Reactor core coolant flow control device and nuclear reactor

Abstract

The utility model relates to the technical field of balance training, and provides a reactor core coolant flow control device and a nuclear reactor, which comprise a liquid supply system, a zirconium box and a flow adjusting device. The liquid supply system is used for providing a coolant; the zirconium box is used for containing nuclear fuel, and a liquid outlet and a liquid inlet which are communicated with the liquid supply system are formed in the zirconium box; the flow adjusting device is arranged between the liquid supply system and the zirconium box and used for controlling the flow of the coolant in the zirconium box. According to the flow adjusting device in the scheme, the temperature deviation of coolants in all the flow channels in the reactor core can be improved, and matching of power and flow is achieved. According to the flow regulating device, the flow distribution of the coolant in the reactor core is optimized, so that the fuel assemblies at all parts can be properly cooled, and the condition of overheating or non-uniform temperature is avoided. Through effective power and flow matching, the reactor can operate more stably, the overall efficiency and safety of the system can be improved, and problems and risks possibly occurring in operation are reduced.

Description

TECHNICAL FIELD

[0001] The utility model relates to nuclear reactor cooling field, especially a kind of reactor core coolant flow control device and nuclear reactor. BACKGROUND

[0002] Natural circulation reactor relies on its own thermodynamic characteristics and geometry to achieve automatic distribution of coolant flow. Usually adopt the design with zirconium box fuel assembly, these assemblies are regarded as multiple parallel closed channels. The flow distribution of coolant depends on the power and resistance relationship of fuel assembly, when fuel assembly power is larger, the required coolant flow will be larger, and the corresponding coolant resistance needs to be smaller.

[0003] However, the power of fuel assembly changes with the increase of service time and burnup. When it is necessary to replace part or all of fuel assembly, there can be significant power difference between new assembly and old assembly. This difference can cause different heat generation of different fuel assemblies, and further affect the flow mode and distribution of coolant in the reactor core. Throughout the life of the reactor, with the continuous occurrence of fuel assembly replacement and power change, the unevenness of flow distribution can gradually intensify. This can cause overheating or insufficient cooling of some parts, thereby increasing the thermal stress of structural materials and possibly affecting the safety of the reactor. SUMMARY

[0004] In view of the above-mentioned disadvantages of the prior art, the purpose of the utility model is to provide a reactor core coolant flow control device and nuclear reactor to match the power and flow of the reactor to better utilize the coolant.

[0005] To achieve the above-mentioned purpose and other related purposes, the utility model provides a reactor core coolant flow control device, applied to nuclear reactor, comprising:

[0006] Liquid supply system for providing coolant;

[0007] Zirconium box for containing nuclear fuel, the zirconium box is provided with liquid outlet and liquid inlet communicated with the liquid supply system;

[0008] Flow regulating device, arranged between the liquid supply system and the zirconium box, for controlling the flow of coolant in the zirconium box.

[0009] In a specific embodiment of the utility model, the flow regulating device is an overflow hole arranged on the flow path of the coolant, and a flow resistance device is arranged in the overflow hole, for controlling the flow area of the overflow hole.

[0010] In a specific embodiment of the utility model, the flow resistance device includes a middle shaft connected with the driving device, a plurality of foldable blades are arranged on the circumference of the middle shaft, and the blades are folded or unfolded along with the rotation of the middle shaft.

[0011] In a specific embodiment of the utility model, the flow hole is arranged at the liquid outlet of the zirconium box.

[0012] In a specific embodiment of the utility model, the flow resistance device is arranged at one end of the flow hole close to the liquid outlet.

[0013] In a specific embodiment of the utility model, the zirconium box is provided with a plurality of flow regulating devices corresponding to each zirconium box.

[0014] In a specific embodiment of the utility model, a lattice plate is further included, the flow hole is arranged on the lattice plate and aligned with the liquid outlet of the zirconium box.

