Correcting device for limiting switch of pneumatic valve of nuclear power plant
By designing a calibration device for the limit switch of pneumatic valves in nuclear power plants, the screw guide mechanism and clamping mechanism are used to achieve accurate correction of the limit switch position, which solves the abnormal control problem caused by the dual limit state, and improves maintenance convenience and correction accuracy.
Patent Information
- Application Number
- CN202411327790.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-24
- Publication Date
- 2025-02-25
AI Technical Summary
The limit switch of the pneumatic valve of the nuclear power plant is prone to double limit state under short stroke conditions, resulting in abnormal controller status, malfunction, false alarm response and verification results, and the narrow installation position is not convenient for on-site maintenance.
A nuclear power plant pneumatic valve limit switch calibration device is designed, including a screw guide mechanism, a clamping mechanism and a stabilizing chassis mechanism. The rotational movement is converted into linear motion by manually rotating the throttle plate, and the position of the limit switch is adjusted. The clamping mechanism is used to stabilize the limit switch and stabilize the chassis mechanism to ensure the stability of the device.
It effectively avoids the dual limit state, ensures that the limit switch outputs signal and feedback control correctly, improves maintenance convenience and correction accuracy, and avoids malfunctions and error states.
Smart Images
Figure CN119508575A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the field of nuclear power technology, and in particular relates to a pneumatic valve limit switch calibration device for a nuclear power plant. Background Art
[0002] The main function of the pneumatic valve limit switch in a nuclear power plant is to automatically output signals and feedback control when the pneumatic valve is opened or closed to a specified position. The installation distance between the open limit switch and the closed limit switch of some short-stroke pneumatic valves in nuclear power plants is small. When the air intake open limit of the pneumatic valve is disengaged to the closed limit trigger, the valve stem drives the limit trigger block to move. During the process, the block has not disengaged from the open limit cam and has triggered the closed limit cam, resulting in a double limit state, and the reverse effect is the same. The double limit state may lead to the following operating conditions: the two limit terminals are 0V at the same time, which may cause abnormal status of the downstream controller and logic block and malfunction of the equipment; the limit signal feedback to the DCS and the status error of the first-layer IA workstation is easy to cause the operator to misjudge and may trigger an alarm response in a short time; the overall calibration of the pneumatic valve may produce an erroneous state, affecting the accuracy and rationality of the calibration results;
[0003] The installation position of this type of short-stroke pneumatic valve is relatively narrow, which is not convenient for personnel to carry out on-site maintenance work, and manual direct adjustment of the limit switch will not guarantee the installation position and trigger margin of the limit. In the relevant technology, there has never been a technology or method for correcting the limit switch position to avoid double limits. Therefore, it is necessary to innovatively design a nuclear power plant pneumatic valve limit switch correction device to solve the above problems. Summary of the invention
[0004] In order to overcome the problems existing in the related art, a pneumatic valve limit switch calibration device for a nuclear power plant is provided.
[0005] According to one aspect of an embodiment of the present disclosure, there is provided a pneumatic valve limit switch calibration device for a nuclear power plant, the device comprising: a lead screw guide mechanism, a clamping mechanism, and a stable chassis mechanism;
[0006] One end of the lead screw guide mechanism is connected to the wheel disc, and the other end is connected to the stable base mechanism, and the stable base mechanism is located on the operating plane; one side of the slider of the lead screw guide mechanism is connected to the clamping mechanism;
[0007] The clamping mechanism is used to clamp the valve limit switch to be adjusted. When the wheel is rotated, the screw guide mechanism converts the rotational angular displacement of the wheel into a linear displacement, and drives the clamping mechanism to adjust the valve limit switch through the slider.
[0008] In a possible implementation, the screw guide rail mechanism includes: a wheel disc, an end cover, a transmission seat, a guide rail, a screw, a slider, a nut seat, and a fixed seat;
[0009] The head end of the guide rail is fixedly connected to the transmission seat, and the end of the guide rail is fixedly connected to the fixed seat; the screw rod is located above the guide rail, the front part of the screw rod is rotatably connected to the transmission seat, the rear part of the screw rod is rotatably connected to the fixed seat, and the screw rod passes through the front end of the transmission seat to install the wheel; the nut seat is threadedly connected between the two ends of the screw rod, and the slider is fixedly installed on the nut seat, and the two ends of the slider are guided by the guide rail; the rotating wheel inputs the rotational torque, so that the slider moves linearly.
