Nuclear power station primary loop flow and temperature composite measurement method and system

Abstract

The invention provides a nuclear power station primary loop flow and temperature composite measurement method and system, and the method comprises the steps: arranging a measurement mechanism at a to-be-measured interface of a to-be-measured main pipeline, enabling the to-be-measured interface to generate hydroacoustic resonance in a primary loop flow velocity range, and calculating the real-time flow velocity and temperature value of a primary loop medium through data collection and processing equipment, compared with a traditional flow velocity and temperature measurement mode, the limitation of the installation position of the measurement mechanism is reduced, the number of openings is reduced by 2 / 3, then the number of primary loop pressure boundary weld joints is reduced, a main pipeline temperature measurement insertion piece is omitted, and the risk of primary loop foreign matter invasion is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of nuclear power plant reactor coolant system safety design, and particularly relates to a nuclear power station one-loop flow and temperature composite measurement method and system. BACKGROUND

[0002] A plurality of groups of flow and temperature sensors are arranged on a main pipe of a reactor coolant system of a nuclear power plant, which are used for monitoring the flow and operation state of one-loop coolant, and the measurement signals are associated with a safety monitoring system, and when an abnormality is monitored, automatic shutdown is triggered, so that the accuracy of measurement plays an important role in keeping the reactor safe operation.

[0003] Since the safety requirement of the one-loop pressure boundary is very high, and the one-loop medium has the characteristics of high temperature, high pressure and high radiation, common volume flow meters, velocity flow meters and electromagnetic flow meters are not suitable for one-loop flow measurement.

[0004] At present, a bend flow meter is mostly used in the one-loop of a nuclear power plant, which utilizes the fact that when fluid flows through a bend pipe, a pressure difference is formed inside and outside the bend pipe, and the differential pressure value is linearly related to the square of the average flow rate, and the flow rate is calculated by measuring the differential pressure value.

[0005] The bend flow meter has the advantages of no pressure loss and strong environmental adaptability, but also has many limitations, such as requirements for the design of the bend pipe structure, and the radius is too large to affect the measurement accuracy, in addition, the bend flow meter needs to be provided with two pressure tapping openings inside and outside the bend pipe, which increases the number of one-loop pressure boundary openings and welds, and increases the risk of one-loop coolant leakage.

[0006] The temperature measurement of the one-loop of a nuclear power plant mostly uses an inserted RTD sensor, and the temperature gauge sleeve needs to be inserted into the main pipe, which may disturb the local flow field of the main pipe, in addition, under the scouring of high-speed fluid, there is a possibility of fatigue fracture failure, which increases the risk of one-loop foreign matter invasion.

[0007] Based on this, the present application provides a nuclear power station one-loop flow and temperature composite measurement method and system to solve one or more of the above technical problems. SUMMARY

[0008] The present application aims to overcome the problems in the prior art that the installation position of the one-loop flow and temperature measurement is limited, the number of one-loop openings is large, and the one-loop insert is included, and provides a nuclear power station one-loop flow and temperature composite measurement method and system.

[0009] The present application solves the above technical problems by the following technical scheme:

[0010] The present application provides a nuclear power station one-loop flow and temperature composite measurement method, which comprises:

[0011] Step 1: Setting a measuring mechanism at a test interface of a main pipeline to be tested; wherein the measuring mechanism includes at least one branch pipe, and a vibration signal measuring sensor is provided at an end of the branch pipe away from the main pipeline to be tested;

[0012] Step 2: using a data acquisition and processing device in communication with the vibration signal measurement sensor to measure the vibration time history of each branch pipe end, and determining the target branch pipe in the acoustic resonance state based on the vibration time history data;

[0013] Step 3: Performing Fourier transform on the maximum vibration time history by the data acquisition and processing equipment to obtain a real-time vibration spectrum, extracting the frequency domain peak vibration intensity and the corresponding peak frequency based on the real-time vibration spectrum, and calculating the average value of the vibration intensity in a specific frequency range outside the acoustic resonance range;

[0014] Step 4: Calculate the medium sound velocity using the peak frequency, the frequency domain peak vibration intensity, and the average vibration intensity;

[0015] Step 5: Calculate the real-time medium temperature and real-time medium density based on the medium sound velocity and the real-time pressure of the power plant primary circuit safety monitoring system;

[0016] Step 6: Calculate the real-time Strouhal number based on the frequency domain peak vibration intensity and the average vibration intensity;

[0017] Step 7: Calculate the real-time flow velocity of the main pipeline using the Strouhal number and the peak frequency;

[0018] Step 8: Calculate the real-time volume flow of the main pipeline using the inner diameter of the main pipeline and the real-time flow velocity, and calculate the mass flow of the main pipeline based on the volume flow and the real-time medium density.

