A substation indoor cable trench humidity control method and control system

Abstract

The application relates to a substation indoor cable trench humidity control system and a control method, which comprises collecting first data and second data; when the first data is lower than a first set value and the second data is not collected, a first device is started, and a second device and a third device are closed; when the first data is higher than a second set value and the second data is not collected, the first device is closed, and the second device and the third device are started; and when the second data is collected, the first device is started, and the second device is closed. The application can prevent humid air in the closed space of the indoor cable trench from entering the electrical cabinet and affecting the normal operation of the electrical equipment, and can effectively exhaust smoke and prevent the smoke from entering the electrical cabinet when the smoke occurs.

Description

Technical Field

[0001] This invention relates to the field of humidity control in indoor cable trenches of substations, and specifically to a method and control system for humidity control in indoor cable trenches of substations. Background Technology

[0002] In some functional rooms of a substation, cable trenches are located below the indoor floor, dividing the indoor space into above-ground and below-ground sections. Above ground, electrical equipment does not release moisture during operation; water vapor in the indoor air comes from moisture exchange between the indoor and outdoor environments, and the relative humidity is typically controlled by dehumidifiers. Below ground, the cable trenches typically have higher humidity due to groundwater and rainwater infiltration. Furthermore, because the cable trenches are relatively sealed, indoor dehumidification equipment cannot control the humidity within them. Additionally, the connections between cables and switchgear, terminal cabinets, and other electrical equipment are not completely sealed, allowing humid air to diffuse into the equipment. According to relevant regulations, fireproof walls are installed at regular intervals within the cable trenches, creating a relatively enclosed area. The gaps in the cables, which cannot be completely sealed, become the only channels for the diffusion of humid air.

[0003] Currently, electrical cabinet exhaust systems all utilize top-mounted ventilation, employing mechanical power or thermal pressure. This neglects to consider the air conditions within the cable trench and the impact of electrical cabinet exhaust on airflow within the trench. Common cable trench ventilation systems also fail to address electrical cabinet exhaust, resulting in a situation where the two interact but are not considered simultaneously. Research indicates that when the humidity within the cable trench is within the normal range, some air infiltration into the electrical cabinet does not affect the internal humidity. However, when the humidity is high, especially when the top-mounted exhaust is constantly open, it exacerbates the infiltration of humid air into the cabinet. If areas within the cabinet have temperatures below the dew point, moisture will condense, leading to reduced insulation, corrosion, and short circuits, thus affecting the safe operation of electrical equipment within the station. Therefore, a dedicated system for indoor cable trench humidity control is needed, simultaneously considering electrical cabinet heat dissipation and cable trench ventilation. This system aims to address the issue of unstable humidity during electrical cabinet exhaust and ensure the safe and stable operation of electrical equipment within the station. Summary of the Invention

[0004] The purpose of this invention is to provide a method and control system for controlling humidity in indoor cable trenches of substations, which can accurately control the humidity of the air in the cable trench and prevent smoke and humid air from entering the equipment.

[0005] A method for controlling humidity in an indoor cable trench of a substation includes: collecting first data and second data; when the first data is lower than a first set value and no second data is collected, turning on a first device and turning off a second device and a third device; the first data includes humidity data, and the second data includes smoke data; the first device includes an electric damper installed in an electrical cabinet; the second device includes an exhaust fan and a first electric fire damper installed at the bottom ventilation opening of the electrical cabinet; the third device includes a second electric fire damper and a dual-purpose axial flow fan installed at the exhaust cavity end of a duct; the exhaust port of the duct is located outside the exterior wall, the air inlet of the duct is connected to the air outlet of the exhaust cavity, and the air inlet of the exhaust cavity is connected to the cable trench; when the first data is higher than a second set value and no second data is collected, turning off the first device and turning on the second and third devices; when the second data is collected, turning on the first device and turning off the second device.

[0006] As a further improvement to the above technical solution: the first data is collected by a humidity sensor, and the second data is collected by a smoke sensor. Both the humidity sensor and the smoke sensor are located in a cable trench and are connected to the controller via a data transmission line.

[0007] As a further improvement to the above technical solution: when the first data is lower than the first set value and no second data is collected, the electrical cabinet is in a natural ventilation state, and dehumidification and heat dissipation are carried out through positive circulation. The positive circulation is that air enters the electrical cabinet from the cable trench and is discharged from the normally open vent located above the electrical cabinet.

[0008] As a further improvement to the above technical solution: when the first data is higher than the second set value and no second data is collected, the cable trench is in a negative pressure state, and dehumidification and heat dissipation are carried out through reverse circulation. The internal circulation is that the dry air in the electrical cabinet enters from the normally open ventilation port at the top of the cabinet and flows into the cable trench from the exhaust port at the bottom of the cabinet.

