Reactor core restraining device of gas cooled reactor and horizontal high-temperature gas cooled reactor

Abstract

The invention discloses a gas cooled reactor core restraint device which is located in a reactor pressure vessel, the reactor core restraint device comprises a restraint cylinder and a heat insulation buffer layer, the restraint cylinder is installed in the reactor pressure vessel, a whole reactor core is contained in the restraint cylinder, and the reactor core is restrained in the restraint cylinder in the radial direction and the circumferential direction; the heat insulation buffer layers are arranged at a plurality of positions on the constraint barrel, at least part of the heat insulation buffer layers are arranged between the reactor core and the constraint barrel, and the heat insulation buffer layers play roles in heat insulation and stress impact absorption. The reactor core restraining device can integrally restrain the reactor core graphite, so that the structural integrity and stability of the reactor core are ensured, and the influence of the convection effect of the coolant on the reactor core power is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of nuclear reactor core restraint structures, and in particular to a gas-cooled reactor core restraint device and a horizontal high-temperature gas-cooled reactor. Background Art

[0002] The high temperature gas-cooled reactor (HTTR) uses a graphite core, TRISO spherical fuel elements and helium coolant, and uses metal straps (commonly used materials are 316H+B16) to circumferentially constrain the core graphite to prevent the graphite blocks stacked in the core from being dislocated during thermal transients. However, due to the obvious creep effect of metal materials under high-temperature service conditions, and the thermal expansion of the metal straps is much greater than that of the core graphite, the circumferential constraint force of the metal straps is significantly relaxed, and can no longer play a good restraining role, which is not conducive to the integrity and safety of the graphite core structure. At the same time, there are gaps between the graphite blocks stacked in the core, and leakage will occur between the high-temperature coolant inside the graphite core and the low-temperature coolant outside, which is not conducive to core temperature control and maintaining power generation efficiency.

[0003] The gas-cooled micro-reactor also uses a stacked graphite core and helium coolant. The difference is that the gas-cooled micro-reactor uses a horizontal nuclear reactor and a TRISO prismatic fuel assembly. Therefore, the graphite core of the gas-cooled micro-reactor will face a more serious graphite block misalignment problem. If the high-temperature gas-cooled reactor uses metal straps to constrain the graphite core, it will also face the same strap loosening and leakage problems.

[0004] Prior art CN218413995U discloses a horizontal high temperature gas-cooled reactor structure, including an internal component and a pressure vessel, wherein the internal component is arranged in the pressure vessel, and the internal component includes a core assembly and a constraint frame structure constraining the core assembly therein, and the constraint frame structure is slidably connected to the pressure vessel so that the internal component can slide axially into or out of the pressure vessel. The constraint frame is a hollow frame composed of a constraint ring, a constraint shaft and a hinge, which constrains the core, but its structure is complex and cannot achieve the effect of overall containment of the core.

[0005] Prior art CN115995304A discloses a horizontal high temperature gas-cooled reactor internals and a horizontal high temperature gas-cooled reactor, which mainly focuses on the structure of the graphite core, and the axial layer and radial layer are cylindrical as a whole, but the patent does not involve the core restraint structure. The restraint method of the graphite core is to compress it by a spring set on the surface of the pressure vessel cylinder.

[0006] In view of the above technical problems, the present invention is specially introduced. Summary of the invention

[0007] The main purpose of the present invention is to provide a gas-cooled reactor core restraint device and a horizontal high-temperature gas-cooled reactor, which are used to provide a structure for overall containment and restraint of the graphite core to solve the problems of loose straps and leakage.

[0008] In order to achieve the above-mentioned object, according to one aspect of the present invention, a gas-cooled reactor core restraint device is provided, which is located in a reactor pressure vessel, and comprises a restraint cylinder and a heat-insulating buffer layer, wherein the restraint cylinder is installed in the reactor pressure vessel, and the core is entirely contained in the restraint cylinder, and the core is restrained in the restraint cylinder in both radial and circumferential directions;

[0009] The thermal insulation buffer layer is arranged at multiple positions on the constraining cylinder, and at least part of the thermal insulation buffer layer is arranged between the core and the constraining cylinder. The thermal insulation buffer layer plays the role of heat insulation and absorbing stress impact.

