Flow control method suitable for on-line detection of SF6 gas by spectroscopy

Abstract

The present application belongs to the technical field of detecting gas flow control, and particularly relates to a flow control method suitable for on-line detection of SF6 gas by spectroscopy. The flow control method is realized by a flow control device suitable for on-line detection of SF6 gas by spectroscopy. The present application changes the temperature in the gas storage tank by a semiconductor refrigeration module, so that the gas pressure in the gas storage tank is stabilized at a pressure value required for a flow of 300 mL / min. The pressure in the gas storage tank is controlled at a pressure value corresponding to the pressure difference by the semiconductor refrigeration module, so that the spectroscopic detection unit detects at the gas flow rate, and has high precision. The present application can effectively reduce the economic cost, has the characteristics of small volume and convenient on-site installation, and can be widely applied to gas flow control when SF6 gas is detected on-line by spectroscopy.

Description

Technical Field

[0001] This invention belongs to the field of gas flow control technology, and particularly relates to a flow control method suitable for online detection of SF6 gas by spectroscopic method. Background Technology

[0002] SF6 gas, due to its strong negative charge and self-healing properties, is widely used as an insulating and arc-extinguishing medium in the gas chambers of various GIS equipment. During operation, GIS equipment may experience latent faults, causing SF6 gas to decompose under the influence of a strong current, producing SF6. x， Where x can take values ​​of 1, 2, 3, 4, and 5, SF x SF6 can react with insulating materials or impurity gases such as N2, O2, and H2O to form toxic or corrosive gases such as SOF2, SO2F2, SOF4, SO2, CO, CF4, HF, and CF4. These gases damage insulating materials, reduce insulation and arc-extinguishing performance, and in severe cases, may lead to the shutdown of GIS equipment. Therefore, the detection of gaseous impurities in SF6 gas is of great significance for ensuring the stable operation of the power grid.

[0003] Spectroscopic methods include infrared absorption spectroscopy and ultraviolet fluorescence spectroscopy. Spectroscopic methods offer advantages such as short detection time, high accuracy and sensitivity, no consumption of the analyte gas, and no impurities generated, making them the most commonly used detection method for online SF6 gas detection in GIS equipment. The flow rate of the analyte gas has a certain impact on the detection accuracy of spectroscopic methods, and generally needs to be controlled within the standard flow rate range of (300±15) mL / min. If the gas flow rate exceeds this range, the measurement accuracy will decrease.

[0004] In existing technologies, high-precision flow controllers are generally used in online detection to achieve flow control, with errors typically not exceeding 1% of full scale. However, due to their high price, often exceeding several thousand yuan, their application in the field of online flow control for spectroscopic SF6 gas detection, where high flow control precision is not required, presents a problem of poor economic efficiency. Furthermore, online detection generally requires small device size and easy installation; integrating a mass flow controller into the device would significantly increase its size, making on-site installation inconvenient.

[0005] Patent application number 2022104768895, publication number CN2114848770A, published on April 30, 2022, discloses a non-destructive online monitoring method and device based on spectroscopy. This application connects a pressure reducing valve, a spectral detection unit, a flow meter, a temperature control unit, and a collection tank in series. The temperature control unit cools the collection tank to reduce pressure, creating a pressure difference of 0.1 MPa with the pressure reduced by the pressure reducing valve. This pressure difference causes the SF6 gas to be measured to pass sequentially through the spectral detection unit and the flow meter, ultimately flowing into the collection tank. The spectral detection unit includes an SO2 fluorescence detection unit, a CO infrared absorption detection unit, and a CF4 infrared absorption detection unit. The flow meter is a mass flow controller. After detection, the temperature control unit heats the collection tank to increase the pressure above the pressure inside the GIS equipment's gas chamber, and then refills the tank with SF6 gas through a refill pipeline.