[0015] In a specific embodiment of the utility model, the plurality of zirconium boxes are arranged in parallel at equal distances, and the liquid outlets and liquid inlets of the plurality of zirconium boxes are aligned.

[0016] In a specific embodiment of the utility model, a timing device for monitoring the use time of the nuclear fuel is further included, and the timing device is in communication connection with the flow regulating device.

[0017] The utility model further discloses a nuclear reactor, which comprises the reactor core coolant flow control device.

[0018] The utility model discloses a reactor core coolant flow control device and nuclear reactor, the flow regulating device in the scheme can improve the temperature deviation of each flow passage coolant in the core, realizes the matching of power and flow.The flow regulating device ensures that each part of fuel assembly can obtain proper cooling by optimizing the flow distribution of coolant in the core, thereby avoiding overheating or uneven temperature conditions.Through effective power and flow matching, the reactor can operate more stably, and the overall efficiency and safety of the system can be improved, and problems and risks that can occur in operation can be reduced. BRIEF DESCRIPTION OF DRAWINGS

[0019] In order to more clearly illustrate the technical scheme of the embodiments of the utility model, the following will briefly introduce the drawings needed to be used in the embodiment description, and obviously, the drawings in the following description are only some embodiments of the utility model, and for those skilled in the art, other drawings can be obtained according to these drawings without creating labor.

[0020] Figure 1The utility model discloses a structure schematic diagram of the flow control device of the reactor core coolant in an embodiment.

[0021] Figure 2 The utility model discloses a structure schematic diagram of the flow control device of the reactor core coolant in an embodiment.

[0022] Figure 3 The utility model discloses a structure schematic diagram of the flow control device of the reactor core coolant in an embodiment.

[0023] Figure 4 The utility model discloses a structure schematic diagram of the flow control device of the reactor core coolant in an embodiment.

[0024] Mark explanation: 10, zirconium box;11, liquid outlet;12, liquid inlet;20, flow hole;30, resistance device;31, middle axle;32, fan blade;40, lattice board. DETAILED DESCRIPTION

[0025] The following through specific concrete example explains the embodiment of the utility model, and the person skilled in the art can easily understand other advantages and effects of the utility model from the content disclosed in the specification. The utility model can also be implemented or applied by another different specific embodiment, and each detail in the specification can be modified or changed based on different viewpoints and applications without departing from the spirit of the utility model. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict.

[0026] It should be noted that the diagrams provided in the following embodiments only illustrate the basic concept of the utility model in a schematic manner, and only show the components related to the utility model in the diagrams, not the number, shape and size of the components during actual implementation. The shape, number and proportion of each component during implementation can be changed arbitrarily, and the component layout pattern can be more complex.

[0027] Natural circulation has been widely used in reactors to simplify the structure of the reactor and improve its inherent safety. The flow distribution of the natural circulation reactor is different from that of the forced circulation reactor. The forced circulation reactor can control the flow distribution to achieve better matching of power and flow. The flow passage of the natural circulation reactor with zirconium box fuel assembly can be regarded as multiple closed parallel channels, and the flow distribution is automatically adjusted according to the relationship between the power and resistance of the fuel assembly.

[0028] If the core flow distribution of a natural circulation reactor is not reasonable, it may cause some fuel assemblies to overheat, which in turn leads to uneven distribution of coolant temperature at the core outlet. This increases the thermal stress of structural materials and even causes fuel assemblies to exceed the thermal safety limit, posing a potential threat to reactor safety.

[0029] Current natural circulation reactor designs usually do not incorporate dedicated flow distribution optimization devices, relying mainly on the thermodynamic properties of their own structure. This may limit their flexibility and adaptability in certain aspects, especially when adjusting the flow distribution to optimize performance or respond to abnormal situations.

[0030] The requirement for core inlet flow distribution generally refers to ensuring that the coolant is evenly distributed to each fuel assembly before entering the core. This is to avoid excessive temperature differences between fuel rods or insufficient cooling in certain areas, which may lead to local overheating or safety problems.

