Grinding device and method for atmospheric relief valve of heavy water reactor nuclear power station

Abstract

The invention belongs to the technical field of nuclear power, and particularly relates to a heavy water reactor nuclear power station atmosphere relief valve grinding device and method. According to the grinding device for the sealing surface of the atmospheric relief valve of the heavy water reactor nuclear power station, the to-be-ground part is effectively clamped through the positioning module, the grinding mould matched with the to-be-ground part is designed and manufactured according to the shape and the size of the to-be-ground part, it is ensured that grinding is in place, and the maintenance quality is guaranteed; rotation driving and up-down driving of the grinding mould are achieved through the grinding module, so that the grinding force can be adjusted at any time in the part grinding process, the grinding face can be kept to be completely attached to the part to be ground, and effective grinding pressing force can be provided in the grinding process. Therefore, safe and efficient grinding treatment on the sealing surface of the atmospheric relief valve of the heavy water reactor nuclear power station 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 has low work efficiency. The electric grinder 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 grinder 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; 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. 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 in the side wall of the driving shaft, the other end of the transmission key is in interference fit with the key groove in 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 be relatively displaced with the telescopic rod in the vertical direction; The lifting motor and the lifting assembly are further arranged in the gear box, 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. 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.

[0006] In a possible implementation, the telescopic rod comprises an upper segment, a middle segment and a lower segment which are sequentially fixedly connected 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 in 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 circumferentially provided with an annular groove extending radially inward; 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 in the side wall of the middle segment above the annular groove, and the other end of each transmission pin is slidably connected with a long pin hole in 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 annular groove; in the case that the grinding mold is pressed against the part to be ground, the step portion at the bottom of the upper segment is pressed against each first pressure sensor on the side wall below the annular groove of the middle segment; 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.

[0007] 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; 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; In each positioning assembly, the positioning clamp is located above the table, and 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, and the straight-line distances between the positioning clamps and the center of the second bevel gear are the same; one end of the shaft is fixedly connected with the first bevel gear, and 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 further engaged with the first rack; 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 the positioning clamps move synchronously.

[0008] 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.

[0009] 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 shoe, 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.

[0010] In a possible implementation, the control terminal can control the grinding motor to change the frequency, so that the rotating speed of the grinding shoe can be adjusted to multiple gears.

[0011] 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.

[0012] According to an aspect of the embodiments of the present disclosure, a heavy water reactor nuclear power plant atmospheric release valve grinding method is provided, which is realized based on the heavy water reactor nuclear power plant atmospheric release valve grinding device. For each part to be ground, the method comprises: Step 100, install the grinding fixture matched with the part to be ground to 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 pressure value currently borne by the part to be ground according to the data collected by each first pressure sensor. When the control terminal judges that the pressure value currently borne by the part to be ground belongs to the pressure threshold interval, it controls the lifting motor to stop driving the telescopic rod, so that the grinding fixture maintains the current spatial position. Step 102, after step 101, the control terminal controls the grinding motor to drive the telescopic rod to rotate, and grinds the part to be ground. During the continuous grinding process, when the control terminal judges that the pressure value currently borne by the part to be ground does not belong to the pressure threshold interval, 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 belongs to the pressure threshold interval, and stops the lifting motor from driving the telescopic rod, so that the grinding fixture maintains the current spatial position. Step 103, the control terminal controls the rotation motor to stop driving the telescopic rod after the grinding time meets the preset requirement, and then controls the lifting motor to drive the telescopic rod to lift.

[0013] In a possible implementation, the method is implemented based on the heavy water reactor nuclear power plant atmospheric release valve grinding device described above, and step 100 includes step 1001. After the part to be ground is placed between the plurality of positioning clamps, the control terminal controls the positioning motor to drive the plurality of positioning clamps to move towards the part to be ground at the same time, and holds and centers the part to be ground.

