Method for measuring phase fraction of multiphase fluid based on non-radiative recombination quantum light source

Abstract

This invention discloses a method for measuring the phase fraction of multiphase fluids based on a non-radiative composite quantum light source, relating to the field of online metering technology for complex multiphase flows in industry. The method includes: S1 Static calibration to obtain the number of quantum projections in oil, gas, water, sand, and fluid-free states; S2 Calibration to obtain the photoelectric effect cross section and Compton scattering cross section at various energies; S3 The multiphase fluid flows through a throttling structure, allowing quantum light to penetrate the multiphase fluid and collecting the number of transmitted quantum projections; S4 Constructing a quantum cross section function relationship equation; S5 Constructing a nonlinear equation set; S6 Solving to obtain the mass phase fraction of each phase. Based on the quantum phase fraction measurement principle of the photoelectric effect and the difference in Compton scattering cross section, this method overcomes the technical limitations of traditional attenuation coefficients, achieving a mass phase fraction measurement accuracy of ±0.1%. The relative errors in mass flow rate measurement for each phase are ±7.5% for gas, ±5% for liquid, and ±3.5% for solid, significantly better than traditional dual-energy gamma metering technology, meeting the requirements of refined production in oil and gas fields and precise control of drilling and fracturing.

Description

Technical Field

[0001] This invention relates to the field of online metering technology for complex multiphase flows in industry, and in particular to a method for measuring the phase fraction of mixed-phase fluids based on a non-radiative composite quantum light source. Background Technology

[0002] Online metering of multiphase flows (gas, liquid, and solid phases) is a core technological bottleneck in industrial fields such as oil and gas extraction, chemical production, and energy transportation. Especially in operation scenarios such as oil and gas wellheads, drilling, fracturing, and cementing, fluids often exhibit characteristics such as high gas-liquid ratios, high sand content, complex and variable flow patterns, and large pressure and temperature ranges, which place extremely high demands on the accuracy, stability, safety, integration, and radiation safety of metering equipment.

[0003] Current industrial multiphase flow metering technologies mainly include: separate metering, ultrasonic metering, capacitance / conductivity tomography, and gamma-ray attenuation metering. Among these, gamma-ray methods have become the mainstream technology for complex operating conditions due to their advantages such as non-invasiveness, interference resistance, no need for rectification, and adaptability to high temperature and high pressure.

[0004] Although existing gamma-type multiphase flow metering patents and products have achieved certain engineering applications, they generally suffer from the following insurmountable technical defects:

[0005] 1) Limitations of measurement principle: The phase fraction is calculated based on the macroscopic linear attenuation coefficient, without distinguishing the microscopic cross-sectional differences between the photoelectric effect and Compton scattering. Under conditions of high sand content and high gas-liquid ratio, the error is as high as 15%–30%, which cannot meet the requirements of fine measurement.

[0006] 2) High radiation safety risks: Traditional radiation sources have an activity level of mostly mCi, requiring strict shielding and qualification permits, and their application is limited in marine platforms, confined spaces, and densely populated areas.

[0007] 3) Weak signal processing capability: It generally uses analog filtering or simple dual-energy counting, which cannot distinguish between slow pulses of photoelectric effect and fast pulses of Compton scattering. It is susceptible to noise, pulse accumulation and interference from cosmic rays, resulting in low signal-to-noise ratio and poor stability.

[0008] 4) Poor structural integration: Most are split installations, which are large in size and have high power consumption, and cannot be embedded in compact equipment such as wellhead choke devices, fracturing manifolds, cementing pipelines, etc.

[0009] In summary, the industry urgently needs a new generation of multiphase flow metering technology that features low radiation exemption, quantum cross section, high precision, embedded integration, and resistance to extreme operating conditions. This invention is proposed to address the aforementioned pain points. Summary of the Invention

[0010] The purpose of this invention is to design a method for measuring the phase fraction of a mixed-phase fluid based on a non-radiative composite quantum light source in order to solve the above problems.