[0010] In a possible implementation, the nut seat is a ball nut seat.
[0011] In a possible implementation, the clamping mechanism includes: a clamping baffle, a telescopic rod, a supporting bottom plate, and a plurality of springs;
[0012] The front end of each spring is fixedly installed inside the slider, and the length and elastic coefficient of each spring are equal, and they can automatically retract after being stretched; the rear end of each spring is fixedly installed on one side of the supporting base plate; the supporting base plate is used to carry the limit switch; a plurality of telescopic rods are connected to the other side of the supporting base plate, and the length of each telescopic rod can be adjusted according to the size of different limit switches; the clamping baffle is connected to the telescopic rod, and is used to clamp the limit switch and stabilize the limit switch.
[0013] In a possible implementation, one side of the supporting base plate is connected to the spring via a short flexible rope.
[0014] In a possible implementation, the stable chassis mechanism includes: a plurality of elastic support structures and a plurality of elastic de-centered disc structures;
[0015] Each elastic de-centered disc structure is fixedly installed at the bottom end of the lead screw guide rail mechanism. Each elastic de-centered disc structure adopts a de-centered disc. A plurality of elastic bracket structures are set up in the gap between the center and the edge of each elastic de-centered disc structure.
[0016] In a possible implementation, in each elastic de-centered circular disc structure, the elastic support structures are evenly distributed around the center of the elastic de-centered circular disc structure.
[0017] In a possible implementation, the angle between every two elastic support structures is 59° to 60°.
[0018] In a possible implementation, the following steps are used to perform the correction work:
[0019] Step 100, stably install the limit switch calibration device next to the pneumatic valve to be calibrated, stretch the clamping mechanism to install the limit switch and support the bottom, and the limit switch to be calibrated is adaptively retracted to be firmly clamped;
[0020] Step 101, determining the angular displacement of the wheel according to the displacement requirement, and rotating the wheel to achieve the effect and correction of the limit switch in the vertical direction;
[0021] Step 102, after the calibration is completed, the limit switch is fixed and the clamping mechanism is stretched to cancel the clamping, and the device is retracted.
[0022] In a possible implementation, in step 101, the angular displacement of the wheel rotation is determined using the following formula:
[0023] φ=xtanθ / d
[0024] Among them, φ is the rotational angular displacement, x is the displacement to be corrected, θ is the angle between the screw axis and the horizontal plane, and d is the cross-sectional diameter of the screw.
[0025] The beneficial effects of the present disclosure are as follows: the present disclosure provides a nuclear power plant pneumatic valve limit switch correction device, a method for correcting the relative position of the limit switch by manually rotating the wheel, a screw guide mechanism for converting rotational motion into linear motion, and a linear displacement for vertically correcting the position of the limit switch; a stable chassis mechanism and a clamping mechanism for stabilizing the device during the correction process. The screw guide mechanism can convert the input rotational force of the wheel into an output clamping mechanism for stabilizing the limit switch, ensuring that the limit switch can correctly output signals and feedback control, and providing a method for avoiding the limit switch correction work in the double limit state, which significantly improves the convenience of maintenance. BRIEF DESCRIPTION OF THE DRAWINGS
[0026] Figure 1 It is a schematic diagram of a nuclear power plant pneumatic valve limit switch calibration device shown in an embodiment of the present disclosure.
[0027] Figure 2 It is a schematic diagram of a screw guide mechanism in a pneumatic valve limit switch correction device for a nuclear power plant shown in an embodiment of the present disclosure.
[0028] Figure 3 It is a schematic diagram of a clamping mechanism in a pneumatic valve limit switch calibration device for a nuclear power plant shown in an embodiment of the present disclosure.
