An ultraviolet spectrum online monitoring device and method for SF6 decomposition component mixed gas

Abstract

An ultraviolet spectrum online monitoring device and method for mixed gas of SF6 decomposition components, the device comprising: an adjustable ultraviolet light source, a detection cell, an ultraviolet sensor, a signal acquisition unit and a wireless transmission unit; the detection cell is composed of a plurality of columnar tanks and a pipeline, and the detection cell is provided with an air inlet and an air outlet; the columnar tank is divided into a head end and a tail end, the head ends of the plurality of columnar tanks are aligned and arranged in parallel, and the plurality of columnar tanks are interconnected through pipelines, the head end of the columnar tank is provided with an adjustable ultraviolet light source, and the head end and the tail end are each provided with an ultraviolet sensor; the ultraviolet sensor is connected to the signal acquisition unit, and the information acquisition unit is connected to the wireless transmission unit. The present invention realizes a device to detect a plurality of SF6 decomposition components simultaneously by optimizing the design of the gas cell, and the detection signal can be transmitted in real time by using the wireless transmission unit, so as to monitor the SF6 decomposition components in real time.

Description

Technical Field

[0001] The present invention belongs to the field of gas detection research, and more specifically, relates to an ultraviolet spectrum online monitoring device and method for a mixed gas of SF6 decomposition components. Background Art

[0002] Sulfur hexafluoride (SF6) is the best known gas insulation medium. Its dielectric strength is about 2.5 times that of air in a uniform electric field, and its arc extinguishing performance is more than 100 times that of air. It has extremely excellent insulation, arc extinguishing performance and physical and chemical properties. Compared with traditional open air-insulated electrical equipment, SF6 gas-insulated electrical equipment such as gas-insulated switchgear (GIS), gas-insulated circuit breakers (GIB), and gas-insulated transformers (GIT) that use 0.3-0.6Mpa SF6 gas as the insulating medium not only effectively improves the insulation strength inside the equipment, but also greatly reduces the size of the equipment. It has many advantages such as small footprint, safe and reliable operation, simple maintenance, and no influence from the external environment. With the increasing tension of urban land and the continuous improvement of grid reliability requirements, SF6 gas-insulated electrical equipment has been widely used as a common electrical equipment in domestic and foreign transmission and distribution networks.

[0003] Since SF6 gas has excellent insulation and arc extinguishing properties, it can improve the insulation strength as an insulating medium and greatly reduce the size of high-voltage equipment. Therefore, it has been widely used in gas-insulated equipment. However, various insulation defects will inevitably appear in the SF6 gas-insulated equipment (SF6 equipment for short) during the manufacturing, transportation, installation, maintenance and operation, such as metal burrs on the conductor, loose parts or poor contact, air gaps formed by the stripping of the conductor and the supporting insulator, residues after maintenance, and metal particles in the cavity, etc., which will cause insulation defects of varying degrees inside the SF6 equipment, thereby causing the electric field inside the equipment to be distorted, and then partial discharge will occur. When partial discharge or overheating occurs inside the GIS equipment, it is often accompanied by various phenomena such as electromagnetic radiation, sound, light, heat, and chemical reactions. The information carried by these phenomena can reflect the insulation defects inside the equipment. Therefore, by effectively utilizing this information, effective detection of the insulation inside the equipment can be achieved, providing a basis for equipment fault diagnosis and status assessment. Summary of the invention

[0004] In order to solve the deficiencies in the prior art, the purpose of the present invention is to solve the problem of errors in the measurement of SF6 decomposition component mixed gas, and further propose an ultraviolet spectrum online monitoring device and method for SF6 decomposition component mixed gas.

[0005] The present invention adopts the following technical solution.