[0006] However, this technology, which uses a flow meter to control the flow rate at 300 mL / min, suffers from drawbacks such as high cost and large device size, making it inconvenient for on-site installation. Therefore, further technological updates are urgently needed. Summary of the Invention

[0007] To address the shortcomings of existing technologies that use mass flow controllers to control the flow rate of the gas being measured, such as high economic costs and large device size which are inconvenient for on-site installation, this invention provides a flow control method suitable for online detection of SF6 gas using spectrophotometry. This method determines the required pressure value in the gas storage tank based on the flow characteristic curve and controls the pressure in the storage tank at that value using a semiconductor cooling module. This eliminates the need for a mass flow controller, achieving flow control for detection and effectively reducing economic costs and device size.

[0008] The technical solution adopted by the present invention to achieve the above objectives is as follows:

[0009] A flow control method for online detection of SF6 gas using spectroscopic methods is implemented using a flow control device suitable for online detection of SF6 gas using spectroscopic methods, comprising: Step 1. Connecting the inlet to a vacuum pump, opening the third solenoid valve, starting the vacuum pump, then closing the third solenoid valve and disconnecting the pipeline; Step 2. Connecting the inlet to an SF6 storage device, opening the third solenoid valve, starting the semiconductor cooling module to lower the temperature of the storage tank, pre-storing SF6 gas in the storage tank, closing the third solenoid valve, and disconnecting the pipeline; Step 3. Connecting the inlet to the gas chamber filling / discharging port of the GIS equipment, setting the pressure reducing valve, opening the first and second solenoid valves, and using the first pressure sensor to detect SF6 gas; Step 4. Calculating the density, pressure, and temperature of the SF6 gas in the storage tank at this time; Step 5. Measuring the ambient temperature using the first temperature sensor, and selecting the target temperature for heating the SF6 gas in the storage tank using the temperature-pressure characteristic curve; Step 6. Activating the semiconductor cooling module to raise the temperature T of the SF6 gas in the storage tank 10.21 Control at T * 2, T * 2 represents the gas temperature at pressure P2, at which point the gas pressure in the storage tank is P2; Step 7. Open the second solenoid valve, allowing the SF6 gas to flow through the spectral detection unit under the pressure difference and enter the storage tank; Step 8. Continue to lower the temperature in the storage tank through the semiconductor cooling module; Step 9. After the detection is completed, open the third solenoid valve, and the semiconductor cooling module is energized in reverse to generate heat, refilling the gas chamber with the SF6 gas consumed in the detection, and based on the P2 detected by the second pressure sensor and the second temperature sensor... 21 and T 21 P 21 The temperature and T required for the gas density to be ρ0 and the pressure to be P2 in the gas storage tank. 21 The required temperature for the gas density in the storage tank to be ρ0+Δρ and the pressure to be P2 is calculated using the Beattie-Bridgman gas state equation. When ρ1=ρ0, heating is stopped and the third solenoid valve is closed.

[0010] Furthermore, the flow control device is composed of an air inlet, a pressure reducing valve, a first solenoid valve, a spectral detection unit, a first pressure sensor, a first temperature sensor, a second solenoid valve, a second pressure sensor, a second temperature sensor, and an air storage tank connected in series. The semiconductor refrigeration module is wrapped around the outside of the air storage tank, and the air storage tank is connected in series with the third solenoid valve and the air inlet via pipelines.

[0011] Furthermore, the air inlet, pressure reducing valve, first solenoid valve, spectral detection unit, first pressure sensor, first temperature sensor, second solenoid valve, second pressure sensor, second temperature sensor, and air tank are connected sequentially via pipelines; one end of the third solenoid valve is connected to the pipeline between the air inlet and the pressure reducing valve, and the other end of the third solenoid valve is connected to the pipeline between the second solenoid valve and the second pressure sensor; the second pressure sensor and the second temperature sensor are mounted on the air tank.

[0012] Furthermore, the spectral detection unit is a single spectral detection unit or an integrated unit of multiple spectral detection units; the forward current of the semiconductor cooling module is for cooling, and the reverse current is for heating.

[0013] Furthermore, the air inlet, the first solenoid valve, the spectral detection unit, the first pressure sensor, the first temperature sensor, the second solenoid valve, the second pressure sensor, the semiconductor refrigeration module, and the third solenoid valve can all transmit information bidirectionally with the microcontroller and are controlled by the microcontroller.

