Novel vortex generator of finned radiator for transformer and mounting device

Abstract

The invention discloses a novel vortex generator of a finned radiator for a transformer and a mounting device. The novel vortex generator comprises the finned radiator, a fixing belt, a vortex generator impressing belt and an inclined hollow triangular conical vortex generator, the finned radiator is connected with the oil collecting pipe to achieve the oil circulation process, the fixing belt is composed of a fixing groove and a fixing bolt and used for fixing the vortex generator impressing belt to the surface of the finned radiator, and fixing buckles connected with the fixing groove are machined at the upper end and the lower end of the vortex generator impressing belt. A row of inclined hollow triangular-cone-shaped vortex generators are machined on the surface, each inclined hollow triangular-cone-shaped vortex generator is composed of an inclined side wing and an inclined hollow triangle, and heat exchange enhancement is achieved by generating vortexes and expanding the vortexes towards the two sides. Compared with a traditional wing section and a mounting mode thereof, the wing section can enhance heat exchange or reduce flow resistance, the comprehensive heat exchange performance is obviously improved, and the wing section has the advantages of being simple in manufacturing process and convenient to mount and dismount.

Description

Technical Field

[0001] The present invention is an innovation of the vortex generator and the installation device, mainly used in the field of enhancing heat transfer of transformer fin radiators. Background Art

[0003] As the core heat dissipation device of the transformer, the traditional heat dissipation capacity of the fin radiator is insufficient. Therefore, improving the heat dissipation efficiency of the fin radiator has become a key problem to be solved urgently. At present, installing a vortex generator on the fin radiator is an effective means to enhance heat transfer. As an effective heat transfer enhancement device, the vortex generator destroys the boundary layer by generating local turbulence and accelerating the fluid, thinning its thickness and promoting fluid mixing, thereby improving the heat transfer efficiency. However, at the same time, the vortex generator will also bring a certain flow resistance, causing pressure loss and weakening the comprehensive heat transfer performance. The comprehensive heat transfer performance of the vortex generator is closely related to its geometric structure. At present, the commonly used trapezoidal airfoil vortex generator has strong heat transfer ability but large resistance, while the triangular airfoil vortex generator has small resistance but poor heat transfer effect. In addition, the existing installation process of the vortex generator is relatively complex, increasing the use cost. Summary of the Invention

[0004] In view of the above technical problems, the present invention innovatively proposes a new type of vortex generator and installation device for transformer fin radiators. The inclined hollow triangular cone vortex generator in the invention can significantly enhance heat transfer or reduce flow resistance, improving the comprehensive heat transfer performance of the radiator. More importantly, this design simplifies the installation process, greatly improving the practicability and operability.

[0005] The present invention can be realized by the following technical solutions:

[0006] A new type of vortex generator and installation device for transformer fin radiators of the present invention includes a fin radiator, a fixing band, a vortex generator embossing band, and an inclined hollow triangular cone vortex generator. The fin radiator is composed of a plurality of fin heat dissipation units and a wind deflector and is connected to the upper and lower oil collecting pipes. The vortex generator embossing band fixed by the fixing band is installed on the surface of part of the oil flow channels of the fin heat dissipation units.

[0007] The fixing band consists of a fixing groove and a fixing bolt. During installation, the fixing groove is fitted and connected to the vortex generator embossing band through a fixing buckle, and then the fixing band is symmetrically placed on both sides of the fin heat dissipation unit and fixed by the fixing bolt.

[0008] The vortex generator embossing band is a long strip of metal sheet, the width of which is equal to the width of the oil flow channel. Fixing buckles are processed at its upper and lower ends and are fitted and connected to the fixing groove. The surface is processed with a plurality of inclined hollow triangular cone vortex generators in an array and is closely attached to the oil flow channel.

[0009] The inclined hollow triangular conical vortex generator consists of an inclined flank and an inclined hollow triangle.

[0010] For the inclined hollow triangular conical vortex generator, the inclined flank rotates inward along the bottom edge of the flank by a certain angle until the top edges of the inclined flanks coincide.

