A first wall structure for a nuclear fusion reactor

Abstract

The present invention discloses a first wall structure for a nuclear fusion reactor, comprising a tungsten armor, a front wall, a fin array and a rear wall, which are connected in sequence through a diffusion welding process. A wing-shaped fin array is provided between the front wall and the rear wall, and the cavity formed serves as a coolant flow channel, and the coolant enters the first wall through a set inlet and outlet. 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, thereby enhancing the heat exchange performance of the first wall. The wing shape adopted in the present invention is an excellent fluid dynamic shape, which can effectively reduce flow separation, thereby significantly reducing the generation of separation vortices, and effectively reducing the pressure loss of the fluid.

Description

Technical Field

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

[0002] As a critical component directly exposed to the high-temperature plasma in a nuclear fusion reactor, the first wall must withstand high heat flux, high-pressure coolant, and complex thermal stresses caused by temperature gradients and thermal expansion. These demanding conditions require the first wall to possess not only excellent cooling capacity to rapidly dissipate heat and maintain material integrity, but also sufficient structural strength to withstand the complex mechanical stresses generated during operation. Furthermore, the design of the first wall must balance coolant flow resistance, avoid excessive pressure drop, and ensure overall system efficiency.

[0003] The traditional first wall cooling structure usually adopts multiple parallel square cooling channels ( Figure 1 ), and the coolant in adjacent channels flows in opposite directions. The counterflow design is intended to reduce the maximum temperature of the coolant downstream structure. 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. As a result, 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 in the first wall. In addition, the parallel channels are coupled with each other, and flow instability is prone to occur under certain 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, it is usually necessary to add flow-disturbing ribs (such as straight ribs, V-shaped ribs ( Figure 2 The first wall structure is characterized by the presence of ribs (as shown in the figure), rifling ribs, etc.) to disrupt the laminar flow of the main coolant stream, causing the coolant boundary layer to mix with the main stream, thereby improving the heat transfer coefficient. However, the introduction of ribs can easily lead to fluid flow separation, especially behind the ribs, where a large number of separation vortices form. Although this disturbance effectively enhances heat exchange and reduces the maximum temperature of the first wall structure, it also significantly increases the coolant pressure drop, leading to 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 nuclear fusion reactor first wall research and development. Summary of the Invention

[0006] To address the problem of excessive coolant pressure drop associated with existing heat exchange enhancement solutions while ensuring sufficient structural strength under design conditions, the present invention provides a first wall structure for a nuclear fusion reactor. This novel first wall structure effectively reduces coolant pressure drop while maintaining efficient cooling capacity and ensuring sufficient structural strength. The fins' turbulence creates boundary layer separation and reattachment between adjacent fins, significantly enhancing heat exchange between the mainstream and the boundary layer. This also effectively increases the heat exchange area, thereby enhancing the heat exchange performance of the first wall. The wing's excellent fluid dynamics effectively reduces flow separation, thereby significantly reducing the generation of separation vortices and effectively reducing fluid pressure loss. Furthermore, the fin array provides connection and support between the front and rear walls, meeting strength requirements under design conditions. This invention abandons the traditional heat exchange enhancement method of adding spoiler ribs within a square channel. Instead, it utilizes wing-shaped fins with excellent flow characteristics as the front and rear wall connection structure and spoiler structure, creating a special-shaped flow channel. This effectively reduces the temperature of the first wall, significantly reduces coolant pressure loss, and avoids the flow instability problem of parallel channels.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions:

[0008] A first wall structure for a nuclear fusion reactor, comprising:

[0009] The tungsten armor is located on the outside of the first wall, with its front side in contact with the plasma and its rear side welded to the front side of the front wall; it only covers the arc section and the heating section of the front wall;

[0010] The front wall is located at the rear side of the tungsten armor, and the front side and the rear side of the tungsten armor are fixedly connected by diffusion welding;

[0011] A fin array is disposed between the front wall and the rear wall, the fin array comprising wing-shaped fins fixedly connected to the rear side of the front wall and the front side of the rear wall by diffusion welding, and adopts an offset array; the fin array comprises a plurality of fins of identical shape; the surface of the fin is symmetrical in the vertical direction, the chord length is 20 mm, the ratio of thickness to chord length is within the range of 0.185 to 0.193, and the ratio of the distance from the leading edge of the maximum thickness of the wing to the chord length is within the range of 0.33 to 0.35;

[0012] A rear wall, located at the rear side of the first wall, providing support for the entire first wall;

[0013] 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.

