Pneumatic Valve Detection System and Pneumatic Valve Detection Method

Abstract

The present invention discloses a pneumatic valve detection system and a pneumatic valve detection method. The pneumatic valve detection system includes a coupling, a support plate, a power device, a pressure sensor, and a displacement sensor. The pneumatic valve detection system has a first detection mode and a second detection mode. When in the first detection mode, the support plate is installed on the valve stem, and the power device drives the support plate to move to drive the valve stem and the pneumatic rod to reciprocate axially together, and the pressure sensor is used to detect the pressure value. When in the second detection mode, the support plate is installed on the valve stem, and the power device drives the support plate to move to drive the valve stem to reciprocate axially, and the pressure sensor is used to detect the pressure value. This pneumatic valve detection system operates efficiently. It directly acts on the valve stem rather than the pneumatic head of the valve body and does not take the force balance during the spool process as the calculation basis. Therefore, there is no requirement for the valve test action to be uniform, which greatly improves the accuracy of the force value, is beneficial to improving the maintenance quality, and improves the safety performance of the equipment.

Description

Technical Field

[0001] The present invention relates to the technical field of valve detection, and particularly to a pneumatic valve detection system and a pneumatic valve detection method. Background Art

[0002] At present, each power plant uses a pneumatic two-position valve diagnostic test system in the field of pneumatic valve maintenance. Using the power plant air source, the air pressure entering the diaphragm air chamber of the valve to be tested is controlled through an air supply control system to provide power for the valve and manipulate the valve to open and close as required. During this process, through relevant sensors installed on the valve and image point taking to obtain the target force value, the air pressure value of the valve diaphragm air chamber, the displacement of the valve stem movement, and the stress parameters on the valve stem are measured, and then the performance parameters related to the valve to be tested are calculated by a computer to provide a basis for valve maintenance.

[0003] At present, the related technology provides force for the valve opening and closing actions through air supply, and measures parameters such as force and displacement during the process to obtain a displacement-force curve graph. The target force value is obtained through image point taking and is for post-analysis. Its force value is obtained based on the mechanical equilibrium condition. Since it is difficult to ensure that the valve opening and closing process is a uniform motion during the air supply process, the force value will be distorted, ultimately affecting the maintenance quality of the valve. Summary of the Invention

[0004] The technical problem to be solved by the present invention is the technical problem that the existing pneumatic valve detection is difficult to ensure that the valve opening and closing process is a uniform motion, which easily leads to distortion of the detected force value and affects the maintenance quality of the valve. The present invention provides a pneumatic valve detection system and a pneumatic valve detection method.

[0005] The technical solution adopted by the present invention to solve its technical problem is: to provide a pneumatic valve detection system. The pneumatic valve includes a yoke, a pneumatic rod, a valve stem, a valve body, and an actuator; the pneumatic rod and the valve stem pass through the yoke and are coaxially arranged; the actuator is connected to the upper end of the yoke, and the actuator includes a disc spring; a valve core for sealing the passage of the valve body is provided at the lower end of the valve stem. The pneumatic valve detection system is characterized in that it includes:

[0006] A coupling for connecting the pneumatic rod and the valve stem in the first detection mode;

[0007] A support plate for being installed on the pneumatic rod or the valve stem;

[0008] A power device for connecting with the support plate to drive the support plate to drive the pneumatic rod and / or the valve stem to axially move;

[0009] A pressure sensor provided between the power device and the yoke to detect the pressure value between the power device and the valve stem;

[0010] A displacement sensor for collecting the displacement and time parameters of the valve stem;

[0011] Wherein, the pneumatic valve detection system has a first detection mode and a second detection mode; when in the first detection mode, the support plate is mounted on the valve stem and abuts against the lower end of the coupling, and the power device drives the support plate to move to drive the valve stem and the pneumatic rod to move axially upward together, and the pressure sensor is used to detect the pressure value of the power device in the first detection mode;

[0012] When in the second detection mode, the support plate is mounted on the valve stem, the power device drives the support plate to drive the valve stem to axially rise towards the pneumatic rod and then release the pressure, and the valve stem moves axially downward away from the pneumatic rod, and the pressure sensor is used to detect the pressure value of the power device in the second detection mode.

[0013] In some embodiments, the pneumatic valve detection system has a third detection mode; the coupling is also used to connect the pneumatic rod and the valve stem in the third detection mode;

[0014] When in the third detection mode, the support plate is mounted on the pneumatic rod, above the coupling, and is connected to the power device, and the power device is also used to apply a quantitative closing and sealing force to the support plate to drive the support plate to move so that the valve stem and the pneumatic rod move axially downward together, and the pressure sensor is used to detect the pressure value of the power device in the third detection mode.

[0015] In some embodiments, the number of the power devices is at least two, and at least two of the power devices are uniformly arranged around the valve stem in the circumferential direction.

