Reactor and its double pressure vessel

Abstract

The present invention relates to a reactor and a double-layer pressure vessel thereof. The double-layer pressure vessel of the reactor includes: an outer container, an inner container, and a heat-conducting structure. The inner container is contained in the outer container, and the outer container and the inner container are spaced apart to form an interlayer; the heat-conducting structure is provided in the interlayer, and the heat-conducting structure is used to conduct the heat of the inner container to the outer container when the temperature of the inner container reaches a predetermined temperature. The pressure vessel adopts an inner and outer container design, which can effectively enclose the inner container in the outer container. Through the heat-conducting structure, the heat of the inner container can be effectively conducted to the environment of the area. In the event of an extreme accident condition such as the complete loss of heat-carrying capacity of the second circuit, the heat of the first circuit can be effectively conducted to control the temperature of the first circuit.

Description

Technical Field

[0001] The present invention relates to the field of nuclear power, and more particularly to a reactor and a double-layer pressure vessel thereof. Background Art

[0002] For a pool-type reactor design, the core, steam generator, and main pump are located within the reactor pressure vessel. During normal operation and design basis accident conditions, heat generated by the reactor core is transferred to the secondary circuit via the steam generator heat transfer tubes, maintaining the primary circuit temperature. However, in extreme accident conditions, the secondary circuit could completely lose its heat-carrying capacity. In this case, heat generated by the core cannot be effectively dissipated, causing the primary circuit temperature to continue to rise, threatening reactor safety. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a reactor and a double-layer pressure vessel thereof in view of the above-mentioned defects of the prior art.

[0004] The technical solution adopted by the present invention to solve the technical problem is to construct a double-layer pressure vessel of a reactor, comprising:

[0005] outer container;

[0006] An inner container is contained within the outer container, with the outer container and the inner container spaced apart to form a sandwich; and

[0007] A heat-conducting structure is provided in the interlayer, and is used for conducting the heat of the inner container to the outer container when the temperature of the inner container reaches a predetermined temperature.

[0008] In some embodiments, the heat-conducting structure includes heat-conducting pipes distributed in the interlayer, so as to conduct heat to the outer container when the temperature in the inner container reaches a predetermined temperature.

[0009] In some embodiments, the heat pipes are evenly distributed in the interlayer; or, the distribution density of the heat pipes near the top of the double-layer pressure container is greater than the distribution density near the bottom of the double-layer pressure container.

[0010] In some embodiments, the heat pipe includes a tube body with a vacuum interior, and a liquid wick and a heat absorbing medium disposed in the tube body;

[0011] The liquid wick is arranged along the tube body so as to be able to absorb the heat absorbing medium;

[0012] The tube body includes two opposite ends, one end of which is arranged on the outer side of the inner container, and the other end is arranged on the inner side of the outer container. When the temperature of the inner container reaches a predetermined temperature, the heat-absorbing medium near the inner container can be evaporated to the end near the outer container for condensation. After condensation, the heat-absorbing medium can flow along the liquid-absorbing core to the end near the inner container.

[0013] In some embodiments, the height position of the tube body at one end of the inner container is lower than the height position of the tube body at one end of the outer container.

[0014] In some embodiments, the wick is arranged along the inner wall of the tube.

[0015] In some embodiments, the tube body includes an evaporation section, an insulation section, and a condensation section connected in sequence;

[0016] The insulation section is made of insulation material, the evaporation section and the condensation section are flat cavities, the side of the evaporation section is attached to and connected to the outer wall of the inner container, and the side of the condensation section is attached to and connected to the inner wall of the outer container.

[0017] In some embodiments, the evaporation section is welded to the outer wall surface of the inner container, and the condensation section is welded to the inner wall surface of the outer container.

[0018] In some embodiments, the outer container and the inner container are coaxially arranged, and the interval between the outer container and the inner container is uniform.

[0019] A reactor comprises the pressure vessel and working equipment arranged in the inner container.

[0020] In some embodiments, the working equipment includes a core, a steam generator, and a main pump. The core is located at the bottom of the inner container, and the steam generator and the main pump are located on a side of the core away from the bottom of the inner container.

