A method and device for measuring the wind speed in a pipeline based on ultrasonic interference

Abstract

The present invention discloses a method and device for measuring the wind speed in a pipeline based on ultrasonic interference. The method arranges a first ultrasonic transmitting unit, a second ultrasonic transmitting unit and an ultrasonic receiving unit, and uses the interference waveform data of the in-phase and anti-phase to calculate the phase difference between the upstream wave and the downstream wave, so as to accurately calculate the wind speed in the pipeline; the device adopts a simplified hardware design, only requires a set of receiving circuits and ADC measurement circuits, reduces the cost and improves the reliability of the system. At the same time, the device stably installs each unit on the inner wall of the air duct through a fixed structure, and the fixed structure adopts the form of a detection box, which can adapt to various complex environments. The method and device are applicable to industrial pipelines, laboratory ventilation systems and other fields, and have the advantages of high precision, low cost and strong environmental adaptability, and are widely applicable to air flow measurement and environmental monitoring.

Description

Technical Field

[0001] The present invention relates to the technical field of ultrasonic measurement, and in particular to a method and a device for measuring pipeline wind speed based on ultrasonic interference. Background Art

[0002] Duct wind speed monitoring plays an important role in ventilation control systems in industrial plants, laboratories and other places. Common wind speed measurement methods include pressure difference (Pitot tube) method, impeller method, hot wire method and ultrasonic time difference method. However, existing wind speed measurement methods have limitations to varying degrees, such as:

[0003] Differential pressure (Pitot tube) method: Due to the square relationship between wind speed and pressure, the accuracy is poor at low wind speeds, and it can only measure the flow rate of clean, non-corrosive gases.

[0004] Impeller method: The response time is long, there are mechanical wear problems, and the life is short.

[0005] Hot wire method: can only measure single-point wind speed and has a long response time.

[0006] Ultrasonic time difference method: A pair of ultrasonic transducers are used to send and receive ultrasonic waves alternately (or simultaneously), and the flow rate of the fluid is indirectly measured by observing the time difference between the downstream and upstream propagation of ultrasonic waves in the medium. It has low mechanical wear and convenient measurement. Although it has strong adaptability, the ultrasonic time difference method of wind speed measurement requires the use of sensor units that can both send and receive ultrasonic waves, and the number must be at least 2 sets. Both sets of sensor units are equipped with integrated sending and receiving circuits, which are costly. In addition, the sending and receiving circuits affect each other and there are interference errors, which affect the measurement accuracy. The delay matching of the two sets of sending and receiving circuits further increases the interference error, which further affects the measurement accuracy. At the same time, there are problems such as high cost and signal delay matching.

[0007] Therefore, how to improve the accuracy and stability of wind speed measurement and reduce the cost has become a key issue that needs to be urgently solved in wind speed measurement technology. Summary of the invention

[0008] Technical purpose: In view of the shortcomings of existing pipeline wind speed measurement methods and measurement devices, the present invention discloses a method and device for measuring pipeline wind speed based on ultrasonic interferometry, which can achieve higher-precision and lower-cost pipeline wind speed measurement.

[0009] Technical solution: To achieve the above technical objectives, the present invention adopts the following technical solution:

[0010] A method for measuring pipeline wind speed based on ultrasonic interferometry specifically comprises the following steps:

[0011] Arrange the first ultrasonic transmitting unit S in the air duct 1 , the second ultrasonic transmitting unit S2 and the ultrasonic receiving unit R, the three are fixed on the inner wall of the air duct body;

[0012] The first ultrasonic transmitting unit S 1 and the second ultrasonic transmitting unit S 2 simultaneously send ultrasonic pulse signals with the same phase to the ultrasonic receiving unit R;

[0013] The ADC measurement unit collects the ultrasonic pulse signals with the same phase received by the ultrasonic receiving unit R, and records the multi-cycle in-phase interference waveform data Y a ;

