Electrical equipment insulation gas recovery displacement device

Abstract

The utility model relates to an electrical equipment insulation gas recovery replacement device, including recovery system, liquefaction filling system, mixed gas distribution system, mixed gas filling system, detection system, vacuumizing system, external interface and pipeline, the external interface includes electrical equipment interface, gas storage tank interface, liquid filling interface, tail gas discharge interface, oil inlet, N2 interface, SF6 interface, recovery system is connected with electrical equipment interface, gas storage tank interface and liquefaction filling system respectively, liquefaction filling system is connected with vacuumizing system and liquid filling interface respectively, vacuumizing system is connected with tail gas discharge interface, oil inlet, mixed gas filling system respectively, mixed gas filling system is connected with mixed gas distribution system and detection system respectively, mixed gas distribution system is connected with N2 interface, SF6 interface respectively, the utility model discloses can configure SF6 -N2 mixed gas, replaces the original pure SF6 gas in electrical equipment to the original SF6 gas carries out recovery, and stores over.

Description

Technical Field

[0001] This utility model relates to gas processing technology, specifically to an electrical equipment insulation gas recovery and replacement device. Background Technology

[0002] SF6 gas is non-toxic, non-flammable, and has excellent insulation properties. Its insulation strength is much higher than that of traditional insulating gases, and it has good arc-quenching properties. Therefore, it is widely used in various electrical equipment.

[0003] However, SF6 is a highly contagious greenhouse gas, with a GWP (Global Warming Potential) 23,500 times that of carbon dioxide. Furthermore, SF6 is expensive. Therefore, recycling and reusing SF6, and replacing pure SF6 with an SF6 / N2 mixture as the insulating medium, not only aligns with national environmental protection policies but also offers the advantage of reducing the operating and maintenance costs of electrical equipment. With industry development, an increasing number of substations are responding to national environmental protection calls by requesting upgrades to replace pure SF6 with an SF6-N2 mixture as the insulating gas for their electrical equipment.

[0004] To address the above situation and meet the needs, this utility model proposes an electrical equipment insulation gas recovery and replacement device. It can quickly recover and transfer SF6 gas from electrical equipment, and, by configuring an SF6-N2 mixed gas in any proportion on-site, fill the electrical equipment with the SF6 mixed gas to achieve the purpose of replacing pure SF6 gas. Utility Model Content

[0005] The purpose of this invention is to provide an electrical equipment insulation gas recovery and replacement device. This device can be configured with SF6-N2 mixed gas to replace the original pure SF6 gas in the electrical equipment, and to recover and transfer the original SF6 gas.

[0006] To achieve the above objectives, the technical solution of this utility model is: an electrical equipment insulating gas recovery and replacement device, comprising a recovery system, a liquefaction filling system, a gas mixing and distribution system, a gas mixing and filling system, a detection system, a vacuum system, an external interface, and pipelines;

[0007] The external interfaces include electrical equipment interfaces, gas tank interfaces, liquid filling interfaces, exhaust gas emission interfaces, oil inlets, N2 interfaces, and SF6 interfaces;

[0008] The recycling system is connected to the electrical equipment interface, the gas storage tank interface, and the liquefied filling system, respectively.

[0009] The liquefaction filling system is connected to the vacuum system and the liquid filling interface, respectively.

[0010] The vacuum system is connected to the exhaust gas outlet, the oil inlet, the gas mixing and filling system, and the exhaust gas outlet, respectively.

[0011] The gas mixing and filling system is connected to the gas mixing and distribution system and the detection system, respectively.

[0012] The gas mixing system is connected to the N2 interface and the SF6 interface respectively.

[0013] Preferably, the recycling system includes a pressure sensor P1, a negative pressure recycling pump, a recycling oil-free compressor, pipelines, and valves V1, V2, V3, V4, V5, and V8; the recycling system is connected to an electrical equipment interface via an electrical equipment interface pipeline; specifically:

[0014] Pressure sensor P1 is installed on the interface pipeline of electrical equipment to detect the pressure of electrical equipment;

[0015] The first end of valve V2 and the first end of valve V1 are connected to the electrical equipment interface pipeline through a pipeline. The second end of valve V2 is connected to the air inlet of the negative pressure recovery pump through a pipeline. The air outlet of the negative pressure recovery pump is connected to the first end of valve V3 through a pipeline. The second end of valve V3 and the second end of valve V1 are connected to the air inlet of the oil-free recovery compressor through a pipeline. The air outlet of the oil-free recovery compressor is connected to the first end of valve V4 through a pipeline. The second end of valve V4 is connected to the first end of valve V5 through a pipeline. The second end of valve V5 is connected to the gas storage tank interface through a pipeline.

[0016] The first end of valve V8 is connected to the interface pipe of electrical equipment through a pipeline, and the second end of valve V8 is connected to the outlet of the oil-free compressor through a pipeline.

[0017] Preferably, the liquefaction filling system includes a refrigerated liquefaction tank, a pressure sensor P2, a refrigeration unit, a temperature sensor, a safety valve, a weighing sensor, a liquid filling machine, a vaporizer, pipelines, and valves V6 and V7.

[0018] The refrigeration liquefaction tank is equipped with a pressure sensor P2, a refrigeration unit, a temperature sensor, a safety valve, and a weighing sensor.

[0019] The gas inlet of the refrigeration liquefaction tank is connected to the second end of valve V4 via a pipeline, the liquid outlet of the refrigeration liquefaction tank is connected to the first end of valve V6 via a pipeline, the second end of valve V6 is connected to the feed port of the liquid filling machine via a pipeline, and the discharge port of the liquid filling machine is connected to the liquid filling interface via a pipeline.

