Device and method for detecting sulfur hexafluoride in low-temperature and high-humidity environment

Abstract

The invention discloses a device and a method for detecting sulfur hexafluoride in a low-temperature and high-humidity environment, and relates to the technical field of electrical equipment state monitoring, and the method comprises the following steps: connecting a quick connector with a sampling port of running sulfur hexafluoride charging equipment, adjusting the temperature and humidity in a constant-temperature and constant-humidity module and a sulfur hexafluoride tester, and measuring the temperature and humidity in the constant-temperature and constant-humidity module; sulfur hexafluoride is conveyed into the sulfur hexafluoride tester through the sampling pipeline, the flow of the sulfur hexafluoride is adjusted, the sulfur hexafluoride purity instrument and the sulfur hexafluoride humidity instrument are washed and tested, and the tail gas is discharged after being treated by the tail gas treatment device. According to the invention, sulfur hexafluoride detection in the low-temperature and high-humidity environment is realized, the problem that sulfur hexafluoride equipment cannot carry out detection in an extreme environment is overcome, and the safe operation level of power grid equipment is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of electrical equipment condition monitoring, and specifically to a sulfur hexafluoride detection device and method under low temperature and high humidity environments; it is used for sulfur hexafluoride detection under low temperature and high humidity environments. Background Technique

[0002] Pure new sulfur hexafluoride gas is a colorless, odorless, non-toxic, non-flammable inert gas at normal temperature and pressure. Its density is 6.16 g / L, about 5 times that of air, and it is one of the heaviest known gases. Due to its good chemical stability and thermal stability, high insulation and arc extinguishing performance, and non-flammable, non-explosive properties, as well as the advantages of compact design, low noise, and anti-pollution of sulfur hexafluoride gas substations, sulfur hexafluoride insulating gas is widely used in electrical equipment such as circuit breakers, instrument transformers, and bushings.

[0003] With the rapid development of the power industry, the commissioning volume of sulfur hexafluoride gas-insulated electrical equipment is also increasing, especially the continuous increase in GIS electrical equipment, and the gas consumption has increased sharply. When the electrical equipment is operating, due to the presence of a small amount of water vapor and contact substances such as black rubber in the sulfur hexafluoride gas chamber under high temperature and high pressure, when the equipment operates normally to generate an arc or abnormal partial discharge, the sulfur hexafluoride gas and impurities will undergo a decomposition reaction, producing hydrogen fluoride (HF), sulfur dioxide (SO 2 ), sulfur oxyfluoride (SOF 2 ), sulfuryl fluoride (SO 2 F 2 ), sulfur tetrafluoride (SF 4 ), sulfuryl tetrafluoride (SOF 4 ), sulfur oxyfluoride (SO 2 F 4 ) and other highly toxic and strongly corrosive substances, which have a strong corrosive effect on the internal metal components, resulting in a significant decline in the insulation performance of the electrical equipment and posing a serious hidden danger to the safe operation of the electrical equipment. For sulfur hexafluoride electrical equipment that has been in operation for a long time, if the sulfur hexafluoride gas inside is directly discharged into the atmosphere, it will pollute the atmospheric environment and pose a threat to human health, and a very small amount of some decomposition products can cause death.

[0004] The detection items of sulfur hexafluoride gas include air (N 2 , O 2 ), carbon tetrafluoride (CF 4 ), sulfur hexafluoride (SF 6 ) purity, SF 6 trace moisture test (H 2O), acidity (HF), hydrolysable fluoride (HF), mineral oil, and toxicity bioassay. The relevant standards clearly require that the sulfur hexafluoride detection should be carried out under the conditions of an environmental temperature not lower than 5°C and a relative humidity not greater than 80%, and avoid detection under adverse weather conditions such as thunder, rain, fog, and snow.

[0005] At present, for the relevant detection items of sulfur hexafluoride-filled equipment in operation, it is only possible to arrange the detection during the day in summer as much as possible to prevent the detection from being unable to be carried out due to too low temperature in winter and high humidity in rainy and snowy weather. However, the sulfur hexafluoride detection project has clear requirements for the detection cycle. After the sulfur hexafluoride is filled and left standing for 24 hours, it is necessary to detect the SF 6 humidity. Environmental factors greatly limit the time for sulfur hexafluoride detection. And sulfur hexafluoride-filled equipment such as circuit breakers and GIS is very important in power grid equipment. If the detection cannot be carried out in time, it will bring unstable factors and risks to the safe and stable operation of the power grid.

