CN113933213B - Binary mixed gas mixing ratio measuring method and device based on gas substitution method - Google Patents
Binary mixed gas mixing ratio measuring method and device based on gas substitution method Download PDFInfo
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Abstract
A binary mixed gas mixing ratio measuring method and device based on a gas substitution method belong to the technical field of electric power system detection and solve the problem of how to measure the mixing ratio of binary mixed gas by adopting the gas substitution method; the technical scheme of the invention is based on the principle of measuring the density of the mixed insulating gas, adopts a gas substitution method to measure the mixed gas ratio of the mixed insulating gas, can meet the existing mixed gas ratio measurement of the binary mixed gas, can also realize the measurement of the mixed gas ratio of the whole range (0% -100%), high precision, linearity, normal pressure and pressure, can also meet the mixed gas ratio detection of other non-insulating binary mixed gases, has wide application range, and can flexibly select components by directly using pure component gas to participate in the test without preparing standard gas, and has low test cost.
Description
Technical Field
The invention belongs to the technical field of power system detection, and relates to a binary mixed gas mixing ratio measuring method and device based on a gas substitution method.
Background
SF 6 The gas is the gas insulating medium with the most excellent performance at present, the insulating performance is about 2.5 times of that of air under the same pressure, the arc extinguishing performance is 100 times of that of air, and the gas is widely applied to electrical equipment with various voltage levels, so that the volume of the electrical equipment is effectively reduced, the occupied area of the equipment is reduced, and the overhaul period of the equipment is prolonged.
However, SF 6 There are also obvious disadvantages, SF 6 Is a strong greenhouse effect gas, and the equivalent greenhouse effect is CO 2 About 3200 years in the atmosphere, and the environmental impact is serious when the gas is discharged into the atmosphere. Furthermore SF 6 Liquefaction of gasThe temperature is higher, once the gas is liquefied, the insulating property of the equipment is greatly reduced, and the safe operation of the equipment is seriously endangered. SF (sulfur hexafluoride) 6 The gas was measured at 0.7MPa (SF in a typical circuit breaker) 6 Pressure of (2) is about-30 ℃, the pure SF is known 6 The gas is not suitable for outdoor use in winter in northeast, xinjiang, inner Mongolia, qinghai-Tibet plateau and other areas.
To cope with SF 6 The problem of easy liquefaction due to the greenhouse effect of (2) is widely adopted at present 6 With another gas, e.g. N 2 Or CF (CF) 4 Mixing to form SF 6 /N 2 Or SF (sulfur hexafluoride) 6 /CF 4 The mixed insulating gas replaces pure SF 6 Is used. The SF in the equipment can be effectively reduced by the mixed gas 6 The dosage of the gas reduces SF in the equipment 6 Liquefaction temperature of gas. SF (sulfur hexafluoride) 6 The performance of the mixed insulating gas is mainly determined by the nature of each gas and the gas mixing ratio of the gases, and the accurate determination of the gas mixing ratio is SF 6 An important basis for mixed gas on-site use.
For the determination of the binary mixed insulating gas mixing ratio, the main methods at present are 3: 1) Gas chromatography. The main components in the mixed gas are separated and quantitatively measured by adopting a gas chromatography method, and then calculated according to a normalization method, so that the mixed gas ratio of the mixed gas is obtained. 2) Thermal conductivity detection. And measuring by a sensor adopting a thermal conductivity principle, and then calculating a measurement result according to an external standard method to obtain the mixed gas ratio of the mixed gas. 3) Infrared spectroscopy. Using SF 6 The gas has characteristic absorption in the infrared light wave band, and the absorption light intensity of the selected wave band and SF in the sample gas are measured 6 And establishing a relation between the concentrations so as to obtain the gas-mixing ratio of the mixed gas. The chromatographic method has the defects of high accuracy, low analysis speed, complex operation, severe environmental requirements, power supply and carrier gas requirement and the like, is not suitable for field measurement, and cannot generally realize full-range mixed gas ratio detection. The thermal conductivity detection method is only suitable for detecting the mixed gas ratio of the binary mixed insulating gas, the mixed gas ratio of the ternary mixed insulating gas cannot be measured, the detection precision is low, and the sensor is easy to generate after long-time useDrift, requires periodic calibration. The infrared spectrometry has low detection precision, is easy to be interfered by the outside, and has the defects of reduced instrument performance and reduced detection accuracy along with the increase of service life, and meanwhile, the instrument cannot be suitable for non-SF 6 Mixed gases (e.g. C 4 F 7 N and CO 2 Mixed gas of (c) and (d) a mixed gas ratio is detected. Document "design of a binary mixed gas concentration ultrasonic measuring instrument" (Wang Mingwei, yao Zhan. Design of a binary mixed gas concentration ultrasonic measuring instrument [ J)]Computer measurement and control, 2010,18 (12): 2908-2910.) discloses a theory that sound velocity has a certain relation with the concentration and temperature of binary mixed gas to be measured according to the propagation of ultrasonic waves in the binary mixed gas, improves a calculation formula of the gas concentration of the binary mixed gas detected by ultrasonic waves, and provides a novel temperature measurement method; however, this document does not address how to measure the binary mixed gas mixture ratio.
