Recovery device for pressure relief of high-pressure natural gas pipeline

Abstract

The utility model relates to the technical field of natural gas pipelines, and discloses a high-pressure natural gas pipeline pressure relief recovery device which comprises a gas storage tank and a recovery tank, the gas storage tank is communicated with a conveying pipeline through a pressure relief pipeline, a main pipeline and a plurality of mutually independent gas storage areas are arranged in the recovery tank, and each gas storage area is communicated with the main pipeline. A recovery control valve is arranged on a pipeline, communicated with the main pipeline, of each gas storage area, one end of the gas storage tank is connected with or disconnected from the main pipeline through a flange, after the gas storage tank is communicated with the recovery tank, all the recovery control valves are sequentially opened, and only one recovery control valve is in an opened state within the same time period. And the air pressure in each air storage area is reduced step by step. According to the natural gas recycling device, the gas storage areas with different pressure grades in the recycling tank are controlled to be sequentially communicated with the gas storage tank, so that natural gas in the gas storage tank is led out according to different pressure grades in a stepped mode, and pressure reduction treatment on the gas storage tank and reasonable recycling of the natural gas in the gas storage tank are achieved.

Description

Technical Field

[0001] The utility model relates to the technical field of natural gas pipelines, in particular to a high-pressure natural gas pipeline pressure relief and recovery device. Background Technique

[0002] Natural gas is recognized as the cleanest fossil energy on the earth and is becoming the main energy commodity. It can be used as city gas, power generation fuel gas, and also as raw materials for chemical products. After natural gas is mined and purified, it is usually transported over long distances on land through pipelines. Due to the relatively high gas pressure in the natural gas pipeline, higher requirements are put forward for the high-pressure natural gas pipeline and each control valve installed on the pipeline.

[0003] During the use of high-pressure natural gas pipelines, the pressure of natural gas in the local pipeline may increase due to pipeline icing and blockage, human operation errors, component failures, wear and other reasons. If the pressure is not relieved in time, the excessive pressure will accelerate the damage of the pipeline and may directly cause safety accidents in severe cases.

[0004] After the pipeline is depressurized, a certain amount of natural gas will be exported. For this part of natural gas, different treatment methods are provided in the prior art. For example, the natural gas exported after depressurization is directly burned, or this part of natural gas is temporarily stored in a buffer gas storage tank. On a pipeline with a large transportation volume, the volume of natural gas exported by one-time pressure relief is large, and direct combustion will cause waste losses that cannot be ignored. However, due to the existence of gas pressure, it is also difficult to recycle the high-pressure natural gas exported by pressure relief and stored in the buffer gas storage tank. Therefore, there is still room for improvement in how to handle the natural gas exported by pressure relief in the existing high-pressure natural gas pipelines. Content of the Utility Model

[0005] Aiming at the problems existing in the prior art: the high-pressure natural gas exported during the pressure relief of the high-pressure natural gas pipeline is difficult to recycle after being stored in the buffer gas storage tank, the purpose of the utility model is to provide a high-pressure natural gas pipeline pressure relief and recovery device, which sequentially connects the gas storage areas with different pressure levels in the recovery tank to the gas storage tank, so as to export the natural gas in the gas storage tank step by step according to different pressure levels, not only realizing the pressure reduction of the gas storage tank, but also reasonably recycling the natural gas in the gas storage tank.

[0006] To achieve the above purpose, the technical solution of the utility model is as follows:

[0007] A high-pressure natural gas pipeline pressure relief recovery device comprises a gas storage tank, which is connected to a delivery pipeline through a pressure relief pipeline, and also comprises a recovery tank, wherein a main pipeline and a plurality of mutually independent gas storage areas are arranged in the recovery tank, each gas storage area is connected to the main pipeline, and a recovery control valve is arranged on the pipeline connecting each gas storage area and the main pipeline, one end of the gas storage tank is connected to or disconnected from the main pipeline through a flange connection, after the gas storage tank is connected to the recovery tank, each recovery control valve is opened in turn, and only one recovery control valve is in an open state in the same time period, and the gas pressure in each gas storage area is reduced stepwise.