[0016] In some embodiments, the support plate has a through hole so that the support plate can be slidably sleeved on the outer periphery of the valve stem, and the pneumatic valve detection system further includes a contact plate fixedly mounted on the valve stem and above the support plate in the second detection mode so that the power device can drive the valve stem to move axially upward.

[0017] In some embodiments, the pneumatic valve detection system further includes a host computer, and the host computer is connected to the pressure sensor and the displacement sensor.

[0018] The present invention also discloses a pneumatic valve detection method, which is applied to the pneumatic valve detection system described in any one of the above embodiments, and is characterized in that it includes the following steps:

[0019] In the first detection mode, connect the coupling between the valve stem and the pneumatic rod. Install the support plate on the valve stem and make it abut against the lower end of the coupling. Start the power device, and the power device applies a force towards the pneumatic rod to the support plate; when the valve stem just starts to move in the stable state, obtain the first force value of the power device;

[0020] When the pneumatic valve is in the fully open state and the valve stem is in the stable state, obtain the second force value of the power device;

[0021] Slowly release the force of the power device. At the same time, the pneumatic rod and the valve stem slowly fall downward under the action of the upper disc spring; when the pneumatic valve is just in the closed state, obtain the third force value of the power device;

[0022] According to the first force value, the second force value and the third force value, calculate the overall friction resistance of the pneumatic valve, the minimum value of the disc spring and the maximum value of the disc spring;

[0023] In the second detection mode, disassemble the coupling from between the pneumatic rod and the valve stem. Start the power device, and the power device applies a force towards the pneumatic rod to the support plate; when the valve stem and the pneumatic rod are in the non-contact stable state, obtain the fourth force value of the power device;

[0024] The power device continues to drive the valve stem to move upward until the valve stem just does not contact the pneumatic rod; slowly release the force of the power device so that the valve stem slowly falls downward under the downward acting force applied by the power device; when the pneumatic valve is just closed and the valve stem and the pneumatic rod are in the non-contact stable state, obtain the fifth force value of the power device;

[0025] According to the fourth force value, the fifth force value and the overall friction resistance of the valve, calculate the packing friction force and the actuator resistance of the pneumatic valve.

[0026] In some embodiments, the pneumatic valve detection method further includes the following steps:

[0027] In the third detection mode, connect the coupling between the valve stem and the pneumatic rod. Install the support plate on the pneumatic rod and connect it to the coupling. Start the power device, and the power device applies a quantitative closing sealing force towards the valve stem to the support plate.

[0028] In some embodiments, the calculation formula for the overall friction resistance of the valve is:

[0029] f = (F1 - F1') / 2;

[0030] The calculation formula for the small value of the disc spring is as follows:

[0031] D1 = F1 - f;

[0032] The calculation formula for the large value of the disc spring is as follows:

[0033] D2 = F2 - f;

[0034] Wherein, f is the overall frictional resistance of the valve; D1 is the small value of the disc spring; D2 is the large value of the disc spring; F1 is the first force value; F2 is the second force value; F1' is the third force value.

[0035] In some embodiments, the calculation formula for the packing friction is as follows:

[0036] Q = (F3 - F3') / 2;

[0037] The calculation formula for the actuator resistance is as follows:

[0038] f1 = f - Q;

[0039] Wherein, Q is the packing friction; f1 is the actuator resistance; F3 is the fourth force value; F3' is the fifth force value.

[0040] In some embodiments, in the first detection mode, according to the first force value, the standard pressure difference resistance, the standard actuator resistance and the standard packing resistance, calculate K according to the following relational formula, and judge whether the margin of the first force value meets the operation and design requirements of the pneumatic valve according to whether K is within the qualified range:

[0041] K = (D1’ - F4 - f1 - Q) / F1;

[0042] Wherein, D1’ is the standard small value of the disc spring of the valve, F4 is the standard pressure difference resistance; f1 is the above-mentioned actuator resistance, Q is the above-mentioned packing friction; when 0 < K ≤ 1, it means that the margin of the first force value meets the design requirements.

[0043] Implementing the present invention has the following beneficial effects: The pneumatic valve detection system operates efficiently. It directly acts on the valve stem rather than the pneumatic head of the valve body, and does not take the force balance during the spool process as the calculation basis. Therefore, there is no requirement for the valve test action to be uniform, which greatly improves the force value accuracy, is beneficial to improving the maintenance quality, and improves the equipment safety performance. Brief Description of the Drawings

[0044] To more clearly illustrate the technical solution of the present invention, the present invention will be further described below in conjunction with the accompanying drawings and embodiments. It should be understood that the following drawings only show some embodiments of the present invention, and thus should not be regarded as limiting the scope. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings. In the drawings:

[0045] Figure 1 is a schematic structural diagram of the pneumatic valve detection system in the first detection mode in some embodiments of the present invention;

[0046] Figure 2 is a schematic structural diagram of the pneumatic valve detection system in the second detection mode in some embodiments of the present invention;

