CN117292855A - Ball bed type high temperature gas cooled reactor emergency shutdown device based on absorption ball - Google Patents
Ball bed type high temperature gas cooled reactor emergency shutdown device based on absorption ball Download PDFInfo
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- CN117292855A CN117292855A CN202311122573.7A CN202311122573A CN117292855A CN 117292855 A CN117292855 A CN 117292855A CN 202311122573 A CN202311122573 A CN 202311122573A CN 117292855 A CN117292855 A CN 117292855A
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- absorption ball
- temperature gas
- gas cooled
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- 238000010521 absorption reaction Methods 0.000 title claims abstract description 60
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims abstract description 28
- 229910002804 graphite Inorganic materials 0.000 claims abstract description 28
- 239000010439 graphite Substances 0.000 claims abstract description 28
- 239000006096 absorbing agent Substances 0.000 claims abstract description 8
- 238000003860 storage Methods 0.000 claims description 32
- 238000005192 partition Methods 0.000 claims description 31
- 239000000463 material Substances 0.000 claims description 14
- 238000002844 melting Methods 0.000 claims description 11
- 230000008018 melting Effects 0.000 claims description 11
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 claims description 10
- 239000010935 stainless steel Substances 0.000 claims description 7
- 229910001220 stainless steel Inorganic materials 0.000 claims description 7
- 229910000925 Cd alloy Inorganic materials 0.000 claims description 5
- BCEYEWXLSNZEFA-UHFFFAOYSA-N [Ag].[Cd].[In] Chemical compound [Ag].[Cd].[In] BCEYEWXLSNZEFA-UHFFFAOYSA-N 0.000 claims description 5
- 238000005253 cladding Methods 0.000 claims description 5
- 239000000446 fuel Substances 0.000 abstract description 14
- 230000009257 reactivity Effects 0.000 abstract description 9
- 230000000694 effects Effects 0.000 abstract description 5
- 239000007789 gas Substances 0.000 description 15
- 238000007599 discharging Methods 0.000 description 8
- 229910010271 silicon carbide Inorganic materials 0.000 description 6
- 238000013459 approach Methods 0.000 description 4
- 238000013461 design Methods 0.000 description 4
- 238000012986 modification Methods 0.000 description 4
- 230000004048 modification Effects 0.000 description 4
- 239000000047 product Substances 0.000 description 4
- 230000002285 radioactive effect Effects 0.000 description 4
- 230000009471 action Effects 0.000 description 3
- 230000008901 benefit Effects 0.000 description 3
- 230000005484 gravity Effects 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- 239000000155 melt Substances 0.000 description 3
- 238000000034 method Methods 0.000 description 3
- 230000002745 absorbent Effects 0.000 description 2
- 239000002250 absorbent Substances 0.000 description 2
- 230000000903 blocking effect Effects 0.000 description 2
- 238000011161 development Methods 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 230000004992 fission Effects 0.000 description 2
- 239000001307 helium Substances 0.000 description 2
- 229910052734 helium Inorganic materials 0.000 description 2
- SWQJXJOGLNCZEY-UHFFFAOYSA-N helium atom Chemical compound [He] SWQJXJOGLNCZEY-UHFFFAOYSA-N 0.000 description 2
- 238000002955 isolation Methods 0.000 description 2
- 230000007774 longterm Effects 0.000 description 2
- 230000000149 penetrating effect Effects 0.000 description 2
- 230000008569 process Effects 0.000 description 2
- 238000012546 transfer Methods 0.000 description 2
- 230000001960 triggered effect Effects 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 239000003086 colorant Substances 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 238000001125 extrusion Methods 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 230000000452 restraining effect Effects 0.000 description 1
- 238000012552 review Methods 0.000 description 1
- 239000002915 spent fuel radioactive waste Substances 0.000 description 1
- 238000003756 stirring Methods 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 239000013589 supplement Substances 0.000 description 1
- 239000002918 waste heat Substances 0.000 description 1
Classifications
-
- G—PHYSICS
- G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
- G21C—NUCLEAR REACTORS
- G21C9/00—Emergency protection arrangements structurally associated with the reactor, e.g. safety valves provided with pressure equalisation devices
- G21C9/02—Means for effecting very rapid reduction of the reactivity factor under fault conditions, e.g. reactor fuse; Control elements having arrangements activated in an emergency
- G21C9/027—Means for effecting very rapid reduction of the reactivity factor under fault conditions, e.g. reactor fuse; Control elements having arrangements activated in an emergency by fast movement of a solid, e.g. pebbles
-
- G—PHYSICS
- G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
- G21C—NUCLEAR REACTORS
- G21C19/00—Arrangements for treating, for handling, or for facilitating the handling of, fuel or other materials which are used within the reactor, e.g. within its pressure vessel
- G21C19/19—Reactor parts specifically adapted to facilitate handling, e.g. to facilitate charging or discharging of fuel elements
-
- G—PHYSICS
- G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
