Electromagnetic excitation high-temperature liquid metal throttling flow measuring system and method

Abstract

The invention provides an electromagnetically-excited high-temperature liquid metal throttling flow measurement system and method, and belongs to the technical field of flow measurement. The method comprises the steps that direct current is connected to an electromagnetic excitation coil, and a direct-current magnetic field is generated around a non-metal pipeline; the magnetic field enables the liquid metal in the pipe to generate a throttling effect, so that the flow velocity is reduced to generate differential pressure; a differential pressure detection module is used for detecting the differential pressure of the liquid metal, a temperature sensor is used for detecting the temperature of the liquid metal in the pipe, and the flow coefficient is corrected; calculating a relational expression between the flow velocity and the flow of the liquid metal according to a Bernoulli equation; and the fluid density of the liquid metal is subjected to temperature compensation correction through the temperature and is substituted into the relational expression of the flow velocity and the flow of the liquid metal. Due to the fact that the physical property (such as density) of the liquid metal can change along with the temperature change, the flow measurement result is directly influenced, temperature compensation is conducted on the flow of the liquid metal, the measurement error can be corrected, and more accurate flow data can be obtained.

Description

Technical Field

[0001] The present invention relates to the technical field of flow measurement, and particularly to an electromagnetic excitation-based high-temperature liquid metal throttling flow measurement system and method. Background Art

[0002] High-temperature liquid metals have properties such as good electrical conductivity, thermal conductivity, plasticity, and chemical stability, and are widely used in multiple fields. In the nuclear industry, high-temperature liquid metals are commonly used as coolants in high-temperature reactors and nuclear power plants; in the aerospace field, high-temperature liquid metals are used in the manufacturing of engine components and the use of fuels; in the alloy preparation field, high-temperature liquid metals are commonly used in the synthesis of new materials and catalysis. High-temperature liquid metal flow measurement is the key to stable production processes and ensuring product quality. Due to the characteristics of high temperature and strong corrosiveness of high-temperature liquid metals, flow measurement is different from other fluids and needs to be selected according to the characteristics, flow velocity, pipe diameter, etc. of high-temperature liquid metals.

[0003] Currently, commonly used flow measurement technologies are mainly divided into measurement technologies with interference components and measurement technologies without interference components. Measurement technologies with interference components refer to those in which the flowmeter used contains obstructive components. Commonly used interference-type liquid metal flow measurement technologies include turbine flowmeter method, vortex street flowmeter method, orifice plate flowmeter method, optical probe flowmeter method, etc. Measurement technologies without interference components refer to those in which the flowmeter used does not contain obstructive components. Such flowmeters do not affect the flow pattern and flow state of the fluid to be measured during the measurement process and have no pressure loss, so they have outstanding advantages in measuring high-temperature liquid metals. In recent years, the measurement technologies without interference components have developed very rapidly. Common non-interference-type liquid metal flow measurement technologies include Coriolis mass flowmeter, electromagnetic flowmeter, ultrasonic flowmeter, photography method, X-ray imaging method, etc.

[0004] Regarding the measurement problems of the flow velocity distribution and flow rate of high-temperature liquid metal in pipes, such as: high measurement environment temperature, conductivity of high-temperature liquid metal, wetting and corrosion between high-temperature liquid metal and the wall of the pipe, large measurement pipe diameter, etc. Although existing electromagnetic flowmeters are applicable to conductive fluids, they usually rely on the measurement of the induced electromotive force under a uniform magnetic field, and cannot distinguish between changes in flow velocity and fluctuations in the conductivity of high-temperature liquid metal. Moreover, the signal-to-noise ratio decreases significantly at low flow velocities (<0.1 m / s), making it difficult to meet the requirements of precise control; the acoustic coupling performance of ultrasonic flowmeters decreases at high temperatures, and their sensitivity to low flow velocities is insufficient; traditional orifice plate flowmeters rely on throttling structures, which are prone to thermal expansion and geometric deformation at high temperatures; the bluff body of vortex flowmeters is easily damaged due to the high temperature, strong corrosiveness, and conductive characteristics of liquid metal, and the damage to the bluff body is extremely likely to cause local solidification and impurity deposition, and it is difficult for optical or thermal sensors to work stably; inducing eddy currents using a high-frequency alternating electromagnetic field (>1 kHz) can avoid mechanical wear, but the alternating magnetic field is prone to cause the skin effect of liquid metal, resulting in an unstable effective throttling area; in the case of a DC magnetic field, the traditional upstream and downstream pressure-taking methods are affected by the sensitivity of the differential pressure signal to the magnetic field position due to the uneven distribution of the magnetic field gradient (simulation shows that the difference in magnetic induction intensity between the pipe center and the wall reaches 15%), and the repeatability error exceeds ±2%. Existing technologies are difficult to balance the long-term structural stability in high-temperature environments and the high-precision measurement requirements for transient flow rates (such as turbulent flow and pulsating flow). Therefore, there is an urgent need for a high-temperature liquid metal flow measurement solution that eliminates physical throttling components, avoids corrosion and wear, adapts to extreme environments, and can accurately measure the flow rate. Summary of the Invention

