Device, configuration method and storage method of hydrogen standard oil sample for transformer oil chromatography verification

Abstract

The invention discloses a device, configuration and storage method of a hydrogen standard oil sample for transformer oil chromatography verification, and relates to the technical field of electrical equipment state monitoring and fault diagnosis, the device comprises a standard oil configuration and storage unit, an outer layer protection unit, an inert gas supply and pressure compensation unit, a hydrogen concentration online monitoring unit and a control unit. The standard oil configuration and storage unit is a stainless steel tank body of which the inner wall is plated with a compact silicon oxide coating, so that hydrogen escape is effectively prevented; the outer-layer protection unit covers the inner tank and forms an inert gas interlayer, and the stable pressure difference between the outer-layer protection unit and the inner tank is maintained through dynamic pressure compensation; the hydrogen concentration monitoring probe monitors the hydrogen concentration in oil in real time, and the control unit automatically adjusts the interlayer pressure or the stirring speed according to data and actively maintains dissolution balance. Through the synergistic effect of the high-barrier material, dynamic pressure compensation and intelligent closed-loop control, the technical problems that hydrogen is easy to permeate and the concentration is easy to attenuate are solved, and the method can be used for on-site calibration of the transformer oil chromatography online monitoring device.

Description

Technical Field

[0001] This invention relates to the field of power equipment condition monitoring and fault diagnosis technology, and in particular to an apparatus, preparation and storage method for hydrogen standard oil samples used in transformer oil chromatography calibration, and a long-term stable storage apparatus and method for hydrogen standard oil samples used in transformer oil chromatography calibration. Background Technology

[0002] Dissolved gas analysis (DGA) in transformer oil is a key technology for monitoring the operating status of oil-immersed high-voltage electrical equipment such as power transformers and diagnosing latent internal faults. Hydrogen (H2), as one of the characteristic dissolved gases in oil, exhibits significant concentration changes that are important indicators for the early diagnosis of discharge faults (such as partial discharge and arc discharge) and certain overheating faults. To ensure the accuracy and comparability of chromatographic analysis data, it is essential to periodically calibrate and verify the performance of online oil chromatography monitoring devices using known and stable hydrogen standard oil samples.

[0003] The preparation of single-component (H2) standard oil samples for insulating oil employs a dynamic equilibrium method (injecting standard gas into a blank oil sample and then stirring thoroughly). The prepared hydrogen standard oil samples are extremely sensitive to storage conditions. Hydrogen has a small molecular weight and high permeability, making it highly susceptible to leakage. Commonly used storage containers (such as disposable oil bags, glass syringes, ordinary reagent bottles, and metal cans) often lack sufficient sealing performance, making it difficult to maintain a stable hydrogen concentration in the oil over long periods. The solubility of hydrogen in oil is significantly affected by temperature; if the storage environment temperature fluctuates, even with a tight seal, the concentration will change, causing concentration drift in the standard oil sample during storage.

[0004] The preparation of standard oil samples carries risks of hydrogen leakage, oxidation, or explosion due to contact with air (oxygen). Storage devices are often simple containers, lacking built-in pressure / temperature monitoring, safety venting, and interfaces for easy non-destructive sampling (such as through septum puncture). The entire process, from preparation, transfer, storage to sampling, is cumbersome and prone to human error and secondary contamination (such as air contamination), affecting the reliability and ease of use of the standard oil samples. After preparation, the standard oil samples need to be calibrated (quantitative analysis using chromatography after offline sampling) before storage. During storage, there is a lack of online or convenient non-destructive methods to verify the hydrogen concentration in the oil in real time or periodically. Before use, it cannot be confirmed whether the current concentration of the standard oil sample is still within the uncertainty range of the nominal value, requiring resampling and calibration, which carries the risk of miscalibration.

[0005] Therefore, there is a need for a method and apparatus that can quickly and accurately prepare standard oil samples of hydrogen at specific concentrations, effectively maintain concentration stability during long-term storage, and possess high safety, ease of operation, and continuous value determination, in order to improve the quality and efficiency of online monitoring device calibration for transformer oil chromatography and ensure the reliability of power equipment condition assessment and fault diagnosis. Summary of the Invention

[0006] In view of the technical problems in the above or existing technologies, such as the easy decay of standard oil concentration and difficulty in long-term stable preservation due to the small size and easy permeability of hydrogen molecules, an apparatus, preparation and storage method for hydrogen standard oil samples for chromatographic calibration of transformer oil are proposed.