[0020] The vaporizer output is connected to the inlet of the oil-free compressor via a pipeline, the vaporizer input is connected to the first end of valve V7 via a pipeline, and the second end of valve V7 is connected to the outlet of the refrigeration liquefaction tank via a pipeline.

[0021] Preferably, the vacuum system includes a vacuum gauge, an oil removal vacuum tank, an oil removal filter element, an immersion pressure transmitter P4, an anti-backflow solenoid valve, a Roots pump, a vacuum pump, pipelines, and valves V13, V14, V15, V16, and V17.

[0022] The oil removal vacuum tank is equipped with an oil removal filter element and an immersion pressure transmitter P4.

[0023] The air inlet of the oil removal vacuum tank is connected to the first end of valve V16, the first end of valve V15, the first end of valve V14, and the first end of valve V13 via pipelines. The second end of valve V16 is connected to a vacuum gauge via a pipeline. The second end of valve V15 is connected to an electrical equipment interface pipeline via a pipeline. The second end of valve V14 is connected to a liquefied filling system. The second end of valve V13 is connected to a mixed gas filling system.

[0024] The oil drain port of the oil removal vacuum tank is connected to the first end of valve V17 via a pipeline, and the second end of valve V17 is connected to the oil inlet via a pipeline.

[0025] The outlet of the oil removal vacuum tank is connected to the inlet of the anti-backflow solenoid valve via a pipeline. The outlet of the anti-backflow solenoid valve is connected to the inlet of the Roots pump via a pipeline. The outlet of the Roots pump is connected to the inlet of the vacuum pump via a pipeline. The outlet of the vacuum pump is connected to the exhaust gas discharge port via a pipeline.

[0026] Preferably, the gas mixing and distribution system includes a first pipeline heater, a first precision filter, a first mass flow controller, a second pipeline heater, a second precision filter, a second mass flow controller, a first mixing tank, a pressure sensor P3, a second mixing tank, a heat exchanger, and pipelines;

[0027] Pressure sensor P3 is installed on the first mixing tank;

[0028] The first mixing tank's first input end is connected to an N2 interface and an SF6 interface via pipelines; a first pipeline heater, a first precision filter, and a first mass flow controller are installed on the connecting pipeline between the first mixing tank and the N2 interface; a second pipeline heater, a second precision filter, a second mass flow controller, and a heat exchanger cold end are installed on the connecting pipeline between the first mixing tank and the SF6 interface; wherein, the heat exchanger cold end is installed on the connecting pipeline between the SF6 interface and the second pipeline heater;

[0029] The output of the first mixing tank is connected to the input of the second mixing tank via a pipeline.

[0030] Preferably, the gas mixing and filling system includes a filling oil-free compressor, a buffer tank, pipelines, and valves V9, V10, and V11;

[0031] The input end of the oil-free compressor is connected to the input end of the second mixing tank via a pipeline. The output end of the oil-free compressor is connected to the input end of the buffer tank via a pipeline. The output end of the buffer tank is connected to the first end of valve V9 via a pipeline. The second end of valve V9 is connected to the first ends of valve V10 and valve V11 via pipelines. The second end of valve V10 is connected to the second input end of the first mixing tank via a pipeline. The second end of valve V11 is connected to the electrical equipment interface pipeline via a pipeline.

[0032] The hot end of the heat exchanger is located on the connecting pipeline between the oil-free compressor and the buffer tank.

[0033] Preferably, the detection system includes: a mixture ratio detector, a detection exhaust gas collection module, pipelines, and valve V12;

[0034] The first end of valve V12 is connected to the second end of valve V9 via a pipeline. The second end of valve V12 is connected to the input end of the mixture ratio detector via a pipeline. The output end of the mixture ratio detector is connected to the exhaust gas collection module via a pipeline.

[0035] Preferably, the electrical equipment interface, gas tank interface, liquid filling interface, exhaust gas emission interface, oil inlet, N2 interface, and SF6 interface are all self-sealing interfaces.

[0036] Preferably, all valves are electric ball valves.

[0037] Preferably, the device further includes a touch screen and a PLC system for display and control.

[0038] Compared with the prior art, the present invention has the following beneficial effects:

[0039] This device is designed with two parallel recovery lines: positive pressure recovery and negative pressure recovery. When the gas pressure in the electrical equipment is higher than atmospheric pressure, only the oil-free compressor is activated for positive pressure recovery; when the gas pressure in the electrical equipment is lower than atmospheric pressure, the negative pressure recovery pump is activated to enhance recovery efficiency and improve the reuse rate of SF6.

[0040] This device is equipped with a weighing sensor at the bottom of the refrigeration liquefaction tank. The data is connected to the PLC system, which can read the weight of the refrigeration liquefaction tank in real time. The weighing sensor has two functions: First, it works in conjunction with the pressure sensor on the refrigeration liquefaction tank to form a double safety measure. During the recycling process, it monitors the weight of the recycled SF6 in real time. When the weight reaches the maximum storage capacity of the refrigeration liquefaction tank, the system automatically shuts off the valves and compressor of the recycling pipeline to prevent overfilling and potential safety accidents. Second, during liquid SF6 filling, it works with the PLC system to precisely control the liquid weight of each cylinder filling. When the weight change of the tank reaches the set filling weight, the liquid filling machine with the electric ball valve will automatically shut off to prevent underfilling or overfilling of the cylinders.

[0041] When SF6 is recharged into electrical equipment, although liquid SF6 will vaporize as its volume increases and its pressure decreases, complete vaporization is difficult to guarantee because pure SF6 needs to be above 45°C to maintain a stable gaseous state. This device is designed with a vaporizer in the pipeline, which can quickly raise the temperature of the SF6 passing through the vaporizer, so that it can be completely vaporized, avoiding the loss of SF6 due to some liquid remaining in the pipeline, and ensuring that the pressure of the gas after being recharged into the electrical equipment is basically the same as before the recovery.

