RU2559119C1 - Device for determination of multiphase fluid flow components - Google Patents

Abstract

FIELD: physics.SUBSTANCE: claimed device comprises X-ray radiation source and detector arranged on opposite sides of multiphase fluid carrying pipe. Pressure transducer is connected to the pipe along with X-ray beam intensity stabilization and control unit. X-ray radiation source and wave-dispersion spectrometer are secured on one shaft perpendicular to pipe mirror axis so that X-ray radiation flows to wave-dispersion spectrometer via openings cut in said pipe. Note here that wave-dispersion spectrometer case houses the monochromatic analyzer arranged at the angle to X-radiation beam to satisfy the Bragg law terms for the line of radiation from X-ray source spectrum. Ionizing radiation scintillation counter is arranged downstream of crystalline monochromatic analyzer in direction of diffracted beam propagation. X-ray beam intensity stabilization and control unit transducer is arranged downstream of crystalline monochromatic analyzer on one axis of X-ray radiation source.EFFECT: higher accuracy and rate of analysis of multiphase flow components.2 dwg

Description

The invention relates to the field of analysis of materials by radiation methods using x-ray radiation and can be used in the oil and gas and chemical industries.

A device for determining the component composition of a multiphase fluid flow [K.V. Rymarenko, “Hydrodynamic research and multiphase flow metering: new possibilities and principles of operation (using the Vx technology as an example)”, Technique and Technologies, December 2010, p. 30-37] comprising a radioactive source on the basis of the isotope Ba ¹³³ and the scintillation detector is rigidly fastened on opposite sides of the pipe through which the multiphase fluid stream flows. The detector and source are fixed on the same axis perpendicular to the pipe so that the radiation from the source to the detector passes through special low-absorbing inserts in the pipe. When using a Venturi tube as a pipe, the axis of the source and detector passes through the narrowest point of the tube.

This device uses a dangerous radioactive source of gamma radiation, with a low intensity of the radiation flux, which leads to a low counting rate of radiation quanta and, as a result, an increase in the measurement time and / or an increase in the statistical measurement error.

A device is known for determining the component composition of a multiphase fluid flow [RU 2466383 C2, IPC G01N 23/12 (2006.01), publ. 06/20/2012], containing a subsystem for creating single-energy or dual-energy X-rays based on X-ray apparatus with X-ray tubes, a detection subsystem consisting of one or two sets of detectors, a computer-based control and data processing subsystem, and an additional system for calibrating the long-term stability of the X-ray beam . In this case, one or more X-ray apparatuses are arranged so that the X-ray radiation generated by them passes through the multiphase fluid stream and enters a set of detectors located on the other side of the stream and into the detector of the calibration system. X-ray apparatus, a set or sets of detectors, and a calibration system are connected to a computer.

In this device, x-ray machines generate radiation with a complex spectral structure, rather than monoenergetic radiation beams, which leads to an increase in systematic and statistical errors in processing the results and determining the component composition.

A device is known for determining the component composition of a multiphase fluid flow [US 20120087467 A1, IPC G01N23 / 223, publ. 04/12/2012], taken as a prototype, containing an x-ray source for generating an x-ray beam with a linear spectrum of secondary fluorescence, generating radiation in the range from 20 to 100 keV, preferably about 60 keV, an energy dispersive detector, sensors for measuring dielectric constant and / or differential pressure, a second detector for accounting for scattered radiation and an x-ray beam intensity monitor mounted on opposite sides of the pipe through which the multiphase fluid flows. The detector and the source are fixed on one axis perpendicular to the pipe so that the radiation from the source to the detector passes through windows made of a material with a low absorption coefficient of radiation, such as titanium, embedded in the pipe. The second detector is mounted on the pipe wall at the same level with the first detector and the radiation source so that the detection direction is perpendicular to the x-ray propagation axis and the symmetry axis of the pipe. An X-ray intensity monitor is installed in the immediate vicinity of the radiation source. Sensors for measuring dielectric constant and / or differential pressure are connected to the pipe separately.

