1. A gas decomposition product component detection system is characterized by comprising a test tank body, a copper pipe, a pressure reducing valve, a gas chromatograph, a four-way valve, a two-way valve 1, a two-way valve 2, a digital gas pressure meter and a vacuum pump;

the test tank body comprises a tank body, electrodes, three observation windows, an air inlet and outlet pipeline and a conducting rod; one end of the conducting rod is connected with the upper cover of the tank body, the other end of the conducting rod is connected with an electrode, the electrode is positioned in the center of the interior of the tank body, an air inlet and outlet pipeline and an observation window are designed on the side wall of the tank body at the horizontal position of the electrode, and the air inlet and outlet pipeline and the three observation windows are uniformly distributed on the side wall in a circle and are opposite in pairs;

one end of the copper pipe is nested in the gas inlet and outlet pipeline and connected to the inside of the tank body, the other end of the copper pipe is connected with the pressure reducing valve, and the other end of the pressure reducing valve is provided with a sample inlet of the gas chromatograph; the gas inlet and outlet pipeline is provided with a four-way joint which is respectively in the pipeline direction and the vertical direction of the pipeline, wherein one side of the vertical direction of the pipeline is provided with a digital gas pressure meter, the other side of the vertical direction of the pipeline is connected with one end of a two-way valve 1, the other end of the two-way valve 1 is respectively connected with experimental gas, one end of a two-way valve 2 is connected with the other end of the two-way valve 2, and the other end of the two-way valve 2 is connected with a vacuum valve.

2. A gas decomposition product component detection method realized by the gas decomposition product component detection system of claim 1, comprising the steps of:

step 1: before the test, vacuumizing the test tank body, closing the pressure reducing valve, confirming that a valve of a steel cylinder containing test gas is in a closed state, sequentially opening the vacuum pump, the two-way valve 2 and the two-way valve 1, starting vacuumizing, vacuumizing for a set time, wherein the number of a digital pressure gauge is-0.001 MPa, and then sequentially closing the two-way valve 1, the two-way valve 2 and the vacuum pump;

step 2: washing the tank body, opening the two-way valve 1, opening a valve of a steel cylinder containing the test gas, filling the test gas into the test tank body until the indication of a digital pressure gauge is 0.01MPa, then pumping out the test gas by using a vacuum pump, and repeating for 3 times;

and step 3: filling a test tank with test gas, calculating the proportion of the required test gas according to the Dalton partial pressure law, then opening the two-way valve 1, opening a valve of a steel cylinder containing the test gas, filling the test gas into the test tank, checking the digital barometer until the digital barometer indicates that the pressure of the gas required by the test, and then closing the two-way valve 1 and the steel cylinder valve;

and 4, step 4: starting a test, namely applying high voltage to the electrodes when the test is started, so that the electrodes discharge to simulate different discharge faults in the GIS, and decomposing the insulating gas in the tank body under the discharge action;

and 5: and after the test is finished, opening the pressure reducing valve, adjusting the sample introduction pressure, sending the tested sample gas into a gas chromatograph for detection, and analyzing the types and the content of the decomposition products of the GIS insulating gas after different discharge faults.

3. The method as claimed in claim 2, wherein said different discharge faults in step 4 include spark discharge and partial discharge.

Background

At present, methods for detecting gas decomposition components mainly comprise a detection tube method, an infrared absorption spectrum method, a magnetic nuclear resonance spectrum method, a gas sensor method, a gas chromatography method, a mass spectrometry method and the like. The detection tube method can only detect some common gases at present, and has no corresponding detection tube for most of decomposition components. The method can only be used as an auxiliary detection method and cannot comprehensively reflect the condition of discharge decomposition components; infrared absorption spectroscopy: for insulating gas with very complex decomposition components, absorption peaks of various substances interfere with each other, so that the substance is difficult to determine qualitatively, and in addition, the intensity of the absorption peak and the content of the substance are not in a strict linear relation and are difficult to accurately quantify; nuclear magnetic resonance equipment is expensive, operation technology is complex, popularization of the nuclear magnetic resonance equipment is limited, and nuclear magnetic resonance spectrum is generated for not all substancesIn the spectrum, the atomic nucleus must have nuclear magnetic properties, namely must be a magnetic nucleus (or called spin nucleus), and some atomic nuclei do not have the nuclear magnetic properties, so that nuclear magnetic resonance spectrum cannot be generated; gas sensors have been developed that can only detect relatively common gases, such as H₂S、SO₂And HF, etc., to SF₆Several important decomposition components have not been detected, such as SOF₄、SO₂F₂、SF₄And SOF₂And the like, some gases may interfere with each other during detection. The gas chromatography has the best effect by comprehensively considering various detection methods. In the test process, a proper decomposition component detection system needs to be established to ensure that the test tank body and the gas chromatograph are perfectly matched to achieve the effect of accurate detection when the gas chromatograph is required to exert the optimal effect. The method has the advantages that the gas composition, content change rule and the like in the tank body are tested after different discharge and overheating faults of the insulating gas are detected, so that the insulation defect type, the discharge type, the fault development trend, the risk degree and the like in the equipment are analyzed and diagnosed, and the method has very important significance for guaranteeing the safe and stable operation of a power grid.

