In-situ calibration system for pipeline sodium flow meter

Abstract

The invention particularly relates to an in-situ calibration system for a pipeline sodium flowmeter. The in-situ calibration system comprises a primary instrument and an in-situ calibration device, the primary instrument is arranged in a pipeline through which sodium liquid flows and is used for generating a cross-correlation flow signal; the in-situ calibration device is used for collecting cross-correlation flow signals generated by the primary instrument, sodium flow measured by the sodium flow meter, electromotive force output by the sodium flow meter and sodium temperature, conducting cross-correlation analysis on the cross-correlation flow signals, calculating the instrument coefficient of the sodium flow meter, updating the instrument coefficient of the sodium flow meter according to the calculated instrument coefficient, and calibrating the sodium flow meter according to the updated instrument coefficient. And completing the in-situ calibration of the sodium flowmeter to be calibrated. Measurement data and fitting correction coefficients under corresponding temperature and flow points are obtained through cross-correlation flow measurement and then serve as standard sodium flow to conduct reverse calibration on the sodium flow meter, and in-situ efficient calibration of the precision and sensitivity of the sodium flow meter is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of automated instruments and meters, and in particular to an in-situ calibration system for a pipeline sodium flowmeter. Background Art

[0002] As a typical field device in the process industry, electromagnetic flowmeter is widely used in metallurgy, chemical industry and nuclear power industry. However, for traditional electromagnetic flowmeter, the temperature of magnetic field will affect the thermal motion of electrons in the material, and then affect the strength of magnetic field, causing the signal measured by the electrode to be inconsistent with the normal working condition. In addition, after the electromagnetic flowmeter has been used for a period of time, the zero point of the sensor of the primary instrument will drift, which will affect the measurement accuracy of the converter of the secondary instrument. Complex working conditions such as the spatiotemporal changes of flow pattern and velocity, pipeline shape, inertia of sensor components, material fatigue and drift of secondary instruments can easily lead to a significant reduction in instrument accuracy. These reasons lead to the need for real-time monitoring and regular calibration of electromagnetic flowmeters.

[0003] Permanent magnetic sodium flowmeter, as a type of electromagnetic flowmeter, is used in the nuclear power industry to monitor and measure the sodium flow of evaporators and superheaters. In order to accurately monitor and measure the sodium flow of evaporators and superheaters, it is necessary to ensure that the measurement accuracy of the permanent magnetic sodium flowmeter is within the specified range. However, after a period of operation, the permanent magnetic sodium flowmeter may have an increase in measurement error due to the decrease of magnetic flux caused by the natural or external influence of the magnetic steel. At the same time, due to the particularity of the sodium operating environment, the permanent magnetic sodium flowmeter is basically impossible to disassemble after subsequent commissioning. At present, Tesla meters are used to measure the magnetic field strength of the magnetic steel to indirectly calibrate the secondary instrument output, but this method cannot achieve real flow verification and correction of the permanent magnetic sodium flowmeter as a whole. In order to ensure the accuracy of subsequent permanent magnetic sodium flowmeter measurements, it is very necessary to study new calibration methods. Summary of the invention

[0004] The object of the present invention is to provide an in-situ calibration system for a pipeline sodium flowmeter, which is designed based on the cross-correlation flow measurement principle. The measurement data and fitting correction coefficients at corresponding temperature and flow points are obtained through cross-correlation flow measurement, and then the sodium flowmeter is reversely calibrated as the standard sodium flow, so as to realize in-situ efficient calibration of the accuracy and sensitivity of the sodium flowmeter.

[0005] In order to achieve the above object, the present invention provides the following technical solutions:

[0006] A pipeline sodium flowmeter in-situ calibration system comprises a primary instrument and an in-situ calibration device; the primary instrument is installed in a pipeline through which sodium liquid flows, and is used to generate a cross-correlated flow signal;

[0007] The in-situ calibration device is used to collect the cross-correlation flow signal generated by the primary instrument, the sodium flow measured by the sodium flowmeter, the output electromotive force and the sodium temperature; perform cross-correlation analysis on the cross-correlation flow signal to obtain the transmission time and the cross-correlation flow; calculate the instrument coefficient of the sodium flowmeter according to the transmission time and the cross-correlation flow, combined with the sodium flow measured by the sodium flowmeter, the output electromotive force and the sodium temperature; update the instrument coefficient of the sodium flowmeter according to the calculated instrument coefficient, and complete the in-situ calibration of the calibrated sodium flowmeter.

