Vortex street flow measuring system and method resistant to vibration interference

Abstract

The invention relates to a vortex street flow system and flow measurement, in particular to an anti-vibration interference vortex street flow measurement system and a measurement method. Comprising a flow signal conditioning channel and a vibration signal conditioning channel which are consistent in structure, are arranged in parallel and are respectively used for receiving and processing signals from an independent flow probe and an independent vibration probe. The dynamic impedance adjusting module is integrated in the flow signal conditioning channel and / or the vibration signal conditioning channel and used for dynamically adjusting the resistance value of an adjustable resistor through an MCU according to the vortex street signal frequency collected in real time so as to change the amplification coefficient of the channel. And the signal processing and judging module is used for carrying out collaborative judgment through frequency domain analysis and correlation calculation based on the two paths of signals processed by the dynamic impedance adjusting module, and distinguishing and extracting an effective vortex street flow frequency. Through a dynamic impedance adjustment method, a flow signal is effectively enhanced, and vibration and random interference are suppressed.

Description

Technical Field

[0001] This invention relates to vortex flow systems and flow measurement, and more particularly to a vibration-resistant vortex flow measurement system and method. Background Technology

[0002] In the field of industrial process flow measurement, vortex flow meters are widely used due to their simple structure and wide range of applicable fluids. However, their measurement principle makes them susceptible to interference from pipeline vibration, especially in complex industrial scenarios with large rotating machinery (such as pumps and compressors) or fluid pulsation. The vibration noise of the pipeline and fluid can be severely coupled into the vortex sensor signal, resulting in a decrease in the signal-to-noise ratio of the flow signal, inaccurate frequency extraction, and thus significant measurement errors or even misjudgments.

[0003] To address these challenges, existing technologies primarily improve signal processing algorithms. For example, the Chinese patent application "Wide-Range Vortex Flowmeter and Flow Calculation Method Based on Dynamic Fourier Transform" (application number 202211275200.9) enhances range adaptability through methods such as dynamic Fourier analysis. However, such solutions are essentially post-processing optimizations of single-channel signals, and their anti-interference capabilities have theoretical bottlenecks: when vibration noise overlaps with the effective vortex flow signal in the frequency domain (especially co-frequency or near-frequency interference), it is difficult to fundamentally distinguish between signal and noise based solely on the spectrum analysis of a single channel, resulting in limited suppression effects. Furthermore, measurement accuracy and stability remain unsatisfactory under strong vibration environments.

[0004] Furthermore, to achieve vibration monitoring and compensation, some solutions introduce independent vibration sensors and dedicated signal conditioning circuits. However, this leads to increased hardware complexity and cost. Moreover, due to the inconsistency in the front-end processing chains (such as amplification and filtering characteristics) of the flow and vibration signals, additional amplitude and phase errors are introduced, making subsequent signal comparison and differential processing difficult and potentially affecting the compensation accuracy.

[0005] Therefore, how to extract vortex flow signals with high precision and high reliability under strong vibration interference, especially in the case of co-frequency interference, while keeping the system hardware simple and cost controllable, remains a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0006] This invention addresses the shortcomings of existing technologies by providing a vibration-resistant vortex flow measurement system and method.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: a vibration-resistant vortex flow measurement system, comprising:

[0008] The flow signal conditioning channel and the vibration signal conditioning channel, which are structurally identical and arranged in parallel, are used to receive and process signals from independent flow probes and vibration probes, respectively.

[0009] The dynamic impedance adjustment module, integrated into the flow signal conditioning channel and / or vibration signal conditioning channel, is used to dynamically adjust an adjustable resistor R based on the real-time acquired vortex shear signal frequency f via the MCU. a The resistance value is adjusted to change the amplification factor k of the channel, thereby achieving adaptive matching of the signal strength of the two channels and dynamic suppression of the vibration signal.

[0010] The signal processing and decision module is used to make a collaborative decision based on the two signals processed by the dynamic impedance adjustment module, through frequency domain analysis and correlation calculation, to distinguish and extract the effective vortex flow frequency.

[0011] Furthermore, the vibration probe and the flow probe constitute a spatially separated dual sensing unit, and the vibration probe is attached to the outer wall of the pipe to pick up the pipe shell vibration caused by external equipment or fluid that overlaps with the flow signal frequency band in situ, so as to provide an independent vibration reference signal for the collaborative decision.

