Cooling structure and single crystal furnace

Abstract

The utility model discloses a cooling structure and a single crystal furnace, the cooling structure is applied to the cooling of a crystal bar in the single crystal furnace, the cooling structure comprises a first annular cooling part and a second annular cooling part, the central axis of the first annular cooling part and the central axis of the second annular cooling part are coaxially arranged; the first annular cooling part is positioned above a crucible in the single crystal furnace, and the second annular cooling part is positioned above the first annular cooling part. According to the cooling structure and the single crystal furnace disclosed by the utility model, through the matching of the first annular cooling part and the second annular cooling part, the cooling effect of the cooling structure is improved, and the effects of increasing the growth pulling speed of a crystal bar and improving crystal formation are achieved.

Description

Technical Field

[0001] This utility model belongs to the field of single crystal furnace technology, specifically relating to a cooling structure and a single crystal furnace. Background Technology

[0002] Water-cooled screens (also known as water-cooled hot screens) are an important component of single crystal furnaces. This device is located inside the single crystal furnace and is filled with circulating cooling water. The cooling water carries away the latent heat of crystallization of the crystal rods, thereby accelerating the growth rate of the crystal rods, increasing equipment capacity, reducing energy consumption, and lowering production costs.

[0003] In the current photovoltaic industry, silicon crystals are grown at high temperatures (above 1400℃), and continuous cooling is required during the Czochralski process to form crystal rods. However, the cooling effect of the current water-cooled screens cannot meet the growing industry demand.

[0004] The information disclosed in this background section is intended only to enhance the understanding of the overall background of this utility model and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Utility Model Content

[0005] The purpose of this invention is to provide a cooling structure and a single crystal furnace that can improve the cooling effect, thereby increasing the growth rate of crystal rods and improving crystal formation.

[0006] To achieve the above objectives, a specific embodiment of this utility model provides the following technical solution: a cooling structure applied to the cooling of a crystal rod in a single crystal furnace, characterized in that the cooling structure includes a first annular cooling section and a second annular cooling section, wherein the central axis of the first annular cooling section is coaxially arranged with the central axis of the second annular cooling section; the first annular cooling section is located above the crucible in the single crystal furnace, and the second annular cooling section is located above the first annular cooling section.

[0007] In one or more embodiments of the present invention, the minimum inner diameter of the second annular cooling portion is greater than or equal to the minimum inner diameter of the first annular cooling portion.

[0008] In one or more embodiments of this utility model, the inner diameter of the second annular cooling part is a fixed value, the inner diameter of the bottom of the first annular cooling part is the minimum inner diameter, the inner diameter of the top is the maximum inner diameter, and the inner diameter of the second annular cooling part is greater than or equal to the minimum inner diameter of the first annular cooling part and less than the maximum inner diameter of the first annular cooling part.

[0009] In one or more embodiments of the present invention, the minimum inner diameter of the first annular cooling portion is between 310mm and 366mm, the maximum inner diameter of the first annular cooling portion is between 500mm and 580mm; and / or, the inner diameter of the second annular cooling portion is between 310mm and 366mm.

[0010] In one or more embodiments of the present invention, there is an overlapping area between the top of the first annular cooling portion and the bottom of the second annular cooling portion, wherein the height h of the overlapping area is less than or equal to 31 mm.

[0011] In one or more embodiments of the present invention, the height of the second annular cooling portion is between 200mm and 450mm; and / or, the distance between the top surface of the second annular cooling portion and the top surface of the first annular cooling portion is less than or equal to 419mm.

[0012] In one or more embodiments of the present invention, the first annular cooling section has a first cooling chamber for containing coolant, the second annular cooling section has a second cooling chamber for containing coolant, and the first cooling chamber and the second cooling chamber are in communication.

[0013] In one or more embodiments of this utility model, the cooling structure further includes an inlet pipe, a connecting pipe, and an outlet pipe. The inlet pipe is connected to the second cooling chamber, the connecting pipe is connected to the first cooling chamber and the second cooling chamber, and the outlet pipe is connected to the first cooling chamber. When the cooling structure is working, the coolant passes through the inlet pipe, the second cooling chamber, the connecting pipe, the first cooling chamber, and the outlet pipe in sequence.