[0014] In a possible implementation, the method is implemented based on the heavy water reactor nuclear power plant atmospheric release valve grinding device described above, and step 1001 further includes that during the process in which the control terminal controls the positioning motor to drive the plurality of positioning clamps to move towards the part to be ground at the same time, the pressure data collected by each second sensor is obtained to determine the clamping pressure value between each positioning clamp and the part to be ground. When the control terminal judges that the clamping pressure value of each positioning clamp belongs to the clamping force threshold interval, it controls the positioning motor to stop driving the positioning clamp, so that each positioning clamp maintains the state of clamping the part to be ground.

[0015] The heavy water nuclear power plant atmospheric release valve grinding device provided by the present disclosure has the beneficial effects that: the heavy water nuclear power plant atmospheric release valve grinding device provided by the present disclosure effectively clamps the part to be ground through the positioning module, and the grinding mold matched with the shape and size of the part to be ground (such as the valve core and the valve seat) is designed and manufactured to ensure that the grinding is in place; the rotation driving and up-down driving of the grinding mold are realized through the grinding module, so that the grinding intensity can be adjusted at any time during the grinding of the part, the grinding surface can be completely attached to the part to be ground, and effective grinding pressure can be provided during the grinding; and thus the sealing surface of the heavy water nuclear power plant atmospheric release valve is safely and efficiently ground. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 is a schematic diagram of a heavy water nuclear power plant atmospheric release valve grinding device according to an embodiment of the present disclosure; Figure 2 is a schematic diagram of a telescopic rod; Figure 3 is a local installation schematic diagram of an upper section of the telescopic rod; Figure 4 is a local installation schematic diagram of the upper section and the middle section of the telescopic rod; Figure 5 is a schematic diagram of a joint; Figure 6 is a schematic diagram of a grinding mold; Figure 7 is an installation schematic diagram of part components in the positioning module; In the figure: 1. table, 2. positioning module, 3. positioning clamp, 4. part, 5. valve core grinding mold, 6. valve seat grinding mold, 7. support, 8. grinding motor, 9. gear box, 10. control terminal, 11. telescopic rod, 12. joint, 13. storage cabinet, 14. interface groove, 15. polygonal groove, 16. lower section, 17. ball, 18. spring, 19. polygonal head, 20. upper section, 21. first pressure sensor, 22. middle section, 23. transmission pin, 24. first rack, 25. first tooth-shaped transmission element, 26. first worm, 27. shaft, 28. first bevel gear, 29. second bevel gear, 30. drive shaft, 38. transmission key, 39. second rack, 40. second tooth-shaped transmission element, 41. second worm. DETAILED DESCRIPTION

[0017] The present disclosure will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0018] 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.

[0019] 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.

[0020] 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.

[0021] 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.

[0022] The table 1 is horizontally arranged, the support 7 is fixedly connected to the table 1 by bolts, the grinding motor 8 and the gear box 9 are fixedly installed on the support 7 by bolts, the grinding motor 8 is drivingly connected to the top end of the telescopic rod 11 through the gear box 9, the telescopic rod 11 is vertically arranged, and the grinding mold is fixedly installed on the bottom end of the telescopic rod 11 through the joint 12; the power output by the grinding motor 8 is transmitted to the telescopic rod 11 through the transmission assembly in the gear box 9, and the grinding motor 8 can drive the telescopic rod 11 to drive the grinding mold to rotate through the joint 12.

[0023] Referring to Figure 2 , the telescopic rod 11 comprises an upper segment 20, a middle segment 22 and a lower segment 16 which are fixedly connected in sequence from top to bottom, for example, the upper segment 20 is connected to the middle segment 22 by a pin, and the middle segment 22 and the lower segment 16 are connected by a pin, or the middle segment 22 and the lower segment 16 can be connected by a key, welded or integrally formed; Figure 1 and Figure 3 , the upper segment 20 is a hollow cylindrical structure, the output end of the gear box 9 is fixedly connected to the upper end of the driving shaft 30, the lower end of the driving shaft 30 is sleeved with the upper segment 20, one end of the transmission key 38 is slidingly connected in the long key groove in the side wall of the driving shaft 30, and the other end of the transmission key 38 is in interference fit with the key groove of the upper segment 20, so that the upper segment 20 is connected to the driving shaft 30 by the transmission key 38, and the driving shaft 30 can drive the upper segment 20 to rotate and move up and down relative to the upper segment 20.