[0012] Furthermore, the dynamic impedance adjustment module determines the amplification factor k in real time through a dynamic amplification factor calculation model embedded in the MCU. This model correlates the real-time acquired vortex shedding signal frequency f with the circuit impedance characteristics and is based on the adjustable resistor R. a The real-time resistance value is calculated.

[0013] The dynamic amplification factor calculation model is defined by the following formula:

[0014]

[0015] In the formula, For flow through the adjustable resistor The equivalent voltage characteristic value corresponding to the original input current signal.

[0016] This refers to the adjustable resistor in the dynamic impedance adjustment module whose resistance value is dynamically set by the MCU.

[0017] This is the reference voltage shared by the flow signal conditioning channel and the vibration signal conditioning channel.

[0018] Z f This is the equivalent complex impedance of the signal conditioning channel feedback network corresponding to the real-time frequency f.

[0019] Z i The equivalent complex impedance is the equivalent complex impedance of the signal conditioning channel input circuit corresponding to the real-time frequency f.

[0020] Furthermore, in the dynamic amplification factor calculation model, the equivalent complex impedance Z of the feedback network... f Equivalent complex impedance Z of the input network i The following calculations are performed using specific circuit parameter models related to the vortex shedding signal frequency f:

[0021]

[0022] .

[0023] Furthermore, the signal processing and decision module is configured to execute an initial state decision procedure to extract valid vortex shedding signal frequencies under conditions of system startup, sudden flow changes, or no stable flow. This procedure includes:

[0024] Synchronously acquired flow channel signal sequence With vibration channel signal sequence Fast Fourier transforms were performed on the flow rate signal spectrum and vibration signal spectrum, respectively.

[0025] Extract the dominant frequency component from the spectrum of the flow signal, denoted as the flow dominant frequency f. f0 and its normalized amplitude .

[0026] Extract the dominant frequency component from the vibration signal spectrum, denoted as the dominant vibration frequency f. v0 and its normalized amplitude .

[0027] Based on a preset vibration intensity threshold T vib and the reliability threshold T of the flow signal fvib And combined with the dominant frequency f f0 with f v0 Based on the relationship, the initial calculation frequency f of the system is determined through the following judgment logic:

[0028] like If the pipeline vibration interference is negligible, then f is adopted. f0 As the calculated frequency f.

[0029] like ,and Then further judgment: if Then determine f f0 If the flow frequency is valid, it is adopted as f. Otherwise, f is determined. f0 Invalid. The preset lower limit frequency of the flow range will be adopted as f.

[0030] like ,and If the flow signal and vibration interference overlap in the frequency domain, then it is determined that the flow signal and vibration interference overlap. In this case, if still adopt f f0 If the signal is deemed unreliable, the lower limit frequency of the flow range is adopted as f.

[0031] Furthermore, the signal processing and decision module is configured to perform the following steady-state decision when the flow is stable:

[0032] Based on the initial calculated frequency f and the system sampling parameters, a frequency sequence f(n) is generated for analysis.

[0033] Based on the frequency sequence f(n), the dynamic amplification factor calculation model is invoked to generate the corresponding amplification factor sequence k(n).

[0034] Using the amplification factor sequence k(n) and a preset channel compensation factor sequence k exp (n), calculate the flow channel signal sequence according to the following formula. With vibration channel signal sequence Correlation sequence R f,v (i):

[0035]

[0036] For R f,v (i) Perform frequency domain transformation to obtain the energy spectrum sequence S f,v (m), and find its maximum energy value. .

[0037] like If the frequency is positive, then it is determined to be a valid flow frequency. Otherwise, it is determined to be a non-valid flow. Where T... f0 2 This indicates the preset zero-point threshold T. f0 The square of.

[0038] Furthermore, it also includes a display module, the screen of which is divided into an upper half and a lower half. The upper half displays the instrument status, instantaneous flow rate, cumulative flow rate, flow frequency, and sampling rate. The lower half displays multiple information screens in a cyclical manner, including a first information screen displaying a spectrum diagram and a second information screen displaying a time-domain waveform diagram.

