Impulsive force type flowmeter and flow measuring method

Abstract

The invention relates to the technical field of flow measurement, and discloses an impulsive flow meter and a flow measurement method. The throttling device aims to solve the technical problems that in the prior art, a throttling device is high in installation cost, and measurement fails due to leakage and blockage of a pressure tapping pipe. According to the impulsive force type flowmeter, the detection element arranged in the pipeline can sense the impulsive force of the fluid. The force acts on a sensitive element piezo-electric crystal sealed at the root of the strip-shaped plate, the piezo-electric crystal generates electric charges, and the electric charges are processed and calculated through an electronic circuit, converted into standard analog signals or digital signals in direct proportion to the fluid flow and displayed on the spot or transmitted to a control room, so that the flow of various fluids is measured. The strip-shaped thin plate which is used as a detection element and provided with the circulation hole can stably and sensitively measure the flow of various fluids such as gas, liquid, steam and the like including viscous, dirty and dust media, and has the advantages of being convenient to install and use, stable and reliable in work, high in measurement accuracy, wide in measuring range, wide in application range and the like.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of flow measurement, in particular to a force type flow meter and a flow measurement method. BACKGROUND

[0002] Flow meters are widely used automatic instruments, among which the most widely used are throttling devices, vortex flow meters, turbine flow meters, float flow meters, target flow meters, etc. Each of them has certain advantages but also has disadvantages limiting their application. For example, the throttling device must have a pair of pressure taking pipes, which has high installation cost and often encounters problems such as pressure taking pipe leakage and blockage, resulting in measurement failure; the vortex flow meter produces oscillation when the fluid pipeline is shaken, which easily causes zero drift and measurement error; the turbine flow meter is easily blocked by impurities when measuring fluid containing impurities; the float flow meter has high installation cost and does not allow viscous substances; the target flow meter reduces the measurement accuracy due to the vortex behind the target sheet, and the zero point is easily shifted and has to be adjusted to zero on site. Users urgently need a flow meter which is simple to install, stable and reliable in operation, suitable for various types of fluid, has low total cost including the flow meter itself and supporting instruments, and has high measurement accuracy. SUMMARY

[0003] In view of the above technical problems, the present application provides a force type flow meter and a flow measurement method, which are suitable for measuring various fluids, especially viscous, dirty, dusty and other fluids that cannot be measured by other flow meters. The technical problems of the prior art, such as high installation cost of throttling devices and frequent problems such as pressure taking pipe leakage and blockage, resulting in measurement failure; the vortex flow meter produces oscillation when the fluid pipeline is shaken, which easily causes zero drift and measurement error; the turbine flow meter is easily blocked by impurities when measuring fluid containing impurities; the float flow meter has high installation cost and does not allow viscous substances; the target flow meter reduces the measurement accuracy due to the vortex behind the target sheet, and the zero point is easily shifted and has to be adjusted to zero on site, are solved.

[0004] According to one aspect of the present application, a force type flow meter is provided, which comprises a force receiving plate arranged in a fluid pipeline, the force receiving plate being a strip-shaped plate, and the plate surface of the force receiving plate being arranged vertically to the fluid flow direction; the length of the force receiving plate is less than the inner diameter of the fluid pipeline, so that the force receiving plate can move freely in the pipeline; A plurality of circular balance holes for eliminating the vortex behind the plate are arranged on the plate surface of the force receiving plate; The root of the force receiving plate is encapsulated with a force sensitive element for sensing the force generated by the fluid impact on the force receiving plate; The force sensitive element is electrically connected to a signal processing unit for receiving the signal of the force sensitive element and converting it into flow information; The force-receiving plate, the force sensing element and the signal processing unit are integrated into a plug-in assembly. The signal processing unit comprises a power module for converting 24V DC input into 3.3V DC to supply power to internal circuits of the instrument, and a signal acquisition module comprising a piezoelectric sensor, a pressure sensor and a temperature sensor, the piezoelectric sensor being connected to a charge amplifier; a sensor signal output end of the signal acquisition module is connected to a controller, the controller being configured with an analog-to-digital converter, an input end of the controller being connected to a key input circuit, the controller further being communicatively connected to an LCD display circuit for displaying flow data; the controller is connected to an output module via an opto-isolator.