[0029] Figure 4 It is a schematic diagram of a bottom plate mechanism in a nuclear power plant pneumatic valve limit switch calibration device shown in an embodiment of the present disclosure. DETAILED DESCRIPTION
[0030] The present disclosure is further described in detail below with reference to the accompanying drawings and specific embodiments.
[0031] Unless otherwise defined, the technical and scientific terms used in the present disclosure have the same meanings as those generally understood by those skilled in the art to which the present disclosure belongs; the terms used in the present disclosure are only for the purpose of describing specific embodiments and are not intended to limit the present disclosure; the term "including" and any variations thereof in the present disclosure are intended to cover non-exclusive inclusions. Obviously, the embodiments described in the present disclosure are only part of the embodiments of the present disclosure, not all of the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by ordinary technicians in the field without making creative efforts are within the scope of protection of the present disclosure.
[0032] Reference to "embodiments" in this disclosure means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the disclosure. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.
[0033] Figure 1 Schematic diagram of a pneumatic valve limit switch calibration device for a nuclear power plant shown in an embodiment of the present disclosure. Figure 1 As shown, the device includes: a screw guide mechanism 1, a clamping mechanism 2, and a stable chassis mechanism 3.
[0034] Figure 2 is a schematic diagram of a screw guide mechanism in a pneumatic valve limit switch calibration device for a nuclear power plant shown in an embodiment of the present disclosure, such as Figure 2 The screw guide rail mechanism 1 shown includes: a wheel plate 11, an end cover 12, a transmission seat 13, a guide rail 14, a nut seat 15, a slider 16, a screw 17, and a fixed seat 18.
[0035] The head end of the guide rail 14 is fixedly connected to the transmission seat 13, and the tail end of the guide rail 14 is fixedly connected to the fixed seat 18; the screw rod 17 is located above the guide rail 14, the front part of the screw rod 17 is rotatably connected to the transmission seat 13, and the rear part of the screw rod 17 is rotatably connected to the fixed seat 18, and the screw rod passes through the front end of the transmission seat 13 to install the wheel disc 11; the nut seat 15 is threadedly connected between the two ends of the screw rod 17, and the slider 16 is fixedly installed on the nut seat 15, and the two ends of the slider 16 are guided by the guide rail 14; the rotating wheel disc 11 inputs the rotational torque, so that the slider 16 performs a linear motion.
[0036] Since the correction of the upper limit switch is a micro adjustment, the present disclosure uses the screw drive as the basic model. The screw drive is based on the meshing action of the thread, converting the rotational motion into linear motion, and the linear displacement generated by each rotation of the nut is the same as the lead, so the rotation angle can be reversed according to the required displacement. The lead is usually only a few millimeters, which is very suitable for micro adjustment. In order to reduce the efficiency impact caused by the friction between the threaded rod and the nut, in a possible implementation method, the nut seat is a ball nut seat, and the contact between the ball and the screw thread realizes power transmission, which can effectively reduce friction and improve transmission efficiency and displacement accuracy.
[0037] The conventional screw guide mechanism is input with rotation torque by the motor in the end cover 12. The present disclosure is based on the conventional mechanism, removes the motor in the end cover 12, and installs a wheel 11 at the head end of the screw. The maintenance personnel slightly rotate the wheel to input rotation torque, so that the slider 16 performs linear micro-movement. The head end of the guide rail 14 is vertically connected to the transmission seat 13 by bolts, and the end of the guide rail 14 is vertically connected to the fixing seat 18 by bolts; the transmission seat 13 is connected to the end cover 12 by bolts, which is used to transmit torque and fix the screw, thereby ensuring the efficiency of torque transmission.