[0005] In order to overcome the deficiencies of the prior art, the object of the present invention is to provide an electromagnetic excitation high-temperature liquid metal throttling flow measurement system and method.

[0006] To achieve the above object, the present invention provides the following solutions: An electromagnetic excitation high-temperature liquid metal throttling flow measurement system, comprising: An electromagnetic excitation coil, wound around a non-metallic pipe, for generating a DC magnetic field around the non-metallic pipe. When liquid metal passes through the non-metallic pipe, it will be affected by the DC magnetic field to produce a throttling effect, resulting in the contraction of the flow velocity of the liquid metal and generating a pressure difference; A differential pressure detection module, arranged on both sides of the electromagnetic excitation coil, for real-time monitoring of the differential pressure of the liquid metal; A temperature sensor, for detecting the temperature of the liquid metal; A signal processing and calculation unit, for calculating the flow rate of the liquid metal according to the differential pressure and temperature of the liquid metal.

[0007] Preferably, the electromagnetic excitation coil adopts a spiral structure, with a pure copper wire on the inner layer and a high-temperature resistant insulating layer on the outer layer, and the number of turns of the coil N = 200.

[0008] The present invention also provides a method for measuring the throttling flow rate of high-temperature liquid metal by electromagnetic excitation, including: Step 1: Connect a direct current to the electromagnetic excitation coil to generate a direct current magnetic field around the non-metallic pipeline. This direct current magnetic field will cause throttling effect on the liquid metal, resulting in the contraction of its flow velocity and generating a differential pressure. Step 2: Use a differential pressure detection module to detect the differential pressure of the liquid metal, and use a temperature sensor to detect the temperature of the liquid metal in the pipeline. Step 3: Calculate the relationship between the flow velocity and flow rate of the liquid metal according to Bernoulli's equation. Step 4: Perform temperature compensation and correction on the fluid density of the liquid metal using temperature to obtain the temperature-compensated and corrected fluid density of the liquid metal. Step 5: Substitute the temperature-compensated and corrected fluid density of the liquid metal into the relationship between the flow velocity and flow rate of the liquid metal to obtain the flow rate of the liquid metal in the target pipeline.

[0009] Preferably, in the said Step 3, it includes: Regard the direct current magnetic field as a non-contact throttling element. When the liquid metal moves in the direct current magnetic field, throttling of the liquid metal in the pipeline occurs: Wherein, is the velocity before the throttling element, is the velocity after the throttling element, is the pressure difference before and after the throttling element, is the fluid density of the liquid metal.

[0010] From the incompressible continuity equation:

[0011] Wherein, is the velocity before the throttling element, is the cross-sectional area of the pipeline, is the fluid flow cross-sectional area where the flow velocity contraction occurs at the throttling element, equivalent to the original throttling element opening area, determined by simulation; is the fluid velocity where the flow velocity contraction occurs at the throttling element, is the velocity after the throttling element, is the fluid cross-sectional area after the throttling element.

[0012] Since it is difficult to determine the area of the fluid cross-sectional area after the throttling element, therefore, use the fluid flow cross-sectional area where the flow velocity contraction occurs at the throttling element to substitute, and at the same time consider the mechanical energy loss, and adopt coefficient correction:

[0013] Among them, is the cross-sectional area of the pipeline, is the cross-sectional area of the fluid flow where the flow velocity contracts at the throttling element, which is equivalent to the original opening area of the throttling element and is determined by simulation; is the fluid velocity where the flow velocity contracts at the throttling element, is the cross-sectional area of the fluid after the throttling element, is the pressure difference before and after the throttling element, is the density of the liquid metal fluid, is the correction coefficient.

