Fluid measurement experiment device

Abstract

The utility model belongs to the field of teaching experiment equipment, and particularly relates to a fluid measurement experiment device. Comprising an induced draft fan used for driving air to flow so that the air can obtain the flowing speed; the frequency converter is used for changing the rotating speed of the induced draft fan and further changing the air flowing speed, namely air speed; the ventilation pipeline is used for providing a specified path for flowing air, the two different ventilation pipelines are applied, and the variable-diameter pipeline can obtain different flow speeds under the same flow through measurement according to different circulation sections; and the other pipe is a transparent square pipe, so that students can measure and calculate the wind speed and the flow according to the Bernoulli principle. The pitot tube measurement system is used for being inserted into the ventilation pipeline for parameter measurement, and the reference measurement mechanism is used for verifying measurement data.

Description

Technical Field

[0001] The utility model belongs to the field of teaching experimental equipment, and in particular relates to a fluid measurement experimental device. Background Art

[0002] Fluid mechanics is a key discipline in engineering and physics, and the principles of measuring flow velocity and flow rate are a core component of fluid mechanics experimental teaching. While traditional fluid measurement devices can meet basic experimental requirements, in practice, students often struggle to intuitively understand the key physical phenomena involved in the measurement process. Furthermore, the inflexible structure of the devices hinders engagement and hands-on experience. Furthermore, many measurement devices lack real-time data calibration and visualization support, making it difficult for students to understand experimental principles and analyze data.

[0003] Therefore, designing a fluid measurement experimental device specifically for teaching is a practical requirement for students to understand the core principles of fluid velocity and flow measurement and master common measurement methods through intuitive observation and independent operation. In particular, by incorporating modern data acquisition and control technologies, students can more easily obtain real-time experimental data, which helps deepen their understanding of the principles of fluid dynamics measurement. Utility Model Content

[0004] In order to solve the above problems, the present invention provides a new technical solution:

[0005] A fluid measurement experimental device, comprising:

[0006] Induced draft fan is used to drive the air to flow and make the air gain flow speed;

[0007] The frequency converter is used to change the speed of the induced draft fan, thereby changing the air flow speed, that is, the wind speed;

[0008] Ventilation ducts are used to provide a designated path for flowing air. Two different types of ventilation ducts are used in this application. One is a variable diameter duct, which can be measured to obtain different flow rates at different flow cross-sections under the same flow rate; the other is a transparent square tube, which allows students to experience using Bernoulli's principle to measure wind speed and flow.

[0009] Pitot tube measuring system for insertion into ventilation ducts to measure parameters,

[0010] Reference measurement institutes for verifying measurement data.

[0011] Furthermore, the device also includes a computer control unit for controlling the frequency converter and receiving data related to the reference measurement mechanism. The computer interface is connected to the collected data to make the experiment more efficient.

[0012] Furthermore, the Pitot tube measurement system includes a Pitot tube body and a differential pressure indicator mechanism, which is a parallel level tube or differential pressure transmitter. The parallel level tube or differential pressure transmitter can display the static and dynamic pressures of a fluid flowing through the Pitot tube, thereby obtaining a pressure differential. The fluid's flow velocity and flow rate can then be calculated using the Bernoulli principle.

[0013] Furthermore, the reference measurement mechanism includes a vortex flowmeter for verifying the measurement results.

[0014] Furthermore, the ventilation duct is a variable diameter duct, which has three or more different inner diameters. This allows users to intuitively experience the change in flow rate when the same flow rate of fluid flows through cross-sectional areas with different inner diameters.

[0015] Furthermore, at least one detection hole is provided in each section of the variable diameter pipe with different inner diameters for inserting the Pitot tube body.

[0016] Furthermore, the ventilation duct is a transparent square tube, and a plurality of detection holes are evenly distributed on the same cross section of the square tube.

[0017] Furthermore, a depth reference line is provided on the side wall of the ventilation duct, so that the depth position of the pitot tube can be located relatively accurately in the experiment.

