A gas-insulated metal-enclosed switchgear with easy heat dissipation

Abstract

A gas-insulated metal-enclosed switchgear that is easy to dissipate heat, wherein a heat dissipation top cover (11) is provided on the top of the switchgear, and the interior of the switchgear is divided into a front cabinet (7), a middle cabinet (23) and a rear cabinet (25); a square air chamber (20) is fixedly supported by an air chamber bracket (24) in the middle of the middle cabinet (23); the square air chamber (20) includes an outlet bushing (8), a copper busbar (18), a 4# inner cone (17) and a heating element of a test joint (2# inner cone) (21) which are evenly and dispersedly arranged in the square air chamber (20); three vertical outlet bushings (8) externally connected to a connecting busbar (9) located above the square air chamber (20) are arranged in an oblique "I" shape on the front of the top plate of the square air chamber (20); a circuit breaker (4) and an isolating switch (6) located in the front cabinet are installed on an aluminum alloy installation plate (5) to form a whole, and then installed on the front plate of the square air chamber (20). The present invention can control the temperature rise of a series of gas-insulated metal-enclosed switchgear within a reasonable range.

Description

Technical Field

[0001] The invention relates to a series of gas-insulated metal-enclosed switch cabinets which are easy to dissipate heat in the power industry. Background Art

[0002] The series of gas-insulated metal-enclosed switchgear C-GIS belongs to the power distribution equipment in the medium voltage field. The voltage level is generally 7.2~40.5kV, and the current level is generally divided into 630A, 1250A, 2000A, 2500A, and 3150A. The gas chamber is welded by stainless steel plates. The primary flow part is encapsulated in a closed gas chamber. The relative pressure inside the gas chamber is 0.02~0.05 MPa. The gas is generally pure SF6 gas, compressed air, compressed N2, compressed CO2, CF4, C-C4F8, C3F8, C2F6, CF3I, and a mixture of SF6 and the above gases. The series of gas-insulated metal-enclosed switchgear is suitable for 7.2~40.5kV transmission and distribution systems to receive and distribute electric energy, and realize real-time control, protection, measurement, monitoring, communication and other functions of the power system in normal operation and fault conditions. It is suitable for control and protection in places such as power, metallurgy, ports, construction, chemical industry, electrified railways, etc., and is particularly suitable for use in harsh environmental conditions such as underground, plateau, frozen soil, coastal, and humid environments. As more users recognize the miniaturization and maintenance-free requirements of the series of gas-insulated metal-enclosed switchgear, this series of products is widely used in various places, which also brings higher and higher requirements for the rated current level. The current levels of 2000A and 2500A have been widely used in the industry, and some industries and some places require the use of current levels of 1.1×2500A and 1.1×3150A.

[0003] Compared with air-insulated metal-enclosed switchgear, the heating power of the two switchgears is basically the same under the condition of the same current level, but the air-insulated metal-enclosed switchgear is much larger than the gas-insulated metal-enclosed switchgear, and the overall heat dissipation area is also much larger, and its heat dissipation effect is better. The primary circuit part of the air-insulated metal-enclosed switchgear is generally equipped with a busbar room, a circuit breaker room and a cable room. The compartments are generally separated by metal partitions. The protection level is generally IP2X. The heat exchange between the compartments can be carried out by convection. The heat in the higher temperature area can be transferred to the lower temperature area by convection. There are heat dissipation holes in many positions of the air-insulated switchgear, which can realize convection with the external environment, or forced convection can be realized by installing a fan; fundamentally solving the problem of excessive temperature rise of the switchgear.

[0004] The primary circuit part of the gas-insulated metal-enclosed switchgear is also equipped with a busbar chamber, a circuit breaker chamber and a cable chamber. Due to different design ideas, it is generally divided into a double-chamber structure and a single-chamber structure. The double-chamber structure is to seal the busbar part and the three-position isolating / earthing switch in one chamber, called the busbar chamber, and the circuit breaker is sealed in another chamber, called the circuit breaker chamber. The two chambers are connected to the primary conductive part by embedding solid insulating flanges. The single-chamber structure is to encapsulate the busbar part with solid insulation encapsulation technology, seal the three-position isolating / earthing switch and the circuit breaker in one chamber, and design a special insulating cone to connect the insulated busbar with the primary conductive part in the sealed chamber. Regardless of whether it is a double-chamber structure or a single-chamber structure, in order to prevent the leakage of insulating gas, the primary conductive part and the insulating gas are completely enclosed in a sealed chamber, and the protection level of the chamber is generally IP65~IP67. It is difficult to take away the heat of the heating components by gas convection between the chambers and the chambers to the outside. At the same time, in order to reduce the heat caused by ferromagnetic eddy current loss and meet the requirements of corrosion resistance and high strength, the air chamber is welded from stainless steel plates. The heat generated inside the air chamber can only be exchanged with the outside world through the stainless steel plates, and the thermal conductivity of stainless steel plates is very low, so less heat is conducted out through stainless steel plates. Therefore, as users' demand for gas-insulated switchgear, especially high-current equipment, increases, it is particularly important to solve the temperature rise problem of high current.

