Method and device for determining the measuring section structure of an ultrasonic water meter, and ultrasonic water meter

Abstract

The present invention discloses a method and device for determining the structure of the metering section of an ultrasonic water meter, and an ultrasonic water meter, which relate to the field of structural design. When the shape parameters of the first transition curve, the shape parameters of the second transition curve, the shape parameters of the third transition curve, and the length and width of the rectifying blade of the metering section structure take different values ​​within their respective value ranges, a structural combination is obtained. The flow field distribution, pressure loss, and waveform of the receiving end signal corresponding to the structural combination can be obtained by simulation, and can be used to evaluate whether the ultrasonic water meter meets the index requirements. After the model is constructed, the structural combination can be adjusted continuously according to the flow field distribution, pressure loss, and waveform of the receiving end signal output by the structural combination model, and whether the index requirements are met according to the results output by the model. After the index requirements are met, the structural combination can be obtained without artificial experience, and the obtained structural combination does not need a large number of experiments to verify the feasibility, and the feasibility can be determined using the model.

Description

Technical Field

[0001] The invention relates to the field of structural design, and in particular to a method and device for determining the structure of a measuring section of an ultrasonic water meter, and an ultrasonic water meter. Background Art

[0002] Ultrasonic water meters have many technical indicators, among which pressure loss, flow field sensitivity level, range ratio and production efficiency are all related to the structural design of the ultrasonic water meter metering section. The current structural design of the ultrasonic water meter metering section is mainly based on public molds, which are provided by specialized base meter design and production manufacturers, and cannot meet all technical indicator requirements. A small number of manufacturers have independent design capabilities, but the design generally considers the flow field sensitivity level and pressure loss as the main considerations, relies on manual experience, requires a large number of experiments to verify feasibility, and it is difficult to ensure that the optimal is achieved. Summary of the invention

[0003] The purpose of the present invention is to provide a method and device for determining the structure of the metering section of an ultrasonic water meter, and an ultrasonic water meter, which do not require artificial experience to obtain the structural combination, and at the same time, the obtained structural combination does not require a large number of experiments to verify the feasibility, and the feasibility can be determined using a model.

[0004] In order to solve the above technical problems, the present invention provides a method for determining the structure of a metering section of an ultrasonic water meter, wherein the metering section structure of the ultrasonic water meter includes a transducer, an upper reflector, a lower reflector, a pipeline and two rectifying blades, wherein the upper reflector forms an edge of a first transition curve with the inner side of the upper tube wall of the pipeline, and forms an edge of a second transition curve with the central axis of the pipeline, and the lower reflector forms an edge of a third transition curve with the inner side of the lower tube wall of the pipeline, and the rectifying blade is L-shaped and both ends are in contact with the edge of the third transition curve;

[0005] The method for determining the structure of the ultrasonic water meter measuring section comprises:

[0006] Determine a plurality of structural combinations of shape parameters of the first transition curve, shape parameters of the second transition curve, shape parameters of the third transition curve, and length and width of the rectifying blade within respective value ranges, wherein the shape parameters are related to the shape of the curve;

[0007] The ultrasonic water meter is simulated according to the plurality of structural combinations to obtain the flow field distribution, pressure loss and waveform of the receiving end signal of the transducer of the ultrasonic water meter, wherein the flow field distribution includes the flow velocity, and the pressure loss includes the water pressure loss from the inlet to the outlet of the ultrasonic water meter pipeline;

[0008] The model is trained using the plurality of structural combinations, the flow field distribution of the ultrasonic water meter obtained by simulation, the pressure loss and the waveform of the receiving end signal;

[0009] With the goal of meeting the index requirements of the ultrasonic water meter, the value of the structural combination is adjusted, and the adjusted structural combination is input into the model. When the flow field distribution, pressure loss and waveform of the receiving-end signal of the ultrasonic water meter output by the model meet the index requirements of the ultrasonic water meter, the structural combination input into the model is used as the structural dimension of the ultrasonic water meter.

[0010] On the other hand, determining a plurality of structural combinations in which the shape parameters of the first transition curve, the shape parameters of the second transition curve, the shape parameters of the third transition curve, and the length and width of the straightening blade are within respective value ranges includes:

[0011] Determine the expression for the Witoshinsky curve, which is ;

[0012] Among them, R is the cross-sectional radius at point X of the contraction section, R0 is the cross-sectional radius at the exit of the contraction section, R1 is the cross-sectional radius at the entrance of the contraction section, X is the independent variable, and X1 is the length of the contraction section;

[0013] Determine multiple structural combinations of shape parameters R0, R1 and X1 of the first transition curve, shape parameters R0, R1 and X1 of the second transition curve, shape parameters R0, R1 and X1 of the third transition curve, and length and width of the straightening blade within their respective value ranges.

[0014] On the other hand, the flow field distribution, pressure loss and waveform of the receiving end signal of the ultrasonic water meter output by the model meet the index requirements of the ultrasonic water meter, including:

[0015] Obtaining an error value of the ultrasonic water meter according to the flow field distribution of the ultrasonic water meter;

[0016] If the error value is within a preset error range, it is determined that the ultrasonic water meter passes the flow field sensitivity level evaluation;

[0017] Determining the accuracy of the ultrasonic water meter according to the waveform of the receiving end signal;

[0018] If the accuracy is within a preset accuracy range, it is determined that the ultrasonic water meter passes the accuracy evaluation;

[0019] When the pressure loss is within a preset pressure loss range, the ultrasonic water meter passes the flow field sensitivity level evaluation, and the ultrasonic water meter passes the accuracy evaluation, it is determined that the index requirements of the ultrasonic water meter are met.

