Reactor waste heat removal system

Abstract

An embodiment of the present application provides a reactor waste heat removal system, comprising: a first cylinder, arranged in a reactor vessel and on the outside of a core, a first opening and a second opening being provided on the top of the first cylinder, the second opening being located below the first opening; a second cylinder, arranged in the reactor vessel and on the outside of the first cylinder, a first gap being formed between the second cylinder and the reactor vessel; a heat exchange module, for cooling the coolant in the core, the heat exchange module being connected to the second opening; a circulation module, being connected to the heat exchange module; a shell, arranged on the outside of the reactor vessel, a second gap being formed between the shell and the reactor vessel, the second gap being connected to the external environment, so that air can enter the second gap to cool the coolant in the first gap.

Description

Technical Field

[0001] The present application relates to the technical field of nuclear reactors, and in particular to a reactor waste heat removal system. Background Art

[0002] After a reactor shuts down, residual heat from the core needs to be removed. During a normal shutdown, some power components can continue to operate, and forced coolant circulation can be used to remove the residual heat. However, if the reactor shuts down unexpectedly due to an accident, the power components may not be able to continue operating, requiring natural coolant circulation to remove the residual heat. The residual heat removal systems proposed in the related art use separate forced and natural coolant circulation systems, making them difficult to meet the requirements of reactor miniaturization.

[0003] On the other hand, for some reactors that use liquid metal as coolant, the waste heat removal system provided in the relevant technology may cause the coolant to be overcooled at certain points and solidify if the electric heating system fails to work properly. Summary of the Invention

[0004] In view of the above problems, the present application is proposed to provide a reactor waste heat removal system that overcomes the above problems or at least partially solves the above problems.

[0005] An embodiment of the present application provides a reactor waste heat removal system, wherein the reactor includes a reactor vessel and a core arranged in the reactor vessel, and the system includes: a first cylinder, which is arranged in the reactor vessel and on the outside of the core, and a first opening and a second opening are provided on the top of the first cylinder, and the second opening is located below the first opening; a second cylinder, which is arranged in the reactor vessel and on the outside of the first cylinder, and a first gap is formed between the second cylinder and the reactor vessel; a heat exchange module for cooling the coolant in the core, and the heat exchange module is connected to the second opening; a circulation module, which is connected to the heat exchange module, and the circulation module is opened When the reactor core is started, the coolant in the core can enter the heat exchange module through the second opening under the drive of the circulation module, and then enter the top of the first gap and flow downward. When the circulation module is closed, the coolant in the core can enter the top of the first gap through the first opening under thermal drive and flow downward. The coolant in the first gap can flow to the bottom of the reactor vessel and return to the core through the bottom of the first cylinder; the shell is arranged on the outside of the reactor vessel, and a second gap is formed between the shell and the reactor vessel. The second gap is connected to the external environment, so that air can enter the second gap to cool the coolant in the first gap.

[0006] The reactor waste heat removal system provided in the embodiment of the present application organically combines the forced circulation and natural circulation paths of the coolant, thereby eliminating the need to set up a forced circulation system and a natural circulation system separately, which can better meet the miniaturization requirements of the reactor and provide more space in the miniaturized reactor to set up other systems, such as a thermoelectric conversion system. Therefore, the requirements for the thermoelectric conversion method are lower, and there is more flexibility in the selection of the thermoelectric conversion method.

[0007] At the same time, in this embodiment, the air flowing in the second gap is used as the heat exchange medium for heat exchange, which can reduce costs on the one hand, and on the other hand, when applied to a reactor using liquid metal as a coolant, it can greatly reduce the probability of the liquid metal coolant being supercooled and solidified. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 is a cross-sectional schematic diagram of a reactor waste heat removal system according to an embodiment of the present application;

[0009] Figure 2 Schematic diagram of a coolant circulation path in a reactor waste heat removal system in one use state according to an embodiment of the present application;

[0010] Figure 3 Schematic diagram of the coolant circulation path of the reactor waste heat removal system in another usage state according to an embodiment of the present application. DETAILED DESCRIPTION

[0011] To make the purpose, technical solutions, and advantages of this application more clear, the technical solutions of this application will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of this application. Obviously, the described embodiment is only one embodiment of this application, not all embodiments. Based on the described embodiments of this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0012] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in this application should have the usual meanings understood by people with ordinary skills in the field to which this application belongs. If the full text involves descriptions such as "first" and "second", the "first" and "second" descriptions are only used to distinguish similar objects, and cannot be understood as indicating or implying their relative importance, order of precedence, or implicitly indicating the number of technical features indicated. It should be understood that the data described by "first" and "second" can be interchangeable under appropriate circumstances. If "and / or" appears in the full text, its meaning includes three parallel solutions. Taking "A and / or B" as an example, it includes Solution A, Solution B, or solutions that meet both A and B.