The disadvantage of the prototype is to reduce the intensity of the characteristic lines due to re-radiation, since the intensity of the secondary fluorescence is three orders of magnitude lower than the primary [Gryaznov A.Yu. Development of hardware and methodological methods for increasing the analytical characteristics of an energy-dispersive X-ray fluorescence analyzer // The dissertation for the degree of candidate of technical sciences. Specialty: 05.27.02. St. Petersburg - 2004]. A decrease in intensity leads either to an increase in statistical errors in determining the component composition, or to an increase in the measurement time in order to compensate for errors. The disadvantages also include the presence of background radiation, which consists of scattered bremsstrahlung with a continuous spectrum and characteristic K _β radiation, the total intensity of the background radiation is comparable to the intensity of the useful characteristic K _α radiation, which leads to undesirable loading of the detector. In addition, the limitation of energy dispersive detectors used in the device is a significant dead time of spectrometric channels, which limits the speed.

The objective of the invention is to improve the accuracy and speed of analysis of the component composition of a multiphase fluid stream.

The proposed device for determining the component composition of the multiphase fluid flow, as in the prototype, contains an x-ray source and a detector mounted on opposite sides of the pipe through which the multiphase fluid flows, so that the radiation from the source to the detector passes through special windows, embedded in the pipe, from a material with a low absorption coefficient of radiation, such as titanium, a pressure measuring sensor connected to the pipe, a sensor for monitoring and stabilizing the intensity of tgenovskogo beam.

According to the invention, an X-ray generator based on an X-ray tube with a single target is selected as an X-ray source, a scintillation counter of ionizing radiation is used as a detector, and a current-mode scintillation block of X-ray detection is selected as a sensor for controlling and stabilizing the X-ray intensity. The X-ray source and wave dispersion spectrometer located in the housings are rigidly fixed on opposite sides of the pipe on one axis perpendicular to the axis of symmetry of the pipe so that the radiation from the X-ray source to the wave dispersion spectrometer passes through windows cut into the pipe. A crystal monochromator analyzer is located in the body of the wave dispersive spectrometer, mounted at an angle to the beam from the x-ray source so that the Bragg condition for the emission line from the spectrum of the x-ray source is fulfilled. Behind the crystal monochromator-analyzer, a scintillation counter of ionizing radiation is installed in the direction of diffracted beam propagation. The X-ray intensity control and stabilization sensor is installed behind the crystalline monochromator-analyzer on the same axis as the X-ray source. The temperature sensor for the multiphase liquid is embedded in the pipe. X-ray source, X-ray intensity control and stabilization sensor, multiphase liquid pressure and temperature sensors, ionizing radiation scintillation counter are connected to a computer.

In the proposed device, the use of an x-ray source with one target (without a secondary target) eliminates the stage of re-radiation (excitation of secondary fluorescence), which allows to increase the intensity of x-rays used to analyze the component composition of the multiphase fluid flow, since the intensity of the secondary fluorescence is three orders of magnitude lower than the primary [Gryaznov A.Yu. Development of hardware and methodological methods for increasing the analytical characteristics of an energy-dispersive X-ray fluorescence analyzer // The dissertation for the degree of candidate of technical sciences. Specialty: 05.27.02. St. Petersburg - 2004]. The use of a crystalline monochromator-analyzer can reduce the loss of x-ray intensity when receiving monochromatic radiation, since the loss of intensity is determined by the reflection coefficient of radiation in the diffraction direction, which is at least 50%. An increase in the intensity of x-ray radiation leads to a decrease in the statistical measurement error and, as a consequence, to an increase in the measurement accuracy and / or a decrease in the time spent on the study, since the statistical error is determined by the formula:

- относительная статистическая ошибка;Where

- relative statistical error;

- среднее число квантов, зарегистрированных за секунду, которое прямо пропорционально интенсивности;

- the average number of quanta recorded per second, which is directly proportional to the intensity;

- время измерения в секундах.

- measurement time in seconds.

In addition, the accuracy of determining the component composition of the multiphase fluid flow of the proposed device is higher due to the fact that it provides a smaller relative fraction of background radiation in the spectrum. A comparison of the relative distribution of radiation intensities in the spectrum for the prototype (Fig. 1 a)) and the proposed device (Fig 1 b)) shows that the background radiation level in the proposed device is about 10 times lower.

Thus, the proposed device for determining the component composition of a multiphase fluid stream in comparison with the prototype has increased accuracy and speed of analysis.

In FIG. Figure 1 shows the emission spectra from an x-ray source: a) Fluor'X [US 20120087467], b) based on a BSV-29 tube after reflection from a tungsten crystal.

In FIG. 2 shows a diagram of a device for determining the component composition of a multiphase fluid.

