CN117197993A - Smoke sensor utilizing astigmatism principle and dimming principle - Google Patents
Smoke sensor utilizing astigmatism principle and dimming principle Download PDFInfo
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- CN117197993A CN117197993A CN202311359598.9A CN202311359598A CN117197993A CN 117197993 A CN117197993 A CN 117197993A CN 202311359598 A CN202311359598 A CN 202311359598A CN 117197993 A CN117197993 A CN 117197993A
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- 239000000779 smoke Substances 0.000 title claims abstract description 112
- 201000009310 astigmatism Diseases 0.000 title claims abstract description 10
- 238000001514 detection method Methods 0.000 claims abstract description 39
- 238000000149 argon plasma sintering Methods 0.000 claims abstract description 8
- 238000005070 sampling Methods 0.000 claims abstract description 8
- 239000002245 particle Substances 0.000 claims description 48
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- 239000003086 colorant Substances 0.000 abstract description 3
- 239000008187 granular material Substances 0.000 abstract description 3
- 238000010586 diagram Methods 0.000 description 4
- IMNFDUFMRHMDMM-UHFFFAOYSA-N N-Heptane Chemical compound CCCCCCC IMNFDUFMRHMDMM-UHFFFAOYSA-N 0.000 description 3
- 230000007547 defect Effects 0.000 description 3
- 239000006185 dispersion Substances 0.000 description 3
- 238000000034 method Methods 0.000 description 2
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- 238000010521 absorption reaction Methods 0.000 description 1
- 101150102866 adc1 gene Proteins 0.000 description 1
- 101150042711 adc2 gene Proteins 0.000 description 1
- 230000002238 attenuated effect Effects 0.000 description 1
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- 238000002485 combustion reaction Methods 0.000 description 1
- 238000007405 data analysis Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
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- 239000004033 plastic Substances 0.000 description 1
- 229920003023 plastic Polymers 0.000 description 1
- 229920002635 polyurethane Polymers 0.000 description 1
- 239000004814 polyurethane Substances 0.000 description 1
- 230000000630 rising effect Effects 0.000 description 1
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Abstract
The invention discloses a smoke sensor utilizing a light scattering principle and a light attenuation principle, which comprises a sensor base, an air inlet net cover and a diode structure, wherein the sensor base and the air inlet net cover are mutually clamped, and the diode structure is positioned in a detection area inside the sensor base. The diode structure comprises a photodiode, two infrared emission diodes and a sensor circuit, wherein the two infrared emission diodes are a dimming infrared emission diode and a astigmatism infrared emission diode, the dimming infrared emission diode and the astigmatism infrared emission diode are connected with the sensor circuit through the photodiode, and the photodiode is used for sampling sensor signals of the dimming infrared emission diode and the astigmatism infrared emission diode. Through a photodiode, the photoelectric sensor of two kinds of principles of timesharing drive obtains two sets of signals that photoelectric signal trend is opposite, judges different granule, the smog of different colours more easily, and more accurate judgement conflagration can distinguish the burning thing even.
Description
Technical Field
The invention relates to the technical field of fire detection, in particular to a smoke sensor utilizing a light scattering principle and a dimming principle.
Background
Most of the smoke-sensing fire detection technologies in the current market utilize the scattering principle of smoke particles on light, specifically the Mie scattering principle, and an infrared emission diode with the wavelength of 940nm and a photodiode with the receivable wavelength of 840-1100 nm, so that under the normal smokeless condition, the photodiode cannot receive the light emitted by the infrared emission diode due to the effect of a darkroom, and no photocurrent is generated. When smoke particles enter a detection area of the sensor, light beams emitted by the infrared emission diode are scattered due to the action of the smoke particles, the photoelectric diode can receive scattered infrared light to generate photocurrent, the scattered light received by the photoelectric diode is enhanced along with the increase of the concentration of the smoke particles, the generated photocurrent is increased, and when the photocurrent reaches an alarm threshold value, the detector emits an alarm signal. The technical proposal has strong light intensity on scattered light generated by white smoke or gray smoke with the grain diameter of 0.3-1 mu m. However, the light irradiates the dark black smoke particles, the light is attenuated by absorption, the scattered light is weakened, and the photocurrent generated by the photodiode is small. For this problem, it is common practice to reduce the alarm threshold (disadvantage: easy false alarm), one to use forward scattering and one to use backward scattering and total two infrared emitting diodes (disadvantage: no forward scattering or backward scattering, black smoke is obvious to scatter infrared light), or to make an algorithm for the smoke rising curve of polyurethane plastic open flame and n-heptane open flame in the combustion laboratory in the product standard (disadvantage: practical application scene and laboratory are not the same, the method is only used for over-standard, practical field is not practical), or to add an NTC thermistor to assist judgment (disadvantage: increase cost), to use a plurality of infrared emitting diodes with different wavelengths, such as an infrared emitting diode, and a blue infrared emitting diode (disadvantage: algorithm is complex, cost is high). The proposal is that the cost is increased, the manufacturing difficulty is increased, or the reliability of judging black smoke in the actual use scene is reduced.
