CN211820897U - Device capable of being quickly and automatically closed and natural gas wellhead emergency cut-off device - Google Patents

Abstract

The utility model relates to a but quick automatic closing valve's device when trigger condition belongs to safety guarantee technical field. The invention effectively avoids the replacing process of the blasting needle by using the technical means of overpressure control pilot valve, pressure loss control pilot valve, oil circuit design and the like and by using the motion of the piston, thereby not only saving the material cost, but also saving the time cost. In addition, the acting force of the medium pressure on the overpressure control pilot valve and the pressure loss control pilot valve is directly utilized to realize overpressure triggering and pressure loss triggering, other converters are not needed, and the method is more direct and sensitive and has higher reaction speed. Simultaneously the utility model discloses can utilize spring pretension regulator in the spring department of superpressure control pilot valve and insufficient pressure control pilot valve, consequently can make more convenient, accurate to the threshold value control of superpressure and insufficient pressure.

Description

Device capable of being quickly and automatically closed and natural gas wellhead emergency cut-off device

Technical Field

The invention relates to a device capable of quickly and automatically closing a valve under a trigger condition, in particular to a device capable of quickly and automatically closing and a natural gas wellhead emergency cut-off device, and belongs to the technical field of safety guarantee.

Background

Because gas or liquid can have pressure changes during the conveying process, the whole conveying process has safety hazards. Therefore, in general, a device is provided in each of the pipes to control the flow of gas or liquid, thereby preventing a safety accident caused by a change in pressure in the pipe. It is common practice to provide these devices with actuators to enable quick and sensitive closing operations of the devices.

For example, in the construction of natural gas production works, it is common to provide such pressure-sensitive devices that can be quickly and urgently shut off when the pressure exceeds a set range. When the pressure of the medium at the wellhead exceeds a preset high-pressure limit value, the device can be quickly and automatically closed, and downstream equipment is prevented from being damaged due to pressure overload; meanwhile, when the pressure of the medium at the wellhead is lower than a preset low-pressure limit value, the device can be automatically closed quickly, and the device for placing the system is damaged.

The inventor of the present invention discloses a natural gas wellhead emergency cut-off device in CN 207246497U. In the patent, a blasting needle is used as a trigger element, so that a gas passage of a natural gas wellhead can be cut off with high precision and high speed.

However, during use, we have found that this device still suffers from disadvantages, such as the fact that the lancet, which is the trigger element, is damaged during triggering, which results in no way to repeat its use many times, and that the lancet must be replaced after triggering of the device to be reset, which not only increases the cost of consumables, but also increases the time cost of resetting. Meanwhile, as a gas-liquid conversion system is required in the design, the whole structure is complex and the cost is relatively high.

Therefore, how to solve the problems actually generated in the application and to provide a more optimized design and solution is the direction of the continuous research efforts of the present inventors.

Disclosure of Invention

The invention aims to find a new technical scheme, which can optimize a resetting link and reduce the cost of consumables and time for resetting after triggering.