[0024] The gear box 9 further comprises a lifting motor and a lifting assembly, the lifting assembly comprises a second rack 39, a second tooth-shaped transmission element 40 and a second worm 41; the output end of the lifting motor is connected with the second worm 41, as shown in Figure 3 , the second rack 39 is fixedly connected to the side surface of the driving shaft 30, the second worm 41 is horizontally arranged, and the second rack 39 is vertically arranged; the second tooth-shaped transmission element 40 is engaged with the second worm 41 and the second rack 39 at the same time, when the lifting motor drives the second worm 41 to rotate, the second worm 41 drives the second tooth-shaped transmission element 40 to rotate, so as to drive the second rack 39 to move in the vertical direction, and the telescopic rod 11 moves up and down through the power transmission of the lifting motor and the lifting assembly. 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. Therefore, the up and down movement, rotation, linkage of the up and down movement and rotation of the telescopic rod are comprehensively realized.

[0025] It should be noted that the tooth-shaped transmission element in the present disclosure can be, for example, a gear or a turbine, and the specific form of the tooth-shaped transmission element is not limited in the present disclosure; the lifting assembly represents a linear actuator for converting the rotary 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 the specific structure of the lifting assembly is not limited in the present disclosure.

[0026] As Figure 4As shown, the lower end of the upper section 20 is sleeved on the outer upper end of the middle section 22; the bottom end edge of the upper section 20 has a step portion extending radially inward, and the side wall of the middle section 22 is circumferentially provided with a ring groove extending radially inward, the inner side edge of the step portion abuts against the groove bottom of the ring groove, wherein the surface inside the ring groove opposite to the groove opening and farthest away is the groove bottom, and the surfaces on both sides between the groove opening and the groove bottom are the side walls. The middle section 22 is pin-connected with the upper section 20 through a plurality of transmission pins 23, one end of each transmission pin 23 is in interference fit with the side wall of the middle section 22 above the ring groove, and the other end of each transmission pin 23 is in sliding connection with the long pin hole provided in the side wall of the upper section 20, and the long pin hole of the upper section 20 is arranged in the vertical direction. In this way, the upper section 20 can not only move relative to the middle section 22 in the vertical direction, but also drive the middle section 22 to rotate.

[0027] The side wall below in the ring groove is fixedly connected with a plurality of first pressure sensors 21; the control terminal 10 is in communication connection with the plurality of first pressure sensors 21, and the control terminal 10 determines the current pressure value borne by the part to be ground according to the pressure data collected by each first pressure sensor 21. In the case that the bottom end of the telescopic rod 11 does not press against the object, the side wall above in the ring groove abuts against the upper end surface of the step portion, and the other end of the transmission pin 23 abuts against the inner wall below of the long pin hole, so that the middle section 22 is hung at the bottom end of the upper section 20, and the telescopic rod 11 is in a naturally drooping state; in the process that the lifting motor drives the telescopic rod 11 to move downward (i.e. move toward the part to be ground) with the grinding jig, if the grinding jig touches the part to be ground, the lower section 16 and the middle section 22 are blocked and stopped from moving downward and remain relatively stationary with the part to be ground, and the upper section 20 continues to move downward until the bottom end of the step portion touches each first pressure sensor 21 of the side wall below in the ring groove of the middle section 22, and since the upper section 20 is still driven downward, the upper section 20 continuously applies downward pressure to each first pressure sensor 21, and the control terminal controls the lifting motor to stop driving the telescopic rod so that the grinding jig remains in the current state of pressing against the part to be ground, in the case that the current pressure value borne by the part to be ground is determined to belong to the pressure threshold interval. In this way, the distance of the telescopic rod is accurately controlled according to the actual pressure value borne by the part to be ground, so that the grinding jig and the part to be ground automatically maintain a suitable pressing force, and the telescopic rod 11 is prevented from being excessively lowered to cause damage to the part.