[0018] Furthermore, an angle reference line is provided on the upper surface of the ventilation duct to reduce measurement errors caused by angle deviations when inserting the same Pitot tube into the duct at different times during the experiment.

[0019] The utility model has the following beneficial effects:

[0020] This device, combining a variable-diameter pipe and a transparent square tube, allows students to observe air flow and experience the effects of varying pipe diameters on fluid velocity, visually demonstrating the practical application of Bernoulli's principle. The varying cross-sections within the variable-diameter pipe provide a variety of flow velocity conditions, allowing students to observe the effect of varying cross-sections on flow velocity at the same flow rate. The transparent square tube further enhances the visualization of the experiment, allowing students to clearly see the Pitot tube during measurement, thereby deepening their understanding of the fundamental principles of fluid mechanics.

[0021] This device is equipped with two measuring devices: a Pitot tube measurement system and a vortex flowmeter, forming the primary measurement and calibration system. The Pitot tube measures static and dynamic pressures to obtain a pressure differential, which is then used to calculate flow velocity and flow rate based on the Bernoulli principle. The vortex flowmeter acts as a reference measurement mechanism to verify and calibrate the data, ensuring the accuracy of the measured data. This data calibration process helps students understand the differences between different measurement methods and enhances the reliability of experimental results.

[0022] The device controls the induced draft fan speed through a computer control unit linked to a frequency converter, enabling rapid adjustment of wind speed to meet a variety of experimental conditions. A computer interface connects to the data collected by the reference measurement mechanism, enabling real-time data acquisition and processing. This makes experimental operations more convenient and efficient, reducing manual errors. Real-time data acquisition and visualization capabilities allow students to intuitively analyze data changes and quickly draw experimental conclusions.

[0023] The device features inspection holes at different inner diameter sections of the ventilation duct. Students can insert the pitot tube at different locations, varying the depth and angle to perform multi-directional measurements. The inspection holes are evenly spaced across the cross-section of the transparent square tube. Depth reference lines are also provided on the side walls, and angle reference lines on the top surface. This facilitates student positioning and alignment of measurement points during the experiment, reducing errors caused by angle and depth deviations and improving the accuracy of experimental operations.

[0024] This device is suitable for various teaching scenarios, including flow velocity and flow measurement and Bernoulli equation verification. The variable-diameter pipe and various pipe diameter designs allow students to experience the distribution of different fluid flow velocities. The Pitot tube measurement system supports measurement in multiple positions and directions, meeting the needs of diverse experimental content and greatly enhancing the device's teaching adaptability. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a schematic diagram of the connection of the induced draft fan and the variable diameter pipe and other equipment in the first embodiment of the present utility model;

[0026] Figure 2 This is an overall schematic diagram of the second embodiment of the present utility model;

[0027] Figure 3 This is a schematic diagram of the connection between the induced draft fan and the square tube in Example 2 of the present utility model;

[0028] Figure 4 It is a partial cross-sectional schematic diagram of the second embodiment of the present utility model.

[0029] 1. Induced draft fan; 2. Frequency converter; 3. Control unit; 4. Reducer pipe; 5. Inspection hole; 6. Pitot tube; 7. Transparent square tube; 8. Inspection hole; 9. End cover; 10. Elastic gasket; 11. Locking ring; 12. Static pressure outlet; 13. Dynamic pressure outlet; 14. Differential pressure transmitter; 15. Vortex flowmeter; 16. Depth reference line; 17. Angle reference line. DETAILED DESCRIPTION

[0030] Example 1:

[0031] A fluid measurement experimental device comprises an induced draft fan 1 and a frequency converter 2 for driving the induced draft fan 1. The frequency converter 2 is connected to a control host 3.

[0032] The air outlet of the induced draft fan 1 is connected to a variable diameter pipe 4, the cross section of which is circular and has five different inner diameters, each section of which is provided with a detection hole 8 for inserting a pitot tube 6 for measurement.