[0014] Furthermore, the temperature mentioned in step 4 is measured by a second temperature sensor:

[0015] P=(RTB-A)ρ 2 +RTρ; (1)

[0016] A = 73.882 × 10 -5 -5.132105×10 -7 ρ;

[0017] B = 2.50695 × 10 -3 -2.12283×10 -6 ρ;

[0018] R = 56.9502 × 10 -5 ;

[0019] In the above formula, P is the SF6 gas pressure, in 0.1 MPa; T is the SF6 gas temperature, in K; and ρ0 is the SF6 gas density, in kg / m³. 3 A and B have values ​​in the above formula, and R is a constant.

[0020] Furthermore, the temperature-pressure characteristic curve is determined as follows:

[0021] The temperature and pressure characteristic curves were obtained experimentally and include:

[0022] Given a fixed material, length, and degree of curvature of the gas pipeline, the pressure difference between the inlet and outlet of the pipeline and the flow rate satisfy the following relationship:

[0023]

[0024]

[0025] Among them, Q s The actual mass flow rate of the gas in the pipeline is expressed in kg / s.

[0026] Q m The mass flow rate of the gas in the pipeline under congested flow conditions is expressed in kg / s.

[0027] P1 and P2 are the upstream and downstream pressures of the pipeline, respectively, in Pa;

[0028] ρ0 is the density of SF6 gas under standard conditions, in kg / m³. 3 ;

[0029] T0 and T1 are the standard temperature and the upstream temperature of the pipeline, respectively, in K.

[0030] b is the critical pressure ratio;

[0031] C is the sound conductance, in meters (m). 3 / S·Pa.

[0032] Furthermore, the temperature in the gas storage tank is further reduced by the semiconductor cooling module, wherein the cooling temperature T is:

[0033] T = T S +(T P / T S )×t (2)

[0034] Where t is the detected time, in seconds (s). s T is the temperature required for SF6 gas to have a density ρ0 and a pressure P2 in the storage tank. p Let P be the temperature required for the SF6 gas in the storage tank to have a density of ρ0 + Δρ and a pressure of P2, where Δρ = 5.472 × 10⁻⁶. -3 / V.

[0035] A computer device includes a storage medium, a processor, and a computer program stored on the storage medium and executable on the processor, wherein the processor executes the computer program to implement the steps of any of the flow control methods for online detection of SF6 gas using spectroscopic methods.

[0036] A computer storage medium storing a computer program, which, when executed by a processor, implements the steps of any of the flow control methods described above for online detection of SF6 gas using spectroscopic methods.

[0037] The present invention has the following beneficial effects and advantages:

[0038] This invention uses a semiconductor cooling module to change the temperature in the gas storage tank, thereby stabilizing the gas pressure in the tank at the pressure value required to achieve a flow rate of 300 mL / min. The semiconductor cooling module then controls the pressure in the gas storage tank to the pressure value corresponding to this pressure difference, enabling the spectral detection unit to perform detection at this gas flow rate with high accuracy.

[0039] This invention eliminates the need for a flow meter, effectively reducing economic costs, and features a small size for easy on-site installation. It is suitable for gas flow control during online detection of SF6 gas using spectrophotometry. Attached Figure Description

[0040] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0041] Figure 1 This is a schematic diagram illustrating the principle of the online monitoring method of the present invention.

[0042] In the diagram: 1. Air inlet, 2. Pressure reducing valve, 3. First solenoid valve, 4. Spectral detection unit, 5. First pressure sensor, 6. First temperature sensor, 7. Second solenoid valve, 8. Second pressure sensor, 9. Second temperature sensor, 10. Air tank, 11. Semiconductor refrigeration module, 12. Third solenoid valve. Detailed Implementation

[0043] To better understand the above-mentioned objectives, features, and advantages of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0044] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and therefore the scope of protection of the invention is not limited to the specific embodiments disclosed below.

[0045] The following reference Figure 1 The technical solutions of some embodiments of the present invention are described below.