[0031] As shown in Figure 1 The utility model discloses a kind of core coolant flow control devices, applied to nuclear reactor, including liquid supply system, zirconium box 10 and flow regulating device.

[0032] Liquid supply system is used to provide the system of coolant to nuclear reactor. Including pipeline system and the import connected with core. Coolant storage pool is used to store spare coolant, and replenish coolant circulation system when needed.

[0033] Zirconium box 10 is used to contain nuclear fuel. Zirconium box 10 usually adopts zirconium alloy as main material, most commonly Zircaloy-4 alloy (Zircaloy-4), which has good corrosion resistance and mechanical strength, and also performs well in high temperature and radiation environment. Zirconium box 10 is usually long tubular or short cylindrical, and specific shape and size will be different according to the type of nuclear fuel, reactor design and fuel arrangement. Generally speaking, zirconium box 10 needs enough length to contain nuclear fuel, and needs to maintain the stability and durability of its structure under different operating conditions. Liquid outlet 11 and liquid inlet 12 are usually provided on zirconium box 10 for coolant in and out. These ports are usually connected to the pipeline of coolant supply system, to ensure that the coolant can flow around the fuel rod, effectively cooling the nuclear fuel. Both ends of zirconium box 10 are open, and coolant flows into one end of zirconium box 10 and flows out from the other end to cool the fuel assembly in zirconium box 10.

[0034] A flow regulating device is provided between the coolant supply system and the zirconium box 10 to control the flow rate of the coolant in the zirconium box 10. The flow regulating device can include a regulating valve, a flow meter, a throttling device, etc. The regulating valve controls the flow rate of the coolant by adjusting the opening of the valve. The regulating valve can be manually operated or adjusted by an automatic control system according to the operating state of the reactor as needed. The flow meter is used to measure the actual flow rate of the coolant through the pipe. Although they cannot directly regulate the flow by themselves, they are often used in conjunction with regulating valves or other control devices to provide real-time flow information and feedback to help operators or automatic control systems adjust the settings of the flow control devices. The throttling device restricts the flow rate of the coolant by providing an orifice or other flow rate limiting device inside the pipe to control the flow rate. This method is often used in situations where simple and reliable flow control is required.

[0035] As shown in Figure 2 , the flow regulating device is an orifice 20 provided in the flow path of the coolant, and a flow resistance device 30 is provided in the orifice 20 to control the flow area of the orifice 20. The orifice 20 is a hole passage provided in the pipe to restrict the area through which the fluid passes, thereby controlling the flow rate. It is usually a circular or square hole passage, and its size can be designed according to the required flow control effect. The flow resistance device 30 provided inside the orifice 20 can be one or more additional components or structures. Its main function is to adjust the flow area of the orifice 20. These flow resistance devices 30 can be adjustable or fixed, and the degree of restriction of the fluid passing through the hole passage can be adjusted by changing its position, shape or material properties.

[0036] As shown in Figure 3 , 4 , the flow resistance device 30 includes a central shaft 31 connected to a driving device, and a plurality of overlapping vanes 32 are provided circumferentially around the central shaft 31, which are folded or unfolded with the rotation of the central shaft 31. The central shaft 31 is the core component of the flow resistance device 30, which is connected to the driving device such as a motor or a manual operating device. The central shaft 31 can rotate along its axis to drive the vanes 32 to fold or unfold. The vanes 32 are provided circumferentially around the central shaft 31, and they can overlap together. Each vane 32 can move along the direction of the central shaft 31 to respond to the rotational movement of the central shaft 31. When the central shaft 31 rotates, the unfolding or folding of the vanes 32 changes the effective flow area in the orifice 20 or pipe. Unfolding the vanes 32 will reduce the passage area for the fluid to pass through, thereby reducing the flow rate; while folding the vanes 32 will increase the passage area, thereby increasing the flow rate. The driving device controls the rotation of the central shaft 31, which can accurately adjust the degree of unfolding or folding of the vanes 32, thereby achieving accurate control of the flow rate of the fluid.

