Heavy water reactor nuclear power plant atmospheric release valve grinding apparatus and method

Abstract

The present disclosure belongs to the technical field of nuclear power, and particularly relates to a heavy water reactor nuclear power plant atmospheric release valve grinding device and method. The heavy water reactor nuclear power plant atmospheric release valve sealing surface grinding device provided by the present disclosure effectively clamps the part to be ground through a positioning module, designs and manufactures a grinding mold matched with the shape and size of the part to be ground, ensures that the grinding is in place, and guarantees the maintenance quality; the rotation driving and up-down driving of the grinding mold are realized through a grinding module, so that the grinding intensity can be adjusted at any time during the grinding of the part, the grinding surface can not only be completely attached to the part to be ground, but also can provide effective grinding pressure during the grinding process; thus, safe and efficient grinding treatment of the heavy water reactor nuclear power plant atmospheric release valve sealing surface is realized.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of nuclear power, and particularly relates to a grinding device and method for an atmospheric release valve of a heavy water reactor nuclear power plant. BACKGROUND

[0002] The main steam system of the heavy water reactor unit transports steam generated by the steam generator to the steam turbine generator unit and other auxiliary steam systems. Each main steam system of the unit is composed of four main steam pipelines, and four main steam safety valves, one main steam isolation valve and one atmospheric release valve are evenly arranged on each main steam pipeline. The atmospheric release valve can be used to discharge steam when the steam condenser is unavailable. The discharge capacity of a single atmospheric release valve is 10% of the rated steam production of a single steam generator. Meanwhile, the atmospheric release valve is used in the following three working conditions: loss of four-level power supply leading to unavailability of the condenser steam discharge valve, loss of the condenser leading to unavailability of the condenser steam discharge valve, and main system temperature rise (the condenser steam discharge valve is not yet available).

[0003] Generally, the atmospheric release valve of the heavy water reactor unit is a 6-inch nuclear 2-level control valve. In order to strengthen the sealing and reduce the width of the sealing surface, the sealing surface is designed as an inclined surface. The grinding accuracy of the sealing surface directly affects the sealing effect of the valve during valve disassembly and sealing surface grinding. The manual grinding method is widely used in the field of valve grinding in nuclear power plants. This method uses sandpaper or grinding paste to complete the grinding and repair of the sealing surface through rough grinding and fine grinding. Manual grinding has strict requirements for the experience and skills of the operator and is low in work efficiency. The electric grinding machine is also a commonly used grinding tool, which can greatly improve the grinding efficiency. However, due to the inclined surface of the atmospheric release valve, it is difficult to set up the electric grinding machine and perform grinding. Therefore, how to improve the maintenance efficiency and quality of the special-shaped sealing surface of the atmospheric release valve has become a problem to be solved. SUMMARY

[0004] In order to overcome the problems in the related art, a grinding device and method for an atmospheric release valve of a heavy water reactor nuclear power plant are provided.

[0005] According to an aspect of an embodiment of the present disclosure, a grinding device for an atmospheric release valve of a heavy water reactor nuclear power plant is provided, which comprises a grinding module, a positioning module, a control terminal and a table; the positioning module is arranged on the table and is used for horizontally fixing a part to be ground;

[0006] The grinding module comprises a support, a grinding motor, a lifting motor, a gear box, an extension rod and a plurality of grinding fixtures. Different grinding fixtures are used to fit different parts for grinding. The support is fixedly connected to the horizontally arranged table. The grinding motor and the gear box are fixedly connected to the support. The extension rod is vertically arranged. The grinding motor is in transmission connection with the top end of the extension rod through the gear box. The bottom end of the extension rod is fixedly installed with a grinding fixture.

[0007] The upper part of the telescopic rod is a hollow structure, the output end of the gear box is fixedly connected with the upper end of the driving shaft, the upper part of the telescopic rod is sleeved outside the lower end of the driving shaft, one end of the transmission key is slidably connected in the long key groove of the side wall of the driving shaft, the other end of the transmission key is in interference fit with the key groove of the side wall of the telescopic rod, the grinding motor can drive the telescopic rod to rotate through the driving shaft, and the driving shaft can also produce relative displacement with the telescopic rod in the vertical direction;

[0008] The gear box is further provided with a lifting motor and a lifting assembly, the output end of the lifting motor is connected with the telescopic rod through the lifting assembly, and the lifting motor drives the telescopic rod to move linearly in the vertical direction through the lifting assembly;

[0009] The control terminal is in communication connection with the grinding motor and the lifting motor, and can control the start and stop of the grinding motor and / or the lifting motor.

