Control rod passive buffer self-locking device

Abstract

This invention relates to the field of reactor control technology, specifically providing a passive buffer self-locking device for control rods, aiming to solve the problem of control rods lacking self-locking functionality. To this end, the passive buffer self-locking device for control rods of this invention includes a guide tube and a self-locking structure. The guide tube includes an unlocking groove and a self-locking groove spaced apart. One end of the control rod has a locking portion. The self-locking structure switches between a self-locking state restricting the locking portion and the self-locking groove, and an unlocking state releasing the restriction on the locking portion. In the self-locking state, the self-locking structure is adapted to connect with the locking portion and the self-locking groove to self-lock the locking portion. In the unlocking state, the self-locking structure disengages from the locking portion within the unlocking groove to unlock the locking portion. The passive buffer self-locking device for control rods of this invention enables passive self-locking and unlocking of control rods, effectively preventing safety accidents.

Description

Technical Field

[0001] This invention relates to the field of reactor control technology, specifically providing a passive buffer self-locking device for control rods. Background Technology

[0002] Control rods are tools used to rapidly control the reactivity of a nuclear reactor. During normal operation, control rods are used to regulate reactor power, while in accident conditions, control rods are rapidly introduced into negative reactivity to shut down the reactor in an emergency and ensure nuclear safety.

[0003] In an emergency shutdown, the control rods fall into the reactor core under their own weight. To ensure the integrity of the control rod structure, a buffer structure is installed at the end of the control rod's descent. Currently, the buffer structure for the control rods is limited in effectiveness and lacks a self-locking function, making the control rods susceptible to bounce. When a control rod bounces, it can introduce a large amount of positive reactivity into the reactor core in a short period of time, potentially leading to supercritical operation and significantly increasing the reactor core's safety risks.

[0004] On the other hand, in land-based mobile reactors or marine reactors, extreme situations such as tilting and overturning can occur during operation. If the control rods do not have a self-locking function after falling into the reactor core, the control rods will move out of the core when the core tilts or overturns, making it impossible to shut down the reactor and thus causing a safety accident. Summary of the Invention

[0005] The present invention aims to solve the above-mentioned technical problem, namely, to solve the problem that existing control rods do not have a self-locking function during use.

[0006] For this purpose, the present invention provides a passive buffer self-locking device for a control rod, the device comprising:

[0007] The guide tube has a channel through which the control rod passes. The channel is provided with an unlocking groove and a self-locking groove that are spaced apart. The unlocking groove is located above the self-locking groove. The end of the control rod facing the self-locking groove has a locking part.

[0008] The self-locking structure switches between a self-locking state that restricts the locking part from the self-locking groove and an unlocking state that releases the restriction on the locking part;

[0009] In the self-locking state, the self-locking structure is adapted to and connected with the locking part and the self-locking groove to achieve self-locking of the locking part; in the unlocking state, the self-locking structure disengages from the locking part in the unlocking groove to achieve unlocking of the locking part.

[0010] In the preferred embodiment of the above-mentioned passive buffer self-locking device for the control rod, the self-locking structure includes:

[0011] A fixing base, the fixing base having an internal structure forming an accommodating space, and a plurality of positioning holes being provided on the radial outer wall of the accommodating space extending from the unlocking groove to the self-locking groove;

[0012] A locking assembly is provided on the fixed base. In the self-locking state, the locking assembly is engaged with the locking part; in the unlocking state, the locking assembly is disengaged from the locking part.

[0013] The self-locking components are disposed in the accommodating space, and there are multiple self-locking components, each corresponding to one of the multiple positioning holes. One end of the self-locking component abuts against the locking component.

[0014] In the self-locking state, the other end of the self-locking component protrudes from the positioning hole and matches the self-locking groove to achieve self-locking of the locking part; in the unlocking state, the other end of the self-locking component retracts into the positioning hole to achieve unlocking of the locking part.

[0015] In the preferred embodiment of the above-mentioned passive buffer self-locking device for the control rod, the fixing base includes:

[0016] Top plate, the clamping assembly is inserted into the top plate;

[0017] The side plate is a vertically arranged annular plate, and the top of the side plate is connected to the top plate. A plurality of positioning holes are evenly arranged on the side plate along the circumference.

[0018] A base plate, which is connected to the bottom of the side plate.

[0019] In the preferred embodiment of the above-mentioned passive buffer self-locking device for the control rod, a through hole is provided on the top plate;

[0020] The clamping assembly includes:

[0021] A locking seat, wherein a sliding rod is provided at the bottom of the locking seat, and one end of the sliding rod away from the locking seat passes through the through hole and extends into the receiving space, wherein at least one lever is provided on the sliding rod;

[0022] A first return spring is sleeved on the slide rod, one end of the first return spring is fixed on the slide rod, and the other end of the first return spring abuts against the bottom of the top plate;

[0023] The locking claws are multiple in number and arranged in a circumferential array on the top of the locking seat. The locking claws are self-resetting structures.

