Transformer oil chromatographic monitoring device

Abstract

This disclosure relates to the field of power equipment monitoring technology, and provides a transformer oil chromatography monitoring device, comprising: an oil sample acquisition module, the oil sample acquisition module including at least a heated oil extraction pipe, the heated oil extraction pipe being used to heat the oil sample extracted from the transformer in a low-temperature environment; an oil-gas separation module, used to receive the oil sample and precipitate the mixed gas to be tested from the oil sample at a first target temperature; a first temperature control module, used to maintain the temperature of the oil-gas separation module at the first target temperature; a chromatography analysis module, used to separate and detect the mixed gas to be tested at a second target temperature, and generate an electrical signal corresponding to the gas concentration; a second temperature control module, used to maintain the temperature of the chromatography analysis module at the second target temperature; and a control module, used to control the operating power of the first and second temperature control modules, and also used to receive the electrical signal and determine the gas concentration data based on the electrical signal.

Description

Technical Field

[0001] This disclosure relates to the field of power equipment monitoring technology, and more specifically, to a transformer oil chromatography monitoring device. Background Technology

[0002] In the field of power equipment condition monitoring, although transformer oil chromatography online monitoring technology is relatively mature, many key problems have still been exposed in its practical application in high-altitude and cold regions.

[0003] Existing equipment generally suffers from insufficient environmental adaptability design. Core components such as chromatographic columns experience a sharp drop in separation efficiency at low temperatures. Gas pumps and oil pumps are prone to jamming and damage due to increased lubricant viscosity or embrittlement of seals. Frequent malfunctions, such as oil circuit freezing and communication interruptions, severely affect the stability and reliability of monitoring. At the same time, traditional equipment relies on expensive bottled high-purity nitrogen as a carrier gas, and the high degree of specialization of spare parts and reliance on original equipment manufacturer (OEM) technology for maintenance result in high maintenance costs throughout the entire life cycle.

[0004] Conventional solutions in the industry are mostly reactive remedial measures such as post-fault repair or the addition of external insulation facilities. These fail to address the low-temperature compatibility issue at the system level and cannot meet the core requirements of high-altitude and cold regions for stable operation of equipment around the clock, effective data transmission, and low-cost operation and maintenance. Therefore, there is an urgent need to develop an online transformer oil chromatography monitoring device that is systematically optimized for low-temperature environments. Summary of the Invention

[0005] The purpose of this disclosure is to provide a transformer oil chromatography monitoring device to solve the above-mentioned technical problems.

[0006] To achieve the above objectives, this disclosure provides a transformer oil chromatographic monitoring device, comprising: An oil sample collection module, comprising at least a heated oil sampling pipe, wherein the heated oil sampling pipe is used to heat the oil sample extracted from the transformer in a low-temperature environment; An oil-gas separation module is used to receive oil samples and separate the mixed gas to be tested from the oil samples at a first target temperature; The first temperature control module is thermally coupled to the oil-gas separation module and is used to maintain the temperature of the oil-gas separation module at the first target temperature. The chromatographic analysis module is used to separate and detect the gas mixture to be tested at a second target temperature and generate an electrical signal corresponding to the gas concentration. The second temperature control module is thermally coupled to the chromatography analysis module and is used to maintain the temperature of the chromatography analysis module at the second target temperature. The control module is used to control the operating power of the first temperature control module and the second temperature control module, and is also used to receive the electrical signal and determine the gas concentration data based on the electrical signal.

[0007] Optionally, the transformer oil chromatography monitoring device further includes: The carrier gas generation module is connected to the carrier gas inlet of the chromatographic analysis module and is used to prepare ambient air as carrier gas and transmit it to the chromatographic analysis module. The carrier gas is used to propel the mixed gas to be tested through the chromatographic column.

[0008] Optionally, the carrier gas generation module includes an air compressor and a multi-stage purifier, wherein the air inlet of the multi-stage purifier is connected to the air outlet of the air compressor; The air compressor is used to draw in ambient air and generate compressed air; The multi-stage purifier is used to purify the compressed air in order to output carrier gas.

[0009] Optionally, the multi-stage purifier includes at least a water removal module, a hydrocarbon removal module, and a carbon dioxide removal module.

[0010] Optionally, the transformer oil chromatography monitoring device further includes: The evacuation module is connected to the flow path of the oil sample collection module and is used to evacuate residual liquid in the flow path.

[0011] Optionally, the venting module further includes a venting valve, which is located at the output end of the oil sample acquisition module and connected to the control module; The control module is also used to control the vent valve to open during sampling intervals or before shutdown, so as to discharge residual liquid in the flow path.

[0012] Optionally, the heat tracing oil pipe includes an oil pipe body, an electric heat tracing cable laid along the axial direction of the oil pipe body, and an outermost heat insulation layer, wherein the electric heat tracing cable is connected to the control module.

[0013] Optionally, the oil sample acquisition module further includes: A low-temperature flexible pipeline is connected between the heated oil extraction pipeline and the oil-gas separation module to achieve a flexible connection of the oil circuit in a low-temperature environment.

[0014] Optionally, the control module is also used to determine whether the transformer has a fault based on the concentration data, and to generate a fault diagnosis conclusion.

[0015] Optionally, the transformer oil chromatography monitoring device further includes: A communication module, which is connected to the control module, is used to send the concentration data to the backend server.