[0008] As one of the achievable ways, the primary instrument comprises a turbulence generator, a first signal receiver, a second signal receiver and a sodium flowmeter; the turbulence generator is located upstream of the first signal receiver and the second signal receiver; the sodium flowmeter is between the first signal receiver and the second signal receiver; the first signal receiver and the second signal receiver are at a fixed distance and are mutually correlated;

[0009] The sodium in the pipeline flows through the turbulence generator to generate a turbulence signal with an inherent frequency characteristic related to the sodium flow rate; the turbulence signal flows through the first signal receiver to generate a first flow fluctuation signal, and flows through the second signal receiver to generate a second flow fluctuation signal; the first flow fluctuation signal and the second flow fluctuation signal are cross-correlated flow signals.

[0010] As one of the achievable methods, the in-situ calibration device is a portable and movable structure, including a portable instrument box and a secondary instrument installed in the portable instrument box, an NI acquisition card, a host computer and a UPS power supply; the UPS power supply provides power for the host computer and the secondary instrument;

[0011] The secondary instrument is used to collect the cross-correlation flow signal; the cross-correlation flow signal is filtered and then transmitted to the NI acquisition card;

[0012] NI acquisition card, used to receive the cross-correlated flow signals transmitted by the secondary instrument and import them into the host computer;

[0013] The upper computer is installed with cross-correlation flow measurement and calculation software for cross-correlation analysis of cross-correlation flow signals to obtain transmission time and cross-correlation flow; the instrument coefficient of the sodium flowmeter is calculated based on the transmission time and cross-correlation flow, combined with the sodium flow measured by the sodium flowmeter and the output electromotive force and sodium temperature; the instrument coefficient of the sodium flowmeter is updated according to the calculated instrument coefficient to complete the in-situ calibration of the calibrated sodium flowmeter.

[0014] As one of the possible implementations, the instrument coefficient of the sodium flow meter includes the coefficient of the flow rate-electromotive force-sodium temperature relationship;

[0015] Cross-correlation flow measurement and calculation software, including a main monitoring program and functional modules composed of subprograms; the functional modules include a cross-correlation analysis module, a flow calculation module, a temperature measurement module, a parameter input module, a flow-time curve fitting module and a flow-electromotive force-sodium temperature curve fitting module;

[0016] The main monitoring program is the general scheduling program of the cross-correlation flow measurement and calculation software, which is used to call various functional modules;

[0017] A cross-correlation analysis module, used to perform cross-correlation analysis on cross-correlation traffic signals to obtain transmission time;

[0018] A flow calculation module, used for calculating the cross-correlation flow according to the transmission time, the inner diameter of the pipeline and the cross-correlation flow signal electrode spacing;

[0019] Temperature measurement module, used to collect sodium temperature; parameter input module, used to manually input parameters;

[0020] The sodium flow-transmission time curve fitting module is used to establish the sodium flow-transmission time relationship according to the sodium flow and transmission time measured by the standard sodium flow meter during the initial calibration;

[0021] The sodium flow-electromotive force-sodium temperature curve fitting module is used for the initial calibration to calculate the sodium flow-electromotive force-sodium temperature relationship according to the sodium flow measured by the standard sodium flowmeter, the electromotive force output by the sodium flowmeter and the sodium temperature; when the sodium flowmeter is calibrated again, the coefficient of the flow-electromotive force-sodium temperature relationship is corrected.

[0022] As one of the feasible ways, when the sodium flowmeter is in normal use, the flow in the pipeline is calculated based on the sodium temperature, the electromotive force output by the sodium flowmeter and the initially calibrated sodium flow-electromotive force-sodium temperature relationship.