[0020] On the other hand, obtaining the error value of the ultrasonic water meter according to the flow field distribution of the ultrasonic water meter includes:

[0021] When simulating the ultrasonic water meter, a spoiler is added to the ultrasonic water meter, and the spoiler includes a velocity profile, a left-hand rotation, and a right-hand rotation;

[0022] Determine the water velocity v of the acoustic path in the ultrasonic water meter before adding the spoiler i , the water flow velocity v in the acoustic path of the ultrasonic water meter after adding the spoiler o ;

[0023] Determine the water flow velocity v of the sound path in the ultrasonic water meter before adding the spoiler i and the water flow velocity v of the acoustic path in the ultrasonic water meter after adding the spoiler o Determine the maximum deviation, the expression of the maximum relative deviation is rd F =(v i -v o ) / v o ;

[0024] Among them, rd F is the maximum relative deviation;

[0025] If the error value is within a preset error range, determining that the ultrasonic water meter passes the flow field sensitivity level evaluation includes:

[0026] If the maximum relative deviation is not greater than 1 / 2 of the maximum allowable error, it is determined that the ultrasonic water meter passes the flow field sensitivity level evaluation.

[0027] On the other hand, determining the accuracy of the ultrasonic water meter according to the waveform of the receiving end signal includes:

[0028] Determining the range ratio and calibration coefficient linearity of the ultrasonic water meter;

[0029] The range ratio and the linearity of the calibration coefficient are weighted to obtain the accuracy, and the expression of the accuracy is Arracy=α×std_dtof / dtof Q2 +(1-α) ×eval_K;

[0030] Among them, Arracy is the accuracy, std_dtof / dtof Q2 is the range ratio, which characterizes the influence of water flow direction on ultrasonic wave in still water. eval_K is the linearity of the calibration coefficient, which characterizes the error between the waveforms of the receiving end signal. α is the weight of the range ratio, and 1-α is the weight of the linearity of the calibration coefficient.

[0031] On the other hand, the process of determining the range ratio of the ultrasonic water meter includes:

[0032] In still water without a spoiler installed, a first ultrasonic signal is sent along the direction of the water flow, and a second ultrasonic signal is sent against the direction of the water flow;

[0033] Determine a standard deviation std_dtof of a time difference between receiving the first ultrasonic signal and receiving the second ultrasonic signal;

[0034] Determine the theoretical time difference dtof of the boundary flow point Q2 ;

[0035] Determine the expression of the range ratio, the expression of the range ratio is std_dtof / dtof Q2 .

[0036] On the other hand, the process of determining the linearity of the calibration coefficient includes:

[0037] Determine the flow rate of each flow point and the average of the time difference between receiving the ultrasonic signal and transmitting the ultrasonic signal at the flow point according to the waveform of the receiving end signal, wherein the flow point includes a minimum flow rate of the ultrasonic water meter, a common flow rate of the ultrasonic water meter, a boundary flow rate between the minimum flow rate and the common flow rate, and an overload flow rate of the ultrasonic water meter.

[0038] The mean of the time difference is used as the independent variable, and the flow rate is used as the dependent variable for piecewise linear fitting. After fitting, the linearity of the calibration coefficient is obtained. The relationship of the linearity of the calibration coefficient is: ;

[0039] Where rdmax is the maximum fitting error, N is the number of segments of the piecewise linear fitting, i is the i-th segment, and the fitting error expression is rd=(vfr calc -vfr real ) / vfr real , rd is the fitting error, vfr calc is the flow rate obtained by fitting, vfr real The flow rate is determined based on the waveform of the signal at the receiving end.

[0040] On the other hand, with the goal of meeting the index requirements of the ultrasonic water meter, the value of the structural combination is adjusted, and the adjusted structural combination is input into the model. When the flow field distribution, pressure loss and waveform of the receiving end signal of the ultrasonic water meter output by the model meet the index requirements of the ultrasonic water meter, the structural combination input into the model is used as the structural size of the ultrasonic water meter, including:

[0041] Initialize the number of iterations, crossover factor and mutation factor;

[0042] determining a set of values ​​for said structure combinations and inputting them into said model;

[0043] Obtaining the flow field distribution, pressure loss and waveform of the receiving end signal output by the model, and using the flow field distribution, pressure loss and waveform of the receiving end signal output by the model as the parent population;

[0044] The number of iterations is increased by one, and based on the crossover factor and the mutation factor, individuals are randomly selected from the parent population for crossover and mutation to obtain a test population;

[0045] Determining the fitness of the parent population and the fitness of the test population respectively, and generating a progeny population according to the fitness of the parent population and the fitness of the test population;

[0046] Determine the crowding distance of individuals in the offspring population, and remove individuals whose crowding distance is lower than the preset distance;

[0047] Determine whether the current number of iterations reaches the preset number of iterations;

[0048] If so, determine that the structural combination corresponding to the offspring population is the adjusted structural combination, and input the adjusted structural combination into the model. When the flow field distribution, pressure loss and waveform of the receiving-end signal of the ultrasonic water meter output by the model meet the index requirements of the ultrasonic water meter, the structural combination input into the model is used as the structural dimensions of the ultrasonic water meter;

[0049] If not, return to the step of increasing the number of iterations by one, and randomly selecting individuals from the parent population for crossover and mutation based on the crossover factor and the mutation factor to obtain a test population.

[0050] In order to solve the above technical problems, the present invention also provides a device for determining the structure of a measuring section of an ultrasonic water meter, comprising:

[0051] Memory for storing computer programs;

[0052] The processor is used to implement the steps of the above-mentioned method for determining the measuring section structure of the ultrasonic water meter when executing the computer program.