[0016] Through the above technical solution, the first and second temperature control modules independently and precisely control the temperature of the oil-gas separation module and the chromatographic analysis module, respectively, ensuring that both are always at their optimal operating temperatures. Combined with the heated oil sampling pipe, this prevents oil samples from freezing or increasing in viscosity at the source, effectively solving frequent malfunctions such as a sudden drop in column separation efficiency, oil circuit freezing, and pump jamming at low temperatures, avoiding the passive remedial shortcomings of traditional post-treatment maintenance or external insulation. Secondly, the control module not only precisely adjusts the power of each temperature control module to achieve energy-saving temperature control, but also directly outputs gas concentration data based on the electrical signals generated by the chromatographic analysis module, ensuring real-time and effective data transmission and processing. This achieves comprehensive adaptation to low-temperature environments, meeting the core needs of power equipment in cold regions for all-weather stable monitoring and low-cost operation and maintenance, and significantly improving operational stability in cold environments.

[0017] Other features and advantages of this disclosure will be described in detail in the following detailed description section. Attached Figure Description

[0018] The accompanying drawings are provided to further illustrate the present disclosure and form part of the specification. They are used together with the following detailed description to explain the present disclosure, but do not constitute a limitation thereof. In the drawings: Figure 1 This is a block diagram illustrating a transformer oil chromatography monitoring device according to an exemplary embodiment.

[0019] Explanation of reference numerals in the attached figures 100-Transformer oil chromatography monitoring device, 10-Oil sample acquisition module, 20-Oil-gas separation module, 30-First temperature control module, 40-Chromatographic analysis module, 50-Second temperature control module, 60-Control module. Detailed Implementation

[0020] The specific embodiments of this disclosure will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit this disclosure.

[0021] In the following description, the words "first" and "second" are used only to distinguish the purpose of the description and should not be interpreted as indicating or implying relative importance or order.

[0022] In the field of power equipment condition monitoring, although transformer oil chromatography online monitoring technology is relatively mature, it still exposes many key problems in practical applications in high-altitude and cold regions. Transformer oil chromatography online monitoring technology generally adopts gas chromatography, which determines the operating status of power equipment by detecting characteristic gases dissolved in transformer oil (such as hydrogen (H2), carbon monoxide (CO), carbon dioxide (CO2), methane (CH4), ethane (C2H6), ethylene (C2H4), acetylene (C2H2), etc.). Its typical workflow is as follows: First, an oil sample is drawn from the transformer by an oil pump; second, the oil sample is sent to the oil-gas separation unit, where the fault characteristic gas dissolved in the oil is released through physical or mechanical means; third, the separated gas to be tested is delivered to the six-way valve and quantitative tube assembly by a gas pump to complete the quantitative injection of the gas sample; subsequently, the mixed gas enters the chromatographic column, and separation is achieved by utilizing the difference in the partition coefficients of different gas components between the stationary and mobile phases; finally, the concentration of each component gas is detected by a thermal conductivity detector (TCD) or a flame ionization detector (FID), and converted into corresponding electrical signal outputs.

[0023] Existing equipment generally suffers from insufficient environmental adaptability design. Core components such as chromatographic columns experience a sharp drop in separation efficiency at low temperatures. Gas pumps and oil pumps are prone to jamming and damage due to increased lubricant viscosity or embrittlement of seals. Frequent malfunctions, such as oil circuit freezing and communication interruptions, severely affect the stability and reliability of monitoring. At the same time, traditional equipment relies on expensive bottled high-purity nitrogen as a carrier gas, and the high degree of specialization of spare parts and reliance on original equipment manufacturer (OEM) technology for maintenance result in high maintenance costs throughout the entire life cycle.

[0024] Conventional solutions in the industry are mostly reactive remedial measures such as post-fault repair or the addition of external insulation facilities. These solutions fail to address the low-temperature compatibility issue at the system level and cannot meet the core needs of high-altitude and cold regions for stable all-weather operation of equipment, effective data transmission, and low-cost operation and maintenance.

[0025] The inventors have discovered that existing devices have at least the following drawbacks: Firstly, it has extremely poor adaptability to low-temperature environments and cannot meet the needs of cold regions. In frigid areas, it is prone to malfunctions such as a sharp drop in column separation efficiency, gas pump and oil pump jamming, oil circuit freezing and blockage, and embrittlement and cracking of seals, or even complete paralysis.

[0026] The specific reason is as follows: Design limitations: Existing equipment is designed for general environments, has a narrow temperature adaptability range, and is not specifically designed for extreme low temperatures in high-altitude and cold regions; The core components are not customized: the stationary phase of the chromatographic column, the lubricating oil of the gas pump, the piping materials, the seals, etc. are all commercial general models, and their physicochemical properties (such as flexibility, flowability, separation stability) will deteriorate sharply at low temperatures; Inefficient temperature control methods: Relying solely on passive insulation methods such as external insulation cotton and heat tracing tape cannot achieve precise constant temperature control for core units such as oil and gas separation and chromatographic analysis, and is difficult to withstand the impact of extreme low temperatures.

[0027] Secondly, the system suffers from low reliability and a persistently high failure rate. After long-term operation, it frequently experiences core failures such as column aging, gas pump failure, oil circuit damage, and abnormal system board voltage, resulting in a short mean time between failures (MTBF).

[0028] The specific reason is as follows: Imbalance in design priorities: Simply pursuing testing accuracy in a laboratory environment while neglecting the requirements for long-term stability of equipment in harsh field environments (low temperature, electromagnetic interference, etc.) results in excellent performance in the laboratory but poor performance in field environments. Insufficient component compatibility: The collaborative working ability of each component in complex environments was not fully considered during system integration. Although some components meet the standards individually, the overall reliability decreases when they are combined. Lack of preventative design: No proactive protection logic was set up for common faults at low temperatures (such as freezing blockage and component hardening), relying solely on post-failure maintenance, which further amplified the impact of the faults.

[0029] Thirdly, maintenance costs are high and the convenience of operation and maintenance is poor. The total life cycle maintenance cost is high, the burden on users is heavy, and the fault repair cycle is long.

