Alternating-current low-voltage switch cabinet and control method thereof

Abstract

The invention discloses an alternating-current low-voltage switch cabinet and a control method thereof. The alternating-current low-voltage switch cabinet comprises a sealed cabinet body installed on the ground and an electric control unit, wherein low-voltage electrical apparatus elements are installed in the sealed cabinet body; at least two air control chambers are arranged in a vacant position between the electric control unit and the rear side wall of the sealed cabinet body, all the air control chambers are the same in structure, an air duct in each air control chamber is in a U shape, and then a trap is formed at the bottom of each air duct. An upper ultrasonic atomization sheet and a lower ultrasonic atomization sheet are arranged at the bottom of each air duct, the upper ultrasonic atomization sheet is higher than the corresponding trap, and the lower ultrasonic atomization sheet is located in the trap; comprising an underground reservoir, and water in the reservoir circularly flows between each trap and the reservoir through a circulating pipeline. Water mist formed by underground water is used for cooling or heating, the consumed electric energy is lower, and the operation and maintenance cost of the outdoor new energy automobile charging station can be controlled easily.

Description

Technical Field

[0001] The present invention belongs to the technical field of new energy vehicle charging station equipment, and particularly relates to an alternating current low-voltage switch cabinet and a control method thereof. Background Art

[0002] As the number of new energy vehicles increases, the demand for charging becomes greater and greater. New energy vehicle charging stations are constantly expanding, and more outdoor charging stations are being expanded than indoor charging stations. The reason is that outdoor charging stations can utilize open areas such as roadsides, squares, and open-air parking lots, and there is no need to build dedicated indoor spaces. In areas where land resources are relatively abundant, the cost of acquiring sites is low. Secondly, the outdoor environment is well ventilated, which is conducive to the heat dissipation of charging pile equipment, reduces the probability of equipment failure due to overheating, extends the service life of the equipment, and reduces operating and maintenance costs. The power of new energy vehicle charging stations is getting larger and larger. In order to meet the high-power power transmission requirements of charging stations, charging stations are equipped with at least one dedicated AC low-voltage switchgear. However, the current outdoor AC low-voltage switchgear has some shortcomings. 1. The optimal operating temperature of switchgear is typically between 5°C and 40°C. To address heat dissipation issues in summer, existing switchgear in outdoor new energy vehicle charging stations is equipped with dedicated air conditioning systems. However, these air conditioning and cooling systems themselves consume a lot of energy, hindering the operational and maintenance costs of these outdoor new energy vehicle charging stations. In addition to these heat dissipation issues, subzero temperatures in winter can affect the performance of electrical components within the switchgear, such as circuit breakers, contactors, and relays. For example, the operating time of some relays may be prolonged, and the viscosity of the lubricating oil may increase, affecting proper operation. To address the low-temperature issue, conventional approaches involve adding electric heating devices within the cabinet. However, like air conditioning systems, electric heating devices also suffer from high energy consumption. To address this energy consumption issue, one approach is to utilize geothermal resources to reduce energy consumption. For example, patent application number CN201320867649.4 discloses a prefabricated substation enclosure with heat dissipation. This enclosure features a simple structure and uses a combination of cooling water atomizers and ventilation fans to effectively lower the internal temperature of the enclosure, reducing the energy consumption and costs of air conditioning. However, most new energy vehicle charging stations take into account factors such as charging safety and site costs. In the future, most new energy vehicle charging stations will be open-air charging stations and close to roads for easy charging. For example, new energy vehicle charging stations for high-speed servers are places with a lot of dust. The dust in the air is mixed with the circulating water. If it runs for a long time, the sealed cooling room will contain a lot of dust, causing the nozzles and pipes to be blocked. Therefore, this prefabricated substation box with heat dissipation function has the defect of not being equipped with a filtering device.

[0003] 2. In areas where temperatures are neither particularly high nor extremely low year-round, outdoor charging station switchgear uses air cooling. Ventilation holes are provided in the cabinet, allowing fans to exchange heat with the external environment. While air cooling consumes less energy, it can lead to heavy outdoor dust. Simple dust screens are inadequate to address this issue, requiring regular manual cleaning of the cabinet.

[0004] 3. In humid areas or during the rainy season, in order to solve the problem of high air humidity, existing switch cabinets add a drying layer on the basis of the dustproof net. For example, the patent with application number 202411552390.3 discloses a photovoltaic power distribution cabinet, which uses a filter plate structure of a polyester fiber layer sandwiched between a water-absorbing cotton layer. The water-absorbing cotton layer can be dried after absorbing water to restore its drying capacity. The principle of dust prevention and dehumidification is to use two sets of fans and two sets of filter plates, and to achieve the reuse of the filter plates by reversing the fan. However, as the dust gradually increases, the ventilation effect of the polyester fiber layer deteriorates accordingly. The backblowing method can indeed remove some dust that is easy to fall off. Oil particles and the like are stubbornly adhered to the polyester fiber layer and are difficult to blow off. Manual cleaning is still required regularly, and the manual maintenance cost is high.

[0005] In summary, there is a lack of a dedicated AC low-voltage switch cabinet for charging stations that can take into account both heat dissipation and warmth preservation, has low energy consumption, and does not require dust cleaning. Summary of the Invention

[0006] In view of the deficiencies in the prior art, the present invention provides an AC low-voltage switch cabinet, comprising a sealed cabinet installed on the ground, and low-voltage electrical components installed in an electric control unit inside the sealed cabinet; at least two air control chambers are provided in the space between the electric control unit and the rear side wall of the sealed cabinet, and all the air control chambers have the same structure, and the air duct inside each air control chamber is in the shape of a U-shape, thereby forming a water trap at the bottom of each air duct; a fan is provided at one end of the air duct and faces the electric control unit, and the other end of the air duct extends downward to the middle of the rear side wall and the air outlet of the air duct is exposed to the sealed cabinet; an upper ultrasonic atomizing sheet and a lower ultrasonic atomizing sheet are provided at the bottom of each air duct, the upper ultrasonic atomizing sheet is higher than the corresponding water trap, and the lower ultrasonic atomizing sheet is located in the water trap; each Each air duct is provided with a reusable drying filter plate, which is located above the corresponding ultrasonic atomizing sheet; each air duct is provided with a horizontal dust screen, and the dust screen is located between the upper ultrasonic atomizing sheet and the drying filter plate; the inner surface of the side wall of each water trap is covered with a layer of sticky cloth and the outside of the side wall is provided with two driving rollers, and the side wall of the water trap is provided with openings corresponding to the two driving rollers one by one, and the two ends of the sticky cloth extend from the two openings respectively and are wrapped around the two driving rollers one by one; each opening is provided with an adaptive blocking block; it includes a water reservoir installed underground, and the water in the water reservoir circulates between each water trap and the water reservoir through a circulation pipe; each interface connecting the water trap and the circulation pipe is provided with a filter screen.