[0010] In a possible implementation, the telescopic rod comprises an upper segment, a middle segment and a lower segment which are fixedly connected in sequence from top to bottom, the upper segment is a hollow cylindrical structure, the upper segment is sleeved outside the lower end of the driving shaft, the other end of the transmission key is in interference fit with the key groove of the side wall of the upper segment, and the lower end of the upper segment is sleeved outside the upper end of the middle segment; the bottom edge of the upper segment has a step portion extending radially inward, and the side wall of the middle segment is provided with a ring groove extending radially inward in the circumferential direction; the middle segment is connected with the upper segment through a plurality of transmission pins, one end of each transmission pin is in interference fit with a pin hole of the side wall of the middle segment above the ring groove, the other end of each transmission pin is slidably connected with a long pin hole of the side wall of the upper segment, and the long pin hole of the upper segment is arranged in the vertical direction; a plurality of first pressure sensors are fixedly connected to the side wall below the ring groove; in the case that the grinding mold is pressed against the part to be ground, the step portion of the upper segment is pressed against each first pressure sensor of the side wall below the ring groove of the middle segment;

[0011] The control terminal is in communication connection with the plurality of first pressure sensors, and can acquire the pressure data currently collected by the plurality of first pressure sensors, so as to determine the current pressure value borne by the part to be ground.

[0012] In a possible implementation, the positioning module comprises a positioning motor, a second bevel gear and a plurality of positioning assemblies; each positioning assembly comprises a positioning clamp, a first rack, a first tooth-shaped transmission element, a first worm and a shaft; the control terminal is in communication connection with the positioning motor, and is used to control the start and stop of the positioning motor;

[0013] The positioning motor is fixedly installed below the table, the horizontally arranged second bevel gear is installed on the lower surface of the table through a bearing, the output end of the positioning motor is fixedly connected with the second bevel gear, and a plurality of strip-shaped through holes are arranged in the vertical direction of the table, and each strip-shaped through hole is arranged radially around the center of the second bevel gear in a radial manner of the second bevel gear;

[0014] In each positioning assembly, the positioning clamp is located above the table, the first rack, the first toothed transmission element, the first worm and the shaft are located below the table; the positioning clamp is fixedly connected with the first rack through a sliding block, the sliding block is slidingly connected in a strip-shaped through hole, the first rack is opposite to the strip-shaped through hole, the straight-line distance between each positioning clamp and the center of the second bevel gear is the same; one end of the shaft is fixedly connected with the first bevel gear, the other end of the shaft is fixedly connected with the first worm, the first bevel gear is engaged with the second bevel gear, the first worm is engaged with the first toothed transmission element, and the first toothed transmission element is also engaged with the first rack;

[0015] When the positioning motor drives the second bevel gear to rotate, the second bevel gear drives the first bevel gear, the shaft and the first worm to rotate, so as to drive the first toothed transmission element to rotate, thereby enabling the first toothed transmission element to drive the first rack and the positioning clamp to move linearly along the strip-shaped through hole, and each positioning clamp moves synchronously.

[0016] In a possible implementation, each positioning clamp is further provided with a second pressure sensor for clamping the surface of the part to be ground, and the control terminal acquires pressure data from each second pressure sensor to determine the clamping pressure value between the part to be ground and each positioning clamp.

[0017] In a possible implementation, the device further comprises a joint; the joint comprises a plurality of ball beads, a plurality of springs and a polygonal head; a plurality of joint grooves extending in the radial direction are formed in the lower side wall of the telescopic rod, each ball bead is connected in a joint groove through a spring to form a spring plunger; the bottom end of the telescopic rod is fixedly connected with the polygonal head; a polygonal groove extending in the axial direction is formed in the top of each grinding mold, and each polygonal groove can be inserted and matched with the polygonal head; a plurality of interface grooves extending in the radial direction are formed in the inner side wall of each polygonal groove, and each interface groove is inserted and matched with a spring plunger when the polygonal head is inserted into the polygonal groove.

[0018] In a possible implementation, the control terminal can control the grinding motor to vary the frequency, so that the rotating speed of the grinding mold can be adjusted to multiple gears.

[0019] In a possible implementation, the lifting assembly comprises a rack, a second toothed transmission element and a second worm; the output end of the lifting motor is fixedly connected with a horizontally arranged second worm, the side surface of the driving shaft is fixedly connected with a vertically arranged second rack, the second toothed transmission element is engaged with the second worm and the second rack at the same time, and when the lifting motor drives the second worm to rotate, the second worm drives the second toothed transmission element to rotate, so as to drive the second rack and the telescopic rod to move in the vertical direction.

[0020] According to one aspect of the present disclosure, a method for grinding an atmospheric release valve for a heavy water reactor nuclear power plant is provided. The method is implemented based on the aforementioned grinding apparatus for atmospheric release valves in a heavy water reactor nuclear power plant. For each part to be ground, the method includes:

[0021] Step 100: Install the grinding fixture that matches the part to be ground onto the lower end of the telescopic rod, and fix the part to be ground in the positioning module;

[0022] Step 101: After step 100, the control terminal controls the lifting motor to drive the telescopic rod to descend, and determines the current pressure value of the part to be ground based on the data collected by each first pressure sensor. When the control terminal determines that the current pressure value of the part to be ground is within the pressure threshold range, it controls the lifting motor to stop driving the telescopic rod, so that the grinding fixture maintains its current spatial position.