[0005] At present, it is difficult for gas-insulated metal-enclosed switchgear, especially high-current equipment, to meet the temperature rise requirements of national standards and relevant user standards. The problem of excessive temperature rise is becoming more and more prominent. The excessive temperature rise of the switchgear directly affects the safe and stable operation of the equipment. In some areas with heavy loads, the internal overheating of the switchgear has become a common problem in the use of the switchgear. Practice has proved that the temperature rise problem seriously affects the stability and service life of the switchgear operation. Moreover, the overheating problem is an evolving process. If it is not controlled, the degree of overheating will continue to increase and have a great impact on the performance of the insulation parts and the life of the equipment. First, it will reduce the insulation of the insulation parts. Secondly, due to the large temperature changes, the various components in the cabinet will expand to varying degrees. The asynchronous expansion will cause the cracking and deformation of the components or cause air leakage in the air chamber, resulting in more serious consequences. In actual operation, due to improper methods of taking forced air cooling measures, unreasonable air duct design, unreasonable heat dissipation design, etc., the phenomenon of excessive temperature rise of the switchgear still exists.

[0006] For the series of gas-insulated metal-enclosed switchgear (hereinafter referred to as switchgear) with a rated current level of 2500A and below, the relevant standards and user requirements require the use of natural cooling (hereinafter referred to as self-cooling) to solve the temperature rise problem.

[0007] When the rated current level of the equipment reaches 3150A, forced air cooling with an exhaust fan (hereinafter referred to as self-cooling + air cooling) is adopted to meet the temperature rise requirements of national standards and relevant user standards. Summary of the invention

[0008] The technical problem to be solved by the present invention is to provide a gas-insulated metal-enclosed switchgear that is easy to dissipate heat, which can control the temperature rise of a series of gas-insulated metal-enclosed switchgear within a reasonable range, thereby solving the problem that the temperature rise of current gas-insulated metal-enclosed switchgear cannot meet the national standard product rated current and the relevant user standard requirement of 1.1×product rated current.

[0009] To solve the above technical problems, the technical solution adopted by the present invention is as follows:

[0010] A gas-insulated metal-enclosed switch cabinet that is easy to dissipate heat, characterized in that: a heat dissipation top cover 11 is provided on the top of the switch cabinet, and the interior of the switch cabinet is divided into a front cabinet 7, a middle cabinet 23 and a rear cabinet 25;

[0011] A square air chamber 20 is fixedly supported by an air chamber bracket 24 in the middle of the middle cabinet 23. The square air chamber 20 includes the outlet bushing 8, the copper busbar 18, the 4# inner cone 17 and the heating elements of the test joint 2# inner cone 21, which are evenly and dispersedly arranged in the square air chamber 20.

[0012] The three vertical outlet bushings 8 externally connected to the connecting busbar 9 located above the square air chamber 20 are arranged in an oblique "I" shape at the front of the top plate of the square air chamber 20. In the embodiment, three are arranged in a straight line, one is located at a front corner of the top plate of the square air chamber 20, and the other two extend obliquely to the opposite sides;

[0013] The circuit breaker 4 and the isolating switch 6 located in the front cabinet are mounted on the aluminum alloy mounting plate 5 to form a whole, and then mounted on the opening of the front plate of the square air chamber 20 so that the heat in the square air chamber is directly transferred to the aluminum alloy mounting plate.

[0014] Preferably, the front cabinet 7 and the middle cabinet 23 are separated by a first lower mounting partition 2 and an upper partition 10, the first mounting partition 2 is located at the lower part between the front and middle cabinets, the partition 10 is located at the upper part between the front and middle cabinets, the middle cabinet 23 and the rear cabinet 25 are separated by a second mounting partition 15 at the upper part, and the middle cabinet 23 and the rear cabinet 25 have no partition at the lower part and are connected to each other.

[0015] On the basis of the above, the present invention can also have the following preferred solutions for various current levels:

[0016] 1. For switchgear with current level of 1.1×3150A1.1×2500A≯current≤1.1×3150A:

[0017] The insulated tubular busbar 13 on the top of the switch cabinet is vertically connected, that is, the busbar outside the square air chamber is encapsulated with solid insulation, the first current transformer 12 is installed above the square air chamber 20 of the middle cabinet 23, and the three 4# inner cones (17) of the insulated tubular busbar 13 connected to the first current transformer 12 are arranged in a "pin" shape at the rear of the top plate of the square air chamber 20;

[0018] A first heat dissipation air chamber 19 made of aluminum alloy is arranged outside the rear plate of the square air chamber 20 and is connected to the square air chamber 20. The inner and outer surfaces of the first heat dissipation air chamber 19 are provided with heat dissipation fins and are sprayed with black heat dissipation paint.