[0030] The specific reason is as follows: Carrier gas relies on external supply: bottled high-purity nitrogen is commonly used, which has high procurement costs and is inconvenient to transport and replace in remote and cold regions, posing a risk of supply interruption. Highly specialized spare parts: Core spare parts are mostly custom-made by the original manufacturer, which are expensive and have long procurement cycles. They rely on the original manufacturer's technicians for repairs, which further increases labor costs. Passive maintenance mode: It adopts a fault-based repair mode, lacks predictive maintenance design, and sudden failures can easily lead to long-term equipment downtime and significant indirect losses.

[0031] Fourthly, unstable data transmission hinders effective early warning. Communication interruptions frequently occur between field devices and the backend system, preventing the real-time and accurate uploading of monitoring data and thus compromising the core early warning function of online monitoring.

[0032] The specific reason is as follows: The communication design is not adapted to the industrial environment: it uses conventional communication modules and has not been specifically optimized for harsh conditions such as strong electromagnetic interference and ground potential difference in substations. The impact of low temperatures on communication stability has been overlooked: the weakening effect of low temperatures on communication interfaces and line performance has not been considered, and anti-interference measures such as electrical isolation are lacking, making data transmission susceptible to interruptions due to environmental factors.

[0033] Therefore, there is an urgent need to develop an online transformer oil chromatography monitoring device that is systematically optimized for low-temperature environments to solve the following problems: 1. Solve the problem of adaptability to cold environments: To address the issue that existing equipment is not designed to adapt to low-temperature environments, develop a device that can operate stably and reliably in low-temperature environments, avoiding problems such as column failure, gas pump and oil pump jamming, oil circuit freezing and blockage, and embrittlement of seals caused by low temperatures.

[0034] 2. Improve system reliability and reduce failure rate: Solve the problems of frequent failures of core components such as column aging, gas pump malfunction, oil circuit damage and abnormal output voltage of system board that occurred after long-term operation of the original unit. Through technological innovation and system optimization, extend the mean time between failures of the unit.

[0035] 3. Establish data links for effective early warning: Solve the problem of communication failure between field devices and the back-end system, ensuring that monitoring data can be transmitted to the back-end system in real time and accurately, and truly give full play to the core function of online monitoring devices in timely detection of main transformer operation abnormalities and preventing the escalation of faults.

[0036] 4. Reduce total lifecycle maintenance costs: Change the high-cost maintenance model of repairing after failure and purchasing spare parts urgently. By designing a stable and durable system and using readily available carrier gas, significantly reduce spare parts, consumables and labor maintenance costs.

[0037] To address the aforementioned issues, the first and second temperature control modules independently and precisely control the oil-gas separation module 20 and the chromatographic analysis module, respectively, ensuring that both remain at their optimal operating temperatures. Combined with a heated oil sampling pipe, this prevents oil sample freezing or viscosity increases at the source, effectively resolving frequent malfunctions such as sudden drops in column separation efficiency, oil circuit freezing, and pump jamming at low temperatures, avoiding the passive remedial shortcomings of traditional post-treatment repairs or external insulation. Furthermore, the control module not only precisely adjusts the power of each temperature control module for energy-saving temperature control but also directly outputs gas concentration data based on the electrical signals generated by the chromatographic analysis module, ensuring real-time and effective data transmission and processing. This achieves comprehensive adaptation to low-temperature environments, meeting the core requirements of power equipment in cold regions for all-weather stable monitoring and low-cost operation and maintenance, significantly improving operational stability in cold environments.

[0038] Figure 1 This is a block diagram illustrating a transformer oil chromatography monitoring device 100 according to an exemplary embodiment. Please refer to [link / reference]. Figure 1The transformer oil chromatography monitoring device 100 may include an oil sample acquisition module 10, an oil-gas separation module 20, a first temperature control module 30, a chromatography analysis module 40, a second temperature control module 50, and a control module 60.

[0039] The oil sample collection module 10 includes at least a heated oil sampling pipe, which is used to heat the oil sample extracted from the transformer in a low-temperature environment.

[0040] The oil sample collection module 10 is used to extract oil samples from the transformer and transport the extracted oil samples to the oil-gas separation module 20.

[0041] The oil sample collection module 10 may include an oil pump, which provides the power to extract the oil sample. Considering the safety requirements of cold environments and power supply locations, the oil pump can be an explosion-proof type filled with low-temperature lubricating grease. The low-temperature lubricating grease maintains good lubrication performance even in extreme environments ranging from -40°C to -60°C, effectively reducing frictional resistance during low-temperature start-up and operation of the oil pump, and preventing jamming or damage due to increased lubricating oil viscosity. The explosion-proof design ensures safe operation of the oil pump around transformers containing flammable gases, avoiding accidents caused by electrical sparks.

[0042] To address the issue of decreased fluidity or even freezing of oil samples at low temperatures, the oil sample acquisition module 10 may include at least a heated oil sampling pipe. This heated oil sampling pipe is used to heat the oil sample extracted from the transformer at low temperatures.

[0043] Specifically, the heated oil sampling pipe can have a built-in heating element or use a heating tape structure. When the ambient temperature is lower than a preset threshold, the oil sample flowing through the pipe is actively heated to prevent the oil sample from increasing in viscosity or freezing due to low temperature, and to ensure that the oil sample can smoothly enter the subsequent oil-gas separation module 20.

[0044] The oil-gas separation module 20 is used to receive an oil sample and separate the mixed gas to be tested from the oil sample at a first target temperature.

[0045] The oil-gas separation module 20 is connected to the oil sample acquisition module 10 and is used to receive the oil sample from the oil sample acquisition module 10 and separate the mixed gas to be tested from the oil sample at a first target temperature. The first target temperature can be preset to a suitable range (e.g., 40℃~60℃) according to the characteristics of the oil sample and the separation efficiency.

