Switch cabinet dehumidification system

Abstract

The invention relates to the field of switch cabinet dehumidification, and particularly discloses a switch cabinet dehumidification system which comprises an air return pipe and an air supply pipe, a plurality of air return auxiliary pipes are connected to the periphery of the air return pipe, a plurality of air return branch pipes are connected to the peripheries of the air return auxiliary pipes, and a plurality of air supply auxiliary pipes are connected to the periphery of the air supply pipe. The air supply pipe introduces dry air into the switch cabinet through the air supply auxiliary pipe and the air supply branch pipe, so that humid air in the switch cabinet is discharged into the air return pipe through the air return auxiliary pipe and the air return branch pipe, then the humid air in the air return pipe is discharged into the air drying system, and the humid air is dried by the air drying system and then is discharged into the air supply pipe again. The circulation is carried out in this way to ensure that wet air can be discharged in time, it is ensured that air in the switch cabinet is kept dry, dust and dirt can be prevented from entering the switch cabinet, heat preservation cotton is arranged, the heat preservation effect of the top wall of the switch cabinet can be improved, and condensation is prevented from being formed on the top wall of the switch cabinet in the process that the wet air is discharged into the air return branch pipe.

Description

Technical Field

[0001] The present invention relates to the field of dehumidification of switch cabinets, and specifically to a switch cabinet dehumidification system. Background Art

[0002] Due to installation condition limitations, the structure of high-voltage switch cabinets has become increasingly miniaturized, with a compact internal structure, reduced phase-to-phase and phase-to-ground distances of live parts. Therefore, relatively high requirements are imposed on environmental factors. Due to reasons such as manufacturing and operating environments, especially during the periods from May to June and from October to November, the temperature difference between day and night is large, and condensation is extremely likely to form in the switch cabinets. In a high-humidity environment, the insulation performance of the air medium drops significantly. At the same time, high-voltage electrodes are very prone to partial discharge in a high-humidity environment. For solid insulation materials in a high-humidity environment, their insulation performance has changed greatly, and under the influence of partial discharge, the aging of solid insulation materials is prone to accelerate, and the electrical aging and environmental aging of solid insulation materials are usually irreversible. Therefore, there are great potential insulation fault hazards when switch cabinets operate in a high-humidity and highly polluted environment for a long time.

[0003] The traditional dehumidification methods for switch cabinets mainly include the following: First, install a semiconductor condensation dehumidification device inside the switch cabinet. However, this dehumidification method can only dehumidify the area near the equipment inside the switch cabinet, and the dehumidification effect is not significant. After the surface of the condensation sensor is eroded by dust or gas in the air, its characteristics will change, and the sensitivity of the sensor will decrease. Although condensation has occurred on the cabinet wall, the condensation controller still cannot start working in time, which will bring serious consequences and its reliability is poor. Drawing a drain pipe from inside the cabinet cannot guarantee its safety performance.

[0004] Second, install an electric heating dehumidification device inside the switch cabinet. However, this dehumidification method only increases the unsaturated degree of water vapor in the air, and the water vapor inside the cabinet is not discharged, failing to achieve an effective moisture removal effect.

[0005] Third, install a fan on the relief pressure plate at the top of the switch cabinet for dehumidification. When the fan blows in air, it is easy to bring dust and dirt in the switch room into the cabinet, which is likely to aggravate the discharge situation and damage the insulation.

[0006] Fourth, install clay on the switch cabinet door and add a moisture absorbent inside the cabinet. The clay on the cabinet door actually only reduces the water vapor entering the box from the outside, and does not prevent the entry of humid air. Over time, the humidity inside the switch cabinet will still continue to increase. The moisture absorbent has limited water absorption effect, and the absorbed water is difficult to discharge. The humid water vapor still accumulates inside the switch cabinet, and the dehumidification effect is not obvious. Summary of the Invention

[0007] The purpose of the present invention is to provide a switch cabinet dehumidification system to overcome the above-mentioned defects in the prior art.

[0008] A dehumidification system for a switchgear cabinet according to the present invention includes a return air duct and a supply air duct. A plurality of return air sub-ducts are connected to the outer periphery of the return air duct, and a plurality of return air branches are connected to the outer periphery of the return air sub-ducts. A plurality of supply air sub-ducts are connected to the outer periphery of the supply air duct, and a plurality of supply air branches are connected to the outer periphery of the supply air sub-ducts. The number of the supply air branches is the same as that of the return air branches and they are arranged in pairs. Each pair of the supply air branch and the return air branch are respectively connected and communicated with each electrical component chamber in the switchgear cabinet. The return air duct and the supply air duct are connected to an air drying system.