[0042] The vacuum system of this device consists of a vacuum pump and a Roots pump, which has a large flow rate vacuuming capacity and can ensure a high vacuum degree. It can evacuate not only the pipelines and gas tanks of the device itself, but also the external gas storage tank and electrical equipment in the atmospheric chamber. The vacuum system is designed with an oil removal vacuum tank, which contains an oil removal filter and a submersible pressure transmitter. The purpose is to prevent the transformer oil from being extracted in the form of oil mist when the transformer is being evacuated. The oil removal vacuum tank can trap the extracted oil mist and condense it into oil for storage. When the submersible pressure transmitter detects that the oil removal vacuum tank contains warning oil, the PLC system will issue an alert. At this time, the oil inlet can be connected, the valve opened, and the oil removed from the oil removal vacuum tank. The vacuum system is equipped with an anti-backflow solenoid valve, which is linked to the vacuum pump. In the event of a sudden power outage during operation, it quickly cuts off the gas path, preventing vacuum pump oil from being drawn back into the vacuum chamber. Even if the anti-backflow solenoid valve fails to shut off the flow, the vacuum pump oil will be stored in the oil removal vacuum tank. The anti-backflow solenoid valve and the oil removal vacuum tank form a double line of defense, preventing contamination of the electrical equipment's chamber. This system has a relatively complex piping system and offers several optional vacuuming processes. The system selected based on the specific vacuuming requirements can be chosen, or the valves can be manually controlled.

[0043] The gas distribution system employs a high-precision mass flow controller to control the intake volume of N2 and SF6, ensuring accurate component ratios in the SF6-N2 mixture, with an accuracy of ±0.5%. When SF6 flows into the unit from the cylinder, it is in a gas-liquid mixed state. To obtain an accurate mixture, the SF6 entering the unit needs to be heated to ensure complete vaporization. However, the filling compressor outlet temperature is relatively high. Increased temperature leads to increased pressure and compressor load, potentially shortening compressor lifespan. Therefore, cooling is required at the compressor outlet. This unit utilizes a heat exchanger to exchange heat between the SF6 entering the cylinder and the SF6-N2 mixture at the filling compressor outlet. This increases the temperature of the pure SF6 entering the unit, reducing the power consumption of the heaters in the pipeline; it also lowers the compressor outlet temperature, extending compressor lifespan. The gas distribution system employs a two-stage mixing and circulation mixing method to ensure the uniformity of the SF6-N2 mixture. The unit includes a built-in mixing ratio detector to monitor the SF6-N2 mixing ratio in real time, ensuring that the mixed gas entering the electrical equipment meets design requirements.

[0044] When retrofitting electrical equipment by replacing pure SF6 with SF6-N2, this function not only recovers a portion of the SF6, greatly reducing recovery time and saving energy consumption of the compressor and negative pressure recovery pump; on the other hand, the N2 direct charging gas equipment reduces the complicated procedures of externally configuring mixed gas, and the direct utilization of old gas reduces gas transfer and transportation and losses, saving resources.

[0045] During the gas filling process, the detection system can detect the proportion of the configured SF6-N2 mixed gas in real time to ensure that the gas is mixed evenly, the proportion is accurate, and meets the design requirements. After connecting the electrical equipment interface (71) of the device to the electrical equipment using a special gas pipe, the external detection process can be started with one click: the detection system will measure and display the purity of SF6 gas and the content of each component in the electrical equipment on the touch screen, and determine whether the insulating gas in the electrical equipment meets the standard, thus playing a role in the diagnosis of electrical equipment. Attached Figure Description

[0046] Figure 1 This is a schematic diagram of the structure of the recycling and replacement device of this utility model;

[0047] Figure 2 This is a schematic diagram of the SF6 recovery gas circuit for this utility model.

[0048] Figure 3 This is a schematic diagram of the SF6 gas recharge circuit for this utility model.

[0049] Figure 4 This is a schematic diagram of a vacuum pumping system for this utility model.

[0050] Figure 5 This is the filling circuit diagram for the mixed gas distribution tank of this utility model. Detailed Implementation

[0051] The following is in conjunction with the appendix Figure 1-5 The technical solution of this utility model will be described in detail below.

[0052] The problem this invention aims to solve is to provide a solution for replacing the insulating gas in electrical equipment at a substation site. Specifically, this device uses SF6-N2 mixed gas to replace the original pure SF6 gas in the electrical equipment, and then recovers and transfers the original SF6 gas.

[0053] Implementation Plan 1: The pure SF6 inside the electrical equipment is recovered and transferred, and then the electrical equipment is evacuated to ensure the purity of the gas chamber. The SF6-N2 mixed gas is then prepared in the design ratio using this device and filled into the electrical equipment.

[0054] Implementation Plan 2: Partially recover and transfer the pure SF6 gas inside the electrical equipment, and directly charge the electrical equipment with N2 through this device, thereby configuring the electrical equipment with a designed ratio of SF6-N2 mixed gas.

[0055] refer to Figure 1 The present invention provides an electrical equipment insulation gas recovery and replacement device, comprising a recovery system (1), a liquefaction filling system (2), a gas mixing and distribution system (3), a gas mixing and filling system (4), a detection system (5), a vacuum system (6), an external interface, and pipelines.

[0056] The external interfaces include an electrical equipment interface (71), a gas tank interface (72), a liquid filling interface (73), a tail gas emission interface (74), an oil inlet (75), an N2 interface (76), and an SF6 interface (77).