[0014] Furthermore, the fin array is not only used to disturb the flow of coolant and enhance the cooling effect, but also provides structural connection support between the front wall and the rear wall to ensure the overall structural strength of the first wall under design working conditions.

[0015] 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.

[0016] 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.

[0017] Furthermore, the coolant inlet and the coolant outlet are formed by a gap between the front wall and the rear wall.

[0018] Furthermore, the coolant flows into the first wall from the coolant inlet, 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 merged at the trailing edge.

[0019] In the present invention, a fluid 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 as it flows through the channel. The fin array disrupts the coolant flow, disrupting laminar flow and enhancing heat transfer. In the process, it provides the necessary structural support for the front and rear walls, ensuring the structural integrity of the first wall under high-temperature and high-pressure operating conditions. Furthermore, the wing-shaped fins, due to their excellent fluid dynamics, effectively reduce pressure losses during coolant flow, significantly improving cooling efficiency compared to traditional square channel designs.

[0020] 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 to 4.1. 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 and 0.35.

[0021] Beneficial effects:

[0022] 1. The present invention uses a wing-shaped fin array to repeatedly disturb the coolant flow, disrupting the laminar flow state of the coolant mainstream. Boundary layer separation and reattachment will occur between adjacent fins, significantly enhancing the heat exchange effect between the mainstream and the boundary layer, improving the heat exchange performance of the first wall, and reducing the structural temperature of the first wall.

[0023] 2. The present invention adopts wing-shaped fins as the spoiler structure, replacing the traditional square channel spoiler rib design.

[0024] 3. The coolant flow rate on 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.

[0025] 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.

[0026] 5. The distance between the front and rear walls 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), which have been repeatedly designed and verified, provide sufficient support structure for the front and rear walls, while increasing the coolant channel between the front and rear walls.

[0027] 6. Compared with traditional square cooling channels, the present invention abandons the design of parallel channels. The cooling channel is an integrated whole, which improves the space utilization between the front wall and the rear wall and avoids the flow instability problem caused by traditional parallel channels.

[0028] 7. The wing-shaped fins of the present invention are not only used to enhance the turbulence 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.

[0029] 8. The present invention has only one flow channel in the first wall, and the polar temperature distribution is uniform, which avoids the polar temperature fluctuation of traditional square parallel counter-flow channels and reduces the thermal stress caused by local temperature differences. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 Schematic diagram of the first wall structure of a traditional square smooth channel.

[0031] Figure 2 Schematic diagram of the first wall structure of a traditional square smooth channel using V-shaped ribs.

[0032] Figure 3 This is a schematic diagram of a first wall structure for a nuclear fusion reactor according to the present invention.

[0033] Figure 4 This is an exploded view of a first wall structure for a nuclear fusion reactor according to the present invention.

[0034] Figure 5 This is an enlarged view of the details of the first wall structure for a nuclear fusion reactor according to the present invention.

[0035] Figure 6 This is a schematic diagram of the fin arrangement of the first wall structure for a nuclear fusion reactor according to the present invention.

[0036] Among them, the figures are marked as: 1, tungsten armor; 2, front wall; 3, fin array; 4, rear wall; 5, fluid flow channel; 6, coolant inlet; 7, coolant outlet. DETAILED DESCRIPTION

[0037] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only intended to illustrate 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 may be combined with each other as long as they do not conflict with each other.