A device for determining the component composition of a multiphase fluid flow contains an X-ray source 1 (IRI) and a wave dispersive spectrometer 2 (GVA), housed in housings that are rigidly fixed on different sides of the pipe 3, through which the multiphase fluid flows. The pipe 3 may be a conventional cylindrical pipe (separate outlet pipe) or in the form of a venturi. When using a Venturi, the X-ray source 1 (IRI) and wave dispersive spectrometer 2 (GVA) are located on the axis passing through the narrowest point of the pipe 3. The X-ray source 1 (IRI) and wave dispersive spectrometer 2 (GVV) are mounted on one axis perpendicular the axis of symmetry of the pipe 3 so that the radiation from the x-ray source 1 to the wave dispersive spectrometer 2 (GVA) passed through windows 4 and 5 from a material with a low absorption coefficient of radiation, for example, titanium embedded in wow 3.

In the case of wave dispersive spectrometer 2 (GVA), there is a crystalline monochromator-analyzer 6 installed at an angle to the beam from the X-ray source 1 (IRI) so that the Bragg condition for the emission line from the spectrum of the X-ray source 1 (IRI) is satisfied. Behind the crystal monochromator-analyzer 6, a scintillation counter of ionizing radiation 7 (CC) is installed in the direction of diffracted beam propagation. An X-ray intensity control and stabilization sensor 8 (DKS) is installed behind the crystalline monochromator-analyzer 6 on the same axis as the X-ray source 1 (IRI).

Sensors for measuring pressure 9 (DD) and temperature 10 (DT) of multiphase fluid are mounted in pipe 3.

X-ray source 1 (IRI), X-ray intensity control and stabilization sensor 8 (DKS), sensors for measuring pressure 9 (DD) and temperature 10 (DT) of a multiphase liquid, an ionizing radiation scintillation counter 7 (SS) are connected via appropriate control drivers to A computer (not shown in FIG. 2).

As an X-ray source 1 (IRI), an X-ray apparatus based on a known X-ray tube can be selected, for example, a BSV-29 source with a silver anode generating polychromatic bremsstrahlung up to 60 keV and characteristic silver X-ray radiation with energies of 22 and 25 keV (lines K _α and K _β , respectively).

As a crystalline monochromator-analyzer 6, a tungsten crystal or a LiF crystal can be used.

As a scintillation counter of ionizing radiation 7 (CC), a counter based on the BC-408 organic scintillator manufactured by Saint-Gobain Crystals [France http://www.crystals.saint-gobain.com/Crystals_Products.aspx], and silicon can be used a photomultiplier tube (not shown), supplied by SENSL [Ireland, http://www.sensl.com/downloads/ds/DS-MicroFM.pdf], which allows receiving a signal with a rise time of the pulse front of about 100 ps and a recovery time of less than 1 ns

As a sensor for monitoring and stabilizing the intensity of x-ray radiation 8 (DCS), a standard scintillation block for detecting x-ray radiation can be used, for example, produced by SPC "ASPECT" operating in the current mode.

X-ray source 1 (IRI) generates x-ray radiation with a complex spectral composition, which is directed to the pipe 3, through which a multicomponent liquid flows. One part of the x-ray radiation passes through windows 4 and 5 from a material with a low absorption coefficient of radiation and a multiphase fluid flow, the other part passes through the walls of the pipe 3, in which the radiation is almost completely absorbed, thereby forming a narrow radiation beam. A beam passing through a multiphase fluid stream becomes a carrier of information about its characteristics, since depending on the composition and parameters of the multiphase fluid, x-ray radiation is absorbed and scattered in different ways due to the photoelectric effect and Compton scattering. The part of the x-ray beam that passed through without interaction with windows 4 and 5 and the multiphase fluid flow is directed to wave dispersive spectrometer 2 (GVA), where the beam hits the crystal monochromator-analyzer 6. The part of the x-ray beam that satisfies the Bragg condition is diffracted by the crystal monochromator - analyzer 6, and the other part passes it without deviation.

The diffracted radiation is directed to the counter of ionizing radiation 7 (CC), while the spectrum of the diffracted radiation is already a set of monochromatic lines, with energies satisfying the Bragg condition. The scintillation counter of ionizing radiation 7 (CC) separates low and high energy X-ray photons and measures the counting rates in two spectral ranges corresponding to energies of the first and second (or higher) X-ray diffraction order. Simultaneous registration of two lines is achieved by electronic separation of signals in a scintillation counter of ionizing radiation 7 (CC).