Disclosure of Invention
Aiming at the technical problems, the invention provides a smoke sensor which utilizes the light scattering principle and the dimming principle to detect particles with stronger scattered light such as white smoke or ash smoke and the like; the method is mainly used for detecting particles with large dimming rate and small scattering rate such as black smoke by using a dimming principle, thereby solving the defects that the prior art scheme is sensitive to white smoke and insensitive to black smoke.
The technical scheme of the invention is realized as follows:
a smoke sensor using light scattering principle and light attenuation principle comprises a sensor base, an air inlet net cover and a diode structure positioned in a detection area inside the sensor base, which are mutually clamped,
the diode structure consists of a photodiode, two infrared emission diodes and a sensor circuit, wherein the two infrared emission diodes are a dimming infrared emission diode and a astigmatism infrared emission diode which are connected with the sensor circuit through the photodiode together, the photodiode is used for sampling sensor signals of the dimming infrared emission diode and the astigmatism infrared emission diode,
when no smoke particles enter the detection chamber, the sensor signal of the astigmatic infrared emission diode is small, and the sensor signal of the dimming infrared emission diode is large and tends to be saturated;
when white smoke particles enter the detection chamber, the sensor signal of the light-scattering infrared emitting diode increases along with the increase of the smoke particle concentration, and the sensor signal of the light-dimming infrared emitting diode decreases along with the increase of the smoke particle concentration;
when black smoke particles enter the detection chamber, the sensor signal of the light-reducing infrared emitting diode increases along with the increase of the concentration of the smoke particles, and the sensor signal of the light-dispersing infrared emitting diode decreases along with the increase of the concentration of the smoke particles.
In the invention, the infrared emission diode is a diode with the emission wavelength of 940nm, and the photodiode is a photoelectric receiving device with the receiving wavelength of 840-1100 nm, wherein the axial lead of the astigmatic infrared emission diode forms an obtuse angle with the axial lead of the photodiode, and the axial lead of the astigmatic infrared emission diode coincides with the axial lead of the photodiode.
In the invention, the air inlet mesh enclosure is circumferentially and uniformly distributed with a plurality of small holes, smoke particles enter the air inlet mesh enclosure from the small holes, and an airflow diversion structure is arranged in the sensor base and is used for conveying the smoke particles in different directions into the detection area.
In the invention, the airflow diversion structure comprises first airflow diversion grids which are circumferentially distributed on the sensor base at equal intervals, and the first airflow diversion grids are strip-shaped and are used for dividing the sensor base into a plurality of fan-shaped diversion areas, wherein the fan-shaped diversion areas are communicated with the detection areas.
In the invention, one ends of the fan-shaped diversion areas far away from the center of the sensor base are respectively provided with a second airflow diversion grating which is V-shaped and is used for diversion of smoke particles flowing through the fan-shaped diversion areas to the detection areas.
In the invention, a third airflow guide grid and a fourth airflow guide grid are arranged in the middle of the first airflow guide grid, wherein the third airflow guide grid and the fourth airflow guide grid are positioned at the inner side of the second airflow guide grid, and smoke particles guided by the second airflow guide grid are guided to a detection area.
