Method and device for measuring wind speed of pipeline based on ultrasonic interference

Abstract

The invention discloses a method and device for measuring the wind speed of a pipeline based on ultrasonic interferometry, and the method comprises the steps: calculating the phase difference between an uplink wave and a downlink wave through arranging a first ultrasonic transmitting unit, a second ultrasonic transmitting unit and an ultrasonic receiving unit, and employing same-phase and opposite-phase interference waveform data, thereby precisely calculating the wind speed in the pipeline; the device adopts a simplified hardware design, only one group of receiving circuit and ADC measuring circuit are needed, the cost is reduced, the reliability of the system is improved, each unit is stably mounted on the inner wall of the air duct through a fixing structure, and the fixing structure adopts a detection box form and adapts to various complex environments. The method and the device are suitable for the fields of industrial pipelines, laboratory ventilation systems and the like, have the advantages of high precision, low cost, high environmental adaptability and the like, and are widely suitable for airflow 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 an ultrasonic receiving unit R, the three of which 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 At the same time, an ultrasonic pulse signal with the same phase is sent to the ultrasonic receiving unit R;

[0013] 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 ;

[0014] The first ultrasonic transmitting unit S 1 and the second ultrasonic transmitting unit S 2 At the same time, an ultrasonic pulse signal with an opposite phase is sent to the ultrasonic receiving unit R;

[0015] 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 ;

[0016] 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

[0017] 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 ;

[0018] 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.

[0019] Preferably, the propagation time T of the upgoing wave u0 and the propagation time T of the downlink wave d0 Calculated by the following formula:

[0020]

[0021] 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.

[0022] Preferably, the wind speed of the air flow in the air duct is calculated by the following formula:

[0023]

[0024] 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.

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

[0026]

[0027] 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.

[0028] Preferably, the 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.

[0029] A device for measuring wind speed in a pipeline based on ultrasonic interferometry, used to implement the above-mentioned method for measuring wind speed in a pipeline based on ultrasonic interferometry, comprising a first ultrasonic transmitting unit S 1 , the second ultrasonic transmitting unit S 2 , an ultrasonic receiving unit R, an ADC measuring unit and a data processing unit, the first ultrasonic transmitting unit S 1 and the second ultrasonic transmitting unit S 2 The ultrasonic receiving unit R is installed on the inner wall of the air duct through a fixed structure and arranged in a front-to-back interval along the wind direction; the ultrasonic receiving unit R is installed on the first ultrasonic transmitting unit S through a fixed structure 1 and the second ultrasonic transmitting unit S 2 On the inner walls of the opposite air ducts and located on the midline between them;

[0030] 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;

[0031] 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.

[0032] Preferably, the first ultrasonic transmitting unit S 1 , the second ultrasonic transmitting unit S 2 The plane where the ultrasonic receiving unit R is located forms an isosceles triangle, wherein the ultrasonic receiving unit R is at the vertex position, and the first ultrasonic transmitting unit S 1 and the second ultrasonic transmitting unit S 2 At the bottom angle position, the first ultrasonic transmitting unit S 1 and the second ultrasonic transmitting unit S 2 The radial angle range with 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 emit ultrasonic pulse signals of a set frequency, the signal frequency range is 40kHz~1MHz, and the first ultrasonic transmitting unit S 1 and the second ultrasonic transmitting unit S 2 The phase of the transmitted signal is adjustable, which is used to transmit the same phase or opposite phase signal.

[0034] Preferably, 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 duct to prevent gas leakage.

[0035] Beneficial effects: The method and device for measuring pipeline wind speed based on ultrasonic interferometry provided by the present invention have the following advantages:

[0036] Beneficial effects:

[0037] 1. The present invention adopts ultrasonic interferometry to measure wind speed. The wind speed is calculated by using the interference waveform data of the same phase and the opposite phase, thus avoiding the error caused by signal delay matching in the traditional ultrasonic time difference method. By calculating the phase difference between the upgoing and downgoing waves in real time, the wind speed in the pipeline can be measured more accurately, especially in the environment of high wind speed, low temperature or high humidity, the wind speed measurement can still be maintained with high precision.

[0038] 2. The measuring device of the present invention adopts a single receiving circuit and ADC measuring circuit, and does not require the complicated multiple sensors and circuit connections in the traditional wind speed measurement system. 1and the second ultrasonic transmitting unit S 2 Connecting to their own independent transmitting circuits and using the same receiving unit for signal reception not only reduces hardware costs, but also makes the system design more compact and reduces the difficulty of system maintenance.

[0039] 3. The present invention uses a fixed structure to connect the first ultrasonic transmitting unit S 1 , the second ultrasonic transmitting unit S 2 The ultrasonic receiving unit R is firmly installed on the inner wall of the air duct. The fixed 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 of the system during long-term operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art are briefly introduced below.

