Oil filling structure and method of high-voltage and ultra-high-voltage outdoor terminal

Abstract

This application discloses an oil filling structure and method for a high-voltage and ultra-high-voltage outdoor terminal. The oil filling structure of the high-voltage and ultra-high-voltage outdoor terminal includes: a sealed oil tank; a pretreatment unit including a first vacuuming device, a heating device, and a circulation device; the first vacuuming device is connected to the sealed oil tank for evacuating the sealed oil tank; the heating device is disposed in the sealed oil tank for heating the insulating oil; the circulation device is connected to the sealed oil tank and has an atomizing component disposed inside the sealed oil tank, the circulation device being used to extract the insulating oil from the sealed oil tank and atomize it back into the sealed oil tank through the atomizing component; a second vacuuming device is connected to the terminal for evacuating the terminal; and an oil injection device is configured to inject the insulating oil from the sealed oil tank, which has been treated by the pretreatment unit, into the terminal after the second vacuuming device has completed evacuating the terminal. This application can reduce the risk of contamination and improve the purity of the insulating oil.

Description

Technical Field

[0001] This application relates to the field of cable accessories technology, and in particular to an oil filling structure and method for a high-voltage and ultra-high-voltage outdoor terminal. Background Technology

[0002] High-voltage and ultra-high-voltage outdoor terminals are critical equipment in power transmission networks, and their interiors require high-performance insulating oil. The purity of the insulating oil directly affects the operational reliability and lifespan of the terminal. In traditional outdoor terminal filling processes, the addition of insulating oil is a key point of contamination risk. Currently, conventional filling methods mainly fall into two categories: first, operators manually pour insulating oil from pre-packaged drums into the terminal from the top; second, an oil pump is used to directly pump insulating oil from a storage tank into the terminal. However, both of these methods involve open or semi-open operations, making it impossible to prevent air contamination of the insulating oil or remove moisture from it. When insulating oil containing air and moisture enters the terminal, partial discharge easily occurs during operation because the dielectric strength and breakdown field strength of air are much lower than those of the insulating oil. The ozone and nitrogen oxides produced by this discharge further degrade the insulating oil and the terminal's insulation material, potentially developing into dendritic carbonized channels that lead to permanent insulation failure. Moisture also drastically reduces the dielectric strength of the insulating oil, especially when it exists in the form of free water, whose dielectric constant is much higher than that of the insulating oil. Under the influence of an electric field, this forms a low-resistance channel, significantly reducing the breakdown voltage and making internal flashover or breakdown more likely. Therefore, a solution is urgently needed to address the problem of easily contaminated insulating oil during filling. Summary of the Invention

[0003] This application aims to address at least one of the technical problems existing in the prior art. To this end, this application proposes an oil filling structure for high-voltage and ultra-high-voltage outdoor terminals, which can reduce the risk of contamination during the insulating oil filling process and improve the purity of the insulating oil.

[0004] This application also proposes a method for filling high-voltage and ultra-high-voltage outdoor terminals with oil.

[0005] The oil filling structure of the high-voltage and ultra-high-voltage outdoor terminal according to the first aspect of this application includes: A sealed oil tank, wherein insulating oil is provided inside the sealed oil tank; The pretreatment unit includes a first vacuuming device, a heating device, and a circulation device; the first vacuuming device is connected to the sealed oil tank and is used to vacuum the sealed oil tank; the heating device is disposed in the sealed oil tank and is used to heat the insulating oil; the circulation device is connected to the sealed oil tank and has an atomizing component disposed inside the sealed oil tank, the circulation device being used to extract the insulating oil from the sealed oil tank and atomize it through the atomizing component and spray it back into the sealed oil tank; The second vacuuming device is used to connect to the terminal to perform vacuuming on the terminal; An oil injection device is connected between the sealed oil tank and the terminal. The oil injection device is configured to inject the insulating oil in the sealed oil tank, which has been processed by the pretreatment unit, into the terminal after the second vacuuming device has completed the vacuuming of the terminal.