[0028] As Figure 5 and Figure 6As shown, the joint 12 comprises a plurality of beads 17, a plurality of springs 18 and a polygonal head 19; the sidewall of the lower section 16 is provided with a plurality of radially extending joint grooves, each bead 17 is connected in a joint groove by a spring 18 to form a spring plunger; the bottom end of the lower section 16 is fixedly connected to the polygonal head 19; the top of each grinding shoe is provided with an axially extending polygonal groove 15, each polygonal groove 15 can be inserted into the polygonal head 19 to form a plug-in fit; the inner sidewall of each polygonal groove 15 is provided with a plurality of radially extending interface grooves 14, and each interface groove 14 forms a plug-in fit with a spring plunger when the polygonal head 19 is inserted into the polygonal groove 15, so that the joint 12 and the grinding shoe form a close buckle positioning connection relationship, and the power of the grinding motor 8 is mainly transmitted to the grinding shoe by the polygonal head 19 and the polygonal groove 15.

[0029] It should be noted that the polygonal head can be, for example, a four-corner head, a six-corner head or an eight-corner head, and the shape of the polygonal groove is matched with the polygonal head, and the specific form of the polygonal head and the polygonal groove is not limited in the present disclosure.

[0030] Referring to Figure 1 and Figure 7 , the positioning module comprises a positioning motor, a second bevel gear 29 and a plurality of positioning assemblies; each positioning assembly comprises a positioning clamp 3, a first rack 24, a first toothed transmission element 25, a first worm 26 and a shaft 27.

[0031] The positioning motor is fixedly installed below the table 1, the horizontally arranged second bevel gear 29 is installed on the lower surface of the table 1 through a bearing, the output end of the positioning motor is fixedly connected with the second bevel gear 29, and the table 1 is provided with a plurality of strip-shaped through holes in the vertical direction, and each strip-shaped through hole is arranged radially around the center of the second bevel gear 29.

[0032] 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 with the first rack 24 through a sliding block, the sliding block is slidingly connected in a strip-shaped through hole, and the first rack 24 is opposite to the strip-shaped through hole; one end of the shaft 27 is fixedly connected with the first bevel gear 28, the other end of the shaft 27 is fixedly connected with the first worm 26, the first bevel gear 28 is engaged with the second bevel gear 29, the first worm 26 is engaged with the first toothed transmission element 25, and the first toothed transmission element 25 is further engaged with the first rack 24.

[0033] When the positioning motor drives the second bevel gear 29 to rotate, the second bevel gear 29 drives the first bevel gear 28, the shaft 27 and the first worm 26 to rotate, the first worm 26 drives the first tooth-shaped transmission element 25 to rotate, and the first tooth-shaped transmission element 25 drives the first rack 24 to move linearly along the strip-shaped through hole, carrying the positioning clamp 3. 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 clamp 3 and the center of the second bevel gear 29 is the same, each positioning clamp 3 can be driven to move synchronously by the positioning motor, and the shape formed by the inner circle of each positioning clamp 3 always remains concentric, so that the clamping force on the part to be ground on the table 1 is more uniform, and the accurate centering of the part to be ground can be realized at the same time without additional adjustment.

[0034] In a possible implementation, each positioning clamp 3 can be provided with a second pressure sensor for clamping the surface of the part to be ground, and the control terminal 10 can obtain pressure data from the second pressure sensor of each positioning clamp 3 to determine the clamping pressure value between the part to be ground and each positioning clamp 3.

[0035] In a possible implementation, referring to 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 cover.