In the invention, a photodiode fixing support, a light-reducing infrared emission diode fixing support and a light-diffusing infrared emission diode fixing support are arranged on the sensor base, and a photodiode fixing groove, a light-reducing infrared emission diode fixing groove and a light-diffusing infrared emission diode fixing groove are arranged on the air inlet net cover, wherein the sensor base is matched with the air inlet net cover to fix the photodiode, the light-reducing infrared emission diode and the light-diffusing infrared emission diode.
In the invention, a plurality of first buckles are arranged on the sensor base in the circumferential direction, and a second bayonet matched with the first bayonet is arranged on the air inlet screen in the circumferential direction, wherein when the sensor base and the air inlet screen are installed, the first buckles are aligned with the second buckles, and then the second buckles are pushed into the first buckles.
The smoke sensor using the astigmatism principle and the dimming principle has the following beneficial effects:
the invention adopts the forward scattering principle, gives consideration to the smoke particles with large particles and small particles, enables the photodiode to receive enough strong light, adopts the dimming principle, enables the sensor to be sensitive to black smoke, and solves the defects that the prior art scheme is sensitive to white smoke and insensitive to black smoke.
The sensor of the scattering principle and the sensor of the dimming principle are integrated on the same smoke detector, and the two sensors share one photodiode and respectively use two infrared emission diodes; and the sensor signals of the scattering principle and the sensor signals of the dimming principle are sampled in a time sharing manner. When no smoke enters the detection chamber, the signal of the sensor based on the scattering principle is very small, and the signal of the sensor based on the dimming principle is very large, and the detection chamber tends to be saturated. When smoke enters the detection chamber, the signal of the sensor of the scattering principle increases along with the increase of the smoke concentration, is sensitive to white smoke or ash smoke, and has a large signal increasing rate along with the increase of the smoke concentration; the signal of the sensor of the dimming principle decreases with increasing smoke concentration and is sensitive to black smoke, and the signal decrease rate is large with increasing smoke concentration.
The air flow guide structure is arranged in the sensor base, so that smoke particles coming from different directions can reach the detection area at the same time, and no difference of different directions on the sensitivity of the smoke detector is ensured.
Through a photodiode, the photoelectric sensor of two kinds of principles of timesharing drive obtains two sets of signals that photoelectric signal trend is opposite, judges different granule, the smog of different colours more easily, and more accurate judgement conflagration can distinguish the burning thing even.
Drawings
FIG. 1 is a schematic diagram of a split structure of a smoke sensor according to the present invention;
FIG. 2 is a circuit functional diagram of a smoke sensor of the present invention;
FIG. 3 is a schematic view of the structure of the air intake net cover of the present invention;
FIG. 4 is a schematic diagram of a diode mounting groove according to the present invention;
FIG. 5 is a schematic view of the sensor base of the present invention;
FIG. 6 is a schematic view of the flow diversion of the sensor base of the present invention;
FIG. 7 is a schematic diagram of an assembled structure of the smoke sensor of the present invention;
fig. 8 is a schematic view of the structure of the smoke detection chamber of the smoke sensor of the present invention.
The reference numerals are expressed as: the sensor base 10, the first buckle 11, the first airflow diversion grid 12, the second airflow diversion grid 13, the third airflow diversion grid 14, the fourth airflow diversion grid 15, the photodiode fixing support 16, the light-reduction infrared emission diode fixing support 17, the light-dispersion infrared emission diode fixing support 18, the air intake net cover 20, the second buckle 21, the diversion grid plate 22, the air intake net hole 23, the photodiode fixing groove 24, the light-reduction infrared emission diode fixing groove 25, the light-dispersion infrared emission diode fixing groove 26, the diode structure 30, the photodiode 31, the photodiode pin 31'1, the light-reduction infrared emission diode 32, the light-reduction infrared emission diode pin 32'1, the infrared emission diode 33, the light-dispersion infrared emission diode pin 33'1 and the detection area 34.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.
Aiming at the defect that the existing smoke sensor is insensitive to black smoke response. The invention relates to a photoelectric smoke sensor which simultaneously utilizes a scattered light principle and a dimming principle. The scattered light principle is mainly used for detecting particles with stronger scattered light such as white smoke or ash smoke; the principle of light attenuation is mainly used for detecting particles with large light attenuation rate and small scattering rate such as black smoke.