[0014] Let the flow coefficient be expressed as:

[0015] Among them, represents the flow coefficient, which is calibrated by experiments; represents the correction coefficient; is the cross-sectional area of the pipeline; is the cross-sectional area of the fluid flow where the flow velocity contracts at the throttling element, which is equivalent to the original opening area of the throttling element and is determined by simulation.

[0016]

[0017] Among them, represents the flow coefficient, which is calibrated by experiments; is the cross-sectional area of the fluid flow where the flow velocity contracts at the throttling element, which is equivalent to the original opening area of the throttling element and is determined by simulation; is the pressure difference before and after the throttling element, is the density of the liquid metal fluid, represents the liquid metal flow rate.

[0018] Preferably, in the step 4, the formula:

[0019] is used to perform temperature compensation and correction on the density of the liquid metal fluid to obtain the corrected liquid metal density; among them, represents the density of the liquid metal fluid after temperature compensation and correction, represents the density of the liquid metal before correction, represents the coefficient of thermal expansion, represents the current temperature of the liquid metal, represents the initial temperature of the liquid metal.

[0020] The present invention also provides an electronic device, including a bus, a transceiver, a memory, a processor, and a computer program stored on the memory and executable on the processor. The transceiver, the memory, and the processor are connected through the bus. It is characterized in that when the computer program is executed by the processor, the steps in the above-mentioned method for measuring the throttling flow rate of high-temperature liquid metal by electromagnetic excitation are implemented.

[0021] The present invention also provides a computer-readable storage medium, on which a computer program is stored. It is characterized in that when the computer program is executed by a processor, the steps in the above-mentioned method for measuring the throttling flow rate of high-temperature liquid metal by electromagnetic excitation are implemented.

[0022] According to the specific embodiments provided by the present invention, the following technical effects are disclosed by the present invention: The present invention provides a system and method for measuring the throttling flow rate of high-temperature liquid metal by electromagnetic excitation. Compared with the prior art, since the physical properties (such as density) of liquid metal change with temperature, directly affecting the flow measurement result, the present invention can correct the measurement error through temperature compensation and obtain more accurate flow data; in addition, the present invention utilizes an electromagnetic excitation coil to enable the liquid metal to generate a throttling effect and achieve non-contact flow control. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the embodiments. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0024] Figure 1 It is a schematic diagram of the overall structure of the system provided by the present invention; Figure 2 It is a COMSOL simulation magnetic field distribution diagram provided by the present invention; Figure 3 It is a flow velocity-pressure difference characteristic curve diagram provided by the present invention; Figure 4 It is a pipe internal pressure distribution diagram provided by the present invention; Figure 5 It is a flow measurement process diagram provided by the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0025] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0026] Referring to "embodiments" herein means that the specific features, structures, or characteristics described in connection with the embodiments can be included in at least one embodiment of the present application. The phrase appears at various positions in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments.

[0027] The terms "first", "second", "third", "fourth", etc. in the specification, claims, and accompanying drawings of the present application are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion. For example, including a series of steps, processes, methods, etc. is not limited to the listed steps, but optionally also includes steps not listed, or optionally also includes other step elements inherent to these processes, methods, products, or devices.

[0028] To make the above objectives, features, and advantages of the present invention more obvious and understandable, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0029] Please refer to Figures 1-5 , an electromagnetic excitation high-temperature liquid metal throttling flow measurement system, comprising: An electromagnetic excitation coil, wound around a non-metallic pipe, for generating a direct current magnetic field around the non-metallic pipe. When the liquid metal passes through the non-metallic pipe, it will be affected by the direct current magnetic field, resulting in throttling, thereby causing the liquid metal flow velocity to contract and generating a pressure difference; A differential pressure detection module, arranged on both sides of the electromagnetic excitation coil, for real-time monitoring of the differential pressure of the liquid metal; A temperature sensor, for detecting the temperature of the liquid metal; A signal processing and calculation unit, for calculating the flow rate of the liquid metal according to the differential pressure and temperature of the liquid metal.

