greenhouse gases, and causes serious economic losses. Utility Model Content

[0004] In order to improve the environmental pollution caused by natural gas venting and its waste of resources, the present application provides a system for recovering natural gas vented from a gas compressor station.

[0005] The present application provides a system for recovering natural gas vented from a compressor station using the following technical solution:

[0006] A system for recovering natural gas vented from a gas compressor station, comprising a station compressor, a primary recovery passage and a secondary recovery passage, wherein the station compressor is provided with a station compressor inlet and a station compressor outlet;

[0007] One end of the primary recovery passage is interconnected with the station compressor outlet, and the other end of the primary recovery passage is interconnected with the station compressor inlet. A primary booster is provided on the primary recovery passage, and the primary booster is interconnected with the dry gas seal venting end of the natural gas long-distance pipeline;

[0008] One end of the secondary recovery passage is interconnected with the station compressor outlet, and the other end of the secondary recovery passage is interconnected with the station compressor inlet. A reciprocating compressor, a high-pressure gas storage tank and a secondary booster are sequentially arranged on the secondary recovery passage in the direction close to the station compressor inlet, and the secondary booster is interconnected with the dry gas sealed vent end of the natural gas long-distance pipeline.

[0009] By adopting the above technical solution, in the early stage of maintenance of the natural gas long-distance pipeline, since the initial gas pressure of the vented natural gas is relatively high (about 9MPag), the pressure difference between the inlet and outlet of the station compressor can be used as the driving force to automatically transfer the vented natural gas to the first-stage booster, thereby completing the first-stage recovery of the vented natural gas.

[0010] In the later stage of the maintenance of the natural gas long-distance pipeline, since the pressure of the vented natural gas gradually decreases (less than 2MPag), the pressure difference between the inlet and outlet of the station compressor is used as the power, and the pressure difference between the high-pressure gas storage tank and the compressor inlet is also needed as an auxiliary power to make the vented natural gas with reduced pressure automatically transferred to the secondary booster, thereby completing the secondary recovery of the vented natural gas.

[0011] And because the vented natural gas with higher pressure and the vented natural gas with lower pressure are recovered differently, the recovery effect of the vented natural gas is further improved, the waste of resources is effectively improved, and the pollution to the environment is reduced.

[0012] Optionally, a first control valve and a second control valve are provided on the primary recovery passage, wherein the first control valve is provided between the station compressor outlet and the primary supercharger, and the second control valve is provided between the station compressor inlet and the primary supercharger;

[0013] The secondary recovery passage is provided with a third control valve, a fourth control valve, a fifth control valve and a sixth control valve. The third control valve is provided between the station compressor outlet and the reciprocating compressor, the fourth control valve is provided between the reciprocating compressor and the high-pressure gas storage tank, the fifth control valve is provided between the high-pressure gas storage tank and the secondary supercharger, and the sixth control valve is provided between the secondary supercharger and the station compressor inlet.

[0014] By adopting the above technical solution, due to the settings of the first control valve, the second control valve, the third control valve, the fourth control valve, the fifth control valve and the sixth control valve, when the reciprocating compressor, the high-pressure gas storage tank, the first-stage supercharger and the second-stage supercharger are damaged, a certain section of the first-stage recovery passage or a certain section of the second-stage recovery passage can be repaired separately, effectively reducing the difficulty of repairing the entire system.

[0015] Optionally, a switching valve is provided between the first-stage supercharger and the second-stage supercharger, and the switching valve is interconnected with a dry gas sealing vent end of a natural gas long-distance pipeline.

[0016] By adopting the above technical solution, since a switching valve is provided between the first-stage supercharger and the second-stage supercharger, during the inspection and maintenance of the natural gas long-distance pipeline, the staff can control the switching valve according to the pressure of the vented natural gas, thereby allowing the vented natural gas with a higher pressure to enter the first-stage supercharger and the vented natural gas with a lower pressure to enter the second-stage supercharger, thereby making the recovery of the vented natural gas simpler, more convenient and smoother.

[0017] Optionally, the switching valve includes a valve base pipe, a switching block and a plugging assembly;

[0018] The valve base pipe includes a primary transverse pipe, a secondary transverse pipe and a vertical pipe, the inlet of the primary transverse pipe is interconnected with the dry gas sealing venting end of the natural gas long-distance pipeline, and the outlet of the primary transverse pipe is interconnected with the primary supercharger; the secondary transverse pipe is arranged in the primary transverse pipe, the inlet of the secondary transverse pipe is interconnected with the primary transverse pipe, and the outlet of the secondary transverse pipe is interconnected with the secondary supercharger, a switching groove is penetrated through the lower end surface of the secondary transverse pipe, and the secondary transverse pipe is interconnected with the primary transverse pipe through the switching groove;

[0019] The vertical pipe is arranged on the upper end surface of the first-level horizontal pipe, the vertical pipe is communicated with the second-level horizontal pipe, the vertical pipe is coaxially arranged with the switching groove, and the switching block is slidably connected to the vertical pipe and the switching groove;

[0020] A through groove is formed through the side wall of the switching block, and the plugging assembly is arranged at the inlet of the secondary cross pipe. When the vented natural gas does not pass into the primary cross pipe, the switching block blocks the primary cross pipe, the plugging assembly blocks the inlet of the secondary cross pipe, and the through groove is communicated with the inlet of the secondary cross pipe; when the vented natural gas passes into the primary cross pipe at a higher pressure, the switching block opens the primary cross pipe, the through groove and the inlet of the secondary cross pipe are staggered, and the plugging assembly opens the inlet of the secondary cross pipe; when the pressure of the vented natural gas decreases, the switching block blocks the primary cross pipe, and the through groove is communicated with the inlet of the secondary cross pipe.