[0007] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0008] The present invention provides an apparatus, preparation and storage method for hydrogen standard oil sample for chromatographic calibration of transformer oil, including: a standard oil preparation and storage unit, which includes an integrated stainless steel tank, the inner wall of which is coated with a dense silicon oxide coating, for containing the prepared hydrogen standard oil sample.

[0009] The outer protective unit is a sealed shell that tightly covers the outside of the standard oil preparation storage unit, forming a closed inert gas interlayer between it and the outer wall of the standard oil preparation storage unit.

[0010] An inert gas supply and pressure compensation unit, connected to the inert gas interlayer, is used to fill the interlayer with inert gas and maintain a dynamic and stable pressure difference between it and the interior of the standard oil configuration storage unit.

[0011] The hydrogen concentration online monitoring unit includes at least two hydrogen concentration monitoring probes that extend into the standard oil configuration storage unit for real-time monitoring of the dissolved hydrogen concentration in the oil.

[0012] The control unit is electrically connected to the hydrogen concentration online monitoring unit and the inert gas supply and pressure compensation unit, respectively. The control unit is configured to automatically adjust the operation of the inert gas supply and pressure compensation unit according to the reading of the hydrogen concentration monitoring probe and the preset concentration-pressure-temperature relationship model, so as to maintain the gas-liquid dissolution balance inside the standard oil configuration storage unit.

[0013] Furthermore,

[0014] The inert gas supply and pressure compensation unit includes a high-pressure inert gas source, a pressure reducing valve, a gas replenishing valve, and a pressure control unit disposed within the inert gas interlayer.

[0015] The control unit receives a signal from the pressure control unit. When the pressure inside the standard oil configuration storage unit drops or the temperature rises, causing the pressure difference to exceed the threshold, the control unit opens the gas replenishment valve to replenish gas to the inert gas jacket until the pressure difference returns to the set value.

[0016] Furthermore,

[0017] The control unit is configured with a differential pressure threshold of 15 kPa. The condition for triggering pressure compensation is that the internal pressure of the standard oil storage unit drops by more than 0.05 MPa or its internal temperature rises by more than 1°C.

[0018] Furthermore,

[0019] The standard oil storage unit is equipped with a magnetic stir bar. The control unit is also used to automatically adjust the stirring rate of the magnetic stir bar according to the real-time concentration and its changing trend measured by the hydrogen concentration monitoring probe, so as to promote the uniform distribution of hydrogen without disrupting the dissolution balance.

[0020] Furthermore,

[0021] It also includes an emergency hydrogen venting unit connected to the control unit, the emergency hydrogen venting unit including a hydrogen venting pipeline and a hydrogen venting valve disposed at the top of the inner wall of the device;

[0022] The device is also equipped with a hydrogen leak detection probe with a sensitivity of not less than 0.01 ppm. When the hydrogen leak detection probe detects that the ambient hydrogen concentration reaches a first threshold, the control unit triggers the emergency hydrogen venting unit to start venting hydrogen. When the hydrogen concentration is detected to drop below a second threshold, the control unit controls the emergency hydrogen venting unit to shut down.

[0023] The method for preparing and storing hydrogen standard oil samples for transformer oil chromatographic calibration includes the following steps:

[0024] S1. Blank oil preparation: Inject blank insulating oil into the degassing unit and degas continuously for 0.5 hours at 80℃ and a vacuum of 25 Pa until the gas content is below 0.1%;

[0025] S2. High-precision configuration: The blank oil processed in step S1 is transported to the standard oil configuration storage unit. High-purity hydrogen gas with a purity of ≥99.999% is bubbled into the oil at a constant rate using a high-vacuum bubbling method, while stirring at a rate of 500 rpm, until the relative deviation of the hydrogen concentration in the oil measured three times in a row is within ±0.5%, and it is determined that gas-liquid dissolution equilibrium has been reached, thus obtaining a hydrogen standard oil sample.