[0023] As one of the feasible ways, the sodium flow rate-electromotive force-sodium temperature curve fitting module performs coefficient correction on the flow rate-electromotive force-sodium temperature relationship, including the following steps:

[0024] Calculate the sodium flow rate according to the transmission time and the initially calibrated sodium flow rate-transmission time relationship;

[0025] According to the calculated sodium flow rate, sodium temperature and the electromotive force output by the sodium flowmeter, the coefficient of the sodium flow rate-electromotive force-sodium temperature relationship is corrected to complete the in-situ calibration of the sodium flowmeter.

[0026] As one of the achievable methods, the cross-correlation analysis module performs cross-correlation analysis on the cross-correlation traffic signal to obtain the transmission time, including the following steps:

[0027] Performing cross-correlation analysis on the cross-correlation traffic signals to generate a cross-correlation function;

[0028] The time corresponding to the peak of the cross-correlation function is read as the transmission time.

[0029] As one of the possible implementations, the flow calculation module calculates the cross-correlation flow according to the following formula:

[0030]

[0031] Where Q is the cross-correlation flow, in m 3 / h; D is the inner diameter of the pipeline, in m; L is the cross-correlation flow signal electrode spacing, which is the electrode spacing between the first signal receiver and the second signal receiver, in m; τ is the cross-correlation flow signal transmission time, in s.

[0032] As one of the achievable ways, the functional module also includes an acquisition card control module, a data display module, a self-calibration module, a communication module and a data storage module;

[0033] The acquisition card control module is used to control the number of signal paths that the NI acquisition card acquires synchronously;

[0034] Data display module, used to display process parameters and calibration results in the form of data, graphics or charts;

[0035] Self-calibration module, used to complete the self-calibration function of the cross-correlation flow measurement calculation software and generate a self-calibration report;

[0036] Communication module, used to complete the communication between the cross-correlation flow measurement calculation software and the external data acquisition system and laser printer;

[0037] The data storage module is used to store the calibration results of the sodium flowmeter, the sodium flow-electromotive force-sodium temperature relationship and the sodium flow-transmission time relationship.

[0038] Beneficial technical effects of the present invention:

[0039] The pipeline sodium flowmeter in-situ calibration system of the present invention is designed based on the cross-correlation flow measurement principle. After the measurement data and fitting correction coefficients at corresponding temperature and flow points are obtained through cross-correlation flow measurement, the sodium flowmeter is reversely calibrated as the standard sodium flow, thereby realizing in-situ efficient calibration of the accuracy and sensitivity of the sodium flowmeter, reducing the manpower and time invested in the calibration of the sodium flowmeter, improving the reliability of the calibration of the sodium flowmeter, and effectively ensuring the safe and stable operation of the unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 It is a structural schematic diagram of an embodiment of a primary instrument;

[0041] Figure 2 It is a schematic diagram of the cross-correlation flow measurement principle;

[0042] Figure 3 A schematic diagram of the structure of an embodiment of a cross-correlation flow measurement calculation software;

[0043] Figure 4 A schematic flow chart of an embodiment of a method for preliminary calibration of a pipeline sodium flowmeter;

[0044] Figure 5 A flow chart of an embodiment of a method for periodically calibrating a pipeline sodium flowmeter. DETAILED DESCRIPTION

[0045] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used in the specification of the application are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned figure descriptions are intended to cover non-exclusive inclusions.

[0046] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0047] The technical solution of the present invention is clearly and completely described below in conjunction with the accompanying drawings and specific embodiments.

[0048] Cross-correlation flow measurement has many significant features such as non-contact measurement and not being affected by external environmental factors. The sodium flowmeter in-situ calibration system provided in this embodiment is designed based on the cross-correlation flow measurement principle. The measurement data and fitting correction coefficients at the sodium temperature and sodium flow points are obtained through cross-correlation flow measurement, and then the sodium flowmeter is reversely calibrated as the standard sodium flow, so as to realize the in-situ calibration of the sodium flowmeter and ensure that the accuracy and sensitivity of the sodium flowmeter meet the requirements of the nuclear power industry.

