Cooling unit

Abstract

The utility model relates to the technical field of refrigerating systems, in particular to a cooling unit. The cooling assembly comprises a frame and an axial flow fan, the frame comprises an installation box body and an air inlet box body which are connected with each other, the axial flow fan is installed in the installation box body, a heat exchange layer and a noise reduction layer are arranged in the side wall of the air inlet box body, a heat exchanger is arranged in the heat exchange layer, and a plurality of noise reduction blades are arranged in the noise reduction layer. The multiple silencing blades are arranged at intervals in the axis direction of the air inlet box body, and gaps between the silencing blades communicate with the air inlet cavity. The air inlet box has the advantages that the heat exchange layer and the noise reduction layer are arranged in the side wall of the air inlet box body, so that air entering the air inlet cavity in the air inlet box body from the external environment must be subjected to heat exchange through the heat exchange layer, and noise spread outwards from the air inlet cavity also must be subjected to noise reduction through the noise reduction layer. According to the cooling assembly, the specific structure and the arrangement angle of the silencing blades in the silencing layer are reasonably arranged, the noise reduction effect is maximized while air entering is not affected by the silencing blades, and therefore the overall use experience of the cooling assembly is optimized.

Description

Technical Field

[0001] The utility model relates to the technical field of refrigeration systems, in particular to a cooling unit. Background Art

[0002] The cooling unit is a key equipment in the reactor building of a nuclear power plant. It can provide a suitable temperature and humidity environment for the normal operation of the reactor building of a nuclear power plant and during shutdown and refueling.

[0003] In order to ensure that the temperature of the reactor building of a nuclear power plant meets the requirements, high-power axial flow fans are usually used in the cooling units, but at the same time, the axial flow fans bring a lot of noise when working. Utility Model Content

[0004] Based on this, the utility model provides a cooling unit for the above technical problems.

[0005] 14. The cooling unit as claimed in claim 13, wherein the cooling unit comprises: a frame, comprising an installation box and an air inlet box, the installation box and the air inlet box being connected, the installation box being provided with an installation cavity, and the air inlet box being provided with an air inlet cavity; an axial flow fan being installed in the installation cavity, and the air inlet and air outlet of the axial flow fan being arranged along the axial direction of the installation cavity, and the air inlet cavity is located on a side of the axial flow fan where the air inlet is opened, and the air inlet connects the air outlet and the air inlet cavity; the air inlet box has an inner side close to the axis and an outer side far away from the axis, a heat exchange layer and a sound absorbing layer are sequentially arranged in the side walls of the air inlet box along the direction from the inside to the outside, a heat exchanger is provided in the heat exchange layer, and a plurality of sound absorbing blades are provided in the sound absorbing layer, and the plurality of sound absorbing blades are arranged at intervals along the axial direction of the air inlet box, and the gaps between the sound absorbing blades are connected to the air inlet cavity.

[0006] With such a configuration, the air inlet and air outlet of the axial flow fan are arranged along the axial direction of the installation cavity. Therefore, when the axial flow fan is working, the air flows from the air inlet to the air outlet, that is, along the axial direction of the installation cavity. Because the air inlet cavity is connected to the installation cavity, the air first enters the air inlet cavity, then enters the axial flow fan from the air inlet, and finally flows out from the air outlet, forming an air flow path that flows along the axial direction of the installation box. The heat exchanger arranged in the side wall of the air inlet box is used to contact and exchange heat with the air, and the silencer blades are used to collide with the noise emitted by the axial flow fan, stop the propagation path of the noise sound wave, and consume the energy after multiple reflections, thereby reducing the noise. The heat exchanger is arranged in the heat exchange layer, and the silencer blades are arranged in the silencer layer to avoid interference between the two structures. The noise sound wave propagation of the axial flow fan needs to pass through the heat exchanger, and the heat exchanger collides with the sound wave to dissipate energy, which can also achieve a certain noise reduction effect.

[0007] In one embodiment, the noise reduction blades are all arranged at an inclination, and an end of the noise reduction blade away from the mounting box is located on the inner side of an end of the noise reduction blade close to the mounting box.

[0008] In one embodiment, the angle between the silencer blade and the horizontal direction is α, and α satisfies: 40°≤α≤60°.