Radiation transmitted without deviation enters the X-ray radiation intensity control and stabilization sensor 8 (DCS), which detects the total current generated by radiation in a sensitive volume, which carries information about the integral radiation intensity at a particular moment in time, and is used for normalization.

At the same time, sensors for measuring pressure 9 (DD) and temperature 10 (DT) of a multiphase liquid measure the temperature and pressure of the liquid flow, used to refine the values of the absorption coefficients of the flow components.

Data from sensors for monitoring and stabilizing the intensity of x-ray radiation 8 (DCS), measuring pressure 9 (DD) and temperature 10 (DT) of a multiphase liquid, from a scintillation counter of ionizing radiation 7 (SS) are sent to a computer. In this case, the counting rates along two monochromatic lines recorded by an ionizing radiation counter 7 (SS) and pressure measuring sensors 9 (DD) and temperature 10 (DT) are used to calculate the mass fractions of the individual components of a multiphase liquid, and using the software, a system of the form :

I (E ₁ ) = I ₀ (E ₁ ) exp [-LΣμ _i (E ₁ , p, T) w _i ρ _i (p, T)];

I (E ₂ ) = I ₀ (E ₂ ) exp [-LΣμi (E ₂ , p, T) wiρi (p, T)];

...

Σw _i = 1,

where I (E _1,2 ) is the intensity of x-rays with an energy of E _1,2 incident on the stream of a multiphase liquid;

I ₀ (E _1,2 ) is the intensity of x-ray radiation with an energy of E _1,2 passing through the stream without interaction;

L is the distance traveled by radiation through a multiphase fluid stream;

μ _i (E _1,2 , p, T) is the mass absorption coefficient of radiation with energy E _1,2 at temperature T and pressure p for the i-th component;

w _i - mass fraction of the i-th component;

ρ _i (p, T) is the density of the ith component at temperature T and pressure p.

Values of I ₀ (E ₁ ), I ₀ (E ₂ ), etc. determined from measurements in the absence of fluid flow in the pipe 3 or from preliminary modeling, and I (E ₁ ), I (E ₂ ), etc. - from the counting speeds when measured on pipe 3 with a multiphase fluid flow.

Thus, using the proposed device when registering count rates in two spectral ranges, the composition of the three-component stream is controlled, for example, an oil-water-gas stream, which is in demand in the oil industry.

Values I (E ₁ ), I ₀ (E ₁ ), I (E ₂ ), I ₀ (E ₂ ), etc. normalized in accordance with the current value recorded by the control sensor, and stabilization of the intensity of x-ray radiation 8 (DCS) at the corresponding time, which reduces the statistical spread of data due to fluctuations in the current and voltage of the x-ray source 1 (IRI).

Claims (1)

A device for determining the component composition of a multiphase fluid flow, containing an x-ray source and a detector mounted on opposite sides of the pipe through which the multiphase fluid flows, so that the radiation from the source to the detector passes through special windows cut into the pipe from material with low absorption coefficient of radiation, for example titanium, a pressure measuring sensor connected to the pipe, an X-ray intensity control and stabilization sensor, characterized by m, that an X-ray generator based on an X-ray tube with one target was selected as an X-ray source, a scintillation counter of ionizing radiation was used as a detector, a current-mode scintillation block of X-ray detection was selected as a sensor for controlling and stabilizing the X-ray beam, wherein the x-ray source and wave dispersive spectrometer are placed in cases that are rigidly fixed to different The sides of the tube, the x-ray source and the wave dispersion spectrometer are fixed on one axis perpendicular to the axis of symmetry of the tube so that the radiation from the x-ray source to the wave dispersion spectrometer passes through the windows cut into the pipe, and a crystal monochromator analyzer installed in the body of the wave dispersion spectrometer is installed at an angle to the beam from the x-ray source so that the Bragg condition for the emission line from the spectrum of the source X-ray radiation, a scintillation counter of ionizing radiation is installed behind the crystal monochromator-analyzer in the direction of diffracted beam propagation, and a sensor for controlling and stabilizing the x-ray intensity is installed behind the crystal monochromator-analyzer on the same axis as the x-ray source, while the temperature sensor of the multiphase liquid is cut into the pipe , and the source of x-ray radiation, a sensor for controlling and stabilizing the intensity of x-ray and radiation, pressure and temperature sensors for measuring multiphase fluid, ionizing radiation scintillation counter linked to a computer.

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