[0039] A vibration-resistant vortex flow measurement method includes the following steps:

[0040] S1. Simultaneously acquire the original vortex street signal and the original pipeline vibration signal through the flow signal conditioning channel and vibration signal conditioning channel with consistent hardware circuit structure.

[0041] S2. Based on the signal frequency information obtained through real-time processing, dynamically calculate and adjust the amplification coefficients of the flow signal conditioning channel and / or vibration signal conditioning channel to match the signal strength of the two channels and suppress vibration interference.

[0042] S3. Based on the two dynamically adjusted signals, frequency domain analysis and correlation calculation are used for collaborative processing and decision-making to distinguish and extract the effective vortex flow frequency.

[0043] S4. Calculate and output the final flow rate value based on the effective vortex flow frequency.

[0044] Furthermore, S2 specifically includes:

[0045] S21. Using the current dominant signal frequency f as input, and based on a preset dynamic amplification factor calculation model, calculate the required dynamic amplification factor k. The model includes the frequency f and the adjustable resistor. Resistance value and circuit impedance Z i (f), Z f (f) Related.

[0046] S22. Adjust the adjustable resistor in the signal conditioning channel via the microcontroller. The resistance value is adjusted to achieve dynamic control of the amplification factor k.

[0047] S3 specifically includes:

[0048] S31: Determine the system's operating condition. If it is in an initial unstable state, execute the initial fast decision sub-process. If it is in a stable flow state, execute the steady-state enhancement decision sub-process.

[0049] S32: Output the final effective flow frequency based on the executed subprocess.

[0050] Furthermore, the initial fast decision sub-process is as follows:

[0051] The initial spectra of the two signals are compared, based on the dominant vibration frequency f. v0 With the dominant frequency f f0 The relationship between f and the comparison between its normalized amplitude and the preset threshold, from f v0 f f0 Alternatively, select the calculation frequency from a preset lower limit frequency.

[0052] The steady-state enhancement decision sub-process is as follows:

[0053] The dynamic amplification coefficient sequence k(n) is calculated based on the current frequency range, and the gain of the two signals is normalized.

[0054] The normalized signal is compared with a compensation coefficient sequence k.exp (n) Combined, calculate its weighted cyclic cross-correlation sequence R f,v (i) for the cross-correlation sequence R f,v (i) The energy spectrum is obtained by performing frequency domain transformation, and the effective flow frequency is confirmed by judging whether the maximum component of the energy spectrum exceeds the threshold.

[0055] Compared with the prior art, the present invention has the following advantages.

[0056] This invention utilizes a dual-channel parallel conditioning system with identical hardware drive circuitry, ensuring that the flow and vibration signals maintain the same amplitude and phase characteristics from the front end, thus resolving the compensation accuracy bottleneck caused by heterogeneous channels. Furthermore, it introduces a frequency-compliant dynamic impedance adjustment module. By calculating and adjusting the dynamic amplification factor and adjustable resistor based on the signal frequency in real time, the system can dynamically reshape the amplitude-frequency characteristics of the signal conditioning channel. This not only adaptively controls the signal amplitude within the optimal quantization range but also provides targeted real-time suppression of vibration components with frequencies different from the flow rate, achieving "pre-separation" of interference at the analog front end and reducing the burden on digital processing. Attached Figure Description

[0057] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. The scope of protection of the present invention is not limited to the following description.

[0058] Figure 1 This is a schematic diagram of the dual-probe vortex flowmeter device in an embodiment.

[0059] Figure 2 This is a flowchart illustrating the operation of the dual-probe vortex flowmeter in this embodiment.

[0060] Figure 3 This is the first screen display of the dual-probe vortex flowmeter in the embodiment.

[0061] Figure 4 This is the second screen display of the dual-probe vortex flowmeter in the embodiment. Detailed Implementation

[0062] The technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. Based on the embodiments of this disclosure, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this disclosure.

[0063] The terminology used in the embodiments of this disclosure is for the purpose of describing particular embodiments only and is not intended to be limiting of this disclosure. The singular forms “a,” “the,” and “the” as used in the embodiments of this disclosure and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0064] Depending on the context, words such as “if” or “suppose” used here can be interpreted as “when”, “in response to determination”, or “in response to detection”.

