A composite microchannel and super boil-off structure cooled deflector target

Abstract

The present application belongs to the field of fusion reactor filter target plate cooling, and particularly relates to a filter target plate with composite micro-channel and super-vaporization structure cooling. The filter target plate comprises a plasma-facing material layer, a stress buffer layer, a micro-channel and super-vaporization composite structure heat sink, and a stainless steel cover plate. The micro-channel cooling is used in the micro-channel and super-vaporization composite structure heat sink corresponding to the strike point area of the target plate, and the super-vaporization channel cooling is used in the micro-channel and super-vaporization composite structure heat sink corresponding to the remaining area of the target plate. The present application can significantly reduce the surface temperature of the plasma-facing material in the strike point area of the target plate, prolong the service life of the filter target plate, and more efficiently transfer the ultra-high heat load deposited in the strike point area of the filter target plate, so as to ensure that the temperature of the plasma-facing material is lower than the recrystallization temperature of the material.

Description

Technical Field

[0001] This invention belongs to the field of fusion reactor divertor target plate cooling, specifically relating to a divertor target plate cooled by a composite microchannel and supervaporization structure. Background Technology

[0002] The progress of human civilization is closely related to energy development. Compared to fission energy, fusion energy has abundant fuel reserves and produces products that do not pollute the atmosphere and have low radioactivity, making it an excellent choice for humanity's basic energy source. Fusion reactions are mainly achieved through gravitational confinement, inertial confinement, and magnetic confinement. Among these, the magnetically confined tokamak is the most promising device for achieving controlled thermonuclear fusion. The divertor is a crucial component of the tokamak device. Particles from the plasma are confined within the divertor by its internal magnetic field. The divertor effectively shields the device from impurities from the walls, reducing contamination of the central plasma and removing particle and heat flows from the central plasma, as well as helium ash produced during the nuclear fusion reaction.

[0003] During operation, the divertor's outer wall directly faces the plasma on one side, subjecting it to high heat load irradiation from the plasma. In recent years, the China Fusion Engineering Test Reactor (CFETR) has placed even higher demands on the divertor target surface's heat load capacity, particularly in the high heat load region of the impact point, where the maximum steady-state heat flux density can reach 20 MW / m². 2 Transient speeds can reach 40 MW / m 2 Therefore, in the face of a working environment with uneven heat flux density distribution on the divertor target plate and localized extremely high heat flux density, appropriate cooling methods must be adopted to cool the divertor target plate and ensure efficient heat load removal. Current flat-plate divertor targets employ a single supervaporization structure. While this structure allows the fluid near the wall to reach saturation temperature earlier and vaporize, thereby removing a large amount of latent heat of vaporization, it still cannot meet the localized 20MW / m² heat load requirement. 2 The heat flux density requires heat dissipation. Therefore, in order to effectively remove the 20MW / m² deposited in the target impact area of ​​the divertor plate... 2 The extremely high heat flux density necessitates the introduction of cooling channel structures with higher heat exchange efficiency. Microchannel heat sinks possess advantages such as a large surface area to volume ratio, high heat dissipation efficiency per unit area, and high critical heat flux density, enabling efficient cooling of the divertor target plate in the impact point region and improving the safety and reliability of fusion device operation.

[0004] Chinese patent application publication number CN110729058 A discloses a high-heat-load unit component for a fusion reactor divertor based on microchannel phase change cooling. This invention uses a microchannel heat sink as a heat dissipation device for the divertor target plate. Utilizing the microscale effect and boiling heat transfer characteristics of the microchannel heat sink, the heat load on the surface of the divertor target plate can be removed quickly and effectively. However, in practical applications, the overall heat load of the divertor target plate is very large, requiring a high working fluid flow rate to reduce the fluid temperature rise. At high flow rates, microchannels generate significant flow resistance, making them unsuitable for use alone on a divertor target plate. Summary of the Invention

[0005] The purpose of this invention is to provide a divertor target plate cooled by a composite microchannel and supervaporization structure, addressing the problem of excessively high temperatures of plasma-facing materials in the impact region of a fusion reactor divertor target plate. This invention incorporates a microchannel structure within the supervaporization channel target plate for heat dissipation in the impact region, and optimizes the shape and connection method of the supervaporization channel fins to improve overall heat transfer performance, ultimately resulting in an optimized divertor target plate. This invention is particularly suitable for divertor target plates in magnetic confinement fusion tokamak devices, effectively reducing the surface temperature of the target plate's impact region during operation.