[0014] The first ultrasonic transmitting unit S 1 and the second ultrasonic transmitting unit S 2 simultaneously send ultrasonic pulse signals with opposite phases to the ultrasonic receiving unit R;

[0015] The ADC measurement unit collects the ultrasonic pulse signals with opposite phases received by the ultrasonic receiving unit R, and records the multi-cycle anti-phase interference waveform data Y b ;

[0016] The data processing unit calculates the upstream interference waveform data Y a and the downstream interference waveform data Y b based on the in-phase interference waveform data Y u and the anti-phase interference waveform data Y d , where

[0017] Based on the zero-crossing moments of the upstream interference waveform data Y u and the downstream interference waveform data Y d , fit the curve and calculate the propagation time T u0 of the upstream wave and the T d0 of the downstream wave;

[0018] Calculate the wind speed and air volume of the air flow in the air duct through the time difference of the propagation time and combine with the geometric parameters of the air duct, and output the calculation results.

[0019] Preferably, the propagation time T u0 of the upstream wave and the propagation time T d0 of the downstream wave are calculated by the following formula:

[0020]

[0021] where V represents the wind speed of the air flow in the air duct, L represents the propagation path length of the ultrasonic wave, α represents the angle between the ultrasonic wave propagation direction and the radial direction of the air duct, and C represents the propagation speed of the ultrasonic wave in still air.

[0022] Preferably, the air velocity in the air duct is calculated by the following formula:

[0023]

[0024] wherein, V represents the air velocity in the air duct, L represents the propagation path length of the ultrasonic wave, α represents the angle between the ultrasonic wave propagation direction and the radial direction of the air duct, ΔT = T d0 - T u0 , represents the time difference between the upward wave and the downward wave, T u0 represents the propagation time of the upward wave, T d0 represents the propagation time of the downward wave.

[0025] Preferably, the air volume in the air duct is calculated by the following formula:

[0026]

[0027] wherein, Q represents the air volume in the air duct, D represents the diameter of the air duct, and V represents the air velocity in the air duct.

[0028] Preferably, the calculation formula for the in-phase interference waveform data Y a is: The calculation formula for the anti-phase interference waveform data Y b is: wherein, A u and A d respectively represent the amplitude of the upward wave and the amplitude of the downward wave, ω represents the angular frequency of the ultrasonic pulse signal, t represents the time variable during the propagation of the ultrasonic pulse signal, and respectively represent the initial phase angle of the upward wave and the initial phase angle of the downward wave.

[0029] An apparatus for measuring the air velocity in a pipeline based on ultrasonic interference, which is used to implement the method for measuring the air velocity in a pipeline based on ultrasonic interference described above, includes a first ultrasonic transmitting unit S 1 , a second ultrasonic transmitting unit S 2 , an ultrasonic receiving unit R, an ADC measurement unit, and a data processing unit. The first ultrasonic transmitting unit S 1 and the second ultrasonic transmitting unit S 2 are installed on the inner wall of the air duct by a fixing structure and arranged at intervals in the front and back along the air flow direction; the ultrasonic receiving unit R is installed on the inner wall of the air duct opposite to the first ultrasonic transmitting unit S 1 and the second ultrasonic transmitting unit S 2 and is located on the midline between the two;

[0030] An ADC measurement unit is used to sample the ultrasonic pulse signal received by the ultrasonic receiving unit R, and the sampling frequency is at least 5 times the ultrasonic frequency;

[0031] A data processing unit is used to store and process the ultrasonic pulse signals of multiple cycles in the same phase and opposite phase, and calculate and output the wind speed value.

[0032] Preferably, the plane where the first ultrasonic transmitting unit S 1 , the second ultrasonic transmitting unit S 2 and the ultrasonic receiving unit R is an isosceles triangle, where the ultrasonic receiving unit R is at the apex position, and the first ultrasonic transmitting unit S 1 and the second ultrasonic transmitting unit S 2 are at the base angle positions. The included angle range between the first ultrasonic transmitting unit S 1 and the second ultrasonic transmitting unit S 2 and the radial direction of the air duct is 15° to 60°.