[0021] By adopting the above technical solution, in the early stage of maintenance of the natural gas long-distance pipeline, since the vented natural gas has a higher gas pressure, the staff can move the switching block, thereby prompting the switching block to release the blockage of the first-level cross pipe. After that, the vented natural gas can be transferred to the first-level booster through the first-level cross pipe.

[0022] In the later stage of the maintenance of the natural gas long-distance pipeline, since the vented natural gas has a lower gas pressure, the staff can move the switching block again, so that the switching block can seal the first-level cross pipe again, and cause the through groove and the inlet of the second-level cross pipe to be connected with each other. After that, the vented natural gas can be transferred to the second-level booster through the second-level cross pipe.

[0023] Since the switching valve is doubly blocked by the switching block and the natural gas blocking assembly, the possibility of the venting natural gas with a higher pressure entering the secondary supercharger through the secondary cross pipe is effectively reduced, thereby indirectly reducing the waste of power on the high-pressure gas storage tank.

[0024] Optionally, a guide surface is provided on the lower end surface of the switching block, and the guide surface gradually tilts upward toward a direction close to the inlet of the first-level cross pipe.

[0025] By adopting the above technical solution, when the vented natural gas is passed into the primary transverse pipe, the plugging assembly blocks the inlet of the secondary transverse pipe, and the switching block blocks the primary transverse pipe; when the natural gas contacts the guide surface and applies force, the natural gas forces the switching block to slide upward through the guide surface, thereby prompting the natural gas to pass from the primary transverse pipe into the primary supercharger. At this time, the through groove and the inlet of the secondary transverse pipe are intertwined, and the plugging assembly opens the inlet of the secondary transverse pipe;

[0026] When the pressure of natural gas decreases, the switching block gradually slides downward under the action of gravity. When the through groove and the inlet of the secondary cross pipe are connected to each other, the vented natural gas enters the secondary supercharger through the secondary cross pipe. Since the effect of the vented natural gas on the guide surface is relatively reduced, the lower end face of the switching block finally abuts against the inner wall of the primary cross pipe, thereby completing the blocking of the primary cross pipe.

[0027] Due to the setting of the guide surface, when the switching block needs to be moved, the air pressure of the released natural gas can directly control the up and down sliding of the switching block through the guide surface, effectively reducing the difficulty of controlling the switching block.

[0028] Optionally, the cross-section of the switching block is a quadrilateral.

[0029] By adopting the above technical solution, when the natural gas is vented to exert force on the guide surface, since the cross-section of the switching block is a quadrilateral, the switching block itself is not easy to rotate circumferentially in the horizontal direction and the vertical direction, so that the force exerted by the vented natural gas on the guide surface is completely used to drive the switching block to slide up and down, so that the transfer of the vented natural gas is smoother and the opening of the first-level cross pipe by the switching block is simpler.

[0030] Optionally, the vertical tube includes a tube body and an end cover, the tube body is arranged on the first-level cross tube, the end cover is arranged at an end of the tube body away from the first-level cross tube, and a through hole is opened through the end cover, and the aperture of the through hole is smaller than the shortest length of the upper end surface of the switching block.

[0031] By adopting the above technical solution, when the natural gas is vented through the guide surface to drive the switching block to slide upward, since the aperture of the through hole is smaller than the shortest length of the upper end surface of the switching block, the end cover can limit the movement of the switching block, effectively reducing the possibility of the switching block completely detaching from the vertical pipe, and indirectly improving the blocking effect of the switching block on the primary and secondary horizontal pipes.

[0032] Optionally, the blocking assembly includes a control panel, a mandrel, a plurality of limit feet, a connecting rope and a blocking block, the mandrel and the plurality of limit feet are arranged on the lower end surface of the control panel, and the plurality of limit feet are evenly arranged circumferentially with the mandrel as the center; a placement groove is provided on the lower groove wall of the entrance of the secondary cross tube, a connecting groove is provided on the vertical tube and the secondary cross tube, one end of the connecting groove is communicated with the entrance of the secondary cross tube, and the other end of the connecting groove is communicated with the through hole; the connecting rope is passed through the connecting groove, one end of the connecting rope is fixedly connected to the blocking block, and the other end of the connecting rope is fixedly connected to the mandrel;

[0033] When the vented natural gas does not pass into the primary cross pipe, the end of the limit foot away from the control board abuts against the lower end surface of the end cover, the push rod passes through the through hole and is accommodated in the vertical pipe, and the blocking block blocks the entrance of the secondary cross pipe; when the vented natural gas passes into the primary cross pipe at a higher pressure, the switching block abuts against the lower end surface of the end cover; the push rod passes through the through hole, the end of the limit foot away from the control board abuts against the hole wall of the through hole, the blocking block is inserted into the placement groove, and the blocking block opens the entrance of the secondary cross pipe.

