Device and system for measuring main feed water flow of nuclear energy facility

Abstract

The utility model discloses a nuclear energy facility main feed water flow measuring device and system, and relates to the technical field of nuclear industry measurement, and the nuclear energy facility main feed water flow measuring device comprises a straight pipe section connected with a main feed water main pipeline, at least three groups of ultrasonic flow measuring assemblies, and a main feed water temperature measuring group correspondingly connected with a secondary transmitter group in the ultrasonic flow measuring assemblies. Wherein the ultrasonic flow measuring assembly comprises an ultrasonic flow measuring probe group mounted on the straight pipe section, a clamping tool for fixing the ultrasonic flow measuring probe group on the straight pipe section, and a secondary transmitter group correspondingly connected with the ultrasonic flow measuring probe group. Related measurement parameters of different laminar flows of the main feed water are collected through the ultrasonic flow measurement probe set according to different laminar flows, the flow of the main feed water is calculated on the basis of the related measurement parameters of the different laminar flows, and the calculation precision of the flow of the main feed water can be greatly improved.

Description

Technical Field

[0001] This application relates to the field of nuclear industry measurement technology, and particularly to a measuring device and system for the main feed water flow of nuclear energy facilities. Background Art

[0002] In the known technology, a throttling device and a differential pressure transmitter are combined to measure the main feed water flow in nuclear energy facilities.

[0003] The measurement result error of the differential pressure transmitter is large. Especially in a high static pressure environment, the differential pressure transmitter cannot completely correct or offset the additional error caused by the high static pressure within the entire measurement range, that is, the differential pressure transmitter cannot perform full-range compensation.

[0004] Exemplarily, due to factors such as structure or material, the measurement error of the differential pressure transmitter increases with the increase of the high static pressure in a high static pressure environment.

[0005] Moreover, the differential pressure measurement signal value needs to be square-rooted before it is approximately proportional to the volume flow signal, which further results in lower measurement accuracy of the differential pressure transmitter in the small flow rate section.

[0006] Therefore, the accuracy of the measurement result of the main feed water flow in nuclear energy facilities in the known technology is not high. Utility Model Content

[0007] In view of the above problems, this application provides a measuring device and system for the main feed water flow of nuclear energy facilities to achieve the purpose of improving the main feed water measurement accuracy. The specific solutions are as follows:

[0008] In the first aspect of this application, a measuring device for the main feed water flow of nuclear energy facilities is provided, including:

[0009] A straight pipe section connected to the main feed water main pipe;

[0010] At least three groups of ultrasonic flow measurement components;

[0011] The ultrasonic flow measurement component includes: an ultrasonic flow measurement probe group installed on the straight pipe section; and a clamping tooling for fixing the ultrasonic flow measurement probe group on the straight pipe section according to different laminar flows of the main feed water, where each pair of ultrasonic flow measurement probes in the ultrasonic flow measurement probe group corresponds to a different laminar flow in the main feed water; a secondary transmitter group correspondingly connected to the ultrasonic flow measurement probe group;

[0012] And a main feed water temperature measurement group correspondingly connected to the secondary transmitter group.

[0013] In a possible implementation, the straight pipe section includes a micro-protrusion structure.

[0014] In a possible implementation, the ultrasonic flow measurement probes in the ultrasonic flow measurement probe group are connected to the secondary transmitters in the secondary transmitter group one by one through dedicated measurement cables.

[0015] In a possible implementation, the ultrasonic flow measurement assembly further includes a fixed sleeve group;

[0016] The fixed sleeves in the fixed sleeve group are welded to the clamping holes of the clamping tooling; the fixed sleeves in the fixed sleeve group are assembled with the ultrasonic flow measurement probes in the ultrasonic flow measurement probe group one by one.

[0017] In a possible implementation, the ultrasonic flow measurement probes are vertically assembled into the corresponding fixed sleeves to ensure that the ultrasonic flow measurement probes measure the flow velocity of the main feed water corresponding laminar flow in the straight pipe section according to the vertical emission angle.

[0018] In a possible implementation, the straight pipe section is connected to the main feed water main pipeline by welding or assembling flanges.

[0019] In a possible implementation, the main feed water temperature measurement group includes patch thermometers and temperature measurement cables that correspond one by one to the ultrasonic flow measurement assembly;

[0020] The patch thermometers are connected to the secondary transmitters in the secondary transmitter group one by one through the temperature measurement cables.

