A stepped fractal oil path radiator for a transformer

Abstract

This invention discloses a stepped fractal oil circuit radiator for transformers, comprising an oil inlet pipe, a group of heat sinks, and an oil outlet pipe. The oil inlet pipe is inclined, and the oil outlet pipe is horizontal. The heat sink group consists of multiple heat sinks arranged side by side. Fractal channels are raised on the surface of the heat sinks, formed by curves with at least two levels of fractal contours sweeping along a tortuous path. The total cross-sectional area of ​​the cooling oil channels within the heat sinks and the number of fractal channels increase in a stepped manner along the arrangement direction of the heat sinks. An array of through holes is present on the surface of the heat sinks, evenly distributed between the fractal channels. The through holes on adjacent heat sinks are staggered along the arrangement direction of the heat sinks. Advantages: By balancing the distribution of cooling oil flow and using stepped fractal channels, the heat transfer attenuation problem along the arrangement direction of the heat sinks is solved, as well as the bottleneck problem of heat dissipation efficiency in compact radiator design. The staggered arrangement of through holes solves the problem of enhanced air-side heat transfer and uneven heat dissipation efficiency distribution under complex wind conditions.

Description

Technical Field

[0001] This invention relates to the field of radiator technology, and more specifically to a stepped fractal oil circuit radiator for transformers. Background Technology

[0002] Transformers are key equipment used for high- and low-voltage conversion in long-distance power transmission and transformation systems. They generate a lot of heat during operation. If the heat cannot be dissipated quickly and in a timely manner, the heat accumulation will pose a hidden danger to the safe operation of the equipment and system. Therefore, it is necessary to use efficient heat dissipation technology to cool down the transformer.

[0003] The key equipment for transformer heat dissipation is the plate-type radiator, with cooling oil as the heat dissipation medium. As the cooling oil passes through the transformer, it carries away heat. After its temperature rises, the oil enters the radiator and flows downwards within the fins. Simultaneously, ambient air flows upwards through narrow channels between the parallel fins, resulting in counter-current heat exchange between the air and the cooling oil. After the oil temperature decreases, it returns to the transformer from the bottom, completing one heat dissipation cycle. However, without an additional power source for this process due to energy conservation considerations, the heat dissipation efficiency through natural convection is severely limited. Furthermore, to avoid spatial interference and achieve miniaturization, the fins are typically arranged compactly side-by-side, further limiting heat dissipation efficiency and making it difficult to evenly distribute the heat transfer capacity between the fins. This is especially problematic in complex wind conditions, easily leading to increased system entropy. The current cooling oil flow path also results in better heat transfer between fins closer to the transformer, further exacerbating the uneven heat distribution. Therefore, it is essential to invent a novel radiator that simultaneously addresses the issues of low energy consumption, miniaturization, high efficiency, and uniform heat distribution. Summary of the Invention

[0004] To address the aforementioned problems, this invention provides a stepped fractal oil circuit radiator for transformers, thereby solving the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: A stepped fractal oil circuit radiator for transformers consists of an oil inlet pipe, a heat sink group, and an oil outlet pipe. The oil inlet pipe is an inclined pipe, the heat sink group consists of multiple heat sinks arranged in parallel, the top of the heat sink is connected to the oil inlet pipe, the surface of the heat sink has fractal flow channels and through holes with fractal contours, and the oil outlet pipe is a horizontal pipe connected to the bottom of the heat sink.

[0006] The inlet end of the oil inlet pipe is located at the highest point of the entire device. The cross-sectional area of ​​the cavity in the heat sink gradually increases along the flow direction of the oil inlet pipe. The heat sink is formed by the base plate being closed and sealed. The fractal flow channel protrudes along the surface of the base plate to form a fractal surface. The fractal flow channel is distributed in a tortuous manner along the surface of the base plate.

[0007] The number of fractal channels increases in stages along the direction of heat sink arrangement, forming a stepped fractal oil circuit radiator. The through holes are located on the heat sink and are evenly distributed near the curved sections of the fractal channels. The through holes on adjacent heat sinks are staggered along the direction of heat sink arrangement.