[0011] The bottom side length of the inclined hollow triangular conical vortex generator d , the skew of the inclined flank is β , the inclination angle between the inclined hollow triangular conical vortex generator and the oncoming flow α , the thickness of the inclined hollow triangular conical vortex generator is t , the height of the inclined flank is h 1, the height of the inclined hollow triangle is h 2, and the width is l .

[0012] The inclined hollow triangle can reduce the flow resistance of the fluid, and at the same time can avoid the extrusion deformation during the processing and rotation of the inclined flank, reducing the processing difficulty.

[0013] The skew of the inclined flank β and the inclination angle α While reducing the resistance and promoting the formation of vortices, it can also extend the vortices to both sides and the flow direction, strengthening the secondary flow.

[0014] Compared with the prior art, the present invention has the following advantages:

[0015] (1) The designed inclined hollow triangular conical vortex generator in the present invention has a higher comprehensive heat transfer capacity under forced convection conditions compared with the traditional airfoil vortex generator, that is, it can take away more heat from the surface of the finned radiator under the same pump power conditions. Under natural convection conditions, it can significantly enhance heat transfer, that is, the heat flux density is higher.

[0016] (2) The inclined hollow triangular conical vortex generator of the present invention has a simple structure and is convenient for processing.

[0017] (3) Different from the traditional process of pasting multiple independent vortex generators on the surface of the heat sink, the present invention adopts a new modular installation scheme: First, the vortex generator and the fixing buckle structure are integrally formed on the vortex generator imprinting tape; Then, the fixing buckle on the vortex generator imprinting tape is engaged and connected with the fixing groove on the fixing tape; Then, the fixing tape is symmetrically placed on both sides of the finned heat dissipation unit; Finally, the installation is completed by tightening with bolts. This method significantly improves the installation convenience. In the scenarios of equipment maintenance and function upgrade, users can easily complete the disassembly and transformation operations. Compared with the traditional pasting method, it shows stronger structural flexibility and engineering practicability, effectively reducing the operation and maintenance costs of the whole life cycle of the equipment. Description of the Drawings

[0019] Figure 1 Axonometric schematic diagram of an embodiment of the present invention;

[0020] Figure 2 Schematic diagram of the installation position of a fixed belt for a vortex generator of the present invention;

[0021] Figure 3 Flow chart for manufacturing a fixed belt, an embossed belt for a vortex generator, and a vortex generator of the present invention;

[0022] Figure 4 Axonometric schematic diagram of an inclined hollow triangular cone vortex generator of the present invention;

[0023] Figure 5 Front view and dimension schematic diagram of an inclined hollow triangular cone vortex generator, a semi-separated inclined trapezoidal wing vortex generator, a trapezoidal wing vortex generator, and a triangular wing vortex generator in a specific embodiment of the present invention;

[0024] Figure 6 Axonometric schematic diagram of the air-side heat dissipation channel in a specific embodiment of the present invention;

[0025] Figure 7 Schematic diagram of the layout of vortex generators in a specific embodiment of the present invention;

[0026] Figure 8 Graph of the change of the wall heat flux density with the wall temperature under natural convection of four vortex generators in a specific embodiment of the present invention;

[0027] Figure 9 Graph of the change of the wall Nusselt number ratio with the Reynolds number under forced convection of four vortex generators in a specific embodiment of the present invention;

[0028] Figure 10 Graph of the change of the friction factor ratio with the Reynolds number under forced convection of four vortex generators in a specific embodiment of the present invention;

[0029] Figure 11 Comprehensive heat transfer performance evaluation factor under forced convection of three vortex generators in a specific embodiment of the present invention PEC Graph of the change with the Reynolds number.