[0006] An ultraviolet spectrum online monitoring device for SF6 decomposition component mixed gas, comprising: an adjustable ultraviolet light source, a detection cell, an ultraviolet sensor, a signal acquisition unit and a wireless transmission unit;

[0007] The detection pool is composed of a plurality of columnar tanks and pipes, and is provided with an air inlet and an air outlet;

[0008] The columnar tank is divided into a head end and a tail end. The head ends of multiple columnar tanks are aligned and arranged in parallel. Multiple columnar tanks are interconnected through pipelines. The head end of the columnar tank is provided with an adjustable ultraviolet light source, and the head end and the tail end are each provided with an ultraviolet sensor.

[0009] The ultraviolet sensor is connected to the signal collection unit, and the information collection unit is connected to the wireless transmission unit.

[0010] Furthermore, the number of the columnar tanks is 3.

[0011] Furthermore, the adjustable ultraviolet light sources are ultraviolet light sources that emit external light of 280-320nm, 190-210nm and 200-210nm respectively.

[0012] Furthermore, the air inlet includes a first air inlet and a second air inlet, the first air inlet is used to introduce the mixed gas of SF6 decomposition components, and the second air inlet is used to introduce the gas after the scrubbing operation is completed.

[0013] Furthermore, the monitoring device also includes: a gas extraction device and a valve;

[0014] The valve is arranged on the air outlet, and the air outlet is connected with the air extraction equipment.

[0015] Furthermore, the monitoring device also includes: a controller, which is connected to the adjustable ultraviolet light source, the signal acquisition unit, the wireless transmission unit, the air extraction device and the valve through a control line.

[0016] Furthermore, the monitoring device also includes: a pressure sensor, which is arranged inside the detection pool.

[0017] Furthermore, the detection pool is made of fiberglass, and a Teflon tube is used to connect the gas outlet and the gas extraction device.

[0018] Further, the following steps are included:

[0019] Step 1, using the first gas inlet to pass the SF6 decomposition component mixed gas into the detection cell;

[0020] Step 2, irradiate ultraviolet light matching the mixed gas of SF6 decomposition components into the detection cell;

[0021] Step 3, using an ultraviolet sensor to collect ultraviolet light after absorbing the mixed gas and ultraviolet light that is not absorbed by the mixed gas;

[0022] Step 4: convert the light intensity signal of the ultraviolet light collected by the ultraviolet sensor into an electrical signal and transmit it to the signal collection unit for monitoring.

[0023] Furthermore, before executing step 1, the step 1 also includes:

[0024] Step S11, passing the gas for scrubbing into the detection pool through the second gas inlet until the indication of the pressure sensor is positive;

[0025] Step S12, leaving the scrubbed gas in the detection pool for tens of seconds;

[0026] Step S13, open the air outlet and the air extraction device to perform air extraction operation. When the pressure sensor reading no longer changes, stop the air extraction and close the air outlet.

[0027] The beneficial effects of the present invention are that, compared with the prior art, the present invention has the following advantages:

[0028] (1) By optimizing the design of the gas pool, a device can be used to simultaneously detect multiple SF6 decomposition components. The detection signal can be transmitted in real time using a wireless transmission unit to monitor the SF6 decomposition components in real time.

[0029] (2) The device layout is reasonable and easy to arrange. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is an ultraviolet spectrum online monitoring device for SF6 decomposition component mixed gas.

[0031] In the figure: 1. adjustable ultraviolet light source; 2. detection cell; 3. ultraviolet sensor; 4. signal acquisition unit; 5. wireless transmission unit; 6. first air inlet; 7. second air inlet; 8. air outlet; 9. exhaust equipment; 10. protective shell; 11. controller; 12. pressure sensor. DETAILED DESCRIPTION

[0032] The present application is further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and cannot be used to limit the protection scope of the present application.