[0026] S3. Dynamic Balance Storage: During storage, the control unit maintains a dynamic and stable pressure difference between the inert gas jacket and the standard oil storage unit through the inert gas supply and pressure compensation unit according to a preset program; at the same time, the hydrogen concentration online monitoring unit periodically measures the hydrogen concentration in the oil and feeds the data back to the control unit.

[0027] S4. Concentration Maintenance and Correction: If the control unit analysis finds that the hydrogen concentration tends to exceed the nominal value uncertainty range, then according to the built-in concentration-pressure-temperature relationship model, the control unit intervenes in the dissolution equilibrium by finely adjusting the pressure of the inert gas interlayer or starting the stirrer to perform short-term stirring at a low rate to maintain the concentration stability.

[0028] Furthermore,

[0029] In step S2, the high-vacuum bubbling method has a hydrogen injection rate of 50 mL / min and a bubbler aperture of ≤20 μm.

[0030] Furthermore,

[0031] The dynamic stable pressure difference is 15 kPa.

[0032] Furthermore,

[0033] It also includes safety monitoring steps: the internal space of the device is monitored in real time by a hydrogen leak detection probe with a sensitivity of 0.01ppm. When the hydrogen concentration reaches 1000ppm, the emergency hydrogen discharge unit is automatically activated to discharge the hydrogen and perform self-check and alarm for the leak point.

[0034] The beneficial effects of this invention are as follows:

[0035] This invention fundamentally solves the problem of hydrogen concentration decay caused by its small molecular weight and high permeability through the synergistic effect of a "high-barrier inner tank + dynamic pressure compensation outer cover". The standard oil preparation storage unit adopts an integrated stainless steel tank with a dense silicon oxide coating on the inner wall, resulting in a hydrogen diffusion coefficient as low as 10⁻¹² to 10⁻¹⁰ cm² / s, preventing hydrogen molecules from escaping at the material level. The inert gas interlayer formed between the outer protective unit and the standard oil preparation storage unit maintains a dynamically stable pressure difference under the control of the control unit. When the pressure in the inner tank decreases, the nitrogen in the outer layer forms a "counter-pressure barrier" to inhibit hydrogen diffusion and drive the redissolution of trace amounts of hydrogen. Experimental data show that the device and method of this invention can achieve a hydrogen standard oil sample concentration decay rate of ≤0.08% within a 6-month storage period, while traditional oil storage bags can only maintain it for a few days and ordinary oil storage tanks can only maintain it for about a week, achieving a stable period of more than half a year.

[0036] Secondly, this invention breaks through the traditional "discard after preparation" mode and introduces the intelligent concept of "full-process dynamic maintenance". Two redundant hydrogen concentration monitoring probes monitor the dissolved hydrogen concentration in the oil in real time and the measurement repeatability deviation is ≤±1.5%. The control unit makes intelligent decisions based on the built-in concentration-pressure-temperature relationship model. When the concentration deviates, it can automatically fine-tune the inert gas jacket pressure or start the magnetic stir bar at a low speed of 250 rpm for a short time to restore uniformity, ensuring that the standard oil sample is always within the nominal value uncertainty range. There is no need to resample and set values ​​before use, avoiding secondary pollution and human error.

[0037] Furthermore, this invention constructs a complete safety protection system from prevention and monitoring to disposal. The high-sensitivity hydrogen leak monitoring probe has a sensitivity of 0.01ppm, which can detect trace leaks in a timely manner. When the ambient hydrogen concentration reaches 1000ppm, the control unit automatically triggers the emergency hydrogen exhaust unit to start strong ventilation and cut off the non-explosion-proof power supply. After the concentration drops below 50ppm and there is no leak after self-test, it automatically resets. The entire device uses light-shielding materials and a constant temperature unit to control the ambient temperature. All valves use all-metal diaphragm valves and the sealing structure uses a combination of metal gaskets and spring energy storage sealing rings to eliminate the risk of leakage from the source.

[0038] Finally, this invention achieves full automation of the entire process from blank oil degassing, standard oil sample preparation, long-term storage to online retrieval. The control unit uniformly schedules all components to avoid human error. The hydrogen-containing waste gas discharged from the degassing unit is directly discharged after being treated by the catalytic oxidation device. The failed oil sample can be transported back to the degassing unit for re-degassing through the second oil pump 23 to achieve recycling. No waste oil is generated, which meets environmental protection requirements. It has important industrial application value for ensuring the accurate calibration of transformer oil chromatography online monitoring devices and ensuring the safe and stable operation of power equipment. Attached Figure Description

[0039] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0040] Figure 1 This is a schematic diagram of the apparatus for hydrogen standard oil sample used in the chromatographic calibration of transformer oil according to the present invention.

