Gas standard system for on-line monitoring of gas dissolved in oil

Abstract

The invention discloses an on-line monitoring gas standard system for gas dissolved in oil, which comprises a shell (1), a display (2) is arranged at the top of the shell (1), a power supply module (3) and an industrial personal computer (4) are arranged in the shell (1), a data processing system is arranged in the industrial personal computer (4), the industrial personal computer (4) is electrically connected with the display (2), and the display (2) is electrically connected with the data processing system. The shell (1) is provided with n1 standard gas connectors, a nitrogen connector and a standby connector, each standard gas connector is connected with a standard gas cylinder (5), each nitrogen connector is connected with a nitrogen cylinder (6), the standard gas cylinders (5) and the nitrogen cylinders (6) are communicated with a first multi-way valve (7) through pipelines connected to the connectors, the first multi-way valve (7) is connected with a second multi-way valve (9) through a connecting pipeline (8), and the second multi-way valve (9) is connected with the standby connector. The second multi-way valve (9) is connected with n2 quantitative units (10), and an outlet of each quantitative unit (10) is communicated with an inlet of a measurement and control unit (11) through a pipeline.

Description

Technical Field

[0001] This invention relates to the field of transformers, and in particular to an online monitoring system for dissolved gases in oil. Background Technology

[0002] Online monitoring devices for dissolved gases in oil are core monitoring equipment for ensuring the safe operation of power transformers. In the final stage of their manufacturing, each unit must be precisely calibrated to establish the accuracy and repeatability of its gas concentration measurements. Currently, the industry widely adopts the calibration method based on standard insulating oil samples (hereinafter referred to as the "oil standard method") as the "gold standard" for factory inspection; however, this method faces many insurmountable technical bottlenecks in production practice.

[0003] On the existing production line, the implementation process of the "oil standard method" is as follows: First, in a laboratory environment, simulating real transformer oil, standard gas is dissolved in insulating oil to prepare a standard oil sample; then, the standard oil sample is injected into the online monitoring device to be calibrated on the production line; the device starts its built-in oil-gas separation module to extract the dissolved gas in the oil and send it to the detector; finally, the detector reading is compared with the offline data of the standard oil sample to complete the fitting of the calibration curve.

[0004] Although this method attempts to simulate the final working scenario of the equipment, it exposes the following fundamental flaws in the production process: The calibration reference transfer chain is lengthy, introducing key uncertainty factors: The core measurement accuracy of online monitoring devices depends on the performance of their detection units. However, the calibration benchmark (gas concentration) of the "oil standard method" must undergo two unnecessary physicochemical processes—"dissolving in oil" and then "removing from oil"—before it can be transferred to the detection unit. Degassing efficiency is a critical and highly fluctuating variable, affected by various factors such as oil properties, temperature, and vacuum level, making it extremely difficult to maintain 100% stability and consistency in production. Therefore, the final calibration result is actually a function of "(actual gas concentration) × (degassing efficiency)," rather than a reflection of the detection unit's true performance. This results in inherently insufficient calibration accuracy, making it impossible to directly and purely assess the quality of this core component, the detection unit. It may misjudge a high-precision detector as unqualified due to fluctuations in degassing efficiency, or mask linear defects in the detector itself, severely impacting the consistency and reliability of the finished product quality.

[0005] 2. Low production efficiency, unable to meet the demands of large-scale manufacturing: Process time consumption: It involves a series of steps such as oil injection, degassing and balancing, measurement, oil drainage, pipeline cleaning and drying. The calibration time for a single piece of equipment is as long as one week, which seriously restricts the production cycle and becomes a bottleneck for production capacity.

[0006] High cost: Certification-grade standard insulating oil samples are difficult to prepare, expensive, and are disposable, resulting in huge material costs in large-scale production.

[0007] Complex operation: The processing of liquid oil samples is difficult to automate fully and relies heavily on manual operation, which not only increases labor costs but also introduces the risk of human error due to inconsistencies in operation.

