Verification device of ultrasonic wind speed sensor for coal mine tunnel

Abstract

The invention discloses a verification device of an ultrasonic wind measurement sensor for a coal mine tunnel, and relates to the technical field of verification devices. Comprising a test wind tunnel, the test wind tunnel comprises a calibration section, a contraction section, an experiment section and an expansion section which are sequentially connected and communicated, one end, far away from the experiment section, of the expansion section is connected with an air return shaft, the side wall of the experiment section is provided with an extending hole, and the inner wall of the experiment section is provided with a fixing support; the ultrasonic wind speed sensor is fixed on the fixing support, a humidity sensor, a barometer and a temperature sensor are further arranged in the experiment section, a dust nozzle of the coal mine dust spraying device extends into the experiment section, a pitot tube is arranged, a probe of the pitot tube enters the experiment section through an extending hole, and one end, far away from the probe, of the pitot tube is connected with a differential pressure sensor. According to the verification device of the ultrasonic wind sensor for the coal mine tunnel, the environment in the coal mine tunnel is simulated, and the ultrasonic wind speed sensor used in the coal mine tunnel is verified.

Description

Technical Field

[0001] The present invention relates to the technical field of calibration devices, and more particularly to a calibration device for an ultrasonic wind speed sensor used in a coal mine tunnel. Background Art

[0002] At present, ultrasonic wind speed sensors are widely used for real-time collection of wind speed during the construction of intelligent ventilation systems in mines. The principle is mainly to use the time it takes for ultrasonic waves to propagate in the air to calculate the wind speed. The propagation speed of ultrasonic waves in the air will be superimposed on the airflow speed in the wind direction. The accurate wind speed and wind direction can be obtained through calculation.

[0003] However, although this type of sensor has obvious advantages over traditional sensors in terms of accuracy, response speed, maintenance and scope of application, there are currently no relevant calibration procedures and standards to ensure that its measurement precision and accuracy can meet on-site needs.

[0004] Therefore, in order to further study the measurement accuracy and range of ultrasonic wind speed sensors, how to provide a device for calibrating the sensitivity of ultrasonic wind speed sensors in coal mine tunnels is an urgent problem that needs to be solved by those skilled in the art. Summary of the Invention

[0005] In view of this, the present invention provides a calibration device for an ultrasonic wind speed sensor used in a coal mine tunnel, which simulates the environment in a coal mine tunnel and calibrates the ultrasonic wind speed sensor used in the coal mine tunnel. To achieve the above purpose, the present invention adopts the following technical solutions:

[0006] The present invention provides a calibration device for an ultrasonic wind speed sensor for a coal mine tunnel, which is used for calibrating an ultrasonic wind speed sensor in a coal mine tunnel, comprising:

[0007] A test wind tunnel comprises a calibration section, a contraction section, a test section, and an expansion section, wherein the calibration section, contraction section, test section, and expansion section are sequentially connected and communicate with each other; the cross-sectional area of ​​the contraction section at one end near the calibration section is larger than the cross-sectional area of ​​the end near the test section; the cross-sectional area of ​​the expansion section at one end near the test section is smaller than the cross-sectional area of ​​the end away from the test section; the end of the expansion section away from the test section is connected to a return air shaft; an insertion hole is provided on a side wall of the test section; a fixing bracket is provided on an inner wall of the test section; the ultrasonic wind speed sensor is fixed on the fixing bracket; a humidity sensor, a barometer, and a temperature sensor are also provided in the test section;

[0008] A coal mine dust injection device, wherein the nozzle of the coal mine dust injection device extends into the interior of the experimental section;

[0009] A Pitot tube, wherein a probe of the Pitot tube enters the experimental section through an insertion hole, and a pressure difference sensor is connected to an end of the Pitot tube away from the probe.

[0010] Furthermore, an atomizing nozzle is provided in the experimental section, and an input end of the atomizing nozzle extends out of the experimental section and is connected to a water source.

[0011] Furthermore, it also includes a filter membrane, which is arranged on the outside of the static pressure hole and the total pressure hole of the Pitot tube and is used to filter the air entering the static pressure hole and the total pressure hole.

[0012] Furthermore, the coal mine dust injection device is an aerosol injection generator, which is used to inject coal mine dust into the experimental section.