[0006] The technical solution to achieve the purpose of this invention is: a divertor target plate cooled by a composite microchannel and supervaporization structure, comprising a plasma-facing material layer, a stress buffer layer, a microchannel and supervaporization composite structure heat sink, and a stainless steel cover plate.

[0007] In the microchannel and supervaporization composite heat sink, the area corresponding to the impact point of the target plate is cooled by microchannel, while the remaining area corresponding to the target plate is cooled by supervaporization channel.

[0008] Furthermore, the plasma-facing material layer has a flat plate structure with a thickness of 1-10 mm, and the material is tungsten or a tungsten alloy.

[0009] Furthermore, the stress buffer layer has a flat plate structure with a thickness of 1-5 mm and is made of oxygen-free copper.

[0010] Furthermore, the heat sink material for the microchannel and supervaporization composite structure is either chromium zirconium copper (CuCrZr) or oxide dispersion strengthened copper alloy (ODS-Cu).

[0011] Furthermore, the microchannel has a double-layer channel. The upper channel is a microchannel with a hydraulic diameter of 0.1-2 mm, and the lower channel is a smooth channel without internal ribs. A gap is left between the fins of the upper channel and the upper surface of the dividing layer between the upper and lower channels.

[0012] Furthermore, the flow channels formed within the upper channel can be any one of the following: a straight rectangular arrangement, a gradually expanding rectangular arrangement, an orthogonal network structure, a tree-like fractal structure, or an alveolar structure.

[0013] Furthermore, the upper surface of the supervaporization channel is integrally provided with multiple parallel transverse ribs, with a gap between the bottom of the transverse ribs and the bottom surface of the supervaporization channel, and a groove is reserved between the two ends of the transverse ribs and the inner walls on both sides of the supervaporization channel. The shape of the transverse cross section of the transverse ribs is any one of rectangle, rounded rectangle, sine curve and triangle.

[0014] Furthermore, the supervaporization channel and the microchannel are connected by a U-shaped flow channel or directly.

[0015] Furthermore, when the supervaporization channel and the microchannel are connected by a U-shaped flow channel, the microchannel and the supervaporization channels on both sides are processed separately. The stainless steel cover plate on the lower side of the supervaporization channel is processed with a U-shaped channel with a rectangular cross-section in the part adjacent to the microchannel. The microchannel and the supervaporization channel are provided with end plates at their adjacent ends. Through the cooperation of the end plates and the U-shaped channels, the supervaporization channel and the microchannel are connected by a U-shaped flow channel.

[0016] Furthermore, the stress buffer layer is welded to the plasma-facing material layer and the heat sink of the microchannel and supervaporization composite structure on both sides, and the microchannel and supervaporization composite structure heat sink and the stainless steel cover plate are welded together.

[0017] Compared with the prior art, the significant advantages of this invention are:

[0018] (1) The present invention utilizes microchannel cooling technology to dissipate heat in the impact point area. This technology combines microscale effect and boiling heat transfer characteristics, and has high heat transfer capacity and extremely high critical heat flux density. It can effectively reduce the temperature of the impact point area of ​​the divertor target plate and improve the service life of the target plate.

[0019] (2) The present invention designs a double-layer microchannel structure heat sink for the target plate impact area of ​​a divertor. The heat sink has both high heat exchange efficiency and can maintain a small pressure drop under high flow rate.

[0020] (3) The present invention adopts a design method for divertor target plate cooling with composite microchannel and supervaporization structure, which can significantly improve the overall performance of divertor target plate.

[0021] (4) The present invention connects the microchannel structure and the supervaporization structure through a U-shaped flow channel, so that the gas-liquid two-phase flow is fully mixed in the U-shaped flow channel, thereby realizing the complete condensation of the bubbles in the supercooled liquid and avoiding channel blockage caused by the bubbles entering the microchannel structure. Attached Figure Description

[0022] Figure 1This is a schematic diagram of Example 1 of the divertor target plate cooled by the composite microchannel and supervaporization structure of the present invention, where a is an overall schematic diagram of the target plate structure, b is a cross-sectional view of the supervaporization channel region, and c is a cross-sectional view of the microchannel region.

[0023] Figure 2 Example 1 is a three-dimensional perspective view of the connection between the supervaporization channel region and the microchannel region.

[0024] Figure 3 This is a schematic diagram of Example 2 of the divertor target plate cooled by the composite microchannel and supervaporization structure of the present invention, where a is an overall schematic diagram of the target plate structure, b is a cross-sectional view of the supervaporization channel region, and c is a cross-sectional view of the microchannel region.