[0046] Example 1

[0047] This invention provides an embodiment of a flow control method suitable for online detection of SF6 gas using spectroscopic methods, such as... Figure 1 As shown, Figure 1 This is a schematic diagram of the principle of the online monitoring method of the present invention. The present invention is realized by a flow control device suitable for online detection of SF6 gas by spectrometry. Specifically, when the pressure at the front end of the spectrometry detection unit is standard atmospheric pressure, the gas temperature in the gas storage tank is controlled by a semiconductor cooling module, thereby controlling the gas pressure in the gas storage tank, so that the pressure difference between the front and rear ends of the spectrometry detection unit is stabilized at a set value. Under the set pressure difference, the flow rate of SF6 gas flowing through the spectrometry detection unit is stabilized at about 300 mL / min.

[0048] In the diagram, the control device's air inlet 1, pressure reducing valve 2, first solenoid valve 3, spectral detection unit 4, first pressure sensor 5, first temperature sensor 6, second solenoid valve 7, second pressure sensor 8, second temperature sensor 9, and air storage tank 10 are connected in series. More specifically, the air inlet 1, pressure reducing valve 2, first solenoid valve 3, spectral detection unit 4, first pressure sensor 5, first temperature sensor 6, second solenoid valve 7, second pressure sensor 8, second temperature sensor 9, and air storage tank 10 are connected in series via pipelines using a conventional method. Additionally, a semiconductor cooling module 11 is encased outside the air storage tank 10. The forward current of the semiconductor cooling module 11 is for cooling, and the reverse current is for heating.

[0049] The third solenoid valve 12 is a recharge line, which is connected in series with the gas storage tank 10 via a pipeline to the third solenoid valve 12 and the air inlet 1. One end of the third solenoid valve 12 is connected to the pipeline between the air inlet 1 and the pressure reducing valve 2 in a conventional manner, and the other end of the third solenoid valve 12 is connected to the pipeline between the second solenoid valve 7 and the second pressure sensor 8 in a conventional manner.

[0050] The second pressure sensor 8 and the second temperature sensor 9 are installed on the gas storage tank 10. Specifically, the second pressure sensor 8 is installed on the pipeline between the solenoid valve 7 and the gas storage tank 10, and is close to the gas storage tank 10. The second temperature sensor 9 is installed on the tank body of the gas storage tank 10, with the temperature detection probe close to the semiconductor refrigeration module 11.

[0051] The spectral detection unit 4 can be a single spectral detection unit or an integrated unit of multiple spectral detection units.

[0052] In this invention, each component, including the air inlet 1, the first solenoid valve 3, the spectral detection unit 4, the first pressure sensor 5, the first temperature sensor 6, the second solenoid valve 7, the second pressure sensor 8, the semiconductor refrigeration module 11, and the third solenoid valve 12, can transmit information bidirectionally with the microcontroller and be controlled by the microcontroller.

[0053] This invention discloses a flow control method for online detection of SF6 gas using spectroscopic methods. The method utilizes a flow control device suitable for online detection of SF6 gas using spectroscopic methods. The required pressure difference in the gas storage tank at a flow rate of 300 mL / min and standard atmospheric pressure at 20°C is determined through a flow characteristic curve. A semiconductor refrigeration module controls the pressure in the gas storage tank to the pressure value corresponding to this pressure difference, thereby enabling the spectroscopic detection unit to perform detection at this gas flow rate with high accuracy. The specific process includes the following steps:

[0054] Step 1. First, connect the air inlet 1 to the vacuum pumping device, open the third solenoid valve 12, start the vacuum pumping device and stop when the pressure reaches 133Pa, close the third solenoid valve 12, and disconnect the pipeline.

[0055] Step 2. Connect the air inlet 1 to the SF6 storage device, open the third solenoid valve 12, start the semiconductor cooling module 11 to control the temperature of the storage tank 10 at 20℃, and then pre-store SF6 gas into the storage tank 10, conforming to the GBT12022-2014 industrial sulfur hexafluoride standard. When the second pressure sensor 8 displays pressure P... 20 When the pressure is 0.07 MPa, close the third solenoid valve 12 and disconnect the pipeline;

[0056] Step 3. Connect the air inlet 1 to the air chamber charging / discharging port of the GIS equipment, and adjust the pressure P of the pressure reducing valve. aSet to 0.1MPa, open the first solenoid valve 3 and the second solenoid valve 7, and the first pressure sensor 5 detects SF6 gas as P1.