[0033] The fundamental of ultraviolet spectrum trace gas detection technology lies in the specific absorption of ultraviolet light by the gas molecules to be tested. When the gas molecules to be tested are irradiated with ultraviolet light, they will absorb photons of corresponding energy, causing the molecules to transition from low energy level to high energy level. Since the energy is absorbed by the molecules to be tested, the intensity of ultraviolet light after irradiating the molecules to be tested decreases macroscopically. This phenomenon is called ultraviolet spectrum absorption, which satisfies the basic law of light absorption - Beer-Lambert law. The ultraviolet absorption spectrum is mainly caused by the excitation transition of the external electrons in the molecules in different energy level orbits by the corresponding photons. Since the number of electron layers of different molecules and the energy level of each layer of electrons are not the same, there are obvious differences in the absorption of light by different molecules. Different molecules have different ultraviolet absorption spectra, so the qualitative and quantitative research of unknown gases can be realized by analyzing the peak position, peak value and other information of the absorption spectrum. Ultraviolet absorption spectroscopy has been widely used in gas detection, which can realize non-contact detection, thereby avoiding damage to the environment in which the gas to be tested is located. In addition, since the ultraviolet absorption method has a short measurement time and a fast response, it is very suitable for real-time online detection of gases. Therefore, the present invention is committed to an efficient and accurate method for detecting the decomposition components of SF6, and simultaneously detecting multiple decomposition components of SF6 while ensuring accuracy, so as to achieve the purpose of online monitoring, thereby timely grasping the status of GIS equipment and ensuring safe and stable operation of the equipment.

[0034] In order to achieve the above-mentioned purpose, the present invention provides an ultraviolet spectrum online monitoring device for SF6 decomposition component mixed gas, including: an adjustable ultraviolet light source 1, a detection cell 2, an ultraviolet sensor 3, a signal acquisition unit 4, a wireless transmission unit 5, a protective shell 10, a controller 11 and a pressure sensor 12.

[0035] The detection pool 2 is composed of three columnar tanks and pipelines. Figure 1 As shown, the columnar tank is cylindrical and is divided into a head end and a tail end. The head ends of the three columnar tanks are aligned and arranged side by side, and the columnar tanks are interconnected by pipes.

[0036] Each columnar tank is provided with an adjustable ultraviolet light source 1 at the head end, and an ultraviolet sensor 3 at the head end and the tail end. The ultraviolet sensor at the tail end is used to detect ultraviolet light after absorbing the mixed gas, and the ultraviolet sensor at the head end is used to detect ultraviolet light that has not absorbed the mixed gas. That is to say, each adjustable ultraviolet light source 1 not only emits ultraviolet light into the columnar tank, but also synchronously emits ultraviolet light to the outside of the detection pool 2, and is received by the two ultraviolet sensors at the tail end and the head end respectively. It can be understood that Figure 1 There are 3 adjustable UV light sources 1 and 6 UV sensors 3 in total.

[0037] Furthermore, the three adjustable ultraviolet light sources 1 are ultraviolet light sources that can emit ultraviolet light of 280-320nm (SO2), 190-210nm (CS2) and 200-210nm (H2S). It should be noted that in the ultraviolet light of 280-320nm, the absorption intensity of SO2, the main decomposition component in the mixed gas of SF6 decomposition components, is relatively high; in the ultraviolet light of 190-210nm, the absorption intensity of CS2, the main decomposition component, is relatively high; in the ultraviolet light of 200-210nm, the absorption intensity of H2S, the main decomposition component, is relatively high. The decomposition components of SF6 can be effectively detected.

[0038] The ultraviolet sensor 3 is connected to the signal acquisition unit 4.

[0039] The information collection unit 4 is connected to the wireless transmission unit 5 .

[0040] The detection pool is provided with two air inlets, namely the first air inlet 6 and the second air inlet 7. The first air inlet 6 is used to introduce the mixed gas of the decomposed components of SF6, hereinafter referred to as the gas to be tested; the second air inlet 7 is used to introduce the gas after the gas washing operation is completed. Furthermore, valves are installed on the first air inlet 6, the second air inlet 7 and the air outlet 8. The valves are used to isolate the internal and external environments of the detection pool.