[0025] Figure 4 The diagram shows the numerical simulation results of the divertor target plate in Embodiment 1 of the present invention, where a is the temperature cloud map of the symmetry plane and b is the velocity vector map of the symmetry plane.

[0026] Explanation of reference numerals in the attached figures:

[0027] 1-Plasma-facing material layer, 2-Stress buffer layer, 3-Microchannel and supervaporization composite structure heat sink, 31-Microchannel, 32-Supervaporization channel, 33-Upper channel of microchannel structure, 34-Lower channel of microchannel structure, 4-Stainless steel cover plate, 5-Impact point area of ​​target plate, 6-Remaining area of ​​target plate, 7-U-shaped flow channel. Detailed Implementation

[0028] The present invention will now be described in further detail with reference to the accompanying drawings.

[0029] A divertor target plate cooled by a composite microchannel and supervaporization structure is disclosed. The divertor target plate structure includes a plasma-facing material layer 1, a stress buffer layer 2, a microchannel and supervaporization composite heat sink 3, and a stainless steel cover plate 4. The impact point region 5 (high heat load region) of the target plate is cooled by the microchannel structure 31, and the remaining region 6 (low heat load region) of the target plate is cooled by the supervaporization channel structure 32.

[0030] The plasma-facing material layer 1 has a flat plate structure with a thickness of 1-10 mm and is made of tungsten W or W alloy.

[0031] The stress buffer layer 2 is a flat plate structure with a thickness of 1-5 mm and is made of oxygen-free copper (Cu).

[0032] The microchannel structure 3 is made of chromium zirconium copper CuCrZr or oxide dispersion strengthened copper alloy ODS-Cu.

[0033] The microchannel 31 has a double-layer channel. The upper channel 33 is a microchannel with a hydraulic diameter of 0.1-2 mm, and the lower channel 34 is a smooth channel without internal ribs.

[0034] The upper channel 33 can be any one of the following: a straight rectangular arrangement, a gradually expanding rectangular arrangement, an orthogonal network structure, a tree-like fractal structure, or an alveolar structure.

[0035] The supervaporization channel 32 is made of CuCrZr or ODS-Cu.

[0036] The transverse inner rib shape of the supervaporization channel 32 can be any one of a rectangle, a rounded rectangle, a sine curve, or a triangle.

[0037] The supervaporization channel 32 and the microchannel 31 are connected by a U-shaped flow channel or directly. The U-shaped flow channel is machined on a stainless steel cover plate and has a rectangular cross-section.

[0038] The stress buffer layer 2 is welded to the plasma-facing material layer 1 and the heat sink of the microchannel and supervaporization composite structure on both sides respectively.

[0039] Example 1

[0040] like Figure 1 As shown, Figure 1 A preferred embodiment of a divertor target plate cooled by a composite microchannel and supervaporization structure is provided:

[0041] The divertor target plate preferably has a 5mm thick W material layer 1 facing the plasma, a 1mm thick oxygen-free Cu stress buffer layer 2, a CuCrZr material for the microchannel and supervaporization composite heat sink 3, and a 316L stainless steel cover plate structure 4. The overall length of the target plate is 1400mm. The microchannel structure 31 has a double-layer channel. The upper channel 33 is a microchannel, which can be any one of the following: a straight rectangular arrangement, a gradually expanding rectangular arrangement, an orthogonal network structure, a tree-like fractal structure, or an alveolar structure. It is preferably an open straight rectangular microchannel with a length of 56mm, a height of 1mm, a width of 0.3mm, a spacing of 0.3mm, and a gap of 0.3mm between the fins and the bottom surface of the channel. The lower channel 34 is a smooth channel without internal ribs, preferably a rectangular channel with a height of 3mm and a width of 51.9mm. The transverse ribs of the supervaporization channel 32 are designed to be rectangular, rounded rectangular, sinusoidal, or triangular, preferably rectangular, depending on requirements. The rib height is 5mm, the width is 2.2mm, the spacing is 9.7mm, the gap between the ribs and the bottom surface of the channel is 8mm, and there are 5mm wide grooves on both sides. The supervaporization channel 32 is connected to the microchannel 31 by a U-shaped flow channel. The U-shaped flow channel is machined on a stainless steel cover plate, and its cross-section is rectangular. The inlet cross-section is 45.5mm long and 15mm wide, the outlet cross-section is 45.5mm long and 18mm wide, the distance between the inlet and outlet is 8mm, and the radius of its flow channel corners is 5mm; as shown in Figure 2. The stress buffer layer 2 is welded to the plasma-facing material layer 1 and the heat sink 3 of the microchannel and supervaporization composite structure on both sides, respectively.