Disclosure of Invention

Aiming at the problems in the prior art, the invention provides a gas decomposition product component detection system and a gas decomposition product component detection method. And detecting the components of the gas decomposition products after different discharge types and local overheating faults, and performing fault diagnosis by using the decomposition components in the GIS.

In order to solve the technical problems, the invention adopts the following technical scheme:

on one hand, the gas decomposition product component detection system comprises a test tank body, a copper pipe, a pressure reducing valve, a gas chromatograph, a four-way valve, a two-way valve 1, a two-way valve 2, a digital gas pressure meter and a vacuum pump.

The test tank body comprises a tank body, electrodes, three observation windows, an air inlet and outlet pipeline and a conducting rod; one end of the conducting rod is connected with the upper cover of the tank body, the other end of the conducting rod is connected with an electrode, the electrode is positioned in the center of the interior of the tank body, an air inlet and outlet pipeline and an observation window are designed on the side wall of the tank body at the horizontal position of the electrode, and the air inlet and outlet pipeline and the three observation windows are uniformly distributed on the side wall in a circle and are opposite in pairs;

one end of the copper pipe is nested in the gas inlet and outlet pipeline and connected to the inside of the tank body, the other end of the copper pipe is connected with the pressure reducing valve, and the other end of the pressure reducing valve is provided with a sample inlet of the gas chromatograph. The method comprises the following steps that a four-way valve is arranged on an air inlet pipeline and an air outlet pipeline, wherein the four-way valve is respectively in the pipeline direction and the vertical direction of the pipeline, a digital barometer is installed on one side of the vertical direction of the pipeline, the other side of the pipeline is connected with one end of a two-way valve 1, the other end of the two-way valve 1 is respectively connected with experimental gas, one end of a two-way valve 2 is connected with the other end of the two-way valve 2, and the other end of the two-way valve 2 is connected with a vacuum valve;

in another aspect, a method for detecting a component of a gas decomposition product, which is implemented by the above gas decomposition product component detection system, includes the steps of:

step 1: before the test, the test tank body is vacuumized, the pressure reducing valve is closed, the valve of the steel cylinder containing the test gas is confirmed to be in a closed state, the vacuum pump, the two-way valve 2 and the two-way valve 1 are sequentially opened, vacuumizing is started, the vacuumizing is performed for a set time, the number of a digital pressure gauge is-0.001 MPa, and then the two-way valve 1, the two-way valve 2 and the vacuum pump are sequentially closed.

Step 2: and (3) washing the tank, opening the two-way valve 1, opening a valve of a steel cylinder containing the test gas, filling the test gas into the test tank until the indication of the digital pressure gauge is 0.01MPa, pumping out the test gas by using a vacuum pump, and repeating for 3 times.

And step 3: filling test gas into the test tank, calculating the proportion of the required test gas according to the Dalton partial pressure law, then opening the two-way valve 1, opening a valve of a steel cylinder containing the test gas, filling the test gas into the test tank, checking the digital barometer until the digital barometer indicates that the pressure of the gas required by the test, and then closing the two-way valve 1 and the steel cylinder valve.

And 4, step 4: starting a test, namely applying high voltage to the electrodes when the test is started, so that the electrodes discharge to simulate different discharge faults including spark discharge and partial discharge in the GIS, and insulating gas in the tank body is decomposed under the discharge action;

and 5: and after the test is finished, opening the pressure reducing valve, adjusting the sample introduction pressure, sending the tested sample gas into a gas chromatograph for detection, and analyzing the types and the content of the decomposition products of the GIS insulating gas after different discharge faults.