[0053] In order to solve the above technical problems, the present invention also provides an ultrasonic water meter, the metering section structure of the ultrasonic water meter includes a transducer, an upper reflector, a lower reflector, a pipeline and two straightening blades, the upper reflector forms an edge of a first transition curve with the inner side of the upper tube wall of the pipeline, the upper reflector forms an edge of a second transition curve with the central axis of the pipeline, the lower reflector forms an edge of a third transition curve with the inner side of the lower tube wall of the pipeline, the straightening blade is L-shaped and both ends are in contact with the edge of the third transition curve, the shape parameters of the first transition curve, the shape parameters of the second transition curve, the shape parameters of the third transition curve and the length and width of the straightening blade are obtained by the steps of the above-mentioned method for determining the metering section structure of the ultrasonic water meter.

[0054] The present application provides a method, device and ultrasonic water meter for determining the structure of the metering section of an ultrasonic water meter, which relates to the field of structural design. When the shape parameters of the first transition curve, the shape parameters of the second transition curve, the shape parameters of the third transition curve and the length and width of the rectifier blade of the metering section structure take different values ​​within their respective value ranges, a structural combination is obtained. The flow field distribution, pressure loss and waveform of the receiving end signal corresponding to the structural combination can be obtained by simulation, which can be used to evaluate whether the ultrasonic water meter meets the index requirements. After the model is constructed, the flow field distribution, pressure loss and waveform of the receiving end signal output by the structural combination model can be continuously adjusted, and the index requirements can be determined according to the results of the model output. After the index requirements are met, the structural combination can be obtained without manual experience, and the obtained structural combination does not require a large number of experiments to verify the feasibility. The feasibility can be determined using the model. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the prior art and the drawings required for use in the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0056] Figure 1 A flow chart of a method for determining a measuring section structure of an ultrasonic water meter provided by the present invention;

[0057] Figure 2 A schematic diagram of the structure of a measuring section of an ultrasonic water meter provided by the present invention;

[0058] Figure 3 A schematic diagram of the structure of a Witosinski curve provided by the present invention;

[0059] Figure 4 A schematic structural diagram of a device for determining a measuring section structure of an ultrasonic water meter provided by the present invention.

[0060] Description of reference numerals:

[0061] 1. First transition curve; 2. Second transition curve; 3. Third transition curve; 4. Rectifying blade. DETAILED DESCRIPTION

[0062] The core of the present invention is to provide a method and device for determining the structure of the metering section of an ultrasonic water meter and an ultrasonic water meter. No artificial experience is required to obtain the structural combination, and the obtained structural combination does not require a large number of experiments to verify the feasibility. The feasibility can be determined using a model.

[0063] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0064] Figure 1 A flow chart of a method for determining a measuring section structure of an ultrasonic water meter provided by the present invention, Figure 2 A schematic diagram of the structure of a measuring section of an ultrasonic water meter provided by the present invention;

[0065] The metering section structure of the ultrasonic water meter includes a transducer, an upper reflector, a lower reflector, a pipeline and two rectifying blades. The upper reflector and the inner side of the upper pipe wall of the pipeline form the edge of the first transition curve 1, the upper reflector and the central axis of the pipeline form the edge of the second transition curve 2, the lower reflector and the inner side of the lower pipe wall of the pipeline form the edge of the third transition curve 3, and the rectifying blade 4 is L-shaped and both ends are in contact with the edge of the third transition curve 3;

[0066] The method for determining the structure of the ultrasonic water meter measurement section includes:

[0067] S11: determining a plurality of structural combinations of shape parameters of a first transition curve, a second transition curve, a third transition curve, and lengths and widths of straightening blades within respective value ranges, wherein the shape parameters are related to the shapes of the curves;

[0068] The metering section structure of the ultrasonic water meter includes a transducer, an upper reflector, a lower reflector, a pipeline and two rectifying blades. The two ends of the upper reflector respectively form two first transition curve edges with the inner side of the upper tube wall of the pipeline, the two ends of the upper reflector respectively form two second transition curve edges with the central axis of the pipeline, the lower reflector and the central axis form a trapezoid, the two ends of the lower reflector and the inner side of the lower tube wall of the pipeline form a third transition curve edge, the rectifying blade is L-shaped, one side of the rectifying blade is parallel to the central axis and the end point is in contact with the edge of the third transition curve, the other side of the rectifying blade is perpendicular to the central axis and the end point is in contact with the edge of the third transition curve, the transmitting end of the transducer is arranged at one end of the upper reflector, and the receiving end of the transducer is arranged at the other end of the upper reflector. The transducer is used to send ultrasonic waves from the transmitting end and receive ultrasonic waves reflected by the upper reflector and the lower reflector from the receiving end.

[0069] The measuring section of the ultrasonic water meter includes the ultrasonic water meter sound path and the reflector bracket (the reflector bracket is used to generate the sound path for ultrasonic propagation, mainly composed of the reflector and the supporting structure of the reflector. Ultrasonic waves propagate in water and are reflected by the reflector, which is the sound path). The structural design of the measuring section will affect the technical indicators of the ultrasonic water meter, such as pressure loss, flow field sensitivity level, range ratio, accuracy and production efficiency.