[0030] In the figure: 1 is a finned radiator, 1-1 is an oil collecting pipe, 1-2 is a fin unit, 1-2-1 is an oil flow channel, 1-3 is a wind deflector, 2 is a fixed belt, 2-1 is a fixed groove, 2-2 is a fixing bolt, 3 is an embossed belt for a vortex generator, 3-1 is a fixing buckle, 4 is an inclined hollow triangular cone vortex generator, 4-1 is an inclined side wing, 4-2 is an inclined hollow triangle.

[0031] Specific Embodiments of the Present Invention

[0032] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only partial embodiments of the present invention, rather than all embodiments. Any other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts belong to the scope of protection of the present invention.

[0033] As Figure 1 、 Figure 2 and Figure 3 shown, a heat transfer enhancement device for a chip radiator used in a transformer of the present invention includes a chip radiator (1), a fixing band (2), an eddy current generator embossing band (3), and an inclined hollow triangular eddy current generator (4). The chip radiator is composed of a plurality of chip heat dissipation units (1-2) and a wind baffle (1-3) and is connected to the upper and lower header pipes (1-1). An eddy current generator embossing band (3) fixed by a fixing band (2) is installed on the surface of the oil flow channel (1-2-1) of the chip heat dissipation unit (1-2).

[0034] Specifically, the fixing band (2) is composed of a fixing groove (2-1) and a fixing bolt (2-2). During installation, the fixing groove (2-1) is fitted and connected to the eddy current generator embossing band (3) through a fixing buckle (3-1), and then the fixing band (2) is symmetrically placed on both sides of the chip heat dissipation unit (1-2) and fixed by the fixing bolt (2-2).

[0035] Specifically, the eddy current generator embossing band (3) is a long strip of metal sheet, the width of which is equal to the width of the oil flow channel (1-2-1). Fixing buckles (3-1) are processed at its upper and lower ends and are fitted and connected to the fixing groove (2-1). A plurality of inclined hollow triangular eddy current generators (4) are processed on the surface in an array manner and are closely attached to the oil flow channel (1-2-1).

[0036] Specifically, the inclined hollow triangular eddy current generator (4) is composed of an inclined flank (4-1) and an inclined hollow triangle (4-2).

[0037] Specifically, the inclined hollow triangular eddy current generator (4) is such that the inclined flank (4-1) rotates inward along the bottom edge of the flank until the top edge of the inclined flank (4-1) coincides.

[0038] Specifically, the bottom side length of the inclined hollow triangular eddy current generator (4) d , the skew of the inclined flank (4-1) is β , the inclination angle of the inclined hollow triangular eddy current generator (4) with respect to the oncoming flow α , the thickness of the inclined hollow triangular eddy current generator (4) ist , the height of the inclined wing (4-1) is h 1. The height of the inclined hollow triangle (4-2) is h 2, width is l .

[0039] Specifically, the inclined hollow triangle (4-2) can reduce the flow resistance of the fluid, and at the same time can avoid extrusion deformation during the processing and rotation of the inclined wing (4-1), thereby reducing the processing difficulty.

[0040] Specifically, the tilted wing (4-1) skewness β and inclination α While reducing resistance and promoting vortex formation, it can also extend the vortex to both sides and the flow direction to strengthen the secondary flow.

[0041] Compared with the traditional airfoil vortex generator, the inclined hollow triangular cone vortex generator designed in the present invention has a higher comprehensive heat exchange capacity under forced convection conditions, that is, it can take away more heat from the surface of the fin radiator under the same pump power conditions. It can significantly enhance heat exchange under natural convection conditions, that is, the heat flux density is higher.

[0042] The inclined hollow triangular cone vortex generator of the present invention has a simple structure and is easy to manufacture.

