WO2021056613A1 - Device capable of quickly and automatically closing and emergency shutoff device at natural gas wellhead - Google Patents

Abstract

A device capable of quickly and automatically closing under a triggering condition, and which relates to the technical field of safety protection. The device capable of quickly and automatically closing uses an overpressure control pilot valve (5), an underpressure control pilot valve (6) and an oil circuit design, and uses a piston movement to effectively prevent a replacement process of a blasting pin, which saves not only the cost of consumables but also the time cost. In addition, the device capable of quickly and automatically closing directly makes use of the acting force of medium pressure on the overpressure control pilot valve and the underpressure control pilot valve so as to implement overpressure triggering and underpressure triggering, which not only does not require other converters, but is also is more direct and sensitive and has a higher reaction speed. The device capable of quickly and automatically closing may also, at springs of the overpressure control pilot valve and the underpressure control pilot valve, use spring pre-tightening regulators, so that the control of the overpressure and underpressure threshold values may be quicker, more convenient and more accurate.

Description

Device capable of quickly and automatically shutting off and natural gas wellhead emergency cut-off device Technical field

The invention relates to a device that can quickly and automatically close a valve when a trigger condition is triggered, in particular to a device that can quickly and automatically close and a natural gas wellhead emergency shutoff device, and belongs to the technical field of safety assurance.

Background technique

As the gas or liquid is transported, there may be pressure changes that may cause safety hazards in the entire transport process. Therefore, in general, devices are installed on the pipeline to control the flow of gas or liquid, so as to avoid safety accidents caused by pressure changes in the pipeline. A common method is to set up actuators for these devices, so that the devices can be closed quickly and sensitively.

For example, in the construction of natural gas collection projects, such pressure-sensitive devices are usually installed, which can quickly and urgently cut off the pressure when the pressure exceeds the set range. When the wellhead medium pressure exceeds the preset high pressure limit, the device can quickly and automatically shut down to prevent downstream equipment from being damaged due to pressure overload; at the same time when the wellhead medium pressure is lower than the preset low pressure limit, the device can also quickly and automatically shut down , The placement system equipment is destroyed.

The inventor of the present invention discloses a natural gas wellhead emergency shut-off device in CN207246497U. In this patent, a blasting needle is used as the trigger element, which can cut off the gas passage of the natural gas wellhead with high precision and quickly.

However, during use, we found that this device still has some shortcomings. For example, the blasting needle used as the trigger element is damaged during the triggering process, which makes it impossible to use it repeatedly. It must be used after the device is triggered. Replacement of the blasting needle can only be reset. This method not only increases the cost of consumables, but also increases the time cost of resetting. At the same time, due to the need to use a gas-liquid conversion system in the design, the overall structure is more complicated and the cost is relatively high.

Therefore, how to solve these problems actually generated in the application and propose a more optimized design and solution is the direction that the inventor has been working hard to study.

Summary of the invention

The purpose of the present invention is to find a new technical solution, which can optimize the reset link and reduce the cost of consumables and time cost for resetting after triggering.