[0009] Through the above technical solution, the supply air duct introduces dry air into the switchgear cabinet through the supply air sub-ducts and the supply air branches, so that the humid air in the switchgear cabinet is discharged into the return air duct through the return air sub-ducts and the return air branches. Then, the humid air in the return air duct is discharged into the air drying system, and after being dried by the air drying system, it is re-discharged into the supply air duct. Such a cycle is carried out to ensure that the wet air can be discharged in time, keep the air in the switchgear cabinet dry, and at the same time avoid dust and dirt from entering the switchgear cabinet.

[0010] Further, the supply air branch and the return air branch penetrate through the top wall of the switchgear cabinet. Clamping rings are fixed on the outer peripheries of the supply air branch and the return air branch, and the clamping rings are in contact with the top surface of the switchgear cabinet. Threaded connecting pipes are in threaded connection with the lower openings of the supply air branch and the return air branch. A limiting ring is fixed on the outer periphery of the threaded connecting pipe, and the upper end surface of the limiting ring is in contact with the top wall of the switchgear cabinet.

[0011] Through the above technical solution, the cooperation of the limiting ring and the clamping ring can clamp and fix the lower ends of the supply air branch and the supply air sub-duct on the top wall of the switchgear cabinet, improving the connection strength between the supply air branch and the supply air sub-duct and the switchgear cabinet.

[0012] Further, a flow guide plate is arranged on the lower side of the supply air branch. The cross section of the flow guide plate is in a "U" shape. A flow guide cavity is formed between the flow guide plate and the side wall and the top wall of the switchgear cabinet. The lower end of the supply air branch is communicated with the flow guide cavity. The lower end of the flow guide cavity is open. The flow guide plate is composed of a vertical plate and a horizontal plate. The horizontal plate is horizontally arranged and fixed on the top wall of the switchgear cabinet. One end of the flow guide cavity far away from the side wall of the switchgear cabinet in the horizontal direction is closed. The vertical plate is vertically arranged and fixed on the side wall of the switchgear cabinet.

[0013] Through the above technical solution, the setting of the flow guide plate enables the formed flow guide cavity to accurately guide the dry air discharged from the lower end of the supply air branch, improving the dehumidification effect.

[0014] Further, the length of the vertical plate is 3 cm - 5 cm less than the height of its corresponding electrical component chamber.

[0015] Through the above technical solution, the dry air discharged from the lower end of the deflector is at the bottom of the electrical component chamber. As the dry air is continuously injected, the humid air in the electrical component chamber can be discharged from the lower end of the return air branch pipe, so that the dry air can quickly fill the electrical component chamber.

[0016] Further, a shield is provided on the lower side of the air supply sub-pipe. The shield is fixed to the top surface of the switch cabinet. The air supply branch pipe and the return air branch pipe penetrate through the shield, and the shield is filled with heat-insulating cotton.

[0017] Through the above technical solution, the setting of the heat-insulating cotton can increase the heat-insulating effect of the top wall of the switch cabinet, reduce the heat exchange between the external environment temperature and the top wall of the switch cabinet, thereby increasing the temperature of the top wall of the switch cabinet and preventing humid air from forming condensation on the top wall of the switch cabinet during the process of being discharged into the return air branch pipe.

[0018] Further, a heat-conducting ring is sleeved on the outer periphery of the air supply branch pipe, and a plurality of heat-conducting fins are fixedly arranged on the outer periphery of the heat-conducting ring. The heat-conducting fins penetrate through the heat-insulating cotton along the thickness direction of the heat-insulating cotton, and the heat-conducting fins are in contact with the top surface of the switch cabinet.

[0019] Through the above technical solution, the setting of the heat-conducting fins enables the temperature on the air supply branch pipe to be quickly transferred to the top wall of the switch cabinet, so that the temperature of the top wall of the switch cabinet can be close to the temperature of the air supply branch pipe, further increasing the temperature of the top wall of the switch cabinet.

[0020] Further, the air drying system includes an evaporator, a compressor, a condenser and an expansion valve. The compressor and the expansion valve are connected by a copper pipe. The copper pipe passes through the evaporator and the condenser. A refrigerant flows in the copper pipe. One end of the return air pipe for exhausting air is connected to the air inlet of the evaporator, and one end of the air supply pipe for admitting air is connected to the air outlet of the evaporator. The air with moisture enters the evaporator and condenses on the surface of the copper pipe to realize air drying.

[0021] Through the above technical solution, the humid air is input into the evaporator through the return air pipe. After contacting the copper pipe, the moisture in the humid air condenses on the outer periphery of the copper pipe, so that the humid air is dried, and the dried air is injected into the air supply pipe.