[0007] The preferred solution of the AC low-voltage switchgear in the present invention is as follows: the outer surface of each water trap side wall is provided with a transverse chute corresponding to each blocking block, and a telescopic motor connected to the blocking block is provided in the transverse chute, and the telescopic motor pushes the blocking block to slide along the transverse chute to the corresponding opening A preferred embodiment of the AC low-voltage switchgear cabinet of the present invention is that each adjacent air control chamber is connected by a ventilation duct, located between the drying filter plate and the corresponding upper ultrasonic atomizing plate, and equipped with a solenoid valve. In internal circulation mode, the solenoid valve is activated to ensure air flow within the sealed cabinet.

[0008] A preferred embodiment of the AC low-voltage switchgear of the present invention comprises a water reservoir with stainless steel sidewalls and a water pump connected to a corresponding circulation pipeline. Stainless steel has excellent thermal conductivity and strong corrosion resistance. The water reservoir is buried 5-10 meters underground, and the rapid thermal conductivity of the water reservoir facilitates heat exchange between water and the underground soil.

[0009] The beneficial effects of the AC low-voltage switchgear of the present invention are: 1. The reservoir is buried underground, maintaining a constant underground temperature year-round. In summer, the water temperature within the reservoir is significantly lower than the ambient temperature. Low-temperature water mist reduces the inlet air temperature, cooling the electronic control unit (ECU). This heat is then removed and dissipated through external circulation. Compared to existing air conditioning systems, using groundwater mist for cooling consumes less energy, helping to control the operating and maintenance costs of outdoor new energy vehicle charging stations.

[0010] 2. In winter, the sealed cabinet is isolated from the outside air, and water mist, which is higher than the ground temperature, heats the circulating air. The heat absorbed by the water is then absorbed by the underground soil. Compared with existing electric heating devices, this system consumes less energy and fully utilizes natural resources.

[0011] 3. During external circulation cooling, the outside air mixes with the water mist, drawing dust from the air into the water reservoir, removing dust while cooling the cabinet. During internal circulation heating, the air inside the sealed cabinet does not circulate with the outside, preventing dust from entering. In both modes, external dust is prevented from entering, significantly improving dust protection compared to existing air-cooled cooling systems.

[0012] 4. Water mist is used to cool down or heat up the air while capturing dust in the air. Due to the intermolecular force, most of the small water droplets in the water mist will adhere to the surface of the dust screen when passing through the dust screen. The small water droplets gather into large water droplets and finally fall back to the water trap with the dust. Some of the dust in the water in the water trap will adhere to the sticky cloth on the side wall of the water trap. The sticky cloth is used to remove the dust and prevent it from sticking to the side wall of the water trap, thereby improving the cleaning effect. The dust sticking, drive roller and blocking block work together to automatically complete the cleaning, solving the problem of high labor costs caused by manual cleaning of conventional dust screens, and at the same time overcoming the technical difficulty of incomplete cleaning of existing forward and reverse blowing systems.

[0013] 5. Internal circulation can be achieved by raising the water level and sealing the trap. External circulation can also be achieved by lowering the water level and connecting the trap to the outside. Automatic switching between internal and external modes based on weather conditions such as high heat, high humidity, and low temperatures further reduces energy consumption for heat dissipation and insulation. This system balances summer heat dissipation and winter warmth, avoiding the high energy consumption of existing cooling and heating systems. It also features automatic dust removal.

[0014] The present invention also provides a control method for an AC low-voltage switchgear. Based on the aforementioned AC low-voltage switchgear, two air control chambers are provided, one of which is a first air control chamber and the other is a second air control chamber. When the temperature inside the sealed cabinet exceeds the optimal operating temperature of the electronic control unit, such as in summer, heat from the electronic control unit needs to be discharged from the sealed cabinet.

[0015] First, the water pump corresponding to the first air control chamber injects an appropriate amount of water into the first air control chamber's water trap, bringing the water level to the same level as the first air control chamber's lower ultrasonic atomizer. Water circulates between the water trap and the reservoir. The lower ultrasonic atomizer activates to spray water mist, and the fan starts and rotates forward. External air enters the first air control chamber's air duct, mixes with the water mist, and is cooled before passing through the drying filter plate and entering the sealed cabinet. The fan in the second air control chamber starts and rotates backward. Heat inside the sealed cabinet is discharged along with the air passing through the drying filter plate in the second air control chamber's air duct.

[0016] When the drying filter plate of the first air control chamber is saturated with water, the water pump corresponding to the first air control chamber discharges all the water in the water trap of the first air control chamber into the water reservoir, the lower ultrasonic atomizer stops, and the fan of the first air control chamber reverses. The heat in the sealed cabinet is discharged after the air passes through the drying filter plate in the air duct of the first air control chamber. The drying filter plate is heated and gradually recovers its water absorption capacity. If the heat in the sealed cabinet is not enough to dry the drying filter plate, the electric heating wire of the first air control chamber starts to heat up until the drying filter plate recovers its water absorption capacity. The water pump corresponding to the second air control chamber injects an appropriate amount of water into the water trap of the second air control chamber so that the water level is flush with the lower ultrasonic atomizer of the second air control chamber, and the water circulates between the water trap and the water reservoir; the fan of the second air control chamber rotates forward, and the external air enters the air duct of the second air control chamber and is mixed with the water mist and cooled down, and then passes through the drying filter plate and enters the sealed cabinet.