In order to achieve the purpose, the invention discloses a device which is suitable for the emergency cut-off of a natural gas wellhead and can be quickly and automatically closed, the device comprises a switch valve, a single-action actuating mechanism used for controlling the switch valve, the single-action actuating mechanism is a hydraulic oil control single-action actuating mechanism, the device also comprises an oil storage tank, a piston cavity of the single-action actuating mechanism is communicated with the oil storage tank through an actuating mechanism oil injection pipeline, the device also comprises an overpressure control pilot valve and a pressure loss control pilot valve, overpressure oil injection holes and overpressure oil outlet holes are correspondingly arranged on two sides of the side wall of the overpressure control pilot valve, two annular grooves are arranged on a piston rod of the overpressure control pilot valve and are respectively an overpressure passage groove and an overpressure closed groove, the oil injection holes (or the overpressure oil outlet holes) are always positioned at the overpressure passage groove, and the overpressure oil outlet holes (rear overpressure oil injection holes) are positioned at the overpressure closed groove under the static state, at the overpressure passage groove in a compressed state of the spring; the two 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, a piston rod of the pressure-deficient control pilot valve is provided with two annular grooves which are a pressure-deficient passage groove and a pressure-deficient closed-circuit groove respectively, the pressure-deficient oil outlet (or pressure-deficient oil injection hole) is always positioned at the pressure-deficient passage groove, the pressure-deficient oil injection hole (or pressure-deficient oil outlet) is positioned at the pressure-deficient closed-circuit groove under the state that a spring is compressed, and is positioned at the pressure-deficient passage groove under the state that the spring returns to a static state; the oil injection device is characterized in that the overpressure oil injection hole is communicated with the oil storage tank through an overpressure control pilot valve oil injection pipeline, the pressure loss oil injection hole is communicated with the oil storage tank through a pressure loss control pilot valve oil injection pipeline, the overpressure oil outlet hole is communicated with the oil storage tank through an overpressure oil return pipeline, the pressure loss oil injection hole is communicated with the oil storage tank through a pressure loss oil return pipeline, the overpressure control pilot valve oil injection pipeline is connected with the pressure loss control pilot valve oil injection pipeline in parallel, and after the overpressure control pilot valve oil injection pipeline is connected in parallel, the overpressure control pilot valve oil injection pipeline is connected with the pressure loss control pilot valve oil injection pipeline in parallel to form a main pipeline, and the overpressure oil return pipeline is connected with the pressure loss.

Preferably, the overpressure control pilot valve and the pressure loss control pilot valve are respectively provided with a spring pre-tightening regulator, the spring pre-tightening regulator comprises a spring connecting block, the spring connecting block is provided with a bolt hole, the spring pre-tightening regulating valve further comprises a spring pre-tightening regulating bolt, the spring pre-tightening regulating bolt is arranged in the bolt hole, the spring connecting block is located in the piston shell, and the spring pre-tightening regulating bolt is exposed outside the piston shell.

Further preferably, a pressure relief bypass is further arranged on the oil supply main pipeline, the pressure relief bypass is formed by connecting one end of the pressure relief bypass with the oil storage tank and communicating the other end of the pressure relief bypass with the oil supply main pipeline, and a pressure relief valve is further arranged on the pressure relief pipe.

In a preferred embodiment, the single-acting actuator is a fork-lift single-acting actuator.

In addition, in a preferred technical scheme, still including manual pressure testing pump, manual pressure testing pump includes pressure testing oil drum, pressure testing handle, the pressure testing oil drum passes through the connecting rod and is connected with pressure testing handle, pressure testing handle one end is fixed, and the other end uses this fixed point to rotate as the axle center, and manual pressure testing pump's exit still is provided with the check valve.

The oil storage tank is provided with the natural gas wellhead emergency cut-off device which is provided with the device capable of being quickly and automatically closed, the switching valve device is arranged on a natural gas pipeline, an upstream pipeline is arranged at the upstream of the switching valve, a downstream pipeline is arranged at the downstream of the switching valve, and the upstream pipeline is respectively communicated with the overpressure control pilot valve and the pressure loss control pilot valve through a first sampling pipeline and a second sampling pipeline.

In a preferred technical scheme, a first manual cut-off valve and a second manual cut-off valve are further arranged on the first sampling pipeline and the second sampling pipeline respectively.

The above-mentioned constructions are described here, above all, as single-acting actuators which are generally pneumatic, i.e. driven by an air supply, but in the present case are hydraulic oil-controlled single-acting actuators. The position where the hydraulic oil acts is the piston cavity of the single-acting actuator.

Specifically, the shifting fork type single-action actuating mechanism preferably used in the invention comprises a piston rod, a shifting fork mechanism, a spring and an outer shell, wherein one end of the shifting fork mechanism is fixed by a shaft, the shaft is fixed in the outer shell, the other end of the shifting fork mechanism is fixed on the piston rod, one end of the piston rod is fixed with the inner side of the outer shell through the spring, and the other end of the piston rod is matched with the shell to form a piston cavity. Because under the static state, the piston cavity is filled with oil, pressure is generated on the spring, the spring is in a compression state, the fork pulling mechanism is located at the first position (namely the opening position of the switch valve), when the triggering condition is met and the oil return oil way is opened, the oil in the piston cavity flows back to the oil cylinder, the pressure on the spring disappears, the spring returns to the non-compression state due to the self restoring force, and the fork pulling mechanism rotates and is located at the second position (namely the closing position of the switch valve).