[0065] For ease of understanding, the embodiments of this disclosure will be described in detail first.

[0066] I. For example Figure 1 As shown, the hardware structure of the vibration-resistant vortex flow measurement system includes: a flow signal input module, a vibration signal input module, an MCU calculation circuit, a temperature detection circuit, a pressure detection circuit, a display circuit, and a pulse output circuit. The vortex probe for flow signal detection is connected to the flow signal input module, and the vortex probe for vibration signal detection is connected to the vibration signal input module. Both signals are processed and then input to the ADC of the MCU calculation module. The MCU calculates and outputs the results. The temperature and pressure detection circuits are acquired by the ADC of the MCU calculation module. The MCU calculation module calculates the input signals from the vortex sensor, temperature detection circuit, and pressure sensor, producing the frequency and flow rate. The frequency is output from the frequency output module, and the flow rate is output from the display module. The display module shows the frequency data and a spectrum analysis graph.

[0067] The flow signal input module and vibration signal input module employ identical hardware circuit structures and electronic component selections in their drive circuits, achieving a modular design. Simultaneously, the system, through a dynamic impedance adjustment module and a dual-signal collaborative decision module, works together within the MCU calculation module to suppress vibration interference and extract the flow frequency.

[0068] 2. The flow probe employs a vortex flow sensor. The vibration probe uses a high-sensitivity piezoelectric stress sensor, which is installed on the outer wall of the pipe being measured to pick up in situ pipe shell vibrations induced by external equipment or fluid that overlap with the flow signal frequency band. These two probes constitute a spatially separated dual-sensing unit, providing independent vibration reference signals for subsequent collaborative decision-making.

[0069] The flow and vibration signals are fed into signal conditioning channels with identical topologies and key component types. Each channel includes a charge amplifier (for piezoelectric signals), a programmable gain amplifier, a filter circuit, and an ADC driver circuit. The core of the gain adjustment is a digital signal (such as SPI / I) input from the MCU. 2C) Adjustable resistor R that controls the resistance value a It is placed in the amplifier's feedback network. This standardized design reduces cost and maintenance complexity.

[0070] III. MCU Calculation Module Processing Flow:

[0071] 1. The MCU uses a quasi-synchronous sampling method to alternately sample the two ADCs to obtain a discrete flow signal sequence. and pipeline vibration signal sequence X v (n), where n=0,1,2,……N-1 is the sampling point index, and N is the number of sampling points.

[0072] 2. The MCU calculation module is implemented through a dynamic amplification factor calculation model embedded in the MCU. This dynamically adjusts the channel gain k, i.e., the dynamic amplification factor k, based on the real-time signal frequency, ensuring the signal peak is within the optimal input range of the ADC and initially suppressing vibration.

[0073] The dynamic amplification factor k is calculated according to the following formula 1:

[0074]

[0075] In the formula, k is the dynamic amplification coefficient of the original input signal intensity characteristic value and the ADC acquisition signal of the MCU, and V in R represents the original input signal intensity characteristic value. a The resistance value of the adjustable resistor is dynamically set by the MCU. a Resistance, V ref It serves as a voltage reference.

[0076] Formula 2:

[0077]

[0078] In the formula, For the feedback circuit impedance, To calculate the frequency, the constant in the formula is... , The parameters are not arbitrarily selected; they are a set of collaborative optimization parameters determined through multiple iterative experiments to ensure that the amplitude and phase frequencies of the flow signal and vibration signal reach the preset optimal matching state after being processed by a standardized hardware channel within the operating frequency range of the vortex flowmeter.

[0079] Formula 3:

[0080]

[0081] In the formula, For the input circuit impedance, To calculate the frequency, in the formula, 51, It is a constant.

[0082] The MCU adjusts the adjustable resistor R via a digital interface based on the calculated value of k. a The resistance value is adjusted to change the gain of the signal conditioning channel in real time, thus achieving adaptive matching.

[0083] 3. Implementation of the signal processing and decision module:

[0084] Set the zero-point threshold T via program. f0 Flow threshold T fvib Vibration threshold T vib T is set according to different media and operating conditions. f0 T fvib T vib .