[0046] For example, the oil-gas separation module 20 employs the principle of membrane degassing, with an internal degassing chamber containing a permeable membrane. When the oil sample flows through one side of the membrane, the characteristic gases dissolved in the oil (such as H2, CO, CH4, C2H4, C2H2, etc.) permeate through the membrane to the other side driven by the concentration gradient, thus achieving rapid separation of the gas and liquid phases and directly obtaining the target gas mixture. To prevent a decrease in oil-gas separation efficiency at low temperatures, the entire degassing chamber is placed in a temperature-controlled chamber to maintain a first target temperature. At the first target temperature, the oil sample viscosity decreases and the gas diffusion rate increases, ensuring that the characteristic gases can fully and stably permeate through the membrane and precipitate. The separated oil sample can be returned to the transformer via a return oil pipeline or discharged into a waste oil collection device.

[0047] The first temperature control module 30 is thermally coupled to the oil-gas separation module 20 and is used to maintain the temperature of the oil-gas separation module 20 at the first target temperature.

[0048] Thermal coupling can refer to a direct or indirect heat transfer path between two components, enabling the effective transfer of heat from one component to the other, thereby achieving coordinated temperature control.

[0049] The first temperature control module 30 can be thermally coupled to the oil-gas separation module 20 (e.g., by attaching with thermally conductive silicone grease, embedding a heating rod, or wrapping with a heating plate). The first temperature control module 30 is used to maintain the temperature of the oil-gas separation module 20 at a first target temperature.

[0050] The first temperature control module 30 may include a temperature sensor (such as a platinum resistance thermometer PT100) and a heating actuator (such as a PTC heater or resistance wire), and achieves precise constant temperature through closed-loop control.

[0051] The chromatographic analysis module 40 is used to separate and detect the gas mixture to be tested at the second target temperature and generate an electrical signal corresponding to the gas concentration.

[0052] The second target temperature can be higher than the first target temperature (e.g., 70℃~90℃) to ensure that the chromatographic column has stable separation efficiency. The chromatographic analysis module 40 may include a chromatographic column and a detector (such as a thermal conductivity detector (TCD) or a flame ionization detector (FID)). The chromatographic column is used to separate the components of the gas mixture to be tested, and the detector outputs an analog electrical signal related to the gas concentration.

[0053] Because different gas molecules have different adsorption / dissolution capacities on the stationary phase of the chromatographic column, they are separated and elute from the column sequentially over time. The TCD converts the gas concentration into an electrical signal by detecting changes in the gas's thermal conductivity. This electrical signal is acquired, amplified, and digitized by the control module 60.

[0054] The second temperature control module 50 is thermally coupled to the chromatography analysis module 40 and is used to maintain the temperature of the chromatography analysis module 40 at the second target temperature.

[0055] The second temperature control module 50 may also include an independent temperature sensor and heating execution unit to achieve high-precision independent temperature control of the chromatographic analysis area.

[0056] The control module 60 is used to control the operating power of the first temperature control module 30 and the second temperature control module 50, and also to receive electrical signals and determine the gas concentration data based on the electrical signals.

[0057] The control module 60 is electrically connected to the first temperature control module 30, the second temperature control module 50, and the chromatographic analysis module 40, respectively. The control module 60 can be used to control the operating power of the first temperature control module 30 and the second temperature control module 50, for example, through PWM (Pulse Width Modulation) or PID (Proportional-Integral-Derivative) regulation, to achieve precise closed-loop control of the temperature of each module.

[0058] The control module 60 is also used to receive the electrical signal output by the chromatography analysis module 40 and convert the electrical signal into the concentration data of the corresponding gas according to the preset correspondence (e.g., calibration curve or algorithm).

[0059] For example, the control module 60 identifies, integrates, and calculates the concentration of the electrical signal. The working principle of the transformer oil chromatography monitoring device 100 is as follows: First, an oil sample is drawn from the transformer via a heated oil sampling pipe in the oil sample acquisition module 10. The sample is actively heated at a low temperature to prevent freezing or excessive viscosity. Next, the oil sample enters the oil-gas separation module 20. Under the maintenance of the first temperature control module 30, the oil-gas separation module 20 is stably controlled at a first target temperature, allowing the characteristic gases dissolved in the oil sample to fully and stably precipitate, forming the analyte mixture. Then, the analyte mixture is sent to the chromatography analysis module 40. At this time, the second temperature control module 50 stably controls the chromatography analysis module 40 at a second target temperature, ensuring good separation performance of the chromatographic column. The mixed gas is separated sequentially in the chromatographic column according to the differences in retention time of each component and enters the detector sequentially. The detector generates an electrical signal corresponding to the concentration of each gas. Finally, the control module 60 receives this electrical signal and processes the data according to an internally preset concentration-voltage calibration curve or algorithm to calculate the precise concentration data of each characteristic gas. Meanwhile, the control module 60 dynamically adjusts the heating power of the first temperature control module 30 and the second temperature control module 50 based on the current temperature feedback signal in order to maintain the long-term stability of the two target temperatures.

[0060] The first temperature control module 30 and the second temperature control module 50 independently and precisely control the temperature of the oil-gas separation module 20 and the chromatographic analysis module 40, respectively, ensuring that both are always at their optimal operating temperatures. Combined with the heated oil sampling pipe, this prevents oil samples from freezing or increasing in viscosity at the source, effectively solving frequent malfunctions such as a sudden drop in column separation efficiency, oil circuit freezing, and pump jamming at low temperatures, avoiding the passive remedial shortcomings of traditional post-treatment repairs or external insulation. Secondly, the control module 60 not only precisely adjusts the power of each temperature control module to achieve energy-saving temperature control, but also directly outputs gas concentration data based on the electrical signals generated by the chromatographic analysis module 40, ensuring real-time and effective data transmission and processing. This achieves comprehensive adaptation to low-temperature environments, meeting the core needs of power equipment in cold regions for all-weather stable monitoring and low-cost operation and maintenance, and significantly improving operational stability in cold environments.