[0024] In the preferred embodiment of the above-mentioned passive buffer self-locking device for the control rod, the locking claw is hinged to the locking seat, and a roller is provided on the top of the locking claw on the side opposite to the control rod.

[0025] In the unlocked state, the roller is located within the unlocking groove, and the tops of the plurality of locking claws are folded outward at a predetermined angle.

[0026] In the preferred embodiment of the above-mentioned passive buffer self-locking device for the control rod, the self-locking component includes:

[0027] An annular fixing plate is disposed at the bottom of the top plate. The annular fixing plate is provided with a plurality of guide holes, each of which corresponds one-to-one with a plurality of positioning holes. Each positioning hole forms a self-locking path with the slide rod, wherein the self-locking path radiates outward from the center of the guide tube.

[0028] Locking blocks, the number of which matches the number of guide holes, are configured to move along the self-locking path.

[0029] In the preferred embodiment of the above-mentioned passive buffer self-locking device for the control rod, the locking block includes:

[0030] A locking rod, the cross-sectional shape of which is consistent with the cross-sectional shape of the positioning hole, a locking protrusion is provided at one end of the locking rod facing the slide rod, and a guide slope is formed at the position where the locking protrusion abuts the lever, the guide slope being arranged in an upward inclined direction;

[0031] A movable protrusion is rotatably connected to the end of the locking rod away from the slide rod;

[0032] The locking rod is equipped with a protective cylinder and a second return spring, with the two ends of the second return spring abutting against the annular fixing plate and the protective cylinder, respectively.

[0033] In the preferred embodiment of the above-mentioned passive buffer self-locking device for the control rod, the diameter of the guide tube gradually decreases from top to bottom.

[0034] In the preferred embodiment of the above-mentioned passive buffer self-locking device for the control rod, the passive buffer self-locking device for the control rod further includes:

[0035] A base, wherein a guide protrusion adapted to the bottom of the guide tube is provided on the base, and a mounting seat is provided on the guide protrusion;

[0036] The elastic reset member has its bottom abutting against the mounting base and its top abutting against the bottom of the self-locking structure.

[0037] In the preferred embodiment of the above-mentioned passive buffer self-locking device for the control rod, the elastic reset element includes a buffer spring;

[0038] Both the mounting base and the self-locking structure are equipped with buffer spring guide cylinders.

[0039] When the above technical solution is adopted, the self-locking device of the present invention enables the control rod to achieve self-locking between the locking part and the self-locking component under its own gravity. Furthermore, the control rod can be unlocked by relying on an external device, so that the self-locking device can realize the passive self-locking and unlocking process in a passive state.

[0040] On the other hand, when the self-locking device tilts or overturns during use, the self-locking structure of the present invention can stably lock the control rod inside the guide tube, effectively preventing safety accidents. Attached Figure Description

[0041] The preferred embodiments of the present invention are described below with reference to the accompanying drawings, in which:

[0042] Figure 1 This is a schematic diagram of the structure of a passive buffer self-locking device according to an exemplary embodiment;

[0043] Figure 2 This is a schematic diagram of the structure of the guide tube in a passive buffer self-locking device according to an exemplary embodiment.

[0044] Figure 3 yes Figure 2 An enlarged schematic diagram of part A in the diagram.

[0045] Figure 4 This is a schematic diagram (in the self-locking state) of a self-locking structure in a passive buffer self-locking device according to an exemplary embodiment.

[0046] Figure 5 This is a schematic diagram of the self-locking structure in a passive buffer self-locking device (unlocked state) according to an exemplary embodiment.

[0047] Figure 6 This is a schematic diagram of the various states during the self-locking process of the control rod falling in a passive buffer self-locking device, according to an exemplary embodiment.

[0048] Figure 7 yes Figure 6 An enlarged schematic diagram of part B in the diagram.

[0049] Figure 8 yes Figure 6 An enlarged schematic diagram of part C in the diagram.

[0050] Figure 9yes Figure 6 An enlarged schematic diagram of part D in the diagram.

[0051] Figure 10 This is a schematic diagram of the various states during the unlocking and reset process of the control rod in a passive buffer self-locking device according to an exemplary embodiment.

[0052] Figure 11 yes Figure 10 An enlarged schematic diagram of part E in the diagram.

[0053] Figure 12 yes Figure 10 An enlarged schematic diagram of part F in the diagram.

[0054] Figure 13 yes Figure 10 An enlarged schematic diagram of part G in the diagram.

