Multi-probe smoke sensor with low false alarm rate for underground coal mine

Abstract

The utility model relates to the technical field of smoke sensors, in particular to a low-false-alarm-rate multi-probe smoke sensor for an underground coal mine, which comprises a transmitter and a secondary instrument, the transmitter comprises a transmitter electrical assembly packaged by epoxy, the transmitter electrical assembly comprises a transmitter plate, a probe plate and an optical labyrinth which are connected together, and the optical labyrinth is arranged on the transmitter plate. A gas-sensitive probe, a temperature and humidity probe and a photoelectric probe are mounted on the probe plate, a single chip microcomputer I is arranged on the transmitter plate, and the single chip microcomputer I receives sampling temperature, humidity and smoke information collected by the temperature and humidity probe, the gas-sensitive probe and the photoelectric probe and converts the sampling temperature, humidity and smoke information into switching value digital signals; the secondary instrument is connected with the transmitter through the wire harness, the secondary instrument comprises a single-chip microcomputer II, a sound-light alarm circuit and a display circuit, the single-chip microcomputer II performs data analysis on the switching value digital signal, the data is displayed through the display circuit, and sound-light alarm can be realized through the sound-light alarm circuit. According to the utility model, the influence of painting on the sensor is solved; and the transmitter can be independently replaced.

Description

TECHNICAL FIELD

[0001] The utility model relates to a smoke sensor technology field especially a low false alarm rate multi-probe smoke sensor for underground coal mine. BACKGROUND

[0002] The smoke of fire is a mixture of gas, liquid and solid particles, which has physical characteristics such as volume, mass, temperature and charge. According to the above physical characteristics, there are three principles for smoke detection: ion type, optical type and gas sensitive type. Among them, the gas sensitive type smoke sensor is composed of a heating wire and a sensitive material. The heating wire can heat the sensitive material to several hundred degrees Celsius. The difficulty of current passing depends on the number of free electrons in the sensitive material. When the sensor is in clean air, the oxygen in the air will capture free electrons, reducing the number of free electrons in the sensitive material, causing the sensor resistance to rise, making it difficult for current to pass. When the sensor contacts reducing gas, oxygen will react with these gases to release electrons, reducing the sensor resistance and making it easier for current to pass. The gas sensitive type smoke sensor is less affected by dust, but is affected by paint, alcohol, propane, methane, formaldehyde and other gases. Since the standardization of construction in underground coal mines requires painting, paint is easy to trigger false alarms of gas sensitive type smoke sensors.

[0003] Photoelectric smoke sensors are sensitive to smoldering smoke (slow burning phenomenon without flame) but are easily affected by dust and water vapor. When water is sprayed to remove dust in underground coal mines, water droplets can enter the air chamber and easily trigger false alarms of photoelectric smoke sensors.

[0004] Ion type smoke sensors are suitable for detecting open fires and are sensitive to small particle smoke (i.e. smoke particles are very small when the flame burns vigorously).

[0005] Therefore, the existing mine smoke sensor often has false alarm phenomena when used in underground coal mines due to high heat, high humidity, high dust, painting and other environmental influences. INVENTION CONTENTS

[0006] The technical problem to be solved by the utility model is to solve the problems of the prior art in the above background technology, and to provide a low false alarm rate multi-probe smoke sensor for underground coal mines.

[0007] The technical solution adopted by the utility model to solve the technical problem is: a low false alarm rate multi-probe smoke sensor for underground coal mines, comprising:

[0008] The transmitter comprises an epoxy encapsulated transmitter electrical assembly, which comprises a transmitter board, a probe board and an optical labyrinth connected together, the probe board is provided with a gas sensitive probe, a temperature and humidity probe and a photoelectric probe, the transmitter board is provided with a single-chip microcomputer I, the single-chip microcomputer I receives the sampling temperature and humidity and smoke information collected by the temperature and humidity probe, the gas sensitive probe and the photoelectric probe, and converts them into on-off digital signals;

[0009] The secondary instrument is connected with the transmitter through a wire harness, and comprises a single-chip microcomputer II, an audible and visual alarm circuit and a display circuit, the single-chip microcomputer II performs data analysis on the on-off digital signals, displays them through the display circuit, and can realize audible and visual alarm through the audible and visual alarm circuit.