[0006] The oil filling structure of the high-voltage and ultra-high-voltage outdoor terminal according to the embodiments of this application has at least the following beneficial effects: On the one hand, it enables vacuum sealing during the insulating oil filling process. The pretreatment unit and the second vacuum pumping device independently pretreat the oil source and the terminal, respectively. Then, the oil filling device fills the insulating oil under vacuum conditions in both locations, greatly reducing the possibility of the insulating oil coming into contact with air during the filling process and reducing the risk of pollution caused by the introduction of air and moisture from the source. On the other hand, it enables deep purification of the insulating oil. By setting up a pretreatment unit, the moisture in the insulating oil can be accelerated to evaporate through heating. The air and evaporated moisture in the sealed oil tank can be extracted to the outside of the sealed oil tank through vacuuming. At the same time, the low-pressure environment established can also lower the boiling point of water and accelerate the evaporation of moisture. By circulating and continuously atomizing the insulating oil in the sealed oil tank, the surface area of ​​the oil is increased, which is more conducive to the evaporation of moisture. The three work together to efficiently and deeply remove moisture and gas from the insulating oil, so that the oil reaches extremely high purity before being injected into the terminal.

[0007] According to some embodiments of this application, the preprocessing unit further includes: A stirrer is provided inside the sealed oil tank for stirring the insulating oil.

[0008] According to some embodiments of this application, a first pipeline and a second pipeline are connected in parallel between the sealed oil tank and the terminal. The first pipeline is equipped with the oil injection device and a first control valve group, which is used to control the opening and closing of the first pipeline. The second pipeline is equipped with a second control valve group, which is used to control the opening and closing of the second pipeline.

[0009] According to some embodiments of this application, the second control valve assembly is configured to connect the second pipeline before the oil injection device injects oil into the terminal, so that the sealed oil tank is connected to the interior of the terminal.

[0010] According to some embodiments of this application, the first control valve group includes a first valve and a second valve, the second control valve group includes a third valve and a fourth valve, the first valve and the third valve are disposed adjacent to the sealed oil tank, and the second valve and the fourth valve are disposed adjacent to the terminal.

[0011] According to some embodiments of this application, the sealed oil tank is provided with an air extraction port above the liquid surface of the insulating oil, and a gas-liquid separator is provided inside the air extraction port, and the first vacuum device is connected to the air extraction port.

[0012] According to some embodiments of this application, the atomizing component includes an atomizing nozzle, and the circulation device includes a first oil pump, the oil inlet of the first oil pump being connected to the bottom of the sealed oil tank, and the oil outlet being connected to the top space of the sealed oil tank through the atomizing nozzle.

[0013] The oil filling method for a high-voltage and ultra-high-voltage outdoor terminal according to the second aspect of this application, applied to the oil filling structure of the high-voltage and ultra-high-voltage outdoor terminal of the above embodiment, includes the following steps: Insulating oil pretreatment: The insulating oil in the sealed oil tank is heated to a set temperature range. Then, the sealed oil tank is evacuated. During the evacuation process, the insulating oil in the sealed oil tank is atomized and circulated, and the temperature of the insulating oil is maintained within the set temperature range. The atomization and circulation process includes continuously drawing the insulating oil from the sealed oil tank and atomizing it back into the sealed oil tank through the atomization component. Terminal preprocessing: Vacuuming the terminal; Insulating oil filling: After the terminal pretreatment is completed, the insulating oil in the sealed oil tank after the insulating oil pretreatment is injected into the terminal.

[0014] According to some embodiments of this application, the set temperature range is 65°C to 70°C.

[0015] According to some embodiments of this application, a first pipeline and a second pipeline are connected in parallel between the sealed oil tank and the terminal. The oil injection device is installed on the first pipeline, and a second control valve group is installed on the second pipeline to control the on / off state of the second pipeline. The step of injecting the insulating oil pretreated from the sealed oil tank into the terminal includes: First, control the second control valve group to connect the second pipeline, so that the sealed oil tank is connected to the inside of the terminal. Then, control the oil injection device to inject the insulating oil in the sealed oil tank into the terminal.

[0016] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0017] The present application will be further described below with reference to the accompanying drawings and embodiments, wherein: Figure 1 This is an overall schematic diagram of the oil filling structure of the high-voltage and ultra-high-voltage outdoor terminal according to an embodiment of this application; Figure 2 yes Figure 1 Partial structural diagram; Figure 3 yes Figure 1 Another part of the structural diagram.

[0018] Icon labels: Sealed oil tank 100, air extraction port 101, first pipeline 110, first valve 111, second valve 112, second pipeline 120, third valve 121, fourth valve 122, gas-liquid separator 130, oil filling plug 140, third pipeline 150, fifth valve 151, first pressure gauge 160, first vacuum breaking valve 170, first gas drying and filtering device 171; First vacuum pumping device 200, first vacuum pump 210; Heating device 300, immersion heating rod 310, sealing flange 320, temperature control unit 330; The circulation device 400, the atomizing component 410, the first oil pump 420, the fourth pipeline 430, and the sixth valve 431 are included. Second vacuum pumping device 500, second vacuum pump 510; Terminal 600, second pressure gauge 610, second vacuum breaking valve 620, second gas drying and filtering device 621; Oil injection device 700, second oil pump 710; Mixer 800. Detailed Implementation

[0019] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0020] In the description of this application, it should be understood that the orientation descriptions, such as up, down, etc., are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application 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, and therefore should not be construed as a limitation of this application.