[0014] In one or more embodiments of this utility model, the second annular cooling section is fixed above the first annular cooling section by the water inlet pipe, the connecting pipe and the water outlet pipe.

[0015] In one or more embodiments of this utility model, an observation window is provided at the bottom of the second annular cooling section. The observation window extends upward from the bottom surface of the second annular cooling section by a predetermined distance s. The predetermined distance s and the height h of the overlapping area satisfy the following relationship: sh ≥ 105 mm.

[0016] A specific embodiment of this utility model also provides a single crystal furnace, including a furnace body, a furnace cover, and a cooling structure as described above, wherein the cooling structure is located within the furnace cavity formed by the furnace body and the furnace cover.

[0017] Compared with the prior art, the cooling structure and single crystal furnace of this utility model improve the cooling performance of the entire cooling structure and increase the heat dissipation efficiency of the crystal rod through the cooperation of the first annular cooling part and the second annular cooling part, thereby achieving the effect of increasing the crystal rod growth rate and improving crystal formation. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a three-dimensional schematic diagram of the cooling structure in Embodiment 1 of this utility model;

[0020] Figure 2 This is a front view of the cooling structure in Embodiment 1 of this utility model;

[0021] Figure 3 This is a cross-sectional view of the cooling structure in Embodiment 1 of this utility model;

[0022] Figure 4 This is a partial cross-sectional view of the cooling structure in Embodiment 1 of this utility model;

[0023] Figure 5 This is a perspective view of the second annular cooling section in Embodiment 1 of this utility model;

[0024] Figure 6 This is a partial cross-sectional view of the single crystal furnace in Embodiment 1 of this utility model;

[0025] Figure 7 This is a schematic diagram of the interior of the second annular cooling section in Embodiment 2 of this utility model.

[0026] Explanation of key figure labels:

[0027] 100. Cooling structure; 110. First annular cooling section; 111. First cavity; 112. First outer wall; 113. Second outer wall; 114. First opening; 115. Second opening; 116. First cooling chamber; 120. Second annular cooling section; 121. Second cavity; 122. Second liquid inlet; 123. Second liquid outlet; 124. Second cooling chamber; 125. Second guide plate; 126. Observation window; 131. Water inlet pipe; 132. Connecting pipe; 133. Water outlet pipe; 200. Furnace cover; 210. Throat. Detailed Implementation

[0028] To enable those skilled in the art to better understand the technical solutions of this utility model, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of this utility model.

[0029] As mentioned in the background section, water-cooled screens are commonly used in single crystal furnaces as cooling structures for cooling crystal rods. The cooling structure of this invention is part of a single crystal furnace, which is a device that melts polycrystalline materials such as polycrystalline silicon using a graphite heater in an inert gas environment (mainly nitrogen and helium) and grows dislocation-free single crystals using the Czochralski method.

[0030] Example 1

[0031] like Figures 1 to 3 As shown, in one embodiment of the present invention, the single crystal furnace includes a furnace body (not shown in the figure), a furnace cover 200, and a cooling structure 100. The cooling structure 100 is located within the furnace cavity formed by the furnace body and the furnace cover 200. The single crystal furnace also includes a crucible (not shown in the figure) disposed within the furnace cavity.

[0032] The cooling structure 100 includes a first annular cooling section 110 and a second annular cooling section 120. The central axis of the first annular cooling section 110 and the central axis of the second annular cooling section 120 are coaxially arranged. The first annular cooling section 110 is located above the crucible in the single crystal furnace, and the second annular cooling section 120 is located above the first annular cooling section 110.

[0033] It should be noted that the crystal rod can be a single-crystal silicon rod, etc. Taking a single-crystal silicon rod as an example, during the crystal pulling process, the single-crystal silicon rod is formed from the silicon liquid in the crucible at the bottom of the single-crystal furnace through the crystal pulling process and passes through the first annular cooling section 110 and the second annular cooling section 120. The main function of the first annular cooling section 110 and the second annular cooling section 120 is to cool the crystal rod as it passes through. The cooling structure 100 of this utility model increases the cooling distance of the cooling structure 100 on the crystal rod in the vertical direction (i.e., the direction corresponding to the central axis of the first annular cooling section 110) by the upper and lower arranged first annular cooling section 110 and second annular cooling section 120, thereby increasing the cooling effect of the cooling structure 100 on the crystal rod.