[0013] Furthermore, the filter membrane is a polytetrafluoroethylene microporous membrane.

[0014] Furthermore, an observation window is provided on the side wall of the experimental section, and transparent glass is provided at the observation window.

[0015] Furthermore, pressure sensors are provided at both ends of the contraction section.

[0016] Furthermore, the calibration section and the contraction section overlap at their respective ends.

[0017] Furthermore, the Pitot tube and the ultrasonic wind speed sensor are symmetrically arranged on both sides of the experimental section.

[0018] It can be seen from the above technical solution that compared with the prior art, the present invention discloses a calibration device for an ultrasonic wind speed sensor for a coal mine tunnel, wherein the ultrasonic wind speed sensor is placed in an experimental section, the wind speed of the experimental section is measured, dust is sprayed into the experimental section through a coal mine dust injection device to simulate the environment in the coal mine tunnel, the dynamic pressure of the experimental section is measured through a Pitot tube, the theoretical wind speed of the experimental section is measured by a pressure difference method using dynamic pressure, humidity, temperature and air pressure, the theoretical wind speed is compared with the wind speed measured by the ultrasonic wind speed sensor, the measurement accuracy of the ultrasonic wind speed sensor in the coal mine tunnel is calibrated, and the accuracy of the ultrasonic wind speed sensor used in the coal mine tunnel is ensured. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0020] Figure 1A front view of an ultrasonic wind speed sensor for a coal mine tunnel provided by the present invention;

[0021] Figure 2 The present invention provides Figure 1 Enlarged view of point A in the middle;

[0022] Figure 3 A side view of the experimental section of the ultrasonic wind speed sensor for coal mine tunnels provided by the present invention;

[0023] Figure 4 A top view of the experimental section of the ultrasonic wind speed sensor for coal mine tunnels provided by the present invention;

[0024] Figure 5 This is a top view of the calibration device for the ultrasonic wind speed sensor for coal mine tunnels provided by the present invention.

[0025] In the figure: 1. Calibration section; 2. Contraction section; 3. Experimental section; 4. Expansion section; 5. Return air shaft; 6. Observation window; 7. Access hole; 8. Coal mine dust injection device; 9. Adjustment bracket; 10. Dust nozzle; 11. Ultrasonic wind speed sensor; 12. Pitot tube; 13. Atomizing nozzle. DETAILED DESCRIPTION

[0026] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0027] See also Figure 1-5 The embodiment of the present invention discloses a calibration device for an ultrasonic wind speed sensor for a coal mine tunnel, which is used for calibrating an ultrasonic wind speed sensor in a coal mine tunnel, comprising:

[0028] The test wind tunnel includes a calibration section 1, a contraction section 2, a test section 3, and an expansion section 4. The calibration section 1, the contraction section 2, the test section 3, and the expansion section 4 are sequentially connected and communicated with each other. The cross-sectional area of ​​the contraction section 2 at one end near the calibration section 1 is larger than the cross-sectional area of ​​the end near the test section 3. The cross-sectional area of ​​the expansion section 4 at one end near the test section 3 is smaller than the cross-sectional area of ​​the end away from the test section 3. The end of the expansion section 4 away from the test section 3 is connected to a return air shaft 5. An insertion hole 7 is provided on the side wall of the test section 3. A fixing bracket 9 is provided on the inner wall of the test section 3. An ultrasonic wind speed sensor 10 is fixed on the fixing bracket 9. A humidity sensor, a barometer, and a temperature sensor are also provided in the test section 3.

[0029] A coal mine dust injection device 8, wherein the dust nozzle 10 of the coal mine dust injection device 8 extends into the interior of the experimental section 3;

[0030] The Pitot tube 12 has a probe that extends into the experimental section 3 through the insertion hole 7 , and a differential pressure sensor is connected to one end of the Pitot tube 12 that is away from the probe.

