Compact low-voltage cabinet with high heat dissipation performance

Abstract

The utility model relates to a compact low-voltage cabinet with high heat dissipation performance, which comprises a low-voltage cabinet body, a frame circuit breaker is arranged in the middle of the low-voltage cabinet body and comprises a frame circuit breaker upper busbar and a frame circuit breaker lower busbar, and an axial flow fan mounting seat is arranged on the outer side of the middle of the low-voltage cabinet body. The low-voltage cabinet body is provided with an axial flow fan mounting base, the axial flow fan mounting base comprises an upper end plate, an upper transverse plate, an inclined plate and a lower transverse plate which are connected in sequence, side baffles are arranged on the two sides between the upper transverse plate and the lower transverse plate, an axial flow fan is mounted on the inclined plate, an air outlet of the axial flow fan faces an upper busbar of the frame circuit breaker, and a ventilation opening is formed in the lower end of the low-voltage cabinet body. According to the utility model, the inclined axial flow fan is utilized to directly blow to the busbar on the frame circuit breaker, so that the low-voltage cabinet of the box-type substation has better heat dissipation performance.

Description

Technical Field

[0001] This utility model relates to the field of prefabricated substations, specifically a compact low-voltage switchgear with high heat dissipation performance. Background Technology

[0002] Prefabricated substations are widely used in various string and centralized photovoltaic power stations. String-type prefabricated substations typically use a combination of frame circuit breakers, copper busbars, molded case circuit breakers, and incoming cables for their low-voltage side cabinets, while centralized prefabricated substations typically use a combination of frame circuit breakers, copper busbars, and incoming cables. As the variety and capacity of prefabricated substations increase, the specifications of frame circuit breakers and their copper busbars are also becoming larger. For example, in an 800V AC system, the frame rating of the frame circuit breaker can reach 5000A, 6000A, or even 8000A, which leads to increased heat generation within the cabinet. Furthermore, the layout design of the low-voltage cabinet requires greater compactness. For instance, patents such as CN219286948U and CN207124385U disclose compact low-voltage cabinets with different structures. However, a compact layout also reduces the internal space, making it easier for heat to accumulate and causing temperature increases. Furthermore, with the increasing number of secondary communication and protection devices in the transformer substation, the added heat-generating components will further lead to an increase in the internal temperature of the low-voltage cabinet.

[0003] The busbar of a frame circuit breaker is a core component for carrying and distributing electrical energy. If the internal temperature of the low-voltage cabinet is too high, it will affect the busbar of the frame circuit breaker. First, the high temperature inside the cabinet will accelerate the aging of the busbar insulation material, which will reduce the insulation performance of the busbar and cause partial discharge or creepage. Second, the high temperature at the busbar connection will also accelerate the oxidation of metal and the formation of an oxide film. This will lead to an increase in contact resistance and further aggravate the heating, thus forming a vicious cycle of "thermal runaway". In severe cases, it will cause the connection point to melt or even cause arc discharge.

[0004] Existing low-voltage switchgear heat dissipation structures in prefabricated substations typically employ an upper-end fan and a lower-end heat dissipation vent. This structure allows air inside the switchgear to circulate with outdoor air, carrying away heat from the switchgear. For example, patent CN207559306U discloses a low-voltage switchgear busbar box with a cooling fan structure, featuring a cooling fan body at the upper end and heat dissipation holes around the lower perimeter. However, for compact low-voltage switchgear with the frame circuit breaker busbar located in the middle, the heat dissipation effect of the above-mentioned structure is insufficient to meet the heat dissipation needs of the frame circuit breaker busbar, especially at the overlap of the upper and lower busbars of the frame circuit breaker. Relying solely on the air circulation method within the low-voltage switchgear to remove the heat generated at the copper busbar overlap is far from adequate. Utility Model Content

[0005] The purpose of this invention is to provide a compact low-voltage switchgear with high heat dissipation performance, which utilizes an inclined axial flow fan to directly blow air onto the busbar of the frame circuit breaker, thereby giving the low-voltage switchgear of the box-type substation better heat dissipation performance.