[0041] Figure 2 This is a schematic diagram of the process steps for preparing and storing hydrogen standard oil samples for transformer oil chromatography calibration according to the present invention.

[0042] 1-Degassing unit, 2-First valve, 3-First pipeline, 4-First exhaust valve, 5-First exhaust pipeline, 6-First exhaust port, 7-First temperature control unit, 8-Second valve, 9-Second pipeline, 10-First oil pump, 11-Third valve, 12-Third pipeline, 13-Oil temperature monitoring unit, 14-Fourth valve, 15-Fourth pipeline, 16-Standard oil preparation and storage unit, 17-Magnetic stir bar, 18-Hydrogen concentration monitoring probe, 19-Pressure control unit, 20-Second temperature control unit, 21-Fifth valve, 22-Fifth pipeline, 23-Second Oil pump, 24-Sixth valve, 25-Sixth pipeline, 26-Second vent valve, 27-Check valve, 28-Second vent pipeline, 29-Hydrogen leak monitoring probe, 30-Second vent port, 31-Hydrogen storage tank, 32-Pressure reducing valve, 33-Seventh valve, 34-Seventh pipeline, 35-Outer protection unit, 36-Eighth valve, 37-Eighth pipeline, 38-Third oil pump, 39-Ninth valve, 40-Ninth pipeline, 41-Emergency hydrogen venting unit, 42-Control unit, 43-Constant temperature unit, 44-Hydrogen standard oil sample preparation and storage device. Detailed Implementation

[0043] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0044] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0045] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that is mutually exclusive with other embodiments.

[0046] Example 1

[0047] like Figure 1 As shown in the figure, this embodiment provides a long-term stable storage device for hydrogen standard oil samples used for chromatographic calibration of transformer oil. The device mainly includes: a degassing unit 1, a standard oil preparation and storage unit 16, an outer protection unit 35, an inert gas supply and pressure compensation unit, an online hydrogen concentration monitoring unit, a control unit 42, and related pipelines and valves.

[0048] The degassing unit 1 is a sealed container used for deep degassing of blank insulating oil. The degassing unit 1 has a first pipeline 3 for injecting blank insulating oil, and a first temperature control unit 7 at its bottom for heating the oil sample. The top of the degassing unit 1 is connected to a first exhaust valve 4 and a first exhaust port 6 via a first exhaust pipeline 5 to discharge the degassed gas. The lower part of the degassing unit 1 is connected to a first oil pump 10 via a second pipeline 9, and the outlet of the first oil pump 10 is connected to an oil temperature monitoring unit 13 via a third pipeline 12. The outlet of the oil temperature monitoring unit 13 is connected to the upper left port of the standard oil preparation and storage unit 16 via a fourth pipeline 15. Each of the above pipelines is equipped with a first valve 2, a second valve 8, a third valve 11, and a fourth valve 14 to control the opening and closing of the oil circuit.

[0049] The standard oil storage unit 16 is a core component of this invention, comprising a single stainless steel tank with a dense silica coating deposited on its inner wall via chemical vapor deposition or a sol-gel method. This coating has an extremely low hydrogen diffusion coefficient, typically around 10. -12 Up to 10 -10 cm 2 Within a range of / s, it can effectively prevent hydrogen molecules from escaping through the tank wall. The standard oil preparation and storage unit 16 is equipped with a magnetic stirrer 17 to stir the oil sample during preparation and storage, promoting hydrogen dissolution and uniform distribution. The top of the standard oil preparation and storage unit 16 is equipped with two hydrogen concentration monitoring probes 18 for real-time monitoring of the dissolved hydrogen concentration in the oil; it also has a pressure control unit 19, including a pressure sensor, for monitoring the pressure inside the tank; and a second temperature control unit 20 for precisely controlling the oil temperature inside the tank. The bottom of the standard oil preparation and storage unit 16 has a seventh pipeline 34, connected to the hydrogen storage tank 31 via a seventh valve 33 and a pressure reducing valve 32, for injecting high-purity hydrogen into the oil during preparation. The lower part of the standard oil preparation and storage unit 16 also has an eighth pipeline 37, connected to a third oil pump 38 via an eighth valve 36. The outlet of the third oil pump 38 is connected to a ninth valve 39 via a ninth pipeline 40, for transporting the stored standard oil sample to an external online oil chromatography monitoring device.