[0033] Different results can be measured at measuring points with different inner diameters to verify the flow velocity changes brought about by different inner diameter sections at the same flow rate.

[0034] Example 2:

[0035] A fluid measurement experimental device comprises an induced draft fan 1 and a frequency converter 2 for driving the induced draft fan 1. The frequency converter 2 is connected to a control host 3.

[0036] The air outlet of the induced draft fan 1 is connected to a transparent square tube 7. Multiple test holes 8 are evenly spaced across the same cross-section of its upper wall. The test holes 8 where the pitot tube 6 is not inserted are capped with end caps 9. When the pitot tube 6 is inserted to the specified depth, it is locked with a locking ring 11 equipped with an elastic washer 10. The static pressure outlet 12 and dynamic pressure outlet 13 of the pitot tube 6 are connected to the two ends of a differential pressure transmitter, respectively. The differential pressure transmitter is connected to the control unit 3. The pressure differential value is displayed on the display screen of the control unit 3. A vortex flowmeter 15 is also installed on the measuring square tube and connected to the control unit 3.

[0037] A depth reference line 16 is provided on the side wall of the transparent square tube 7 ; an angle reference line 17 is provided on one side of the top detection hole 8 , and the angle reference line 17 is parallel to the direction of the square tube.

[0038] Experimental procedures

[0039] 1. Select the experimental pitot tube 6, record the number and calibration coefficient of the pitot tube 6, and fill in the table;

[0040] 2. According to the principle for determining the characteristic velocity point (select one of the three methods: the isotropic method, the logarithmic linear method, and the Chebyshev method), calibrate the vertical measuring rod of the pitot tube 6;

[0041] 3. Turn on the centrifugal fan;

[0042] 4. Adjust the opening of the air regulating valve and wait for 3 minutes to allow the fan to operate stably;

[0043] 5. Record atmospheric temperature;

[0044] 6. Read the measured flow value from the standard flow meter (vortex flowmeter 15);

[0045] 7. Insert the Pitot tube 6 and measure the differential pressure (i.e., dynamic pressure value) at three positions corresponding to the method according to the principle of determining the selected characteristic velocity point;

[0046] 8. Adjust the opening of the air regulating valve, repeat steps 4 to 7 twice, and then measure the values ​​at two different flow rates;

[0047] 9. After measuring the data under three different flow rates, the experiment ends.

Claims

1. A fluid measurement experimental device, characterized in that: The device comprises: Induced draft fan, used to drive the air to flow; A frequency converter, used to change the speed of the induced draft fan; Ventilation ducts, used to provide designated paths for moving air; A Pitot tube measurement system, used for inserting into the ventilation duct to measure parameters; Reference measurement institutes for verifying measurement data.

2. A fluid measurement experimental device according to claim 1, characterized in that: It also includes a computer control unit for controlling the frequency converter and receiving data related to the reference measurement mechanism.

3. A fluid measurement experimental device according to claim 1, characterized in that: The Pitot tube measurement system includes a Pitot tube body and a pressure difference indicating mechanism, and the pressure difference indicating mechanism is a parallel liquid level tube or a pressure difference transmitter.

4. A fluid measurement experimental device according to claim 1, characterized in that: The reference measurement mechanism includes a vortex flowmeter.

5. A fluid measurement experimental device as claimed in claim 3, characterized in that: The ventilation duct is a variable diameter duct, and the variable diameter duct has more than three different inner diameters at the same time.

6. A fluid measurement experimental device according to claim 5, characterized in that: The different inner diameter sections of the variable diameter pipe are provided with at least one detection hole for inserting the Pitot tube body.

7. A fluid measurement experimental device according to claim 1, characterized in that: The ventilation duct is a transparent square tube, and a plurality of detection holes are evenly distributed on the same cross section of the square tube.

8. A fluid measurement experimental device according to claim 7, characterized in that: The side wall of the ventilation duct is provided with a depth reference line.

9. A fluid measurement experimental device according to claim 7, characterized in that: An angle reference line is provided on the upper surface of the ventilation duct.

Images