[0021] In a possible implementation, it further includes a measurement bench;

[0022] The straight pipe section is placed on the measurement bench.

[0023] The second aspect of the present application provides a measurement system for the main feed water flow of a nuclear energy facility, including the measurement device for the main feed water flow of a nuclear energy facility and a diagnostic cabinet as described in any one of the above;

[0024] The measurement device for the main feed water flow of a nuclear energy facility is connected to the diagnostic cabinet through a communication cable.

[0025] In a possible implementation, the secondary transmitter group in the measurement device for the main feed water flow of a nuclear energy facility is connected to the diagnostic cabinet through a communication cable.

[0026] With the above technical solutions, the measuring device and system for the main feed water flow rate of a nuclear energy facility provided by this application include a straight pipe section connected to the main feed water main pipe, at least three groups of ultrasonic flow measuring components, and a main feed water temperature measuring group corresponding to and connected to the secondary transmitter group in the ultrasonic flow measuring components. Among them, the ultrasonic flow measuring component includes an ultrasonic flow measuring probe group installed on the straight pipe section, a clamping tool for fixing the ultrasonic flow measuring probe group on the straight pipe section, and a secondary transmitter group corresponding to and connected to the ultrasonic flow measuring probe group. By collecting relevant measurement parameters of different laminar flows of the main feed water through the ultrasonic flow measuring probe group and calculating the main feed water flow rate based on the relevant measurement parameters of different laminar flows, the calculation accuracy of the main feed water flow rate can be greatly improved.

[0027] Furthermore, taking the relevant measurement parameters and the main feed water temperature data collected by the main feed water temperature measuring group as the basis for calculating the main feed water flow rate when inputting them into the secondary transmitter group together further improves the accuracy of the main feed water flow rate measurement.

[0028] On the other hand, the ultrasonic flow measuring probe group in this application uses ultrasonic waves to collect relevant measurement parameters, and can measure the relevant measurement parameters of different laminar flows of the main feed water without contacting the main feed water in the straight pipe section, thereby realizing non-contact measurement of the main feed water flow rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Combined with the drawings and referring to the following specific embodiments, the above and other features, advantages and aspects of each embodiment of the present disclosure will become more obvious. Throughout the drawings, the same or similar reference numerals represent the same or similar elements. It should be understood that the drawings are schematic, and the original components and elements are not necessarily drawn to scale.

[0030] Figure 1 It is a composition structure diagram of the measuring device for the main feed water flow rate of a nuclear energy facility provided by this application;

[0031] Figure 2 It is a composition structure diagram of the measuring system for the main feed water flow rate of a nuclear energy facility provided by this application;

[0032] Figure 3 It is an example diagram of the working principle of the measuring system for the main feed water flow rate of a nuclear energy facility provided by this application;

[0033] Figure 4 It is an example diagram of the principle of accurate measurement of medium temperature and medium density compensation provided by this application;

[0034] Figure 5 It is a schematic diagram of the principle of the laminar flow compensation algorithm provided by this application.

[0035] Reference Numerals:

[0036] 1 - Straight pipe section; 2 - Ultrasonic flow measurement assembly; 2 - 1 - Ultrasonic flow measurement probe group; 2 - 2 - Clamping tooling; 2 - 3 - Secondary transmitter group; 3 - Main feed water temperature measurement group; 4 - Diagnostic cabinet. Specific embodiments

[0037] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to 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 of the embodiments. In the description of the present invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present invention. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. Multiple technical solutions in the same embodiment, as well as multiple technical solutions in different embodiments, can be arranged and combined to form new technical solutions without contradiction or conflict, and all are within the scope of protection required by the present invention.

[0038] The following describes the embodiments of the present application with reference to the accompanying drawings. As known to those of ordinary skill in the art, with the development of technology and the emergence of new scenarios, the technical solutions provided in the embodiments of the present application are also applicable to similar technical problems.

[0039] In a nuclear power plant, the main feed water in the main pipeline is heated by a nuclear reactor and converted into high-temperature and high-pressure steam for power generation, hydrogen production, industrial heat utilization, and other purposes.

[0040] In this process, in order to ensure the normal and safe operation of the nuclear reactor, it is necessary to measure the flow rate of the main feed water in the main pipeline. Moreover, the measurement of the flow rate of the main feed water in the main pipeline requires a high level of reliable redundancy.