[0006] In the prior art, the Chinese authorized patent publication number: CN 117805221 A, discloses a sulfur hexafluoride detection device and method for a GIS equipment room, including a data acquisition module, a mobile control module, a core control module, a vacuum pump, a power supply battery, a sampling pipeline, a MEMS ion mobility spectrometry analysis module, and a mobile vehicle; the data acquisition module is fixedly installed at the front end of the mobile vehicle, and the vacuum pump and the MEMS ion mobility spectrometry analysis module are arranged adjacent to each other at the rear end of the mobile vehicle; the mobile control module and the power supply battery are arranged adjacent to each other between the data acquisition module and the vacuum pump, and the data acquisition module is connected to the vacuum pump and the MEMS ion mobility spectrometry analysis module respectively through the sampling pipeline; both the MEMS ion mobility spectrometry analysis module and the data acquisition module

[0007] are connected to the mobile control module, and the mobile control module is communicatively connected to the core control module; it solves the technical problem that in the prior art, the number of GIS devices is huge, and there is a large lag in manual meter reading, resulting in low detection efficiency of sulfur hexafluoride. Summary of the Invention

[0008] The technical problem to be solved by the present invention is to disclose a sulfur hexafluoride detection device and method in a low-temperature and high-humidity environment in view of the deficiencies of the prior art, and solve the problem that sulfur hexafluoride equipment cannot be detected in an extreme low-temperature and high-humidity environment.

[0009] To achieve the above object, the present invention is realized through the following technical solutions: A sulfur hexafluoride detection device in a low-temperature and high-humidity environment, including a sampling component and a sulfur hexafluoride tester;

[0010] The sampling component includes a sampling fixture, a quick interface, a constant temperature and humidity module, a first temperature and humidity adjustment module, a first pipeline, and a pipeline penetration fixing module;

[0011] The left end of the constant temperature and humidity module is fixedly connected to the sampling fixture through the quick interface, and the right end of the constant temperature and pressure module is fixedly connected to the left end of the sulfur hexafluoride tester through the first pipeline and the pipeline penetration fixing module; the first temperature and humidity adjustment module is fixedly installed on the constant temperature and humidity module;

[0012] Inside the sulfur hexafluoride tester, there are a gas detection component and an exhaust gas treatment component;

[0013] The gas detection component includes a sulfur hexafluoride comprehensive detection module, a helium ion storage tank, a pressure reducing valve, and a sulfur hexafluoride humidity test module;

[0014] A first flow regulating valve is fixedly installed at the upper end of the sulfur hexafluoride comprehensive detection module. The middle of the sulfur hexafluoride comprehensive detection module is connected to a third valve, and the other end of the third valve is fixedly connected to the helium ion storage tank through a pressure reducing valve;

[0015] The lower end of the sulfur hexafluoride comprehensive detection module is fixedly connected to the sulfur hexafluoride humidity test module through a fourth pipeline and a fifth pipeline;

[0016] The upper end of the sulfur hexafluoride humidity test module is connected to a second flow regulating valve and a fourth valve at the right end of a three-way valve. The left end of the three-way valve is fixedly connected to the right end of a first valve, and the first valve is fixedly connected to the pipeline penetration fixing module; The bottom of the sulfur hexafluoride tester is equipped with moving pulleys.

[0017] Furthermore:

[0018] The exhaust gas treatment component includes a sulfur hexafluoride exhaust gas treatment module and a fifth valve;

[0019] The upper end of the sulfur hexafluoride exhaust gas treatment module is connected to the fourth pipeline connecting the sulfur hexafluoride comprehensive detection module; the upper end of the sulfur hexafluoride exhaust gas treatment module is connected to the fifth pipeline connecting the sulfur hexafluoride humidity test module; the lower end of the sulfur hexafluoride exhaust gas treatment module is fixedly connected to the upper end of the fifth valve, and the lower end of the fifth valve is fixedly connected to a seventh pipeline for exhaust gas discharge.

[0020] Furthermore:

[0021] The pipeline penetration fixing module is a device for transporting sulfur hexafluoride gas through pipelines;

[0022] The quick interface adopts a top pressure design;

[0023] The sampling fixture adopts an openable and adjustable design;

[0024] The capacity of the helium ion storage tank is 5L;

[0025] The first pipeline is made of polytetrafluoroethylene pipe, and the inner diameter of the first pipeline is 2.5 mm; the outside of the first pipeline is wrapped with a heat-insulating and moisture-proof outer layer;

[0026] The second pipeline, the third pipeline, the fourth pipeline, the fifth pipeline, the sixth pipeline and the seventh pipeline are made of stainless steel pipes.