[0008] The utility model is further configured such that: the recovery control valve corresponding to the gas storage area communicated with the gas storage tank is closed when the pressure in the gas storage tank is equal to that in the gas storage area.

[0009] The utility model is further configured as follows: it also includes a controller, a first pressure sensor is arranged on the gas storage tank, a second pressure sensor is arranged on each gas storage area in the recovery tank, the recovery control valve is an electric valve, all the recovery control valves, the first pressure sensor and the second pressure sensor are electrically connected to the controller, and when the pressures detected by the first pressure sensor and the second pressure sensor are equal, the controller controls the recovery control valve corresponding to the current gas storage area to close.

[0010] The utility model is further configured as follows: a first ball valve is arranged at one end of the gas storage tank connected to the main pipeline, and a second ball valve is arranged at one end of the recovery tank connected to the gas storage tank.

[0011] The utility model is further configured as follows: the pressure relief pipeline comprises a safety valve and a first one-way valve, the safety valve is installed on the delivery pipeline, and the first one-way valve is located between the safety valve and the gas storage tank.

[0012] The utility model is further configured to include: a return air pipeline, the return air pipeline is connected with the delivery pipeline and the gas storage tank, and a return air control valve and a second non-return valve are arranged on the return air pipeline.

[0013] The utility model is further configured as follows: a pressure relief valve is arranged on the gas storage tank.

[0014] The utility model is further configured such that the volume of each gas storage area in the recovery tank increases step by step.

[0015] The utility model is further configured to include a buzzer electrically connected to the controller, and the controller controls the buzzer to emit a prompt sound.

[0016] The present utility model is further configured as follows: An alarm and positioning module is further provided on the gas storage tank. The alarm and positioning module is electrically connected to the first pressure sensor on the gas storage tank. The alarm and positioning module sends out an alarm message and provides position information when the pressure in the gas storage tank rises.

[0017] In summary, the beneficial effects achieved by the present utility model are as follows:

[0018] (1) The conveying pipeline is connected to the gas storage tank through a pressure relief pipeline. When the abnormal air pressure in the conveying pipeline rises to the warning value, the safety valve on the pressure relief pipeline opens, and the excess gas flows into the gas storage tank, enabling the conveying pipeline to relieve pressure. If the pressure in the gas storage tank is equal to that in the conveying pipeline and the pressure in the conveying pipeline is still higher than the warning value, the pressure relief valve on the gas storage tank opens to discharge the natural gas that cannot be stored into the blow-off pipeline, avoiding accidents caused by excessive pressure in the conveying pipeline and the gas storage tank.

[0019] (2) After the fault of the conveying pipeline is eliminated, the pressure in the conveying pipeline returns to normal. If the pressure in the gas storage tank is higher than that in the conveying pipeline, a part of the natural gas in the gas storage tank flows back into the conveying pipeline through the return gas pipeline until the air pressure in the gas storage tank is equal to that in the conveying pipeline. The second one-way valve on the return gas pipeline can prevent natural gas from further entering the gas storage tank when the pressure in the gas storage tank is lower than that in the conveying pipeline.

[0020] (3) When the pressure in the gas storage tank does not exceed the pressure in the conveying pipeline, the gas storage tank is connected to the recovery tank. Under the control of the recovery control valve, the gas storage areas with different pressure levels in the recovery tank are sequentially connected to the gas storage tank, so as to export the natural gas in the gas storage tank step by step according to different pressure levels. This not only realizes the pressure reduction treatment of the gas storage tank, ensures the pressure relief function of the gas storage tank for the conveying pipeline, but also reasonably recovers and utilizes the natural gas in the gas storage tank.

[0021] (4) The volumes of the gas storage areas in the recovery tank increase step by step, so that the natural gas in the gas storage tank can be maximally recovered according to different volumes.

[0022] (5) The recovery control valves are all controlled by the controller to open and close, thus realizing the automatic recovery of the natural gas in the gas storage tank. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model, the following will briefly introduce the drawings required to be used in the description. Obviously, the drawings described below are only some embodiments recorded in the present utility model. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings.