[0023] Step 102: After step 101, the control terminal controls the grinding motor to drive the telescopic rod to rotate and grind the part to be ground. During the continuous grinding process, if the control terminal determines that the pressure value currently borne by the part to be ground is not within the pressure threshold range, it controls the lifting motor to adjust the position of the telescopic rod in the vertical direction until the pressure value currently borne by the part to be ground is within the pressure threshold range, and then stops the lifting motor to drive the telescopic rod, so that the grinding fixture maintains its current spatial position.

[0024] Step 103: After the grinding time meets the preset requirements, the control terminal controls the rotary motor to stop driving the telescopic rod, and then controls the lifting motor to drive the telescopic rod to rise.

[0025] In one possible implementation, the method is based on the above-mentioned grinding device for atmospheric release valve of heavy water reactor nuclear power plant. Step 100 includes step 1001, after placing the part to be ground between multiple positioning fixtures, the control terminal controls the positioning motor to drive the multiple positioning fixtures to move simultaneously toward the part to be ground, so as to hold and center the part to be ground.

[0026] In one possible implementation, the method is based on the above-mentioned grinding device for atmospheric release valve of heavy water reactor nuclear power plant. Step 1001 further includes the following steps: during the process of the control terminal controlling the positioning motor to drive multiple positioning clamps to move simultaneously toward the part to be ground, pressure data collected by each second sensor is acquired, and the clamping pressure value between each positioning clamp and the part to be ground is determined. When the control terminal determines that the clamping pressure value of each positioning clamp is within the clamping force threshold range, it controls the positioning motor to stop driving the positioning clamp, so that each positioning clamp maintains the current state of clamping the part to be ground.

[0027] The beneficial effects of this disclosure are as follows: The grinding device for the atmospheric release valve of the heavy water reactor nuclear power plant provided by this disclosure effectively clamps the parts to be ground through the positioning module. According to the shape and size of the parts to be ground (such as valve core and valve seat), a grinding jig that matches them is designed and manufactured to ensure that the grinding is in place. The grinding module realizes the rotation drive and up-down drive of the grinding jig, thereby allowing the grinding force to be adjusted at any time during the grinding process. This not only keeps the grinding surface completely in contact with the parts to be ground, but also provides effective grinding clamping force during the grinding process. Thus, the sealing surface of the atmospheric release valve of the heavy water reactor nuclear power plant can be safely and efficiently ground. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of a grinding device for an atmospheric release valve in a heavy water reactor nuclear power plant, as shown in an embodiment of this disclosure.

[0029] Figure 2 This is a schematic diagram of a telescopic pole;

[0030] Figure 3 This is a partial installation diagram of the upper section of the telescopic pole;

[0031] Figure 4 This is a partial installation diagram of the upper and middle sections of the telescopic pole;

[0032] Figure 5 This is a schematic diagram of the connector;

[0033] Figure 6 This is a schematic diagram of the grinding fixture;

[0034] Figure 7 This is a schematic diagram showing the installation of some components in the positioning module;

[0035] In the picture:

[0036] 1. Table, 2. Positioning module, 3. Positioning fixture, 4. Parts, 5. Valve core grinding fixture

[0037] 6. Valve seat grinding fixture; 7. Bracket; 8. Grinding motor; 9. Gearbox; 10. Control terminal; 11. Telescopic rod.

[0038] 12. Connector; 13. Locker; 14. Interface groove; 15. Multi-angled groove; 16. Lower section; 17. Bead.

[0039] 18. Spring; 19. Multi-angled head; 20. Upper section; 21. First pressure sensor; 22. Middle section; 23. Drive pin;

[0040] 24. First rack; 25. First toothed transmission element; 26. First worm gear; 27. Shaft; 28. First bevel gear;

[0041] 29. Second bevel gear; 30. Drive shaft; 38. Transmission key; 39. Second rack;

[0042] 40. Second toothed transmission element; 41. Second worm gear. Detailed Implementation

[0043] The present disclosure will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0044] Unless otherwise defined, the technical and scientific terms used in this disclosure have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains; the terminology used in this disclosure is for the purpose of describing particular embodiments only and is not intended to be limiting of this disclosure; the term "comprising" and any variations thereof in this disclosure are intended to cover non-exclusive inclusion. Clearly, the embodiments described in this disclosure are only a part of the embodiments of this disclosure, and not all of them. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of this disclosure without inventive effort are within the scope of protection of this disclosure.

[0045] In this disclosure, the reference to "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this disclosure. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0046] Figure 1 This is a schematic diagram of a grinding device for an atmospheric release valve in a heavy water reactor nuclear power plant, as shown in an embodiment of this disclosure. Figure 1 As shown, the device includes: a grinding module, a positioning module 2, a control terminal 10, and a table 1.