[0009] In one embodiment, the chord length of the silencer blade is H, and the axial spacing between two adjacent silencer blades is L, satisfying 0.8≤H / L≤1.5.

[0010] In one embodiment, the spacing between adjacent noise reduction blades gradually increases along the axial direction away from the mounting box.

[0011] In one embodiment, along the axial direction of the mounting box, the distance between two adjacent silencer blades closest to one end of the mounting box is defined as L1, and the distance between two adjacent silencer blades farthest from one end of the mounting box is defined as L2, satisfying 1.15L1≤L2≤1.2L1.

[0012] In one embodiment, the noise reduction blade is a hollow structure.

[0013] In one embodiment, the axial flow fan includes a first guide vane, an impeller and a second guide vane, and the axial flow fan is configured with an air duct, which extends from one end of the axial flow fan to the other end along the axial direction of the axial flow fan, the end of the air duct close to the air inlet cavity is the air inlet, and the end of the air duct away from the air inlet cavity is the air outlet, the first guide vane is connected to the inner wall of the air duct formed by the axial flow fan, and is located on the side of the impeller close to the air inlet, and the second guide vane is connected to the inner wall of the air duct and is located on the side of the impeller close to the air outlet.

[0014] In one embodiment, the axial flow fan further includes a guide cover, which is located in the air duct and connected to a side of the first guide vane facing the air inlet, and the guide cover is configured as a micro-perforated plate structure.

[0015] In one embodiment, the air inlet box is configured as a rectangular frame structure, and the air inlet box has four side surfaces, and each of the side surfaces is sequentially provided with a heat exchange layer and a sound absorbing layer along a direction from the inside to the outside.

[0016] In one embodiment, the heat exchanger includes heat exchange fins and a heat exchange unit, the heat exchange unit is connected to the heat exchange fins, a plurality of heat exchange tubes are provided in the heat exchange unit, and the heat exchange tubes are passed through the heat exchange holes.

[0017] Compared with the prior art, the present application makes the air flow path more suitable for axial flow fans by setting up an axially arranged installation box and an air inlet box. In addition, a heat exchange layer and a sound-absorbing layer are set in the side wall of the air inlet box, so that the air entering the air inlet cavity in the air inlet box from the external environment must pass through the heat exchange layer for heat exchange, and the noise propagating outward from the air inlet cavity must also pass through the sound-absorbing layer for noise reduction. The specific structure and layout angle of the sound-absorbing blades in the sound-absorbing layer are also reasonably set, so that the sound-absorbing blades can maximize the noise reduction effect without affecting the air inlet, thereby optimizing the overall use experience of the cooling component. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A simplified structural diagram of one embodiment of the cooling unit provided by the utility model;

[0019] Figure 2 A schematic diagram of the structure of one embodiment of the cooling unit provided by the utility model;

[0020] Figure 3 A schematic diagram of the structure of the silencer blades of one embodiment of the cooling unit provided by the utility model;

[0021] Figure 4 A cross-sectional view of a muffler blade of one embodiment of a cooling unit provided by the utility model;

[0022] Figure 5 A partially enlarged cross-sectional view of a muffler blade of one embodiment of a cooling unit provided by the utility model;

[0023] Figure 6 A schematic structural diagram of an axial flow fan of one embodiment of a cooling unit provided by the utility model;

[0024] Figure 7 This is a schematic structural diagram of a heat exchanger in one embodiment of a cooling unit provided by the utility model.

[0025] The symbols in the figure mean the following:

[0026] 100. Cooling unit; 10. Frame; 11. Installation box; 111. Installation cavity; 12. Air inlet box; 121. Air inlet cavity; 13. Heat exchange layer; 14. Silence layer; 20. Axial fan; 21. Air inlet; 22. Air outlet; 23. First guide vane; 24. Air guide cover; 26. Air duct; 30. Heat exchanger; 31. Heat exchange unit; 32. Heat exchange tube; 33. Heat exchange fin; 34. Heat exchange hole; 40. Silence blade. DETAILED DESCRIPTION

[0027] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0028] It should be noted that when a mechanism is referred to as being "fixed to" or "set on" another mechanism, it may be directly on the other mechanism or there may be a central mechanism. When a mechanism is considered to be "connected to" another mechanism, it may be directly connected to the other mechanism or there may be a central mechanism at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in the specification of this application are for illustrative purposes only and do not represent the only implementation method.