[0034] By adopting the above technical solution, when the natural gas is discharged and forces the switching block to slide upward through the guide surface, the upper end surface of the switching block first abuts against the push rod, and the push rod slides upward and detaches from the vertical pipe under the drive of the switching block, and the limit foot also detaches from the vertical pipe under the drive of the push rod, thereby releasing the limiting effect on the blocking block, prompting the blocking block to be inserted into the placement groove under the action of gravity, and then automatically opening the entrance of the secondary horizontal pipe.

[0035] When the pressure of the vented natural gas gradually decreases, the switching block gradually slides downward under the action of gravity. When the through groove and the inlet of the secondary cross pipe are connected to each other, the vented natural gas enters the secondary supercharger through the secondary cross pipe. Since the vented natural gas is relatively reduced under the action of the guide surface, the lower end face of the switching block finally abuts against the inner wall of the primary cross pipe, thereby completing the blocking of the primary cross pipe.

[0036] When the vented natural gas needs to be recovered again, the staff can press down the control panel. At this time, the top rod is again passed through the through hole and accommodated in the vertical pipe. The end of the limit foot away from the control panel abuts against the lower end surface of the end cover, and the sealing plate blocks the entrance of the secondary horizontal pipe again under the traction of the connecting rope.

[0037] Since the blocking block can automatically open the entrance of the secondary cross pipe under the action of gravity and the switching block, the staff does not need to manually open the entrance of the secondary cross pipe, further reducing the difficulty of controlling the entrance of the secondary cross pipe.

[0038] Optionally, the limit foot includes a connecting rod and a guide ball, the connecting rod is arranged on the lower end surface of the control board, the connecting rod gradually tilts outward in a direction away from the control board, and the guide ball is arranged at one end of the connecting rod away from the control board;

[0039] When the vented natural gas does not pass into the primary transverse pipe, the outer circumferential surface of the guide ball abuts against the lower end surface of the end cover; when the vented natural gas passes into the primary transverse pipe at a higher pressure, the outer circumferential surface of the guide ball abuts against the hole wall of the through hole.

[0040] By adopting the above technical solution, since the limit foot includes a connecting rod and a guide ball, when the top rod drives the limit foot to slide upward, the guide ball can give an inward force to the connecting rod, thereby prompting the connecting rod to automatically deform inward, thereby reducing the obstruction of the guide ball to the upward sliding of the limit foot, and further reducing the operational difficulty of opening the entrance of the secondary cross pipe.

[0041] Optionally, an annular groove is provided on the wall of the through hole, and when the vented natural gas is passed into the first-level cross pipe at a relatively high pressure, the guide ball is inserted into the annular groove.

[0042] By adopting the above technical solution, when the guide ball is transferred to the through hole, the anti-blocking block can drive the push rod to slide upward through the connecting rope, and the guide ball will also slide upward under the drive of the push rod. Due to the setting of the annular groove, when the guide ball slides to the position of the annular groove, the guide ball can be inserted into the annular groove, and the groove wall of the annular groove can limit the guide ball, thereby reducing the possibility of the push rod and the limiting foot completely detaching from the through hole.

[0043] In summary, the present application includes at least one of the following beneficial technical effects:

[0044] 1. Due to the different recovery of vented natural gas with higher pressure and vented natural gas with lower pressure, the recovery effect of vented natural gas is further improved, which effectively improves the waste of resources and reduces pollution to the environment;

[0045] 2. When the reciprocating compressor, high-pressure gas storage tank, primary supercharger, or secondary supercharger is damaged, the staff can repair a certain section of the primary recovery path or a certain section of the secondary recovery path separately, effectively reducing the difficulty of repairing the entire system;

[0046] 3. During the inspection and maintenance of the natural gas long-distance pipeline, the staff can control the switching valve according to the gas pressure of the vented natural gas, making the recovery of the vented natural gas simpler, more convenient and smoother. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 It is a schematic diagram of the system for recovering natural gas vented from a compressor station in the first connection state.

[0048] Figure 2 It is a schematic diagram of the system for recovering natural gas vented from a compressor station in the second connection state.

[0049] Figure 3 It is a schematic diagram of the system for recovering natural gas vented from a compressor station in the third connection state.

[0050] Figure 4 It is a structural schematic diagram of a switching valve.

[0051] Figure 5 is along Figure 4 Section view along line AA.

[0052] Figure 6 It is a cross-sectional schematic diagram of a switching valve in the early stage of maintenance of a long-distance natural gas pipeline.

[0053] Figure 7 It is a cross-sectional schematic diagram of a switching valve in the later stage of maintenance of a long-distance natural gas pipeline.