[0008] 3. Hindering Production Automation and Digital Upgrades: Modern intelligent manufacturing pursues end-to-end automation and data-driven processes. The introduction of liquid oil samples makes the calibration process involve numerous pipeline connections, liquid transportation, and cleaning steps, making it difficult to integrate into a seamless automated production line and becoming a significant obstacle to building a digital smart factory.

[0009] 4. Inability to perform pre-testing and diagnostics on core components: In modular production and incoming material inspection, the performance of gas detection units needs to be evaluated quickly and independently. The "oil label method" requires the detection unit to be assembled into a complete unit before it can be performed, which cannot detect quality problems of core components in the early stages, reducing the flexibility of the production process and the foresight of quality control.

[0010] Therefore, a method or apparatus is needed to solve the above problems. Summary of the Invention

[0011] The present invention addresses the aforementioned shortcomings of existing technologies by proposing an online gas meter system for monitoring dissolved gases in oil that is simple in structure, ingenious in design, rational in layout, can accurately reflect the performance of the detection unit, and is highly efficient and low in cost.

[0012] The technical solution of this invention is: an online monitoring gas meter system for dissolved gases in oil, comprising a housing 1, characterized in that: a display 2 is provided on the top of the housing 1, a power module 3 and an industrial control computer 4 are provided inside the housing 1, the industrial control computer 4 is provided with a data processing system, and the industrial control computer 4 is electrically connected to the display 2. The housing 1 is provided with n1 standard gas interfaces, one nitrogen interface, and one spare interface. A standard gas cylinder 5 is connected to the standard gas interface, and a nitrogen cylinder 6 is connected to the nitrogen interface. Both the standard gas cylinder 5 and the nitrogen cylinder 6 are connected to a first multi-way valve 7 via pipes connected to the interfaces. The first multi-way valve 7 is connected to a second multi-way valve 9 via a connecting pipe 8. The second multi-way valve 9 is connected to n2 metering units 10. The outlet of each metering unit 10 is connected to the inlet of a measurement and control unit 11 via a pipe. The quantitative unit 10 includes a third multi-way valve 12. One connector of the third multi-way valve 12 is connected to the outlet connector of the second multi-way valve 9. The third multi-way valve 12 also has n3 quantitative tube connectors 14. Each quantitative tube connector 14 is equipped with a first solenoid valve 15. Each quantitative tube connector 14 is connected to the inlet of a quantitative tube 16. The outlet of the quantitative tube 16 is connected to the inlet of a manifold 17 via a quantitative tube outlet pipe. The n3 quantitative tubes 16 and the manifold 17 are connected in parallel. A first pressure sensor 18, a second solenoid valve 19, and a first check valve 20 are sequentially installed on the quantitative tube outlet pipe and the manifold 17 outlet pipe. The outlet pipe of the manifold 17 is connected to the inlet of a measurement and control unit 11. A pressure regulating valve 21 is provided on the connecting pipe 8, and the pressure regulating valve 21 is also electrically connected to the digital display 22.

[0013] The system also includes a low-pressure stabilizing unit 23, which is connected in parallel with all the metering units 10 via pipelines.

[0014] The low-pressure stabilizing unit 23 includes a condenser container 24. The inlet end of the condenser container 24 is connected to the gas source through a pipeline with a second one-way valve 25. A drain pipeline 26 is provided at the bottom of the condenser container 24. A second pressure sensor 27 is also provided on the condenser container 24. The outlet end of the condenser container 24 is connected to the molecular sieve container 29 and the pressure compensation container 30 in sequence through a pipeline with a first-stage pressure regulating valve 28. The outlet end of the pressure compensation container 30 is connected to the third multi-way valve 12 in the metering unit 10 through a pipeline with a second-stage pressure regulating valve 31. A third solenoid valve 34 is also provided on this pipeline. The molecular sieve container 29 is equipped with a 5A molecular sieve. A pressure compensation module 32 is connected to the pressure compensation container 30.

[0015] An venting pipe 33 is provided on the pipeline between the second multi-way valve 9 and the metering unit 10, and an venting valve and a silencer are provided on the venting pipe 33.