[0034] The fact that the central axis of the first annular cooling section 110 is coaxial with the central axis of the second annular cooling section 120 can minimize the size of the entire cooling structure 100 and facilitate the passage of the crystal rod through the first annular cooling section 110 and the second annular cooling section 120.

[0035] In this invention, the first annular cooling section 110 is equivalent to a water-cooled screen in the prior art. The first annular cooling section 110 of this invention can be directly selected from the common water-cooled screen structure on the market. Therefore, this invention can directly add a second annular cooling section 120 to the existing water-cooled screen structure on the market to obtain the cooling structure 100 of this invention.

[0036] Specifically, in this embodiment, the inner wall of the first annular cooling section 110 forms a first cavity 111 with openings at both ends, and the inner wall of the second annular cooling section 120 forms a second cavity 121 with openings at both ends. Both the first cavity 111 and the second cavity 121 are used for the crystal rod to pass through.

[0037] like Figures 1 to 3 In this embodiment, the first annular cooling section 110 has a first opening 114 and a second opening 115 at its top and bottom, respectively, which communicate with the first cavity 111. The inner diameter of the first annular cooling section 110 gradually decreases from the top to the bottom. Therefore, the diameter of the first opening 114 is the maximum inner diameter of the first annular cooling section 110, and the diameter of the second opening 115 is the minimum inner diameter of the first annular cooling section 110.

[0038] like Figure 3 As shown, the opening sizes at both ends of the second annular cooling section 120 are equal, and the inner diameter of the second annular cooling section 120 is a fixed value, that is, the inner diameter of the second annular cooling section 120 is equal from top to bottom.

[0039] In this embodiment, the inner diameter of the second annular cooling section 120 is equal to the minimum inner diameter of the first annular cooling section 110, and the inner diameter of the second annular cooling section 120 is smaller than the maximum inner diameter of the first annular cooling section 110.

[0040] Preferably, the minimum inner diameter of the first annular cooling section 110 is between 310mm and 366mm, the maximum inner diameter of the first annular cooling section 110 is between 500mm and 580mm, and the inner diameter of the second annular cooling section 120 is between 310mm and 366mm.

[0041] Taking a single crystal furnace for preparing 210N type crystal rods (with a diameter of 295mm) as an example, the inner diameter of the second annular cooling section 120 can be 360mm (the opening size at both ends of the second annular cooling section 120 is 360mm), which ensures safe feeding while effectively removing heat from the crystal rod. The inner diameter of the second annular cooling section 120 can be adjusted according to the actual size of the crystal rod.

[0042] In other embodiments, the inner diameter of the second annular cooling section 120 is larger than the inner diameter of the bottom of the first annular cooling section 110 (i.e., the diameter of the second opening 115), and the inner diameter of the second annular cooling section 120 is smaller than the inner diameter of the top of the first annular cooling section 110 (i.e., the diameter of the first opening 114).

[0043] In other embodiments, the inner diameter of the second annular cooling section 120 may not be a fixed value, but may be similar to the inner diameter of the first annular cooling section 110, that is, the inner diameter of the second annular cooling section 120 gradually decreases from the top to the bottom. In this case, the minimum inner diameter of the second annular cooling section 120 is greater than or equal to the minimum inner diameter of the first annular cooling section 110.

[0044] like Figure 4 As shown, the bottom of the second annular cooling section 120 is partially inserted into the first cavity 111 at the top of the first annular cooling section 110. Therefore, there is an overlapping area between the top of the first annular cooling section 110 and the bottom of the second annular cooling section 120. The height h of the overlapping area is less than or equal to 31 mm. This arrangement can further ensure the cooling effect of the cooling structure 100.

[0045] Preferably, the height of the second annular cooling section 120 is between 200mm and 450mm. The height of the second annular cooling section 120 is the dimension of the second annular cooling section 120 along its axial direction.

[0046] Preferably, the distance between the top surface of the second annular cooling section 120 and the top surface of the first annular cooling section 110 is less than or equal to 419 mm.

[0047] In addition, the outer side of the bottom of the second annular cooling section 120 in this embodiment is provided with a slope, which serves to avoid the first annular cooling section 110.