[0022] The beneficial effects of the present invention are as follows: The air supply duct introduces dry air into the switch cabinet through the air supply sub-duct and the air supply branch pipe, so that the humid air in the switch cabinet is discharged into the air return duct through the air return sub-duct and the air return branch pipe. Then, the humid air in the air return duct is discharged into the air drying system. After being dried by the air drying system, the humid air is re-discharged into the air supply duct. This cycle ensures that the humid air can be discharged in time, keeps the air in the switch cabinet dry, and can prevent dust and dirt from entering the switch cabinet. The setting of the heat preservation cotton can increase the heat preservation effect of the top wall of the switch cabinet and prevent the formation of condensation on the top wall of the switch cabinet during the process of discharging the humid air into the air return branch pipe. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a schematic structural diagram of the present invention; Figure 2 is the present invention Figure 1 the sectional view taken along line A-A in; Figure 3 is the present invention Figure 2 the enlarged view at C in; Figure 4 is the present invention Figure 1 the sectional view taken along line B-B in; Figure 5 is the present invention Figure 4 the enlarged view at D in; Figure 6 is the exploded view of the present invention; Figure 7 is the schematic structural diagram of the flow guiding plate in the present invention; Figure 8 is the schematic structural diagram of the heat preservation cotton in the present invention; Figure 9 is the schematic structural diagram of the air drying system in the present invention.

[0024] In the figure: 2, copper pipe; 3, evaporator; 4, compressor; 5, condenser; 6, refrigerant storage tank; 7, drying filter; 8, solenoid valve; 9, expansion valve; 10, air return duct; 11, air return sub-duct; 12, air return branch pipe; 20, air supply duct; 21, air supply sub-duct; 22, air supply branch pipe; 23, snap ring; 24, limit ring; 25, threaded connecting pipe; 30, shield; 40, heat preservation cotton; 50, heat conducting fin; 51, heat conducting ring; 60, vertical plate; 61, flow guiding cavity; 62, horizontal plate. DETAILED DESCRIPTION OF THE INVENTION

[0025] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the attached Figure 1The orientation or positional relationship shown is only for the purpose of facilitating the simplified description of the present invention, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation on the present invention.

[0026] In order to make the purpose and advantages of the present invention more clear, the following specifically describes the present invention in conjunction with embodiments. It should be understood that the following text is only used to describe one or several specific implementation manners of the present invention, and does not strictly limit the scope of protection specifically claimed by the present invention. As used herein, the terms "up and down" and "left and right" are not limited to their strict geometric definitions, but include tolerances for machining or human errors that are reasonable and inconsistent. The specific features of a switchgear dehumidification system are described in detail below: An embodiment of the present invention: Referring to Figures 1-9 , the present invention provides a switchgear dehumidification system, including a return air duct 10 and a supply air duct 20. A plurality of return air sub-ducts 11 are connected to the outer periphery of the return air duct 10, and a plurality of return air branches 12 are connected to the outer periphery of the return air sub-ducts 11. A plurality of supply air sub-ducts 21 are connected to the outer periphery of the supply air duct 20, and a plurality of supply air branches 22 are connected to the outer periphery of the supply air sub-ducts 21. The number of the supply air branches 22 is the same as that of the return air branches 12 and they are arranged in pairs. Each pair of the supply air branches 22 and the return air branches 12 are respectively connected and communicated with each electrical component chamber in the switchgear. The number and distribution of the supply air branches 22 and the return air branches 12 can be adaptively set according to the distribution of different electrical component chambers in different switchgears. The return air duct 10 and the supply air duct 20 are connected to an air drying system, and the return air duct 10 and the supply air duct 20 can be fixed to the wall at the installation position of the switchgear or suspended above the ceiling.

[0027] Referring to Figures 1-6 , through holes are opened on the top wall of the switchgear for the supply air branches 22 and the return air branches 12 to penetrate the top wall of the switchgear. Clamping rings 23 are fixed on the outer peripheries of the supply air branches 22 and the return air branches 12, and the clamping rings 23 are in contact with the top surface of the switchgear. Threaded connection pipes 25 are connected by internal threads to the lower openings of the supply air branches 22 and the return air branches 12, and limiting rings 24 are fixed on the outer peripheries of the threaded connection pipes 25, and the upper end surfaces of the limiting rings 24 are in contact with the top wall of the switchgear.