[0009] A humidity control system for indoor cable trenches in substations includes: an electrical cabinet, a data acquisition and control unit, and a cable trench ventilation device; the electrical cabinet includes a base plate, with a normally open ventilation opening at the upper end and an electric air valve installed at the lower end; the data acquisition unit includes a humidity sensor and a smoke sensor located in the cable trench, and both the humidity sensor and the smoke sensor are connected to the controller inside the electrical cabinet.

[0010] As a further improvement to the above technical solution: the cable trench ventilation device includes a duct and an exhaust cavity. The duct is located between the exhaust cavity and the outer wall. The air inlet of the duct is connected to the air outlet of the exhaust cavity. The air outlet of the duct passes through the outer wall and is connected to the atmosphere. The exhaust cavity is located between the cable trench and the firewall. The air inlet of the exhaust cavity is connected to the cable trench. A damper assembly is provided at one end of the duct located in the exhaust cavity.

[0011] As a further improvement to the above technical solution:

[0012] The damper assembly includes a filter screen, a second fire damper, and a fan, which are installed sequentially from bottom to top at the air inlet of the air duct. The filter screen is fixed at the port of the air duct.

[0013] The electrical cabinet includes a base plate, on which an exhaust vent and a first wire opening are provided. Inside the electrical cabinet, at the exhaust vent, there is a first fire damper, an electric air damper, and an exhaust fan. The first fire damper and the exhaust fan are both controlled by the controller.

[0014] The electrical cabinet is equipped with a horizontal exhaust baffle; the exhaust baffle is provided with an air guide corresponding to the exhaust port and a second wire opening corresponding to the first wire opening.

[0015] To achieve the above objectives, the present invention adopts the following technical solution:

[0016] As can be seen from the above technical solution, the humidity control system and control method for indoor cable trenches in substations described in this invention can prevent humid air in the enclosed space of the indoor cable trench from entering the electrical cabinet and affecting the normal operation of electrical equipment. It can also effectively exhaust smoke when smoke is generated and prevent smoke from entering the electrical cabinet. Attached Figure Description

[0017] The present invention will now be described by way of example with reference to the accompanying drawings. These drawings, together with the embodiments, are used to explain the present invention and do not constitute a limitation thereof. In the drawings:

[0018] Figure 1 This is a top view of the present invention;

[0019] Figure 2 This is the present invention. Figure 1 A partial schematic diagram of the AA section view;

[0020] Figure 3 This is the present invention. Figure 1 A partial schematic diagram of the BB cross-sectional view;

[0021] Figure 4 This is the present invention. Figure 1 A partial schematic diagram of the CC section view;

[0022] Figure 5 This is a front view of the electrical cabinet of the present invention;

[0023] Figure 6 This is a schematic diagram of the exhaust baffle in the electrical cabinet of the present invention;

[0024] Figure 7 This is a schematic diagram of the structure of the electrical cabinet base plate of the present invention;

[0025] Figure 8 This is the present invention. Figure 6 A sectional view of DD. Detailed Implementation

[0026] The present invention will now be described in detail with reference to exemplary embodiments shown in the accompanying drawings. However, it should be understood that the present invention may be implemented in many different forms and should not be construed as limited to the embodiments set forth herein. These embodiments are provided herein to make the disclosure of the present invention more complete and to fully convey the inventive concept to those skilled in the art.

[0027] In the description of this invention, it should be understood that the terms "center," "lateral," "longitudinal," "front," "rear," "left," "right," "upper," "lower," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the scope of protection of this invention.

[0028] In response to the shortcomings of the prior art pointed out in the background section, the inventors, after careful analysis, believe that the existing manual calibration process is prone to the breakage of the insulating porcelain support. The main reason is that the disconnecting switch is located at a high position, and when the operator observes from a low position and manually adjusts it with the insulating rod, the viewing angle and the force applied to the insulating rod are both tilted, and multiple calibrations may be required. Based on the above ideas, embodiments of the present invention provide the following improved device and its method of use.

[0029] like Figure 1 As shown, the substation indoor cable trench humidity control system of this embodiment includes: electrical cabinet 1, data acquisition and control unit and cable trench ventilation device 2;

[0030] The electrical cabinet 1 includes a base plate 11 and a cabinet door 15. The upper end of the electrical cabinet 1 is provided with a normally open ventilation port 12, and the lower end is equipped with an electric air valve 13. The data acquisition unit includes a humidity sensor 4 and a smoke sensor 5 located in the cable trench 3. Both the humidity sensor 4 and the smoke sensor 5 are connected to the controller inside the electrical cabinet 1.