[0033] Preferably, the first ultrasonic transmitting unit S 1 and the second ultrasonic transmitting unit S 2 can both emit ultrasonic pulse signals with a set frequency, and the signal frequency range is 40 kHz to 1 MHz. Moreover, the transmission signal phases of the first ultrasonic transmitting unit S 1 and the second ultrasonic transmitting unit S 2 are adjustable to achieve the transmission of signals in the same phase or opposite phase.

[0034] Preferably, the fixing structure is in the form of a detection box. An embedding structure is arranged inside the detection box for embedding the ultrasonic transmitting unit and the ultrasonic receiving unit into the inner wall of the air duct. A sealing gasket is arranged at the part where the detection box contacts the outer wall of the pipeline to prevent gas leakage.

[0035] Advantageous effects: The method and device for measuring the wind speed of a pipeline based on ultrasonic interference provided by the present invention have the following

[0036] Advantageous effects:

[0037] 1. The present invention uses the ultrasonic interference method for wind speed measurement, calculates the wind speed through the interference waveform data in the same phase and opposite phase, avoids the errors caused by signal delay matching in the traditional ultrasonic time difference method, and can measure the wind speed in the pipeline more accurately by calculating the phase difference between the upstream and downstream waves in real time. Especially in an environment with high wind speed, low temperature or high humidity, it can still maintain high-precision wind speed measurement.

[0038] 2. The measurement device of the present invention uses a single receiving circuit and ADC measurement circuit, without the need for complex multiple sensors and circuit connections in the traditional wind speed measurement system. By 1and the second ultrasonic transmitting unit S 2 They are connected to respective independent transmitting circuits and use the same receiving unit for signal reception, which not only reduces the hardware cost, but also makes the system design more compact and reduces the system maintenance difficulty.

[0039] 3. In the present invention, the first ultrasonic transmitting unit S 1 , the second ultrasonic transmitting unit S 2 and the ultrasonic receiving unit R are firmly installed on the inner wall of the air duct through a fixing structure. The fixing structure adopts the form of a detection box, and the ultrasonic transmitting unit and the ultrasonic receiving unit are embedded in the inner wall of the air duct, which can adapt to different pipe sizes and airflow environments. Even in harsh industrial environments, mines and other complex places, the device of the present invention can still maintain stable measurement performance, provide accurate wind speed data, and reduce the maintenance requirements during the long-term operation of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art.

[0041] Figure 1 is a schematic structural diagram of the present invention;

[0042] Figure 2 is a waveform schematic diagram of an ultrasonic pulse signal;

[0043] Figure 3 is a schematic circuit structure diagram among the various units of the device of the present invention;

[0044] Figure 4 is a schematic diagram of the fixing structure of the ultrasonic transmitting unit and the ultrasonic receiving unit of the present invention;

[0045] Figure 5 is a schematic diagram of the embedded installation structure of the ultrasonic transmitting unit of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0046] The following will more clearly and completely illustrate the present invention by way of a preferred embodiment in conjunction with the drawings, but the present invention is not limited to the scope of the described embodiments.

[0047] The present invention provides a method for measuring the wind speed in a pipeline based on ultrasonic interference, which specifically includes the following steps:

[0048] Arrange the first ultrasonic transmitting unit S 1 , the second ultrasonic transmitting unit S 2 and the ultrasonic receiving unit R on the inner wall of the air duct; among them, the two ultrasonic transmitting units are installed on the inner wall of the air duct and arranged at intervals in the front and back along the air flow direction to ensure the uniformity of the ultrasonic signal propagation. The ultrasonic receiving unit R is arranged at the first ultrasonic transmitting unit S1 and the second ultrasonic transmitting unit S 2 On the inner walls of the opposing air ducts and on their midlines to ensure receiving ultrasonic signals emitted from the two transmitting units;

[0049] The first ultrasonic transmitting unit S 1 and the second ultrasonic transmitting unit S 2 Simultaneously send ultrasonic pulse signals with the same phase to the ultrasonic receiving unit R;

