Vacuum degassing device, method and on-line monitoring device for dissolved gases in oil
Patent Information
- Application Number
- CN202510193546.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-21
- Publication Date
- 2026-08-21
AI Technical Summary
[0003]传统的油中溶解气体脱气方法有振荡、顶空、喷淋、真空等方法，虽然，它们均有各自的不足，或速度慢或效率不高或重复性不好，但是相比之下，真空脱气技术为全脱气技术，满足变电站现场恶劣的工作环境，与其他脱气技术相比，同样的油样脱出的故障气体多，进入后端检测单元的气量大，提高设备检测精度，代表了变压器油中溶解气体在线监测系统脱气技术的发展方向
[0021] This invention first evacuates the inner cavity of the oil tank. Then, during oil circulation, headspace gas is introduced using the Venturi effect, allowing the oil to mix thoroughly in the enclosed space. This causes the gas in the oil to bubble and overflow above the oil chamber, quickly achieving gas-liquid equilibrium. This method is fast, efficient, and stable. Furthermore, its degassing method in the enclosed space eliminates the introduction of interfering or background gases, ensuring that the transformer oil can be used for recharging without contamination.
Smart Images
Figure CN122605230A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of online monitoring of transformer oil, and relates to a vacuum degassing device, method, and online monitoring device for dissolved gas in oil. Background Technology
[0002] One of the most critical aspects of achieving online monitoring of dissolved gases in transformer oil is oil-gas separation. The stability and accuracy of oil-gas separation technology directly determine the stability and accuracy of the online monitoring equipment.
[0003] Traditional methods for degassing dissolved gases in oil include oscillation, headspace, spraying, and vacuum methods. While each has its own shortcomings—such as slow speed, low efficiency, or poor repeatability—vacuum degassing technology stands out as a comprehensive degassing technique. It is well-suited to the harsh working environment of substations and, compared to other degassing technologies, removes more fault gases from the same oil sample, resulting in a larger volume of gas entering the downstream detection unit and improving equipment detection accuracy. This represents the future direction of degassing technology in online monitoring systems for dissolved gases in transformer oil. This invention, based on vacuum degassing technology and combined with headspace degassing, presents a vacuum degassing device and method. Summary of the Invention
[0004] To address the shortcomings of existing technologies, this invention provides a vacuum degassing device, a method, and an online monitoring device for dissolved gas in oil.
[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: A vacuum degassing device, This includes the oil tank and the vent pipe, oil drain pipe, oil circulation pipeline, gas circulation pipeline and oil inlet pipe installed on the oil tank; The oil tank is a sealed cavity, and a piston and a lead screw that pulls the piston are installed inside the oil tank. The piston divides the oil tank into an air chamber and an oil chamber, and the lead screw passes through the air chamber. The air chamber is connected to the atmosphere via an exhaust valve; The bottom of the oil chamber is connected to an oil drain pipe, and an oil drain valve is installed on the oil drain pipe. The air inlet of the air outlet pipe is located on the piston and connected to the oil chamber, while the air outlet of the air outlet pipe protrudes out of the air chamber. The oil chamber is connected to the oil circulation pipeline, and the two ends of the oil circulation pipeline are respectively connected to the lower part of the oil chamber. The oil inlet end of the oil circulation pipeline is equipped with an on / off valve. The Venturi jet large-diameter inlet end, oil pump, and flow meter are connected in series along the oil flow direction. The oil chamber is connected to the air circulation pipeline. One end of the air circulation pipeline is connected to the air outlet pipe, and the other end is connected to the small diameter end of the Venturi jet. An air inlet valve is installed at the air inlet end of the air circulation pipeline, and a second air outlet valve is installed at the air outlet end (small diameter end of the Venturi jet). It also includes an oil inlet pipe, which connects to the front stage of the oil pump via an oil inlet valve.
[0006] Furthermore, the outlet end of the oil circulation pipeline is located at the bottom of the oil chamber of the oil tank.
[0007] It also includes temperature sensors and pressure sensors for measuring oil temperature and oil pressure.
[0008] It also includes a heating and humidifying device surrounding the oil tank, along with a temperature sensor to achieve precise temperature control.
[0009] Furthermore, a sintered filter is installed at the air inlet port of the exhaust pipe.
