CN116246805A

CN116246805A - Reactor shielding assembly

Info

Publication number: CN116246805A
Application number: CN202211656575.XA
Authority: CN
Inventors: 刘建昌; 张拓益; 马小雅; 赵晓晗; 欧阳勇; 杨江; 冯涵; 刘金林; 魏诗颖
Original assignee: China General Nuclear Power Corp; China Nuclear Power Technology Research Institute Co Ltd; CGN Power Co Ltd
Current assignee: China General Nuclear Power Corp; China Nuclear Power Technology Research Institute Co Ltd; CGN Power Co Ltd
Priority date: 2022-12-22
Filing date: 2022-12-22
Publication date: 2023-06-09

Abstract

The invention discloses a reactor shielding assembly which can be used for a reactor pressure vessel, wherein the reactor shielding assembly comprises a shielding piece and at least one heat pipe; the shielding piece is arranged on the periphery of the pressure container, and the heat pipe is internally provided with a phase-change heat exchange medium and a capillary structure; the heat pipe comprises an embedded section at least partially embedded in the shielding piece and a heat exchange section arranged outside the shielding piece; the phase-change heat exchange medium in the embedded section absorbs the heat of the shielding piece, is vaporized, flows into the heat exchange section to exchange heat and condense, and flows back to the embedded section through the capillary structure. According to the reactor shielding assembly, the heat pipe is partially embedded into the shielding piece, so that the heat dissipation efficiency of the shielding piece is greatly improved, and the shielding function of the shielding piece is stably maintained for a long time.

Description

Reactor shielding assembly

Technical Field

The invention relates to the technical field of nuclear power plant system equipment and safety, in particular to a reactor shielding assembly.

Background

To accommodate the multipurpose development of nuclear energy, advanced compact deployment requirements are becoming mainstream. When the core begins to operate, the fuel in the core undergoes a fission reaction, which generates a large amount of neutrons, gamma rays, and beta rays. In order to ensure the safety of equipment, shielding layers are required to be arranged around the reactor, so that irradiation damage to equipment and instruments around the reactor pressure vessel is reduced.

In the shielding design, heat generation of shielding materials caused by radiation is also required to be considered, and in the traditional reactor design, heat dissipation of the shielding layers is generally ensured by reasonable arrangement modes such as arrangement of heat preservation layers and the like; in a compact arrangement reactor, the heat-insulating layer is arranged in such a way that the heat dissipation requirement of the shielding layer cannot be met.

Disclosure of Invention

The technical problem to be solved by the present invention is to address at least one of the drawbacks of the related art mentioned in the background art above: in a compact arrangement reactor, the heat dissipation requirement of a shielding layer cannot be met by arranging a heat preservation layer and the like, and a reactor shielding assembly is provided.

The technical scheme adopted for solving the technical problems is as follows: constructing a reactor shield assembly for a reactor pressure vessel, the reactor shield assembly comprising a shield and at least one heat pipe; the shielding piece is arranged on the periphery of the pressure container 4, a phase-change heat exchange medium and a capillary structure are arranged in the heat pipe 2, and the heat pipe comprises an embedded section at least partially embedded into the shielding piece and a heat exchange section arranged outside the shielding piece; the phase-change heat exchange medium in the embedded section absorbs heat of the shielding piece, is vaporized, flows into the heat exchange section to exchange heat and condense, and flows back to the embedded section through the capillary structure.

Preferably, in the reactor shielding assembly according to the present invention, the shielding member is provided with a mounting groove having at least one end in communication with the outside, and the embedded section is at least partially entered into the mounting groove and fixedly connected to the shielding member.

Preferably, in the reactor shield assembly according to the present invention, a portion of the insertion section into which the shield is inserted is flat plate-shaped.

Preferably, in the reactor shielding assembly according to the present invention, the embedded segment is welded or riveted to the shield.

Preferably, in the reactor shielding assembly of the present invention, the reactor shielding assembly further includes a cold source, and the heat exchange section is at least partially disposed in the cold source; the heat exchange section comprises a transition section and a condensation section, the transition section is connected with the embedding section and the condensation section, and the condensation section is arranged in the cold source.

Preferably, in the reactor shielding assembly according to the present invention, a plurality of heat exchange fins are disposed at the periphery of the condensation section.

Preferably, in the reactor shielding assembly according to the present invention, the cold source includes a suppression pool provided at a lower side of the pressure vessel, and cooling water injected in the suppression pool; the condensing section is arranged in the cooling water.

Preferably, in the reactor shielding assembly according to the present invention, the cold source includes a gas, and the condensing section is exposed to the gas.

Preferably, in the reactor shielding assembly according to the present invention, the shielding member is a shielding member for shielding neutrons and gamma rays.