[0005] In some embodiments of the present disclosure, the power module comprises a DC 24V input terminal; the DC 24V input terminal is connected to an LC filter circuit comprising an inductor L1 and capacitors C32 and C35; the LC filter circuit is connected to a DC-DC step-down conversion chip U2 for converting the filtered voltage to 3.3V; an output end of the DC-DC step-down conversion chip U2 is connected to output filter capacitors C36 and C7.

[0006] In some embodiments of the present disclosure, the signal acquisition module is connected to a sensor signal amplification circuit comprising multiple-stage operational amplifiers for amplifying millivolt-level weak signals from the sensors to the input range required by the analog-to-digital converter.

[0007] In some embodiments of the present disclosure, the key input circuit comprises multiple independent key branches, each key branch comprising a tactile switch; one end of the tactile switch is connected to a 3.3V power supply via a pull-up resistor, and the other end is grounded.

[0008] In some embodiments of the present disclosure, the output module comprises: an analog output unit for converting signals generated by the controller into 4-20mA current signal output; a digital output unit for providing an RS485 communication interface; a pulse output unit for converting signals generated by the controller into frequency or pulse signal output.

[0009] In some embodiments of the present disclosure, the analog output unit comprises a digital-to-analog conversion chip U11, an input end of the digital-to-analog conversion chip U11 receiving a PWM control signal from the controller; a signal output end of the digital-to-analog conversion chip U11 is connected to a cascaded operational amplifier U12A and an operational amplifier U12B; a signal output end of the operational amplifier U12B is connected to a voltage reference chip U13 and a transistor Q2 to form a constant current source circuit and generate a stable 4-20mA current output; The digital-to-analog conversion chip U11 is connected with a reference voltage source, which comprises an operational amplifier U3, a voltage dividing resistor R23 and a voltage dividing resistor R25, and is configured to provide a reference voltage of 2.5V for the digital-to-analog conversion chip; The pulse quantity output unit comprises an optoelectronic isolator U32, and an output end of the optoelectronic isolator U32 is connected with a transistor switch amplification circuit composed of transistors Q3, Q4 and Q5 to generate a frequency or pulse signal.

[0010] In some embodiments of the present disclosure, the controller is connected with the external data storage circuit through an I2C bus communication.

[0011] In some embodiments of the present disclosure, the ratio of the width of the force-receiving plate to the inner diameter of the pipeline is between 0.1 and 0.8; the ratio of the diameter of the circular balance hole to the width of the plate is between 0.1 and 0.6, and the number of the circular balance holes is between 0 and 20.

[0012] In some embodiments of the present disclosure, the force-sensitive element is a piezoelectric crystal.

[0013] In some embodiments of the present disclosure, the plug-in assembly further comprises an insert extending from the pipeline wall to the inside of the pipeline, one end of the insert being connected with the force-receiving plate and the other end being fixed to the pipeline wall of the fluid pipeline through a mounting seat.

[0014] In some embodiments of the present disclosure, the plug-in assembly further comprises an in-line sealing mechanism for preventing fluid leakage, and an in-line isolation ball valve is installed below the in-line sealing mechanism.

[0015] A fluid pipeline flow measurement method using a force flowmeter, comprising the following steps: S1, signal sensing and acquisition: The fluid vertically impacts the force-receiving plate, and the fluid impact force is sensed; The fluid impact force is converted into a corresponding electrical signal by the force-sensitive element packaged at the root of the force-receiving plate; The charge signals from the force-sensitive element, the pressure sensor and the temperature sensor are synchronously acquired S2, signal processing and calculation: a. Signal conditioning: the collected millivolt-level or charge-level weak signal is amplified and filtered, and is converted into a digital signal; b. Flow calculation: based on the charge signal, the impact force F of the fluid on the force-receiving plate is calculated A C D ρν 2 , wherein: A is the effective area of the force-receiving plate; C D is the drag coefficient of the force-receiving plate; ρ is the density of the fluid; ν is the flow rate of the fluid, and the flow rate Q is calculated; c. Multi-parameter compensation: using the collected static pressure signal and temperature signal to compensate the flow Q; S3, flow information output: The final flow information after compensation is output in at least one of the following ways: Analog output: convert the flow value into a linear 4-20mA analog current signal output; Digital output: output the flow data through the RS485 digital communication interface; Pulse output: convert the flow value into a frequency or pulse signal output proportional to it.