[0006] The objective of this utility model is achieved through the following technical solution:

[0007] A compact low-voltage switchgear with high heat dissipation performance includes a low-voltage cabinet. A frame circuit breaker is installed inside the middle of the low-voltage cabinet. The frame circuit breaker includes an upper busbar and a lower busbar. An axial flow fan mounting base is provided on the outer side of the middle of the low-voltage cabinet. The axial flow fan mounting base includes an upper end plate, an upper horizontal plate, an inclined plate, and a lower horizontal plate connected in sequence. Side baffles are provided on both sides between the upper and lower horizontal plates. The axial flow fan is installed on the inclined plate, and the air outlet of the axial flow fan faces the upper busbar of the frame circuit breaker. A ventilation opening is provided at the lower end of the low-voltage cabinet.

[0008] The upper horizontal plate, lower horizontal plate, and side baffles on both sides form a guide hood that directs the airflow.

[0009] A filter screen is installed on the inclined plate at the position corresponding to the air outlet of the axial flow fan.

[0010] The low-pressure cabinet is equipped with a temperature sensor, and the axial flow fan starts when the temperature sensor detects that the ambient temperature inside the low-pressure cabinet exceeds the set temperature.

[0011] The low-voltage cabinet is equipped with a cooling fan at the top.

[0012] The lower horizontal plate of the axial flow fan mounting base is provided with a lower end plate at the end away from the inclined plate, and the upper end plate and the lower end plate are respectively fixed to the low-voltage cabinet by bolts.

[0013] Both the upper and lower end plates are provided with horizontal adjustment slots, and the low-voltage cabinet is provided with vertical adjustment slots. The horizontal adjustment slots and the corresponding vertical adjustment slots are arranged perpendicularly and intersecting each other. After passing through the corresponding set of horizontal and vertical adjustment slots, the bolt is connected to the nut, and the nut is located at the outer end of the bolt.

[0014] The low-voltage cabinet has two protective baffles on its outer side, and the lower ends of the two protective baffles are connected by a lower baffle. The axial flow fan mounting base is located between the two protective baffles, and the top end of the upper plate of the axial flow fan mounting base has an adapter sleeve that is rotatably fitted onto a hinge shaft. The two ends of the hinge shaft are respectively installed on the protective baffles on the corresponding sides. The lower end of the protective baffle has an arc-shaped adjustment groove. The lower end of the side baffle of the axial flow fan mounting base has an adjustment slide shaft, and the adjustment slide shaft passes through the adjustment groove on the corresponding side. The adjustment slide shaft has two locking nuts, one of which is located inside the side baffle and the other is located outside the protective baffle.

[0015] The advantages and positive effects of this utility model are as follows:

[0016] 1. This utility model utilizes an inclined axial flow fan to directly blow air onto the upper busbar of the frame circuit breaker, thereby enabling the air to flow downwards at a greater flow rate and faster, and finally exiting from the ventilation opening at the lower end of the low-voltage cabinet. This effectively reduces the temperature of the upper and lower busbars of the frame circuit breaker, eliminating potential safety and quality hazards to the low-voltage cabinet caused by excessively high temperatures at the busbar overlap.

[0017] 2. The axial flow fan mounting base of this utility model uses an upper horizontal plate, a lower horizontal plate, and side baffles on both sides to form a guide cover to guide the airflow, which can minimize the loss of airflow from the axial flow fan.

[0018] 3. The axial flow fan mounting base of this utility model can be a fixed structure or an adjustable structure, which makes it convenient to adjust according to the position of the busbar on the frame circuit breaker inside the low-voltage cabinet, thus improving the flexibility of use.

[0019] 4. This utility model places the axial flow fan and its mounting base outside the low-voltage cabinet, which does not occupy the internal space of the low-voltage cabinet, thus ensuring a compact layout inside the low-voltage cabinet. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the internal structure of this utility model.

[0021] Figure 2 for Figure 1 Left view of the present invention.

[0022] Figure 3 for Figure 2 Enlarged schematic diagram of the mounting base for a central axial flow fan.

[0023] Figure 4 for Figure 3 AA section view,

[0024] Figure 5This is a front view of another axial flow fan mounting base used in this utility model.

[0025] Figure 6 for Figure 5 Right view of the mounting base for the axial flow fan.

[0026] Figure 7 for Figure 6 A schematic diagram showing the state of the mounting base of the axial flow fan after angle adjustment.

