A control rod driving device for a nuclear reactor

Abstract

The present invention discloses a control rod drive device for a nuclear reactor, which includes a drive mechanism, a folding component and a control rod assembly. The control rod assembly is connected to the folding component, the drive mechanism controls the movement of the control rod assembly, and the control rod assembly can be bent to achieve the storage of the control rod assembly in the folding component. The control rod drive device for a nuclear reactor of the present invention controls the lifting and lowering movement of the control rod assembly and the process of storing the control rod assembly in the folding component through the drive mechanism, thereby reducing the required vertical space, so that the control rod drive device can be better applied to operating environments such as small reactors or modular reactors. At the same time, the control rod drive device for a nuclear reactor of the present invention is distinguished from the rigid control rods in all currently active nuclear power plants and nuclear reactors by the bending of the flexible portion of the control rod assembly. The successful implementation of this solution will provide a practical reference for better expanding the development of new structures of nuclear reactors.

Description

Technical Field

[0001] The present invention relates to the field of nuclear reactor equipment, and in particular to a control rod driving device for a nuclear reactor. Background Art

[0002] The control rod drive is a device installed on the nuclear reactor vessel, which is mainly composed of a drive mechanism and a control rod. The control rod body has a "neutron poison" that can absorb neutrons. By inserting the control rod downward, more neutrons are absorbed, thereby slowing down the rate of nuclear fission reaction. Lifting the control rod can reduce the rate of neutron absorption, thereby speeding up the nuclear reaction rate. The insertion depth of the control rod in the core is adjusted to achieve the function of adjusting the power of the nuclear reactor and emergency shutdown.

[0003] In traditional nuclear power control rod drive devices, the control rod assembly is a rigid rod structure. The control rod drive device uses gravity as the power source for dropping the rods. The designer only needs to select the power source for lifting the control rods. The control rod drive device has a large vertical space requirement and requires a stable operating environment, but earthquake conditions must be considered. Therefore, traditional nuclear power control rod drive devices need to be installed in a space that is large enough in the vertical direction, and the control rod dropping action is completed with the assistance of gravity, and the control rod lifting action is completed with the drive of other forms of power sources.

[0004] However, with the development of technology, the emergence of small reactors and modular reactors has shown differences from traditional reactors in terms of installation space and operating environment. Traditional control rod drive devices are not suitable for the operating environment of small reactors and modular reactors, so it is necessary to propose a new control rod drive device. Summary of the invention

[0005] The technical problem to be solved by the present invention is to overcome the defect in the prior art that the vertical space required for the control rod drive device is too large and cannot be applied to small reactors and modular reactors, and to provide a control rod drive device for a nuclear reactor.

[0006] The present invention solves the above technical problems through the following technical solutions:

[0007] A control rod drive device for a nuclear reactor, characterized in that the control rod drive device comprises a drive mechanism, a retracting component and a control rod assembly, the control rod assembly is connected to the retracting component, the drive mechanism controls the movement of the control rod assembly, and the control rod assembly can be bent to achieve the retraction of the control rod assembly into the retracting component.

[0008] In the present solution, the above structure is adopted to significantly reduce the vertical space required for the operating environment by bending part of the control rod assembly and storing it in the space of the folding component, so that the control rod drive device can be better applied to small reactors or modular reactors.

[0009] Preferably, the control rod assembly comprises a flexible portion, and an end portion of the flexible portion is connected to the retracting component.

[0010] In this solution, the above structure is adopted to enable part of the control rod assembly to have the ability to bend, so that the lifting and lowering of the control rod assembly can be achieved through bending movement.

[0011] Preferably, the control rod assembly further comprises a rigid portion, wherein the rigid portion is connected to an end of the flexible portion away from the retracting component.

[0012] In this solution, the above structure is adopted, and the rigid part improves the mechanical strength of the control rod, is resistant to high temperatures, and ensures the combustion level of the fuel.

[0013] Preferably, the flexible portion includes a plurality of flexible units, and the plurality of flexible units are serially connected in sequence through a ball hinge rod.

[0014] In this solution, a flexible portion is formed by a plurality of flexible units, so that the control rod assembly has windability similar to a chain structure, and the running route of the control rod assembly is no longer a fixed straight line. In addition, the connection method of the ball hinge rod makes the control rod assembly flexible while being able to withstand a certain thrust.

[0015] Preferably, the retracting component comprises a winding wheel and a support frame, the winding wheel is rotatably connected to the support frame, the driving mechanism drives the winding wheel to rotate, and the control rod assembly is connected to the winding wheel.

