CN-121978257-A - Device, configuration and storage method of hydrogen standard oil sample for transformer oil chromatographic verification

CN121978257ACN 121978257 ACN121978257 ACN 121978257ACN-121978257-A

Abstract

The invention discloses a device, a configuration and a storage method of a hydrogen standard oil sample for transformer oil chromatographic verification, and relates to the technical field of power equipment state monitoring and fault diagnosis. The storage unit is a stainless steel tank with a compact silicon oxide coating plated on the inner wall, the outer layer protection unit is coated on the outer layer protection unit and forms an inert gas interlayer, 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 stirring rate according to data and actively maintains dissolution balance. The invention solves the technical problems of easy permeation and easy attenuation of the concentration of hydrogen through the synergistic effect of high barrier materials, dynamic pressure compensation and intelligent closed-loop control, and can be used for on-site verification of an on-line monitoring device of transformer oil chromatography.

Inventors

HU ZISHU
HAN DANDAN
LUO YUAN
LI GUOBIN
WANG TINGWANG
ZHANG LIANG
LI SHIHAO
ZHAO JU
ZHENG JINCHI
ZOU MENG

Assignees

国网新疆电力有限公司电力科学研究院

Dates

Publication Date: 20260505
Application Date: 20260316

Claims (10)

1. A device for verifying a hydrogen standard oil sample for transformer oil chromatography, It is characterized in that the method comprises the steps of, Comprising the following steps: The standard oil configuration storage unit (16) comprises a stainless steel integrated tank body, wherein a compact silicon oxide coating is plated on the inner wall of the tank body and is used for accommodating a configured hydrogen standard oil sample; the outer layer protection unit (35) is a sealed shell, is tightly covered outside the standard oil configuration storage unit (16), and forms a closed inert gas interlayer with the outer wall of the standard oil configuration storage unit (16); An inert gas supply and pressure compensation unit which is communicated with the inert gas interlayer and is used for filling inert gas into the interlayer and maintaining dynamic stable pressure difference between the inert gas and the inside of the standard oil configuration storage unit (16); The hydrogen concentration on-line monitoring unit comprises at least two hydrogen concentration monitoring probes (18) which extend into the oil standard configuration storage unit (16) and are used for monitoring the concentration of dissolved hydrogen in oil in real time; The control unit (42) is respectively and electrically connected with the hydrogen concentration on-line monitoring unit and the inert gas supply and pressure compensation unit, and the control unit (42) is configured to automatically adjust the actions of the inert gas supply and pressure compensation unit according to the reading of the hydrogen concentration monitoring probe (18) and a preset concentration-pressure-temperature relation model so as to maintain the gas-liquid dissolution balance in the standard oil configuration storage unit (16).
2. The device according to claim 1, It is characterized in that the method comprises the steps of, The inert gas supply and pressure compensation unit comprises a high-pressure inert gas source (31), a pressure reducing valve (32), a gas supplementing valve (33) and a pressure control unit (19) arranged in the inert gas interlayer; The control unit (42) receives the signal of the pressure control unit (19), and when the pressure difference change exceeds a threshold value due to the pressure drop or the temperature rise in the standard oil configuration storage unit (16), the air supplementing valve (33) is controlled to be opened to supplement air to the inert gas interlayer until the pressure difference is restored to a set value.
3. The device according to claim 2, It is characterized in that the method comprises the steps of, The pressure difference threshold value configured by the control unit (42) is 15kPa, and the condition for triggering pressure compensation is that the internal pressure of the standard oil configuration storage unit (16) falls by more than 0.05MPa or the internal temperature thereof rises by more than 1 ℃.
4. The device according to claim 1, It is characterized in that the method comprises the steps of, The standard oil configuration storage unit (16) is internally provided with a magnetic stirrer (17), and the control unit (42) is also used for automatically adjusting the stirring rate of the magnetic stirrer (17) according to the real-time concentration and the change trend thereof measured by the hydrogen concentration monitoring probe (18) so as to promote the uniform distribution of hydrogen on the premise of not damaging the dissolution balance.
5. The device according to claim 1, It is characterized in that the method comprises the steps of, The emergency hydrogen discharging unit (41) is connected with the control unit (42), and the emergency hydrogen discharging unit (41) comprises a hydrogen discharging pipeline and a hydrogen discharging valve which are arranged at the top of the inner wall of the device; The hydrogen leakage monitoring probe (29) is further arranged in the device, the sensitivity of the hydrogen leakage monitoring probe is not lower than 0.01ppm, when the hydrogen leakage monitoring probe (29) detects that the concentration of the environmental hydrogen reaches a first threshold value, the control unit (42) triggers the emergency hydrogen discharging unit (41) to open hydrogen discharging, and when the concentration of the hydrogen is detected to be lower than a second threshold value, the control unit (42) controls the emergency hydrogen discharging unit (41) to close.
6. A hydrogen standard oil sample configuration and storage method for transformer oil chromatographic verification, A device for using the hydrogen standard oil sample for transformer oil chromatographic verification according to any one of claim 1 to 5, It is characterized in that the method comprises the steps of, The method comprises the following steps: s1, preparing blank oil, namely injecting the blank insulating oil into a degassing unit (1), and continuously degassing for 0.5 hour under the conditions of 80 ℃ and 25 Pa ℃ of vacuum degree to ensure that the gas content is lower than 0.1%; S2, high-precision configuration, namely conveying the blank oil processed in the step S1 to a standard oil configuration storage unit (16), adopting a high-vacuum bubbling method, bubbling high-purity hydrogen with the purity of more than or equal to 99.999% into the oil at a constant rate, and stirring at a rate of 500rpm until the relative deviation of the hydrogen concentration in the oil measured for three times continuously is within +/-0.5%, and judging that the gas-liquid dissolution balance is achieved to obtain a hydrogen standard oil sample; S3, dynamic balance storage, wherein during the storage period, a control unit (42) maintains dynamic stable pressure difference between the inert gas interlayer and the inside of the standard oil configuration storage unit (16) through the inert gas supply and pressure compensation unit according to a preset program, and meanwhile, the hydrogen concentration on-line monitoring unit periodically measures the hydrogen concentration in oil and feeds data back to the control unit (42); And S4, concentration maintenance and correction, namely if the control unit (42) analyzes that the hydrogen concentration has a trend exceeding the uncertainty range of the nominal value, according to a built-in concentration-pressure-temperature relation model, performing short-time stirring at a lower speed by fine-adjusting the pressure of the inert gas interlayer or starting the stirrer (17), and performing intervention on dissolution balance to maintain concentration stability.
7. The method according to claim 6, wherein the method comprises, It is characterized in that the method comprises the steps of, The high vacuum bubbling method in the step S2 has the hydrogen injection rate of 50 mL/min and the pore diameter of the bubbler of less than or equal to 20 mu m.
8. The method according to claim 6, wherein the method comprises, It is characterized in that the method comprises the steps of, The dynamic steady pressure difference was 15kPa.
9. The method according to claim 6, wherein the method comprises, It is characterized in that the method comprises the steps of, The method also comprises a safety monitoring step of monitoring the internal space of the device in real time through a hydrogen leakage monitoring probe (29) with the sensitivity of 0.01ppm, automatically starting an emergency hydrogen discharging unit (41) to discharge hydrogen when the concentration of the hydrogen is detected to reach 1000ppm, and performing self-checking and alarming on leakage points.
10. A transformer oil chromatography on-line monitoring system calibration platform comprising the apparatus of any one of claims 1 to 5.