[0036] In a possible implementation, a heavy water reactor nuclear power plant atmospheric release valve grinding method is provided, which is realized based on the heavy water reactor nuclear power plant atmospheric release valve grinding device described above. For each part to be ground, the method comprises the following steps: Step 100: Install the grinding mold matched with the part to be ground to the lower end of the telescopic rod, and fix the part to be ground in the positioning module. Since the atmospheric release valve has a special-shaped sealing surface and other components, a general grinding method cannot completely match the special-shaped structure at one time, so it cannot effectively repair the damage to the sealing surface. The present disclosure creatively provides a plurality of grinding molds, which can accurately match parts with different structures to complete repair in cooperation with the device. Due to the convenience of special tools, the overall maintenance time is greatly shortened.

[0037] Step 101, after step 100, the control terminal controls the lifting motor to drive the telescopic rod to descend, and after the grinding mold is pressed against the part to be ground, the control terminal determines the pressure value currently borne by the part to be ground according to the data collected by each first pressure sensor. In the case where the control terminal determines that the pressure value currently borne by the part to be ground belongs to the pressure threshold interval, the control terminal controls the lifting motor to stop driving the telescopic rod, so that the grinding mold maintains the current spatial position, and the required pressing force is pressed against the part to be ground, which can effectively avoid the phenomenon that the telescopic rod is excessively lowered, causing damage to the grinding mold and the part to be ground, etc. In addition, relevant engineering personnel can set different numerical values of the pressure threshold interval (for example, 5-10N) in the control terminal according to the needs of grinding parts, so that the grinding force of the grinding mold on the parts can be accurately controlled according to the actual grinding needs, and different application scenarios can be flexibly adapted.

[0038] Step 102, the control terminal controls the grinding motor to drive the telescopic rod to rotate, and grinds the part to be ground. During the continuous grinding process, 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 interval, the control terminal controls the lifting motor to drive the telescopic rod to move downward until the pressure value currently borne by the part to be ground belongs to the pressure threshold interval, and stops the lifting motor to drive the telescopic rod, so that the grinding mold maintains the 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 interval, the control terminal controls the lifting motor to drive the telescopic rod to move upward until the pressure value currently borne by the part to be ground belongs to the pressure threshold interval, and stops the lifting motor to drive the telescopic rod, so that the grinding mold maintains the current spatial position; since during the grinding process, as the surface of the part to be ground is continuously thinned, the pressing force between the grinding mold and the part will be continuously weakened. To solve this problem, the present disclosure uses multiple first pressure sensors to monitor the pressure value between the grinding mold and the part in real time, and adjusts the position of the telescopic rod in the vertical direction when the pressure value deviates from the pressure threshold interval, so as to timely adjust the grinding pressing force to the required pressure threshold interval, accurately guarantee the continuous grinding pressing force from the numerical value level, and significantly improve the quality and efficiency of grinding. In addition, the multiple first pressure sensors are ingeniously arranged in the telescopic rod, which can accurately and timely obtain pressure data without any interference to the grinding process.

[0039] In step 103, the control terminal controls the rotary motor to stop driving the telescopic rod after the grinding time meets the preset requirement, and then controls the lifting motor to drive the telescopic rod to lift. For each part to be ground of the valve, the method of steps 100 to 103 can be used to perform grinding, thereby ensuring the maintenance efficiency and quality of the maintenance of the special-shaped sealing surface and other parts of the atmospheric release valve. In this way, the disclosure can free manpower by automatically controlling the grinding operation, and can automatically complete coarse grinding and fine grinding by adjusting the rotating speed and the pressure. The grinding mold is automatically stopped after being pressed to the set pressure, which can ensure a certain pressing force during grinding and prevent damage to the part to be ground due to untimely control or excessive pressing.

[0040] In one possible implementation, step 100 includes step 1001. After the part to be ground is placed between the plurality of positioning clamps, the control terminal controls the positioning motor to drive the plurality of positioning clamps to move towards the part to be ground at the same time, and holds and centers the part to be ground. The linkage control of the positioning clamps ensures that the clamping always forms a concentric circle, ensures accurate centering and positioning while clamping the part, and can accurately grind to the required position.