[0010] Furthermore, the constraint cylinder body comprises a constraint cylinder cover, a constraint cylinder body and a constraint cylinder bottom. The constraint cylinder body is circumferentially closed and integral. The constraint cylinder cover and the constraint cylinder bottom are respectively arranged at two ends of the constraint cylinder body.

[0011] Furthermore, the restraining cylinder body and the restraining cylinder bottom are integrally formed.

[0012] Furthermore, the material constraining the cylinder includes a carbon-based carbon fiber composite material.

[0013] Furthermore, the material of the thermal insulation buffer layer includes carbon aerogel, and the thermal insulation buffer layer has a porous structure.

[0014] Furthermore, the heat-insulating buffer layer includes a first heat-insulating buffer layer arranged on the inner side of the constraint tube cover and the constraint tube bottom, and also includes a second heat-insulating buffer layer arranged on the inner side of the constraint tube body.

[0015] Furthermore, the core restraint device also includes a plurality of first stops and a plurality of second stops arranged on the inner wall of the reactor pressure vessel, wherein the plurality of first stops are distributed on the circumferential outer side of the restraint tube cover, and the plurality of second stops are distributed on the circumferential outer side of the restraint tube bottom.

[0016] Furthermore, a plurality of slots are respectively arranged on the circumference of the constraint tube cover and the constraint tube bottom, and the plurality of slots are respectively matched with the plurality of first stoppers or the plurality of second stoppers.

[0017] Furthermore, the heat-insulating buffer layer includes a third heat-insulating buffer layer, and the third heat-insulating buffer layer is arranged at a position on the first stopper and the second stopper that contacts the card slot.

[0018] Furthermore, a plurality of cushion blocks are arranged on the circumferential outer side of the constraint barrel, and two sides of the cushion blocks are respectively matched with the inner wall of the reactor pressure vessel and the circumferential outer wall of the constraint barrel.

[0019] Furthermore, the thermal insulation buffer layer also includes a fourth buffer thermal insulation layer, and the fourth buffer thermal insulation layer is arranged on a side of the cushion block close to the inner wall of the reactor pressure vessel.

[0020] Furthermore, the shape of the circumferential inner wall of the constraining barrel is set to be polygonal and matched with the outer wall of the core.

[0021] Furthermore, a plurality of first holes and second holes are provided on the restraining cylinder cover and the first heat-insulating buffer layer inside thereof, which are used for passing coolant and installing control rods respectively.

[0022] Furthermore, a converging opening is provided at the center of the bottom of the constraint cylinder, and the outer wall of the converging opening has a curved surface structure.

[0023] To achieve the above object, according to another aspect of the present invention, a horizontal high temperature gas-cooled reactor structure is proposed, comprising a reactor pressure vessel and a core, and also comprising the core restraint device according to the above.

[0024] By applying the technical solution of the present invention, at least the following beneficial effects are achieved:

[0025] 1. The core restraint device of the present invention is provided with a restraint cylinder and a thermal insulation buffer layer. The restraint cylinder plays a role of overall containment and restraint on the core, and facilitates the overall loading and unloading of the core, thereby ensuring the structural integrity and stability of the core; the thermal insulation buffer layer can absorb the impact load of the core and reduce the heat transferred from the core to the outside.

[0026] 2. The core restraint device of the present invention has a simple structure, convenient manufacturing, integral molding, and easy installation by designing the structure of the restraint cylinder, thereby avoiding the influence of the unavoidable convection effect of the metal core strap on the core power, and the stress relaxation caused by high-temperature expansion, which leads to reduced restraint effect and affects the stability and integrity of the core structure.

[0027] 3. The core restraint device of the present invention selects materials for the restraint cylinder and the thermal insulation buffer layer so that the restraint cylinder has excellent properties of high temperature resistance, high strength and high toughness, which is sufficient to withstand the respective loads of the core. The thermal insulation buffer layer has the characteristics of high temperature resistance and low density, and has good effects of heat insulation and stress absorption.

[0028] 4. The core restraint device of the present invention restrains the restraint cylinder in the axial direction and prevents the restraint cylinder from rotating by designing the matching relationship between multiple blocks and slots. Multiple pads are designed to support and restrain the restraint cylinder in the circumferential direction to maintain the annular space between the restraint cylinder and the inner wall of the pressure vessel.