Disclosure of Invention
The invention aims to solve the technical problem of how to measure the mixed gas ratio of binary mixed gas by adopting a gas substitution method.
The invention solves the technical problems through the following technical scheme:
the binary mixed gas ratio measuring method based on the gas substitution method is applied to a mixed gas ratio measuring device, and the mixed gas ratio measuring device comprises: the device comprises a U-shaped oscillating tube (1), a magnet (2), an electronic excitation oscillator (3), a frequency counter (4), a pressure sensor (5), a first temperature sensor (6), a second temperature sensor (7), a third temperature sensor (8), a temperature control heat preservation layer (9), a three-way valve (10) and an air outlet valve (11); the bottom of the U-shaped oscillating tube (1) is fixedly provided with a magnet (2), and the upper parts of two vertical tubes of the U-shaped oscillating tube (1) are respectively provided with a frequency counter (4); the pipe orifice of the left vertical pipe of the U-shaped oscillating pipe (1) is in sealing connection with the first port of the three-way valve (10) through a pipeline, the second port and the third port of the three-way valve (10) are respectively connected with the outside through pipelines, and the pressure sensor (5) is in sealing connection with the pipeline between the pipe orifice of the left vertical pipe of the U-shaped oscillating pipe (1) and the first port of the three-way valve (10); the pipe orifice of the right vertical pipe of the U-shaped oscillating pipe (1) is in sealing connection with the air inlet end of the air outlet valve (11) through a pipeline, and the air outlet end of the air outlet valve (11) is in sealing connection with an exhaust pipeline; the first temperature sensor (6) is arranged between the left vertical pipe and the right vertical pipe of the U-shaped oscillating pipe (1); the electronic excitation oscillator (3) is arranged below the fixed magnet (2); u type oscillating tube (1), magnet (2), electron excitation oscillator (3), frequency counter (4), pressure sensor (5), first temperature sensor (6), air outlet valve (11) all install in accuse temperature heat preservation (9), second temperature sensor (7) install on accuse temperature heat preservation (9) outer wall, third temperature sensor (8) install on accuse temperature heat preservation (9) inner wall.
The method for measuring the mixed gas ratio comprises the following steps:
s1, calibrating a mixed gas ratio measuring device;
s2, filling pressure P into the U-shaped oscillating tube (1) 0 The oscillation period T observed when the mixed gas in the U-shaped oscillation tube (1) is recorded 0 The density of the binary mixed gas under the standard state is measured to be ρ 0 Build density ρ 0 Relationship with first elemental gas volume, density at standard conditions, second elemental gas volume, density at standard conditions;
s3, continuously filling binary mixed gas to be detected into the U-shaped oscillating tube (1) until the pressure is P 1 So that P 1 ＝2P 0 Recording the observed oscillation period T when the mixed gas in the U-shaped oscillation tube (1) is in the state 1 The density of the gas in the U-shaped oscillating tube (1) under the standard state is measured to be ρ 1 Build density ρ 1 Relationship with first elemental gas volume, density at standard conditions, second elemental gas volume, density at standard conditions;
s4, releasing the binary mixed gas in the U-shaped oscillating tube (1) to the pressure of P 0 Then filling pure first unitary gas into the U-shaped oscillating tube (1) until the pressure is P 1 Instead, record the observed oscillation period T when the mixed gas in the U-shaped oscillation tube (1) is in the state 2 The density of the gas in the U-shaped oscillating tube (1) under the standard state is measured to be ρ 2 Build density ρ 2 With the first element gas volume, density under standard conditions and second element gasRelationship of volume and density in standard state;
s5, calculating the volume of the second binary gas by comparing the change of the gas density in the replacement front and rear U-shaped oscillating tubes (1) and combining the densities of the first binary gas and the second binary gas in the standard state, so as to obtain the gas-gas mixing ratio of the binary mixed gas.
The technical scheme of the invention is based on the principle of measuring the density of the mixed insulating gas, adopts a gas substitution method to measure the mixed gas ratio of the mixed insulating gas, can meet the existing mixed gas ratio measurement of the binary mixed gas, can also realize the measurement of the mixed gas ratio of the whole range (0% -100%), high precision, linearity, normal pressure and pressure, can also meet the mixed gas ratio detection of other non-insulating binary mixed gases, has wide application range, and can flexibly select components by directly using pure component gas to participate in the test without preparing standard gas, and has low test cost.
As a further improvement of the technical scheme of the invention, the method for calibrating the mixed gas ratio measuring device comprises the following steps: firstly, connecting an air inlet pipeline of a U-shaped oscillating tube (1) with clean air, and opening an air inlet valve (10) and an air outlet valve (11) to enable the air to keep stable flow rate to flush the U-shaped oscillating tube (1) and the corresponding pipeline; then closing the air inlet valve (10) and the air outlet valve (11), enabling the temperature of the measuring device to be constant through the temperature control heat preservation layer (9), controlling the air outlet valve (11) to balance the gas pressure in the U-shaped oscillating tube (1) with the atmospheric pressure, and recording the reading P of the pressure sensor (5) at the moment; starting the measuring device to record a stable oscillation period T A And the temperature t of the U-shaped oscillating tube (1) A The method comprises the steps of carrying out a first treatment on the surface of the After the air calibration is finished, the pure water is replaced for calibration, the U-shaped oscillating tube (1) is flushed by the pure water, then the U-shaped oscillating tube (1) is filled with the pure water, no bubbles exist in the water in the tube, the temperature of the measuring device and the pure water in the tube is stabilized through the temperature control heat preservation layer (9), the measuring device is started, and the stable oscillating period T is recorded w And the temperature t of the U-shaped oscillating tube (1) w The method comprises the steps of carrying out a first treatment on the surface of the And finally, calculating the constant F of the U-shaped oscillating tube (1) according to the recorded data.
