A nitrogen-oxygen detection unit and method based on a self-generating gas source

Abstract

The application discloses a nitrogen-oxygen detection unit and method based on a self-produced gas source, which comprises a detector part, a characteristic gas venting part, a gas sampling and feeding part, a gas flow rate control part and a carrier gas generating module; the detector part is used for separating and calculating the concentration of nitrogen, oxygen and other characteristic gases; the characteristic gas venting part is used for discharging the residual characteristic gases in the gas circuit before each work; the gas sampling and feeding part provides the oxygen, nitrogen and other characteristic gas components separated from the transformer internal oil sample for the detector part; and the gas flow rate control part and the carrier gas generating module provide high-purity air as the carrier gas for the detector part. The method of the application adopts the self-produced gas source, improves the operation efficiency and stability of the oil chromatographic device of the extra-high voltage transformer substation while meeting the safety requirement, and provides effective guarantee for the safe operation of the transformer substation.

Description

TECHNICAL FIELD

[0001] The present application relates to the electrical field, and particularly to a nitrogen and oxygen detection unit and method based on a self-generating gas source. BACKGROUND

[0002] In recent years, the power industry has increasingly high requirements for the safety of operating equipment, and the insulation condition of large transformers, as the main equipment for power transmission, is one of the key factors for the safe operation of the power system. In particular, extra-high voltage transformers, due to their complex structure, will face more severe forms than ordinary substations in the operation of the transformer. If the equipment failure is not isolated in time, the accident will expand, the power grid will shake and even be split, and a large-scale power outage will seriously affect the daily work and life of residents. Therefore, the safety and reliability of the main transformer and high-voltage reactor have become the focus of the power grid operation, and through the online monitoring device to monitor the operation of the transformer in real time, timely detection and diagnosis of internal faults, make up for the shortcomings of laboratory chromatographic analysis method that cannot monitor in time, provide important data for real-time monitoring of the operation state of the transformer, and thus improve the life management level of the equipment, which is an important means to ensure the safe and economic operation of the transformer and the power grid system. The oil chromatographic device used in the extra-high voltage substation on the market has low nitrogen and oxygen detection precision, poor gas-tightness of the pressure reducing valve with a gas cylinder interface, high replacement cost of the argon cylinder, and other problems, which brings great inconvenience to the promotion and stable operation of the oil chromatographic device in the extra-high voltage substation. SUMMARY

[0003] The present application aims to provide a nitrogen and oxygen detection unit and method based on a self-generating gas source, to improve the nitrogen and oxygen detection precision of the substation oil chromatograph, avoid frequent replacement of the argon cylinder, and improve the operation efficiency of the substation oil chromatographic device.

[0004] Technical scheme: The present application discloses a nitrogen and oxygen detection unit and method based on a self-generating gas source, which comprises a detector part, a characteristic gas venting part, a gas sampling and feeding part, a gas flow rate control part, and a carrier gas generating module. The detector part is used to separate and calculate the concentration of nitrogen and oxygen and other characteristic gases. The characteristic gas venting part is used to discharge the residual characteristic gas in the gas circuit before each work. The gas sampling and feeding part provides oxygen and nitrogen and other characteristic gas components separated from the transformer internal oil sample for the detector part. The gas flow rate control part and the carrier gas generating module provide high-purity air as the carrier gas for the detector part.

[0005] Specifically, the detector part comprises a double-channel TCD detector, a nitrogen and oxygen ratio detector, and a chromatographic column.

[0006] The double-channel TCD detector can detect the conventional seven characteristic gases, including H2, CO, CO2, CH4, C2H4, C2H6 and C2H2, and the nitrogen-oxygen ratio detector can detect the concentrations of nitrogen and oxygen, and the chromatographic column can separate the nitrogen and oxygen and other characteristic gases in the mixed gas one by one.

[0007] Specifically, the characteristic gas venting part includes a first venting electromagnetic valve, a second venting electromagnetic valve, a sampling electromagnetic valve and a main electromagnetic valve.

[0008] The first venting electromagnetic valve inlet is connected to the first gas outlet through a pipeline, and the first venting electromagnetic valve outlet is connected to the sampling electromagnetic valve inlet through a pipeline.

[0009] The second venting electromagnetic valve inlet is connected to the second gas outlet through a pipeline, and the second venting electromagnetic valve outlet is connected to the main electromagnetic valve inlet through a pipeline, and the main electromagnetic valve outlet is connected to the sampling electromagnetic valve inlet through a pipeline; wherein the gas outlet is connected to the pipeline between the second venting electromagnetic valve and the main electromagnetic valve through a pipeline.