[0054] Explanation of reference numerals: 1. station compressor; 2. primary recovery passage; 3. secondary recovery passage; 4. switching valve; 11. station compressor inlet; 12. station compressor outlet; 21. primary supercharger; 22. first control valve; 23. second control valve; 24. primary main valve; 31. reciprocating compressor; 32. high-pressure gas storage tank; 33. secondary supercharger; 34. third control valve; 35. fourth control valve; 36. fifth control valve; 37. sixth control valve; 38. secondary main valve; 41. valve Base pipe; 42, switching block; 43, plugging assembly; 411, primary transverse pipe; 412, secondary transverse pipe; 413, vertical pipe; 421, through groove; 422, guide surface; 431, control panel; 432, top rod; 433, limit foot; 434, connecting rope; 435, plugging block; 4121, switching groove; 4122, placement groove; 4123, connecting groove; 4131, tube body; 4132, end cover; 4331, connecting rod; 4332, guide ball; 41321, through hole; 41322, annular groove. DETAILED DESCRIPTION

[0055] The following is combined with Figure 1-7 This application is described in further detail.

[0056] The present application embodiment discloses a system for recovering natural gas vented from a gas compressor station. Figure 1The system for recovering the vented natural gas of the gas compressor station includes a station compressor 1, a primary recovery passage 2 and a secondary recovery passage 3, wherein the station compressor 1 is provided with a station compressor inlet 11 and a station compressor outlet 12, the primary recovery passage 2 and the secondary recovery passage 3 are both interconnected with the station compressor 1, and there are three connection states between the primary recovery passage 2 and the secondary recovery passage 3 and the station compressor 1, which are as follows:

[0057] Reference Figure 1 , which is the first connection state of the primary recovery passage 2 and the secondary recovery passage 3 with the station compressor 1 in the embodiment of the present application. Specifically, in this connection state, one end of the primary recovery passage 2 is interconnected with the station compressor outlet 12, and the other end of the primary recovery passage 2 is interconnected with the station compressor inlet 11. A primary booster 21 is connected in series in the middle of the primary recovery passage 2, and the primary booster 21 is interconnected with the dry gas seal venting end of the natural gas long-distance pipeline.

[0058] One end of the secondary recovery passage 3 is interconnected with the station compressor outlet 12, and the other end of the secondary recovery passage 3 is interconnected with the station compressor outlet 12. On the secondary recovery passage 3, a reciprocating compressor 31, a high-pressure gas storage tank 32 and a secondary supercharger 33 are sequentially connected in series in the direction close to the station compressor inlet 11, and the primary supercharger 21 is also interconnected with the dry gas sealing venting end of the natural gas long-distance pipeline.

[0059] In the early stage of the maintenance of the natural gas long-distance pipeline, since the initial pressure of the vented natural gas is relatively high (about 9MPag), the vented natural gas with higher pressure can still be automatically transferred to the first-stage booster 21 under the premise of using only the pressure difference between the inlet and outlet of the station compressor 1 as the power, thereby completing the first-stage recovery of the vented natural gas.

[0060] In the later stage of the maintenance of the natural gas long-distance pipeline, since the pressure of the vented natural gas gradually weakens (less than 2MPag), the vented natural gas with a lower pressure is difficult to be automatically transferred to the first-stage booster 21 under the premise of using only the pressure difference between the inlet and outlet of the station compressor 1 as the power.

[0061] Therefore, the staff needs to disconnect the first-stage booster 21 from the dry gas sealed vent end of the natural gas long-distance pipeline, and connect the second-stage booster 33 to the dry gas sealed vent end of the natural gas long-distance pipeline, so as to use the pressure difference between the inlet and outlet of the station compressor 1 as power while also using the pressure difference between the high-pressure gas storage tank 32 and the compressor inlet as auxiliary power, thereby completing the operation of automatically transferring the vented natural gas with lower pressure to the second-stage booster 33.

[0062] Continue to refer to Figure 1In this connection state, the first recovery passage 2 is also connected in series with a first control valve 22, a second control valve 23 and a first main valve 24, wherein the first control valve 22 is installed between the station compressor outlet 12 and the first booster 21, the second control valve 23 is installed between the station compressor inlet 11 and the first booster 21, and the first main valve 24 is installed between the first booster 21 and the dry gas sealing venting end of the natural gas long-distance pipeline.

[0063] The secondary recovery passage 3 is also connected in series with a third control valve 34, a fourth control valve 35, a fifth control valve 36, a sixth control valve 37 and a secondary main valve 38, wherein the third control valve 34 is installed between the station compressor outlet 12 and the reciprocating compressor 31, the fourth control valve 35 is installed between the reciprocating compressor 31 and the high-pressure gas storage tank 32, the fifth control valve 36 is installed between the high-pressure gas storage tank 32 and the secondary booster 33, the sixth control valve 37 is installed between the secondary booster 33 and the station compressor inlet 11, and the secondary main valve 38 is installed between the secondary booster 33 and the dry gas sealing venting end of the natural gas long-distance pipeline.

[0064] Therefore, when any part of the primary recovery passage 2 or the secondary recovery passage 3 is damaged, the part can be repaired individually by opening and closing the first control valve 22, the second control valve 23, the third control valve 34, the fourth control valve 35, the fifth control valve 36, the sixth control valve 37, the primary main valve 24 and the secondary main valve 38.

[0065] In addition, when it is necessary to recover the vented natural gas with a higher pressure, the staff can open the primary main valve 24, the first control valve 22 and the second control valve 23, close the secondary main valve 38 and the fifth control valve 36, and then complete the primary recovery of the vented natural gas. When it is necessary to recover the vented natural gas with a lower pressure, the staff can open the secondary main valve 38, the third control valve 34, the fourth control valve 35, the fifth control valve 36 and the sixth control valve 37, close the primary main valve 24 and the first control valve 22, and then complete the secondary recovery of the vented natural gas.