[0010] Furthermore, the inner wall of the oil tank is equipped with an upper limit and a lower limit. The piston moves between the upper limit and the lower limit. The lower limit is set above the pressure sensor, and the upper limit is set above the oil sample inlet.
[0011] It also includes a sensor detection module, whose air inlet is connected to the air outlet pipe via a switching valve.
[0012] Furthermore, the piston screw adopts a hollow tube structure, with the exhaust pipe passing through the hollow tube of the screw and connecting to the piston and the oil chamber.
[0013] A vacuum degassing method includes the following steps: Step S1: Connect the oil tank's gas chamber to the atmosphere, and lower the oil tank piston to the first target position; Step S2: Keep the gas chamber of the oil tank connected to the atmosphere, open the oil inlet valve on the oil inlet pipe, close other valves, and fill the oil tank with a quantitative oil sample. During the filling process, control the oil tank piston to move slowly upward and keep the oil tank pressure value P1 constant until the filling is completed. The steps to confirm the quantitative oil sample are: obtain the flow rate of the flow meter, obtain the opening and closing time of the oil inlet valve on the oil inlet pipe, and multiply the two.
[0014] Specifically, the oil drain valve of the drain pipe, the oil inlet valve of the oil circulation pipeline, and the second outlet valve of the outlet end (small diameter end of the Venturi jet) of the air circulation pipeline are closed. The oil inlet valve on the inlet pipe is opened. Then, the oil sample from the transformer is pumped into the oil tank under the action of the oil pump. It flows through the Venturi jet (large diameter inlet end), the oil pump and the flow meter into the oil chamber of the oil tank. The amount of oil sample filled can be calculated according to the flow meter. When the amount of oil n meets the requirements, the oil pump stops.
[0015] Step S3: Connect the oil tank's gas chamber to the atmosphere, close other valves, and control the oil tank piston to continue moving upward to the second target position, with a settling time T1; The second target location in step S3 refers to the position above the oil sample in the oil tank.
[0016] Furthermore, by setting an upward limit at a position where the oil sample is effectively vacuumed, the upward limit 16 set inside the oil tank can ensure that the piston 7 moves in the same trajectory each time. At this point, the upward limit is the second target position.
[0017] Step S4: Open the oil inlet shut-off valve of the oil circulation pipeline, the second outlet valve of the outlet end (small diameter end of the Venturi jet) of the gas circulation pipeline, the first outlet valve on the outlet pipe, and the inlet valve of the gas circulation pipeline. Close other valves, start the oil pump, and control the flow rate through the flow meter to make the oil sample in the oil tank circulate in the oil circulation pipeline at the target flow rate for a period of time T2, so that the gas is fully mixed in the oil and then the gas in the oil overflows. In step S3, the gas formed in the upper layer of the oil tank chamber is mixed with gas and liquid through the gas outlet pipe 3 and the gas circulation pipe 4 and injected into the oil in the oil tank chamber by the Venturi jet.
[0018] Step S5: Open the oil inlet valve on the oil inlet pipe and the first vent valve on the vent pipe, close other valves, start the oil pump, so that oil enters the oil inlet pipe, the oil level in the oil chamber rises, and pushes the gas overflowing from the top of the oil chamber in step S4 to be output through the first vent valve on the vent pipe.
[0019] Step S3 also includes monitoring the oil chamber pressure value in real time during the settling time T1. If the oil chamber pressure value is greater than the preset threshold, the machine is stopped for maintenance. After maintenance is completed, the machine is restarted, the oil tank is evacuated, and steps 1 to 5 are executed again.
[0020] Furthermore, an online gas monitoring device for oil in a vacuum degassing apparatus having the above-mentioned features is used, wherein the vacuum degassing apparatus is used to perform the above-mentioned vacuum degassing method.
[0021] This invention first evacuates the inner cavity of the oil tank. Then, during oil circulation, headspace gas is introduced using the Venturi effect, allowing the oil to mix thoroughly in the enclosed space. This causes the gas in the oil to bubble and overflow above the oil chamber, quickly achieving gas-liquid equilibrium. This method is fast, efficient, and stable. Furthermore, its degassing method in the enclosed space eliminates the introduction of interfering or background gases, ensuring that the transformer oil can be used for recharging without contamination. Attached Figure Description
[0022] Figure 1 This is a schematic diagram of the gas path control principle of the present invention. Detailed Implementation
[0023] like Figure 1 As shown, a vacuum degassing device, It includes oil tank 1 and the gas outlet pipe 3, oil discharge pipe 2, oil circulation pipe 5, gas circulation pipe 4 and oil inlet pipe 6 installed on the oil tank; The oil tank 1 is a sealed cavity. Inside the oil tank 1, there is a piston 7 and a lead screw 8 that pulls the piston 7. The piston 1 divides the oil tank into an air chamber and an oil chamber. The lead screw 8 passes through the air chamber. In this embodiment, the oil tank 1 is a cylindrical sealed cavity.