[0010] Further, one end of the wire harness is provided with a straight pin connector connected with the transmitter board, and the other end of the wire harness is provided with a terminal connected with the secondary instrument.

[0011] Further, one surface of the transmitter board facing the probe board is welded with a surface-mounted nut column, one end of the optical labyrinth is provided with a mounting edge with a mounting hole, and the optical labyrinth is fixed on the probe board through a screw, which is connected with the surface-mounted nut column after passing through the mounting hole and the probe board in sequence.

[0012] Further, the transmitter further comprises a pipeline assembly and an air chamber assembly, the air chamber assembly is installed at the lower part of the pipeline assembly to form a cavity for mounting the transmitter electrical assembly.

[0013] Still further, the optical labyrinth is located in the air chamber assembly, the air chamber assembly comprises an outer shell, an inner shell and a bottom cover, the inner shell is a circular truncated cone structure with one end being open, a plurality of groups of first strip-shaped smoke inlets are uniformly arranged on the outer periphery of the inner shell, and a plurality of groups of rectangular smoke inlets are uniformly arranged on the bottom wall of the inner shell, the outer shell is a circular truncated cone structure with two ends being open, a plurality of groups of second strip-shaped smoke inlets are arranged on the outer periphery of the outer shell, the second strip-shaped smoke inlets and the first strip-shaped smoke inlets are alternately distributed in space, one end of the outer shell is provided with a ring-shaped flange, the bottom cover comprises a connecting portion, a supporting column and a bottom plate, the connecting portion is annular, and a ring-shaped convex ring is arranged on the upper edge of the connecting portion, the convex ring is located in the outer shell and is blocked by the flange, the supporting column is arc-shaped and connected between the connecting portion and the edge of the bottom plate, and the bottom plate is conical and provided with a through hole in the middle.

[0014] Still further, the outer shell is provided with a plurality of groups of third strip-shaped smoke inlets between the bottom of the outer shell and the two adjacent groups of second strip-shaped smoke inlets.

[0015] Still further, the outer shell, the inner shell and the bottom cover are all formed by ABS injection molding, and are welded into an integral structure after being assembled.

[0016] Further, the gas chamber assembly cover is provided with a transparent protective cover, and the bottom surface of the transparent protective cover is provided with a protrusion matched with the through hole.

[0017] Further, the top of the transparent protective cover is uniformly provided with a plurality of buckles lapped on the top surface of the gas chamber assembly, and a U-shaped groove is formed in the transparent protective cover on the two sides of each buckle.

[0018] Further, the pipeline assembly comprises an upper pipeline and a lower pipeline, the upper part of the lower pipeline extends into the upper pipeline, and the two are connected through a nut, and a sealing ring assembly is arranged at the connecting position of the two.

[0019] The beneficial effects of the present application are as follows: the gas sensitive probe, the temperature and humidity probe and the photoelectric probe are fused, the photoelectric probe can support rough particle size measurement, different types of smoke and common interference sources can be distinguished, and the influence of paint brushing on the sensor is solved;

[0020] The secondary instrument and the transmitter are designed in a split modular manner, and the transmitter can be replaced alone.

[0021] The first strip-shaped smoke inlet hole is uniformly distributed on the outer periphery of the inner shell, and a plurality of groups of second strip-shaped smoke inlet holes are formed on the outer periphery of the outer shell, and the second strip-shaped smoke inlet holes and the first strip-shaped smoke inlet holes are alternately distributed in space structure; without affecting the floating of smoke particles into the internal space, water droplets entering the air chamber during coal mine dust suppression water flushing can be avoided to cause false alarm;

[0022] The gas chamber assembly and the optical labyrinth are detachable structures, which are convenient for on-site dust removal treatment. BRIEF DESCRIPTION OF DRAWINGS

[0023] The present application will be further described below in combination with the drawings and examples.