[0038] Figure 3 is a schematic diagram of a clamping mechanism in a pneumatic valve limit switch calibration device for a nuclear power plant shown in an embodiment of the present disclosure, see Figure 2 and Figure 3 The clamping mechanism includes: a clamping baffle 21, a telescopic rod 22, a support base plate 23, and a plurality of springs 24. The front end of each spring 24 is fixedly installed inside the slider 16, and the length and elastic coefficient of each spring 24 are equal, and they can automatically retract after being stretched; the rear end of each spring 24 is fixedly installed on one side of the support base plate 23 (one side of the support base plate 23 can be connected to the spring 24 through a tough short rope), and the support base plate 23 is used to carry the limit switch, which plays a delayed triggering role, and the spring 24 will be stretched only after the tough short rope is straightened; the other side of the support base plate 23 is connected to a plurality of telescopic rods 22, and the length of each telescopic rod 22 can be adjusted according to the size of different limit switches; the clamping baffle 21 is connected to the telescopic rod 22, and is used to clamp the limit switch and stabilize the limit switch. When pre-clamping the limit switch, the clamping mechanism has an adaptive adjustment function to ensure that the limit switch remains stable during the calibration process, and is suitable for limit switches of various sizes and different heights, and has universal applicability.
[0039] Figure 4 is a schematic diagram of a bottom plate mechanism in a pneumatic valve limit switch calibration device for a nuclear power plant shown in an embodiment of the present disclosure, such as Figure 4As shown, the stable chassis mechanism includes: a plurality of elastic support structures 31 and a plurality of elastic de-centered disc structures 32. Each elastic de-centered disc structure 32 is fixedly installed at the bottom of the fixed seat by bolts. Each elastic de-centered disc structure 32 adopts a de-centered disc, which has an anti-dumping function and can also evenly distribute the load. Compared with a polygonal structure that is easy to tilt and the load is concentrated at the vertex, it is most stable when the number of sides of the shape tends to infinity and the curvatures in all directions are equal, that is, a circular structure. A plurality of elastic support structures 31 are set up in the gap between the center and the edge of each elastic de-centered disc structure 32. The elastic support structures 31 are evenly distributed around the center of the elastic de-centered disc structure 32, and the angle between each two elastic support structures 31 is 59° to 61°. Due to the different gravity of the structures in each direction of the device, the center of gravity of the device body is offset, and the structural characteristics of the stable chassis mechanism 3 that can withstand high loads and evenly distribute the load can ensure that the device is firmly on the ground. On the basis of a stable load-bearing device, the vector torques of each elastic support structure 31 offset each other, and a stable state can be achieved as much as possible.
[0040] The present invention uses a screw guide mechanism to realize the correction of the pneumatic valve limit switch, takes the wheel as the torque input source, and converts the output linear displacement by rotating the wheel to correct the position of the limit switch. It has the advantages of high universality, precision and high stability.
[0041] The invention discloses two stabilizing mechanisms, namely a clamping mechanism and a stabilizing chassis mechanism. During the calibration process of the limit switch, the clamping mechanism is used to stabilize the limit switch. Its adaptive clamping function can ensure the stability of the limit switch during the calibration process, and is applicable to limit switches of different sizes. The stabilizing chassis mechanism disclosed in the invention has the structural characteristics of being able to withstand high loads and evenly distribute the loads, and can stabilize the device with a center of gravity offset on the ground to prevent the device from tilting during the calibration process. The device body is kept stable to prevent tilting.
[0042] In addition, the disclosed device occupies a small horizontal space and can replace the limit switch calibration work of maintenance personnel when it is put into use on-site in a narrow area, greatly improving convenience. The disclosed device is simple to operate and easy to maintain.
[0043] In an application example, the following steps are used to perform the calibration work.
[0044] Step 100, stably install the limit switch calibration device next to the pneumatic valve to be calibrated, stretch the clamping mechanism to install the limit switch and support the bottom, and the limit switch to be calibrated will adaptively retract to be firmly clamped.
[0045] Step 101, according to the displacement requirement, determine the rotation angle displacement of the wheel disc, and rotate the wheel disc to realize the action and correction of the limit switch in the vertical direction.
[0046] Step 102, after the calibration is completed, the limit switch is fixed and the clamping mechanism is stretched to cancel the clamping, and the device is retracted.
[0047] In a possible implementation, φ = 2xtanθ / d, and the angular displacement of the wheel is calculated. The angular displacement φ, the displacement to be corrected x, the angle θ between the screw shaft and the horizontal plane, and the cross-sectional diameter of the screw d. According to the formula, the angular displacement φ is independent of the rotational torque and the wheel diameter.
[0048] In this way, maintenance personnel can use the device disclosed in the present invention to perform accurate calibration according to the conversion method of the rotational angular displacement, which is simple to operate and easy to maintain.
