Radiating fin with two-wing structure for magnetron

Abstract

The invention discloses a two-wing structure radiating fin for a magnetron, which comprises a radiating fin body, two ends of two opposite sides of the radiating fin body are respectively connected with a plurality of small radiating wings, the radiating fin body between the small radiating wings at two ends forms a middle radiating fin, and the included angles between the small radiating wings and the horizontal direction are different. The small radiating wings at the two ends of the radiating fin body are arranged in a crossed and staggered manner; according to the two-wing structure, through the crossed and staggered arrangement, the situation that the heat exchange capacity is weakened due to the fact that the front wing shields the rear wing and the rear wing is in poor contact with air is reduced, the direct contact capacity of the two wings and the air is effectively improved, disturbance of the two wings of the cooling fin to the air is enhanced, the turbulence effect is enhanced, and the heat exchange efficiency is improved. Therefore, the heat exchange effect of the two wings is improved, the temperature of the central anode body is reduced, and the working performance of the magnetron is further improved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of magnetron, and relates to a magnetron anode body heat dissipation device, in particular to a two-wing structure heat dissipation fin for a magnetron. BACKGROUND

[0002] As the core power device of the microwave heating device, the core function of the magnetron is to control the electron flow by applying a magnetic field, and then generate a strong high-frequency electromagnetic wave to realize efficient heating of the material. In this working process, the magnetron, especially its anode heat dissipation unit, will accumulate a large amount of Joule heat due to the bombardment of high-energy electrons and high-frequency eddy current loss, resulting in a sharp rise in temperature. The continuous high-temperature thermal load and the repetitive thermal stress and thermal fatigue effect caused thereby are the key factors causing the performance degradation, efficiency reduction and even ultimate failure of the magnetron. Therefore, the effective heat dissipation capacity of the magnetron is a decisive factor for the long-term working stability, reliability and overall service life of the magnetron.

[0003] As the mainstream heat dissipation method for the magnetron anode body, the air-cooled heat dissipation increases the heat dissipation area through the heat dissipation fin group arranged on the surface of the magnetron anode body, and realizes the convective heat transfer by means of the forced air flow generated by the cooling fan of the equipment. However, with the continuous increase of the power of the magnetron, in order to achieve sufficient heat dissipation intensity, the air pressure and air volume of the cooling fan must be greatly increased, which directly leads to a significant increase in the operating noise of the fan, seriously affecting the user experience and working environment of the household product, reducing customer satisfaction, and becoming an important obstacle to product upgrading.

[0004] How to meet the increasingly stringent high-power heat dissipation requirements and effectively suppress or even significantly reduce the operating noise caused by forced air cooling has become a key technical bottleneck that needs to be broken through in the design of the magnetron and the development of the application equipment. Although the existing heat dissipation fins have undergone many improvement measures in their surface structures, the influence of the arrangement mode of the two-wing structure on the heat dissipation capacity is ignored. The two-wing structure not only plays an important role in reducing the bypass air leakage of the magnetron, but is also affected by the fin thermal boundary layer. Therefore, improving the two-wing structure of the magnetron fin through design has become a key way to improve the heat dissipation capacity of the magnetron fin, and thus to reduce the temperature of the central anode body and improve the working performance of the anode body. SUMMARY

[0005] In view of the deficiencies in the prior art, the purpose of the present application is to provide a two-wing structure heat dissipation fin for a magnetron, which effectively improves the heat dissipation capacity of the magnetron anode body.

[0006] In order to achieve the above-mentioned purpose, the technical scheme adopted by the present application is as follows: A two-wing structure heat sink for magnetron, comprising a heat sink body, a heat sink center through hole is formed in the middle of the heat sink body, the heat sink center through hole is closely combined with the magnetron anode body; a certain height of the flange is vertically arranged along the edge of the heat sink center through hole, the heat sink body is connected with a plurality of heat dissipation wings at two ends of the opposite sides respectively, the heat sink body between the two ends of the heat dissipation wings forms the middle heat dissipation fin; the two heat dissipation wings at the position of the two ends of the heat sink body are arranged in spatial axis symmetry, the angle between each heat dissipation wing at the same end of the heat sink body and the horizontal direction is-90°~90°, and the angles between each heat dissipation wing and the horizontal direction are different, so that each heat dissipation wing at the two ends of the heat sink body is arranged in cross and staggered.

[0007] Preferably, the heat dissipation wings at the same end of the heat sink body are at least 4.