As a further improvement of the technical scheme of the invention, the calculation formula of the constant F of the measuring device is as follows:
wherein F represents the constant of the U-shaped oscillating tube (1); ρ w Represents the density of water at the test temperature in g/cm 3 ；ρ A Represents the density of air at the test temperature in g/cm 3 ；T w The unit of the oscillation period observed when the U-shaped oscillation tube (1) is filled with water is s; t (T) A The unit of the oscillation period observed when the U-shaped oscillation tube (1) is air is s.
As a further improvement of the technical scheme of the invention, the density ρ is 0 Density ρ 1 Density ρ 2 The calculation formula is as follows:
wherein ρ is w Represents the density of water at the test temperature in g/cm 3 ；T w The unit of the oscillation period observed when the U-shaped oscillation tube (1) is filled with water is s.
As a further improvement of the technical scheme of the invention, the density ρ is established 0 The relationship with the first elemental gas volume, the density in the standard state, and the second elemental gas volume, the density in the standard state is as follows:
ρ 0 V 0 ＝V 1 ρ 11 +V 2 ρ 12 (3)
wherein V is 1 The volume of the first element gas in the mixed gas is called as volume hereinafter, and the second element gas and the third element gas are the same; v (V) 2 For the volume of the second binary gas ρ 11 Is the density of the first element gas in the standard state ρ 12 Is the density of the second binary gas in the standard state.
As a further improvement of the technical scheme of the invention, the density ρ is established 1 The relationship with the first elemental gas volume, the density in the standard state, and the second elemental gas volume, the density in the standard state is as follows：
ρ 1 V 0 ＝2V 1 ρ 11 +2V 2 ρ 12 (4)。
As a further improvement of the technical scheme of the invention, the density ρ is established 2 The relationship with the first elemental gas volume, the density in the standard state, and the second elemental gas volume, the density in the standard state is as follows:
as a further improvement of the technical scheme of the invention, the method for obtaining the mixed gas ratio of the binary mixed gas by calculating the volume of the second binary gas is as follows:
from equation (5) -equation (4):
thus obtaining V 2 Then:
V 1 ＝V 0 -V 2 (7)
the binary gas mixing ratio can be calculated by carrying in the formula (8):
as a further improvement of the technical scheme of the invention, the binary mixed gas is as follows: SF (sulfur hexafluoride) 6 /N 2 Or SF (sulfur hexafluoride) 6 /CF 4 Or C 4 F 7 N/CO 2 。
The device of the binary mixed gas ratio measuring method based on the gas substitution method comprises the following components: the device comprises a U-shaped oscillating tube (1), a magnet (2), an electronic excitation oscillator (3), a frequency counter (4), a pressure sensor (5), a first temperature sensor (6), a second temperature sensor (7), a third temperature sensor (8), a temperature control heat preservation layer (9), a three-way valve (10) and an air outlet valve (11); the bottom of the U-shaped oscillating tube (1) is fixedly provided with a magnet (2), and the upper parts of two vertical tubes of the U-shaped oscillating tube (1) are respectively provided with a frequency counter (4); the pipe orifice of the left vertical pipe of the U-shaped oscillating pipe (1) is in sealing connection with the first port of the three-way valve (10) through a pipeline, the second port and the third port of the three-way valve (10) are respectively connected with the outside through pipelines, and the pressure sensor (5) is in sealing connection with the pipeline between the pipe orifice of the left vertical pipe of the U-shaped oscillating pipe (1) and the first port of the three-way valve (10); the pipe orifice of the right vertical pipe of the U-shaped oscillating pipe (1) is in sealing connection with the air inlet end of the air outlet valve (11) through a pipeline, and the air outlet end of the air outlet valve (11) is in sealing connection with an exhaust pipeline; the first temperature sensor (6) is arranged between the left vertical pipe and the right vertical pipe of the U-shaped oscillating pipe (1); the electronic excitation oscillator (3) is arranged below the fixed magnet (2); u type oscillating tube (1), magnet (2), electron excitation oscillator (3), frequency counter (4), pressure sensor (5), first temperature sensor (6), air outlet valve (11) all install in accuse temperature heat preservation (9), second temperature sensor (7) install on accuse temperature heat preservation (9) outer wall, third temperature sensor (8) install on accuse temperature heat preservation (9) inner wall.
The invention has the advantages that:
the technical scheme of the invention is based on the principle of measuring the density of the mixed insulating gas, adopts a gas substitution method to measure the mixed gas ratio of the mixed insulating gas, can meet the existing mixed gas ratio measurement of the binary mixed gas, can also realize the measurement of the mixed gas ratio of the whole range (0% -100%), high precision, linearity, normal pressure and pressure, can also meet the mixed gas ratio detection of other non-insulating binary mixed gases, has wide application range, and can flexibly select components by directly using pure component gas to participate in the test without preparing standard gas, and has low test cost.
