Simulation fuel assembly and simulation reactor core assembly

Abstract

The invention provides a simulated fuel assembly and a simulated core assembly. The simulation fuel assembly comprises an inlet flow equalizing unit located at an inlet of the simulation fuel assembly and used for equalizing flow and preventing foreign matters; the flow measuring unit is positioned below the inlet flow equalizing unit and is used for measuring the flow entering the simulation fuel assembly; the resistance piece is located below the flow measuring unit; the resistance adjusting device is located below the resistance piece and used for adjusting the resistance of the simulation fuel assembly; and the inlet flow equalizing unit, the flow measuring unit, the resistance piece and the resistance adjusting device simulate the resistance characteristic of the solid reactor fuel assembly together, so that the resistance coefficient of the simulated fuel assembly is equal to that of the solid reactor fuel assembly.

Description

Technical Field

[0001] The invention relates to the field of nuclear reactors, in particular to a simulated fuel assembly and a simulated core assembly. Background Art

[0002] According to the requirements of the nuclear safety guideline HAD102 / 07 "Safety Design of Nuclear Power Plant Core", the design of the reactor internals must ensure that the coolant can be distributed to the fuel assemblies and related core structures in appropriate proportions to provide the cooling conditions required by the reactor.

[0003] Therefore, before the new reactor type is put into use, it is necessary to carry out a reactor hydraulic simulation test to verify whether the core flow distribution can meet the requirements of thermal and safety analysis. Before carrying out the reactor hydraulic simulation test, it is necessary to design a simulated fuel assembly that can replace the real fuel assembly to simulate the real fuel assembly.

[0004] In order to overcome the above-mentioned defects of the prior art, the art is in urgent need of a simulated fuel assembly and a simulated core assembly, which can simulate the real fuel assembly in the reactor hydraulic simulation test and reflect the resistance characteristics of the real fuel assembly. At the same time, the inlet flow rate can also be measured. By measuring the inlet flow rate by simulating the fuel assembly, the distribution characteristics of the core inlet flow rate can be further evaluated. Summary of the invention

[0005] A brief summary of one or more aspects is given below to provide a basic understanding of these aspects. This summary is not an exhaustive overview of all conceived aspects, and is neither intended to identify the key or critical elements of all aspects nor to define the scope of any or all aspects. Its only purpose is to give some concepts of one or more aspects in a simplified form as a prelude to a more detailed description that will be given later.

[0006] In order to overcome the above-mentioned defects of the prior art, the present invention provides a simulated fuel assembly and a simulated core assembly, which can simulate the real stack fuel assembly and reflect the resistance characteristics of the real stack fuel assembly in the reactor hydraulic simulation test, and at the same time, can also measure the inlet flow rate. By measuring the inlet flow rate by simulating the fuel assembly, the distribution characteristics of the core inlet flow rate can be further evaluated.

[0007] Specifically, the above-mentioned simulated fuel assembly provided according to the first aspect of the present invention includes: an inlet flow balancing unit, located at the inlet of the simulated fuel assembly, for balancing the flow and preventing foreign matter; a flow measuring unit, located below the inlet flow balancing unit, for measuring the flow entering the simulated fuel assembly; a resistance member, located below the flow measuring unit; a resistance adjusting device, located below the resistance member, for adjusting the resistance of the simulated fuel assembly; and the inlet flow balancing unit, the flow measuring unit and the resistance member together simulate the resistance characteristics of the real stack fuel assembly so that the resistance coefficient of the simulated fuel assembly is equal to that of the real stack fuel assembly.

[0008] Preferably, in an embodiment of the present invention, the inlet flow balancing unit is a grid plate.

[0009] Preferably, in an embodiment of the present invention, the flow measurement unit is a Venturi tube.

[0010] Preferably, in one embodiment of the present invention, the resistance element is a plate bundle area structure.

[0011] Preferably, in an embodiment of the present invention, the resistance member is a porous plate.