[0038] Example

[0039] like Figures 3 to 6 As shown, this embodiment provides a first wall structure for a nuclear fusion reactor, comprising a tungsten armor 1, a front wall 2, a fin array 3, and a rear wall 4. The fin array 3 is disposed 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 sequentially connected by diffusion welding to form an integrated structure. The fin array 3 is composed of a plurality of wing-shaped fins.

[0040] The front wall 2, fin array 3, and rear wall 4 collectively form a coolant flow channel 5. Coolant flow channel 5 has a coolant inlet 6 and a coolant outlet 7 at either end, formed by gaps formed by the front wall 2 and rear wall 4. Coolant enters the interior of the first wall through the coolant inlet 6, is repeatedly disturbed by the fin array 3 within the flow channel 5, and then flows out through the coolant outlet 7. As the coolant flows within the flow channel 5, it flows from the leading edge to the trailing edge of the airfoil-shaped fins.

[0041] During actual operation, tungsten armor 1 directly contacts high-temperature plasma, subjecting it to high heat flux. Heat absorbed by tungsten armor 1 is transferred to front wall 2, where the portion of front wall 2 in direct contact with the coolant immediately transfers the heat to the coolant, achieving efficient heat exchange. Heat from the area where front wall 2 is welded to fin array 3 is transferred to the coolant via fin array 3.

[0042] After entering the coolant flow channel 5, the coolant repeatedly separates and merges along the leading and trailing edges of the fin array 3. This repeated disturbance of the main flow significantly enhances the heat exchange effect and effectively reduces the temperature of the first wall. The wing-shaped fin shape has an excellent flow shape, ensuring a low pressure drop throughout the coolant flow process.

[0043] The wing-shaped fin array 3 can be machined directly onto the rear wall 4 through electro-etching or chemical etching. To achieve a higher surface quality for the coolant flow path, the rear wall 4 can be milled directly onto the rear wall 4. The tungsten armor 1, front wall 2, and rear wall 4 with the machined fin array are secured together by diffusion welding. The welded first wall is then bent into a U-shape by stamping at high temperature.

[0044] Preferably, the cross-sectional shape of the wing-shaped fin is a wing-shaped shape with symmetrical upper and lower surfaces. Other wing shapes may also be selected according to fluid properties and design requirements.

[0045] 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 of a, preferably a=32.6mm. The first row of fins is offset in the horizontal direction by a / 2, that is, 16.3mm. At the same time, the second row of fins is shifted in the vertical direction by b, preferably b=7.6mm, a / b=4.29±0.05. All the 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, i.e. 6b) ..., to form a fin array. Other arrangements can also be selected based on the optimization results.

[0046] Preferably, the chord length of the fin is 20 mm, the wing thickness is 5 mm, and the distance from the maximum thickness to the leading edge is 6.5 mm.

[0047] 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.

[0048] Preferably, Figure 6 As shown, the fin chord length is 20 mm, the fin thickness is 3.78 mm, the horizontal offset of the fin 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.

[0049] In the description of the present invention, “a plurality of” means at least two, for example, two, three, etc., unless otherwise clearly and specifically defined.

[0050] In the description of this specification, reference to the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples" 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 appropriate manner in any one or more embodiments or examples. In addition, those skilled in the art may combine and combine different embodiments or examples described in this specification, as well as features of different embodiments or examples, unless they are mutually inconsistent.

[0051] 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 principles of the present invention should be included in the scope of protection 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, with its front side in contact with the plasma and its rear side 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 at 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 in the upper and lower parts, the chord length is 20 mm, the ratio of thickness to chord length is within 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 within the range of 0.33 to 0.35; A rear wall (4), located on the rear side of the first wall, providing support for the entire first wall; 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 the design working 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 within the flow channel, 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 through the fluid flow channel (5) and then flows out from the coolant outlet (7); the coolant is split from the leading edge of the fin array (3) and merges at the trailing edge.

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