- G21C—NUCLEAR REACTORS
- G21C5/00—Moderator or core structure; Selection of materials for use as moderator
- G21C5/14—Moderator or core structure; Selection of materials for use as moderator characterised by shape
-
- G—PHYSICS
- G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
- G21C—NUCLEAR REACTORS
- G21C9/00—Emergency protection arrangements structurally associated with the reactor, e.g. safety valves provided with pressure equalisation devices
- G21C9/02—Means for effecting very rapid reduction of the reactivity factor under fault conditions, e.g. reactor fuse; Control elements having arrangements activated in an emergency
Landscapes
- Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Plasma & Fusion (AREA)
- General Engineering & Computer Science (AREA)
- High Energy & Nuclear Physics (AREA)
- Devices And Processes Conducted In The Presence Of Fluids And Solid Particles (AREA)
Abstract
The invention relates to the field of safety facilities of pebble-bed high-temperature gas cooled reactors, in particular to an absorption-pebble-bed high-temperature gas cooled reactor emergency shutdown device. The reactor comprises a plurality of conical graphite blocks, a plurality of vent holes, a shell, a discharge pipe and a feed pipe, wherein graphite plates are fixedly connected to the outer edges of the upper end surfaces of the conical graphite blocks, the shell is wrapped outside the reactor, the feed pipe is arranged at the top of the reactor, and the discharge pipe is arranged at the bottom of the reactor; the shutdown assembly includes an absorber ball reservoir removably attached to the top of the reactor. When serious accidents occur and the temperature of the bottom of the reactor core is higher than 2000 ℃, the absorption balls drop into a reactor core ball bed area, and the reactor core reactivity is reduced to stop the reactor; at the same time, the fuel sphere is discharged out of the core through the weep hole and then through the discharge line, achieving shutdown. By simultaneously passively shutting down the upper portion of the reactor and the lower portion of the reactor, the shutdown speed is increased, and the shutdown effect is more remarkable.
Description
Technical Field
The invention relates to the field of safety facilities of pebble-bed high-temperature gas cooled reactors, in particular to an absorption-pebble-bed high-temperature gas cooled reactor emergency shutdown device.
Background
The ball bed type high temperature gas cooled reactor adopts ball type fuel element and realizes the on-line refueling function without shutdown based on the loading and unloading of the element. The fuel elements are randomly piled up in the reactor core to form a spherical bed, and the spherical bed type porous medium heat exchange type is presented.
However, in the case of extreme accident, such as earthquake accident, the pebble bed high temperature gas cooled reactor is easy to cause the following conditions: 1. the control rod driving mechanism fails, and the control rod fails to fall. 2. Steam generator heat transfer pipe big break, steam gets into the reactor core and introduces the positive reactivity, and reactor power continuously rises, and reactor core temperature rises. At this time, the reactor core only has temperature feedback, and the safety of the reactor core cannot be ensured. In addition, after reactor core shutdown, due to the fact that the temperature of the waste heat discharged out of the reactor core is reduced, positive reactivity is introduced by the temperature negative feedback effect, shutdown margin is reduced, and the reactor may be re-critical.
Therefore, the pebble-bed high-temperature gas cooled reactor lacks a reactivity suppressing means that works normally in an extreme accident situation.
Disclosure of Invention
This section is intended to summarize some aspects of embodiments of the invention and to briefly introduce some preferred embodiments, which may be simplified or omitted from the present section and description abstract and title of the application to avoid obscuring the objects of this section, description abstract and title, and which is not intended to limit the scope of this invention.
The present invention has been made in view of the above and/or problems occurring in the prior art.
Therefore, the technical problem to be solved by the invention is that the pebble-bed high-temperature gas cooled reactor lacks a reactivity restraining device which works normally under the condition of extreme accidents.
In order to solve the technical problems, the invention provides the following technical scheme: an absorption ball-based pebble-bed high-temperature gas cooled reactor emergency shutdown device comprises,
the reactor comprises a plurality of conical graphite blocks, a plurality of vent holes, a shell, a discharge pipe and a feed pipe, wherein graphite plates are fixedly connected to the outer edges of the upper end faces of the conical graphite blocks, the conical graphite blocks and the graphite plates form a reactor body, the shell is wrapped outside the reactor, the feed pipe is arranged at the top of the reactor, the discharge pipe is arranged at the bottom of the reactor, and the vent holes are vertically formed in the conical graphite blocks;
a shutdown assembly includes an absorber ball reservoir removably connected to the reactor roof.