[0027] Among them, 1 is the low-voltage cabinet, 101 is the upper busbar of the frame circuit breaker, 102 is the lower busbar of the frame circuit breaker, 103 is the main busbar, 104 is the knife fuse switch, 105 is the low-voltage voltage transformer, 106 is the electricity meter, 107 is the fuse, 108 is the terminal box, 109 is the vertical adjustment slot, 2 is the axial flow fan mounting base, 201 is the upper end plate, 202 is the inclined plate, 203 is the lower end plate, 204 is the side baffle, 205 is the horizontal adjustment slot, 206 is the upper horizontal plate, 207 is the lower horizontal plate, 208 is the adjusting slide shaft, 209 is the locking nut, 210 is the protective baffle, 2101 is the adjusting slide groove, 2102 is the lower baffle, 211 is the hinge shaft, 3 is the axial flow fan, and 4 is the filter screen. Detailed Implementation

[0028] The present invention will now be described in further detail with reference to the accompanying drawings.

[0029] like Figures 1-7 As shown, this utility model includes a low-voltage cabinet 1, and as... Figure 1 As shown, a frame circuit breaker is installed inside the middle of the low-voltage cabinet 1. The frame circuit breaker includes an upper busbar 101 and a lower busbar 102. An axial flow fan mounting base 2 is installed on the outer side of the middle of the low-voltage cabinet 1. Figures 3-7 As shown, the axial flow fan mounting base 2 includes an upper end plate 201, an upper horizontal plate 206, an inclined plate 202, and a lower horizontal plate 207 connected in sequence, and side baffles 204 are provided on both sides between the upper horizontal plate 206 and the lower horizontal plate 207, as shown. Figure 1 As shown, the axial flow fan 3 is installed on the inclined plate 202, and the air outlet of the axial flow fan 3 faces the upper busbar 101 of the frame circuit breaker. The lower end of the low-voltage cabinet 1 is provided with a ventilation opening.

[0030] This invention utilizes the axial flow fan 3 to directly blow air onto the upper busbar 101 of the frame circuit breaker, and causes the air to flow downwards along the lower busbar 102 of the frame circuit breaker, finally exiting through the ventilation opening at the lower end of the low-voltage cabinet 1. This airflow generated by the axial flow fan 3 directly removes the heat generated by the upper and lower busbars 101 and 102 of the frame circuit breaker, effectively reducing their temperatures. Furthermore, the upper horizontal plate 206, lower horizontal plate 207, and side baffles 204 on both sides form a guide shroud to guide the airflow, minimizing air loss from the axial flow fan 3. Simultaneously, the guide shroud further prevents external foreign objects from entering the low-voltage cabinet 1.

[0031] like Figure 1 and Figure 4 As shown, a filter screen 4 is provided on the inclined plate 202 at the position corresponding to the air outlet of the axial flow fan 3 to prevent foreign objects from being blown into the cabinet. In this embodiment, the filter screen 4 is a 3-10 mesh steel wire mesh.

[0032] like Figure 1 As shown in this embodiment, the upper part of the low-voltage cabinet 1 is equipped with components such as an electricity meter 106 and a fuse 107. The upper part of the low-voltage cabinet 1 is equipped with a low-voltage voltage transformer 105. The middle part of the low-voltage cabinet 1 is equipped with a knife-fuse switch 104. The lower part of the low-voltage cabinet 1 is equipped with a main busbar 103. The side of the low-voltage cabinet 1 away from the axial flow fan 3 is equipped with a terminal box 108. The electricity meter 106, fuse 107, low-voltage voltage transformer 105, knife-fuse switch 104, main busbar 103, terminal box 108, etc. are all technologies known in the art.

[0033] A temperature sensor is installed at a suitable location inside the low-pressure cabinet 1 to monitor the internal temperature in real time. In this embodiment, the angle α between the inclined plate 202 and the horizontal plane is ≥60°, and the axial flow fan 3 starts when the internal ambient temperature of the low-pressure cabinet 1 exceeds 45°C and stops when the internal ambient temperature of the low-pressure cabinet 1 is ≤45°C. The temperature sensor is a commercially available product.

[0034] The upper end of the low-voltage cabinet 1 can be equipped with a conventional cooling fan as needed. This is a well-known technology in the field. For example, see patent CN207559306U. In this case, the electricity meter 106, fuse 107 and other components inside the upper end of the low-voltage cabinet 1 can be cooled by the cooling fan. The axial flow fan 3 is mainly used to cool the upper busbar 101 and lower busbar 102 of the frame circuit breaker, which generate a lot of heat.