[0050] The ADC measurement unit collects the ultrasonic pulse signals with the same phase received by the ultrasonic receiving unit R and records the multi - cycle in - phase interference waveform data Y a ;

[0051] The first ultrasonic transmitting unit S 1 and the second ultrasonic transmitting unit S 2 Simultaneously send ultrasonic pulse signals with opposite phases to the ultrasonic receiving unit R. Here, the phase of the transmitted signal of the second ultrasonic transmitting unit S 2 is adjusted to 180° to form an anti - phase signal;

[0052] The ADC measurement unit collects the ultrasonic pulse signals with opposite phases received by the ultrasonic receiving unit R and records the multi - cycle anti - phase interference waveform data Y b ;

[0053] The specific processing process of the ADC measurement unit for the ultrasonic pulse signals is as follows: The ultrasonic receiving unit R receives the ultrasonic pulse signals emitted from the first and second ultrasonic transmitting units S 1 and S 2 ; The ADC measurement unit samples the analog signal at a certain sampling frequency. Usually, the sampling frequency needs to meet the requirements of the Nyquist theorem, that is, the sampling frequency is at least twice the signal bandwidth to prevent aliasing. Each time a sample is taken, the ADC converts the amplitude value of the analog signal into a corresponding digital value, and this digital value represents the amplitude of the signal at a specific moment.

[0054] After sampling, the amplitude of the signal will be quantized into a finite number of digital values. The ADC uses a certain resolution (such as 8 - bit, 12 - bit, 16 - bit or higher resolution) to quantize the amplitude of the signal, which means that the amplitude of the input signal will be divided into several levels and mapped to an integer range. The corresponding digital value is the discrete representation of the analog signal at a specific time point, and it can be transmitted to the data processing unit for subsequent analysis.

[0055] The converted digital signal will be transmitted to the data processing unit, and the digital signal is further processed in the data processing unit, including filtering, gain adjustment, phase difference calculation, etc.

[0056] The data processing unit calculates the upstream interference waveform data Y a and the anti-phase interference waveform data Y b based on the in-phase interference waveform data Y u and the downstream interference waveform data Y d , where in this embodiment, after the first ultrasonic transmitting unit S 1 and the second ultrasonic transmitting unit S 2 start to transmit the ultrasonic pulse signal and after a time T1, the data processing unit extracts the received periodic ADC data starting from the time point T1;

[0057] When the air flow in the air duct flows forward or backward along the length direction of the air duct, the propagation states of the ultrasonic pulse signals transmitted from the first ultrasonic transmitting unit S 1 and the second ultrasonic transmitting unit S 2 received by the receiving unit R are as follows: when one is with the wind, the other is against the wind. The wave propagating with the wind is called the downstream wave, and the wave propagating against the wind is called the upstream wave.

[0058] As Figure 2 shown in the measured graph of the interference waveform of the ultrasonic signal, by performing addition and subtraction operations on the signals, the interference components of the upstream wave and the downstream wave are separated from the received signal data. The red curve in the figure represents the in-phase interference waveform data Y a , the dark green curve represents the anti-phase interference waveform data Y b , and it can be seen from the figure that the curves of the two are out of phase; the black curve in the figure represents the downstream interference waveform data Y d , indicating that the downstream wave interference data is separated by performing subtraction operations on the signal data of the in-phase interference waveform data Y a and the anti-phase interference waveform data Y b . It can be seen from the figure that twice the downstream wave interference signal data is extracted. The light green curve represents the upstream interference waveform data Y u , indicating that the upstream wave interference data is separated by performing addition operations on the signal data of the in-phase interference waveform data Y a and the anti-phase interference waveform data Y b . It can be seen from the figure that twice the upstream wave interference signal data is extracted.