[0021] In the description of this application, "multiple" refers to two or more. The use of "first" and "second" is for the purpose of distinguishing technical features only and should not be construed as indicating or implying relative importance, or implicitly indicating the number of technical features indicated, or the order in which the technical features are indicated.

[0022] In the description of this application, unless otherwise expressly defined, terms such as "setup," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this application in conjunction with the specific content of the technical solution.

[0023] Reference Figures 1 to 3 As shown, an embodiment of the oil filling structure of a high-voltage and ultra-high-voltage outdoor terminal of this application includes: a sealed oil tank 100, a pretreatment unit, a second vacuuming device 500, and an oil filling device 700.

[0024] The sealed oil tank 100 is a pressure vessel, and the sealed oil tank 100 contains insulating oil to be added. The insulating oil may be silicone oil.

[0025] The pretreatment unit is used to pre-treat the insulating oil in the sealed oil tank 100 by degassing and dehumidifying. The pretreatment unit includes a first vacuum device 200, a heating device 300, and a circulation device 400. The first vacuum device 200 is connected to the sealed oil tank 100 and is used to vacuum the sealed oil tank 100 to establish and maintain a treatment environment below atmospheric pressure. The heating device 300 is installed in the sealed oil tank 100 and is used to heat the insulating oil in the sealed oil tank 100 to accelerate the evaporation of moisture in the insulating oil. The circulation device 400 is connected to the sealed oil tank 100 and has an atomizing component 410 installed in the sealed oil tank 100. The circulation device 400 is used to extract the insulating oil from the sealed oil tank 100 and atomize it through the atomizing component 410 and spray it back into the sealed oil tank 100 to perform atomization and circulation treatment on the insulating oil in the sealed oil tank 100. Since the surface area of ​​the oil increases after atomization, it is conducive to the evaporation of moisture.

[0026] The second vacuum device 500 is used to connect to the terminal 600 to evacuate the terminal 600, remove the air and moisture therein, and prepare a negative pressure clean space for receiving clean insulating oil.

[0027] The oil injection device 700 is connected between the sealed oil tank 100 and the terminal 600. The oil injection device 700 is configured to inject the insulating oil in the sealed oil tank 100, which has been processed by the pretreatment unit, into the terminal 600 after the second vacuum device 500 completes the vacuuming of the terminal 600.

[0028] In use, the first vacuuming device 200, heating device 300 and circulation device 400 are used to perform synergistic processing of vacuuming the sealed oil tank 100, heating the insulating oil and atomizing and circulating it to remove air and moisture mixed in the insulating oil until the insulating oil reaches the set cleanliness and dryness; at the same time or subsequently, the second vacuuming device 500 is used to vacuum the terminal 600; after the above steps are completed, the oil injection device 700 is started to inject the insulating oil in the sealed oil tank 100 after the pretreatment unit into the terminal 600 until the set liquid level is reached.

[0029] The oil filling structure of the high-voltage and ultra-high-voltage outdoor terminal in this embodiment has two main advantages. First, it enables vacuum sealing during the insulating oil filling process. The pretreatment unit and the second vacuum pumping device 500 independently pre-treat the oil source and the terminal 600, respectively. Then, the oil filling device 700 fills the insulating oil under vacuum conditions in both locations, greatly reducing the possibility of the insulating oil coming into contact with air during the filling process and reducing the risk of contamination caused by the introduction of air and moisture from the source. Second, it enables deep purification of the insulating oil. By setting up the pretreatment unit, the moisture in the insulating oil can be accelerated to evaporate through heating. The air and evaporated moisture in the sealed oil tank 100 are extracted to the outside of the sealed oil tank 100 through vacuum pumping. At the same time, the low-pressure environment established can also lower the boiling point of water and accelerate the evaporation of moisture. By circulating and continuously atomizing the insulating oil in the sealed oil tank 100, the surface area of ​​the oil is increased, which is more conducive to the evaporation of moisture. The three factors work together to efficiently and deeply remove moisture and gas from the insulating oil, so that the oil reaches extremely high purity before being injected into the terminal 600.