[0047] Positioning module 2 is set on the table to horizontally fix the part 4 to be ground. The positioning module can be, for example, an elastic claw or clamp that is fixedly connected to the table, which can fix the part to be ground horizontally on the table. The grinding module includes: multiple grinding jigs, bracket 7, grinding motor 8, lifting motor, gearbox 9, telescopic rod 11, and connector 12. Each grinding jig is different, and different grinding jigs are used to fit and grind parts of different parts of the valve. For example, the grinding jigs may include valve core grinding jig 5 for grinding valve cores and valve seat grinding jig 6 for grinding valve seats. It should be noted that the appropriate grinding jig can be manufactured according to the shape of the part to be ground. This disclosure does not limit the number and type of grinding jigs. In this way, irregularly shaped parts of any shape can be fitted and ground as needed, thereby flexibly adapting to different application scenarios. Control terminal 10 is placed on table 1. A storage cabinet 13 can also be set under table 1 for storing grinding-related items.

[0048] The table 1 is set horizontally, and the bracket 7 is fixedly connected to the table 1 by bolts. The grinding motor 8 and the gearbox 9 are fixedly installed on the bracket 7 by bolts. The grinding motor 8 is connected to the top of the telescopic rod 11 through the gearbox 9. The telescopic rod 11 is set vertically, and the grinding fixture is fixedly installed at the bottom of the telescopic rod 11 through the connector 12. The power output by the grinding motor 8 is transmitted to the telescopic rod 11 through the transmission component in the gearbox 9. The grinding motor 8 can drive the telescopic rod 11 to drive the grinding fixture to rotate through the connector 12.

[0049] See Figure 2 The telescopic rod 11 includes an upper section 20, a middle section 22, and a lower section 16 that are fixedly connected from top to bottom. For example, the upper section 20 is pin-connected to the middle section 22, and the middle section 22 is pin-connected to the lower section 16. The middle section 22 and the lower section 16 can also be keyed, welded, or formed as a single piece. See also Figure 1 and Figure 3 The upper section 20 is a hollow cylindrical structure. The output end of the gearbox 9 is fixedly connected to the upper end of the drive shaft 30. The upper section 20 is sleeved on the outer side of the lower end of the drive shaft 30. One end of the transmission key 38 is slidably connected in the long keyway on the side wall of the drive shaft 30. The other end of the transmission key 38 is interference-fitted with the keyway of the upper section 20, so that the upper section 20 is key-connected to the drive shaft 30 through the transmission key 38. The drive shaft 30 can drive the upper section 20 to rotate and can also move up and down relative to the upper section 20.

[0050] The gearbox 9 also contains a lifting motor and a lifting assembly. The lifting assembly includes a second rack 39, a second toothed transmission element 40, and a second worm gear 41. The output end of the lifting motor is connected to the second worm gear 41, such as... Figure 3As shown, a second rack 39 is fixedly connected to the side of the drive shaft 30. The second worm gear 41 is horizontally arranged, and the second rack 39 is vertically arranged. The second toothed transmission element 40 meshes with both the second worm gear 41 and the second rack 39. When the lifting motor drives the second worm gear 41 to rotate, the second worm gear 41 drives the second toothed transmission element 40 to rotate, thereby causing the second rack 39 to move vertically. The telescopic rod 11 moves up and down through the power transmission of the lifting motor and the lifting assembly. The control terminal is communicatively connected to the grinding motor and the lifting motor, and can control the start and stop of the grinding motor and / or the lifting motor. Thus, the up-and-down movement and rotation of the telescopic rod, as well as the linkage between up-and-down movement and rotation, are comprehensively realized.

[0051] It should be noted that the toothed transmission element in this disclosure can be, for example, a gear or a turbine, and this disclosure does not limit the specific form of the toothed transmission element; the lifting assembly refers to a linear actuator that converts the rotational motion output by the lifting motor into linear motion, and the lifting assembly can be, for example, a lead screw or a belt and chain assembly, and this disclosure does not limit the specific structure of the lifting assembly.

[0052] like Figure 4 As shown, the lower end of the upper section 20 is fitted over the upper end of the middle section 22. The bottom edge of the upper section 20 has a stepped portion extending radially inward. The side wall of the middle section 22 has a radially inward extending annular groove. The inner edge of the stepped portion presses against the bottom of the annular groove. The surface inside the annular groove that is opposite to the groove opening and furthest away is the groove bottom. The two surfaces between the groove opening and the groove bottom inside the annular groove are the side walls. The middle section 22 is pin-connected to the upper section 20 by multiple drive pins 23. One end of each drive pin 23 is interference-fitted with a pin hole located above the annular groove on the side wall of the middle section 22. The other end of each drive pin 23 is slidably connected to an elongated pin hole on the side wall of the upper section 20. The elongated pin hole of the upper section 20 is set vertically. In this way, the upper section 20 can move relative to the middle section 22 in the vertical direction and can also drive the middle section 22 to rotate.