[0011] The present invention achieves the above objectives through the following technical solutions:

[0012] A method for measuring the phase fraction of a miscible fluid based on a non-radiative composite quantum source includes:

[0013] S1. Under conditions where the throttling structure is filled with oil, gas, water, sand, and no fluid, respectively, four energy levels of photons are generated through a non-radiative composite photon source. The number of photons of the four energy levels projected under the oil, gas, water, and sand conditions is measured by a multi-channel detector array. And the number of projections in a fluid-free state. Where i = gas, liquid, solid, and j represents the energy level, with values ​​of 1, 2, 3, and 4; the non-radiative composite quantum source and the multi-channel detector array are located on both sides of the throat of the throttling structure;

[0014] S2. Based on the quantum mechanical laws governing the interaction between light quanta and matter, the photoelectric effect cross sections of the gas, liquid, and solid phases at various energies were calibrated. With Compton scattering cross section Establish a cross-section-energy-correspondence database;

[0015] S3. The mixed-phase fluid flows through the throttling structure to form a stable and uniform flow field; the non-radiative composite photon source generates photons of four energy levels that penetrate the mixed-phase fluid; the multi-channel detector array collects the number N of transmitted photons in real time, and the incident count rate of the generated photons is N0.

[0016] S4, Calibrated photoelectric effect cross section With Compton scattering cross section The quantum cross-section function relation equation is constructed as follows: Among them, among them, Let be the density of the i-th phase. Where L is the mass phase fraction and L is the penetration path length of the photon in the mixed-phase fluid;

[0017] S5. Utilizing the four energy levels E output from a composite quantum source j Substituting the characteristic energies of into the quantum cross-section function relation equations, a system of nonlinear equations is constructed, expressed as: ; where N 0,1 This represents the 31keV photon count in a fluidless state; N x,1 Represents the 31keV photon count in oil, gas, water, and sand states; N 0,2 This represents the 81 keV photon count in a fluidless state; N x,2 Represents the 81 keV photon count in oil, gas, water, and sand states; N 0,3This represents the 356keV photon count in a fluid-free state; N x,3 Represents the 356keV photon count in oil, gas, water, and sand states; N 0,4 This represents the 22keV photon count in a fluid-free state; N x,4 This represents the 22keV photon count in the states of oil, gas, water, and sand.

[0018] S6. The mass phase fractions of the gas, liquid, and solid phases are obtained by iterative solution algorithm. .

[0019] The beneficial effects of this invention are as follows: Based on the photoelectric effect and the quantum phase separation measurement principle of the Compton scattering cross section difference, it breaks through the technical limitations of the traditional attenuation coefficient, and the measurement accuracy of mass phase fraction reaches ±0.1%. The relative errors of mass flow rate measurement for each phase are ±7.5% for gas, ±5% for liquid, and ±3.5% for solid, which are significantly better than the traditional dual-energy gamma metering technology (error 10%-20%), and meet the requirements of refined production in oil and gas fields and precise control of drilling and fracturing. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0021] Therefore, the detailed description of the embodiments of the present invention provided below is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0022] It should be noted that the terms "first," "second," etc., are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0023] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, terms such as "set" and "connection" should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0024] A method for measuring the phase fraction of a miscible fluid based on a non-radiative composite quantum source includes:

[0025] S1. Under conditions where the throttling structure is filled with oil, gas, water, sand, and no fluid, respectively, four energy levels of photons are generated through a non-radiative composite photon source. The number of photons of the four energy levels projected under the oil, gas, water, and sand conditions is measured by a multi-channel detector array. And the number of projections in a fluid-free state. Where i = gas, liquid, solid, and j represents the energy level, with values ​​of 1, 2, 3, and 4; the non-radiative composite quantum source and the multi-channel detector array are located on both sides of the throat of the throttling structure;

[0026] S2. Based on the quantum mechanical laws governing the interaction between light quanta and matter, the photoelectric effect cross sections of the gas, liquid, and solid phases at various energies were calibrated. With Compton scattering cross section Establish a cross-section-energy-correspondence database;

[0027] S3. The mixed-phase fluid flows through the throttling structure to form a stable and uniform flow field; the non-radiative composite photon source generates photons of four energy levels that penetrate the mixed-phase fluid; the multi-channel detector array collects the number N of transmitted photons in real time, and the incident count rate of the generated photons is N0.