[0057] The recycling system (1) is connected to the electrical equipment interface (71), the gas storage tank interface (72), and the liquefaction filling system (2), respectively;

[0058] The liquefaction filling system (2) is connected to the vacuum system (6) and the liquid filling interface (73) respectively;

[0059] The vacuum system (6) is connected to the exhaust gas outlet (74), the oil inlet (75), and the gas mixing filling system (4), respectively.

[0060] The gas mixing filling system (4) is connected to the gas mixing distribution system (3) and the detection system (5) respectively;

[0061] The gas mixing system (3) is connected to the N2 interface (76) and the SF6 interface (77) respectively.

[0062] In this embodiment, the recycling system (1) includes a pressure sensor P1 (101), a negative pressure recycling pump (104), a recycling oil-free compressor (106), pipelines, and valves V1, V2, V3, V4, V5, and V8; the recycling system (1) is connected to an electrical equipment interface (71) via an electrical equipment interface pipeline; specifically:

[0063] Pressure sensor P1 (101) is installed on the interface pipeline of electrical equipment to detect the pressure of electrical equipment;

[0064] The first end of valve V2 (103) and the first end of valve V1 (102) are connected to the electrical equipment interface pipeline through a pipeline. The second end of valve V2 (103) is connected to the air inlet of negative pressure recovery pump (104) through a pipeline. The air outlet of negative pressure recovery pump (104) is connected to the first end of valve V3 (105) through a pipeline. The second end of valve V3 (105) and the second end of valve V1 (102) are connected to the air inlet of recovery oil-free compressor (106) through a pipeline. The air outlet of recovery oil-free compressor (106) is connected to the first end of valve V4 (107) through a pipeline. The second end of valve V4 (107) is connected to the first end of valve V5 (108) through a pipeline. The second end of valve V5 (108) is connected to the gas storage tank interface (72) through a pipeline.

[0065] The first end of valve V8 (109) is connected to the electrical equipment interface pipeline through a pipeline, and the second end of valve V8 (109) is connected to the air outlet of oil-free compressor (106) through a pipeline.

[0066] In this embodiment, the liquefaction filling system (2) includes a refrigerated liquefaction tank (201), a pressure sensor P2 (202), a refrigeration unit (203), a temperature sensor (204), a safety valve (205), a weighing sensor (206), a liquid filling machine (208), a vaporizer (210), pipelines, and valves V6 and V7.

[0067] The refrigeration liquefaction tank (201) is equipped with a pressure sensor P2 (202), a refrigeration unit (203), a temperature sensor (204), a safety valve (205), and a weighing sensor (206).

[0068] The air inlet of the refrigeration liquefaction tank (201) is connected to the second end of valve V4 (107) through a pipeline. The liquid outlet of the refrigeration liquefaction tank (201) is connected to the first end of valve V6 (207) through a pipeline. The second end of valve V6 (207) is connected to the feed port of the liquid filling machine (208) through a pipeline. The discharge port of the liquid filling machine (208) is connected to the liquid filling interface (73) through a pipeline.

[0069] The output end of the vaporizer (210) is connected to the inlet of the oil-free compressor (106) via a pipeline, the input end of the vaporizer (210) is connected to the first end of valve V7 (209) via a pipeline, and the second end of valve V7 (209) is connected to the outlet of the refrigeration liquefaction tank (201) via a pipeline.

[0070] This device offers the following recycling options:

[0071] (1) The pure SF6 gas in the electrical equipment is recovered into the refrigeration liquefaction tank, and after refrigeration and liquefaction, it is filled into 40L steel cylinders for storage;

[0072] (2) Store the pure SF6 gas in an external gas storage tank for transfer from electrical equipment;

[0073] (3) The pure SF6 gas in the electrical equipment is recovered into the built-in gas storage tank for temporary liquefaction and storage, and then refilled into the electrical equipment when needed.

[0074] like Figure 2 As shown, the electrical equipment and the electrical equipment interface (71) on the device are connected by a dedicated gas guide pipe. The recycling process is started with one click on the touch screen: the system automatically opens the electric ball valve V1 (102) and the electric ball valve V4 (107), and turns on the recycling oil-free compressor (106). SF6 gas is recycled from the electrical equipment into the refrigeration liquefaction tank (201). When the pressure sensor P1 (101) detects that the gas pressure in the electrical equipment is lower than 0.1 MPa, it automatically closes the electric ball valve V1 (102), opens the electric ball valves V2 (103) and V3 (105), and starts the negative pressure recycling pump (104). When the pressure sensor P1 (101) detects that the gas pressure in the electrical equipment is lower than 100 Pa, it closes the electric ball valves V2 (103), V3 (105), and V4 (107), turns off the negative pressure recycling pump (104) and the recycling oil-free compressor (106), and stops the recycling operation.

[0075] While recovering SF6 gas, the device automatically turns on the refrigeration unit (203). The refrigeration unit exchanges heat with the SF6 gas in the refrigeration liquefaction tank (201) through circulating refrigerant, thereby cooling the SF6 gas. The SF6 gas is liquefied under high pressure and low temperature.

[0076] After the SF6 gas is liquefied in the refrigerated liquefaction tank (201), the liquid filling interface (73) of the device is connected to the steel cylinder with a special pipe, and the liquid SF6 filling operation is started with one click: open the electric ball valve V6 (207), start the liquid filling machine (208), and fill the liquid SF6 into the steel cylinder.