[0053] Multiple first pressure sensors 21 are fixedly connected to the lower sidewall of the annular groove. The control terminal 10 is communicatively connected to the multiple first pressure sensors 21, and the control terminal 10 determines the pressure value currently borne by the part to be ground based on the pressure data collected by each first pressure sensor 21. When the bottom end of the telescopic rod 11 does not press against an object, the upper sidewall of the annular groove presses against the upper end face of the step, and the other end of the transmission pin 23 presses against the lower inner wall where the long pin hole is located, so that the middle section 22 is suspended at the bottom end of the upper section 20, and the telescopic rod 11 is in a natural hanging state. During the process of the lifting motor driving the telescopic rod 11 to move downward with the grinding fixture (i.e., moving towards the part to be ground), if the grinding fixture touches the part to be ground, the lower section 16 and the middle section 22 are blocked and stop moving downward and remain relatively stationary with respect to the part to be ground, while the upper section 20 continues to move downward until the bottom end of the step touches the middle section 21. Each first pressure sensor 21 on the lower sidewall of the annular groove of section 22 is continuously subjected to downward pressure by the upper section 20, which is still driven downward. When the control terminal determines that the pressure value currently borne by the part to be ground is within the pressure threshold range, it controls the lifting motor to stop driving the telescopic rod, so that the grinding fixture maintains the current state of pressing against the part to be ground. Thus, the distance of the telescopic rod is precisely controlled according to the actual pressure value borne by the part to be ground, so that the grinding fixture and the part to be ground automatically maintain a suitable clamping force, preventing the telescopic rod 11 from being excessively lowered and causing damage to the part.

[0054] like Figure 5 and Figure 6 As shown, the connector 12 includes multiple balls 17, multiple springs 18, and polygonal heads 19; multiple radially extending connector grooves are provided on the side wall of the lower section 16, and each ball 17 is connected to a connector groove through a spring 18 to form a spring plunger; the bottom end of the lower section 16 is fixedly connected to the polygonal head 19; each grinding fixture has an axially extending polygonal groove 15 on its top, and each polygonal groove 15 can be inserted into the polygonal head 19; multiple radially extending interface grooves 14 are provided on the inner side wall of each polygonal groove 15. When the polygonal head 19 is inserted into the polygonal groove 15, each interface groove 14 is inserted into a spring plunger, so that the connector 12 and the grinding fixture form a tight snap-fit ​​positioning connection. The power of the grinding motor 8 is mainly transmitted to the grinding fixture by the polygonal head 19 and the polygonal groove 15.

[0055] It should be noted that the polygonal head can be, for example, a square head, a hexagonal head, or an octagonal head, and the shape of the polygonal groove is adapted to the polygonal head. This disclosure does not limit the specific shape of the polygonal head or the polygonal groove.

[0056] See Figure 1 and Figure 7The positioning module includes: a positioning motor, a second bevel gear 29, and multiple positioning components; each positioning component includes: a positioning fixture 3, a first rack 24, a first toothed transmission element 25, a first worm gear 26, and a shaft 27.

[0057] The positioning motor is fixedly installed under the table 1. The horizontally set second bevel gear 29 is installed on the lower surface of the table 1 through bearings. The output end of the positioning motor is fixedly connected to the second bevel gear 29. The table 1 has multiple strip-shaped through holes in the vertical direction. Each strip-shaped through hole is arranged radially around the center of the second bevel gear 29.

[0058] In each positioning assembly, the positioning clamp 3 is located above the table 1, and the first rack 24, the first toothed transmission element 25, the first worm 26, and the shaft 27 are located below the table 1. The positioning clamp 3 is fixedly connected to the first rack 24 via a slider, which is slidably connected in a strip-shaped through hole, with the first rack 24 facing the strip-shaped through hole. One end of the shaft 27 is fixedly connected to the first bevel gear 28, and the other end of the shaft 27 is fixedly connected to the first worm 26. The first bevel gear 28 meshes with the second bevel gear 29, and the first worm 26 meshes with the first toothed transmission element 25. The first toothed transmission element 25 also meshes with the first rack 24.

[0059] When the positioning motor drives the second bevel gear 29 to rotate, the second bevel gear 29 drives the first bevel gear 28, shaft 27, and first worm gear 26 to rotate. The first worm gear 26 drives the first toothed transmission element 25 to rotate. The first toothed transmission element 25 drives the first rack 24 to carry the positioning fixture 3 in a linear motion along the strip-shaped through hole. Since each strip-shaped through hole is arranged radially around the center of the second bevel gear 29, and the linear distance between each positioning fixture 3 and the center of the second bevel gear 29 is the same, the positioning motor can drive each positioning fixture 3 to move synchronously. The shape formed by the inner rings of each positioning fixture 3 always remains a concentric circle, resulting in a more uniform clamping force on the parts to be ground on the table 1. Precise centering of the parts to be ground can be achieved while tightening without additional adjustment.

[0060] In one possible implementation, a second pressure sensor may be provided on the surface of each positioning fixture 3 for holding the part to be ground. The control terminal 10 obtains pressure data from the second pressure sensor provided on each positioning fixture 3 and determines the clamping pressure value between the part to be ground and each positioning fixture 3.

[0061] In one possible implementation, see Figure 1 The storage cabinet 13 of the table 1 can be divided into two parts: the upper part is a drawer and the lower part is a cabinet with a hinged door.