[0085] When the instrument is powered on for the first time, or when the flow rate fluctuates, or when there is no flow, calculate the frequency in formula 3 according to the following method. :

[0086] vortex flow signal sequence Perform a Fast Fourier Transform (FFT) to obtain the amplitude sequence of the flow signal. For vortex shedding vibration signal sequences Perform a Fast Fourier Transform (FFT) to obtain the amplitude sequence of the flow signal. For the amplitude sequence respectively and Sort and find the maximum amplitude of the traffic channel. and the maximum amplitude of the vibration channel Calculate separately corresponding frequency ,and corresponding frequency .

[0087] if If so, it is determined to be without vibration. To calculate frequency .

[0088] if ,and ,and ,but Determined as vibration frequency, Determined as flow frequency, in To calculate frequency .

[0089] if ,and ,and ,but Determined as vibration frequency, If a frequency is deemed invalid, the frequency corresponding to the lower limit of the flow rate will be used for calculation. .

[0090] if ,and, ,and ,but Determined as vibration frequency, Determined as flow frequency, in To calculate frequency .

[0091] if ,and ,and ,but Determined as vibration frequency, If a frequency is deemed invalid, the frequency corresponding to the lower limit of the flow rate will be used for calculation. .

[0092] When the instrument flow rate is stable, calculate it using the following method:

[0093] Calculate the sequence according to the following formula and sequence Corresponding frequency sequence and sequence .

[0094] Formula 4:

[0095]

[0096] in , The number of sampling points. The sampling rate.

[0097] The above calculation frequency Substituting the frequencies into formulas 3, 2, and 1, calculate the amplification factor sequence corresponding to different frequencies. .

[0098] For flow signal sequence and pipeline vibration signal sequence Calculate using the following formula:

[0099] Formula 5:

[0100]

[0101] in This is a coefficient sequence for the flow rates at the same frequency in both the flow channel and the vibration channel.

[0102] For sequence Perform a Fast Fourier Transform (FFT) to obtain the sequence. The sequence is then sorted from largest to smallest to obtain the result. , .in for The maximum value.

[0103] if ,but The corresponding frequency is determined to be the effective flow frequency.

[0104] if If so, it is determined that there is no traffic.

[0105] Example 4, such as Figure 3-4 To facilitate on-site debugging, in addition to displaying the instrument status, instantaneous flow rate, and cumulative flow rate, the instrument homepage further displays the current flow frequency, sampling rate, spectrum graph, time domain waveform graph, instrument sampling status, input frequency, dynamic amplification factor, signal strength, flow frequency, and flow amplitude.

[0106] To achieve the above objectives on a 128x64 display, the screen is divided into two display areas: an upper half of 128x46 pixels and a lower half of 128x18 pixels. The upper half of the screen displays the instrument status, instantaneous flow rate, cumulative flow rate, flow frequency, and sampling rate in a fixed manner. The lower half of the screen is a second screen that displays these information in a loop. The first screen displays the spectrum, the frequency and amplitude corresponding to the largest amplitude, and the frequency and amplitude corresponding to the second largest amplitude. The second screen displays the time-domain waveform, the instrument sampling status, the input frequency, the dynamic amplification factor, and the signal strength.

[0107] Example 1: The specific implementation of this solution is illustrated below using an ultra-wide range DN150 pipe diameter dual-probe vortex flow meter:

[0108] The ultra-wide range DN150 vortex flow meter has a frequency range of 7Hz to 500Hz and a sampling point of 512.

[0109] Initial sampling rate of the vortex street in a DN150 pipe. The value is 2000, and then the dynamic calculation is based on the frequency corresponding to the previous flow. .

[0110] Set the MCU's ADC sampling rate The value is 4000. The MCU alternately acquires vortex flow signals and pipeline vibration signals. This sampling method can achieve relative synchronization of the two signal acquisitions while ensuring high sampling efficiency, providing a reliable data foundation for subsequent accurate analysis of flow signals and assessment of the impact of pipeline vibration on flow measurement.