[0021] The reactor and double-layer pressure vessel thereof implementing the present invention have the following beneficial effects: the pressure vessel adopts an inner and outer container design, which can effectively contain the inner container within the outer container, and through the heat-conducting structure, the heat of the inner container can be effectively exported to the environment of the area where it is located. In the event of extreme accident conditions such as the complete loss of heat-carrying capacity of the secondary circuit, the heat of the primary circuit can be effectively exported to control the temperature of the primary circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0023] Figure 1 is a schematic diagram of a partial cross-sectional structure of a pressure vessel in an embodiment of the present invention;

[0024] Figure 2 yes Figure 1 A schematic diagram of the enlarged structure of the partial view A;

[0025] Figure 3 yes Figure 2 Schematic diagram of the middle heat pipe as viewed from the right. DETAILED DESCRIPTION

[0026] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, specific embodiments of the present invention are now described in detail with reference to the accompanying drawings.

[0027] A reactor in a preferred embodiment of the present application includes a pressure vessel 10 and working equipment disposed in the pressure vessel 10 , wherein the working equipment includes a reactor core, a steam generator, and a main pump.

[0028] like Figure 1 As shown, the reactor pressure vessel 10 has a double-layer structure. Specifically, the pressure vessel 10 comprises an outer vessel 11, an inner vessel 12, and a heat-conducting structure 20. The inner vessel 12 is housed within the outer vessel 11, with the outer and inner vessels 11 and 12 spaced apart to form an interlayer. The heat-conducting structure 20 is located in the interlayer and is used to conduct heat from the inner vessel 12 to the outer vessel 11 when the temperature of the inner vessel 12 reaches a predetermined level.

[0029] It should be noted that, in some embodiments, the reactor core, steam generator, and main pump are all housed within the inner container 12, with the reactor core located at the bottom of the inner container 12, and the steam generator and main pump located on the side of the reactor core away from the bottom of the inner container 12. In other words, the steam generator and main pump are located higher than the reactor core within the inner container 12.

[0030] Because a heat-conducting structure 20 is provided between the inner container 12 and the outer container 11, and when the temperature of the inner container 12 reaches a predetermined temperature, the heat from the inner container 12 is transferred outward to the outer container 11. This effectively dissipates heat generated by the core, preventing a continuous increase in the primary circuit temperature, and thus in the temperature inside the pressure vessel 10, thereby improving reactor safety.

[0031] The heat-conducting structure 20 transfers heat from the inner container 12 to the outer container 11 only when the temperature of the inner container 12 reaches a predetermined temperature. Specifically, during normal reactor operation, heat generated by the core is continuously transferred to the secondary circuit via the steam generator. During this period, the wall temperature of the inner container 12 does not reach the predetermined temperature, and the heat-conducting structure 20 does not transfer heat. The wall temperature of the outer container 11 remains the same as the ambient temperature.

[0032] When an accident occurs, if the secondary circuit can still carry heat normally, although the temperature of the primary circuit coolant will rise briefly, the core heat can still be effectively removed through the secondary circuit. At this time, the wall temperature of the inner container 12 is still lower than the predetermined temperature, that is, the heat-conducting structure 20 still does not dissipate heat to the outside, and the wall temperature of the outer container 11 is the same as the ambient temperature.

[0033] If an accident causes the secondary circuit to be heated, the core heat cannot be effectively dissipated, the primary circuit coolant temperature continues to rise, and the temperature of the inner container 12 wall continues to rise. When the temperature of the inner container 12 wall exceeds a predetermined temperature, the heat transfer structure 20 activates, dissipating the heat from the inner container 12 outward to the outer container 11. Specifically, the core heat is transferred to the inner container 12 via the coolant. The inner container 12 then conducts heat through the heat transfer structure 20, transferring the heat from the inner container 12 to the outer container 11. The heat is then transferred to the surrounding air through natural convection and radiation from the outer wall of the outer container 11.

[0034] As needed, the outer container 11 is secured in a compartment within the reactor building, directly exposed to the surrounding air. Before the thermal conductive structure 20 is activated, the wall temperature of the outer container 11 is the same as the ambient temperature. Once the thermal conductive structure 20 is activated and continuously dissipating heat from the primary circuit, the wall of the outer container 11 absorbs heat, raising its temperature. This heat is then transferred to the surrounding air through natural convection and radiation.

[0035] The pressure vessel 10 adopts the design of inner and outer containers 11, which can effectively contain the inner container 12 within the outer container 11. Through the heat-conducting structure 20, the heat of the inner container 12 can be effectively exported to the environment of the area. In the event of extreme accident conditions such as the complete loss of heat-carrying capacity of the second circuit, the heat of the first circuit can be effectively exported to control the temperature of the first circuit.