[0035] In one embodiment of this utility model, the axial flow fan mounting base 2 can be fixed to the low-pressure cabinet 1, such as... Figure 4As shown, in this embodiment, the lower horizontal plate 207 of the axial fan mounting base 2 is provided with a lower end plate 203 at the end away from the inclined plate 202, and the upper end plate 201 and the lower end plate 203 are fixed to the low-pressure cabinet 1 by bolts.

[0036] In another embodiment of this utility model, the axial flow fan mounting base 2 can be finely adjusted up and down or left and right according to the position of the busbar 101 on the frame circuit breaker, such as... Figure 3 As shown, in this embodiment, both the upper end plate 201 and the lower end plate 203 are provided with horizontal adjustment grooves 205, and the low-voltage cabinet 1 is provided with vertical adjustment grooves 109. The horizontal adjustment grooves 205 and the corresponding vertical adjustment grooves 109 are arranged perpendicularly and intersectingly. After the bolt passes through the corresponding set of horizontal adjustment grooves 205 and vertical adjustment grooves 109, it is connected to the nut. The nut is located at the outer end of the bolt. When adjusting, the operator screws the nut outward (but does not disengage it from the bolt) so that it is no longer clamped with the bolt nut. At this time, the position of the axial flow fan mounting base 2 can be finely adjusted to ensure that its air outlet can be aligned with the busbar 101 on the frame circuit breaker as much as possible. When the axial flow fan mounting base 2 is adjusted up and down, it drives the bolt to move along the vertical adjustment groove 109. When the axial flow fan mounting base 2 is adjusted left and right, the axial flow fan mounting base 2 is first lifted to the required height by the operator or other auxiliary tools, and then the axial flow fan mounting base 2 is driven to move left and right. At this time, the bolt moves relative to the horizontal adjustment groove 205.

[0037] In another embodiment of this utility model, the axial flow fan mounting base 2 can be adjusted in angle according to the position of the busbar 101 on the frame circuit breaker, such as... Figures 5-7 As shown, in this embodiment, the low-pressure cabinet 1 has two protective baffles 210 on its outer side, and the lower ends of the two protective baffles 210 are connected by a lower baffle 2102. The axial flow fan mounting base 2 is located between the two protective baffles 210, and the top end of the upper plate 201 of the axial flow fan mounting base 2 has an adapter sleeve that is rotatably fitted onto a hinge shaft 211. The two ends of the hinge shaft 211 are respectively installed on the protective baffles 210 on the corresponding sides. The lower end of the protective baffle 210 has an arc-shaped adjusting groove 2101. The lower end of the side baffle 204 of the axial flow fan mounting base 2 has an adjusting slide shaft 208, and the adjusting slide shaft 208 passes through the adjusting groove 2101 on the corresponding side. The adjusting slide shaft 208 has two locking nuts 209, one locking nut 209 is located inside the side baffle 204, and the other locking nut 209 is located outside the protective baffle 210. In this embodiment, during adjustment, as follows... Figures 6-7As shown, the operator screws the locking nut 209 on the outer side of the protective baffle 210 outward (without disengaging it from the adjusting slide shaft 208) so that the two locking nuts 209 on the adjusting slide shaft 208 no longer clamp the side baffle 204 and the protective baffle 210 on the corresponding side. At this time, the axial flow fan mounting base 2 can rotate around the hinge shaft 211 to achieve angle adjustment, and as shown... Figure 7 As shown, after the axial fan mounting base 2 is rotated outward to its maximum angle, the β-angle gap formed between the axial fan mounting base 2 and the low-pressure cabinet 1 can still be blocked by the protective baffle 210. This can minimize the loss of air from the axial fan 3 and prevent foreign objects from entering the low-pressure cabinet 1 through the β-angle gap. At this time, there will be a narrow gap between the lower end of the axial fan mounting base 2 and the lower baffle 2101. At the same time, a section of the adjusting slide 2101 will not be blocked by the side baffle 204, forming a gap. However, the gaps are extremely limited and have little impact on the air output of the axial fan 3, which can be ignored. After the angle of the axial fan mounting base 2 is adjusted, the locking nut 209 on the outside of the protective baffle 210 is tightened again to re-cooperate with the locking nut 209 on the inside of the side baffle 204 to lock both sides of the axial fan mounting base 2.