[0111] Taking an industrial site as an example, after the flow meter was installed, the operation of the equipment caused pipeline vibration. The frequency and amplitude of the pipeline vibration were measured and calculated, and the vibration frequency was 26.5Hz. The value is 6~8; when the flow frequency is 26~27Hz, The value is 30~65; when the flow rate is the lower limit of 7Hz, its corresponding value is... The value is 8~10. Set the instrument parameters: vibration threshold. Set to 4, traffic threshold Set to 20; zero-point threshold Set it to 5.

[0112] like Figure 2 As shown, the flow meter is powered on and running. Calculate the flow rate according to the following steps:

[0113] Frequency step 201: The instrument is powered on, and the initial sampling calculates the coefficients based on the frequency corresponding to the lower limit of the flow rate. ,Adjustment The register is at its minimum value. To reach the maximum multiple, begin sampling.

[0114] Step 202: Wait for sampling to complete.

[0115] Step 203: Perform Fast Fourier Transform (FFT) on the vortex flow signal and vibration signal, sort the calculation results, and obtain the maximum amplitude of the flow channel. and the corresponding frequency ,and .

[0116] Step 204: Based on the initial power-on of the instrument as mentioned in the main text of the invention, determine... Is it the frequency corresponding to valid traffic?

[0117] Step 205, if If the frequency is not the frequency corresponding to the effective flow rate, then the lower limit of the flow meter frequency is the calculated frequency. ;if This refers to the frequency corresponding to the effective flow rate; the flow channel frequency is the calculation frequency. .

[0118] Step 206, based on the current calculation frequency Adjust the Ra register and begin sampling.

[0119] Step 207: Calculate the amplification factor sequence according to Formulas 3, 2, and 1 as described in the invention. .

[0120] Step 208: Wait for sampling to complete.

[0121] Step 209, calculate according to formula 5 The sequence is processed, and a Fast Fourier Transform (FFT) is performed. sequence.

[0122] Step 210, for Sort the sequence from largest to smallest ,in This is the maximum frequency.

[0123] Step 211, determine Is it greater than .

[0124] Step 212, if Greater than , The corresponding frequency is determined to be the effective flow frequency, and this frequency is used as the calculation frequency; otherwise, the lower limit of the flow meter frequency is used as the calculation frequency. Return to step 206 to continue execution.

[0125] Example 2: Further application of a wide-range vortex flowmeter with a range ratio of 1:40, combined with a DN50 pipe diameter:

[0126] The MCU used in this embodiment has a 16-bit ADC and DMA functionality.

[0127] A vortex flow meter with a DN50 pipe diameter and a range ratio of 1:40 has a flow range of approximately 10 m³ / h. 3 / h~400m 3 / h corresponds to a frequency range of 30Hz~1200Hz.

[0128] After the instrument is powered on, it defaults to calculating based on a lower frequency limit of 30Hz. , By setting the register, , Enable the MCU's ADC and DMA functions to sample the flow and vibration signals, and then perform calculations. After the calculations are complete, assuming the current flow corresponds to a frequency of 500Hz, then... , Set via register. , Continue using this set of parameters to sample and calculate the flow rate.

[0129] Minimum flow rate for DN50 pipe diameter: 10m³ 3 / h, with a theoretical error of 0.325%, the vortex shear input signal is a quasi-sine wave signal. The program further improves the measurement accuracy through a sine wave fitting algorithm. The minimum flow rate actually measured by the instrument in the field is 10m³ / h. 3The repeatability per hour is less than 0.15%, which meets the requirement of 0.3% repeatability for small flow rates in Class 1.0 tables.

[0130] DN50 pipe diameter maximum flow rate 400m³ 3 The theoretical error is 0.29%, and the actual measurement error is less than 0.1% after the program calculates using a sine wave fitting algorithm, which meets the requirements of 0.3% repeatability and 1% measurement error for a Class 1.0 table.

[0131] This invention monitors pipeline vibration in real time using a vibration probe and employs a dynamic impedance method to more effectively extract the valid flow signal. This results in a more accurate acquisition of the flow frequency compared to traditional vortex flow meters, significantly improving flow measurement accuracy and reducing measurement errors. Even under complex operating conditions with multiple interferences, the measurement error of this invention is less than ±1%.