[0029] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0030] In the present application, unless otherwise clearly specified and limited, a first feature being “above” or “below” a second feature may mean that the first feature is directly in contact with the second feature, or the first feature and the second feature are indirectly in contact through an intermediate medium. Moreover, a first feature being “above”, “above” or “above” a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being “below”, “below” or “below” a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0031] Unless otherwise defined, all technical and scientific terms used in the specification of this application have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The term "and / or" used in the specification of this application includes any and all combinations of one or more related listed items.

[0032] The utility model provides a cooling unit 100, which is applied to a refrigeration system in a nuclear reactor plant for heat exchange refrigeration and can also reduce the noise of an axial flow fan 20 therein.

[0033] See also Figure 1-Figure 2 The cooling assembly includes a frame 10 and an axial flow fan 20. The frame 10 includes a mounting box 11 and an air inlet box 12. The mounting box 11 and the air inlet box 12 are connected. A mounting cavity 111 is provided in the mounting box 11. An air inlet cavity 121 is provided in the air inlet box 12. The mounting cavity 111 and the air inlet cavity 121 are connected. The axial flow fan 20 is installed in the mounting cavity 111, and the air inlet 21 and the air outlet 22 of the axial flow fan 20 are arranged along the axial direction of the mounting cavity 111. The air inlet cavity 121 is located on a side of the axial flow fan 20 where the air inlet 21 is provided. The air inlet 21 is connected to the air outlet 22 and the air inlet cavity 121. The air inlet box body 12 has an inner side close to the axis and an outer side away from the axis. A heat exchange layer 13 and a sound-absorbing layer 14 are sequentially arranged in the side wall of the air inlet box body 12 along the direction from the inside to the outside. A heat exchanger 30 is arranged in the heat exchange layer 13, and a plurality of sound-absorbing blades 40 are arranged in the sound-absorbing layer 14. The plurality of sound-absorbing blades 40 are arranged at intervals along the axial direction of the air inlet box body 12, and the gaps between the sound-absorbing blades 40 are connected to the air inlet cavity 121.

[0034] See also Figure 6 The air inlet 21 and the air outlet 22 of the axial flow fan 20 are arranged along the axial direction of the installation cavity 111. Therefore, when the axial flow fan 20 is working, the air flows from the air inlet 21 to the air outlet 22, that is, along the axial direction of the installation cavity 111. Because the air inlet cavity 121 is connected to the installation cavity 111, the air first enters the air inlet cavity 121, then enters the axial flow fan 20 from the air inlet 21, and finally flows out from the air outlet 22, forming an air flow path along the axial direction of the installation box 11. The heat exchanger 30 arranged in the side wall of the air inlet box 12 is used to contact and exchange heat with the air, and the silencer blades 40 are used to collide with the noise emitted by the axial flow fan 20, stop the propagation path of the noise sound wave, and consume the energy after multiple reflections, thereby achieving the effect of reducing noise. The heat exchanger 30 is arranged in the heat exchange layer 13, and the silencer blades 40 are arranged in the silencer layer 14 to avoid mutual interference between the two structures. The noise sound waves of the axial flow fan 20 need to pass through the heat exchanger 30 to propagate. The heat exchanger 30 collides with the sound waves to dissipate energy, which can also achieve a certain noise reduction effect.

[0035] In this embodiment, the cooling unit 100 is installed vertically, that is, the axis of the frame 10 and the axis of the axial flow fan 20 are perpendicular to the ground. Preferably, the installation box 11, the air inlet box 12 and the axial flow fan 20 are coaxially arranged, so that the air inlet path is more consistent and smooth, the connection between each structure is more neat, the force is balanced, and stress bias is avoided.

[0036] Furthermore, the silencer blades 40 are all arranged at an angle, so that the silencer blades 40 can guide the air and improve the noise reduction effect.

[0037] It should be explained that the air inlet direction here refers to the horizontal direction. In the present embodiment, air enters the air inlet chamber 121 from the outside through the gaps between adjacent silencer blades 40 and the hollows of the heat exchanger 30, and then flows from the air inlet chamber 121 to the axial flow fan 20. Therefore, the air inlet direction refers to the horizontal direction pointing to the inside of the air inlet chamber 121.