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

[0042] Figure 2 Schematic diagram of the waveform of ultrasonic pulse signal;

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

[0044] Figure 4 It 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 This is a schematic diagram of the embedded installation structure of the ultrasonic transmitting unit of the present invention. DETAILED DESCRIPTION

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

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

[0048] The first ultrasonic transmitting unit S is arranged on the inner wall of the air duct. 1 , the second ultrasonic transmitting unit S 2 And ultrasonic receiving unit R; wherein two ultrasonic transmitting units are installed on the inner wall of the air duct and arranged in a front-to-back interval along the wind flow direction to ensure the uniformity of ultrasonic signal propagation, and the ultrasonic receiving unit R is arranged in the first ultrasonic transmitting unit S1 and the second ultrasonic transmitting unit S 2 On the inner walls of the opposite air ducts and located on the midline of the two, ensuring that the ultrasonic signals emitted from the two transmitting units are received;

[0049] The first ultrasonic transmitting unit S 1 and the second ultrasonic transmitting unit S 2 At the same time, an ultrasonic pulse signal with the same phase is sent to the ultrasonic receiving unit R;

[0050] 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 ;

[0051] The first ultrasonic transmitting unit S 1 and the second ultrasonic transmitting unit S 2 At the same time, an ultrasonic pulse signal with an opposite phase is sent to the ultrasonic receiving unit R, and the second ultrasonic transmitting unit S is adjusted. 2 The phase of the transmitted signal is 180°, forming an anti-phase signal;

[0052] 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 ;

[0053] The specific processing process of the ADC measurement unit for the ultrasonic pulse signal is as follows: the ultrasonic receiving unit R receives the ultrasonic pulse signal from the first and second ultrasonic transmitting units S 1 and S 2 The ultrasonic pulse signal is transmitted; 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 the sample is taken, the ADC converts the amplitude value of the analog signal into a corresponding digital value, which 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 will use a certain resolution (such as 8 bits, 12 bits, 16 bits or higher) 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 point in time, which can be transmitted to the data processing unit for subsequent analysis.

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

[0056] 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 In this embodiment, the first ultrasonic transmitting unit S 1 and the second ultrasonic transmitting unit S 2 After T1 time has passed since the ultrasonic pulse signal was sent, the data processing unit extracts the received periodic ADC data starting from T1 time point;

[0057] When the wind in the duct flows forward or backward along the length of the duct, the receiving unit R receives the ultrasonic signal from the first ultrasonic transmitting unit S 1 and the second ultrasonic transmitting unit S 2 The propagation state of the transmitted ultrasonic pulse signal is: when one is with the wind, the other is against the wind. The wave propagating with the wind is called a downwind wave, and the wave propagating against the wind is called an upwind wave.

[0058] like Figure 2 The figure shows the measured interference waveform of the ultrasonic signal. By adding and subtracting the signal, the interference components of the upgoing and downgoing waves 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 , it can be seen from the figure that the two curves are inverse; the black curve in the figure represents the downlink interference waveform data Y d , which means that by interfering the waveform data Y a and anti-phase interference waveform data Y b The signal data is subtracted to separate the downlink interference data. It can be seen from the figure that twice the downlink interference signal data is extracted. The light green curve represents the uplink interference waveform data Y u , which means that by interfering the waveform data Y a and anti-phase interference waveform data Y b The signal data is added to separate the upgoing wave interference data. It can be seen from the figure that twice the upgoing wave interference signal data is extracted.

[0059] 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 ;

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

[0061]

[0062] The formula of the anti-phase interference waveform data function is expressed as:

[0063]

[0064] Among them, A u and A d They represent the up-wave amplitude and the down-wave amplitude respectively, ω represents the angular frequency of the ultrasonic pulse signal, and t represents the time variable of the ultrasonic pulse signal during the propagation process, which is used to describe the time domain change of the signal. and represent the initial phase angle of the upgoing wave and the initial phase angle of the downgoing wave respectively;

[0065] Uplink interference waveform data Y u The function formula is expressed as:

[0066]

[0067] Downlink interference waveform data Y d The function formula is expressed as:

[0068]

[0069] You can get

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

[0071] Similarly, substitute the N data obtained by the ADC measurement unit into the downlink interference waveform data Y d , get the coordinates of N points: By fitting the cosine curve according to the known N points, the Nth zero-crossing time T can be obtained. dn .

[0072] 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.

[0073] 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:

[0074]

[0075] Among them, V represents the wind speed of the air flow 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, C represents the propagation speed of the ultrasonic wave in still air, and the propagation time of the upgoing wave T is u0 and the propagation time T of the downlink wave d0 That is the 0th zero-crossing moment of both.

[0076] According to the calculated propagation time T of the upgoing wave u0 and the propagation time T of the downlink wave d0 Combined with the calculation formula, the wind speed of the airflow in the air duct can be calculated by the following formula:

[0077]

[0078] 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.