[0019] The first fan 3 is installed on the lower first mounting partition 2 between the front cabinet 7 and the middle cabinet 23 of the switch cabinet; the second fan 16 is installed on the second mounting partition 13 on the middle cabinet 23 and the rear cabinet 25, and corresponding ventilation holes 28 are opened at the lower part of the front door 1 of the front cabinet 7, the lower part of the rear sealing plate 27 of the rear cabinet 25 and the cabinet top.

[0020] The first fan 3 and the second fan 16 are two or more fans connected in parallel.

[0021] The bottom plate of the square air chamber 20 is provided with a pressure release device 22 according to the prior art.

[0022] The heat dissipation chamber is of prior art, namely, a plurality of heat sinks. The heat dissipation chamber 30 is connected with the square chamber 20 by opening a hole in the wall of the square chamber and sealing it directly with the wall of the heat dissipation chamber, so that the heat in the square chamber is directly transferred to the heat dissipation chamber.

[0023] 2. For switchgear with current level of 1.1×2500A1.1×1250A≯current≤1.1×2500A:

[0024] The cable 32 at the bottom of the switch cabinet is vertically inlet / outlet. The second current transformer 29 is installed below the square air chamber 20 of the middle cabinet 23. The cables 32 (3 single-phase cables, 9 three-phase cables) connected to the second current transformer 29 are arranged side by side at the bottom of the square air chamber 20. The 3# inner cones 31 (3 single-phase cables, 9 three-phase cables) in the square air chamber 20 are evenly distributed on the bottom plate of the square air chamber 20.

[0025] A first heat dissipation air chamber 19 and a second heat dissipation air chamber 30 made of aluminum alloy are respectively arranged outside the rear plate of the square air chamber 20 and at the rear of the top plate and are connected to the square air chamber 20. The inner and outer surfaces of the first and second heat dissipation air chambers are provided with heat sinks and sprayed with black heat dissipation paint.

[0026] A pressure release device 22 is provided on the side of the second heat dissipation air chamber 30 .

[0027] 3. For switchgear with current level of 1.1×1250A and current ≤1.1×1250A:

[0028] The cable 32 at the bottom of the switch cabinet is vertically inlet / outlet. The second current transformer 29 is installed below the square air chamber 20 of the middle cabinet 23. The external cable connector 33 of the second current transformer 29 is arranged side by side at the front and bottom of the square air chamber 20 and evenly distributed.

[0029] A heat dissipation cover plate 34 made of aluminum alloy is installed outside the rear plate of the square air chamber 20 and is in close contact with the rear plate of the square air chamber 20 ; the inner and outer surfaces of the heat dissipation cover plate 34 are provided with heat dissipation fins and are sprayed with black heat dissipation paint.

[0030] A pressure release device 22 is provided at the rear of the bottom plate of the square air chamber 20 .

[0031] The present invention has the following advantages:

[0032] 1. Different forms of heat dissipation solutions are set according to different current levels and different requirements, which effectively solves the temperature rise problem of the switch cabinet. It cleverly combines heat conduction, convection and radiation. While increasing the heat dissipation area of ​​the air chamber and increasing radiation heat dissipation, it rationally utilizes the thermal conductivity of the material to enhance heat conduction, rationally arranges components and connects copper busbars, and reduces the area where the local heating temperature is too high.

[0033] 2. Use the "double-fan forced circulation heat dissipation design" to speed up the flow of gas outside the air chamber, and use gas convection to quickly transfer and diffuse heat, so as to effectively reduce the overall temperature of the air chamber.

[0034] 3. By utilizing the "self-cooling double chimney heat dissipation design" and the principle of "chimney effect", a "double chimney" is formed inside the switch cabinet, forming a local gas circulation in the switch cabinet, accelerating the flow rate of gas inside the switch cabinet, and utilizing gas convection to quickly transfer and diffuse heat, thereby effectively reducing the overall temperature of the gas chamber.

[0035] 4. According to the different currents, the heat dissipation chambers or heat dissipation boxes / plates are organically combined to form serialization, standardization and modularization; effectively reducing the processing, manufacturing and assembly costs.

[0036] 5. The space of the switch cabinet is effectively utilized. On the basis of completing the design function, the overall size of the switch cabinet is not increased, so as to effectively reduce the overall temperature of the gas chamber.