[0016] In some embodiments of the present disclosure, after S3, S4, online maintenance is further included: when maintenance or replacement is needed, the plug-in assembly containing the impact plate and the force sensing element is taken out of the pipeline without stopping the fluid flow in the pipeline by operating the online isolation ball valve and the online sealing mechanism.

[0017] The present application has the following advantages: The present application provides a flow meter which uses a strip-shaped thin plate with flow-through holes (balance holes) to detect the impact force of fluid instead of the static pressure difference, thereby avoiding the use of static pressure difference pressure pipeline, reducing installation costs and avoiding failures caused by pipeline blockage and leakage; the strip-shaped thin plate has a length L2 and a width L1, and n flow-through holes (balance holes) with a diameter d are opened on it. The values are determined by considering the fluid impact force and the size of the vortex behind the impact plate. The vortex area behind the plate can be reduced or eliminated, the fluid balance between the two sides of the plate is maintained, the plate shaking is avoided, and the measurement signal is stable, thereby fundamentally solving the problem of target flow meter. The force sensing element uses a piezoelectric crystal instead of a strain gauge, thereby avoiding the creep of the sensing element, ensuring stable and reliable operation, and the excellent electrical properties of the piezoelectric crystal ensure that the flow meter can obtain high accuracy. The measurement element that senses the impact force is a strip-shaped plate instead of a circular plate, thereby facilitating the formation of an insert type and reducing the cost of on-site installation. The measurement element is a thin plate that is not prone to sticking to impurities like a float, and can measure the flow of dirty and viscous media. In order to facilitate on-site installation, it is designed as an insert type or an online plug-in type, which can be maintained, adjusted or replaced online, and the on-site zero adjustment work is simple and easy.

[0018] The flow conversion force detection element of the present application is a strip-shaped thin plate with flow-through holes (balance holes), which makes the flow conversion force signal sensitive, stable and repeatable. The force sensing element that converts force into electrical signal is a piezoelectric crystal, which has excellent electrical properties to ensure high accuracy of signal processing and conversion. These two characteristics make the present application have the advantages of stable and reliable operation, high measurement accuracy, simple on-site installation and maintenance, low cost, wide range, wide application range, etc. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 This is a schematic diagram of the structure of an impulse flow meter; Figure 2 for Figure 1 Front view of the impact plate of a medium-impact flow meter; Figure 3 This is a schematic diagram of the impulse flow meter structure in Example 2; Figure 4 This is a block diagram of the signal processing unit. Figure 5 This is the circuit schematic of the power module; Figure 6 This is a schematic diagram of a key input circuit. Figure 7 This is a schematic diagram of an analog output circuit. Figure 8 Schematic diagram of frequency or pulse equivalent output circuit; Figure 9 This is the schematic diagram of the controller circuit. Figure 10 This is a schematic diagram of a signal reference circuit. Figure 11 This is a schematic diagram of a sensor signal amplification circuit. Figure 12 This is a schematic diagram of an external data storage circuit. The components in the diagram are named as follows: 1. Fluid pipe; 2. Impact plate; 3. Signal processing unit; 4. Insert; 5. Mounting base; 6. Online sealing mechanism; 7. Online isolation ball valve; 8. Piezoelectric crystal; 9. Circular balance hole. Detailed Implementation

[0020] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention. Example 1

[0021] This example discloses an impulse flow meter; see [link to relevant documentation]. Figures 1 to 12 The impulsive flow meter includes an impact plate 2 installed inside a fluid pipe 1. The impact plate 2 is a strip-shaped thin plate, and the plate surface of the impact plate 2 is perpendicular to the fluid flow direction. The length of the impact plate 2 is less than the inner diameter of the fluid pipe 1 so that the impact plate 2 can move freely inside the pipe. Several circular balance holes 9 are provided on the surface of the impact plate 2 to eliminate the vortex behind the plate; A force-sensitive element is encapsulated at the root of the impact plate 2 to sense the force generated by the impact plate 2 due to fluid impact; The force-sensitive element is electrically connected to the signal processing unit 3, which is used to receive the signal from the force-sensitive element and convert it into flow information; The force plate 2, the force sensing element and the signal processing unit 3 are integrated into a plug-in assembly; The signal processing unit 3 comprises a power module for converting 24V DC input into 3.3V DC to supply power to internal circuits of the meter; and a signal acquisition module, which comprises a piezoelectric sensor, a pressure sensor and a temperature sensor, the piezoelectric sensor being connected to a charge amplifier; a sensor signal output end of the signal acquisition module being connected to a controller, the controller being configured with an analog-to-digital converter, an input end of the controller being connected to a key input circuit, the controller further being communicatively connected to an LCD display circuit for displaying flow data; and the controller being connected to an output module via an opto-isolator.