The structure that needs to explain in addition is superpressure control pilot valve and pressure-deficient control pilot valve, and the pilot valve comprises piston rod, the piston sleeve with piston rod airtight fit, passes through the spring to be fixed to the piston sleeve inner wall at one end of piston rod, forms a piston chamber at the other end of piston rod and piston sleeve cooperation, just can realize the slip of piston rod in the piston sleeve through the size change between the pressure in the piston chamber and the spring bounce. When the side wall of the piston sleeve is provided with two through holes with different horizontal positions, the opening and closing of the piston channel can be realized by utilizing the annular groove formed on the pilot valve and combining the movement of the piston rod. It is specifically explained here that the passage is open when the through holes at different levels are simultaneously in one annular groove; when the through holes at different levels are not located in one annular groove at the same time, the passage is closed.

After the technical scheme disclosed by the invention is adopted, because the overpressure control pilot valve or the pressure loss control pilot valve moves in a piston motion process in the triggering process, when the system pressure returns to normal, the system can automatically reset to a static original position state under the action of the spring, so that the replacement process of the blasting needle is avoided, the material cost is saved, and the time cost is also saved. In addition, the acting force of the pressure of the medium on the overpressure control pilot valve and the pressure loss control pilot valve is directly utilized to realize overpressure triggering and pressure loss triggering, other converters are not needed, and the method is more direct and sensitive and has higher reaction speed. In addition, because the spring pre-tightening regulator can be used at the spring of the overpressure control pilot valve and the pressure loss control pilot valve, the threshold control of overpressure and pressure loss can be more convenient and accurate.

Drawings

Fig. 1 is a schematic view of the device capable of being automatically closed quickly in a static state when the device is installed at a natural gas wellhead.

Fig. 2 is an enlarged view of the overpressure control pilot valve and the pressure loss control pilot valve.

Fig. 3 is a schematic view of the overpressure condition of the present apparatus for rapid automatic shutoff at a natural gas wellhead.

Fig. 4 is a schematic view of the pressure loss state of the device capable of being rapidly and automatically closed installed at the opening of a natural gas well.

Detailed Description

In order that the invention may be better understood, we now provide further explanation of the invention with reference to specific examples.