[0037] 6. Without affecting the protection level, use the shell of the switch cabinet, open holes on the front door, rear door or rear cover as air inlets, and the holes on the top cover as air outlets, which cooperate with the heat dissipation air chamber or heat dissipation plate to form a reasonable ventilation channel outside the air chamber, so as to effectively reduce the overall temperature of the air chamber. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1A This is the 1.1×3150A design structure scheme of Example 1 (self-cooling dual-fan heat dissipation design main view schematic diagram;

[0039] Figure 1B It is a left side schematic diagram of the first embodiment;

[0040] Figure 1C It is a top view schematic diagram of a square air chamber of Embodiment 1;

[0041] Figure 2 This is a schematic diagram of heat flow outside the air chamber of Example 1;

[0042] Figure 3 Schematic diagram of heat flow inside and outside the air chamber of Example 1;

[0043] Figure 4A This is the 1.1×2500A design structure scheme of Example 2 (self-cooling double chimney heat dissipation design main view schematic diagram;

[0044] Figure 4B It is a left side schematic diagram of the second embodiment;

[0045] Figure 4C It is a top view schematic diagram of a square air chamber of Embodiment 2;

[0046] Figure 5 This is a schematic diagram of heat flow outside the air chamber of Example 2;

[0047] Figure 6 It is a schematic diagram of heat flow inside and outside the air chamber of Example 2;

[0048] Fig. 7A This is the 1.1×1250A design structure scheme of Example 3 (self-cooling double chimney heat dissipation design main view schematic diagram;

[0049] Figure 7B It is a left side schematic diagram of Embodiment 3;

[0050] Figure 7C It is a top view schematic diagram of a square air chamber of Embodiment 3;

[0051] Figure 8 This is a schematic diagram of heat flow outside the air chamber of Example 3;

[0052] Fig. 9 Schematic diagram of the air chamber and the heat flow inside and outside the air chamber of Example 3.

[0053] Reference numerals in the figures refer to:

[0054] Front door 1, first installation partition 2, first fan 3, circuit breaker 4, aluminum alloy mounting plate 5, disconnecting switch 6, front cabinet 7, outgoing bushing 8, connecting bus 9, upper partition 10, heat dissipation top cover 11, first current transformer 12, tubular bus 13, ordinary top cover 14, second installation partition 15, second fan 16, 4# inner cone (17), copper bus 18, first heat dissipation air chamber 19, square air chamber 20, test joint 21, pressure relief device 22, middle cabinet 23, air chamber support 24, rear cabinet 25, chassis 26, rear sealing plate 27, ventilation hole 28, second current transformer 29, second heat dissipation air chamber 30, 3# inner cone 31, cable 32, external cable joint 33, heat dissipation cover plate 34. Specific implementation mode

[0055] Referring to the attached drawings, the basic structure of the present invention is as follows: A heat dissipation top cover 11 and an ordinary top cover 14 are provided on the top of the switch cabinet. The interior of the switch cabinet is divided into a front cabinet 7, a middle cabinet 23, and a rear cabinet 29, and is installed on a chassis 26. The front cabinet 7 and the middle cabinet 23 are separated by an upper partition 10 installed on the upper part and a first installation partition 2 installed on the lower part. The upper part between the middle cabinet 23 and the rear cabinet 25 is separated by a second installation partition 15. There is no partition between the lower parts of the middle cabinet 23 and the rear cabinet 25, and they are interconnected. A square air chamber 20 is fixedly supported in the middle of the middle cabinet 23 by an air chamber support 24. Heating elements including an outgoing bushing 8, a copper bus 18, a 4# inner cone 17, and a test joint 21 are evenly and dispersedly arranged in the square air chamber 20. Three vertical outgoing bushings 8 connecting to a connecting bus 9 located above the square air chamber (20) are arranged in an oblique "one" shape at the front part of the top plate of the square air chamber 20. Specifically, three are arranged in a straight line, one is located at a front corner of the top plate of the square air chamber 20, and the other two extend obliquely towards the opposite sides. The circuit breaker 4 and the disconnecting switch 6 located in the front cabinet are installed on an aluminum alloy mounting plate 5 to form a whole, and then installed on the opening of the front plate of the square air chamber 20.

[0056] On the above basis, the present invention can also have the following preferred solutions for various current levels:

[0057] 1. For a switch cabinet with a current level of 1.1 × 3150A ≤ current ≤ 1.1 × 3150A

[0058] Referring to Figures 1A to 3 , which is the first embodiment of the present invention. It adopts a vertical incoming line method of a tubular bus 13 with insulation at the top of the switch cabinet, that is, the bus outside the cabinet (including outside the square air chamber 20) is encapsulated with solid insulation. The first current transformer 12 is installed above the square air chamber 20 in the middle cabinet 23. The 4# inner cones (17) of the tubular bus 13 connected externally through the first current transformer 12 are arranged in a "pin" shape at the rear part of the top plate of the square air chamber 20. Specifically, one inner cone socket corresponds to the middle of the rear edge of the top plate, and the other two are correspondingly arranged slightly in front on both sides.

[0059] A first heat dissipation air chamber 19 made of aluminum alloy is arranged outside the rear plate of the square air chamber 20 and is connected to the square air chamber 20 . The inner and outer surfaces of the first heat dissipation air chamber 19 are provided with heat dissipation fins and are sprayed with black heat dissipation paint.