[0070] It is understandable that in the design process of the ultrasonic water meter, there must be an upper reflector, a lower reflector, a pipeline and two straightening blades, but the shape of the curve formed by the upper reflector, the lower reflector and the tube wall can be different. The shape of the curve is determined by the shape parameter. The shape parameter has a corresponding value range, and there are many values ​​of the shape parameter within the value range. The length and height of the same L-shaped straightening blade also need to set multiple parameters, so the shape parameters of the first transition curve, the shape parameters of the second transition curve, the shape parameters of the third transition curve and the length and width of the straightening blade can form a variety of structural combinations under different values. Each structural combination may meet the index requirements of the ultrasonic water meter, or it may not. Whether the index requirements are met should be determined based on simulation.

[0071] S12: simulating the ultrasonic water meter according to various structural combinations to obtain the flow field distribution, pressure loss and waveform of the receiving end signal of the transducer of the ultrasonic water meter, wherein the flow field distribution includes the flow velocity, and the pressure loss includes the water pressure loss from the inlet to the outlet of the ultrasonic water meter pipeline;

[0072] In order to improve the efficiency of the test, the ultrasonic water meter constructed based on a variety of structural combinations is simulated. Without using the actual ultrasonic water meter, the flow field distribution, pressure loss and waveform of the receiving end signal of the ultrasonic water meter under the structural combination can be known by using only the simulation model.

[0073] S13: using various structural combinations, flow field distribution of the ultrasonic water meter obtained by simulation, pressure loss and waveform of the receiving end signal to train the model;

[0074] The model trained using the simulation data can predict the flow field distribution, pressure loss and receiving end signal based on the input structure combination without the need for further simulation.

[0075] S14: With the goal of meeting the index requirements of the ultrasonic water meter, the value of the structural combination is adjusted, and the adjusted structural combination is input into the model. When the flow field distribution, pressure loss and waveform of the receiving-end signal of the ultrasonic water meter output by the model meet the index requirements of the ultrasonic water meter, the structural combination input into the model is used as the structural size of the ultrasonic water meter.

[0076] The index requirements of ultrasonic water meters are determined based on the flow field distribution, pressure loss and waveform of the receiving end signal. If the flow field distribution, pressure loss and waveform of the receiving end signal output by the model based on the input structure combination meet the index requirements, then the structure combination is a size that can be actually applied. Therefore, by continuously adjusting the value of the structure combination, the structure combination that meets the index requirements can be determined.

[0077] The present application provides a method for determining the structure of the metering section of an ultrasonic water meter, which relates to the field of structural design. When the shape parameters of the first transition curve, the shape parameters of the second transition curve, the shape parameters of the third transition curve, and the length and width of the rectifier blade of the metering section structure take different values ​​within their respective value ranges, a structural combination is obtained. The simulation can obtain the flow field distribution, pressure loss, and waveform of the receiving end signal corresponding to the structural combination, which can be used to evaluate whether the ultrasonic water meter meets the index requirements. After the model is constructed, the structural combination can be adjusted continuously according to the flow field distribution, pressure loss, and waveform of the receiving end signal output by the structural combination model, and whether the index requirements are met according to the results of the model output. After the index requirements are met, the structural combination can be obtained without manual experience, and the obtained structural combination does not require a large number of experiments to verify the feasibility. The feasibility can be determined using the model.

[0078] Based on the above embodiments:

[0079] Figure 3 A schematic diagram of the structure of a Witosinski curve provided by the present invention;

[0080] In some embodiments, the first transition curve, the second transition curve, and the third transition curve are all Witosinski curves, and multiple structural combinations of shape parameters of the first transition curve, shape parameters of the second transition curve, shape parameters of the third transition curve, and length and width of the straightening blade within their respective value ranges are determined, including:

[0081] Determine the expression of the Witoshinsky curve, which is ;

[0082] Among them, R is the cross-sectional radius at point X of the contraction section, R0 is the cross-sectional radius at the exit of the contraction section, R1 is the cross-sectional radius at the entrance of the contraction section, X is the independent variable, and X1 is the length of the contraction section;

[0083] Determine various structural combinations of shape parameters R0, R1 and X1 of the first transition curve, shape parameters R0, R1 and X1 of the second transition curve, shape parameters R0, R1 and X1 of the third transition curve, and length and width of the rectifying blade within their respective value ranges.

[0084] In some embodiments, the flow field distribution, pressure loss and waveform of the receiving end signal of the ultrasonic water meter output by the model meet the index requirements of the ultrasonic water meter, including:

[0085] The error value of the ultrasonic water meter is obtained according to the flow field distribution of the ultrasonic water meter;

[0086] If the error value is within the preset error range, it is determined that the ultrasonic water meter has passed the flow field sensitivity level evaluation;

[0087] Determine the accuracy of the ultrasonic water meter based on the waveform of the signal at the receiving end;

[0088] If the accuracy is within the preset accuracy range, it is determined that the ultrasonic water meter has passed the accuracy evaluation;

[0089] When the pressure loss is within the preset pressure loss range, the ultrasonic water meter passes the flow field sensitivity level evaluation, and the ultrasonic water meter passes the accuracy evaluation, it is determined that the index requirements of the ultrasonic water meter are met.