Drawings
FIG. 1 is a block diagram of a binary mixed gas mixture ratio measuring device based on a gas substitution method;
FIG. 2 is a flow chart of a binary mixed gas mixture ratio measurement method based on a gas substitution method;
fig. 3 is a schematic diagram of the principle of measuring the mixed gas ratio of binary mixed gas by the gas substitution method.
Detailed Description
For the purpose of making the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the technical solutions in the embodiments of the present invention will be clearly and completely described in the following in conjunction with the embodiments of the present invention, and it is apparent that the described embodiments are some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
The technical scheme of the invention is further described below with reference to the attached drawings and specific embodiments:
1. structural composition of the device
As shown in fig. 1, the binary mixed gas mixture ratio measuring device based on the gas substitution method includes: the device comprises a U-shaped oscillating tube (1), a magnet (2), an electronic excitation oscillator (3), a frequency counter (4), a pressure sensor (5), a first temperature sensor (6), a second temperature sensor (7), a third temperature sensor (8), a temperature control heat preservation layer (9), a three-way valve (10) and an air outlet valve (11).
The U-shaped oscillating tube (1) is made of boronized glass, the volume of the U-shaped oscillating tube is 3mL (calibrated by a water injection weighing method), the magnet (2) is fixed at the bottom of the U-shaped oscillating tube (1), and the upper parts of two vertical tubes of the U-shaped oscillating tube (1) are respectively provided with a frequency counter (4); the pipe orifice of the left vertical pipe of the U-shaped oscillating pipe (1) is in sealing connection with the first port of the three-way valve (10) through a pipeline, the second port and the third port of the three-way valve (10) are respectively connected with the outside through pipelines, the pressure sensor (5) is in sealing connection with the pipeline between the pipe orifice of the left vertical pipe of the U-shaped oscillating pipe (1) and the first port of the three-way valve (10), and the three-way valve (10) is used for controlling different gases to enter the U-shaped oscillating pipe (1); the pressure sensor (5) is used for monitoring the pressure value of the gas in the U-shaped oscillating tube (1), and the detection precision is +/-0.01 kPa; the pipe orifice of the right vertical pipe of the U-shaped oscillating pipe (1) is in sealing connection with the air inlet end of the air outlet valve (11) through a pipeline, and the air outlet end of the air outlet valve (11) is in sealing connection with an exhaust pipeline; the first temperature sensor (6) is arranged between the left vertical pipe and the right vertical pipe of the U-shaped oscillating pipe (1); the electronic excitation oscillator (3) is installed in the below that is fixed with magnet (2), U type oscillating tube (1), magnet (2), electronic excitation oscillator (3), frequency counter (4), pressure sensor (5), first temperature sensor (6), air outlet valve (11) all install in accuse temperature heat preservation (9), second temperature sensor (7) install on accuse temperature heat preservation (9) outer wall, accuse temperature heat preservation (9) be used for carrying out temperature regulation and control to the test area, third temperature sensor (8) install on accuse temperature heat preservation (9) inner wall.
2. Principle of measuring substance density by U-shaped oscillating tube method
The U-shaped oscillating tube (1) method for measuring the density of a substance has been widely used for many years, and has the advantages of rapidness, reliability, high accuracy, high measurement precision and the like. The principle of detecting the density of the substances by using the oscillating tube method is that the oscillating frequency of a U-shaped glass tube based on electromagnetic induction is utilized, namely, a magnet is fixed on a U-shaped glass measuring tube, the U-shaped glass measuring tube is oscillated by an electronic excitation oscillator, the oscillating period of the glass tube is measured by an oscillating sensor, and each U-shaped glass tube has the characteristic frequency or oscillates according to the natural frequency. When the glass tube is filled with an object, its frequency is a function of the mass of the filling material in the tube. As the mass of the substance increases its frequency decreases, i.e. the oscillation period T increases. During measurement, certain substances are selected as standard substances, and the density value of the measured substances is calculated through the difference value of the oscillation frequency between the measured substances and the standard substances after the frequency is measured.
The U-shaped oscillating tube (1) needs to be measured for instrument constant F before testing, and is generally measured by adopting at least two standard substances, wherein the density interval of the two standard substances is required to cover the density range of a test sample. For SF 6 The gas has a density of 6.16kg/m at 20 DEG C 3 Therefore, air and pure water can be selected as standard substances, and the constant F of the instrument can be calculated through the density measurement result of the U-shaped oscillating tube (1) on the standard substances:
wherein the method comprises the steps ofF represents the instrument constant of the tester of the U-shaped oscillating tube (1); ρ w Represents the density of water at the test temperature in g/cm 3 (ρ at 20 ℃ C.) w ＝0.9982g/cm 3 )；ρ A Represents the density of air at the test temperature in g/cm 3 (ρ at 20 ℃ C.) A ＝0.00120g/cm 3 )；T w The unit of the oscillation period observed when the U-shaped oscillation tube (1) is filled with water is s; t (T) A The unit of the oscillation period observed when the U-shaped oscillation tube (1) is air is s.