[0008] The outlet end of the oil outlet pipe and the inlet end of the oil inlet pipe are located on the same side.

[0009] There are cavities between the base plates that make up the same heat sink. The cavities are connected to the fractal flow channels. There is an oil distribution channel between the oil inlet pipe and the heat sink. The oil distribution channel connects the oil inlet pipe, the fractal flow channels and the cavities. After the cooling oil in the heat sink descends, it flows directly into the oil outlet pipe.

[0010] The fractal flow channel extends downwards from the oil distribution channel to near the lower edge of the heat sink. The fractal surface constituting the fractal flow channel is formed by sweeping along the path of the fractal flow channel with two or more levels of fractal curves. The bends of the fractal surface of the fractal flow channel are rounded.

[0011] The total cross-sectional area of ​​the cavity and the fractal flow channel gradually increases along the direction of the heat sink arrangement.

[0012] All the through holes on a single heat sink form the base plate of the heat sink.

[0013] The through holes on a single heat sink are arranged in a uniform array to cover the entire surface of the heat sink, and the through holes are staggered to make the heat sink completely opaque along the arrangement direction.

[0014] The beneficial effects of this invention compared to the prior art are: The technical solution of this invention features an inclined oil inlet pipe at the top of the radiator, which adds gravity-driven flow to the cooling oil within the pipe. Simultaneously, the flow area of ​​the cooling oil inside the heat sink gradually increases along the arrangement direction, reducing the oil flow resistance further away from the transformer and improving the uniformity of cooling oil flow between different heat sinks. This indirectly improves the heat transfer uniformity of the entire heat sink group. The number of fractal channels increases in stages along the heat sink arrangement direction, balancing the heat transfer capacity between different heat sinks through changes in heat dissipation area and air-side turbulence modulation. The tortuous path and fractal contour of the extended surface of the heat sink substrate allow for unrestricted expansion of the overall specific surface area of ​​the radiator without compressing the airflow space between the heat sinks, enabling compact and miniaturized equipment while maintaining its heat dissipation capacity. The staggered through-holes on the heat sink solve the airflow obstruction problem between the heat sinks, especially improving the overall heat dissipation uniformity of the radiator under complex wind conditions, significantly reducing the system entropy increase. The through-holes also form an impact array on the surface of all heat sinks, significantly enhancing the air-side heat transfer capacity. Attached Figure Description

[0015] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0016] Figure 1 This is a three-dimensional view of a stepped fractal oil circuit radiator for transformers according to the present invention.

[0017] Figure 2 This is a partial view of the oil inlet pipe and the heat sink cavity inlet inside the oil inlet pipe.

[0018] Figure 3 This is a partial cross-sectional view of the heat sink and fractal flow channel.

[0019] Figure 4 This is a cross-sectional view of the heat sink.

[0020] Figure 5 It is a diagram showing the arrangement of fractal flow channels and through holes on the surface of each heat sink along the arrangement direction.

[0021] In the diagram: 1. Oil inlet pipe; 11. Inlet end; 2. Heat sink group; 21. Heat sink; 22. Fractal flow channel; 23. Through hole; 24. Substrate plate; 25. Cavity; 26. Oil distribution channel; 3. Oil outlet pipe; 31. Outlet end. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to its embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and do not limit the scope of protection of the invention.

[0023] Example like Figures 1-5 As shown, a stepped fractal oil circuit radiator for transformers consists of an oil inlet pipe 1, a heat sink group 2, and an oil outlet pipe 3. The oil inlet pipe 1 is an inclined pipe, the heat sink group 2 is composed of multiple heat sinks 21 arranged in parallel, the top of the heat sink 21 is connected to the oil inlet pipe 1, the surface of the heat sink 21 has fractal flow channels 22 with fractal contours and through holes 23, and the oil outlet pipe 3 is a horizontal pipe and is connected to the bottom of the heat sink 21.