[0017] When the drying filter plate of the second air control chamber is saturated with water. The water pump corresponding to the second air control chamber discharges all the water in the water trap of the first air control chamber into the water reservoir, the lower ultrasonic atomizer stops, and the fan of the second air control chamber reverses. The heat in the sealed cabinet is discharged after the air passes through the drying filter plate in the air duct of the second air control chamber. The drying filter plate is heated and its water absorption capacity is restored. If the heat in the sealed cabinet is not enough to dry the drying filter plate, the electric heating wire of the second air control chamber starts to heat up until the drying filter plate restores its water absorption capacity. The water pump corresponding to the first air control chamber injects an appropriate amount of water into the water trap of the first air control chamber so that the water level is flush with the lower ultrasonic atomizer of the first air control chamber, and the water circulates between the water trap and the water reservoir; the fan of the first air control chamber rotates forward, and the external air enters the air duct of the first air control chamber and is mixed with the water mist to cool down, and then passes through the drying filter plate and enters the sealed cabinet; Finally, repeat the above steps until the temperature inside the sealed cabinet is no higher than the optimal operating temperature of the electronic control unit.

[0018] The present invention also provides another control method for an AC low-voltage switchgear. Based on the above-mentioned AC low-voltage switchgear, two air control chambers are provided, one of which is a first air control chamber and the other is a second air control chamber. When the temperature inside the sealed cabinet is lower than the optimal operating temperature of the electronic control unit, the following steps are performed: First, the water pump corresponding to the first air control chamber injects an appropriate amount of water into the first air control chamber's water trap, sealing the trap until the water level is flush with the first air control chamber's upper ultrasonic atomizer. Water circulates between the trap and the water reservoir. The upper ultrasonic atomizer activates to spray water mist, and the fan starts and rotates forward. The water pump corresponding to the second air control chamber injects an appropriate amount of water into the second air control chamber's water trap, sealing the trap until the water level is flush with the second air control chamber's upper ultrasonic atomizer. Water circulates between the trap and the water reservoir, and the fan starts and rotates in reverse. The solenoid valve of the ventilation duct opens, and air circulates between the sealed cabinet, the first air control chamber, and the second air control chamber.

[0019] Secondly, the air is mixed with water mist and heated up in the process of passing through the first air control chamber. The mixed air passes through the drying filter plate of the first air control chamber before entering the sealed cabinet. When the drying filter plate of the first air control chamber is saturated with water, the upper ultrasonic atomizing plate of the first air control chamber stops and the fan reverses. The upper ultrasonic atomizing plate of the second air control chamber starts and the fan rotates forward. The air flows in the opposite direction. The air is mixed with water mist and heated up in the process of passing through the second air control chamber. The mixed air passes through the drying filter plate of the second air control chamber before entering the sealed cabinet. At the same time, the dry air passes through the The air passes through the drying filter plate of the second air control chamber, and the drying filter plate gradually recovers its water absorption capacity; when the drying filter plate of the second air control chamber is saturated with water, the upper ultrasonic atomizing plate of the second air control chamber stops, and the fan rotates forward; the upper ultrasonic atomizing plate of the first air control chamber starts, and the fan reverses; the air flows forward, and in the process of passing through the first air control chamber, it mixes with the water mist and heats up. The mixed air passes through the drying filter plate of the first air control chamber and then enters the sealed cabinet. At the same time, the dry air passes through the drying filter plate of the second air control chamber, and the drying filter plate gradually recovers its water absorption capacity; Finally, repeat the above steps until the temperature inside the sealed cabinet is no lower than the optimal operating temperature of the electronic control unit.

[0020] The present invention also provides a method for cleaning an AC low-voltage switchgear cabinet. Based on the aforementioned AC low-voltage switchgear, each water trap is equipped with a turbidity meter and a drain pipe. Dust in the air mixes with water mist, which then passes through a dust screen. As the water mist collects on the screen, more and more small water droplets accumulate. Under the action of gravity, the dust-entrained water droplets continuously drip into the water trap. When the turbidity value of the water in a particular water trap exceeds a set value, the specific cleaning steps are as follows: First, the water pump in the circulation pipeline is stopped, halting water circulation. The drain pipe is opened, and the water in the water trap is sucked out, directly draining most of the dust mixed in the water. Once the wastewater is drained, the telescopic shafts of the two telescopic motors retract, and the sealing blocks are withdrawn from the corresponding openings along the transverse chute, opening the two openings. Then, the two drive rollers rotate synchronously in the forward direction, wrapping a section of sticky cloth with dust attached around the right drive roller. The telescopic motor corresponding to the right drive roller pushes the corresponding sealing block to the opening, leaving a gap between the opening and the sealing block, the width of the gap no greater than the thickness of the sticky cloth. The two drive rollers rotate counterclockwise synchronously, using the width of the gap to scrape off some of the dust on the sticky cloth. Compared to existing forward and reverse cleaning methods, this cleaning method has greater direct scraping power and is particularly suitable for stubborn dirt such as oil particles, achieving a more thorough cleaning effect. This continues until a section of the sticky cloth with dust adheres to it wraps around the left drive roller, at which point the telescopic motor corresponding to the right drive roller drives the sealing block back. Next, the telescopic motor corresponding to the left drive roller pushes the corresponding sealing block to the opening, leaving a gap between the opening and the sealing block. The width of the gap is no greater than the thickness of the sticky cloth. The two drive rollers rotate clockwise synchronously, scraping off some of the dust on the sticky cloth until a section of the sticky cloth with dust adheres to it wraps around the right drive roller, at which point the telescopic motor corresponding to the left drive roller drives the sealing block back. Repeat the forward and reverse scraping steps. If it cannot be completely removed in one time, repeat the cleaning several times until all the dust on the sticky cloth is scraped off. The sticky cloth is reset, the telescopic shafts of the two telescopic motors are extended, and the blocking blocks block the corresponding openings along the horizontal slide grooves. The cleaning is completed, and the water pump of the circulation pipe is turned on to resume water circulation. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments recorded in this application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0022] Figure 1 This is a three-dimensional diagram of the AC low-voltage switchgear cabinet of the present invention after the rear side wall is hidden; Figure 2 A perspective view of an AC low-voltage switchgear cabinet according to the present invention; Figure 3is a cross-sectional view of the AC low-voltage switchgear of the present invention; Figure 4 for Figure 3 Stereoscopic image of Figure 5 This is a three-dimensional diagram of the AC low-voltage switchgear of the present invention with the electric control unit and a partially sealed cabinet hidden; Figure 6 Schematic diagram of the structure of a single air control chamber in the present invention; Figure 7 for Figure 6 Cross-sectional view along the AA axis; Figure 8 for Figure 6 Cross-sectional view along the BB direction; Figure 9 for Figure 6 Stereoscopic image.