[0022] The power module comprises a DC 24V input terminal; the DC 24V input terminal is connected to an LC filter circuit, which comprises an inductor L1 and capacitors C32 and C35; the LC filter circuit is connected to a DC-DC step-down conversion chip U2 for converting the filtered voltage into 3.3V; and an output end of the DC-DC step-down conversion chip U2 is connected to output filter capacitors C36 and C7.

[0023] The signal acquisition module is connected to a sensor signal amplification circuit, which comprises multiple-stage operational amplifiers for amplifying millivolt-level weak signals from the sensors to the input range required by the analog-to-digital converter.

[0024] The key input circuit comprises multiple independent key branches, each of which comprises a tactile switch; one end of the tactile switch is connected to a 3.3V power supply via a pull-up resistor, and the other end is grounded.

[0025] The output module comprises: an analog output unit for converting signals generated by the controller into 4-20mA current signal output; a digital output unit for providing an RS485 communication interface; a pulse output unit for converting signals generated by the controller into frequency or pulse signal output.

[0026] The analog output unit comprises a digital-to-analog conversion chip U11, an input end of which receives PWM control signals from the controller; a signal output end of the digital-to-analog conversion chip U11 is connected to cascaded operational amplifier U12A and operational amplifier U12B; a signal output end of the operational amplifier U12B is connected to voltage reference chip U13 and transistor Q2 to form a constant current source circuit and generate a stable 4-20mA current output; The digital-to-analog conversion chip U11 is connected to a reference voltage source comprising operational amplifier U3, voltage dividing resistor R23 and voltage dividing resistor R25 for providing a reference voltage of 2.5V for the digital-to-analog conversion chip; The pulse quantity output unit comprises an optoelectronic isolator U32, and an output end of the optoelectronic isolator U32 is connected to a transistor switch amplification circuit composed of transistors Q3, Q4 and Q5 to generate a frequency or pulse signal.

[0027] The controller is connected to the external data storage circuit through an I2C bus communication.

[0028] The ratio of the width of the impact plate 2 to the inner diameter of the pipeline is between 0.1 and 0.8; the ratio of the diameter of the circular balance hole to the width of the plate is between 0.1 and 0.6, and the number of circular balance holes is 0 to 20.

[0029] The force sensing element is a piezoelectric crystal 8.

[0030] The plug-in assembly further comprises an insert 4 extending from the pipeline wall to the inside of the pipeline, one end of the insert 4 being connected to the impact plate 2 and the other end being fixed to the pipeline wall of the fluid pipeline 1 through a mounting seat 5.

[0031] The plug-in assembly further comprises an in-line sealing mechanism 6 for preventing fluid leakage, and an in-line isolation ball valve 7 is installed below the in-line sealing mechanism 6.

[0032] A flow measurement method in a fluid pipeline 1 using an impact flowmeter, comprising the following steps: S1, signal sensing and acquisition: The fluid vertically impacts the impact plate 2, and the fluid impact force is sensed; The fluid impact force is converted into a corresponding electrical signal by the force sensing element packaged at the root of the impact plate 2; Synchronous acquisition of charge signals from the force sensing element, pressure sensor, and temperature sensor S2, signal processing and calculation: a. Signal conditioning: amplify and filter the collected millivolt-level or charge-level weak signals and convert them into digital signals; b. Flow calculation: based on the charge signal, calculate the impact force F of the fluid on the impact plate 2 A C D ρν 2 , wherein: A is the effective area of the impact plate 2; C D is the drag coefficient of the impact plate 2; ρ is the density of the fluid; ν is the flow rate of the fluid, and the flow rate Q is calculated; c. Multi-parameter compensation: use the collected static pressure signal and temperature signal to compensate the flow rate Q; S3, flow information output: The final flow information after compensation is output in at least one of the following ways: Analog output: convert the flow value into a linear 4-20mA analog current signal output; Digital output: output flow data through RS485 digital communication interface; Pulse output: convert flow value into proportional frequency or pulse signal output.