[0057] Step 4. Calculate the SF6 gas density ρ0 in storage tank 10 at this time using the Beattie-Bridgman gas law. Where the pressure is P. 20 The temperature is T 20 The temperature is measured by the second temperature sensor 9.

[0058] P=(RTB-A)ρ 2 +RTρ; (1)

[0059] A = 73.882 × 10 -5 -5.132105×10 -7 ρ;

[0060] B = 2.50695 × 10 -3 -2.12283×10 -6 ρ;

[0061] R = 56.9502 × 10 -5 ;

[0062] In the above formula, P is the SF6 gas pressure, in 0.1 MPa; T is the SF6 gas temperature, in K; and ρ0 is the SF6 gas density, in kg / m³. 3 A and B have values ​​in the above formula, and R is a constant.

[0063] Step 5. The ambient temperature T1 is measured by the first temperature sensor 6. This temperature can be regarded as the gas temperature upstream of the pipeline, that is, the gas in the gas chamber is at the ambient temperature. According to the temperature-pressure characteristic curve, the required SF6 gas pressure P2 in the gas storage tank 10 under the condition of the upstream gas temperature T1 is obtained, and the gas temperature T when the SF6 gas density ρ0 and the pressure P2 are calculated according to the Beattie-Bridgman gas state equation. * 2.

[0064] Step 6. Activate the semiconductor cooling module 11 to raise the temperature T of the SF6 gas in the gas storage tank 10. 21 Control at T * 2, T * 2 represents the gas temperature at pressure P2, at which point the gas pressure in the storage tank is P2.

[0065] That is, by using a semiconductor cooling module, the temperature in the gas storage tank is reduced to T. * 2, thereby reducing the pressure to P2.

[0066] Step 7. Open the second solenoid valve 7. Under the action of the pressure difference ΔP (=P1-P2), the SF6 gas flows through the spectral detection unit at a flow rate Q of 300ml / min and finally enters the gas storage tank 10.

[0067] Step 8. Since SF6 gas is continuously entering the gas storage tank 10, the semiconductor cooling module 11 needs to continue to reduce the temperature in the gas storage tank 10. The cooling temperature T is:

[0068] Since the SF6 gas flow rate Q is 300 ml / min, the corresponding mass flow rate Q is... s =3.04×10 -5 If the gas flow rate is kg / s, then the gas increase in storage tank 10 per second is 3.04 × 10⁻⁶ kg / s. -5 kg, given that the volume of the gas storage tank 10 is V (m³) 3 Each test lasted 3 minutes, therefore, the density increase in gas storage tank 10 at the end of the test was Δρ = 5.472 × 10⁻⁶. -3 / V, at this time the density is ρ0+Δρ; based on the initial density ρ0 in the gas storage tank 10 and the density ρ0+Δρ in the gas storage tank 10 at the end of the test, the gas temperature T at the pressure P2 under this density is calculated by equation (1). S and T P Perform a fit on this temperature:

[0069] T = T S +(T P / T S )×t (2)

[0070] Where t is the detected time, in seconds (s). s and T P The temperatures required for the gas density in the gas storage tank to be ρ0 and ρ0+Δρ respectively, and the pressure to be P2, can be obtained from equation (1).

[0071] Step 9. After the test is completed, open the third solenoid valve 12, and the semiconductor cooling module 11 is energized in reverse to generate heat. Based on the P detected by the second pressure sensor 8 and the second temperature sensor 9... 21 and T 21 P 21 At this time, the gas pressure in the gas storage tank is T. 21 This is the temperature of the gas in the storage tank at this time.

[0072] The density ρ1 of SF6 gas is calculated using the Beattie-Bridgman gas law. Heating is stopped when ρ1 = ρ0, and the third solenoid valve 11 is closed. During this heating stage, the SF6 gas consumed by the test is refilled into the gas chamber.