As shown in fig. 1, the device capable of being automatically closed quickly and suitable for emergency shut-off of a natural gas wellhead comprises a switching valve 1, a single-acting actuator 2 for controlling the switching valve, a single-acting actuator controlled by hydraulic oil, a storage tank 3, an overpressure oil injection hole 501 and an overpressure oil outlet hole 502 which are correspondingly arranged on two sides of a side wall of the overpressure control pilot valve 5, two annular grooves which are an overpressure passage groove 503 and an overpressure closed groove 504 respectively are arranged on a piston rod of the overpressure control pilot valve, viewed from fig. 2, the overpressure oil injection hole 501 is always located at the overpressure passage groove 503, the overpressure oil outlet hole 502 is located at the overpressure closed groove 504 in a spring static state (in a state in fig. 2), when the piston rod is pushed to move upwards and the spring is compressed, the overpressure passage groove 503 positioned below is communicated with the overpressure oil outlet hole 502, so that the overpressure oil inlet hole 501 and the overpressure oil outlet hole 502 are communicated with the overpressure passage groove 503 to form an oil passage, in a state that the spring is compressed, and with reference to fig. 2, the piston rod is positioned at the overpressure passage groove 503; continuing to refer to fig. 2, the two sides of the side wall of the pressure-deficient control pilot valve 6 are correspondingly provided with pressure-deficient oil injection 601 and pressure-deficient oil outlet 602, the piston rod of the pressure-deficient control pilot valve is provided with two annular grooves, namely a pressure-deficient passage groove 603 and a pressure-deficient closed passage groove 604, the pressure-deficient oil outlet 602 is always located at the pressure-deficient passage groove 603, the pressure-deficient oil inlet 604 is located at the pressure-deficient closed passage groove 604 in a state where the spring is compressed (in a state shown in fig. 2), at the pressure loss passage groove 603 in the spring return rest state, in conjunction with fig. 2, when the piston rod moves downward under the spring resilience, the elastic potential energy of the spring is released, and at this time, the pressure loss passage groove 603 located above moves downward and communicates with the oil hole 601, therefore, the pressure-deficient oil injection hole 601 and the pressure-deficient oil outlet hole 602 are both communicated with the pressure-deficient passage groove 603 to form an oil passage; referring to fig. 1 below, the overpressure oil injection hole 501 is communicated with the oil storage tank 3 through an overpressure control pilot valve oil injection pipeline 7, the pressure loss oil injection hole 601 is communicated with the oil storage tank 3 through a pressure loss control pilot valve oil injection pipeline 8, the overpressure oil outlet hole 502 is communicated with the oil storage tank 3 through an overpressure oil return pipeline 9, the pressure loss oil injection hole 602 is communicated with the oil storage tank 3 through a pressure loss oil return pipeline 10, the overpressure control pilot valve oil injection pipeline 7 is connected in parallel with the pressure loss control pilot valve oil injection pipeline 8, and after the overpressure control pilot valve oil injection pipeline is connected in parallel, the overpressure control pilot valve oil injection pipeline 7 is connected in parallel with the actuator oil injection pipeline 4 to form an oil injection main pipeline 11, and the overpressure oil return pipeline 9 is connected in parallel with the pressure loss oil return pipeline 10.

In this embodiment, it is further preferable that the overpressure control pilot valve and the pressure-loss control pilot valve are respectively provided with a spring pre-tightening adjuster, the spring pre-tightening adjuster includes a spring connecting block 12, the spring connecting block is provided with a bolt hole, and the spring pre-tightening adjuster further includes a spring pre-tightening adjusting bolt 13, the spring pre-tightening adjusting bolt is installed in the bolt hole, the spring connecting block is located in the piston housing, and the spring pre-tightening adjusting bolt is exposed outside the piston housing.

Meanwhile, as shown in fig. 1, a pressure relief bypass 14 is further provided on the main oil supply pipeline 11, the pressure relief bypass is formed by a pressure relief pipe, one end of the pressure relief bypass is connected with the oil storage tank 3, and the other end of the pressure relief bypass is communicated to the main oil supply pipeline, and a pressure relief valve 15 is further provided on the pressure relief pipe.

As shown in fig. 1-4, the single-acting actuator is a fork-type single-acting actuator. With particular reference to fig. 1, we see that the shifting fork type single-acting actuator comprises a piston rod 201, a shifting fork mechanism 202, a spring 203 and an outer housing 204, one end of the shifting fork mechanism is fixed by a shaft, as indicated by point a in fig. 1, the shaft is fixed in the outer housing, the other end of the shifting fork mechanism is fixed on the piston rod, as indicated by point B in fig. 1, one end of the piston rod is fixed with the inner side of the outer housing by the spring, and the other end of the piston rod is matched with the housing to form a piston cavity 205. Because under the static state, the piston cavity is filled with oil, pressure is generated on the spring, the spring is in a compression state, the fork pulling mechanism is located at the first position (namely the opening position of the switch valve), when the triggering condition is met and the oil return oil way is opened, the oil in the piston cavity flows back to the oil cylinder, the pressure on the spring disappears, the spring returns to the non-compression state due to the self restoring force, and the fork pulling mechanism rotates and is located at the second position (namely the closing position of the switch valve).