[0030] In practical applications, an excitation coil wound around a non-metallic (ceramic) pipe generates a stable DC magnetic field around the pipe by applying a 20A direct current excitation to the excitation coil. Then, due to the conductivity of the liquid metal, when the liquid metal passes through the pipe, the movement of the liquid metal will be affected by the magnetic field, resulting in a throttling effect inside it, causing the high-temperature liquid metal to have a flow velocity contraction. The electromagnetic excitation coil is equivalent to a non-contact throttling element, generating a pressure difference before and after the throttling element. The inner layer of the electromagnetic excitation coil is made of pure copper wire, and the outer layer is coated with a high-temperature resistant protective layer to prevent damage caused by high temperature. When an electric current passes through the wire, the transmitting coil generates a magnetic field; High-precision differential pressure sensors are symmetrically installed on the left and right sides of the electromagnetic coil area to monitor the periodic pressure difference fluctuations of the high-temperature liquid metal in real time. The temperature compensation unit mainly corrects the diaphragm thermal deformation error in real time; The signal processing and calculation unit processes the collected differential pressure signals, such as amplification, filtering, and noise reduction; The pipe unit is made of a non-magnetic high-temperature resistant material (such as high-temperature resistant ceramic), with an inner diameter of 40mm, and is used to transport high-temperature liquid metal fluid.

[0031] In practical applications, winding the electromagnetic excitation coil around a non-metallic pipe avoids the coil being damaged by high temperature and corroded due to direct contact with the liquid metal fluid, improving the service life of the equipment. In addition, a silicon nitride coating (0.5mm) is covered on the inner wall of the non-metallic pipe to reduce the adhesion of the liquid metal, and the electromagnetic coil is wrapped with a high-temperature resistant coating material.

[0032] The specific operation process of a high-temperature liquid metal throttling flow measurement system with electromagnetic excitation in the present invention is as follows: Step 1: The electromagnetic excitation coil adopts a spiral structure. The inner layer is made of pure copper wire (radius 2.5mm), and the outer layer is coated with a high-temperature insulation layer (thickness 0.5mm). Through simulation, the number of coil turns N = 200 is optimized to make the magnetic induction intensity in the central area of the pipe reach 0.68T, and the gradient distribution uniformity error < 5%. Apply a 20A direct current excitation to two groups of electromagnetic excitation coils, and the excitation frequency is 100HZ; Step 2: The bilateral differential pressure detection module consists of a differential pressure detection device and a temperature compensation module. Differential pressure tapping ports are symmetrically arranged on both sides of the axial center line of the electromagnetic coil (the spacing is about 50mm). Through finite element simulation analysis and verification, the influence of the magnetic field gradient on the bilateral pressure difference at this spacing can be offset by more than 90%. The differential pressure diaphragm is made of sapphire doped with tungsten (thermal expansion coefficient 4.6×10⁻ 6 / ℃), which is matched with the pipe substrate material (silicon nitride, thermal expansion coefficient 3.2×10⁻ 6 / ℃). Combining with a Pt100 temperature sensor to correct the diaphragm thermal deformation error in real time, and synchronously collect the bilateral differential pressure P and the fluid temperature T; Step 3: Process the differential pressure signal and temperature obtained by the bilateral differential pressure detection module through the signal processing and calculation unit. Based on a digital lock-in amplifier (bandwidth 10 kHz) and an embedded flow calculation engine, calculate the real-time conductivity of the liquid metal, and calculate the flow rate through the flow settlement engine; Step 4: Conduct simulation analysis and verification. Based on the COMSOL Multiphysics multi-physics simulation software, establish a flow measurement model of a pipeline (diameter 40 mm), a coil (200 turns), and liquid metal (lead-bismuth alloy). Under the conditions of an inlet flow rate of 0.1 - 1 m / s and a fluid temperature of 600 °C, the magnetic field intensity distribution is as Figure 2 shown. At the center of the pipeline, B = 0.68 T, and at the edge, B = 0.5 T. The gradient uniformity meets the design requirements. The differential pressure is proportional to the square of the flow rate, and the theoretical model is correct.