[0023] Figure numerals: sealed cabinet 1, water reservoir 2, water pump 3, electronic control unit 4, wind control room 5, air duct 6, fan 7, upper ultrasonic atomizer 8, lower ultrasonic atomizer 9, water trap 10, drying filter plate 11, ventilation pipe 12, solenoid valve 13, water inlet pipe 14, return pipe 15, electric heating wire 16, drain pipe 17, driving roller 18, telescopic motor 19, dust screening net 20, sticky cloth 21, guide roller 22, opening 23, blocking block 24, horizontal slide 25, ash box 26. DETAILED DESCRIPTION

[0024] In view of the deficiencies in the prior art, the inventors of this case have proposed the technical solution of the present invention after long-term research and extensive practice. The following will further explain the technical solution, its implementation process and principles, etc. in conjunction with the drawings in the embodiments of this application and specific implementation cases.

[0025] Example 1: like Figure 1 and Figure 2 As shown, embodiment 1 provides an AC low-voltage switch cabinet, including a sealed cabinet 1 installed on the ground and a water reservoir 2 installed underground. The side wall material of the water reservoir 2 is stainless steel, and a water pump 3 connected to the corresponding circulation pipe is provided in the water reservoir 2. Stainless steel has good thermal conductivity and strong corrosion resistance. The water reservoir 2 is buried 5-10 meters underground. The fast heat conduction water reservoir 2 is conducive to heat exchange between water and underground soil. The low-voltage electrical components are installed in the electric control unit 4 inside the sealed cabinet 1. There are at least an even number of air control chambers 5 in the space between the electric control unit 4 and the rear side wall of the sealed cabinet 1. This embodiment takes six air control chambers 5 as an example. All air control chambers 5 have the same structure, and all air control chambers 5 are arranged in a straight line at the rear of the sealed cabinet 1 along the length direction of the sealed cabinet 1.

[0026] The specific structure of each air control chamber 5 is as follows: like Figure 3 、 Figure 4 and Figure 5 As shown, the shape of the air duct 6 inside each air control chamber 5 is U-shaped, and a water trap 10 is formed at the bottom of each air duct 6. The cross-sectional shape of the air duct 6 is rectangular. Two fans 7 are provided at one end of the air duct 6 and face the electronic control unit 4. The other end of the air duct 6 extends downward to the middle of the rear side wall and the air outlet of the air duct 6 is exposed to the sealed cabinet 1. An upper ultrasonic atomizer sheet 8 and a lower ultrasonic atomizer sheet 9 are provided at the bottom of each air duct 6. The upper ultrasonic atomizer sheet 8 is higher than the corresponding water trap 10, and the lower ultrasonic atomizer sheet 9 is located in the water trap 10. When the water level of the water trap 10 is higher than the entire water trap 10, the water trap 10 is water-sealed, so that the air control chamber 5 is blocked from the outside. In addition, three reusable drying filter plates 11 are provided in each air duct 6. The desiccant filled in the drying filter plate 11 can be a montmorillonite desiccant. Montmorillonite desiccant has the characteristics of fast adsorption speed and large adsorption capacity. Montmorillonite desiccant can be dried at a relatively low temperature (e.g., 60-80°C) to remove adsorbed moisture, allowing for reuse. The desiccant filling the filter drier 11 can also be activated alumina desiccant, which has a large specific surface area and strong adsorption properties, absorbing moisture through physical adsorption. Alumina desiccant can be regenerated by purging with dry air, removing moisture from the desiccant, thereby restoring its drying capacity and avoiding high-temperature reduction. Activated carbon desiccant also absorbs moisture from the air through physical adsorption and can also be restored by purging with dry air. The specific desiccant used depends on the specific situation and is not limited in this embodiment. The filter drier 11 is located above the corresponding ultrasonic atomizer, and each air duct 6 is equipped with an electric heating wire 16 located above the corresponding filter drier 11. The filter drier 11 intercepts moisture from the air, preventing excessive moisture from entering the sealed cabinet 1. The electric heating wire 16 can be activated and deactivated according to temperature requirements to reduce energy consumption. In addition, each adjacent air control chamber 5 is connected by a ventilation pipe 12, which is located between the drying filter plate 11 and the corresponding upper ultrasonic atomizing plate 8, and is equipped with a solenoid valve 13. In the internal circulation mode, the solenoid valve 13 is opened to realize the air flow inside the sealed cabinet 1.

[0027] This embodiment uses an ultrasonic atomizer to atomize water at a temperature lower or higher than that of the sealed cabinet 1, and then directly mixes it with the air. The cooling or heating effect on the air is much better than the cooling or heating effect of using a heat exchanger, and the cooling or heating speed is faster. If a heat exchange device such as a heat exchange plate or heat exchange tube is connected to the circulation pipe of this embodiment, and such a heat exchange device is used to indirectly raise or lower the air temperature, on the one hand, the cooling or heating effect is not as good as the ultrasonic atomizer in this embodiment. On the other hand, the flow channel inside the heat exchange device such as the heat exchange plate or heat exchange tube has a small diameter and a large flow resistance, which requires increasing the power of the water pump 3, and correspondingly increases energy consumption, and cannot further reduce the energy consumption of the heat dissipation process or the energy consumption of the heating process.

[0028] The principle of reusing the drying filter plate 11 in this embodiment is the same as that of the existing rotary dehumidifier, which switches between moisture absorption and regeneration, and regenerates by using the heat discharged from the sealed cabinet 1 to avoid direct heat discharge causing heat energy waste, thereby achieving the effect of energy saving and emission reduction.

[0029] like Figure 1 As shown, this embodiment also includes a control unit and temperature and humidity sensors installed within the sealed cabinet 1, a liquid level sensor installed at each water trap 10, a drain pipe, a turbidity meter, and a solenoid valve 13 installed in the circulation pipe. The drain pipe 17 is connected to an external suction system for quickly extracting sewage from the water trap 10.