[0029] 5. The core restraint device of the present invention can absorb the circumferential and axial impact loads of the graphite core by setting the specific positions of the first, second, third and fourth thermal insulation buffer layers, protect the core and fuel, and minimize the heat transferred from the core to the pressure vessel. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

[0031] Figure 1 A cross-sectional schematic diagram of a gas-cooled reactor core restraint device according to an embodiment is shown;

[0032] Figure 2 Shows Figure 1 AA section diagram in;

[0033] Figure 3 Shows Figure 1 Schematic diagram of the BB cross section.

[0034] The above drawings include the following reference numerals:

[0035] 1. Constraint barrel cover; 2, 12. First thermal insulation buffer layer; 3. First stopper; 10. Second stopper; 4, 9. Third thermal insulation buffer layer; 5. Constraint barrel body; 6. Second thermal insulation buffer layer; 7. Pad; 8. Fourth thermal insulation buffer layer; 11. Constraint barrel bottom; 13. Converging port; 14. Reactor pressure vessel; 15. Control rod; 16. Fuel area; 17. Core; 18. First hole; 19. Second hole. DETAILED DESCRIPTION

[0036] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0037] The present invention is further described in detail below in conjunction with specific embodiments, and these embodiments cannot be understood as limiting the scope of protection claimed by the present invention. The term "including" when used indicates the existence of a feature, but does not exclude the existence or addition of one or more other features; the orientation or position relationship indicated by the terms "lateral", "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inside", "outside", etc. is based on the orientation or position relationship shown in the drawings, which is only for the convenience of description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention; in addition, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance.

[0038] In the description, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected, or indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. In addition, in the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0039] Example:

[0040] The present invention proposes a gas-cooled reactor core restraint device, such as Figure 1 As shown, the core restraint device is located in the reactor pressure vessel 14, and the core restraint device includes a restraint cylinder and a thermal insulation buffer layer. The restraint cylinder is installed in the reactor pressure vessel 14, and the core 17 is entirely contained in the restraint cylinder, and the core 17 is restrained in the restraint cylinder in both radial and circumferential directions.

[0041] The thermal insulation buffer layer is arranged at multiple positions on the constraint cylinder, and at least part of the thermal insulation buffer layer is arranged between the core 17 and the constraint cylinder, and the thermal insulation buffer layer plays the role of heat insulation and stress impact absorption. The constraint cylinder plays the role of overall containment and constraint on the core, and facilitates the overall loading and unloading of the core, ensuring the structural integrity and stability of the core; the thermal insulation buffer layer can absorb the impact load of the core and reduce the heat transferred from the core to the outside.

[0042] Specifically, the constraint cylinder comprises a constraint cylinder cover 1, a constraint cylinder body 5 and a constraint cylinder bottom 11. The constraint cylinder body 5 is circumferentially closed and integral. The constraint cylinder cover 1 and the constraint cylinder bottom 11 are respectively arranged at both ends of the constraint cylinder body 5. Preferably, the constraint cylinder body 5 and the constraint cylinder bottom 11 are integrally formed.

[0043] The core restraint device of the present application has a simple structure, is easy to manufacture, is integrally formed, and is easy to install, thereby avoiding the unavoidable convection effect of metal core straps that affects the core power, as well as stress relaxation caused by high-temperature expansion, which leads to reduced restraint effect and affects the stability and integrity of the core structure.

[0044] Preferably, the material constraining the cylinder includes a carbon-based carbon fiber composite material, and more preferably a carbon / carbon composite material, which has excellent properties of high density, high temperature resistance, high strength, and high toughness, and is used to bear various loads of the entire core.

[0045] Preferably, the material of the heat-insulating buffer layer includes carbon aerogel, which has the characteristics of high temperature resistance, low density, and low thermal conductivity, and can play a good role in heat insulation. The heat-insulating buffer layer has a porous structure and can also play a role in absorbing stress impact.

[0046] The heat-insulating buffer layer includes first heat-insulating buffer layers 2 and 12 arranged inside the constraint cylinder cover 1 and the constraint cylinder bottom 11, and also includes a second heat-insulating buffer layer 6 arranged inside the constraint cylinder body 5. They are used to absorb the axial and circumferential impact loads of the graphite core, protect the core and fuel, and minimize the heat transfer from the core to the pressure vessel.

[0047] Combination Figure 2 As shown, the core restraint device also includes a plurality of first stops 3 and a plurality of second stops 10 arranged on the inner wall of the reactor pressure vessel 14 , wherein the plurality of first stops 3 are distributed on the circumferential outer side of the restraint barrel cover 1 , and the plurality of second stops 10 are distributed on the circumferential outer side of the restraint barrel bottom 11 .