[0038] The end of the muffler blade 40 away from the mounting box 11 is located on the inner side of the end of the muffler blade 40 close to the mounting box 11. Figure 2 That is to say, the air flowing from the outside toward the inside of the air inlet chamber 121 will be guided by the silencer blades 40 to flow downward, and the gas enters the air inlet chamber 121 downward to make the noise radiation propagate upward as much as possible, thereby reducing the impact on the operating space.

[0039] Specifically, see Figure 3-Figure 5 , the angle between the muffler blade 40 and the horizontal direction is α, and α satisfies: 40°≤α≤60°. In this way, it can prevent the muffler blade 40 from having an angle that is too large, so that the path for air circulation between adjacent muffler blades 40 becomes too narrow, and air cannot smoothly enter the air inlet chamber 121, and it can also prevent the angle from being too small, so that the muffler and noise reduction effect is difficult to achieve.

[0040] Exemplarily, α is 45°, 50°, 55°, etc., but is not limited to the above two endpoint values, and only needs to be between 40° and 60°.

[0041] The chord length of the silencer blade 40 is H, and the axis spacing between two adjacent silencer blades 40 is L, which satisfies 0.8≤H / L≤1.5. Figure 4 It should be explained that the chord length of the silencer blade 40 refers to the width H of the silencer blade 40 along the inclination direction of the silencer blade 40, and the spacing L of the silencer blade 40 refers to the shortest distance L between the endpoints of two adjacent silencer blades 40 on the same side. The ratio between the two is actually the definition of blade density. The smaller the blade density, the greater the reverse thrust efficiency, and as the fan pressure ratio increases, the increase in the reverse thrust efficiency is also greater. Therefore, the blade density is reasonably set here, so that the cooling unit 100 can integrate power consumption and air intake efficiency, and the power consumption will not be too large while ensuring the air intake volume.

[0042] Exemplarily, the ratio of H / L is 0.9, 1.0, 1.1, 1.2, 1.31, 1.46, etc., but is not limited to the two endpoint values ​​mentioned above.

[0043] The spacing between adjacent muffler blades 40 gradually increases along the axial direction away from the mounting box 11. Since the closer to the axial flow fan 20, the stronger the pressure, and the farther away from the axial flow fan 20, the weaker the pressure generated by the axial flow fan 20. Therefore, such a setting can integrate the pressure in the axial direction and balance the pressure.

[0044] Furthermore, along the axial direction of the mounting box 11, the spacing between two adjacent silencer blades 40 closest to one end of the mounting box 11 is defined as L1, and the spacing between two adjacent silencer blades 40 farthest from one end of the mounting box 11 is defined as L2, satisfying 1.15L1≤L2≤1.2L1. In this way, the relationship between the spacing sizes at both ends of the top and bottom along the axial direction is set, that is, although the distance between the silencer blades 40 gradually increases, the increase value cannot be too much, otherwise it is easy to cause pressure imbalance. The present application reasonably sets the distance L2 from the farthest end of the axial flow fan 20 to not exceed 1.2 times the spacing from the nearest end, that is, to avoid the pressure imbalance again after the spacing between the two silencer blades 40 at the far end of the axial flow fan 20 is too large. At the same time, L2 cannot be less than 1.15 times L1, which is also to ensure pressure balance.

[0045] In this embodiment, the muffler blade 40 is a hollow structure, and the cross section of the muffler blade 40 is streamlined. The muffler blade 40 with a hollow structure can absorb sound more effectively, and can also have a good noise reduction effect in a wider octave band, and because the muffler blade 40 is streamlined, the inlet wind resistance can be minimized. It should be explained that the streamlined shape mentioned here is a shape that can facilitate air flow, such as a circular arc or a non-circular arc curve shape.

[0046] The silencer blade 40 is made of a stainless steel micro-perforated plate structure. The stainless steel material enables the silencer blade 40 to be suitable for use in the nuclear power containment environment (non-metallic materials such as glass wool cannot be used because they are not resistant to radiation), and the micro-perforated plate structure can further reduce noise.