[0013] The embodiment of the present application provides a reactor waste heat removal system, which is applied to a reactor, referring to Figure 1 The reactor may include a reactor vessel 1 and a core 2 disposed in the reactor vessel 1. The reactor vessel 1 and the core 2 may adopt structures provided in relevant technologies in the art. In some cases, the reactor vessel 1 may include an inner shell and an outer shell. The space between the inner and outer shells may be filled with a protective gas, such as an inert gas such as helium, to ensure safe operation of the reactor.

[0014] The reactor waste heat removal system provided in this embodiment can be applied to any suitable reactor, and is particularly applicable to miniaturized reactors that use liquid metal as a coolant, such as lead-based reactors.

[0015] Reference Figure 1 The reactor waste heat removal system provided in the embodiment of the present application includes a first cylinder 10 , a second cylinder 20 , a heat exchange module 30 , a circulation module 40 and a shell 50 .

[0016] The first cylinder 10 is disposed in the reactor vessel 1 and outside the core 2. The first cylinder 10 may have a shape that matches the core 2. Its top may be fixed to the reactor vessel, and its bottom may be open and fixed to the core 2. The first cylinder 10 is provided with a first opening 11 and a second opening 12, wherein the second opening 12 is below the first opening 11. The coolant in the core may circulate out of the first cylinder 10 through one or more of the first opening 11 and the second opening 12, and ultimately return to the core 2 through the open bottom of the first cylinder 10. The specific circulation path of the coolant will be described in detail in the relevant section below.

[0017] The first opening 11 and the second opening 12 may be arranged around the first cylinder 10 . The specific arrangement may be selected by those skilled in the art according to actual needs and is not limited thereto.

[0018] The second cylinder 20 is also disposed in the reactor vessel 1 and outside the first cylinder 10. The second cylinder 20 can be fixed to the reactor vessel 1 by means of a suitable connecting device, and a first gap 21 is formed between the second cylinder 20 and the reactor vessel 1.

[0019] The heat exchange module 30 is used to cool the coolant in the reactor core 2 and is connected to the second opening 12. The heat exchange module 30 can be a heat exchange device commonly used in the art, and a heat exchange medium, such as water or air, can flow through it. The coolant is cooled by heat exchange between the heat exchange medium and the coolant. The circulation module 40 is connected to the heat exchange module 30 and can include a circulation pump that can circulate the coolant to remove excess heat from the reactor.

[0020] The shell 50 is disposed outside the reactor vessel 1 and can be secured to the reactor vessel 1 using any suitable securing method, without limitation. A second gap 51 is formed between the shell 50 and the reactor vessel 1. This second gap 51 can communicate with the external environment, allowing air from the external environment to enter the second gap 51 and exchange heat with the coolant flowing in the first gap 21, thereby cooling the coolant. The shell 50 can be provided with a suitable opening to facilitate communication between the second gap 51 and the external environment. The specific configuration of the opening will be described in the relevant sections below and will not be repeated here.

[0021] After the reactor is shut down normally, the circulation module 40 and the heat exchange module 30 can operate normally. Therefore, the circulation module 40 can be turned on to drive the coolant to circulate, and the coolant can be cooled with the help of the heat exchange module 30. Figure 2 Schematic diagram of the coolant circulation path in the reactor when the circulation module 40 is turned on is shown in FIG, wherein the black arrows indicate the flow direction of the coolant and the grey arrows indicate the flow direction of the air.