[0055] Explanation of reference numerals in the attached figures:

[0056] 1. Guide tube; 11. Channel; 12. Unlocking groove; 13. Self-locking groove;

[0057] 2. Control rod; 21. Locking part; 211. Guide section; 212. First cylindrical section; 213. Second cylindrical section; 214. Dome section;

[0058] 3. Self-locking structure; 31. Fixed base; 310. Accommodating space; 311. Top plate; 312. Side plate; 313. Bottom plate; 3121. Through hole; 32. Clamping assembly; 321. Clamping seat; 323. First return spring; 323. Locking claw; 324. Slide rod; 325. Lever; 326. Roller; 33. Self-locking assembly; 331. Fixed base; 3311. Guide hole; 332. Locking block; 3321. Locking rod; 3322. Movable protrusion; 3323. Locking protrusion; 3324. Guide slope; 3325. Protective cylinder; 3326. Second return spring; 34. Positioning hole;

[0059] 4. Base; 41. Guide protrusion; 42. Mounting base; 43. Buffer spring guide cylinder;

[0060] 5. Elastic reset component. Detailed Implementation

[0061] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0062] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0063] like Figure 1As shown, an exemplary embodiment of the present invention provides a passive buffer self-locking device for a control rod. The passive buffer self-locking device for the control rod includes a guide tube 1 and a self-locking structure 3.

[0064] Guide tube 1 is a hollow tubular structure, as shown in the reference. Figure 2 and Figure 3 As shown, with the plane perpendicular to the vertical direction as the longitudinal section, the shape of the longitudinal section of the guide tube 1 can be, but is not limited to, a square, an inverted isosceles trapezoid, an inverted right trapezoid, etc.

[0065] The guide tube 1 has a channel 11 through which the control rod 2 passes. The channel 11 has an unlocking groove 12 and a self-locking groove 13 spaced apart, with the unlocking groove 12 located a predetermined distance above the self-locking groove 13. This predetermined distance can be flexibly set based on the height of the self-locking structure 3 or the reset stroke of the elastic reset member used subsequently, and is not specifically limited here.

[0066] Reference Figure 3 As shown, in one example, the longitudinal cross-sectional shape of the unlocking groove 12 includes an arc-shaped groove. The arc-shaped groove, arranged from top to bottom, comprises an upper half and a lower half, with the opening size of the upper half being smaller than that of the lower half. In another example, the longitudinal cross-sectional shape of the unlocking groove 12 may also include a trapezoid, with two horizontal sides of the trapezoid arranged vertically, wherein the shorter horizontal side is located away from the centerline of the guide tube 1. Two inclined sides of the trapezoid are arranged vertically at intervals, each inclined side comprising a first inclined side and a second inclined side, the length of the first inclined side being less than the length of the second inclined side, and the first inclined side being located above the second inclined side.

[0067] To facilitate the placement of certain structures in the self-locking structure 3 (such as the locking claw 323 and the roller 326) within the arc-shaped groove or trapezoid in the unlocked state, the depth of the arc-shaped groove or the height of the trapezoid is approximately 1 / 3 to 2 / 3 of the wall thickness of the guide tube 1. When the depth of the arc-shaped groove or the height of the trapezoid is less than 1 / 3 of the wall thickness of the guide tube 1, the dimensions of certain structures in the self-locking structure 3 (such as the locking claw 323 and the roller 326) are too small, resulting in lower structural strength and a shorter service life for these structures. When the depth of the arc-shaped groove or the height of the trapezoid is greater than 2 / 3 of the wall thickness of the guide tube 1, the wall thickness of the guide tube 1 at the unlocking groove 12 becomes too thin, reducing the structural strength and service life of the guide tube 1.

[0068] Reference Figure 3As shown, in one example, the longitudinal cross-sectional shape of the self-locking groove 13 includes a semi-circular groove or a V-shaped groove, so that some structures in the self-locking structure 3 (such as the movable protrusion 3322) can be engaged with the semi-circular groove or V-shaped groove. It should be noted that the depth of the self-locking groove 13 accounts for 1 / 3 to 1 / 2 of the wall thickness of the guide tube 1, so as to effectively ensure the self-locking effect between the self-locking structure 3 and the self-locking groove 13 during the self-locking process, and at the same time, it can also effectively ensure the overall structural strength of the guide tube 1.

[0069] Reference Figure 1 and combined Figure 3 As shown, the end of the control rod 2 facing the self-locking groove 13 has a locking part 21. This locking part 21 is used in conjunction with the self-locking structure 3 to lock the control rod 2 inside the guide tube 1. The locking part 21 includes a guide section 211, a first cylindrical section 212, a second cylindrical section 213, and a dome section 214 connected sequentially from top to bottom. The guide section 211 is an inverted frustum structure, and the sidewalls of this inverted frustum structure serve a guiding function, for example, facilitating the smooth contact of certain structures in the self-locking structure 3 (such as the locking claw 323) with the top surface of the second cylindrical section 213. The diameter of the first cylindrical segment 212 is smaller than the diameter of the second cylindrical segment 213. The side wall of the guide segment 211, the outer wall of the first cylindrical segment 212, and the top surface of the second cylindrical segment 213 form a locking groove. This locking groove corresponds to the size of a part of the self-locking structure 3 (such as the locking claw 323), thereby using the self-locking structure 3 to lock the locking part 21. The bottom of the dome segment 214 is a smooth guide surface to facilitate the smooth movement of the control rod 2 within the channel 11.