Therefore, the U-shaped oscillation tube (1) is used for detecting the binary mixed gas, and the oscillation period T of the mixed gas is measured Mixing The density ρ of the mixed gas can be obtained Mixing ：
Wherein: ρ Mixing Represents the density, g/cm, of the mixture at the test temperature 3 ；ρ w Represents the density of water at the test temperature in g/cm 3 ；T w The unit of the oscillation period observed when the U-shaped oscillation tube (1) is filled with water is s; t (T) Mixing The unit of the oscillation period observed when the mixed gas is in the U-shaped oscillation tube (1) is s.
3. Measuring binary gas mixture ratio
3.1 principle
SF at normal temperature and pressure 6 The mixed gas can be treated as an ideal gas. For binary mixed gases, when the mixing ratio of the two gases is determined, the density of the mixed gas at a specific temperature and pressure is also determined. The invention adopts a gas substitution method to measure, namely, high-purity component gas is used for substituting part of mixed insulating gas to be measured, then density changes of the gas before and after substitution are compared, and the gas-mixing ratio of the mixed insulating gas to be measured is calculated. The binary mixed gas is as follows: SF (sulfur hexafluoride) 6 /N 2 Or SF (sulfur hexafluoride) 6 /CF 4 Or C 4 F 7 N/CO 2 。
As shown in FIG. 2, SF is used 6 /N 2 For example, the binary mixed gas is SF 6 The second binary gas is N 2 ：
a. Firstly, filling the U-shaped oscillating tube (1) with pressure P 0 The density of the mixed insulating gas to be measured at 20 ℃ is ρ 0 ；
b. Continuously filling mixed insulating gas to be tested into the U-shaped oscillating tube (1) until the pressure is P 1 So that P 1 ＝2P 0 The density of the gas in the U-shaped pipe at 20 ℃ is measured to be ρ 1 ；
c. Releasing the gas in the U-shaped oscillating tube (1) to a pressure of P 0 (or re-filling the U-shaped oscillating tube (1) with pressure P 0 To-be-tested mixed insulating gas) and then continuously filling high-purity SF into the U-shaped oscillating tube (1) 6 Gas to pressure P 1 The density of the gas in the U-shaped oscillating tube (1) at 20 ℃ is measured to be ρ 2 ；
d. SF at 20℃and not too high a gas pressure (several atmospheres) 6 The gas can be treated and calculated as an ideal gas, the ratio of the pressures of the gases being equal to the ratio of the volumes.
As shown in FIG. 3, the above operation corresponds to the pressure being P 1 Half of the gas in the sample to be tested is used in an equal volume of high purity SF 6 Gas substitution, in fact corresponding to half of the N in the mixed insulating gas to be tested 2 With SF of equal volume 6 Instead of. By comparing the change of the gas density before and after replacement, combining SF 6 Density and N of (2) 2 Can establish a density with N 2 Correspondence between volumes, thereby realizing N 2 And the volume is accurately measured, so that the mixed gas ratio of the binary mixed gas is obtained.
3.2 operational flow of the device
1) Device calibration
The device is calibrated when it is first used. And (3) calibrating the U-shaped oscillating tube (1) by using air and water as standard substances. Firstly, clean air is introduced into a U-shaped oscillating tube (1) through a three-way valve (10), and the reading of a pressure sensor (5) is recorded to be P Empty space By controlling the temperatureThe temperature of the heat preservation layer (9) is controlled, three temperature sensors of the first temperature sensor (6), the second temperature sensor (7) and the third temperature sensor (8) are read, after the air and the U-shaped oscillating tube (1) reach the set temperature and are stable, the electronic excitation oscillator (3) is started for measurement, and the oscillation period T is recorded through the frequency counter (4) and the first temperature sensor (6) A Temperature t of U-shaped tube A . After air measurement is finished, water is injected into the U-shaped oscillating tube (1) through the three-way valve (10), no bubble exists in the water in the tube, the temperature is controlled through the temperature control and insulation layer (9), and after the temperature of the water and the U-shaped oscillating tube (1) reaches the set temperature and is stable, the oscillating period T is recorded through the frequency counter (4) and the first temperature sensor (6) w And the temperature t of the U-shaped oscillating tube (1) w . The instrument constant F of the device is calculated according to equation (1).