Description

Device, configuration and storage method of hydrogen standard oil sample for transformer oil chromatographic verification Technical Field The invention relates to the technical field of power equipment state monitoring and fault diagnosis, in particular to a device, a configuration and a storage method of a hydrogen standard oil sample for transformer oil chromatographic verification, and a long-acting stable storage device and a method of the hydrogen standard oil sample for transformer oil chromatographic verification. Background Analysis of Dissolved Gas (DGA) in transformer oil is a key technology for monitoring the operation state of oil immersed high-voltage electrical equipment such as power transformers and diagnosing internal latent faults. Hydrogen (H2) is one of the characteristic gases dissolved in oil, and its concentration variation is of great significance for early diagnosis of discharge faults (e.g. partial discharge, arc discharge) and some overheat faults. To ensure accuracy and comparability of chromatographic data, the online oil chromatography monitoring device must be periodically calibrated and performance checked using a known and stable standard oil sample of hydrogen. The standard oil sample is prepared by adopting a dynamic balance method (after standard gas is injected into a blank oil sample and uniformly stirred) in the preparation of the insulating oil single-component (H2) standard oil sample. The formulated hydrogen standard oil sample is extremely sensitive to storage conditions. The hydrogen has small molecular weight and strong permeability, and is easy to leak and escape. Often, storage containers (e.g., disposable oil bags, glass syringes, common reagent bottles, metal cans) often have insufficient sealing properties, and it is difficult to maintain stable hydrogen concentration in the oil for a long period of time. The solubility of hydrogen in oil is greatly affected by temperature, and if the storage environment temperature fluctuates, even if the seal is perfect, the concentration will change, resulting in a drift in the concentration of standard oil samples during storage. The oil-marking configuration process presents a risk of hydrogen leakage, exposure to air (oxygen) leading to oxidation or explosion of the oil sample. Storage devices tend to be simple containers, lacking built-in pressure/temperature monitoring, safety venting, and interface designs that facilitate non-destructive sampling (e.g., by septum penetration). The whole process is complicated from configuration, transfer and storage to sampling, and is easy to introduce human errors and secondary pollution (such as air mixing), and the reliability and the use convenience of the standard oil sample are affected. After the oil standard preparation is completed, the oil standard is stored after the oil standard preparation is required to be fixed (after off-line sampling, quantitative analysis is performed by a chromatograph). During storage, there is a lack of online or convenient non-destructive means to verify the hydrogen concentration in the oil in real time or periodically. Before use, whether the current concentration of the standard oil sample is still in the uncertainty range of the nominal value cannot be confirmed, the nominal value needs to be sampled again, and the risk of miscalibration exists. Therefore, a method and a device which can rapidly and accurately prepare a hydrogen standard oil sample with specific concentration, can effectively maintain concentration stability in a long-term storage process, and simultaneously have high safety, operation convenience and continuous constant value are needed, so that the quality and effect of the verification of an online monitoring device for transformer oil chromatography are improved, and the reliability of state evaluation and fault diagnosis of power equipment is ensured. Disclosure of Invention In view of the above or the technical problems in the prior art that the concentration of the standard oil is easy to be attenuated and difficult to stably preserve for a long time due to small hydrogen molecules and easy permeation, the device, the configuration and the storage method of the hydrogen standard oil sample for transformer oil chromatographic verification are provided. In order to solve the technical problems, the invention provides the following technical scheme: The invention provides a device, a configuration and a storage method of a hydrogen standard oil sample for transformer oil chromatographic verification, which comprises a standard oil configuration storage unit, a storage unit and a storage unit, wherein the standard oil configuration storage unit comprises a stainless steel integrated tank body, and a compact silicon oxide coating is plated on the inner wall of the tank body and is used for accommodating the configured hydrogen standard oil sample; The outer layer protection unit is a sealed shell and is tightly covered o