[0016] Compared with the prior art, the present invention has the following advantages: This type of online dissolved gas monitoring system for oil features a simple structure, ingenious design, and reasonable layout. It utilizes a multi-port-to-multi-port configuration, coupled with a control computer to coordinate the control of different multi-port valves, to connect different calibration gas cylinders with different measurement and control units. Simultaneously, multiple metering tubes of varying volumes can be installed in the metering unit. By controlling the multi-port valves within the metering unit, gas samples of different volumes, including mixed gas samples, can be obtained. Furthermore, it incorporates a low-pressure flow stabilization unit, which operates on each metering unit to achieve a stable calibration environment, thereby preventing pressure variations from affecting metering accuracy. This design, which incorporates a low-pressure flow stabilization unit, significantly reduces the potential leakage rate at various joints and seals, and effectively prevents standard gas contamination and sensor performance degradation caused by external air backflow into the gas path. Simultaneously, stable low-flow operation avoids detector overload, extending its service life.

[0017] This system offers precise data analysis, effectively reducing manual maintenance and ensuring continuous and reliable monitoring data. Control of flow rate and pressure prevents peak tailing and overlap caused by unstable airflow, ensuring that the detected concentrations of faulty gases such as CH4 and C2H2 closely match the true values. Furthermore, its simple manufacturing process and low production cost make it a system with numerous advantages, particularly suitable for widespread application in this field, and its market prospects are very promising. Attached Figure Description

[0018] Figure 1 This is a three-dimensional structural diagram of an embodiment of the present invention.

[0019] Figure 2 This is a cross-sectional view of the housing portion in an embodiment of the present invention.

[0020] Figure 3 This is a system composition diagram of an embodiment of the present invention.

[0021] Figure 4 This is a schematic diagram of the quantitative unit portion in an embodiment of the present invention.

[0022] Figure 5 This is a schematic diagram of the low-voltage current stabilizing unit in an embodiment of the present invention. Detailed Implementation

[0023] Specific embodiments of the present invention will now be described in conjunction with the accompanying drawings. Figures 1 to 5 As shown: An online dissolved gas monitoring system for oil includes a housing 1 as a base, a display 2 mounted on the top of the housing 1, a power module 3 and an industrial computer 4 housed inside the housing 1, the industrial computer 4 containing a data processing system, and the industrial computer 4 electrically connected to the display 2. The housing 1 is provided with n1 standard gas interfaces, one nitrogen interface, and one spare interface. A standard gas cylinder 5 is connected to the standard gas interface, and a nitrogen cylinder 6 is connected to the nitrogen interface. Both the standard gas cylinder 5 and the nitrogen cylinder 6 are connected to a first multi-way valve 7 via pipes connected to the interfaces. The first multi-way valve 7 is connected to a second multi-way valve 9 via a connecting pipe 8. The second multi-way valve 9 is connected to n2 metering units 10. The outlet of each metering unit 10 is connected to the inlet of a measurement and control unit 11 via a pipe. The quantitative unit 10 includes a third multi-way valve 12. One connector of the third multi-way valve 12 is connected to the outlet connector of the second multi-way valve 9. The third multi-way valve 12 also has n3 quantitative tube connectors 14. Each quantitative tube connector 14 is equipped with a first solenoid valve 15. Each quantitative tube connector 14 is connected to the inlet of a quantitative tube 16. The outlet of the quantitative tube 16 is connected to the inlet of a manifold 17 via a quantitative tube outlet pipe. The n3 quantitative tubes 16 and the manifold 17 are connected in parallel. A first pressure sensor 18, a second solenoid valve 19, and a first check valve 20 are sequentially installed on the quantitative tube outlet pipe and the manifold 17 outlet pipe. The outlet pipe of the manifold 17 is connected to the inlet of a measurement and control unit 11. A pressure regulating valve 21 is provided on the connecting pipe 8, and the pressure regulating valve 21 is also electrically connected to the digital display 22.

[0024] The system also includes a low-pressure stabilizing unit 23, which is connected in parallel with all the metering units 10 via pipelines.