[0024] Figure 1Schematic diagram of the connection relationship between the high-pressure natural gas pipeline and the gas storage tank in the present utility model;

[0025] Figure 2 Schematic diagram of the structure of the recovery tank in the present utility model;

[0026] Figure 3 Schematic diagram of the control principle of the recovery tank in the present utility model.

[0027] In the figure: 1, conveying pipeline; 2, gas storage tank; 21, pressure relief valve; 22, first pressure sensor; 23, first ball valve; 3, pressure relief pipeline; 31, safety valve; 32, first one-way valve; 4, return gas pipeline; 41, return gas control valve; 42, second one-way valve; 5, recovery tank; 51, second ball valve; 52, main pipeline; 53, recovery control valve; 54, first gas storage area; 55, second gas storage area; 56, third gas storage area; 57, fourth gas storage area; 58, fifth gas storage area; 59, sixth gas storage area; 501, second pressure sensor. Specific implementation mode

[0028] The following combines the accompanying drawings in the embodiments of the present utility model to clearly and completely describe the technical solutions in the embodiments of the present utility model. Obviously, the described embodiments are part of the embodiments of the present utility model, rather than all the embodiments.

[0029] Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative work belong to the protection scope of the present utility model.

[0030] As shown in the attached Figures 1-3 As shown in the figure, a high-pressure natural gas pipeline pressure relief and recovery device is used to relieve the pressure of the conveying pipeline 1 and recover the natural gas discharged from the conveying pipeline 1 during pressure relief. The pressure relief and recovery device includes a gas storage tank 2 and a recovery tank 5.

[0031] High-pressure natural gas is conveyed in the conveying pipeline 1, and the gas storage tank 2 is a closed pressure vessel. A pressure relief pipeline 3 connecting the two is arranged between the conveying pipeline 1 and the gas storage tank 2. The pressure relief pipeline 3 includes a safety valve 31 and a first one-way valve 32.

[0032] The safety valve 31 is installed on the conveying pipeline 1. The safety valve 31 is an automatic valve in the prior art. When the pressure in the conveying pipeline 1 rises above the warning value, the safety valve 31 opens, and the natural gas is discharged along the pressure relief pipeline 3 to prevent the air pressure in the conveying pipeline 1 from exceeding the warning value.

[0033] The first check valve 32 is located between the safety valve 31 and the gas storage tank 2. Since the pressure in the gas storage tank 2 is less than the pressure in the conveying pipeline 1, when the pressure in the conveying pipeline 1 rises above the warning value, the safety valve 31 opens, and the high-pressure natural gas in the conveying pipeline 1 enters the gas storage tank 2 through the safety valve 31 and the first check valve 32; however, when the pressure in the gas storage tank 2 exceeds the pressure in the conveying pipeline 1, the first check valve 32 can prevent the natural gas in the gas storage tank 2 from flowing back to the conveying pipeline 1 by itself.

[0034] A return gas pipeline 4 connecting the conveying pipeline 1 and the gas storage tank 2 is also provided between the conveying pipeline 1 and the gas storage tank 2. The return gas pipeline 4 includes a return gas control valve 41 and a second check valve 42.

[0035] The return gas control valve 41 is used to control the on-off of the return gas pipeline 4, and an ordinary ball valve can be selected.

[0036] After the failure of the conveying pipeline 1 is eliminated, due to pressure relief, some natural gas enters the gas storage tank 2, and the natural gas in the gas storage tank 2 cannot flow back to the conveying pipeline 1 by itself. If the pressure in the gas storage tank 2 is higher than the pressure in the conveying pipeline 1, some natural gas in the gas storage tank 2 can flow back to the conveying pipeline 1 through the opened return gas control valve 41 and the second check valve 42 until the gas pressure in the gas storage tank 2 is equal to the gas pressure in the conveying pipeline 1.