[0077] When it is necessary to transfer SF6 from the electrical equipment to the external gas storage tank, a special gas guide pipe is used to connect the electrical equipment and the electrical equipment interface (71) on the device, and to connect the gas storage tank and the gas storage tank interface (72) on the device. One-click start of gas transfer operation: Open electric ball valve V1 (102), electric ball valve V4 (107), and electric ball valve V5 (108), and turn on the oil-free recovery compressor (106). SF6 gas is transferred from the electrical equipment to the external gas storage tank. When the pressure sensor P1 (101) detects that the gas pressure in the electrical equipment is lower than 0.1MPa, the electric ball valve V1 (102) is automatically closed, and the electric ball valves V2 (103) and V3 (105) are opened to start the negative pressure recovery pump (104). When the pressure sensor P1 (101) detects that the gas pressure in the electrical equipment is lower than 100Pa, it automatically closes the electric ball valves V2 (103), V3 (105), V4 (107), and V5 (108), shuts down the negative pressure recovery pump (104) and the oil-free recovery compressor (106), and stops the gas transfer operation.

[0078] like Figure 3 For situations requiring maintenance of electrical equipment, SF6 gas must first be recovered and temporarily stored in a refrigerated liquefaction tank (201). When the volume of SF6 gas is larger than that of the refrigerated liquefaction tank, the refrigeration unit is turned on to liquefy the SF6, reducing the volume occupied. After the maintenance of the electrical equipment is completed, the SF6 gas is recharged into the electrical equipment. Connect the electrical equipment and the electrical equipment interface (71) on the device with a dedicated gas guide pipe, and start the gas recharge operation process with one button: open the electric ball valves V7 (209) and V8 (109), turn on the vaporizer (210) and the recovery oil-free compressor (106). The SF6 in the tank is heated by the vaporizer (210) and converted into a gaseous state. It is then pushed by the recovery oil-free compressor (106) and charged into the electrical equipment. When the pressure sensor P1 (101) detects that the pressure in the electrical equipment has reached the required pressure, or when the weighing sensor (206) detects that there is no SF6 in the refrigeration liquefaction tank (201), the electric ball valves V7 (209) and V8 (109) are automatically closed, the vaporizer (210) and the oil-free recovery compressor (106) are shut down, and the SF6 recharging operation is completed.

[0079] In this embodiment, the vacuum system (6) includes a vacuum gauge (605), an oil removal vacuum tank (606), an oil removal filter element (607), an immersion pressure transmitter P4 (608), an anti-backflow solenoid valve (609), a Roots pump (610), a vacuum pump (611), pipelines, and valves V13, V14, V15, V16, and V17;

[0080] The oil removal vacuum tank (606) is equipped with an oil removal filter element (607) and an immersion pressure transmitter P4 (608).

[0081] The air inlet of the oil removal vacuum tank (606) is connected to the first end of valve V16 (604), the first end of valve V15 (603), the first end of valve V14 (602), and the first end of valve V13 (601) through a pipeline. The second end of valve V16 (604) is connected to the vacuum gauge (605) through a pipeline. The second end of valve V15 (603) is connected to the electrical equipment interface pipeline through a pipeline. The second end of valve V14 (602) is connected to the liquefaction filling system (2). The second end of valve V13 (601) is connected to the mixed gas filling system (4).

[0082] The oil drain port of the oil removal vacuum tank (606) is connected to the first end of valve V17 (612) through a pipeline, and the second end of valve V17 (612) is connected to the oil inlet (75) through a pipeline.

[0083] The outlet of the oil removal vacuum tank (606) is connected to the inlet of the anti-backflow solenoid valve (609) through a pipeline. The outlet of the anti-backflow solenoid valve (609) is connected to the inlet of the Roots pump (610) through a pipeline. The outlet of the Roots pump (610) is connected to the inlet of the vacuum pump (611) through a pipeline. The outlet of the vacuum pump (611) is connected to the exhaust gas discharge port (74) through a pipeline.

[0084] Before each workflow begins, the machine must be evacuated to ensure that the internal pipelines and gas tanks are pure and free of impurities, and to ensure that the insulating gas is not contaminated. Vacuum evacuation options include: evacuating all systems of the machine; evacuating the recovery and liquefaction filling systems; and evacuating the gas mixing and filling systems.

[0085] refer to Figure 4 When the machine is vacuuming, the exhaust gas collection tank is connected to the exhaust gas discharge port (74) of the device using a special air pipe. The machine vacuuming operation is started with one click on the touch screen: the system automatically opens the valves and anti-backflow solenoid valve (609) of the corresponding pipeline according to the selected machine vacuuming process, and starts the vacuum pump (611) to carry out the vacuuming operation. After the vacuuming starts, the system automatically opens the electric ball valve V16 (604), and the vacuum gauge (605) will monitor the vacuum degree of the device in real time. The data is transmitted to the PLC system and displayed on the touch screen. When the device vacuum degree reaches the set protection pressure of the Roots pump (610), the Roots pump (610) starts automatically to enhance the vacuuming capacity. When the vacuum degree reaches 10Pa, all valves are automatically closed and the vacuum pump (611) and Roots pump (610) are stopped.

[0086] After recovering SF6 gas from the electrical equipment, this device initiates the vacuuming process with a single button press: the system automatically opens the electric ball valve V15 (603) and the anti-backflow solenoid valve (609), and starts the vacuum pump (611) to perform vacuuming. After vacuuming begins, the system automatically opens the electric ball valve V16 (604), and the vacuum gauge (605) monitors the vacuum level of the electrical equipment in real time. When the vacuum level of the electrical equipment reaches the set protection pressure of the Roots pump (610), the Roots pump (610) automatically starts to enhance the vacuuming capacity. When the vacuum level reaches 10Pa, after a 30-minute delay (which can be manually adjusted), all valves are automatically closed, and the vacuum pump (611) and the Roots pump (610) are stopped.