[0031] The cable trench ventilation device 2 includes a duct 21 and an exhaust cavity 22. The duct 21 is located between the exhaust cavity 22 and the outer wall 6. The air inlet of the duct 21 is connected to the air outlet of the exhaust cavity 22. The air outlet of the duct 21 passes through the outer wall 6 and is connected to the atmosphere. The exhaust cavity 22 is located between the cable trench 3 and the firewall 8. The air inlet of the exhaust cavity 22 is connected to the cable trench 3. A damper assembly 9 is provided at one end of the duct 21 located in the exhaust cavity 22.

[0032] like Figure 3 , 4 As shown, the damper assembly 9 consists of a filter screen 91, a second fire damper 92, and a fan 93, installed sequentially from bottom to top at the air inlet of the duct 21. The filter screen 91 is fixed at the port of the duct 21. The filter screen 91 is mainly used to filter debris in the cable trench 3 to prevent solid particles from entering the duct 21 with the air during airflow.

[0033] like Figure 7 As shown, to facilitate wire installation, an exhaust vent 111 and a first wire opening 112 are provided on the base plate 11. The number and arrangement of the exhaust vent 111 and the first wire opening 112 can be set according to actual needs. A first fire damper 17 and an exhaust fan 111 are installed at the exhaust vent 111 inside the electrical cabinet 1. Both the first fire damper 17 and the exhaust fan 111 are controlled by a controller. Based on data collected by the smoke sensor 5 and the humidity sensor 4, the exhaust fan 111 and the first fire damper 17 are actively opened or closed to control the humidity of the air in the cable trench 3, preventing smoke and humid air from entering the equipment.

[0034] The fire dampers described in this embodiment are all electric fire dampers. Humidity sensor 4 and smoke sensor 5 are installed at regular intervals under the cable trench cover near electrical cabinet 1 (for centrally arranged electrical cabinets, sensors can be installed in groups). The data transmission line enters electrical cabinet 1 through the wire opening on the bottom plate 11 of electrical cabinet and is led out synchronously with the control line of electrical cabinet.

[0035] like Figure 8 As shown, an exhaust baffle 14 is also fixedly installed inside the electrical cabinet 1. The exhaust baffle 14 is horizontally arranged, and an air guide 141 is provided in the middle of the exhaust baffle 14. The air guide 141 is mainly used to guide the direction of airflow and prevent air from forming vortex inside the electrical cabinet 1. Second wire openings 142 corresponding to the first wire opening 112 are provided on both sides of the exhaust baffle 14 to facilitate the installation of wires.

[0036] This embodiment also discloses a method for controlling humidity in indoor cable trenches of substations, specifically including the following steps:

[0037] The system collects first data and second data, the first data including humidity data and the second data including smoke data; the first device includes an electric air valve 13 installed in the electrical cabinet 1; the second device includes an exhaust fan 111 and a first electric fire damper 17 installed at the bottom ventilation opening of the electrical cabinet 1; the third device includes a second electric fire damper 92 and a fan 93 installed at the exhaust cavity end of the air duct 21; in this embodiment, the fan 93 is a dual-purpose axial flow fan.

[0038] When the first data is lower than the first set value and no second data is collected, the first device is activated, i.e., the electric air valve 13 is activated, and the second and third devices are deactivated, i.e., the exhaust fan 111, the first electric fire damper 12, the second electric fire damper 92, and the dual-purpose axial flow fan 93 are deactivated. When the first data is higher than the second set value and no second data is collected, the first device is deactivated, i.e., the electric air valve 13 is deactivated, and the second and third devices are activated, i.e., the exhaust fan 111, the first electric fire damper 17, the second electric fire damper 92, and the dual-purpose axial flow fan 93 are activated. When the second data is collected, the first device is activated, i.e., the electric air valve 13 is activated, and the second device is deactivated, i.e., the exhaust fan 111 and the first electric fire damper 17 are deactivated, as detailed below:

[0039] (1) When the humidity sensor 4 in the cable trench 3 collects a value lower than the set value and no smoke sensor 5 collects smoke, the electric air valve 13 of all electrical cabinets 1 is opened, and the exhaust fan 111, the first electric fire damper 17, the second fire damper 92 and the dual-purpose axial flow fan 93 in the cable trench exhaust device 2 are closed. The electrical cabinet 1 is in a natural ventilation state. The indoor air enters through the lower electric air valve 13 and is discharged through the upper normally open vent 12 under the action of thermal pressure, while taking away the heat dissipation inside the electrical cabinet 1. At this time, the relative humidity in the cable trench 3 is lower than the limit value. A small amount of air infiltrates into the electrical cabinet 1 from the bottom and is heated to further reduce the relative humidity, so there will be no condensation problem.