[0090] The metering section of the ultrasonic water meter includes the ultrasonic water meter sound path and the reflector bracket (the reflector bracket is used to generate the sound path for ultrasonic propagation, which is mainly composed of the reflector and the support structure of the reflector. Ultrasonic waves propagate in water and are reflected by the reflector, which is the sound path). The design of the metering section structure will affect the technical indicators of the ultrasonic water meter, such as pressure loss, flow field sensitivity level, range ratio, accuracy and production efficiency. The reflector bracket structure will also affect the effective cross-sectional area of ​​the water flow. When the cross-sectional area changes, the water flow velocity will also change accordingly. If the effective cross-sectional area becomes smaller, the water flow velocity increases, and the measurement accuracy of the water flow velocity remains unchanged, the measurable range will become wider, that is, the design range ratio will become larger. At the same time, the effective cross-sectional area becomes smaller, the pressure loss increases, and the water supply cost increases. The structural installation position of the reflector bracket will affect the flow field distribution in the ultrasonic water meter pipe, causing the flow field sensitivity of the ultrasonic water meter to change, that is, the anti-disturbance ability. If the flow field is evenly distributed through reasonable structural design, the ultrasonic signal will have less energy loss when propagating on the sound path, the signal-to-noise ratio will be high, and the accuracy will be easier to ensure. At the same time, reasonable sound path and reflector bracket structure design will improve the linearity of the calibration coefficient within the flow measurement range, reduce the factory calibration cost of ultrasonic water meters, and improve production efficiency.

[0091] In some embodiments, obtaining an error value of the ultrasonic water meter according to the flow field distribution of the ultrasonic water meter includes:

[0092] When simulating the ultrasonic water meter, a spoiler is added to the ultrasonic water meter, and the spoiler includes velocity profile, left rotation and right rotation;

[0093] Determine the water velocity v in the acoustic path of the ultrasonic water meter before adding the spoiler i , the water velocity v in the acoustic path of the ultrasonic water meter after adding the spoiler o ;

[0094] Determine the water velocity v in the sound path of the ultrasonic water meter before adding the spoiler i And the water velocity v in the acoustic path of the ultrasonic water meter after adding the spoiler o Determine the maximum deviation. The expression for the maximum relative deviation is rd F =(v i -v o ) / v o ;

[0095] Among them, rd F is the maximum relative deviation;

[0096] If the error value is within the preset error range, it is determined that the ultrasonic water meter has passed the flow field sensitivity level evaluation, including:

[0097] If the maximum relative deviation is not greater than 1 / 2 of the maximum allowable error, it is determined that the ultrasonic water meter has passed the flow field sensitivity level evaluation.

[0098] At the flow point Q3, different types of spoilers (velocity profile, left-handed, right-handed) are installed at the inlet and outlet of the ultrasonic water meter. The velocity v_i on the sound channel line (the sound channel line is the sound path) is calculated through the flow field distribution data output by the simulation or neural network model, and the maximum relative deviation rd from the result v_0 without installing the spoiler is F , not more than half of the maximum allowable error of the ultrasonic water meter. Flow field sensitivity level index: Install different types of spoilers and do not install spoilers, and perform calibration at room temperature and Q3 flow point. The relative deviation between the two should not exceed half of the maximum allowable error.

[0099] Usually ultrasonic water meters have four flow points: Q1, Q2, Q3, and Q4:

[0100] Q1 is the minimum flow rate, which means the minimum flow rate that requires the water meter indication to conform to the maximum allowable error.

[0101] Q2 is the boundary flow rate, which is usually between the common flow rate Q3 and the minimum flow rate Q1, and decomposes the flow range into two high and low flow zones with specific maximum allowable errors.

[0102] Q3 is the commonly used flow rate, which refers to the maximum allowable flow rate under rated working conditions. Under this flow rate, the ultrasonic water meter should meet the maximum allowable error when working normally.

[0103] Q4 is the overload flow, which requires the ultrasonic water meter to meet the maximum allowable error requirements in a short period of time, and then maintain the maximum flow of the metering characteristics under rated working conditions.

[0104] In some embodiments, determining the accuracy of the ultrasonic water meter according to the waveform of the receiving end signal includes:

[0105] Determine the range ratio and calibration factor linearity of ultrasonic water meters;

[0106] The accuracy is obtained by weighted calculation of the range ratio and the linearity of the calibration coefficient. The expression of accuracy is Arracy=α×std_dtof / dtof Q2 +(1-α) ×eval_K;

[0107] Among them, Arracy is the accuracy, std_dtof / dtof Q2 is the range ratio, which characterizes the influence of water flow direction on ultrasonic wave in still water. eval_K is the linearity of calibration coefficient, which characterizes the error between the waveforms of the receiving end signal. α is the weight of the range ratio, and 1-α is the weight of the linearity of calibration coefficient.

[0108] Accuracy is a weighted product of turndown and calibration factor linearity.

[0109] In some embodiments, the process of determining the range ratio of the ultrasonic water meter includes:

[0110] In still water without a spoiler installed, a first ultrasonic signal is sent along the direction of the water flow, and a second ultrasonic signal is sent against the direction of the water flow;

[0111] Determine the standard deviation std_dtof of the time difference between receiving the first ultrasonic signal and receiving the second ultrasonic signal;

[0112] Determine the theoretical time difference dtof of the boundary flow point Q2 ;

[0113] Determine the expression for the range ratio. The expression for the range ratio is std_dtof / dtof Q2 .

[0114] The propagation time difference of the upstream and downstream receiving signals. The ultrasonic water meter will send ultrasonic signals in the direction of water flow and the countercurrent direction respectively. When there is water flow, the ultrasonic propagation time (arrival time) in both directions will be affected, resulting in a time difference. In still water, without installing a spoiler, the output receiving end signal is used for Monte Carlo simulation to calculate the standard deviation of the time difference std_dtof. The standard deviation of the time difference std_dtof is not allowed to exceed one-half of the maximum allowable error of the ultrasonic water meter Q2 flow. dtof Q2 It is the theoretical time difference corresponding to the Q2 flow point.