[0050] The outer protective unit 35 is a sealed housing that tightly covers the exterior of the standard oil preparation storage unit 16, forming a closed inert gas interlayer between it and the outer wall of the standard oil preparation storage unit 16. The outer protective unit 35 itself can be made of stainless steel or high-density polyethylene, and the interior can be lined with rubber to improve sealing. The inert gas interlayer is connected to the inert gas supply and pressure compensation unit via pipelines. The inert gas supply and pressure compensation unit includes a high-pressure inert gas source 31, a pressure reducing valve 32, a seventh valve 33 (used as a make-up valve), and a pressure sensor installed within the inert gas interlayer. This unit is used to fill the interlayer with inert gas and maintain a dynamically stable pressure difference between it and the interior of the standard oil preparation storage unit 16.

[0051] The online hydrogen concentration monitoring unit includes two redundant hydrogen concentration monitoring probes 18, which extend into the standard oil storage unit 16 for real-time monitoring of dissolved hydrogen concentration in the oil. The repeatability deviation of the two probes is controlled within ±1.5%, ensuring the reliability of the monitoring data.

[0052] The control unit 42 is a programmable logic controller or an industrial control computer, which is electrically connected to the hydrogen concentration monitoring probe 18, the pressure control unit 19, the second temperature control unit 20, the hydrogen leakage monitoring probe 29, the magnetic stir bar 17, each valve, and the oil pump. The control unit 42 receives signals from each sensor and automatically adjusts the valve opening and closing, pump start and stop, stirring rate, and heating / cooling power according to a preset program to achieve intelligent closed-loop control of the entire configuration and storage process.

[0053] The device also includes a temperature control unit 43 to maintain the internal ambient temperature at 20±0.5℃. The temperature control unit 43 can utilize a high-precision semiconductor cooling / heating module. The device casing is made of light-shielding material to prevent light exposure from causing oil degradation.

[0054] To ensure safety, the device is equipped with a hydrogen leak detection probe 29, with a sensitivity of no less than 0.01 ppm and a wide measurement range, used to monitor for hydrogen leaks in the internal space of the device in real time. An emergency hydrogen venting unit 41 is installed on the top of the inner wall of the device, including a hydrogen venting pipeline and a hydrogen venting valve. When the hydrogen leak detection probe 29 detects that the ambient hydrogen concentration reaches the first threshold, the control unit 42 immediately triggers the emergency hydrogen venting unit 41 to open, forcibly venting the leaking hydrogen to a safe outdoor area; simultaneously, an audible and visual alarm is activated, and the non-explosion-proof power supply is automatically cut off. Once the hydrogen concentration drops below the second threshold and the system self-checks for leaks, the emergency hydrogen venting unit 41 automatically shuts down, and the system can attempt to return to normal operation.

[0055] The device also includes a second oil pump 23 and a sixth pipeline 25, which are used to transport oil samples that do not meet the concentration requirements or waste oil samples back to the degassing unit 1 for re-degassing treatment, thereby realizing the recycling of oil samples. Regarding waste gas treatment, the hydrogen-containing waste gas discharged from the degassing unit 1 can be introduced into the catalytic oxidation device through a pipeline, mixed with an appropriate amount of air, and converted into water vapor under the action of a palladium-based catalyst. After condensation, it is directly discharged.

[0056] Example 2

[0057] This embodiment describes in detail the specific steps for preparing and storing hydrogen standard oil samples using the apparatus described in Embodiment 1.

[0058] Step S1: Blank Oil Preparation: First, inject clean, new transformer oil into degassing unit 1 through the first pipeline 3. Close all exhaust valves and start the first temperature control unit 7 to heat the oil to 80℃. Simultaneously, turn on the vacuum pump to evacuate degassing unit 1 to a vacuum level of 25 Pa, and continue degassing under these conditions for 0.5 hours. During the degassing process, dissolved hydrogen, hydrocarbon gases, carbon monoxide, carbon dioxide, nitrogen, oxygen, etc., in the oil are gradually removed and discharged through the first exhaust valve 4 and the first exhaust pipeline 5. After degassing, the gas content in the oil can be less than 0.1%, obtaining a blank oil sample that meets the requirements.