[0019] According to one embodiment of the present invention, the longest branch pipe among the branch pipes in step 1 is provided with an expanded diameter pipe.

[0020] According to one embodiment of the present invention, the vibration signal measuring sensor in step 2 is connected to the data analysis and processing device via a signal connection cable;

[0021] The data analysis and processing equipment is in communication connection with the primary circuit safety monitoring system of the power station.

[0022] According to one embodiment of the present invention, in step 3, the maximum value of the Y axis is extracted from the real-time vibration spectrum as the frequency domain peak vibration intensity, the corresponding X axis value is extracted as the peak frequency, and all Y values ​​in a specific frequency range outside the X axis resonance range are extracted and averaged to obtain the average value of the turbulent vibration intensity that increases with the increase of flow velocity.

[0023] According to one embodiment of the present application, in the step 4, the formula for calculating the sound velocity is:

[0024] C=(4L+0.6d)*f;

[0025] Wherein, C is the sound velocity of the medium in the main pipe to be measured, L is the equivalent length between the inner wall of the main pipe to be measured and the inner wall of the closed end of the target branch pipe after correction, d is the inner diameter of the target branch pipe, and f is the peak frequency of the target branch pipe.

[0026] Wherein, the target branch pipe is an acoustic resonance branch pipe.

[0027] According to one embodiment of the present application, when the target branch pipe is provided with a diameter expansion pipe, the acoustic membrane state frequency of the acoustic cavity structure is obtained through acoustic simulation analysis, and the equivalent length between the inner wall of the main pipe to be measured and the inner wall of the closed end of the target branch pipe is corrected.

[0028] According to one embodiment of the present application, in the step 5, the real-time medium temperature and the real-time medium density are calculated by using the sound velocity of the medium and the real-time pressure of the power plant primary loop safety monitoring system according to the IAPWS-IF97 formula.

[0029] According to one embodiment of the present application, in the step 6, the real-time Strouhal number is obtained through the calibrated relationship curve between acoustic resonance intensity and Strouhal number; wherein the relationship curve between acoustic resonance intensity and Strouhal number is:

[0030] ;

[0031] Wherein, a is the peak vibration intensity in the frequency domain, is the average vibration intensity, is the Strouhal number.

[0032] According to one embodiment of the present application, in the step 7, the formula for calculating the real-time flow rate of the main pipe is:

[0033] ;

[0034] Wherein, f is the peak frequency, d is the inner diameter of the target branch pipe, is the Strouhal number.

[0035] According to one embodiment of the present application, after the step 8, further comprising:

[0036] Step 9, transmitting the main pipe flow rate and temperature data to the power plant primary loop safety monitoring system.

[0037] A computer program product according to a second aspect of the application comprises a computer program which, when executed by a processor, implements the steps performed by a computer in the method according to the first aspect.

[0038] A computer-readable storage medium according to a third aspect of the application has a computer program which, when executed by a processor, implements the steps performed by a computer in the method according to the first aspect.

[0039] A measurement system according to a fourth aspect of the application comprises a memory capable of storing instructions executable by a processor, and a processor capable of executing the instructions to implement the steps performed by a computer in the method according to the first aspect.

[0040] The positive progress effect of the application is that:

[0041] The nuclear power plant primary circuit flow and temperature composite measurement method sets a measurement mechanism at the to-be-measured interface of the to-be-measured main pipeline, so that flow sound resonance occurs in the primary circuit flow speed range, and then the real-time flow speed and temperature value of the primary circuit medium are calculated by using a data acquisition and processing device. Compared with the traditional flow speed and temperature measurement method, the measurement mechanism installation position restriction is reduced, the number of openings is reduced by 2 / 3, the number of primary circuit pressure boundary welds is reduced, the main pipeline temperature measurement insert is cancelled, and the risk of primary circuit foreign matter invasion is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0042] The above and other features, properties, and advantages of the application will become more apparent by referring to the following description in conjunction with the accompanying drawings and examples, in which:

[0043] Figure 1 It is a schematic diagram of the flow sound resonance principle;

[0044] Figure 2 It is a schematic diagram of the arrangement of the measurement mechanism of the application;

[0045] Figure 3 It is a schematic diagram of the vibration spectrum processing of the application;

[0046] Figure 4 It is a schematic diagram of the relationship curve between the sound resonance intensity and the Strouhal number of the application;

[0047] Figure 5 It is a flowchart of the nuclear power plant primary circuit flow and temperature composite measurement method of the application;

[0048] Figure 6 It is a schematic diagram of the structure of the measurement system of the application.