[0073] In the aforementioned flow control method, the flow characteristic curve needs to be obtained experimentally first. Once the device is designed, its internal pipe material, length, degree of curvature, upstream pipe temperature, and pressure are all determined. Therefore, the gas flow rate in the pipe is only positively correlated with the downstream pipe pressure. Thus, this invention obtains the required downstream pipe pressure for a gas flow rate of Q (300 ml / min) under different upstream pipe temperatures through experiments. Eight sets of upstream pipe temperature experiments were conducted, obtaining eight sets of data. Curve fitting was performed on the data in the Origin data processing software to obtain the temperature-pressure characteristic curve. This curve represents the correspondence between the upstream pipe temperature and the downstream pipe pressure.

[0074] According to the ISO 6358 standard flow formula developed by the International Organization for Standardization (ISO), under the condition that the gas pipeline material, length, and degree of curvature are constant, the pressure difference between the inlet and outlet of the pipeline and the flow rate satisfy the following relationship:

[0075]

[0076]

[0077] Among them, Q s The actual mass flow rate of the gas in the pipeline is expressed in kg / s.

[0078] Q m The mass flow rate of the gas in the pipeline under congested flow conditions is expressed in kg / s.

[0079] P1 and P2 are the upstream and downstream pressures of the pipeline, respectively, in Pa;

[0080] ρ0 is the density of SF6 gas under standard conditions, in kg / m³. 3 ;

[0081] T0 and T1 are the standard temperature and the upstream temperature of the pipeline, respectively, in K.

[0082] b is the critical pressure ratio;

[0083] C is the sound conductance, in meters (m). 3 / S·Pa.

[0084] With the gas pipeline material, length, degree of curvature, upstream temperature, and pressure remaining constant (upstream pressure fixed at 0.1 MPa), multiple sets of data can be obtained through repeated experiments. and The parameters b and C can be obtained numerically using the least squares method. By changing the upstream temperature of the pipeline to -10℃, -5℃, 0℃, 5℃, 10℃, 15℃, 20℃, and 25℃, the corresponding parameters b and C are obtained, and then the flow characteristic curves at different upstream temperatures are obtained.

[0085] Q in the flow characteristic curve s The actual mass flow rate of the gas in the pipeline needs to be converted from the flow rate Q (300 ml / min) to mass flow rate. The density of SF6 gas under standard conditions is known to be 6.08 kg / m³. 3 Therefore, the mass flow rate Q corresponding to Q(300ml / min) is... s =3.04×10 -5 kg / s.

[0086] In Q s Q m (This value is related to the pipeline structure characteristics and upstream pipeline temperature, and is a fixed value under the condition that the above conditions remain unchanged.) With P1 determined, the downstream pipeline pressure P2 is calculated based on the flow characteristic curves obtained at different upstream pipeline temperatures. This yields eight sets of data on upstream pipeline temperature T1 and downstream pipeline pressure P2. The data is then used in the data processing software Origin for curve fitting to obtain the temperature-pressure characteristic curve. This curve represents the correspondence between upstream pipeline temperature and downstream pipeline pressure.

[0087] Example 2

[0088] This invention provides another embodiment of a flow control method applicable to online detection of SF6 gas using spectroscopic methods. To further improve the applicability of this method, in the experiment to determine the flow characteristic curves at different temperatures, the upstream temperature of the pipeline can be arbitrarily selected within the range of -40℃ to 35℃ to obtain the corresponding parameters b and C, thereby obtaining the flow characteristic curves at different upstream temperatures. Other method steps are the same as described above. Generally speaking, the more upstream temperature values ​​are taken in the experiment, and the more uniform the distribution of values ​​within the above temperature range, the closer the fitted temperature-pressure characteristic curve will be to the true value.