In order to achieve this purpose of the invention, the present invention discloses a device suitable for emergency shut-off of natural gas wellheads, which can quickly and automatically close. The device includes an on-off valve for controlling a single-acting actuator of the on-off valve, and the single-acting actuator is a hydraulic The oil-controlled single-acting actuator further includes an oil storage tank. The piston chamber of the single-acting actuator is communicated with the oil storage tank through an oil injection pipeline of the actuator, and also includes an overpressure control pilot valve and a pressure deficit control pilot valve, Both sides of the side wall of the overpressure control pilot valve are correspondingly provided with an overpressure oil injection hole and an overpressure oil outlet, and the piston rod of the overpressure control pilot valve is provided with two annular grooves, which are respectively an overpressure passage groove And the overpressure closed-circuit groove, the overpressure oil injection hole (or overpressure oil outlet) is always located at the overpressure passage groove, and the overpressure oil outlet (post-overpressure oil injection hole) is located in the static state of the spring The overpressure closed circuit groove is located at the overpressure passage groove when the spring is compressed; both sides of the side wall of the pressure control pilot valve are correspondingly provided with a pressure oil injection hole and a pressure oil outlet, and pressure control The piston rod of the pilot valve is provided with two annular grooves, namely a pressure-deficient passage groove and a pressure-deficient closed-circuit groove. The pressure-deficient oil outlet (or pressure-deficient oil injection hole) is always located at the groove of the pressure-deficient passage , The underpressure oil injection hole (or underpressure oil outlet) is located at the underpressure closed-circuit groove when the spring is compressed, and is located at the underpressure passage groove when the spring returns to a static state; the overpressure oil injection hole and The oil storage tanks are connected through an overpressure control pilot valve oil injection line, the underpressure oil injection hole is connected with the oil storage tank through a underpressure control pilot valve oil injection line, and the overpressure oil outlet hole and the oil storage tank pass through The overpressure oil return pipeline is connected, and the underpressure oil outlet is connected with the oil storage tank through the underpressure return oil pipeline, and the overpressure control pilot valve oil injection line and the underpressure control pilot valve oil injection line are connected in parallel, And after it is connected in parallel, it is connected in parallel with the oil injection pipeline of the executive structure to form an oil injection main pipeline, and the overpressure oil return pipeline is connected in parallel with the underpressure oil return pipeline.

Further preferably, the overpressure control pilot valve and the underpressure control pilot valve are respectively provided with a spring pretension regulator, the spring pretension regulator includes a spring connection block, and a bolt hole is opened on the spring connection block , It also includes a spring pre-tension adjusting bolt, the spring pre-tension adjusting bolt is installed in the bolt hole, the spring connecting block is located in the piston housing, and the spring pre-tension adjusting bolt is exposed outside the piston housing.

Further preferably, a pressure relief bypass is further provided on the oil supply main pipeline, and the pressure relief bypass is formed by a pressure relief pipe connected to the oil storage tank at one end and connected to the oil supply main pipeline at the other end. A pressure relief valve is provided.

In a preferred technical solution, the single-acting actuator is a fork-type single-acting actuator.

In addition, in a preferred technical solution, a manual pressure test pump is also included. The manual pressure test pump includes a pressure test oil barrel and a pressure test handle. The pressure test oil barrel is connected to the pressure test handle through a connecting rod. One end of the pressure test handle is fixed, and the other end rotates with the fixed point as an axis. A check valve is also provided at the outlet of the manual pressure test pump.

Oil storage tank is a natural gas wellhead emergency shut-off device equipped with the aforementioned device that can be quickly and automatically closed. The switch valve is installed on the natural gas pipeline. The upstream pipeline is located upstream of the switch valve, and the downstream pipeline located downstream of the switch valve is the downstream pipeline. The first sampling pipeline and the second sampling pipeline are respectively communicated with the overpressure control pilot valve and the underpressure control pilot valve.

In a preferred technical solution, the first sampling line and the second sampling line are further provided with a first manual shut-off valve and a second manual shut-off valve, respectively.

Here we need to explain the several structures mentioned above. First, it is a single-acting actuator. The single-acting actuator is generally pneumatic, that is, driven by air, but in the present invention, it is hydraulic Single-acting actuator for oil control. The position where the hydraulic oil acts is the piston chamber of the single-acting actuator.

Specifically, the fork-pull-type single-acting actuator preferably used in the present invention includes a piston rod, a fork-pull mechanism, a spring, and an outer shell. One end of the fork-pull mechanism is fixed with a shaft, and the shaft is fixed in the outer shell. The other end of the fork pulling mechanism is fixed on the piston rod, one end of the piston rod is fixed to the inner side of the outer casing through a spring, and the other end of the piston rod cooperates with the casing to form a piston cavity. Since the piston cavity is full of oil in a static state, pressure is generated on the spring to make it in a compressed state, and the fork pulling mechanism is in the first position (that is, the switch valve is open position). When the trigger condition is met, the oil return circuit is blocked. When opening, the oil in the piston cavity returns to the oil cylinder, the pressure on the spring disappears, the spring returns to a non-compressed state due to its own restoring force, and the fork pulling mechanism rotates to the second position (ie, the on-off valve closed position).