[0033] It should be noted that the detection of liquid metal flow in a pipeline is a very special field. The electromagnetic excitation coil mentioned in the present invention uses a non-contact method, which is equivalent to a non-contact throttling element, generating a differential pressure before and after the throttling element.

[0034] Apply a direct current excitation to the excitation coil to generate a uniform and stable magnetic field around the pipeline. Then, due to the conductivity of the liquid metal, when the liquid metal passes through the pipeline, the movement of the liquid metal will be affected by the magnetic field, causing a controllable Lorentz force to be generated inside it, driving the high-temperature liquid metal to contract in flow velocity. The electromagnetic excitation coil is equivalent to a non-contact throttling element, resulting in a differential pressure before and after the throttling element.

[0035] The present invention also provides an anti-interference design for the electromagnetic excitation high-temperature liquid metal throttling flow measurement system. Wrap a 0.5 mm thick permalloy layer around the differential pressure sensor to make the external magnetic field interference < 1 mT; adopt the lock-in amplification technology to extract the differential pressure signal and suppress the noise introduced by the direct current wave.

[0036] The present invention also provides the flow measurement of lead-bismuth alloy in a molten salt energy storage system. The coil insulation layer uses a plasma-sprayed boron nitride coating (thickness 200 ), and after the corrosion test (immersed in a lead-bismuth environment at 700 °C for 500 hours), the insulation resistance still remains > 1 ; The differential pressure impulse pipe is internally provided with a self-cleaning structure to prevent metal deposition and blockage through periodic reverse pulse gas flow (nitrogen); at the flow rate point of 5 m³ / h, the simulation prediction = 12.3 kPa, and the actual measurement = 12.5 kPa, with a deviation of 1.6%; in the dynamic response test, when the flow rate undergoes a step change (2 m³ / h → 5 m³ / h), the system response time ≤ 50 ms, which is better than that of a traditional differential pressure gauge (> 200 ms).

[0037] In the embodiments of the present invention, the electromagnetic coil needs to be able to withstand a high-temperature environment and at the same time generate a stable and uniform magnetic field. The electromagnetic coil material is selected as a copper wire with high conductivity. The copper wire has a diameter of 5 mm, and the excitation coil has 200 turns. And a high-temperature resistant protective layer is coated on the electromagnetic coil to prevent the high temperature of the liquid metal from damaging the electromagnetic coil.

[0038] The measurement pipeline is made of high-temperature resistant and weak-current high-permeability magnetic materials (such as high-temperature resistant ceramics), which is suitable for the magnetic field generated by the electromagnetic excitation coil to penetrate into the pipeline better, and can prevent the high temperature of the liquid metal from damaging the pipeline. A silicon nitride coating (0.5 mm) is coated inside the pipeline to prevent the high-temperature liquid metal from sticking to the wall.

[0039] Differential pressure sensors are symmetrically placed on the left and right sides of the coil coverage area with a sampling rate of 10 kHz, a resolution of 0.01 Pa, and a spacing of L. An electromagnetic shielding structure is used to prevent electromagnetic interference. The signal processing and calculation unit includes a digital lock-in amplifier, a filter, a digital converter, an embedded flow engine, etc., which can amplify, filter, and denoise the differential pressure signal.

[0040] In the embodiments of the present invention, the electromagnetic excitation coil is wound around the pipeline in a non-contact manner. During the installation process, a gap of about 0.1 mm is allowed between the electromagnetic excitation coil and the pipeline.

[0041] The present invention also provides a method for measuring the throttling flow rate of high-temperature liquid metal by electromagnetic excitation, including: Step 1: Connect direct current to the electromagnetic excitation coil to generate a direct current magnetic field around the non-metallic pipeline; Step 2: Use the differential pressure detection module to detect the differential pressure of the liquid metal, and use the temperature sensor to detect the temperature of the liquid metal inside the pipeline; Step 3: Calculate the relationship between the flow velocity and flow rate of the liquid metal according to Bernoulli's equation; In step 3, the direct current magnetic field is regarded as a non-contact throttling element. When the liquid metal moves in the direct current magnetic field, throttling of the liquid metal inside the pipeline occurs:

[0042] Among them, is the velocity before the throttling element, is the velocity after the throttling element, is the pressure difference before and after the throttling element, is the density of the liquid metal fluid.