[0022] like Figure 2 As shown, when the circulation module 40 is opened, the coolant in the core 2 will enter the heat exchange module 30 through the second opening 12 driven by the circulation module 40. The heat exchange module 30 will then perform the first heat exchange. Then, driven by the circulation module 40, the coolant will enter the top of the first gap 21 and flow downward. Because the second opening 12 is located below the first opening 11, the coolant will hardly flow out of the first cylinder 10 through the first opening 11 at this time. After flowing to the bottom of the reactor vessel 1, the coolant in the first gap 21 will return to the core 2 through the open bottom of the first cylinder 10, thus completing the forced circulation of the coolant.

[0023] As the coolant flows downward in the first gap 21, it will undergo a second heat exchange with the air in the second gap 51. At this time, the air at the bottom of the second gap 51 will be heated and flow upward and leave the second gap 51, releasing the heat of the coolant to the external environment. At the same time, new cold air will enter the second gap 51, forming an air circulation, thereby continuously exchanging heat with the coolant.

[0024] When the reactor stops operating unexpectedly due to some accidents, it is still necessary to discharge the residual heat of the reactor. At this time, the circulation module 40 may not be able to be turned on due to power failure. Therefore, it is necessary to complete the discharge of residual heat through the natural circulation of the coolant. Figure 3, a schematic diagram of the coolant circulation path in the reactor when the circulation module 40 is closed is shown. Similarly, the black arrows indicate the flow direction of the coolant, and the gray arrows indicate the flow direction of the air.

[0025] When the circulation module 40 is closed, the coolant, which has lost its drive, will flow out of the first cylinder 10 through the first opening 11. The coolant near the first cylinder 10 is close to the core 2 and has a higher temperature, while the coolant at the first gap 21 exchanges heat with the air in the second gap 51 and has a relatively low temperature. In addition, the coolant temperature at the bottom of the first gap 21 will be lower than the coolant temperature at the top of the first gap 21. Therefore, driven by thermal force, the coolant flowing out of the first opening 11 will flow to the top of the first gap 21 and downward to the bottom of the reactor vessel 1, and then return to the core 2 through the open bottom of the first cylinder 10, completing the natural circulation and cooling of the coolant.

[0026] During this process, the flow path of the air in the second gap 51 is the same as the flow path of the air in the second gap 51 when the circulation module 40 is turned on, and will not be described again.

[0027] The reactor waste heat removal system of this embodiment organically combines the forced circulation and natural circulation paths of the coolant, thereby eliminating the need to set up a forced circulation system and a natural circulation system separately, which can better meet the miniaturization requirements of the reactor and provide more space in the miniaturized reactor to set up other systems, such as a thermoelectric conversion system. As a result, the requirements for the thermoelectric conversion method are lower, and there is more flexibility in the selection of the thermoelectric conversion method.

[0028] At the same time, in this embodiment, the air flowing in the second gap 51 is used as the heat exchange medium for heat exchange, which can reduce costs on the one hand, and on the other hand, when applied to a reactor using liquid metal as a coolant, it can greatly reduce the probability of the liquid metal coolant being supercooled and solidified.

[0029] In some embodiments, the system may further include a cover plate 60 that is slidably connected to the first cylinder 10. The density of the cover plate 60 is less than that of the coolant, so that the cover plate 60 can float on the coolant liquid surface. Therefore, when the coolant liquid level changes, the cover plate 60 will also slide on the first cylinder 10 with the change in the liquid level.

[0030] Reference Figure 2When the circulation module 40 is turned on, a large amount of coolant will enter the heat exchange module 30 through the second opening 12 driven by the circulation module 40, so that the coolant liquid level near the first cylinder 10 will drop. At this time, the cover plate 60 will drop along the first cylinder 10 to cover the first opening 11, avoiding the forced circulation of the coolant, and preventing part of the coolant from flowing out of the first cylinder 10 from the first opening 11 and circulating naturally, thereby increasing the efficiency of the forced circulation.

[0031] Reference Figure 3 When the circulation module 40 is closed, the coolant will not be forced to enter the heat exchange module 30 through the second opening 12, causing the coolant liquid level near the first cylinder 10 to rise. At this time, the cover plate 60 will rise along the first cylinder 10 to expose the first opening 11, allowing the coolant to begin natural circulation.