[0024] Figure 1 is a structural schematic view of the present application.

[0025] Figure 2 is a principle block diagram of the present application.

[0026] Figure 3 is a sectional view of the transmitter in the present application.

[0027] Figure 4 is a structural schematic view of the electrical assembly of the transmitter in the present application.

[0028] Figure 5 is Figure 4 a structural schematic view of the optical labyrinth.

[0029] Figure 6 is a structural schematic view of the gas chamber assembly in the present application.

[0030] Figure 7 is a structural schematic view of the transparent protective cover in the utility model.

[0031] In the figure: 1, transmitter; 11, transmitter board; 12, probe board; 13, optical labyrinth; 14, single-chip microcomputer one; 15, table nut column; 16, screw; 17, shell; 171, second strip-shaped smoke inlet hole; 172, baffle; 173, third strip-shaped smoke inlet hole; 18, inner shell; 181, first strip-shaped smoke inlet hole; 182, rectangular smoke inlet hole; 19, bottom cover; 191, connecting part; 1911, convex ring; 192, support column; 193, bottom plate; 1931, through hole; 110, transparent protective cover; 1101, protrusion; 1102, buckle; 1103, U-shaped groove; 111, upper pipeline; 112, lower pipeline; 113, nut; 114, O-ring; 115, rubber sealing gasket; 2, secondary instrument; 21, single-chip microcomputer two; 22, audible and visual alarm circuit; 23, display circuit; 24, power supply circuit; 25, level output circuit; 26, RS485 circuit; 27, infrared receiving circuit; 3, wire harness. DETAILED DESCRIPTION

[0032] The utility model will be explained further in detail in combination with the drawings. These drawings are all simplified schematic views, and only illustrate the basic structure of the utility model in a schematic manner, so they only show the components related to the utility model.

[0033] As Figures 1-4 shown, a low false alarm rate multi-probe smoke sensor for underground coal mine comprises a transmitter 1 and a secondary instrument 2, the transmitter 1 comprises an epoxy encapsulated transmitter electrical assembly, the transmitter electrical assembly comprises a transmitter board 11, a probe board 12 and an optical labyrinth 13 connected together, the probe board 12 is provided with a gas sensitive probe, a temperature and humidity probe and a photoelectric probe, the transmitter board 11 is provided with a single-chip microcomputer one 14, the single-chip microcomputer one 14 receives the sampling temperature and humidity and smoke information collected by the temperature and humidity probe, the gas sensitive probe and the photoelectric probe, and converts them into on-off quantity digital signals; the secondary instrument 2 is connected with the transmitter 1 through a wire harness 3, the secondary instrument 2 comprises a single-chip microcomputer two 21, an audible and visual alarm circuit 22 and a display circuit 23, the single-chip microcomputer two 21 carries out data analysis on the on-off quantity digital signals, and displays them through the display circuit 23, and can realize audible and visual alarm through the audible and visual alarm circuit 22.