[0008] Preferably, the heat dissipation wings at the same end of the heat sink body comprise a bending lower wing near the end of the air inlet and outlet and a bending upper wing near the end, and a plurality of middle wings between the bending lower wing near the end and the bending upper wing near the end.

[0009] Preferably, the middle wings are sawtooth-shaped, ladder-shaped or rectangular.

[0010] Preferably, the two adjacent sawtooth-shaped wings at the same end of the heat sink body are arranged in opposite sawtooth directions.

[0011] Preferably, the two adjacent ladder-shaped wings at the same end of the heat sink body are arranged in opposite ladder directions.

[0012] Preferably, the two ends of the heat sink body at the opposite sides are respectively sheared and bent to form a plurality of heat dissipation wings.

[0013] Preferably, grooves are arranged between the middle heat dissipation fin and the heat dissipation wings at the two ends.

[0014] Compared with the prior art, the present application has at least the following beneficial effects: The two-wing structure heat dissipation fin for the magnetron is characterized in that two wings arranged in a space axis symmetry are arranged at both ends of the heat dissipation fin body, and the included angles of each heat dissipation small wing with the horizontal direction are different, which can make each part of the two-wing fin directly contact with air, reduce the heat exchange capacity caused by the shielding of the front wing to the rear wing, effectively increase the direct contact capacity of the two wings with air, and cross and stagger arrange the heat dissipation small wings at both ends of the heat dissipation fin body, so as to enhance the disturbance of the two wings of the heat dissipation fin to air, enhance the turbulent flow effect, and further improve the heat exchange effect of the two wings.

[0015] The grooves are arranged between the middle heat dissipation fin and the heat dissipation small wings at both ends, the two-wing structure utilizes the groove area of the existing structure to the small wings, and changes the angles of the two wings of the heat dissipation fin, so that the two-wing ends of the heat dissipation fin can extend to the air bypass area of the magnetron more, reduce the bypass amount of the cold air of the magnetron, and utilize the cold air more.

[0016] The middle small wings are sawtooth-shaped, ladder-shaped or rectangular, the shape of the middle small wings of the two wings is changed, the local disturbance of the small wings to air is increased, the turbulent flow effect is caused, the heat exchange capacity of the middle small wings is improved, and the heat exchange effect of the whole heat dissipation fin is further improved.

[0017] The two-wing structure only needs to cut and fold the two wings of the heat dissipation fin, does not need to increase an additional process, and obtains different numbers, shapes and angles of the two-wing structures according to the cutting times, cutting modes and folding degrees, is easy to realize in the production process, and is extremely convenient to install in the space axis symmetry mode. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 is a structural schematic diagram of the present application; Figure 2 is a structural schematic diagram of the existing magnetron heat dissipation fin; Figure 3 is a ladder-shaped small wing schematic diagram; Figure 4 is an included angle schematic diagram of each small wing with the horizontal direction in the two wings; Figure 5 is a schematic diagram of one side small wing in the two wings with six pieces; Figure 6is a schematic diagram of the change of the thermal boundary layer thickness along the flow direction; Fig. 1 is a flip, 2 is a side edge sawtooth upturned winglet, 3 is a middle heat dissipation fin, 4 is a terminal with a folding down winglet, 5 is a side edge sawtooth down winglet, 6 is a terminal with a folding up winglet, 7 is a fin center hole, 8 is a wind speed inlet, 9 is a wind speed outlet, 10 is a horizontal winglet on the wind speed inlet side, 11 is a horizontal winglet on the wind speed inlet side, 12 is an upturned winglet in the middle of the two wings, 13 is a down winglet in the middle of the two wings, 14 is a horizontal winglet on the wind speed outlet side, 15 is a stepped down winglet, 16 is a stepped up winglet, 17 is the angle between the winglet and the horizontal direction α， 18 is the thermal boundary layer thickness δ, 19 is the direction x of air flow along the fin surface. DETAILED DESCRIPTION

[0019] The scheme of the present application is described in detail below through specific implementation.

[0020] Referring to Figure 1 , the two-wing structure heat dissipation fin of the magnetron of the present application comprises a heat dissipation fin body, a heat dissipation fin center hole 7 formed in the middle of the heat dissipation fin body, a flip 1 with a certain height vertically arranged along the edge of the heat dissipation fin center hole 7 and directly contacting the anode body, and four heat dissipation winglets formed at the two ends of the opposite sides of the heat dissipation fin body, respectively. The four heat dissipation winglets are designed to be spatially axisymmetric, which provides convenience for subsequent installation.