2) Sample detection
The sample to be tested is connected to a mixed insulating gas interface to be tested of a three-way valve (10), the sample gas is utilized to sweep the U-shaped oscillating tube (1) for 3-5 min, the air inlet is stopped, the three-way valve (10) is closed, and the air outlet valve (11) is regulated to enable the gas pressure in the U-shaped oscillating tube (1) to reach the reading of the pressure sensor (5) to be 0.1MPa. The temperature control and insulation layer (9) is opened to enable the temperature of the U-shaped oscillating tube (1) to be 20+/-0.01 ℃ (measured by the first temperature sensor (6)), the electronic excitation oscillator (3) is opened to start measurement, and the oscillation period T is recorded by the frequency counter (4) and the first temperature sensor (6) Measuring And the temperature t of the U-shaped oscillating tube (1) Measuring The density of the sample mixed gas is measured to be ρ according to the formula (2) 0 。
Continuously filling mixed insulating gas to be tested into the U-shaped oscillating tube (1) through the three-way valve (10) until the reading of the pressure sensor (5) is P 1 Let P 1 ＝2P 0 According to the above steps, the gas density ρ in the U-shaped oscillation tube (1) at 20 ℃ is measured 1 。
3) Pure SF 6 Gas substitution
Opening an air outlet valve (11) to make the air pressure in the U-shaped oscillating tube (1) be P 1 The pressure of the mixed insulating gas to be tested is released to the pressure sensor (5) and is read as P 0 (U-shaped vibration can also be adoptedAfter the mixed insulating gas to be detected in the oscillating tube (1) is completely emptied, the pressure is refilled to P 0 To be tested) and closing the air outlet valve (11). High-purity SF is introduced into the U-shaped oscillating tube (1) through a three-way valve (10) 6 The gas to pressure sensor (5) reads P 0 The three-way valve (10) is closed, the temperature of the U-shaped oscillating tube (1) is 20+/-0.01 ℃ through the temperature control and insulation layer (9), the temperature is measured through the first temperature sensor (6), the electronic excitation oscillator (3) is opened, the measurement is started, and the oscillation period T is recorded through the frequency counter (4) and the first temperature sensor (6) Measuring And the temperature t of the U-shaped oscillating tube (1) Measuring The density of the gas in the U-shaped oscillating tube (1) at this time is measured as ρ according to the formula (2) 2 . After the test is finished, the air outlet valve (11) is opened to release the pressure in the U-shaped oscillating tube (1), and the three-way valve (10) is opened to use the high-purity SF 6 And (3) fully flushing the U-shaped oscillating tube (1) and the corresponding pipelines, and closing the instrument.
3.3 calculation procedure
Filling the U-shaped oscillating tube (1) with pressure P 0 Is assumed to be SF in the mixed insulating gas to be tested in the U-shaped oscillating tube (1) at the moment 6 The volume of the gas is V sF6 ，N 2 The volume of the gas is V N2 The density of the mixed insulating gas to be measured at the moment is measured to be ρ 0 Then:
ρ 0 V 0 ＝V SF6 ρ SF6 +V N2 ρ N2 (3)
continuously filling mixed insulating gas to be tested into the U-shaped pipe until the pressure is P 1 (P 1 ＝2P 0 ) The gas density at this time was measured to be ρ 1 。
ρ 1 V 0 ＝2V SF6 ρ SF6 +2V N2 ρ N2 (4)
The pressure of the mixed insulating gas to be tested in the U-shaped oscillating tube (1) is reduced to P 0 Then is filled with pure SF 6 Gas to P 1 At this time, the density of the gas in the U-shaped oscillating tube (1) is measured to be ρ 2 ：
Subtracting equation (4) from equation (5):
thus obtaining V N2 Then:
V SF6 ＝V 0 -V N2 (7)
the binary gas mixing ratio can be calculated by carrying in the formula (8):
the above embodiments are only for illustrating the technical solution of the present invention, and are not limiting; although the invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present invention.
Claims (10)
1. The binary mixed gas ratio measuring method based on the gas substitution method is characterized by being applied to a mixed gas ratio measuring device, wherein the mixed gas ratio measuring device comprises the following components: the device comprises a U-shaped oscillating tube (1), a magnet (2), an electronic excitation oscillator (3), a frequency counter (4), a pressure sensor (5), a first temperature sensor (6), a second temperature sensor (7), a third temperature sensor (8), a temperature control heat preservation layer (9), a three-way valve (10) and an air outlet valve (11); the bottom of the U-shaped oscillating tube (1) is fixedly provided with a magnet (2), and the upper parts of two vertical tubes of the U-shaped oscillating tube (1) are respectively provided with a frequency counter (4); the pipe orifice of the left vertical pipe of the U-shaped oscillating pipe (1) is in sealing connection with the first port of the three-way valve (10) through a pipeline, the second port and the third port of the three-way valve (10) are respectively connected with the outside through pipelines, and the pressure sensor (5) is in sealing connection with the pipeline between the pipe orifice of the left vertical pipe of the U-shaped oscillating pipe (1) and the first port of the three-way valve (10); the pipe orifice of the right vertical pipe of the U-shaped oscillating pipe (1) is in sealing connection with the air inlet end of the air outlet valve (11) through a pipeline, and the air outlet end of the air outlet valve (11) is in sealing connection with an exhaust pipeline; the first temperature sensor (6) is arranged between the left vertical pipe and the right vertical pipe of the U-shaped oscillating pipe (1); the electronic excitation oscillator (3) is arranged below the fixed magnet (2); the U-shaped oscillating tube (1), the magnet (2), the electronic excitation oscillator (3), the frequency counter (4), the pressure sensor (5), the first temperature sensor (6) and the air outlet valve (11) are all arranged in the temperature control heat preservation layer (9), the second temperature sensor (7) is arranged on the outer wall of the temperature control heat preservation layer (9), and the third temperature sensor (8) is arranged on the inner wall of the temperature control heat preservation layer (9);