[0059] Based on the zero-crossing moments of the upstream interference waveform data Y u and the downstream interference waveform data Y d , fit the curve and calculate the propagation time T u0 of the upstream wave and the T d0 of the downstream wave;

[0060] In one embodiment, the formula expression of the in-phase interference waveform data function is:

[0061]

[0062] The formula expression of the inverse interference waveform data function is as follows:

[0063]

[0064] Wherein, A u and A d respectively represent the amplitude of the upstream wave and the amplitude of the downstream wave, ω represents the angular frequency of the ultrasonic pulse signal, t represents the time variable of the ultrasonic pulse signal during propagation, and this variable is used to describe the time-domain change of the signal. and respectively represent the initial phase angle of the upstream wave and the initial phase angle of the downstream wave;

[0065] The function formula of the upstream interference waveform data Y u is expressed as:

[0066]

[0067] The function formula of the downstream interference waveform data Y d is expressed as:

[0068]

[0069] That is, we can obtain

[0070] Substitute the N data obtained by the ADC measurement unit into the upstream interference waveform data Y u , and the coordinates of N points are respectively: Fit a cosine curve according to the known N points, and then the Nth zero-crossing time T un can be obtained.

[0071] Similarly, substitute the N data obtained by the ADC measurement unit into the downstream interference waveform data Y d , and the coordinates of N points are obtained: Fit a cosine curve according to the known N points, and then the Nth zero-crossing time T dn can be obtained.

[0072] Calculate the wind speed and air volume of the air flow in the air duct through the time difference of the propagation time and combine with the geometric parameters of the air duct, and output the calculation results.

[0073] The propagation time T u0 of the upstream wave and the propagation time T d0 of the downstream wave are calculated by the following formula:

[0074]

[0075] Wherein, V represents the wind speed of the air flow in the air duct, L represents the propagation path length of the ultrasonic wave, α represents the angle between the ultrasonic wave propagation direction and the radial direction of the air duct, C represents the propagation speed of the ultrasonic wave in still air, and the propagation time T of the upward wave u0 and the propagation time T of the downward wave d0 are the 0th zero-crossing moments of the two.

[0076] According to the calculated propagation time T of the upward wave u0 and the propagation time T of the downward wave d0 and combining with its calculation formula, the wind speed of the air flow in the air duct can be calculated by the following formula:

[0077]

[0078] Wherein, V represents the wind speed of the air flow in the air duct, L represents the propagation path length of the ultrasonic wave, α represents the angle between the ultrasonic wave propagation direction and the radial direction of the air duct, ΔT = T d0 -T u0 , represents the time difference between the upward wave and the downward wave, T u0 represents the propagation time of the upward wave, T d0 represents the propagation time of the downward wave.

[0079] According to the calculation formula of the wind speed of the air flow in the air duct, the air volume in the air duct can be calculated by the following formula:

[0080]

[0081] Wherein, Q represents the air volume in the air duct, D represents the diameter of the air duct, and V represents the wind speed of the air flow in the air duct.

[0082] As Figure 1 shown, the present invention also provides a device for measuring the wind speed of a pipeline based on ultrasonic interference, which is used to implement the method for measuring the wind speed of a pipeline based on ultrasonic interference described above, and includes a first ultrasonic transmitting unit S 1 , a second ultrasonic transmitting unit S 2 , an ultrasonic receiving unit R, an ADC measurement unit, and a data processing unit. The first ultrasonic transmitting unit S 1 and the second ultrasonic transmitting unit S 2 are installed on the inner wall of the air duct through a fixed structure and arranged at intervals in the front and back along the air flow direction; the ultrasonic receiving unit R is installed on the inner wall of the air duct opposite to the first ultrasonic transmitting unit S 1 and the second ultrasonic transmitting unit S 2 , and is located on the midline between the two;

[0083] The ADC measurement unit is used to sample the ultrasonic pulse signal received by the ultrasonic receiving unit R

[0084] A data processing unit, configured to store and process in-phase and anti-phase ultrasonic pulse signals of multiple cycles, calculate and output a wind speed value.