In addition, the structure that needs to be explained is the overpressure control pilot valve and the underpressure control pilot valve. The pilot valve is composed of a piston rod and a piston sleeve airtightly fitted with the piston rod. One end of the piston rod is fixed to the piston sleeve by a spring. On the inner wall, the other end of the piston rod is matched with the piston sleeve to form a piston cavity. The sliding of the piston rod in the piston sleeve can be realized by the change in the pressure in the piston cavity and the spring rebound force. When two through holes with different levels are opened on the side wall of the piston sleeve, the opening and closing of the piston passage can be realized by using the annular groove formed on the pilot valve and the movement of the piston rod. Here is a specific explanation. When the through holes at different levels are in an annular groove at the same time, the passage is opened at this time; when the through holes at different levels are not in the same annular groove at the same time, the passage is closed at this time.

After adopting the technical solution disclosed in the present invention, since the overpressure control pilot valve or the underpressure control pilot valve is a piston movement during the triggering process, when the system pressure returns to normal, it can be automatically reset to the static home position due to the action of the spring , Thus avoiding the blasting needle replacement process, not only saves the cost of consumables but also saves time and cost. In addition, in the present invention, the force of the pressure of the medium on the overpressure control pilot valve and the underpressure control pilot valve is directly used to achieve overpressure triggering and underpressure triggering, not only without other converters, but also more direct, sensitive, and faster. Faster. In addition, since the springs of the overpressure control pilot valve and the underpressure control pilot valve can be used to preload the regulator in the present invention, the threshold control of overpressure and underpressure can be made more convenient and accurate.

Description of the drawings

Figure 1 is a schematic diagram of the static state of the device that can quickly and automatically shut down installed at the natural gas wellhead.

Figure 2 is an enlarged view of the overpressure control pilot valve and the underpressure control pilot valve.

Figure 3 is a schematic diagram of the overpressure state of the device that can quickly and automatically shut down installed at the natural gas wellhead.

Figure 4 is a schematic diagram of the pressure deficit state of the device that can be quickly and automatically shut down installed at the natural gas wellhead.

detailed description

In order to better understand the present invention, we will further illustrate the present invention in conjunction with specific embodiments below.