[0033] After S3, S4, online maintenance is also included: when maintenance or replacement is needed, by operating the online isolation ball valve 7 and the online sealing mechanism 6, the plug-in assembly containing the force-receiving plate 2 and the force-sensitive element is taken out of the pipeline without stopping the fluid flow in the pipeline.

[0034] Attached Figure 1 On the outer wall of the fluid pipeline 1 with an inner diameter of 200 mm, a mounting seat 5 is welded, and an assembly including a converter, an insert 4, a piezoelectric crystal 8, and a force-receiving plate 2 is inserted, the front of the force-receiving plate 2 is aligned to face the positive direction of the fluid, the insert 4 and the mounting seat 5 are connected firmly with fasteners, and the output line of the converter is connected to the display, completing the installation work. The calculation example of the force received by the force-receiving plate 2 is: assuming that the maximum flow rate of the fluid is 180 m 3 / h, the medium is water, the temperature is 50°C, the pressure is 0.3 MPa, the density of water is p = 988.24 kg / m3, and DN200 pipe 2 is selected according to the maximum flow rate value, the area A of the force-receiving plate 2 is 0.004 m 2 , the resistance coefficient C D = 1.2, the fluid flow rate v = 1.67 m / s, and the force received by the force-receiving plate 2 is calculated by the general technical formula: F= A C D ρν 2 = 6.615 N (Newton) = 0.674 kg (kilogram force) According to this force F, the model of the piezoelectric crystal 8 is selected, and the parameters of the data processing unit are further adjusted, so that the display value of the converter at the maximum flow rate of the fluid is 180 m 3 / h. Example 2

[0035] See the attached Figure 3 , this example mainly illustrates the online plug-in structure of the force type flowmeter, which can be installed online during normal operation, and does not need to close the valve and interrupt operation like the existing target type flowmeter when maintenance or zero point adjustment is needed, which is not beneficial to users. The design and calculation of the flowmeter itself are the same as in Example 1, which is omitted here. This embodiment 2 adds an online isolation ball valve 7 and an online sealing mechanism 6, When measuring dirty viscous fluid, impurities may stick to the force plate 2 over time, affecting the measurement. The present application can raise the force plate 2 without interrupting the process flow, and after the force plate 2 is separated from the fluid, try to close the online isolation ball valve 7, confirm that the force plate 2 is above the valve, then close the ball valve, disassemble the connecting part, take out the force plate 2 for cleaning, and reverse the operation to restore the flowmeter to work.

[0036] During operation, the CPU receives input signals from multiple sensors, processes them, and outputs analog signals, digital signals, and display information. The power supply part includes a DC / DC module that converts the input 24V DC to 5V DC, which is used by the CPU and other circuit modules.

[0037] The input signal sources include a piezoelectric crystal 8: the output signal is amplified by an amplifier and sent to the CPU. The pressure sensor outputs a small voltage signal (unit: mV) for measuring pressure values. The temperature sensor also outputs a mV level signal for monitoring the environment or device temperature. The keys are connected to the CPU. They are used to set parameters, switch modes, and other operations.

[0038] The CPU is responsible for collecting and processing all sensor data. It contains analog-to-digital conversion (ADC), data operation, and control logic.

[0039] LCD display: receives data from the CPU and communicates through the I²C bus. It displays real-time measurement results (such as pressure, temperature, etc.).

[0040] Single pulse output signal path: CPU → Amplification → Shaping → Unit pulse output.

[0041] 4-20mA analog output signal path: unit pulse output → f / V (frequency to voltage) → V / I (voltage to current).

[0042] RS485 digital signal output provides a serial communication interface.

[0043] The power supply circuit converts the input DC voltage (DC 24V) to a stable output voltage (3.3V) for subsequent circuit use. The input part provides a 24V DC power supply. R1 is a current limiting resistor, C10 is an input filter capacitor, L1 is an inductor, and C32 and C35 form an LC filter. C37 is a electrolytic capacitor connected to the ground.

[0044] U2 is a step-down DC-DC converter chip that converts a higher input voltage to a lower output voltage.

[0045] C36 output end of the energy storage capacitor. C7 output filter capacitor. After the output voltage, supply voltage for subsequent circuit.