[0025] The low-pressure stabilizing unit 23 includes a condenser container 24. The inlet end of the condenser container 24 is connected to the gas source through a pipeline with a second one-way valve 25. A drain pipeline 26 is provided at the bottom of the condenser container 24. A second pressure sensor 27 is also provided on the condenser container 24. The outlet end of the condenser container 24 is connected to the molecular sieve container 29 and the pressure compensation container 30 in sequence through a pipeline with a first-stage pressure regulating valve 28. The outlet end of the pressure compensation container 30 is connected to the third multi-way valve 12 in the metering unit 10 through a pipeline with a second-stage pressure regulating valve 31. A third solenoid valve 34 is also provided on this pipeline. The molecular sieve container 29 is equipped with a 5A molecular sieve. A pressure compensation module 32 is connected to the pressure compensation container 30.

[0026] An venting pipe 33 is provided on the pipeline between the second multi-way valve 9 and the metering unit 10, and an venting valve and a silencer are provided on the venting pipe 33.

[0027] The working process of the online monitoring gas standard system for dissolved gases in oil in this embodiment of the invention is as follows: When a certain gas needs to be detected by a certain measuring unit, the control system first sends a signal to the first multi-way valve 7. The first multi-way valve 7 controls the opening of the port corresponding to the standard gas cylinder 5 containing the gas. After the gas sample enters the first multi-way valve 7, it enters the second multi-way valve 9 through the connecting pipeline 8. The pressure regulating valve 21 set on the connecting pipeline 8 is pre-adjusted to control the gas pressure entering the second multi-way valve 9. The digital display 22 can display the current gas pressure in the connecting pipeline 8 in real time. At the same time, the control system will also control the second multi-way valve 9 to open the port connected to the target measurement and control unit 11. At the same time, the gas sample will enter the quantitative unit 10 to realize the quantitative sampling operation. Then, the third solenoid valve 34 on the pipeline corresponding to the quantitative unit 10 will open, and the low-pressure stabilizing unit 23 will work to send the gas sample into the corresponding measurement and control unit 11 using air at constant pressure, so as to realize the measurement of the quantitative gas sample. After the measurement is completed, the low-pressure stabilizing unit 23 operates to purge all pipelines through which the previous gas sample flowed. The purged air enters the measurement and control unit 11 and is discharged into the environment through the built-in venting pipeline within the measurement and control unit 11. Then, the control system also controls the first multi-way valve 7 to operate, opening the port corresponding to the nitrogen cylinder 6. The nitrogen in the nitrogen cylinder 6 is purged along the pipeline through which the previous gas sample flowed, passing through the first multi-way valve 7, connecting pipeline 8, and second multi-way valve 9, and finally discharged through the venting pipeline 33 (venting valve is open). During this process, no noise is generated due to the presence of the silencer.

[0028] Multiple different types of metering tubes 16 can be connected to the third multi-way valve 12 in the metering unit 10. By controlling the first solenoid valve 15 on the metering tube connector 14 connected to these metering tubes 16, the amount of gas sample to be obtained can be selected. For example, three types of metering tubes 16 with capacities of 10ml, 20ml and 50ml can be connected to the metering unit 10. When the first solenoid valve 15 on the metering tube connector 14 corresponding to 10ml is opened, 10ml of gas sample can be obtained. When the first solenoid valve 15 on the metering tube connector 14 corresponding to 20ml is opened, 20ml of gas sample can be obtained. These gas samples directly enter the measurement and control unit 11 after passing through the manifold 17. The two first solenoid valves 15 can be opened simultaneously to allow the gas samples in the two quantitative tubes 16 to enter the manifold 17 and mix there (at this time, the second solenoid valve 19 at the outlet of the manifold 17 is closed) to obtain 30ml of gas sample. Then the second solenoid valve 19 at the outlet of the manifold 17 is opened, the third solenoid valve 34 corresponding to the quantitative unit 10 is opened, the low-pressure stabilizing unit 23 works, and the gas sample is sent into the corresponding measurement and control unit 11 using air at constant pressure to measure the gas sample. The specific working process of the low-pressure stabilizing unit 23 is as follows: Air from the air source enters the condensing container 24 through the pipeline where the second one-way valve 25 is located. The condensing container 24 is equipped with fins. After the air flows through the fins, the moisture in the air will come into contact with them and condense into liquid. Finally, it will collect at the bottom of the condensing container 24. The dried air, after the moisture has been removed, enters the molecular sieve container 29 after the pressure is regulated by the first-stage pressure regulating valve 28. It will come into full contact with the molecular sieve. While further drying and dehydrating, it can also remove impurities in the air to obtain clean air. After the clean air enters the pressure compensation container 30, the pressure compensation module 32 can detect its pressure. If it finds that the pressure does not meet the requirements, the pressure compensation module 32 will compensate the pressure of the air in it. Finally, the air is input into the third multi-way valve 12 in the quantitative unit 10 after passing through the second-stage pressure regulating valve 31. This system can perform detection of different standard gases in different measurement and control units 11, and can quickly match them according to actual needs, effectively improving work efficiency; at the same time, it can also realize the determination of a single standard gas with different quantities.

