First wall structure for nuclear fusion reactor

Abstract

The invention discloses a first wall structure for a nuclear fusion reactor, which comprises a tungsten armor, a front wall, a fin array and a rear wall which are sequentially connected through a diffusion welding process. A wing-shaped fin array is arranged between the front wall and the rear wall, a formed cavity serves as a coolant flow channel, and coolant enters the first wall through a set inlet and a set outlet. Due to disturbance of the fins, boundary layer separation and reattachment are generated between the adjacent fins, the heat exchange effect between the main flow and the boundary layer is remarkably enhanced, the heat exchange area is effectively increased, and therefore the heat exchange performance of the first wall is enhanced. The wing shape adopted by the invention is an excellent hydrodynamic appearance, and flow separation can be effectively reduced, so that the generation of separation vortexes can be greatly reduced, and the pressure loss of fluid can be effectively reduced.

Description

Technical Field

[0001] The invention belongs to the field of nuclear fusion reactors, and in particular relates to a first wall structure used in a nuclear fusion reactor. Background Art

[0002] As an important component in a nuclear fusion reactor that is directly exposed to high-temperature plasma, the first wall must withstand high heat flux density, high-pressure coolant, and complex thermal stresses caused by temperature gradients and thermal expansion. These harsh working conditions require that the first wall not only have excellent cooling capabilities to quickly dissipate heat and maintain material integrity, but also have sufficient structural strength to cope with the various complex mechanical stresses generated during operation. In addition, the design of the first wall must also take into account the balance of coolant flow resistance, avoid excessive pressure drop, and ensure the overall operating efficiency of the system.

[0003] The traditional first wall cooling structure usually adopts multiple parallel square cooling channels ( Figure 1 ), and the coolant in adjacent channels flows in the opposite direction. The counterflow design is intended to reduce the maximum temperature of the structure downstream of the coolant. However, in-depth research has found that heat exchange inevitably occurs between adjacent channels, resulting in the coolant temperature at the inlet of the heating section being higher than the inlet temperature of the first wall, so the maximum temperature reduction of the first wall heating section is limited. In addition, this design will also cause significant temperature fluctuations along the pole direction of the first wall, increasing the risk of local thermal stress and material failure of the first wall. In addition, the parallel channels are coupled with each other, and flow instability is prone to occur under some operating conditions, causing equipment and system oscillations, threatening the safe operation of the reactor.

[0004] In order to improve the heat transfer capacity of the traditional square channel, spoiler ribs (such as straight ribs, V-shaped ribs ( Figure 2 The first wall structure is equipped with a plurality of ribs (as shown in the figure), rifling ribs, etc.) to destroy the laminar state of the coolant mainstream and promote the mixing of the coolant boundary layer with the mainstream, thereby improving the heat transfer coefficient. However, the introduction of spoiler ribs can easily lead to fluid flow separation, especially on the rear side of the spoiler ribs, where a large number of separation vortices will be formed. Although this disturbance effectively enhances heat exchange and reduces the maximum temperature of the first wall structure, it also significantly increases the pressure drop of the coolant, resulting in a significant increase in pump power and even a decrease in the overall operating efficiency and economy of the reactor.

[0005] Therefore, designing a new first wall structure that takes into account both efficient cooling and structural strength while reducing coolant pressure drop has become one of the current focuses of research and development of the first wall of nuclear fusion reactors. Summary of the invention

[0006] In order to solve the problem of excessive coolant pressure drop caused by the existing enhanced heat exchange scheme and ensure sufficient structural strength under the design conditions, the present invention provides a first wall structure for a nuclear fusion reactor, which is a new first wall structure that can effectively reduce the coolant pressure drop while maintaining efficient cooling capacity and ensure that the first wall has sufficient structural strength. Due to the disturbance of the fins, boundary layer separation and reattachment occur between adjacent fins, which significantly enhances the heat exchange effect between the mainstream and the boundary layer, and the heat exchange area is effectively increased, so the heat exchange performance of the first wall is enhanced. The excellent fluid dynamic shape of the wing shape can effectively reduce flow separation, so the generation of separation vortex can be greatly reduced, so that the pressure loss of the fluid can be effectively reduced. In addition, the fin array also provides connection and support between the front wall and the rear wall to meet the strength requirements under the design conditions. The present invention abandons the traditional enhanced heat exchange method of adding spoiler ribs in a square channel, adopts wing-shaped fins with excellent flow characteristics as the front wall and rear wall connection structure and spoiler structure, and establishes a special-shaped flow channel, which not only effectively reduces the temperature of the first wall, but also significantly reduces the pressure loss of the coolant, and avoids the flow instability problem of the parallel channel.