[0038] The working principle of this utility model is as follows:

[0039] In addition to using a conventional upper cooling fan to dissipate heat through airflow inside the low-voltage cabinet 1, this invention also features an inclined axial fan 3 on one side of the middle of the low-voltage cabinet 1. The airflow from the axial fan 3 is directly directed towards the upper busbar 101 of the frame circuit breaker, allowing air to flow downwards along the lower busbar 102 of the frame circuit breaker at a greater flow rate and faster, and finally exiting through the ventilation opening at the lower end of the low-voltage cabinet 1. This effectively reduces the temperature of the upper busbar 101 and the lower busbar 102 of the frame circuit breaker, eliminating potential safety and quality hazards to the low-voltage cabinet caused by excessively high temperatures at the busbar joints.

Claims

1. A compact low voltage switchgear with high heat dissipation performance, characterized in that: The device includes a low-voltage cabinet (1), in which a frame circuit breaker is provided in the middle, and the frame circuit breaker includes an upper busbar (101) and a lower busbar (102). An axial flow fan mounting base (2) is provided on the outer side of the middle of the low-voltage cabinet (1), and the axial flow fan mounting base (2) includes an upper end plate (201), an upper horizontal plate (206), an inclined plate (202) and a lower horizontal plate (207) connected in sequence. Side baffles (204) are provided on both sides between the upper horizontal plate (206) and the lower horizontal plate (207). An axial flow fan (3) is installed on the inclined plate (202), and the air outlet of the axial flow fan (3) faces the upper busbar (101) of the frame circuit breaker. A ventilation opening is provided at the lower end of the low-voltage cabinet (1).

2. The compact low-voltage switchgear with high heat dissipation performance according to claim 1, characterized in that: The upper horizontal plate (206), the lower horizontal plate (207), and the side baffles (204) on both sides form a guide hood that guides the airflow.

3. The compact low-voltage switchgear with high heat dissipation performance according to claim 1, characterized in that: A filter screen (4) is provided on the inclined plate (202) at the position corresponding to the air outlet of the axial flow fan (3).

4. The compact low-voltage switchgear with high heat dissipation performance according to claim 1, characterized in that: The low-pressure cabinet (1) is equipped with a temperature sensor, and the axial flow fan (3) starts when the temperature sensor detects that the ambient temperature inside the low-pressure cabinet (1) exceeds the set temperature.

5. The compact low-voltage switchgear with high heat dissipation performance according to claim 1, characterized in that: The low-pressure cabinet (1) is equipped with a cooling fan at the top.

6. The compact low-voltage switchgear with high heat dissipation performance according to claim 1, characterized in that: The lower horizontal plate (207) of the axial fan mounting base (2) is provided with a lower end plate (203) at the end away from the inclined plate (202), and the upper end plate (201) and the lower end plate (203) are respectively fixed to the low-pressure cabinet (1) by bolts.

7. The compact low-voltage switchgear with high heat dissipation performance according to claim 6, characterized in that: Both the upper end plate (201) and the lower end plate (203) are provided with horizontal adjustment grooves (205), and the low-voltage cabinet (1) is provided with vertical adjustment grooves (109). The horizontal adjustment grooves (205) and the corresponding vertical adjustment grooves (109) are arranged perpendicularly and intersecting each other. After the bolt passes through the corresponding set of horizontal adjustment grooves (205) and vertical adjustment grooves (109), it is connected to the nut, and the nut is located at the outer end of the bolt.

8. The compact low-voltage switchgear with high heat dissipation performance according to claim 1, characterized in that: The low-pressure cabinet (1) is provided with two protective baffles (210) on its outer side, and the lower ends of the two protective baffles (210) are connected by a lower baffle (2102). The axial flow fan mounting base (2) is located between the two protective baffles (210), and the top end of the upper plate (201) of the axial flow fan mounting base (2) is provided with a transition sleeve that is rotatably fitted onto a hinge shaft (211). The two ends of the hinge shaft (211) are respectively installed on the protective baffles (210) on the corresponding sides. (210) The lower end is provided with an arc-shaped adjustment groove (2101). The lower end of the side baffle (204) of the axial flow fan mounting base (2) is provided with an adjustment slide shaft (208). The adjustment slide shaft (208) passes through the adjustment groove (2101) on the corresponding side. The adjustment slide shaft (208) is provided with two locking nuts (209). One locking nut (209) is located inside the side baffle (204), and the other locking nut (209) is located outside the protective baffle (210).

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