[0049] 1, to-be-measured main pipeline; 11, to-be-measured interface;

[0050] 2, first branch pipe;

[0051] 3. second branch pipe;

[0052] 4. third branch pipe;

[0053] 5. diameter expansion pipe;

[0054] 6. vibration signal measurement sensor;

[0055] 7. connecting cable;

[0056] 8. data acquisition and processing device;

[0057] 9. nuclear power plant primary loop safety monitoring system; 91. pressure data input channel; 92. flow and temperature data output channel. DETAILED DESCRIPTION

[0058] In order to make the above objectives, features and advantages of the present application more obvious and easy to understand, the specific embodiments of the present application will be described in detail below with reference to the accompanying drawings.

[0059] Reference will now be made in detail to the embodiments of the present application, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. In addition, although the terms used in the present application are selected from generally known and used terms, some of the terms mentioned in the description of the present application can be selected by the applicant in his or her judgment, and the detailed meanings thereof are described in the relevant parts of the description. Furthermore, the present application should not be construed as being limited only to the actual terms used but also to the meanings of each term based on the descriptions made herein.

[0060] The present application is based on the principle of calculating flow rate and temperature from the vibration signal of the branch pipe flow sound resonance as follows:

[0061] According to the 1 / 4 wavelength theory, the acoustic frequency of the stagnant flow branch pipe is related to the stagnant flow pipe length and the medium acoustic velocity, so that after the branch pipe vibration frequency is measured and the branch pipe length is known, the medium acoustic velocity can be calculated. The medium acoustic velocity is related to the temperature and pressure of the medium, so that the medium temperature can be calculated from the acoustic velocity and the measured pressure value.

[0062] Reference Figure 1 According to the flow sound resonance theory, when the high-speed fluid in the main pipe flows through the stagnant branch pipe port, the shear layer separation occurs, vortex flow without specific frequency is generated, and wideband excitation of turbulent flow is formed. Within a certain range of flow velocity, the vortex frequency is locked by the stagnant pipe acoustic frequency, and pressure pulsation of specific frequency occurs, i.e. flow sound resonance occurs, Figure 1It is a flow sound resonance schematic diagram. After entering the flow sound coupling interval, the sound resonance intensity gradually increases with the increase of the flow rate, gradually decreases after reaching the peak, and then gradually decreases until leaving the flow sound coupling resonance interval, so that the flow rate of the main pipeline can be calculated by the sound vibration frequency and vibration intensity.

[0063] Based on this, the present application provides a kind of nuclear power station one loop flow and temperature composite measurement method, comprising:

[0064] Step 1, the measuring mechanism is arranged at the to-be-measured interface of the to-be-measured main pipeline;Wherein, the measuring mechanism includes at least one branch pipe, and the end of the branch pipe away from the to-be-measured main pipeline is provided with a vibration signal measurement sensor.

[0065] Reference Figure 2 , Figure 2 The structure of the measuring mechanism is shown in the schematic diagram. Moreover, Figure 2 The number of branch pipes in the above-mentioned measuring mechanism is taken as an example for illustration. However, the number of branch pipes can be one, two or more, which is not limited herein and can be set according to actual needs. The vibration signal measurement sensor can be a conventional vibration sensor, including but not limited to an acceleration sensor, a speed sensor, a displacement sensor, or can also be a dynamic pressure sensor, and the specific type is not limited herein.

[0066] Specifically, the measuring mechanism includes a to-be-measured main pipeline 1, a first branch pipe 2, a second branch pipe 3, a third branch pipe 4, a diameter expansion pipe 5, three vibration signal measurement sensors 6, a connecting cable 7, a data acquisition and processing device 8, a power station one loop safety monitoring system 9, a pressure data input channel 91, and a flow and temperature data output channel 92. The diameter expansion pipe 5 is installed on the first branch pipe 2.