As shown in Figure 1, a device suitable for emergency shut-off of natural gas wellheads can be quickly and automatically closed. The device includes an on-off valve 1, a single-acting actuator 2 for controlling the on-off valve, and the single-acting actuator is a single-acting actuator controlled by hydraulic oil. The acting actuator further includes an oil storage tank 3. The piston chamber 201 of the single acting actuator and the oil storage tank 3 are communicated with the oil filling pipe 4 of the execution structure, and also includes an overpressure control pilot valve 5 and a pressure deficit control pilot valve 6. With reference to Figure 2, we can see that both sides of the side wall of the overpressure control pilot valve 5 are provided with an overpressure oil injection hole 501 and an overpressure oil outlet 502 correspondingly, and the piston rod of the overpressure control pilot valve is provided with two There are two annular grooves, namely the overpressure passage groove 503 and the overpressure closed-circuit groove 504. The overpressure oil injection hole 501 is always located at the overpressure passage groove 503, and the overpressure oil outlet 502 is in the spring static state. The bottom is located at the overpressure closed circuit groove 504 (in the state of Figure 2), and at the overpressure passage groove 503 when the spring is compressed. With reference to Figure 2, when the piston rod is pushed and moved upward, the spring is compressed. The overpressure passage groove 503 located below communicates with the overpressure oil outlet hole 502, so that the overpressure oil injection hole 501 and the overpressure oil outlet hole 502 are both connected with the overpressure passage groove 503, thereby forming an oil passage; continue to refer to In Fig. 2, both sides of the side wall of the pressure-deficient control pilot valve 6 are correspondingly provided with a pressure-deficient oil injection, 601 and a pressure-deficient oil outlet 602. The piston rod of the pressure-deficient control pilot valve is provided with two annular grooves, respectively Is the pressure-deficient passage groove 603 and the pressure-deficient closed-circuit groove 604, the pressure-deficient oil outlet 602 is always located at the pressure-deficient passage groove 603, and the pressure-deficient oil injection hole 604 is in the compressed state of the spring (as shown in Figure 2 In the shown state) is located at the pressure-deficient closed-circuit groove 604, and is located at the groove 603 of the pressure-deficient passage when the spring returns to a static state. With reference to Figure 2, when the piston rod moves downward under the action of the spring's resilience, the elastic potential energy of the spring Is released. At this time, the upper pressure-deficient passage groove 603 moves downward and communicates with the oil injection hole 601, so that the pressure-deficient oil injection hole 601 and the oil outlet 602 are all connected with the pressure-deficient passage groove 603 to form oil. 1, the overpressure oil injection hole 501 and the oil storage tank 3 are connected through the overpressure control pilot valve oil injection pipeline 7, the underpressure oil injection hole 601 and the oil storage tank 3 are controlled by pressure loss The pilot valve oil injection pipe 8 is connected, the overpressure oil outlet 502 and the oil storage tank 3 are communicated through an overpressure oil return pipe 9, and the underpressure oil outlet 602 and the oil storage tank 3 are communicated through a underpressure oil return pipe The circuit 10 is connected, the overpressure control pilot valve oiling pipe 7 is connected in parallel with the deficient pressure control pilot valve oiling pipe 8, and after being connected in parallel, it is connected in parallel with the actuator oiling pipe 4 to form the oiling main pipe 11. The overpressure oil return pipeline 9 and the underpressure oil return pipeline 10 are connected in parallel.

In this embodiment, it is further preferred that the overpressure control pilot valve and the underpressure control pilot valve are respectively provided with a spring pretension regulator, and the spring pretension regulator includes a spring connection block 12, and the spring connection block A bolt hole is opened on the upper side, and further includes a spring pre-tension adjusting bolt 13, the spring pre-tension adjusting bolt is installed in the bolt hole, the spring connecting block is located in the piston housing, and the spring pre-tension adjusting bolt is exposed outside the piston housing in vitro.

At the same time, as shown in FIG. 1, the main oil supply pipeline 11 is also provided with a pressure relief bypass 14. The pressure relief bypass has one end connected to the oil storage tank 3, and the other end is connected to the pressure relief pipe of the main oil supply pipeline. It is formed that a pressure relief valve 15 is also provided on the pressure relief pipe.

As shown in Figures 1 to 4, the single-acting actuator is a fork-type single-acting actuator. With particular reference to Figure 1, we see that the fork-pulling single-acting actuator includes a piston rod 201, a fork-pulling mechanism 202, a spring 203, and an outer shell 204. One end of the fork-pulling mechanism is fixed by a shaft, as shown in Figure 1. At point A, the shaft is fixed in the outer shell, and the other end of the fork pulling mechanism is fixed on the piston rod, as shown in point B in Figure 1. One end of the piston rod is fixed to the inside of the outer shell by a spring, and the other end of the piston rod is connected to the shell The piston cavity 205 is formed in cooperation. Since the piston cavity is full of oil in a static state, pressure is generated on the spring to make it in a compressed state, and the fork pulling mechanism is in the first position (that is, the switch valve is open position). When the trigger condition is met, the oil return circuit is blocked. When opening, the oil in the piston cavity returns to the oil cylinder, the pressure on the spring disappears, the spring returns to a non-compressed state due to its own restoring force, and the fork pulling mechanism rotates to the second position (ie, the on-off valve closed position).

In this embodiment, we further disclose a preferred technical solution, which also includes a manual pressure test pump. The manual pressure test pump includes a pressure test oil drum 1701 and a pressure test handle 1702. The pressure test oil drum passes The connecting rod 1703 is connected with a pressure test handle. One end of the pressure test handle is fixed, and the other end rotates around the fixed point as an axis. A check valve 16 is also provided at the outlet of the manual pressure test pump.