[0030] In this embodiment, the water in the reservoir 2 circulates between each trap 10 and the reservoir 2 through a circulation pipeline, meaning that all traps 10 share the water in the reservoir 2. Furthermore, a filter is installed at the interface between each trap 10 and the circulation pipeline to prevent dust from flowing back into the reservoir 2. The circulation pipeline includes an inlet pipe 14 and a return pipe 15. The water pump 3 is connected to the lower end of the inlet pipe 14, the upper end of which is connected to the corresponding trap 10. The return pipe 15 extends downward from the trap 10 into the reservoir 2. The solenoid valve 13 of the circulation pipeline is installed on the return pipe 15. The water level in the trap 10 is controlled by switching the solenoid valve 13 in the return pipe 15 on and off and by starting and stopping the water pump 3. The control unit's input is electrically connected to the temperature and humidity sensors, all liquid level sensors, and all turbidity meters, and its output is electrically connected to all water pumps 3, all electric heating wires 16, all upper ultrasonic atomizers 8, all lower ultrasonic atomizers 9, all fans 7, all drive rollers 18, and all telescopic motors 19. The control unit, temperature and humidity sensors, and liquid level sensors are not shown in the figure. The control unit's storage unit stores an automatic temperature control program that automatically starts and stops various components based on the temperature and humidity within the sealed cabinet 1.

[0031] In this embodiment, a horizontal dust screen 20 is provided in each air duct 6, and the dust screen 20 is located between the upper ultrasonic atomizing plate 8 and the drying filter plate 11. The function of the dust screen 20 is to intercept most of the water mist, extend the effective water absorption time of the drying filter plate 11, and also to intercept dust. When the water in the water trap 10 becomes turbid, some of the dust in the water will adhere to the side walls of the water trap 10. To clean this dust, a layer of sticky cloth 21 is covered on the inner surface of the side wall of each water trap 10. The cross-section of the water trap 10 is rectangular, and a guide roller 22 is provided at each corner. The sticky cloth 21 is sequentially passed around the outside of the guide roller 22, so that the sticky cloth 21 is attached to the side wall. Two drive rollers 18 are provided on the outside of the side wall. The side wall of the water trap 10 is provided with openings 23 corresponding to the two drive rollers 18. The two ends of the sticky cloth 21 extend from the two openings 23 and are wound around the two drive rollers 18 in a one-to-one manner. In addition, each opening 23 is equipped with a matching blocking block 24. The outer surface of the sidewall of each trap 10 is provided with a transverse chute 25 corresponding to each blocking block 24. A telescopic motor 19 connected to the blocking block 24 is installed within the transverse chute 25. The telescopic motor 19 pushes the blocking block 24 along the transverse chute 25 to the corresponding opening 23. When the telescopic shaft of the telescopic motor 19 is extended, it pushes the blocking block 24 along the transverse chute 25 to the corresponding opening 23, thereby blocking the opening 23. Conversely, when the telescopic shaft of the telescopic motor 19 is retracted, it pulls the blocking block 24 along the transverse chute 25, causing the blocking block 24 to withdraw from the corresponding opening 23, thereby opening the corresponding opening 23.

[0032] Example 2: Embodiment 2 provides a control method for an AC low-voltage switchgear. Based on the AC low-voltage switchgear of Embodiment 1, this embodiment's control method is used for heat dissipation control. At least two air control chambers 5 are provided, and four, six, or eight air control chambers 5 may also be provided, without limitation in this embodiment. Two air control chambers 5 form a group. A greater number of air control chambers 5 provides greater heat dissipation capability.

[0033] Take a group of air control chambers 5 as an example: one of the air control chambers 5 is the first air control chamber 5, and the other air control chamber 5 is the second air control chamber 5. When the temperature inside the sealed cabinet 1 is higher than the optimal operating temperature of the electronic control unit 4, such as in summer, the heat of the electronic control unit 4 needs to be discharged from the sealed cabinet 1.

[0034] First, under the control of the control unit, the water pump 3 corresponding to the first air control chamber 5 injects an appropriate amount of water into the water trap 10 of the first air control chamber 5, so that the water level is flush with the lower ultrasonic atomizer plate 9 of the first air control chamber 5, and the water circulates between the water trap 10 and the water reservoir 2. Here, the real-time water level is fed back by the liquid level sensor, and water circulation is achieved through the opening of the solenoid valve 13 of the return pipe 15 and the power of the water pump 3, but the liquid level remains unchanged. The lower ultrasonic atomizer plate 9 is started to spray water mist, and the fan 7 is started and rotated forward. The external air enters the air duct 6 of the first air control chamber 5 and is mixed with the water mist and cooled. It then passes through the drying filter plate 11 and enters the sealed cabinet 1. The fan 7 of the second air control chamber 5 is started and reversed, and the heat inside the sealed cabinet 1 is discharged after the air passes through the drying filter plate 11 in the air duct 6 of the second air control chamber 5.

[0035] Through the feedback of the temperature and humidity data inside the sealed cabinet 1 by the temperature and humidity sensor, when the drying filter plate 11 of the first air control chamber 5 is saturated with water, the control unit causes the water pump 3 corresponding to the first air control chamber 5 to discharge all the water in the water trap 10 of the first air control chamber 5 into the water reservoir 2, the lower ultrasonic atomizer 9 stops, and the fan 7 of the first air control chamber 5 reverses. The heat in the sealed cabinet 1 is discharged after passing through the drying filter plate 11 in the air duct 6 of the first air control chamber 5 with the air. The drying filter plate 11 is heated and gradually recovers its water absorption capacity. If the heat in the sealed cabinet 1 is not enough to dry the drying filter plate 11, the electric heating wire 16 of the first air control chamber 5 starts to heat up until the drying filter plate 11 recovers its water absorption capacity. The water pump 3 corresponding to the second air control chamber 5 injects an appropriate amount of water into the water trap 10 of the second air control chamber 5, so that the water level is flush with the lower ultrasonic atomizer 9 of the second air control chamber 5, and the water circulates between the water trap 10 and the water reservoir 2; the fan 7 of the second air control chamber 5 rotates forward, and the external air enters the air duct 6 of the second air control chamber 5 and is mixed with the water mist and cooled, and then passes through the drying filter plate 11 and enters the sealed cabinet 1.