[0132] This invention effectively enhances the flow signal and suppresses vibration and random interference through a dynamic impedance adjustment method. Furthermore, it employs an energy distribution-based judgment method, enabling the flow meter to maintain stable and accurate measurement even in complex industrial environments and with strong pipeline vibrations, thus ensuring the reliability of flow measurement. For example, in industrial scenarios where large machinery operates and causes strong vibrations, traditional flow meters exhibit drastic data fluctuations, while the flow meter of this invention can output stable and accurate flow data.

[0133] The vibration channel and flow measurement channel of this invention share the same hardware drive circuit, employing the same circuit architecture and electronic component selection principles to achieve modular design and production. This not only reduces production costs but also improves production efficiency, while facilitating later maintenance and upgrades, reducing maintenance time and costs, and increasing the service life and stability of the equipment.

[0134] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "preferred embodiment," "detailed description," or "preferred embodiment," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0135] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features. Therefore, these modifications or substitutions do not cause the essence of the corresponding technical solutions to depart from the scope defined by the claims of the present invention.

Claims

1. A vibration-resistant vortex flow measurement system, characterized in that, include: The flow signal conditioning channel and the vibration signal conditioning channel, which are structurally identical and arranged in parallel, are used to receive and process signals from independent flow probes and vibration probes, respectively. The dynamic impedance adjustment module, integrated into the flow signal conditioning channel and / or vibration signal conditioning channel, is used to dynamically adjust an adjustable resistor R based on the real-time acquired vortex shear signal frequency f via the MCU. a The resistance value is adjusted to change the amplification factor k of the channel, thereby achieving adaptive matching of the signal strength of the two channels and dynamic suppression of the vibration signal. The signal processing and decision module is used to make a collaborative decision based on the two signals processed by the dynamic impedance adjustment module, through frequency domain analysis and correlation calculation, to distinguish and extract the effective vortex flow frequency.

2. The measurement system according to claim 1, characterized in that, The vibration probe and the flow probe constitute a spatially separated dual sensing unit. The vibration probe is attached to the outer wall of the pipe and is used to pick up the pipe shell vibration caused by external equipment or fluid that overlaps with the flow signal frequency band in situ, so as to provide an independent vibration reference signal for the collaborative decision.

3. The measurement system according to claim 1, characterized in that, The dynamic impedance adjustment module determines the amplification factor k in real time through a dynamic amplification factor calculation model embedded in the MCU. This model correlates the real-time acquired vortex shedding signal frequency f with the circuit impedance characteristics and is based on the adjustable resistor R. a The real-time resistance value is calculated; The dynamic amplification factor calculation model is defined by the following formula: ； In the formula, For flow through the adjustable resistor The equivalent voltage characteristic value corresponding to the original input current signal; This refers to the adjustable resistor in the dynamic impedance adjustment module, whose resistance value is dynamically set by the MCU. The reference voltage shared by the flow signal conditioning channel and the vibration signal conditioning channel; Z f The equivalent complex impedance of the signal conditioning channel feedback network corresponding to the real-time frequency f; Z i The equivalent complex impedance is the equivalent complex impedance of the signal conditioning channel input circuit corresponding to the real-time frequency f.

4. The measurement system according to claim 3, characterized in that, In the dynamic amplification factor calculation model, the equivalent complex impedance Z of the feedback network f Equivalent complex impedance Z of the input network i The following calculations are performed using specific circuit parameter models related to the vortex shedding signal frequency f: ； 。 5. The measurement system according to claim 3, characterized in that, The signal processing and decision module is configured to execute an initial state decision procedure to extract valid vortex shedding signal frequencies under conditions of system startup, sudden flow changes, or unstable flow; this procedure includes: Synchronously acquired flow channel signal sequence With vibration channel signal sequence Fast Fourier transforms were performed on the two signals to obtain the corresponding flow signal spectrum and vibration signal spectrum. Extract the dominant frequency component from the spectrum of the flow signal, denoted as the flow dominant frequency f. f0 and its normalized amplitude ; Extract the dominant frequency component from the vibration signal spectrum, denoted as the dominant vibration frequency f. v0 and its normalized amplitude ; Based on a preset vibration intensity threshold T vib and the reliability threshold T of the flow signal fvib And combined with the dominant frequency f f0 with f v0 Based on the relationship, the initial calculation frequency f of the system is determined through the following judgment logic: like If the pipeline vibration interference is negligible, then f is adopted. f0 As the calculation frequency f; like ,and Then further judgment: if Then determine f f0 If the flow frequency is valid, it is adopted as f; otherwise, f is determined. f0 Invalid; adopt the preset lower limit frequency of the flow range as f. like ,and If the flow signal and vibration interference overlap in the frequency domain, then it is determined that the flow signal and vibration interference overlap. In this case, if still adopt f f0 If f is used, then the signal is deemed unreliable, and the lower limit frequency of the flow range is adopted as f.