[0027] Furthermore:

[0028] A method for detecting sulfur hexafluoride in a low-temperature and high-humidity environment is carried out according to the following steps:

[0029] Step (1): Connect the quick connector to the operating sulfur hexafluoride equipment. The first temperature and humidity adjustment module adjusts the temperature of the first constant temperature and humidity module, and the first temperature and humidity adjustment module adjusts the humidity of the sulfur hexafluoride tester;

[0030] Step (2): Open the sampling port of the sulfur hexafluoride equipment, and the sulfur hexafluoride gas is transported through the first pipeline into the sulfur hexafluoride tester;

[0031] Step (3): The three-way valve in the sulfur hexafluoride tester divides the sulfur hexafluoride gas into two parts. One part of the sulfur hexafluoride gas passes through the first flow regulating valve and the sulfur hexafluoride comprehensive detection module measures the purity of sulfur hexafluoride, and the other part of the sulfur hexafluoride gas passes through the second flow regulating valve and the sulfur hexafluoride humidity test module measures the humidity of sulfur hexafluoride; after the measurement is completed, the measurement results are displayed, and finally the sulfur hexafluoride tester is rinsed;

[0032] Step (4): During the process of testing the purity and humidity of sulfur hexafluoride gas in the above steps, the sulfur hexafluoride detection module monitors the leakage of sulfur hexafluoride gas in real time. After the test is completed, the sulfur hexafluoride gas is processed by the sulfur hexafluoride tail gas treatment module and then discharged.

[0033] Even further:

[0034] In the step (1), the first temperature and humidity adjustment module adjusts the temperature to 20±1°C and the humidity to 15% to 25%;

[0035] The low-temperature and high-humidity environment means that the environmental temperature is lower than 5°C and the environmental humidity is greater than 80%.

[0036] Even further:

[0037] In the step (2), during the flushing, the flow rate in the pipeline is 30 mL / min to 35 mL / min; the flushing time is 3 min to 5 min.

[0038] Even further:

[0039] In step (3), the sulfur hexafluoride comprehensive detection module and the humidity test module conduct detections simultaneously; the sulfur hexafluoride gas flow rate in the sulfur hexafluoride comprehensive detection module is 2.5 mL / min, and the sulfur hexafluoride gas flow rate in the sulfur hexafluoride humidity detection module is 20 mL / min;

[0040] The pressure of the pressure reducing valve at the outlet of the helium ion storage tank is 0.2 MPa to 0.25 MPa.

[0041] Furthermore:

[0042] In step (3), the sulfur hexafluoride comprehensive detection module uses helium as a carrier gas and adopts chromatography to detect the content of each component in sulfur hexafluoride;

[0043] The gas components measured by the sulfur hexafluoride comprehensive detection module include: air, CF 4 , C 2 F 6 , C 3 F 8 , and the purity of sulfur hexafluoride is in mass fraction, and the calculation formula is as follows:

[0044] Formula 1: S = 1 - [(S1 + S2 + S3) / 1000000];

[0045] In Formula 1: S is the purity of sulfur hexafluoride, with the unit of %;

[0046] S1 is the mass fraction of CF in sulfur hexafluoride, with the unit of mg / kg; 4 S2 is the mass fraction of C in sulfur hexafluoride, with the unit of mg / kg;

[0047] S2 is the mass fraction of C in sulfur hexafluoride, with the unit of mg / kg; 2 F 6 S3 is the mass fraction of C in sulfur hexafluoride, with the unit of mg / kg;

[0048] S3 is the mass fraction of C in sulfur hexafluoride, with the unit of mg / kg; 3 F 8 Because the sulfur hexafluoride detection value is in volume fraction, it is necessary to convert the detected components into mass fraction, and the conversion formula is as follows:

[0049] Formula 2: Z = V × (M1 / M);

[0050] In Formula 2:

[0051] Z is the mass fraction component value in sulfur hexafluoride, with the unit of mg / kg;

[0052] V is the component volume fraction in sulfur hexafluoride, with the unit of uL / L;

[0053] V is the component volume fraction in sulfur hexafluoride, with the unit of uL / L;

[0054] M1 is the molar mass of the detected component, with the unit of g / mol;

[0055] M is the molar mass in sulfur hexafluoride, with the unit of g / mol;

[0056] Since the molar masses of each component and sulfur hexafluoride are known values, this formula can be simplified to:

[0057] Formula Three: Z = k × V;

[0058] In the said Formula Three:

[0059] Z is the mass fraction component value in sulfur hexafluoride, with the unit of mg / kg;

[0060] V is the component detection value in sulfur hexafluoride, with the unit of μL / L;

[0061] k is the conversion system for converting the volume fraction of each component into the mass fraction;

[0062] Among them, k(CF 4 ) is 0.602, k(C 2 F 6 ) is 0.945, k(C 3 F 8 ) is 1.288, k(H 2 O) is 0.123;

[0063] In the said step (3), the sulfur hexafluoride comprehensive detection module and the humidity test module automatically perform continuous measurement twice, and the average value of the two measurement values is the final measurement value;

[0064] The said final measurement value needs to meet the standard deviation, and the standard deviation needs to be < ±10.0%. If the standard deviation is greater than the set value, automatic remeasurement will be performed; among them, the standard deviation calculation formula is as follows:

[0065] Formula Four: R = (S1 - S2) / S;

[0066] In the said Formula Four:

[0067] R is the repeatability of the sulfur hexafluoride measured twice continuously;

[0068] S1 is the measured value of each component of sulfur hexafluoride for the first time;

[0069] S2 is the measured value of each component of sulfur hexafluoride for the second time;

[0070] S is the average value of the sulfur hexafluoride components measured twice continuously;

[0071] When performing the sulfur hexafluoride comprehensive test, CF 4 and C 2 F6 , C 3 F 8 If the standard deviations of all three components meet the requirements, it is determined that the final value meets the requirements.

[0072] Furthermore:

[0073] In the step (4), when the concentration of sulfur hexafluoride reaches 50 ppm in the sulfur hexafluoride leakage monitoring module, the leakage warning light turns on.

[0074] Compared with the prior art, the present invention has the following beneficial effects:

[0075] The present invention provides a sulfur hexafluoride detection device and method in a low-temperature and high-humidity environment; through the operations of sampling, detecting, and tail gas treatment of sulfur hexafluoride by a sulfur hexafluoride tester, the problem that sulfur hexafluoride equipment cannot be detected in extreme environments is overcome. BRIEF DESCRIPTION OF THE DRAWINGS

[0076] Figure 1 It is a schematic structural diagram of the sulfur hexafluoride detection device of the present invention;

[0077] Figure 2 It is a schematic flow diagram of the sulfur hexafluoride detection method of the present invention

[0078] Figure 3 It is the sulfur hexafluoride detection result of the present invention.

[0079] Description of the reference numerals:

[0080] 1 - Sampling fixture, 2 - Quick interface, 3 - Temperature and humidity control module, 4 - First temperature and humidity adjustment module, 5 - First pipeline, 6 - Second pipeline, 7 - Third pipeline, 8 - Fourth pipeline, 9 - Fifth pipeline, 10 - Sixth pipeline, 11 - Seventh pipeline, 12 - First valve, 13 - Second valve, 14 - Third valve, 15 - Fourth valve, 16 - Fifth valve, 17 - Three-way valve, 18 - First flow regulating valve, 19 - Second flow regulating valve, 20 - Sulfur hexafluoride comprehensive detection module, 21 - Helium ion storage tank, 22 is a pressure reducing valve, 23 - Sulfur hexafluoride humidity test module, 24 - Sulfur hexafluoride tail gas treatment module, 25 - Sulfur hexafluoride tester, 26 - Second temperature and humidity adjustment module, 27 is a pipeline penetration fixing module, 28 - Moving pulley, 29 - Sulfur hexafluoride leakage monitoring module. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0081] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0082] As Figure 1 shown, it shows a schematic structural diagram of a sulfur hexafluoride detection device of the present invention, including: a sampling component and a sulfur hexafluoride tester 25;

[0083] The sampling component includes a sampling holder 1, a quick interface 2, a constant temperature and humidity module 3, a first temperature and humidity adjustment module 4, a first pipeline 5, and a pipeline penetration fixing module 27;

[0084] The left end of the constant temperature and humidity module 3 is fixedly connected to the sampling holder 1 through the quick interface 2, and the right end of the constant temperature and pressure module 3 is fixedly connected to the left end of the sulfur hexafluoride tester 25 through the first pipeline 5 and the pipeline penetration fixing module 27; the first temperature and humidity adjustment module 4 is fixedly installed on the constant temperature and humidity module 3;

[0085] The sulfur hexafluoride tester 25 internally includes a gas detection component and an exhaust gas treatment component;

[0086] The gas detection component includes a sulfur hexafluoride comprehensive detection module 20, a helium ion storage tank 21, a pressure reducing valve 22, and a sulfur hexafluoride humidity test module 23;

[0087] The upper end of the sulfur hexafluoride comprehensive detection module 20 is fixedly installed with a first flow regulating valve 18, the middle of the sulfur hexafluoride comprehensive detection module 20 is connected to a third valve 14, and the other end of the third valve 14 is fixedly connected to the helium ion storage tank 21 through a pressure reducing valve 22;

[0088] The lower end of the sulfur hexafluoride comprehensive detection module 20 is fixedly connected to the sulfur hexafluoride humidity test module 23 through a fourth pipeline 8 and a fifth pipeline 9;

[0089] The upper end of the sulfur hexafluoride humidity test module 23 is connected to a second flow regulating valve 19 and a fourth valve 15 at the right end of a three-way valve 17, the left end of the three-way valve 17 is fixedly connected to the right end of a first valve 12, and the first valve 12 is fixedly connected to the pipeline penetration fixing module 27; the bottom of the sulfur hexafluoride tester 25 is equipped with moving pulleys 28; among them, 4 moving pulley rollers are installed, and when transferring the position, the device can be moved to the best detection location by pushing the rollers;