[0067] The to-be-measured main pipeline 1 has one to-be-measured interface 11 on the straight pipe section, and the branch pipe is connected to the to-be-measured main pipeline 1 by welding. The first branch pipe 2, the second branch pipe 3 and the third branch pipe 4 have different lengths, the first branch pipe 2 has the longest length and is used to form the flow sound resonance of the low flow rate interval, the second branch pipe 3 has a medium length and is used to form the flow sound resonance of the medium flow rate interval, and the third branch pipe 4 has the shortest length and is used to form the flow sound resonance of the high flow rate interval. The diameter expansion pipe 5 is installed on the first branch pipe 2, but the number of diameter expansion pipes 5 is not limited to one and can be respectively arranged on the first branch pipe 2, the second branch pipe 3 and the third branch pipe 4.

[0068] The first branch pipe 2, the second branch pipe 3 and the third branch pipe 4 are provided with vibration signal measurement sensors 6 at the ends away from the to-be-measured main pipeline 1, the vibration signal measurement sensors 6 are used to measure the vibration response of the end of the branch pipe, the vibration signal measurement sensors 6 are connected to the data acquisition and processing device 8 through the signal connecting cable 7, and the data acquisition and processing device 8 is used for data acquisition and calculation of the temperature and flow data of the medium in the main pipeline.

[0069] The data acquisition and processing device 8 obtains real-time pressure data from the power plant primary circuit safety monitoring system 9 through the pressure data input channel 91, and outputs real-time flow and temperature data to the power plant primary circuit safety monitoring system 9 through the flow and temperature data output channel 92.

[0070] It should be noted that, Figure 2 Three branch pipes are taken as examples for illustration, but the specific number is not limited. Different numbers of branch pipes can be selected for measurement as needed.

[0071] Step 2, measure the vibration time history of the end of each branch pipe by using the data acquisition and processing device in communication connection with the vibration signal measurement sensor, and determine the target branch pipe in the acoustic resonance state according to the vibration time history data.

[0072] It can be seen that the kinetic energy of the resonant branch pipe fluid forms a positive feedback cycle with the acoustic pressure oscillation energy and the pipe wall vibration energy, and the energy continues to accumulate, so the branch pipe corresponding to the data with the strongest vibration intensity is the target branch pipe, which also corresponds to the resonant branch pipe.

[0073] Therefore, the target branch pipe in the acoustic resonance state can be determined according to the vibration time history data.

[0074] Step 3, perform Fourier transform on the maximum vibration time history by the data acquisition and processing device to obtain a real-time vibration spectrum, extract the frequency domain peak vibration intensity and the corresponding peak frequency according to the real-time vibration spectrum, and calculate the average vibration intensity of a specific frequency range outside the acoustic resonance interval.

[0075] That is, the maximum vibration time history corresponds to the branch pipe signal with the strongest acoustic resonance energy, and selecting this signal for Fourier transform can ensure that the acoustic resonance frequency amplitude is much higher than the background noise, and can avoid the interference of low-energy signals of other non-resonant branch pipes with the frequency domain feature extraction. Moreover, only the signal with the highest energy is subjected to Fourier transform, which can reduce the data processing amount and meet the real-time measurement requirement.

[0076] Specifically, for the vibration time history and the vibration intensity, according to the type of the vibration signal measurement sensor, the acceleration sensor can obtain a time history curve of acceleration varying with time, and the vibration intensity obtained by processing is the acceleration amplitude, for the velocity sensor, a time history curve of velocity varying with time can be obtained, and the vibration intensity obtained by processing is the velocity amplitude, for the displacement sensor, a time history curve of displacement varying with time can be obtained, and the vibration intensity obtained by processing is the displacement amplitude, and for the dynamic pressure sensor, a time history curve of pressure pulsation varying with time can be obtained, and the vibration intensity obtained by processing is the pressure pulsation amplitude.

[0077] This application uses an acceleration sensor to measure an acceleration time course and process it to obtain an acceleration amplitude as an example for explanation, but is not limited to this.

[0078] For details, please refer to Figure 3 , Figure 3 The diagram shows the vibration spectrum processing. The maximum value of the Y axis is extracted as the frequency domain peak vibration intensity, the corresponding X axis value is extracted as the peak frequency f, and all Y axis values ​​in a specific frequency range (55-70Hz in this case) outside the X axis resonance range are averaged to obtain the average vibration intensity. .