6. The measurement system according to claim 5, characterized in that, The signal processing and decision module is configured to perform the following steady-state decision when the traffic is stable: Based on the initial calculated frequency f and the system sampling parameters, a frequency sequence f(n) is generated for analysis. Based on the frequency sequence f(n), the dynamic amplification factor calculation model is invoked to generate the corresponding amplification factor sequence k(n); Using the amplification factor sequence k(n) and a preset channel compensation factor sequence k exp (n), calculate the flow channel signal sequence according to the following formula. With vibration channel signal sequence Correlation sequence R f,v (i): ； For R f,v (i) Perform frequency domain transformation to obtain the energy spectrum sequence S f,v (m), and find its maximum energy value. ; like If the frequency is positive, then the corresponding frequency is determined to be a valid flow frequency; otherwise, it is determined to be a non-valid flow frequency; where T f0 2 This represents the preset zero-point threshold T. f0 The square of.

7. The vortex flow measurement system according to claim 1, characterized in that, It also includes a display module, the screen of which is divided into an upper half and a lower half; the upper half displays the instrument status, instantaneous flow rate, cumulative flow rate, flow frequency and sampling rate; the lower half displays multiple information screens in a cyclic manner, including a first information screen displaying a spectrum diagram and a second information screen displaying a time-domain waveform diagram.

8. A method for measuring vortex flow rate resistant to vibration interference, characterized in that, Includes the following steps: S1. Simultaneously acquire the original vortex shedding signal and the original pipeline vibration signal through the flow signal conditioning channel and vibration signal conditioning channel with consistent hardware circuit structure; S2. Based on the signal frequency information obtained through real-time processing, dynamically calculate and adjust the amplification coefficients of the flow signal conditioning channel and / or vibration signal conditioning channel to match the signal strength of the two channels and suppress vibration interference. S3. Based on the two dynamically adjusted signals, frequency domain analysis and correlation calculation are used for collaborative processing and decision-making to distinguish and extract the effective vortex flow frequency. S4. Calculate and output the final flow rate value based on the effective vortex flow frequency.

9. The flow measurement method according to claim 8, characterized in that, S2 specifically includes: S21. Using the current dominant signal frequency f as input, and based on a preset dynamic amplification factor calculation model, calculate the required dynamic amplification factor k. The model includes the frequency f and the adjustable resistor. Resistance value and circuit impedance Z i (f), Z f (f) Related; S22. Adjust the adjustable resistor in the signal conditioning channel via the microcontroller. The resistance value is adjusted to achieve dynamic control of the amplification factor k; S3 specifically includes: S31: Determine the system operating condition. If it is in an initial unstable state, execute the initial fast decision sub-process; if it is in a stable flow state, execute the steady-state enhancement decision sub-process. S32: Output the final effective flow frequency based on the executed subprocess.

10. The flow measurement method according to claim 9, characterized in that, The initial fast decision sub-process is as follows: The initial spectra of the two signals are compared, based on the dominant vibration frequency f. v0 With the dominant frequency f f0 The relationship between f and the comparison between its normalized amplitude and the preset threshold, from f v0 f f0 Alternatively, select the calculation frequency from a preset lower limit frequency; The steady-state enhancement decision sub-process is as follows: Calculate the dynamic amplification coefficient sequence k(n) based on the current frequency range, and normalize the gain of the two signals; The normalized signal is compared with a compensation coefficient sequence k. exp (n) Combined, calculate its weighted cyclic cross-correlation sequence R f,v (i) for the cross-correlation sequence R f,v (i) The energy spectrum is obtained by performing frequency domain transformation, and the effective flow frequency is confirmed by judging whether the maximum component of the energy spectrum exceeds the threshold.

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