[0028] S4, Calibrated photoelectric effect cross section With Compton scattering cross section The quantum cross-section function relation equation is constructed as follows: Among them, among them, Let be the density of the i-th phase. Where L is the mass phase fraction and L is the penetration path length of the photon in the mixed-phase fluid;

[0029] S5. Utilizing the four energy levels E output from a composite quantum source j Substituting the characteristic energies of into the quantum cross-section function relation equations, a system of nonlinear equations is constructed, expressed as: ; where N 0,1 This represents the 31keV photon count in a fluidless state; N x,1 Represents the 31keV photon count in oil, gas, water, and sand states; N 0,2 This represents the 81 keV photon count in a fluidless state; N x,2 Represents the 81 keV photon count in oil, gas, water, and sand states; N 0,3 This represents the 356keV photon count in a fluid-free state; N x,3 Represents the 356keV photon count in oil, gas, water, and sand states; N 0,4 This represents the 22keV photon count in a fluid-free state; N x,4This represents the 22keV photon count in the states of oil, gas, water, and sand.

[0030] S6. The mass phase fractions of the gas, liquid, and solid phases are obtained by iterative solution algorithm. .

[0031] The throttling structure is a Venturi tube with a throat diameter ratio ranging from 0.3 to 0.75, an inlet cone angle ranging from 20° to 22°, an outlet cone angle ranging from 7° to 15°, and the throat section of the Venturi tube is surfacing with Stellite alloy.

[0032] The venturi tube has a throat diameter ratio of 0.5, an inlet cone angle of 21°, an outlet cone angle of 10°, and the throat section is constructed using Stellite alloy overlay welding.

[0033] The non-radiative composite quantum light source is a mixture of Ba-133 with an activity of less than 2.5 μCi and silver powder. The silver powder has a particle size of less than 0.1 μm and a mass of 1 μg to 10 μg.

[0034] The silver powder has a particle size of 0.08 μm and the activity of Ba-133 is 1.8 μCi.

[0035] The multi-channel detector array is a CZT semiconductor detector.

[0036] The non-radiative composite quantum light source is composed of Ba-133 with an activity of <2.5 μCi and microgram-level ultrafine silver powder with a particle size of <0.1 μm. Relying on the 25.5 keV Auger-K electrons generated by the Ba-133 quantum light source, the fused Ag powder is directly bombarded, exciting the generation of a 22.16 keV (nominal 22 keV) Ag-Kα1 characteristic quantum light source, and simultaneously outputting the 31 keV, 81 keV, and 356 keV characteristic energy spectra of the Ba-133 daughter nucleus Cs-133, forming a complete four-spectrum composite light source. The source chamber adopts a high-temperature and high-pressure resistant sealed structure, embedded in the throat section of the Venturi tube, and arranged relatively parallel to the detector array. The encapsulation layer is made of PEEK material to ensure that the quantum light transmittance is ≥90% and the sealing safety is guaranteed.

[0037] The excitation process of the 22keV characteristic photon is as follows: 25.5keV Auger-K electrons released by a non-radioactive Ba-133 photon source directly act on microgram-level Ag powder in a fused state, causing the K-shell electrons of Ag atoms to ionize and generate vacancies; the outer electrons of Ag atoms jump from the L-shell to the K-shell to fill the vacancies, releasing Ag-Kα1 characteristic photons with an energy of 22.16keV, forming a 22keV photon peak.

[0038] The throttling structure uses a Venturi tube with a throat diameter ratio of 0.30-0.75, preferably 0.4-0.6; the inlet cone angle is 21°±1° and the outlet cone angle is 7°-15°, which is used to form a stable and uniform flow field for the mixed-phase fluid and reduce the influence of flow pattern fluctuations on the measurement; the throat section is made of Stellite alloy or metal ceramic coating material to improve the resistance to erosion by high sand content fluids and extend the service life of the equipment.

[0039] The multi-channel detector array uses a CZT semiconductor detector with an energy resolution of ≤5%. It is arranged in parallel with the non-radiative composite photon source to collect multi-energy photon spectrum signals of the transmission mixed fluid and achieve accurate counting of photons of different energies.

[0040] Steps S4-S6 are all calculated by the FPGA signal processing unit, which includes an integrated fast / slow dual-channel filtering shaping module, a stacking correction module, a pulse amplitude analysis module, a coincidence counting module, and an online solution module. It uses an ALTERA EP4CE series FPGA chip, which can process 16 signals per cycle. It distinguishes between slow pulses of the photoelectric effect and fast pulses of Compton scattering through a coincidence time window of 1-10ns, performs filtering, correction, and counting processing on the energy spectrum signal, and constructs functional relationship equations based on the photoelectric effect and Compton scattering cross section to solve the mass phase fraction of the gas-liquid-solid three phases in real time with a solution time of <10ms.