[0010] The sampling electromagnetic valve inlet is connected to the third gas outlet through a pipeline, and the sampling electromagnetic valve outlet is connected to the quantitative ring inlet through a pipeline, and the quantitative ring outlet is connected to the sampling electromagnetic valve inlet through a pipeline.

[0011] Specifically, the gas sampling and sampling part includes a sampling electromagnetic valve, a three-way electromagnetic valve, a quantitative ring, a sampling electromagnetic valve and a main electromagnetic valve.

[0012] When the three-way electromagnetic valve is switched to the sampling state, the carrier gas flows to the detector part through the pipeline; when it is switched to the sampling state, the carrier gas flows to the quantitative ring through the pipeline, and the nitrogen and oxygen and other characteristic gases are swept to the detector part.

[0013] Specifically, the gas flow rate control part and the carrier gas generation module include a pipeline connected in sequence carrier gas generation module, fourth gas outlet, pressure gauge, steady flow valve, pressure reducing valve and three-way electromagnetic valve; the carrier gas generation module uses high-purity air generated by an air compressor as carrier gas.

[0014] Preferably, the pipeline is made of 3mm stainless steel.

[0015] A nitrogen-oxygen detection method based on a self-produced gas source, comprising the following steps:

[0016] S1: The residual nitrogen and oxygen and other characteristic gases in the pipeline are exhausted;

[0017] S2: Perform cyclic quantitative sampling state, at this time the carrier gas module always sweeps the detector part;

[0018] S3: The three-way solenoid valve switches to the injection state, and the carrier gas module purges nitrogen, oxygen and other characteristic gases in the quantitative loop to the detector section;

[0019] S4: The detector separates and responds to the characteristic gases, and calculates the concentrations of the corresponding nitrogen, oxygen and other characteristic gases.

[0020] Beneficial effects: Compared with the prior art, the present invention has the following significant advantages:

[0021] (1) This invention controls the opening and closing of the first and second venting solenoid valves, the sampling solenoid valve, the three-way solenoid valve and the main solenoid valve, and uses the carrier gas to circulate and flush the gas path, so that there are no residual nitrogen, oxygen and other characteristic gases in the gas path before sampling, thus ensuring the consistency and high accuracy of online chromatographic data.

[0022] (2) The use of an air compressor to generate high-purity carrier gas for use in chromatographic columns and detectors eliminates the need for conventional argon gas cylinder devices, reducing the maintenance costs of oil chromatography devices and the safety hazards caused by gas cylinders.

[0023] (3) By measuring the changes in the proportion of dissolved oxygen and nitrogen in the oil, the actual concentrations of oxygen and nitrogen can be calculated, and the operating status of the transformer can be reflected in real time, thereby improving the reliability, accuracy and maintenance-free performance of the online oil chromatography monitoring device in the substation. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the detection unit of the present invention. Detailed Implementation

[0025] The technical solution of the present invention will be further described below with reference to the accompanying drawings.

[0026] like Figure 1 As shown, the nitrogen and oxygen detection unit based on self-generated gas source includes a detector section, a characteristic gas venting section, a gas sampling and injection section, a gas flow rate control section, and a carrier gas generation module.

[0027] (1) The detector section is used to separate and calculate the concentrations of nitrogen, oxygen and other characteristic gases, specifically including a dual-channel TCD detector 1, a nitrogen-oxygen ratio detector 2 and a chromatographic column 3.

[0028] The dual-channel TCD detector 1 can detect seven common characteristic gases, including H2, CO, CO2, CH4, C2H4, C2H6, and C2H2. It converts the changes in the resistance of the thermistor bridge into corresponding electrical signals, calculates the corresponding concentration values ​​by observing the changes in the electrical signal fluctuations, and determines whether there is an internal discharge phenomenon during the normal operation of the transformer, thus providing a reference for operators.

[0029] The nitrogen-oxygen ratio detector 2 can respond to the nitrogen-oxygen gas therein, and can reflect the nitrogen-oxygen ratio value in the characteristic gas in real time through the resistance change. Through the obtained ratio curve equation, the corresponding nitrogen and oxygen concentrations are calculated, and the internal oxidation degree of the transformer is obtained, thereby providing a basis for operation and maintenance.