[0049] The embodiments of the present disclosure have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles of the embodiments, practical applications, or improvements to the technology in the market, or to enable other persons of ordinary skill in the art to understand the embodiments disclosed herein.
Claims
1. A pneumatic valve limit switch calibration device for a nuclear power plant, characterized in that: The device comprises: a screw guide mechanism, a clamping mechanism, and a chassis stabilizing mechanism; One end of the lead screw guide mechanism is connected to the wheel disc, and the other end is connected to the stable base mechanism, and the stable base mechanism is located on the operating plane; one side of the slider of the lead screw guide mechanism is connected to the clamping mechanism; The clamping mechanism is used to clamp the valve limit switch to be adjusted. When the wheel is rotated, the screw guide mechanism converts the rotational angular displacement of the wheel into a linear displacement, and drives the clamping mechanism to adjust the valve limit switch through the slider.
2. The device according to claim 1, characterized in that The screw guide rail mechanism comprises: a wheel disc, an end cover, a transmission seat, a guide rail, a screw, a slider, a nut seat, and a fixing seat; The head end of the guide rail is fixedly connected to the transmission seat, and the end of the guide rail is fixedly connected to the fixed seat; the screw rod is located above the guide rail, the front part of the screw rod is rotatably connected to the transmission seat, the rear part of the screw rod is rotatably connected to the fixed seat, and the screw rod passes through the front end of the transmission seat to install the wheel; the nut seat is threadedly connected between the two ends of the screw rod, and the slider is fixedly installed on the nut seat, and the two ends of the slider are guided by the guide rail; the rotating wheel inputs the rotational torque, so that the slider moves linearly.
3. The device according to claim 2, characterized in that The nut seat is a ball nut seat.
4. The device according to claim 1, characterized in that The clamping mechanism comprises: a clamping baffle, a telescopic rod, a supporting bottom plate, and a plurality of springs; The front end of each spring is fixedly installed inside the slider, and the length and elastic coefficient of each spring are equal, and they can automatically retract after being stretched; the rear end of each spring is fixedly installed on one side of the supporting base plate; the supporting base plate is used to carry the limit switch; a plurality of telescopic rods are connected to the other side of the supporting base plate, and the length of each telescopic rod can be adjusted according to the size of different limit switches; the clamping baffle is connected to the telescopic rod, and is used to clamp the limit switch and stabilize the limit switch.
5. The device according to claim 4, characterized in that One side of the supporting base plate is connected to the spring through a short flexible rope.
6. The device according to claim 1, characterized in that The stable chassis mechanism comprises: a plurality of elastic bracket structures and a plurality of elastic de-centered disc structures; Each elastic de-centered disc structure is fixedly installed at the bottom end of the lead screw guide rail mechanism. Each elastic de-centered disc structure adopts a de-centered disc. A plurality of elastic bracket structures are set up in the gap between the center and the edge of each elastic de-centered disc structure.
7. The device according to claim 1, characterized in that In each elastic coreless disc structure, each elastic support structure is evenly distributed around the center of the elastic coreless disc structure.
8. The device according to claim 1, characterized in that The included angle between each two elastic support structures is 59° to 60°.
9. The device according to claim 1, characterized in that Use the following steps to perform the calibration: Step 100, stably install the limit switch calibration device next to the pneumatic valve to be calibrated, stretch the clamping mechanism to install the limit switch and support the bottom, and the limit switch to be calibrated is adaptively retracted to be firmly clamped; Step 101, determining the angular displacement of the wheel according to the displacement requirement, and rotating the wheel to achieve the effect and correction of the limit switch in the vertical direction; Step 102, after the calibration is completed, the limit switch is fixed and the clamping mechanism is stretched to cancel the clamping, and the device is retracted.
10. The device according to claim 9, characterized in that In step 101, the angular displacement of the wheel rotation is determined using the following formula: φ=xtanθ / d Among them, φ is the rotational angular displacement, x is the displacement to be corrected, θ is the angle between the screw axis and the horizontal plane, and d is the cross-sectional diameter of the screw.