[0007] In order to achieve the above object, the present invention adopts the following technical scheme: A first wall structure for a nuclear fusion reactor, comprising: The tungsten armor is located outside the first wall, with the front side contacting the plasma and the rear side being welded to the front side of the front wall; it only covers the arc section and the heating section of the front wall; The front wall is located at the rear side of the tungsten armor, and the front side is fixedly connected with the rear side of the tungsten armor by diffusion welding; A fin array is arranged between the front wall and the rear wall, the fin array is composed of wing-shaped fins, and is fixedly connected to the rear side of the front wall and the front side of the rear wall by diffusion welding, and the fin array adopts an offset array; the fin array is composed of a plurality of fins of the same shape; the surface of the fin is symmetrical up and down, the chord length is 20 mm, the ratio of thickness to chord length is in the range of 0.185 to 0.193, and the distance between the maximum thickness of the wing and the leading edge and the chord length is between 0.33 and 0.35; A rear wall, located at the rear side of the first wall, providing support for the entire first wall; A coolant flow channel is formed between the front wall, the fin array and the rear wall. A coolant inlet and a coolant outlet are provided in the coolant flow channel. When the coolant flows in the coolant flow channel, it is disturbed by the fin array.

[0008] Furthermore, the fin array is not only used to disturb the flow of the coolant and enhance the cooling effect, but also provides a structural connection support between the front wall and the rear wall to ensure the overall structural strength of the first wall under the designed working conditions.

[0009] Furthermore, each fin of the fin array has a wing-shaped cross-section of the same size, and the fin has low resistance and excellent fluid dynamics performance, effectively reducing coolant pressure loss.

[0010] Furthermore, the coolant flow channel uses a wing-shaped fin array as a disturbance and connection structure in the flow channel, thereby achieving efficient use of the space between the front wall and the rear wall, so that the coolant flow channel forms a whole.

[0011] Furthermore, the coolant inlet and the coolant outlet are formed by a gap between the front wall and the rear wall.

[0012] Furthermore, the coolant flows into the first wall from the coolant inlet, and flows out from the coolant outlet after passing through the fluid flow channel; the coolant is split from the leading edge of the fin array and converges at the trailing edge.

[0013] In the present invention, a fluid flow channel for coolant flow is formed between the front wall, the fin array and the rear wall. The coolant enters the first wall through the coolant inlet and is disturbed by the wing-shaped fin array when flowing through the flow channel. The fin array disrupts the coolant flow, breaks the laminar flow, enhances the heat exchange effect, and provides necessary structural support for the front wall and the rear wall in the process, ensuring the structural integrity of the first wall under high temperature and high pressure conditions. At the same time, the wing-shaped fins effectively reduce the pressure loss in the coolant flow due to their excellent fluid dynamics, and significantly improve the cooling efficiency compared with the traditional square channel design.

[0014] In the present invention, the fin surface is symmetrical up and down, the chord length L is 20 mm, and the ratio of the chord length L to the maximum thickness t is in the range of 3.9-4.1, and the ratio of the distance h from the maximum thickness of the wing to the leading edge to the chord length L is between 0.33-0.35.

[0015] Beneficial effects: 1. The present invention uses a wing-shaped fin array to repeatedly disturb the coolant, thereby destroying the laminar state of the coolant mainstream. Boundary layer separation and reattachment will occur between adjacent fins, which significantly enhances the heat exchange effect between the mainstream and the boundary layer, improves the heat exchange performance of the first wall, and reduces the structural temperature of the first wall.

[0016] 2. The present invention adopts wing-shaped fins as the spoiler structure, replacing the traditional square channel spoiler rib design.

[0017] 3. The coolant flow rate of the first wall is relatively high, and the medium is deionized water. After repeated design and optimization, the fin chord length L=20mm, thickness t=5mm, and the ratio L / t=4 are adopted. The symmetrical design of the upper and lower surfaces can effectively avoid coolant flow separation and reduce coolant momentum loss.

[0018] 4. The first wall needs to withstand the high heat flux from the plasma on one side, and the fin thickness is designed to be 5mm to avoid the formation of local hot spots.