Preferably, the absorption ball storage part comprises a storage box, a flange plate and an absorption ball, wherein a flange plate is arranged at the lower end of the outer circumferential surface of the storage box, the flange plate is fixedly connected to the upper end of the circumferential surface of the shell, the flange plate arranged on the circumferential surface of the lower end of the storage box is detachably connected with the flange plate through bolts, the absorption ball is placed in the storage box, and the feeding pipe is fixedly connected to the top of the storage box and downwards extends to the inside of the reactor.
Preferably, a first partition plate is fixedly connected to the inner circumferential surface of the storage tank, and the first partition plate is in contact with the top of the reactor.
Preferably, a second partition plate is fixedly connected to the inner circumferential surface of the storage box, the second partition plate is located on the upper side of the first partition plate, and the first partition plate and the second partition plate are fixedly connected with the circumferential surface of the feeding pipe.
Preferably, the first separator is made of stainless steel with a melting point of 2000 ℃.
Preferably, the second separator is made of stainless steel with a melting point of 2200 ℃.
Preferably, the absorption ball is composed of two layers of materials, the inner layer of the absorption ball is a silver-indium-cadmium alloy (Ag-In-Cr) sphere, and the outer layer of the absorption ball is a silicon carbide (SiC) cladding.
Preferably, the radius of the absorption ball is 3-5 cm, and the radius of the inner layer of the absorption ball is larger than the thickness of the outer layer of the absorption ball.
Preferably, a feed hopper is arranged at the upper end of the feed pipe, and the upper half part of the feed hopper is positioned outside the storage box.
Preferably, the shutdown assembly further comprises a trigger piece and a vibration piece, wherein the trigger piece is embedded in the bottom of the reactor, and the vibration piece is embedded in the bottom of the reactor.
The invention has the beneficial effects that: in the invention, when the temperature of the bottom of the reactor core is higher than 2000 ℃ due to serious accidents, the absorption balls drop into the reactor core ball bed area, and the reactor core reactivity is reduced to stop the reactor; at the same time, the fuel sphere is discharged out of the core through the weep hole and then through the discharge line, achieving shutdown. By simultaneously passively shutting down the upper portion of the reactor and the lower portion of the reactor, the shutdown speed is increased, and the shutdown effect is more remarkable.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for the description of the embodiments will be briefly described below, it being obvious that the drawings in the following description are only some embodiments of the present invention, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art. Wherein:
FIG. 1 is a schematic structural diagram of a pebble-bed high-temperature gas cooled reactor emergency shutdown device based on an absorption sphere;
FIG. 2 is a cross-sectional view of an absorbent ball storage member;
FIG. 3 is a block diagram of an absorbent ball;
FIG. 4 is a vertical cross-sectional view of FIG. 1;
fig. 5 is an enlarged view at a in fig. 4;
FIG. 6 is an enlarged view at B in FIG. 4;
FIG. 7 is a transverse cross-sectional view of FIG. 1;
FIG. 8 is a schematic structural view of a vibration block-proof member;
fig. 9 is a vertical cross-sectional view of fig. 8.
Detailed Description
In order that the above-recited objects, features and advantages of the present invention will become more readily apparent, a more particular description of the invention will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings.
In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention, but the present invention may be practiced in other ways other than those described herein, and persons skilled in the art will readily appreciate that the present invention is not limited to the specific embodiments disclosed below.
In the following detailed description of the embodiments of the present invention, reference is made to the accompanying drawings, which form a part hereof, and in which are shown by way of illustration only, and in which is shown by way of illustration only, and in which the scope of the invention is not limited for ease of illustration. In addition, the three-dimensional dimensions of length, width and depth should be included in actual fabrication.
Further still, reference herein to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic may be included in at least one implementation of the invention. The appearances of the phrase "in one embodiment" in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments.
Example 1
Referring to fig. 1-4, the embodiment provides a pebble-bed high-temperature gas cooled reactor emergency shutdown device based on absorption balls, which comprises a reactor 100, wherein the reactor 100 comprises a plurality of conical graphite blocks 101, vent holes 102, a shell 103, a discharge pipe 104 and a feed pipe 105, the conical graphite blocks 101 are annularly spliced to form the reactor bottom of the reactor 100, graphite plates 101a are fixedly connected to the outer edge of the upper end surface of each conical graphite block 101, the graphite plates 101a are spliced into a circular column, the graphite plates 101a form the reactor wall of the reactor 100, the shell 103 is wrapped outside the reactor 100, the feed pipe 105 is arranged at the top of the reactor 100, the discharge pipe 104 is arranged at the bottom of the reactor 100, and the vent holes 102 are vertically formed inside the conical graphite blocks 101;
the shutdown assembly 200 includes an absorber ball reservoir 201, the absorber ball reservoir 201 being removably attached to the top of the reactor 100.