[0066] Reference Figure 2, which is the second connection state of the primary recovery passage 2 and the secondary recovery passage 3 with the station compressor 1 in the embodiment of the present application. Specifically, relative to the first connection state in the embodiment of the present application, in this connection state, the end of the primary recovery passage 2 away from the station compressor outlet 12 is interconnected with the secondary booster 33, and the second control valve 23 is installed between the secondary booster 33 and the primary booster 21, while the secondary booster 33 is no longer interconnected with the dry gas sealing venting end of the natural gas long-distance pipeline. Of course, the secondary main valve 38 is no longer installed between the secondary booster 33 and the dry gas sealing venting end of the natural gas long-distance pipeline.

[0067] When it is necessary to recover the vented natural gas with a higher pressure, the staff can open the first-level main valve 24, the first control valve 22, the second control valve 23 and the sixth control valve 37, and close the fifth control valve 36. Then, under the premise of using the pressure difference between the inlet and outlet of the station compressor 1 as the power, the vented natural gas with a higher pressure can still automatically pass through the first-level booster 21 and the second-level booster 33, thereby completing the first-level recovery of the vented natural gas.

[0068] When it is necessary to recover the vented natural gas with a lower pressure, the staff can open the first-level main valve 24, the first control valve 22, the second control valve 23, the third control valve 34, the fourth control valve 35, the fifth control valve 36 and the sixth control valve 37. Then, under the premise of using the pressure difference between the inlet and outlet of the station compressor 1 as the main power and the pressure difference between the high-pressure gas storage tank 32 and the compressor inlet as the auxiliary power, the vented natural gas with a lower pressure can automatically pass through the first-level supercharger 21 and the second-level supercharger 33, thereby completing the secondary recovery of the vented natural gas.

[0069] Reference Figure 3 , which is the third connection state of the primary recovery passage 2 and the secondary recovery passage 3 with the station compressor 1 in the embodiment of the present application. Specifically, relative to the first connection state in the embodiment of the present application, in this connection mode, the primary main valve 24 is no longer installed between the primary booster 21 and the dry gas seal venting end of the natural gas long-distance pipeline, and the secondary main valve 38 is no longer installed between the secondary booster 33 and the dry gas seal venting end of the natural gas long-distance pipeline. In this connection mode, a switching valve 4 is installed between the primary booster 21 and the secondary booster 33, and the switching valve 4 is connected to the dry gas seal venting end of the natural gas long-distance pipeline.

[0070] When it is necessary to recover the vented natural gas with a higher pressure, the staff can connect the dry gas sealed venting end of the natural gas long-distance pipeline with the first-stage supercharger 21 by switching valve 4, thereby completing the first-stage recovery of the vented natural gas. When it is necessary to recover the vented natural gas with a lower pressure, the staff can connect the dry gas sealed venting end of the natural gas long-distance pipeline with the second-stage supercharger 33 by switching valve 4, thereby completing the second-stage recovery of the vented natural gas.

[0071] The structure of the switching valve 4 is as follows:

[0072] Reference Figure 4 and Figure 5 The switching valve 4 includes a valve base pipe 41, a switching block 42 and a plugging assembly 43, wherein the valve base pipe 41 includes a primary transverse pipe 411, a secondary transverse pipe 412 fixedly connected to the primary transverse pipe 411, and a vertical pipe 413 fixedly connected to the outer peripheral surface of the primary transverse pipe 411. It should be noted that in this embodiment, the primary transverse pipe 411, the secondary transverse pipe 412 and the vertical pipe 413 are all square pipes, and for the convenience of description, the direction in which the primary transverse pipe 411 approaches the vertical pipe 413 is taken as the upper direction, and the direction in which the primary transverse pipe 411 is away from the vertical pipe 413 is taken as the lower direction.

[0073] The inlet of the primary cross pipe 411 is interconnected with the dry gas sealing venting end of the natural gas long-distance pipeline, and the outlet of the primary cross pipe 411 is interconnected with the primary supercharger 21. The inlet of the secondary cross pipe 412 is interconnected with the primary cross pipe 411, and the outlet of the secondary cross pipe 412 is interconnected with the secondary supercharger 33, and the plugging component 43 is arranged at the inlet of the secondary cross pipe 412, and the plugging component 43 is used to plug the inlet of the secondary cross pipe 412.

[0074] The vertical pipe 413 includes a pipe body 4131 and an end cover 4132, wherein the pipe body 4131 is fixedly connected to the upper end surface of the primary pipe body 4131, and the pipe body 4131 is connected to the secondary transverse pipe 412. The lower end surface of the secondary transverse pipe 412 is penetrated with a switching groove 4121 coaxial with the pipe body 4131, the switching groove 4121 is connected to the primary transverse pipe 411, and the switching block 42 slides up and down in the pipe body 4131, the switching groove 4121 and the primary transverse pipe 411. The end cover 4132 is fixedly connected to one end of the pipe body 4131 away from the primary transverse pipe 411, and the upper end surface of the end cover 4132 is penetrated with a through hole 41321, and the aperture of the through hole 41321 is smaller than the shortest length of the upper end surface of the switching block 42.