[0024] The air chamber is connected to the atmosphere through exhaust valve D7. As a feasible implementation, the air chamber can also be connected to the atmosphere through an exhaust pipe, on which exhaust valve D7 is installed. The vent pipe 3 is installed on the piston 7 and connected to the oil chamber, with the vent end of the vent pipe 3 protruding from the vent chamber. In this embodiment, it is feasible to install a first vent valve D8 on the vent pipe 3 to control its opening and closing. Furthermore, the vent pipe 3 is inserted into the hollow lead screw 8 (the lead screw 8 pulls the piston 7 to reciprocate) and installed on the piston 7 and connected to the oil chamber, so that the vent pipe 3 and the piston 7 move as one.
[0025] The bottom of the oil chamber is connected to the oil drain pipe 2, and an oil drain valve D2 is installed on the oil drain pipe 2; the oil chamber is also connected to the oil inlet pipe 6, and an oil inlet valve D4 is installed on the oil inlet pipe 6. In order to achieve precise control of the oil inlet volume, an oil pump 9 and a flow meter 10 are installed on the oil inlet pipe; the oil drain pipe 2 and the oil inlet pipe 6 can be set up separately, or they can be shared through pipelines and valves, as long as the relevant functional modules are isolated during application. Figure 1 In the embodiment shown, both the oil inlet pipe 6 and the oil outlet pipe 2 are shared with the oil circulation pipeline 5. The oil outlet pipe 2 and the oil inlet pipe 6 are respectively connected to the oil circulation pipeline 5, and the two are isolated by the on / off valve D3.
[0026] The oil chamber is connected to the oil circulation pipeline 5, with both ends of the oil circulation pipeline 5 connected to the oil chamber. An on / off valve D3 is installed at the oil inlet end of the oil circulation pipeline 5. A Venturi jet injector 11 (large-diameter inlet end), an oil pump 9, and a flow meter 10 are connected in series along the oil flow direction. As a feasible implementation, the two ends of the oil circulation pipeline 5 are connected to the bottom of the oil chamber and spaced apart. An on / off valve D3 is installed at the oil inlet end of the oil circulation pipeline 5. A Venturi jet injector 11 (large-diameter inlet end), an oil pump 9, and a flow meter 10 are connected in series along the oil flow direction at the oil outlet end. Considering precise control of the oil inlet flow, the oil inlet pipe 6 can also be installed before the oil pump 9 and the flow meter 10. Figure 1 In this embodiment, the oil inlet pipe 6 is connected to the oil inlet of the oil pump 9 via the oil inlet valve D4.
[0027] The oil chamber is connected to the air circulation pipeline 4. One end of the air circulation pipeline 4 is connected to the air outlet pipe 3, and the other end is connected to the small diameter end of the Venturi jet 11. An air inlet valve D12 is installed at the air inlet end of the air circulation pipeline 4, and a second air outlet valve D5 is installed at the air outlet end of the air circulation pipeline 4 (the small diameter end of the Venturi jet). like Figure 1In the embodiment shown, the oil chamber is connected to the air circulation pipeline 4. One end of the air circulation pipeline 4 is connected to the air outlet pipeline 3 (or can be directly connected to the oil chamber), and the other end is connected to the small diameter end of the Venturi jet 11. An air inlet valve D12 is provided at the air inlet end of the air circulation pipeline 4, and a second air outlet valve D5 is provided at the air outlet end of the air circulation pipeline 4 (the small diameter end of the Venturi jet). Oil circulation line 5 and gas circulation line 4 flow through the large-diameter inlet end and small-diameter end of Venturi ejector 11, respectively, and then return to oil tank 1 via oil pump 9 and flow meter 10. Flow meter 10 monitors and precisely controls the flow rate to ensure the mixture flows at the target velocity. During the vacuuming process, after the insulating oil in oil tank 1 is evacuated, gas is released into the upper part of the oil tank's gas chamber. During the oil-gas circulation process, the gas in the upper part of the oil chamber is drawn through the outlet pipe along the gas circulation line to the small-diameter end of Venturi ejector 11, where it is drawn into oil circulation line 5 and dissolved in the oil.