[0043] From the incompressible continuity equation:

[0044] Among them, is the velocity before the throttle piece, is the cross-sectional area of the pipeline, is the cross-sectional area of the fluid flow where the velocity contraction occurs at the throttle piece, equivalent to the original throttle piece opening area, determined by simulation; is the velocity of the fluid where the velocity contraction occurs at the throttle piece, is the velocity after the throttle piece, is the cross-sectional area of the fluid after the throttle piece.

[0045] Due to the difficulty in determining the cross-sectional area of the fluid after the throttle piece, the cross-sectional area of the fluid where the velocity contraction occurs at the throttle piece is used for substitution. At the same time, considering the mechanical energy loss, coefficient correction is adopted:

[0046] Among them, is the cross-sectional area of the pipeline, is the cross-sectional area of the fluid flow where the velocity contraction occurs at the throttle piece, equivalent to the original throttle piece opening area, determined by simulation; is the velocity of the fluid where the velocity contraction occurs at the throttle piece, is the cross-sectional area of the fluid after the throttle piece, is the pressure difference before and after the throttle piece, is the density of the liquid metal fluid, is the correction coefficient.

[0047] Let the flow coefficient be expressed as:

[0048] Among them, represents the flow coefficient, calibrated by experiments; represents the correction coefficient; is the cross-sectional area of the pipeline; is the cross-sectional area of the fluid flow where the velocity contraction occurs at the throttle piece, equivalent to the original throttle piece opening area, determined by simulation.

[0049]

[0050] Among them, represents the flow coefficient, calibrated by experiments; is the cross-sectional area of the fluid flow where the velocity contraction occurs at the throttle piece, equivalent to the original throttle piece opening area, determined by simulation; is the pressure difference before and after the throttle piece, is the density of the liquid metal fluid, represents the liquid metal flow rate.

[0051] Step 4: Perform temperature compensation and correction on the fluid density of the liquid metal using temperature to obtain the temperature-compensated and corrected fluid density of the liquid metal. In the said Step 4, the formula is adopted:

[0052] Perform temperature compensation and correction on the fluid density of the liquid metal to obtain the temperature-compensated and corrected fluid density of the liquid metal; where represents the temperature-compensated and corrected fluid density of the liquid metal, represents the density of the liquid metal before correction, represents the coefficient of thermal expansion, represents the current temperature of the liquid metal, represents the initial temperature of the liquid metal.

[0053] Next, the present invention further illustrates a method for measuring the throttling flow rate of high-temperature liquid metal with electromagnetic excitation in combination with specific embodiments: Step 1: Use a differential pressure detection device to detect the differential pressure signal at the left and right symmetric positions of the electromagnetic coil in the pipeline, and use a temperature sensor to detect the temperature of the liquid metal in the pipeline. Step 2: Use a signal processing and calculation device to process the differential pressure signal such as amplification and noise reduction, and substitute the differential pressure and temperature obtained by the differential pressure detection device into the flow formula to calculate the flow rate. Step 3: Conduct simulation analysis and verification, establish a COMSOL simulation model, couple multiple physical fields, and verify the actual reliability of the model.

[0054] In the embodiments of the present invention, due to the instability of the liquid metal and the interference of the high-temperature environment, there are noises and interferences in the differential pressure signal, which affect the accuracy and stability of the measurement results. The purpose of signal processing and calculation is to improve the accuracy and stability of the measurement.

[0055] The signal processing and calculation in the present invention are specifically as follows: Step 2.1: The electromagnetic field is equivalent to a non-contact throttling element, generating a differential pressure before and after the throttling element:

[0056] where is the differential pressure before and after the throttling element, is the pressure before the throttling element, is the pressure after the throttling element.

[0057] According to Bernoulli's equation:

[0058] where is the velocity before the throttling element, is the velocity after the throttling element, is the density of the liquid metal fluid.

[0059] After rearrangement, we get:

[0060] Among them, is the velocity before the throttling element, is the velocity after the throttling element, is the pressure difference before and after the throttling element, is the density of the liquid metal fluid.

[0061] From the incompressible continuity equation:

[0062] Among them, is the velocity before the throttling element, is the cross-sectional area of the pipeline, is the cross-sectional area of the fluid flow where the flow velocity contracts at the throttling element, which is equivalent to the original opening area of the throttling element and is determined by simulation; is the fluid velocity where the flow velocity contracts at the throttling element, is the velocity after the throttling element, is the cross-sectional area of the fluid after the throttling element.