[0041] The gas outlet 8 is connected to the gas extraction device 9. Furthermore, the gas outlet 8 and the gas extraction device 9 can be connected using a Teflon tube. The gas outlet 8 is used to discharge the detection gas, the washing gas and other impurities in the detection pool. A valve is installed on the gas outlet 8 to isolate the environment inside and outside the detection pool.

[0042] The controller 11 is connected to the adjustable ultraviolet light source 1, the signal acquisition unit 4, the wireless transmission unit 5, the air extraction device 9, and the valve through the control line to perform control.

[0043] The pressure sensor 12 is arranged inside the detection pool 2, and is used to detect the pressure changes in the gas pool and transmit the pressure data to the controller and the signal acquisition unit. The controller controls the air extraction equipment and the valve according to the pressure data, and the signal acquisition unit transmits the collected pressure data to the user end via the wireless transmission unit.

[0044] The protective housing 10 is arranged outside the main body of the device to prevent damage to the internal units (except the exhaust equipment) during installation and operation and maintenance.

[0045] The present invention has high requirements on the structural strength, stability and anti-interference ability of the device due to the need to set the device in the electrical equipment, the complex environment in the electrical equipment, and the need to vacuum the detection pool when the device performs the gas washing operation. Based on this, the material of the detection pool 2 is selected from glass fiber reinforced plastics with high strength, and the adjustable ultraviolet light source 1, the detection pool 2, the ultraviolet sensor 3, the signal collection unit 4, and the wireless transmission unit 5 adopt a compact and reasonable layout to reduce the overall volume of the device and can be placed in the electrical equipment. The signal collection unit 4 and the wireless transmission unit 5 use equipment with strong anti-interference ability so that they can work normally in the strong electromagnetic environment of the electrical equipment. The ultraviolet sensor is arranged at the tail end and the head end of the columnar can, and the non-dispersive ultraviolet gas analysis technology is adopted. The ultraviolet light source is collected through the ultraviolet sensor at the head end as a reference channel. Since the UV sensor at the head end is close to the UV light source, the UV light emitted is almost not interfered by the gas to be tested. The detection signal of the UV sensor at the tail end of the columnar tank is processed with the reference channel signal of the UV sensor at the head end of the columnar tank, so that it can still maintain good detection performance in a harsh environment. A protective shell 10 is set on the outside of the entire device to protect the internal components from damage due to collisions. The pressure sensor 5 monitors the pressure changes in the gas pool in real time to prevent changes in the detection environment in the gas pool and the occurrence of safety accidents.

[0046] In actual detection, both the gas flow rate and the temperature and pressure inside the gas chamber will affect the detection results. The monitoring device disclosed in the present invention adopts this connected gas chamber design structure, which can ensure that the temperature and pressure inside the gas chamber are consistent when detecting three gases. After the gas is introduced, the gas to be tested is more evenly diffused to the three connected gas chambers, ensuring that the content of each component in the three gas chambers is exactly the same, eliminating the errors caused by uneven gas diffusion and inconsistent temperature and pressure inside the gas chamber.

[0047] The present invention also discloses an ultraviolet spectrum online monitoring method for a mixed gas of SF6 decomposition components, comprising the following steps:

[0048] Step 1, using the first gas inlet 6 to pass the mixed gas of SF6 decomposition components into the detection cell;

[0049] Furthermore, due to the structure of the detection pool of the present invention, it is usually necessary to perform a gas washing operation on the detection pool before detection. The gas washing operation is also included before step 1, specifically:

[0050] Step S11, passing the gas for scrubbing into the detection cell through the second gas inlet 7 until the indication of the pressure sensor is positive; wherein the scrubbing gas may be nitrogen.

[0051] Step S12, leaving the scrubbed gas in the detection pool for tens of seconds;

[0052] Step S13, opening the air outlet 8 and the air extraction device to perform air extraction operation, when the pressure sensor reading no longer changes, stop the air extraction and close the air outlet 8;

[0053] Usually, the above steps S11 to S13 need to be performed three times in succession. The scrubbing operation discharges the impurities remaining in the detection pool, avoids the interference caused by the impurities during the detection of SF6 decomposition components, and improves the detection environment in the detection pool.