[0085] The first ultrasonic transmitting unit S 1 and the second ultrasonic transmitting unit S 2 and the ultrasonic receiving unit R are in an isosceles triangle plane, where the ultrasonic receiving unit R is at the apex position, and the first ultrasonic transmitting unit S 1 and the second ultrasonic transmitting unit S 2 are at the base angle positions. The first ultrasonic transmitting unit S 1 and the second ultrasonic transmitting unit S 2 have a radial angle α with the air duct in the range of 15° to 60°, that is, Figure 1 the included angle α 1 is equal to the included angle α 2 and both are α. And it is optimal when the included angle is set to be in the range of 30° to 45°, which is convenient for setting and wind speed calculation.

[0086] The first ultrasonic transmitting unit S 1 and the second ultrasonic transmitting unit S 2 can both emit ultrasonic pulse signals with a set frequency. The signal frequency range is 40 kHz to 1 MHz. The frequency range of conventional products is 200 kHz to 300 kHz. The higher the frequency, the higher the cost. This technical solution can further reduce the lower limit of the ultrasonic frequency range to 40 kHz, which is convenient for physical application and has low cost. And the first ultrasonic transmitting unit S 1 and the second ultrasonic transmitting unit S 2 have adjustable transmission signal phases for realizing the transmission of in-phase or anti-phase signals.

[0087] In one embodiment, the first ultrasonic transmitting unit S 1 is connected to a first ultrasonic transmitting wave circuit, the second ultrasonic transmitting unit S 2 is connected to a second ultrasonic transmitting circuit, and the ultrasonic receiving unit R is connected to an ultrasonic receiving circuit.

[0088] As Figure 3 shown, in one embodiment, the circuit part of the device of the present invention is implemented by the following structural block diagram. An MCU is used as the core control unit of the measuring device to coordinate the operation of each unit, control the signal transmission timing, phase adjustment and signal acquisition of the ultrasonic transmitting unit, and complete the calculation and processing of data. The internal functional modules of the MCU include a timer and an ADC measurement unit. Among them, a positioner is used to generate high-precision timing signals to ensure the signal transmission synchronization or set phase difference of the two ultrasonic transmitting units. The timer controls the frequency, pulse width and transmission time of the signal;

[0089] The ADC measurement unit converts the analog signal received by the ultrasonic receiving unit into a digital signal and samples it at a fixed frequency more than 5 times that of the ultrasonic wave for subsequent data processing.

[0090] The ultrasonic driver receives the trigger signal from the timer and generates a sine wave pulse signal with a specific frequency to drive the ultrasonic transmitting unit to emit an ultrasonic pulse signal. The power of the driving signal is adjustable to adapt to the transmission requirements of different pipe diameters or media, and it supports adjusting the phase of the transmitted signal to complete the emission of in-phase or anti-phase signals.

[0091] Ultrasonic transmitting unit S 1 and S 2 Transmit ultrasonic pulse signals into the air duct, where S 1 and S 2 are respectively responsible for the signal transmission of the up-wave and down-wave. The frequency of the transmitted signal is controlled by the driving module, and the phase of the signal can be set to in-phase (0°) or anti-phase (180°) through the driving module. When the signal is anti-phase, the timer output of S 2 is inverted to achieve a 180° phase difference adjustment, and the output of S 1 remains unchanged, and then the ultrasonic drive and ADC sampling are triggered again.

[0092] The ultrasonic receiving unit R is used to receive the ultrasonic pulse signals transmitted by the ultrasonic transmitting units S 1 and S 2 The signal propagated through the air flow may have certain attenuation and phase shift. The ultrasonic receiving unit can receive weak signals to ensure stable detection even when the signal attenuation is severe. The output signal is transmitted to the AGC module to compensate for the amplitude change of the received signal.

[0093] The AGC adjusts the gain of the analog signal output by the ultrasonic receiving unit to stabilize the signal amplitude, eliminate the signal intensity difference caused by the transmission distance or medium change; automatically adjust the amplitude of the received signal to ensure that the dynamic range of the subsequent ADC conversion is in the optimal working range and reduce the influence of environmental noise on the signal quality.