[0030] Based on the above embodiments, it should be noted that a specific operating mode of the insulating oil pretreatment process is as follows: First, the heating device 300 is started to heat the insulating oil in the sealed oil tank 100 to a set temperature range (e.g., 65℃~70℃); after the oil temperature reaches the set temperature range, the first vacuum device 200 is started to evacuate the sealed oil tank 100; when the required vacuum degree (e.g., 10℃) is reached in the tank... 2 Pa~10 5 When the pressure reaches 100 Pa, the circulation device 400 is restarted for atomization circulation. Vacuuming and atomization circulation are continued, and the heating device 300 maintains the temperature of the insulating oil within the aforementioned set temperature range or a nearby range, until the operator observes no condensate discharge from the exhaust port of the first vacuum device 200. This indicates that the moisture in the insulating oil has been sufficiently removed. Then, the first vacuum device 200 and the circulation device 400 can be turned off to complete the pretreatment. It should be noted that the heating device 300 can continue to operate until the oil filling is complete before being turned off, ensuring the fluidity of the insulating oil during the filling process and preventing it from solidifying due to temperature drop.

[0031] Of course, the above-described sequence of operations is only one possible implementation. In other optional implementations, the heating device 300, the first vacuuming device 200, and the circulation device 400 can also be started simultaneously, that is, heating, vacuuming, and atomization circulation can begin at the same time.

[0032] It should be noted that when the pressure is 10... 2 Pa~10 5 When the temperature is within the range of Pa, the boiling point of water can be reduced to 10℃~50℃.

[0033] Reference Figure 1 and Figure 2 As shown, in some embodiments of this application, the top of the sealed oil tank 100 is provided with an oil inlet, and an oil plug 140 is provided at the oil inlet to facilitate the addition of insulating oil into the sealed oil tank 100.

[0034] Reference Figure 1 As shown, in some embodiments of this application, the pretreatment unit further includes a stirrer 800, which is disposed in the sealed oil tank 100 and located at its bottom for stirring the insulating oil. The stirrer 800 can be started synchronously with the heating device 300. By stirring the insulating oil, local overheating can be avoided during heating. At the same time, stirring can also accelerate the evaporation of moisture and gas in the insulating oil.

[0035] The agitator 800 may include a drive motor, a transmission shaft, and a stirring blade. The drive motor is fixedly installed on the outside of the sealed oil tank 100, and its output shaft can pass into the tank through a dynamic sealing structure. The transmission shaft is connected to the output shaft of the drive motor, and the stirring blade is fixedly installed at the end of the transmission shaft and immersed below the surface of the insulating oil. Specifically, the stirring blade may adopt one of the following structures: anchor type, paddle type, turbine type, or ribbon type; this embodiment does not impose a specific limitation.

[0036] Reference Figure 1 and Figure 2 As shown, in some embodiments of this application, the sealed oil tank 100 has an exhaust port 101 above the surface of the insulating oil, and a gas-liquid separator 130 is provided inside the exhaust port 101. The first vacuum device 200 includes a first vacuum pump 210, which is located outside the sealed oil tank 100. The suction port of the first vacuum pump 210 is connected to the exhaust port 101. The first vacuum pump 210 is used to evacuate the sealed oil tank 100, while the gas-liquid separator 130 is used to prevent insulating oil droplets from being sucked into the first vacuum pump 210. Specifically, the gas-liquid separator 130 can be a cyclone type.

[0037] Reference Figure 1 and Figure 2As shown, in some embodiments of this application, the suction port of the first vacuum pump 210 is connected to the suction port 101 of the sealed oil tank 100 through a third pipeline 150, and a fifth valve 151 is provided on the third pipeline 150 to control its opening and closing.

[0038] It should be noted that the exhaust port of the first vacuum device 200 mentioned above refers to the exhaust port of the first vacuum pump 210.

[0039] Reference Figure 2 As shown, in some embodiments of this application, a first pressure gauge 160 is also provided at the top of the sealed oil tank 100 to facilitate the detection of the pressure inside the tank.

[0040] Reference Figure 2 As shown, in some embodiments of this application, the sealed oil tank 100 is connected to a first vacuum breaking valve 170, which is used to break the vacuum in the sealed oil tank 100 (for example, after the oil filling of the terminal 600 is completed) to restore its internal pressure to atmospheric pressure. The air inlet of the first vacuum breaking valve 170 is connected to an integrated first gas drying and filtering device 171. The first gas drying and filtering device 171 may include a filter canister containing a desiccant (such as molecular sieve, silica gel or activated alumina), whose inlet is connected to the atmosphere and whose outlet is connected to the first vacuum breaking valve 170, for drying and filtering the air drawn in during vacuum breaking.