[0041] The principles of quantum interaction include: the photoelectric effect and Compton scattering;

[0042] Photoelectric effect: dominated by low energy range, cross section ∝ Z 4 ⁻ 5 / E³・ 5 Used to distinguish between gas and solid;

[0043] Compton scattering: Dominates the high-energy range, with a cross-section ∝ Z / E, used to distinguish between gas and liquid reactions. Total cross-sectional reaction probability: Rayleigh scattering is negligible.

[0044] The specific measurement method is as follows:

[0045] 1) Static calibration:

[0046] ① Empty pipe calibration: When there is no fluid in the pipe, measure the number of light quanta transmitted without a medium. (j=1,2,3,4, corresponding to the 22 / 31 / 81 / 356keV energy range), used as the system baseline;

[0047] ② Single-phase calibration: Fill the pipe with oil, gas, water, and sand (simulating solid phase) respectively, and measure the number of transmitted photons of each energy level. (i = gas, liquid, solid), based on the quantum mechanical laws governing the interaction between light quanta and matter, the photoelectric effect cross sections of the gas, liquid, and solid phases at various energies were calibrated. With Compton scattering cross section Establish a cross-section-energy-correspondence database.

[0048] 2) Online measurement:

[0049] The mixed-phase fluid flows through a throttling structure (Venturi tube) to form a stable and uniform flow field; the composite quantum source emits multi-energy photons that penetrate the mixed-phase fluid; a multi-channel detector array collects the transmitted photon energy spectrum signal in real time and transmits it to the FPGA signal processing unit.

[0050] 3) Phase decomposition calculation (constructing functional relationships based on quantum cross sections):

[0051] FPGA signal processing unit based on calibrated photoelectric effect cross section With Compton scattering cross section We construct quantum cross-sectional function relation equations and directly solve for the mass fraction of each phase.

[0052] ① Based on the quantum mechanical principle of the interaction between light quanta and matter, the relationship between the transmission light quantum count rate N and the incident count rate N0 is determined by the total reaction cross section (photoelectric effect cross section + Compton scattering cross section). The quantum cross section function equation is constructed as follows: ;in, Let be the photoelectric effect cross section (calibration value) of the i-th phase (gas / liquid / solid) at energy E. Let be the Compton scattering cross section (calibrated value) of the i-th phase at energy E. Let be the density of the i-th phase; Let be the mass phase fraction to be determined; L is the penetration path length of a photon in a mixed-phase fluid.

[0053] ②Solving the problem simultaneously with multiple energies: Using the multiple characteristic energies (22keV, 31keV, 81keV, 356keV) output by the composite quantum source, substitute them into the above cross-sectional function relationship to construct a system of nonlinear equations, expressed as: ;

[0054] The equations can be solved directly using an iterative solution algorithm built into the FPGA (such as the Newton-Raphson method) to obtain the mass phase fractions of the gas, liquid, and solid phases. The measurement accuracy reaches ±0.1%.

[0055] The present invention has the following advantages:

[0056] (1) Radiation safety compliance: The activity of the composite photonic quantum source is <2.5μCi, which is far below the radiation exemption threshold of major countries / regions such as China, the European Union, the United States, and the IAEA. No radiation safety license is required, and there is no radiation protection pressure in the field application, making it suitable for various work scenarios.

[0057] (2) Extremely high measurement accuracy: Based on the photoelectric effect and the quantum phase separation measurement principle of the Compton scattering cross section difference, it breaks through the technical limitations of the traditional attenuation coefficient. The measurement accuracy of mass phase fraction reaches ±0.1%, and the relative errors of mass flow rate measurement of each phase are ±7.5% for gas, ±5% for liquid, and ±3.5% for solid, which are significantly better than the traditional dual-energy gamma metering technology (error 10%-20%), meeting the requirements of refined production in oil and gas fields and precise control of drilling and fracturing.