[0115] In some embodiments, the process of determining the linearity of the calibration coefficients includes:

[0116] Determine the flow rate of each flow point and the average value of the time difference between receiving the ultrasonic signal and transmitting the ultrasonic signal at the flow point according to the waveform of the receiving end signal, the flow point includes one or more combinations of the minimum flow rate of the ultrasonic water meter, the common flow rate of the ultrasonic water meter, the boundary flow rate between the minimum flow rate and the common flow rate, and the overload flow rate of the ultrasonic water meter;

[0117] The mean of the time difference is used as the independent variable and the flow rate is used as the dependent variable for piecewise linear fitting. After fitting, the linearity of the calibration coefficient is obtained. The relationship between the linearity of the calibration coefficient is: ;

[0118] Among them, rdmax is the maximum fitting error, N is the number of segments of piecewise linear fitting, i is the i-th segment, and the expression of fitting error is rd=(vfr calc -vfr real ) / vfr real , rd is the fitting error, vfr calc is the flow rate obtained by fitting, vfr real The flow rate is determined based on the waveform of the signal at the receiving end.

[0119] The output receiving end signal is used for Monte Carlo simulation to calculate the mean time difference of flow points Q1~Q4. The independent variable is the mean time difference and the dependent variable is the instantaneous flow. A piecewise linear fitting is performed. The number of segments does not exceed 6, and the maximum error introduced by linear fitting in each flow interval does not exceed 0.1%.

[0120] Monte Carlo simulation is performed using the output receiving end signal to calculate the time difference mean of the flow points Q1~Q4, which can derive a one-to-one correspondence between the time difference and the flow. The time difference and instantaneous flow at this time are regarded as true values. With the independent variable as the time difference mean and the dependent variable as the instantaneous flow, piecewise linear fitting is performed, with the number of segments not exceeding 6. Through piecewise linear fitting, the instantaneous flow value calculated using the time difference is obtained.

[0121] The maximum error introduced by linear fitting in each flow interval does not exceed 0.1%. The maximum error between the calculated instantaneous flow value and the true value is also the error introduced by linear fitting. The error calculation formula is rd=(vfr calc -vfr real ) / vfr real .

[0122] In some embodiments, the value of the structure combination is adjusted to meet the index requirements of the ultrasonic water meter, and the adjusted structure combination is input into the model. When the flow field distribution, pressure loss and waveform of the receiving end signal of the ultrasonic water meter output by the model meet the index requirements of the ultrasonic water meter, the structure combination input into the model is used as the structural size of the ultrasonic water meter, including:

[0123] Initialize the number of iterations, crossover factor and mutation factor;

[0124] Determine the values ​​of a set of structural combinations and input them into the model;

[0125] The flow field distribution, pressure loss and waveform of the receiving end signal output by the model are obtained, and the flow field distribution, pressure loss and waveform of the receiving end signal output by the model are used as the parent population;

[0126] The number of iterations is increased by one, and based on the crossover factor and mutation factor, individuals are randomly selected from the parent population for crossover and mutation to obtain the test population;

[0127] The fitness of the parent population and the fitness of the test population are determined respectively, and the offspring population is generated according to the fitness of the parent population and the fitness of the test population;

[0128] Determine the crowding distance of individuals in the offspring population, and remove individuals whose crowding distance is lower than the preset distance;

[0129] Determine whether the current number of iterations reaches the preset number of iterations;

[0130] If so, the structural combination corresponding to the offspring population is determined to be the adjusted structural combination, and the adjusted structural combination is input into the model. When the flow field distribution, pressure loss and waveform of the receiving-end signal of the ultrasonic water meter output by the model meet the index requirements of the ultrasonic water meter, the structural combination input into the model is used as the structural size of the ultrasonic water meter;

[0131] If not, return to the step of increasing the number of iterations by one, and randomly selecting individuals from the parent population for crossover and mutation based on the crossover factor and mutation factor to obtain the test population.

[0132] Taking pressure loss, flow field sensitivity level and accuracy as optimization targets, the optimization variables are defined as structural size parameters.

[0133] Set the search range of the differential evolution algorithm for the structural size of the ultrasonic water meter measurement segment, establish the initial structural model of the ultrasonic water meter measurement segment, initialize the maximum number of iterations, crossover factor and mutation factor

[0134] The initial structural model is randomly generated within the search range, and the results (flow field distribution, pressure loss, receiving end signal) under the structural parameters are substituted into the neural network model as the parent population. The number of iterations is increased by 1, and the objective function value is calculated using Monte Carlo simulation. According to the objective function and constraints, the fitness of individuals in the parent population is calculated.

[0135] Based on the crossover factor and the mutation factor, individuals are randomly selected from the parent population for crossover and mutation to generate a test population; the fitness of individuals in the test population is calculated, the fitness of individuals in the parent population is compared with that of individuals in the test population, and the offspring population is generated according to the comparison results;

[0136] Perform non-dominated sorting of individuals in the offspring population; calculate the crowding distance of individuals in the offspring population, and remove individuals with relatively small crowding distances to keep the number of individuals in the offspring population consistent with the number of individuals in the initial population;

[0137] Determine whether the current number of iterations has reached the maximum number of iterations required. If so, complete the parameter optimization and end the process;

[0138] After the optimization is completed, the simulation model is established using the optimal size parameters, and finite element simulation is performed to verify the effectiveness and accuracy of the optimization based on the simulation results.

[0139] Figure 4 A schematic diagram of a structure of a device for determining a measuring section structure of an ultrasonic water meter provided by the present invention, wherein the device for determining a measuring section structure of an ultrasonic water meter comprises:

[0140] A memory 41, used for storing computer programs;

[0141] The processor 42 is used to implement the steps of the above-mentioned method for determining the measuring section structure of the ultrasonic water meter when executing the computer program.