[0094] The process of data processing and wind speed calculation is as follows: Data flow: The ADC measurement unit digitizes the analog signal processed by the AGC and transmits it to the MCU. The MCU extracts the propagation time of the up-wave and down-wave through the signal processing algorithm, calculates the propagation time difference, and calculates the wind speed V and air volume Q in the air duct according to the propagation time difference and the geometric parameters of the ultrasonic propagation path.

[0095] Such as Figure 4 and Figure 5The specific schematic diagram of the fixing structure and the schematic diagram of installing the ultrasonic transmitting unit using the fixing structure are respectively shown. In one embodiment, the fixing structure adopts the form of a detection box. An embedding structure is arranged inside the detection box for embedding the ultrasonic transmitting unit and the ultrasonic receiving unit into the inner wall of the air duct. A sealing gasket is arranged at the part where the detection box contacts the outer wall of the pipeline to prevent gas leakage.

[0096] The material of the sealing gasket can be selected from high-temperature and corrosion-resistant rubber or silica gel, and the compression amount of the sealing gasket is 5% - 15%.

[0097] In one embodiment, the fixing structure further includes a vibration-proof component, specifically a shock-absorbing washer and a rigid support component. The shock-absorbing washer is sleeved outside the ultrasonic transmitting unit and the ultrasonic receiving unit and directly contacts the inner wall of the opening on the inner wall of the pipeline. The material of the shock-absorbing washer is wear-resistant rubber or silica gel, which is used to absorb the mechanical shock generated by the vibration of the pipeline. The detection box is fixed on the outer wall of the pipeline through the rigid support component, and the support component has high strength and anti-deformation ability to ensure the stability of the detection unit in a vibrating environment.

[0098] The above are only the preferred embodiments of the present invention. It should be pointed out that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and modifications can be made, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A method for measuring pipeline wind speed based on ultrasonic interferometry, characterized in that: The specific steps include: A first ultrasonic transmitting unit S1, a second ultrasonic transmitting unit S2 and an ultrasonic receiving unit R are arranged in the air duct, and the three are fixed on the inner wall of the air duct body; The first ultrasonic transmitting unit S1 and the second ultrasonic transmitting unit S2 simultaneously transmit ultrasonic pulse signals of the same phase to the ultrasonic receiving unit R; The ADC measurement unit collects the in-phase ultrasonic pulse signal received by the ultrasonic receiving unit R and records the multi-cycle in-phase interference waveform data Y a ; The first ultrasonic transmitting unit S1 and the second ultrasonic transmitting unit S2 simultaneously transmit ultrasonic pulse signals of opposite phases to the ultrasonic receiving unit R; The ADC measurement unit collects the anti-phase ultrasonic pulse signal received by the ultrasonic receiving unit R and records the multi-cycle anti-phase interference waveform data Y b ; The data processing unit is based on the in-phase interference waveform data Y a and anti-phase interference waveform data Y b Calculate the uplink interference waveform data Y u and downlink interference waveform data Y d ,in Based on the uplink interference waveform data Y u and downlink interference waveform data Y d At the zero-crossing moment, fit the curve and calculate the propagation time T of the upgoing wave u0 and the T of the down wave d0 ; The wind speed and air volume of the air flow in the duct are calculated by combining the time difference of the propagation time with the geometric parameters of the duct and the calculation results are output.

2. The method for measuring pipeline wind speed based on ultrasonic interferometry according to claim 1 is characterized in that: The propagation time of the upgoing wave is T u0 and the propagation time T of the downlink wave d0 Calculated by the following formula: Among them, V represents the wind speed of the air flow in the air duct, L represents the propagation path length of the ultrasonic wave, α represents the angle between the propagation direction of the ultrasonic wave and the radial direction of the air duct, and C represents the propagation speed of the ultrasonic wave in still air.