[0089] Example 3

[0090] This invention provides another embodiment of a flow control method suitable for online detection of SF6 gas using spectroscopic methods. To achieve precise flow control under cold conditions, in the experiment to determine the flow characteristic curves at different temperatures, the upstream temperature of the pipeline can also be taken as -35℃, -30℃, -25℃, -20℃, -15℃, -10℃, -5℃, 0℃, and 5℃. The corresponding parameters b and C are obtained at these upstream temperatures, thereby obtaining the flow characteristic curves at different upstream temperatures. Other method steps are the same as in Embodiment 1.

[0091] Example 4

[0092] This invention provides another embodiment of a flow control method applicable to online detection of SF6 gas using spectroscopic methods. To achieve precise flow control under warm conditions, in the experiment to determine the flow characteristic curves at different temperatures, the upstream temperature of the pipeline can be taken as 0℃, 5℃, 10℃, 15℃, 20℃, 25℃, 30℃, 35℃, and 40℃. The corresponding parameters b and C are obtained at these upstream temperatures, thereby obtaining the flow characteristic curves at different upstream temperatures. Other method steps are the same as in Embodiment 1.

[0093] Example 5

[0094] Based on the same inventive concept, embodiments of the present invention also provide a computer device, including a storage medium, a processor, and a computer program stored on the storage medium and executable on the processor. When the processor executes the computer program, it implements the steps of the flow control method for online detection of SF6 gas using spectroscopic methods as described in any of embodiments 1 to 4.

[0095] Example 6

[0096] Based on the same inventive concept, embodiments of the present invention also provide a computer storage medium storing a computer program, which, when executed by a processor, implements the steps of a flow control method for online detection of SF6 gas using spectroscopic methods as described in any of embodiments 1 to 4.

[0097] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0098] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0099] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0100] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0101] In this invention, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. The terms "connection" and "fixed" should be interpreted broadly; for example, "connection" can mean a fixed connection, a detachable connection, or an integral connection. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0102] In the description of this invention, it should be understood that the indicated orientation or positional relationship is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this invention and simplifying the description, and is not intended to indicate or imply that the device or unit referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this invention.

[0103] In the description of this specification, the terms "one embodiment," "some embodiments," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0104] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A flow control method suitable for online detection of SF6 gas using spectroscopic methods, characterized in that: This is achieved using a flow control device suitable for online detection of SF6 gas by spectroscopic method, including: Step 1. Connecting the inlet to a vacuum pump, opening the third solenoid valve, starting the vacuum pump to evacuate, then closing the third solenoid valve and disconnecting the pipeline; Step 2. Connecting the inlet to an SF6 storage device, opening the third solenoid valve, starting the semiconductor cooling module to lower the temperature of the storage tank, pre-storing SF6 gas in the storage tank, closing the third solenoid valve, and disconnecting the pipeline; Step 3. Connecting the inlet to the gas chamber filling / discharging port of the GIS equipment, setting the pressure reducing valve, opening the first and second solenoid valves, and using the first pressure sensor to detect SF6 gas; Step 4. Calculate the density, pressure, and temperature of SF6 gas in the storage tank at this time; Step 5. Measure the ambient temperature using the first temperature sensor, and select the target temperature for heating the SF6 gas in the storage tank based on the temperature-pressure characteristic curve; The temperature-pressure characteristic curve is determined as follows: The temperature-pressure characteristic curve is obtained experimentally, including the following relationship between the inlet and outlet pressure difference and the flow rate, under the condition that the gas pipeline material, length, and degree of curvature are constant: （3）； （4）； Among them, Q s Q represents the actual mass flow rate of the gas in the pipeline, in kg / s. m P1 represents the mass flow rate of the gas in the pipeline under congested flow conditions, in kg / s; P2 and P1 represent the upstream and downstream pressures of the pipeline, in Pa; ρ0 represents the density of SF6 gas under standard conditions, in kg / m³. 3 T0 and T1 are the standard temperature and upstream temperature of the pipeline, respectively, in K; b is the critical pressure ratio; C is the sonic conductance, in m. 3 / S·Pa; Step 6. Activate the semiconductor cooling module to raise the temperature T of the SF6 gas in the gas storage tank 10. 21 Control at T * 2, T * Step 2 represents the gas temperature at pressure P2, at which point the gas pressure in the storage tank is P2; Step 7. Open the second solenoid valve, allowing the SF6 gas to flow through the spectral detection unit under the pressure difference and enter the storage tank; Step 8. Continue to lower the temperature in the storage tank through the semiconductor cooling module, where the cooling temperature T is: T = T S +(T) P / T S )×t (2); where t is the detected time, in seconds (T) s T is the temperature required for SF6 gas to have a density ρ0 and a pressure P2 in the storage tank. p Let P be the temperature required for the SF6 gas in the storage tank to have a density of ρ0 + Δρ and a pressure of P2, where Δρ = 5.472 × 10⁻⁶. -3 / V: Step 9. After the test is completed, open the third solenoid valve, and the semiconductor cooling module is energized in reverse to generate heat, refilling the gas chamber with the SF6 gas consumed during the test. The readings are then calculated based on the P values ​​detected by the second pressure sensor and the second temperature sensor. 21 and T 21 P 21 The temperature and T required for the gas density to be ρ0 and the pressure to be P2 in the gas storage tank. 21 The required temperature for the gas density in the storage tank to be ρ0+Δρ and the pressure to be P2 is calculated using the Beattie-Bridgman gas state equation. When ρ1=ρ0, heating is stopped and the third solenoid valve is closed.