[0079] Step 4: Calculate the medium sound velocity using the peak frequency, the frequency domain peak vibration intensity, and the average vibration intensity.

[0080] According to the flow-acoustic resonance theory, the relationship between sound frequency and flow velocity can be described by the following formula:

[0081] ; (1)

[0082] Wherein, d is the inner diameter of the branch pipe opening, which is selected according to the layout conditions of the main pipeline. The present invention preferably uses a DN25 branch pipe to form flow acoustic resonance while reducing the size of the primary circuit rupture. In other optional implementation scenarios, branch pipes of other diameters can also be selected, which is not limited here; Indicates the flow velocity of the main pipeline. The flow velocity measurement range can be determined based on the designed flow velocity range of the primary circuit. is the Strouhal number, a dimensionless number used to describe the oscillatory flow mechanism, and is related to parameters such as the Reynolds number of the fluid and the diameter ratio of the branch pipe to the main pipe. In the range of about 0.2~0.6, flow acoustic resonance occurs.

[0083] It should be noted that, The acoustic frequency of a stagnant branch, for a single stagnant branch, can be expressed as follows based on the 1 / 4 wavelength theory:

[0084] ; (2)

[0085] in, The sound velocity of the medium in the main pipeline to be tested can be calculated based on the design temperature and pressure range of the primary circuit and the thermodynamic properties of water and water-vapor standards such as the international standard IAPWS-IF97 formula. L is the length from the inner wall of the main pipeline to be tested to the inner wall of the closed end of the branch pipe. The sound velocity range of the medium in the primary circuit can be calculated according to formula (1) to meet the flow-acoustic resonance. Requested ,according to and C, calculate the required branch pipe length.

[0086] That is, formula (1), d is a constant value, v is a range of loop design flow rate, The value range of f can be calculated.

[0087] In formula (2), C is the range of the sound speed of the medium in the main pipe, d is a constant value, and f is the range value obtained from formula (1). Thus, according to formula (2), the value range of L can be calculated, and the extreme values at both ends of the range and the intermediate value can be selected as the length of the branch pipe required. After the length of the branch pipe is obtained, the measurement mechanism can be designed.

[0088] It should be noted that the flow rate range of the main pipe is generally 0-25 m / s, and a single stagnation branch pipe structure cannot cover the flow rate range requirement. Therefore, a multi-order acoustic mode branch pipe structure with different frequencies is designed, so that different branch pipes form acoustic resonance at different flow rate intervals. The nth order acoustic mode frequency of the multi-branch structure Can be expressed by the following formula:

[0089] ; (3)

[0090] Wherein, represents the distance from the inner wall of the closed end of the nth branch pipe to the inner wall of the main pipe.

[0091] It can be seen that the number of branches increases or decreases according to the range of the range required to be covered. For example, a diameter expansion pipe can be added to the branch pipe to act as a Helmholtz resonance cavity, so as to reduce the acoustic frequency of the branch pipe, thereby covering a wider frequency range.

[0092] Since the acoustic frequency is mainly related to the length of the branch pipe, the direction of the branch pipe can be adjusted by adding a bend or an elbow to the branch pipe according to the actual arrangement space. Then, more accurate acoustic mode frequencies can be obtained through simulation analysis by using finite element analysis software such as ANSYS, and the equivalent length can be obtained by correction according to the calculation results.

[0093] After the acoustic cavity structure is designed, the branch pipe structure mode needs to be calculated and checked to avoid the inherent frequency of the structure falling within the acoustic resonance frequency range, which may interfere with the measurement.

[0094] The range of the acoustic resonance formed by the flow is related to the Reynolds number of the fluid, the ratio of the diameter of the branch pipe to the diameter of the main pipe, and other parameters. In addition, the acoustic resonance strength is related to the actual stiffness and damping of the pipe structure. Therefore, after the measurement mechanism is designed, manufactured and installed, the vibration of the branch pipe needs to be measured and calibrated at different flow rates, and the relationship curve between the accurate acoustic resonance strength and can be obtained by fitting, as shown in formula (4).