[0061] In one possible implementation, the transformer oil chromatography monitoring device 100 may further include: The carrier gas generation module is connected to the carrier gas inlet of the chromatography analysis module 40 and is used to prepare ambient air as carrier gas and transfer it to the chromatography analysis module 40. The carrier gas is used to drive the mixed gas to be tested through the chromatography column.

[0062] The carrier gas generation module may include an air filter, an air pump, a drying unit, and a gas buffer tank. Ambient air is first filtered to remove dust and particulate matter, then pumped into the drying unit where moisture is removed through physical or chemical methods (such as molecular sieve adsorption, condensation dehumidification, etc.) to obtain dry, clean air as the carrier gas. This carrier gas is temporarily stored in the gas buffer tank to stabilize the gas flow pressure before being sent to the chromatographic analysis module 40 through the carrier gas inlet. During chromatographic analysis, the carrier gas continuously flows through the chromatographic column, carrying the components of the analyte mixture along the column, thereby driving the components to repeatedly distribute between the stationary and mobile phases, achieving separation.

[0063] Using the above-mentioned carrier gas generation module, there is no need to connect to expensive bottled high-purity nitrogen or frequently change gas cylinders. Carrier gas can be generated directly on-site using the surrounding ambient air, which significantly reduces the cost of consumables and the complexity of operation and maintenance. It is especially suitable for substations in remote, cold regions with inconvenient transportation.

[0064] In one possible implementation, the carrier gas generation module may include an air compressor and a multi-stage purifier, with the air inlet of the multi-stage purifier connected to the air outlet of the air compressor.

[0065] Air compressors are used to draw in ambient air and generate compressed air; Multi-stage purifiers are used to purify compressed air for output as carrier air.

[0066] An air compressor has an air inlet and an air outlet. Its air inlet is connected to the ambient air and is used to draw in ambient air and compress it to generate compressed air with a certain pressure.

[0067] The multi-stage purifier has an inlet and an outlet. The inlet is connected to the outlet of the air compressor, and the outlet is connected to the carrier gas inlet of the chromatographic analysis module 40. The multi-stage purifier receives compressed air from the air compressor and purifies it to remove impurities, moisture, and interfering gas components, thereby outputting high-purity carrier gas that meets the requirements of chromatographic analysis.

[0068] With the above configuration, there is no need to rely on external bottled high-purity nitrogen. The carrier gas can be prepared directly on-site using ambient air, which significantly reduces the cost of carrier gas use and the complexity of operation and maintenance. It is especially suitable for high-altitude and remote areas where there is a lack of gas supply or where it is difficult to transport gas cylinders.

[0069] Furthermore, the oil-gas separation module 20 may also include an injection and separation module, which is located between the degassing chamber and the chromatographic analysis module 40. This module is used to quantitatively sample the gas mixture to be tested and switch it to the chromatographic analysis flow path. Specifically, the injection and separation module includes a solenoid six-way valve and a quantitative tube. The solenoid six-way valve has multiple ports, which are respectively connected to the gas outlet of the degassing chamber, the carrier gas inlet, the quantitative tube, and the injection port of the chromatographic analysis module 40. The quantitative tube is used to store a certain volume of the gas mixture to be tested from the degassing chamber, realizing the quantitative collection of gas samples. During operation, the solenoid six-way valve is first in the "sampling position," and the gas mixture to be tested precipitated in the degassing chamber flows through the quantitative tube, filling the quantitative tube with the gas mixture to be tested. Subsequently, the solenoid six-way valve switches to the "injection position," and the carrier gas provided by the carrier gas generation module flows through the quantitative tube, purging the gas mixture to be tested in the quantitative tube into the chromatographic analysis module 40, completing the injection operation. The electromagnetic six-way valve is electrically connected to the control module 60, which controls the timing and sequence of its valve position switching.

[0070] In one possible implementation, the multi-stage purifier may include at least a water removal module, a hydrocarbon removal module, and a carbon dioxide removal module.

[0071] A multi-stage air purifier may include a water removal module, a hydrocarbon removal module, and a carbon dioxide removal module arranged sequentially along the airflow direction. The water removal module may use molecular sieves or desiccants to remove moisture; the hydrocarbon removal module may use activated carbon or catalytic combustion to remove hydrocarbon impurities; and the carbon dioxide removal module may use adsorbents such as alkali asbestos or quicklime. Compressed air flows through these modules sequentially to obtain dry, clean, high-purity carrier air.

[0072] Building upon this, multi-stage air purifiers can also include an oxygen removal module. A multi-stage air purifier can include a water removal module, a hydrocarbon removal module, a carbon dioxide removal module, and an oxygen removal module. The oxygen removal module removes oxygen from compressed air, which can be achieved through chemical adsorption or catalytic deoxygenation. Specifically, the oxygen removal module can be filled with a deoxidizing agent (such as a manganese-based deoxidizer, a copper-based deoxidizer, or a precious metal-supported deoxidizer). When compressed air flows through the oxygen removal module, oxygen reacts chemically with the deoxidizing agent and is selectively adsorbed, thus achieving deoxygenation. Alternatively, the oxygen removal module can be equipped with a catalytic deoxygenation unit, where, in the presence of an appropriate amount of hydrogen, oxygen reacts catalytically with hydrogen to produce water, which is then removed through subsequent drying.