[0037] As shown in Figure 1 The flow orifice 20 is arranged at the outlet 11 of the zirconium can 10. The flow orifice 20 is arranged at the outlet 11 of the zirconium can 10, which is where the coolant flows out of the nuclear fuel rod or the zirconium can 10. Its main function is to limit the area through which the fluid passes, thereby controlling the speed and amount of coolant flow out. This ensures that the coolant flows out of the fuel rod at an appropriate rate, effectively taking away the heat generated by the fuel rod.

[0038] As shown in Figure 2 The flow resistor 30 is arranged at one end of the flow orifice 20 close to the outlet 11. The flow resistor 30 is arranged at one end of the flow orifice 20 close to the outlet 11, so that when the fuel assembly is refueled, the corresponding position of the flow resistor 30 is in the exposed state, and the maintenance personnel can easily make necessary adjustments without having to move or reinstall other components.

[0039] As shown in Figure 1 The zirconium can 10 is provided with multiple flow regulating devices, one for each zirconium can 10. Each zirconium can 10 is equipped with a flow regulating device, which means that there are multiple independently operating flow resistors 30 and flow orifices 20 configurations in the system. Each flow regulating device can accurately regulate the flow and speed of the coolant according to the specific needs of the zirconium can 10 it is in. Each zirconium can 10 independently controls its coolant flow, which can optimize the cooling effect according to the thermal load and working conditions of each fuel element, ensuring that the nuclear fuel operates within a safe temperature range.

[0040] As shown in Figure 1 It also includes a grid plate 40, and the flow orifice 20 is arranged on the grid plate 40 and aligned with the outlet 11 of the zirconium can 10. The grid plate 40 is an important component in the nuclear reactor, used to support and position the fuel elements (such as the zirconium can 10) and the structure around them. It is usually made of metal material and has a porous structure, allowing coolant to flow through and transfer heat.

[0041] As shown in Figure 1 A plurality of zirconium cans 10 are arranged in parallel and equidistantly, and the outlets 11 and inlets 12 of the plurality of zirconium cans 10 are aligned. Parallel arrangement ensures that each zirconium can 10 in the reactor can uniformly receive heat and neutron flux, thereby improving the fuel utilization and performance stability of the reactor. The aligned arrangement ensures that the coolant can effectively flow into the zirconium can 10, cool the fuel, and then flow out of the zirconium can 10, taking away the heat. The effectiveness of this process is crucial to the safety and performance of the reactor.

[0042] As shown in Figure 1The illustrated embodiment also includes a timing device for monitoring the usage time of the nuclear fuel, which is communicatively connected with the flow regulating device. The timing device records the running time of the nuclear fuel in the reactor, which can be measured in hours, days, or other appropriate time units. The communicative connection between the timing device and the flow regulating device means that they can exchange data and information with each other. For example, the timing device can receive the coolant flow and pressure data sent by the flow regulating device to monitor the actual cooling condition of the nuclear fuel. At the same time, the timing device can also send instructions to the flow regulating device or receive status information to adjust the operation of the cooling system if necessary.

[0043] A temperature sensor for monitoring the temperature of the coolant can also be provided at the outlet of each zirconium box 10, and the flow is adjusted according to the temperature of the coolant monitored by the temperature sensor. When the temperature sensor monitors a higher temperature of the coolant, the flow regulating device can adjust to reduce the resistance, thereby increasing the flow. By increasing the flow amount of the coolant, the temperature of the coolant can be effectively reduced, and the cooling efficiency of the system can be improved. When the temperature sensor monitors a lower temperature of the coolant, the flow regulating device can correspondingly increase the resistance to reduce the flow. This helps to prevent the coolant from flowing through the system in a super-cooled state, while ensuring that the system operates within the designed temperature range.