The absorption ball storage piece 201 comprises a storage box 201a, a flange 201b and an absorption ball 201e, wherein a flange plate is arranged at the lower end of the outer circumferential surface of the storage box 201a, the flange 201b is fixedly connected to the upper end of the circumferential surface of the shell 103, the flange plate arranged on the circumferential surface of the lower end of the storage box 201a is detachably connected with the flange 201b through bolts, the absorption ball 201e is placed in the storage box 201a, and a feed pipe 105 is fixedly connected to the top of the storage box 201a and extends downwards to the inside of the reactor 100.
The inner circumferential surface of the storage tank 201a is fixedly connected with a first partition plate 201c, and the first partition plate 201c is contacted with the top of the reactor 100.
The inner circumferential surface of the storage box 201a is fixedly connected with a second partition plate 201d, the second partition plate 201d is positioned on the upper side of the first partition plate 201c, and the first partition plate 201c and the second partition plate 201d are fixedly connected with the circumferential surface of the feeding pipe 105.
The first separator 201c is a stainless steel material having a melting point of 2000 ℃.
The second separator 201d is a stainless steel material having a melting point of 2200 ℃.
The absorption ball 201e is composed of two layers of materials, the inner layer of the absorption ball 201e is a silver-indium-cadmium alloy Ag-In-Cr sphere, and the outer layer of the absorption ball 201e is a silicon carbide SiC cladding.
The radius of the absorption ball 201e is 3-5 cm, and the radius of the inner layer of the absorption ball 201e is larger than the thickness of the outer layer of the absorption ball 201 e.
The feed tube 105 is provided at its upper end with a feed hopper 105a, the upper half of the feed hopper 105a being located outside the storage bin 201 a.
When the reactor core is in serious accident, when the temperature of the top of the reactor 100 rises to 2000 ℃, the first partition plate 201c at the bottom of the storage box 201a is melted, hot helium gas enters a space between the first partition plate 201c and the second partition plate 201d and begins to heat the second partition plate 201d; if a serious accident continues, the temperature of the upper part of the reactor core rises to 2200 ℃, the second partition plate 201d melts, the absorption balls 201e drop into the reactor core ball bed area, and the reactor core reactivity is reduced to stop the reactor.
Wherein 2200 ℃ is selected as the device trigger threshold because: the SiC material in the high temperature stack spherical fuel element at this temperature has a reduced ability to coat the radioactive fission product, resulting in an increased loop radioactivity and an increased risk of radioactive product leakage.
Preferably, the absorption ball 201e is a spherical element with a radius of 4cm, and is composed of two layers of materials, the inner layer is a silver-indium-cadmium alloy (Ag-In-Cr) sphere with a radius of 3cm as an absorber, the absorption cross section of the material for neutrons is extremely large, the outer layer is a silicon carbide (SiC) cladding with a thickness of 1cm, the melting point of the silicon carbide is higher than 3000 ℃, the boundary integrity of the absorption ball 201e is ensured under the condition of extreme accidents, and reliable bearing performance can still be provided and structural integrity is maintained.
Preferably, the bottom of the storage tank 201a is provided with two layers of baffles, which can provide a temperature threshold to avoid the risk of deformation of the baffles caused by the long-term approach of the top of the reactor 100 to a temperature value of 2000 ℃ (for example, if the absorption balls 201e are directly placed on the first baffle 201c, when the temperature approaches the melting point of the first baffle 201c, the rigidity of the first baffle 201c is reduced, and the gravity of the absorption balls 201e causes the deformation of the first baffle 201 c. However, the temperature is still lower than 2000 ℃, the reactor 100 is safe, but when the temperature is still 1900+celsius, the first baffle 201c is gradually damaged due to the pressure of the absorption balls 201e, so that when the temperature is lower than 2000 ℃, the system is triggered to cause shutdown.
Example 2
Referring to fig. 1-9, the present embodiment provides a triggering member 202 and a vibrating member 203 of a pebble-bed high temperature gas cooled reactor emergency shutdown device based on an absorption pebble, specifically,
the trigger piece 202 is embedded at the bottom of the reactor 100, and the vibration piece 203 is embedded at the bottom of the reactor 100.
The trigger 202 includes a leak 202a, a block 202b, a baffle 202c and a rectangular rod housing 202i, the leak 202a penetrating the tapered graphite block 101 up and down and penetrating the housing 103. The leak holes 202a are distributed in annular equidistant mode, the blocks 202b are positioned inside the leak holes 202a and far away from the central shaft of the reactor 100, the blocks 202b are fixedly connected to the upper end of the conical graphite block 101, the baffle 202c is hinged to the blocks 202b, the rectangular rod shells 202i are consistent in number with the leak holes 202a, the rectangular rod shells 202i extend into the leak holes 202a and are radially and slidably connected to the conical graphite block 101, and one end, far away from the blocks 202b, of the baffle 202c is slidably connected with the upper end face of the rectangular rod shells 202 i.
