Full-scale automatic calibration coal mine laser dust concentration detection device and method

Abstract

The invention relates to a full-scale automatic calibration coal mine laser dust concentration detection device and method, and belongs to the technical field of coal mine dust concentration detection. The device comprises a power supply and digital signal processing part and a dust concentration detection probe, the dust concentration detection probe comprises a dust guide plate, a dust concentration testing part and a control and signal processing circuit board; the dust concentration testing part comprises a laser, a dust concentration detection area, an optical filter, an optical trap, a scattered light intensity detector, two automatic calibration scattering sheets and a scattering sheet hiding groove. When the detection device works normally, the scattering sheet is hidden in the hiding groove, so that the scattering sheet is prevented from being polluted by dust; when the detection device needs to be calibrated, a digital signal is transmitted to the circuit board to control the motor to push the scattering sheet out of the scattering sheet hiding groove, the scattering sheet is made to be perpendicular to the laser beam, and it is guaranteed that the laser beam vertically passes through the center of the scattering sheet. The device is simple in structure, and can achieve the full-scale automatic calibration of the detection device.

Description

Technical Field

[0001] The invention belongs to the technical field of coal mine dust concentration detection, and relates to a full-range automatic calibration coal mine laser dust concentration detection device and method. Background Art

[0002] The hazard of coal mine dust is still a shortcoming of coal mine safety production. The dust generated during coal mine production is prone to cause coal mine dust explosions and pneumoconiosis. Therefore, it is urgent to speed up coal mine dust control, realize accurate detection of coal mine dust, and create a clean coal mine environment.

[0003] The light scattering method for detecting dust concentration is widely used, with high accuracy and sensitivity. It is also the earliest technology used in coal mine dust concentration sensors. However, the coal mine environment is complex, the dust concentration is high, and the water vapor content is high. It is very easy for the scattered light intensity sensing device to be contaminated by dust, which reduces the detection accuracy of the light scattering method dust concentration sensor or even makes it ineffective. Workers are required to frequently maintain the dust sensor, and the maintenance process is extremely complicated and easy to damage the detection unit. Therefore, it is difficult to apply the light scattering method for detecting dust concentration in coal mines. Therefore, there is an urgent need for a dust concentration detection device that can automatically calibrate to achieve accurate detection of dust concentration. Summary of the invention

[0004] In view of this, the purpose of the present invention is to provide a full-range automatic calibration coal mine laser dust concentration detection device and method to solve the problem that the current dust concentration detection device has low sensitivity due to the contamination of the photodiode, resulting in large dust concentration detection errors. At the same time, it also solves the problem that the current detection method only requires single-point calibration of the dust concentration test device, and the equipment is complex and large.

[0005] In order to achieve the above object, the present invention provides the following technical solutions:

[0006] A full-range automatic calibration coal mine laser dust concentration detection device, comprising a power supply and digital signal processing part and a dust concentration detection probe; the power supply and digital signal processing part comprises a circuit board 8, a display window 3 and an audible and visual alarm 2; the dust concentration detection probe comprises a dust deflector 5, a dust concentration test part 10 and a control and signal processing circuit board 25; the dust concentration test part 10 comprises a laser 17, a dust concentration detection area 18, a filter 19, a light trap 20, and a scattered light intensity detector 24;

[0007] Under the action of wind flow, external dust enters the dust concentration detection area 18 inside the detection device through the guide hole 13 of the dust guide plate 5, and then flows out through the guide hole at the other end of the dust guide plate 5 under the action of wind flow; the laser 17 emits a laser beam through the dust concentration detection area 18, and then reaches the light trap 20, the dust in the dust concentration detection area 18 scatters the laser, the scattered light passes through the filter 19 and reaches the scattered light intensity detector 24, the scattered light intensity detector 24 transmits the detection value to the control and signal processing circuit board 25, and then transmits the digital signal to the circuit board 8 through the shielding line 9, performs secondary calculations to obtain the dust concentration value of the detection area, displays the detection value in the display window 3, and uploads the test result to the monitoring system through the power supply and signal terminal 4, if the detected dust concentration value is greater than the set threshold, the sound and light alarm 2 will send a warning signal.