[0047] Figure 3 is a schematic structural diagram of the pneumatic valve detection system in the second detection mode in some other embodiments of the present invention;

[0048] Figure 4 is a schematic structural diagram of the pneumatic valve detection system in the third detection mode in some embodiments of the present invention. Detailed Embodiments

[0049] To have a clearer understanding of the technical features, objectives, and effects of the present invention, the detailed embodiments of the present invention will now be described in detail with reference to the accompanying drawings. In the following description, it should be understood that the orientation or positional relationships indicated by "front", "rear", "upper", "lower", "left", "right", "longitudinal", "transverse", "vertical", "horizontal", "top", "bottom", "inner", "outer", "head", "tail", etc. are based on the orientation or positional relationships shown in the drawings and are specific to the orientation structure and operation. This is only for the convenience of describing the technical solution and does not indicate that the indicated device or element must have a specific orientation. Therefore, it should not be construed as a limitation to the present invention.

[0050] It should also be noted that, unless otherwise clearly specified and defined, terms such as "installation", "connection", "attachment", "fixation", "setting" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components or the interaction relationship between two components. When a component is referred to as "above" or "below" another component, the component can be "directly" or "indirectly" located above the other component, or there may also be one or more intermediate components. Terms such as "first", "second", "third", etc. are only for the convenience of describing the technical solution of the present invention, and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, features defined with "first", "second", "third", etc. can explicitly or implicitly include one or more of such features. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0051] In the following description, for the purpose of illustration rather than limitation, specific details such as specific system structures, technologies, etc. are proposed to thoroughly understand the embodiments of the present invention. However, those skilled in the art should clearly understand that the present invention can also be implemented in other embodiments without these specific details. In other cases, the detailed descriptions of well-known systems, devices, circuits, and methods are omitted to avoid unnecessary details from interfering with the description of the present invention.

[0052] Please refer to Figures 1 to 2 , the present invention shows a pneumatic valve detection system 4. The pneumatic valve includes a yoke 1, a pneumatic rod 2, a valve stem 3, a valve body, and an actuator; the pneumatic rod 2 and the valve stem 3 pass through the yoke 1 and are coaxially arranged; the actuator is connected to the upper end of the yoke 1, and the actuator includes a disc spring; the lower end of the valve stem 3 is provided with a valve core for sealing the passage of the valve body. The pneumatic valve detection system 4 includes:

[0053] A coupling 41, which is used to connect the pneumatic rod 2 and the valve stem 3 in the first detection mode;

[0054] A support plate 42, which is used to be installed on the pneumatic rod 2 or the valve stem 3 and is used to drive the pneumatic rod 2 and / or the valve stem 3 to move. Among them, the support plate 42 can be fixedly connected to the pneumatic rod 2 or the valve stem 3 by itself, or can be slidably arranged on the pneumatic rod 2 or the valve stem 3 by itself and realize the common movement with the pneumatic rod 2 or the valve stem 3 through the cooperation of other limiting structures.

[0055] For example, the support plate 42 has through holes so that the support plate 42 can be slidably sleeved on the outer periphery of the valve stem 3 or the pneumatic rod 2, and can be used to abut against the coupling 41 together, so as to drive the valve stem 3 and / or the pneumatic rod 2 to move axially under the action of the power device 44. Wherein, when the coupling 41 is installed between the pneumatic rod 2 and the valve stem 3, the outer diameter of the coupling 41 is greater than the inner diameter of the through hole on the support plate 42, and the coupling 41 forms a limit and resistance against one side of the support plate 42 facing the pneumatic rod 2, or the coupling 41 forms a limit and resistance against one side of the support plate 42 facing the valve stem 3. Therefore, when an upward force is applied to the support plate 42, the support plate 42 can drive the valve stem 3 to move upward, or when a downward force is applied to the support plate 42, the support plate 42 can drive the pneumatic rod 2 to move downward.

[0056] For example, the support plate 42 is sleeved on the valve stem 3, and the coupling 41 is installed between the pneumatic rod 2 and the valve stem 3. At this time, by connecting the power device 44 to the lower surface of the support plate 42, an upward force can be applied to the support plate 42. The power device 44 can drive the support plate 42 to move and can make the support plate 42 abut against the lower end of the coupling 41 to drive the valve stem 3 to move upward.

[0057] Again, for example, the support plate 42 is sleeved on the pneumatic rod 2, and the coupling 41 is installed between the pneumatic rod 2 and the valve stem 3. At this time, by connecting the power device 44 to the lower surface of the support plate 42, a downward force can be applied to the support plate 42.

[0058] Preferably, the through hole of the support plate 42 can be larger than the outer diameters of the valve stem 3 and the pneumatic rod 2, so that the support plate 42 can be conveniently installed on the valve stem 3 and the pneumatic rod 3.