[0087] In this embodiment, the gas mixing and distribution system (3) includes a first pipeline heater (301), a first precision filter (302), a first mass flow controller (303), a second pipeline heater (304), a second precision filter (305), a second mass flow controller (306), a first mixing tank (307), a pressure sensor P3 (308), a second mixing tank (309), a heat exchanger (310), and pipelines;

[0088] A pressure sensor P3 (308) is installed on the first mixing tank (307);

[0089] The first input end of the first mixing tank (307) is connected to the N2 interface (76) and the SF6 interface (77) respectively through pipelines; the first pipeline heater (301), the first precision filter (302), and the first mass flow controller (303) are arranged on the connecting pipeline between the first mixing tank (307) and the N2 interface (76); the second pipeline heater (304), the second precision filter (305), the second mass flow controller (306), and the cold end of the heat exchanger (310) are arranged on the connecting pipeline between the first mixing tank (307) and the SF6 interface (77); wherein, the cold end of the heat exchanger (310) is arranged on the connecting pipeline between the SF6 interface (77) and the second pipeline heater (304);

[0090] The output of the first mixing tank (307) is connected to the input of the second mixing tank (309) via a pipeline.

[0091] In this embodiment, the gas mixing filling system (4) includes a filling oil-free compressor (401), a buffer tank (402), pipelines and valves V9, V10, and V11;

[0092] The input end of the filling oilless compressor (401) is connected to the input end of the second mixing tank (309) through a pipeline. The output end of the filling oilless compressor (401) is connected to the input end of the buffer tank (402) through a pipeline. The output end of the buffer tank (402) is connected to the first end of valve V9 (403) through a pipeline. The second end of valve V9 (403) is connected to the first end of valve V10 (404) and the first end of valve V11 (405) through a pipeline. The second end of valve V10 (404) is connected to the second input end of the first mixing tank (307) through a pipeline. The second end of valve V11 (405) is connected to the electrical equipment interface pipeline through a pipeline.

[0093] The hot end of the heat exchanger (310) is located on the connecting pipeline between the oil-free compressor (401) and the buffer tank (402).

[0094] In this embodiment, the detection system includes: a mixture ratio detector (502), a detection exhaust gas collection module (503), and pipelines and valves V12;

[0095] The first end of valve V12 (501) is connected to the second end of valve V9 (403) through a pipeline. The second end of valve V12 (501) is connected to the input end of the mixing ratio detector (502) through a pipeline. The output end of the mixing ratio detector (502) is connected to the detection exhaust gas collection module (503) through a pipeline.

[0096] This device has the following three gas distribution and filling functions:

[0097] (1) This device can be configured on-site with any proportion of SF6-N2 mixed gas to replace pure SF6 gas in electrical equipment;

[0098] (2) This device can recover part of the SF6 gas in the electrical equipment and then directly charge it with N2, and configure the SF6-N2 mixed gas inside the electrical equipment;

[0099] (3) This device can be directly charged with pre-configured SF6-N2 mixed gas.

[0100] refer to Figure 5When configuring SF6-N2 mixed gas, a dedicated gas pipe is used to connect the N2 cylinder to the N2 interface (76) and the SF6 cylinder to the SF6 interface (77). The SF6-N2 gas mixing operation is started with one key: the first pipeline heater (301) and the second pipeline heater (304) are started. The liquid N2 and SF6 in the gas cylinder enter the device and are completely vaporized when passing through the pipeline heater to form a stable flow gas. The first precision filter (302) and the second precision filter (305) can remove water vapor and impurities from the N2 and SF6 gases respectively to ensure gas purity. The first mass flow controller (303) and the second mass flow controller (306) can accurately control the N2 and SF6 intake flow rates according to the required ratio of mixed gas. The gas mixing system is designed with two-stage mixing in the first mixing tank (308) and the second mixing tank (309). After N2 and SF6 are fully mixed, the oil-free filling compressor (401) provides power to fill the mixed gas into the buffer tank (402).

[0101] Before filling the electrical equipment, the detection system is activated with a single button: open the electric ball valves V9 (403) and V12 (501), start the mixing ratio detector (502), and check whether the mixed gas is uniform and whether the ratio meets the design standard. If multiple tests show that the mixed gas is not uniform, the system will automatically open the electric ball valve V10 (404), and the mixed gas will return to the first mixing tank (307) for remixing. This cycle continues until the mixture is uniform. If the mixing ratio exceeds the design mixing ratio range, the PLC system will calculate the difference and correct the inlet flow of the first mass flow controller (303) and the second mass flow controller (306). The exhaust gas detected by the mixing ratio detector (502) is collected by a dedicated exhaust gas collection module (503) and processed uniformly to ensure zero gas emissions.

[0102] Once the mixed gas passes the test, the filling operation is initiated with a single button: the electric ball valves V9 (403) and V12 (501) are automatically closed, the mixing ratio detector (502) is turned off, and the electric ball valve V11 (405) is opened to fill the electrical equipment with the mixed gas. When the pressure sensor P1 (101) detects that the gas pressure inside the electrical equipment has reached the design standard, the electric ball valve V11 (405) and the filling oil-free compressor (401) are automatically closed, and the filling operation is stopped.

[0103] For some substations that require on-site replacement of insulating gas for electrical equipment, in order to improve the efficiency of the renovation, this device can recover some of the SF6 gas inside the electrical equipment and then directly charge the electrical equipment with N2, directly configuring a certain proportion of SF6-N2 mixed gas inside the electrical equipment.