[0034] As Figure 2As shown, the transmitter electrical assembly further comprises a signal conditioning and amplification circuit and a peripheral circuit, smoke enters the transmitter 1 through the optical labyrinth 13, the gas sensitive probe and the photoelectric probe detect the change of the external smoke concentration in real time, when the smoke concentration in the measured environment reaches a certain degree, the gas sensitive probe and the photoelectric probe both collect smoke, the single-chip microcomputer 14 outputs a smoke alarm digital signal to the secondary instrument 2; when the single-chip microcomputer 14 detects that one of the probes fails, while giving an E2 fault reminder, if the other probe detects smoke at this time, the single-chip microcomputer 14 outputs a smoke alarm digital signal to the secondary instrument 2. The secondary instrument 2 performs digital display and external signal output, and realizes the function of sound and light alarm output. Among them, the main function of the transmitter board 11 is to integrate the minimum system of the single-chip microcomputer, realize power taking from the secondary instrument 2 and UART data communication interaction with the secondary instrument 2. The secondary instrument 2 further comprises a power supply circuit 24, a level output circuit 25, an RS485 circuit 26 and an infrared receiving circuit 27, the power supply circuit 24 supplies power to the secondary instrument 2 and the transmitter 1, the level output circuit 25 is connected with an active switching value, controls the on-off of the circuit according to the switching signal, the RS485 circuit 26 is connected with an upper computer, and the infrared receiving circuit 27 is used for receiving an infrared signal of an external remote controller to perform related operations.

[0035] The photoelectric probe samples ADPD188BI, which uses a dual-wavelength technology for backscattering, two integrated LEDs emit light of two different wavelengths: one is 470nm (blue light), and the other is 850nm (infrared light). The LEDs emit several microseconds of LED short pulses in two independent time slots, and the emitted light is scattered back to the photodiode by the particulate matter in the air. The dual-wavelength mode can distinguish the particle size of the particulate matter, and realize the distinction of combustible and interfering substances. According to the statistical data, the combustible particle size is less than 1um, distributed between 100nm and 400nm, the dust is 11um-10um, and the water vapor is greater than 1um. Assuming that the LED light power remains constant, the ADPD188BI output value increases with time, indicating that the particulate matter in the air is increasing or accumulating.

[0036] Among them, one end of the wire harness 3 is provided with a straight pin connector connected with the transmitter board 11, SAN2.0 straight pin plug-in board welding is adopted; the other end of the wire harness 3 is provided with a terminal connected with the secondary instrument 2, and PH2.0 terminal is preferred because the secondary instrument 2 adopts PH2.0-5Pin terminal.

[0037] The side of the transmitter board 11 facing the probe board 12 is welded with a surface-mounted nut column 15, such as Figure 5As shown, one end of the optical labyrinth 13 is provided with a mounting edge with mounting holes; the optical labyrinth 13 is fixed on the probe plate 12 through the screws 16, which are connected with the surface mounting nut columns 15 after passing through the mounting holes and the probe plate 12 in sequence. The probe plate 12 is welded with 2.54mm 1X5P single-row pins and 2.54mm 1X4P single-row pins, the transmitter plate 11 is welded with 2 surface mounting nut columns (SMT SO-M3-6ET) 15, then the optical labyrinth 13, the probe plate 12 and the transmitter plate 11 are fixed through 2 M3 screws 16, the pin feet on the side of the welded assembled transmitter plate 11 are welded, and finally a whole hardware assembly is formed.

[0038] The transmitter 1 further comprises a pipeline assembly and an air chamber assembly, the air chamber assembly is installed at the lower part of the pipeline assembly, and forms a chamber for installing the electrical assembly of the transmitter. As shown in Figure 4 As shown, the pipeline assembly comprises an upper pipeline 111 and a lower pipeline 112, the lower pipeline 112 extends into the upper pipeline 111 at the upper part, and the two are connected through a nut 113, and the connecting part of the two is provided with a sealing ring assembly, which comprises an O-ring 114 and a rubber sealing gasket 115.