[0041] To meet the above requirements, in the known technology, a throttling device and a differential pressure transmitter are used to measure the flow rate of the main feed water in the main pipeline of nuclear energy facilities. This measurement method in the known technology can ensure that the measurement of the flow rate of the main feed water has a high level of reliable redundancy and real-time response. However, there are the following problems:

[0042] The measurement scheme for the main feed water in the main pipeline in the known technology is a contact measurement scheme. The throttling device in the measurement device is continuously scoured by the medium in the main pipeline, and it is difficult to quantitatively evaluate the mechanical wear of the throttling device. Therefore, after the measurement device for the main feed water flow rate in the known technology operates for a certain period, the accuracy of the mechanical part of the throttling device will decrease.

[0043] To address the problem of reduced accuracy of the mechanical part of the throttling device, the throttling device needs to be replaced regularly. However, replacing the throttling device is somewhat difficult. First of all, there are many factors affecting the difficulty of replacing the throttling device, such as the weight of the throttling device, whether it is welded to the pipeline, the weight of the secondary clamping, the on-site layout space after installation, etc. These influencing factors will all increase the difficulty of replacing the throttling device.

[0044] Specifically, nuclear energy facilities have extremely high safety standards, and any maintenance and replacement operations need to strictly follow safety regulations. Therefore, when replacing the throttling device, it is necessary to ensure that it does not affect the normal operation of the entire system and avoid causing high-energy leakage or other safety hazards. During the specific replacement process, it may be necessary to isolate or shut down part of the system, which requires precise temporary adjustment and strict monitoring to ensure that the system is always in a controllable state.

[0045] The main feedwater pipeline is the main channel connecting the steam generator and the main feedwater pump. It is generally composed of straight pipe sections, elbows, and nozzles. The throttling device is usually installed at key positions on these pipelines. Before disassembling and installing the throttling device, it is necessary to understand and handle these complex geometric structures in detail. Moreover, the replacement work of the throttling device needs to be carried out in a narrow or inconvenient operation space, which further increases the difficulty and risk of replacing the throttling device.

[0046] The accuracy of the throttling device will directly affect the measurement accuracy of the main feedwater flow rate, thereby affecting the operation efficiency and safety performance of the nuclear power plant. When replacing a new throttling device, it is necessary to ensure that its installation position, angle, and connection method all meet extremely high accuracy requirements. Moreover, the calibration and measurement after replacement are also crucial. It is necessary to use high-precision standard equipment for multiple rounds of verification to ensure that the performance of the replaced throttling device meets the design requirements.

[0047] In summary, the combined effect of these influencing factors makes the replacement of the throttling device a complex and highly difficult engineering task.

[0048] On the other hand, the accuracy of the main feedwater flow rate measurement device used in the known technology is not high.

[0049] For a differential pressure transmitter, its measurement result is greatly affected by high static pressure and cannot be compensated over the full range. Moreover, since the measured signal value of the differential pressure transmitter needs to be square-rooted before it can be approximately proportional to the volume flow signal, the measurement accuracy of the same differential pressure transmitter in the small flow rate section is even lower. Therefore, the measurement accuracy of the main feedwater flow rate in the known technology is low, and it is difficult to achieve a measurement accuracy of 1% FS (Full Scale).

[0050] Moreover, when multiple differential pressure transmitters are included in the measurement device, it is also necessary to install instrument impulse pipes accordingly, which poses a challenge to the on-site installation and layout of the main feed water measurement device.

[0051] To solve the above problems, the present application provides a measurement device and system for the main feed water flow rate of nuclear power facilities.

[0052] See Figure 1 , the composition structure diagram of the measurement device for the main feed water flow rate of nuclear power facilities provided by the present application.

[0053] The measurement device for the main feed water flow rate of nuclear power facilities provided by the present application mainly includes:

[0054] A straight pipe section 1, at least three groups of ultrasonic flow measurement components 2, and a main feed water temperature measurement group 3.

[0055] Among them, the straight pipe section 1 is connected to the main feed water main pipe to receive the main feed water transported from the main pipe. Specifically, the connection method between the straight pipe section 1 and the main pipe can be welding or assembling a flange.

[0056] The straight pipe section 1 includes two sections at the front and back. Its function is to form a stable flow field, and forming a stable flow field is the measurement basis for the ultrasonic flow measurement component 2. Moreover, the inside of the straight pipe section 1 includes a micro-protrusion structure, which is obtained through high-precision processing and is mainly used to control the pipe roughness of the straight pipe section 1 and improve the measurement accuracy of the ultrasonic flow measurement component 2 installed in the straight pipe section 1.