[0070] Reference Figure 1 As shown, the self-locking structure 3 is disposed inside the guide tube 1 and located in the area between the unlocking groove 12 and the self-locking groove 13. The self-locking structure 3 is configured to switch between a self-locking state that restricts the locking part 21 and the self-locking groove 13 and an unlocking state that releases the restriction of the locking part 21.

[0071] In the self-locking state, the self-locking structure 3, the locking part 21, and the self-locking groove 13 are adapted and connected to achieve self-locking of the locking part 21 (i.e., control rod 2). It should be noted that in the emergency shutdown state, the control rod 2 falls under its own gravity, the locking part 21 contacts the self-locking structure 3, and the self-locking process is completed at the location of the self-locking groove 13. When the emergency shutdown state is lifted and the reactor needs to restart, the drive mechanism for controlling the control rod 2 is ready for safe operation. At this time, the control rod 2 is lifted upwards using the drive mechanism, and the self-locking structure 3 disengages from the locking part 21 within the unlocking groove 12, thereby unlocking the locking part 21. It should be noted that the drive mechanism for controlling the movement of the control rod 2 can adopt a drive structure from the prior art; the specific structure of the drive mechanism will not be described in detail here.

[0072] In this embodiment of the passive buffer self-locking device, the self-locking structure 3, in conjunction with the free-fall action of the control rod 2, enables the self-locking of the control rod 2 in an emergency shutdown state. Simultaneously, a drive mechanism can be used to unlock the control rod 2 from the self-locking structure 3, allowing the self-locking device to perform passive self-locking and unlocking processes on the control rod 2 without a passive system. Furthermore, during reactor operation or use of the self-locking device, if the reactor or the self-locking device tilts or overturns, the self-locking structure 3 can stably lock the control rod 2 within the guide tube 1, effectively preventing subsequent safety accidents.

[0073] Reference Figure 4 and combined Figure 5 As shown, in some embodiments, the self-locking structure 3 includes a fixing base 31, a clamping component 32, and a self-locking component 33. The fixing base 31 is internally configured to form an accommodating space 310, and a plurality of positioning holes 34 are provided on the radial outer wall of the accommodating space 310. The shape of the positioning holes 34 may include, but is not limited to, circles, squares, rhombuses, ellipses, etc. In this embodiment, the positioning holes 34 are square.

[0074] The locking assembly 32 is mounted on the fixed base 31. In the self-locking state, the locking assembly 32 is locked to the locking part 21. In the unlocking state, the locking assembly 32 separates from the locking part 21 at the unlocking groove position, and the locking assembly 32 realizes the self-locking or unlocking process of the control rod 2.

[0075] The self-locking component 33 is disposed within the accommodating space 310. There are multiple self-locking components 33, and the number of self-locking components 33 corresponds one-to-one with the number of positioning holes 34. One end of the self-locking component 33 abuts against the locking component 32. In the self-locking state, the other end of the self-locking component 33 protrudes from the positioning hole 34 and matches the self-locking groove 13, thereby completing the self-locking process of the locking part 21. In the unlocked state, the other end of the self-locking component 33 retracts into the positioning hole 34, realizing the unlocking process of the locking part 23.

[0076] In this embodiment, the clamping component 32 is disposed on the fixed base 31. In the self-locking state, the clamping component 32 clamps and fixes the locking part 21. At the same time, multiple self-locking components 33 are disposed in the fixed base 31, corresponding one-to-one with the number of positioning holes 34. The self-locking components 33, in conjunction with the self-locking groove 13, lock the locking part 21 in the channel 11 of the guide tube 1, effectively preventing the subsequent rebound of the control rod 2, thereby reducing the risk of subsequent safety accidents in the reactor.

[0077] Reference Figure 4 As shown, in some embodiments, the fixing base 31 includes a top plate 311, a side plate 312, and a bottom plate 313. The clamping assembly 32 passes through the top plate 311.

[0078] The side plate 312 is a vertically oriented annular plate, and its top is connected to the top plate 311. The side plate 312 and the top plate 311 can be integrally formed to facilitate the manufacturing of the fixing base 31 and improve its structural strength. Alternatively, the side plate 312 and the top plate 311 can be detachably connected to facilitate the installation and removal of the clamping assembly 32. Multiple positioning holes 34 are evenly arranged around the side plate 312 along the circumferential direction of the guide tube 1 to ensure that the clamping effect on the control rod 2 is equal in all radial directions when locking it.

[0079] The bottom of the base plate 313 is connected to the bottom of the side plate 312. The connection between the base plate 313 and the side plate 312 is detachable, such as by bolt or welding.

[0080] In this embodiment, the fixing base 31, composed of the top plate 311, side plate 312, and bottom plate 313, has a simple structure and is easy to manufacture. The internal accommodating space 310 of the fixing base 31 also provides a good mounting body for the self-locking component 33, while reducing the design volume of the fixing base 31, thereby reducing the space occupied by the passive buffer self-locking device.