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

[0080]

[0081] 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.

[0082] like Figure 1 As shown, the present invention also provides a device for measuring pipeline wind speed based on ultrasonic interferometry, which is used to implement the above-mentioned method for measuring pipeline wind speed based on ultrasonic interferometry, comprising a first ultrasonic transmitting unit S 1 , the second ultrasonic transmitting unit S 2 , an ultrasonic receiving unit R, an ADC measuring unit and a data processing unit, the first ultrasonic transmitting unit S 1 and the second ultrasonic transmitting unit S 2 The ultrasonic receiving unit R is installed on the inner wall of the air duct through a fixed structure and arranged in a front-to-back interval along the wind direction; the ultrasonic receiving unit R is installed on the first ultrasonic transmitting unit S through a fixed structure 1 and the second ultrasonic transmitting unit S 2 On the inner walls of the opposite air ducts and located on the midline between them;

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

[0084] 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.

[0085] The first ultrasonic transmitting unit S 1 , the second ultrasonic transmitting unit S 2 The plane where the ultrasonic receiving unit R is located forms an isosceles triangle, wherein the ultrasonic receiving unit R is at the vertex position, and the first ultrasonic transmitting unit S 1 and the second ultrasonic transmitting unit S 2 The first ultrasonic transmitting unit S 1 and the second ultrasonic transmitting unit S 2 The radial angle α with the air duct ranges from 15° to 60°, that is, Figure 1 The angle α 1 Angle α 2 They are all equal to α, and the best value is when the angle is set to 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 All of them can emit ultrasonic pulse signals of set frequency, the signal frequency range is 40kHz~1MHz, the frequency range of conventional products is 200kHz~300KHz, the higher the frequency, the higher the cost, the technical solution can further reduce the lower limit of the ultrasonic frequency range to 40kHZ, the actual application is convenient and the cost is low; and the first ultrasonic transmitting unit S 1 and the second ultrasonic transmitting unit S 2 The phase of the transmitted signal is adjustable, which is used to transmit the same phase or opposite phase signal.

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

[0088] like Figure 3 As shown, in one embodiment, the circuit part of the device of the present invention is implemented by the following structural block diagram, and 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 the data. The internal functional modules of the MCU include a timer and an ADC measuring unit, wherein the locator is used to generate a high-precision timing signal to ensure that the signal transmission of the two ultrasonic transmitting units is synchronized or the phase difference is set, and 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 ultrasound receiving unit into a digital signal and samples it at a fixed frequency that is more than 5 times that of ultrasound for subsequent data processing.

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

[0091] Ultrasonic transmission unit S 1 and S 2 Send ultrasonic pulse signal to the inside of the air duct, where S 1 and S 2 They are responsible for transmitting the uplink and downlink signals respectively. The frequency of the transmitted signal is controlled by the driver module. The phase of the signal can be set to the same phase (0°) or opposite phase (180°) by the driver module. When the signal is in opposite phase, S 2 The timer output is reversed to achieve 180° phase difference adjustment, S 1 The output remains unchanged, triggering the ultrasonic drive and ADC sampling again.

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

[0093] AGC performs gain adjustment on the analog signal output by the ultrasonic receiving unit to stabilize the signal amplitude and eliminate the signal strength difference caused by the transmission distance or medium change; it automatically adjusts the received signal amplitude to ensure that the dynamic range of subsequent ADC conversion is within the optimal working range and reduce the impact of environmental noise on 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 passes it to the MCU. The MCU extracts the propagation time of the upgoing wave and the downgoing 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 based on the propagation time difference and the geometric parameters of the ultrasonic propagation path.

[0095] like Figure 4 and Figure 5The figures show a specific schematic diagram of the fixed structure and a schematic diagram of installing the ultrasonic transmitting unit using the fixed structure. In one embodiment, the fixed structure is in the form of a detection box, and an embedded structure is arranged inside the detection box to embed 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 portion between the detection box and the outer wall of the duct to prevent gas leakage.

[0096] The material of the sealing gasket can be high temperature resistant and corrosion resistant rubber or silicone, and the compression amount of the sealing gasket is 5% to 15%.

[0097] In one embodiment, the fixed structure also includes an anti-vibration component, specifically a shock-absorbing gasket and a rigid support component. The shock-absorbing gasket is sleeved on the outside of the ultrasonic transmitting unit and the ultrasonic receiving unit, and directly contacts the inner wall of the hole in the inner wall of the pipe. The material of the shock-absorbing gasket is wear-resistant rubber or silicone, which is used to absorb the mechanical impact caused by the vibration of the pipe. The detection box is fixed to the outer wall of the pipe by a rigid support component. The support component has high strength and deformation resistance to ensure the stability of the detection unit in a vibration environment.

[0098] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection 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.

Images