Control chain device, nuclear reactor and control method

Abstract

The invention discloses a control chain device, a nuclear reactor and a control method, the nuclear reactor comprises a reactor core, the reactor core comprises a plurality of control chain mounting holes and a reactor core shell, the control chain device comprises a plurality of control chains, a driving wheel and a driving motor, each control chain comprises a mounting rope and a plurality of absorbers with preset lengths, and the absorbers are arranged in the mounting rope. The absorbers are all arranged on the outer side of the mounting rope, and the driving wheel is arranged above the reactor core through a supporting piece; one end of the control chain is aligned with one control chain mounting hole, and the other end of the control chain is arranged between the reactor core shell and the nuclear reactor shell; the driving motor drives the driving wheel to rotate, and the driving wheel drives the control chain to reciprocate. The control chain can be bent, the size of the nuclear reactor can be reduced, the cost is further reduced, the application scene is widened, the control power is low, driving can be achieved only by dozens of watts, control is more accurate through the driving motor, and a basis is provided for achieving miniaturization of the nuclear reactor.

Description

Technical Field

[0001] The invention relates to a control chain device, a nuclear reactor and a control method. Background Art

[0002] Nuclear reactors are used to control and maintain nuclear fission chain reactions to generate energy. Nuclear fission is the process by which an atomic nucleus splits after absorbing a neutron, releasing energy, more neutrons, and radiation. Nuclear reactors can be used for purposes such as power generation, research, and the manufacture of nuclear weapons materials.

[0003] The control rods of a pressurized water reactor are controlled by magnetic lifters, which have a complex structure and high cost.

[0004] The control rods need to be inserted into a 10m diameter conduit, and 24 rods form one driver. When inserted simultaneously, the resistance is very large. In the water, each step is lifted by about 10mm, and it is required to quickly descend to the bottom within two seconds, which often fails to meet the requirements. There is a risk of rod jamming. In the prior art, the control rod magnetic lifting tube is produced, and there is a rod jamming phenomenon. After changing and relaxing the tolerance, the rod jamming is changed during thermal expansion. The rod length is 3.3m, which increases the height of the pressure vessel barrel and greatly increases the manufacturing cost.

[0005] The control rod structure of boiling water reactors and pressurized water reactors is different. The boiling water reactor is a cross-shaped structure, and the driving method is often hydraulic, which is achieved by a nitrogen pressurized water tank. The pressure in the pressurized water is often maintained at 16Mpa, and the structure is complex.

[0006] The control rods are very long and are often made into thin rods. Each rod is loaded with very little absorber (8% silver, 15% indium, 5% cadmium), which is not conducive to absorbing neutrons.

[0007] The pebble bed high temperature gas-cooled reactor has a 15% excess which is only used for power regulation and the control rod structure is more complex, so the temperature increase is not good for the absorber. Summary of the invention

[0008] The technical problem to be solved by the present invention is to overcome the defects of the prior art in that the control rods have high control consumption, the control rods are too long and the absorber content is low, and to provide a control chain device, a nuclear reactor and a control method that can be bent, can reduce the size of the nuclear reactor, thereby reducing costs and broadening application scenarios, has low control power and uses a drive motor to make the control more precise.

[0009] The present invention solves the above technical problems through the following technical solutions:

[0010] A control chain device for a nuclear reactor, characterized in that the nuclear reactor comprises a core, the core comprises a plurality of control chain mounting holes and a core shell, the control chain device comprises a plurality of control chains, a driving wheel and a driving motor, each control chain comprises a mounting rope and a plurality of absorbers of preset lengths,

[0011] The absorbers are all arranged outside the installation ropes, and the driving wheels are arranged above the core through supporting members;

[0012] One end of the control chain is aligned with a control chain mounting hole, and the other end of the control chain is arranged between the core shell and the nuclear reactor shell;

[0013] The driving motor drives the driving wheel to rotate, and the driving wheel drives the control chain to reciprocate.

[0014] Preferably, the absorber is made of cadmium-indium-silver alloy, a stainless steel shell is provided on the outside of the absorber, and the installation rope is a steel wire rope.

[0015] Preferably, the absorbent body is in a capsule shape, the driving wheel is a gear, and the tooth surface shape of the gear matches the shape of the absorbent body.

[0016] Preferably, a spacer is provided between two adjacent absorbent bodies.

[0017] Preferably, a first guide cylinder is provided above the control chain mounting hole, a second guide cylinder is provided between the core shell and the nuclear reactor shell, and the driving wheel drives the control chain to reciprocate in the first guide cylinder and the second guide cylinder.