[0073] After the compressed air flows through the above modules in sequence, moisture, hydrocarbons, carbon dioxide and oxygen are effectively removed, resulting in a dry, clean, and high-purity carrier gas with low oxygen content, which meets the strict requirements of gas chromatography analysis for carrier gas purity.

[0074] In one possible implementation, the transformer oil chromatography monitoring device 100 may further include: The drain module is connected to the flow path of the oil sample collection module 10 and is used to drain residual liquid in the flow path.

[0075] The oil sample acquisition module 10 includes at least a heated oil sampling pipe and corresponding connecting pipes. When oil sampling is completed or the device enters standby mode, some oil sample may remain inside the pipes. If this residual oil sample remains in the pipes for a long time, especially in low-temperature environments, it is prone to viscosity increase, solidification, or oxidation, leading to pipe blockage or affecting the representativeness of the next sampling result. To solve this problem, a draining module is connected to the flow path of the oil sample acquisition module 10 to drain the residual liquid in the flow path under preset conditions (e.g., after each sampling, before the device enters standby mode, or during scheduled system maintenance).

[0076] For example, the venting module may include a venting valve and a venting pipeline. The venting valve is located at the lowest point or end of the flow path of the oil sample collection module 10, with its inlet connected to the flow path and its outlet connected to the venting pipeline. When venting is required, the venting valve opens, and the residual oil sample is discharged through the venting pipeline under gravity or external air pressure. The discharged oil sample can be directly returned to the transformer oil tank (via the return oil pipeline) or collected in a waste oil container for unified treatment.

[0077] Furthermore, the venting module may also include a purging unit. This purging unit is used to introduce compressed air or carrier gas into the flow path when the venting valve is opened, so as to purge the residual oil sample adhering to the pipe wall, improve the venting effect, and prevent cross-contamination between different batches of oil samples.

[0078] By setting up a venting module, residual oil samples in the sampling flow path can be automatically vented, effectively avoiding pipeline freezing and oil sample contamination, improving the accuracy of monitoring data and the reliability of long-term device operation, and is especially suitable for substations in high-altitude and cold regions that require long-term unattended operation.

[0079] In one possible implementation, the venting module further includes a venting valve, which is located at the output end of the oil sample collection module 10 and connected to the control module 60. The control module 60 is also used to control the vent valve to open during sampling intervals or before shutdown to drain residual liquid in the flow path.

[0080] The venting module includes a venting valve. This venting valve is located at the output end of the oil sample collection module 10, specifically at the end or lowest point of the flow path of the oil sample collection module 10, to facilitate the smooth discharge of residual liquid under gravity or pressure. The inlet of the venting valve is connected to the flow path of the oil sample collection module 10, and its outlet is connected to a venting pipeline or a return oil pipeline.

[0081] The vent valve is electrically connected to the control module 60. The control module 60 is also used to control the vent valve to open during sampling intervals or before shutdown to drain residual liquid in the flow path. Essentially, after completing an oil sample collection and entering a sampling interval, or upon receiving a shutdown command to enter standby or maintenance mode, the control module 60 sends an opening command to the vent valve. The vent valve then opens, and the residual oil sample in the flow path is discharged through the vent valve under gravity or driven by residual pressure within the system. After a preset venting time (e.g., 5-30 seconds), the control module 60 sends a closing command to the vent valve, which closes, completing the venting operation.

[0082] The control module 60 can automatically control the opening and closing of the vent valve according to the working status of the device, and promptly remove residual oil samples in the flow path during non-sampling periods. This effectively avoids problems such as pipeline freezing and poor sampling repeatability caused by the viscosity increase, solidification or oxidation of residual oil samples in low-temperature environments, thus improving the long-term stability and data accuracy of the monitoring device.

[0083] In one possible implementation, the heat-tracing oil extraction pipe may include an oil pipe body, an electric heat tracing tape laid along the axial direction of the oil pipe body, and an outermost heat insulation layer, wherein the electric heat tracing tape is connected to the control module 60.

[0084] The oil pipe body is used for oil sample flow, and its two ends are connected to the transformer oil inlet and the oil-gas separation module 20, respectively. The electric heating tape is laid along the axial direction of the oil pipe body on its outer wall. It can be tightly attached to the surface of the oil pipe body by means of winding, parallel bonding, or spiral arrangement to ensure that heat can be efficiently transferred to the oil sample inside the oil pipe body. The outermost layer of the electric heating tape and the oil pipe body is covered to reduce heat loss to the external environment, improve heat tracing efficiency, and reduce energy consumption.

[0085] The electric heating tape is electrically connected to the control module 60. The control module 60 is used to control the working power of the electric heating tape according to the ambient temperature or the temperature of the oil pipe body. When the ambient temperature is lower than the preset threshold (e.g., 0℃ or -10℃), the control module 60 supplies power to the electric heating tape, causing it to heat up and heat the oil sample in the oil pipe body. When the temperature rises to the preset upper limit or enters a non-sampling state, the control module 60 can reduce or cut off the power supply to the electric heating tape to achieve energy-saving operation.

[0086] For example, the heated oil sampling tubing may also include a temperature sensor (such as a thermocouple or platinum resistance thermometer), which is disposed on the outer wall of the tubing body or embedded inside the tubing body and connected to the control module 60. Based on the actual temperature feedback from the temperature sensor, the control module 60 dynamically adjusts the working power of the electric heating tape using PID regulation or on / off control to maintain the oil sample temperature within the preset heating target range (e.g., 10℃~30℃), preventing the oil sample from increasing in viscosity or freezing due to low temperature.