As shown in fig. 1 to 8, the smoke sensor using the light scattering principle and the dimming principle of the present invention includes a sensor base 10, an air intake screen 20, and a diode structure 30. The sensor base 10 and the air inlet net cover 20 are clamped with each other, and the diode structure 30 is located in a detection area inside the sensor base 10. The diode structure 30 consists of one photodiode 31, two infrared emitting diodes and a sensor circuit. The two infrared emission diodes are a light-reducing infrared emission diode 32 and a light-dispersing infrared emission diode 33, the light-reducing infrared emission diode 32 and the light-dispersing infrared emission diode 33 are connected with a sensor circuit through a photodiode 31, the photodiode 31 is used for sampling sensor signals of the light-reducing infrared emission diode 32 and the light-dispersing infrared emission diode 33, wherein when no smoke particles enter a detection area 34, the sensor signal of the light-dispersing infrared emission diode 33 is small, and the sensor signal of the light-reducing infrared emission diode 32 is large and tends to be saturated. When white smoke particles enter the detection area 34, the sensor signal of the astigmatic infrared emission diode 33 increases along with the increase of the smoke particle concentration, and the sensor signal of the dimmer infrared emission diode 32 decreases along with the increase of the smoke particle concentration; when black smoke particles enter the detection zone 34, the sensor signal of the light-reducing infrared emitting diode 32 increases with increasing smoke particle concentration, and the sensor signal of the light-diffusing infrared emitting diode 33 decreases with increasing smoke particle concentration. Through a photodiode, the photoelectric sensor of two kinds of principles of timesharing drive obtains two sets of signals that photoelectric signal trend is opposite, judges different granule, the smog of different colours more easily, and more accurate judgement conflagration can distinguish the burning thing even.
In the embodiment, the infrared emission diode is a diode with an emission wavelength of 940nm, and the photodiode is a photoelectric receiving device with a receiving wavelength of 840-1100 nm, wherein the axial lead of the astigmatic infrared emission diode forms an obtuse angle with the axial lead of the photodiode, alpha is more than 90 degrees, and the axial lead of the light-reducing infrared emission diode coincides with the axial lead of the photodiode. The infrared emitting diode and the photodiode are arranged in the base fixing groove and then are wrapped into a closed space by the air inlet net cover arranged on the periphery and the top of the base, at the moment, external natural light is blocked by the diversion structure and cannot enter the detection area, but smoke particles can enter the detection area along the air inlet channel.
In this embodiment, the air inlet mesh enclosure 20 is uniformly distributed with a plurality of holes in the circumferential direction to form an air inlet mesh enclosure 23, smoke particles enter the air inlet mesh enclosure 20 from the air inlet mesh enclosure 23, and an airflow guiding structure is arranged in the sensor base 10 and is used for conveying the smoke particles in different directions into the detection area 34. The airflow guiding structure comprises first airflow guiding grids 12, wherein the first airflow guiding grids 12 are circumferentially distributed on the sensor base 10 at equal intervals, the first airflow guiding grids 12 are long strips and are used for dividing the sensor base 10 into a plurality of fan-shaped guiding areas, and the fan-shaped guiding areas are communicated with the detection areas 34. The ends of the fan-shaped diversion areas far away from the circle center of the sensor base 11 are respectively provided with a second airflow diversion grating 13, and the second airflow diversion grating 13 is V-shaped and is used for diversion of smoke particles flowing through the fan-shaped diversion areas to the detection areas 34. The middle part of the first airflow diversion grating 12 is provided with a third airflow diversion grating 14 and a fourth airflow diversion grating 15, wherein the third airflow diversion grating 14 and the fourth airflow diversion grating 15 are positioned at the inner side of the second airflow diversion grating 13, and smoke particles guided by the second airflow diversion grating 13 are guided to the detection area 34, so that the smoke particles coming from different directions can all reach the detection area at the same time, and no difference of sensitivity of the smoke detector in different directions is ensured.
In this embodiment, the sensor base 10 is provided with a photodiode fixing support 16, a light-reducing infrared emission diode fixing support 17 and a light-diffusing infrared emission diode fixing support 18, and the air intake screen 20 is provided with a photodiode fixing groove 24, a light-reducing infrared emission diode fixing groove 25 and a light-diffusing infrared emission diode fixing groove 26. The sensor base 10 is matched with the air intake net cover 20 for fixing the photodiode 31, the light-reducing infrared emitting diode 32 and the light-diffusing infrared emitting diode 33.