[0090] The exhaust gas treatment component includes a sulfur hexafluoride exhaust gas treatment module 24 and a fifth valve 16;

[0091] The upper end of the sulfur hexafluoride tail gas treatment module 24 is connected to the sulfur hexafluoride comprehensive detection module 20 through the fourth pipeline 8; the upper end of the sulfur hexafluoride tail gas treatment module 24 is connected to the sulfur hexafluoride humidity test module 23 through the fifth pipeline 9; the lower end of the sulfur hexafluoride tail gas treatment module 24 is fixedly connected to the upper end of the fifth valve 16, and the lower end of the fifth valve 16 is fixedly connected to the seventh pipeline for tail gas emission.

[0092] Among them, the pipeline penetration fixing module 27 is a device for transporting sulfur hexafluoride gas through pipelines;

[0093] The quick interface 2 adopts a top-pressure design. When the quick connection reaches a certain position, the top-pressure needle of the quick interface 2 opens the sampling port, effectively avoiding air leakage and ensuring the safety of gas sampling.

[0094] The sampling fixator 1 adopts an openable and adjustable design. The sampling fixator 1 is a telescopic module. Before the connection for quick connection operation, the opening of the fixed sampling fixator 1 is large, which is convenient for the quick connection to dock with the sampling port. After the quick connection, the opening can be adjusted so that the sampling fixator 1 is firmly fixed to the pipeline at the sampling port of the original sulfur hexafluoride equipment.

[0095] The capacity of the helium ion storage tank 21 is 5L, which can meet the requirement of continuously detecting the components of more than 1000 bottles of sulfur hexafluoride gas.

[0096] The first pipeline 5 is made of polytetrafluoroethylene tube, and the inner diameter of the first pipeline (5) is 2.5mm; the outside of the first pipeline (5) is wrapped with a heat-insulating and moisture-proof outer layer, effectively isolating the influence of the external environment on the pipeline.

[0097] The second pipeline (6), the third pipeline (7), the fourth pipeline (8), the fifth pipeline (9), the sixth pipeline (10) and the seventh pipeline (11) are made of stainless steel tubes, which are convenient for maintaining the shape and reducing the dead volume, and improving the detection accuracy.

[0098] As Figure 2 shown, it shows the schematic flow chart of the sulfur hexafluoride detection method of the present invention, including the following steps:

[0099] Step (1): Connect the quick connector 2 to the operating sulfur hexafluoride equipment. The first temperature and humidity adjustment module 4 adjusts the temperature of the first constant temperature and humidity module 3, and the first temperature and humidity adjustment module 4 adjusts the humidity of the sulfur hexafluoride tester 25.

[0100] Step (2): Open the sampling port of the sulfur hexafluoride equipment, and the sulfur hexafluoride gas is transported to the sulfur hexafluoride tester 25 through the first pipeline 5.

[0101] Step (3): The three-way valve 17 in the sulfur hexafluoride tester 25 divides the sulfur hexafluoride gas into two parts. One part of the sulfur hexafluoride gas passes through the first flow regulating valve 18, and the sulfur hexafluoride purity is measured by the sulfur hexafluoride comprehensive detection module 20. The other part of the sulfur hexafluoride gas passes through the second flow regulating valve 19, and the sulfur hexafluoride humidity is measured by the sulfur hexafluoride humidity test module 23. After the measurement is completed, the measurement results are displayed, and finally the sulfur hexafluoride tester 25 is rinsed.

[0102] Step (4): During the process of testing the purity and humidity of the sulfur hexafluoride gas in Step (3), the sulfur hexafluoride detection module 29 monitors the leakage of the sulfur hexafluoride gas in real time. After the test is completed, the sulfur hexafluoride gas is treated and discharged through the sulfur hexafluoride tail gas treatment module 24.

[0103] Among them, in Step (1), the first temperature and humidity adjustment module 4 adjusts the temperature to 20±1°C and the humidity to 15% to 25%; the low-temperature and high-humidity environment means that the environmental temperature is lower than 5°C and the environmental humidity is greater than 80%.

[0104] In Step (2), the flow rate in the pipeline during flushing is 30 mL / min to 35 mL / min; the flushing time is 3 min to 5 min. If the flushing time is too long, it may cause insufficient pressure in the equipment and waste sulfur hexafluoride gas.

[0105] In Step (3), the sulfur hexafluoride comprehensive detection module 20 and the humidity test module 23 carry out detections simultaneously; the flow rate of the sulfur hexafluoride gas in the sulfur hexafluoride comprehensive detection module 20 is 2.5 mL / min, and the flow rate of the sulfur hexafluoride gas in the sulfur hexafluoride humidity detection module 23 is 20 mL / min.