[0048] During the crystal pulling process, it is generally necessary to use a camera to measure parameters such as the diameter and temperature of the crystal rod. The camera can capture images of the crystal rod and the liquid surface of the molten silicon in the single crystal furnace, thereby obtaining parameters such as the diameter and temperature of the crystal rod. Therefore, an observation window 126 is provided on the second annular cooling section 120 in this embodiment.

[0049] Specifically, such as Figure 1 , Figure 4 and Figure 5 As shown, the observation window 126 is disposed at the bottom of the second annular cooling section 120. The observation window 126 extends upward from the bottom surface of the second annular cooling section 120 by a predetermined distance s. In this embodiment, the predetermined distance s and the height h of the overlapping area satisfy the following relationship: sh ≥ 105 mm.

[0050] like Figure 1 , Figure 2 , Figure 3 and Figure 6 As shown, the outer wall of the first annular cooling section 110 includes a first outer wall 112 and a second outer wall 113 along its top to bottom direction. Along its top to bottom direction, the outer diameter of the first outer wall 112 is the same, while the outer diameter of the second outer wall 113 gradually decreases.

[0051] like Figure 6 As shown, in this embodiment, the outer diameter of the top of the first annular cooling section 110 is larger than the outer diameter of the bottom. The furnace cover 200 has a throat 210. The outer diameter of the top of the first annular cooling section 110 is larger than the inner diameter of the throat 210 on the furnace cover 200. During operation, the cooling structure 100 sometimes needs to move up and down along its axial direction. When the first annular cooling section 110 moves up and down, its top cannot be inserted into the throat 210. When the size of the single crystal furnace is fixed, that is, when the inner diameter of the throat 210 on the furnace cover 200 is fixed, the maximum value of the axial length of the first annular cooling section 110 is limited by the axial dimension of the single crystal furnace. That is, the cooling length and area of ​​the first annular cooling section 110 on the crystal rod in the axial direction are fixed. Under the condition that other conditions remain unchanged, the cooling effect cannot be improved by increasing the axial length of the first annular cooling section 110.

[0052] To solve the above problems, such as Figure 5 As shown, the projection area of ​​the second annular cooling section 120 in the single crystal furnace of this invention on the radial section of the throat 210 is located inside the throat 210, that is, the outer diameter of the top of the second annular cooling section 120 is smaller than the inner diameter of the throat 210. When the cooling structure 100 needs to move up and down along its axial direction, the second annular cooling section 120 can be inserted into the throat 210. Without changing the existing single crystal furnace, compared with the existing water-cooled screen, the axial cooling length and cooling area of ​​the cooling structure 100 of this invention are increased, thereby improving the cooling effect of the cooling structure 100.

[0053] like Figure 3 As shown, the outer wall and inner wall of the first annular cooling section 110 cooperate to form a first cooling cavity 116. The first cooling cavity 116 is not connected to the first cavity 111. The cooling cavity can contain coolant, thereby improving the cooling effect of the first annular cooling section 110.

[0054] like Figure 3 and Figure 5 As shown, in this embodiment, the outer wall and inner wall of the second annular cooling section 120 cooperate to form a second cooling cavity 124. The inner wall of the second annular cooling section 120 forms a second cavity 121 with openings at both ends. The second cavity 121 is used for the crystal rod to pass through. The second cooling cavity 124 is not connected to the second cavity 121. The cooling cavity can contain coolant, thereby improving the cooling effect of the second annular cooling section 120.

[0055] Preferably, the coolant in this embodiment is cooling water.

[0056] like Figures 1 to 3 As shown, the cooling structure 100 in this embodiment further includes an inlet pipe 131, a connecting pipe 132, and an outlet pipe 133. The inlet pipe 131 is connected to the second cooling chamber 124, the connecting pipe 132 is connected to the first cooling chamber 116 and the second cooling chamber 124, and the outlet pipe 133 is connected to the first cooling chamber 116. When the cooling structure 100 is working, the coolant passes sequentially through the inlet pipe 131, the second cooling chamber 124, the connecting pipe 132, the first cooling chamber 116, and the outlet pipe 133. This improves the cooling effect of the entire cooling structure 100.