[0057] The ultrasonic flow measurement component 2 is installed on the above-mentioned straight pipe section 1. The ultrasonic flow measurement component is mainly composed of three parts: an ultrasonic flow measurement probe group 2-1, a clamping tooling 2-2 for fixing the ultrasonic flow measurement probe group 2-1 on the straight pipe section 1, and a secondary transmitter group 2-3 corresponding to the ultrasonic flow measurement probe group 2-1.

[0058] As Figure 1 shown, the ultrasonic flow measurement probe group 2-1 is installed in pairs on the straight pipe section.

[0059] It should be noted that the ultrasonic flow measurement probe group 2-1 is at least 3 groups, and the specific number of groups is determined according to the size of the main pipe and the number of representative laminar flow surfaces of the main feed water in the pipe. That is to say, the number of groups of the ultrasonic flow measurement probe group 2 corresponds to the number of laminar flow surfaces of the main feed water in the main pipe.

[0060] Specifically, it can also be determined whether more ultrasonic flow measurement probe groups 2 can be installed according to the physical occupancy size of the ultrasonic flow measurement probes. Exemplarily, it is expected to install 3 groups of ultrasonic flow measurement probe groups 2 in a pipe with an inner diameter of 168 mm, and theoretically, more ultrasonic flow measurement probe groups 2 can be installed in a thicker pipe.

[0061] It is understandable that the ultrasonic flow measurement probe group 2-1 can output at least three groups of independent flow measurement signals, thus ensuring the redundant reliability of the main feed water regulation control. When the inner diameter of the main feed water pipe is large, more than three groups of ultrasonic flow measurement probe groups 2-1 are arranged on the straight pipe section 1. The more than three groups of ultrasonic flow measurement probe groups 2-1 can be used as standby measurement groups and can also realize high-order debugging and calibration channels.

[0062] The clamping tooling 2-2 fixes the paired ultrasonic flow measurement probes in the ultrasonic flow measurement probe group 2-1 on the straight pipe section 1 according to different laminar flows of the main feed water. That is, the function of the clamping tooling is to accurately install the paired ultrasonic flow measurement probes at positions corresponding to different laminar flows in the main feed water.

[0063] Specifically, the ultrasonic flow measurement assembly 2 further includes a fixed sleeve group. Each fixed sleeve in the fixed sleeve group is welded on the clamping hole in the clamping tooling 2-2. The ultrasonic flow measurement probes in the ultrasonic flow measurement probe group 2-1 can be assembled with the fixed sleeves through threaded interfaces matching the fixed sleeves. After assembly, reliable fixation is achieved through the clamping structure in the clamping tooling. Among them, the number of fixed sleeves is the same as the number of groups of the ultrasonic flow measurement probe group 2-1 and is pre-welded on the clamping holes in the clamping tooling 2-2. Generally, the number of clamping holes in the clamping tooling 2-2 is the same as the number of groups of the ultrasonic flow measurement probe group 2-1.

[0064] Moreover, the ultrasonic flow measurement probes are vertically assembled into the fixed sleeves to ensure that the ultrasonic flow measurement probes measure the flow velocity of a certain laminar flow surface in the main feed water corresponding to the pair of ultrasonic flow measurement probes according to the vertical emission angle formed after assembly. That is, each pair of ultrasonic flow measurement probes in the ultrasonic flow measurement probe group 2-1 measures at positions corresponding to different laminar flow surfaces in the main feed water. It should be noted that the ultrasonic flow measurement probes can specifically be ultrasonic flowmeter probes. The ultrasonic flowmeter is mainly used to measure the fluid flow rate. In this application, it mainly measures the flow rate of the main feed water. The measurement principle is based on the difference in the propagation time or frequency of ultrasonic waves in the main feed water to deduce the flow velocity of the main feed water, and then obtain the flow rate of the main feed water. The measurement principles of ultrasonic flowmeters include time difference method, Doppler method, noise method and other related methods. In this application, the time difference method is mainly used to measure the flow velocity of the main feed water. The time difference method calculates the flow velocity by using the time difference between the propagation times of ultrasonic waves in the downstream and upstream directions. The downstream propagation time decreases, and the upstream propagation time increases. By accurately measuring the time difference between the two, the fluid velocity is calculated.