[0047] It should be explained that the micro-perforated plate is a perforated plate with a perforation diameter of less than 1 mm. The sound absorption structure formed by the micro-perforated plate can increase the flow resistance of the structure without adding porous materials, broaden the effective frequency range of sound absorption, and has a simple structure and predictable sound absorption characteristics.

[0048] The axial flow fan 20 includes a first guide vane 23, an impeller (not shown in the figure) and a second guide vane (not shown in the figure). The axial flow fan 20 is configured with an air duct 26, which extends from one end of the axial flow fan 20 to the other end along the axial direction of the axial flow fan 20. The end of the air duct 26 close to the air inlet cavity 121 is the air inlet 21, and the end of the air duct 26 away from the air inlet cavity 121 is the air outlet 22. The first guide vane 23 is connected to the inner wall of the air duct 26 formed by the axial flow fan 20 and is located on the side of the impeller close to the air inlet 21. The second guide vane is connected to the inner wall of the air duct 26 and is located on the side of the impeller close to the air outlet 22. Both the first guide vane 23 and the second guide vane can guide the flow direction of the air, and the impeller is connected to the motor to drive the air flow. The first guide vane 23 is arranged on the front side of the impeller to guide the air into the axial flow fan 20, and the second guide vane is arranged on the rear side of the impeller to guide the air out.

[0049] The axial flow fan 20 further includes a guide cover 24, which is located in the air duct 26 and connected to the side of the first guide vane 23 facing the air inlet 21. The guide cover 24 is configured as a micro-perforated plate structure. The guide cover 24 is a component structure of the axial flow fan 20, and its noise reduction effect is shown. The guide cover 24 is configured as a micro-perforated plate structure, and its noise reduction effect is more obvious. The specific technical effect of the micro-perforated plate structure has been described in detail above and will not be repeated here.

[0050] Moreover, in this embodiment, the air inlet box 12 is configured as a rectangular frame structure, and the air inlet box 12 has four sides, and each side is sequentially provided with a heat exchange layer 13 and a sound absorbing layer 14 along the direction from the inside to the outside. In this way, the air entering the air inlet cavity 121 from all directions needs to exchange heat with the heat exchange layer 13 and be guided by the sound absorbing layer 14. The noise emitted by the axial flow fan 20 must be reduced by the sound absorbing layer 14 before it can be transmitted outward.

[0051] Of course, in other embodiments, the air inlet box 12 may also be configured as a cylindrical frame structure, which can also act on air and sound waves in all directions, and is not limited to the above-mentioned rectangular frame structure.

[0052] See also Figure 7 The heat exchanger 30 includes a heat exchange fin 33 and a heat exchange unit 31. The heat exchange unit 31 is connected to the heat exchange fin 33. A plurality of heat exchange tubes 32 are provided in the heat exchange unit 31. The heat exchange fin 33 is provided with a plurality of heat exchange tubes 32 arranged at intervals and passed through the heat exchange holes 34. The heat exchange fin 33 increases the contact area between the heat exchange tube 32 and the air, thereby improving the heat exchange efficiency between the heat exchanger 30 and the air.

[0053] Along the axial direction of the frame 10 , a plurality of heat exchange units 31 are arranged at intervals in the heat exchange layer 13 on each side to further improve the heat exchange efficiency.

[0054] Compared with the prior art, the present application makes the air flow path more suitable for the axial flow fan 20 by setting the axially arranged installation box 11 and the air inlet box 12. In addition, a heat exchange layer 13 and a sound absorbing layer 14 are set in the side wall of the air inlet box 12, so that the air entering the air inlet cavity 121 in the air inlet box 12 from the external environment must pass through the heat exchange layer 13 for heat exchange, and the noise propagating outward from the air inlet cavity 121 must also pass through the sound absorbing layer 14 for noise reduction. The specific structure and layout angle of the sound absorbing blade 40 in the sound absorbing layer 14 are also reasonably set, so that the sound absorbing blade 40 maximizes the noise reduction effect while not affecting the air entry, thereby optimizing the overall use experience of the cooling component.

[0055] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0056] The above-mentioned embodiments only express several implementation methods of the utility model, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the utility model patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the utility model, which all belong to the protection scope of the utility model. Therefore, the protection scope of the utility model patent shall be based on the attached claims.