[0060] The first fan 3 is installed on the first mounting partition 2 at the bottom between the front cabinet 7 and the middle cabinet 23 of the switch cabinet; the second fan 16 is installed on the second mounting partition 15 between the middle cabinet 23 and the rear cabinet 25. Corresponding ventilation holes 28 are opened at the lower part of the front door 1 of the front cabinet 7, the lower part of the rear sealing plate 27 of the rear cabinet 25 and the cabinet top. The bottom plate of the square air chamber 20 is provided with a pressure release device 22, which is a prior art. The first fan 3 and the second fan 16 can be two or more parallel machines.

[0061] In order to achieve the purpose of heat dissipation, under the premise of meeting the insulation requirements, the heating elements are evenly arranged in the square air chamber 20 in this embodiment to avoid heat accumulation caused by dense components and the generation of high points of temperature rise. The copper busbar 18 is designed to be spaced at a certain distance and evenly distributed to increase the effect of heat dissipation and heat transfer. The outlet sleeve 8 connecting the busbar 9 is evenly arranged in an oblique "I" shape on the top cover of the square air chamber 20. The 4# outlet cone 17 and the tubular busbar 13 constitute the tubular busbar entry mode at the top of the switch cabinet, and are arranged in a "pin" shape to maximize their mutual spacing. The tubular busbar 11 is a busbar part that is encapsulated with solid insulation encapsulation technology and extends out of the cabinet. A large amount of heat can be transferred out of the cabinet, which not only meets the temperature rise requirements, but also meets the insulation requirements and is convenient for users to connect.

[0062] A first heat dissipation chamber 19 is arranged at the upper rear part of the square chamber 20 and is connected to the square chamber 20, that is, a hole is opened on the wall of the square chamber and is directly sealed with the wall of the heat dissipation chamber, so that the heat in the square chamber is directly transferred to the heat dissipation chamber. The first heat dissipation chamber 19 is welded with aluminum alloy profiles with high thermal conductivity. The inner and outer surfaces of the first heat dissipation chamber 19 have heat sinks to increase the area of ​​heat absorption and heat dissipation. The inner and outer surfaces of the first heat dissipation chamber 19 are sprayed with black heat dissipation paint. Heat will be absorbed to the inner surface of the chamber by conduction, radiation, and convection. Through the heat exchange between the inner and outer surfaces, more heat is transferred to the external environment in the form of radiation, conduction, and convection. The aluminum alloy mounting plate 5 of the circuit breaker 4 and the disconnector 6 is made of aluminum alloy material with high thermal conductivity. Through the heat exchange between the inner and outer surfaces, more heat is transferred to the external environment in the form of radiation, conduction, and convection. A first fan 3 is installed at the front lower part of the front cabinet of the switch cabinet, and a second fan 16 is installed at the rear upper part of the rear cabinet of the switch cabinet. When the fan is working, a forced heat dissipation cycle is formed outside the square air chamber 20, thereby enhancing the convection heat dissipation outside the square air chamber 20. Corresponding ventilation holes 28 are provided at the lower part of the front door 1 of the front cabinet 7, the lower part of the rear sealing plate 27 of the rear cabinet 25, and the cabinet top heat dissipation top cover 11, so as to further force the cold air outside the switch cabinet to exchange heat convection with the hot air inside the switch cabinet, effectively reduce the temperature outside the square air chamber, and accelerate the heat exchange from the box to the outside of the box, thereby solving the temperature rise problem of the gas-insulated metal-enclosed switch cabinet.

[0063] When the switch cabinet is powered on, the components in the square air chamber 20 will generate heat. The greater the current, the greater the heat generated, and the temperature of each component will rise. Since the square air chamber 20 is filled with insulating gas with a certain pressure, in order to prevent leakage of the insulating gas, the primary conductive part and the insulating gas are completely enclosed in a sealed air chamber, and it is difficult for the square air chamber 20 to remove the heat of the heating components from the outside by gas convection. The heat is mainly absorbed into the inner surface of the air chamber by conduction, radiation, and partial convection. Through the heat exchange between the inner and outer surfaces of the air chamber, more heat is transferred to the external environment in the form of radiation, conduction, and convection. In the front part of the square air chamber 20, an aluminum alloy heat dissipation mounting plate 5 of the circuit breaker (4) and the disconnector (6) is installed; in the rear part of the square air chamber, an aluminum alloy first heat dissipation air chamber 19) is installed. These two places are the places with the highest heat transfer efficiency, and more heat is transferred to the external environment in the form of radiation, conduction, and convection. The first fan 3 is installed at the front lower part of the front cabinet (7) of the switch cabinet, and the second fan 16 is installed at the rear upper part of the rear cabinet. Two fans can be installed side by side depending on the flow rate of the fans. The entire switch cabinet can be installed with 4 fans. When working, a forced heat dissipation cycle is formed outside the square air chamber 20, which enhances the external convection heat dissipation of the square air chamber 20. Corresponding ventilation holes 28 are opened at the lower part of the front door 1 of the front cabinet 7, the lower part of the rear sealing plate 27 of the rear cabinet 25, and the cabinet top heat dissipation cover 11, so as to further force the cold air outside the switch cabinet to exchange convection heat with the hot air inside the switch cabinet, effectively reduce the temperature inside the square air chamber, and solve the temperature rise problem of the gas-insulated metal-enclosed switch cabinet. Relevant standards and user requirements are met.