[0012] Preferably, in an embodiment of the present invention, the resistance adjustment device comprises a throttle ring and an adjusting cone, the throttle ring is used to achieve coarse adjustment of the resistance by changing the size, and the resistance is finely adjusted by changing the relative position of the adjusting cone and the throttle ring.

[0013] Preferably, in an embodiment of the present invention, the position of the adjusting cone is fixed by a locking nut.

[0014] In addition, the above-mentioned simulated core assembly provided according to the second aspect of the present invention includes multiple simulated fuel assemblies provided according to the first aspect of the present invention, and the inlet flow distribution characteristics of the simulated core assembly are evaluated based on the flow results measured by the flow measurement units of the multiple simulated fuel assemblies. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The above features and advantages of the present invention can be better understood after reading the detailed description of the embodiments of the present disclosure in conjunction with the following drawings. In the drawings, the components are not necessarily drawn to scale, and components with similar related properties or features may have the same or similar reference numerals.

[0016] Figure 1 The schematic diagram of the structure of the existing real pile fuel assembly is shown;

[0017] Figure 2 A schematic diagram of a simulated fuel assembly according to some embodiments of the present invention is shown;

[0018] Figure 3 A schematic diagram of a resistance adjustment device according to a simulated fuel assembly 200 is shown;

[0019] Figure 4 A schematic diagram showing a simulation of a fuel assembly 200 in which an adjusting cone of a resistance adjusting device is not screwed into a throttle ring;

[0020] Figure 5 A schematic diagram showing the adjustment cone of the resistance adjustment device of the simulated fuel assembly 200 being screwed into the throttle ring; and

[0021] Figure 6 A schematic diagram of a core provided according to some embodiments of the present invention is shown.

[0022] Reference numerals:

[0023] 100: Full stack fuel assembly;

[0024] 110: Handle;

[0025] 120: Plate bundle area;

[0026] 130: Tube socket;

[0027] 200: simulated fuel assembly;

[0028] 210: inlet current balancing unit;

[0029] 220: Venturi tube;

[0030] 230: Plate bundle area structure;

[0031] 241: throttle ring;

[0032] 242: Adjustment cone;

[0033] 243: Fixed fins;

[0034] 244: Locking nut;

[0035] 600: simulated core assembly; and

[0036] 610: Simulated fuel assembly. DETAILED DESCRIPTION

[0037] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. Note that the aspects described below in conjunction with the accompanying drawings and specific embodiments are only exemplary and should not be construed as limiting the scope of protection of the present invention in any way.

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

[0039] In addition, the terms "upper", "lower", "left", "right", "top", "bottom", "horizontal" and "vertical" used in the following description should be understood as the directions shown in the paragraph and the related drawings. Such relative terms are only used for the convenience of description and do not mean that the device described therein must be manufactured or operated in a specific direction, and therefore should not be understood as limiting the present invention.

[0040] It is understood that although the terms "first", "second", "third", etc. may be used herein to describe various components, regions, layers and / or parts, these components, regions, layers and / or parts should not be limited by these terms, and these terms are only used to distinguish different components, regions, layers and / or parts. Therefore, the first component, region, layer and / or part discussed below may be referred to as a second component, region, layer and / or part without departing from some embodiments of the present invention.

[0041] As mentioned above, before the new reactor type is put into operation, a reactor hydraulic simulation test needs to be carried out to verify whether the core flow distribution can meet the requirements of thermal and safety analysis. Before carrying out the reactor hydraulic simulation test, a simulated fuel assembly that can replace the real fuel assembly needs to be designed to simulate the real fuel assembly.

[0042] Please refer to Figure 1 , Figure 1 A schematic structural diagram of an existing solid stack fuel assembly is shown.