[0030] The chromatographic column 3 can separate the corresponding characteristic gas according to the speed of the characteristic gas flowing in the chromatographic filling material, and separate the nitrogen-oxygen and other characteristic gases in the mixed gas one by one.

[0031] (2) The characteristic gas venting part is used to discharge the residual characteristic gas in the gas circuit before each work, and specifically includes a first venting electromagnetic valve 9, a second venting electromagnetic valve 8, a sampling electromagnetic valve 7, and a main electromagnetic valve 5.

[0032] The first venting electromagnetic valve 9 inlet is connected to the first gas outlet 18 through a pipeline, and the first venting electromagnetic valve 9 outlet is connected to the sampling electromagnetic valve 4 inlet through a pipeline.

[0033] The second venting electromagnetic valve 8 inlet is connected to the second gas outlet 17 through a pipeline, the second venting electromagnetic valve 8 outlet is connected to the main electromagnetic valve 5 inlet through a pipeline, and the main electromagnetic valve 5 outlet is connected to the sampling electromagnetic valve 4 inlet through a pipeline; wherein the gas outlet 16 is connected to the pipeline between the second venting electromagnetic valve 8 and the main electromagnetic valve 5 through a pipeline.

[0034] The sampling electromagnetic valve 7 inlet is connected to the third gas outlet 15 through a pipeline, the sampling electromagnetic valve 7 outlet is connected to the quantitative ring 6 inlet through a pipeline, and the quantitative ring 6 outlet is connected to the sampling electromagnetic valve 4 inlet through a pipeline.

[0035] The working process of the characteristic gas venting is as follows: the third gas outlet 15 and 16 are connected to the degassing unit, which separates the gas in the transformer oil sample; the venting electromagnetic valves 8 and 9 are respectively connected to the second gas outlet 17 and the first gas outlet 18 through 3mm stainless steel pipes; first, the sampling electromagnetic valve 4 and the main electromagnetic valve 5 need to be closed during venting, and the sampling electromagnetic valve 7, the venting electromagnetic valves 8 and 9 are opened; the air pump of the degassing unit inhales air from the second gas outlet 17, and then passes through the gas outlet 16, the third gas outlet 15, the sampling electromagnetic valve 7, the quantitative ring 6 in turn to form a complete loop back to the first gas outlet 18, thereby ensuring that the characteristic gas in the gas circuit and the quantitative ring can be purged out.

[0036] (3) The gas sampling and sampling part provides the dissolved oxygen and nitrogen and other characteristic gas components in the transformer internal oil sample for the detector part, specifically including sampling solenoid valve 7, three-way solenoid valve 13, quantitative ring 6, sampling solenoid valve 4 and main solenoid valve 5; in the sampling state, the carrier gas flows to the detector part through the pipeline through the three-way solenoid valve 13; in the sampling state, the carrier gas flows to the quantitative ring 6 through the pipeline through the three-way solenoid valve 13, and the nitrogen and oxygen and other characteristic gases are blown to the detector part.

[0037] When the degassing unit is working, that is, in the sampling state, the main solenoid valve 5 and the sampling solenoid valve 7 are opened, the sampling solenoid valve 4, the three-way solenoid valve 13, the vent solenoid valve 8 and 9 are closed. The gas pump separates the dissolved gas in the oil sample, blows it to the outlet 15 through the gas pump, and then through the quantitative ring 6, the main solenoid valve 5 to the gas outlet 16 back to the degassing unit, forming an internal gas circulation, until the oil gas balance state.

[0038] When the degassing unit stops working, that is, in the sampling state, the sampling solenoid valve 4 and the three-way solenoid valve 13 are opened, the main solenoid valve 5, the sampling solenoid valve 7, the vent solenoid valve 8 and 9 are closed, and the three-way solenoid valve state is switched. The gas of the carrier gas generation module blows the characteristic gas into the chromatographic column.

[0039] (4) The gas flow rate control part and the carrier gas generation module provide high-purity air as the carrier gas for the detector part. Specifically including the pipeline connected in turn carrier gas generation module, fourth gas outlet 14, pressure gauge 11, steady flow valve 12, pressure reducing valve 10.

[0040] The functions of the pressure reducing valve 10 and the steady flow valve 12 are to ensure that the gas generated by the carrier gas generation module always maintains a constant flow rate, and to stabilize the pre-column pressure of the pressure gauge 11 at 0.12mpa; the carrier gas generation module can independently generate the gas used by the detection unit through the air compressor. The gas is filtered by water and small particle impurities, and finally enters the detection unit through the pressure reducing valve 10 and the steady flow valve 12.