[0028] It also includes a temperature sensor 12 and a pressure sensor 13 for measuring oil temperature and oil pressure. The oil chamber is designed with a temperature sensor 12 and a pressure sensor 13. In order to prevent the oil pressure from not being measured when the piston 7 moves to the bottom, it is preferred to set the pressure sensor 13 at the bottom of the oil chamber. It also includes a sensor detection module, whose air inlet is connected to the air outlet pipe via a switching valve D10. As one feasible implementation, the sensor detection module is connected to the outlet of the air outlet pipe 3, and the detection air is switched on and off via the switching valve D10.
[0029] Furthermore, a sintered filter 14 is installed at the air inlet end of the air outlet pipe 3. This prevents dissolved gases in the oil from carrying oil mist into the detection module.
[0030] Furthermore, an upper limit 16 and a lower limit 15 are provided on the inner wall of the oil tank, and the piston 7 moves between the upper limit 16 and the lower limit 15. The lower limit 15 is located above the pressure sensor 13, and the piston 7 stops moving at the lower limit 15 to avoid affecting the pressure sensor 13; the upper limit 16 is located above the oil sample inlet, leaving space so that dissolved gases in the oil can be released after the oil sample is evacuated.
[0031] Furthermore, a second outlet valve D5 is installed at the outlet end (small diameter end of the Venturi jet) of the gas circulation pipeline 4, a first outlet valve D8 is installed on the outlet pipe 3, and an inlet valve D12 is installed at the inlet end of the gas circulation pipeline 4. When these valves are opened, the oil sample circulates, causing the dissolved gas in the oil to be rapidly released.
[0032] A vacuum degassing method includes the following steps: Step S1: Connect the gas chamber of oil tank 1 to the atmosphere, and the piston 7 of oil tank moves downward to the first target position; The opening and closing of the exhaust valve D7 controls whether the gas chamber is connected to the atmosphere or closed. When exhaust valve D7 is open, the oil tank piston 7 descends to the lowest point of the oil tank under the push of the screw; at this time, the lowest point of the oil tank is the first target position. When the inner wall of the oil tank is equipped with a downward limit 15, the oil tank piston 7 stops descending to the downward limit 15. At this time, the position of the downward limit 15 is the first target position. Figure 1 In the embodiment shown, a downward limit is set above the pressure sensor 13 near the bottom of the inner wall of the oil tank. Then, the oil tank piston 7 stops at the downward limit 15 to avoid affecting the bottom pressure sensor 13.
[0033] Step S2: Keep the gas chamber of the oil tank connected to the atmosphere, open the oil inlet valve D4 on the oil inlet pipe 6, close other valves, and fill the oil tank with a quantitative oil sample. During the filling process, control the oil tank piston 7 to move upward slowly, keep the oil tank pressure value P1 unchanged, until the filling is completed. This step ensures that the amount of oil injected each time is the same. The oil tank piston 7 moves upward slowly while maintaining the oil tank pressure at P1, ensuring that dissolved gases in the oil sample are fully extracted under vacuum. The specific actions are as follows: With the drain valve D2 on drain pipe 2, the inlet valve D3 on oil circulation pipe 5, and the second outlet valve D5 at the outlet end (small diameter end of Venturi jet) of air circulation pipe 4 closed, and the inlet valve D4 on inlet pipe 6 opened, the oil sample from the transformer will flow into the oil tank chamber through inlet pipe 6 under the action of oil pump 9. The oil sample will then pass through the large diameter inlet end of the Venturi jet, oil pump 9, and flow meter 10. The amount of oil sample injected can be calculated based on the flow meter. When the oil volume n meets the requirements, the oil pump stops. Alternatively, if inlet pipe 6 is directly connected to the inlet end of oil pump 9 via inlet valve D4, the oil sample flowing into the oil tank chamber will not need to pass through the Venturi jet and will directly enter the oil tank chamber via oil pump 9 and flow meter 10.