[0058] (3) Adaptable to complex working conditions: The embedded integrated structure is suitable for compact installation spaces such as oil and gas wellheads and drilling manifolds; the Venturi throttling structure can form a stable flow field; the Stellite alloy / metal ceramic material is resistant to erosion by high sand content fluids and can operate stably under extreme working conditions such as wellhead pressure of 140MPa, temperature of 200℃ and sand content of 0-5%.

[0059] 4) Strong real-time performance and stability: FPGA hardware-based signal processing and calculation, with a calculation time of <10ms, enables real-time online measurement; FPGA conformal energy spectrum filtering technology can improve the signal-to-noise ratio to 50:1, maintaining stable measurement even under high count rate and strong interference environments, without problems such as pulse accumulation and noise interference.

[0060] (5) High global protection value: The core innovation of the technical solution is clear, covering core modules such as composite photonic quantum source, quantum cross section measurement principle, FPGA coincidence spectrum filtering, and embedded integrated structure. It can achieve global patent protection through PCT international application and multi-country national phase application, and is adapted to the needs of the international oil and gas industry market.

[0061] Example 1

[0062] This embodiment provides a quantum phase separation measurement technology and a gas-liquid-solid three-phase mass flow metering method based on a composite optical quantum source, which is applied to the production miscibility metering of onshore oilfield wellheads. The specific parameters are as follows:

[0063] System components:

[0064] Throttling structure: Venturi tube, throat diameter ratio 0.5, inlet cone angle 21°, outlet cone angle 10°, throat section is made of Stellite alloy weld overlay;

[0065] Composite photonic quantum source: Ba-133 activity 1.8μCi, silver powder particle size 0.08μm, particle size <0.1μm, embedded in the throat segment of Venturi tube;

[0066] Detector array: CZT semiconductor detectors, with an energy resolution of 5%@20keV, consisting of 4 groups arranged in parallel with the photon source;

[0067] FPGA signal processing unit: ALTERA EP4CE10F17C8N chip, integrating fast / slow dual-channel filtering, stacking correction, coincidence counting and other modules, with a coincidence time window of 5ns.

[0068] Measurement steps:

[0069] ① Static calibration: Complete single-phase calibration for empty pipe, oil, gas, water, and sand, obtaining the values ​​of each phase under four energy levels. and Establish a cross-section database;

[0070] ②Online measurement: The wellhead produces a miscible fluid (gas, oil, water, and sand phases, with a sand content of 2%) which flows through the venturi tube. The detector collects the transmitted light quantum energy spectrum signal and transmits it to the FPGA.

[0071] ③ Signal processing: The FPGA performs signal filtering, stacking correction, coincidence counting, and extracts 4 sets of net energy counts, achieving a signal-to-noise ratio of 55:1;

[0072] ④ Phase decomposition calculation: Based on the calibrated quantum cross section, construct the functional relationship equation, solve the four sets of energy equations simultaneously, and obtain the mass phase fraction of gas, liquid and solid phases with an accuracy of ±0.08%. The relative errors of the three-phase flow measurement are ±7% for gas, ±4.5% for liquid and ±3% for solid.

[0073] Performance verification: The system in this embodiment operated continuously for 12 months with no significant fluctuation in measurement error and a failure rate of <0.5%, which is significantly better than the traditional dual-energy gamma flow meter (failure rate of 5%), and meets the metering requirements of onshore oilfield wellheads.

[0074] Example 2

[0075] This embodiment provides a quantum phase separation measurement technology and a gas-liquid-solid three-phase mass flow metering method based on a composite optical quantum source, which is applied to the metering of mixed phases injected at the wellhead during shale gas well fracturing operations. Specific parameters are as follows:

[0076] System components:

[0077] Throttling structure: Venturi tube, throat diameter ratio 0.4, inlet cone angle 20°, outlet cone angle 7°, throat section with metal-ceramic coating;

[0078] Composite photonic quantum source: Ba-133 activity 2.2μCi, silver powder particle size 0.09μm, embedded in the throttling structure of the fracturing manifold;

[0079] Detector array: CZT semiconductor detector, energy resolution 1%@122keV, 4 groups in total;

[0080] FPGA signal processing unit: conforms to a time window of 3ns, suitable for high flow rate and high pressure conditions in fracturing operations.

[0081] Measurement steps:

[0082] Similar to Example 1, after static calibration, the mixed-phase fluid (fracturing fluid + sand + gas) injected during fracturing is measured online to calculate the phase fraction and flow rate.