[0041] In one possible implementation, step 1001 further includes, after the part to be ground is placed between the plurality of positioning clamps, the control terminal controls the positioning motor to drive the plurality of positioning clamps to move towards the part to be ground at the same time, and obtains the pressure data collected by each second sensor to determine the clamping pressure value between each positioning clamp and the part to be ground. When the control terminal determines that the clamping pressure value of each positioning clamp belongs to the clamping force threshold interval, the control terminal controls the positioning motor to stop driving the positioning clamp, and each positioning clamp maintains the current clamping state, thereby preventing the positioning clamp from clamping the part to be ground too hard and causing damage to the part.

[0042] In an application example, taking the grinding work of the atmosphere release valve of a nuclear power plant as an example, after the atmosphere release valve is disassembled, the valve core, valve seat and other parts to be ground obtained by disassembling are sequentially ground by the device, the grinding jig matched with the parts to be ground is installed at the lower end of the telescopic rod, and the angle between the grinding jig and the grinding surface of the matched parts and the axis is consistent. After the parts to be ground are placed between the plurality of positioning clamps, the control terminal controls the positioning motor to drive the plurality of positioning clamps to clamp and center the parts to be ground, and after the clamping force of the parts to be ground by the positioning clamps meets the requirements, the control terminal controls the positioning motor to stop working, and then controls the lifting motor to lower the telescopic rod, so that the grinding jig presses against the parts to be ground, and after the pressing force of the parts to be ground by the grinding jig 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, so as to grind the parts to be ground. The control terminal can control the grinding motor to vary the frequency, so that the rotating speed of the grinding jig can be adjusted to multiple gears, such as 15 rpm, 30 rpm, 45 rpm and 60 rpm. A manual switch and a timing switch are configured. The control terminal uses a touch display screen to display the control process of grinding the parts, the grinding rotating speed and the real-time force of the parts. During the grinding process, the control terminal controls the pressing force of the grinding jig on the parts to be ground to be within the required threshold range, and after the grinding time meets the preset requirements, the control terminal controls the telescopic rod to be lifted. During use, the parts are well clamped, the centering of the parts and the grinding jig meets the requirements, the grinding effect is remarkable, and the sealing surface after grinding has no visible scratches and damage. After the parts of the atmosphere release valve are ground and reassembled, they are put into operation, and the sealing effect is good, and the internal leakage defect is eliminated.

[0043] The above has described the embodiments of the present disclosure, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes are obvious to those skilled in the art without departing from the scope and spirit of the described embodiments. The selection of the terms used herein is intended to best explain the principles, practical applications or improvements to the technology in the market of the embodiments, or to enable other ordinary skilled persons in the art to understand the embodiments disclosed herein.

Claims

1. A heavy water reactor nuclear power plant atmospheric release valve grinding apparatus, characterized by, The device 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; 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 for fitting different parts to be ground; the support is fixedly connected to the 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, and one grinding fixture is fixedly installed at the bottom end of the extension rod; The upper part of the extension rod is in a hollow structure, the output end of the gear box is fixedly connected to the upper end of the driving shaft, the upper part of the extension rod is sleeved outside the lower end of the driving shaft, one end of the transmission key is slidably connected to the long key groove in the side wall of the driving shaft, the other end of the transmission key is in interference fit with the key groove in the side wall of the extension rod, and the grinding motor can drive the extension rod to rotate through the driving shaft; the driving shaft can also be relatively displaced with the extension rod in the vertical direction; The lifting motor and a lifting assembly are further arranged in the gear box, the output end of the lifting motor is connected to the extension rod through the lifting assembly, and the lifting motor drives the extension rod to move linearly in the vertical direction through the lifting assembly; 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.