[0016] In this solution, the support frame provides stable support for the curling wheel of the retracting component, and the curling wheel allows the control rod assembly to be stored in its rotation space, effectively reducing the occupied space in the vertical direction.

[0017] Preferably, the retracting component further comprises a guide tube, the guide tube is connected to the crimping wheel, and the control rod assembly passes through the guide tube.

[0018] In this solution, the movement direction of the control rod assembly is guided by the guide tube to accommodate the non-winding movement of the control rod assembly.

[0019] Preferably, the retracting component further comprises at least one limiting component, a gap is defined between the limiting component and an outer circumferential surface of the crimping wheel, and the control rod assembly passes through the gap.

[0020] In this solution, the above structure is adopted to effectively limit the movement trajectory of the flexible unit through the limiting component, ensuring that it will not separate from the curling wheel due to centrifugal force, thereby enhancing the stability of the movement of the flexible part.

[0021] Preferably, the limiting component includes a stabilizing wheel and an arc portion, the stabilizing wheel is connected to the support frame and the arc portion protrudes radially inwardly along the curling wheel, and the stabilizing wheel and the arc portion both form the gap with the outer circumferential surface of the curling wheel.

[0022] In this solution, the arc-shaped portion limits and corrects the annular motion of the control rod assembly and enhances the stability of the movement of the flexible portion. The stabilizing wheel can provide pulling force to prevent jamming and stacking during the movement of the flexible portion, thereby ensuring the reliability of the control rod drive device's rod lifting and rod lowering motion.

[0023] Preferably, the driving mechanism comprises a motor and a reducer, the motor is connected to an input end of the reducer, and an output end of the reducer is connected to the folding component.

[0024] In this solution, the movement speed of the control rod lifting and lowering can be accurately controlled by using the motor and the reducer in coordination, thereby controlling the reaction rate and enhancing the safety of the control rod drive device.

[0025] On the basis of being in accordance with the common sense in the art, the above-mentioned preferred conditions can be arbitrarily combined to obtain the preferred embodiments of the present invention.

[0026] The positive and progressive effects of the present invention are:

[0027] The control rod drive device for a nuclear reactor of the present invention controls the lifting and lowering movement of the control rod assembly and the process of storing the control rod assembly in the storage component through a driving mechanism, thereby reducing the required vertical space, so that the control rod drive device can be better applied to operating environments such as small reactors or modular reactors. At the same time, the control rod drive device for a nuclear reactor of the present invention is distinguished from the rigid control rods in all currently used nuclear power plants and nuclear reactors through the bending of the flexible part of the control rod assembly. The successful implementation of this solution will provide a practical reference for better expanding the development of new structures of nuclear reactors. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a schematic diagram of the overall structure of the control rod drive device.

[0029] Figure 2 This is a schematic diagram of the disassembled control rod assembly of the control rod drive device.

[0030] Figure 3 for Figure 2 An enlarged schematic diagram of part A of the control rod assembly.

[0031] Figure 4 for Figure 2 An enlarged schematic diagram of part B of the control rod assembly.

[0032] Figure 5This is a schematic diagram of the disassembly of the retracted components of the control rod drive unit.

[0033] Figure 6 This is a schematic diagram of the disassembled drive mechanism of the control rod drive unit.

[0034] Figure 7 Schematic diagram of the rod-dropping motion of the control rod drive device.

[0035] Figure 8 for Figure 7 An enlarged schematic diagram of part C of the control rod drive device.

[0036] Description of reference numerals:

[0037] Driving mechanism 1

[0038] Motor 11

[0039] Reducer 12

[0040] Folding part 2

[0041] Curling wheel 21

[0042] Support frame 22

[0043] Guide tube 23

[0044] Limiting component 24

[0045] Stabilizing wheel 241

[0046] Arc portion 242

[0047] Control rod assembly 3

[0048] Flexible portion 31

[0049] Flexible unit 311

[0050] Ball joint rod 312

[0051] Fixed ball unit 313

[0052] Lock nut 314

[0053] Rigid portion 32 DETAILED DESCRIPTION

[0054] The present invention will be described more clearly and completely below by way of embodiments and in conjunction with the accompanying drawings, but the present invention is not limited to the scope of the following embodiments. It should be particularly pointed out that the movement modes in the description are only used for explanation and are not limiting conditions of the present invention.

[0055] like Figure 1A control rod drive device for a nuclear reactor is shown, which includes a drive mechanism 1, a retracting component 2 and a control rod assembly 3. The control rod assembly 3 is connected to the retracting component 2. The drive mechanism 1 controls the movement of the control rod assembly 3. The control rod assembly 3 can be bent to achieve the retraction of the control rod assembly 3 into the retracting component 2.