[0021] Referring to Figure 4 , by folding the winglets, according to the different degrees of folding, the angles between the heat dissipation winglets at the same end of the heat dissipation fin body and the horizontal direction are-90°~90°, and the angles between the heat dissipation winglets at the same end of the heat dissipation fin body and the horizontal direction α 17 are all different, so that the heat dissipation winglets at the two ends of the heat dissipation fin body are arranged in a staggered and crossed manner. By arranging the winglets in a staggered and crossed manner, when air passes through the wind speed inlet 8 and exchanges heat with the heat dissipation winglets, the temperature of the air along the path gradually rises, resulting in a decrease in the temperature difference of the winglets near the wind speed outlet 9 side and a decrease in the temperature gradient, which reduces the heat exchange capacity of the winglets near the wind speed outlet side. By arranging the winglets in a staggered and crossed manner, the contact between the winglets near the outlet side and the low-temperature air can be increased, thereby enhancing the heat exchange. In addition, by arranging the winglets in a staggered and crossed manner, the situation that the rear winglets are less in contact with air due to the shielding of the front winglets can be alleviated. The recess 10 is arranged between the middle heat dissipation fin 3 and the heat dissipation winglets at the two ends.

[0022] As Figure 5 and Figure 6As shown, according to the characteristics of the thermal boundary layer, when the fin is just in contact with the fluid, the part of the small wing near the air inlet side of the front end of the small wing starts to develop the thermal boundary layer, which is usually thin, the heat exchange is strong, and the surface temperature is relatively low. Along the flow direction to the downstream, the part of the small wing near the air outlet side of the rear end of the small wing gradually thickens the thermal boundary layer, the thermal resistance increases, the heat exchange weakens, and the surface temperature of the fin gradually rises. The corresponding formula is Wherein x is the distance from the leading edge of the fin, δ is the boundary layer thickness at x from the leading edge, Re x is the Reynolds number with x as the characteristic length. Therefore, in this embodiment, one side of the left and right wings is cut into four small wings. Compared with the two or three small wings of the existing fin, the distance x along the flow direction of the single small wing is reduced, which can better enable the small wing to contact the air before the thermal boundary layer is fully developed and thickened, thereby improving the heat exchange capacity of the small wing and improving the overall heat exchange effect.

[0023] Referring to Figure 1 , the four small wings of the fin body at each end include the bent-down small wings 4 near the ends of the air inlet and outlet and the bent-up small wings 6 at the ends, and the side sawtoothed down small wings 5 and the side sawtoothed up small wings 2 located between the bent-down small wings 4 at the ends and the bent-up small wings 6 at the ends. Two adjacent sawtoothed small wings are arranged in opposite sawtoothed directions.

[0024] Referring to Figure 2 , the existing microwave oven magnetron heat dissipation fin includes a fin center through hole 7, a groove 10 connecting the middle heat dissipation fin and the two-wing heat dissipation fin, a horizontal small wing 10 near the air inlet side of the air inlet and outlet, a horizontal small wing 14 near the air outlet side of the air inlet and outlet, an up small wing 12 in the middle of the two wings, a down small wing 13 in the middle of the two wings, and a space axisymmetric structure of the existing heat dissipation fin. The heat dissipation fin is cooled by forced air cooling. Air passes through the air inlet 8, exchanges heat with the heat dissipation fin, and carries away heat. Hot air is blown out through the air outlet 9.

[0025] Referring to Figure 3 , in another embodiment, of the four small wings of the fin body at each end of the present application, two middle small wings are in the form of a stepped structure, i.e., two small wings away from the air inlet and outlet are stepped down small wings 15 and stepped up small wings 16. The two adjacent stepped small wings at the same end of the fin body are arranged in opposite stepped directions. By changing the cutting method, the small wings are cut, which can save materials on the one hand and can change the disturbance of the two wings to the air through different structures on the other hand, thereby enhancing the local turbulence and further improving the heat exchange capacity of the two wings. However, since the cutting will reduce the heat exchange area of the two wings, it is necessary to balance the heat exchange area and the heat exchange coefficient to reasonably cut to maximize the improvement of the heat exchange capacity.

[0026] Referring toFigure 5 By cutting the middle small wings of the two wings of the fin, and then bending the small wings at a certain angle, and ensuring that the front and back of the small wings are staggered, six small wings are formed at both ends of the two sides of the fin body, the middle small wings are rectangular structures, and a model diagram with six small wings on one side is obtained.