[0064] See also FIG. 4A to FIG. 6 , which is the second embodiment of the gas-insulated metal-enclosed switchgear with easy heat dissipation of the present invention, and its corresponding current level is 1.1×2500A - it can also be called a self-cooling double chimney heat dissipation design scheme.

[0065] The basic structure of this embodiment is the same as that of the first embodiment, and the special features for the current level of 1.1×2500A are as follows:

[0066] See also FIG. 4A to FIG. 4C When the user requires the switch cabinet to have lower cable entry and when the incoming current is 2500A or below, the user generally requires the switch cabinet to have multiple cables entering and exiting at the bottom.

[0067] This embodiment adopts the vertical inlet / outlet line mode of the cable 32 at the bottom of the switch cabinet. The second current transformer 29 is installed below the square air chamber 20 of the middle cabinet 23. The cables 32 connected to the second current transformer 29 are single-phase, three-phase, and nine in total, arranged side by side at the bottom of the square air chamber 20. The 3# inner cone 31 in the square air chamber 20 is single-phase, three-phase, and nine in total, evenly distributed on the bottom plate of the square air chamber 20.

[0068] The three vertical outlet bushings 8 externally connected to the connecting busbar 9 located above the square air chamber 20 are arranged in an oblique "I" shape at the front of the top plate of the square air chamber 20. In this embodiment, three bushings are arranged in a straight line, one is located at a front corner of the square air chamber top plate, and the other two extend obliquely to the opposite sides.

[0069] A first heat dissipation chamber 19 and a second heat dissipation chamber 30 made of aluminum alloy are respectively arranged outside the rear plate of the square air chamber 20 and at the rear of the top plate and are connected to the square air chamber 20. Heat dissipation fins are arranged on the inner and outer surfaces of the heat dissipation chambers 19 and 30 and are sprayed with black heat dissipation paint. A pressure release device 22 is arranged on the side of the second heat dissipation chamber 30.

[0070] In order to achieve the purpose of heat dissipation, under the premise of meeting the insulation requirements, the heating elements are evenly arranged in the air chamber to avoid heat accumulation caused by dense components and the generation of high points of temperature rise; the copper busbar 18 is designed to be spaced a certain distance and evenly distributed to increase the effect of heat dissipation and heat transfer; the outlet cone 8 connecting the busbar 9 is evenly arranged in an oblique "I" shape on the top cover of the square air chamber 20, and the 3# cable cone 31 is evenly distributed on the bottom plate of the square air chamber 20, and it is ensured that the cable 32 can smoothly pass through the second current transformer 29.

[0071] A second heat dissipation air chamber 30 is arranged on the top of the square air chamber 20, and a first heat dissipation air chamber 19 is arranged on the upper rear part of the square air chamber to form a double heat dissipation box. Both heat dissipation boxes are connected to the square air chamber 20. The first and second heat dissipation air chambers 19 and 30 are welded by aluminum alloy profiles with high thermal conductivity. The inner and outer surfaces of each heat dissipation air chamber are provided with heat sinks to increase the area of ​​heat absorption and heat dissipation. The inner and outer surfaces of the heat dissipation air chamber are sprayed with black heat dissipation paint. Heat will be absorbed into the inner surface of the air chamber by conduction, radiation and convection. Through the heat exchange between the inner and outer surfaces, more heat is transferred to the external environment in the form of radiation, conduction and convection.

[0072] The aluminum alloy mounting plate 5 of the circuit breaker 4 and the disconnector 6 is made of an aluminum alloy material with high thermal conductivity. Through the heat exchange between the inner and outer surfaces, more heat is transferred to the external environment in the form of radiation, conduction and convection.

[0073] When the switch cabinet is powered on, the components in the square air chamber (20) will generate heat. The greater the current, the greater the heat generated, and the temperature of the components will rise. Since the square air chamber 20 is filled with insulating gas with a certain pressure, in order to prevent leakage of the insulating gas, the primary conductive part and the insulating gas are completely enclosed in a sealed air chamber. It is difficult for the square air chamber 20 to remove the heat of the heating components from the outside by gas convection. The heat is mainly absorbed into the inner surface of the air chamber by conduction, radiation, and partial convection. Through the heat exchange between the inner and outer surfaces of the air chamber, more heat is transferred to the external environment in the form of radiation, conduction, and convection.