The sensor base circumference is provided with a plurality of first buckle 11, and the air inlet screen panel 20 circumference is provided with the second bayonet socket 21 that cooperatees with first bayonet socket 11. When the sensor base 10 and the air intake screen 20 are installed, the photodiode 31, the light-reducing infrared emission diode 32 and the light-diffusing infrared emission diode 33 are respectively clamped into the photodiode fixing support 16, the light-reducing infrared emission diode fixing support 17 and the light-diffusing infrared emission diode fixing support 18, and then the photodiode fixing groove 24, the light-reducing infrared emission diode fixing groove 25 and the light-diffusing infrared emission diode fixing groove 26 on the air intake screen 20 are respectively aligned with the photodiode fixing support 16, the light-reducing infrared emission diode fixing support 17 and the light-diffusing infrared emission diode fixing support 18 on the sensor base 10, and the circumferential rotation of the air intake screen 20 is limited. Finally, the first buckle 11 is aligned with the second buckle 21, and then the second buckle 21 is pushed into the first buckle 11, so that the axial movement of the air inlet screen 20 is limited.
In this embodiment, the photodiode fixing support 16, the light-reducing infrared emitting diode fixing support 17 and the light-diffusing infrared emitting diode fixing support 18, which are provided inside the sensor base 10, are provided with diode pin holes 19. When the photodiode 31, the light-reducing infrared emission diode 32 and the light-diffusing infrared emission diode 33 are mounted on the photodiode fixing groove 24, the light-reducing infrared emission diode fixing groove 25 and the light-diffusing infrared emission diode fixing groove 26, the photodiode pin 31'1, the light-reducing infrared emission diode pin 32'1 and the light-diffusing infrared emission diode pin 33'1 thereon penetrate through the diode pin hole 19.
Further, the specific working principle of the smoke sensor is as follows: as shown in fig. 2, the MCU monitors the smoke sensor once every several seconds, when monitoring, the MCU firstly closes K1 and K2, connects the photodiode D3 with the amplifying and sampling circuit U1 of the scattering principle, then drives the light signals received by the infrared emitting diodes D1 and D3 of the scattering principle to be converted into voltage signals by the amplifying and sampling circuit U1, the Output signal Output1 obtained is an analog signal, the MCU samples and converts the analog signal into a digital signal by the ADC1 and records Data1, and finally disconnects K1 and K2. After a period of time, K3 and K4 are closed, the photodiode D3 is connected with an amplifying and sampling circuit U2 of a dimming principle, then an optical signal received by the infrared emitting diode D2 of the dimming principle is driven to be converted into a voltage signal through the U2 amplifying and sampling circuit, the obtained Output signal Output2 is an analog signal, the MCU is sampled and converted into a digital signal through the ADC2 and records Data2, and finally K3 and K4 are disconnected. The MCU analyzes the Data of Data1 and Data 2. When no smoke enters the detection zone, the Data for Data1 is very small, while the Data for Data2 is very large, tending to saturate. When smoke enters the detection area, data of Data1 increases along with the increase of the smoke concentration and is sensitive to white smoke or ash smoke, the Data growth rate of the Data1 is large along with the increase of the smoke concentration, but the Data growth rate of the Data1 is insensitive to black smoke, and the Data growth rate of the Data1 is not large along with the increase of the smoke concentration; data of Data2 decreases with increasing smoke concentration and is sensitive to black smoke, data decrease rate of Data2 is large with increasing smoke concentration, while Data decrease rate of Data2 is not sensitive to white smoke or gray smoke, and Data decrease rate of Data2 is not large with increasing smoke concentration. Through the Data analysis with the two outstanding characteristics of Data1 and Data2, the algorithm for distinguishing the granularity of the smoke and the color of the smoke can be summarized, the fire disaster can be more accurately identified, and false alarm is avoided.
The foregoing description of the preferred embodiments of the invention is not intended to be limiting, but rather is intended to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.