The trigger piece 202 further comprises an extension block 202d, a cavity 201d-1, a round rod 202f, a rectangular block 202e and a first spring 202g, wherein the extension block 202d corresponds to the rectangular rod shell 202i in position and is fixedly connected to the circumferential surface of the shell 103, the cavity 201d-1 is radially distributed, the cavity 201d-1 is sequentially formed in the extension block 202d, the shell 103 and the conical graphite block 101 from outside to inside, the round rod 202f is fixedly connected to two ends of the cavity 201d-1, the rectangular block 202e is located in the cavity 201d-1 and is slidably connected to the round rod 202f, one end of the first spring 202g is fixedly connected to the rectangular block 202e, the other end of the first spring 202g is fixedly connected to the end of the cavity 201d-1, and the rectangular rod shell 202i extends into the cavity 201d-1 and is fixedly connected to the rectangular block 202 e.
The rectangular rod shell 202i is radially and slidably connected with a spring rod 202h, and the spring rod 202h is cylindrical. The elastic rod 202h penetrates through the rectangular block 202e and the cavity 201d-1 and extends to the outside of the extension block 202d, the groove body 202h-1 is formed in the circumferential surface of one end, far away from the extension block 202d, of the elastic rod 202h at equal intervals, the elastic block 202h-2 is connected in the groove body 202h-1 in a non-rotating mode, a torsion spring is arranged at the rotating connection position of the elastic block 202h-2, and the blocking piece 202h-3 is fixedly connected to the circumferential surface of the elastic rod 202 h. Wherein, the elastic block 202h-2 can be opened in the groove body 202h-1 in a direction far away from the elastic rod 202h or gathered in a direction close to the elastic rod 202h, and the elastic block 202h-2 is made of stainless steel with a melting point of 2000 ℃.
The circumference surface of one end of the conical graphite block 101 far away from the extension block 202d is fixedly connected with a hollowed-out shell 202j, and the elastic rod 202h radially penetrates through the leak hole 202a and extends into the hollowed-out shell 202 j. The hollowed out shell 202j serves to protect the bullet 202h-2 from the extrusion collision of the fuel ball.
The center of the lower end face of the shell 103 is fixedly connected with a connecting pipe 202l, the bottom of a reactor 100 reactor cavity is in a conical design, the top end of the connecting pipe 202l is fixedly connected with the center of the bottom of the reactor 100 reactor cavity, the discharge pipe 104 is positioned inside the connecting pipe 202l and is rotationally connected with the connecting pipe 202l, the edge of the lower end face of the shell 103 is fixedly connected with a conical bucket block 202k, the conical bucket block 202k extends downwards and is fixedly connected with the circumferential surface of the connecting pipe 202l, leakage holes two 202l-2 are formed in the circumferential surfaces of the connecting pipe 202l and the discharge pipe 104 at equal intervals in an annular mode, and leakage holes one 202l-1 are formed in the tops of the connecting pipe 202l and the discharge pipe 104.
The vibration member 203 comprises a conical groove 203a, an adjusting cylinder 203b, a piston plate 203c and a second spring 203d, wherein the conical groove 203a is formed in the lower end of the conical bucket block 202k, an air inlet pipe 203h is fixedly connected to the outer portion of the conical bucket block 202k, the air inlet pipe 203h is communicated with the conical groove 203a, and a one-way valve is arranged in the air inlet pipe 203 h. The adjusting cylinder 203b is located under the conical groove 203a, the adjusting cylinder 203b is fixedly connected to the conical bucket block 202k and is communicated with the conical groove 203a, the piston plate 203c is located inside the adjusting cylinder 203b and is connected to the adjusting cylinder 203b in a sliding mode, the lower end of the adjusting cylinder 203b is closed, one end of the second spring 203d is fixedly connected to the center of the lower end face of the piston plate 203c, and the other end of the second spring 203d is fixedly connected to the bottom of the adjusting cylinder 203 b.
The vibration piece 203 further comprises a vertical rod 203e, a movable plate 203f and a dredging rod 203g, wherein the vertical rod 203e is fixedly connected to the lower end face of the piston plate body 203c, the vertical rod 203e downwards penetrates through the bottom of the adjusting cylinder 203b and is slidably connected with the bottom of the adjusting cylinder 203b, an air outlet hole is formed in the circumferential surface of the lower end of the adjusting cylinder 203b, the movable plate 203f is fixedly connected to the lower end of the vertical rod 203e, the dredging rod 203g is fixedly connected to the upper end face of the movable plate 203f, and the dredging rod 203g avoids the leakage hole 202a and upwards extends into the reactor 100.
The circumferential surface of the dredging rod 203g positioned in the conical groove 203a is fixedly connected with a dredging block 203g-1 in an annular equidistant manner, and the circumferential surface of the upper end of the dredging rod 203g positioned in the reactor 100 cavity is also fixedly connected with a dredging block 203g-1 in an annular equidistant manner. An isolation pipe 203a-1 is arranged in the conical groove 203a at a position corresponding to the dredging rod 203g, and the dredging rod 203g penetrates through the isolation pipe 203a-1.