[0065] It should be noted that the ultrasonic flow measurement probe group 2-1 is fixed on the clamping tooling 2-2 welded to the outside of the straight pipe section 1. The ultrasonic flow measurement probe group 2-1 uses ultrasonic waves to collect relevant parameters of different laminar flows of the main feed water and can achieve non-contact measurement. The advantages of non-contact measurement are as follows: The ultrasonic flow measurement probe can be replaced and repaired without isolating or shutting down some systems; there will be no problem of mechanical wear of the measuring device, and naturally there will be no problem of affecting the measurement accuracy due to mechanical wear.

[0066] The number of the secondary transmitter groups 2-3 is also the same as the number of groups of the ultrasonic flow measurement probe group 2-1. Specifically, for the paired ultrasonic flow measurement probes corresponding to the laminar flow of the main feed water, the relevant parameters collected by them are correspondingly input into the secondary transmitter connected to the paired ultrasonic flow measurement probes. The function of the secondary transmitter is to further convert and process the signals transmitted by the ultrasonic flow measurement probe group 2-1 and the primary feed water temperature measurement group 3.

[0067] The ultrasonic flow measurement probes are connected to the secondary transmitters one by one through special measurement cables. The ultrasonic flow measurement probe group 2-1 inputs at least 3 groups of independent flow measurement signals output by it into their respective corresponding secondary transmitters through the special measurement cables. The number of the special measurement cables is also the same as the number of groups of the ultrasonic flow measurement probe group 2-1. That is to say, each pair of ultrasonic flow measurement probes has a dedicated special measurement cable to transmit the flow measurement signals collected by itself to the corresponding secondary transmitter.

[0068] The secondary transmitter group 2-3 also receives the medium temperature information collected in the primary feed water temperature measurement group 3. The primary feed water temperature measurement group includes at least 3 combinations of patch thermometers and temperature measurement cables. The number of the patch thermometers is the same as the number of the secondary transmitters in the secondary transmitter group 2-3. The patch thermometers are used to collect the medium temperature signals and input the collected temperature signals into the secondary transmitters correspondingly.

[0069] After receiving the medium flow velocity of the corresponding laminar flow in the straight pipe section 1 collected by the ultrasonic flowmeter through the special measurement cable, the secondary transmitter can directly output the volume flow of the main feed water after calculation. After receiving the medium temperature signal of the same laminar flow corresponding to the above ultrasonic flowmeter collected by the patch thermometer through the temperature measurement cable, the secondary transmitter identifies the threshold temperature through the medium temperature signal, and further can calculate the medium density, that is, the main feed water density, by using the density polynomial formula of the medium temperature signal and the main feed water medium, and finally can also obtain the mass flow of the main feed water through conversion.

[0070] Optionally, the measuring device for the main feed water flow of the nuclear energy facility provided in this application further includes a measuring bench, and the straight pipe section 1 is placed on the measuring bench.

[0071] Regarding the setting of the test bench, in order to match the differences in the actual measured flow velocities of the main feed water on different laminar flow surfaces in the straight pipe section, a test bench is built under actual temperature, pressure, and flow velocity conditions to facilitate the subsequent measurement of relevant parameters of the main feed water in different laminar flows.

[0072] This application provides a non-contact, high-precision main feed water flow measurement device with a simple, stable, and reliable structure. The measurement device for the main feed water flow of this nuclear energy facility has a simple, stable, and reliable structure, specifically manifested in that the tooling processing is less difficult compared to orifice plates, Venturi tubes, etc. in throttling devices. The comparison method of the manufacturing cost can be: comparing the tooling costs of the measurement tooling for the main feed water flow of the nuclear energy facility in this application with the same caliber and orifice plates, Venturi tubes in throttling devices. The tooling cost of the measurement device for the main feed water flow of the nuclear energy facility provided in this application is lower and the quality is reliable.

[0073] Moreover, after the straight pipe section of the measurement device for the main feed water flow of the nuclear energy facility is installed with clamping tooling and mechanical design online, non-contact measurement of the main feed water flow can be achieved under various temperature and pressure conditions, and the pressure loss can be ignored, improving the operating economy of the main feed water pump. This measurement device is convenient for regular maintenance and calibration, and disassembly and assembly are no longer difficult.

[0074] More importantly, the measurement accuracy of this measurement device is high. The real-time measurement accuracy can reach 0.5%FS - 1%FS (0.5%FS in the 50% - 100% flow range, 1%FS in the flow range below 50%). The repeatability of each independent measurement channel is good, reaching 0.1%FS - 0.3%FS (0.1%FS in the 50% - 100% flow range, 0.3%FS in the flow range below 50%). The real-time performance is guaranteed, and the interval for obtaining measurement results is less than 200ms. This measurement device can also be directly connected to the regulating valve of the main feed water control loop to achieve real-time control of the main feed water flow.