[0049] See also Figure 1-5 The pipeline sodium flowmeter in-situ calibration system of this embodiment includes a primary instrument and an in-situ calibration device; the primary instrument is installed in the pipeline through which the sodium liquid flows, and is used to generate a cross-correlated flow signal;

[0050] The in-situ calibration device is used to collect the cross-correlation flow signal generated by the primary instrument, the sodium flow measured by the sodium flowmeter, the output electromotive force and the sodium temperature; perform cross-correlation analysis on the cross-correlation flow signal to obtain the transmission time and the cross-correlation flow; calculate the instrument coefficient of the sodium flowmeter according to the transmission time and the cross-correlation flow, combined with the sodium flow measured by the sodium flowmeter, the output electromotive force and the sodium temperature; update the instrument coefficient of the sodium flowmeter according to the calculated instrument coefficient, and complete the in-situ calibration of the calibrated sodium flowmeter.

[0051] In this embodiment, the primary instrument includes a turbulence generator, a first signal receiver, a second signal receiver and a sodium flowmeter; the turbulence generator is upstream of the first signal receiver and the second signal receiver; the sodium flowmeter is between the first signal receiver and the second signal receiver; the first signal receiver and the second signal receiver are at a fixed distance and are mutually correlated; the sodium in the pipeline flows through the turbulence generator to generate a turbulence signal with an inherent frequency characteristic related to the sodium flow; the turbulence signal flows through the first signal receiver to generate a first flow fluctuation signal, and flows through the second signal receiver to generate a second flow fluctuation signal; the first flow fluctuation signal and the second flow fluctuation signal are mutually correlated flow signals.

[0052] In this embodiment, the in-situ calibration device is a portable and movable structure, including a portable instrument box and a secondary instrument installed in the portable instrument box, a NI acquisition card, a host computer and a UPS power supply; the UPS power supply provides power for the host computer and the secondary instrument to ensure continuous power consumption during the entire calibration process;

[0053] The secondary instrument is used to collect the cross-correlation flow signal; the cross-correlation flow signal is filtered and then transmitted to the NI acquisition card;

[0054] NI acquisition card, used to receive the cross-correlated flow signals transmitted by the secondary instrument and import them into the host computer;

[0055] The upper computer is installed with cross-correlation flow measurement and calculation software for cross-correlation analysis of cross-correlation flow signals to obtain transmission time and cross-correlation flow; the instrument coefficient of the sodium flowmeter is calculated based on the transmission time and cross-correlation flow, combined with the sodium flow measured by the sodium flowmeter and the output electromotive force and sodium temperature; the instrument coefficient of the sodium flowmeter is updated according to the calculated instrument coefficient to complete the in-situ calibration of the calibrated sodium flowmeter.

[0056] In this embodiment, the instrument coefficient of the sodium flow meter includes the coefficient of the flow rate-electromotive force-sodium temperature relationship;

[0057] Cross-correlation flow measurement and calculation software, including a main monitoring program and functional modules composed of subprograms; the functional modules include a cross-correlation analysis module, a flow calculation module, a temperature measurement module, a parameter input module, a flow-time curve fitting module and a flow-electromotive force-sodium temperature curve fitting module;

[0058] The main monitoring program is the general scheduling program of the cross-correlation flow measurement and calculation software, which is used to call various functional modules;

[0059] A cross-correlation analysis module, used to perform cross-correlation analysis on cross-correlation traffic signals to obtain transmission time;

[0060] A flow calculation module, used for calculating the cross-correlation flow according to the transmission time, the inner diameter of the pipeline and the cross-correlation flow signal electrode spacing;

[0061] Temperature measurement module, used to collect sodium temperature; parameter input module, used to manually input parameters;

[0062] The sodium flow-transmission time curve fitting module is used to establish the sodium flow-transmission time relationship of the sodium flowmeter according to the sodium flow and transmission time measured by the standard sodium flowmeter during the initial calibration;

[0063] The sodium flow-electromotive force-sodium temperature curve fitting module is used for the initial calibration to calculate the sodium flow-electromotive force-sodium temperature relationship of the sodium flowmeter according to the sodium flow measured by the standard sodium flowmeter, the electromotive force output by the sodium flowmeter and the sodium temperature; when the sodium flowmeter is calibrated again, the coefficient of the flow-electromotive force-sodium temperature relationship of the sodium flowmeter is corrected.