[0037] If the pressure in the gas storage tank 2 is lower than the pressure in the conveying pipeline 1, the second check valve 42 can prevent the high-pressure natural gas in the conveying pipeline 1 from further entering the gas storage tank 2 through the return gas pipeline 4.

[0038] A first pressure sensor 22 for real-time detection of the gas pressure in the gas storage tank 2 is provided on the gas storage tank 2, and a pressure relief valve 21 is also provided on the gas storage tank 2. When too much natural gas enters the gas storage tank 2 and the gas pressure in the gas storage tank 2 exceeds the set value, the pressure relief valve 21 opens to discharge the natural gas that the gas storage tank 2 cannot store to the blow-off pipeline, avoiding accidents due to excessive pressure in the conveying pipeline 1 and the gas storage tank 2.

[0039] An alarm positioning module commonly used in the prior art and a communication module for communicating with the monitoring room are also provided on the gas storage tank 2. The alarm positioning module is electrically connected to the first pressure sensor 22 and the communication module on the gas storage tank 2. When the first pressure sensor 22 detects an increase in the gas pressure in the gas storage tank 2, at this time, the gas pressure in the conveying pipeline 1 has risen to the warning value, and the alarm positioning module sends an alarm message and provides location information to the monitoring room through the communication module, facilitating the maintenance personnel to arrive quickly to eliminate the fault.

[0040] One end of the gas storage tank 2 connected to the recovery tank 5 is provided with a first ball valve 23, and the first ball valve 23 is used to seal the gas storage tank 2. The first ball valve 23 is opened when the gas storage tank 2 is in communication with the recovery tank 5 to introduce the natural gas in the gas storage tank 2 into the recovery tank 5. When it is necessary to completely empty the gas storage tank 2, it can also be achieved by opening the first ball valve 23.

[0041] One end of the recovery tank 5 connected to the gas storage tank 2 is provided with a second ball valve 51. One end of the gas storage tank 2 where the first ball valve 23 is located is connected and disconnected from one end of the second ball valve 51 on the recovery tank 5 through flange connection.

[0042] The recovery tank 5 is a closed pressure vessel. A main pipeline 52 and a plurality of independent gas storage areas are arranged in the recovery tank 5. Each gas storage area is communicated with the main pipeline 52, and a recovery control valve 53 is arranged on the pipeline where each gas storage area is communicated with the main pipeline 52.

[0043] In this embodiment, a total of six independent gas storage areas are arranged in the recovery tank 5, namely the first gas storage area 54, the second gas storage area 55, the third gas storage area 56, the fourth gas storage area 57, the fifth gas storage area 58 and the sixth gas storage area 59, and the pressure levels of the six gas storage areas decrease step by step.

[0044] The recovery control valve 53 is an electric valve, for example, an electric ball valve can be selected. A second pressure sensor 501 for real-time detection of the air pressure in the corresponding gas storage area is arranged on each gas storage area in the recovery tank 5.

[0045] All the recovery control valves 53, the second pressure sensors 501 and the first pressure sensor 22 on the gas storage tank 2 are electrically connected to the controller. After the gas storage tank 2 is in communication with the recovery tank 5, the controller controls each recovery control valve 53 to open in sequence through a preset control logic, and only one recovery control valve 53 is in the open state at the same time period. Only when the pressures detected by the first pressure sensor 22 and the second pressure sensor 501 on the current gas storage area are equal, the controller controls the recovery control valve 53 corresponding to the current gas storage area to close and controls the recovery control valve 53 of the next gas storage area to open.

[0046] The pressure relief and recovery device in the present utility model further includes a buzzer electrically connected to the controller. When the air pressure in the last gas storage area in the recovery tank 5 is equal to the air pressure in the gas storage tank 2, the controller controls the recovery control valve 53 corresponding to the current gas storage area to close and controls the buzzer to emit a prompt sound to the on-site staff. At this time, the recovery work of the natural gas in the gas storage tank 2 has been completed, and the second ball valve 51 and the first ball valve 23 can be closed and the connection between the gas storage tank 2 and the recovery tank 5 can be disconnected.