In this embodiment, we have still further disclosed a preferred technical scheme, still including manual pressure testing pump, manual pressure testing pump includes pressure testing oil drum 1701, pressure testing handle 1702, pressure testing oil drum passes through connecting rod 1703 and is connected with the pressure testing handle, pressure testing handle one end is fixed, and the other end uses this fixed point to rotate as the axle center, and manual pressure testing pump's exit still is provided with check valve 16.

In the embodiment, we further disclose a natural gas wellhead emergency cut-off device with the device capable of quickly and automatically closing, as shown in fig. 1-4, a switch valve 1 is arranged on a natural gas pipeline, an upstream pipeline 18 is arranged upstream of the switch valve, and a downstream pipeline 19 is arranged downstream of the switch valve, and the upstream pipeline is communicated with an overpressure control pilot valve 5 and a pressure-loss control pilot valve 6 through a first sampling pipeline 20 and a second sampling pipeline 21 respectively.

Further preferably, in a preferred embodiment, the first sampling line 20 and the second sampling line 21 are further provided with a first manual cut-off valve 22 and a second manual cut-off valve 23, respectively.

In the following, we will explain how the device disclosed by the invention can rapidly realize the cut-off of the switch valve under the overpressure and underpressure conditions by combining fig. 1, fig. 3 and fig. 4.

First, the positions of the components of the device are shown in FIG. 1 under normal system pressure conditions. We see that in this state, both the overpressure control pilot valve and the pressure-deficient control pilot valve are in a closed-passage state, i.e. a cut-off state, and the spring in the single-acting actuator is in a compressed energy storage state due to the action of the hydraulic oil, and at this time, the switch valve is in an open state, and the natural gas flows into the downstream pipeline through the switch valve via the upstream pipeline, and the whole system operates normally.

We will then refer to fig. 3 to illustrate how a quick shut-off is achieved during overpressure conditions. As shown in fig. 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 described above, the spring is compressed in this state, and at this time, the overpressure passage groove located below is communicated with the overpressure oil outlet, so that the overpressure oil inlet and the overpressure oil outlet are both communicated with the overpressure passage groove, so that the oil passage is conducted, the hydraulic oil in the piston cavity of the single-acting actuator flows back to the oil cylinder through the oil passage, and at the same time, as the hydraulic oil in the piston cavity flows back to the oil storage tank through the passage, the acting force on the spring disappears, the spring is released from the compressed state under the restoring force, the piston rod moves rightward along with the oil passage, and the fork-pulling mechanism rotates 90 °, so that the switch valve is switched to the closed state, and the purpose.

We will then refer to fig. 4 to illustrate how a quick shut-off is achieved during a low pressure condition. As shown in fig. 4, when the pressure in the upstream line is lower than the set low pressure threshold, the balance between the pressure and the spring in the pressure-loss control piston is broken, the spring pushes the piston to move downward under the action of the restoring force, as shown, in this state, the pressure-loss passage groove located above moves downward and communicates with the oil hole, so that the pressure-loss oil injection hole and the pressure-loss oil injection hole both communicate with the pressure-loss passage groove, so that the oil passage is conducted, the hydraulic oil in the piston cavity of the single-action actuator flows back to the oil tank through the oil passage, and at the same time, as the hydraulic oil in the piston cavity flows back to the oil tank through the passage, the acting force on the spring disappears, the spring is released from the compression state under the action of the restoring force, the piston rod moves rightward therewith, and the fork-pulling mechanism rotates 90 degrees, so that the switching valve is switched to the closing state, the purpose of quick cutting is achieved.

When the pressure is recovered to a normal range, the whole device can be recovered to the state shown in the figure 1 only by injecting the hydraulic oil of the oil storage tank into the piston cavity of the single-action actuating mechanism again through the manual pressure test pump.

The whole process is not only quick, but also convenient and fast to recover, and accessories and the like do not need to be replaced.

What has been described above is a specific embodiment of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principle of the present invention, and such improvements and modifications are also considered to be within the scope of the present invention.