[0062] In one possible implementation, a method for grinding an atmospheric release valve for a heavy water reactor nuclear power plant is provided. The method is based on the aforementioned grinding apparatus for atmospheric release valves in a heavy water reactor nuclear power plant. For each part to be ground, the method includes:

[0063] Step 100: Install the grinding fixture, which is compatible with the part to be ground, onto the lower end of the telescopic rod, and fix the part to be ground in the positioning module. Because the atmospheric release valve has irregularly shaped sealing surfaces and other components, general grinding methods cannot completely fit the irregular structure in one go, thus failing to effectively repair damage to the sealing surface. This disclosure creatively provides a variety of grinding fixtures; different grinding fixtures can accurately fit parts with different structures, and together with the device, the repair can be completed. Due to the convenience of specialized tools, the overall maintenance time is greatly shortened.

[0064] Step 101: After step 100, the control terminal controls the lifting motor to drive the telescopic rod downwards. After the grinding fixture presses against the part to be ground, the control terminal determines the current pressure value borne by the part to be ground based on the data collected by each first pressure sensor. If the control terminal determines that the current pressure value borne by the part to be ground is within the pressure threshold range, it controls the lifting motor to stop driving the telescopic rod, so that the grinding fixture maintains its current spatial position and presses against the part to be ground with the required clamping force. This effectively avoids damage to the grinding fixture and the part to be ground due to excessive lowering of the telescopic rod. In addition, relevant engineers can set different pressure threshold ranges (e.g., 5-10N) in the control terminal according to the needs of the part to be ground. This allows for precise control of the grinding force of the grinding fixture on the part according to actual grinding needs, flexibly adapting to different application scenarios.

[0065] Step 102: The control terminal controls the grinding motor to drive the telescopic rod to rotate, grinding the part to be ground. During continuous grinding, when the control terminal determines that the pressure value currently borne by the part to be ground is less than the minimum value of the pressure threshold range, it controls the lifting motor to drive the telescopic rod downward until the pressure value currently borne by the part to be ground falls within the pressure threshold range, then stops the lifting motor to drive the telescopic rod, keeping the grinding fixture in its current spatial position. When the control terminal determines that the pressure value currently borne by the part to be ground is greater than the maximum value of the pressure threshold range, it controls the lifting motor to drive the telescopic rod upward until the pressure value currently borne by the part to be ground falls within the pressure threshold range, then stops the lifting motor to drive the telescopic rod, keeping the grinding fixture in its current spatial position. Since the surface of the part being ground continuously thins during the grinding process, the clamping force between the grinding fixture and the part will continuously weaken. To address this issue, this disclosure uses multiple first pressure sensors to monitor the pressure value between the grinding fixture and the part in real time. When the pressure value deviates from the pressure threshold range, the position of the telescopic rod in the vertical direction is adjusted to promptly adjust the grinding clamping force to the required pressure threshold range. This numerically ensures a continuous grinding clamping force, significantly improving the quality and efficiency of grinding. In addition, multiple primary pressure sensors are cleverly installed in the telescopic rod, which can accurately acquire pressure data in real time without interfering with the grinding process.

[0066] In step 103, after the grinding time meets the preset requirements, the control terminal controls the rotary motor to stop driving the telescopic rod, and then controls the lifting motor to drive the telescopic rod to rise. For each part of the valve to be ground, grinding can be performed using the methods from steps 100 to 103, thereby ensuring the efficiency and quality of maintenance for parts such as the irregular sealing surface of the atmospheric release valve. In this way, this disclosure completes the grinding operation automatically, freeing up manpower. The adjustable speed and pressure can automatically complete rough grinding and fine grinding. The grinding fixture automatically stops after pressing down to the set pressure, ensuring sufficient downward pressure during grinding without damaging the parts to be ground due to untimely control or excessive pressure.

[0067] In one possible implementation, step 100 includes step 1001, whereby after placing the part to be ground between multiple positioning fixtures, the control terminal controls the positioning motor to drive the multiple positioning fixtures to move simultaneously toward the part to be ground, thereby clamping and centering the part. The linkage control of the positioning fixtures ensures that the clamping always forms a concentric circle, ensuring accurate centering and positioning while clamping the part, enabling precise grinding to the required position.

[0068] In one possible implementation, step 1001 further includes placing the part to be ground between multiple positioning fixtures, then controlling the positioning motor to drive the multiple positioning fixtures to move simultaneously toward the part to be ground, acquiring pressure data collected by each second sensor, determining the clamping pressure value between each positioning fixture and the part to be ground, and when the control terminal determines that the clamping pressure value of each positioning fixture is within the clamping force threshold range, controlling the positioning motor to stop driving the positioning fixtures, and each positioning fixture maintains its current clamping state, thereby preventing the positioning fixtures from clamping the part to be ground with excessive force and causing damage to the part.