[0095] ; (4)

[0096] wherein, represents the sound resonance peak vibration intensity in the frequency domain after Fourier transform of the vibration time history;

[0097] is the vibration intensity average value, representing the vibration intensity average value in the frequency domain in a specific frequency range outside the sound resonance interval, used to characterize the non-resonant turbulent vibration that increases with the increase of flow velocity, and is calculated by eliminating the influence of turbulent vibration with the increase of flow velocity, so as to accurately reflect the relationship with the sound resonance intensity.

[0098] Please refer to Figure 4 , Figure 4 shows the relationship curve between the sound resonance intensity and the Strouhal number, and the vibration intensity and are measured at different flow velocities, and the accurate relationship curve of is obtained by fitting.

[0099] Step 5, the real-time medium temperature and the real-time medium density are calculated based on the medium sound velocity and the real-time pressure of the power station primary circuit safety monitoring system.

[0100] Specifically, according to the international standard IAPWS-IF97 formula, the real-time medium temperature and the real-time medium density are calculated based on the medium sound velocity and the real-time pressure of the power station primary circuit safety monitoring system.

[0101] It should be noted that according to the international standard IAPWS-IF97 formula, the medium temperature and the medium density obtained by the known sound velocity and pressure value are the technical means familiar to those skilled in the art, which will not be repeated here.

[0102] For example, the temperature T is solved by iteration of the sound velocity equation: ; wherein p represents the pressure, and T represents the temperature; the temperature T is calculated by the link iteration or the dichotomy method; and for the density p, the following formula is used to calculate: ; wherein g is the specific Gibbs free energy, and P is the pressure.

[0103] Step 6, the real-time Strouhal number is calculated based on the frequency domain peak vibration intensity and the vibration intensity average value.

[0104] That is, based on the frequency domain peak vibration intensity a and the reference vibration intensity (the average vibration intensity), the real-time value is obtained by the calibrated relationship curve between the sound resonance intensity and , that is, formula (4).

[0105] Step 7, the real-time flow rate of the main pipe is calculated by using the Strouhal number and the peak frequency.

[0106] Specifically, the calculation formula of the main pipe flow rate is as follows:

[0107] v = f * d / S ;

[0108] Wherein, f is the peak frequency, d is the inner diameter of the target branch pipe, and S is the Strouhal number.

[0109] Step 8, the real-time volume flow rate of the main pipe is calculated by using the inner diameter size of the main pipe and the real-time flow rate, and the real-time mass flow rate of the main pipe is calculated according to the volume flow rate and the real-time medium density.

[0110] That is, the cross-sectional area of the main pipe can be calculated by using the inner diameter size of the main pipe, and the volume flow rate of the main pipe can be obtained by multiplying the cross-sectional area by the real-time volume flow rate. The mass flow rate of the main pipe can be obtained by multiplying the volume flow rate of the main pipe by the real-time medium density.

[0111] As shown in the following Figure 5 , Figure 5 the flow chart of the measurement method is shown, and the specific steps are as follows:

[0112] 1. The vibration time history of each branch pipe end is measured by using a vibration signal measurement sensor, and the one-loop pressure is read, the target branch pipe in the acoustic resonance state is determined according to the vibration intensity;

[0113] 2. The maximum vibration time history and the one-loop pressure are subjected to Fourier transform by using a data analysis processing device, the real-time vibration frequency spectrum is obtained, the frequency domain peak vibration intensity frequency f is identified, and the frequency domain peak vibration intensity a and the reference vibration intensity are identified ;

[0114] 3. Based on the real-time acoustic vibration frequency f and the equivalent length of the branch pipe n in the acoustic resonance state, the real-time medium acoustic velocity is calculated by using the above formula (3);

[0115] 4. Based on the acoustic velocity and the real-time pressure provided by the one-loop safety monitoring system, the real-time medium temperature T is calculated by using the international standard IAPWS-IF97 formula and other methods, and the real-time medium density p is also calculated;

[0116] 5. Based on the frequency domain peak vibration intensity a and the average vibration intensity , the real-time value is obtained by using the relationship curve between the calibrated acoustic resonance intensity and , that is, the above formula (4).

[0117] 6、based on The real-time flow rate of the main pipe is calculated by the above formula (1) ;

[0118] 7、The real-time volume flow rate is calculated according to the inner diameter size of the main pipe and the real-time flow rate , and the mass flow rate is calculated according to the real-time medium density .

[0119] Therefore, based on the acoustic resonance principle, the application can be installed on a straight pipe section, and compared with the traditional elbow flow meter, the installation position condition restriction is reduced, and the structure design of the elbow radius and the to-be-measured main pipe is not required.