Preferably, in the reactor shielding assembly according to the present invention, the shielding member is composed of a single shielding material or composed of a plurality of shielding materials.

By implementing the invention, the following beneficial effects are achieved:

under the condition that the shielding assembly of the reactor meets the shielding design requirement of rays, the heat pipe is partially embedded into the shielding piece, so that the heat dissipation efficiency of the shielding piece is greatly improved, and the shielding function of the shielding piece is stably maintained for a long time.

Drawings

The invention will be further described with reference to the accompanying drawings and examples, in which:

FIG. 1 is a schematic view of a reactor shield assembly of the present invention;

FIG. 2 is a schematic view of a reactor shield assembly according to one embodiment of the invention;

fig. 3 is a schematic view of a reactor shield assembly according to another embodiment of the invention.

Detailed Description

For a clearer understanding of technical features, objects and effects of the present invention, a detailed description of embodiments of the present invention will be made with reference to the accompanying drawings.

It should be noted that, without conflict, the embodiments of the present invention and features of the embodiments may be combined with each other.

In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, are merely for convenience in describing the present invention and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first", "a second", etc. may explicitly or implicitly include one or more such feature. In the description of the present invention, unless otherwise indicated, the meaning of "a plurality" is two or more.

In the description of the present invention, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be either fixedly connected, detachably connected, or integrally connected, for example; can be mechanically or chemically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art in a specific case.

Referring to fig. 1-3, one embodiment of the present invention discloses a reactor shield assembly that may be used with a reactor pressure vessel 4, the reactor shield assembly comprising: a shielding piece 1 arranged at the periphery of the pressure vessel and at least one heat pipe 2 arranged at the outer side of the shielding piece 1;

the heat pipe 2 comprises an embedding section 21 at least partially embedded in the shielding member 1, a heat exchange section arranged outside the shielding member 1, and a phase change heat exchange medium and a capillary structure arranged in the heat pipe 2; the phase change heat exchange medium in the embedded section 21 absorbs heat of the shielding member 1, is vaporized, flows into the heat exchange section to exchange heat and condense, and flows back to the embedded section 21 through the capillary structure. Preferably, the phase change heat exchange medium of the present invention may be an absorption liquid.

The heat exchange principle of the heat pipe 2 of the reactor shielding assembly is that when a heat source generated by the shielding layer supplies heat to the heat pipe in the embedded section 21, the phase-change heat exchange medium absorbs heat and is vaporized into steam, the steam flows to the heat exchange section at a high speed along the cavity of the heat pipe 2 under the action of pressure difference, and the steam is condensed into liquid after releasing latent heat to the outside in the heat exchange section; when the phase-change heat exchange medium evaporates in the evaporation section, the gas-liquid interface is concave to form a plurality of meniscus liquid surfaces to generate capillary pressure, the liquid phase-change heat exchange medium returns to the embedding section 21 under the action of reflux power such as the capillary pressure of the tube core and gravity, and the like, and continues to absorb heat and evaporate, and the heat is continuously transferred from the hot end embedding section 21 to the cold end heat exchange section through the evaporation and condensation of the phase-change heat exchange medium in a circulating way. The heat pipe 2 transfers heat by using phase change conversion of the phase change heat exchange medium, and thus has a great heat transfer capacity and heat transfer efficiency.

The reactor shielding assembly heat pipe 2 adopts an passive working principle, and utilizes natural circulation to realize heat exchange, thereby improving the reliability and inherent safety of related equipment of the nuclear power plant. And the technology of the heat pipe 2 at the present stage tends to be perfect and has wide application, and the manufacturing process of the heat pipe 2 can meet various design requirements. The heat exchange efficiency can be greatly improved and the economical efficiency can be enhanced by utilizing the heat pipe 2 for heat exchange. The shape, the size, the heat exchange area and the arrangement position of the heat pipe 2 can be flexibly adjusted according to the requirements and the heat exchange requirements. The design of the heat pipe 2 can be very well adapted to the arrangement and area requirements of the shielding 1, facilitating a compact arrangement. Under the condition of meeting the shielding design requirement of rays, the heat pipe 2 is partially embedded into the shielding piece 1, so that the heat dissipation efficiency of the shielding piece 1 is greatly improved, and the shielding function of the shielding piece 1 is stably maintained for a long time.