Claims

1. A cooling unit, characterized in that: The cooling unit comprises: The frame (10) comprises a mounting box (11) and an air inlet box (12), wherein the mounting box (11) and the air inlet box (12) are connected, a mounting cavity (111) is provided in the mounting box (11), and an air inlet cavity (121) is provided in the air inlet box (12); An axial flow fan (20) is installed in the installation cavity (111), and the air inlet (21) and the air outlet (22) of the axial flow fan (20) are arranged along the axial direction of the installation cavity (111), and the air inlet cavity (121) is located on a side of the axial flow fan (20) where the air inlet (21) is provided, and the air inlet (21) is connected to the air outlet (22) and the air inlet cavity (121); The air inlet box (12) has an inner side close to the axis and an outer side away from the axis. The side wall of the air inlet box (12) is sequentially provided with a heat exchange layer (13) and a sound absorbing layer (14) along the direction from the inner side to the outer side. The heat exchange layer (13) is provided with a heat exchanger (30). The sound absorbing layer (14) is provided with a plurality of sound absorbing blades (40). The plurality of sound absorbing blades (40) are arranged at intervals along the axis direction of the air inlet box (12), and the gaps between the sound absorbing blades (40) are connected to the air inlet cavity (121).

2. The cooling unit according to claim 1, characterized in that: The silencer blades (40) are all arranged at an inclination, and one end of the silencer blade (40) away from the installation box (11) is located on the inner side of one end of the silencer blade (40) close to the installation box (11).

3. The cooling unit according to claim 2, characterized in that: The included angle between the noise reduction blade (40) and the horizontal direction is α, and α satisfies: 40°≤α≤60°.

4. The cooling unit according to claim 1, characterized in that: The chord length of the silencer blade (40) is H, and the axial distance between two adjacent silencer blades (40) is L, satisfying 0.8≤H / L≤1.

5.

5. The cooling unit according to claim 1, characterized in that: Along the axial direction away from the installation box (11), the spacing between adjacent silencer blades (40) gradually increases.

6. The cooling unit according to claim 5, characterized in that: Along the axial direction of the installation box (11), the distance between two adjacent silencer blades (40) closest to one end of the installation box (11) is defined as L1, and the distance between two adjacent silencer blades (40) farthest from one end of the installation box (11) is defined as L2, satisfying 1.15L1≤L2≤1.2L1.

7. The cooling unit according to any one of claims 1 to 6, characterized in that: The noise-absorbing blade (40) is a hollow structure.

8. The cooling unit according to any one of claims 1 to 6, characterized in that: The axial flow fan (20) comprises a first guide vane (23), an impeller and a second guide vane. The axial flow fan (20) is configured with an air duct (26). The air duct (26) extends from one end of the axial flow fan (20) to the other end along the axial direction of the axial flow fan (20). The end of the air duct (26) close to the air inlet cavity (121) is the air inlet (21), and the end of the air duct (26) away from the air inlet cavity (121) is the air outlet (22). The first guide vane (23) is connected to the inner wall of the air duct (26) formed by the axial flow fan (20) and is located on a side of the impeller close to the air inlet (21). The second guide vane is connected to the inner wall of the air duct (26) and is located on a side of the impeller close to the air outlet (22).

9. The cooling unit according to claim 8, characterized in that: The axial flow fan (20) further comprises a flow guide cover (24), wherein the flow guide cover (24) is located in the air duct (26) and is connected to a side of the first guide vane (23) facing the air inlet (21), and the flow guide cover (24) is configured as a micro-perforated plate structure.

10. The cooling unit according to any one of claims 1 to 6, characterized in that: The air inlet box (12) is configured as a rectangular frame structure, and the air inlet box (12) has four side surfaces, each of which is provided with a heat exchange layer (13) and a sound absorbing layer (14) in sequence along a direction from the inside to the outside.

11. The cooling unit according to claim 1, characterized in that: The heat exchanger (30) comprises a heat exchange fin (33) and a heat exchange unit (31), wherein the heat exchange unit (31) is connected to the heat exchange fin (33), a plurality of heat exchange tubes (32) are provided in the heat exchange unit (31), a plurality of heat exchange holes (34) arranged at intervals are opened on the heat exchange fin (33), and the heat exchange tubes are passed through the heat exchange holes (34).

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