[0064] In this embodiment, when the sodium flowmeter is used normally, the flow rate in the pipeline is calculated based on the sodium temperature, the electromotive force output by the sodium flowmeter, and the initially calibrated sodium flow rate-electromotive force-sodium temperature relationship.

[0065] After the sodium flowmeter is used for a period of time, the sodium flow-electromotive force-sodium temperature relationship changes, but the sodium flow-transmission time relationship remains unchanged, and the sodium flow-electromotive force-sodium temperature relationship needs to be corrected by a coefficient. In this embodiment, as one of the achievable methods, the sodium flow-electromotive force-sodium temperature curve fitting module corrects the flow-electromotive force-sodium temperature relationship of the sodium flowmeter by a coefficient, including the following steps:

[0066] Calculate the sodium flow rate according to the transmission time and the initially calibrated sodium flow rate-transmission time relationship;

[0067] According to the calculated sodium flow rate, sodium temperature and the electromotive force output by the sodium flowmeter, the coefficient of the sodium flow rate-electromotive force-sodium temperature relationship is corrected to complete the in-situ calibration of the sodium flowmeter.

[0068] In this embodiment, the cross-correlation analysis module performs cross-correlation analysis on the cross-correlation traffic signal to obtain the transmission time, including the following steps:

[0069] Performing cross-correlation analysis on the cross-correlation traffic signals to generate a cross-correlation function;

[0070] The time corresponding to the peak of the cross-correlation function is read as the transmission time.

[0071] In this embodiment, the flow calculation module calculates the cross-correlation flow according to the following formula:

[0072]

[0073] Where Q is the cross-correlation flow, in m 3 / h; D is the inner diameter of the pipeline, in m; L is the cross-correlation flow signal electrode spacing, which is the electrode spacing between the first signal receiver and the second signal receiver, in m; τ is the cross-correlation flow signal transmission time, in s.

[0074] In this embodiment, the cross-correlation flow measurement and calculation software has an operation interface and a human-computer interaction window, which is convenient for entering and reading data; the functional modules also include an acquisition card control module, a data display module, a self-calibration module, a communication module and a data storage module;

[0075] The acquisition card control module is used to control the number of signal paths that the NI acquisition card acquires synchronously;

[0076] A data display module is used to display process parameters and calibration results in the form of data, graphics or charts, such as displaying the signal collected by the NI acquisition card and the sodium flow-transmission time relationship and the sodium flow-electromotive force-sodium temperature relationship of the sodium flowmeter;

[0077] Self-calibration module, used to complete the self-calibration function of the cross-correlation flow measurement calculation software and generate a self-calibration report;

[0078] Communication module, used to complete the communication between the cross-correlation flow measurement calculation software and the external data acquisition system and laser printer;

[0079] The data storage module is used to store the calibration results of the sodium flowmeter, the sodium flow-electromotive force-sodium temperature relationship and the sodium flow-transmission time relationship.