[0059] Preferably, the support plate 42 can be two semi-cylindrical bodies, and their openings are connected opposite to each other, and can be fixed by means of bolt connection or snap connection.

[0060] As Figure 3 shown, preferably, in some embodiments, the pneumatic valve detection system 4 can also include a contact plate 43 fixedly installed on the valve stem 3 and located above the support plate 42 in the second detection mode, so that the power device 44 can drive the valve stem 3 to move axially upward.

[0061] Preferably, the contact plate 43 can be detachably and fixedly installed on the valve stem 3. When the support plate 42 is sleeved on the outer periphery of the valve stem 3, it can move along the valve stem 3 and be connected to the contact plate 43. The contact plate 43 forms a limit on the upward movement of the support plate 42. And at this time, the support plate 42 can have a certain automatic adjustment function, can stably abut against the contact plate 43, and avoid uneven forces indirectly acting on the valve stem 3 by the power devices 44 on both sides.

[0062] Preferably, the abutting plate 43 can be two semi - ring structures, which are sleeved and fixed on one end of the valve stem 3 close to the pneumatic rod 2 by means of threaded connection or snap - connection, or installed on one side of the pneumatic rod 2 close to the valve stem 3.

[0063] The power device 44 is used to connect with the support plate 42 or the abutting plate 43 to drive the support plate 42 to drive the valve stem 3 to axially move; preferably, the number of the power devices 44 is at least two, and at least two power devices 44 are evenly arranged around the valve stem 3 in the circumferential direction, which can make the valve stem 3 move axially evenly. The power device 44 can be, including but not limited to, a hydraulic drive device or an electric device.

[0064] In addition, by arranging two or more power devices 44 evenly distributed in the circumferential direction, when the support plate 42 moves, in the case where the output actions of different power devices 44 are not synchronized, the support plate 42 has a certain automatic adjustment function, so that the support plate 42 can be more smoothly abutted against the coupling 41 and apply force to the valve stem 3 in a multi - point balanced manner.

[0065] Preferably, the power device 44 can include a hydraulic cylinder 441, a hydraulic rod 442, an oil circuit 443, an oil tank 444, an oil pump 445, a distributor 446 and a pressure relief valve 447.

[0066] Among them, the hydraulic cylinder 441 can be installed on the inner circumference of the yoke 1, the hydraulic rod 442 is telescopically installed in the hydraulic cylinder 441, and one end of the hydraulic rod 442 can be connected to the support plate 42, and the connection here is correspondingly butt - joint, bonding, snap - connection or threaded connection, etc. according to the specific detection mode. For example, in the first detection mode, one end of the hydraulic rod 442 is butted against the support plate 42, because during the falling process of the first detection mode, the power device 44 does not require the support plate 42 to apply pressure, and the valve stem 3 and the like need to automatically fall under the elastic force of the disc spring above the pneumatic rod 2. In the second detection mode, the power device 44 needs to be fixedly connected to the lower end of the support plate 42 (such as bonding, snap - connection, threaded connection, etc.), because during the falling process of the second detection mode, the force of the disc spring will not be applied to the valve stem 3.

[0067] One end of each oil circuit 443 is connected to the driving space of the hydraulic cylinder 444, the other end is connected to the distributor 446, the distributor 446 is connected to the oil tank 444 through a first pipeline, the oil pump 445 is installed on the first pipeline, the distributor 446 can also be connected to the oil tank 444 through a second pipeline to form a circulation loop, and the pressure relief valve 447 is installed on the second pipeline connecting the oil tank 444 and the distributor 446.

[0068] A pressure sensor 45 is disposed between the power device 44 and the bracket 1 to detect the pressure value between the power device 44 and the valve stem 3, can detect the pressure value applied to the support plate 42, and thus can obtain the pressure value indirectly applied by the power device 44 to the pneumatic rod 2 and / or the valve stem 3, and detect the pressure received by the power device 44 from the valve stem 3;

[0069] A displacement sensor 46 is used to collect the displacement and time parameters of the valve stem 3; preferably, the displacement sensor 46 is disposed on the side of the support plate 42 facing the power device 44.

[0070] Among them, the pneumatic valve detection system 4 has a first detection mode and a second detection mode; when in the first detection mode, the support plate 42 is installed on the valve stem 3 and abuts against the lower end of the coupling 41, and the power device 44 drives the support plate 42 to move to drive the valve stem 3 and the pneumatic rod 2 to move axially upward together, and the pressure sensor 45 is used to detect the pressure value of the power device 44 in the first detection mode;

[0071] When in the second detection mode, the support plate 42 is installed on the valve stem 3, and the abutting plate 43 can be installed on the valve stem 3 and located on the side of the support plate 42 facing the pneumatic rod 3. The power device 44 drives the support plate 42 to move to drive the valve stem 3 to move axially upward toward the pneumatic rod 2 and then release the pressure, and the valve stem 3 moves axially downward away from the pneumatic rod 2. The pressure sensor 45 is used to detect the pressure value of the power device 44 in the second detection mode.