[0075] In summary, the measurement device for the main feed water flow of the nuclear energy facility provided in this application includes a straight pipe section connected to the main feed water main pipe, at least three groups of ultrasonic flow measurement components, and a main feed water temperature measurement group corresponding to the secondary transmitter group in the ultrasonic flow measurement components. Among them, the ultrasonic flow measurement component includes an ultrasonic flow measurement probe group installed on the straight pipe section, a clamping tooling for fixing the ultrasonic flow measurement probe group on the straight pipe section, and a secondary transmitter group corresponding to the ultrasonic flow measurement probe group. This application calculates the main feed water flow based on the relevant measurement parameters of different laminar flows of the main feed water collected by the ultrasonic flow measurement probe group according to different laminar flows, which can greatly improve the calculation accuracy of the main feed water flow.

[0076] Furthermore, relevant measurement parameters and the main feed water temperature data collected by the main feed water temperature measurement group are input into the secondary transmitter group together as the basis for calculating the main feed water flow quality, further improving the accuracy of the primary measurement of the main feed water flow.

[0077] On the other hand, the ultrasonic flow measurement probe group in this application uses ultrasonic waves to collect relevant measurement parameters, and can measure the relevant measurement parameters of different laminar flows of the main feed water without contacting the main feed water in the straight pipe section, thereby realizing non-contact measurement of the main feed water flow.

[0078] In addition to the above-mentioned measurement device for the main feed water flow of nuclear power facilities, this application also provides a measurement system for the main feed water flow of nuclear power facilities.

[0079] The measurement system for the main feed water flow of nuclear power facilities includes the measurement device for the main feed water flow of nuclear power facilities mentioned above and a diagnostic cabinet.

[0080] See Figure 2 , the composition structure diagram of the measurement system for the main feed water flow of nuclear power facilities provided by this application.

[0081] As Figure 2 shown, the measurement device for the main feed water flow of nuclear power facilities is connected to the diagnostic cabinet 4 through a communication cable.

[0082] Specifically, the secondary transmitter group 2-3 in the measurement device for the main feed water flow of nuclear power facilities is connected to the diagnostic cabinet 4 through a communication cable. The secondary transmitters in the secondary transmitter group 2-3 transmit the data collected by the ultrasonic flow measurement probe group 2-1 and the main feed water temperature measurement group 3 to the diagnostic cabinet 4 through the communication cable. The diagnostic cabinet 4 analyzes the parameter groups corresponding to different laminar flows, calculates and corrects them online, so as to diagnose whether the parameter groups corresponding to different laminar flows are in a healthy state. If there are unhealthy parameters in the parameter groups corresponding to different laminar flows, the diagnostic cabinet 4 will generate corrected parameters and alarm and maintenance information accordingly, and send the corrected parameters to the secondary transmitter group 2-3 at a preset time, so as to obtain more accurate main feed water flow measurement data in the follow-up. It should be noted that the diagnostic cabinet 4 mainly corrects the data collected by the ultrasonic flow measurement probe group 2-1, and the data output by the diagnostic cabinet 4 can reach ultra-high precision, specifically up to 0.3%FS.

[0083] Optionally, see Figure 3 , the working principle example diagram of the measurement system for the main feed water flow of nuclear power facilities provided by this application.

[0084] The ultrasonic flow measurement probe group 2-1 is used to measure the flow velocities of different laminar flows of the main feed water. In this example, taking the paired ultrasonic flow measurement probes for measuring a single laminar flow in the main feed water, the secondary transmitter corresponding to the paired ultrasonic flow measurement probes, and the acquisition data in the patch thermometer as examples, the process of calculating the main feed water flow based on the acquisition data in the main feed water flow measurement system of the nuclear power facility is described.

[0085] First, the paired ultrasonic flow measurement probes collect the flow velocities of their corresponding laminar flows, and input the collected flow velocity data into the secondary transmitter. The secondary transmitter uses the laminar flow compensation algorithm and the pipeline area compensation algorithm to obtain the medium flow velocity, and further obtains the volume flow velocity of the main feed water after conversion.