The invention has the following beneficial effects:

the invention provides a gas decomposition product component detection system and a method, which have the following beneficial effects:

1. the gas collected after the test can be guaranteed to be the gas after discharge decomposition, and the copper pipe is used as a gas production pipeline to guarantee that the gas is not adsorbed, so that the content error of the decomposition component caused by adsorption on the gas is eliminated.

2. The invention can detect the decomposition products of the insulating gas under different GIS internal faults.

3. The gas collection aspect is improved, the traditional method for collecting gas by using a gas collection bag is changed, after the test is finished, the pressure reducing valve is opened, and the tested gas is directly pumped to a gas chromatograph for detection by utilizing the pressure difference between the inside and the outside of the tank body. The air is prevented from being mixed into the sample in the process of sampling by the gas collection bag, so that the detection result is not influenced.

Drawings

FIG. 1 is a view showing the construction of a gas decomposition product component detection system;

wherein, (1) -observation window, (2) -copper pipe, (3) -inlet and outlet pipeline, (4) -pressure reducing valve, (5) -digital barometer, (6) -four-way, (7) -two-way valve 1, (8) -two-way valve 2, (9) -gas chromatograph, (10) -vacuum pump, (11) -test gas;

FIG. 2 is a view showing the structure of a copper pipe;

FIG. 3 is a view of the exterior of the experimental tank;

FIG. 4 is a view of a portion of the detection system;

FIG. 5 is a diagram showing the results of detection of the decomposition products of the gas after the test without the copper pipe mounted;

fig. 6 is a diagram showing the results of detection of the gas decomposition products after the test after the copper pipe is mounted.

Detailed Description

The following detailed description of embodiments of the present invention is provided in connection with the accompanying drawings and examples. The following examples are intended to illustrate the invention but are not intended to limit the scope of the invention.

On one hand, the gas decomposition product component detection system comprises a test tank body, a copper pipe (2), a pressure reducing valve (4), a gas chromatograph (9), a cross joint (6), a two-way valve (1) (7), a two-way valve (2) (8), a digital gas pressure meter (5) and a vacuum pump (10) as shown in figure 1.

The exterior of the test tank body is shown in figure 3 and comprises a tank body, electrodes, three observation windows (1), an air inlet and outlet pipeline (3) and a conducting rod; one end of the conducting rod is connected with the upper cover of the tank body, the other end of the conducting rod is connected with an electrode, the electrode is positioned in the center of the interior of the tank body, an air inlet and outlet pipeline (3) and an observation window (1) are designed on the side wall of the tank body at the horizontal position of the electrode, and the air inlet and outlet pipeline (3) and the three observation windows (1) are uniformly distributed on the periphery of the side wall and are opposite to each other in pairs;

the diameter of the air inlet and outlet pipeline is 50mm, and the aim is to smoothly inflate the tank body before the test; in order to test the even distribution of the electric field in the tank body, the simulation calculation shows that the test electrode is arranged in the center of the tank body to be the best, therefore, the electrode discharge area has a certain distance from the gas chromatograph, in order to collect the gas near the electrode discharge area, a copper pipe matched with a gas collection port in the pressure reducing valve is designed, the copper pipe is shown in figure 2, the outer diameter of the copper pipe is 5mm, the copper pipe mainly plays a role in air entraining, the gas near the electrode discharge area is introduced into the gas chromatograph for detection, and the accuracy of the test result is ensured. One end of the copper pipe is nested in the gas inlet and outlet pipeline and connected to the inside of the tank body, but the electric field generated after the high voltage is applied to the electrodes is not influenced, the other end of the copper pipe is connected with the pressure reducing valve, and the other end of the pressure reducing valve is provided with a sample inlet of the gas chromatograph. A four-way valve is arranged on the gas inlet and outlet pipeline, which is respectively in the pipeline direction and the vertical direction of the pipeline, as shown in fig. 4, wherein a digital barometer is arranged on one side of the pipeline in the vertical direction, the other side of the pipeline is connected with one end of a two-way valve 1, the other end of the two-way valve 1 is respectively connected with experimental gas, one end of a two-way valve 2 is connected with a vacuum valve, and the other end of the two-way valve 2 is connected with a vacuum valve;

in this example, the highest withstand pressure of the test tank for simulating the GIS is 1 MPa. The tank body is made of stainless steel materials, the inner diameter of the pipe wall is 212mm, the outer diameter of the pipe wall is 220mm, two observation windows with the same size and a flange opening for gas production are arranged on the outer side of the pipe wall at the horizontal position of the electrode, the inner diameter of the flange of each observation window is 90mm, and the outer diameter of the flange of each observation window is 174 mm; the diameter of the upper cover plate and the lower cover plate is 275mm, the thickness of the upper cover plate and the lower cover plate is 12mm, the joint of the conducting rod and the cover plate is processed by adopting corrugated pipe sealing, and the motion stroke of the conducting rod is 0-40 mm.