[0057] The first annular cooling section 110 has a first liquid inlet (not shown) and a first liquid outlet (not shown) connected to the first cooling chamber 116 on its inner wall. The second annular cooling section 120 has a second liquid inlet 122 and a second liquid outlet 123 connected to the second cooling chamber 124 on its outer wall. The second liquid outlet 123 is connected to the first liquid inlet via a connecting pipe 132. The water inlet pipe 131 is connected to the second liquid inlet 122, and the water outlet pipe 133 is connected to the second liquid outlet 123. In this embodiment, the coolant enters through the water inlet pipe 131 and exits through the water outlet pipe 133.

[0058] One end of the connecting pipe 132 is fixedly installed on the inner wall of the first annular cooling section 110, and the other end is fixedly installed on the outer wall of the second annular cooling section 120. This arrangement reduces the space occupied by the entire cooling structure 100 and improves the mechanical connection strength and stability between the first annular cooling section 110 and the second annular cooling section 120. One end of the water outlet pipe 133 is fixedly installed on the outer wall of the first annular cooling section 110, and the other end of the water outlet pipe 133 is connected to the first cooling chamber 116 inside the first annular cooling section 110.

[0059] Furthermore, the water outlet pipe 133 is fixedly installed on the outer wall of the second annular cooling section 120. This fixed installation refers to a mechanical connection, designed to enhance the strength and stability of the mechanical connection between the water outlet pipe 133 and the second annular cooling section 120. The second cooling chamber 124 of the second annular cooling section 120 is not directly connected to the water outlet pipe 133; instead, the second cooling chamber 124 is connected to the water outlet pipe 133 through the first cooling chamber 116 of the first annular cooling section 110. Preferably, the water outlet pipe 133 and the outer wall of the second annular cooling section 120 can be connected using commercially available connectors or connection structures.

[0060] Furthermore, the connecting pipe 132 is arranged close to and connected to the water inlet pipe 131. The connection between the connecting pipe 132 and the water inlet pipe 131 is a mechanical connection, intended to enhance the strength and stability of the mechanical connection between the pipes and between the pipes and the second annular cooling section 120 and the first annular cooling section 110. The connecting pipe 132 and the water inlet pipe 131 are not directly connected; they are connected through the second cooling chamber 124 of the second annular cooling section 120. Preferably, the connecting pipe 132 and the water inlet pipe 131 can be connected using commercially available connectors or connection structures.

[0061] In this embodiment, the water inlet pipe 131 and the water outlet pipe 133 are respectively located on opposite sides of the second annular cooling section 120; in other embodiments, the water inlet pipe 131 and the water outlet pipe 133 may be located on the same side of the second annular cooling section 120 or at other locations.

[0062] In other embodiments, the cooling structure 100 may include an inlet pipe 131 and an outlet pipe 133. The first cooling chamber 116 is directly connected to the inlet pipe 131 and the outlet pipe 133, and the second cooling chamber 124 is also directly connected to the inlet pipe 131 and the outlet pipe 133. That is, the inlet pipe 131 can deliver coolant to the first cooling chamber 116 and the second cooling chamber 124 respectively, and the coolant in the first cooling chamber 116 and the second cooling chamber 124 is discharged through the outlet pipe 133 respectively.

[0063] In other embodiments, the cooling structure 100 includes only an inlet pipe 131 and an outlet pipe 133. The inlet pipe 131 is directly connected to the second cooling chamber 124, and the outlet pipe 133 is directly connected to the first cooling chamber 116. The first cooling chamber 116 and the second cooling chamber 124 are connected by other structures, such as connecting pipes.

[0064] Furthermore, such as Figure 1 and Figure 2 As shown, there is a certain distance between the connection points of the water inlet pipe 131 and the water outlet pipe 133 with the second annular cooling section 120 and the top of the second annular cooling section 120. This arrangement is so that when the cooling structure 100 needs to move up and down along its axis during operation, the top of the second annular cooling section 120 can be inserted into the throat 210 on the furnace cover 200.

[0065] Example 2

[0066] The cooling structure in this embodiment is basically the same as that in Embodiment 1, except that: at least one first guide plate (not shown in the figure) is provided between the outer wall and the inner wall of the first annular cooling section 110 in this embodiment to divide the first cooling chamber 116 into several interconnected flow channels. That is, through the cooperation of the first guide plate, the outer wall and the inner wall of the first annular cooling section 110, the first cooling chamber 116 is divided into several interconnected flow channels, thereby ensuring that the coolant can fill the entire first cooling chamber 116 and improve the cooling performance of the coolant in the first cooling chamber 116. The flow channels can be connected end-to-end, or the flow channels can be serpentine or spiral structures. Specifically, the structure of the first guide plate in the first annular cooling section 110 can refer to the internal structure of the water-cooled jacket in the prior art, and will not be discussed in detail here.