[0043] Unlike the traditional process of pasting multiple independent vortex generators on the surface of the heat sink, the present invention adopts a new modular installation solution: first, the vortex generator and the fixing buckle structure are integrally formed on multiple vortex generator embossed belts; then, the fixing buckle on the vortex generator embossed belt is engaged with the fixing groove on the fixing belt; then, the fixing belt is symmetrically placed on both sides of the sheet-type heat dissipation unit; finally, the installation is completed by tightening with bolts. This method significantly improves the convenience of installation. In the scenarios of equipment maintenance and function upgrades, users can easily complete the disassembly and modification operations. Compared with the traditional pasting method, it shows stronger structural flexibility and engineering practicality, effectively reducing the operation and maintenance costs of the equipment throughout its life cycle. Specific embodiments

[0045] In order to verify the superiority of the inclined hollow triangular cone vortex generator proposed in the present invention, the heat flux density of the trapezoidal channel with the vortex generator is calculated by natural convection. q and the convective heat transfer coefficient h , q and h The larger the value, the stronger the heat transfer capacity. Calculate the Nusselt number of the trapezoidal channel with vortex generator by forced convection. Nu and friction factor f And the Nusselt number of the trapezoidal channel without vortex generator installed Nu 0 and friction factorf 0 , the Nusselt number ratio is obtained Nu / Nu 0 and the friction factor ratio f / f 0 , and the comprehensive heat transfer performance evaluation factor is calculated PEC . PEC The larger the value, the stronger the comprehensive heat transfer performance.

[0046] The following are the explanations and descriptions of the terms involved in the present invention:

[0047] Heat flux density: , where Q is the total heat transfer amount of the wall surface, A is the surface area of the wall surface in contact with air.

[0048] Nusselt number: , where k is the thermal conductivity of air, D is the hydraulic diameter of the air channel.

[0049] Darcy friction factor: , where Δ p is the pressure difference between the inlet and outlet of the air channel, ρ is the air density, u is the inlet flow velocity, L is the length of the air channel.

[0050] Reynolds number :, where μ is the dynamic viscosity of air.

[0051] Heat transfer performance evaluation factor: , where Nu 0, f 0 represent the average Nusselt number and the Darcy friction factor of the trapezoidal channel without the installation of the vortex generator respectively. PEC reflects the trade-off between the heat transfer enhancement effect and the pump work consumption, that is, the comprehensive heat transfer performance. When PEC > 1, it indicates that the heat transfer channel enhances heat transfer under the same pump work condition.

[0052] Specifically set as: The heat transfer effects of the inclined hollow triangular cone vortex generator are calculated and compared with those of the widely used delta wing vortex generator, trapezoidal wing vortex generator, and the new but not popular semi-separated inclined trapezoidal vortex generator. The sizes of the four vortex generators are as Figure 5 shown. The air channel between two adjacent sheet-type heat dissipation units is simplified into a rectangular channel. The size and boundary conditions of the rectangular channel are as Figure 6As shown, the air temperature is 303 K, the surface temperature of the finned heat sink is 343 K, the natural convection inlet is a pressure inlet, and the Reynolds number range of the forced convection inlet is 5000 - 16000. Among them, the number of inclined hollow triangular pyramid vortex generators arranged is 100, and the arrangement method is as Figure 7 shown. The arrangement methods of the other three types of vortex generators are the same as the above method.

[0053] Figure 8 Figure 6 is a graph showing the variation of the heat flux density with the wall temperature under natural convection of the four types of vortex generators. The research results show that the heat flux density of each type of vortex generator is positively correlated with the wall temperature. Among them, the inclined hollow triangular pyramid vortex generator always maintains the highest heat flux density under different wall temperature conditions, followed by the semi-separated inclined trapezoidal vortex generator, the triangular wing vortex generator, and the trapezoidal wing vortex generator respectively. Figure 9 , Figure 10 and Figure 11 Figure 7, Nu / Nu 0, f / f 0 and PEC Figure 8 are the variation laws of the Nusselt number ratio Re of the vortex generator with the Reynolds number under forced convection. Obviously, within the range where Re is lower than 13000, the heat transfer performance of the inclined hollow triangular pyramid vortex generator is significantly higher than that of the semi-separated inclined trapezoidal vortex generator, the triangular wing vortex generator, and the trapezoidal wing vortex generator. The flow resistance of the inclined hollow triangular pyramid vortex generator is not much different from that of the semi-separated inclined trapezoidal wing vortex generator and the triangular wing vortex generator, and is significantly lower than that of the trapezoidal wing vortex generator, making the comprehensive heat transfer performance of the inclined hollow triangular pyramid vortex generator higher than that of the other vortex generators. Within the range where Re is higher than 13000, the heat transfer performance of the inclined hollow triangular pyramid vortex generator decreases compared with the semi-separated inclined trapezoidal vortex generator and the trapezoidal wing vortex generator, but at the same time the flow resistance also decreases, making the comprehensive heat transfer performance of the inclined hollow triangular pyramid vortex generator still the best. It can be seen that at different Reynolds numbers, the comprehensive heat transfer performance of the inclined hollow triangular pyramid vortex generator is higher than that of the traditional triangular wing and trapezoidal vortex generators and the semi-separated inclined trapezoidal vortex generator.