[0008] Preferably, the dust concentration testing part 10 also includes two automatically calibrated scattering plates, namely scattering plate I 15 and scattering plate II 21 and a scattering plate hidden slot; when the dust concentration detection device is working normally, the scattering plates are hidden in the hidden slot to prevent the scattering plates from being contaminated by dust; when the dust concentration detection device needs to be calibrated, the digital signal is transmitted to the circuit board 8 to control the motor to push the scattering plate out of the scattering plate hidden slot, and place the scattering plate perpendicular to the laser beam to ensure that the laser beam passes vertically through the center of the scattering plate.

[0009] Furthermore, the scattering sheet I15 has high purity, and the scattered light generated by the designed scattering sheet is equivalent to 200mg / m 3 The scattered light generated by the coal powder, the purity of the scattering sheet Ⅱ21 is low, and the scattered light generated by the designed scattering sheet is equivalent to 600mg / m 3 The scattered light generated by the coal powder, the superposition of scattering sheet Ⅰ15 and scattering sheet Ⅱ21, is equivalent to 800mg / m 3 The scattered light produced by the coal powder;

[0010] The calibration status includes four states:

[0011] State 1: Both the scattering sheet Ⅰ15 and the scattering sheet Ⅱ21 are in the hidden slot, which is the zero point, and the dust concentration test value is a1;

[0012] State 2: Scattering sheet I 15 is in the hidden slot, scattering sheet II 21 is in the dust concentration detection area 18, and the simulated dust concentration is 200 mg / m 3 Calibration sheet, dust concentration test value a2;

[0013] State 3: Scattering sheet I 15 is in the dust concentration detection area 18, scattering sheet II 21 is in the hidden slot, and the simulated dust concentration is 600 mg / m 3 Calibration sheet, dust concentration test value a3;

[0014] State 4: Scattering sheet I15 and scattering sheet II21 are both in dust concentration detection area 18, and the simulated dust concentration is 800 mg / m 3 Calibration sheet, dust concentration test value a4.

[0015] Further, the automatic calibration process is specifically as follows: first, a judgment is made. If the test error of any of the four states exceeds 15%, that is, formula S1 is satisfied, the circuit board 8 will issue an instruction to perform full-scale automatic calibration. The dust concentration detection device receives the calibration instruction of the circuit board 8, turns off the laser, hides the scattering sheet I 15 and the scattering sheet II 21, and the test data is (a1, 0) (test value before calibration, calibration target value). Turn on the laser 17, push out the scattering sheet I, hide the scattering sheet II, and the test data is (a2, 200) (test value before calibration, calibration target value). Turn on the laser, push out the scattering sheet II, hide the scattering sheet I, and the test data is (a3, 600) (test value before calibration, calibration target value). Turn on the laser, push out the scattering sheet II, push out the scattering sheet I, and the test data is (a4, 800) (test value before calibration, calibration target value). Then, the full-scale automatic calibration is performed according to formula S2. After the calibration is completed, turn on the laser and return to the detection state.

[0016] Conditional formula for entering calibration state:

[0017]

[0018] When any of the four conditions is met, the sensor enters the full range automatic calibration process;

[0019] Full range automatic calibration formula:

[0020]

[0021] Where y is the calibration target value and x is the test value before calibration.

[0022] The beneficial effects of the present invention are as follows: the present invention solves the problem of reduced detection accuracy of the dust concentration sensor in a coal mine after being contaminated by dust, adopts a simple structure and can realize automatic calibration of the dust concentration detection device over the entire range, rather than single-point calibration, thereby ensuring the detection accuracy of each point in the full range of the dust concentration detection equipment, and ensuring the validity of the detection data of the dust concentration sensor in underground coal mines, and the device and method have high adaptability to harsh dust environments.