[0027] The two-wing structure of the fin in the application is verified by numerical simulation compared with the existing fin in the background art. STAR-CCM+ software is used for numerical simulation of three fins, and the boundary conditions, fin spacing and external environmental factors are the same, wherein the inlet condition is mass flow inlet, the mass flow rate is 0.0057 kg·s -1 , the environmental temperature is 298 K, the pressure outlet is set, the center anode body power is 300 W, and the contact thermal resistance between the heat dissipation fin and the center anode body is set to 5×10 -4 m 2 ·K·W -1 .

[0028] The numerical simulation results are shown in the following table: Performance comparison of the existing fin and the fin of the application: According to the simulation results, in the case of the existing three fins, the anode body temperature of the existing fin is 394.2 DEG C, and the anode body temperature of the new two-wing heat dissipation fin is 352.3 DEG C. Compared with the existing fin, the new two-wing structure makes the anode body temperature drop by 41.9 DEG C, greatly reducing the temperature of the anode body. The simulation results show that the heat exchange coefficient and heat exchange capacity of the new two-wing heat dissipation fin are improved to different degrees.

[0029] Performance comparison of different small wing numbers in the new two-wing fin: By increasing the number of small wings in the two wings to six small wings on one side, the temperature of the center anode body is reduced by 8.1 DEG C compared with the temperature of the center anode body with four small wings on one side. The heat exchange capacity and average heat exchange coefficient of the two wings are improved to a certain extent, but the temperature of the magnetron anode body of the new six small wings is reduced by 50 DEG C compared with the existing fin structure under the same conditions, greatly improving the heat exchange performance of the fin.

[0030] Since the maximum temperature of the magnetron of the microwave oven is generally not more than 350 DEG C, and the number of fins on the existing magnetron of the microwave oven on the market is generally 4-6, at least 50 DEG C temperature drop of the anode body can be obtained by adopting the novel two-wing structure, the adoption of the structure of the application can realize that three fins realize that the temperature of the anode body is lower than 350 DEG C, and then at least one fin on a magnetron of the microwave oven can be reduced, the consumption of several ten million fins can be saved every year, the cost of the fins is greatly reduced, and the use amount of the material is also saved.

[0031] Therefore, the two-wing structure of the application has obvious superiority.

Claims

1. A two-wing structure heat sink for a magnetron, characterized by: The fin body is provided with a fin center through hole (7) in the middle of the fin body, the fin center through hole (7) is closely combined with the magnetron anode body, a certain height of the flange (1) is vertically arranged along the edge of the fin center through hole (7), a plurality of fin small wings are connected to the two ends of the opposite sides of the fin body respectively, the fin body between the two end fin small wings forms the middle fin (3), the two end fin small wings of the fin body are arranged in space axis symmetry, the angle between each fin small wing of the same end of the fin body and the horizontal direction is-90°~90°, and the angles between each fin small wing and the horizontal direction are different, so that each fin small wing of the two ends of the fin body is arranged in cross and staggered.

2. The two-wing structure heat sink for a magnetron as recited in claim 1, wherein: The same end of the fin body has at least four fin small wings.

3. The two-wing structure heat sink for a magnetron as recited in claim 2, wherein: The same end of the fin body includes the bending lower fin wing (4) near the end of the air inlet and outlet, the bending upper fin wing (6) at the end, and a plurality of middle fin wings between the bending lower fin wing (4) and the bending upper fin wing (6).

4. The two-wing structure heat sink for a magnetron according to claim 3, wherein: The middle fin wing is sawtooth-shaped, ladder-shaped or rectangular.

5. The two-wing structure heat sink for a magnetron as claimed in claim 4, wherein: The same end of the fin body has two adjacent sawtooth-shaped fin wings, and the sawtooth directions are opposite.

6. The two-wing structure heat sink for a magnetron as claimed in claim 4, wherein: The same end of the fin body has two adjacent ladder-shaped fin wings, and the ladder directions are opposite.

7. The two-wing structure heat sink for a magnetron according to any one of claims 1 to 6, wherein: The two ends of the opposite sides of the fin body are respectively sheared and bent to form a plurality of fin small wings.

8. The two-wing structure heat sink for a magnetron according to any one of claims 1 to 6, wherein: The middle fin (3) and the fin small wings at the two ends are provided with grooves (10).

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