[0081] Reference Figure 4 As shown, in some embodiments, a through hole 3121 is provided on the top plate 311. The locking assembly 32 includes a locking seat 321, a first return spring 322, and a locking claw 323.

[0082] A sliding rod 324 is provided at the bottom of the locking seat 321. The end of the sliding rod 324 away from the locking seat 321 passes through the through hole 3121 and extends into the receiving space 310. The shape of the through hole 3121 is the same as the cross-sectional shape of the sliding rod 324. For example, when the through hole 3121 is square, the cross-sectional shape of the sliding rod 324 is also square. It should be noted that the through hole 3121 is not circular in shape, so as to reduce the offset or rotation of the relative position between the locking seat 321 and the top plate 311 during use, thereby effectively improving the self-locking accuracy of the subsequent self-locking assembly 33.

[0083] When the cross-sectional shape of the slide bar 324 is circular, during the control process of the control rod 2, the locking component 32 cooperates with the self-locking component 33, and after the long-term self-locking and unlocking process of the control rod 2, the relative position between the slide bar 324 and the through hole 3121 may shift or rotate. This causes the part of the structure in the self-locking component 33 that cooperates with the positioning hole 34 (such as the locking block 332 and the movable protrusion 3322) to also shift or rotate. Consequently, this part of the structure of the self-locking component 33 cannot pass through the positioning hole 34, thus failing to achieve the corresponding self-locking effect.

[0084] Reference Figure 4 As shown, at least one lever 325 is provided on the slide bar 324. In one example, two levers 325 may be provided on the slide bar 324, and the two levers 325 are symmetrically arranged about the axis of the slide bar 324. The lever 325 is used in conjunction with the self-locking assembly 33, and the cross-sectional shape of the lever 325 includes, but is not limited to, a circle. The process of using the lever 325 and the self-locking assembly 33 is described in detail in the following embodiments.

[0085] The first return spring 322 is sleeved on the slide rod 324. One end of the first return spring 322 is fixed on the slide rod 324, while the other end of the first return spring 322 abuts against the bottom of the top plate 311.

[0086] There are multiple locking claws 323. These multiple locking claws 323 are arranged in a circumferential array on the top of the locking seat 321. The locking claws 323 have a self-resetting structure; for example, a spring or torsion spring reset structure connects the locking claw 323 to the locking seat 321. However, not limited to the above reset method, the locking claws 323 can also be elastomer structures, such as ethylene propylene diene monomer (EPDM), thermoplastic vulcanizate (TPV), or thermoplastic elastomer (TPE). It should be noted that when the locking claw 323 is an elastomer structure, one end of the locking claw 323 can be fixedly connected to or hinged to the top surface of the locking seat 321.

[0087] In this embodiment, multiple locking claws 323 can engage with the locking part 21 to lock the outer periphery of the locking part 21 in a distributed manner in the self-locking state, ensuring the uniform arrangement of multiple engagement positions, thereby ensuring and improving the stability of the self-locking of the control rod 2.

[0088] Reference Figure 4 and Figure 5 As shown, in some embodiments, one end of the locking claw 323 is hinged to the locking seat 321. The shape of the locking claw 323 may include, but is not limited to, an L-shape. Of course, the longer end of the L-shaped locking claw 323 is hinged to the locking seat 321, and the shorter end of the L-shaped locking claw 323 is oriented towards the axis of the guide tube 1. A roller 326 is provided on the top of the locking claw 323, away from the control rod 2. The roller 326 is used to engage with the groove wall of the unlocking groove 12 and the inner wall of the guide tube 1 (the inner wall located between the unlocking groove 12 and the self-locking groove 13 in the guide tube 1), and assists the locking claw 323 in moving on the groove wall and inner wall during the self-locking or unlocking process, improving the smoothness of the self-locking device during use.

[0089] In the unlocked state, the roller 326 is located within the unlocking groove 12, and the rolling surface of the roller 326 can contact a portion of the groove wall in the unlocking groove 12. The tops of the multiple locking claws 323 are turned outward at a predetermined angle so that the locking part 21 can smoothly enter the clamping space formed by the tops of the multiple locking claws 323. It should be noted that the predetermined angle is defined as the acute angle between the extension line of the longer end of the L-shaped locking claw 323 and the top surface of the locking seat 321, and the angle range of this predetermined angle includes 1° to 15°. In a preferred example, this predetermined angle is 8° so that the locking claw 323 and the top surface of the second cylindrical section 213 of the locking part 21 can smoothly complete the engagement or disengagement process.

[0090] In one example, there are four locking claws 323. The four locking claws 323 are arranged in a circumferential array on the top surface of the locking seat 321.

[0091] Reference Figure 5 and combined Figure 4 As shown, in some embodiments, the self-locking assembly 33 includes an annular fixing plate 331 and a locking block 332.