the method for measuring the mixed gas ratio comprises the following steps:
s1, calibrating a mixed gas ratio measuring device;
s2, filling pressure P into the U-shaped oscillating tube (1) 0 The oscillation period T observed when the mixed gas in the U-shaped oscillation tube (1) is recorded 0 The density of the binary mixed gas under the standard state is measured to be ρ 0 Build density ρ 0 Relationship with first elemental gas volume, density at standard conditions, second elemental gas volume, density at standard conditions;
s3, continuously filling binary mixed gas to be detected into the U-shaped oscillating tube (1) until the pressure is P 1 So that P 1 ＝2P 0 Recording the observed oscillation period T when the mixed gas in the U-shaped oscillation tube (1) is in the state 1 The density of the gas in the U-shaped oscillating tube (1) under the standard state is measured to be ρ 1 Build density ρ 1 Relationship with first elemental gas volume, density at standard conditions, second elemental gas volume, density at standard conditions;
s4, releasing the binary mixed gas in the U-shaped oscillating tube (1) to the pressure of P 0 Then the pure first unitary gas is filled into the U-shaped oscillating tube (1) until the pressure is P 1 Instead, record the U-shaped oscillation at this timePeriod T of oscillation observed when the tube (1) is filled with a mixed gas 2 The density of the gas in the U-shaped oscillating tube (1) under the standard state is measured to be ρ 2 Build density ρ 2 Relationship with first elemental gas volume, density at standard conditions, second elemental gas volume, density at standard conditions;
s5, calculating the volume of the second binary gas by comparing the change of the gas density in the replacement front and rear U-shaped oscillating tubes (1) and combining the densities of the first binary gas and the second binary gas in the standard state, so as to obtain the gas-gas mixing ratio of the binary mixed gas.
2. The binary mixed gas ratio measuring method based on the gas substitution method according to claim 1, wherein the method for calibrating the mixed gas ratio measuring device is as follows: firstly, connecting an air inlet pipeline of a U-shaped oscillating tube (1) with clean air, and opening an air inlet valve (10) and an air outlet valve (11) to enable the air to keep stable flow rate to flush the U-shaped oscillating tube (1) and the corresponding pipeline; then closing the air inlet valve (10) and the air outlet valve (11), enabling the temperature of the measuring device to be constant through the temperature control heat preservation layer (9), controlling the air outlet valve (11) to balance the gas pressure in the U-shaped oscillating tube (1) with the atmospheric pressure, and recording the reading P of the pressure sensor (5) at the moment; starting the measuring device to record a stable oscillation period T A And the temperature t of the U-shaped oscillating tube (1) A The method comprises the steps of carrying out a first treatment on the surface of the After the air calibration is finished, the pure water is replaced for calibration, the U-shaped oscillating tube (1) is flushed by the pure water, then the U-shaped oscillating tube (1) is filled with the pure water, no bubbles exist in the water in the tube, the temperature of the measuring device and the pure water in the tube is stabilized through the temperature control heat preservation layer (9), the measuring device is started, and the stable oscillating period T is recorded w And the temperature t of the U-shaped oscillating tube (1) w The method comprises the steps of carrying out a first treatment on the surface of the And finally, calculating the constant F of the U-shaped oscillating tube (1) according to the recorded data.
3. The binary mixed gas mixture ratio measuring method based on the gas substitution method according to claim 2, wherein the constant F of the measuring device is calculated by the following formula:
wherein F represents the constant of the U-shaped oscillating tube (1); ρ w Represents the density of water at the test temperature in g/cm 3 ；ρ A Represents the density of air at the test temperature in g/cm 3 ；T w The unit of the oscillation period observed when the U-shaped oscillation tube (1) is filled with water is s; t (T) A The unit of the oscillation period observed when the U-shaped oscillation tube (1) is air is s.
4. The method for measuring the mixed gas ratio of binary mixed gas based on the gas substitution method according to claim 3, wherein the density ρ is 0 Density ρ 1 Density ρ 2 The calculation formula is as follows:
wherein ρ is w Represents the density of water at the test temperature in g/cm 3 ；T w The unit of the oscillation period observed when the U-shaped oscillation tube (1) is filled with water is s.
5. The method for measuring the mixed gas ratio of binary mixed gas based on the gas substitution method according to claim 4, wherein the density ρ is established 0 The relationship with the first elemental gas volume, the density in the standard state, and the second elemental gas volume, the density in the standard state is as follows:
ρ 0 V 0 ＝V 1 ρ 11 +V 2 ρ 12 (3)
wherein V is 1 For the volume of the first unitary gas, V 2 For the volume of the second binary gas ρ 11 Is the density of the first element gas in the standard state ρ 12 Is the density of the second binary gas in the standard state.