[0032] The cover 60 can be arranged inside the first cylinder 10, or the cover 60 can be annular and arranged outside the first cylinder 10. There is no specific limitation on this. It only needs that the cover 60 can slide along the first cylinder 10 and can cover or expose the first opening 11.

[0033] In some embodiments, reference may still be made to Figure 1 The heat exchange module 30 may include a heat exchanger 31 and a first annular chamber 32. The heat exchanger 31 and the first annular chamber 32 are connected. For example, the heat exchanger 31 may be arranged in the first annular chamber 32, and the cooling medium may be passed into the heat exchanger 31 to exchange heat with the coolant entering the first annular chamber 32.

[0034] The first annular chamber 32 is disposed in the second cylinder 20 and outside the first cylinder 10. The first annular chamber 32 extends along the axial direction of the core 2. Those skilled in the art can use a suitable cylinder structure to form the first annular chamber 32 without limitation.

[0035] The top and bottom of the first annular chamber 32 may form openings, wherein the top opening may be connected to the second opening 12, and the bottom opening may be connected to the circulation module 40. In this embodiment, referring to Figure 2 During forced circulation, the coolant, after entering the second annular chamber 42, flows downward from the top of the second annular chamber 42, while the coolant in the core 2 flows from the bottom to the top. This allows the coolant in the second annular chamber 42 to form convection with the coolant in the core 2, further improving the efficiency of waste heat removal. Furthermore, the shape and location of the second annular chamber 42 avoid occupying space at the top of the core, thereby better meeting the design requirements of miniaturized reactors.

[0036] In some embodiments, still referring to Figure 1The circulation module 40 may include a circulation pump 41 and a second annular chamber 42 , and the circulation pump 41 may be connected to the second annular chamber 42 to achieve related functions.

[0037] The second annular chamber 42 is arranged in the second cylinder 20 and outside the first annular chamber 32. The second annular chamber 42 extends along the axial direction of the core 2. Similarly, those skilled in the art can set the second annular chamber 42 in a manner similar to the first annular chamber 32, and there is no limitation on this.

[0038] The top and bottom of the second annular chamber 42 can also form openings, and its bottom opening is connected to the bottom opening of the first annular chamber 32. The top opening is located above the second cylinder 20. Driven by the circulating pump 41, the coolant flowing out of the first annular chamber 32 will flow upward from the bottom of the second annular chamber 42 and enter the top of the first gap 21 from the opening at the top of the second annular chamber 42.

[0039] In this embodiment, refer to Figure 2 During forced circulation, the flow direction of the coolant in the second annular chamber 42 is from bottom to top, while the flow direction of the coolant in the first annular chamber 32 and the first gap 21 is from top to bottom, forming convection with the coolant in the second annular chamber 42, thereby further improving the efficiency of waste heat discharge.

[0040] It is understandable that some coolants may have purification requirements, such as liquid metal coolants, etc. Therefore, in some embodiments, reference is still made to Figure 1 The system may further include a purification module 70. The purification module 70 may be a device commonly used in the art for purifying the coolant. Those skilled in the art may select the device according to actual needs and there is no limitation on this.

[0041] The purification module 70 can be connected to the circulation module 40. The purification module 70 is used to purify the coolant. When the circulation module 40 is turned on, the coolant can also be driven to circulate between the purification module 70 and the circulation module 40. Figure 2 During the forced circulation process, a portion of the coolant will enter the purification module 70, and after purification, it will return to the circulation module 40 to complete the subsequent circulation.

[0042] In this embodiment, the purification module 70 is integrated into the waste heat removal system, thereby further freeing up space inside the reactor and better meeting the requirements of a miniaturized reactor.

[0043] In some embodiments, specifically, the purification module 70 may include a purifier 71 and a third annular chamber 72 . The purifier 71 is connected to the third annular chamber 72 to purify the coolant entering the third annular chamber 72 .

[0044] The third annular chamber 72 is arranged in the second cylinder 20 and between the first annular chamber 32 and the second annular chamber 42. The third annular chamber 72 extends along the axial direction of the core. Similarly, the third annular chamber 72 can be arranged in a manner similar to the first annular chamber 32 and the second annular chamber 42, which will not be repeated here.