[0142] For an introduction to the device for determining the measuring section structure of the ultrasonic water meter provided in the present application, please refer to the above-mentioned embodiments, which will not be described in detail here.

[0143] The present application also provides an ultrasonic water meter, including a metering section structure of the ultrasonic water meter including a transducer, an upper reflector, a lower reflector, a pipeline and two rectifying blades, two first transition curve edges are formed between the two ends of the upper reflector and the inner side of the upper tube wall of the pipeline, two second transition curve edges are formed between the two ends of the upper reflector and the central axis of the pipeline, the lower reflector and the central axis form a trapezoid, the two ends of the lower reflector and the inner side of the lower tube wall of the pipeline form a third transition curve edge, the rectifying blade is L-shaped, one side of the rectifying blade is parallel to the central axis and the end point is in contact with the edge of the third transition curve, and the rectifying blade The other side is perpendicular to the central axis and the endpoint is in contact with the edge of the third transition curve. The transmitting end of the transducer is arranged at one end of the upper reflector, and the receiving end of the transducer is arranged at the other end of the upper reflector. The transducer is used to send ultrasonic waves from the transmitting end and receive ultrasonic waves reflected by the upper reflector and the lower reflector from the receiving end. The first transition curve, the second transition curve and the third transition curve are all Witosinski curves. The shape parameters of the first transition curve, the shape parameters of the second transition curve, the shape parameters of the third transition curve and the length and width of the straightening blade are determined by the steps of the above-mentioned method for determining the metering section structure of the ultrasonic water meter.

[0144] For the introduction of the ultrasonic water meter provided in this application, please refer to the above embodiments, which will not be repeated here.

[0145] It should also be noted that, in this specification, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprise", "include" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the statement "comprises a ..." does not exclude the presence of other identical elements in the process, method, article or device including the element.

[0146] Professionals may further appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described in the above description according to function. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professionals and technicians may use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0147] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for determining the structure of a measuring section of an ultrasonic water meter, characterized in that: The metering section structure of the ultrasonic water meter includes a transducer, an upper reflector, a lower reflector, a pipeline and two rectifying blades, the upper reflector forms an edge of a first transition curve with the inner side of the upper pipe wall of the pipeline, the upper reflector forms an edge of a second transition curve with the central axis of the pipeline, the lower reflector forms an edge of a third transition curve with the inner side of the lower pipe wall of the pipeline, and the rectifying blade is L-shaped and both ends are in contact with the edge of the third transition curve; The method for determining the structure of the ultrasonic water meter measuring section comprises: Determine a plurality of structural combinations of shape parameters of the first transition curve, shape parameters of the second transition curve, shape parameters of the third transition curve, and length and width of the rectifying blade within respective value ranges, wherein the shape parameters are related to the shape of the curve; The ultrasonic water meter is simulated according to the plurality of structural combinations to obtain the flow field distribution, pressure loss and waveform of the receiving end signal of the transducer of the ultrasonic water meter, wherein the flow field distribution includes the flow velocity, and the pressure loss includes the water pressure loss from the inlet to the outlet of the ultrasonic water meter pipeline; The model is trained using the plurality of structural combinations, the flow field distribution of the ultrasonic water meter obtained by simulation, the pressure loss and the waveform of the receiving end signal; With the goal of meeting the index requirements of the ultrasonic water meter, the value of the structural combination is adjusted, and the adjusted structural combination is input into the model. When the flow field distribution, pressure loss and waveform of the receiving-end signal of the ultrasonic water meter output by the model meet the index requirements of the ultrasonic water meter, the structural combination input into the model is used as the structural dimensions of the ultrasonic water meter; The flow field distribution, pressure loss and waveform of the receiving end signal of the ultrasonic water meter output by the model meet the index requirements of the ultrasonic water meter, including: When simulating the ultrasonic water meter, a spoiler is added to the ultrasonic water meter, and the spoiler includes a velocity profile, a left-hand rotation, and a right-hand rotation; Determine the water velocity v of the acoustic path in the ultrasonic water meter before adding the spoiler i , the water flow velocity v in the acoustic path of the ultrasonic water meter after adding the spoiler o ; Determine the water flow velocity v of the sound path in the ultrasonic water meter before adding the spoiler i and the water flow velocity v of the acoustic path in the ultrasonic water meter after adding the spoiler o Determine the maximum relative deviation, the expression of the maximum relative deviation is rd F =(v i -v o ) / v o ; Among them, rd F is the maximum relative deviation; If the maximum relative deviation is not greater than 1 / 2 of the maximum allowable error, it is determined that the ultrasonic water meter passes the flow field sensitivity level evaluation; Determining the range ratio and calibration coefficient linearity of the ultrasonic water meter; The range ratio and the linearity of the calibration coefficient are weighted to obtain the accuracy, and the expression of the accuracy is Arracy=α×std_dtof / dtof Q2 +(1-α)×eval_K; Among them, Arracy is the accuracy, std_dtof / dtof Q2 is the range ratio, which characterizes the influence of water flow direction on ultrasonic wave in static water, eval_K is the calibration coefficient linearity, which characterizes the error between the waveforms of the receiving end signal, α is the weight of the range ratio, and 1-α is the weight of the calibration coefficient linearity; If the accuracy is within a preset accuracy range, it is determined that the ultrasonic water meter passes the accuracy evaluation; When the pressure loss is within a preset pressure loss range, the ultrasonic water meter passes the flow field sensitivity level evaluation, and the ultrasonic water meter passes the accuracy evaluation, it is determined that the index requirements of the ultrasonic water meter are met.