[0080] This embodiment also provides a method for initial calibration of a pipeline sodium flowmeter, comprising the following steps:

[0081] 1. Under the same working condition, that is, when the sodium flow and sodium temperature remain unchanged, the secondary instrument collects the cross-correlation flow signal and performs digital filtering and waveform display; the cross-correlation flow measurement calculation software collects or manually inputs the sodium temperature and the electromotive force output by the sodium flowmeter, and manually inputs the standard sodium flow measured by the standard sodium flowmeter;

[0082] 2. The secondary instrument imports the cross-correlated flow signals of no less than 180s into the host computer through the NI acquisition card, and calibrates no less than three groups of cross-correlated flow signals collected at one flow point at a time;

[0083] 3. The cross-correlation flow measurement and calculation software performs cross-correlation analysis on the collected cross-correlation flow signals and calculates the transmission time;

[0084] 4. The cross-correlation flow measurement calculation software outputs the corresponding (4-20) mA current value according to the calculation results;

[0085] 5. Under the same working conditions, that is, without changing the sodium flow rate and sodium temperature, repeat steps 3-4 and calculate the transmission time multiple times;

[0086] 6. The cross-correlation flow measurement calculation software averages the calculation results of the transmission time as the transmission time under the same working conditions;

[0087] 7. When the working condition is changed, that is, the sodium flow rate or sodium temperature is changed, steps 1-6 are repeated, and the cross-correlation flow measurement calculation software obtains the calculated transmission time under different working conditions;

[0088] 8. The cross-correlation flow measurement calculation software establishes, stores and displays the sodium flow-transmission time relationship and the sodium flow-electromotive force-sodium temperature relationship based on the transmission time calculated under different working conditions, the standard sodium flow, the input sodium temperature and the electromotive force output by the sodium flowmeter.

[0089] This embodiment also provides a pipeline sodium flowmeter periodic calibration method, comprising the following steps:

[0090] 1. Under the adjustment working condition, that is, changing the sodium flow rate and sodium temperature, make the sodium flow rate and sodium temperature approach the sodium flow rate and sodium temperature of the initial calibration;

[0091] 2. The secondary instrument collects the cross-correlation flow signal and performs digital filtering and waveform display; the cross-correlation flow measurement calculation software collects or manually inputs the sodium temperature, the electromotive force output by the sodium flowmeter and the measured sodium flow;

[0092] 3. The secondary instrument will import the cross-correlated flow signals of no less than 180s into the host computer through the NI acquisition card; no less than three groups of cross-correlated flow signals collected at one flow point should be calibrated at one time;

[0093] 4. The cross-correlation flow measurement and calculation software calculates the transmission time based on the cross-correlation flow signal; and calculates the standard sodium flow based on the transmission time and the initially calibrated sodium flow-transmission time relationship;

[0094] 5. The cross-correlation flow measurement calculation software outputs the corresponding (4-20) mA current value according to the calculation results;

[0095] 6. Under the same working condition, that is, without changing the sodium flow rate and sodium temperature, repeat steps 1-5, and the cross-correlation flow measurement calculation software averages multiple standard sodium flow rates as the standard sodium flow rate under the same working condition;

[0096] 7. The cross-correlation flow measurement calculation software establishes the relationship between the standard sodium flow and the measured sodium flow according to the transmission time and standard sodium flow calculated under different working conditions, as well as the sodium flow measured by the manually input sodium flow meter in the same time period;

[0097] The cross-correlation flow measurement calculation software calculates the measurement error of the sodium flow meter; according to the calculated sodium flow, the sodium temperature measured by the sodium flow meter and the output electromotive force, the coefficient of the sodium flow-electromotive force-sodium temperature relationship is corrected to obtain the correction coefficient of the flow value-electromotive force-sodium temperature relationship;

[0098] 8. The cross-correlation flow measurement calculation software determines whether the measurement error of the sodium flow meter exceeds the set value; if the measurement error of the sodium flow meter exceeds the set value, the correction coefficient of the flow value-electromotive force-sodium temperature relationship is input into the sodium flow meter to complete the coefficient correction of the flow value-electromotive force-sodium temperature relationship;

[0099] 9. After the coefficients of the flow value-electromotive force-sodium temperature relationship are corrected, repeat steps 3-7 to recalculate the measurement error of the sodium flowmeter; until the measurement error of the sodium flowmeter is less than the set value, the regular calibration of the sodium flowmeter is completed; if the measurement error of the sodium flowmeter is greater than or equal to the set value, repeat steps 3-7 until the measurement error of the sodium flowmeter is less than the set value, and the regular calibration of the sodium flowmeter is completed.