[0041] In some embodiments of this application, the heating device 300 may be implemented using a variety of heating methods known in the art according to actual process requirements, such as electric heating rods, electric heating belts, or jacketed heat medium circulation heating.

[0042] For example, refer to Figure 1 and Figure 2 As shown, the heating device 300 can adopt an integrated structure. This structure mainly consists of an immersion heating rod 310, a sealing flange 320, and a temperature control unit 330. The immersion heating rod 310 is sealed and fixed to the side wall or top cover of the sealed oil tank 100 through the sealing flange 320. Its heating part extends into and is submerged below the surface of the insulating oil to directly heat the oil. The sealing flange 320 needs to have good sealing performance and high temperature resistance and insulating oil resistance material properties to ensure long-term sealing reliability. The temperature control unit 330 can be integrated into the sealing flange 320 or set nearby for real-time monitoring of the temperature of the insulating oil.

[0043] Reference Figure 1 and Figure 2As shown, in some embodiments of this application, the atomizing component 410 includes an atomizing nozzle, and the circulation device 400 includes a first oil pump 420 and a fourth pipeline 430. One end of the fourth pipeline 430 is connected to the bottom of the sealed oil tank 100, and the other end is connected to the atomizing nozzle, which is located in the top space of the sealed oil tank 100. The first oil pump 420 is connected in series on the fourth pipeline 430, with its inlet facing the bottom of the sealed oil tank 100 to connect to the bottom of the sealed oil tank 100. The outlet of the first oil pump 420 is connected to the atomizing nozzle to connect to the top space of the sealed oil tank 100. The first oil pump 420 can pump out the insulating oil at the bottom of the sealed oil tank 100 and deliver it to the atomizing nozzle for atomization and spraying into the top space inside the tank, thereby achieving atomization circulation.

[0044] In addition, a sixth valve 431 is connected in series on the fourth pipeline 430 between the oil inlet of the first oil pump 420 and the sealed oil tank 100 to control the opening and closing of the fourth pipeline 430.

[0045] Reference Figure 1 and Figure 3 As shown, in some embodiments of this application, the second vacuum device 500 includes a second vacuum pump 510, which can be connected to the terminal 600 via a pipeline with a quick connector for quick and sealed docking, thereby performing vacuuming treatment inside the terminal 600.

[0046] Reference Figure 3 As shown, in some embodiments of this application, the terminal 600 is connected to a second pressure gauge 610 to detect the pressure inside the terminal 600.

[0047] Reference Figure 3 As shown, in some embodiments of this application, the terminal 600 is connected to a second vacuum breaking valve 620, which is used to break the vacuum in the terminal 600 after oil filling is completed, so that its internal pressure is restored to atmospheric pressure. The air inlet of the second vacuum breaking valve 620 is connected to an integrated second gas drying and filtering device 621, which is used to dry and filter the gas entering the terminal 600. The second gas drying and filtering device 621 can adopt the same structure as the first gas drying and filtering device 171.

[0048] Reference Figure 1 and Figure 3As shown, in some embodiments of this application, a first pipeline 110 and a second pipeline 120 are connected in parallel between the sealed oil tank 100 and the terminal 600. That is, one end of the first pipeline 110 and the second pipeline 120 are connected to the sealed oil tank 100 and the other end is connected to the terminal 600. An oil injection device 700 and a first control valve group are provided on the first pipeline 110. The first control valve group is used to control the opening and closing of the first pipeline 110. A second control valve group is provided on the second pipeline 120. The second control valve group is used to control the opening and closing of the second pipeline 120. When the first control valve group is connected to the first pipeline 110 and the oil injection device 700 is started, insulating oil can be injected from the sealed oil tank 100 into the terminal 600. When the second control valve group is connected to the second pipeline 120, the interior of the sealed oil tank 100 and the interior of the terminal 600 can be connected through the second pipeline 120.

[0049] In this embodiment, by setting up a first pipeline 110 and a second pipeline 120 that are connected in parallel and independently controlled to switch on and off, the physical separation and independent control of pressure balance and insulating oil filling functions can be achieved, which is beneficial to achieving an optimized process sequence of first establishing system pressure balance and then performing clean oil filling.

[0050] It should be noted that all the above-mentioned pipelines can use rubber hoses with spiral steel wires, which can withstand external pressure and the rubber material does not react with insulating oil (such as silicone oil).