[0034] Step S3: Connect the oil tank's gas chamber to the atmosphere, close other valves, and control the oil tank piston to continue moving upward to the second target position, with a settling time T1; In step S3, the second target position refers to the position above the oil sample in the oil tank. Furthermore, by setting an upward limit switch at a position where the vacuum effect on the oil sample is good, the upward limit switch 16 set inside the oil tank can ensure that the piston 7's trajectory is consistent each time. Under the condition of the same oil sample injection volume, this ensures consistent oil sample test data and good repeatability. At this point, the upward limit switch is the second target position.
[0035] Step S4: Open the oil inlet shut-off valve D3 of oil circulation pipeline 5, the second outlet valve D5 of the outlet end (small diameter end of Venturi jet) of gas circulation pipeline 4, the first outlet valve D8 on outlet pipe 3, and the inlet valve D12 of gas circulation pipeline 4. Close other valves, start oil pump 9, and control the flow rate through flow meter 10 so that the oil sample in the oil tank chamber circulates in the oil circulation pipeline at the target flow rate. Then, the gas formed in the upper layer of the oil tank chamber in step S3 is mixed with gas and liquid through outlet pipe 3 and gas circulation pipeline 4 and injected into the oil in the oil tank chamber by Venturi jet 11 for a duration of T2, so that the gas is fully mixed in the oil and thus drives the gas in the oil to overflow.
[0036] The oil-gas mixing process is as follows: Oil sample from the oil tank chamber flows out from the inlet port (001) of oil circulation pipeline 5, passing through the inlet shut-off valve D3 of oil circulation pipeline 5, the large-diameter inlet end of Venturi jet injector 11, oil pump 9, and flow meter 10 into the oil tank. Gas formed in the upper layer of the oil tank chamber in step S3 enters the oil tank through the sintered filter at the inlet end of outlet pipe 3, the first outlet valve D8 on outlet pipe 3, the inlet valve D12 at the inlet end of gas circulation pipeline 4, the second outlet valve D5 at the outlet end (small-diameter end of Venturi jet injector) of gas circulation pipeline 4, the small-diameter end of Venturi jet injector 11, oil pump 9, and flow meter 10. The mixture is held for a duration T2, allowing the gas to fully mix in the oil, thereby causing the gas in the oil to bubble and overflow. The oil sample circulation maintains a target flow rate, the flow range of which is obtained experimentally.
[0037] Step S5: Open the oil inlet valve D4 on the oil inlet pipe 6 and the first vent valve D8 on the vent pipe 3, close other valves, start the oil pump 9, so that oil enters the oil inlet pipe 6, the oil level in the oil chamber rises, and pushes the gas overflowing from the top of the oil chamber in step S4 to be output for testing through the first vent valve D8 of the vent pipe 3.
[0038] Step S3 also includes real-time monitoring of the oil tank pressure value P2 during the settling time T1. When the oil tank pressure value P2 is greater than the preset threshold, the machine is stopped for maintenance. After maintenance is completed, the machine is restarted, the oil tank is evacuated, and steps 1 to 5 are executed again.
[0039] When the air inlet of the sensor detection module is connected to the air outlet pipe 3 through the switch valve D10, the switch valve D10 of the air inlet of the sensor detection module is opened simultaneously in step S5. Then, the gas overflowing from the top of the oil chamber in step S4 enters the sensor module through the first air outlet valve D8 of the air outlet pipe 3 and the switch valve D10 of the air inlet of the sensor detection module, and can be directly detected.
[0040] The various valves in this invention can be implemented using either solenoid valves or manual valves. When solenoid valves are selected, automatic control can be achieved through a microprocessor controller or a PLC controller. The control of the various components and related valve assemblies in this invention, achieved through various automation methods such as microcontroller (MCU) and PLC configuration for automatic monitoring, is also a common technique used by those skilled in the art, and will not be described further here. Any variations or applications made based on the essential control principles of this invention are also within the scope of protection of this patent.
[0041] This embodiment does not impose any limitation on the shape, material, structure, etc. of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention shall fall within the protection scope of the technical solution of the present invention.