[0075] A through slot 421 is formed through the side wall of the switching block 42, and a guide surface 422 is provided on the lower end surface of the switching block 42, and the guide surface 422 gradually tilts upward toward the inlet of the primary transverse pipe 411. When the primary transverse pipe 411 is not vented with natural gas, the lower end surface of the switching block 42 abuts against the inner wall of the primary transverse pipe 411, that is, the switching block 42 blocks the primary transverse pipe 411. The through slot 421 is connected to the inlet of the secondary transverse pipe 412, and the blocking assembly 43 blocks the inlet of the secondary transverse pipe 412.

[0076] When the primary cross pipe 411 is fed with vented natural gas, the vented natural gas pressure is relatively high (9 MPag) in the early stage of the maintenance of the natural gas long-distance pipeline, so the vented natural gas will continue to exert force on the guide surface 422 along direction a, and the guide surface 422 automatically forces the switching block 42 to slide upward, thereby releasing the blockage of the primary cross pipe 411, and allowing the vented natural gas to be transferred to the primary supercharger 21 through the primary cross pipe 411. At this time, the through groove 421 and the inlet of the secondary cross pipe 412 are intertwined, and the switching block 42 forces the blocking component 43 to release the blockage of the secondary cross pipe 412.

[0077] In the later stage of the maintenance of the natural gas long-distance pipeline, the gas pressure of the vented natural gas gradually decreases. When the gas pressure of the vented natural gas is less than 2MPag, the switch block 42 will automatically slide downward under the action of gravity. When the through groove 421 and the inlet of the secondary cross pipe 412 are connected to each other, the force of the vented natural gas on the guide surface 422 will gradually decrease, and finally the lower end surface of the switch block 42 will abut against the inner wall of the primary cross pipe 411 again, thereby completing the blocking of the primary cross pipe 411. At this time, the through groove 421 is completely connected with the inlet of the secondary cross pipe 412, so that the vented natural gas can be transferred to the secondary supercharger 33 through the secondary cross pipe 412.

[0078] It should be noted that the cross section of the switching block 42 is a quadrilateral. Specifically, in this embodiment, the cross sections of the switching block 42 in the horizontal direction are all rectangular, and the cross sections of the switching block 42 in the vertical direction are rectangular or trapezoidal, so that when the natural gas is vented and force is continuously applied to the guide surface 422 along the direction a, the switching block 42 is not easy to rotate in the horizontal direction or the vertical direction, so that the switching block 42 can slide upward normally.

[0079] Continue to refer to Figure 4 and Figure 5The plugging assembly 43 includes a control panel 431, a push rod 432, a plurality of limit feet 433, a connecting rope 434 and a plugging block 435. The control panel 431 is arranged above the end cover 4132, and the outer diameter of the control panel 431 is larger than the aperture of the through hole 41321. The push rod 432 is fixedly connected to the center of the lower end surface of the control panel 431, and when the first-level horizontal pipe 411 is not fed with vented natural gas, the push rod 432 passes through the through hole 41321 and is accommodated in the pipe body 4131.

[0080] A plurality of limiting feet 433 are fixedly connected to the edge of the lower end surface of the control plate 431. For example, four limiting feet 433 are provided. The four limiting feet 433 are arranged at even intervals in the circumferential direction with the top rod 432 as the center. It should be noted that, in this embodiment, the limiting feet 433 include a connecting rod 4331 and a guide ball 4332, wherein the connecting rod 4331 is fixedly connected to the lower end surface of the control plate 431, and the connecting rod 4331 gradually tilts outward in the direction away from the control plate 431. The guide ball 4332 is fixedly connected to one end of the connecting rod 4331 away from the control plate 431, and when no venting natural gas is introduced into the first-level cross pipe 411, the outer peripheral surface of the guide ball 4332 abuts against the upper end surface of the end cover 4132.

[0081] A placement groove 4122 is provided at the lower groove wall of the entrance of the secondary transverse tube 412, and a connection groove 4123 is provided at the upper groove wall of the entrance of the secondary transverse tube 412, and the connection groove 4123 sequentially penetrates the tube body 4131 and the end cover 4132. A connection rope 434 is accommodated in the connection groove 4123, and one end of the connection rope 434 is fixedly connected to the lower end of the top rod 432, and the other end of the connection rope 434 is fixedly connected to the blocking block 435, and the blocking block 435 reciprocates and slides between the entrance of the secondary transverse tube 412 and the placement groove 4122.

[0082] Reference Figure 5 and Figure 6 When the switch block 42 slides upward under the action of the vented natural gas, the upper end surface of the switch block 42 first abuts against the lower end of the push rod 432. At this time, the switch block 42 drives the push rod 432 to slide upward, and the guide ball 4332 forces the connecting rod 4331 to deform inward under the drive of the push rod 432, thereby prompting the guide ball 4332 to move into the through hole 41321. Since the guide ball 4332 no longer restricts the movement of the connecting rope 434, the blocking block 435 will slide downward under the action of gravity and finally be inserted into the placement groove 4122. At this time, the through groove 421 and the entrance of the secondary transverse pipe 412 are intertwined, and the blocking block 435 releases the blocking of the secondary transverse pipe 412.