[0044] Before the nuclear reactor is first loaded with fuel assemblies, pre-design and calculation are usually performed to determine the power of each fuel assembly as a function of time during the initial period of operation (first cycle). These calculations are based on the design parameters of the reactor, the characteristics of the fuel assemblies, and the expected operating conditions. According to the design and simulation, the power change of each fuel assembly when it is running in the core can be predicted. According to the predicted power change, the required flow passage resistance coefficient of each fuel assembly can be determined. The flow passage resistance coefficient determines the distribution of coolant flow in the core. By adjusting the corresponding flow holes 20 (or other design parameters) of each assembly, the coolant flow around the fuel assembly can be distributed according to the specific power of the fuel assembly, thereby effectively cooling the fuel and maintaining the stable operation of the reactor.

[0045] During the operation of the reactor, the fuel assemblies will gradually burn out or need to be replaced over time. At each refueling, the following operations can be performed according to the refueling plan and actual situation:

[0046] The power prediction of the new fuel assembly is based on its specific fuel type and design parameters. According to these predictions, the flow passage area and flow passage resistance coefficient of the corresponding flow holes 20 of the new assembly can be adjusted to optimize its cooling effect and power distribution in the core.

[0047] Sometimes old fuel assemblies can be rearranged or reloaded at different positions to make full use of their remaining fuel performance. When reloading, it is necessary to adjust the corresponding flow area of the flow hole 20 and the flow resistance coefficient according to its current power and position, to ensure coordination and balance with new assemblies and other old assemblies.

[0048] The utility model discloses still a kind of nuclear reactor, including the reactor coolant flow control device as above.

[0049] To sum up, the utility model discloses a kind of reactor coolant flow control device, the flow regulating device in the above scheme can improve the temperature deviation of each flow passage coolant in core, realize the matching of power and flow.The flow regulating device is by optimizing the flow distribution of coolant in core, ensure that each part of fuel assembly can obtain appropriate cooling, to avoid overheating or temperature uneven situation.By effective power and flow matching, reactor can more stably operate, and can improve the overall efficiency and safety of system, reduce the problems and risks that can appear in operation.

[0050] The above embodiment is only illustrative of the principle and effect of the utility model, and is not used to limit the utility model. Any person skilled in the art can modify or change the above embodiment without departing from the spirit and scope of the utility model. Therefore, all equivalent modifications or changes completed by those skilled in the art without departing from the spirit and technical thought disclosed by the utility model should be covered by the claims of the utility model.

[0051] In the description herein, many specific details are provided, such as examples of components and / or methods, to provide a thorough understanding of embodiments of the application. Persons skilled in the art, however, will recognize that embodiments of the application can be practiced without one or more of the specific details. In other instances, well-known structures, materials, or operations have not been shown or described in detail in order to avoid obscuring aspects of embodiments of the application.

[0052] References in the specification to "one embodiment", "an embodiment", or "the embodiments", mean that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the application, and is not necessarily included in all embodiments. The various appearances of the phrase "in one embodiment" or "in an embodiment" or "in the embodiments" in various places in the specification are not necessarily referring to the same embodiment. Furthermore, the particular features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. It should be understood that the application encompasses other variations, modifications, and alternatives of the application as can be suggested by the principles of the application and the following examples.

[0053] It will also be understood that one or more of the elements illustrated in the drawings, alone or in combination, can also be implemented in a more separated or more integrated manner. In addition, it will be understood that the application can also include other elements not specifically shown in the drawings.

[0054] In addition, unless explicitly stated otherwise, any directional or position terms used herein, such as "above", "below", "up", "down", "left", "right", "out", "in", "front", "back", "bottom", "top", etc., should be construed to be illustrative only and not necessarily limiting. Furthermore, the term "or" as used herein is generally intended to mean "and / or" unless otherwise indicated. Combinations of components or steps will also be perceived as being implied even if not explicitly described as such.

[0055] As used in the description of the application and the following claims, the terms "a", "an" and "the" including their grammatical variations, mean "one or more" unless otherwise indicated. As used in the description of the application and the following claims, the term "in" includes "in" and "on" unless otherwise indicated.