Claims

1. A new type of eddy current generator and installation device for a chip radiator used in a transformer, characterized in that, It includes a finned radiator (1), a fixing band (2), an eddy current generator imprinting band (3), and an inclined hollow triangular eddy current generator (4). The finned radiator is composed of a plurality of finned heat dissipation units (1-2) and a wind deflector (1-3) and is connected to the upper and lower oil collecting pipes (1-1). An eddy current generator imprinting band (3) fixed by a fixing band (2) is installed on the surface of the oil flow channel (1-2-1) of the finned heat dissipation unit (1-2).

2. The novel eddy current generator and installation device for the chip radiator used in a transformer according to claim 1, wherein, The fixing band (2) consists of a fixing groove (2-1) and a fixing bolt (2-2). During installation, the fixing groove (2-1) is fitted and connected to the eddy current generator imprinting band (3) through a fixing buckle (3-1), and then the fixing band (2) is symmetrically placed on both sides of the finned heat dissipation unit (1-2) and fixed by the fixing bolt (2-2).

3. The novel eddy current generator and installation device for a chip radiator used in a transformer according to claim 1, characterized in that, The eddy current generator imprinting band (3) is a long strip of metal sheet, the width of which is equal to the width of the oil flow channel (1-2-1). Fixing buckles (3-1) are processed at its upper and lower ends and are fitted and connected to the fixing groove (2-1). A plurality of inclined hollow triangular eddy current generators (4) are processed on the surface in an array manner and are closely attached to the oil flow channel (1-2-1).

4. The novel eddy current generator and installation device for a chip radiator used in a transformer according to claim 3, characterized in that, The inclined hollow triangular eddy current generator (4) consists of an inclined flank (4-1) and an inclined hollow triangle (4-2).

5. A novel eddy current generator and installation device for a chip radiator used in a transformer according to claim 4, characterized in that, The inclined hollow triangular eddy current generator (4) is such that the inclined flank (4-1) rotates inward by a certain angle along the bottom edge of the flank until the top edges of the inclined flanks (4-1) coincide.

6. A novel eddy current generator and installation device for a chip radiator of a transformer according to claim 4, characterized in that, The bottom side length of the inclined hollow triangular conical vortex generator (4) d , the skewness of the inclined flank (4-1) is β , the inclination angle between the inclined hollow triangular conical vortex generator (4) and the oncoming flow α , the thickness of the inclined hollow triangular conical vortex generator (4) is t , the height of the inclined flank (4-1) is h 1, the height of the inclined hollow triangle (4-2) is h 2, and the width is l .

7. A novel eddy current generator and installation device for a chip radiator used in a transformer according to claim 4, characterized in that, The inclined hollow triangle (4-2) can reduce the flow resistance of the fluid, and at the same time can avoid the extrusion deformation during the processing and rotation of the inclined flank (4-1), reducing the processing difficulty.

8. A novel eddy current generator and installation device for a chip radiator of a transformer according to claim 6, characterized in that, The skewness of the inclined flank (4-1) β and the dip angle α While reducing resistance and promoting vortex formation, it can also extend the vortex to both sides and the flow direction, strengthening the secondary flow.

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