[0024] Preferably, the inlet pipe 1 has an inclination angle of 30°, the heat sink group 2 consists of 7 to 10 heat sinks 21 of equal height arranged side by side, the fractal flow channels 22 are symmetrically arranged along both sides of the heat sink 21, and the through holes 23 are arranged in the center between adjacent fractal flow channels 22. The effect is that the flow velocity of the cooling oil in the inlet pipe 1 is moderate, the inlet cross-sectional area of ​​the heat sink 21 in the inlet pipe 1 naturally increases gradually along the flow direction, which is conducive to making the cooling oil flow rate into each heat sink 21 balanced, and there is no spatial interference between the through holes 23 and the fractal flow channels 22. The air-side heat transfer intensity of the heat sink 21 is evenly distributed.

[0025] The inlet end 11 of the oil inlet pipe 1 is located at the highest point of the entire device. The cross-sectional area of ​​the cavity 25 in the heat sink 21 gradually increases along the arrangement direction of the heat sink 21. The heat sink 21 is formed by the base plate 24 being closed and sealed. The fractal flow channel 22 protrudes along the surface of the base plate 24 to form a fractal surface. The fractal flow channel 22 is distributed in a tortuous manner along the surface of the base plate 24.

[0026] Preferably, the width of the cavity 25 within the heat sink 21 remains constant and is approximately equal to the width of the base plate 24. The protruding hydraulic diameter of the fractal flow channel 22 is slightly larger than the width of the cavity 25, and it is distributed in an S-shape on the surface of the base plate 24. The effect is that, due to the inclined arrangement of the oil inlet pipe 1 and the equal height of the heat sink 21, the inlet cross-sectional area of ​​the cavity 25 can be gradually increased along the arrangement direction of the heat sink 21 without increasing the width of the cavity 25, thereby improving the compactness of the radiator along the arrangement direction of the heat sink 21. In addition, the cooling oil tends to enter the fractal flow channel 22 in the cavity 25 and flows downward in it with lower resistance. At the same time, the fractal flow channel 22 does not cause spatial interference to adjacent heat sinks 21.

[0027] The number of fractal channels 22 increases in stages along the arrangement direction of the heat sink 21, forming a stepped fractal oil circuit radiator. The through holes 23 are located on the heat sink 21 and are evenly arranged near the curved section of the fractal channel 22. The through holes 23 on adjacent heat sinks 21 are staggered along the arrangement direction of the heat sink 21.

[0028] Preferably, a heat sink group 2 is composed of eight heat sinks 21. The first and second heat sinks 21 have five fractal flow channels 22 arranged on one side; the third to fifth heat sinks 21 have seven fractal flow channels 22 arranged on one side; and the sixth to eighth heat sinks have nine fractal flow channels 22 arranged on one side. The number and arrangement of through holes 23 on the first heat sink 21 are 3 rows × 4 columns; the number and arrangement of through holes 23 on the second heat sink 21 are 2 rows × 4 columns; the number and arrangement of through holes 23 on the third heat sink 21 are 3 rows × 3 columns; the number and arrangement of through holes 23 on the fourth heat sink 21 are 2 rows × 4 columns; the number and arrangement of through holes 23 on the fifth heat sink 21 are 3 rows × 3 columns; the number and arrangement of through holes 23 on the sixth heat sink 21 are 3 rows × 4 columns; and the number and arrangement of through holes 23 on the seventh heat sink 21 are... The number and arrangement of the 3 are 2 rows × 5 columns, and the number and arrangement of the through holes 23 on the eighth heat sink 21 are 3 rows × 4 columns. The effect is that the number of fractal flow channels 22 increases in a stepwise manner along the arrangement direction of the heat sink 21. The flow resistance in the downstream heat sink 21 is less than the flow resistance in the upstream heat sink 21, thereby enhancing the balance of cooling oil flow distribution between the fins and improving heat transfer uniformity. At the same time, it does not destroy the geometric constraints between the heat sink 21 and the oil inlet pipe 1 and the oil outlet pipe 3. In addition, it ensures that the through holes 23 on adjacent heat sinks 21 do not overlap along the arrangement direction of the heat sink 21, so that air jet impact can be formed on the air side surface of all heat sinks 21. At the same time, it ensures that the through holes 23 on each heat sink 21 are fully covered and evenly distributed, thereby forming uniform enhanced heat dissipation on the air side surface of all heat sinks 21.