In another aspect, a method for detecting a component of a gas decomposition product, which is implemented by the above gas decomposition product component detection system, includes the steps of:

step 1: before the test, the test tank body is vacuumized, the pressure reducing valve is closed, the valve of the steel cylinder containing the test gas is confirmed to be in a closed state, the vacuum pump, the two-way valve 2 and the two-way valve 1 are sequentially opened, vacuumizing is started for two hours, the number of the digital pressure gauge is-0.001 MPa, and then the two-way valve 1, the two-way valve 2 and the vacuum pump are sequentially closed.

Step 2: and (3) washing the tank, opening the two-way valve 1, opening a valve of a steel cylinder containing the test gas, filling the test gas into the test tank until the indication of the digital pressure gauge is 0.01MPa, pumping out the test gas by using a vacuum pump, and repeating for 3 times.

And step 3: filling test gas into the test tank, calculating the proportion of the required test gas according to the Dalton partial pressure law, then opening the two-way valve 1, opening a valve of a steel cylinder containing the test gas, filling the test gas into the test tank, checking the digital barometer until the digital barometer indicates that the pressure of the gas required by the test, and then closing the two-way valve 1 and the steel cylinder valve.

And 4, step 4: starting a test, namely applying high voltage to the electrodes when the test is started, so that the electrodes discharge to simulate different discharge faults (including spark discharge and partial discharge) in the GIS, and decomposing the insulating gas in the tank body under the discharge action;

and 5: after the test is finished, opening a pressure reducing valve, adjusting the sample introduction pressure, sending the tested sample gas into a gas chromatograph for detection, and analyzing the types and the contents of the decomposition products of the GIS insulating gas after different discharge faults;

in order to prevent the gas production pipe from influencing the detection result by adsorbing the decomposition components, the gas production pipe extending into the tank body through the gas production port is selected from a capillary copper pipe, the copper pipe can be bent, the outer diameter of the copper pipe is 5mm, the copper pipe can be closely connected with a pressure reducing valve at the other end, and the gas tightness can be guaranteed.

The content detection of components is also different due to the difference of sample injection pressure, a pressure reducing valve is connected between the gas production pipe and the sample injection port in order to adjust the sample injection pressure, and the pressure reducing valve adopts a knob to adjust the input pressure, so that the detection effect is better.

LX-3100A Portable SF₆The helium ion comprehensive detector adopts 2 detectors (PDD1 and PDD2) to detect inorganic substances and organic substances respectively, adopts 5 switching valves to turn on and off to send sample gas into 6 chromatographic columns for separation, wherein the chromatographic columns 1, 2 and 3 are used for separating inorganic substances, and the chromatographic columns 4 and 5 are used for separating H₂S、COS、C₃F₈、SOF₂、SO₂F₂Chromatographic column 6 for separating SO₂、CS₂Finally, the effect of feeding inorganic substances into detector PDD1 and organic substances into detector PDD2 is achieved, and the detector can be used for H₂、O₂、N₂、CH₄、CF₄、CO、CO₂、C₂F₆、C₃F₈、SO₂F₂、SOF₂、SO₂、H₂S、COS、CS₂、NF₃、NO₂、H₂And (4) analyzing and detecting the O and other 18 decomposition products, and providing more comprehensive and accurate test data for judging faults of the gas charging power equipment such as the GIS and the like.

As shown in fig. 5 and 6, the results of the gas chromatograph for the post-test gas decomposition products are shown, wherein fig. 5 shows the results of the gas chromatograph without copper tubes, and it shows that no decomposition products can be detected, mainly because the gas chromatograph is a sensitive instrument, the content of some decomposition products is inherently low, the short-time diffusion can be diffused into the gas inlet and outlet pipelines, but is not in the detection range of the gas chromatograph, and the content of the gas decomposition products in the pipelines is not the true content of the post-test decomposition products. FIG. 6 shows the result of detecting the decomposition products of the gas after the copper tube is added, which has good detection effect, not only eliminates the difficulty that trace components are difficult to detect, but also ensures the authenticity of the detection result.

Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit of the corresponding technical solutions and scope of the present invention as defined in the appended claims.