[0051] In some specific embodiments of this application, the second control valve group is configured to: connect the second pipeline 120 before the oil injection device 700 injects oil into the terminal 600, so as to connect the sealed oil tank 100 and the terminal 600 internally, perform pressure balance, eliminate the pressure difference between the sealed oil tank 100 and the terminal 600, so as to make the subsequent oil injection smoother and more stable; after the sealed oil tank 100 and the terminal 600 are connected through the second pipeline 120, the first control valve group is controlled to connect the first pipeline 110 and start the oil injection device 700 to inject oil.

[0052] It should be noted that both the first conduit 110 and the second conduit 120 can be connected to the terminal 600 via quick connectors for quick and sealed connection.

[0053] It should also be noted that the connection between the first pipeline 110 and the sealed oil tank 100 is below the liquid level in the sealed oil tank 100, and the connection between the second pipeline 120 and the sealed oil tank 100 is above the liquid level in the sealed oil tank 100; the ends of the first pipeline 110 and the second pipeline 120 away from the sealed oil tank 100 are both connected to the top of the terminal 600.

[0054] Reference Figure 1 and Figure 3As shown, in some embodiments of this application, the first control valve group includes a first valve 111 and a second valve 112, and the second control valve group includes a third valve 121 and a fourth valve 122. The first valve 111 and the third valve 121 are disposed adjacent to the sealed oil tank 100, and the second valve 112 and the fourth valve 122 are disposed adjacent to the terminal 600. The oil injection device 700 includes a second oil pump 710, which is located between the first valve 111 and the second valve 112. It should be noted that the first valve 111, the second valve 112, the third valve 121, and the fourth valve 122 can all control the on / off state of the pipeline at the valve location.

[0055] It is understandable that the first pipe 110 and the second pipe 120 usually have a certain length and may contain residual air. Therefore, in this embodiment, by setting two valves on each of the first pipe 110 and the second pipe 120, when evacuating the terminal 600, the second valve 112 and the fourth valve 122 adjacent to the terminal 600 can be opened first to evacuate the terminal 600 and remove the air from the first pipe 110 and the second pipe 120 at the same time. After the terminal 600 is evacuated and the insulating oil pretreatment is completed, the third valve 121 is opened to completely connect the second pipe 120 and establish pressure balance. Then, the first valve 111 is opened and the oil injection device 700 is started to inject oil. In this way, the risk of air contamination of the insulating oil can be further reduced.

[0056] This application also proposes an oil filling method for high-voltage and ultra-high-voltage outdoor terminals, applied to the oil filling structure of the high-voltage and ultra-high-voltage outdoor terminals in the above embodiments, which includes the following steps: insulating oil pretreatment, terminal pretreatment, and insulating oil filling.

[0057] The insulating oil pretreatment steps include: heating the insulating oil in the sealed oil tank 100 to a set temperature range using a heating device 300; then, vacuuming the sealed oil tank 100 using a first vacuuming device 200; during the vacuuming process, atomizing and circulating the insulating oil in the sealed oil tank 100 using a circulation device 400; and maintaining the temperature of the insulating oil within the set temperature range using the heating device 300. The atomizing and circulating process includes: continuously drawing the insulating oil from the sealed oil tank 100 using the circulation device 400 and atomizing and spraying it back into the sealed oil tank 100 using an atomizing component 410; and stopping the vacuuming and atomizing circulation of the insulating oil when no condensate is discharged from the exhaust port of the first vacuuming device 200 (i.e., the exhaust port of the first vacuum pump 210), thus completing the insulating oil pretreatment steps.

[0058] The pre-treatment steps for the terminal include: vacuuming the terminal 600 using the second vacuuming device 500; this step can be performed before or in parallel with the pre-treatment of the insulating oil.

[0059] The steps for adding insulating oil include: after completing the terminal pretreatment, the insulating oil pretreated in the sealed oil tank 100 is injected into the terminal 600 through the oil injection device 700 until the specified liquid level is reached in the terminal 600. It should be noted that the heating device 300 can continue to operate until the insulating oil addition is complete before being shut off, ensuring the fluidity of the insulating oil during the injection process and preventing it from solidifying due to temperature drop.