[0029] The outlet end 31 of the oil outlet pipe 3 and the inlet end 11 of the oil inlet pipe 1 are located on the same side. Preferably, the oil outlet pipe 3 and the oil inlet pipe 1 are parallel in the vertical direction, and the outlet end 31 and the inlet end 11 are in the same position in the horizontal direction. This facilitates the installation and positioning between the radiator and the corresponding transformer.

[0030] There is a cavity 25 between the base plates 24 that make up the same heat sink 21. The cavity 25 is connected to the fractal flow channel 22. There is an oil distribution channel 26 between the oil inlet pipe 1 and the heat sink 21. The oil distribution channel 26 connects the oil inlet pipe 1, the fractal flow channel 22 and the cavity 25. After the cooling oil in the heat sink 21 descends, it flows directly into the oil outlet pipe 3.

[0031] Preferably, the oil distribution channels 26 within the same heat sink 21 have the same width as the cavity 25. The path of the oil distribution channels 26 is such that they start from the oil inlet pipe 1 and pass sequentially through the upper inlet of the fractal flow channel 22. The oil distribution channels 26 on both sides are axially symmetrical about the axis of the oil inlet pipe 1 on the heat sink 21. As a result, the cooling oil can be evenly distributed to the inlet of each fractal flow channel 22 under the action of gravity within the oil distribution channels 26, enhancing the uniformity of the cooling oil flow along the width direction of the heat sink 21, thereby further improving the uniformity of the heat transfer capacity distribution along the span of the radiator.

[0032] The fractal flow channel 22 extends downward from the oil distribution channel 26 to near the lower edge of the heat sink 21. The fractal surface constituting the fractal flow channel 22 is formed by sweeping along the path of the fractal flow channel 22 by two or more fractal curves. The bends of the fractal surface of the fractal flow channel 22 are rounded.

[0033] Preferably, the length of the fractal flow channel 22 on the same heat sink 21 is such that its lower end is distributed along the lower edge of the heat sink 21, and the fractal flow channel 22 is formed by sweeping along an S-shaped path with two levels of Koch curves from top to bottom. The bends of the fractal flow channel 22 contour curve are rounded with 90° rounded corners. The effect is to generate an orderly vortex system on the air side of the heat sink 21, thereby enhancing the air side heat transfer of the heat sink 21 under low resistance conditions, while effectively preventing the accumulation of cooling oil on the oil side of the heat sink 21 and clogging of the flow channel.

[0034] The total cross-sectional area of ​​the cavity 21 and the fractal flow channel 22 gradually increases along the arrangement direction of the heat sink 21. Preferably, the width of the cavity 21 remains constant, and its inlet length gradually increases along the arrangement direction of the heat sink 21 due to its connection with the inclined oil inlet pipe 1. The cross-sectional area of ​​a single fractal flow channel 22 increases gradually along the arrangement direction of the heat sink 21 at a rate of 3% to 5%. The effect is that the growth rate of the total cross-sectional area of ​​the cavity 21 and the fractal flow channel 22 is controlled by the increasing number of fractal flow channels 22 and the co-distribution of the cross-sectional area of ​​a single fractal flow channel 22, so that the variation range of the total cross-sectional area in the heat sink 21 along its arrangement direction is kept within a reasonable range.

[0035] All the through holes 23 on a single heat sink 21 form the base plate 24 of the heat sink 21. Preferably, the through holes 23 are circular holes with the hole axis parallel to the thickness direction of the base plate 24 and the hole diameter is slightly smaller than the hydraulic diameter of the fractal flow channel 22. The effect is that the highest jet impact intensity can be formed on the surface of the heat sink 21, and effective heat dissipation compensation can be formed for the weak heat transfer area between the air-side turbulence area of ​​the fractal flow channel 22. At the same time, it is convenient to open the hole.