[0069] In one application example, taking the grinding of an atmospheric release valve in a nuclear power plant as an example, after disassembling the atmospheric release valve, the valve core and valve seat obtained from the disassembly are ground sequentially using the device disclosed herein. A grinding jig adapted to the part to be ground is installed at the lower end of the telescopic rod, and the angle between the grinding surface of the grinding jig and the grinding surface of the adapted part and the axis is consistent. After the part to be ground is placed between multiple positioning jigs, the control terminal controls the positioning motor to drive the multiple positioning jigs to clamp and center the part to be ground. After the clamping force of the positioning jig on the part meets the requirements, the control terminal controls the positioning motor to stop working and then controls the lifting motor to lower the telescopic rod. After the grinding jig presses against the part to be ground and the clamping force of the grinding jig on the part meets the requirements, the control terminal controls the lifting motor to stop working and then controls the grinding motor to drive the telescopic rod to rotate, thus grinding the part to be ground. The control terminal can control the frequency converter of the grinding motor, allowing the grinding jig speed to be adjusted to multiple levels, such as 15rpm, 30rpm, 45rpm, and 60rpm. It is equipped with a manual switch and a timer for shutdown. The control terminal uses a touch screen to display the control process of grinding each part, the grinding speed, and the real-time force on the part. During grinding, the control terminal maintains the clamping force of the grinding jig on the part within the required threshold range. After the grinding time meets the preset requirements, the control terminal raises the telescopic rod. During use, the parts are well clamped, the alignment between the parts and the grinding jig meets the requirements, the grinding effect is significant, and the sealing surface is free of visible scratches and damage after grinding. After grinding, the atmospheric release valve is reassembled and put into operation, with good sealing performance and elimination of internal leakage defects.

[0070] The various embodiments of this disclosure have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or improvement of the technology in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A grinding device for an atmospheric release valve in a heavy water reactor nuclear power plant, characterized in that, The device includes: a grinding module, a positioning module, a control terminal, and a table; the positioning module is set on the table and is used to horizontally fix the parts to be ground. The grinding module includes: a support, a grinding motor, a lifting motor, a gearbox, a telescopic rod, and multiple grinding jigs. Different grinding jigs are used to grind different parts. The support is fixedly connected to the table, the grinding motor and the gearbox are fixedly connected to the support, the telescopic rod is set vertically, the grinding motor is connected to the top of the telescopic rod through the gearbox, and a grinding jig is fixedly installed at the bottom of the telescopic rod. The upper part of the telescopic rod is hollow. The output end of the gearbox is fixedly connected to the upper end of the drive shaft. The upper part of the telescopic rod is sleeved on the outer side of the lower end of the drive shaft. One end of the transmission key is slidably connected in the long keyway on the side wall of the drive shaft. The other end of the transmission key is interference-fitted with the keyway on the side wall of the telescopic rod. The grinding motor can drive the telescopic rod to rotate through the drive shaft. The drive shaft can also generate relative displacement with the telescopic rod in the vertical direction. The gearbox is also equipped with a lifting motor and a lifting assembly. The output end of the lifting motor is connected to the telescopic rod through the lifting assembly. The lifting motor drives the telescopic rod to move linearly in the vertical direction through the lifting assembly. The control terminal is communicatively connected to the grinding motor and the lifting motor, and can control the start and stop of the grinding motor and / or the lifting motor; The telescopic rod comprises an upper section, a middle section, and a lower section fixedly connected from top to bottom. The upper section is a hollow cylindrical structure and is sleeved on the outer side of the lower end of the drive shaft. The other end of the transmission key is interference-fitted with the keyway on the side wall of the upper section. The lower end of the upper section is sleeved on the outer side of the upper end of the middle section. The bottom edge of the upper section has a stepped portion extending radially inward. The side wall of the middle section has a radially inwardly extending annular groove circumferentially formed. The middle section is pin-connected to the upper section via multiple transmission pins. One end of each transmission pin is interference-fitted with a pin hole located above the annular groove on the side wall of the middle section. The other end of each transmission pin is slidably connected to a long pin hole formed on the side wall of the upper section. The long pin hole of the upper section is set vertically. Multiple first pressure sensors are fixedly connected to the lower side wall of the annular groove. When the grinding fixture presses against the part to be ground, the bottom end of the stepped portion of the upper section presses against each of the first pressure sensors on the lower side wall of the annular groove of the middle section. The control terminal is connected to multiple first pressure sensors and can acquire the pressure data currently collected by the multiple first pressure sensors, thereby determining the pressure value currently borne by the part to be ground. Based on the aforementioned apparatus, each part to be ground is processed using the following steps: Step 100: Install the grinding fixture that matches the part to be ground onto the lower end of the telescopic rod, and fix the part to be ground in the positioning module; Step 101: After step 100, the control terminal controls the lifting motor to drive the telescopic rod to descend, and determines the current pressure value of the part to be ground based on the data collected by each first pressure sensor. When the control terminal determines that the current pressure value of the part to be ground is within the pressure threshold range, it controls the lifting motor to stop driving the telescopic rod, so that the grinding fixture maintains its current spatial position. Step 102: After step 101, the control terminal controls the grinding motor to drive the telescopic rod to rotate and grind the part to be ground. During the continuous grinding process, if the control terminal determines that the pressure value currently borne by the part to be ground is not within the pressure threshold range, it controls the lifting motor to adjust the position of the telescopic rod in the vertical direction until the pressure value currently borne by the part to be ground is within the pressure threshold range, and then stops the lifting motor to drive the telescopic rod, so that the grinding fixture maintains its current spatial position. Step 103: After the grinding time meets the preset requirements, the control terminal controls the rotary motor to stop driving the telescopic rod, and then controls the lifting motor to drive the telescopic rod to rise.