Claims (8)
1. A smoke sensor using light scattering principle and light attenuation principle comprises a sensor base, an air inlet net cover and a diode structure positioned in a detection area inside the sensor base, which are mutually clamped,
the diode structure consists of a photodiode, two infrared emission diodes and a sensor circuit, wherein the two infrared emission diodes are a dimming infrared emission diode and a astigmatism infrared emission diode which are connected with the sensor circuit through the photodiode together, the photodiode is used for sampling sensor signals of the dimming infrared emission diode and the astigmatism infrared emission diode,
when no smoke particles enter the detection chamber, the sensor signal of the astigmatic infrared emission diode is small, and the sensor signal of the dimming infrared emission diode is large and tends to be saturated;
when white smoke particles enter the detection chamber, the sensor signal of the light-scattering infrared emitting diode increases along with the increase of the smoke particle concentration, and the sensor signal of the light-dimming infrared emitting diode decreases along with the increase of the smoke particle concentration;
when black smoke particles enter the detection chamber, the sensor signal of the light-reducing infrared emitting diode increases along with the increase of the concentration of the smoke particles, and the sensor signal of the light-dispersing infrared emitting diode decreases along with the increase of the concentration of the smoke particles.
2. The smoke sensor of claim 1 wherein the infrared emitting diode is a diode with an emission wavelength of 940nm and the photodiode is a photo-receiving device with a receiving wavelength of 840-1100 nm, wherein the axis of the astigmatic infrared emitting diode forms an obtuse angle with the axis of the photodiode, and the axis of the astigmatic infrared emitting diode coincides with the axis of the photodiode.
3. The smoke sensor according to claim 1 or 2, wherein the air inlet mesh enclosure is circumferentially and uniformly provided with a plurality of small holes, smoke particles enter the air inlet mesh enclosure from the small holes, and an air flow guiding structure is arranged in the sensor base and is used for conveying smoke particles in different directions into the detection area.
4. A smoke sensor according to claim 3 wherein the airflow directing structure comprises first airflow directing gratings circumferentially equidistantly distributed on the sensor base, the first airflow directing gratings being elongate for dividing the sensor base into a plurality of fan-shaped directing areas, wherein the plurality of fan-shaped directing areas are each in communication with the detection area.
5. The smoke sensor of claim 4 wherein the ends of the plurality of fan-shaped flow guiding areas remote from the center of the sensor base are each provided with a second airflow guiding grating, the second airflow guiding grating being V-shaped for guiding smoke particles flowing through the fan-shaped flow guiding areas to the detection areas.
6. The smoke sensor of claim 5, wherein a third airflow deflector and a fourth airflow deflector are disposed in the middle of the first airflow deflector, wherein the third airflow deflector and the fourth airflow deflector are located inside the second airflow deflector, and smoke particles guided by the second airflow deflector are guided to the detection area.
7. The smoke sensor of claim 1, 2 or 6 wherein the sensor base is provided with a photodiode mount, a light-reducing infrared emission diode mount and a light-diffusing infrared emission diode mount, and the air intake screen is provided with a photodiode mount, a light-reducing infrared emission diode mount and a light-diffusing infrared emission diode mount, wherein the sensor base is matched with the air intake screen for fixing the photodiode, the light-reducing infrared emission diode and the light-diffusing infrared emission diode.
8. The smoke sensor of claim 7 wherein said sensor base is circumferentially provided with a plurality of first catches and the air intake screen is circumferentially provided with a second catch that mates with the first catch, wherein the first catch is aligned with the second catch and the second catch is pushed into the first catch when the sensor base and the air intake screen are installed.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311359598.9A CN117197993A (en) | 2023-10-20 | 2023-10-20 | Smoke sensor utilizing astigmatism principle and dimming principle |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311359598.9A CN117197993A (en) | 2023-10-20 | 2023-10-20 | Smoke sensor utilizing astigmatism principle and dimming principle |
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| CN117197993A true CN117197993A (en) | 2023-12-08 |
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| CN202311359598.9A Pending CN117197993A (en) | 2023-10-20 | 2023-10-20 | Smoke sensor utilizing astigmatism principle and dimming principle |
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- 2023-10-20 CN CN202311359598.9A patent/CN117197993A/en active Pending
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