[0045] The third annular chamber 72 is also formed with openings at the top and bottom. The bottom opening is connected to the bottom opening of the second annular chamber 42, and the top opening is substantially flush with the top opening of the second annular chamber 42. Figure 2 During forced circulation, since the coolant in the second annular chamber 42 flows from the bottom to the top, the coolant at the bottom of the third annular chamber 72 will be sucked into the second annular chamber 42. At the same time, since the opening at the top of the second annular chamber 42 is roughly flush with the opening at the top of the third annular chamber 72, the coolant flowing out of the top of the second annular chamber 42 will be partially diverted to the third annular chamber 72, thereby realizing coolant circulation between the circulation module 40 and the purification module 70.

[0046] In some embodiments, a collecting chamber 22 may be provided at the bottom of the second cylinder 20, and the bottom openings of the first annular chamber 32, the second annular chamber 42 and the third annular chamber 72 are connected to the collecting chamber 22. Thus, there is no need to set up dedicated pipelines to achieve connection between these openings, which saves costs and installation difficulty, and at the same time, increases the efficiency of coolant circulation.

[0047] In some embodiments, a filler 80 may be provided inside the second cylinder 20. It is understandable that although some structures are provided in the second cylinder 20, there are still gaps. During the natural circulation process, coolant will still enter the gaps in the second cylinder 20, resulting in a decrease in the natural circulation efficiency of the coolant. In this embodiment, a filler 80 is further provided in the second cylinder 20 to fill the gaps in the second cylinder 20, thereby reducing the amount of coolant flowing into the second cylinder 20 during the natural circulation process and improving the efficiency of the natural circulation.

[0048] In some embodiments, filler 80 may be a neutron shielding material, thereby further shielding the core 2 from neutron radiation. This embodiment further integrates the reactor's neutron shielding structure into the residual heat removal system, improving safety while freeing up space within the reactor and better meeting the requirements of miniaturized reactors.

[0049] In some embodiments, reference may still be made to Figure 1The housing 50 is provided with multiple air inlets 52 at the bottom and multiple air outlets 53 at the top, thereby better communicating between the second gap 51 and the external environment. The air outlets 53 can be connected to an exhaust device such as an exhaust chimney to meet relevant exhaust requirements in the field and increase exhaust efficiency.

[0050] In some embodiments, multiple air inlets 52 and multiple air outlets 53 can be arranged at equal intervals along the circumference of the shell 50. For example, four air inlets 52 and four air outlets 53 can be set, which are spaced 90 degrees apart from each other, thereby increasing the air flow efficiency in the second gap 51 and further improving the efficiency of waste heat discharge.

[0051] In some embodiments, the system may further include a fan 90 connected to the housing 50, and configured to introduce air into the second gap 51. It is understood that, compared to the natural circulation of air, using the fan 90 to force air circulation can further improve the efficiency of air circulation, thereby improving the efficiency of waste heat removal. Furthermore, in this embodiment, the heat dissipation efficiency of the coolant during forced circulation can be controlled by controlling the power of the fan 90 and the power of the circulation module 40, further preventing the liquid metal coolant from solidifying due to excessive cooling.

[0052] Furthermore, the present embodiment is provided with both the fan 90 and the air inlet 52 . When the fan 90 cannot be started in an accident situation, the natural circulation of air can still be completed through the air inlet 52 .

[0053] In some embodiments, the air inlet 52 is further configured to have an adjustable opening. Thus, the air circulation efficiency in the second gap 51 can be adjusted by adjusting the opening of the air inlet 52, thereby controlling the heat dissipation efficiency. Furthermore, when the reactor is operating normally, the air inlet 52 can be closed, thereby reducing heat loss during operation and improving the reactor's thermoelectric conversion efficiency.

[0054] In some embodiments, the air inlet 52 is configured to be closed when the fan 90 is turned on. At this time, the air flow efficiency in the second gap 51 will completely depend on the power of the fan 90, so that the heat dissipation efficiency can be controlled more accurately.

[0055] In some embodiments, the aforementioned functions of the air inlet 52 can be manually performed by an operator. In some embodiments, the air inlet 52 can be configured to automatically perform the aforementioned functions. For example, the air inlet 52 can be provided with an electromagnetic switch electrically connected to the fan 90. When the fan 90 is turned on, the electromagnetic switch is energized, closing the air inlet 52. Furthermore, the electromagnetic switch in this embodiment can be closed in the event of an accident, causing the air inlet 52 to automatically open, thereby improving control efficiency and preventing the reactor's residual heat from being unable to be discharged in a timely manner after an accident.