Claims
1. A vacuum degassing device, characterized in that: This includes the oil tank and the vent pipe, oil drain pipe, oil circulation pipeline, gas circulation pipeline and oil inlet pipe installed on the oil tank; The oil tank is a sealed cavity, and a piston and a lead screw that pulls the piston are installed inside the oil tank. The piston divides the oil tank into an air chamber and an oil chamber, and the lead screw passes through the air chamber. The air chamber is connected to the atmosphere via an exhaust valve; The bottom of the oil chamber is connected to an oil drain pipe, and an oil drain valve is installed on the oil drain pipe. The air inlet end of the air outlet pipe is located on the piston and connected to the oil chamber, while the air outlet end of the air outlet pipe penetrates the air outlet chamber. The oil chamber is connected to the oil circulation pipeline, and the two ends of the oil circulation pipeline are respectively connected to the lower part of the oil chamber. The oil inlet end of the oil circulation pipeline is equipped with an on / off valve. The Venturi jet large-diameter inlet end, oil pump, and flow meter are connected in series along the oil flow direction. The oil chamber is connected to the air circulation pipeline. One end of the air circulation pipeline is connected to the air outlet pipe, and the other end is connected to the small diameter end of the Venturi jet. An air inlet valve is installed at the air inlet end of the air circulation pipeline, and a second air outlet valve is installed at the small diameter end of the Venturi jet at the air outlet end of the air circulation pipeline. It also includes an oil inlet pipe, which connects to the front stage of the oil pump via an oil inlet valve.
2. The vacuum degassing device according to claim 1, characterized in that, The outlet end of the oil circulation pipeline is located at the bottom of the oil tank's oil chamber.
3. The vacuum degassing device according to claim 1, characterized in that, It also includes temperature sensors and pressure sensors for measuring oil temperature and oil pressure.
4. The vacuum degassing device according to claim 1, characterized in that, It also includes a heating and humidifying device surrounding the oil tank, along with a temperature sensor to achieve precise temperature control.
5. The vacuum degassing device according to claim 1, characterized in that, A sintered filter is installed at the air inlet port of the exhaust pipe.
6. The vacuum degassing device according to claim 1, characterized in that, The inner wall of the oil tank is equipped with an upper limit and a lower limit. The piston moves between the upper limit and the lower limit. The lower limit is set above the pressure sensor, and the upper limit is set above the oil sample inlet.
7. A degassing method based on the vacuum degassing apparatus according to any one of claims 1 to 6, characterized in that, Includes the following steps: Step S1: Connect the oil tank's gas chamber to the atmosphere, and lower the oil tank piston to the first target position; Step S2: Keep the gas chamber of the oil tank connected to the atmosphere, open the oil inlet valve on the oil inlet pipe, close other valves, and fill the oil tank with a quantitative oil sample. During the filling process, control the oil tank piston to move slowly upward and keep the oil tank pressure value P1 constant until the filling is completed. Step S3: Connect the oil tank's gas chamber to the atmosphere, close other valves, and control the oil tank piston to continue moving upward to the second target position, with a settling time T1; Step S4: Open the oil inlet shut-off valve of the oil circulation pipeline, the second outlet valve of the outlet of the gas circulation pipeline, the first outlet valve on the outlet pipe, and the inlet valve of the gas circulation pipeline. Close other valves, start the oil pump, and control the flow rate through the flow meter so that the oil sample in the oil tank chamber circulates in the oil circulation pipeline at the target flow rate for a duration of T2. Step S5: Open the oil inlet valve on the oil inlet pipe and the first vent valve on the vent pipe, close other valves, start the oil pump, so that oil enters the oil inlet pipe, the oil level in the oil chamber rises, and pushes the gas overflowing from the top of the oil chamber in step S4 to be output through the first vent valve on the vent pipe.
8. A degassing method based on the vacuum degassing apparatus according to any one of claims 1 to 7, characterized in that, The steps in step S2 to confirm the quantitative oil sample are: obtaining the flow rate of the flow meter, obtaining the opening and closing time of the oil inlet valve on the oil inlet pipe, and multiplying the two.
9. A degassing method based on the vacuum degassing apparatus according to any one of claims 1 to 7, characterized in that, Step S3 also includes real-time monitoring of the oil chamber pressure value during the settling time T1. When the oil chamber pressure value is greater than the preset threshold, the machine is stopped for maintenance. After maintenance is completed, the machine is restarted, the oil tank is evacuated, and steps 1 to 5 are executed again.
10. An online monitoring device for dissolved gas in oil, characterized in that, The vacuum degassing apparatus according to any one of claims 1 to 6 is used to perform the vacuum degassing method according to any one of claims 7 to 9.