[0043] like Figure 1 As shown, the solid fuel assembly 100 is a plate-shaped fuel assembly, which is composed of a lifting beam 110, a plate bundle area 120 and a tube seat 130. The lifting beam 110 can be used to lift the solid fuel assembly 100 to facilitate the installation of the solid fuel assembly 100. The plate bundle area 120 can be a region composed of multiple plate-shaped fuels arranged in parallel. The tube seat 130 is used to fix the solid fuel assembly 100. The solid fuel assembly 100 is inserted into the grid plate, and the contraction section of the tube seat 130 can be used to contact the grid plate.

[0044] In order to overcome the above-mentioned defects of the prior art, the present invention provides a simulated fuel assembly and a simulated core assembly, which can simulate the real stack fuel assembly and reflect the resistance characteristics of the real stack fuel assembly in the reactor hydraulic simulation test, and at the same time, can also measure the inlet flow rate. By measuring the inlet flow rate by simulating the fuel assembly, the distribution characteristics of the core inlet flow rate can be further evaluated.

[0045] The simulated fuel assembly provided by the present invention is a special type of test piece that can reflect the characteristics of real reactor fuel assemblies in reactor hydraulic simulation tests. By simulating the fuel assembly and the simulated core assembly including multiple simulated fuel assemblies, the reactor core resistance characteristics can be simulated, and the flow rates entering each simulated fuel assembly of the reactor can be measured to evaluate the flow distribution characteristics of the inlet of the simulated core assembly.

[0046] Please refer to Figure 2 , Figure 2 A schematic diagram of a simulated fuel assembly provided according to some embodiments of the present invention is shown.

[0047] like Figure 2 As shown, the simulated fuel assembly 200 may include an inlet flow balancing unit 210. The inlet flow balancing unit 210 may be located at the inlet of the simulated fuel assembly 200. The inlet flow balancing unit 210 may be used for flow balancing and may also be used to prevent foreign matter from entering the simulated fuel assembly 200. In addition, the inlet flow balancing unit 210 may provide a certain resistance for the simulated fuel assembly 200.

[0048] In some preferred embodiments, the inlet flow balancing unit 210 may be a grid plate.

[0049] The simulated fuel assembly may further include a flow measurement unit. The flow measurement unit is located below the inlet flow equalization unit and is used to measure the flow entering the simulated fuel assembly, acting as a flow meter. In addition, the flow measurement unit may also provide a certain resistance for the simulated fuel assembly 200.

[0050] exist Figure 2 In the illustrated embodiment, the flow measurement unit may be a funnel-shaped venturi tube 220 that contracts first and then gradually expands. The venturi tube 220 is located below the inlet flow equalization unit 210 to measure the flow entering the simulated fuel assembly 200. The venturi flowmeter has no moving parts and has better stability than the turbine flowmeter. In addition, the venturi tube 220 can not only measure the flow entering the simulated fuel assembly 200 in the research reactor hydraulic simulation test, thereby evaluating the core inlet flow distribution characteristics, but also provide resistance for the simulated fuel assembly 200.

[0051] In some optional embodiments, the venturi tube 220 in the simulated fuel assembly 200 structure may be replaced by other types of flow measurement devices. For example, in some embodiments, the flow measurement unit may include an orifice flow meter.

[0052] The simulated fuel assembly may include a resistance member located below the flow measurement unit, and the resistance member may be used to simulate the fluidity of a real stack fuel assembly.

[0053] like Figure 2 As shown, the simulated fuel assembly 200 can be designed with a plate bundle area structure 230 as a resistance member. The plate bundle area structure 230 is located below the venturi tube 220. The plate bundle area structure 230 can reflect the resistance characteristics of the real stack fuel assembly and simulate the flow characteristics of the real stack plate-shaped fuel assembly through a similar plate bundle area shape.

[0054] In some embodiments, the resistance member of the simulated fuel assembly may also be replaced by other resistance members such as a porous plate.

[0055] like Figure 2 As shown, the inlet flow balancing unit 210, the venturi tube 220 and the plate bundle area structure 230 all provide resistance for the simulated fuel assembly 200. The resistance provided by the inlet flow balancing unit 210, the venturi tube 220 and the plate bundle area structure 230 of the simulated fuel assembly 200 can make the resistance characteristics of the simulated fuel assembly 200 as consistent as possible with the resistance characteristics of the real stack fuel assembly.