[0031] When calibrating the ultrasonic wind speed sensor 10, a fan is placed at the end of the calibration section 1 away from the contraction section 2. The fan is used to blow air into the tunnel. The air blown by the fan forms a uniform airflow through the calibration section 1 and then enters the contraction section 2. The uniform airflow is accelerated by the contraction section 2 and enters the test section 3. The coal mine dust injection device 8 injects dust into the test section 3 to simulate the environment in the coal mine tunnel. The speed of the airflow entering the test section 3 is measured by the ultrasonic wind speed sensor 10. At the same time, the uniform airflow flows through the pitot tube 12 in the test section 3. At this time, the differential pressure sensor connected to the pitot tube 12 can measure the dynamic pressure of the test section 3. The dynamic pressure measured by the differential pressure sensor and the temperature measured by the temperature sensor are combined with the air pressure measured by the barometer and the humidity measured by the humidity sensor to calculate the theoretical wind speed value through the differential pressure method. By comparing the theoretical wind speed value with the wind speed value measured by the ultrasonic wind speed sensor 10, the measurement accuracy of the ultrasonic wind speed sensor 10 in the coal mine tunnel is verified.

[0032] The steps to calculate the theoretical wind speed value using the pressure difference method are as follows:

[0033] Calculate the absolute temperature T:

[0034] T=273.15+t

[0035] Where T is the absolute temperature and t is the temperature measured by the temperature sensor;

[0036] Calculate the saturated water vapor pressure P sat :

[0037]

[0038] Where, P sat is the saturated water vapor pressure at the current temperature, and T is the absolute temperature;

[0039] Calculate the air density ρ:

[0040]

[0041] Where: ρ is the air density, P0 is the air pressure measured by the barometer, The humidity of experimental section 3 measured by the humidity sensor, P sat is the saturated water vapor pressure at the current temperature, R is the dry air gas constant, and T is the absolute temperature;

[0042] Calculation of wind speed:

[0043] Where: v is the calculated theoretical wind speed;

[0044] The wind speed sensor is calibrated by comparing the calculated theoretical wind speed value with the wind speed value measured by the ultrasonic wind speed sensor 10 .

[0045] In some embodiments, the end of the Pitot tube 12 away from the experimental section 3 is connected to two pressure sensors. In this case, the pressure difference ΔP is calculated as:

[0046] ΔP=P 总压 -P 静压

[0047] Where: ΔP is the dynamic pressure, P 总压 is the total pressure hole pressure measured by the pressure sensor, P 静压 The pressure of the static pressure hole measured by the pressure sensor.

[0048] In some embodiments, an atomizing nozzle 13 is further provided in the experimental section 3 , and an input end of the atomizing nozzle 13 extends out of the experimental section 3 and is connected to a water source.

[0049] Water mist is sprayed into the experimental section 3 through the atomizing nozzle 13 to increase the humidity of the experimental section 3, so that the environment of the experimental section 3 is more in line with the real environment in the coal mine tunnel, ensuring the accuracy of the calibration result of the ultrasonic wind speed sensor 10.

[0050] In some embodiments, a filter membrane is further included. The filter membrane is disposed outside the static pressure hole and the total pressure hole of the Pitot tube 12 to filter the air entering the static pressure hole and the total pressure hole.

[0051] Impurities and water vapor in the air flow into the Pitot tube 12 are filtered through the filter membrane to prevent the impurities and water vapor in the air flow from clogging the total pressure hole and the static pressure hole of the Pitot tube 12, thereby ensuring accurate measurement of the pressure difference.

[0052] In some embodiments, the coal mine dust injection device 8 is an aerosol jet generator, which is used to inject coal mine dust into the experimental section 3.

[0053] In some embodiments, the filter membrane is a polytetrafluoroethylene microporous membrane.

[0054] In some embodiments, an observation window 6 is provided on the side wall of the experimental section 3 , and transparent glass is provided at the observation window 6 .

[0055] The calibration process of the ultrasonic wind speed sensor 10 is observed through the observation window 6 .

[0056] In some embodiments, pressure sensors are provided at both ends of the contraction section 2 .

[0057] The flow field characteristics of the contraction section 2 are monitored and verified by the pressure sensors at both ends of the contraction section 2 to ensure that the airflow reaches an ideal flow state before entering the experimental section 3.

[0058] In some embodiments, the ends of the calibration section 1 and the contraction section 2 that are close to each other coincide with each other.

[0059] By overlapping the calibration section 1 and the contraction section 2, the connection strength between the calibration section 1 and the contraction section 2 is ensured, and the air tightness of the connection between the calibration section 1 and the contraction section 2 is ensured.