[0072] As Figure 4 shown, preferably, the pneumatic valve detection system has a third detection mode; the coupling 41 is also used to connect the pneumatic rod 2 and the valve stem 3 in the third detection mode;

[0073] When in the third detection mode, the support plate 42 is installed on the pneumatic rod 2, above the coupling 41, and is connected to the power device 44. The power device 44 is also used to apply a quantitative closing and sealing force to the support plate 42 to drive the support plate 42 to move so that the valve stem 3 and the pneumatic rod 2 move axially downward together. The pressure sensor 45 is used to detect the pressure value of the power device 44 in the third detection mode. Through this pressure value, the power device 44 can apply a quantitative closing and sealing force to the valve stem 3. Thus, in this third detection mode, the pneumatic valve detection system is used to apply a quantitative closing and sealing force to the valve core.

[0074] In some embodiments, the pneumatic valve detection system 4 further includes a host computer, which is connected to the pressure sensor 45 and the displacement sensor 46, and is used for processing the pressure value data collected by the power device 44 and the displacement and time parameters of the valve stem 3 collected by the displacement sensor 46. It is also connected to the power device 44 and is used to control the operation of the power device 44 to achieve automatic control and avoid excessive human intervention factors that may affect the accuracy of the data.

[0075] Understandably, the pneumatic valve detection system 4 has the following beneficial effects: The pneumatic valve detection system operates efficiently. It acts directly on the valve stem 3 rather than the pneumatic head of the valve body and does not calculate based on the force balance during the spool process. Therefore, there is no requirement for the valve test action to be uniform, which greatly improves the accuracy of the force value, is beneficial to improving the maintenance quality, and enhances the safety performance of the equipment.

[0076] Beneficial effects: Improve the sealing reliability of the equipment, improve the efficiency of maintenance work, reduce working hours, and reduce the overhaul cost of the power plant.

[0077] The present invention also discloses a pneumatic valve detection method, which uses the above-mentioned pneumatic valve detection system 4 and includes the following steps:

[0078] In the first detection mode, connect the coupling 41 between the valve stem 3 and the pneumatic rod 2, install the support plate 42 on the valve stem 3 and abut against the lower end of the coupling 41, start the power device 44, and the power device 44 applies a force towards the pneumatic rod 2 direction to the support plate 42; when the valve stem 3 just starts to move in the stable state, obtain the first force value of the power device 44.

[0079] Obtain the second force value of the power device 44 when the pneumatic valve is in the fully open state and the valve stem 3 is in the stable state.

[0080] Slowly release the force of the power device 44. At the same time, the pneumatic rod 2 and the valve stem 3 slowly fall downward under the action of the upper disc spring; when the pneumatic valve is just in the closed state, obtain the third force value between the hydraulic drive device (power device 44) and the yoke 1, that is, the pressure from the disc spring received by the power device 44 at this time.

[0081] According to the first force value, the second force value, and the third force value, calculate the overall friction resistance of the pneumatic valve, the minimum value of the disc spring, and the maximum value of the disc spring.

[0082] In the second detection mode, disassemble the coupling 41 from between the pneumatic rod 2 and the valve stem 3, start the power device 44, and the power device 44 applies a force towards the pneumatic rod 2 direction to the support plate 42; obtain the fourth force value of the hydraulic drive device (power device 44) when the valve stem 3 and the pneumatic rod 2 are not in contact and in the stable state.

[0083] The power device continues to drive the valve stem 3 upward until the valve stem 3 just stops contacting the pneumatic rod 2; slowly release the force of the power device 44 so that the valve stem 3 slowly falls downward under the downward acting force applied by the power device 44; obtain the fifth force value of the hydraulic drive power device 44 in the stable state where the pneumatic valve is just closed and the valve stem 3 does not contact the pneumatic rod 2.

[0084] Calculate the packing friction and actuator resistance of the pneumatic valve according to the fourth force value, the fifth force value and the overall valve friction resistance.

[0085] In some embodiments, the pneumatic valve detection method further includes the following steps:

[0086] In the third detection mode, connect the coupling 41 between the valve stem 3 and the pneumatic rod 2, install the support plate 42 on the pneumatic rod 42 and connect it with the coupling 41, start the power device 44, and the power device 44 applies a quantitative closing and sealing force towards the valve stem 3 to the support plate 42; this quantitative closing and sealing force is the closing compensation force applied to the valve to be tested, and is used to detect whether the valve can be fully closed by applying a specific closing compensation force when it cannot be sealed under special circumstances.