[0056] In addition, the simulated fuel assembly may include a resistance adjusting device located below the resistance member, and the resistance adjusting device may be used to adjust the resistance of the simulated fuel assembly so that the resistance coefficient of the simulated fuel assembly is the same as the resistance coefficient of the real stack fuel assembly.

[0057] Please continue to refer to Figure 2 A resistance adjustment device may be provided below the plate bundle region structure 230 of the simulated fuel assembly 200. The resistance adjustment device may include a throttle ring 241 and an adjustment cone 242.

[0058] Specifically, please refer to Figures 3 to 5 , Figure 3 A schematic diagram of a resistance adjustment device according to a simulated fuel assembly 200 is shown. Figure 4 A schematic diagram showing a simulation of a fuel assembly 200 in which the adjusting cone of the resistance adjusting device is not screwed into the throttle ring, Figure 5 A schematic diagram showing the adjustment cone of the resistance adjustment device of the simulated fuel assembly 200 being screwed into the throttle ring is shown.

[0059] like Figure 3 As shown, the resistance adjustment device may include a fixing fin 243 and a locking nut 244 in addition to the throttle ring 241 and the adjustment cone 242 .

[0060] The throttle ring 241 can be replaced with a throttle ring 241 of different sizes to achieve coarse adjustment of the resistance of the simulated fuel assembly 200 .

[0061] Fine adjustment of the resistance of the simulated fuel assembly 200 can be achieved by changing the relative positions of the adjustment cone 242 and the throttle ring 241 .

[0062] The fixed fin 243 can be fixed to the inner wall of the simulated fuel assembly 200 , and the adjusting cone 242 is connected to the fixed fin 243 by threads. The adjusting cone 242 can be moved upward or downward by screwing the adjusting cone 242 , thereby adjusting the relative position of the adjusting cone 242 and the throttle ring 241 .

[0063] As the relative positions of the adjustment cone 242 and the throttle ring 241 change, the flow area inside the simulated fuel assembly 200 can be changed to adjust the resistance of the simulated fuel assembly 200.

[0064] like Figure 4 and Figure 5 As shown, the adjusting cone 242 moves upward, Figure 4 Move the position shown to Figure 5 Compared to Figure 4 In the case where the relative position shown is far away (i.e., when the adjusting cone 242 is not screwed into the throttle ring 241), Figure 5 In the case where the relative positions of the adjusting cone 242 and the throttle ring 241 are relatively close (ie, when the adjusting cone 242 is screwed into the throttle ring 241), the resistance of the simulated fuel assembly 200 becomes higher based on the change in the internal flow area.

[0065] Please continue to refer to Figure 3 The position of the adjusting cone 242 can be fixed by the locking nut 244. The locking nut 244 and the adjusting cone 242 can also be connected by threads.

[0066] The resistance adjustment device can continuously adjust the resistance of the simulated fuel assembly 200 so that the resistance characteristics of the simulated fuel assembly 200 match the resistance characteristics of the real fuel assembly as much as possible. When the resistance coefficient of the simulated fuel assembly 200 is adjusted to be the same as that of the real fuel assembly, the position of the adjustment cone 242 is fixed by the locking nut 244 to prevent it from loosening.

[0067] In other embodiments, the resistance adjustment device of the throttle ring plus the adjustment cone may also be replaced by a resistance adjustment device of other structural types.

[0068] For example, in some embodiments, the resistance adjustment device may be a damper-type resistance adjustment device or a lateral adjustment cone device.

[0069] In this way, the simulated fuel assembly provided by the present invention can simulate the resistance characteristics of a real stack fuel assembly through an inlet flow equalizing unit, a flow measuring unit, a resistance member and a resistance adjusting device, thereby ensuring that the flow measuring unit can measure the inlet flow in a simulated fuel assembly that is consistent with the resistance characteristics of a real stack fuel assembly, thereby ensuring the availability and accuracy of the measurement results.