[0106] The pressure of the pressure reducing valve 22 at the outlet of the helium ion storage tank 21 is 0.2 MPa to 0.25 MPa.

[0107] In Step (4), when the sulfur hexafluoride concentration reaches 50 ppm in the sulfur hexafluoride leakage monitoring module 29, the leakage warning light is on.

[0108] As Figure 3 shown, it shows the sulfur hexafluoride detection results of the present invention.

[0109] In Step (3), the sulfur hexafluoride comprehensive detection module 20 uses helium as a carrier gas and adopts chromatography to detect the content of each component in sulfur hexafluoride.

[0110] The gas components measured by the sulfur hexafluoride comprehensive detection module include: air, CF 4 、C 2 F 6 、C 3 F8 , the purity of sulfur hexafluoride is the mass fraction, and the calculation formula is as follows:

[0111] Formula 1: S = 1 - [(S1 + S2 + S3) / 1000000];

[0112] In the above Formula 1: S is the purity of sulfur hexafluoride, with the unit of %;

[0113] S1 is the mass fraction of CF4 in sulfur hexafluoride, with the unit of mg / kg;

[0114] S2 is the mass fraction of C2F6 in sulfur hexafluoride, with the unit of mg / kg;

[0115] S3 is the mass fraction of C3F8 in sulfur hexafluoride, with the unit of mg / kg;

[0116] Because the detected value of sulfur hexafluoride is the volume fraction, it is necessary to convert the detected components into mass fractions. The conversion formula is as follows:

[0117] Formula 2: Z = V × (M1 / M);

[0118] In the above Formula 2:

[0119] Z is the mass fraction component value in sulfur hexafluoride, with the unit of mg / kg;

[0120] V is the component volume fraction in sulfur hexafluoride, with the unit of uL / L;

[0121] M1 is the molar mass of the detected component, with the unit of g / mol;

[0122] M is the molar mass in sulfur hexafluoride, with the unit of g / mol;

[0123] Since the molar masses of each component and sulfur hexafluoride are known values, this formula can be simplified to:

[0124] Formula 3: Z = k × V;

[0125] In the above Formula 3:

[0126] Z is the mass fraction component value in sulfur hexafluoride, with the unit of mg / kg;

[0127] V is the component detected value in sulfur hexafluoride, with the unit of uL / L;

[0128] k is the conversion system for converting the volume fraction of each component into the mass fraction;

[0129] Among them, k(CF 4 ) is 0.602, k(C 2 F 6 ) is 0.945, k(C3 F 8 ), 1.288 is k(H 2 O) 0.123;

[0130] In the step (3), the sulfur hexafluoride comprehensive detection module (20) and the humidity test module (23) automatically perform continuous measurement twice, and the average value of the two measurement values is the final measurement value;

[0131] The final measurement value needs to meet the standard deviation, and the standard deviation needs to be < ±10.0%. If the standard deviation is greater than the set value, it will be automatically retested; among them, the standard deviation calculation formula is as follows:

[0132] Formula Four: R = (S1 - S2) / S;

[0133] The formula Four is:

[0134] R is the repeatability of the sulfur hexafluoride measured twice continuously;

[0135] S1 is the measured value of each component of sulfur hexafluoride for the first time;

[0136] S2 is the measured value of each component of sulfur hexafluoride for the second time;

[0137] S is the average value of the sulfur hexafluoride components measured twice continuously;

[0138] When the sulfur hexafluoride is comprehensively tested, CF 4 , C 2 F 6 , C 3 F 8 The standard deviations of the three components all meet the requirements, then it is determined that the final value meets the requirements;

[0139] In the specific implementation, the environmental humidity is 41%, the environmental temperature is 14.6 °C, the sample to be detected is 8L, and the instrument used is a desktop helium ion gas chromatograph. Among them, the minimum detection limit of the desktop helium ion gas chromatograph is: air: 0.1 μL / L, CF 4 : 0.1 μL / L, C 2 F 6 : 0.1 μL / L, C 3 F 8 : 0.1 μL / L; The detection results obtained by using the above formula are:

[0140] Sulfur hexafluoride (SF 6 ) purity (mass fraction) / 10 -2 , reference value: ≥99.9, the final value: 99.98;

[0141] Air (mass fraction) / 10 -6, Reference value: ≤300, the final value: 57.2;

[0142] Carbon tetrafluoride (CF 4 ), (mass fraction) / 10 -6 , Reference value: ≤100, the final value: 8.0;

[0143] Hexafluoroethane (C 2 F 6 ), (mass fraction) / 10 -6 , Reference value: ≤200, the final value: 37.6;

[0144] Octafluoropropane (C 3 F 8 ), (mass fraction) / 10 -6 , Reference value: ≤50, the final value: 2.9

[0145] Water (H 2 O), (mass fraction) / 10 -6 , Reference value: ≤5, the final value: 1.8; Finally, it is concluded that the sample to be tested meets the requirements.