[0086] At the same time, the patch thermometer inputs the collected medium temperature signal into the secondary transmitter. The secondary transmitter identifies the threshold temperature, and further can accurately measure the instantaneous temperature of the main feed water in the pipeline by using the acoustic velocity temperature measurement method. The medium density can be obtained by using the polynomial formula of temperature and the medium density of the main feed water. After converting the medium density, the mass flow rate of the main feed water can be obtained. It should be noted that the acoustic velocity temperature measurement method can be realized by the ultrasonic flowmeter in the ultrasonic flow measurement component.

[0087] Exemplarily, refer to Figure 4 , the schematic diagram of the principle of accurate measurement of medium temperature and medium density compensation provided by this application.

[0088] After the secondary transmitter receives the medium temperature signal collected by the patch thermometer, it analyzes to obtain the threshold temperature and the temperature change trend within a preset time period, and generates a flow velocity-temperature curve graph as shown in Figure 4 . The accurate medium temperature is obtained by using the temperatures in the left and right half regions in Figure 4 . Then, the accurate medium density is calculated by using the medium density polynomial. The calculation formula of the medium density can be:

[0089]

[0090] Among them, is the medium density, C K is the temperature polynomial coefficient of each order, and T is the temperature.

[0091] Exemplarily, refer to Figure 5 , the schematic diagram of the principle of the laminar flow compensation algorithm provided by this application.

[0092] As shown in Figure 5As shown in the figure, the main feed water in the straight pipe section is divided into 3 to N laminar flow surfaces, and laminar flow surface ultrasonic transducer probes are correspondingly installed. Since the main feed water will be affected by many factors such as different temperatures, pressures, kinematic viscosities, self-gravity, eddy currents or turbulences during movement, the flow velocities of different laminar flow surfaces actually collected will be different. In this application, by building a test bench under actual temperature, pressure and flow velocity conditions, the flow velocity value curves under different laminar flow surfaces are measured and obtained, and the flow velocity value curves are linearly written into the secondary transmitter in segments for flow velocity compensation, which will enable each laminar flow surface to achieve a repeatability of 0.1% - 0.3% among each other while obtaining high-precision flow velocity measurement results, thus ensuring that the ultrasonic flow measurement components corresponding to each laminar flow surface can output reliable flow measurement signals.

[0093] Specifically, the volume flow rate of the main feed water is calculated according to the calculation formula of the volume flow rate synthesis principle. The calculation formula is as follows:

[0094] flowrate volume =vπr 2

[0095] Among them, flowrate volume is the volume flow rate, v is the medium flow velocity measured by the ultrasonic flowmeter, and r is the pipe radius of the straight pipe section.

[0096] After the acquisition data of the paired ultrasonic flow measurement probes pass through the laminar flow compensation algorithm and the volume flow rate synthesis calculation in sequence, finally, according to the mass flow rate synthesis formula, the mass flow rate of the main feed water is calculated. The calculation formula of the mass flow rate is as follows:

[0097] flowrate mass =ρvπr 2

[0098] Among them, flowrate mass is the mass flow rate, and ρ is the medium density.

[0099] It should be noted that Figure 3 all kinds of compensation algorithms appearing in it do not occupy too much memory and do not require high computing power. During the flow measurement process, grouping is carried out according to different laminar flows to realize the flow measurement of the main feed water separately between different laminar flows, and no comprehensive output is required. Moreover, in practical applications, the calculation period of the single volume flow rate in the secondary transmitter is less than 200ms, which can ensure the real-time nature of the calculation.

[0100] The diagnostic cabinet is mainly responsible for collecting the working condition parameters of the measuring device for the main feed water flow of the nuclear energy facility, and performing high-order calculation and analysis on all the original data in the secondary transmitter group 2-3 collected. In the non-real-time case, an ultra-high accuracy of 0.3% can be obtained (at least guaranteed within the flow range of 50% to 100%), and parameters ① to ⑥ are analyzed and corrected online based on the working condition parameters. The revised parameters are sent down to the secondary transmitters through communication cables. Moreover, when the diagnostic cabinet analyzes and diagnoses unhealthy collected data, it will generate alarm and maintenance information and give feedback.

[0101] In summary, for the measuring system of the main feed water flow of the nuclear energy facility provided by this application, the diagnostic cabinet can detect the working conditions of the measuring device for the main feed water flow of the nuclear energy facility throughout the process, correct the parameters collected by the measuring device for the main feed water flow of the nuclear energy facility online. At the same time, it will also feedback the specific information that needs to be repaired of the measuring device for the main feed water flow of the nuclear energy facility to the staff, without the need for the staff to monitor the operating status of the measuring device for the main feed water flow of the nuclear energy facility in real time.