[0074] A second heat dissipation chamber 30 is installed at the top of the square air chamber 20. The second heat dissipation chamber is the place with the highest heat transfer efficiency, and directly transfers heat to the outside of the cabinet through the heat dissipation top cover (11). At the front of the square air chamber, an aluminum alloy mounting plate (5) of a circuit breaker (4) and an isolating switch (6) is installed. At the rear of the square air chamber (20), a first heat dissipation chamber 19 is installed. These two places are places with relatively high heat transfer efficiency. More heat is transferred to the outside of the square air chamber in the form of radiation, conduction, and convection, and a high temperature area is formed there, that is: the aluminum alloy mounting plate 5 and the first heat dissipation chamber 19 respectively form a "thermal pressure difference" in the middle part of the front cabinet 7 and the rear cabinet 25, using the principle of hot air rising to achieve natural ventilation and strengthen air convection. The hot air is quickly discharged from the top of the switch cabinet along the channel due to the effect of density difference, which is a double chimney effect. During the design, without affecting the installation of components, the dual channels of the front cabinet 7 and the rear cabinet 25 are kept unobstructed as much as possible, and corresponding ventilation holes 28 are opened at the lower part of the front door 1 of the front cabinet 7, the lower part of the rear sealing plate 27 of the rear cabinet 25 and the heat dissipation top cover 11 on the cabinet top, so as to further conduct convection heat exchange between the cold air outside the switch cabinet and the hot air inside the switch cabinet, effectively reduce the temperature inside the square air chamber, solve the temperature rise problem of the gas-insulated metal-enclosed switch cabinet, and meet the relevant standards and user requirements.

[0075] See also FIG. 7A to FIG. 9 , which is the third embodiment of the gas-insulated metal-enclosed switchgear with easy heat dissipation of the present invention, and its corresponding current level is 1.1×1250A, or it is called a self-cooling double-chimney heat dissipation design scheme.

[0076] The only difference between this embodiment and the second embodiment is that no heat dissipation air chamber is set on the outside of the rear plate of the square air chamber 20 and the rear part of the top plate. Only an aluminum alloy heat dissipation cover plate 32 is installed on the outside of the rear plate of the square air chamber 20 and is tightly attached to the opening of the rear plate of the square air chamber 20.

[0077] As shown in Figure 7: When the user requires the switch cabinet to have lower cable entry and when the incoming current is 1250A or below, the user generally requires the switch cabinet to have multiple cable entry and exit at the bottom.

[0078] Depend on FIG. 7A to FIG. 9 As shown: In order to achieve the purpose of heat dissipation, under the premise of meeting the insulation requirements, the heating elements are evenly arranged in the square air chamber 20 to avoid heat accumulation caused by dense components and the generation of high points of temperature rise; the outlet sleeve 8 of the copper busbar 18 is evenly arranged in an oblique "I" shape on the top cover of the square air chamber 20, and the cable connector 33 is evenly distributed on the front lower part of the square air chamber 20.

[0079] An aluminum alloy heat dissipation cover plate 34 with high thermal conductivity is arranged at the rear of the square air chamber 20. The aluminum alloy mounting plate 5 of the circuit breaker 4 and the disconnector 6 is made of an aluminum alloy material with high thermal conductivity. Through the heat exchange between the inner and outer surfaces, more heat is transferred to the external environment in the form of radiation, conduction and convection.

[0080] When the switch cabinet is powered on, the components in the air chamber will generate heat. The greater the current, the greater the heat generated, and the temperature of the components will increase. Since the square air chamber 20 is filled with insulating gas with a certain pressure, in order to prevent leakage of the insulating gas, the primary conductive part and the insulating gas are completely enclosed in a sealed air chamber, and it is difficult for the air chamber to carry away the heat of the heating components to the outside by gas convection; the heat is mainly absorbed into the inner surface of the air chamber by conduction, radiation, and partial convection. Through the heat exchange between the inner and outer surfaces of the square air chamber 20, more heat is transferred to the external environment in the form of radiation, conduction, and convection.

[0081] In front of the square air chamber 20, an aluminum alloy mounting plate 5 for the circuit breaker 4 and the isolating switch 6 is installed, and in the rear of the square air chamber 20, a heat dissipation cover plate 34 is installed. These two places are places with the highest heat transfer efficiency. More heat is transferred to the external environment in the form of radiation, conduction, and convection, and a higher temperature area is formed there, namely: the aluminum alloy mounting plate 5 and the heat dissipation cover plate 34 form a "thermal pressure difference" in the middle part of the front cabinet 7 and the rear cabinet 25 respectively, and natural ventilation is realized by using the principle of hot air rising, and air convection is enhanced. The hot air is quickly discharged from the top of the switch cabinet along the channel due to the effect of density difference, which is the double chimney effect. During the design, the passage is kept unobstructed as much as possible without affecting the installation of components, and corresponding ventilation holes 28 are opened at the lower part of the front door 1 of the front cabinet 7, the lower part of the rear sealing plate 27 of the rear cabinet 25 and the cabinet top heat dissipation cover 11, so as to further conduct convection heat exchange between the cold air outside the switch cabinet and the hot air inside the switch cabinet, effectively reduce the temperature inside the square air chamber 20, solve the temperature rise problem of the gas-insulated metal-enclosed switch cabinet, and meet the relevant standards and user requirements.