[0146] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A sulfur hexafluoride detection device in a low temperature and high humidity environment, Features: include: Sampling kit and sulfur hexafluoride tester (25); The sampling assembly comprises a sampling fixture (1), a quick interface (2), a constant temperature and humidity module (3), a first temperature and humidity adjustment module (4), a first pipeline (5) and a pipeline crossing and fixing module (27); The left end of the constant temperature and humidity module (3) is fixedly connected to the sampling fixture (1) via the quick interface (2); the right end of the constant temperature and pressure module (3) is fixedly connected to the left end of the sulfur hexafluoride tester (25) via the first pipeline (5) and the pipeline crossing fixing module (27); the first temperature and humidity adjustment module (4) is fixedly mounted on the constant temperature and humidity module (3); The sulfur hexafluoride tester (25) includes a gas detection component and an exhaust gas treatment component; The gas detection assembly comprises a sulfur hexafluoride comprehensive detection module (20), a helium ion storage tank (21), a pressure reducing valve (22), and a sulfur hexafluoride humidity testing module (23); A first flow regulating valve (18) is fixedly mounted on the upper end of the sulfur hexafluoride comprehensive detection module (20); a third valve (14) is connected in the middle of the sulfur hexafluoride comprehensive detection module (20); and the other end of the third valve (14) is fixedly connected to the helium ion storage tank (21) via a pressure reducing valve (22); The lower end of the sulfur hexafluoride comprehensive detection module (20) is fixedly connected to the sulfur hexafluoride humidity test module (23) via a fourth pipeline (8) and a fifth pipeline (9); The upper end of the sulfur hexafluoride humidity test module (23) is connected to the second flow regulating valve (19) and the fourth valve (15) and the right end of the three-way valve (17); the left end of the three-way valve (17) is fixedly connected to the right end of the first valve (12); the first valve (12) is fixedly connected to the pipeline crossing fixed module (27); and a movable pulley (28) is installed at the bottom of the sulfur hexafluoride tester (25).

2. A sulfur hexafluoride detection device in a low temperature and high humidity environment according to claim 1, Features: The tail gas treatment component comprises a sulfur hexafluoride tail gas treatment module (24) and a fifth valve (16); The upper end of the sulfur hexafluoride tail gas treatment module (24) is connected to the fourth pipeline (8) to the sulfur hexafluoride comprehensive detection module (20); the upper end of the sulfur hexafluoride tail gas treatment module (24) is connected to the fifth pipeline (9) to the sulfur hexafluoride humidity test module (23); the lower end of the sulfur hexafluoride tail gas treatment module (24) is fixedly connected to the upper end of the fifth valve (16), and the lower end of the fifth valve (16) is fixedly connected to the seventh pipeline for tail gas discharge.

3. A sulfur hexafluoride detection device in a low temperature and high humidity environment according to claim 1, Features: The pipeline crossing fixing module (27) is a device for conveying sulfur hexafluoride gas through the pipeline; The quick interface (2) adopts a top-pressing design; The sampling fixture (1) adopts an adjustable opening design; The helium ion storage tank (21) has a capacity of 5L; The first pipeline (5) is a polytetrafluoroethylene tube, and the inner diameter of the first pipeline (5) is 2.5 mm; the first pipeline (5) is wrapped with a heat-insulating and moisture-insulating outer layer; The second pipeline (6), the third pipeline (7), the fourth pipeline (8), the fifth pipeline (9), the sixth pipeline (10) and the seventh pipeline (11) are made of stainless steel pipes.

4. A method for detecting sulfur hexafluoride in a low temperature and high humidity environment. Using a sulfur hexafluoride detection device in a low temperature and high humidity environment as described in any one of claims 1 to 3, Features: Follow these steps: Step (1): connecting the quick connector (2) to the running sulfur hexafluoride equipment, the first temperature and humidity adjustment module (4) adjusting the temperature of the first constant temperature and humidity module (3), and the first temperature and humidity adjustment module (4) adjusting the humidity of the sulfur hexafluoride tester (25); Step (2): opening the sampling port of the sulfur hexafluoride equipment, and transporting the sulfur hexafluoride gas to the sulfur hexafluoride tester (25) through the first pipeline (5); Step (3): the three-way valve (17) in the sulfur hexafluoride tester (25) divides the sulfur hexafluoride gas into two parts, one part of the sulfur hexafluoride gas passes through the first flow regulating valve (18) and uses the sulfur hexafluoride comprehensive detection module (20) to measure the sulfur hexafluoride purity, and the other part of the sulfur hexafluoride gas passes through the second flow regulating valve (19) and uses the sulfur hexafluoride humidity test module (23) to measure the sulfur hexafluoride humidity; after the measurement is completed, the measurement result is displayed, and finally the sulfur hexafluoride tester (25) is flushed; Step (4): During the test of the purity and humidity of sulfur hexafluoride gas in step (3), the sulfur hexafluoride detection module (29) monitors the leakage of sulfur hexafluoride gas in real time. After the test is completed, the sulfur hexafluoride gas is treated by the sulfur hexafluoride tail gas treatment module (24) and then discharged.