[0100] In this embodiment, when the sodium flow meter is initially calibrated or periodically calibrated, the cross-correlation flow measurement calculation software collects a cross-correlation flow signal for a period of not less than 180 seconds each time, collects multiple times, and the sampling frequency is 10kHz;

[0101] After removing the mean and low-pass filtering of the collected cross-correlation flow signals, the cross-correlation flow measurement and calculation software performs the following steps to obtain the cross-correlation analysis results under the same working conditions:

[0102] After filtering, the N-point cross-correlation traffic signals are intercepted from the beginning for cross-correlation analysis to obtain the transmission time;

[0103] After the end, slide back M points and intercept the cross-correlation traffic signal of N points for cross-correlation analysis to obtain the transmission time; M = N / 2, N = 90000;

[0104] Repeat the above steps until all the cross-correlation flow signals collected by the cross-correlation flow measurement and calculation software have completed cross-correlation analysis;

[0105] The positive cross-correlation analysis results of the leading cross-correlation flow signal and the lagging cross-correlation flow signal are discarded; the middle 60% of the cross-correlation analysis results are averaged and the absolute value is taken as the cross-correlation analysis result under the same working condition.

[0106] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A pipeline sodium flowmeter in-situ calibration system, characterized in that: It includes a primary instrument and an in-situ calibration device; the primary instrument is installed in a pipeline through which the sodium liquid flows, and is used to generate a cross-correlated flow signal; The in-situ calibration device is used to collect the cross-correlation flow signal generated by the primary instrument, the sodium flow measured by the sodium flowmeter, the output electromotive force and the sodium temperature; perform cross-correlation analysis on the cross-correlation flow signal to obtain the transmission time and the cross-correlation flow; calculate the instrument coefficient of the sodium flowmeter according to the transmission time and the cross-correlation flow, combined with the sodium flow measured by the sodium flowmeter, the output electromotive force and the sodium temperature; update the instrument coefficient of the sodium flowmeter according to the calculated instrument coefficient, and complete the in-situ calibration of the calibrated sodium flowmeter.

2. The pipeline sodium flowmeter in-situ calibration system according to claim 1, characterized in that: The primary instrument comprises a turbulence generator, a first signal receiver, a second signal receiver and a sodium flowmeter; the turbulence generator is located upstream of the first signal receiver and the second signal receiver; the sodium flowmeter is between the first signal receiver and the second signal receiver; the first signal receiver and the second signal receiver are at a fixed distance and are mutually correlated; the sodium in the pipeline flows through the turbulence generator to generate a turbulence signal with an inherent frequency characteristic related to the sodium flow; The disturbance signal flows through the first signal receiver to generate a first flow fluctuation signal, and flows through the second signal receiver to generate a second flow fluctuation signal; The first flow fluctuation signal and the second flow fluctuation signal are cross-correlated flow signals.

3. The pipeline sodium flowmeter in-situ calibration system according to claim 1, characterized in that: The in-situ calibration device is a portable and movable structure, including a portable instrument box and a secondary instrument installed in the portable instrument box, a NI acquisition card, a host computer and a UPS power supply; the UPS power supply provides power for the host computer and the secondary instrument; The secondary instrument is used to collect the cross-correlation flow signal; the cross-correlation flow signal is filtered and then transmitted to the NI acquisition card; NI acquisition card, used to receive the cross-correlated flow signals transmitted by the secondary instrument and import them into the host computer; The upper computer is installed with cross-correlation flow measurement and calculation software for cross-correlation analysis of cross-correlation flow signals to obtain transmission time and cross-correlation flow; the instrument coefficient of the sodium flowmeter is calculated based on the transmission time and cross-correlation flow, combined with the sodium flow measured by the sodium flowmeter and the output electromotive force and sodium temperature; the instrument coefficient of the sodium flowmeter is updated according to the calculated instrument coefficient to complete the in-situ calibration of the calibrated sodium flowmeter.