[0092] An annular fixing plate 331 is disposed at the bottom of the top plate 311. Multiple guide holes 3311 are provided on the annular fixing plate 331, the number of which is the same as the number of positioning holes 34, and each guide hole 3311 corresponds one-to-one with a positioning hole 34. (Refer to...) Figure 4 and combined Figure 5 As shown, in one example, there are two positioning holes 34 and two guide holes 3311. Each positioning hole 34 forms a self-locking path with the slide rod 324 (not shown in the figure). That is, multiple positioning holes 34 correspond to multiple self-locking paths, which radiate outwards from the center of the guide tube 1.

[0093] The number of locking blocks 332 matches the number of guide holes 3311, and the locking blocks 332 are configured to move along a self-locking path. That is, the locking blocks 332 can move along the self-locking path toward the positioning hole 34, or they can move along the self-locking path toward the slide bar 324. One end of the locking block 332 toward the positioning hole 34 can pass through the positioning hole 34 and be inserted into the self-locking groove 13, thereby completing the self-locking process of the control rod 2.

[0094] In this embodiment, the guide holes 3311 and positioning holes 34, which are arranged in a one-to-one correspondence, can effectively ensure the self-locking effect of the locking block 332. At the same time, the use of multiple self-locking paths arranged in a radial pattern ensures a uniform locking force on the outer periphery of the control rod 2, reducing the probability of damage during the locking process of the control rod 2.

[0095] Reference Figure 5 As shown, in some embodiments, the locking block 332 includes a locking rod 3321 and a movable protrusion 3322. The cross-sectional shape of the locking rod 3321 is consistent with the cross-sectional shape of the positioning hole 34. For example, both the cross-sectional shape of the locking rod 3321 and the cross-sectional shape of the positioning hole 34 are square, so that the positioning hole 34 can play a positioning and guiding role, facilitating the passage of the locking rod 3321 through the positioning hole 34.

[0096] A locking protrusion 3323 is provided at the end of the locking rod 3321 facing the slide rod 324. A guide slope 3324 is formed at the position where the locking protrusion 3323 abuts against the lever 325, and the guide slope 3324 is arranged in an upward inclined direction. During the self-locking process, the self-locking component 33 moves downward under the gravity of the control rod 2, causing the locking block 332 to move outward along the self-locking path while moving downward, thereby causing the guide slope 3324 to move in a downward inclined direction and finally contact the lever 325, thus completing the self-locking process of the control rod 2. The movement of the above components during the unlocking process of the control rod 2 is opposite to the movement shape of the above components during the self-locking process.

[0097] In order to reduce the longitudinal design dimensions of the self-locking component 33 and effectively ensure the smoothness of the self-locking and unlocking processes, in this embodiment, the inclination angle of the guide ramp 3324 is in the range of 35° to 45°. In one example, the inclination angle of the guide ramp 3324 is 40°.

[0098] The movable protrusion 3322 is tumbledly connected to the end of the locking rod 3321 away from the slide bar 324. In one example, the movable protrusion 3322 may include, but is not limited to, a rolling steel ball, wherein a fixed groove (not shown in the figure) is provided at the top end of the locking rod 3321 away from the slide bar 324, the rolling steel ball is embedded in the fixed groove, and the rolling steel ball rotates freely in the fixed groove, thereby facilitating the locking block 332 to quickly and accurately enter the self-locking groove 13 (self-locking process), or to allow the locking block 332 to smoothly exit from the self-locking groove 13 (unlocking process).

[0099] A protective cylinder 3325 and a second return spring 3326 are provided on the locking rod 3321. The protective cylinder 3325 is located on the locking rod 3321 between the positioning hole 34 and the guide hole 3311. The protective cylinder 3325 includes an abutment plate and a protective plate. The abutment plate is fixed on the locking rod 3321, and the protective plate is an annular structure plate. One end of the protective plate is fixed to the abutment plate along the self-locking path, and the end of the protective plate facing the slide rod has an open opening. The second return spring 3326 is sleeved on the locking rod 3321, and both ends of the second return spring 3326 abut against the annular fixing plate 331 and the protective cylinder 3325, respectively. One end of the second return spring 3326 extends into the open opening and abuts against the abutment plate. The compression process of the second return spring 3326 can be the unlocking process of the control rod 2, and the reset process of the second return spring 3326 can be the self-locking process of the control rod 2.

[0100] In this embodiment, by utilizing the guide slope 3324, the lever 325, and the second return spring 3326, along with the positioning hole 34, the guide hole 3311, the locking lever 3321, and the movable protrusion 3322, the self-locking and unlocking process of the control rod 2 can be quickly realized. The structure is simple and the design is reasonable.

[0101] Reference Figure 1 and Figure 2 As shown, in some embodiments, the diameter of the guide tube 1 gradually decreases from top to bottom. That is, the diameter of the upper end of the guide tube 1 is larger than the diameter of the lower end of the guide tube 1.