[0048] Furthermore, a plurality of slots are respectively arranged on the circumference of the constraint cylinder cover 1 and the constraint cylinder bottom 11, and the plurality of slots are respectively matched with the plurality of first stoppers 3 or the plurality of second stoppers 10, so as to constrain the constraint cylinder in the axial direction and prevent the constraint cylinder from rotating.

[0049] In addition, the heat insulation buffer layer includes a third heat insulation buffer layer 4, 9, which is arranged at the position of the first stopper 3 and the second stopper 10 in contact with the slot, and is used to absorb the axial load of the restraining cylinder in the pressure vessel and reduce the heat conduction to the pressure vessel.

[0050] Combination Figure 1 and Figure 3 As shown, a plurality of pads 7 are arranged on the circumferential outer side of the constraint barrel 5, and the two sides of the pads 7 are respectively matched with the inner wall of the reactor pressure vessel 14 and the circumferential outer wall of the constraint barrel 5, so as to support and constrain the constraint barrel in the circumferential direction and maintain the annular space between the constraint barrel and the inner wall of the pressure vessel.

[0051] Furthermore, the heat insulating buffer layer further includes a fourth heat insulating buffer layer 8, which is arranged on the side of the cushion block 7 close to the inner wall of the reactor pressure vessel 14, and is used to absorb the circumferential load of the barrel 5 in the pressure vessel and reduce the heat conduction to the pressure vessel.

[0052] Preferably, the circumferential inner wall of the constraining barrel 5 is configured to be polygonal in shape and matches with the outer wall of the core 17 to effectively prevent the core from rotating within the constraining barrel 5 .

[0053] Combination Figure 1 and Figure 2As shown, the constraint tube cover 1 and the first heat insulating buffer layer 2 inside thereof are provided with a plurality of first holes 18 and second holes 19, respectively used for coolant to pass through and for installing the control rod 15. A convergence port 13 is provided at the center of the constraint tube bottom 11, and the outer wall of the convergence port 13 has a curved surface structure.

[0054] In this way, the coolant can flow radially along the outer wall of the converging port 13 into the gap between the constraining cylinder 5 and the inner wall of the pressure vessel, flow axially between the multiple gaskets 7, flow from the first hole 18 on the constraining cylinder cover 1 into the fuel area 16 inside the core 17, and flow out of the constraining cylinder from the converging port 13 after converging.

[0055] According to another aspect of the present invention, a horizontal high temperature gas-cooled reactor structure is proposed, comprising a reactor pressure vessel 14 and a core 17, and also comprising the core restraint device according to the above.

[0056] In summary, from the above description, it can be seen that the above embodiments of the present invention achieve the following technical effects:

[0057] 1. The core restraint device of the present invention is provided with a restraint cylinder and a thermal insulation buffer layer. The restraint cylinder plays a role of overall containment and restraint on the core, and facilitates the overall loading and unloading of the core, thereby ensuring the structural integrity and stability of the core; the thermal insulation buffer layer can absorb the impact load of the core and reduce the heat transferred from the core to the outside.

[0058] 2. The core restraint device of the present invention has a simple structure, convenient manufacturing, integral molding, and easy installation by designing the structure of the restraint cylinder, thereby avoiding the influence of the unavoidable convection effect of the metal core strap on the core power, and the stress relaxation caused by high-temperature expansion, which leads to reduced restraint effect and affects the stability and integrity of the core structure.

[0059] 3. The core restraint device of the present invention selects materials for the restraint cylinder and the thermal insulation buffer layer so that the restraint cylinder has excellent properties of high temperature resistance, high strength and high toughness, which is sufficient to withstand the respective loads of the core. The thermal insulation buffer layer has the characteristics of high temperature resistance and low density, and has good effects of heat insulation and stress absorption.

[0060] 4. The core restraint device of the present invention restrains the restraint cylinder in the axial direction and prevents the restraint cylinder from rotating by designing the matching relationship between multiple blocks and slots. Multiple pads are designed to support and restrain the restraint cylinder in the circumferential direction to maintain the annular space between the restraint cylinder and the inner wall of the pressure vessel.