[0036] The pressure vessel 10 also includes a top cover (not shown) positioned above the interlayer, creating a closed space within the interlayer that maintains atmospheric pressure during operation. This closed interlayer design provides insulation for the inner vessel 12 during normal reactor operation. If cracks or breaches develop in the inner vessel 12, reactor coolant leaks into the interlayer, preventing significant coolant loss.

[0037] In this embodiment, the outer container 11 and the inner container 12 each include a bottom and a body, and the bottoms of both containers are concave arc surfaces, so that the outer container 11 and the inner container 12 are cup-shaped. In other embodiments, the outer container 11 and the inner container 12 may also be concave hemispherical.

[0038] Preferably, the sizes of the outer container 11 and the inner container 12 are proportional, so that they can be nested with each other and maintain uniform spacing between the layers.

[0039] Furthermore, in order to achieve the support and positioning of the inner and outer containers 11, the pressure vessel 10 also includes a positioning structure (not shown) arranged between the inner side of the outer container 11 and the outer wall surface of the inner container 12. Preferably, the positioning structure can be used to allow the outer container 11 and the inner container 12 to be coaxially arranged, and the spacing between the outer container 11 and the inner container 12 can be uniform.

[0040] Combine Figures 1 to 3 As shown, in some embodiments, the heat-conducting structure 20 includes heat pipes 21 distributed within the interlayer to conduct heat to the outer container 11 when the temperature within the inner container 12 reaches a predetermined temperature. The heat pipes 21 have a heat-conducting function and are elements that achieve heat transfer through the phase change of the working fluid within them. The heat pipes 21 are distributed at intervals within the interlayer to conduct heat from the inner container 12 to the outside.

[0041] In some embodiments, the heat pipe 21 may be a temperature-activated heat pipe. The heat pipe 21 will not start operating until the temperature reaches the activation temperature of the heat pipe 21. The activation temperature of the heat pipe 21 is equal to a predetermined temperature. Thus, when the wall surface of the inner container 12 reaches the predetermined temperature, the heat pipe 21 will start normally and conduct heat from the inner container 12 to the outside.

[0042] In some embodiments, the plurality of heat pipes 21 are evenly distributed within the interlayer, that is, the plurality of heat pipes 21 are evenly distributed between the outer container 11 and the inner container 12. This facilitates even transfer of heat from the inner container 12 to the outer container 11.

[0043] In some embodiments, the distribution density of the heat pipes 21 near the top of the double-layer pressure vessel is greater than that near the bottom. In other words, the number of heat pipes 21 near the top of the double-layer pressure vessel is greater than that near the bottom. It is understood that the greater the number of heat pipes 21, the more heat can be dissipated. During reactor operation, the top of the inner vessel 12 typically heats up faster than the bottom. Because, in this embodiment, the distribution density of the heat pipes 21 near the top of the double-layer pressure vessel is greater than that near the bottom, that is, a greater number of heat pipes 21 near the top of the inner vessel 12 facilitates faster heat transfer from the top of the inner vessel 12 to the outside. Of course, in some embodiments, in addition to arranging a greater number of heat pipes 21 near the top of the inner vessel 12, more heat pipes 21 can also be arranged in other high-temperature areas. The number of heat pipes 21 and their arrangement within the interlayer are not limited.

[0044] It should be noted that when the wall temperature of the inner container 12 increases, not all heat pipes 21 are activated simultaneously. For example, in some cases, the top of the inner container 12 may heat up faster than the bottom. In this case, the heat pipes 21 at the top are activated to control the wall temperature at the top of the inner container 12. If the wall temperature at the bottom of the inner container 12 does not continue to rise, the heat pipes 21 near the bottom of the inner container 12 will not be put into operation. If the temperature at the bottom of the inner container 12 continues to rise, the heat pipes 21 near the bottom of the inner container 12 will gradually be put into operation.

[0045] Furthermore, preferably, the heat conducting pipe 21 includes a tube body with a vacuum interior, and a liquid wick and a heat absorbing medium arranged in the tube body. The liquid wick is arranged along the tube body to absorb the heat absorbing medium.