[0063] Since it is difficult to determine the area of the cross-sectional area of the fluid after the throttling element , the cross-sectional area of the fluid flow where the flow velocity contracts at the throttling element is used for substitution. At the same time, considering the mechanical energy loss, coefficient correction is adopted:

[0064] Among them, is the cross-sectional area of the pipeline, is the cross-sectional area of the fluid flow where the flow velocity contracts at the throttling element, which is equivalent to the original opening area of the throttling element and is determined by simulation; is the fluid velocity where the flow velocity contracts at the throttling element, is the cross-sectional area of the fluid after the throttling element, is the pressure difference before and after the throttling element, is the density of the liquid metal fluid, is the correction coefficient.

[0065] Step 2: Obtain the relationship between flow rate and pressure difference: Let the flow coefficient be expressed as:

[0066] Among them, represents the flow coefficient, which is calibrated by experiments; represents the correction coefficient; is the cross-sectional area of the pipeline; is the cross-sectional area of the fluid flow where the flow velocity contracts at the throttling element, equivalent to the original opening area of the throttling element, determined by simulation.

[0067]

[0068] Among them, represents the flow coefficient, calibrated by experiments; is the cross-sectional area of the fluid flow where the flow velocity contracts at the throttling element, equivalent to the original opening area of the throttling element, determined by simulation; is the pressure difference before and after the throttling element, is the density of the liquid metal fluid, represents the liquid metal flow rate.

[0069] Step 2.3 performs temperature compensation:

[0070] Among them, represents the density of the liquid metal fluid after temperature compensation correction, represents the density of the liquid metal before correction, represents the coefficient of thermal expansion, represents the current temperature of the liquid metal, represents the initial temperature of the liquid metal.

[0071] The physical properties of liquid metal (such as density) change with temperature, which directly affects the flow measurement result. Through temperature compensation, the present invention can correct the measurement error and obtain more accurate flow data.

[0072] The present invention also provides an electronic device, including a bus, a transceiver, a memory, a processor, and a computer program stored on the memory and executable on the processor. The transceiver, the memory, and the processor are connected through the bus. It is characterized in that when the computer program is executed by the processor, it implements the steps in the above-mentioned electromagnetic excitation high-temperature liquid metal throttling flow measurement method. Compared with the prior art, the beneficial effects of the electronic device provided by the present invention are the same as those of the above-mentioned electromagnetic excitation high-temperature liquid metal throttling flow measurement method, which will not be elaborated here.

[0073] The present invention also provides a computer-readable storage medium, on which a computer program is stored. It is characterized in that when the computer program is executed by a processor, it implements the steps in the above-mentioned electromagnetic excitation high-temperature liquid metal throttling flow measurement method. Compared with the prior art, the beneficial effects of the computer-readable storage medium provided by the present invention are the same as those of the above-mentioned electromagnetic excitation high-temperature liquid metal throttling flow measurement method, which will not be elaborated here.

[0074] The various embodiments in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. For the same or similar parts among the various embodiments, reference can be made to each other. For the methods disclosed in the embodiments, since they correspond to the devices disclosed in the embodiments, the description is relatively simple. For related parts, reference can be made to the description of the device part.

[0075] Specific examples are used in this article to elaborate on the principles and implementation manners of the present invention. The descriptions of the above embodiments are only used to help understand the method of the present invention and its core idea. At the same time, for those of ordinary skill in the art, based on the idea of the present invention, there will be changes in the specific implementation manners and application scopes. In summary, the content of this specification should not be construed as a limitation on the present invention.

Claims

1. An electromagnetically excited high-temperature liquid metal throttling flow measurement system, characterized in that: include: The electromagnetic excitation coil is wound around the non-metallic pipe and is used to generate a DC magnetic field around the non-metallic pipe. When the liquid metal passes through the non-metallic pipe, it will be affected by the DC magnetic field to produce a throttling effect in the pipe, causing the liquid metal flow rate to shrink and generate a pressure difference. The differential pressure detection module is arranged on both sides of the electromagnetic excitation coil and is used to monitor the differential pressure of the liquid metal in real time; Temperature sensor, used to detect the temperature of liquid metal; The signal processing and solving unit is used to calculate the flow rate of the liquid metal according to the differential pressure and temperature of the liquid metal.