Specifically:

the material of the shield 1 is chosen according to the shielding requirements. According to the irradiation source intensity and the ray type of the reactor pressure vessel (4) under the conditions of power operation and shutdown and the shielding performance of different shielding materials, the shielding design is developed by combining the set shielding design targets, such as a gamma dose rate target after shielding, and the like, including determining the type, thickness, installation position and the like of the shielding materials. First, a proper shielding material type is selected according to the shielding object of the shielding member 1, and when the reactor core starts to operate, the fuel in the reactor core undergoes a fission reaction, so that a large amount of neutrons, gamma rays and beta rays are generated. Where neutrons and gamma rays may penetrate the walls of the pressure vessel. In order to ensure the safety of equipment, the shielding piece 1 is arranged on the periphery of the pressure vessel, and the shielding piece 1 is used for shielding neutrons and gamma rays, so that neutrons and gamma rays penetrating through the wall surface of the pressure vessel can be shielded, and irradiation damage of irradiation to equipment and instruments around the reactor pressure vessel (4) is reduced. Next, the main structure of the shield 1 is determined, and the shield 1 may be composed of a single shielding material or composed of a plurality of shielding materials as long as it is satisfied that neutrons and gamma rays can be shielded. Finally, the mounting position of the shielding 1 is determined, and the reactor shielding assembly may be arranged, for example, above the pressure vessel roof, around the flange face of the pressure vessel, etc., depending on the shielding requirements, preferably by means of support brackets, to be fixed in the designed mounting position.

And according to the radiation source and the radiation type of the reactor pressure vessel 4 under the conditions of power operation and shutdown, carrying out the calculation of the heating value of the shielding member 1, and according to the heating value, the heat dissipation capacity of the heat pipe 2 and the temperature limit of the shielding member 1, determining the installation positions of the heat pipe 2 sections and the number of the heat pipes 2.

As shown in fig. 2 and 3, since the shield 1 is arranged in a place closer to the pressure vessel, heat inside the shield 1 is efficiently taken out from time to time in order to secure the effect of the shield 1. The shielding member 1 is provided with a mounting groove at least one end of which communicates with the outside, and the embedded section 21 is at least partially entered into the mounting groove and fixedly connected with the shielding member 1. Preferably, the mounting slots are open inside the shield 1, at the side walls of the shield 1, to facilitate the entry of the embedded segments 21.

Further, as shown in fig. 1, in order to meet the requirement of controlling the temperature of the shielding member 1, the temperature of the shielding member 1 is uniformly distributed as much as possible, and the portion of the embedded section 21 embedded in the shielding member 1 is flat plate-shaped to increase the contact area with the shielding member 1. Correspondingly, the mounting groove is also in a flat plate shape. The embedded section 21 is installed outside the shielding member 1 and embedded in the shielding member 1, and the side close to the reactor pressure vessel 4 is the inner side, so that the contact thermal resistance between the evaporation section and the shielding member 1 is reduced, and the thermal resistance between the heat pipe 2 and the shielding member 1 is ensured to meet the design requirement.

To prevent the embedded segment 21 from loosening and coming off the shield 1, the embedded segment 21 is welded or riveted to the shield 1 after the embedded segment 21 is inserted into the mounting groove. Preferably, the junction of the embedded segment 21 with the outside of the shield 1 is welded or riveted to the outer surface of the shield 1.

As shown in fig. 1, in order to enhance the heat dissipation effect, the reactor shielding assembly further comprises a cold source 3, and the heat exchange section is at least partially arranged in the cold source 3; the heat exchange section comprises a transition section 22 and a condensation section 23, the transition section 22 is connected with the embedded section 21 and the condensation section 23, and the condensation section 23 is arranged in the cold source 3. Through reasonable in design's changeover portion 22 length and structural style, arrange condensation segment 23 in cold source 3 can satisfy the suitable position of heat dissipation demand. Preferably, the transition section 22 may be a thermally insulating material. Depending on the heat dissipation requirements of the shielding 1 and the heat dissipation conditions outside the condensation section 23, the outer envelope of the condensation section 23 may be designed as a light pipe or fin type, preferably the condensation section 23 is provided with several heat exchange fins at its periphery.

To increase the heat exchange efficiency, the heat pipe 2 assembly comprises several heat pipes 2 arranged side by side. The embedded section 21 and the shielding piece 1 ensure that the thermal resistance between the heat pipe 2 and the shielding piece 1 meets the design requirement in a close fitting mode, and if necessary, a heat conducting agent can be smeared at the joint of the embedded section 21 and the shielding piece 1 so as to reduce the contact thermal resistance between the evaporation section and the shielding piece 1.

As shown in fig. 3, the compact arrangement core bottom is typically provided with a hold-down tank 31 for stabilizing the primary loop pressure and accident water level injection. The cold source 3 comprises a pressure suppressing tank 31 arranged at the lower side of the pressure vessel and cooling water 32 injected into the pressure suppressing tank 31; the condensing section 23 is disposed in the cooling water 32. Preferably, the condensing section 23 is ensured to be below the water level of the hold-down tank 31.