2. The grinding device for the atmospheric release valve of a heavy water reactor nuclear power plant according to claim 1, characterized in that, The positioning module includes: a positioning motor, a second bevel gear, and multiple positioning components; each positioning component includes: a positioning fixture, a first rack, a first toothed transmission element, a first worm gear, and a shaft; the control terminal is communicatively connected to the positioning motor and is used to control the start and stop of the positioning motor. The positioning motor is fixedly installed under the table. The horizontally set second bevel gear is installed on the lower surface of the table through bearings. The output end of the positioning motor is fixedly connected to the second bevel gear. The table has multiple strip-shaped through holes in the vertical direction. Each strip-shaped through hole is arranged radially around the center of the second bevel gear. In each positioning assembly, the positioning fixture is located above the table, while the first rack, the first toothed transmission element, the first worm, and the shaft are located below the table. The positioning fixture is fixedly connected to the first rack via a slider, which is slidably connected in a strip-shaped through hole. The first rack is directly opposite the strip-shaped through hole, and each positioning fixture is equidistant from the center of the second bevel gear. One end of the shaft is fixedly connected to the first bevel gear, and the other end is fixedly connected to the first worm. The first bevel gear meshes with the second bevel gear, the first worm meshes with the first toothed transmission element, and the first toothed transmission element also meshes with the first rack. When the positioning motor drives the second bevel gear to rotate, the second bevel gear drives the first bevel gear, shaft, and first worm to rotate, thereby driving the first toothed transmission element to rotate. This causes the first toothed transmission element to drive the first rack and positioning fixture to move linearly along the strip-shaped through hole, and all positioning fixtures move synchronously.

3. The grinding device for the atmospheric release valve of a heavy water reactor nuclear power plant according to claim 2, characterized in that, Each positioning fixture is equipped with a second pressure sensor on its surface for holding the part to be ground. The control terminal obtains pressure data from each second pressure sensor to determine the clamping pressure value between the part to be ground and each positioning fixture.

4. The grinding device for the atmospheric release valve of a heavy water reactor nuclear power plant according to claim 1, characterized in that, The device further includes a connector; the connector includes multiple balls, multiple springs, and a polygonal head; multiple radially extending connector grooves are provided on the lower side wall of the telescopic rod, and each ball is connected to a connector groove by a spring to form a spring plunger; the bottom end of the telescopic rod is fixedly connected to the polygonal head; each grinding die has an axially extending polygonal groove on its top, and each polygonal groove can be inserted into the polygonal head; multiple radially extending interface grooves are provided on the inner side wall of each polygonal groove, and when the polygonal head is inserted into the polygonal groove, each interface groove is inserted into a spring plunger.

5. The grinding device for the atmospheric release valve of a heavy water reactor nuclear power plant according to claim 1, characterized in that, The control terminal can control the frequency conversion of the grinding motor, so that the speed of the grinding die can be adjusted to multiple levels.

6. The grinding device for the atmospheric release valve of a heavy water reactor nuclear power plant according to claim 1, characterized in that, The lifting assembly includes a rack, a second toothed transmission element, and a second worm. The output end of the lifting motor is fixedly connected to a horizontally arranged second worm, and the side of the drive shaft is fixedly connected to a vertically arranged second rack. The second toothed transmission element meshes with both the second worm and the second rack. When the lifting motor drives the second worm to rotate, the second worm drives the second toothed transmission element to rotate, thereby driving the second rack and the telescopic rod to move in the vertical direction.

7. A grinding method for an atmospheric release valve in a heavy water reactor nuclear power plant, characterized in that, The method is based on the grinding device for the atmospheric release valve of the heavy water reactor nuclear power plant as described in claim 3. Step 100 includes step 1001, after placing the part to be ground between multiple positioning fixtures, the control terminal controls the positioning motor to drive the multiple positioning fixtures to move simultaneously toward the part to be ground, thereby clamping and centering the part to be ground.

8. The grinding method for the atmospheric release valve of a heavy water reactor nuclear power plant according to claim 7, characterized in that, Step 1001 also includes the following steps: during the process of the control terminal controlling the positioning motor to drive multiple positioning fixtures to move simultaneously toward the part to be ground, the control terminal acquires the pressure data collected by each second sensor, determines the clamping pressure value between each positioning fixture and the part to be ground, and when the control terminal determines that the clamping pressure value of each positioning fixture is within the clamping force threshold range, the control terminal controls the positioning motor to stop driving the positioning fixture, so that each positioning fixture maintains the current state of clamping the part to be ground.

Images