Claims

1. A gas-insulated metal-enclosed switchgear that is easy to dissipate heat, characterized by: The switch cabinet is provided with a heat dissipation cover (11) on the top of the switch cabinet, and the interior of the switch cabinet is divided into a front cabinet (7), a middle cabinet (23) and a rear cabinet (25); a square air chamber (20) is fixedly supported by an air chamber bracket (24) in the middle of the middle cabinet (23), and heating elements including an outlet bushing (8), a copper busbar (18), a 4# inner cone (17) and a test joint 2# inner cone (21) are evenly and dispersedly arranged in the square air chamber (20); three vertical outlet bushings (8) externally connected to the connecting busbar (9) located above the square air chamber (20) are arranged in an oblique "I" shape on the front part of the top plate of the square air chamber (20); the circuit breaker (4) and the isolating switch (6) located in the front cabinet are mounted on the aluminum alloy mounting plate (5) to form a whole and then mounted on the opening of the front plate of the square air chamber (20); The front cabinet (7) and the middle cabinet (23) are separated by a first lower mounting partition (2) and an upper partition (10), the first mounting partition (2) being located at the lower portion between the front and middle cabinets, the partition (10) being located at the upper portion between the front and middle cabinets, the middle cabinet (23) and the rear cabinet (25) being separated at the upper portion by a second mounting partition (15), the middle cabinet (23) and the rear cabinet (25) having no partition at the lower portion, and being interconnected.

2. The gas-insulated metal-enclosed switchgear with easy heat dissipation according to claim 1 is characterized in that: For a switch cabinet with a current level of 1.1×3150A, the insulated tubular busbar (13) on the top of the switch cabinet is vertically connected, that is, the busbar outside the square air chamber is encapsulated with solid insulation; the first current transformer (12) is installed above the square air chamber (20) of the middle cabinet (23), and three 4# inner cones (17) of the insulated tubular busbar (13) connected to the first current transformer (12) are arranged in a "pin" shape at the rear of the top plate of the square air chamber (20); a first heat sink made of aluminum alloy is arranged outside the rear plate of the square air chamber (20). The air chamber (19) is connected to the square air chamber (20); the inner surface and the outer surface of the first heat dissipation air chamber (19) are provided with heat dissipation fins and are sprayed with black heat dissipation paint; the first fan (3) is installed on the first mounting partition (2) at the bottom between the front cabinet (7) and the middle cabinet (23) of the switch cabinet; the second fan (16) is installed on the second mounting partition (15) at the top of the middle cabinet (23) and the rear cabinet (25); corresponding ventilation holes (28) are opened at the bottom of the front door (1) of the front cabinet (7), the bottom of the rear cover plate (27) of the rear cabinet (25) and the cabinet top.

3. The gas-insulated metal-enclosed switchgear with easy heat dissipation according to claim 2 is characterized in that: The bottom plate of the square air chamber (20) is provided with a pressure release device (22).

4. The gas-insulated metal-enclosed switchgear with easy heat dissipation according to claim 1 is characterized in that: For a switch cabinet with a current level of 1.1×2500A, a vertical inlet / outlet line mode is adopted for the cables (32) at the bottom of the switch cabinet. The second current transformer (29) is installed below the square air chamber (20) of the middle cabinet (23). The cables (32) connected to the outside of the second current transformer (29) are arranged side by side at the bottom of the square air chamber (20). The 3# inner cones (31) in the square air chamber (20) are evenly distributed on the bottom plate of the square air chamber (20). A first heat dissipation air chamber (19) and a second heat dissipation air chamber (30) made of aluminum alloy are respectively arranged on the outside of the rear plate of the square air chamber (20) and the rear part of the top plate and are connected to the square air chamber (20). The inner and outer surfaces of the first and second heat dissipation air chambers are provided with heat dissipation fins and sprayed with black heat dissipation paint.

5. The gas-insulated metal-enclosed switchgear with easy heat dissipation according to claim 4 is characterized in that: A pressure release device (22) is provided on the side of the second heat dissipation air chamber (30).

6. The gas-insulated metal-enclosed switchgear with easy heat dissipation according to claim 1 is characterized in that: For a switch cabinet with a current level of 1.1×1250A, the cables (32) at the bottom of the switch cabinet are vertically input / output, the second current transformer (29) is installed below the square air chamber (20) of the middle cabinet (23), and the cable connectors (33) are connected to the second current transformer (29) and arranged in parallel at the front and bottom of the square air chamber (20) and evenly distributed; a heat dissipation cover plate (34) made of an aluminum alloy material and in close contact with the rear plate of the square air chamber (20) is installed outside the rear plate of the square air chamber (20); the inner surface and the outer surface of the heat dissipation cover plate (34) are provided with heat sinks and are sprayed with black heat dissipation paint.

7. The gas-insulated metal-enclosed switchgear with easy heat dissipation according to claim 6 is characterized in that: A pressure release device (22) is provided at the rear of the bottom plate of the square air chamber (20).

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