[0046] Four independent key input circuit, for detecting the state of four keys.

[0047] Pull-up resistor (R31~R34): 10KΩ ±1% resistance,

[0048] Decoupling capacitor (C41~C44): each key in parallel with a 100nF capacitor, for filtering out noise, improve signal stability.

[0049] When the key is not pressed, through the pull-up resistor, the corresponding pin (Key0~Key3) voltage is high (3.3V). When the key is pressed, the pin is directly grounded through the key, the voltage becomes low (0V). For microcontroller to read the key state.

[0050] HC-1.25-8A interface control liquid crystal display, display related information.

[0051] Current source output circuit, can produce adjustable small current (40-20mA) as analog signal output, Input signal PWM_C connected to chip U11, U11 is a digital analog converter (DAC).

[0052] The first stage of the operational amplifier (U12A) amplifies the analog signal from U11. The second stage of the operational amplifier (U12B) further amplifies or adjusts. The output is driven by R7 to drive the subsequent circuit.

[0053] U13 is a voltage reference or voltage regulator chip, C53 is the output end of the decoupling capacitor.

[0054] Frequency or pulse equivalent output, for the input signal to frequency or pulse equivalent output circuit.

[0055] U32 opto-isolator, Q3 and Q4, Q5, NPN transistor, constitute a transistor amplifier and switching circuit. Realize frequency or pulse equivalent output.

[0056] Signal ADC reference for generating a stable reference voltage (VREF) for analog-to-digital converter (ADC) use.

[0057] U3 operational amplifier, R23, R25: resistance voltage divider network, A3.3V divided into 2.5V reference voltage.

[0058] Sensor signal amplification circuit for amplifying weak signals from the sensor and transmitting them to the ADC for digital processing.

[0059] Multiple operational amplifiers are used for signal amplification. The first stage operational amplifier receives the sensor signal and performs a preliminary amplification. The second stage operational amplifier further amplifies the signal, and the third stage operational amplifier finally amplifies and outputs the signal to the AD5 pin.

[0060] The weak analog signal output by the sensor is amplified to a range suitable for ADC input.

[0061] The external data storage is used to connect an external storage chip. The collected data is written into the storage through IIC protocol communication with the external storage.

[0062] Although some preferred embodiments of the present application have been described, those skilled in the art can make further changes and modifications to these embodiments once they know the basic inventive concept. Therefore, the appended claims are intended to cover all such changes and modifications as falling within the scope of the present application.

[0063] Obviously, various modifications and changes can be made to the present application by those skilled in the art without departing from the spirit and scope of the present application. Thus, it is intended that the present application embrace all such modifications and changes as fall within the scope of the appended claims and their equivalents.

Claims

1. An impulse flow meter, characterized in that: The device includes a pressure-receiving plate installed inside a fluid pipeline. The pressure-receiving plate is a thin strip plate with its surface perpendicular to the fluid flow direction. The length of the pressure-receiving plate is less than the inner diameter of the fluid pipeline, allowing the pressure-receiving plate to move freely within the pipeline. The surface of the pressure-receiving plate has several circular balance holes for eliminating vortices behind the plate. The ratio of the width L1 of the pressure-receiving plate to the inner diameter D of the pipeline is between 0.1 and 0.

8. The ratio of the diameter d of the circular balancing hole to the plate width L1 is between 0.1 and 0.6, and the number of the circular balancing holes is between 0 and 20. A force-sensitive element is encapsulated at the root of the impact plate for sensing the force generated by the fluid impact on the impact plate; the force-sensitive element is a piezoelectric crystal. The force-sensitive element is electrically connected to the signal processing unit, which is used to receive the signal from the force-sensitive element and convert it into flow information; The impact plate, force-sensitive element and signal processing unit are integrated into a pluggable component; The signal processing unit includes a power supply module for converting externally input 24V DC power into 3.3V DC power to supply power to the internal circuitry of the instrument; it also includes a signal acquisition module, which includes a piezoelectric sensor, a pressure sensor, and a temperature sensor. The piezoelectric sensor interface is connected to a charge amplifier. The sensor signal output terminal of the signal acquisition module is connected to a controller, which is equipped with an analog-to-digital converter. The input terminal of the controller is connected to a key input circuit, and the controller is also communicatively connected to an LCD display circuit for displaying flow data. The controller is connected to the output module via an opto-isolator.