3. The method for measuring pipeline wind speed based on ultrasonic interferometry according to claim 2 is characterized in that: The wind speed of the air flow in the air duct is calculated by the following formula: Where V represents the wind speed of the airflow in the duct, L represents the propagation path length of the ultrasonic wave, α represents the angle between the ultrasonic wave propagation direction and the radial direction of the duct, ΔT = T d0 -T u0 , represents the time difference between the upgoing wave and the downgoing wave, T u0 represents the propagation time of the upgoing wave, T d0 represents the propagation time of the downlink wave.

4. The method for measuring pipeline wind speed based on ultrasonic interferometry according to claim 3 is characterized in that: The air volume in the duct is calculated by the following formula: Among them, Q represents the air volume in the air duct, D represents the diameter of the air duct, and V represents the wind speed of the air flow in the air duct.

5. The method for measuring pipeline wind speed based on ultrasonic interferometry according to claim 1, characterized in that: In-phase interference waveform data Y a The calculation formula is: Anti-phase interference waveform data Y b The calculation formula is: Among them, A u and A d They represent the upgoing wave amplitude and the downgoing wave amplitude respectively, ω represents the angular frequency of the ultrasonic pulse signal, t represents the time variable of the ultrasonic pulse signal during the propagation process, and They represent the initial phase angle of the upgoing wave and the initial phase angle of the downgoing wave respectively.

6. A device for measuring wind speed in a pipeline based on ultrasonic interferometry, used to implement a method for measuring wind speed in a pipeline based on ultrasonic interferometry as described in any one of claims 1 to 5, characterized in that: The ultrasonic receiving unit R comprises a first ultrasonic transmitting unit S1, a second ultrasonic transmitting unit S2, an ultrasonic receiving unit R, an ADC measuring unit and a data processing unit. The first ultrasonic transmitting unit S1 and the second ultrasonic transmitting unit S2 are mounted on the inner wall of the air duct through a fixed structure and are arranged in a front-to-back interval along the wind flow direction. The ultrasonic receiving unit R is mounted on the inner wall of the air duct opposite to the first ultrasonic transmitting unit S1 and the second ultrasonic transmitting unit S2 through a fixed structure and is located on the midline of the two. An ADC measuring unit, used for sampling the ultrasonic pulse signal received by the ultrasonic receiving unit R, with the sampling frequency being at least 5 times the ultrasonic frequency; The data processing unit is used to store and process multi-cycle ultrasonic pulse signals with the same phase and opposite phase, and calculate and output the wind speed value.

7. The device for measuring wind speed in a pipeline based on ultrasonic interferometry according to claim 6, characterized in that: The plane where the first ultrasonic transmitting unit S1, the second ultrasonic transmitting unit S2 and the ultrasonic receiving unit R are located is an isosceles triangle, wherein the ultrasonic receiving unit R is at the vertex position, the first ultrasonic transmitting unit S1 and the second ultrasonic transmitting unit S2 are at the bottom angle position, and the radial angle range between the first ultrasonic transmitting unit S1 and the second ultrasonic transmitting unit S2 and the air duct is 15° to 60°.

8. The device for measuring wind speed in a pipeline based on ultrasonic interferometry according to claim 6, characterized in that: The first ultrasonic transmitting unit S1 and the second ultrasonic transmitting unit S2 can both transmit ultrasonic pulse signals of a set frequency, the signal frequency range is 40kHz to 1MHz, and the transmission signal phases of the first ultrasonic transmitting unit S1 and the second ultrasonic transmitting unit S2 are adjustable to achieve the transmission of in-phase or anti-phase signals.

9. The device for measuring wind speed in a pipeline based on ultrasonic interferometry according to claim 6, characterized in that: The fixed structure is in the form of a detection box, and an embedded structure is arranged inside the detection box for embedding the ultrasonic transmitting unit and the ultrasonic receiving unit into the inner wall of the air duct. A sealing gasket is arranged at the contact position between the detection box and the outer wall of the pipe to prevent gas leakage.

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