[0028] Referring to Figure 4 , Figure 5 , Figure 7, a flow guide plate is arranged on the lower side of the air supply branch pipe 22. The cross-section of the flow guide plate is in a "U" shape. A flow guide cavity 61 is formed between the flow guide plate and the side wall and the top wall of the switch cabinet. The lower end of the air supply branch pipe 22 is communicated with the flow guide cavity 61. The lower end of the flow guide cavity 61 is open. The flow guide plate is composed of a vertical plate 60 and a horizontal plate 62. The horizontal plate 62 is horizontally arranged and fixed on the top wall of the switch cabinet. The part of the horizontal plate 62 located below the air supply branch pipe 22 is arranged as an inclined plane sloping downward, so as to increase the flow guiding effect on the dry air and accelerate the input of the dry air from the air supply branch pipe 22 into the flow guide cavity 61. One end of the flow guide cavity 61 far away from the side wall of the switch cabinet in the horizontal direction is closed. The vertical plate 60 is vertically arranged and fixed on the side wall of the switch cabinet. The length of the vertical plate 60 is 3 cm - 5 cm less than the height of its corresponding electrical component chamber.

[0029] Refer to Figures 6-8 , a protective cover 30 is arranged on the lower side of the air supply auxiliary pipe 21. The protective cover 30 is fixed on the top surface of the switch cabinet. The air supply branch pipe 22 and the return air branch pipe 12 penetrate through the protective cover 30. The protective cover 30 is filled with heat-insulating cotton 40. A heat-conducting ring 51 is sleeved on the outer periphery of the air supply branch pipe 22. A plurality of heat-conducting fins 50 are fixedly arranged on the outer periphery of the heat-conducting ring 51. The heat-conducting fins 50 penetrate through the heat-insulating cotton 40 along the thickness direction of the heat-insulating cotton 40, and the heat-conducting fins 50 are in contact with the top surface of the switch cabinet.

[0030] Refer to Figure 9 , the air drying system includes an evaporator 3, a compressor 4, a condenser 5 and an expansion valve 9. The compressor 4 and the expansion valve 9 are connected by a copper pipe 2. The copper pipe 2 passes through the evaporator 3. The output end of the compressor 4 is connected with a refrigerant storage tank 6 by a copper pipe 2. The liquid discharge port of the refrigerant storage tank 6 is connected with a drying filter 7 by a copper pipe 2. The drying filter 7 is connected with the expansion valve 9 by a copper pipe 2. The flow of the refrigerant in the copper pipe 2 is controlled by an electromagnetic valve 8 between the drying filter 7 and the expansion valve 9. The condenser 5 is arranged between the compressor 4 and the refrigerant storage tank 6. The copper pipe 2 between the condenser 5 and the compressor 4 condenses the refrigerant therein from a gaseous state to a liquid state through the refrigerant storage tank 6. The refrigerant flows in the copper pipe 2. One end of the return air pipe 10 for exhausting air is connected with the air inlet of the evaporator 3. One end of the air supply pipe 20 for admitting air is connected with the air outlet of the evaporator. An air extraction fan is arranged at the air inlet end of the air supply pipe 20. The air extraction fan is driven by a motor and can suck the dry air in the evaporator 3 into the air supply pipe 20, so as to realize the reciprocating circulation of the air in the present invention. The air with moisture enters the evaporator 3 and condenses on the surface of the copper pipe 2 to realize the drying of the air. A drain port is arranged in the evaporator 3, and the condensed liquid water is discharged through the drain port.

[0031] When the present invention is in use, the air drying system is started and the exhaust fan rotates, causing air to circulate within the dehumidification system provided by the present invention. The air in the air supply duct 20 is injected into the switchgear through the air supply branch duct 22 and the air supply auxiliary duct 21, while the humid air in the switchgear is input into the air return duct 10 through the air return branch duct 12 and the air return auxiliary duct 11, and then input into the evaporator 3 through the air return duct 10. The refrigerant within the copper tube 2 located in the evaporator 3 vaporizes from a liquid state to a gaseous state, thereby absorbing a large amount of heat, which causes the surface temperature of the copper tube 2 located in the evaporator 3 to decrease. Then, the moisture in the humid air condenses on the surface of the copper tube 2, so that the humid air is dried and then input into the air supply duct 20, and then input into the switchgear through the air supply branch duct 22 and the air supply auxiliary duct 21. The dry air is input into the diversion cavity 61 from the lower end of the air supply branch duct 22. Under the guidance of the diversion cavity 61, the dry air is output from the lower end of the diversion cavity 61. Then, the humid air in the electrical component chamber is discharged upward into the air return branch duct 12, and then input into the air drying system through the air return auxiliary duct 11 and the air return duct 10. This cycle is repeated to keep the air in the switchgear dry.