In use, during normal discharging, the discharging pipe 104 is rotated, so that the first leakage hole 202l-1 formed in the top of the connecting pipe 202l coincides with the first leakage hole 202l-1 formed in the top of the discharging pipe 104, and a channel of the first leakage hole 202l-1 is opened. The spent fuel balls in the reactor 100 are discharged from the first leakage holes 202l-1, and the second leakage holes 202l-2 formed in the circumferential surface of the connecting pipe 202l are staggered with the second leakage holes 202l-2 formed in the circumferential surface of the discharging pipe 104; when discharging is not needed, the discharging pipe 104 is rotated, so that the first leakage hole 202l-1 formed in the top of the connecting pipe 202l is staggered from the first leakage hole 202l-1 formed in the top of the discharging pipe 104, the first leakage hole 202l-1 is closed, the second leakage hole 202l-2 formed in the circumferential surface of the connecting pipe 202l coincides with the second leakage hole 202l-2 formed in the circumferential surface of the discharging pipe 104, and a second leakage hole 202l-2 channel is opened.
When a serious accident occurs in the reactor core, and the temperature of the top of the reactor 100 rises to 2000 ℃, the first partition plate 201c at the bottom of the storage tank 201a melts, and hot helium gas enters a space between the first partition plate 201c and the second partition plate 201d and begins to heat the second partition plate 201d; if a serious accident continues, the temperature of the upper part of the reactor core rises to 2200 ℃, the second partition plate 201d melts, the absorption balls 201e drop into the reactor core ball bed area, and the reactor core reactivity is reduced to stop the reactor.
Wherein 2200 ℃ is selected as the device trigger threshold because: the SiC material in the high temperature stack spherical fuel element at this temperature has a reduced ability to coat the radioactive fission product, resulting in an increased loop radioactivity and an increased risk of radioactive product leakage.
Preferably, the absorption ball 201e is a spherical element with a radius of 4cm, and is composed of two layers of materials, the inner layer is a silver-indium-cadmium alloy (Ag-In-Cr) sphere with a radius of 3cm as an absorber, the absorption cross section of the material for neutrons is extremely large, the outer layer is a silicon carbide (SiC) cladding with a thickness of 1cm, the melting point of the silicon carbide is higher than 3000 ℃, the boundary integrity of the absorption ball 201e is ensured under the condition of extreme accidents, and reliable bearing performance can still be provided and structural integrity is maintained.
Preferably, the bottom of the storage tank 201a is provided with two layers of baffles, which can provide a temperature threshold to avoid the risk of deformation of the baffles caused by the long-term approach of the top of the reactor 100 to a temperature value of 2000 ℃ (for example, if the absorption balls 201e are directly placed on the first baffle 201c, when the temperature approaches the melting point of the first baffle 201c, the rigidity of the first baffle 201c is reduced, and the gravity of the absorption balls 201e causes the deformation of the first baffle 201 c. However, the temperature is still lower than 2000 ℃, the reactor 100 is safe, but when the temperature is still 1900+celsius, the first baffle 201c is gradually damaged due to the pressure of the absorption balls 201e, so that when the temperature is lower than 2000 ℃, the system is triggered to cause shutdown.
Meanwhile, when a serious accident occurs, the temperature of the bottom of the reactor core is higher than 2000 ℃, the elastic block 202h-2 in the tank body 202h-1 is melted, under the action of the first spring 202g, the rectangular block 202e drives the rectangular rod shell 202i and the elastic rod 202h to radially move in the direction away from the hollowed shell 202j, the baffle 202c is out of support due to the movement of the rectangular rod shell 202i, the baffle 202c rotates downwards under the action of self gravity of the baffle 202c and the pressure of the fuel ball, and at the moment, the leak hole 202a is opened. Most of the fuel spheres in the reactor 100 cavity drop down into the conical bucket 202k through the leak 202a, roll into the discharge tube 104 through the leak two 202l-2, and exit the core through the discharge tube 104.
When the fuel ball falls down into the conical shaped bucket 202k through the weep hole 202a, the fuel ball transfers a portion of the heat to the conical shaped bucket 202k, where the air inside the conical shaped slot 203a expands thermally. Since the adjustment cylinder 203b communicates with the tapered groove 203a, when the air inside the tapered groove 203a and inside the adjustment cylinder 203b expands due to heat, the gas above the adjustment cylinder 203b presses the piston plate 203c downward, and the second spring 203d is in a compressed state. When the piston plate 203c moves down to the lower side of the air outlet, the high-pressure air expanded in the adjusting cylinder 203b is instantaneously discharged from the air outlet, the air pressure received by the piston plate 203c is instantaneously reduced, and the piston plate 203c moves up under the action of the second spring 203 d. With this cycle, the piston plate 203c moves up and down inside the adjustment cylinder 203 b. The air intake pipe 203h communicating with the tapered groove 203a serves to supplement the effect of the external air to the inside of the tapered groove 203a, so that the inside of the tapered groove 203a always has a sufficient amount of air for thermal expansion to provide driving force.