[0019] 5. The distance between the front wall and the rear wall is 8mm, and the pressure resistance is 15.5MPa. The fin chord length L, thickness t and offset parameters (a=32.6mm, b=7.6mm) that have been repeatedly designed and verified provide sufficient support structure for the front wall and the rear wall, while increasing the coolant channel between the front wall and the rear wall.

[0020] 6. Compared with the traditional square cooling channel, the present invention abandons the design of parallel channels. The cooling channel is a whole, which improves the space utilization between the front wall and the rear wall and avoids the problem of flow instability caused by the traditional parallel channels.

[0021] 7. The wing-shaped fins of the present invention are not only used to enhance the disturbance and heat exchange effect of the coolant, but also provide sufficient structural support between the front wall and the rear wall, meeting the strength requirements of the first wall under the design working conditions.

[0022] 8. In the present invention, there is only one flow channel in the first wall, and the polar temperature distribution is uniform, which avoids the polar temperature fluctuation of the traditional square parallel countercurrent channel and reduces the thermal stress caused by the local temperature difference. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 Schematic diagram of the first wall structure of a traditional square smooth channel.

[0024] Figure 2 Schematic diagram of the first wall structure of a traditional square smooth channel using V-shaped ribs.

[0025] Figure 3 This is a schematic diagram of a first wall structure for a nuclear fusion reactor according to the present invention.

[0026] Figure 4 This is an exploded view of a first wall structure for a nuclear fusion reactor according to the present invention.

[0027] Figure 5 This is an enlarged view of the details of a first wall structure for a nuclear fusion reactor according to the present invention.

[0028] Figure 6 The figure is a schematic diagram of the fin arrangement of the first wall structure for a nuclear fusion reactor according to the present invention.

[0029] Among them, the figure markings are: 1. tungsten armor; 2. front wall; 3. fin array; 4. rear wall; 5. fluid flow channel; 6. coolant inlet; 7. coolant outlet. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0031] Example like Figure 3~Figure 6 As shown, the first wall structure for a nuclear fusion reactor provided in this embodiment includes a tungsten armor 1, a front wall 2, a fin array 3, and a rear wall 4. The fin array 3 is arranged between the front wall 2 and the rear wall 4. The tungsten armor 1, the front wall 2, the fin array 3 and the rear wall 4 are fixedly connected by diffusion welding in sequence to form an integral structure. The fin array 3 is composed of a plurality of wing-shaped fins.

[0032] The front wall 2, the fin array 3 and the rear wall 4 together form a coolant flow channel 5. The two ends of the coolant flow channel 5 are respectively a coolant inlet 6 and a coolant outlet 7, which are formed by the gap formed by the front wall 2 and the rear wall 4. The coolant enters the interior of the first wall from the coolant inlet 6, and flows out from the coolant outlet 7 after being repeatedly disturbed by the fin array 3 in the fluid flow channel 5. During the flow of the coolant in the fluid flow channel 5, the coolant flows from the leading edge to the trailing edge of the wing-shaped fin.

[0033] In actual operation, the tungsten armor 1 is in direct contact with high-temperature plasma and is subjected to high heat flow. The heat absorbed by the tungsten armor 1 is transferred to the front wall 2, and the part of the front wall 2 that is in direct contact with the coolant immediately transfers the heat to the coolant, achieving efficient heat exchange. The heat in the area where the front wall 2 is welded to the fin array 3 is transferred to the coolant through the fin array 3.

[0034] After entering the coolant flow channel 5, the coolant repeatedly separates and merges along the leading edge and trailing edge of the fin array 3. The repeated disturbance of the mainstream significantly enhances the heat exchange effect and effectively reduces the temperature of the first wall. The shape of the wing-shaped fin has an excellent flow shape, ensuring a low pressure drop of the coolant during the entire flow process.

[0035] The fin array 3 composed of wing-shaped fins can be directly processed on the rear wall 4 by electro-etching or chemical etching. In order to obtain a higher surface quality of the coolant flow channel, it can be directly milled on the rear wall 4 by machining. The tungsten armor 1, the front wall 2 and the rear wall 4 with the processed fin array are fixed together by diffusion welding. The first wall that has been welded and fixed is bent into a U shape by stamping at high temperature.

[0036] Preferably, the cross-sectional shape of the wing-shaped fin is a wing-shaped shape with symmetry between the upper and lower surfaces. Other wing shapes may also be selected according to fluid properties and design requirements.