[0018] Preferably, the first guide cylinder and the second guide cylinder are integrally formed, a connecting guide cylinder is provided between the first guide cylinder and the second guide cylinder, a control window is provided at the bottom of the connecting guide cylinder, the driving wheel passes through the control window and engages with the control chain, and the second guide cylinder is fixed to the inner side of the nuclear reactor shell.

[0019] Preferably, the control chain device further comprises guide wheels, each guide wheel corresponds to a driving wheel, and the guide wheels are arranged on the inner side of the driving wheels or the driving wheels are arranged on the inner side of the guide wheels.

[0020] Preferably, the driving wheels are divided into several groups, the axes of the driving wheels in the same group are located on the same straight line, and the driving wheels in each group are driven by the same driving motor.

[0021] Preferably, each control chain mounting hole in the core corresponds to a control chain mounting hole in the same group, and the control chain mounting hole and the control chain mounting holes in the same group are axially symmetrical. The control chain device includes a connecting rod, and the two ends of the connecting rod are respectively connected to two driving wheels. The control chain driven by the two driving wheels connected to the same connecting rod is installed in the control chain mounting hole in the same group, and the connecting rod is connected to the drive motor through a gear.

[0022] The present invention also provides a nuclear reactor, which is characterized in that the nuclear reactor includes the control chain device as described above.

[0023] The present invention also provides a control method for controlling the control chain device as described above, characterized in that the control method comprises:

[0024] Neutron irradiation activation of the antimony core;

[0025] Install the antimony core in the beryllium sleeve;

[0026] Install the beryllium sleeve containing the antimony core into the neutron source installation hole;

[0027] Get the core temperature;

[0028] The driving motor is controlled according to the core temperature to adjust the number and depth of the control chain entering the control chain installation hole.

[0029] 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.

[0030] The positive and progressive effects of the present invention are:

[0031] 1. The control chain can be bent, which shortens the size of the cylinder and reduces the cost of the cylinder.

[0032] 2. The control power is reduced and only tens of watts are needed to drive it.

[0033] 3. More accurate control.

[0034] 4. More absorbers lead to higher efficiency in absorbing neutrons.

[0035] 5. The control chain is more advanced, easier to control and reduces failure.

[0036] This application provides a technical basis for the miniaturization of nuclear reactors, making micro reactors possible. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 This is a schematic structural diagram of a control chain device according to Embodiment 1 of the invention.

[0038] Figure 2 This is a schematic diagram of the structure of the nuclear reactor of embodiment 1 of the invention.

[0039] Figure 3 This is a schematic diagram of the structure of the control chain of embodiment 1 of the invention.

[0040] Figure 4 This is a schematic diagram of the top view of the core structure of embodiment 1 of the invention.

[0041] Figure 5 This is a schematic diagram of the structure of the neutron source core block of Invention Example 1.

[0042] Figure 6Another schematic diagram of the structure of the neutron source core block of Invention Example 1.

[0043] Figure 7 This is a schematic structural diagram of a control chain device according to Embodiment 1 of the invention.

[0044] Figure 8 This is a schematic structural diagram of the guide cylinder of embodiment 1 of the invention.

[0045] Fig. 9 This is a schematic structural diagram of a control chain device according to Embodiment 2 of the invention. DETAILED DESCRIPTION

[0046] The present invention is further described below by way of examples, but the present invention is not limited to the scope of the examples.

[0047] Example 1

[0048] In this embodiment, the directions or positional relationships indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. are based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0049] See also Figures 1 to 8 , this embodiment provides a nuclear reactor.

[0050] The nuclear reactor includes a core 11 and a control chain device 21 .

[0051] The core includes a plurality of control chain installation holes 111 and a core shell 112 , and each control chain installation hole 111 is correspondingly installed with a control chain.

[0052] The control chain device 21 includes a plurality of control chains 211 , a driving wheel 212 and a driving motor 213 .

[0053] Each control chain 211 includes a mounting rope 214 and a plurality of absorbers 215 of a predetermined length. In this embodiment, the number of the control chain 211 and the number of the control chain mounting holes 111 are both 6.

[0054] The absorbers 215 are all arranged outside the installation ropes 214, and the driving wheels 212 are arranged above the core through the support members 216. The installation ropes are formed by winding a plurality of steel wires.

[0055] One end of the control chain 211 is aligned with a control chain mounting hole 111 , and the other end of the control chain 211 is disposed between the core shell 112 and the nuclear reactor shell 113 .

[0056] The driving motor 213 drives the driving wheel 212 to rotate, and the driving wheel 212 drives the control chain 211 to reciprocate.