4. The pipeline sodium flowmeter in-situ calibration system according to claim 3, characterized in that: The instrument coefficient of the sodium flowmeter includes the coefficient of the flow rate-electromotive force-sodium temperature relationship; Cross-correlation flow measurement and calculation software, including a main monitoring program and functional modules composed of subprograms; the functional modules include a cross-correlation analysis module, a flow calculation module, a temperature measurement module, a parameter input module, a flow-time curve fitting module and a flow-electromotive force-sodium temperature curve fitting module; The main monitoring program is used to call each functional module; the cross-correlation analysis module is used to perform cross-correlation analysis on the cross-correlation traffic signal to obtain the transmission time; A flow calculation module, used for calculating the cross-correlation flow according to the transmission time, the inner diameter of the pipeline and the cross-correlation flow signal electrode spacing; The temperature measurement module is used to collect the sodium temperature; the parameter input module is used to manually input parameters; the sodium flow-transmission time curve fitting module is used to establish the sodium flow-transmission time relationship according to the sodium flow and transmission time measured by the standard sodium flowmeter during the initial calibration; The sodium flow-electromotive force-sodium temperature curve fitting module is used for the initial calibration to calculate the sodium flow-electromotive force-sodium temperature relationship according to the sodium flow measured by the standard sodium flowmeter, the electromotive force output by the sodium flowmeter and the sodium temperature; when the sodium flowmeter is calibrated again, the coefficient of the flow-electromotive force-sodium temperature relationship is corrected.

5. The pipeline sodium flowmeter in-situ calibration system according to claim 4, characterized in that: When the sodium flowmeter is in normal use, the flow in the pipeline is calculated based on the sodium temperature, the electromotive force output by the sodium flowmeter and the initially calibrated sodium flow-electromotive force-sodium temperature relationship.

6. The pipeline sodium flowmeter in-situ calibration system according to claim 4, characterized in that: The sodium flow rate, electromotive force, and sodium temperature curve fitting module corrects the coefficient of the flow rate, electromotive force, and sodium temperature relationship, including the following steps: Calculate the sodium flow rate according to the transmission time and the initially calibrated sodium flow rate-transmission time relationship; According to the calculated sodium flow rate, sodium temperature and the electromotive force output by the sodium flowmeter, the coefficient of the sodium flow rate-electromotive force-sodium temperature relationship is corrected to complete the in-situ calibration of the sodium flowmeter.

7. The pipeline sodium flowmeter in-situ calibration system according to claim 4, characterized in that: The cross-correlation analysis module performs cross-correlation analysis on the cross-correlation traffic signals to obtain the transmission time, including the following steps: Performing cross-correlation analysis on the cross-correlation traffic signals to generate a cross-correlation function; The time corresponding to the peak of the cross-correlation function is read as the transmission time.

8. The pipeline sodium flowmeter in-situ calibration system according to claim 4, characterized in that: The flow calculation module calculates the cross-correlation flow according to the following formula: Where Q is the cross-correlation flow, in m 3 / h; D is the inner diameter of the pipeline, in m; L is the cross-correlation flow signal electrode spacing, which is the electrode spacing between the first signal receiver and the second signal receiver, in m; τ is the cross-correlation flow signal transmission time, in s.

9. The pipeline sodium flowmeter in-situ calibration system according to claim 4, characterized in that: The functional modules also include an acquisition card control module, a data storage module and a data storage module; The acquisition card control module is used to control the number of signal paths that the NI acquisition card acquires synchronously; Data display module, used to display process parameters and calibration results in the form of data, graphics or charts; The data storage module is used to store the calibration results of the sodium flowmeter, the sodium flow-electromotive force-sodium temperature relationship and the sodium flow-transmission time relationship.

10. The pipeline sodium flowmeter in-situ calibration system according to claim 9, characterized in that: The functional modules also include a self-calibration module and a communication module; Communication module, used to complete the communication between the cross-correlation flow measurement calculation software and the external data acquisition system and laser printer; The self-calibration module is used to complete the self-calibration function of the cross-correlation flow measurement calculation software and generate a self-calibration report.

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