[0036] When the drying filter plate 11 of the second air control chamber 5 is saturated with water, the water pump 3 corresponding to the second air control chamber 5 discharges all the water in the water trap 10 of the first air control chamber 5 into the water reservoir 2, the lower ultrasonic atomizer 9 stops, and the fan 7 of the second air control chamber 5 reverses. The heat in the sealed cabinet 1 is discharged after passing through the drying filter plate 11 in the air duct 6 of the second air control chamber 5. The drying filter plate 11 is heated and its water absorption capacity is restored. If the heat in the sealed cabinet 1 is not enough to dry the drying filter plate 11, the electric heating wire 16 of the second air control chamber 5 starts to heat up until the drying filter plate 11 restores its water absorption capacity. The water pump 3 corresponding to the first air control chamber 5 injects an appropriate amount of water into the water trap 10 of the first air control chamber 5, so that the water level is flush with the lower ultrasonic atomizer 9 of the first air control chamber 5, and the water circulates between the water trap 10 and the water reservoir 2; the fan 7 of the first air control chamber 5 rotates forward, and the external air enters the air duct 6 of the first air control chamber 5, mixes with the water mist, and is cooled. Then, it passes through the drying filter plate 11 and enters the sealed cabinet 1; Finally, the control unit repeats the above steps until the temperature inside the sealed cabinet 1 is no higher than the optimal operating temperature of the electronic control unit 4. If there are two or more groups of air control chambers 5, the same steps are repeated to improve the heat dissipation efficiency.

[0037] The heat dissipation principle of this embodiment is as follows: the optimal operating temperature range for AC low-voltage switchgear is typically 5-35°C. Because the underground soil temperature is constant relative to the ground, it stabilizes at 15-20°C in summer. Compared to the ground temperature above 40°C, low-temperature water mist is used to reduce the inlet air temperature, cooling the electronic control unit 4 while simultaneously removing heat for external circulation. Compared to existing air conditioning systems, using groundwater-generated water mist for cooling consumes less electricity, helping to control the operating and maintenance costs of outdoor new energy vehicle charging stations.

[0038] The desiccant of the drying filter plate 11 in this embodiment is montmorillonite desiccant.

[0039] Example 3: Example 3 provides another control method for an AC low-voltage switchgear. Based on the AC low-voltage switchgear of Example 1, the control method of this embodiment is used for temperature control. Example 3 is the same as Example 2 in that at least two air control chambers 5 are provided, and the number of air control chambers 5 is an even number.

[0040] When the internal temperature of the sealed cabinet 1 is lower than the optimal operating temperature of the electronic control unit 4, the steps are as follows: First, the control unit instructs the water pump 3 corresponding to the first air control chamber 5 to inject an appropriate amount of water into the water trap 10 of the first air control chamber 5, sealing the water trap 10 until the water level is flush with the upper ultrasonic atomizer plate 8 of the first air control chamber 5 and water circulates between the water trap 10 and the water reservoir 2. The upper ultrasonic atomizer plate 8 is activated to spray water mist, and the fan 7 is started and rotated forward. The water pump 3 corresponding to the second air control chamber 5 injects an appropriate amount of water into the water trap 10 of the second air control chamber 5, sealing the water trap 10 until the water level is flush with the upper ultrasonic atomizer plate 8 of the second air control chamber 5 and water circulates between the water trap 10 and the water reservoir 2. The fan 7 is started and rotated backward. Here, the water level is also obtained in real time based on the liquid level sensor, and water circulation is achieved through the opening of the solenoid valve 13 of the return pipe 15 and the power of the water pump 3. The control unit opens the solenoid valve 13 of the ventilation pipe 12, and air circulates between the sealed cabinet 1, the first air control chamber 5, and the second air control chamber 5.

[0041] Secondly, the air is mixed with the water mist and heated up in the process of flowing through the first air control chamber 5. The mixed air passes through the drying filter plate 11 of the first air control chamber 5 before entering the sealed cabinet 1. When the drying filter plate 11 of the first air control chamber 5 is saturated with water, the control unit stops the upper ultrasonic atomizing plate 8 of the first air control chamber 5 and the fan 7 reverses; the upper ultrasonic atomizing plate 8 of the second air control chamber 5 starts and the fan 7 rotates forward; the air flows in the opposite direction, and the air is mixed with the water mist and heated up in the process of flowing through the second air control chamber 5. The mixed air passes through the drying filter plate 11 of the second air control chamber 5 before entering the sealed cabinet 1. At the same time, the dry air passes through the drying filter plate 11 of the second air control chamber 5, and the drying filter plate 11 gradually recovers its water absorption capacity. force; when the drying filter plate 11 of the second air control chamber 5 is saturated with water, the upper ultrasonic atomizing plate 8 of the second air control chamber 5 stops, and the fan 7 rotates forward; the upper ultrasonic atomizing plate 8 of the first air control chamber 5 starts, and the fan 7 reverses; the air flows forward, and the air is mixed with the water mist and heated up in the process of flowing through the first air control chamber 5. The mixed air passes through the drying filter plate 11 of the first air control chamber 5 and then enters the sealed cabinet 1. At the same time, the dry air passes through the drying filter plate 11 of the second air control chamber 5, and the drying filter plate 11 gradually recovers its water absorption capacity; Finally, the above steps are repeated until the internal temperature of the sealed cabinet 1 is not lower than the optimal operating temperature of the electronic control unit 4 .

[0042] The principle of increasing the temperature inside the sealed cabinet 1 in this embodiment is that the temperature of the soil layer 5-10 degrees below ground in winter is generally 5-10 degrees Celsius, which is much higher than the ground temperature below zero. The internal circulating air is heated by water temperature to maintain the temperature inside the sealed cabinet 1 at or above 5 degrees Celsius, so that the electronic control unit 4 remains in optimal working condition. Compared with existing electric auxiliary heating devices, this device consumes less energy and fully utilizes natural resources.

[0043] In this embodiment, the desiccant for the drying filter plate 11 is activated alumina or activated carbon.

[0044] It should be understood that the above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with this technology to understand the content of the present invention and implement it accordingly. It cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, they can make some simple deductions or substitutions without departing from the concept of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the scope of protection of the present invention.