[0023] Other advantages, objectives and features of the present invention will be described in the following description to some extent, and to some extent, will be obvious to those skilled in the art based on the following examination and study, or can be taught from the practice of the present invention. The objectives and other advantages of the present invention can be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be described in detail below in conjunction with the accompanying drawings, wherein:

[0025] Figure 1 This is a schematic diagram of the structure of the full-range automatic calibration coal mine laser dust concentration detection device of the present invention;

[0026] Figure 2 This is a schematic diagram of the structure of the dust concentration test part;

[0027] Figure 3 This is a schematic diagram of the internal structure of the dust concentration detection probe;

[0028] Figure 4 It is a schematic diagram of calibration status;

[0029] Figure 5 This is a schematic diagram of calibration status 2;

[0030] Figure 6 This is a schematic diagram of calibration status three;

[0031] Figure 7 This is a schematic diagram of calibration status 4;

[0032] Figure 8 This is the full range automatic calibration flow chart.

[0033] Figure markings: 1-bracket, 2-sound and light alarm, 3-display window, 4-power and signal terminals, 5-dust deflector, 6-front shell, 7-rear shell, 8-circuit board, 9-shielding wire (connecting the probe), 10-dust concentration test part, 11-fixing bolt, 12-probe metal shell, 13-(dust) guide hole, 14-scattering plate I hidden groove, 15-scattering plate I, 16-motor I, 17-laser, 18-dust concentration detection area, 19-filter, 20-light trap, 21-scattering plate II, 22-motor II, 23-scattering plate II hidden groove, 24-scattered light intensity detector, 25-control and signal processing circuit board. DETAILED DESCRIPTION

[0034] The following describes the embodiments of the present invention by specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments only illustrate the basic concept of the present invention in a schematic manner, and the following embodiments and the features in the embodiments can be combined with each other without conflict.

[0035] Among them, the drawings are only used for illustrative explanations, and they only represent schematic diagrams rather than actual pictures, and should not be understood as limitations on the present invention. In order to better illustrate the embodiments of the present invention, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of actual products. For those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted.

[0036] The same or similar numbers in the drawings of the embodiments of the present invention correspond to the same or similar parts; in the description of the present invention, it should be understood that if the terms "upper", "lower", "left", "right", "front", "rear", etc. indicate the orientation or position relationship, they are based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, the terms describing the position relationship in the drawings are only used for illustrative purposes and cannot be understood as limiting the present invention. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0037] See also Figures 1 to 8 The embodiment of the present invention provides a full-range automatic calibration coal mine laser dust concentration detection device, including a power supply and a digital signal processing part and a dust concentration detection probe. Figure 1 and Figure 2 shown.

[0038] The power supply and digital signal processing part mainly includes the device bracket 1, sound and light alarm 2, display window 3, power supply and signal terminal 4, circuit board 8, front shell 6, rear shell 7, shielding wire (connecting the probe) 9. The dust concentration detection probe includes the dust concentration test part 10 and the dust guide plate 5 (with a 40mm*5mm guide hole 13), fixing bolts 11, and the metal shell 12 of the probe.

[0039] The working process of the dust concentration detection device is as follows: dust outside the dust enters the internal test area of ​​the detection device through the guide hole 13 of the dust guide plate 5 under the action of wind flow, and then flows out through the guide hole at the other end of the dust guide plate 5 under the action of wind flow. Dust in the internal test area of ​​the dust concentration detection probe scatters the laser, and the scattered light passes through the filter 19 and reaches the scattered light intensity detector 24. The scattered light intensity detector 24 transmits the detection value to the control and signal processing circuit board 25, and then transmits the digital signal to the circuit board 8 through the shielding line 9. The secondary operation is performed to obtain the dust concentration value of the test area, and the detection value is displayed in the display window 3, and the test result is uploaded to the monitoring system through the power supply and signal terminal 4. If the detected dust concentration value is greater than the set threshold, the sound and light alarm 2 will send a warning signal.