[0039] The optical labyrinth 13 is located in the air chamber assembly, as shown in Figure 3 and Figure 6 As shown, the air chamber assembly comprises an outer shell 17, an inner shell 18 and a bottom cover 19, the inner shell 18 is a circular truncated cone structure with an open end, a plurality of groups of first strip-shaped smoke inlet holes 181 are uniformly arranged on the outer periphery of the inner shell 18, a plurality of groups of rectangular smoke inlet holes 182 are uniformly arranged on the bottom wall of the inner shell 18, the outer shell 17 is a circular truncated cone structure with open ends, a plurality of groups of second strip-shaped smoke inlet holes 171 are arranged on the outer periphery of the outer shell 17, the second strip-shaped smoke inlet holes 171 and the first strip-shaped smoke inlet holes 181 are alternately distributed in space structure, one end of the outer shell 17 is provided with a ring-shaped flange 172, the bottom cover 19 comprises a connecting part 191, a support column 192 and a bottom plate 193, the connecting part 191 is annular, and a ring 1911 is arranged on the upper edge of the connecting part 191, the ring 1911 is located in the outer shell 17 and is blocked by the flange 172, the support column 192 is arc-shaped and connected between the edge of the connecting part 191 and the bottom plate 193, and the bottom plate 193 is conical and has a through hole 1931 in the middle.

[0040] Preferably, the third strip-shaped smoke inlet holes 173 are evenly distributed between the bottom of the shell 17 and the two adjacent groups of second strip-shaped smoke inlet holes 171. The shell 17, the inner shell 18 and the bottom cover 19 are all formed by ABS injection molding, and are ultrasonically welded into an integral structure after being assembled, which is firm and reliable. The maximum diameter of the first strip-shaped smoke inlet holes 181, the second strip-shaped smoke inlet holes 171 and the third strip-shaped smoke inlet holes 173 is 1.2 mm, which can prevent spherical objects with a diameter of 1.3±0.05 mm from invading the optical labyrinth 13 and prevent flying insects from entering; the main body of the transmitter 1 is epoxy poured, and the pins of the surface components of the transmitter 1 in contact with the air are subjected to paint brushing treatment; and the protection level of the air chamber assembly can reach IP65.

[0041] The air chamber assembly cover is provided with a transparent protective cover 110, and the bottom surface of the transparent protective cover 110 is provided with a protrusion 1101 matched with the through hole 1931. The top of the transparent protective cover 110 is uniformly distributed with a plurality of buckles 1102 lapped on the top surface of the air chamber assembly, and a U-shaped groove 1103 is formed on both sides of the transparent protective cover 110. The transparent protective cover 110 plays a role in dustproof and anti-falling before the smoke sensor of the embodiment is used. The smoke sensor of the embodiment needs to be preheated and self-calibrated when powered on, and needs to be performed in a clean environment. Since the dust in the underground is large and the environment is unstable, the transparent protective cover 110 can play a protective role. After preheating for 5 minutes (i.e., the preheating and self-calibration work have been completed), the transparent protective cover 110 needs to be pulled out, and the smoke sensor enters a normal working state.

[0042] Based on the above ideal embodiments according to the present application, through the above description, relevant personnel can make various changes and modifications without deviating from the technical idea of the present application. The technical scope of the present application is not limited to the content in the specification, and must be determined according to the scope of the claims.

Claims

1. A low false alarm rate multi-probe smoke sensor for use in a coal mine underground, characterised in that, The utility model relates to a kind of smoke sensor, including: Transmitter (1), the transmitter (1) includes epoxy encapsulated transmitter electrical components, the transmitter electrical components include transmitter board (11), probe board (12) and optical labyrinth (13) connected together, gas sensitive probe, temperature and humidity probe and photoelectric probe are mounted on the probe board (12), single-chip microcomputer one (14) is equipped on the transmitter board (11), the sampling temperature and humidity and smoke information collected by temperature and humidity probe, gas sensitive probe and photoelectric probe are received by the single-chip microcomputer one (14), and it is converted into on-off quantity digital signal; Secondary instrument (2), the secondary instrument (2) is connected with transmitter (1) by wiring harness (3), secondary instrument (2) includes single-chip microcomputer two (21), audible and visual alarm circuit (22) and display circuit (23), the single-chip microcomputer two (21) carries out data analysis to on-off quantity digital signal, and is shown by display circuit (23), and can be realized audible and visual alarm by audible and visual alarm circuit (22).