[0056] The above description of the illustrated embodiments of the application (including what is described in the abstract) is not intended to be exhaustive or to limit the application to the precise forms disclosed. While specific embodiments of, and examples for, the application are described herein for illustrative purposes, various equivalent modifications are possible within the spirit and scope of the application, as those skilled in the relevant art will recognize and appreciate. As indicated, these modifications can be made to the above described embodiments and yet the application will remain within the scope of the application. Accordingly, while the application is susceptible to various modifications and alternative forms, specific embodiments and examples thereof have been shown and described in detail herein. However, it should be understood that the application is not to be limited to the particular embodiments and examples disclosed, but to include all such as can fall within the scope of the application, which scope is to be accorded the broadest application so as to encompass all equivalent modifications and alternative forms as can be specifically adapted to the performance of the application in its various embodiments.

[0057] The systems and methods have been described herein in general terms as to aid in understanding the details of the application. In addition, various specific details have been presented to provide a general understanding of the embodiments of the application. However, a person skilled in the relevant art will recognize that the embodiments of the application can be practiced without one or more of the specific details, or with other devices, systems, assembles, methodologies, components, materials, and / or the like. In other instances, well known structures, materials, and / or operations have not been shown or described in detail to avoid obscuring aspects of the embodiments of the application.

[0058] Thus, although the present application has been described herein with reference to particular embodiments thereof, changes in form and detail can be made to modifications being within the scope and spirit of the application and it is understood that this application is to be limited only by the appended claims, and equivalents thereof. A number of modifications can be made to adapt a particular situation or material to the essential scope and spirit of the present application. The application is not intended to be limited to the specific embodiments shown and described herein, but rather, is to be accorded the full scope that the words employ in the appended claims, and any equivalents thereof. The scope of the present application is thus only limited by the appended claims.

Claims

1. A core coolant flow control device, applied to a nuclear reactor, characterized in that, The application relates to a nuclear fuel assembly, comprising: a coolant supply system for providing coolant; a zirconium box for containing nuclear fuel, the zirconium box being provided with an outlet and an inlet communicating with the coolant supply system; a flow regulating device arranged between the coolant supply system and the zirconium box for controlling the flow of coolant in the zirconium box.

2. The reactor core coolant flow control device according to claim 1, characterized by The flow regulating device is a flow hole arranged in the flow path of the coolant, and a flow resistance device is arranged in the flow hole for controlling the flow area of the flow hole.

3. The reactor core coolant flow control device of claim 2, wherein, The flow resistance device comprises a central shaft connected with a driving device, and a plurality of foldable vanes are arranged on the circumference of the central shaft, and the vanes are folded or unfolded along with the rotation of the central shaft.

4. The reactor core coolant flow control device of claim 2, wherein, The flow hole is arranged at the outlet of the zirconium box.

5. The core coolant flow control apparatus according to claim 2, characterized by The flow resistance device is arranged at one end of the flow hole close to the outlet.

6. The core coolant flow control apparatus according to claim 2, characterized by A plurality of zirconium boxes are arranged, and one flow regulating device is arranged for each zirconium box.

7. The reactor core coolant flow control device according to claim 2, characterized by A lattice plate is further arranged, and the flow hole is arranged on the lattice plate and aligned with the outlet of the zirconium box.

8. The reactor core coolant flow control device of claim 7, wherein, The plurality of zirconium boxes are arranged in parallel at equal distances, and the outlets and inlets of the plurality of zirconium boxes are aligned.

9. The reactor core coolant flow control device in accordance with claim 1, wherein, A timing device for monitoring the service time of the nuclear fuel is further arranged, and the timing device is communicatively connected with the flow regulating device.

10. A nuclear reactor, characterized by, The application further relates to a nuclear fuel assembly comprising the core coolant flow control device as claimed in any one of claims 1-9.

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