[0070] The second aspect of the present invention further provides a simulated core assembly, which may include a plurality of simulated fuel assemblies provided by the first aspect of the present invention.

[0071] Please refer to Figure 6 , Figure 6 A schematic diagram of a core provided according to some embodiments of the present invention is shown.

[0072] like Figure 6 As shown, the simulated core assembly 600 may include a plurality of simulated fuel assemblies 610. The simulated core assembly 600 may evaluate the inlet flow distribution characteristics of the simulated core assembly 600 based on the flow results measured by the flow measurement units of the plurality of simulated fuel assemblies 610.

[0073] For example, in some embodiments, the simulated core assembly may include multiple Figure 2 As shown in the simulated fuel assembly 200, the venturi tube 220 of each simulated fuel assembly 200 can measure the flow entering the simulated fuel assembly 200 separately in the research reactor hydraulic simulation test. The measurement results of the venturi tubes 220 of multiple simulated fuel assemblies 200 are integrated to evaluate the inlet flow distribution characteristics of the simulated core assembly.

[0074] The resistance characteristics and flow characteristics of the simulated fuel assembly provided by the first aspect of the present invention are consistent with those of the actual fuel assembly, thereby ensuring the accuracy of the measurement and evaluation of the inlet flow distribution characteristics.

[0075] In summary, the simulated fuel assembly and simulated core assembly provided by the present invention can simulate the real stack fuel assembly and reflect the resistance characteristics of the real stack fuel assembly in the reactor hydraulic simulation test. At the same time, the inlet flow can also be measured. By measuring the inlet flow by the simulated fuel assembly, the distribution characteristics of the core inlet flow can be further evaluated.

[0076] The previous description of the disclosure is provided to enable any person skilled in the art to make or use the disclosure. Various modifications to the disclosure will be apparent to those skilled in the art, and the general principles defined herein may be applied to other variations without departing from the spirit or scope of the disclosure. Thus, the disclosure is not intended to be limited to the examples and designs described herein, but should be granted the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A simulated fuel assembly, characterized in that: include: An inlet flow equalization unit, located at the inlet of the simulated fuel assembly, is used to equalize the flow and prevent foreign matter; A flow measurement unit, located below the inlet flow balancing unit, for measuring the flow entering the simulated fuel assembly; A resistance member, located below the flow measurement unit; a resistance adjustment device, located below the resistance member, for adjusting the resistance of the simulated fuel assembly; as well as The inlet flow balancing unit, the flow measurement unit, the resistance element and the resistance adjustment device together simulate the resistance characteristics of the real stack fuel assembly, so that the resistance coefficient of the simulated fuel assembly is equal to that of the real stack fuel assembly.

2. The simulated fuel assembly according to claim 1, characterized in that The inlet flow balancing unit is a grid plate.

3. The simulated fuel assembly according to claim 1, characterized in that The flow measurement unit is a Venturi tube.

4. The simulated fuel assembly according to claim 1, characterized in that The resistance member is a plate bundle area structure.

5. The simulated fuel assembly according to claim 1, characterized in that The resistance member is a porous plate.

6. The simulated fuel assembly according to claim 1, wherein: The resistance adjustment device comprises a throttle ring and an adjustment cone. The throttle ring can achieve rough adjustment of the resistance by changing its size, and the resistance can be finely adjusted by changing the relative position of the adjustment cone and the throttle ring.

7. The simulated fuel assembly according to claim 6, characterized in that The position of the adjusting cone is fixed by a locking nut.

8. A simulated core assembly, characterized in that: The method comprises a plurality of simulated fuel assemblies according to any one of claims 1 to 7, and the inlet flow distribution characteristics of the simulated core assembly are evaluated based on the flow results measured by the flow measurement units of the plurality of simulated fuel assemblies.

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