Claims (6)

1. Device that can fast self-closing, its characterized in that: the device comprises a switch valve, a single-action executing mechanism for controlling the switch valve, an overpressure control pilot valve and a pressure-loss control pilot valve, wherein the single-action executing mechanism is controlled by hydraulic oil, the oil storage tank is also included, a piston cavity of the single-action executing mechanism is communicated with the oil storage tank through an executing mechanism oil injection pipeline, an overpressure oil injection hole and an overpressure oil outlet hole are correspondingly arranged on two sides of the side wall of the overpressure control pilot valve, two annular grooves are arranged on a piston rod of the overpressure control pilot valve and are respectively an overpressure passage groove and an overpressure closed groove, the overpressure oil injection hole or the overpressure oil outlet hole is always positioned at the overpressure passage groove, the overpressure oil outlet hole or the back overpressure oil injection hole is positioned at the overpressure closed groove in a static state of the spring, and is positioned at the overpressure passage groove in a compressed state of the spring; the two 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 discharge hole, a piston rod of the pressure-deficient control pilot valve is provided with two annular grooves which are a pressure-deficient passage groove and a pressure-deficient closed-circuit groove respectively, the pressure-deficient oil discharge hole or the pressure-deficient oil discharge hole is always positioned at the pressure-deficient passage groove, the pressure-deficient oil injection hole or the pressure-deficient oil discharge hole is positioned at the pressure-deficient closed-circuit groove under the state that a spring is compressed, and is positioned at the pressure-deficient passage groove under the state that the spring is restored to be static; the oil injection device is characterized in that the overpressure oil injection hole is communicated with the oil storage tank through an overpressure control pilot valve oil injection pipeline, the pressure loss oil injection hole is communicated with the oil storage tank through a pressure loss control pilot valve oil injection pipeline, the overpressure oil outlet hole is communicated with the oil storage tank through an overpressure oil return pipeline, the pressure loss oil injection hole is communicated with the oil storage tank through a pressure loss oil return pipeline, the overpressure control pilot valve oil injection pipeline is connected with the pressure loss control pilot valve oil injection pipeline in parallel, and after the overpressure control pilot valve oil injection pipeline is connected in parallel, the overpressure control pilot valve oil injection pipeline is connected with the actuator oil injection pipeline in parallel to form a main oil injection pipeline, and the overpressure oil return pipeline is connected with the pressure loss oil return pipeline.

2. The device capable of being automatically and rapidly closed according to claim 1, wherein: the overpressure control pilot valve and the pressure loss control pilot valve are respectively provided with a spring pre-tightening regulator, the spring pre-tightening regulator comprises a spring connecting block, a bolt hole is formed in the spring connecting block, the spring pre-tightening regulating device further comprises a spring pre-tightening regulating bolt, the spring pre-tightening regulating bolt is arranged in the bolt hole, the spring connecting block is located in the piston shell, and the spring pre-tightening regulating bolt is exposed outside the piston shell.

3. A device that can be automatically and rapidly closed according to any one of claims 1-2, wherein: the single-action actuating mechanism is a shifting fork type single-action actuating mechanism.

4. A device that can be automatically and rapidly closed according to any one of claims 1-2, wherein: still including manual pressure testing pump, manual pressure testing pump includes pressure testing oil drum, pressure testing handle, the pressure testing oil drum passes through the connecting rod and is connected with the pressure testing handle, pressure testing handle one end is fixed, and the other end uses this fixed point to rotate as the axle center, manual pressure testing pump's exit still is provided with the check valve.

5. A natural gas wellhead emergency shut-off device equipped with the device capable of rapid automatic closing according to any one of claims 1 to 4, characterized in that: the switching valve device is arranged on the natural gas pipeline, an upstream pipeline is positioned on the upstream of the switching valve, a downstream pipeline is positioned on the downstream of the switching valve, and the upstream pipeline is respectively communicated with the overpressure control pilot valve and the pressure-loss control pilot valve through a first sampling pipeline and a second sampling pipeline.

6. A natural gas wellhead emergency shut-off device according to claim 5, characterized in that: and the first sampling pipeline and the second sampling pipeline are respectively provided with a first manual cut-off valve and a second manual cut-off valve.

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