2. The electromagnetically excited high-temperature liquid metal throttling flow measurement system according to claim 1, characterized in that: The electromagnetic excitation coil adopts a spiral structure, the inner layer is a pure copper wire, the outer layer is covered with a high temperature resistant insulation layer, and the number of coil turns N=200.

3. A method for measuring the throttling flow of high-temperature liquid metal using electromagnetic excitation, characterized in that: include: Step 1: Connect direct current to the electromagnetic excitation coil to generate a direct current magnetic field around the non-metallic pipe; Step 2: Use the differential pressure detection module to detect the differential pressure of the liquid metal, and use the temperature sensor to detect the temperature of the liquid metal in the tube; Step 3: Calculate the relationship between the liquid metal flow rate and flow rate according to the Bernoulli equation; Step 4: Using the temperature to perform temperature compensation correction on the fluid density of the liquid metal to obtain the temperature compensated and corrected fluid density of the liquid metal; Step 5: Substitute the temperature-compensated corrected density of the liquid metal fluid into the relationship between the liquid metal flow velocity and the flow rate to obtain the liquid metal flow rate in the target pipeline.

4. The electromagnetically excited high-temperature liquid metal throttling flow measurement method according to claim 3, characterized in that: In step 3, it includes: The DC magnetic field is regarded as a non-contact throttling device. When the liquid metal moves in the DC magnetic field, the throttling of the liquid metal in the pipeline occurs: in, is the speed before the throttle, is the speed after the throttle, is the pressure difference before and after the throttling element, is the density of liquid metal fluid; From the incompressible continuity equation: in, is the speed before the throttle, is the cross-sectional area of ​​the pipe, The cross-sectional area of ​​the fluid flow where the flow velocity is reduced at the throttling device is equivalent to the original opening area of ​​the throttling device and is determined by simulation; is the fluid velocity that produces flow contraction at the throttling element, is the speed after the throttle, is the cross-sectional area of ​​the fluid after the throttling element; Since the cross-sectional area of ​​the fluid after the throttling element The area is difficult to determine, so the cross-sectional area of ​​the fluid that produces flow velocity contraction at the throttling device is used. Instead, taking into account the mechanical energy loss, a coefficient correction is used: in, is the cross-sectional area of ​​the pipe, The cross-sectional area of ​​the fluid flow where the flow velocity is reduced at the throttling device is equivalent to the original opening area of ​​the throttling device and is determined by simulation; is the fluid velocity that produces flow contraction at the throttling element, is the cross-sectional area of ​​the fluid after the throttling device, is the pressure difference before and after the throttling element, is the density of liquid metal fluid, is the correction factor; Let flow coefficient It is expressed as: in, It represents the flow coefficient, which is calibrated by experiments; represents the correction factor; is the cross-sectional area of ​​the pipe; Equivalent to the original throttling opening area, determined by simulation; in, It represents the flow coefficient, which is calibrated by experiments; The cross-sectional area of ​​the fluid flow where the flow velocity is reduced at the throttling device is equivalent to the original opening area of ​​the throttling device and is determined by simulation; is the pressure difference before and after the throttling element, is the density of liquid metal fluid, Indicates the liquid metal flow rate.

5. The electromagnetically excited high-temperature liquid metal throttling flow measurement method according to claim 4, characterized in that: In step 4, the formula is used: The temperature compensation correction is performed on the fluid density of the liquid metal to obtain the temperature-compensated corrected liquid metal fluid density; wherein, represents the density of liquid metal fluid after temperature compensation correction, represents the density of liquid metal before correction, is the coefficient of thermal expansion, Indicates the current temperature of the liquid metal. represents the initial temperature of liquid metal.

6. An electronic device, comprising a bus, a transceiver, a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the transceiver, the memory, and the processor are connected via the bus, wherein: When the computer program is executed by the processor, the steps in the electromagnetically excited high-temperature liquid metal throttling flow measurement method according to any one of claims 3 to 5 are implemented.

7. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps in the electromagnetically excited high-temperature liquid metal throttling flow measurement method according to any one of claims 3 to 5 are implemented.

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