[0059] Step S2: High-precision configuration: Open the fourth valve 14, start the first oil pump 10, and deliver the degassed blank oil to the standard oil configuration storage unit 16 via the oil temperature monitoring unit 13. When the oil volume reaches the preset volume, stop the oil delivery and close the fourth valve 14. Start the magnetic stirrer 17 and stir at a rate of 500 rpm. Open the seventh valve 33, and the high-purity hydrogen in the hydrogen storage tank 31, after being pressurized by the pressure reducing valve 32, is continuously bubbled into the oil at a rate of 50 mL / min through the microporous bubbler at the end of the seventh pipeline 34. The hydrogen concentration monitoring probe 18 monitors the hydrogen concentration in the oil in real time. When the relative deviation of the hydrogen concentration measured three times consecutively is within ±0.5%, and there is no obvious upward or downward trend, it is determined that gas-liquid dissolution equilibrium has been reached. At this time, close the hydrogen valve and the stirrer, record the equilibrium pressure and concentration value, and obtain the hydrogen standard oil sample.

[0060] Step S3: Dynamic Balance Storage: After configuration, the device automatically switches to storage mode. The control unit 42 uses the second temperature control unit 20 to precisely control the oil temperature in the standard oil configuration storage unit 16 at 20.0±1.0℃, with a temperature difference fluctuation ≤±2℃.

[0061] Simultaneously, the control unit 42 reads the pressure P_in inside the standard oil configuration storage unit 16 and the pressure P_out in the inert gas jacket, as measured by the pressure control unit 19. The control unit 42 opens the seventh valve 33 to fill the jacket with high-purity nitrogen gas until the pressure difference between P_out and P_in reaches and stabilizes at 15 kPa.

[0062] Subsequently, the control unit 42 continuously monitors the changes in P_in and P_out. When P_in decreases due to temperature fluctuations or trace infiltration, causing the pressure difference to deviate from 15 kPa beyond the allowable range, the control unit 42 automatically opens the gas supply valve to replenish gas to the interlayer until the pressure difference returns to 15 kPa; conversely, if P_out is too high, the pressure can be appropriately released through the second exhaust valve 26. This dynamic maintenance of the pressure difference effectively prevents hydrogen from permeating outward.

[0063] Step S4: Concentration Maintenance and Correction: During storage, the two hydrogen concentration monitoring probes 18 automatically measure the hydrogen concentration in the oil every 8 hours and send the data to the control unit 42.

[0064] The control unit 42 compares the measured concentration with the initial calibration value. If a slow downward trend in concentration is detected, the control unit 42 determines whether intervention is necessary based on the built-in concentration-pressure-temperature relationship model. If the model indicates that the concentration decrease is mainly caused by a pressure decrease, the compensation effect is enhanced by fine-tuning the inert gas jacket pressure. If signs of stratification or unevenness appear in the concentration, the control unit 42 will start the magnetic stirrer 17 at a low speed of 250 rpm for a short time to restore uniformity, and then stop stirring to avoid disrupting the balance with continuous stirring. Through the above closed-loop control, the long-term stability of the standard oil sample concentration is ensured.

[0065] Step S5: Safety Monitoring: Throughout the configuration and storage process, the hydrogen leak detection probe 29 operates continuously. Once the ambient hydrogen concentration reaches 1000 ppm, the control unit 42 immediately triggers the emergency hydrogen venting unit 41 to start forced ventilation, simultaneously shutting down all non-explosion-proof electrical equipment and triggering an alarm on the human-machine interface. After the hydrogen concentration drops below 50 ppm and the system confirms through self-test that there are no leaks, the emergency hydrogen venting unit 41 automatically shuts down, and the system can resume normal operation.