[0056] The control rod drive device for a nuclear reactor of the present invention controls the lifting and lowering movement of the control rod assembly 3 and the process of storing the control rod assembly 3 in the storage component 2 through the driving mechanism 1, thereby reducing the required vertical space, so that the control rod drive device can be better applied to operating environments such as small reactors or modular reactors. At the same time, the control rod drive device for a nuclear reactor of the present invention is distinguished from the rigid control rods in all currently used nuclear power plants and nuclear reactors through the bending of the flexible portion 31 of the control rod assembly 3. The successful implementation of this solution will provide a practical reference for better expanding the development of new structures of nuclear reactors.

[0057] like Figure 2 As shown, the control rod assembly 3 includes a flexible portion 31, and the end of the flexible portion 31 is connected to the retracting member 2. The flexible portion 31 includes a neutron poison, a metal cladding, etc. The flexible portion 31 has the ability to bend, so that the control rod assembly 3 can be lifted and lowered by bending.

[0058] like Figure 2 As shown, the control rod assembly 3 further includes a rigid portion 32, which is connected to the end of the flexible portion 31 away from the retracting member 2. The rigid portion 32 improves the mechanical robustness of the control rod, is resistant to high temperatures, and ensures the combustion level of the fuel.

[0059] like Figure 3 As shown, the flexible part 31 includes a plurality of flexible units 311, and the plurality of flexible units 311 are connected in series in sequence through a ball hinge rod 312. The plurality of flexible units 311 constitute the flexible part 31, and the flexible units 311 are divided into two types, one is a flexible unit 311 containing neutron poison, and the other is a flexible unit 311 not containing neutron poison. The plurality of flexible units 311 can be formed by connecting small cylindrical poison units in series, and the overall design is a bead chain structure, so that the control rod assembly 3 has the winding property similar to the chain structure, and the running route of the control rod assembly 3 is no longer a fixed straight line, and the connection method of the ball hinge rod 312 makes the control rod assembly 3 flexible and can withstand a certain thrust. One end of the ball hinge rod 312 is a smooth ball head, and the other end is a concave spherical surface. With this structure, the smooth ball head end of the ball hinge rod 312 can be embedded in the concave spherical surface of the previous section, while providing a concave spherical surface for the next section to embed the ball head. The ball hinge rod 312 is fixed by a concave arc pressure cover at the front and back. The flexible part 31 connected in series in this way can meet the requirements of bending movement between the units of the flexible part 31.

[0060] like Figure 5 As shown, the folding component 2 includes a winding wheel 21 and a support frame 22. The winding wheel 21 is rotatably connected to the support frame 22. The driving mechanism 1 drives the winding wheel 21 to rotate, and the control rod assembly 3 is connected to the winding wheel 21. The winding wheel 21 becomes a storage device for the control rod assembly 3. In the traditional mechanism, the control rod assembly 3 is placed in the vertical cylinder above the reactor in the form of a rod body. In this embodiment, the vertical space is replaced by a rotation space. The winding wheel 21 is provided with a fixing pin for providing power to the control rod body when the control rod assembly 3 is lifted. The support frame 22 provides stable support for the winding wheel 21 of the folding component 2. The winding wheel 21 allows the control rod assembly 3 to be stored in its rotation space, effectively reducing the occupied space in the vertical direction. The end of the flexible portion 31 connected to the winding wheel 21 is provided with a fixing ball unit 313 and a locking nut 314. The fixing ball unit 313 is fixed on the winding wheel 21 (please refer to Figure 4 and 8 ), the fixed ball unit 313 connects the winding wheel 21 and the flexible part 31 as a whole. As the winding wheel 21 rotates, the fixed ball unit 313 can be driven to perform a circular motion, thereby pulling the flexible part 31 to perform a circular motion, and then driving the control rod assembly 3 to complete the lifting motion.

[0061] like Figure 5 As shown, the retracting component 2 further includes a guide tube 23, which is connected to the winding wheel 21, and the control rod assembly 3 passes through the guide tube 23. The guide tube 23 can be divided into a vertical tube and an arc tube, the vertical tube is used to accommodate the rigid part 32, and the arc tube is used to accommodate the flexible part 31. The rigid part 32 only moves in the vertical channel, and the flexible part 31 can meet two vertical and bending movement modes. The movement direction of the control rod assembly 3 is guided by the guide tube 23 to accommodate the non-winding movement of the control rod assembly 3.

[0062] like Figure 5 As shown, the retracting component 2 further includes at least one limiting component 24, and a gap is formed between the limiting component 24 and the outer circumference of the winding wheel 21, and the control rod assembly 3 passes through the gap. The limiting component 24 effectively limits the movement trajectory of the flexible unit 311, ensuring that it will not separate from the winding wheel 21 due to centrifugal force, and enhancing the stability of the movement of the flexible part 31.