[0067] like Figure 7 As shown, in this embodiment, at least one second guide plate 125 is provided between the outer wall and the inner wall of the second annular cooling section 120 to divide the second cooling chamber 124 into several interconnected flow channels. That is, through the cooperation of the second guide plate 125 and the outer and inner walls of the second annular cooling section 120, the second cooling chamber 124 is divided into several interconnected flow channels, thereby ensuring that the coolant can fill the entire second cooling chamber 124 and improve the cooling performance of the second cooling chamber 124. Figure 7 The dashed lines with arrows indicate the direction of coolant flow.

[0068] In other embodiments, the number, position, structural shape, and interconnection of the multiple second diversion plates 125, as well as the number, position, structural shape, and interconnection of the multiple diversion channels, can be adjusted and designed, as long as it can ensure that the coolant fills the entire second cooling chamber 124 as much as possible.

[0069] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0070] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A cooling structure for cooling crystal rods in a single crystal furnace, characterized in that, The cooling structure includes a first annular cooling section and a second annular cooling section, wherein the central axis of the first annular cooling section and the central axis of the second annular cooling section are coaxially arranged; the first annular cooling section is located above the crucible in the single crystal furnace, and the second annular cooling section is located above the first annular cooling section.

2. The cooling structure according to claim 1, characterized in that, The inner diameter of the second annular cooling section is greater than or equal to the minimum inner diameter of the first annular cooling section.

3. The cooling structure according to claim 2, characterized in that, The inner diameter of the second annular cooling section is a fixed value. The inner diameter of the bottom of the first annular cooling section is the minimum inner diameter, and the inner diameter of the top is the maximum inner diameter. The inner diameter of the second annular cooling section is greater than or equal to the minimum inner diameter of the first annular cooling section, and less than the maximum inner diameter of the first annular cooling section.

4. The cooling structure according to claim 2, characterized in that, The minimum inner diameter of the first annular cooling section is between 310 mm and 366 mm, and the maximum inner diameter of the first annular cooling section is between 500 mm and 580 mm; and / or, the inner diameter of the second annular cooling section is between 310 mm and 366 mm.

5. The cooling structure according to claim 2, characterized in that, There is an overlapping area between the top of the first annular cooling section and the bottom of the second annular cooling section, and the height h of the overlapping area is less than or equal to 31 mm.

6. The cooling structure according to claim 1, characterized in that, The height of the second annular cooling section is between 200mm and 450mm; and / or the distance between the top surface of the second annular cooling section and the top surface of the first annular cooling section is less than or equal to 419mm.

7. The cooling structure according to claim 1, characterized in that, The first annular cooling section has a first cooling chamber for containing coolant, and the second annular cooling section has a second cooling chamber for containing coolant. The first cooling chamber and the second cooling chamber are in communication.

8. The cooling structure according to claim 7, characterized in that, The cooling structure further includes an inlet pipe, a connecting pipe, and an outlet pipe. The inlet pipe is connected to the second cooling chamber, the connecting pipe is connected to the first cooling chamber and the second cooling chamber, and the outlet pipe is connected to the first cooling chamber. When the cooling structure is working, the coolant passes through the inlet pipe, the second cooling chamber, the connecting pipe, the first cooling chamber, and the outlet pipe in sequence.

9. The cooling structure according to claim 8, characterized in that, The second annular cooling section is fixed above the first annular cooling section via the inlet pipe, the connecting pipe, and the outlet pipe.

10. The cooling structure according to claim 5, characterized in that, An observation window is provided at the bottom of the second annular cooling section. The observation window extends upward from the bottom surface of the second annular cooling section by a predetermined distance s. The predetermined distance s and the height h of the overlapping area satisfy the following relationship: sh ≥ 105 mm.

11. A single crystal furnace, characterized in that, It includes a furnace body, a furnace cover, and a cooling structure as described in any one of claims 1 to 10, wherein the cooling structure is located within the furnace cavity formed by the furnace body and the furnace cover.

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