[0120] The application only needs one to-be-measured interface to realize the composite measurement of flow rate and temperature, the traditional elbow flow meter needs to set two pressure tapping openings on the upper and lower surfaces of the elbow, and the thermometer sleeve also needs one opening, a total of three openings, the application only needs one opening, reduces the number of one-loop pressure boundary welds, and reduces the risk of one-loop coolant leakage.

[0121] Meanwhile, the application does not need to be inserted into the to-be-measured main pipe, and solves the disadvantages of the traditional temperature measurement using the inserted RTD sensor, including the potential disturbance to the local flow field of the to-be-measured main pipe and the fatigue fracture failure of the insert under the scouring of high-speed fluid, which may cause the harm of one-loop foreign matter invasion.

[0122] Reference Figure 6 As shown in the figure, the application also provides a control system 1000, which includes a memory 1001 and a processor 1002, the memory can store instructions executable by the processor 1002; the processor 1002 can execute the instructions to realize the steps executed by the computer in the nuclear power plant one-loop flow rate and temperature composite measurement method introduced in the above embodiments.

[0123] It can be understood that it should be noted that the above-mentioned memory and processor are not limited to a specific memory and processor. Furthermore, in the embodiment using a distributed structure, the specific execution terminal of each step can be adjusted according to the actual situation, and the specific scheme of each step realized in a specific terminal should not limit the protection scope of the application.

[0124] According to another aspect of the application, the application also provides a computer readable medium.

[0125] The above computer readable medium provided by the application has computer instructions thereon. When the computer instructions are executed by the processor, the steps executed by the program in the method as introduced in the above embodiments can be implemented.

[0126] According to still another aspect of the present application, the present application also provides a computer program product.

[0127] The computer readable medium provided by the present application includes a computer program which, when executed by a processor, can implement the steps performed by the program executed by the processor in the method as introduced in the above embodiments.

[0128] The various illustrative logical blocks, and circuits described in connection with the embodiments disclosed herein can be implemented or performed with a general purpose processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. The general purpose processor can be a microprocessor, but in the alternative, the processor can be any conventional processor, controller, microcontroller, or state machine. A processor can also be implemented as a combination of computing devices, such as a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

[0129] The steps of a method or algorithm described in connection with the embodiments disclosed herein can be embodied directly in hardware, in a software module executed by a processor, or in a combination of the two. A software module can reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor such that the processor can read information from, and write information to, the storage medium. In the alternative, the storage medium can be integral to the processor. The processor and the storage medium can reside in an ASIC. The ASIC can reside in a user terminal. In the alternative, the processor and the storage medium can reside as discrete components in a user terminal.

[0130] In one or more exemplary embodiments, the functions described can be implemented in hardware, software, firmware, or any combination thereof. If implemented in software as a computer program product, the functions can be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Computer-readable media includes both computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A storage media can be any available media that can be accessed by a computer. By way of example, and not limitation, such computer-readable media can comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer. Also, any connection is properly termed a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of medium. Disk and disc, as used herein, includes compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk and blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above should also be included within the scope of computer-readable media.

[0131] The application has been disclosed with reference to preferred embodiments. However, it will be appreciated that those skilled in the art will be able to devise various arrangements which, although not explicitly described or shown herein, embody the principles of the application and are included within its spirit and scope. Therefore, to the extent there are variations of the application, which are within the spirit and scope of the claims, the specified embodiments are intended to be illustrative only and not restrictive.

Claims

1. A composite measurement method for primary circuit flow and temperature in a nuclear power plant, characterized in that: include: Step 1: Setting a measuring mechanism at a test interface of a main pipeline to be tested; wherein the measuring mechanism includes at least one branch pipe, and a vibration signal measuring sensor is provided at an end of the branch pipe away from the main pipeline to be tested; Step 2: using a data acquisition and processing device in communication with the vibration signal measurement sensor to measure the vibration time history of each branch pipe end, and determining the target branch pipe in the acoustic resonance state based on the vibration time history data; Step 3: Performing Fourier transform on the maximum vibration time history by the data acquisition and processing equipment to obtain a real-time vibration spectrum, extracting the frequency domain peak vibration intensity and the corresponding peak frequency based on the real-time vibration spectrum, and calculating the average value of the vibration intensity in a specific frequency range outside the acoustic resonance range; Step 4: Calculate the medium sound velocity using the peak frequency, the frequency domain peak vibration intensity, and the average vibration intensity; Step 5: Calculate the real-time medium temperature and real-time medium density based on the medium sound velocity and the real-time pressure of the power plant primary circuit safety monitoring system; Step 6: Calculate the real-time Strouhal number based on the frequency domain peak vibration intensity and the average vibration intensity; Step 7: Calculate the real-time flow velocity of the main pipeline using the Strouhal number and the peak frequency; Step 8: Calculate the real-time volume flow of the main pipeline using the inner diameter of the main pipeline and the real-time flow velocity, and calculate the mass flow of the main pipeline based on the volume flow and the real-time medium density.