[0046] The tube body includes two opposite ends, one end of which is arranged on the outer side of the inner container 12, and the other end is arranged on the inner side of the outer container 11. When the temperature of the inner container 12 reaches a predetermined temperature, the heat-absorbing medium near the inner container 12 can be evaporated to the end near the outer container 11 for condensation, and the condensed heat-absorbing medium can flow along the liquid-absorbing core to the end near the inner container 12.

[0047] Furthermore, in some embodiments, the end of the tube disposed in the inner container 12 is closer to the bottom of the pressure vessel 10 than the end disposed in the outer container 11. That is, in the direction from the top of the pressure vessel 10 to the bottom of the pressure vessel 10, the end of the tube disposed in the inner container 12 is higher than the end disposed in the outer container 11. In this way, when the temperature of the inner container 12 does not reach the predetermined operating temperature of the heat-conducting structure 20, the heat-absorbing medium in the heat-conducting tube 20 is stored at the end closer to the inner container 12 due to gravity. When the temperature of the inner container 12 reaches a preset temperature, the heat absorbing medium at the end of the heat pipe 20 near the inner container 12 will be evaporated and vaporized to become a gaseous heat absorbing medium. After the gaseous heat absorbing medium rises to the end near the outer container 11, due to the lower temperature of the outer container 11, the gaseous heat absorbing medium is condensed and turned back into a liquid heat absorbing medium. Subsequently, through the capillary action of the liquid wick, the condensed heat absorbing medium flows along the liquid wick to the end near the inner container 12, and then evaporates under the heating of the inner container 12. This cycle is repeated to achieve the effect of heat conduction and heat dissipation.

[0048] Since the height of the tube body at one end of the inner container 12 is lower than that at one end of the outer container 11, this is conducive to the evaporation and flow of the heat-absorbing medium after heating, and is also conducive to the return of the liquid-absorbing medium along the liquid-absorbing core to the end close to the inner container 12 after condensation.

[0049] The heat absorbing medium can be one of liquid metal, sodium-potassium alloy, and pure sodium, which vaporizes and evaporates after being heated. According to the needs, the heat absorbing medium with a suitable evaporation temperature is selected.

[0050] Preferably, the wick is made of a porous material, allowing the liquid heat-absorbing medium to flow downward through the porous capillary action. The wick is positioned along the inner wall of the tube. After the tube is evacuated, the heat-absorbing medium is injected and then sealed. This placement of the wick along the inner wall of the tube allows space within the tube for the evaporated heat-absorbing medium to circulate.

[0051] Furthermore, in order to better evaporate and condense at both ends, in some embodiments, the tube body includes an evaporation section 211, an insulation section 212 and a condensation section 213 connected in sequence.

[0052] Preferably, the evaporation section 211 and the condensation section 213 are flat cavities with a hollow interior. The side of the evaporation section 211 is attached to and connected to the outer wall of the inner container 12, and the side of the condensation section 213 is attached to and connected to the inner wall of the outer container 11.

[0053] The insulating section 212 is made of insulating material and prevents heat transfer between the evaporation section 211 and the condensation section 213. This prevents the temperature rise in the condensation section 213 from affecting the condensation of the heat-absorbing medium. Heat is absorbed by the evaporation section 211 of the heat pipe 21 and released by the condensation section 213, transferring heat to the outer container 11.

[0054] The flat evaporation section 211 can increase the joint surface between the evaporation section 211 and the outer wall of the inner container 12, and also increase the heating surface of the heat-absorbing medium in the evaporation section 211, thereby absorbing more heat and improving the efficiency of heat conduction.

[0055] The flat condensation section 213 can make the joint surface between the condensation section and the inner wall surface of the outer container 11 larger, and also make the heat dissipation surface of the gaseous heat-absorbing medium in the condensation section 213 larger, quickly conducting heat to the outer container 11, and improving the heat conduction efficiency.

[0056] Preferably, in this embodiment, the evaporation section 211 is welded to the outer wall of the inner container 12, and the condensation section 213 is welded to the inner wall of the outer container 11 to improve the stability of the connection. Of course, the evaporation section 211 can also be locked to the outer wall of the inner container 12 using a locking piece, and the condensation section 213 can be locked to the outer wall of the outer container 11 using a locking piece.