[0040] Self-calibration function of dust concentration detection device: The calibration function is mainly reflected in the internal device of the dust concentration detection part, such as Figure 3 As shown, the laser 17 emits a laser beam which passes through the dust concentration detection area 18 and then reaches the light trap 20. The scattered light passes through the filter to reach the scattered light intensity detector 24 to detect the dust concentration. This device adds two automatically calibrated scattering plates, namely scattering plate Ⅰ15 and scattering plate Ⅱ21. The present invention focuses on the adaptability of the dust concentration device to harsh conditions. In order to accurately calibrate, it is necessary to ensure that the scattering plate is not contaminated by dust and keep the scattering plate clean for a long time. Therefore, a scattering plate hidden groove is set in the device. When the sensor is working normally, the scattering plate is hidden in the hidden groove to prevent the scattering plate from being contaminated by dust. When the dust concentration detection device needs to be calibrated, the controller controls motors Ⅰ and Ⅱ to push the scattering plate out of the scattering plate hidden groove, and make the scattering plate perpendicular to the laser beam to ensure that the laser beam passes vertically through the center of the scattering plate.

[0041] System control flow chart, such as Figure 8 As shown: The dust concentration detection device works in the coal mine under harsh conditions for a long time. The dust will contaminate the filter in the dust concentration detector probe, making the intensity of scattered light passing through the filter lower, resulting in a low output value of the scattered light intensity detector. Therefore, it is necessary to design an automatic calibration device for the sensor to correct the detection value of the sensor at any time to ensure that the dust concentration detection device has a high detection accuracy.

[0042] There is a difference between the designed scattering sheet Ⅰ1 and scattering sheet Ⅱ2. The scattering sheet Ⅰ1 has high purity. The scattered light produced by the designed scattering sheet is equivalent to 200mg / m 3 The scattered light generated by the coal powder, the purity of the scattering sheet Ⅱ2 is low, and the scattered light generated by the designed scattering sheet is equivalent to 600mg / m 3The scattered light generated by the coal powder is equal to the scattered light generated by 800mg / m3 coal powder. The calibration state diagram is shown in Figure 4-7. State 1 is zero point, test value a1, and state 2 is a simulated dust concentration of 200mg / m 3 The calibration piece test value is a2, and state three is the simulated dust concentration of 600 mg / m 3 The calibration piece test value is a3, and state 4 is the simulated dust concentration of 800 mg / m 3 Calibration piece test value a4.

[0043] The full range automatic calibration process is as follows Figure 8 As shown. First, a judgment is made. If the test error of any of the four states exceeds 15% (judgment formula S1), the controller will issue an instruction to perform full-scale automatic calibration. The dust concentration detection device receives the calibration instruction from the controller, turns off the laser, hides the scattering plates I and II, and the test data is (a1, 0) (test value before calibration, calibration target value). Turn on the laser, push out the scattering plate I, hide the scattering plate II, and the test data is (a2, 200) (test value before calibration, calibration target value). Turn on the laser, push out the scattering plate II, hide the scattering plate I, and the test data is (a3, 600) (test value before calibration, calibration target value). Turn on the laser, push out the scattering plate II, push out the scattering plate I, and the test data is (a4, 800) (test value before calibration, calibration target value). Then, the full-scale automatic calibration is performed through formula S2. After the calibration is completed, turn on the laser and return to the detection state.

[0044] Conditional formula for entering calibration state:

[0045]

[0046] When any of the four conditions is met, the sensor enters the full range automatic calibration process;

[0047] Full range automatic calibration formula:

[0048]

[0049] Where y is the calibration target value and x is the test value before calibration.

[0050] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution, which should be included in the scope of the claims of the present invention.

Claims

1. A full-range automatic calibration coal mine laser dust concentration detection device, characterized in that: The device comprises a power supply and digital signal processing part and a dust concentration detection probe; the power supply and digital signal processing part comprises a circuit board (8); the dust concentration detection probe comprises a dust deflector (5), a dust concentration test part (10) and a control and signal processing circuit board (25); the dust concentration test part (10) comprises a laser (17), a dust concentration detection area (18), a filter (19), a light trap (20), and a scattered light intensity detector (24); Under the action of wind flow, external dust enters the dust concentration detection area (18) inside the detection device through the guide hole (13) of the dust guide plate (5), and then flows out through the guide hole at the other end of the dust guide plate (5) under the action of wind flow; the laser (17) emits a laser beam through the dust concentration detection area (18) and then reaches the light trap (20), the dust in the dust concentration detection area (18) scatters the laser, the scattered light passes through the filter (19) and reaches the scattered light intensity detector (24), the scattered light intensity detector (24) transmits the detection value to the control and signal processing circuit board (25), and then transmits the digital signal to the circuit board (8) through the shielding line (9), and performs secondary calculation to obtain the dust concentration value of the detection area.