5. The method for detecting sulfur hexafluoride in a low temperature and high humidity environment according to claim 4, Features: In the step (1), the first temperature and humidity adjustment module (4) adjusts the temperature to 20±1°C and the humidity to 15% to 25%; The low temperature and high humidity environment refers to an environment temperature lower than 5°C and an environment humidity greater than 80%.

6. A method for detecting sulfur hexafluoride in a low temperature and high humidity environment according to claim 4, Features: In step (2), the flow rate in the pipeline during flushing is 30 mL / min to 35 mL / min; and the flushing time is 3 min to 5 min.

7. The method for detecting sulfur hexafluoride in a low temperature and high humidity environment according to claim 4, Features: In the step (3), the sulfur hexafluoride comprehensive detection module (20) and the humidity test module (23) are tested simultaneously; the sulfur hexafluoride gas flow rate in the sulfur hexafluoride comprehensive detection module (20) is 2.5 mL / min, and the sulfur hexafluoride gas flow rate in the sulfur hexafluoride humidity detection module (23) is 20 mL / min; The pressure of the pressure reducing valve (22) at the outlet of the helium ion storage tank (21) is 0.2 MPa to 0.25 MPa.

8. The method for detecting sulfur hexafluoride in a low temperature and high humidity environment according to claim 4, Features: In the step (3), the sulfur hexafluoride comprehensive detection module (20) uses helium as a carrier gas to detect the content of each component in sulfur hexafluoride by chromatography; The gas components measured by the sulfur hexafluoride comprehensive detection module include: air, CF4, C2F6, C3F8, and the purity of sulfur hexafluoride is the mass fraction, and the calculation formula is as follows: Formula 1: S=1-[(S1+S2+S3) / 1000000]; In the formula 1: S is the purity of sulfur hexafluoride, unit is % ‌‌ S1 is the mass fraction of CF4 in sulfur hexafluoride, in mg / kg; S2 is the mass fraction of C2F6 in sulfur hexafluoride, in mg / kg; S3 is the mass fraction of C3F8 in sulfur hexafluoride, in mg / kg; Because the detection value of sulfur hexafluoride is volume fraction, the detected components need to be converted into mass fraction. The conversion formula is as follows: Formula 2: Z = V × (M1 / M); In the formula 2: Z is the mass fraction of sulfur hexafluoride, in mg / kg; V is the volume fraction of the component in sulfur hexafluoride, in uL / L; M1 is the molar mass of the detected component, in g / mol; M is the molar mass of sulfur hexafluoride in g / mol; Since the molar masses of each component and sulfur hexafluoride are known values, the formula can be simplified to: Formula 3: Z = k × V; In the formula 3: Z is the mass fraction of sulfur hexafluoride, in mg / kg; V is the detection value of the components in sulfur hexafluoride, in uL / L; k is the conversion system for converting the volume fraction of each component into mass fraction; Among them, k(CF4) is 0.602, k(C2F6) is 0.945, k(C3F8) is 1.288, and k(H2O) is 0.123; In the step (3), the sulfur hexafluoride comprehensive detection module (20) and the humidity test module (23) automatically perform two consecutive measurements, and the average value of the two measurement values ​​is the final measurement value; The final measured value needs to meet the standard deviation, and the standard deviation needs to be less than ±10.0%. If the standard deviation is greater than the set value, the test will be automatically repeated; the standard deviation calculation formula is as follows: Formula 4: R = (S1-S2) / S; The fourth formula is: R is the repeatability of two consecutive determinations of sulfur hexafluoride; S1 is the first measured value of each component of sulfur hexafluoride; S2 is the second determination value of each component of sulfur hexafluoride; S is the average value of two consecutive measurements of each component of sulfur hexafluoride; When the sulfur hexafluoride is comprehensively tested, the standard deviations of the three components CF4, C2F6, and C3F8 need to meet the requirements, and then it is determined that the final value meets the requirements.

9. The method for detecting sulfur hexafluoride in a low temperature and high humidity environment according to claim 4, Features: In the step (4), when the sulfur hexafluoride concentration reaches 50 ppm, the leakage warning light of the sulfur hexafluoride leakage monitoring module (29) turns on.

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