[0060] The oil filling method for high-voltage and ultra-high-voltage outdoor terminals in this embodiment achieves vacuum sealing during the insulating oil filling process. By independently pre-treating the oil source (sealed oil tank 100) and the terminal 600, and then filling the insulating oil under vacuum conditions in both, the possibility of the insulating oil coming into contact with air during the filling process is greatly reduced, thus reducing the risk of contamination caused by the introduction of air and moisture from the source. On the other hand, it enables deep purification of the insulating oil. By pre-treating the insulating oil before filling, heating is used to accelerate the evaporation of moisture in the insulating oil. Vacuuming is used to extract the air and evaporating moisture from the sealed oil tank 100 to the outside of the sealed oil tank 100. At the same time, the low-pressure environment established can also lower the boiling point of water and accelerate the evaporation of moisture. By circulating and continuously atomizing the insulating oil in the sealed oil tank 100, the surface area of ​​the oil is increased, which is more conducive to the evaporation of moisture. The three factors work together to efficiently and deeply remove moisture and gas from the insulating oil, so that the oil reaches extremely high purity before being injected into the terminal 600.

[0061] In some embodiments of this application, in the insulating oil pretreatment step, the sealed oil tank 100 is first evacuated using a first vacuum device 200 until the pressure inside the tank drops to 10. 2 Pa~10 5 Pa, and then start the circulation device 400 to atomize and circulate the insulating oil in the sealed oil tank 100, while continuing to use the first vacuum device 200 to perform vacuuming.

[0062] In some embodiments of this application, the temperature range is set to 65°C to 70°C. It should be noted that the lower the pressure, the lower the boiling point of water; a pressure of 10... 2 Pa~10 5 Pa, the boiling point of water can be lowered to 10℃~50℃.

[0063] In some embodiments of this application, injecting the insulating oil pretreated in the sealed oil tank 100 into the terminal 600 includes: first controlling the second control valve group to connect the second pipeline 120, so that the sealed oil tank 100 is connected to the inside of the terminal 600 to establish pressure balance; then controlling the oil injection device 700 to inject the insulating oil in the sealed oil tank 100 into the terminal 600. Specifically, first opening both the third valve 121 and the fourth valve 122 to connect the second pipeline 120, then opening both the first valve 111 and the second valve 112, and starting the second oil pump 710 to inject the insulating oil in the sealed oil tank 100 into the terminal 600.

[0064] The following reference Figures 1 to 3 The following describes the detailed steps of an oil filling method for a high-voltage and ultra-high-voltage outdoor terminal according to one specific embodiment, which are performed in the following order: Step 1: Preparations Assemble and connect the oil filling structure of the high-voltage and ultra-high-voltage outdoor terminal to the terminal 600, then open the oil filling plug 140 of the sealed oil tank 100, inject insulating oil into the sealed oil tank 100 to the specified liquid level, and then close the oil filling plug 140.

[0065] Step 2: Insulating oil pretreatment: Start the heating device 300 and stirrer 800 to heat the insulating oil in the sealed oil tank 100 to 65℃~70℃, then open the fifth valve 151 and start the first vacuum pump 210 to evacuate the oil in the sealed oil tank 100 to 10℃. 2 Pa~10 5 Under the low vacuum state of Pa, open the sixth valve 431 and start the first oil pump 420 to extract the insulating oil from the bottom of the sealed oil tank 100 and spray it back to the sealed oil tank 100 from the atomizing nozzle. When no condensate is discharged from the exhaust port of the first vacuum pump 210, close the fifth valve 151 and the first vacuum pump 210 to stop vacuuming, and close the sixth valve 431 and the first oil pump 420 to stop the atomization circulation of the insulating oil. Step 3: Terminal pretreatment and insulating oil filling: Open the second valve 112 and the fourth valve 122, start the second vacuum pump 510, and evacuate the terminal 600 to 10. 2 Pa~10 5 After the low vacuum state of Pa is reached, the second vacuum pump 510 is turned off; then the third valve 121 is opened first to connect the sealing oil tank 100 and the terminal 600 through the internal connection of the second pipeline 120 to establish pressure balance; then the first valve 111 is opened and the second oil pump 710 is started to inject the insulating oil in the sealing oil tank 100 into the terminal 600 until it is filled to the specified liquid level. Step 4: Finishing touches After the insulating oil in terminal 600 is filled to the specified level, close the second valve 112 and the second oil pump 710 to stop the oil filling. Close the fourth valve 122 to cut off the internal connection between the sealed oil tank 100 and terminal 600. Then, restore the terminal 600 to atmospheric pressure through the second vacuum breaking valve 620. Then, turn off the heating device 300 and the agitator 800. Restore the sealed oil tank 100 to atmospheric pressure through the first vacuum breaking valve 170. Then, close the third valve 121, remove the connection to terminal 600, pump out the remaining insulating oil through the second oil pump 710 for proper disposal, remove other devices, and clean for future use.

[0066] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. In addition, those skilled in the art can combine different embodiments or examples described in this specification.

[0067] The embodiments of this application have been described in detail above with reference to the accompanying drawings. However, this application is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of this application.