[0041] The pipelines between the above parts are connected by 3mm stainless steel pipes.

Claims

1. A nitrogen and oxygen detection unit based on a self-generated gas source, characterized in that, It includes a detector section, a characteristic gas venting section, a gas sampling and injection section, a gas flow rate control section, and a carrier gas generation module; The detector section is used to separate and calculate the concentrations of nitrogen, oxygen, and other characteristic gases; the characteristic gas venting section is used to discharge the residual characteristic gases in the gas path before each operation; the gas sampling and injection section provides the detector section with oxygen, nitrogen, and other characteristic gas components separated from the oil sample inside the transformer; the gas flow rate control section and the carrier gas generation module provide the detector section with high-purity air as carrier gas; the characteristic gas venting section includes a first venting solenoid valve (9), a second venting solenoid valve (8), a sampling solenoid valve (7), and a main solenoid valve (5); The inlet of the first venting solenoid valve (9) is connected to the first outlet (18) through a pipeline, and the outlet of the first venting solenoid valve (9) is connected to the inlet of the sample injection solenoid valve (4) through a pipeline. The inlet of the second venting solenoid valve (8) is connected to the second outlet (17) through a pipeline, the outlet of the second venting solenoid valve (8) is connected to the inlet of the main solenoid valve (5) through a pipeline, and the outlet of the main solenoid valve (5) is connected to the inlet of the sample injection solenoid valve (4) through a pipeline; wherein, the outlet (16) is connected to the pipeline between the second venting solenoid valve (8) and the main solenoid valve (5) through a pipeline; The inlet of the sampling solenoid valve (7) is connected to the third outlet (15) through a pipeline, the outlet of the sampling solenoid valve (7) is connected to the inlet of the quantitative loop (6) through a pipeline, and the outlet of the quantitative loop (6) is connected to the inlet of the injection solenoid valve (4) through a pipeline.

2. The nitrogen and oxygen detection unit based on a self-generated gas source according to claim 1, characterized in that, The detector section includes a dual-channel TCD detector (1), a nitrogen-oxygen ratio detector (2), and a chromatographic column (3); The dual-channel TCD detector (1) can detect seven common characteristic gases, including H2, CO, CO2, CH4, C2H4, C2H6, and C2H2. The nitrogen-oxygen ratio detector (2) can detect the concentrations of nitrogen and oxygen. The chromatographic column (3) can separate nitrogen, oxygen, and other characteristic gases from the mixed gas.

3. The nitrogen and oxygen detection unit based on a self-generated gas source according to claim 1, characterized in that, The gas sampling and injection section includes a sampling solenoid valve (7), a three-way solenoid valve (13), a metering loop (6), an injection solenoid valve (4), and a main solenoid valve (5); When the three-way solenoid valve (13) is switched to the sampling state, the carrier gas flows through the three-way solenoid valve (13) and the pipeline to the detector section; when switched to the injection state, the carrier gas flows through the three-way solenoid valve (13) and the pipeline to the quantitative loop (6), purging nitrogen, oxygen and other characteristic gases to the detector section.

4. The nitrogen and oxygen detection unit based on a self-generated gas source according to claim 1, characterized in that, The gas flow rate control section and the carrier gas generation module include a carrier gas generation module, a fourth air outlet (14), a pressure gauge (11), a flow stabilizing valve (12), a pressure reducing valve (10), and a three-way solenoid valve (13) connected in sequence by pipelines; the carrier gas generation module uses high-purity air generated by an air compressor as the carrier gas.

5. The nitrogen and oxygen detection unit based on a self-generated gas source according to any one of claims 3 and 4, characterized in that, The pipeline is made of 3mm stainless steel.

6. A nitrogen and oxygen detection method based on a self-generated gas source nitrogen and oxygen detection unit according to claim 1, characterized in that, Includes the following steps: S1: Purge residual nitrogen, oxygen, and other characteristic gases from the pipeline; S2: In the cyclic quantitative sampling state, the carrier gas module continuously purges the detector section during this time; S3: The three-way solenoid valve switches to the injection state, and the carrier gas module purges nitrogen, oxygen and other characteristic gases in the quantitative loop to the detector section; S4: The detector separates and responds to the characteristic gases, and calculates the concentrations of the corresponding nitrogen, oxygen and other characteristic gases.

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