6. The gas substitution-based method of claim 5The binary mixed gas mixing ratio measuring method is characterized in that the density rho is established 1 The relationship with the first elemental gas volume, the density in the standard state, and the second elemental gas volume, the density in the standard state is as follows:
ρ 1 V 0 ＝2V 1 ρ 11 +2V 2 ρ 12 (4)。
7. the method for measuring the mixed gas ratio of binary mixed gas based on the gas substitution method according to claim 6, wherein the density ρ is established 2 The relationship with the first elemental gas volume, the density in the standard state, and the second elemental gas volume, the density in the standard state is as follows:
8. the method for measuring the mixed gas ratio of the binary mixed gas based on the gas substitution method according to claim 7, wherein the method for calculating the volume of the second binary gas to obtain the mixed gas ratio of the binary mixed gas is as follows:
from equation (5) -equation (4):
thus obtaining V 2 Then:
V 1 ＝V 0 -V 2 (7)
the binary gas mixing ratio can be calculated by carrying in the formula (8):
9. binary mixing based on gas substitution according to any of claims 1-8The gas mixing ratio measuring method is characterized in that the binary mixed gas is as follows: SF (sulfur hexafluoride) 6 /N 2 Or SF (sulfur hexafluoride) 6 /CF 4 Or C 4 F 7 N/CO 2 。
10. The device of the binary mixed gas ratio measuring method based on the gas substitution method is characterized by comprising the following components: the device comprises a U-shaped oscillating tube (1), a magnet (2), an electronic excitation oscillator (3), a frequency counter (4), a pressure sensor (5), a first temperature sensor (6), a second temperature sensor (7), a third temperature sensor (8), a temperature control heat preservation layer (9), a three-way valve (10) and an air outlet valve (11); the bottom of the U-shaped oscillating tube (1) is fixedly provided with a magnet (2), and the upper parts of two vertical tubes of the U-shaped oscillating tube (1) are respectively provided with a frequency counter (4); the pipe orifice of the left vertical pipe of the U-shaped oscillating pipe (1) is in sealing connection with the first port of the three-way valve (10) through a pipeline, the second port and the third port of the three-way valve (10) are respectively connected with the outside through pipelines, and the pressure sensor (5) is in sealing connection with the pipeline between the pipe orifice of the left vertical pipe of the U-shaped oscillating pipe (1) and the first port of the three-way valve (10); the pipe orifice of the right vertical pipe of the U-shaped oscillating pipe (1) is in sealing connection with the air inlet end of the air outlet valve (11) through a pipeline, and the air outlet end of the air outlet valve (11) is in sealing connection with an exhaust pipeline; the first temperature sensor (6) is arranged between the left vertical pipe and the right vertical pipe of the U-shaped oscillating pipe (1); the electronic excitation oscillator (3) is arranged below the fixed magnet (2); u type oscillating tube (1), magnet (2), electron excitation oscillator (3), frequency counter (4), pressure sensor (5), first temperature sensor (6), air outlet valve (11) all install in accuse temperature heat preservation (9), second temperature sensor (7) install on accuse temperature heat preservation (9) outer wall, third temperature sensor (8) install on accuse temperature heat preservation (9) inner wall.
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4175423A (en) * | 1978-05-01 | 1979-11-27 | Sun Oil Company (Delaware) | Apparatus for determining the pulse repetition rate of a fluidic oscillator through which a test gas is flowing |
| CN101346616A (en) * | 2005-12-22 | 2009-01-14 | 恩德莱斯和豪瑟尔两合公司 | Method and device for determining at least one measurable variable of a medium |
| CN108152370A (en) * | 2017-12-20 | 2018-06-12 | 国网河北省电力有限公司电力科学研究院 | A kind of SF6And N2Mixing gas component ratio device for fast detecting and method |
| CN113074320A (en) * | 2021-03-19 | 2021-07-06 | 国网新疆电力有限公司检修公司 | SF (sulfur hexafluoride)6/CF4High-purity separation and recovery device and method for mixed gas |
| CN113092310A (en) * | 2021-04-28 | 2021-07-09 | 国网安徽省电力有限公司电力科学研究院 | Transformer oil gas content testing device and method for measuring density by U-shaped oscillation tube |
-
2021
- 2021-10-14 CN CN202111199041.4A patent/CN113933213B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4175423A (en) * | 1978-05-01 | 1979-11-27 | Sun Oil Company (Delaware) | Apparatus for determining the pulse repetition rate of a fluidic oscillator through which a test gas is flowing |
| CN101346616A (en) * | 2005-12-22 | 2009-01-14 | 恩德莱斯和豪瑟尔两合公司 | Method and device for determining at least one measurable variable of a medium |
| CN108152370A (en) * | 2017-12-20 | 2018-06-12 | 国网河北省电力有限公司电力科学研究院 | A kind of SF6And N2Mixing gas component ratio device for fast detecting and method |
| CN113074320A (en) * | 2021-03-19 | 2021-07-06 | 国网新疆电力有限公司检修公司 | SF (sulfur hexafluoride)6/CF4High-purity separation and recovery device and method for mixed gas |
| CN113092310A (en) * | 2021-04-28 | 2021-07-09 | 国网安徽省电力有限公司电力科学研究院 | Transformer oil gas content testing device and method for measuring density by U-shaped oscillation tube |
Non-Patent Citations (2)
| Title |
|---|
| 不同原理的SF_6混合气体密度监测技术差异分析;刘伟;季严松;刘子恩;房超;方红磊;卢小龙;朱捷;;安徽电气工程职业技术学院学报(第01期);全文 * |
| 电气设备中SF_6混合气体混气比检测技术的研究;陈英;苏镇西;马凤翔;程伟;徐霄筱;朱峰;;高压电器(第12期);全文 * |
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