[0087] The heated oil sampling pipe can actively and controllably heat the oil sample in cold environments, ensuring that the oil sample maintains good fluidity throughout the transportation process. At the same time, the insulation layer reduces heat loss, and the control module 60 achieves energy saving and precise temperature control, fundamentally solving the problem of freezing and blockage of the oil sampling pipe in low-temperature environments.

[0088] In one possible implementation, the oil sample acquisition module 10 may further include: Low-temperature flexible pipeline is connected between the heated oil extraction pipeline and the oil-gas separation module 20 to achieve flexible connection of the oil circuit in low-temperature environment.

[0089] One end of the heated oil sampling pipe is connected to the transformer's oil inlet, and the other end is connected to the oil inlet of the oil-gas separation module 20 via a low-temperature flexible pipeline. Since the heated oil sampling pipe is typically a rigid or semi-rigid structure (e.g., stainless steel or copper pipe), and the relative position between the transformer and the monitoring device may experience slight displacement due to installation tolerances, equipment vibration, or thermal expansion and contraction, directly using a rigid connection can easily lead to stress concentration in the pipeline or loosening of the interface. Furthermore, in extremely cold environments, ordinary rubber or plastic pipelines will harden and become brittle due to low temperatures, losing flexibility and even breaking.

[0090] To address the aforementioned issues, a low-temperature flexible pipeline made of low-temperature resistant elastic materials, such as silicone rubber, fluororubber, or polytetrafluoroethylene (PTFE), is employed. These materials maintain good flexibility and mechanical strength even at extreme low temperatures ranging from -40°C to -50°C. Both ends of this low-temperature flexible pipeline are equipped with connecting joints (such as compression fittings or quick-connect fittings) for sealed connections with the heated oil extraction pipe and the oil-gas separation module 20.

[0091] For example, low-temperature flexible tubing may also include a built-in spiral support frame (such as a stainless steel wire braided layer) to prevent the tubing from being sucked flat under negative pressure or from collapsing due to excessively small bending angles, ensuring smooth flow of oil samples.

[0092] The low-temperature flexible pipeline provides flexible connection compensation for the oil sample collection module 10 in cold environments, effectively absorbing displacement stress caused by vibration, thermal expansion and contraction or installation errors, avoiding pipeline damage or leakage caused by rigid connections. At the same time, its low-temperature resistant material ensures that the flexibility is not lost at low temperatures, further improving the reliability and sealing of the entire oil circuit system in cold regions.

[0093] In one possible implementation, the control module 60 can also be used to determine whether the transformer has a fault based on the concentration data and generate a fault diagnosis conclusion.

[0094] The control module 60 has a pre-installed fault diagnosis rule library, which includes at least the concentration thresholds for various characteristic gases and the criteria for judging the ratios between characteristic gases (such as the three-ratio method, the Davidson triangle method, etc.). After calculating the concentration data of each characteristic gas based on the electrical signal output by the chromatography analysis module 40, the control module 60 further calls the fault diagnosis rule library, compares the current concentration data with the preset thresholds, and calculates the ratios of the relevant characteristic gases to determine whether the transformer has a fault and the type of fault (such as overheating fault, discharge fault, or insulation dampness).

[0095] For example, when the detected acetylene (C2H2) concentration exceeds a preset threshold, the control module 60 can determine that the transformer has a discharge fault; when the ratio of ethylene (C2H4) to ethane (C2H6) exceeds a certain range, it can determine that there is a high-temperature overheating fault. Based on the above judgment results, the control module 60 generates a fault diagnosis conclusion, which may include: fault type, fault severity classification (e.g., normal, caution, abnormal, severe), and corresponding maintenance recommendations.

[0096] The control module 60 can not only detect the concentration of dissolved gases in oil, but also has localized intelligent diagnostic capabilities. It can determine the transformer status and generate conclusions in the first instance, which improves the timeliness of fault response and the intelligence level of the device. It is especially suitable for substations in high-altitude and cold regions with unstable communication conditions or no one on duty.

[0097] In one possible implementation, the transformer oil chromatography monitoring device 100 may further include: The communication module is connected to the control module 60 and is used to send concentration data to the backend server.

[0098] The communication module is connected to the control module 60 via a serial interface (such as RS-232, RS-485), an Ethernet interface, or a board-level bus, and is used to receive data output by the control module 60. After calculating the gas concentration data, the control module 60 sends the concentration data to the backend server through the communication module. Furthermore, when the control module 60 generates a fault diagnosis conclusion based on the concentration data, the communication module can also send this fault diagnosis conclusion to the backend server.

[0099] For example, the communication module can employ either wired or wireless communication. Wired communication methods include fiber optic or Ethernet communication, suitable for scenarios with good network conditions within the substation; wireless communication methods include 4G, 5G, NB-IoT, or BeiDou short message communication, suitable for remote areas or high-altitude substations where communication cabling is difficult. The communication module and the backend server follow an agreed-upon communication protocol (such as Modbus, IEC 61850, or MQTT), encapsulating concentration data and fault diagnosis conclusions into data frames for transmission.

[0100] Furthermore, the communication module can also be used to receive remote instructions from the backend server, such as remotely starting sampling, modifying the sampling period, upgrading the firmware of the control module 60, or resetting the device, thereby realizing remote operation and maintenance and management of the device.

[0101] The communication module enables timely and reliable transmission of real-time monitoring data and intelligent diagnostic conclusions to the backend server, facilitating maintenance personnel to remotely monitor the transformer's operating status and promptly address any anomalies. Simultaneously, the two-way communication capability supports remote control and maintenance of the device, significantly reducing the frequency of on-site manual inspections and maintenance costs, making it particularly suitable for substations in remote, cold regions with poor transportation and harsh winters.