[0054] Furthermore, step 1 specifically includes:

[0055] Open the first gas inlet 6, and pass the mixed gas of the decomposed components of SF6 into the detection cell. The gas filled into the detection cell 2 is allowed to stand for tens of seconds.

[0056] Step 2, irradiating ultraviolet light of a specific wavelength into the detection cell, wherein a mixed gas of SF6 decomposition components is passed through the detection cell, and the specific wavelength refers to a wavelength that matches the mixed gas of SF6 decomposition components;

[0057] Specifically, each columnar tank corresponds to a specific wavelength of ultraviolet light, and therefore, the three adjustable ultraviolet light sources 1 are used to emit ultraviolet light with wavelengths of 280-320 nm (SO2), 190-210 nm (CS2) and 200-210 nm (H2S), respectively.

[0058] Step 3, for any specific wavelength of ultraviolet light, using an ultraviolet sensor to collect ultraviolet light after absorbing the mixed gas and ultraviolet light that is not absorbed by the mixed gas;

[0059] Step 3 specifically includes:

[0060] For any columnar tank and the ultraviolet light source corresponding to the columnar tank, the ultraviolet light directly emitted by the ultraviolet light source is collected by the ultraviolet sensor at the head end of the columnar tank, and the ultraviolet light emitted into the columnar tank by the ultraviolet light source is collected by the ultraviolet sensor at the tail end of the columnar tank.

[0061] Step 4: convert the light intensity signal of the ultraviolet light collected by the ultraviolet sensor into an electrical signal and transmit it to the signal collection unit for monitoring.

[0062] In the above steps, the adjustable ultraviolet light source 1 is started to irradiate ultraviolet light of a specific wavelength into the detection pool 2. The ultraviolet light irradiates the gas molecules of the decomposition components, and the gas molecules of the decomposition components absorb the ultraviolet light. The ultraviolet sensor located at the tail end of the columnar can receives the absorbed ultraviolet light. At the same time, the ultraviolet sensor located at the head end of the columnar can collects the ultraviolet light directly emitted by the ultraviolet light source as a reference signal for the detection signal to more accurately and intuitively detect the main products of the SF6 decomposition components. The ultraviolet sensor converts the changing characteristics of the ultraviolet light into electrical signals and transmits them to the signal acquisition unit. The signal acquisition unit organizes the collected signals and sends them to the user end through the wireless transmission unit. All units are controlled by the controller.

[0063] An adjustable ultraviolet light source is used to illuminate the gas to be tested in the detection pool. The ultraviolet sensor absorbs the ultraviolet light and converts it into an electrical signal. The signal collection unit transmits the collected electrical signals of the main decomposition components to the wireless transmission unit, and the signal data is transmitted to the user end through the wireless transmission unit. The operator can view the concentration information of each decomposition component at the user end for real-time monitoring.

[0064] The present invention uses ultraviolet light of a specific wavelength to detect the decomposition components of SF6, and can effectively measure the changes in light intensity after the ultraviolet light reacts with the decomposition components of SF6 in different bands, thereby realizing the function of detecting multiple decomposition components at the same time; the application of a wireless transmission unit can transmit the detection data in real time, thereby realizing the function of real-time monitoring; the adjustable ultraviolet light source, detection cell, ultraviolet sensor, signal acquisition unit, and wireless transmission unit are reasonably arranged in the device.

[0065] The applicant of the present invention has made a detailed explanation and description of the implementation examples of the present invention in conjunction with the drawings in the specification. However, those skilled in the art should understand that the above implementation examples are only preferred implementation schemes of the present invention, and the detailed description is only to help readers better understand the spirit of the present invention, but not to limit the scope of protection of the present invention. On the contrary, any improvements or modifications based on the inventive spirit of the present invention should fall within the scope of protection of the present invention.