[0083] Performance verification: The system in this embodiment operates stably under extreme conditions of wellhead pressure of 105MPa and flow rate of 20m / s. The accuracy of mass phase fraction measurement is ±0.1%, and the error of sand content measurement is ±2.8%. It can accurately reflect the fracturing injection parameters and provide data support for the optimization of fracturing process.

[0084] The technical solutions of the present invention are not limited to the specific embodiments described above. Any technical modifications made in accordance with the technical solutions of the present invention fall within the protection scope of the present invention.

Claims

1. A method for measuring the phase fraction of a miscible fluid based on a non-radiative composite quantum source, characterized in that, include: S1. Under conditions where the throttling structure is filled with oil, gas, water, sand, and no fluid, respectively, four energy levels of photons are generated through a non-radiative composite photon source. The number of photons of the four energy levels projected under the oil, gas, water, and sand conditions is measured by a multi-channel detector array. And the number of projections in a fluid-free state. Where i = gas, liquid, solid, and j represents the energy level, with values ​​of 1, 2, 3, and 4; the non-radiative composite quantum source and the multi-channel detector array are located on both sides of the throat of the throttling structure; S2. Based on the quantum mechanical laws governing the interaction between light quanta and matter, the photoelectric effect cross sections of the gas, liquid, and solid phases at various energies were calibrated. With Compton scattering cross section Establish a cross-section-energy-correspondence database; S3. The mixed-phase fluid flows through the throttling structure to form a stable and uniform flow field; the non-radiative composite photon source generates photons of four energy levels that penetrate the mixed-phase fluid; the multi-channel detector array collects the number N of transmitted photons in real time, and the incident count rate of the generated photons is N0. S4, Calibrated photoelectric effect cross section With Compton scattering cross section The quantum cross-section function relation equation is constructed as follows: Among them, among them, Let be the density of the i-th phase. Where L is the mass phase fraction and L is the penetration path length of the photon in the mixed-phase fluid; S5. Using the characteristic energies of the four energy levels Ej output by the composite quantum source, respectively, and substituting them into the quantum cross-section function relation equation, a system of nonlinear equations is constructed, expressed as: ; where N 0,1 This represents the 31keV photon count in a fluidless state; N x,1 Represents the 31keV photon count in oil, gas, water, and sand states; N 0,2 This represents the 81 keV photon count in a fluidless state; N x,2 Represents the 81 keV photon count in oil, gas, water, and sand states; N 0,3 This represents the 356keV photon count in a fluid-free state; N x,3 Represents the 356keV photon count in oil, gas, water, and sand states; N 0,4 This represents the 22keV photon count in a fluidless state; N x,4 This represents the 22keV photon count in the states of oil, gas, water, and sand. S6. The mass phase fractions of the gas, liquid, and solid phases are obtained by iterative solution algorithm. .

2. The method for measuring the phase fraction of a mixed-phase fluid based on a non-radiative composite quantum source according to claim 1, characterized in that, The throttling structure is a Venturi tube with a throat diameter ratio ranging from 0.3 to 0.75, an inlet cone angle ranging from 20° to 22°, an outlet cone angle ranging from 7° to 15°, and the throat section of the Venturi tube is surfacing with Stellite alloy.

3. The method for measuring the phase fraction of a mixed-phase fluid based on a non-radiative composite quantum source according to claim 2, characterized in that, The venturi tube has a throat diameter ratio of 0.5, an inlet cone angle of 21°, an outlet cone angle of 10°, and the throat section is constructed using Stellite alloy overlay welding.

4. The method for measuring the phase fraction of a mixed-phase fluid based on a non-radiative composite quantum source according to claim 1, characterized in that, The non-radiative composite quantum light source is a mixture of Ba-133 with an activity of less than 2.5 μCi and silver powder. The silver powder has a particle size of less than 0.1 μm and a mass of 1 μg to 10 μg.

5. The method for measuring the phase fraction of a mixed-phase fluid based on a non-radiative composite quantum source according to claim 4, characterized in that, The silver powder has a particle size of 0.08 μm and the activity of Ba-133 is 1.8 μCi.

6. The method for measuring the phase fraction of a miscible fluid based on a non-radiative composite quantum source according to claim 1, characterized in that, The multi-channel detector array is a CZT semiconductor detector.

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