[0087] Preferably, the calculation formula for the overall valve friction resistance is:

[0088] f = (F1 - F1') / 2;

[0089] The calculation formula for the minimum value of the disc spring is:

[0090] D1 = F1 - f;

[0091] The calculation formula for the maximum value of the disc spring is:

[0092] D2 = F2 - f;

[0093] Wherein, f is the overall valve friction resistance; D1 is the minimum value of the disc spring, D2 is the maximum value of the disc spring (referring to the maximum and minimum values of the force provided by the disc spring during the opening and closing process of the valve); F1 is the first force value; F2 is the second force value; F1' is the third force value.

[0094] Preferably, the calculation formula for the packing friction is:

[0095] Q = (F3 - F3') / 2;

[0096] The calculation formula for the actuator resistance is:

[0097] f1 = f - Q;

[0098] Wherein, Q is the packing friction; f1 is the actuator resistance; F3 is the fourth force value; F3' is the fifth force value.

[0099] Preferably, in the first detection mode, K can also be calculated according to the first force value, the standard differential pressure resistance, the standard actuator resistance, and the standard packing resistance according to the following relational expression, and whether the margin of the first force value meets the requirements of the pneumatic valve operation and design can be determined according to whether K is within the qualified range:

[0100] K = (D1’ - F4 - f1 - Q) / F1;

[0101] Wherein, D1’ is the standard small value of the disc spring of the valve, F4 is the standard differential pressure resistance, which reflects the force of the medium on the valve flap during the normal operation of the valve, and thus the force of the valve flap acting on the valve stem. D1’ and F4 are determined by the pneumatic valve to be measured; f1 is the above-mentioned actuator resistance, and Q is the above-mentioned packing friction.

[0102] When 0 < K ≤ 1, it means that the measured first force value F1 of the valve to be measured is larger, so it has a larger margin and meets the design requirements.

[0103] It can be understood that, as Figure 1 shown, in this embodiment, when the pneumatic valve detection system 4 is in the first detection mode, the power device 44 slowly applies an upward force to the support plate 42 to drive the pneumatic rod 2 and the valve stem 3 to move axially together. The displacement sensor 46 acquires the displacement and time parameter information of the valve stem 3 in real time. When the valve stem 3 just moves (for example, the displacement of the valve stem 3 is greater than 0 and less than 0.01 mm), it is stabilized for a certain time, such as 3 seconds. At this time, the pressure sensor 45 reads the first force value F1 at this time; the power device 44 continues to apply an upward force to the support plate 42 until the valve is fully opened (that is, the valve core at the lower end of the valve stem 3 just completely leaves the channel), the displacement sensor 46 reads the valve stroke S and time t, and after stabilizing for a certain time, such as 3 seconds, the pressure sensor 45 reads the second force value F2 at this time; the power device 44 slowly releases the upward force, the valve starts to close, and the displacement of the valve stem 3 is observed through the displacement sensor 46. When the valve is just fully closed (the displacement is 0 mm), after stabilizing for a certain time, such as 3 seconds, the pressure sensor 45 reads the third force value F1' at this time.

[0104] Wherein, the overall friction resistance of the valve is f, the small value of the disc spring is D1, the large value of the disc spring is D2, f = (F1 - F1') / 2, D1 = F1 - f, D2 = F2 - f.

[0105] Furthermore, as Figure 2 shown, when the pneumatic valve detection system 4 is in the second detection mode, at this time the pneumatic rod 2 is separated from the valve stem 3, and the valve is in the initial closed state. It is confirmed that the support plate 42, the power device 44, the pressure sensor 45, and the displacement sensor 46 are installed in place. Among them, the support plate 42 is installed on one end of the valve stem 3 close to the pneumatic rod 2.

[0106] Apply an upward force to the support plate 42 slowly through the power device 44. Observe the displacement of the valve stem 3 through the displacement sensor 46. The distance between the pneumatic rod 2 and the valve stem 3 at the initial state when they are not in contact is X. Read the displacement of the valve stem 3 in real time through the displacement sensor 46. When the displacement of the valve stem 3 reaches CX, the power device 44 stops outputting force. C is a coefficient, which can be selected to be greater than or equal to 0.3 and less than 1, further preferably greater than or equal to 0.5 and less than 1, and even more preferably greater than or equal to 0.5 and less than or equal to 0.8, such as it can be 0.5X. Stabilize for a certain period of time, such as 3 seconds, and read the fourth force value F3 at this time through the pressure sensor 45. The power device 44 continues to output force until the pneumatic rod 2 and the valve stem 3 are just not in contact (the displacement is less than X, for example, greater than or equal to 0.9X and less than 0.99X), then stop outputting force.

[0107] Slowly release the upward force through the power device 44. At this time, the valve stem 3 moves downward by its own gravity. When the valve starts to close, collect the displacement-time parameters of the valve stem 3 in real time through the displacement sensor 46. When the displacement of the valve stem 3 reaches CX, stop outputting force. After stabilizing for a certain period of time, such as 3 seconds, read the fifth force value F3' at this time through the pressure sensor 45. The packing friction Q can be calculated as Q=(F3 - F3') / 2, and the actuator resistance f1 = f - Q.