[0102] Taking a plane perpendicular to the vertical direction as the longitudinal section, the longitudinal section shape of the guide tube 1 includes, but is not limited to, an inverted isosceles trapezoid. In this inverted isosceles trapezoid, the angle between the inclined side of the isosceles trapezoid and the horizontal side of any isosceles trapezoid is in the range of 1° to 8°, wherein the angle is preferably 5°, so as to effectively ensure the integrity of the overall structure of the control rod during the falling process, and at the same time, to effectively ensure the smoothness of the falling process of the control rod.

[0103] Reference Figure 1 As shown, in some embodiments, the passive buffer self-locking device further includes a base 4 and an elastic reset member 5. The base 4 has a guide protrusion 41 adapted to the bottom of the guide tube 1. A mounting seat 42 is provided on the guide protrusion 41. The base 4 facilitates the installation of the guide tube 1 at a designated location in the reactor.

[0104] The bottom of the elastic reset member 5 abuts against the mounting base 42, and the top of the elastic reset member 5 abuts against the bottom of the self-locking structure 3. Specifically, the top of the elastic reset member 5 abuts against the bottom of the base plate 313 in the self-locking structure 3.

[0105] In this embodiment, the elastic reset member 5 can be placed below the self-locking groove 13 using the mounting base 42 and the base plate 313. The elastic reset member 5 can buffer the self-locking process of the control rod 2 to ensure the integrity of the control rod 2 structure and prevent safety accidents.

[0106] Reference Figure 1 As shown, in some embodiments, the elastic reset member 5 may include, but is not limited to, a buffer spring. A buffer spring guide cylinder 43 is provided on both the mounting base 42 and the self-locking structure 3. The buffer spring guide cylinder 43 on the self-locking structure 3 is located on the ground of the base plate 313. The buffer spring guide cylinder 43 guides and protects the buffer spring during the compression or reset process, thereby improving the service life of the buffer spring.

[0107] Reference Figures 6 to 9 As shown, in an emergency shutdown state, the self-locking process of the passive buffer self-locking device in this embodiment is as follows:

[0108] The control rod 2 moves downwards along channel 11 in the guide tube 1 under its own gravity. Because the guide tube 1 has a narrowing diameter, the resistance experienced by the control rod gradually increases as the inner diameter of the guide tube 1 decreases during its descent, thus utilizing the narrowing diameter of the guide tube 1 to achieve the first stage of buffering for the control rod. (Refer to...) Figure 6 Figures (a) to (b) in the text, and in conjunction with... Figure 7 As shown, when the locking part 21 of the control rod enters the control stroke of the self-locking structure 3, the locking part 21 abuts against the top surface of the locking seat 321, and drives the self-locking structure 3 to continue moving downward. At this time, the roller 326 on the outer side of the locking claw 323, through the inclined surface of the unlocking groove 12, causes the four locking claws 323 to flip inward simultaneously. The control rod continues to move downward, refer to... Figure 6 (c) diagram and combination Figure 8 As shown, when the locking claw 323 is fully engaged in the locking groove of the locking part 21, the control rod continues to move downwards. At this time, the buffer spring begins to be compressed. As the buffer spring is gradually compressed, its rebound force gradually offsets the impact force of the control rod falling, achieving the second level of buffering for the control rod, until the buffer spring is compressed to the designed low position. At this point, the buffer spring completely offsets the impact force of the control rod falling. (Refer to...) Figure 6 (d) diagram and combination Figure 9 As shown, after the buffer spring is compressed to the designed low position, the locking block 332 in the self-locking structure 3 is pushed deeper under the action of the second reset spring 3326, causing the rolling steel ball to be completely locked into the self-locking groove 13, thus realizing the self-locking process of the control rod. Since the control rod is locked in the guide tube 1, the control rod will not move relative to the reactor or the self-locking device if it tilts or overturns during reactor operation or use, effectively preventing subsequent safety accidents.

[0109] When the emergency shutdown is lifted and the reaction needs to restart, the drive mechanism for the control rods is now ready for safe operation. The drive mechanism (not shown in the figure) pulls the control plate upwards vertically, at which point the locking part 21 of the control rod is fully engaged by the locking claw 323. (Refer to...) Figure 10 (a) Figure and combination Figure 11 As shown, during the upward movement of the control rod, the locking seat 321 moves upward under the elastic force of the buffer spring, and the lever 325 contacts the guide slope 3324 under the elastic force of the first return spring 322. (Refer to...) Figure 10 (b) diagram and combination Figure 12As shown, as the locking seat 321 and the lever 325 continue to rise, the locking block 332 overcomes the elastic force of the second return spring 3326 and moves towards the slide bar 324, causing the rolling steel ball to disengage from the self-locking groove 13, thus unlocking the self-locking structure 3 and the guide tube 1. (Refer to...) Figure 10 Figures (c) to (d) and their combination Figure 13 As shown, the control rod is pulled upward by the drive mechanism. When the roller 326 on the outer side of the locking claw 323 enters the unlocking groove 12, the roller 326 moves along the inclined surface of the unlocking groove 12, causing the four locking claws 323 to flip outward simultaneously. The locking part 21 at the lower end of the control rod disengages from the locking claws 323, and the control rod is now unlocked and reset to a free state. After the locking part 21 is completely disengaged from the locking claws 323, the locking seat 321 resets under the action of the buffer spring, and the locking block 332 resets under the action of the second reset spring 3326, thus realizing the unlocking and reset of the self-locking structure 3.