[0036] The through holes 23 on a single heat sink 21 are uniformly arrayed and cover the surface of the heat sink 21. The through holes 23 are staggered so that they are completely opaque along the arrangement direction of the heat sink 21. Preferably, the through holes 23 are arranged on the centerline between adjacent fractal channels 22. For through holes 23 that just overlap along the width direction of the heat sink 21, the position of the through holes 23 can be adjusted along the height direction of the heat sink 21 to make them staggered. The effect is that the through holes 23 have a large position adjustment space and are not restricted by the path of the fractal channels 22. At the same time, in complex environmental wind conditions, a three-dimensional uniform impact heat transfer distribution is formed on the surface of the heat sink 21.

[0037] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the invention. Those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the protection scope of the present invention.

Claims

1. A stepped fractal oil circuit radiator for transformers, comprising an oil inlet pipe (1), a heat sink group (2), and an oil outlet pipe (3), characterized in that: The oil inlet pipe (1) is an inclined pipe, the heat sink group (2) is composed of multiple heat sinks (21) arranged in parallel, the top of the heat sink (21) is connected to the oil inlet pipe (1), the surface of the heat sink (21) has a fractal flow channel (22) with a fractal profile and a through hole (23), and the oil outlet pipe (3) is a horizontal pipe and is connected to the bottom of the heat sink (21); The inlet end (11) of the oil inlet pipe (1) is located at the highest point of the entire device. The cross-sectional area of ​​the cavity (25) in the heat sink (21) gradually increases along the flow direction of the oil inlet pipe (1). The heat sink (21) is formed by closing and sealing the base plate (24). The fractal flow channel (22) protrudes along the surface of the base plate (24) to form a fractal surface. The fractal flow channel (22) is distributed in a tortuous manner along the surface of the base plate (24). The number of fractal channels (22) increases in stages along the arrangement direction of the heat sink (21), forming a stepped fractal oil circuit radiator. The through holes (23) are located on the heat sink (21) and are evenly arranged near the curved section of the fractal channels (22). The through holes (23) on adjacent heat sinks (21) are staggered along the arrangement direction of the heat sink (21). The outlet end (31) of the oil outlet pipe (3) and the inlet end (11) of the oil inlet pipe (1) are located on the same side.

2. The stepped fractal oil circuit radiator for transformers as described in claim 1, characterized in that: There is a cavity (25) between the base plates (24) that constitute the same heat sink (21). The cavity (25) is connected to the fractal flow channel. There is an oil distribution channel (26) between the oil inlet pipe (1) and the heat sink (21). The oil distribution channel (26) connects the oil inlet pipe (1), the fractal flow channel (22) and the cavity (25). The cooling oil in the heat sink (21) flows down and directly flows into the oil outlet pipe (3).

3. A stepped fractal oil circuit radiator for a transformer as described in claim 1 or 2, characterized in that: The fractal flow channel (22) extends downward from the oil distribution channel (26) to near the lower edge of the heat sink (21). The fractal surface constituting the fractal flow channel (22) is formed by sweeping along the path of the fractal flow channel (22) by two or more fractal curves. The bends of the fractal surface of the fractal flow channel (22) are rounded.

4. A stepped fractal oil circuit radiator for a transformer as described in any one of claims 1 to 3, characterized in that: The total cross-sectional area of ​​the cavity (25) and the fractal flow channel (22) gradually increases along the arrangement direction of the heat sink (21).

5. A stepped fractal oil circuit radiator for transformers as described in claim 1, characterized in that: All the through holes (23) on the single heat sink (21) extend through the base plate (24) that constitutes the heat sink (21).

6. A stepped fractal oil circuit radiator for a transformer as described in claim 1 or 5, characterized in that: The through holes (23) on a single heat sink (21) are arranged in a uniform array to cover the surface of the heat sink (21), and the through holes (23) are staggered to make the heat sink (21) completely opaque.

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