[0108] Confirm that each force value meets the program standard, and the valve stroke S and the opening and closing time t meet the re-certification requirements, then it indicates that the test is qualified. Otherwise, adjust or repair the valve for the non-compliant standard parameters, and re-measure the parameters of the valve according to the above steps until all parameters meet the standard.

[0109] In some embodiments, refer back to Figure 1 As shown, when the pneumatic valve detection system 4 is in the first detection mode, the valve seating force can be detected and evaluated online (for valves that can be allowed to open briefly online). Confirm that the coupling 41, the support plate 42, the power device 44, the pressure sensor 45, and the displacement sensor 46 are installed in place. Apply an upward force to the support plate 42 slowly through the power device 44. Observe the displacement parameters of the valve stem 3 through the displacement sensor 46. When the valve stem 3 just starts to move (such as the displacement is greater than 0 and less than 0.01 mm), stabilize for a certain period of time, such as 3 seconds, and read the first force value F1 at this time through the pressure sensor 45. Then compare with the standard small value of the disc spring D1', the standard pressure difference resistance F4, the actuator resistance f1, and the packing friction Q to evaluate whether the margin of the first force value F1 meets the valve operation and design requirements. Details are not described here.

[0110] In some embodiments, refer to Figure 4, the pneumatic valve detection system 4 further includes a third detection mode. When the pneumatic valve detection system 4 is in the third detection mode, a quantitative closing sealing force is provided for the valve to confirm that the coupling 41, the support plate 42, the power device 44, and the pressure sensor 45 are installed in place. The support plate 42 is installed on the pneumatic rod 2 and is located on the side of the coupling 41 away from the valve stem 3. The hydraulic rod 442 of the power device 44 is connected to the support plate 42 to drive the support plate 42 to move downward.

[0111] Among them, the power device 44 outputs force to apply a quantitative closing sealing force u*E1 (the maximum allowable sealing force E1 for valve operation, safety factor u) downward on the support plate 42, and transfers the force to the valve flap sealing surface through the coupling 41 and the valve stem 3. The force value can be read in real time through the pressure sensor 45. It can provide online quantitative sealing force compensation, and at the same time can provide opening power for the pneumatic valve (forced opening can also be carried out when there is back pressure), so that the valve is stabilized at a certain opening degree, ensuring the valve opening and closing functions and improving the valve sealing safety margin.

[0112] It can be understood that the above embodiments only express the preferred implementation modes of the present invention, and the description is relatively specific and detailed, but it cannot be understood as a limitation to the scope of the patent of the present invention; it should be pointed out that for those of ordinary skill in the art, without departing from the concept of the present invention, the above technical features can be freely combined, and several deformations and improvements can also be made, which all belong to the protection scope of the present invention; therefore, all equivalent transformations and modifications made to the scope of the claims of the present invention should fall within the scope covered by the claims of the present invention.

Claims

1. A pneumatic valve detection system, the pneumatic valve comprising a yoke (1), a pneumatic rod (2), a valve stem (3), a valve body and an actuator; the pneumatic rod (2) and the valve stem (3) are disposed coaxially through the yoke (1); the actuator is connected to the upper end of the yoke (1), and the actuator includes a disc spring; a valve core for sealing a passage of the valve body is provided at the lower end of the valve stem (3), characterized in that, The pneumatic valve detection system includes: A coupling (41) for connecting the pneumatic rod (2) and the valve rod (3) in the first detection mode; A support plate (42) for being mounted on the pneumatic rod (2) or the valve rod (3); A power device (44) for connecting with the support plate (42) to drive the support plate (42) to drive the pneumatic rod (2) and / or the valve rod (3) to axially move; the number of the power devices (44) is at least two, and at least two of the power devices (44) are uniformly arranged around the valve rod (3) in the circumferential direction; A pressure sensor (45) arranged between the power device (44) and the bracket (1) to detect the pressure value between the power device (44) and the valve rod (3); A displacement sensor (46) for collecting the displacement and time parameters of the valve rod (3); Wherein, the pneumatic valve detection system has a first detection mode and a second detection mode; when in the first detection mode, the support plate (42) is mounted on the valve rod (3) and abuts against the lower end of the coupling (41), and the power device (44) drives the support plate (42) to move to drive the valve rod (3) and the pneumatic rod (2) to axially move upward together, and the pressure sensor (45) is used to detect the pressure value of the power device (44) in the first detection mode; When in the second detection mode, the support plate (42) is mounted on the valve rod (3), the power device (44) drives the support plate (42) to drive the valve rod (3) to axially rise towards the pneumatic rod (2) and then release the pressure, and the valve rod (3) axially moves downward away from the pneumatic rod (2), and the pressure sensor (45) is used to detect the pressure value of the power device (44) in the second detection mode; The support plate (42) has a through hole so that the support plate (42) can be slidably sleeved on the outer periphery of the valve rod (3), and the pneumatic valve detection system further includes a contact plate (43) fixedly mounted on the valve rod (3) and located above the support plate (42) in the second detection mode, so that the power device (44) can drive the valve rod (3) to axially move upward.