Claims

1. An oil filling structure for a high-voltage and ultra-high-voltage outdoor terminal, characterized in that, include: A sealed oil tank, wherein insulating oil is provided inside the sealed oil tank; The pretreatment unit includes a first vacuuming device, a heating device, and a circulation device; the first vacuuming device is connected to the sealed oil tank and is used to vacuum the sealed oil tank; the heating device is disposed in the sealed oil tank and is used to heat the insulating oil; the circulation device is connected to the sealed oil tank and has an atomizing component disposed inside the sealed oil tank, the circulation device being used to extract the insulating oil from the sealed oil tank and atomize it through the atomizing component and spray it back into the sealed oil tank; The second vacuuming device is used to connect to the terminal to perform vacuuming on the terminal; An oil injection device is connected between the sealed oil tank and the terminal. The oil injection device is configured to inject the insulating oil in the sealed oil tank, which has been processed by the pretreatment unit, into the terminal after the second vacuuming device has completed the vacuuming of the terminal.

2. The oil filling structure of the high-voltage and ultra-high-voltage outdoor terminal according to claim 1, characterized in that, The preprocessing unit further includes: A stirrer is provided inside the sealed oil tank for stirring the insulating oil.

3. The oil filling structure of the high-voltage and ultra-high-voltage outdoor terminal according to claim 1, characterized in that, A first pipeline and a second pipeline are connected in parallel between the sealed oil tank and the terminal. The first pipeline is equipped with the oil injection device and a first control valve group. The first control valve group is used to control the opening and closing of the first pipeline. The second pipeline is equipped with a second control valve group to control the opening and closing of the second pipeline.

4. The oil filling structure of the high-voltage and ultra-high-voltage outdoor terminal according to claim 3, characterized in that, The second control valve assembly is configured to connect the second pipeline before the oil injection device injects oil into the terminal, thereby connecting the sealed oil tank to the interior of the terminal.

5. The oil filling structure of the high-voltage and ultra-high-voltage outdoor terminal according to claim 3, characterized in that, The first control valve group includes a first valve and a second valve, the second control valve group includes a third valve and a fourth valve, the first valve and the third valve are disposed adjacent to the sealed oil tank, and the second valve and the fourth valve are disposed adjacent to the terminal.

6. The oil filling structure of the high-voltage and ultra-high-voltage outdoor terminal according to claim 1, characterized in that, The sealed oil tank has an air extraction port above the surface of the insulating oil, and a gas-liquid separator is provided inside the air extraction port. The first vacuum device is connected to the air extraction port.

7. The oil filling structure of the high-voltage and ultra-high-voltage outdoor terminal according to claim 1, characterized in that, The atomizing component includes an atomizing nozzle, and the circulation device includes a first oil pump. The oil inlet of the first oil pump is connected to the bottom of the sealed oil tank, and the oil outlet is connected to the top space of the sealed oil tank through the atomizing nozzle.

8. A method for filling a high-voltage and ultra-high-voltage outdoor terminal with oil, applied to the oil filling structure of the high-voltage and ultra-high-voltage outdoor terminal as described in claim 1, characterized in that, Includes the following steps: Insulating oil pretreatment: The insulating oil in the sealed oil tank is heated to a set temperature range. Then, the sealed oil tank is evacuated. During the evacuation process, the insulating oil in the sealed oil tank is atomized and circulated, and the temperature of the insulating oil is maintained within the set temperature range. The atomization and circulation process includes continuously drawing the insulating oil from the sealed oil tank and atomizing it back into the sealed oil tank through the atomization component. Terminal preprocessing: Vacuuming the terminal; Insulating oil filling: After the terminal pretreatment is completed, the insulating oil in the sealed oil tank after the insulating oil pretreatment is injected into the terminal.

9. The oil filling method for high-voltage and ultra-high-voltage outdoor terminals according to claim 8, characterized in that, The set temperature range is 65℃~70℃.

10. The oil filling method for high-voltage and ultra-high-voltage outdoor terminals according to claim 8, characterized in that, A first pipeline and a second pipeline are connected in parallel between the sealed oil tank and the terminal. The oil injection device is installed on the first pipeline, and a second control valve group is installed on the second pipeline to control the opening and closing of the second pipeline. The step of injecting the pretreated insulating oil from the sealed oil tank into the terminal includes: First, control the second control valve group to connect the second pipeline, so that the sealed oil tank is connected to the inside of the terminal. Then, control the oil injection device to inject the insulating oil in the sealed oil tank into the terminal.

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