[0104] The SF6 recycling process can be started with one click. During the recycling process, the PLC system can detect the pressure change in the gas chamber of the electrical equipment based on the pressure sensor P1 (101) and convert it into gas volume. When the required amount of SF6 in the SF6-N2 mixture is reached, the recycling operation will automatically stop. Connect the N2 cylinder to the N2 interface (76) and start the N2 direct charging process with one click (see...). Figure 5 ): Start the pipeline heater 1 (301) and fill the oil-free compressor (401). Open the electric ball valves V9 (403) and V11 (405) to directly charge the electrical equipment with N2 until the pressure sensor P1 detects that the gas pressure inside the electrical equipment reaches the design pressure. Then, the direct charging operation of N2 will automatically stop, and N2 and the residual SF6 in the electrical equipment will mix statically. After mixing for a certain period of time, the electric ball valves V11 (405) and V12 (501) and the mixing ratio detector (502) can be opened to detect the uniformity of gas mixing inside the electrical equipment.

[0105] This device can directly charge externally configured standard gas. A special gas pipe is used to connect the standard gas cylinder to the SF6 interface (77). The standard gas direct charging operation can be started with one button: open valves V9 (403) and V11 (405), turn on the oil-free charging compressor (401), and charge the standard gas into the electrical equipment. When the pressure sensor P1 (101) detects that the gas pressure in the electrical equipment reaches the design standard, it automatically closes the electric ball valves V9 (403) and V11 (405) and the oil-free charging compressor (401) to stop the charging operation.

[0106] In this embodiment, the electrical equipment interface (71), gas tank interface (72), liquid filling interface (73), exhaust gas emission interface (74), oil inlet (75), N2 interface (76), and SF6 interface (77) are all self-sealing interfaces.

[0107] In this embodiment, all valves are electric ball valves.

[0108] In this embodiment, the device further includes a touch screen and a PLC system for display and control.

[0109] In summary, the functions of this utility model device include:

[0110] (1) The function of recovering pure SF6 gas, refrigerating and liquefying it, and filling liquid SF6 into steel cylinders in electrical equipment;

[0111] (2) The function of transferring SF6 gas inside electrical equipment to an external gas storage tank;

[0112] (3) The function of recharging the electrical equipment with SF6 that has been recovered into the refrigeration liquefaction tank;

[0113] (4) After recovering the pure SF6 gas in the electrical equipment, prepare an SF6-N2 mixed gas on site and fill the electrical equipment;

[0114] (5) This device has a built-in mixing ratio detector, which can detect the composition and content of the mixed gas and also has the functions of detecting the purity of SF6 gas in electrical equipment and the proportion of each component.

[0115] (6) The function of directly charging electrical equipment with N2 and configuring a certain proportion of SF6-N2 mixed gas inside the equipment;

[0116] (7) Externally configured standard mixed gas direct charging function;

[0117] (8) The device has a built-in vacuum function;

[0118] (9) Vacuuming function for electrical equipment.

[0119] The above are preferred embodiments of this utility model. Any changes made to the technical solution of this utility model that do not exceed the scope of the technical solution of this utility model shall be protected within the scope of this utility model.

Claims

1. An electrical equipment insulating gas recovery and replacement device, characterized in that, Includes a recycling system (1), a liquefaction filling system (2), a gas mixing and distribution system (3), a gas mixing and filling system (4), a detection system (5), a vacuum system (6), external interfaces and pipelines; The external interfaces include an electrical equipment interface (71), a gas tank interface (72), a liquid filling interface (73), a tail gas emission interface (74), an oil inlet (75), an N2 interface (76), and an SF6 interface (77). The recycling system (1) is connected to the electrical equipment interface (71), the gas storage tank interface (72), and the liquefaction filling system (2), respectively; The liquefaction filling system (2) is connected to the vacuum system (6) and the liquid filling interface (73) respectively; The vacuum system (6) is connected to the exhaust gas outlet (74), the oil inlet (75), and the gas mixing filling system (4), respectively. The gas mixing filling system (4) is connected to the gas mixing distribution system (3) and the detection system (5) respectively; The gas mixing system (3) is connected to the N2 interface (76) and the SF6 interface (77) respectively.

2. The electrical equipment insulating gas recovery and replacement device according to claim 1, characterized in that, The recycling system (1) includes a pressure sensor P1 (101), a negative pressure recycling pump (104), a recycling oil-free compressor (106), pipelines, and valves V1, V2, V3, V4, V5, and V8; the recycling system (1) is connected to an electrical equipment interface (71) via an electrical equipment interface pipeline; specifically: Pressure sensor P1 (101) is installed on the interface pipeline of electrical equipment to detect the pressure of electrical equipment; The first end of valve V2 (103) and the first end of valve V1 (102) are connected to the electrical equipment interface pipeline through a pipeline. The second end of valve V2 (103) is connected to the air inlet of negative pressure recovery pump (104) through a pipeline. The air outlet of negative pressure recovery pump (104) is connected to the first end of valve V3 (105) through a pipeline. The second end of valve V3 (105) and the second end of valve V1 (102) are connected to the air inlet of recovery oil-free compressor (106) through a pipeline. The air outlet of recovery oil-free compressor (106) is connected to the first end of valve V4 (107) through a pipeline. The second end of valve V4 (107) is connected to the first end of valve V5 (108) through a pipeline. The second end of valve V5 (108) is connected to the gas storage tank interface (72) through a pipeline. The first end of valve V8 (109) is connected to the electrical equipment interface pipeline through a pipeline, and the second end of valve V8 (109) is connected to the air outlet of oil-free compressor (106) through a pipeline.