[0083] In the later stage of the maintenance of the natural gas long-distance pipeline, as the pressure of the vented natural gas gradually decreases, the switch block 42 will automatically slide downward under the action of gravity, thereby blocking the first-level cross pipe 411. Since the through groove 421 and the inlet of the second-level cross pipe 412 are interconnected, the vented natural gas can be transferred to the second-level supercharger 33 through the second-level cross pipe 412, thereby completing the second-level recovery of the vented natural gas.

[0084] When the discharged natural gas needs to be recovered again, the staff can press down the control panel 431. When the top rod 432 passes through the through hole 41321 again and is accommodated in the tube body 4131, and the outer peripheral surface of the guide ball 4332 abuts against the lower end surface of the end cover 4132 again, the switching valve 4 can be used again.

[0085] In addition, in order to reduce the possibility of the push rod 432 and the limiting foot 433 being completely separated from the through hole 41321, in the present embodiment, an annular groove 41322 is provided on the hole wall of the through hole 41321, so that when the push rod 432 and the limiting foot 433 slide upward, the guide ball 4332 can be inserted into the annular groove 41322, and the groove wall of the annular groove 41322 can limit the guide ball 4332, thereby reducing the possibility of the push rod 432 and the limiting foot 433 being completely separated from the through hole 41321.

[0086] It should be noted that, in this embodiment, the above-mentioned fixed connection can be carried out by conventional fixed connection methods such as one-piece molding, welding fixation, and bolt fixation according to actual conditions.

[0087] The implementation principle of a system for recovering natural gas vented from a gas compressor station in an embodiment of the present application is as follows:

[0088] In the early stage of the maintenance of the natural gas long-distance pipeline, since the initial pressure of the vented natural gas is relatively high (about 9MPag), the vented natural gas with higher pressure can still be automatically transferred to the first-stage booster 21 under the premise of using only the pressure difference between the inlet and outlet of the station compressor 1 as the power, thereby completing the first-stage recovery of the vented natural gas.

[0089] In the later stage of the maintenance of the natural gas long-distance pipeline, since the pressure of the vented natural gas gradually weakens (less than 2MPag), the staff can use the pressure difference between the inlet and outlet of the station compressor 1 as power, and also use the pressure difference between the high-pressure gas storage tank 32 and the compressor inlet as auxiliary power, thereby completing the operation of automatically transferring the vented natural gas with lower pressure to the secondary booster 33.

[0090] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A system for recovering natural gas vented from a gas compressor station, characterized in that: It comprises a station compressor (1), a primary recovery passage (2) and a secondary recovery passage (3), wherein the station compressor (1) is provided with a station compressor inlet (11) and a station compressor outlet (12); One end of the primary recovery passage (2) is interconnected with the station compressor outlet (12), and the other end of the primary recovery passage (2) is interconnected with the station compressor inlet (11). A primary booster (21) is provided on the primary recovery passage (2), and the primary booster (21) is interconnected with a dry gas sealing venting end of a natural gas long-distance pipeline; One end of the secondary recovery passage (3) is interconnected with the station compressor outlet (12), and the other end of the secondary recovery passage (3) is interconnected with the station compressor inlet (11). A reciprocating compressor (31), a high-pressure gas storage tank (32) and a secondary supercharger (33) are sequentially arranged on the secondary recovery passage (3) in a direction close to the station compressor inlet (11). The secondary supercharger (33) is interconnected with a dry gas sealing venting end of a natural gas long-distance pipeline; The first-stage recovery passage (2) is provided with a first control valve (22) and a second control valve (23), wherein the first control valve (22) is provided between the station compressor outlet (12) and the first-stage supercharger (21), and the second control valve (23) is provided between the station compressor inlet (11) and the first-stage supercharger (21); The secondary recovery passage (3) is provided with a third control valve (34), a fourth control valve (35), a fifth control valve (36) and a sixth control valve (37); the third control valve (34) is provided between the station compressor outlet (12) and the reciprocating compressor (31); the fourth control valve (35) is provided between the reciprocating compressor (31) and the high-pressure gas storage tank (32); the fifth control valve (36) is provided between the high-pressure gas storage tank (32) and the secondary supercharger (33); and the sixth control valve (37) is provided between the secondary supercharger (33) and the station compressor inlet (11); A switching valve (4) is provided between the first-stage supercharger (21) and the second-stage supercharger (33), and the switching valve (4) is connected to a dry gas sealing venting end of a natural gas long-distance pipeline; The switching valve (4) comprises a valve base pipe (41), a switching block (42) and a blocking component (43); The valve base pipe (41) comprises a primary transverse pipe (411), a secondary transverse pipe (412) and a vertical pipe (413); the inlet of the primary transverse pipe (411) is mutually connected to the dry gas sealing venting end of the natural gas long-distance pipeline, and the outlet of the primary transverse pipe (411) is mutually connected to the primary supercharger (21); the secondary transverse pipe (412) is arranged in the primary transverse pipe (411), the inlet of the secondary transverse pipe (412) is mutually connected to the primary transverse pipe (411), and the outlet of the secondary transverse pipe (412) is mutually connected to the secondary supercharger (33); a switching groove (4121) is formed through the lower end surface of the secondary transverse pipe (412), and the secondary transverse pipe (412) and the primary transverse pipe (411) are mutually connected through the switching groove (4121); The vertical pipe (413) is arranged on the upper end surface of the first-level horizontal pipe (411), the vertical pipe (413) and the second-level horizontal pipe (412) are communicated with each other, the vertical pipe (413) and the switching groove (4121) are coaxially arranged, and the switching block (42) is slidably connected to the vertical pipe (413) and the switching groove (4121); A through groove (421) is formed through the side wall of the switching block (42). The blocking component (43) is arranged at the inlet of the secondary transverse pipe (412). When the vented natural gas does not flow into the primary transverse pipe (411), the switching block (42) blocks the primary transverse pipe (411), and the blocking component (43) blocks the inlet of the secondary transverse pipe (412). The through groove (421) is in communication with the inlet of the secondary transverse pipe (412). When a relatively high gas pressure is introduced into the primary transverse pipe (411), the switching block (42) opens the primary transverse pipe (411), the through groove (421) and the inlet of the secondary transverse pipe (412) are interlaced, and the blocking component (43) opens the inlet of the secondary transverse pipe (412); when the gas pressure of the vented natural gas decreases, the switching block (42) blocks the primary transverse pipe (411), and the through groove (421) and the inlet of the secondary transverse pipe (412) are communicated with each other.