[0063] like Figure 5As shown, the limiting component 24 includes a stabilizing wheel 241 and an arc-shaped portion 242. The stabilizing wheel 241 is connected to the support frame 22 and the arc-shaped portion 242 protrudes radially inwardly along the winding wheel 21. The stabilizing wheel 241 and the arc-shaped portion 242 form a gap with the outer peripheral surface of the winding wheel 21. When the winding wheel 21 rotates in the reverse direction, not only does the fixed ball unit 313 have a certain thrust on the flexible unit 311, but the stabilizing wheel 241 at the top also rotates in the reverse direction, and through the friction with the flexible portion 31, it will provide a certain pulling force. Under the combined action of the thrust and the pulling force, the flexible portion 31 can complete the transformation from the winding state to the fully unfolded state, thereby completing the rod dropping movement (such as Figure 7 The stabilizing wheel 241 is used to provide power to the rod body when the control rod assembly 3 drops the rod, and the arc portion 242 is used to limit and correct the circular motion of the control rod assembly 3 and enhance the stability of the motion of the flexible portion 31. The stabilizing wheel 241 can provide a pulling force to ensure that the flexible portion 31 does not get stuck or stacked during the motion, thereby ensuring the reliability of the control rod driving device in lifting and dropping the rod.

[0064] like Figure 6 As shown, the drive mechanism 1 includes a motor 11 and a reducer 12, the motor 11 is connected to the input end of the reducer 12, and the output end of the reducer 12 is connected to the folding component 2. The motor 11 and the reducer 12 can be connected by flanges, and the drive mechanism 1 can also include a transmission box, which is composed of a protective cover and a sealing plate, and a gear component is arranged inside the transmission box. The input end of the reducer 12 is connected to one end of the gear component, and the output end is connected to the other end of the gear component. The input end drives the output end to rotate through the meshing gears. The coordinated use of the motor 11 and the reducer 12 enables the movement speed of the control rod lifting and dropping to be accurately controlled, thereby controlling the reaction rate and enhancing the safety of the control rod drive device.

[0065] Although the specific embodiments of the present invention are described above, it should be understood by those skilled in the art that this is only for illustration and the protection scope of the present invention is defined by the appended claims. Those skilled in the art may make various changes or modifications to these embodiments without departing from the principles and essence of the present invention, but these changes and modifications all fall within the protection scope of the present invention.

Claims

1. A control rod drive device for a nuclear reactor, characterized in that: The control rod driving device comprises a driving mechanism, a retracting component and a control rod assembly, wherein the control rod assembly is connected to the retracting component, the driving mechanism controls the movement of the control rod assembly, and the control rod assembly can be bent to achieve the retracting of the control rod assembly into the retracting component; The retracting component comprises a winding wheel and a support frame, the winding wheel is rotatably connected to the support frame, the driving mechanism drives the winding wheel to rotate, and the control rod assembly is connected to the winding wheel; The retracting member further comprises at least one limiting member, wherein a gap is formed between the limiting member and the outer peripheral surface of the crimping wheel, and the control rod assembly passes through the gap; The limiting component includes a stabilizing wheel and an arc-shaped portion, wherein the stabilizing wheel is connected to the support frame and the arc-shaped portion protrudes radially inwardly along the curling wheel, and the stabilizing wheel and the arc-shaped portion both form the gap with the outer peripheral surface of the curling wheel; The stabilizing wheel is used to provide power to the rod body when the control rod assembly falls. When the control rod assembly falls, the stabilizing wheel and the crimping wheel rotate in opposite directions and push and pull the control rod assembly respectively.

2. The control rod drive device according to claim 1, characterized in that: The control rod assembly includes a flexible portion, and an end portion of the flexible portion is connected to the retracting member.

3. The control rod drive device according to claim 2, characterized in that: The control rod assembly further includes a rigid portion connected to an end of the flexible portion away from the retracting member.

4. The control rod drive device according to claim 2, characterized in that: The flexible part comprises a plurality of flexible units, and the plurality of flexible units are serially connected in sequence through a ball hinge rod.

5. The control rod drive device according to claim 1, characterized in that: The retracting component further includes a guide tube, the guide tube is connected to the crimping wheel, and the control rod assembly passes through the guide tube.

6. The control rod drive device according to claim 1, characterized in that: The driving mechanism comprises a motor and a reducer, wherein the motor is connected to an input end of the reducer, and an output end of the reducer is connected to the folding component.

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