[0060] In some embodiments, the Pitot tube 12 and the ultrasonic wind speed sensor 10 are symmetrically arranged on both sides of the experimental section 3 .

[0061] By symmetrically arranging the Pitot tube 12 and the ultrasonic wind speed sensor 10 on both sides of the experimental section 3, the consistency of the airflow state passing through the Pitot tube 12 and the ultrasonic wind speed sensor 10 is ensured, and the accuracy of the calibration of the ultrasonic wind speed sensor 10 is ensured.

[0062] In some embodiments, P = 101325 Pa, t = 25° C., Dynamic pressure 3Pa,

[0063] Calculate Psat:

[0064]

[0065] Calculate the density of moist air ρ:

[0066]

[0067] Calculate wind speed v:

[0068]

[0069] Comparing the measured wind speed with the calculated wind speed to calibrate the ultrasonic wind speed sensor 10;

[0070] Adjust the fan frequency to adjust the speed of the airflow blown out by the fan, and then verify the accuracy of the ultrasonic wind speed sensor 10 under different wind speed conditions. The ultrasonic wind speed sensor 10 that has passed the verification is used in the coal mine tunnel to ensure the accuracy of the wind speed measurement of the ultrasonic wind speed sensor 10 used in the coal mine tunnel.

[0071] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. Reference can be made to the common and similar parts between the various embodiments. For the devices disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple, and the relevant parts can be referred to the method description.

[0072] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A calibration device for an ultrasonic wind speed sensor for a coal mine tunnel, used for calibrating an ultrasonic wind speed sensor in a coal mine tunnel, characterized in that: include: A test wind tunnel comprises a calibration section, a contraction section, a test section, and an expansion section, wherein the calibration section, contraction section, test section, and expansion section are sequentially connected and communicate with each other; the cross-sectional area of ​​the contraction section at one end near the calibration section is larger than the cross-sectional area of ​​the end near the test section; the cross-sectional area of ​​the expansion section at one end near the test section is smaller than the cross-sectional area of ​​the end away from the test section; the end of the expansion section away from the test section is connected to a return air shaft; an insertion hole is provided on a side wall of the test section; a fixing bracket is provided on an inner wall of the test section; the ultrasonic wind speed sensor is fixed on the fixing bracket; a humidity sensor, a barometer, and a temperature sensor are also provided in the test section; A coal mine dust injection device, wherein the dust nozzle of the coal mine dust injection device extends into the interior of the experimental section; A Pitot tube, wherein a probe of the Pitot tube enters the experimental section through an insertion hole, and a pressure difference sensor is connected to an end of the Pitot tube away from the probe.

2. The calibration device for an ultrasonic wind speed sensor for a coal mine tunnel according to claim 1, characterized in that: An atomizing nozzle is also provided in the experimental section, and an input end of the atomizing nozzle extends out of the experimental section and is connected to a water source.

3. The calibration device for an ultrasonic wind speed sensor for a coal mine tunnel according to claim 1, characterized in that: It also includes a filter membrane, which is arranged on the outside of the static pressure hole and the total pressure hole of the Pitot tube and is used to filter the air entering the static pressure hole and the total pressure hole.

4. The calibration device for an ultrasonic wind speed sensor for a coal mine tunnel according to claim 1, characterized in that: The coal mine dust injection device is an aerosol jet generator, which is used to inject coal mine dust into the experimental section.

5. The calibration device for an ultrasonic wind speed sensor for a coal mine tunnel according to claim 3, characterized in that: The filter membrane is a polytetrafluoroethylene microporous membrane.

6. The calibration device for an ultrasonic wind speed sensor for a coal mine tunnel according to claim 1, characterized in that: An observation window is provided on the side wall of the experimental section, and transparent glass is provided at the observation window.

7. The calibration device for an ultrasonic wind speed sensor for a coal mine tunnel according to claim 1, characterized in that: Pressure sensors are provided at both ends of the contraction section.

8. The calibration device for an ultrasonic wind speed sensor for a coal mine tunnel according to claim 1, characterized in that: The calibration section and the contraction section overlap at one end close to each other.

9. The calibration device for an ultrasonic wind speed sensor for a coal mine tunnel according to claim 1, characterized in that: The Pitot tube and the ultrasonic wind speed sensor are symmetrically arranged on both sides of the experimental section.

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