[0066] Step S6: Use of Standard Oil Samples: When standard oil samples are needed to calibrate the online oil chromatography monitoring device, open the ninth valve 39, start the third oil pump 38, and transport the standard oil sample stored in the standard oil preparation storage unit 16 to the monitoring device through the eighth pipeline 37 and the ninth pipeline 40. Since the entire delivery pipeline is a sealed design and uses a diaphragm valve, external gas contamination of the oil sample can be effectively prevented, ensuring that the concentration remains constant during delivery.

[0067] Example 3

[0068] To verify the technical effectiveness of this invention, a comparative experiment was conducted using the device of this invention against existing oil storage bags and ordinary oil storage tanks. Standard oil samples with an initial hydrogen concentration of approximately 100 μL / L were prepared and stored in the dark at 20±1℃. The hydrogen concentration in the oil was periodically sampled and tested, and the results are shown in the table below:

[0069]

[0070] Experimental data show that the device of the present invention reduces the hydrogen concentration decay rate to an extremely low level through the synergistic effect of SiO2 coating barrier, dynamic pressure compensation and intelligent balance maintenance, and achieves long-term stable preservation of hydrogen standard oil samples, with an effect far exceeding that of existing storage methods.

[0071] Example 4

[0072] For waste gas and waste oil treatment, the hydrogen-containing waste gas discharged from degassing unit 1 is introduced into a catalytic oxidation device through a pipeline. After mixing with an appropriate amount of air, under the action of a palladium-based catalyst, the hydrogen is catalytically oxidized into water vapor, and the hydrocarbon gases are oxidized into carbon dioxide and water. The treated gas can be directly discharged after condensation and dehydration. For standard oil samples that do not meet the concentration requirements or have expired, they can be transported back to degassing unit 1 through the sixth pipeline 25 and the second oil pump 23 for re-degassing treatment, realizing the recycling of blank oil, without generating waste oil, and meeting environmental protection requirements.

[0073] In the description of this invention, it should be noted that the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0074] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0075] In the several embodiments provided by this invention, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. The apparatus embodiments described above are merely illustrative. For example, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. Furthermore, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Additionally, the coupling or direct coupling or communication connection shown or discussed may be through some communication interfaces; the indirect coupling or communication connection between devices or units may be electrical, mechanical, or other forms.

[0076] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0077] In addition, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0078] Finally, it should be noted that the above-described embodiments are merely specific implementations of the present invention, used to illustrate the technical solutions of the present invention, and not to limit it. The scope of protection of the present invention is not limited thereto. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can still modify or easily conceive of changes to the technical solutions described in the foregoing embodiments within the technical scope disclosed in the present invention, or make equivalent substitutions for some of the technical features; and these modifications, changes, or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

[0079] Furthermore, although the operations of the method of the present invention are described in a specific order in the accompanying drawings, this does not require or imply that these operations must be performed in that specific order, or that all the operations shown must be performed to achieve the desired result. Additionally or alternatively, certain steps may be omitted, multiple steps may be combined into one step, and / or one step may be broken down into multiple steps.

Claims

1. An apparatus for preparing hydrogen standard oil samples for chromatographic calibration of transformer oil. Its features are, include: The standard oil preparation storage unit (16) includes an integral stainless steel tank with a dense silica coating on the inner wall of the tank for holding prepared hydrogen standard oil samples; The outer protective unit (35) is a sealed shell that tightly covers the outside of the standard oil configuration storage unit (16) and forms a closed inert gas interlayer between it and the outer wall of the standard oil configuration storage unit (16). An inert gas supply and pressure compensation unit is connected to the inert gas interlayer and is used to fill the interlayer with inert gas and maintain a dynamic and stable pressure difference between it and the interior of the standard oil configuration storage unit (16). The hydrogen concentration online monitoring unit includes at least two hydrogen concentration monitoring probes (18) that extend into the standard oil configuration storage unit (16) for real-time monitoring of dissolved hydrogen concentration in the oil; The control unit (42) is electrically connected to the hydrogen concentration online monitoring unit and the inert gas supply and pressure compensation unit, respectively. The control unit (42) is configured to automatically adjust the operation of the inert gas supply and pressure compensation unit according to the reading of the hydrogen concentration monitoring probe (18) and the preset concentration-pressure-temperature relationship model, so as to maintain the gas-liquid dissolution balance inside the standard oil configuration storage unit (16).