[0057] The material of the absorber is cadmium indium silver alloy, the outside of the absorber is provided with a stainless steel shell 218, and the installation rope 214 is a steel wire rope. The cadmium indium silver content of the absorber is 5%, 15%, and 80% respectively.

[0058] The absorbent body is in a capsule shape, the driving wheel is a gear, and the tooth surface shape of the gear matches the shape of the absorbent body.

[0059] A spacer 217 is provided between two adjacent absorbent bodies.

[0060] A first guide cylinder 31 is provided above the control chain installation hole, a second guide cylinder 32 is provided between the core shell 112 and the nuclear reactor shell 113, and the driving wheel 212 drives the control chain to reciprocate in the first guide cylinder and the second guide cylinder.

[0061] The first guide cylinder and the second guide cylinder are integrally formed, a connecting guide cylinder 33 is provided between the first guide cylinder and the second guide cylinder, a control window 34 is provided at the bottom of the connecting guide cylinder, the driving wheel passes through the control window and engages with the control chain, and the second guide cylinder is fixed to the inner side of the nuclear reactor shell.

[0062] The control chain device also includes guide wheels 35, each of which corresponds to a driving wheel, and the guide wheels are arranged on the inner side of the driving wheel or the driving wheel is arranged on the inner side of the guide wheels. In the present embodiment, the driving wheel is arranged on the inner side of the guide wheels.

[0063] Each control chain installation hole in the core corresponds to a control chain installation hole in the same group, and the control chain installation holes and the control chain installation holes in the same group are axially symmetrical.

[0064] The control chain device 21 includes a connecting rod 219, both ends of which are connected to two driving wheels respectively. The control chains driven by the two driving wheels connected to the same connecting rod are installed in the same group of control chain installation holes, and the connecting rod is connected to the driving motor through a gear.

[0065] Using the above-mentioned nuclear reactor and control chain device, this embodiment further provides a control method, including:

[0066] Neutron irradiation activation of the antimony core;

[0067] Install the antimony core in the beryllium sleeve;

[0068] Install the beryllium sleeve containing the antimony core into the neutron source installation hole;

[0069] Get the core temperature;

[0070] The driving motor is controlled according to the core temperature to adjust the number and depth of the control chain entering the control chain installation hole.

[0071] The core further includes a neutron source installation hole 12 .

[0072] The ignition neutron source device includes a neutron source core block 13 , and the neutron source core block includes an antimony core 131 and a beryllium sleeve 132 .

[0073] The antimony core is arranged in the beryllium sleeve, and the neutron source core block is used to be installed in the neutron source installation hole.

[0074] The antimony core and the beryllium sleeve are both cylindrical, the diameter of the antimony core is 1 mm to 2 mm, the inner diameter of the beryllium sleeve matches the diameter of the antimony core, and the wall thickness of the beryllium sleeve is 0.5 mm to 2 mm.

[0075] The antimony core and the beryllium sleeve have the same length, and the length of the beryllium sleeve is 15 mm to 40 mm.

[0076] Specifically, the control method includes:

[0077] The antimony core is activated by neutron irradiation.

[0078] The antimony core is installed in the beryllium sleeve.

[0079] A fixing member is installed above the beryllium sleeve.

[0080] The traction chain is pulled to place the beryllium sleeve equipped with the antimony core into the sub-source guide tube.

[0081] The beryllium sleeve is placed in the neutron source installation hole along the neutron source guide tube by using the traction chain.

[0082] Get the core temperature.

[0083] The driving motor is controlled according to the core temperature to adjust the number and depth of the control chain entering the control chain installation hole.

[0084] Nuclear reactors have a large number of neutron sources for ignition, but they cannot use radium-beryllium sources, polonium-beryllium sources, and certainly not californium sources.

[0085] This embodiment designs an antimony-beryllium source.

[0086] Antimony is abundant, easily available, and cheap.

[0087] Antimony is made into a wire with a diameter of 1.5 mm (preferably), and a section is activated by neutron irradiation.

[0088] Antimony release ray, When the radiation hits beryllium, neutrons are produced.

[0089] ,

[0090] .

[0091] Beryllium is made into a sleeve and put on the antimony wire. After activation, it produces neutrons with higher efficiency than the mixture.

[0092] An absorption shell 17 with a length greater than or equal to the length of the beryllium sleeve is disposed outside the beryllium sleeve, and the absorption shell is made of cadmium indium silver alloy.

[0093] The cadmium, indium and silver contents of the absorption shell are 5%, 15% and 80% respectively.