2. The pneumatic valve detection system according to claim 1, characterized in that, The pneumatic valve detection system has a third detection mode; the coupling (41) is also used for connecting the pneumatic rod (2) and the valve rod (3) in the third detection mode; When in the third detection mode, the support plate (42) is mounted on the pneumatic rod (2), located above the coupling (41), and is connected with the power device (44), and the power device (44) is also used for applying a quantitative closing and sealing force to the support plate (42) to drive the support plate (42) to move so that the valve rod (3) and the pneumatic rod (2) axially move downward together, and the pressure sensor (45) is used to detect the pressure value of the power device (44) in the third detection mode.

3. The pneumatic valve detection system according to any one of claims 1 to 2, characterized in that The pneumatic valve detection system further includes a host computer, which is connected to the pressure sensor (45) and the displacement sensor (46).

4. A pneumatic valve detection method, which is applied to the pneumatic valve detection system described in any one of claims 1 to 3, and is characterized in that, It includes the following steps: In the first detection mode, connect the coupling (41) between the valve stem (3) and the pneumatic rod (2), install the support plate (42) on the valve stem (3) and abut against the lower end of the coupling (41), start the power device (44), and the power device (44) applies a force towards the pneumatic rod (2) direction to the support plate (42); when the valve stem (3) just starts to move in the stable state, obtain the first force value of the power device (44); When the pneumatic valve is in the fully open state and the valve stem (3) is in the stable state, obtain the second force value of the power device (44); Slowly release the force of the power device (44), and at the same time, the pneumatic rod (2) and the valve stem (3) slowly fall downward under the action of the upper disc spring; when the pneumatic valve is just in the closed state, obtain the third force value of the power device (44); According to the first force value, the second force value and the third force value, calculate the overall friction resistance of the pneumatic valve, the minimum value of the disc spring, and the maximum value of the disc spring; In the second detection mode, disassemble the coupling from between the pneumatic rod (2) and the valve stem (3), start the power device (44), and the power device (44) applies a force towards the pneumatic rod (2) direction to the support plate (42); when the valve stem (3) and the pneumatic rod (2) are in the non-contact stable state, obtain the fourth force value of the power device (44); The power device (44) continues to drive the valve stem (3) to move upward until the valve stem (3) just does not contact the pneumatic rod (2); slowly release the force of the power device (44) so that the valve stem (3) slowly falls downward under the downward acting force applied by the power device (44); when the pneumatic valve is just closed and the valve stem (3) and the pneumatic rod (2) are in the non-contact stable state, obtain the fifth force value of the power device (44); According to the fourth force value, the fifth force value and the overall friction resistance of the valve, calculate the packing friction force and the actuator resistance of the pneumatic valve.

5. The pneumatic valve detection method according to claim 4, characterized in that, The pneumatic valve detection method further includes the following steps: In the third detection mode, connect the coupling (41) between the valve stem (3) and the pneumatic rod (2), install the support plate (42) on the pneumatic rod (2) and connect it to the coupling (41), start the power device (44), and the power device (44) applies a quantitative closing and sealing force towards the valve stem (3) direction to the support plate (42).

6. The pneumatic valve detection method according to claim 4, wherein The calculation formula for the overall friction resistance of the valve is: f=(F1 - F1') / 2; The calculation formula for the minimum value of the disc spring is: D1 = F1 - f; The calculation formula for the maximum value of the disc spring is: D2 = F2 - f; Wherein, f is the overall frictional resistance of the valve; D1 is the minimum value of the disc spring; D2 is the maximum value of the disc spring; F1 is the first force value; F2 is the second force value; F1' is the third force value.

7. The pneumatic valve detection method according to claim 6, characterized in that The calculation formula for the packing friction is: Q = (F3 - F3') / 2; The calculation formula for the actuator resistance is: f1 = f - Q; Wherein, Q is the packing friction; f1 is the actuator resistance; F3 is the fourth force value; F3' is the fifth force value.

8. The pneumatic valve detection method according to claim 7, characterized in that, In the first detection mode, according to the first force value, the standard pressure difference resistance, the standard actuator resistance and the standard packing resistance, calculate K according to the following relational formula, and judge whether the margin of the first force value meets the pneumatic valve operation and design requirements according to whether K is within the qualified range: K = (D1’ - F4 - f1 - Q) / F1; Wherein, D1’ is the standard minimum value of the disc spring of the valve, F4 is the standard pressure difference resistance; f1 is the actuator resistance as described above, Q is the packing friction as described above; when 0 < K ≤ 1, it means that the margin of the first force value meets the design requirements.

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