Claims

1. An online monitoring system for dissolved gases in oil, comprising a housing (1), characterized in that: A display (2) is provided on the top of the housing (1). A power module (3) and an industrial computer (4) are provided inside the housing (1). A data processing system is provided inside the industrial computer (4). The industrial computer (4) is electrically connected to the display (2). The housing (1) is provided with n1 standard gas interfaces, one nitrogen interface, and one spare interface. A standard gas cylinder (5) is connected to the standard gas interface, and a nitrogen cylinder (6) is connected to the nitrogen interface. Both the standard gas cylinder (5) and the nitrogen cylinder (6) are connected to a first multi-way valve (7) through pipes connected to the interfaces. The first multi-way valve (7) is connected to a second multi-way valve (9) through a connecting pipe (8). The second multi-way valve (9) is connected to n2 metering units (10). The outlet of each metering unit (10) is connected to the inlet of a measurement and control unit (11) through a pipe. The quantitative unit (10) includes a third multi-way valve (12). One connector of the third multi-way valve (12) is connected to the outlet connector of the second multi-way valve (9). At the same time, the third multi-way valve (12) is also provided with n3 quantitative tube connectors (14). Each quantitative tube connector (14) is provided with a first solenoid valve (15). Each quantitative tube connector (14) is connected to the inlet of a quantitative tube (16). The outlet end of the quantitative tube (16) is connected to the inlet end of the manifold (17) through the quantitative tube outlet pipeline. The n3 quantitative tubes (16) and the manifold (17) are connected in parallel. A first pressure sensor (18), a second solenoid valve (19) and a first check valve (20) are sequentially provided on the quantitative tube outlet pipeline and the manifold (17) outlet pipeline. The outlet pipeline of the manifold (17) is connected to the inlet of a measurement and control unit (11).

2. The online monitoring gas scale system for dissolved gases in oil according to claim 1, characterized in that: A pressure regulating valve (21) is provided on the connecting pipeline (8), and the pressure regulating valve (21) is also electrically connected to the digital display (22).

3. The online monitoring gas scale system for dissolved gases in oil according to claim 1, characterized in that: The system also includes a low-pressure stabilizing unit (23), which is connected in parallel with all the metering units (10) through pipelines.

4. The online monitoring gas meter system for dissolved gases in oil according to claim 3, characterized in that: The low-pressure stabilizing unit (23) includes a condenser (24). The inlet of the condenser (24) is connected to the gas source through a pipeline with a second one-way valve (25). A drain pipeline (26) is provided at the bottom of the condenser (24). A second pressure sensor (27) is also provided on the condenser (24). The outlet of the condenser (24) is connected to the molecular sieve container (29) and the pressure compensation container (30) in sequence through a pipeline with a first-stage pressure regulating valve (28). The outlet of the pressure compensation container (30) is connected to the third multi-way valve (12) in the quantitative unit (10) through a pipeline with a second-stage pressure regulating valve (31). A third solenoid valve (34) is also provided on this pipeline. A 5A molecular sieve is provided inside the molecular sieve container (29). A pressure compensation module (32) is connected to the pressure compensation container (30).

5. The online monitoring gas scale system for dissolved gases in oil according to claim 1, characterized in that: An venting pipe (33) is provided on the pipeline between the second multi-way valve (9) and the metering unit (10), and an venting valve and a silencer are provided on the venting pipe (33).

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