2. The method for determining the structure of the measuring section of an ultrasonic water meter according to claim 1, characterized in that: The first transition curve, the second transition curve and the third transition curve are all Witosinski curves, and multiple structural combinations of shape parameters of the first transition curve, shape parameters of the second transition curve, shape parameters of the third transition curve and the length and width of the straightening blade within their respective value ranges are determined, including: Determine the expression for the Witoshinsky curve, which is Among them, R is the cross-sectional radius at point X of the contraction section, R0 is the cross-sectional radius at the exit of the contraction section, R1 is the cross-sectional radius at the entrance of the contraction section, X is the independent variable, and X1 is the length of the contraction section; Determine multiple structural combinations of shape parameters R0, R1 and X1 of the first transition curve, shape parameters R0, R1 and X1 of the second transition curve, shape parameters R0, R1 and X1 of the third transition curve, and length and width of the straightening blade within their respective value ranges.

3. The method for determining the structure of the measuring section of an ultrasonic water meter according to claim 1, characterized in that: The process of determining the range ratio of the ultrasonic water meter includes: In still water without a spoiler installed, a first ultrasonic signal is sent along the direction of the water flow, and a second ultrasonic signal is sent against the direction of the water flow; Determine a standard deviation std_dtof of a time difference between receiving the first ultrasonic signal and receiving the second ultrasonic signal; Determine the theoretical time difference dtof of the boundary flow point Q2 ; Determine the expression of the range ratio, the expression of the range ratio is std_dtof / dtof Q2 .

4. The method for determining the structure of the measuring section of an ultrasonic water meter according to claim 1, characterized in that: The process of determining the linearity of the calibration coefficient includes: Determine the flow rate of each flow point and the average of the time difference between receiving the ultrasonic signal and transmitting the ultrasonic signal at the flow point according to the waveform of the receiving end signal, wherein the flow point includes a minimum flow rate of the ultrasonic water meter, a common flow rate of the ultrasonic water meter, a boundary flow rate between the minimum flow rate and the common flow rate, and an overload flow rate of the ultrasonic water meter. The mean of the time difference is used as the independent variable, and the flow rate is used as the dependent variable for piecewise linear fitting. After fitting, the linearity of the calibration coefficient is obtained. The relationship of the linearity of the calibration coefficient is: Wherein, rdmax is the maximum fitting error, N is the number of segments of the piecewise linear fitting, i is the i-th segment, and the fitting error expression is rd=(vfr calc -vfr real ) / vfr real , rd is the fitting error, vfr calc is the flow rate obtained by fitting, vfr real The flow rate is determined based on the waveform of the signal at the receiving end.

5. The method for determining the structure of the measuring section of an ultrasonic water meter according to any one of claims 1 to 4, characterized in that: With the goal of meeting the index requirements of the ultrasonic water meter, the value of the structural combination is adjusted, and the adjusted structural combination is input into the model. When the flow field distribution, pressure loss and waveform of the receiving end signal of the ultrasonic water meter output by the model meet the index requirements of the ultrasonic water meter, the structural combination input into the model is used as the structural size of the ultrasonic water meter, including: Initialize the number of iterations, crossover factor and mutation factor; determining a set of values ​​for said structure combinations and inputting them into said model; Obtaining the flow field distribution, pressure loss and waveform of the receiving end signal output by the model, and using the flow field distribution, pressure loss and waveform of the receiving end signal output by the model as the parent population; The number of iterations is increased by one, and based on the crossover factor and the mutation factor, individuals are randomly selected from the parent population for crossover and mutation to obtain a test population; Determining the fitness of the parent population and the fitness of the test population respectively, and generating a progeny population according to the fitness of the parent population and the fitness of the test population; Determine the crowding distance of individuals in the offspring population, and remove individuals whose crowding distance is lower than the preset distance; Determine whether the current number of iterations reaches the preset number of iterations; If so, determine that the structural combination corresponding to the offspring population is the adjusted structural combination, and input the adjusted structural combination into the model. When the flow field distribution, pressure loss and waveform of the receiving-end signal of the ultrasonic water meter output by the model meet the index requirements of the ultrasonic water meter, the structural combination input into the model is used as the structural dimensions of the ultrasonic water meter; If not, return to the step of increasing the number of iterations by one, and randomly selecting individuals from the parent population for crossover and mutation based on the crossover factor and the mutation factor to obtain a test population.

6. A device for determining the structure of a measuring section of an ultrasonic water meter, characterized in that: include: Memory for storing computer programs; A processor is used to implement the steps of the method for determining the measuring section structure of an ultrasonic water meter as described in any one of claims 1 to 4 when executing the computer program.

7. An ultrasonic water meter, characterized in that: The metering section structure of the ultrasonic water meter includes a transducer, an upper reflector, a lower reflector, a pipeline and two straightening blades, the upper reflector forms an edge of a first transition curve with the inner side of the upper tube wall of the pipeline, the upper reflector forms an edge of a second transition curve with the central axis of the pipeline, the lower reflector forms an edge of a third transition curve with the inner side of the lower tube wall of the pipeline, the straightening blade is L-shaped and both ends are in contact with the edge of the third transition curve, the shape parameters of the first transition curve, the shape parameters of the second transition curve, the shape parameters of the third transition curve and the length and width of the straightening blade are obtained by the steps of the method for determining the metering section structure of an ultrasonic water meter as described in any one of claims 1 to 4.

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