[0110] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after such changes or substitutions will all fall within the scope of protection of the present invention.

Claims

1. A passive buffer self-locking device for a control rod, characterized in that, include: The guide tube has a channel through which the control rod passes. The channel is provided with an unlocking groove and a self-locking groove arranged at intervals. The unlocking groove is located above the self-locking groove. The end of the control rod facing the self-locking groove has a locking part. The diameter of the guide tube gradually decreases from top to bottom. The self-locking structure switches between a self-locking state that restricts the locking part from the self-locking groove and an unlocking state that releases the restriction on the locking part; In the self-locking state, the self-locking structure is adapted to and connected with the locking part and the self-locking groove to achieve self-locking of the locking part; In the unlocked state, the self-locking structure disengages from the locking part within the unlocking groove, thereby unlocking the locking part.

2. The passive buffer self-locking device for the control rod according to claim 1, characterized in that, The self-locking structure includes: A fixing base, the fixing base having an internal structure forming an accommodating space, and a plurality of positioning holes being provided on the radial outer wall of the accommodating space extending from the unlocking groove to the self-locking groove; A locking assembly is provided on the fixed base. In the self-locking state, the locking assembly is engaged with the locking part; in the unlocking state, the locking assembly is disengaged from the locking part. The self-locking components are disposed in the accommodating space, and there are multiple self-locking components, each corresponding to one of the multiple positioning holes. One end of the self-locking component abuts against the locking component. In the self-locking state, the other end of the self-locking component protrudes from the positioning hole and matches the self-locking groove to achieve self-locking of the locking part; in the unlocking state, the other end of the self-locking component retracts into the positioning hole to achieve unlocking of the locking part.

3. The passive buffer self-locking device for the control rod according to claim 2, characterized in that, The fixing base includes: Top plate, the clamping assembly is inserted into the top plate; The side plate is a vertically arranged annular plate, and the top of the side plate is connected to the top plate. The plurality of positioning holes are evenly arranged on the side plate in the circumferential direction. A base plate, which is connected to the bottom of the side plate.

4. The passive buffer self-locking device for the control rod according to claim 3, characterized in that, The top plate is provided with through holes; The clamping assembly includes: A locking seat, wherein a sliding rod is provided at the bottom of the locking seat, and one end of the sliding rod away from the locking seat passes through the through hole and extends into the receiving space, wherein at least one lever is provided on the sliding rod; A first return spring is sleeved on the slide rod, one end of the first return spring is fixed on the slide rod, and the other end of the first return spring abuts against the bottom of the top plate; The locking claws are multiple in number and arranged in a circumferential array on the top of the locking seat. The locking claws are self-resetting structures.

5. The passive buffer self-locking device for the control rod according to claim 4, characterized in that, The locking claw is hinged to the locking seat, and a roller is provided on the top of the locking claw on the side opposite to the control rod; In the unlocked state, the roller is located within the unlocking groove, and the tops of the plurality of locking claws are folded outward at a predetermined angle.

6. The passive buffer self-locking device for the control rod according to claim 4, characterized in that, The self-locking component includes: An annular fixing plate is disposed at the bottom of the top plate. The annular fixing plate is provided with a plurality of guide holes, each of which corresponds one-to-one with a plurality of positioning holes. Each positioning hole forms a self-locking path with the slide rod, wherein the self-locking path radiates outward from the center of the guide tube. Locking blocks, the number of which matches the number of guide holes, are configured to move along the self-locking path.

7. The passive buffer self-locking device for the control rod according to claim 6, characterized in that, The locking block includes: A locking rod, the cross-sectional shape of which is consistent with the cross-sectional shape of the positioning hole, a locking protrusion is provided at one end of the locking rod facing the slide rod, and a guide slope is formed at the position where the locking protrusion abuts the lever, the guide slope being arranged in an upward inclined direction; A movable protrusion is rotatably connected to the end of the locking rod away from the slide rod; The locking rod is equipped with a protective cylinder and a second return spring, with the two ends of the second return spring abutting against the annular fixing plate and the protective cylinder, respectively.

8. The passive buffer self-locking device for the control rod according to any one of claims 1-7, characterized in that, The passive buffer self-locking device for the control rod also includes: A base, wherein a guide protrusion adapted to the bottom of the guide tube is provided on the base, and a mounting seat is provided on the guide protrusion; The elastic reset member has its bottom abutting against the mounting base and its top abutting against the bottom of the self-locking structure.

9. The passive buffer self-locking device for the control rod according to claim 8, characterized in that, The elastic reset element includes a buffer spring; Both the mounting base and the self-locking structure are equipped with buffer spring guide cylinders.

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