[0056] Regarding the embodiments of the present invention, it should also be noted that, in the absence of conflict, the embodiments of the present invention and the features therein may be combined with each other to obtain new embodiments.

[0057] The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. The protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A reactor waste heat removal system, wherein the reactor comprises a reactor vessel and a reactor core disposed in the reactor vessel, the system comprising: a first cylinder disposed in the reactor vessel and outside the core, wherein a first opening and a second opening are provided on a top of the first cylinder, and the second opening is located below the first opening; a second cylinder disposed in the reactor vessel and outside the first cylinder, with a first gap formed between the second cylinder and the reactor vessel; a heat exchange module, used for cooling the coolant in the core, the heat exchange module being connected to the second opening; A circulation module connected to the heat exchange module, When the circulation module is opened, the coolant in the core can enter the heat exchange module through the second opening under the drive of the circulation module, and then enter the top of the first gap and flow downward. When the circulation module is closed, the coolant in the core can enter the top of the first gap through the first opening under thermal driving and flow downward. The coolant in the first gap can flow to the bottom of the reactor vessel and return to the core through the bottom of the first cylinder; a shell, disposed outside the reactor vessel, forming a second gap between the shell and the reactor vessel, the second gap being in communication with the external environment so that air can enter the second gap to cool the coolant in the first gap; A cover plate is slidably connected to the first cylinder, and the density of the cover plate is less than the density of the coolant, so that the cover plate can float on the liquid surface of the coolant. When the circulation module is turned on, the coolant liquid level drops, causing the cover plate to descend along the first cylinder to cover the first opening. When the circulation module is closed, the coolant liquid level rises, causing the cover plate to rise along the first cylinder to expose the first opening.

2. The system according to claim 1, wherein: The heat exchange module includes a heat exchanger and a first annular chamber; The first annular chamber is arranged in the second cylinder and outside the first cylinder, the first annular chamber extends along the axial direction of the core, the top opening is connected to the second opening, and the bottom opening is connected to the circulation module; The heat exchanger is connected to the first annular chamber.

3. The system according to claim 2, wherein: The circulation module includes a circulation pump and a second annular chamber; The second annular chamber is disposed in the second cylinder and outside the first annular chamber, the second annular chamber extending along the axial direction of the core, the bottom opening of the second annular chamber being connected to the bottom opening of the first annular chamber, and the top opening being located above the second cylinder; The circulation pump is connected to the second annular chamber.

4. The system according to claim 3, further comprising: The purification module is connected to the circulation module. The purification module is used to purify the coolant. When the circulation module is turned on, it can also drive the coolant to circulate between the purification module and the circulation module.

5. The system according to claim 4, wherein: The purification module includes a purifier and a third annular chamber; The third annular chamber is disposed in the second cylinder and between the first annular chamber and the second annular chamber. The third annular chamber extends along the axial direction of the core, has a bottom opening connected to the bottom opening of the second annular chamber, and has a top opening substantially flush with the top opening of the second annular chamber. The purifier is connected to the third annular chamber.

6. The system according to claim 5, wherein: A collecting chamber is provided at the bottom of the second cylinder, and bottom openings of the first annular chamber, the second annular chamber and the third annular chamber are connected to the collecting chamber.

7. The system according to any one of claims 1 to 6, wherein: A filler is provided inside the second cylinder.

8. The system according to claim 7, wherein: The filler is a neutron shielding material.

9. The system according to claim 1, wherein: The bottom of the shell is provided with a plurality of air inlets, and the top is provided with a plurality of air outlets.

10. The system according to claim 9, wherein: The plurality of air inlets and the plurality of air outlets are arranged at equal intervals along the circumference of the shell.

11. The system of claim 9, further comprising: A fan is connected to the housing and is used to introduce air into the second gap.

12. The system according to claim 11, wherein The air inlet is configured to have an adjustable opening.

13. The system according to claim 12, wherein: The air inlet is configured to close when the fan is turned on.

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