[0040] (2) If any humidity sensor 4 in the cable trench 3 collects a value higher than the set value and all smoke sensors 5 do not collect smoke, then the electric air valve 13 of the electrical cabinet 1 adjacent to the humidity sensor 4 with a value higher than the set value is closed, and the exhaust fan 111, the first fire damper 17, the second fire damper 92 in the cable trench exhaust device 2, and the dual-purpose axial flow fan 93 are opened to exhaust air. At this time, the humid air in the cable trench 3 is exhausted to the outside, and the cable trench 3 is in a negative pressure state. The dry air in the electrical cabinet 1 enters the cable trench 3 by opening the exhaust fan 111 and the first fire damper 17, while taking away the heat dissipation inside the electrical cabinet 1, and at the same time preventing the humid air from entering the electrical cabinet 1.

[0041] (3) When any smoke sensor 5 in the cable trench 3 detects smoke, all exhaust fans 111 and first fire dampers 17 of electrical cabinets 1 are closed, electric air dampers 13 are opened, and electrical cabinets 1 are in a natural ventilation state. Indoor air enters through the lower electric air damper 13 and is discharged through the upper normally open vent 12 under thermal pressure, while taking away the heat dissipation inside electrical cabinets 1. The second fire damper 92 and dual-purpose axial flow fan 93 are opened to exhaust smoke. At this time, the cable trench 3 is in a negative pressure state, and the gas in the cable trench 3 will not enter the electrical cabinets 1.

[0042] It should be noted that the present invention is not limited to the above-described embodiments. Based on the inventive spirit of the present invention, those skilled in the art can make other changes, and these changes made in accordance with the inventive spirit of the present invention should be included within the scope of protection claimed by the present invention.

Claims

1. A method for controlling humidity in indoor cable trenches of substations, characterized in that, include: The system collects first data and second data, the first data including humidity data and the second data including smoke data; the first device includes an electric air valve installed in an electrical cabinet; the second device includes an exhaust fan installed at the bottom ventilation opening of the electrical cabinet and a first electric fire damper; the third device includes a second electric fire damper installed at the exhaust cavity end of the air duct and a dual-purpose axial flow fan; the exhaust port of the air duct is located outside the exterior wall, the air inlet of the air duct is connected to the air outlet of the exhaust cavity, and the air inlet of the exhaust cavity is connected to the cable trench; When the first data is lower than the first set value and no second data is collected, the first device is turned on and the second and third devices are turned off. The electrical cabinet is in a natural ventilation state and dehumidifies and dissipates heat through positive circulation. The positive circulation is that air enters the electrical cabinet from the cable trench and is discharged from the normally open vent located above the electrical cabinet. When the first data is higher than the second set value and no second data is collected, the first device is turned off and the second and third devices are turned on. The cable trench is under negative pressure and dehumidification and heat dissipation are achieved through reverse circulation. The reverse circulation means that the dry air in the electrical cabinet enters through the normally open vent at the top of the cabinet and flows into the cable trench through the exhaust vent at the bottom of the cabinet. When the second data is collected, the first device is turned on, the second device is turned off, and the third device is turned on. The cable trench is under negative pressure, and the gas in the cable trench will not enter the electrical cabinet.

2. The control method according to claim 1, characterized in that, include: The first data is collected by a humidity sensor, and the second data is collected by a smoke sensor. Both the humidity sensor and the smoke sensor are located in a cable trench and are connected to the controller via a data transmission line.

3. A humidity control system for indoor cable trenches in substations, characterized in that, include: Electrical cabinet, data acquisition and control unit, and cable trench ventilation system; The electrical cabinet includes a base plate, on which an exhaust vent and a first wire opening are provided; the upper end of the electrical cabinet is provided with a normally open ventilation vent, and the lower end is equipped with an electric air valve; The data acquisition and control unit includes a humidity sensor and a smoke sensor located in the cable trench, and both the humidity sensor and the smoke sensor are connected to the controller in the electrical cabinet. The electrical cabinet is equipped with a first fire damper, an electric air damper, and an exhaust fan at the exhaust vent. The first fire damper, the electric air damper, and the exhaust fan are all controlled by the controller. The cable trench ventilation device includes a duct and an exhaust cavity. The duct is located between the exhaust cavity and the outer wall. The air inlet of the duct is connected to the air outlet of the exhaust cavity. The air outlet of the duct passes through the outer wall and is connected to the atmosphere. The exhaust cavity is located between the cable trench and the firewall. The air inlet of the exhaust cavity is connected to the cable trench. A damper assembly is provided at one end of the duct located in the exhaust cavity.

4. The humidity control system for indoor cable trenches in substations according to claim 3, characterized in that: The damper assembly includes a filter screen, a second fire damper, and a fan, which are installed sequentially from bottom to top at the air inlet of the air duct. The filter screen is fixed at the port of the air duct.

5. The humidity control system for indoor cable trenches in substations according to claim 3, characterized in that: The electrical cabinet is equipped with a horizontal exhaust baffle; the exhaust baffle is provided with an air guide corresponding to the exhaust port and a second wire opening corresponding to the first wire opening.

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