[0042] An experiment was conducted, with the inlet working fluid flow rate set at 5.4 m³ / s. 3 / h, temperature 25℃, impact point set at the 4th W plate in the high heat load zone, applying 20MW / m 2 The heat flux density, the result is as follows Figure 3 As shown, from Figure 3 As can be seen from part a, the highest temperature of material W is 1000.5℃, which does not exceed the recrystallization temperature of 1200℃, while the pressure drop is only 0.2MPa. From Figure 3 As can be seen from part b, the working fluid is fully mixed in the U-shaped flow channel, causing the bubbles in the supervaporization structure to condense and disappear in the subcooled mainstream, which will not affect the heat exchange in the subsequent microchannel structure.

[0043] Example 2

[0044] like Figure 2 As shown, Figure 2 Another preferred embodiment of a divertor target plate cooled by a composite microchannel and supervaporization structure is presented:

[0045] The difference between Example 2 and Example 1 is that the upper channel 33 of the microchannel 31 has a length of 12mm and a width of 45.5mm, while the lower channel 34 has a height of 2mm and a width of 45.5mm. The gap between the transverse ribs and the bottom surface of the supervaporization channel 32 is 3mm. The supervaporization channel 32 is directly connected to the microchannel 31.

[0046] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A composite microchannel and super boil-off structure cooled depleting filter target plate characterized by, It comprises a plasma-facing material layer (1), a stress buffer layer (2), a micro-channel and super-boiling composite structure heat sink (3) and a stainless steel cover plate (4); The micro-channel and super-boiling composite structure heat sink (3) is cooled by micro-channels (31) corresponding to the impact point area (5) of the target plate, and is cooled by super-boiling channels (32) corresponding to the remaining area (6) of the target plate.

2. The filter target of claim 1, wherein The plasma-facing material layer (1) is a flat plate structure with a thickness of 1-10 mm and is made of tungsten or tungsten alloy.

3. The filter target of claim 1, wherein The stress buffer layer (2) is a flat plate structure with a thickness of 1-5 mm and is made of oxygen-free copper.

4. The filter target of claim 1, wherein The micro-channel and super-boiling composite structure heat sink (3) is made of chromium-zirconium-copper CuCrZr or oxide dispersion strengthened copper alloy ODS-Cu.

5. The filter target of claim 1, wherein The micro-channel (31) has a double-layer channel, the upper layer channel (33) is a micro-channel with a hydraulic diameter of 0.1-2 mm, and the lower layer channel (34) is a smooth channel without internal ribs.

6. The filter target of claim 5, wherein The flow channel formed in the upper layer channel (33) is any one of a straight rectangular arrangement, a gradually expanding rectangular arrangement, an orthogonal network structure, a tree-like fractal structure, and an alveolar structure.

7. The filter target of claim 6, wherein The upper surface of the super-boiling channel (32) is integrally provided with a plurality of parallel transverse fins, a gap is left between the bottom of the transverse fin and the bottom surface of the super-boiling channel (32), a groove is formed by reserving space between the two ends of the transverse fin and the inner walls on both sides of the super-boiling channel (32), and the shape of the transverse cross section of the transverse fin is any one of a rectangle, a rounded rectangle, a sinusoidal curve, and a triangle.

8. The filter target of claim 1, wherein The super-boiling channel (32) is connected to the micro-channel (31) by a U-shaped flow channel or directly.

9. The filter target of claim 8, wherein, When the super-boiling channel (32) is connected to the micro-channel (31) by a U-shaped flow channel, the micro-channel (31) and the super-boiling channels (32) on both sides thereof are processed separately, the lower side of the super-boiling channel (32) corresponds to a part of the stainless steel cover plate adjacent to the micro-channel, and a U-shaped channel with a rectangular cross section is machined in the part, end plates are arranged at the ends of the micro-channel (31) and the super-boiling channel (32), and the super-boiling channel (32) is connected to the micro-channel (31) by the cooperation of the end plates and the U-shaped channel.

10. The filter target of claim 9, wherein, The stress buffer layer (2) is welded to the plasma-facing material layer (1) and the micro-channel and super-boiling composite structure heat sink (3) on both sides thereof, and the micro-channel and super-boiling composite structure heat sink (3) and the stainless steel cover plate (4) are welded.

Images