2. The impulse flow meter as described in claim 1, characterized in that: The power module includes a DC24V input terminal; the DC24V input terminal is connected to an LC filter circuit, which includes an inductor L1 and capacitors C32 and C35; the LC filter circuit is connected to a DC-DC buck converter chip U2, which is used to stably convert the filtered voltage to 3.3V; the output terminal of the DC-DC buck converter chip U2 is connected to output filter capacitors C36 and C7.

3. The impulse flow meter as described in claim 1, characterized in that: The signal acquisition module is connected to the sensor signal amplification circuit, which includes a multi-stage operational amplifier to amplify the weak millivolt-level signal from the sensor to the input range required by the analog-to-digital converter.

4. The impulse flow meter as described in claim 1, characterized in that: The key input circuit includes multiple independent key branches, each including a tactile switch; one end of the tactile switch is connected to a 3.3V power supply via a pull-up resistor, and the other end is grounded.

5. The impulse flow meter as described in claim 1, characterized in that: The output module includes: The analog output unit is used to convert the signals generated by the controller into 4-20mA current signals for output. Digital output unit, used to provide RS485 communication interface; The pulse output unit is used to convert the signal generated by the controller into a frequency or pulse signal output. The analog output unit includes a digital-to-analog converter chip U11, whose input terminal receives a PWM control signal from the controller; the signal output terminal of the digital-to-analog converter chip U11 is connected to cascaded operational amplifiers U12A and U12B; the signal output terminal of the operational amplifier U12B is connected to a voltage reference chip U13 and a transistor Q2 to form a constant current source circuit and generate a stable 4-20mA current output. The digital-to-analog converter chip U11 is connected to a reference voltage source, which consists of an operational amplifier U3, voltage divider resistors R23 and R25, and is used to provide a 2.5V reference voltage for the digital-to-analog converter chip. The pulse output unit includes an opto-isolator U32. The output terminal of the opto-isolator U32 is connected to a transistor switching amplifier circuit composed of transistors Q3, Q4, and Q5 to generate frequency or pulse signals.

6. The impulse flow meter as described in claim 1, characterized in that: The controller communicates with the external data storage circuit via the I²C bus.

7. The impulse flow meter as described in claim 1, characterized in that: The pluggable assembly also includes an insert that extends from the pipe wall into the pipe. One end of the insert is connected to the impact plate, and the other end is fixed to the pipe wall of the fluid pipe via a mounting base.

8. The impulse flow meter as described in claim 1, characterized in that: The plug-in assembly also includes an online sealing mechanism to prevent fluid leakage, with an online isolation ball valve installed below the online sealing mechanism.

9. A method for measuring flow rate in a fluid pipeline, using an impulse flow meter as described in any one of claims 1-8, characterized in that, Includes the following steps: S1. Signal Sensing and Acquisition: The fluid impacts the plate perpendicularly to sense the fluid's force. The fluid impact force is converted into a corresponding electrical signal by a force-sensitive element fixed at the root of the impact plate; Simultaneously acquire charge signals from force-sensitive elements, pressure sensors, and temperature sensors. S2, Signal Processing and Computation: a. Signal conditioning: Amplifying and filtering the acquired weak signals at the millivolt or charge level, and converting them into digital signals; b. Flow rate calculation: Based on the charge signal, the impact force F of the fluid on the impact plate is calculated. AC D ρν 2 Where: A is the effective area of ​​the impact plate; C D ρ is the drag coefficient of the impact plate; ρ is the density of the fluid; ν is the flow velocity of the fluid, and the flow rate Q is calculated. c. Multi-parameter compensation: The flow rate Q is compensated using the collected static pressure and temperature signals; S3, Flow Information Output: The compensated final traffic information will be output in at least one of the following ways: Analog output: Converts the flow rate value into a linear 4-20mA analog current signal output; Digital output: Outputs flow data via an RS485 digital communication interface; Pulse output: Converts the flow rate value into a proportional frequency or pulse signal output.

10. The method for measuring flow rate in a fluid pipeline as described in claim 9, characterized in that: Following S3, there is also S4, online maintenance: when maintenance or replacement is required, the plug-in assembly containing the impact plate and force-sensitive element is removed from the pipeline without stopping the flow of fluid in the pipeline by operating the online isolation ball valve and online sealing mechanism.

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