2. The low false alarm rate multi-probe smoke sensor for underground coal mines of claim 1, wherein: One end of the wiring harness (3) is provided with a straight pin connector connected with the transmitter board (11), and the other end of the wiring harness (3) is provided with a terminal connected with the secondary instrument (2).

3. The low false alarm rate multi-probe smoke sensor for underground coal mines of claim 1, wherein: The surface mounting nut column (15) is welded on one side of the transmitter board (11) facing the probe board (12), one end of the optical labyrinth (13) is provided with a mounting edge with a mounting hole, the optical labyrinth (13) is fixed on the probe board (12) by a screw (16), and the screw (16) is connected with the surface mounting nut column (15) after passing through the mounting hole and the probe board (12) in sequence.

4. The low false alarm rate multi-probe smoke sensor for underground coal mines of claim 1, wherein: The transmitter (1) further includes a pipeline assembly and an air chamber assembly, the air chamber assembly is installed at the lower part of the pipeline assembly, forming a chamber for installing the transmitter electrical components.

5. The low false alarm rate multi-probe smoke sensor for underground coal mines of claim 4, wherein: The optical labyrinth (13) is located in the air chamber assembly, the air chamber assembly includes an outer shell (17), an inner shell (18) and a bottom cover (19), the inner shell (18) is a circular truncated cone structure with one end open, a plurality of groups of first strip-shaped smoke inlets (181) are uniformly arranged on the outer periphery of the inner shell (18), a rectangular smoke inlet (182) is uniformly arranged on the bottom wall of the inner shell (18), the outer shell (17) is a circular truncated cone structure with two ends open, a plurality of groups of second strip-shaped smoke inlets (171) are arranged on the outer periphery of the outer shell (17), the second strip-shaped smoke inlets (171) and the first strip-shaped smoke inlets (181) are alternately distributed in space structure, one end of the outer shell (17) is provided with a ring of retaining edges (172), the bottom cover (19) includes a connecting part (191), a support column (192) and a bottom plate (193), the connecting part (191) is annular, a ring of convex rings (1911) is arranged on the upper edge of the connecting part (191), the convex ring (1911) is located in the outer shell (17), and is blocked by the retaining edge (172), the support column (192) is arc-shaped, and is connected to the edge between the connecting part (191) and the bottom plate (193), the bottom plate (193) is conical, and a through hole (1931) is arranged in the middle.

6. The low false alarm rate multi-probe smoke sensor for underground coal mines of claim 5, wherein: The third strip-shaped smoke inlets (173) are uniformly distributed between the outer shell (17) bottom and adjacent two groups of second strip-shaped smoke inlets (171).

7. The low false alarm rate multi-probe smoke sensor for underground coal mines of claim 5, wherein: The shell (17), the inner shell (18) and the bottom cover (19) are all made by ABS injection molding, and are ultrasonically welded into an integral structure after being assembled.

8. The low false alarm rate multi-probe smoke sensor for underground coal mines of claim 7, wherein: The air chamber assembly cover is provided with a transparent protective cover (110), and the bottom surface of the transparent protective cover (110) is provided with a protrusion (1101) matched with the through hole (1931).

9. The low false alarm rate multi-probe smoke sensor for underground coal mines of claim 8, wherein: The top of the transparent protective cover (110) is uniformly distributed with a plurality of buckles (1102) lapped on the top surface of the air chamber assembly, and the transparent protective cover (110) on the two sides of the buckle (1102) is respectively provided with a U-shaped groove (1103).

10. The low false alarm rate multi-probe smoke sensor for underground coal mine of claim 4, wherein: The pipeline assembly comprises an upper pipeline (111) and a lower pipeline (112), the upper pipeline (111) is inserted into the lower pipeline (112), and the two are connected through a nut (113), and the connection part is provided with a sealing ring assembly.

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