[0061] 5. The core restraint device of the present invention can absorb the circumferential and axial impact loads of the graphite core by setting the specific positions of the first, second, third and fourth thermal insulation buffer layers, protect the core and fuel, and minimize the heat transferred from the core to the pressure vessel.

[0062] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A gas-cooled reactor core restraint device, located in a reactor pressure vessel (14), characterized in that: The core restraint device comprises a restraint cylinder and a heat-insulating buffer layer, the restraint cylinder is installed in the reactor pressure vessel (14), the core (17) is entirely contained in the restraint cylinder, and the core (17) is restrained in the restraint cylinder in both radial and circumferential directions; The thermal insulation buffer layer is arranged at multiple positions on the constraining cylinder, and at least part of the thermal insulation buffer layer is arranged between the core (17) and the constraining cylinder. The thermal insulation buffer layer plays the role of heat insulation and absorbing stress impact.

2. The core restraint device according to claim 1, characterized in that: The restraining cylinder body comprises a restraining cylinder cover (1), a restraining cylinder body (5) and a restraining cylinder bottom (11); the restraining cylinder body (5) is circumferentially closed and is an integrated type; the restraining cylinder cover (1) and the restraining cylinder bottom (11) are respectively arranged at two ends of the restraining cylinder body (5).

3. The core restraint device according to claim 2, characterized in that: The restraining cylinder body (5) and the restraining cylinder bottom (11) are integrally formed.

4. The core restraint device according to any one of claims 1 to 3, characterized in that: The material of the constraining cylinder includes a carbon-based carbon fiber composite material.

5. The core restraint device according to claim 4, characterized in that: The material of the heat-insulating buffer layer includes carbon aerogel, and the heat-insulating buffer layer has a porous structure.

6. The core restraint device according to claim 2, characterized in that: The heat-insulating buffer layer comprises a first heat-insulating buffer layer (2, 12) arranged on the inner side of the constraint cylinder cover (1) and the constraint cylinder bottom (11), and also comprises a second heat-insulating buffer layer (6) arranged on the inner side of the constraint cylinder body (5).

7. The core restraint device according to claim 6, characterized in that: The core restraint device also includes a plurality of first stoppers (3) and a plurality of second stoppers (10) arranged on the inner wall of the reactor pressure vessel (14), wherein the plurality of first stoppers (3) are distributed on the circumferential outer side of the restraint barrel cover (1), and the plurality of second stoppers (10) are distributed on the circumferential outer side of the restraint barrel bottom (11).

8. The core restraint device according to claim 7, characterized in that: A plurality of slots are respectively arranged on the circumference of the constraint cylinder cover (1) and the constraint cylinder bottom (11), and the plurality of slots are respectively matched with the plurality of first stoppers (3) or the plurality of second stoppers (10).

9. The core restraint device according to claim 8, characterized in that: The heat-insulating buffer layer comprises a third heat-insulating buffer layer (4, 9), and the third heat-insulating buffer layer (4, 9) is arranged at positions on the first stopper (3) and the second stopper (10) that are in contact with the card slot.

10. The core restraint device according to claim 2, characterized in that: A plurality of cushion blocks (7) are arranged on the circumferential outer side of the restraining barrel (5), and two sides of the cushion blocks (7) respectively cooperate with the inner wall of the reactor pressure vessel (14) and the circumferential outer wall of the restraining barrel (5).

11. The core restraint device according to claim 10, characterized in that: The thermal insulation buffer layer further comprises a fourth buffer thermal insulation layer (8), and the fourth buffer thermal insulation layer (8) is arranged on a side of the cushion block (7) close to the inner wall of the reactor pressure vessel (14).

12. The core restraint device according to claim 2, characterized in that: The circumferential inner wall of the constraining barrel (5) is configured to be polygonal in shape and matches the outer wall of the core (17).

13. The core restraint device according to claim 6, characterized in that: The restraining cylinder cover (1) and the first heat-insulating buffer layer (2) inside thereof are provided with a plurality of first holes (18) and second holes (19), which are used for passing coolant and installing control rods (15) respectively.

14. The core restraint device according to claim 2, characterized in that: A convergence opening (13) is provided at the center of the constraint cylinder bottom (11), and the outer wall of the convergence opening (13) has a curved surface structure.

15. A horizontal high temperature gas-cooled reactor structure, comprising a reactor pressure vessel (14) and a reactor core (17), characterized in that: It also comprises a core confinement device according to any one of claims 1 to 14.

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