2. The full-range automatic calibration coal mine laser dust concentration detection device according to claim 1 is characterized in that: The dust concentration testing part (10) also includes two automatically calibrated scattering sheets, namely scattering sheet I (15) and scattering sheet II (21), and a scattering sheet hidden slot; when the dust concentration detection device is working normally, the scattering sheets are hidden in the hidden slot to prevent the scattering sheets from being contaminated by dust; when the dust concentration detection device needs to be calibrated, a digital signal is transmitted to the circuit board (8) to control the motor to push the scattering sheet out of the scattering sheet hidden slot, and to place the scattering sheet perpendicular to the laser beam to ensure that the laser beam passes vertically through the center of the scattering sheet.

3. The full-range automatic calibration coal mine laser dust concentration detection device according to claim 2 is characterized in that: The scattering sheet I (15) has high purity and the scattering light generated by the designed scattering sheet is equivalent to 200mg / m 3 The scattered light generated by the coal powder is of low purity. The scattered light generated by the designed scattering sheet is equivalent to 600 mg / m 3 The scattered light generated by the coal powder, the superposition of scattering sheet I (15) and scattering sheet II (21), is equivalent to 800 mg / m 3 The scattered light produced by the coal powder; The calibration status includes four states: State 1: Both scattering sheet I (15) and scattering sheet II (21) are in the hidden slot, which is zero point, and the dust concentration test value is a1; State 2: Scattering sheet I (15) is in the hidden slot, scattering sheet II (21) is in the dust concentration detection area (18), simulated dust concentration is 200 mg / m 3 Calibration sheet, dust concentration test value a2; State 3: Scattering sheet I (15) is in the dust concentration detection area (18), scattering sheet II (21) is in the hidden slot, and the simulated dust concentration is 600 mg / m 3 Calibration sheet, dust concentration test value a3; State 4: Scattering sheet I (15) and scattering sheet II (21) are both in the dust concentration detection area (18), and the simulated dust concentration is 800 mg / m 3 Calibration sheet, dust concentration test value a4.

4. The full-range automatic calibration coal mine laser dust concentration detection device according to claim 3 is characterized in that: The automatic calibration process is specifically as follows: firstly, a judgment is made. If the test error of any of the four states exceeds 15%, that is, the formula S1 is satisfied, the circuit board (8) will issue an instruction to perform full-scale automatic calibration. The dust concentration detection device receives the calibration instruction from the circuit board (8), turns off the laser, hides the scattering sheet I (15) and the scattering sheet II (21), and the test data is (a1, 0). The laser (17) is turned on, the scattering sheet I is introduced, the scattering sheet II is hidden, and the test data is (a2, 200). The laser is turned on, the scattering sheet II is introduced, the scattering sheet I is hidden, and the test data is (a3, 600). The laser is turned on, the scattering sheet II is introduced, the scattering sheet I is introduced, and the test data is (a4, 800). Then, the full-scale automatic calibration is performed according to the formula S2. After the calibration is completed, the laser is turned on and the detection state is returned. Conditional formula for entering calibration state: When any of the four conditions is met, the sensor enters the full range automatic calibration process; Full range automatic calibration formula: Where y is the calibration target value and x is the test value before calibration.

5. The full-range automatic calibration coal mine laser dust concentration detection device according to any one of claims 1 to 4, characterized in that: The power supply and digital signal processing part also includes a display window (3) and an audible and visual alarm (2); when the circuit board (8) performs secondary calculations to obtain a dust concentration value in the detection area, the detection value is displayed in the display window (3), and the test result is uploaded to the monitoring system through the power supply and signal terminal (4); if the detected dust concentration value is greater than a set threshold value, the audible and visual alarm (2) sends out a warning signal.

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