[0047] The second ball valve 51 is connected to the main pipeline 52 and controls the on / off of the main pipeline 52. The second ball valve 51 is used to completely seal the recovery tank 5 to prevent the natural gas in the recovery tank 5 from leaking when the recovery control valve 53 in the recovery tank 5 fails accidentally.

[0048] During the recovery process of the natural gas in the gas storage tank 2, the air pressure in the gas storage tank 2 continuously decreases. Therefore, after the recovery is completed, the air pressure in each gas storage area decreases step by step. To improve the recovery degree of the natural gas in the gas storage tank 2, the volumes of the gas storage areas in the recovery tank 5 are set to increase step by step. Thus, when the air pressure in the gas storage tank 2 is relatively low, the gas storage area connected to it has a larger volume to store as much natural gas with a lower pressure as possible.

[0049] The implementation principle of the above embodiment is as follows:

[0050] When a local blockage fault occurs in the conveying pipeline 1, the local air pressure in the conveying pipeline 1 rises to the warning value, the safety valve 31 on the pressure relief pipeline 3 opens, and the excess gas flows into the gas storage tank 2, so that the conveying pipeline 1 can be depressurized. The first pressure sensor 22 detects that the pressure in the gas storage tank 2 rises, and the alarm positioning module sends an alarm message and provides location information to the monitoring room through the communication module. Before the maintenance personnel arrive at the site to eliminate the fault, all the excess natural gas in the conveying pipeline 1 is discharged into the gas storage tank 2 through the pressure relief pipeline 3. If the pressure in the gas storage tank 2 is equal to that in the conveying pipeline 1 and the pressure in the conveying pipeline 1 is still higher than the warning value, at this time, the natural gas in the conveying pipeline 1 cannot continue to be discharged into the gas storage tank 2. To avoid accidents due to excessive pressure in the conveying pipeline 1 and the gas storage tank 2, the pressure relief valve 21 on the gas storage tank 2 opens to discharge the natural gas that cannot be stored.

[0051] When the maintenance personnel eliminate the fault of the conveying pipeline 1, the pressure in the conveying pipeline 1 returns to normal. At this time, it is determined whether to open the gas return control valve 41 on the gas return pipeline 4 according to the value of the first pressure sensor 22 on the gas storage tank 2. If the pressure in the gas storage tank 2 is higher than the pressure in the conveying pipeline 1, the gas return control valve 41 is opened. Due to the existence of the pressure difference, a part of the natural gas in the gas storage tank 2 flows back into the conveying pipeline 1 through the gas return pipeline 4 until the air pressure in the gas storage tank 2 is equal to the air pressure in the conveying pipeline 1. If the pressure in the gas storage tank 2 is lower than the pressure in the conveying pipeline 1, there is no need to open the gas return control valve 41, and the second one-way valve 42 can also prevent the high-pressure natural gas in the conveying pipeline 1 from further entering the gas storage tank 2 through the gas return pipeline 4.

[0052] At this time, the pressure in the gas storage tank 2 does not exceed the pressure in the conveying pipeline 1. Connect the gas storage tank 2 and the recovery tank 5 through a flange, open the first ball valve 23 and the second ball valve 51, and the main pipeline 52 of the gas storage tank 2 is communicated with the recovery tank 5. The controller controls each recovery control valve 53 to be opened one by one in sequence, and the gas storage areas with different pressure levels in the recovery tank 5 are communicated with the gas storage tank 2 in sequence, and the natural gas in the gas storage tank 2 is exported step by step according to different pressure levels. This not only realizes the pressure reduction treatment of the gas storage tank 2, ensures the pressure relief function of the gas storage tank 2 for the conveying pipeline 1, but also reasonably recovers and utilizes the natural gas in the gas storage tank 2. When the air pressure in the last gas storage area in the recovery tank 5 is equal to the air pressure in the gas storage tank 2, the controller controls the recovery control valve 53 corresponding to the current gas storage area to close and controls the buzzer to send a prompt sound to the on-site staff. At this time, the recovery of the natural gas in the gas storage tank 2 has been completed. Close the second ball valve 51 and the first ball valve 23 and disconnect the connection between the gas storage tank 2 and the recovery tank 5, and then transport the recovery tank 5 to the natural gas recovery place.