2. The system for recovering natural gas vented from a gas compressor station according to claim 1, characterized in that: The lower end surface of the switching block (42) is provided with a guide surface (422), and the guide surface (422) gradually slopes upwards towards the direction approaching the inlet of the first-level horizontal pipe (411).

3. The system for recovering natural gas vented from a gas compressor station according to claim 2, characterized in that: The cross section of the switching block (42) is a quadrilateral.

4. The system for recovering natural gas vented from a gas compressor station according to claim 2, characterized in that: The vertical tube (413) comprises a tube body (4131) and an end cover (4132); the tube body (4131) is arranged on the first-level horizontal tube (411); the end cover (4132) is arranged at one end of the tube body (4131) away from the first-level horizontal tube (411); a through hole (41321) is formed through the end cover (4132); and the aperture of the through hole (41321) is smaller than the shortest length of the upper end surface of the switching block (42).

5. The system for recovering natural gas vented from a gas compressor station according to claim 4, characterized in that: The blocking assembly (43) comprises a control panel (431), a push rod (432), a plurality of limiting feet (433), a connecting rope (434) and a blocking block (435); the push rod (432) and the plurality of limiting feet (433) are arranged on the lower end surface of the control panel (431); the plurality of limiting feet (433) are evenly arranged in the circumferential direction with the push rod (432) as the center; a placement groove (4122) is provided on the lower groove wall of the entrance of the secondary horizontal pipe (412); the vertical pipe (413) and the The secondary transverse tube (412) is provided with a connecting groove (4123), one end of the connecting groove (4123) is in communication with the entrance of the secondary transverse tube (412), and the other end of the connecting groove (4123) is in communication with the through hole (41321); the connecting rope (434) is passed through the connecting groove (4123), one end of the connecting rope (434) is fixedly connected to the blocking block (435), and the other end of the connecting rope (434) is fixedly connected to the top rod (432); When the vented natural gas does not flow into the primary transverse pipe (411), the end of the limit foot (433) away from the control panel (431) abuts against the lower end surface of the end cover (4132), the push rod (432) passes through the through hole (41321) and is accommodated in the vertical pipe (413), and the blocking block (435) blocks the entrance of the secondary transverse pipe (412); when the vented natural gas flows into the primary transverse pipe (411) at a relatively high pressure, the stopper (435) blocks the entrance of the secondary transverse pipe (412). 11), the switching block (42) abuts against the lower end surface of the end cover (4132); the push rod (432) passes through the through hole (41321), and the end of the limiting foot (433) away from the control board (431) abuts against the hole wall of the through hole (41321), and the blocking block (435) is inserted into the placement groove (4122), and the blocking block (435) opens the entrance of the secondary cross pipe (412).

6. The system for recovering natural gas vented from a gas compressor station according to claim 5, characterized in that: The limiting foot (433) comprises a connecting rod (4331) and a guide ball (4332); the connecting rod (4331) is arranged on the lower end surface of the control board (431); the connecting rod (4331) gradually tilts outward in a direction away from the control board (431); and the guide ball (4332) is arranged at one end of the connecting rod (4331) away from the control board (431); When the vented natural gas has not been introduced into the first-stage transverse pipe (411), the outer circumferential surface of the guide ball (4332) abuts against the lower end surface of the end cover (4132); when the vented natural gas is introduced into the first-stage transverse pipe (411) at a relatively high pressure, the outer circumferential surface of the guide ball (4332) abuts against the hole wall of the through hole (41321).

7. The system for recovering natural gas vented from a gas compressor station according to claim 6, characterized in that: The hole wall of the through hole (41321) is provided with an annular groove (41322). When the vented natural gas is passed into the first-stage horizontal pipe (411) at a relatively high pressure, the guide ball (4332) is inserted into the annular groove (41322).

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