[0102] More importantly, in actual operation, the measuring system of the main feed water flow of the nuclear energy facility provided by this application has a high measuring accuracy for the main feed water, which can reach 0.5%FS to 1%FS (0.5%FS within the flow range of 50% to 100%, 1%FS within the flow range below 50%); the repeatability of the measurement results at each independent different level is good, which can reach 0.1% to 0.3% (0.1%FS within the flow range of 50% to 100%, 0.3%FS within the flow range below 50%); the acquisition interval of the measurement results of the main feed water flow is less than 200 ms, ensuring real-time performance; moreover, the measuring system of the main feed water flow of the nuclear energy facility can also be directly connected to the regulating valve of the main feed water control loop to form a comprehensive control system to achieve real-time control of the main feed water flow.

[0103] Finally, it should be noted that the above are only the preferred embodiments of the present utility model and are not used to limit the present utility model. Although the present utility model has been described in detail with reference to the foregoing embodiments, for those skilled in the art, they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present utility model shall be included within the protection scope of the present utility model.

Claims

1. A measuring device for the main feed water flow rate of a nuclear energy facility, characterized in that, Comprising: A straight pipe section connected to the main feed water main pipe; At least three groups of ultrasonic flow measurement components; The ultrasonic flow measurement component includes: an ultrasonic flow measurement probe group installed on the straight pipe section; and a clamping tooling for fixing the ultrasonic flow measurement probe group on the straight pipe section according to different laminar flows of the main feed water, and each pair of ultrasonic flow measurement probes in the ultrasonic flow measurement probe group corresponds one-to-one to different laminar flows in the main feed water; a secondary transmitter group correspondingly connected to the ultrasonic flow measurement probe group; And a main feed water temperature measurement group correspondingly connected to the secondary transmitter group.

2. The measuring device for the main feed water flow rate of a nuclear energy facility according to claim 1, characterized in that, The straight pipe section includes a micro-protrusion structure.

3. The measuring device for the main feed water flow rate of a nuclear energy facility according to claim 1, wherein The ultrasonic flow measurement probes in the ultrasonic flow measurement probe group are correspondingly connected to the secondary transmitters in the secondary transmitter group through special measurement cables one by one.

4. The measuring device for the main feed water flow rate of a nuclear energy facility according to claim 1, characterized in that The ultrasonic flow measurement component further includes a fixed sleeve group; The fixed sleeves in the fixed sleeve group are welded on the clamping holes of the clamping tooling; the fixed sleeves in the fixed sleeve group are assembled with the ultrasonic flow measurement probes in the ultrasonic flow measurement probe group one by one.

5. The measuring device for the main feed water flow rate of a nuclear energy facility according to claim 4, characterized in that, The ultrasonic flow measurement probes are vertically assembled into the corresponding fixed sleeves of the ultrasonic flow measurement probes to ensure that the ultrasonic flow measurement probes measure the flow velocity of the corresponding laminar flow of the main feed water in the straight pipe section according to the vertical emission angle.

6. The measuring device for the main feed water flow rate of a nuclear energy facility according to claim 1, characterized in that, The straight pipe section is connected to the main feed water main pipe by welding or assembling a flange.

7. The measuring device for the main feed water flow rate of a nuclear energy facility according to claim 1, characterized in that, The main feed water temperature measurement group includes a patch thermometer and a temperature measurement cable corresponding one-to-one to the ultrasonic flow measurement component; The patch thermometer is correspondingly connected to the secondary transmitter in the secondary transmitter group through the temperature measurement cable one by one.

8. The measuring device for the main feed water flow rate of a nuclear energy facility according to claim 1, wherein It further includes a measurement bench; The straight pipe section is placed on the measurement bench.

9. A measurement system for the main feed water flow rate of a nuclear energy facility, characterized in that, Including the measurement device and diagnostic cabinet for the main feed water flow of the nuclear power facility according to any one of claims 1 to 8; The measurement device for the main feed water flow of the nuclear power facility is connected to the diagnostic cabinet through a communication cable.

10. The measurement system for the main feed water flow rate of a nuclear energy facility according to claim 9, wherein The secondary transmitter group in the measurement device for the main feed water flow of the nuclear power facility is connected to the diagnostic cabinet through the communication cable.

Images