[0053] Although the preferred embodiments of the present invention have been described, those skilled in the art can make additional changes and modifications once they know the basic creative concept. Therefore, the appended claims are intended to be construed as including the preferred embodiments and all changes and modifications falling within the scope of the present invention. Obviously, those skilled in the art can make various changes and variations to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention is also intended to include these modifications and variations.

Claims

1. A high-pressure natural gas pipeline pressure relief recovery device, comprising a gas storage tank (2), wherein the gas storage tank (2) is connected to a delivery pipeline (1) via a pressure relief pipeline (3), and is characterized in that: The invention also comprises a recovery tank (5), wherein a main pipeline (52) and a plurality of mutually independent gas storage areas are arranged in the recovery tank (5), each gas storage area is connected to the main pipeline (52), and a recovery control valve (53) is arranged on the pipeline connecting each gas storage area to the main pipeline (52). One end of the gas storage tank (2) is connected to or disconnected from the main pipeline (52) through a flange connection. After the gas storage tank (2) is connected to the recovery tank (5), each recovery control valve (53) is opened in sequence and only one recovery control valve (53) is in an open state in the same time period, and the gas pressure in each gas storage area is reduced stepwise.

2. The high-pressure natural gas pipeline pressure relief recovery device according to claim 1 is characterized in that: The recovery control valve (53) corresponding to the gas storage area connected to the gas storage tank (2) is closed when the pressure in the gas storage tank (2) is equal to that in the gas storage area.

3. The high-pressure natural gas pipeline pressure relief recovery device according to claim 2 is characterized in that: The invention also comprises a controller, wherein the gas storage tank (2) is provided with a first pressure sensor (22), each gas storage area in the recovery tank (5) is provided with a second pressure sensor (501), the recovery control valve (53) is an electric valve, and all the recovery control valves (53), the first pressure sensor (22) and the second pressure sensor (501) are electrically connected to the controller, and when the pressures detected by the first pressure sensor (22) and the second pressure sensor (501) are equal, the controller controls the recovery control valve (53) corresponding to the current gas storage area to close.

4. The high-pressure natural gas pipeline pressure relief recovery device according to claim 1, characterized in that: The end of the gas storage tank (2) connected to the main pipeline (52) is provided with a first ball valve (23), and the end of the recovery tank (5) connected to the gas storage tank (2) is provided with a second ball valve (51).

5. The high-pressure natural gas pipeline pressure relief recovery device according to claim 1, characterized in that: The pressure relief pipeline (3) comprises a safety valve (31) and a first one-way valve (32); the safety valve (31) is installed on the delivery pipeline (1); and the first one-way valve (32) is located between the safety valve (31) and the gas storage tank (2).

6. The high-pressure natural gas pipeline pressure relief recovery device according to claim 1, characterized in that: It also comprises an air return pipeline (4), the air return pipeline (4) being in communication with the delivery pipeline (1) and the air storage tank (2), and the air return pipeline (4) being provided with an air return control valve (41) and a second non-return valve (42).

7. The high-pressure natural gas pipeline pressure relief recovery device according to claim 1, characterized in that: The gas storage tank (2) is provided with a pressure relief valve (21).

8. The high-pressure natural gas pipeline pressure relief recovery device according to claim 1, characterized in that: The volume of each gas storage area in the recovery tank (5) increases in steps.

9. The high-pressure natural gas pipeline pressure relief recovery device according to claim 3, characterized in that: It also includes a buzzer electrically connected to the controller, and the controller controls the buzzer to emit a prompt sound.

10. The high-pressure natural gas pipeline pressure relief recovery device according to claim 3, characterized in that: The gas storage tank (2) is also provided with an alarm positioning module, the alarm positioning module being electrically connected to the first pressure sensor (22) on the gas storage tank (2), and the alarm positioning module issuing an alarm message and providing position information when the pressure in the gas storage tank (2) increases.

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