2. The heavy water reactor nuclear power plant atmospheric release valve grinding apparatus of claim 1, wherein, The extension rod comprises an upper segment, a middle segment and a lower segment which are sequentially fixedly connected from top to bottom, the upper segment is in 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 in 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, the side wall of the middle segment is circumferentially provided with a ring groove extending radially inward; the middle segment is connected to the upper segment through a plurality of transmission pins, one end of each transmission pin is in interference fit with a pin hole in the side wall of the middle segment above the ring groove, and the other end of each transmission pin is slidably connected to a long pin hole in 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 fixture is pressed against the part to be ground, the step portion of the upper segment is pressed against each first pressure sensor in the side wall below the ring groove of the middle segment; 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.

3. The heavy water reactor nuclear power plant atmospheric release valve grinding apparatus of claim 2, wherein, 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 for controlling the start and stop of the positioning motor; 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 to the second bevel gear, and a plurality of strip-shaped through holes are arranged in the vertical direction of the table and are arranged radially around the center of the second bevel gear in a radial manner; 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 further engaged with the first rack; 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.

4. The heavy water reactor nuclear power plant atmospheric release valve grinding apparatus of claim 3, wherein, Each positioning clamp for clamping the surface of the part to be ground is further provided with a second pressure sensor, 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.

5. The heavy water reactor nuclear power plant atmospheric release valve grinding apparatus of claim 1, wherein, 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 recess extending in the axial direction is formed in the top of each grinding mold, and each polygonal recess 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 recess, and each interface groove is inserted and matched with a spring plunger when the polygonal head is inserted into the polygonal recess.

6. The heavy water reactor nuclear power plant atmospheric release valve grinding apparatus of claim 1, wherein, 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.

7. The heavy water reactor nuclear power plant atmospheric release valve grinding apparatus of claim 1, wherein, 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.

8. A method of grinding an atmospheric release valve of a heavy water nuclear power plant, characterized by, The method is implemented based on the heavy water reactor nuclear power plant atmospheric release valve grinding device of claim 2, and for each part to be ground, the method comprises: Step 100, installing the grinding mold matched with the part to be ground to the lower end of the telescopic rod, and fixing 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, determines the pressure value currently borne by the part to be ground according to the data collected by each first pressure sensor, and controls the lifting motor to stop driving the telescopic rod when it is determined that the pressure value currently borne by the part to be ground belongs to the pressure threshold interval, so that the grinding mold maintains the current spatial position. In 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, the control terminal 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 belongs to the pressure threshold interval, and stops the lifting motor from driving the telescopic rod, so that the grinding shoe tool maintains the current spatial position, in the case that the pressure value currently borne by the part to be ground does not belong to the pressure threshold interval. In step 103, the control terminal controls the rotation motor to stop driving the telescopic rod after the grinding time length meets the preset requirement, and then controls the lifting motor to drive the telescopic rod to lift.

9. The heavy water reactor nuclear power plant atmospheric release valve grinding method of claim 8, wherein, The method is implemented based on the heavy water reactor nuclear power station atmospheric release valve grinding device of claim 3, and step 100 includes step 1001. After the part to be ground is placed between the plurality of positioning clamps, the control terminal controls the positioning motor to drive the plurality of positioning clamps to move towards the part to be ground at the same time, holds and centers the part to be ground.

10. The heavy water reactor nuclear power plant atmospheric release valve grinding method of claim 9, wherein, The method is implemented based on the heavy water reactor nuclear power station atmospheric release valve grinding device of claim 4, and step 1001 further includes that during the process in which the control terminal controls the positioning motor to drive the plurality of positioning clamps to move towards the part to be ground at the same time, the pressure data collected by each second sensor is acquired to determine the clamping pressure value between each positioning clamp and the part to be ground. When the control terminal determines that the clamping pressure value of each positioning clamp belongs to the clamping force threshold interval, the control terminal controls the positioning motor to stop driving the positioning clamps, so that each positioning clamp maintains the state of clamping the part to be ground.

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