[0045] Example 4: Example 4 provides a cleaning method for an AC low-voltage switch cabinet, which is applied to the AC low-voltage switch cabinet of Example 1. Dust in the air is mixed with water mist along with the air. The water mist passes through the dust-blocking net 20. As the small water droplets gathered on the dust-blocking net 20 become more and more, the water droplets mixed with dust continue to drip into the water trap 10 under the action of gravity. When the turbidity value of the water in a certain water trap 10 is greater than the set value. The specific cleaning steps are: first, the water pump 3 of the circulation pipeline is stopped to stop the water circulation, the drain pipe 17 is opened, the water in the water trap 10 is sucked out, and most of the dust mixed in the water is directly discharged. When the sewage is drained, the telescopic shafts of the two telescopic motors 19 are retracted, and the blocking block 24 withdraws from the corresponding opening 23 along the horizontal slide 25, and the two openings 23 are opened. Then, the two drive rollers 18 rotate forward synchronously, so that a section of sticky cloth 21 with dust adhered to it is wrapped around the right drive roller 18. The telescopic motor 19 corresponding to the right drive roller 18 pushes the corresponding blocking block 24 to the opening 23, leaving a gap between the opening 23 and the blocking block 24. The gap width is no wider than the thickness of the sticky cloth 21. The two drive rollers 18 rotate synchronously, using the gap width to scrape some of the dust off the sticky cloth 21. Compared to existing forward and reverse cleaning methods, this cleaning method provides greater direct scraping force and is particularly suitable for stubborn dirt such as oil particles, achieving a more thorough cleaning effect. To facilitate the collection of scraped dust, a dust collection box 26 is located below the opening 23. The scraped dust falls into the dust collection box 26 for centralized processing. Once the dust-adhered section of the sticky cloth 21 is wrapped around the left drive roller 18, the telescopic motor 19 corresponding to the right drive roller 18 retracts the blocking block 24. Then, the telescopic motor 19 corresponding to the left drive roller 18 pushes the corresponding blocking block 24 to the opening 23, leaving a gap between the opening 23 and the blocking block 24. The width of the gap is no greater than the thickness of the sticky cloth 21. The two drive rollers 18 rotate synchronously forward, scraping some of the dust off the sticky cloth 21 until a section of the sticky cloth 21 with dust adheres to it and wraps around the right drive roller 18. The telescopic motor 19 corresponding to the left drive roller 18 then retracts the blocking block 24. Repeat the forward and reverse scraping steps. If a single attempt is not enough to completely remove the dust from the sticky cloth 21, repeat the process multiple times until all the dust on the sticky cloth 21 is removed. The sticky cloth 21 is reset, the telescopic shafts of the two telescopic motors 19 extend, and the blocking block 24 blocks the corresponding opening 23 along the horizontal chute 25. Cleaning is complete, and the water pump 3 in the circulation pipeline is turned on to resume water circulation.

Claims

1. An AC low-voltage switchgear, characterized by: It includes a sealed cabinet installed on the ground, and low-voltage electrical components are installed in an electric control unit inside the sealed cabinet; at least two air control chambers are provided in the space between the electric control unit and the rear side wall of the sealed cabinet, and all the air control chambers have the same structure, and the shape of the air duct inside each air control chamber is U-shaped, thereby forming a water trap at the bottom of each air duct; a fan is provided at one end of the air duct and faces the electric control unit, and the other end of the air duct extends downward to the middle of the rear side wall and the air outlet of the air duct is exposed to the sealed cabinet; an upper ultrasonic atomizing sheet and a lower ultrasonic atomizing sheet are provided at the bottom of each air duct, the upper ultrasonic atomizing sheet is higher than the corresponding water trap, and the lower ultrasonic atomizing sheet is located in the water trap; Each air duct is equipped with a reusable drying filter plate, which is located above the corresponding ultrasonic atomizing plate; each air duct is equipped with a horizontal dust screen, which is located between the upper ultrasonic atomizing plate and the drying filter plate; the inner surface of the side wall of each water trap is covered with a layer of sticky cloth, and the outside of the side wall is equipped with two drive rollers. The side wall of the water trap is provided with openings corresponding to the two drive rollers, and the two ends of the sticky cloth extend from the two openings and are wound around the two drive rollers in a one-to-one manner; each opening is equipped with an adaptive blocking block; It comprises a water reservoir installed underground, in which water in the water reservoir circulates between each water trap and the water reservoir through a circulation pipe; and a filter is provided at the interface where each water trap is connected to the circulation pipe.

2. The AC low-voltage switchgear according to claim 1, characterized in that: The outer surface of each water trap side wall is provided with a transverse chute corresponding to each blocking block, and a telescopic motor connected to the blocking block is provided in the transverse chute, which pushes the blocking block to slide along the transverse chute to the corresponding opening.

3. The AC low-voltage switchgear according to claim 2, characterized in that: Every two adjacent air control chambers are connected through a ventilation pipe. The ventilation pipe is located between the drying filter plate and the corresponding upper ultrasonic atomizing sheet, and the ventilation pipe is provided with a solenoid valve.

4. The AC low-voltage switchgear according to claim 3, characterized in that: The side wall material of the water reservoir is stainless steel, and a water pump connected to the corresponding circulation pipeline is provided in the water reservoir.

5. The AC low-voltage switchgear according to claim 4, characterized in that: Each air duct is provided with an electric heating wire located above the corresponding drying filter plate.