In this embodiment, we further disclose a natural gas wellhead emergency shut-off device equipped with the aforementioned device that can quickly and automatically shut down. As shown in Figures 1 to 4, the switch valve 1 is installed on the natural gas pipeline and is located on the switch. The upstream of the valve is the upstream pipeline 18, and the downstream of the on-off valve is the downstream pipeline 19. The upstream pipeline communicates with the overpressure control pilot valve 5 and the underpressure control pilot valve 6 through the first sampling pipeline 20 and the second sampling pipeline 21, respectively. .

It is further preferred that in a preferred technical solution, the first sampling line 20 and the second sampling line 21 are further provided with a first manual shut-off valve 22 and a second manual shut-off valve 23, respectively.

Hereinafter, we will explain how the device disclosed in the present invention can quickly cut off the on-off valve under overpressure and underpressure conditions in conjunction with Figure 1, Figure 3, and Figure 4.

First of all, Figure 1 shows the position of each component of the device under normal system pressure. We see that in this state, the overpressure control pilot valve and the underpressure control pilot valve are both in a closed state, that is, a cut-off state, and the spring in the single-acting actuator is compressed due to the action of hydraulic oil. Energy storage state, at this time the on-off valve is in the open state, natural gas flows into the downstream pipeline through the on-off valve through the upstream pipeline, and the entire system operates normally.

Then we refer to Figure 3 to illustrate how to achieve rapid cut-off in overpressure conditions. As shown in Figure 3, when the pressure in the upstream pipeline is higher than the set high pressure threshold, the pressure pushes the piston in the overpressure control pilot valve to move upward. As mentioned above, the spring is compressed in this state. The overpressure passage groove located below communicates with the overpressure oil outlet hole, so that the overpressure oil injection hole and the overpressure oil outlet hole are all connected with the overpressure passage groove, so that the oil passage is conducted, and the piston chamber of the single-acting actuator The hydraulic oil inside flows back to the cylinder through the oil path. At the same time, since the hydraulic oil in the piston cavity flows back to the reservoir through the path, its force on the spring disappears, and the spring is compressed from compression under the action of the restoring force. When the state is released, the piston rod moves to the right, and the fork pulling mechanism is rotated by 90°, so that the on-off valve is switched to the closed state, and the purpose of rapid shut-off is realized.

Then we refer to Figure 4 to illustrate how to achieve rapid cut-off in the depressed condition. As shown in Figure 4, when the pressure in the upstream pipeline is lower than the set low pressure threshold, the balance between the pressure and the spring in the pressure loss control piston is broken, and the spring pushes the piston down under the action of the restoring force , As shown above, in this state, the upper pressure-deficient passage groove moves downward and communicates with the oil injection hole, so that the pressure-deficient oil injection hole and the pressure-deficient oil outlet are all connected with the pressure-deficient passage groove, so that the oil The hydraulic oil in the piston chamber of the single-acting actuator flows back to the oil storage tank through the oil path. At the same time, because the hydraulic oil in the piston chamber flows back to the oil storage tank through the passage, it has an impact on the spring. The force disappears, the spring is released from the compressed state under the action of the restoring force, and the piston rod moves to the right accordingly, and the fork pulling mechanism rotates 90°, so that the on-off valve is switched to the closed state, realizing the purpose of rapid shut-off.

When the pressure returns to the normal range, only the hydraulic oil in the oil storage tank needs to be re-injected into the piston cavity of the single-acting actuator through the manual pressure test pump, and the whole device can be restored to the state shown in Figure 1.

The whole process is not only fast, but also easy to recover, without changing accessories.

The above are the specific embodiments of the present invention. It should be pointed out that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and modifications can be made, and these improvements and modifications are also regarded as the protection scope of the present invention.