[0094] A core upper plate 14 is provided on the top of the core 11, a neutron source guide tube 15 is provided above the core upper plate, a guide tube fixing plate 16 is provided on the top of the neutron source guide tube, the absorption shell 17 is installed above the guide tube fixing plate, and the absorption shell, the neutron source guide tube and the neutron source installation hole are located on the same axis.

[0095] The ignition neutron source device includes a fixing part 18 and a traction chain 19. The fixing part fixes the antimony core and the beryllium sleeve from the top. The traction chain is connected to the fixing part and is used to place the antimony core and the beryllium sleeve along the neutron source guide tube into the neutron source installation hole.

[0096] A support plate 20 is provided at the bottom of the beryllium sleeve, an external thread is provided at the top of the beryllium sleeve, an internal thread matching the external thread is provided at the bottom of the fixing part, and a connecting part connected to the traction chain is provided at the top, and the fixing part is made of beryllium.

[0097] Example 2

[0098] See also Fig. 9 This embodiment is basically the same as Embodiment 1, except that:

[0099] The driving wheels are divided into several groups. The axes of the driving wheels in the same group are located on the same straight line. The driving wheels in each group are driven by the same driving motor 213.

[0100] In this embodiment, the driving wheels are divided into two groups, the axes of each group of driving wheels are the same axis, and a driving rod 2121 passes through the center of the same group of driving wheels, and the driving rod 2121 is connected to the driving motor.

[0101] The driving motor drives the driving rod to rotate, and the driving rod drives the driving wheel of the same group to rotate, thereby driving the control chain of the same group to move.

[0102] Although the specific embodiments of the present invention are described above, those skilled in the art should understand that these are only examples, 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 chain device for a nuclear reactor, characterized in that: The nuclear reactor comprises a core, the core comprises a plurality of control chain mounting holes and a core shell, the control chain device comprises a plurality of control chains, a driving wheel and a driving motor, each control chain comprises a mounting rope and a plurality of absorbers of preset lengths, The absorbers are all arranged outside the installation ropes, and the driving wheels are arranged above the core through supporting members; One end of the control chain is aligned with a control chain mounting hole, and the other end of the control chain is arranged between the core shell and the nuclear reactor shell; The driving motor drives the driving wheel to rotate, and the driving wheel drives the control chain to reciprocate.

2. The control chain device according to claim 1, characterized in that: The absorber is made of cadmium-indium-silver alloy, a stainless steel shell is provided on the outside of the absorber, and the installation rope is a steel wire rope.

3. The control chain device according to claim 1, characterized in that: The absorbent body is in a capsule shape, the driving wheel is a gear, and the tooth surface shape of the gear matches the shape of the absorbent body.

4. The control chain device according to claim 3, characterized in that: A spacer is provided between two adjacent absorbent bodies.

5. The control chain device according to claim 1, characterized in that: A first guide cylinder is arranged above the control chain mounting hole, a second guide cylinder is arranged between the core shell and the nuclear reactor shell, and the driving wheel drives the control chain to reciprocate in the first guide cylinder and the second guide cylinder.

6. The control chain device according to claim 1, characterized in that: The first guide cylinder and the second guide cylinder are integrally formed, a connecting guide cylinder is provided between the first guide cylinder and the second guide cylinder, a control window is provided at the bottom of the connecting guide cylinder, the driving wheel passes through the control window and engages with the control chain, and the second guide cylinder is fixed to the inner side of the nuclear reactor shell.

7. The control chain device according to claim 1, characterized in that: The driving wheels are divided into several groups, the axes of the driving wheels in the same group are located on the same straight line, and the driving wheels in each group are driven by the same driving motor.

8. The control chain device according to claim 1, characterized in that: Each control chain mounting hole in the core corresponds to a control chain mounting hole in the same group, and the control chain mounting holes and the control chain mounting holes in the same group are axially symmetrical. The control chain device includes a connecting rod, and the two ends of the connecting rod are respectively connected to two driving wheels. The control chain driven by the two driving wheels connected to the same connecting rod is installed in the control chain mounting holes in the same group, and the connecting rod is connected to the drive motor through a gear.

9. A nuclear reactor, characterized in that: The nuclear reactor comprises a control chain device as claimed in any one of claims 1 to 8.

10. A control method for controlling a control chain device according to any one of claims 1 to 8, characterized in that: The control method comprises: Neutron irradiation activation of the antimony core; Install the antimony core in the beryllium sleeve; Installing the beryllium sleeve containing the antimony core into the neutron source installation hole; Get the core temperature; The driving motor is controlled according to the core temperature to adjust the number and depth of the control chain entering the control chain installation hole.

Images