2. The flow control method for online detection of SF6 gas by spectroscopic method according to claim 1, characterized in that: The flow control device is composed of an air inlet (1), a pressure reducing valve (2), a first solenoid valve (3), a spectral detection unit (4), a first pressure sensor (5), a first temperature sensor (6), a second solenoid valve (7), a second pressure sensor (8), a second temperature sensor (9), and an air storage tank (10) connected in series. A semiconductor refrigeration module (11) is wrapped around the outside of the air storage tank (10). The air storage tank (10) is connected in series with the third solenoid valve (12) and the air inlet (1) via pipelines.

3. The flow control method for online detection of SF6 gas by spectroscopic method according to claim 2, characterized in that: The air inlet (1), pressure reducing valve (2), first solenoid valve (3), spectral detection unit (4), first pressure sensor (5), first temperature sensor (6), second solenoid valve (7), second pressure sensor (8), second temperature sensor (9) and air tank (10) are connected in sequence by pipelines; one end of the third solenoid valve (12) is connected to the pipeline between the air inlet (1) and pressure reducing valve (2), and the other end of the third solenoid valve (12) is connected to the pipeline between the second solenoid valve (7) and the second pressure sensor (8); the second pressure sensor (8) and the second temperature sensor (9) are installed on the air tank (10).

4. The flow control method for online detection of SF6 gas by spectroscopic method according to claim 2, characterized in that: The spectral detection unit (4) is a single spectral detection unit or an integrated unit of multiple spectral detection units; the forward current of the semiconductor cooling module (11) is for cooling, and the reverse current is for heating.

5. The flow control method for online detection of SF6 gas by spectroscopic method according to claim 2, characterized in that: The air inlet (1), the first solenoid valve (3), the spectral detection unit (4), the first pressure sensor (5), the first temperature sensor (6), the second solenoid valve (7), the second pressure sensor (8), the semiconductor refrigeration module (11), and the third solenoid valve (12) can all transmit information bidirectionally with the microcontroller and are controlled by the microcontroller.

6. The flow control method for online detection of SF6 gas by spectroscopic method according to claim 1, characterized in that: The temperature mentioned in step 4 is measured by the second temperature sensor: （1）； ； ； ； In the above formula, P is the SF6 gas pressure, in 0.1 MPa; T is the SF6 gas temperature, in K; and ρ0 is the SF6 gas density, in kg / m³. 3 A and B have values ​​in the above formula, and R is a constant.

7. A computer device, comprising a storage medium, a processor, and a computer program stored on the storage medium and executable on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the flow control method for online detection of SF6 gas by spectroscopic method as described in any one of claims 1-6.

8. A computer storage medium, characterized in that: The computer storage medium contains a computer program, which, when executed by a processor, implements the steps of a flow control method for online detection of SF6 gas using spectroscopic methods as described in any one of claims 1-6.

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