2. The apparatus according to claim 1, Its features are, The inert gas supply and pressure compensation unit includes a high-pressure inert gas source (31), a pressure reducing valve (32), a gas replenishment valve (33), and a pressure control unit (19) disposed in the inert gas interlayer; The control unit (42) receives the signal from the pressure control unit (19). When the pressure inside the standard oil configuration storage unit (16) drops or the temperature rises, causing the pressure difference to exceed the threshold, the control unit (42) controls the gas replenishment valve (33) to open and replenish the inert gas jacket until the pressure difference is restored to the set value.

3. The apparatus according to claim 2, Its features are, The control unit (42) is configured with a differential pressure threshold of 15 kPa. The condition for triggering pressure compensation is that the internal pressure of the standard oil storage unit (16) drops by more than 0.05 MPa or its internal temperature rises by more than 1 °C.

4. The apparatus according to claim 1, Its features are, The standard oil storage unit (16) is equipped with a magnetic stir bar (17). The control unit (42) is also used to automatically adjust the stirring rate of the magnetic stir bar (17) according to the real-time concentration and its changing trend measured by the hydrogen concentration monitoring probe (18) so as to promote the uniform distribution of hydrogen without disrupting the dissolution balance.

5. The apparatus according to claim 1, Its features are, It also includes an emergency hydrogen venting unit (41) connected to the control unit (42), the emergency hydrogen venting unit (41) including a hydrogen venting pipeline and a hydrogen venting valve disposed on the top of the inner wall of the device; The device is also equipped with a hydrogen leak detection probe (29) with a sensitivity of not less than 0.01 ppm. When the hydrogen leak detection probe (29) detects that the ambient hydrogen concentration reaches the first threshold, the control unit (42) triggers the emergency hydrogen venting unit (41) to start venting hydrogen. When the hydrogen concentration is detected to drop below the second threshold, the control unit (42) controls the emergency hydrogen venting unit (41) to shut down.

6. Preparation and storage method of hydrogen standard oil sample for transformer oil chromatographic calibration. The apparatus used for hydrogen standard oil sample for chromatographic calibration of transformer oil as described in any one of claims 1 to 5. Its features are, Includes the following steps: S1. Blank oil preparation: Inject blank insulating oil into the degassing unit (1) and degas continuously for 0.5 hours at 80℃ and 25 Pa vacuum, so that its gas content is less than 0.1%; S2, High-precision configuration: The blank oil processed in step S1 is transported to the standard oil configuration storage unit (16). High-vacuum bubbling method is used to bubble high-purity hydrogen gas with a purity of ≥99.999% into the oil at a constant rate. At the same time, the oil is stirred at a rate of 500 rpm until the relative deviation of the hydrogen concentration in the oil measured three times in a row is within ±0.5%. It is determined that the gas-liquid dissolution equilibrium has been reached and a hydrogen standard oil sample is obtained. S3. Dynamic Balance Storage: During storage, the control unit (42) maintains a dynamic and stable pressure difference between the inert gas jacket and the standard oil configuration storage unit (16) through the inert gas supply and pressure compensation unit according to a preset program; at the same time, the hydrogen concentration online monitoring unit periodically measures the hydrogen concentration in the oil and feeds the data back to the control unit (42). S4. Concentration Maintenance and Correction: If the control unit (42) finds that the hydrogen concentration tends to exceed the nominal value uncertainty range, it intervenes in the dissolution equilibrium by finely adjusting the pressure of the inert gas interlayer or starting the stirrer (17) to stir for a short time at a low rate according to the built-in concentration-pressure-temperature relationship model, so as to maintain the concentration stability.

7. The method according to claim 6, Its features are, The high-vacuum bubbling method described in step S2 has a hydrogen injection rate of 50 mL / min and a bubbler aperture of ≤20 μm.

8. The method according to claim 6, Its features are, The dynamic stable pressure difference is 15 kPa.

9. The method according to claim 6, Its features are, It also includes safety monitoring steps: the internal space of the device is monitored in real time by a hydrogen leak detection probe (29) with a sensitivity of 0.01ppm. When the hydrogen concentration is detected to reach 1000ppm, the emergency hydrogen discharge unit (41) is automatically activated to discharge the hydrogen and perform self-check and alarm of the leak point.

10. A calibration platform for an online monitoring system for transformer oil chromatography comprising the apparatus of any one of claims 1 to 5.

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