[0032] The dehumidification system provided in this embodiment may further include a humidity sensor. The humidity sensor is installed in the switchgear and is connected to the air drying system through a control system. The control system sets the trigger threshold of the humidity sensor. When the humidity sensor detects that the humidity in the switchgear reaches the threshold, the control system controls the air drying system to start, thereby realizing the dehumidification operation of the switchgear. When the humidity in the switchgear does not reach the threshold, the air drying system is in a standby state to reduce energy consumption.

[0033] Those skilled in the art can clearly understand that various modifications to the above embodiments can be made without departing from the overall spirit and concept of the present invention. All of them fall within the protection scope of the present invention. The protection scope of the present invention is subject to the claims attached to the present invention.

Claims

1. A switchgear cabinet dehumidification system, comprising a return air duct (10) and a supply air duct (20), characterized in that: A plurality of return air sub-pipes (11) are connected to the outer periphery of the return air pipe (10). A plurality of return air branch pipes (12) are connected to the outer periphery of the return air sub-pipes (11). A plurality of supply air sub-pipes (21) are connected to the outer periphery of the supply air pipe (20). A plurality of supply air branch pipes (22) are connected to the outer periphery of the supply air sub-pipes (21). The number of the supply air branch pipes (22) is the same as that of the return air branch pipes (12) and they are arranged in pairs. Each pair of the supply air branch pipes (22) and the return air branch pipes (12) are respectively communicated with each electrical component chamber in the switch cabinet. The return air pipe (10) and the supply air pipe (20) are connected to an air drying system.

2. The dehumidification system for switchgear according to claim 1, wherein: The supply air branch pipes (22) and the return air branch pipes (12) penetrate through the top wall of the switch cabinet. Snap rings (23) are fixed on the outer peripheries of the supply air branch pipes (22) and the return air branch pipes (12). The snap rings (23) are in contact with the top surface of the switch cabinet. Threaded connection pipes (25) are connected to the lower ends of the supply air branch pipes (22) and the return air branch pipes (12) by internal threads. Limit rings (24) are fixed on the outer peripheries of the threaded connection pipes (25). The upper end surfaces of the limit rings (24) are in contact with the top wall of the switch cabinet.

3. The dehumidification system for a switchgear cabinet according to claim 1, wherein: A deflector is arranged on the lower side of the supply air branch pipe (22). The cross section of the deflector is in a "U" shape. A diversion cavity (61) is formed between the deflector and the side wall and the top wall of the switch cabinet. The lower end of the supply air branch pipe (22) is communicated with the diversion cavity (61). The lower end of the diversion cavity (61) is open. The deflector is composed of a vertical plate (60) and a horizontal plate (62). The horizontal plate (62) is horizontally arranged and fixed on the top wall of the switch cabinet. One end of the diversion cavity (61) far away from the side wall of the switch cabinet in the horizontal direction is closed. The vertical plate (60) is vertically arranged and fixed on the side wall of the switch cabinet.

4. The dehumidification system for switchgear according to claim 3, wherein: The length of the vertical plate (60) is 3 cm - 5 cm less than the height of its corresponding electrical component chamber.

5. The dehumidification system for a switchgear cabinet according to claim 1, characterized in that: A shield (30) is arranged on the lower side of the supply air sub-pipe (21). The shield (30) is fixed on the top surface of the switch cabinet. The supply air branch pipes (22) and the return air branch pipes (12) penetrate through the shield (30). Heat insulating cotton (40) is filled in the shield (30).

6. The dehumidification system for switchgear according to claim 5, characterized in that: A heat conducting ring (51) is sleeved on the outer periphery of the supply air branch pipe (22). A plurality of heat conducting fins (50) are fixed on the outer periphery of the heat conducting ring (51). The heat conducting fins (50) penetrate through the heat insulating cotton (40) along the thickness direction of the heat insulating cotton (40). The heat conducting fins (50) are in contact with the top surface of the switch cabinet.

7. A switch cabinet dehumidification system according to claim 1, characterized in that: The air drying system includes an evaporator (3), a compressor (4), a condenser (5) and an expansion valve (9). The compressor (4) and the expansion valve (9) are connected by a copper pipe (2). The copper pipe (2) passes through the evaporator (3) and the condenser (5). A refrigerant flows in the copper pipe (2). The exhaust end of the return air pipe (10) is connected to the air inlet of the evaporator (3). The air inlet end of the supply air pipe (20) is connected to the air outlet of the evaporator (3). The air with moisture enters the evaporator (3) and condenses on the surface of the copper pipe (2) to realize air drying.

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