When the piston plate 203c moves up and down in the adjusting cylinder 203b, the movable plate 203f is driven to move up and down by the vertical rod 203e, the movable plate 203f moves up and down to drive the dredging rod 203g to move up and down, and the dredging block 203g-1 moves up and down when the dredging rod 203g moves up and down to stir the fuel ball in the reactor 100 cavity and the conical bucket 202k, so as to prevent the fuel ball from being blocked in the unloading process, and enable automatic unloading to be smoother. The insulating tube 203a-1 serves to seal the tapered groove 203a, preventing gas inside the tapered groove 203a from flowing out of the tapered groove 203a when the blocking rod 203g moves up and down.
When the temperature of the bottom of the reactor core is higher than 2000 ℃ due to serious accidents, the absorption balls 201e drop into the reactor core ball bed area, and the reactor core reactivity is reduced to stop the reactor; at the same time, the fuel sphere exits the core through the weep hole 202a and then through the discharge tube 104 line, effecting shutdown. By simultaneously passively shutting down the upper portion of the reactor 100 and the lower portion of the reactor 100, the shutdown speed is increased and the shutdown effect is more pronounced.
It is important to note that the construction and arrangement of the present application as shown in a variety of different exemplary embodiments is illustrative only. Although only a few embodiments have been described in detail in this disclosure, those skilled in the art who review this disclosure will readily appreciate that many modifications are possible (e.g., variations in sizes, dimensions, structures, shapes and proportions of the various elements, values of parameters (e.g., temperature, pressure, etc.), mounting arrangements, use of materials, colors, orientations, etc.) without materially departing from the novel teachings and advantages of the subject matter described in this application. For example, elements shown as integrally formed may be constructed of multiple parts or elements, the position of elements may be reversed or otherwise varied, and the nature or number of discrete elements or positions may be altered or varied. Accordingly, all such modifications are intended to be included within the scope of present invention. The order or sequence of any process or method steps may be varied or re-sequenced according to alternative embodiments. In the claims, any means-plus-function clause is intended to cover the structures described herein as performing the recited function and not only structural equivalents but also equivalent structures. Other substitutions, modifications, changes and omissions may be made in the design, operating conditions and arrangement of the exemplary embodiments without departing from the scope of the present inventions. Therefore, the invention is not limited to the specific embodiments, but extends to various modifications that nevertheless fall within the scope of the appended claims.
Furthermore, in an effort to provide a concise description of the exemplary embodiments, all features of an actual implementation may not be described (i.e., those not associated with the best mode presently contemplated for carrying out the invention, or those not associated with practicing the invention).
It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions may be made. Such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure.
It should be noted that the above embodiments are only for illustrating the technical solution of the present invention and not for limiting the same, and although the present invention has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that the technical solution of the present invention may be modified or substituted without departing from the spirit and scope of the technical solution of the present invention, which is intended to be covered in the scope of the claims of the present invention.
Claims (10)
1. The utility model provides a ball bed type high temperature gas cooled reactor emergency shutdown device based on absorption ball which characterized in that: comprising the steps of (a) a step of,
the reactor (100), reactor (100) include toper graphite piece (101), air vent (102), casing (103), row material pipe (104) and inlet pipe (105), toper graphite piece (101) have a plurality ofly, toper graphite piece (101) up end outer edge department fixedly connected with graphite sheet (101 a), toper graphite piece (101) with graphite sheet (101 a) constitute reactor (100) pile body, casing (103) parcel in reactor (100) outside, inlet pipe (105) set up in reactor (100) top, row material pipe (104) set up in reactor (100) bottom, air vent (102) vertically open in inside toper graphite piece (101);
a shutdown assembly (200) comprising an absorber ball reservoir (201), the absorber ball reservoir (201) being removably connected to a top of the reactor (100).
2. The absorption ball-based pebble-bed high temperature gas cooled reactor emergency shutdown device as set forth in claim 1, wherein: the absorption ball storage piece (201) comprises a storage box (201 a), a flange plate (201 b) and an absorption ball (201 e), wherein a flange plate is arranged at the lower end of the outer circumferential surface of the storage box (201 a), the flange plate (201 b) is fixedly connected to the upper end of the circumferential surface of the shell (103), the flange plate arranged on the circumferential surface of the lower end of the storage box (201 a) is detachably connected with the flange plate (201 b) through bolts, the absorption ball (201 e) is placed in the storage box (201 a), and the feeding pipe (105) is fixedly connected to the top of the storage box (201 a) and extends downwards to the inside of the reactor (100).