3. The electrical equipment insulating gas recovery and replacement device according to claim 2, characterized in that, The liquefaction filling system (2) includes a refrigerated liquefaction tank (201), a pressure sensor P2 (202), a refrigeration unit (203), a temperature sensor (204), a safety valve (205), a weighing sensor (206), a liquid filling machine (208), a vaporizer (210), pipelines, and valves V6 and V7. The refrigeration liquefaction tank (201) is equipped with a pressure sensor P2 (202), a refrigeration unit (203), a temperature sensor (204), a safety valve (205), and a weighing sensor (206). The air inlet of the refrigeration liquefaction tank (201) is connected to the second end of valve V4 (107) through a pipeline. The liquid outlet of the refrigeration liquefaction tank (201) is connected to the first end of valve V6 (207) through a pipeline. The second end of valve V6 (207) is connected to the feed port of the liquid filling machine (208) through a pipeline. The discharge port of the liquid filling machine (208) is connected to the liquid filling interface (73) through a pipeline. The output end of the vaporizer (210) is connected to the inlet of the oil-free compressor (106) via a pipeline, the input end of the vaporizer (210) is connected to the first end of valve V7 (209) via a pipeline, and the second end of valve V7 (209) is connected to the outlet of the refrigeration liquefaction tank (201) via a pipeline.

4. The electrical equipment insulating gas recovery and replacement device according to claim 1, characterized in that, The vacuum system (6) includes a vacuum gauge (605), an oil removal vacuum tank (606), an oil removal filter element (607), an immersion pressure transmitter P4 (608), an anti-backflow solenoid valve (609), a Roots pump (610), a vacuum pump (611), pipelines, and valves V13, V14, V15, V16, and V17. The oil removal vacuum tank (606) is equipped with an oil removal filter element (607) and an immersion pressure transmitter P4 (608). The air inlet of the oil removal vacuum tank (606) is connected to the first end of valve V16 (604), the first end of valve V15 (603), the first end of valve V14 (602), and the first end of valve V13 (601) through a pipeline. The second end of valve V16 (604) is connected to the vacuum gauge (605) through a pipeline. The second end of valve V15 (603) is connected to the electrical equipment interface pipeline through a pipeline. The second end of valve V14 (602) is connected to the liquefaction filling system (2). The second end of valve V13 (601) is connected to the mixed gas filling system (4). The oil drain port of the oil removal vacuum tank (606) is connected to the first end of valve V17 (612) through a pipeline, and the second end of valve V17 (612) is connected to the oil inlet (75) through a pipeline. The outlet of the oil removal vacuum tank (606) is connected to the inlet of the anti-backflow solenoid valve (609) through a pipeline. The outlet of the anti-backflow solenoid valve (609) is connected to the inlet of the Roots pump (610) through a pipeline. The outlet of the Roots pump (610) is connected to the inlet of the vacuum pump (611) through a pipeline. The outlet of the vacuum pump (611) is connected to the exhaust gas discharge port (74) through a pipeline.

5. The electrical equipment insulating gas recovery and replacement device according to claim 1, characterized in that, The gas mixing and distribution system (3) includes a first pipeline heater (301), a first precision filter (302), a first mass flow controller (303), a second pipeline heater (304), a second precision filter (305), a second mass flow controller (306), a first mixing tank (307), a pressure sensor P3 (308), a second mixing tank (309), a heat exchanger (310), and pipelines; A pressure sensor P3 (308) is installed on the first mixing tank (307); The first input end of the first mixing tank (307) is connected to the N2 interface (76) and the SF6 interface (77) respectively through pipelines; the first pipeline heater (301), the first precision filter (302), and the first mass flow controller (303) are arranged on the connecting pipeline between the first mixing tank (307) and the N2 interface (76); the second pipeline heater (304), the second precision filter (305), the second mass flow controller (306), and the cold end of the heat exchanger (310) are arranged on the connecting pipeline between the first mixing tank (307) and the SF6 interface (77); wherein, the cold end of the heat exchanger (310) is arranged on the connecting pipeline between the SF6 interface (77) and the second pipeline heater (304); The output of the first mixing tank (307) is connected to the input of the second mixing tank (309) via a pipeline.

6. The electrical equipment insulating gas recovery and replacement device according to claim 5, characterized in that, The gas mixing and filling system (4) includes a filling oil-free compressor (401), a buffer tank (402), pipelines and valves V9, V10 and V11; The input end of the filling oilless compressor (401) is connected to the input end of the second mixing tank (309) through a pipeline. The output end of the filling oilless compressor (401) is connected to the input end of the buffer tank (402) through a pipeline. The output end of the buffer tank (402) is connected to the first end of valve V9 (403) through a pipeline. The second end of valve V9 (403) is connected to the first end of valve V10 (404) and the first end of valve V11 (405) through a pipeline. The second end of valve V10 (404) is connected to the second input end of the first mixing tank (307) through a pipeline. The second end of valve V11 (405) is connected to the electrical equipment interface pipeline through a pipeline. The hot end of the heat exchanger (310) is located on the connecting pipeline between the oil-free compressor (401) and the buffer tank (402).

7. The electrical equipment insulating gas recovery and replacement device according to claim 6, characterized in that, The detection system includes: a mixture ratio detector (502), a detection exhaust gas collection module (503), and pipelines and valves V12; The first end of valve V12 (501) is connected to the second end of valve V9 (403) through a pipeline. The second end of valve V12 (501) is connected to the input end of the mixing ratio detector (502) through a pipeline. The output end of the mixing ratio detector (502) is connected to the detection exhaust gas collection module (503) through a pipeline.

8. The electrical equipment insulating gas recovery and replacement device according to claim 1, characterized in that, The electrical equipment interface (71), gas tank interface (72), liquid filling interface (73), exhaust gas emission interface (74), oil inlet (75), N2 interface (76), and SF6 interface (77) are all self-sealing interfaces.

9. The electrical equipment insulating gas recovery and replacement device according to claim 1, characterized in that, All valves are electric ball valves.

10. The electrical equipment insulating gas recovery and replacement device according to claim 1, characterized in that, The device also includes a touch screen and a PLC system for display and control.

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