Claims (7)

The device capable of quickly closing automatically is characterized in that: the device includes an on-off valve, a single-acting actuator for controlling the on-off valve, the single-acting actuator is a single-acting actuator controlled by hydraulic oil, and also includes an oil storage tank, so The piston chamber of the single-acting actuator is communicated with the oil storage tank through the oil injection pipeline of the actuator, and also includes an overpressure control pilot valve and a depletion control pilot valve. The overpressure control pilot valve is provided on both sides of the side wall correspondingly There are an overpressure oil injection hole and an overpressure oil outlet. The piston rod of the overpressure control pilot valve is provided with two annular grooves, namely an overpressure passage groove and an overpressure closed circuit groove. The overpressure oil injection hole ( (Or overpressure oil outlet) is always located at the groove of the overpressure passage. The overpressure oil outlet (post-overpressure oil injection hole) is located at the overpressure closed circuit groove when the spring is at rest, and is located at the overpressure closed circuit groove when the spring is compressed. At the overpressure passage groove; both sides of the side wall of the pressure-deficient control pilot valve are correspondingly provided with a pressure-deficient oil injection hole and a pressure-deficient oil outlet; the piston rod of the pressure-deficiency control pilot valve is provided with two annular grooves, Respectively, there are a pressure-deficient passage groove and a pressure-deficient closed-circuit groove. The pressure-deficient oil outlet (or pressure-deficient oil injection hole) is always located at the groove of the pressure-deficient passage. ) When the spring is compressed, it is located at the recess of the pressure-deficient closed circuit, and when the spring returns to a static state, it is located at the recess of the pressure-deficient passage; , The under-pressure oil injection hole is communicated with the oil storage tank through a pressure-deficient control pilot valve oil injection pipeline, the overpressure oil outlet is communicated with the oil storage tank through an overpressure oil return pipeline, and the underpressure oil outlet is It communicates with the oil storage tank through a pressure-deficient return pipeline, the overpressure control pilot valve oiling pipeline and the pressure-deficient control pilot valve oiling pipeline are connected in parallel, and after they are connected in parallel, they are then connected in parallel with the actuator oil injection pipeline An oil injection main pipeline is formed, and the overpressure oil return pipeline is connected in parallel with the underpressure oil return pipeline. The device that can quickly and automatically close according to claim 1, wherein the overpressure control pilot valve and the underpressure control pilot valve are respectively provided with a spring preload regulator, and the spring preload regulator comprises The spring connecting block is provided with a bolt hole, and further includes a spring preload adjusting bolt, the spring preload adjusting bolt is installed in the bolt hole, the spring connecting block is located in the piston housing, and the spring The pre-tightening adjustment bolt is exposed outside the piston housing. The device that can quickly and automatically close according to claim 1, characterized in that: a pressure relief bypass is further provided on the oil supply main pipeline, and the pressure relief bypass is connected to the oil storage tank at one end and the other end to the oil supply main pipe. The pressure relief pipe of the road is formed, and the pressure relief pipe is also provided with a pressure relief valve. The device that can quickly and automatically close according to any one of claims 1 to 3, wherein the single-acting actuator is a fork-type single-acting actuator. The device that can quickly and automatically close according to any one of claims 1-3, characterized in that it further comprises a manual pressure test pump, the manual pressure test pump comprising a pressure test oil drum, a pressure test handle, and The pressure test oil drum is connected with the pressure test handle through a connecting rod. One end of the pressure test handle is fixed, and the other end rotates around the fixed point as an axis. The outlet of the manual pressure test pump is also provided with a one-way valve. A natural gas wellhead emergency shut-off device equipped with the device that can be quickly and automatically closed according to any one of claims 1-5, characterized in that: the switch valve device is on the natural gas pipeline, and the upstream pipeline is located upstream of the switch valve. Downstream of the on-off valve is a downstream pipeline, and the upstream pipeline communicates with the overpressure control pilot valve and the underpressure control pilot valve through the first sampling pipeline and the second sampling pipeline, respectively. The natural gas wellhead emergency shut-off device with a device that can quickly and automatically shut down according to claim 6, characterized in that: the first sampling pipeline and the second sampling pipeline are further provided with a first manual shut-off valve and a second manual shut-off valve, respectively. Manual shut-off valve.

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