3. The absorption ball-based pebble-bed high-temperature gas cooled reactor emergency shutdown device according to claim 2, wherein: the inner circumferential surface of the storage box (201 a) is fixedly connected with a first partition plate (201 c), and the first partition plate (201 c) is in contact with the top of the reactor (100).
4. The absorption ball-based pebble-bed high temperature gas cooled reactor emergency shutdown device of claim 3, wherein: the storage box (201 a) is fixedly connected with a second partition plate (201 d) on the inner circumferential surface, the second partition plate (201 d) is located on the upper side of the first partition plate (201 c), and the first partition plate (201 c) and the second partition plate (201 d) are fixedly connected with the circumferential surface of the feeding pipe (105).
5. The absorption ball-based pebble bed high temperature gas cooled reactor emergency shutdown device of claim 3 or 4, wherein: the first separator (201 c) is made of stainless steel with a melting point of 2000 ℃.
6. The absorption ball-based pebble-bed high-temperature gas cooled reactor emergency shutdown device according to claim 4, wherein: and the second separator (201 d) is made of stainless steel with a melting point of 2200 ℃.
7. The absorption ball-based pebble-bed high-temperature gas cooled reactor emergency shutdown device according to claim 2, wherein: the absorption ball (201 e) is composed of two layers of materials, the inner layer of the absorption ball (201 e) is a silver-indium-cadmium alloy (Ag-In-Cr) sphere, and the outer layer of the absorption ball (201 e) is a silicon carbide (SiC) cladding.
8. The absorption ball-based pebble-bed high-temperature gas cooled reactor emergency shutdown device according to claim 7, wherein: the radius of the absorption ball (201 e) is 3-5 cm, and the radius of the inner layer of the absorption ball (201 e) is larger than the thickness of the outer layer of the absorption ball (201 e).
9. The absorption ball-based pebble-bed high-temperature gas cooled reactor emergency shutdown device according to claim 4, wherein: the upper end of the feeding pipe (105) is provided with a feeding hopper (105 a), and the upper half part of the feeding hopper (105 a) is positioned outside the storage box (201 a).
10. The absorption ball-based pebble-bed high temperature gas cooled reactor emergency shutdown device of claim 3, wherein: the shutdown assembly (200) further comprises a trigger piece (202) and a vibration piece (203), wherein the trigger piece (202) is embedded in the bottom of the reactor (100), and the vibration piece (203) is embedded in the bottom of the reactor (100).
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| CN202311122573.7A CN117292855B (en) | 2023-09-01 | 2023-09-01 | Ball bed type high temperature gas cooled reactor emergency shutdown device based on absorption ball |
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| CN202311122573.7A CN117292855B (en) | 2023-09-01 | 2023-09-01 | Ball bed type high temperature gas cooled reactor emergency shutdown device based on absorption ball |
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB8424930D0 (en) * | 1983-10-03 | 1984-11-28 | Kernforschungsanlage Juelich | Lowering reactivity of gas-cooled pebble bed reactor |
| JPH07229991A (en) * | 1994-02-18 | 1995-08-29 | Japan Atom Energy Res Inst | Reserved shutdown device for high temperature gas-cooled reactor |
| CN1447342A (en) * | 2003-04-04 | 2003-10-08 | 清华大学 | Second shutdown system of absorption ball applicable to gas-cooled reactor |
| CN114220569A (en) * | 2021-11-11 | 2022-03-22 | 华能核能技术研究院有限公司 | Compact ball bed high temperature gas cooled reactor primary loop device |
| CN114999696A (en) * | 2022-06-16 | 2022-09-02 | 中国核动力研究设计院 | A remove device that is used for high temperature gas cooled to pile absorption ball |
-
2023
- 2023-09-01 CN CN202311122573.7A patent/CN117292855B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB8424930D0 (en) * | 1983-10-03 | 1984-11-28 | Kernforschungsanlage Juelich | Lowering reactivity of gas-cooled pebble bed reactor |
| JPH07229991A (en) * | 1994-02-18 | 1995-08-29 | Japan Atom Energy Res Inst | Reserved shutdown device for high temperature gas-cooled reactor |
| CN1447342A (en) * | 2003-04-04 | 2003-10-08 | 清华大学 | Second shutdown system of absorption ball applicable to gas-cooled reactor |
| CN114220569A (en) * | 2021-11-11 | 2022-03-22 | 华能核能技术研究院有限公司 | Compact ball bed high temperature gas cooled reactor primary loop device |
| CN114999696A (en) * | 2022-06-16 | 2022-09-02 | 中国核动力研究设计院 | A remove device that is used for high temperature gas cooled to pile absorption ball |
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| Publication number | Publication date |
|---|---|
| CN117292855B (en) | 2024-08-23 |
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