6. A control method for an AC low-voltage switchgear, characterized in that: Based on the AC low-voltage switchgear according to claim 5, there are two air control chambers, one of which is a first air control chamber and the other is a second air control chamber. When the temperature inside the sealed cabinet is higher than the optimal operating temperature of the electronic control unit, the steps are as follows: S1. The water pump corresponding to the first air control chamber injects an appropriate amount of water into the water trap of the first air control chamber, so that the water level is flush with the lower ultrasonic atomizer of the first air control chamber, and the water circulates between the water trap and the water reservoir; the lower ultrasonic atomizer is activated to spray water mist, and the fan is started and rotated forward. The outside air enters the air duct of the first air control chamber, mixes with the water mist, and is cooled. It then passes through the drying filter plate and enters the sealed cabinet. S2: The fan in the second air control chamber starts and reverses, and the heat inside the sealed cabinet is discharged along with the air passing through the drying filter plate in the air duct of the second air control chamber; S3, when the drying filter plate of the first air control chamber is saturated with water; The water pump corresponding to the first air control chamber discharges all the water in the water trap of the first air control chamber into the water reservoir, the lower ultrasonic atomizer stops, and the fan of the first air control chamber reverses to discharge the heat in the sealed cabinet along with the air passing through the drying filter plate in the air duct of the first air control chamber. The drying filter plate is heated and gradually recovers its water absorption capacity. If the heat in the sealed cabinet is not enough to dry the drying filter plate, the electric heating wire of the first air control chamber starts to heat up until the drying filter plate recovers its water absorption capacity. The water pump corresponding to the second air control chamber injects an appropriate amount of water into the water trap of the second air control chamber, so that the water level is flush with the lower ultrasonic atomizer of the second air control chamber, and the water circulates between the water trap and the water reservoir; the fan of the second air control chamber rotates forward, and the outside air enters the air duct of the second air control chamber and mixes with the water mist to cool down, then passes through the drying filter plate and enters the sealed cabinet; S4, when the drying filter plate of the second air control chamber is saturated with water; The water pump corresponding to the second air control chamber discharges all the water in the water trap of the first air control chamber into the water reservoir. The lower ultrasonic atomizer stops, and the fan of the second air control chamber reverses. The heat in the sealed cabinet is discharged along with the air passing through the drying filter plate in the air duct of the second air control chamber. The drying filter plate is heated and restores its water absorption capacity. If the heat in the sealed cabinet is not enough to dry the drying filter plate, the electric heating wire of the second air control chamber starts to heat up until the drying filter plate restores its water absorption capacity. The water pump corresponding to the first air control chamber injects an appropriate amount of water into the water trap of the first air control chamber, so that the water level is flush with the lower ultrasonic atomizer of the first air control chamber, and the water circulates between the water trap and the water reservoir; the fan of the first air control chamber rotates forward, and the outside air enters the air duct of the first air control chamber and mixes with the water mist to cool down, then passes through the drying filter plate and enters the sealed cabinet; S5. Repeat S3 to S4 until the internal temperature of the sealed cabinet is no higher than the optimal operating temperature of the electronic control unit.

7. A control method for an AC low-voltage switchgear, characterized in that: Based on the AC low-voltage switchgear according to claim 5, there are two air control chambers, one of which is a first air control chamber and the other is a second air control chamber. When the temperature inside the sealed cabinet is lower than the optimal operating temperature of the electronic control unit, the steps are as follows: S1. The water pump corresponding to the first air control chamber injects an appropriate amount of water into the water trap of the first air control chamber, sealing the water trap so that the water level is flush with the upper ultrasonic atomizing plate of the first air control chamber and water circulates between the water trap and the water reservoir. The upper ultrasonic atomizing plate is activated to spray water mist, and the fan is started and rotates forward; S2. The water pump corresponding to the second air control chamber injects an appropriate amount of water into the water trap of the second air control chamber, sealing the water trap so that the water level is flush with the upper ultrasonic atomizer of the second air control chamber and the water circulates between the water trap and the water reservoir. The fan starts and reverses; the solenoid valve of the ventilation pipe opens, and air circulates between the sealed cabinet, the first air control chamber, and the second air control chamber; S3, the air is mixed with water mist and heated up in the process of passing through the first air control chamber, and the mixed air passes through the drying filter plate of the first air control chamber before entering the sealed cabinet; when the drying filter plate of the first air control chamber is saturated with water, the upper ultrasonic atomizing plate of the first air control chamber stops and the fan reverses; the upper ultrasonic atomizing plate of the second air control chamber starts and the fan rotates forward; the air flows in the opposite direction, and the air is mixed with water mist and heated up in the process of passing through the second air control chamber, and the mixed air passes through the drying filter plate of the second air control chamber before entering the sealed cabinet, and the dry air is The air passes through the drying filter plate of the second air control chamber, and the drying filter plate gradually recovers its water absorption capacity; when the drying filter plate of the second air control chamber is saturated with water, the upper ultrasonic atomizing plate of the second air control chamber stops, and the fan rotates forward; the upper ultrasonic atomizing plate of the first air control chamber starts, and the fan reverses; the air flows forward, and in the process of passing through the first air control chamber, it mixes with the water mist and heats up. The mixed air passes through the drying filter plate of the first air control chamber and then enters the sealed cabinet. At the same time, the dry air passes through the drying filter plate of the second air control chamber, and the drying filter plate gradually recovers its water absorption capacity; S4. Repeat S3 until the temperature inside the sealed cabinet is no lower than the optimal operating temperature of the electronic control unit.

8. A method for cleaning an AC low-voltage switchgear, characterized by: Based on the AC low-voltage switchgear described in claim 5, each water trap is provided with a turbidity meter and a drain pipe. Dust in the air is mixed with water mist along with the air. The water mist passes through the dust screen. As the small water droplets gathered on the dust screen increase, the water droplets mixed with dust continuously drip into the water trap under the action of gravity. When the turbidity value of the water in a certain water trap exceeds the set value, the cleaning steps are as follows: S1. The water pump in the circulation pipeline stops, and the water circulation stops; S2, the drain pipe is opened and the water in the trap is sucked out; S3, the telescopic shafts of the two telescopic motors retract, and the blocking blocks exit from the corresponding openings along the transverse chute; S4. The two driving rollers rotate synchronously forward, so that a section of sticky cloth with dust adhered to it is wound around the right driving roller; S5. The telescopic motor corresponding to the right driving roller pushes the corresponding blocking block to the opening, and a gap is left between the opening and the blocking block, and the width of the gap is no greater than the thickness of the sticky cloth; S6. The two driving rollers rotate in reverse synchronously, and part of the dust on the sticky cloth is scraped off until a section of the sticky cloth with dust adheres to it is wrapped around the left driving roller, and the telescopic motor corresponding to the right driving roller drives the blocking block to retract; S7. The telescopic motor corresponding to the left driving roller pushes the corresponding blocking block to the opening, and a gap is left between the opening and the blocking block, and the width of the gap is no greater than the thickness of the sticky cloth; S8, the two driving rollers rotate synchronously forward, and part of the dust on the sticky cloth is scraped off until a section of the sticky cloth with dust adhered to it is wrapped around the right driving roller, and the telescopic motor corresponding to the left driving roller drives the blocking block to retract; S9. Repeat S5-S8 until all the dust on the sticky cloth is scraped off, the sticky cloth is reset, the telescopic shafts of the two telescopic motors are extended, and the blocking blocks block the corresponding openings along the horizontal slide grooves. The cleaning is completed, and the water pump of the circulation pipeline is turned on to resume water circulation.

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