In other embodiments, as shown in fig. 2, the cold source 3 further comprises a gas, and the condensing section 23 is exposed to the gas. Preferably, the condensing section 23 is installed in the large space of the containment vessel. In order to ensure that the condensation section 23 is below the water level of the suppressing pool 31 or is installed in a large space of the containment, the transition section 22 is connected to the condensation section 23 as the embedded section 21, the position of the transition section 22 needs to be reasonably arranged, and the transition section 22 needs to pass through the concrete structure of the pit, preferably, the transition section 22 is made of heat insulation material.

The heat exchange process of the reactor shielding assembly comprises the following steps: under the effect of neutrons and gamma rays, the temperature of the shield 1 gradually increases. At this time, the radiation heat-generating of the shielding member 1 transfers heat to the phase-change heat-exchange medium in the heat pipe 2 through the shell of the embedding section 21, the phase-change heat-exchange medium absorbs heat and evaporates, under the action of natural circulation driving force, flows from the embedding section 21 to the cold pipe section in the cavity of the heat pipe 2, transfers heat to the air outside the heat pipe 2 through the shell of the cold pipe section, and returns to the embedding section 21 under the action of capillary force after the phase-change heat-exchange medium condenses after releasing heat, thereby forming a closed circulation in the heat pipe 2. Through the evaporation-condensation process in the heat pipe 2, the radiation heat generated by the heat pipe 2 and the shielding member 1 is effectively led out, and the temperature of the shielding member 1 is further controlled. When the heat release amount of the shielding member 1 decreases, the shielding material temperature gradually decreases, and when the temperature is lower than a certain threshold value, the phase change heat medium in the heat pipe 2 is not evaporated any more, the natural circulation in the heat pipe 2 is interrupted, and the cooling of the shielding material is not continued until the shielding material temperature further increases.

By implementing the invention, the following beneficial effects are achieved:

It is to be understood that the above examples only represent preferred embodiments of the present invention, which are described in more detail and are not to be construed as limiting the scope of the invention; it should be noted that, for a person skilled in the art, the above embodiments or technical features may be freely combined, and several variations and modifications may be made, without departing from the spirit of the invention, which fall within the scope of the invention, i.e. the embodiments described in "some embodiments" may be freely combined with any of the above and below embodiments; therefore, all changes and modifications that come within the meaning and range of equivalency of the claims are to be embraced within their scope.

Claims

1. A reactor shielding assembly for a reactor pressure vessel (4), the reactor shielding assembly comprising:

the shielding piece (1) is arranged at the periphery of the pressure container (4); a kind of electronic device with high-pressure air-conditioning system

At least one heat pipe (2), wherein a phase change heat exchange medium and a capillary structure are arranged in the heat pipe (2), and the heat pipe (2) comprises an embedded section (21) at least partially embedded in the shielding piece (1) and a heat exchange section arranged outside the shielding piece (1);

the phase-change heat exchange medium in the embedded section (21) absorbs heat of the shielding piece (1), is vaporized, flows into the heat exchange section to exchange heat and condense, and flows back to the embedded section (21) through the capillary structure.

2. Reactor shielding assembly according to claim 1, characterized in that the shielding (1) is provided with a mounting groove with at least one end communicating with the outside, the insert section (21) at least partly entering the mounting groove and being fixedly connected with the shielding (1).

3. Reactor shielding assembly according to claim 1, characterized in that the portion of the insertion section (21) into which the shield (1) is inserted is plate-shaped.

4. Reactor shielding assembly according to claim 2, characterized in that the embedded segment (21) is welded or riveted to the shield (1).

5. The reactor shielding assembly according to claim 1, further comprising a cold source (3), the heat exchange section being at least partially disposed in the cold source (3); the heat exchange section comprises a transition section (22) and a condensation section (23), the transition section (22) is connected with the embedded section (21) and the condensation section (23), and the condensation section (23) is arranged in the cold source (3).

6. The reactor shielding assembly according to claim 5, characterized in that the condensing section (23) is peripherally provided with heat exchanging fins.

7. The reactor shielding assembly according to claim 5, characterized in that the cold source (3) comprises a suppression pool (31) arranged at the lower side of the pressure vessel, and cooling water (32) injected in the suppression pool (31); the condensing section (23) is arranged in the cooling water (32).

8. The reactor shielding assembly according to claim 5, characterized in that the cold source (3) comprises a gas, the condensation section (23) being exposed to the gas.

9. The reactor shielding assembly according to claim 1, characterized in that the shielding (1) is a shielding (1) shielding neutrons, gamma rays.

10. Reactor shielding assembly according to any of claims 1-9, wherein the shielding (1) consists of a single shielding material or of a plurality of shielding materials.