2. The nuclear power plant primary circuit flow and temperature composite measurement method according to claim 1, characterized in that: The longest branch pipe among the branch pipes in step 1 is provided with an expanded diameter pipe.

3. The method for composite measurement of flow and temperature of a nuclear power plant primary circuit according to claim 1, characterized in that: The vibration signal measuring sensor in step 2 is connected to the data analysis and processing device via a signal connection cable; The data analysis and processing equipment is in communication connection with the primary circuit safety monitoring system of the power station.

4. The method for composite measurement of flow and temperature in a nuclear power plant primary circuit according to claim 1, characterized in that: In step 3, the maximum value of the Y axis is extracted from the real-time vibration spectrum as the frequency domain peak vibration intensity, the corresponding X axis value is extracted as the peak frequency, and all Y values ​​in a specific frequency range outside the X axis resonance range are extracted and averaged to obtain the average value of the turbulent vibration intensity that increases with the increase of flow velocity.

5. The method for composite measurement of flow and temperature of a primary circuit of a nuclear power plant according to claim 1, characterized in that: In step 4, the calculation formula of the sound speed is: C=(4L+0.6d)*f; Wherein, C is the sound velocity of the medium in the main pipe to be measured, L is the corrected equivalent length between the inner wall of the main pipe to be measured and the inner wall of the closed end of the target branch pipe, d is the inner diameter of the target branch pipe, and f is the peak frequency of the target branch pipe; Wherein, the target branch is an acoustic resonance branch.

6. The method for composite measurement of flow and temperature in a nuclear power plant primary circuit according to claim 5, characterized in that: When the target branch pipe is provided with an expansion pipe, the acoustic membrane state frequency of the acoustic cavity structure is obtained through acoustic simulation analysis, and the equivalent length between the inner wall of the main pipe to be measured and the inner wall of the closed end of the target branch pipe is corrected.

7. The method for composite measurement of flow and temperature in a nuclear power plant primary circuit according to claim 1, characterized in that: In step 5, the real-time medium temperature and real-time medium density are calculated based on the international standard IAPWS-IF97 formula using the medium sound velocity and the real-time pressure of the power plant primary circuit safety monitoring system.

8. The method for composite measurement of flow and temperature in a nuclear power plant primary circuit according to claim 1, characterized in that: In step 6, the real-time Strouhal number is obtained by using the relationship curve between the calibrated acoustic resonance intensity and the Strouhal number; wherein the relationship curve between the acoustic resonance intensity and the Strouhal number is: ； Wherein, a is the peak vibration intensity in the frequency domain, is the average vibration intensity, is the Strouhal number.

9. The method for composite measurement of flow and temperature in a nuclear power plant primary circuit according to claim 1, characterized in that: In step 7, the calculation formula for the real-time flow rate of the main pipeline is: v=f*d / ; Wherein, f is the peak frequency, d is the inner diameter of the target branch, is the Strouhal number.

10. The method for composite measurement of flow and temperature in a primary circuit of a nuclear power plant according to claim 1, characterized in that: After step 8, the method further includes: Step 9: Transmit the main pipeline flow and temperature data to the power plant primary circuit safety monitoring system.

11. A computer program product, characterized in that The method comprises a computer program, which, when executed by a processor, implements the steps performed by a computer in the method according to any one of claims 1 to 10.

12. A computer-readable storage medium, characterized in that The invention provides a computer program, which, when executed by a processor, implements the steps executed by a computer in the method according to any one of claims 1 to 10.

13. A measurement system, characterized in that: include: a memory capable of storing instructions executable by a processor; A processor capable of executing the instructions to implement the steps performed by a computer in the method according to any one of claims 1 to 10.

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