[0057] In other embodiments, the evaporation section 211 and the condensation section 213 can also be made into cavities with other shapes, and the side of the evaporation section 211 that is in contact with the inner container 12 and the side of the condensation section 213 that is in contact with the outer container 11 can be made into flat surfaces to ensure heat absorption and heat dissipation of the two contact surfaces respectively.

[0058] According to the design requirements of the local wall temperature of the inner container 12, the contact area between the evaporation section 211 of the tube body and the inner container 12 is reasonably designed. According to the heat exchange requirements of a single heat pipe 21, the contact area between the condensation section 213 and the outer container 11 is reasonably designed.

[0059] The double-layer pressure container 10 of the present invention has the following advantages:

[0060] The double-layer pressure vessel 10 design can effectively meet the installation requirements of the core, steam generator, main pump and other equipment of the pool-type reactor, and reduce the consequences of coolant loss accidents due to vessel rupture;

[0061] The interlayer between the double-layer containers can provide thermal insulation for the inner container 12;

[0062] Through the temperature-activated heat pipe, under extreme working conditions, the core heat is extracted through the heat conduction path of the inner container 12-heat pipe 21-outer container 11 to control the primary circuit temperature.

[0063] It can be understood that the above technical features can be used in any combination without limitation.

[0064] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention's description and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A double-layer pressure vessel for a reactor, characterized in that: include: outer container (11); an inner container (12) contained within the outer container (11), wherein the outer container (11) and the inner container (12) are spaced apart to form an interlayer; and a heat-conducting structure (20), the heat-conducting structure (20) being provided in the interlayer, and the heat-conducting structure (20) being used to conduct heat of the inner container (12) to the outer container (11) when the temperature of the inner container (12) reaches a predetermined temperature; The heat-conducting structure (20) includes heat-conducting pipes (21) distributed in the interlayer, so as to conduct heat to the outer container (11) when the temperature in the inner container (12) reaches a predetermined temperature; The heat conducting pipe (21) comprises a tube body with a vacuum interior, and a liquid wick and a heat absorbing medium arranged in the tube body; The liquid wick is arranged along the tube body so as to be able to absorb the heat absorbing medium; The tube body includes two opposite ends, one end of which is arranged on the outer side of the inner container (12), and the other end is arranged on the inner side of the outer container (11). When the temperature of the inner container (12) reaches a predetermined temperature, the heat-absorbing medium close to the inner container (12) can be evaporated to the end close to the outer container (11) for condensation, and the heat-absorbing medium after condensation can flow along the liquid-absorbing core to the end close to the inner container (12).

2. The double-layer pressure vessel of the reactor according to claim 1, characterized in that: The heat conducting pipes (21) are evenly distributed in the interlayer; or, the distribution density of the heat conducting pipes (21) near the top of the double-layer pressure container is greater than the distribution density near the bottom of the double-layer pressure container.

3. The double-layer pressure vessel of the reactor according to claim 1, characterized in that: One end of the tube body disposed on the inner container (12) is closer to the bottom of the pressure container (10) than the end disposed on the outer container (11).

4. The double-layer pressure vessel of a reactor according to claim 1, characterized in that: The liquid wick is arranged along the inner wall surface of the tube body.

5. The double-layer pressure vessel of a reactor according to any one of claims 2 to 4, characterized in that: The tube body comprises an evaporation section (211), an insulation section (212), and a condensation section (213) connected in sequence; The insulation section (212) is made of insulation material, the evaporation section (211) and the condensation section (213) are flat cavities, the side of the evaporation section (211) is adhered to and connected to the outer wall of the inner container (12), and the side of the condensation section (213) is adhered to and connected to the inner wall of the outer container (11).

6. The double-layer pressure vessel of the reactor according to claim 5, characterized in that: The evaporation section (211) is welded to the outer wall surface of the inner container (12), and the condensation section (213) is welded to the inner wall surface of the outer container (11).

7. The double-layer pressure vessel of a reactor according to any one of claims 1 to 4, characterized in that: The outer container (11) and the inner container (12) are coaxially arranged, and the outer container (11) and the inner container (12) are evenly spaced apart.

8. A reactor, characterized in that: It comprises the pressure vessel (10) according to any one of claims 1 to 7, and working equipment arranged in the inner container (12).

9. The reactor according to claim 8, characterized in that The working equipment includes a core, a steam generator, and a main pump. The core is located at the bottom of the inner container (12), and the steam generator and the main pump are located on a side of the core away from the bottom of the inner container (12).

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