Claims

1. An ultraviolet spectrum online monitoring device for SF6 decomposition component mixed gas, characterized in that: include: Adjustable ultraviolet light source, detection cell, ultraviolet sensor, signal acquisition unit and wireless transmission unit, and protective housing; The detection pool includes a plurality of columnar tanks and pipelines, wherein one of the columnar tanks is provided with an air inlet and an air outlet; The columnar tank is divided into a head end and a tail end. The head ends of multiple columnar tanks are aligned and arranged in parallel. Multiple columnar tanks are interconnected through pipelines. The head end of the columnar tank is provided with an adjustable ultraviolet light source, and the head end and the tail end are each provided with an ultraviolet sensor. The ultraviolet sensor is connected to the signal collection unit, and the information collection unit is connected to the wireless transmission unit; The protective shell is arranged outside the device body.

2. The ultraviolet spectrum online monitoring device for SF6 decomposition component mixed gas according to claim 1 is characterized in that: The number of columnar tanks is 3.

3. The ultraviolet spectrum online monitoring device for SF6 decomposition component mixed gas according to claim 2 is characterized in that: The adjustable ultraviolet light sources are ultraviolet light sources that emit ultraviolet light of 280-320nm, 190-210nm and 200-210nm respectively.

4. The ultraviolet spectrum online monitoring device for SF6 decomposition component mixed gas according to claim 1 is characterized in that: The gas inlet includes a first gas inlet and a second gas inlet. The first gas inlet is used to introduce the mixed gas of SF6 decomposition components, and the second gas inlet is used to introduce the gas after the scrubbing operation is completed.

5. The ultraviolet spectrum online monitoring device for SF6 decomposition component mixed gas according to claim 1 is characterized in that: The monitoring device also includes: air extraction equipment and valves; The valve is arranged on the air outlet, and the air outlet is connected with the air extraction equipment.

6. The ultraviolet spectrum online monitoring device for SF6 decomposition component mixed gas according to claim 5, characterized in that: The monitoring device also includes: a controller, which is connected with the adjustable ultraviolet light source, the signal acquisition unit, the wireless transmission unit, the air extraction equipment and the valve through a control line.

7. The ultraviolet spectrum online monitoring device for SF6 decomposition component mixed gas according to claim 5 is characterized in that: The monitoring device also includes: a pressure sensor, which is arranged inside the detection pool.

8. The ultraviolet spectrum online monitoring device for SF6 decomposition component mixed gas according to claim 5, characterized in that: The detection pool is made of fiberglass, and the air outlet is connected to the exhaust equipment with a Teflon tube.

9. A method for online ultraviolet spectrum monitoring of mixed gas of SF6 decomposition components, implemented on the monitoring device according to any one of claims 1 to 8, characterized in that: The steps include: Step 1, using the first gas inlet of the detection cell to pass the SF6 decomposition component mixed gas into the detection cell; Step 2, irradiate ultraviolet light matching the mixed gas of SF6 decomposition components into the detection cell; Step 3, using an ultraviolet sensor to collect ultraviolet light after absorbing the mixed gas and ultraviolet light that is not absorbed by the mixed gas; Step 4: convert the light intensity signal of the ultraviolet light collected by the ultraviolet sensor into an electrical signal and transmit it to the signal collection unit for monitoring.

10. The method for online ultraviolet spectrum monitoring of SF6 decomposition component mixed gas according to claim 9, characterized in that: The step 1 also includes before being executed: Step S11, introducing the gas for scrubbing into the detection pool through the second gas inlet of the detection pool until the indication of the pressure sensor inside the detection pool is positive; Step S12, leaving the scrubbed gas in the detection pool for tens of seconds; Step S13, open the air outlet and the air extraction device to perform air extraction operation. When the pressure sensor reading no longer changes, stop the air extraction and close the air outlet.

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