[0037] Preferably, the fin array 3 is arranged in an offset array. Figure 6 For example: the first fin in the upper left corner is used as the parent feature, and the first row of fins is offset in the horizontal direction with a pitch a, preferably a=32.6mm. The first row of fins is offset in the horizontal direction by a / 2, that is, 16.3mm, and the second row of fins is shifted in the vertical direction by b, preferably b=7.6mm, a / b=4.29±0.05. All fins in the first and second rows are offset in the vertical direction by 15.2mm (7.6mm) as a whole. 2, i.e. 2b), 30.4mm (7.6mm 4, i.e. 4b), 45.6mm (7.6mm 6, namely 6b) ..., to form a fin array. Other arrangements may also be selected according to the optimization results.

[0038] Preferably, the fin has a chord length of 20 mm, a wing thickness of 5 mm, and a distance from the leading edge to the maximum thickness of 6.5 mm.

[0039] Preferably, diffusion welding is used to weld the tungsten armor 1, the front wall 2, the fin array 3 and the rear wall 4, and other welding processes such as hot isostatic pressing may also be used.

[0040] Preferably, Figure 6 As shown, the fin chord length is 20 mm, the fin thickness is 3.78 mm, the fin horizontal offset is 32.6 mm, the vertical offset is 15.2 mm, and the horizontal distance between two adjacent rows of fins is 16.3 mm.

[0041] In the description of the present invention, “plurality” means at least two, for example, two, three, etc., unless otherwise clearly and specifically defined.

[0042] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine different embodiments or examples described in this specification and the features of different embodiments or examples, without contradiction.

[0043] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A first wall structure for a nuclear fusion reactor, characterized in that: include: The tungsten armor (1) is located outside the first wall, the front side of which contacts the plasma, and the rear side of which is welded to the front side of the front wall (2); it only covers the arc section and the heating section of the front wall (2); A front wall (2) is located on the rear side of the tungsten armor (1), and the front side is fixedly connected to the rear side of the tungsten armor (1) by diffusion welding; A fin array (3) is arranged between the front wall (2) and the rear wall (4), the fin array (3) is composed of wing-shaped fins, and is fixedly connected to the rear side of the front wall (2) and the front side of the rear wall (4) by diffusion welding, and the fin array adopts an offset array; the fin array (3) is composed of a plurality of fins of the same shape; the surface of the fin is symmetrical up and down, the chord length is 20 mm, the ratio of thickness to chord length is in the range of 0.185 to 0.193, and the ratio of the distance from the maximum thickness of the wing to the leading edge to the chord length is in the range of 0.33 to 0.35; A rear wall (4), located at the rear side of the first wall, providing support for the first wall as a whole; A coolant flow channel (5) is formed between the front wall (2), the fin array (3) and the rear wall (4), and a coolant inlet (6) and a coolant outlet (7) are provided in the coolant flow channel (5). When the coolant flows in the coolant flow channel (5), it is disturbed by the fin array (3).

2. The first wall structure for a nuclear fusion reactor according to claim 1, characterized in that: The fin array (3) is not only used to disturb the flow of the coolant and enhance the cooling effect, but also provides structural connection support between the front wall (2) and the rear wall (4) to ensure the overall structural strength of the first wall under design conditions.

3. The first wall structure for a nuclear fusion reactor according to claim 1 or 2, characterized in that: Each fin of the fin array (3) has a wing-shaped cross-section of the same size, and the fin has low resistance and excellent fluid dynamics performance, effectively reducing coolant pressure loss.

4. The first wall structure for a nuclear fusion reactor according to claim 1 or 2, characterized in that: The coolant flow channel (5) uses a wing-shaped fin array (3) as a disturbance and connection structure in the flow channel, thereby achieving efficient use of the space between the front wall (2) and the rear wall (4), so that the coolant flow channel (5) forms a whole.

5. The first wall structure for a nuclear fusion reactor according to claim 1 or 2, characterized in that: The coolant inlet (6) and the coolant outlet (7) are formed by a gap between the front wall (2) and the rear wall (4).

6. The first wall structure for a nuclear fusion reactor according to claim 1 or 2, characterized in that: The coolant flows into the first wall from the coolant inlet (6), flows out from the coolant outlet (7) after passing through the fluid flow channel (5); the coolant is split from the leading edge of the fin array (3) and converges at the trailing edge.

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