[0102] The aforementioned transformer oil chromatography monitoring device has at least the following advantages: First, thanks to the active temperature control design covering the entire analytical process, the separation efficiency of the chromatographic column, the response sensitivity of the detector, and the permeability of the oil-gas separation membrane are no longer constrained by the harsh external environment. This fundamentally solves the core problem of existing equipment malfunctioning at low temperatures, ensuring the accuracy, continuity, and reliability of monitoring data under all-weather conditions.

[0103] Secondly, by using the inexhaustible ambient air as its gas source and integrating purification technology, it eliminates the dependence on expensive and time-consuming external nitrogen. This significantly reduces long-term operating costs and supply chain risks, making it particularly suitable for remote, high-altitude, and cold regions. It also simplifies maintenance processes and achieves self-sufficiency.

[0104] Third, because the physical and chemical properties of key components (such as material flexibility, lubricant flowability, and stationary phase separation performance) are specifically optimized to adapt to low-temperature environments, hardening, jamming, cracking, or a sudden drop in efficiency will not occur at low temperatures. This greatly reduces the probability of sudden failures caused by component freezing damage, extends the system's mean time between failures (MTBF), and reduces unplanned maintenance and spare parts replacement costs.

[0105] Fourth, the adoption of a communication scheme and electrical isolation measures with strong anti-interference capabilities, suitable for harsh industrial environments, effectively protects data transmission from strong electromagnetic interference and ground potential differences within the substation. This ensures that valuable monitoring data can be uploaded to the control center in real time and completely, providing a solid data foundation for transformer status early warning and fault diagnosis.

[0106] Fifth, by incorporating preventative flow path maintenance functions into the software control logic and implementing physical protection against the risk of residual liquid freezing, the oil and gas lines will not become blocked due to frozen residual droplets during shutdowns or intermittent periods. This avoids system downtime or measurement errors caused by flow path blockages, further improving the success rate and reliability of equipment startup and operation in frigid environments.

[0107] The preferred embodiments of this disclosure have been described in detail above with reference to the accompanying drawings. However, this disclosure is not limited to the specific details of the above embodiments. Within the scope of the technical concept of this disclosure, various simple modifications can be made to the technical solutions of this disclosure, and these simple modifications all fall within the protection scope of this disclosure.

[0108] It should also be noted that the various specific technical features described in the above embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, this disclosure will not describe the various possible combinations separately.

[0109] Furthermore, various different embodiments of this disclosure can be combined in any way, as long as they do not violate the spirit of this disclosure, they should also be regarded as the content disclosed in this disclosure.

Claims

1. A transformer oil chromatographic monitoring device, characterized in that, include: An oil sample collection module, comprising at least a heated oil sampling pipe, wherein the heated oil sampling pipe is used to heat the oil sample extracted from the transformer in a low-temperature environment; An oil-gas separation module is used to receive oil samples and separate the mixed gas to be tested from the oil samples at a first target temperature; The first temperature control module is thermally coupled to the oil-gas separation module and is used to maintain the temperature of the oil-gas separation module at the first target temperature. The chromatographic analysis module is used to separate and detect the gas mixture to be tested at a second target temperature and generate an electrical signal corresponding to the gas concentration. The second temperature control module is thermally coupled to the chromatography analysis module and is used to maintain the temperature of the chromatography analysis module at the second target temperature. The control module is used to control the operating power of the first temperature control module and the second temperature control module, and is also used to receive the electrical signal and determine the gas concentration data based on the electrical signal.

2. The transformer oil chromatography monitoring device according to claim 1, characterized in that, The transformer oil chromatography monitoring device also includes: The carrier gas generation module is connected to the carrier gas inlet of the chromatographic analysis module and is used to prepare ambient air as carrier gas and transmit it to the chromatographic analysis module. The carrier gas is used to propel the mixed gas to be tested through the chromatographic column.

3. The transformer oil chromatography monitoring device according to claim 2, characterized in that, The carrier gas generation module includes an air compressor and a multi-stage purifier, with the air inlet of the multi-stage purifier connected to the air outlet of the air compressor. The air compressor is used to draw in ambient air and generate compressed air; The multi-stage purifier is used to purify the compressed air in order to output carrier gas.

4. The transformer oil chromatography monitoring device according to claim 3, characterized in that, The multi-stage purifier includes at least a water removal module, a hydrocarbon removal module, and a carbon dioxide removal module.

5. The transformer oil chromatography monitoring device according to claim 1, characterized in that, The transformer oil chromatography monitoring device also includes: The evacuation module is connected to the flow path of the oil sample collection module and is used to evacuate residual liquid in the flow path.

6. The transformer oil chromatography monitoring device according to claim 5, characterized in that, The venting module also includes a venting valve, which is located at the output end of the oil sample acquisition module and is connected to the control module. The control module is also used to control the vent valve to open during sampling intervals or before shutdown, so as to discharge residual liquid in the flow path.

7. The transformer oil chromatography monitoring device according to claim 1, characterized in that, The heat-tracing oil extraction pipe includes an oil pipe body, an electric heat tracing cable laid along the axial direction of the oil pipe body, and an outermost heat insulation layer. The electric heat tracing cable is connected to the control module.

8. The transformer oil chromatographic monitoring device according to any one of claims 1-7, characterized in that, The oil sample collection module also includes: A low-temperature flexible pipeline is connected between the heated oil extraction pipeline and the oil-gas separation module to achieve a flexible connection of the oil circuit in a low-temperature environment.

9. The transformer oil chromatography monitoring device according to claim 1, characterized in that, The control module is also used to determine whether the transformer has a fault based on the concentration data, and to generate a fault diagnosis conclusion.

10. The transformer oil chromatography monitoring device according to claim 1, characterized in that, The transformer oil chromatography monitoring device also includes: A communication module, which is connected to the control module, is used to send the concentration data to the backend server.

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