CN100511304C - Photoelectric smoke sensing fire detecting method and apparatus based on depolarization rate - Google Patents
Photoelectric smoke sensing fire detecting method and apparatus based on depolarization rate Download PDFInfo
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- CN100511304C CN100511304C CNB2006100971913A CN200610097191A CN100511304C CN 100511304 C CN100511304 C CN 100511304C CN B2006100971913 A CNB2006100971913 A CN B2006100971913A CN 200610097191 A CN200610097191 A CN 200610097191A CN 100511304 C CN100511304 C CN 100511304C
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Abstract
The invention relates to a photo-electricity smoke sensing fire detection method and device based on depolarizing rate. Its features are that light beam is emitted to the smoke particle by the polarizer; the plane of the incidence beam is used as scattering base plane; the up and down sides of the receiving plane normal to the scattering base plane are set same two the first and second photo-electricity receivers both of which are aimed at the particle scattering center; and one of which end is set one polarization verifying machine; the optical axis of the polarizer and polarization verifying machine are normal to the scattering base plane. It uses the change of the polarization feature in particle light scattering to identify ash smoke particle, dark smoke particle, dust, water vapor interference source particle, reduce the rate of false alarm of the smoke sensing detecting, increase its response sensitivity.
Description
Technical field:
The invention belongs to the fire detection technology field, particularly based on the photoelectric smoke fire hazard detecting method and the device of depolarized rate.
Background technology:
" fire safety evaluating periodical " (Fire Safety Journal of Britain issuing, 1997, the 29 volumes, the 77-85 page or leaf) point out, smoke particle is one of early stage key character parameter of fire, and carrying out fire early detection based on the smoke particle light scattering principle is a kind of most important fire detecting method.And according to Maxwell's electromagnetic scattering theory as can be known, comprised 3 important informations in the grain optical scattering process, i.e. light intensity, polarization and phase place, wherein phase information obtain difficulty, and obtaining of light intensity and polarization information is simpler.Existing photoelectric smoke detector, as U.S. Pat 2002084907, the smoke Detection Techniques that Jap.P. JP2004227452 and European patent DE69608363D are mentioned, all only adopt the criterion of the scattered light intensity of smoke particle as detection of fires, fail to utilize the polarization information of more deep reflection grain optical scattering essential characteristic, can not reliably and effectively discern grey cigarette, black smoke and dust, water vapor interference source particle, thereby can't eliminate because the wrong report that the interference source particle causes at all, simultaneously its consistance to the response sensitivity of various dissimilar smoke particles is relatively poor, has limited the further raising of sensitivity.
Summary of the invention:
The objective of the invention is to propose a kind of photoelectric smoke fire hazard detecting method and device based on depolarized rate, utilize the variation of polarization characteristic in the grain optical scattering process, discern grey smoke particle, black smoke particle and dust, water vapour interference source particle, reduce the rate of false alarm of smoke detection, improve its response sensitivity.
Photoelectric smoke sniffer based on depolarized rate of the present invention, comprise, light beam in light source 1 outgoing is incident on a certain scattering angle θ of the smoke particle 3 back generation light scattering in the cylindrical detection chamber 7, is provided with the first strong photelectric receiver 5 of receiving scattered light; It is characterized in that: establish described light source 1 along continuous straight runs outgoing beam, elder generation is through the polarizer 2 before being incident to smoke particle 3, with the plane through this incident beam and level is scattering reference plane 8, on reception plane 9 perpendicular to this scattering reference plane 8, the both sides up and down that are close to and are symmetrical in this scattering reference plane 8 are installed two identical, as to have identical scattering angle θ first photelectric receiver 5 and second photelectric receivers 6 respectively, and are the particle scattering center to the center of circle in 7 rounded bottom surfaces of quasi-cylindrical detection cavity chamber all; Install one at the front end of first photelectric receiver 5 or second photelectric receiver 6 and test inclined to one side device 4; The described polarizer 2 and test the direction of optic axis of inclined to one side device 4 all perpendicular to scattering reference plane 8.
The scattering reference plane 8 of described level also can be the arbitrary plane through incident beam.
Photoelectric smoke fire hazard detecting method based on depolarized rate of the present invention comprises and measures the scattered light intensity be incident to the light beam on scattering angle θ behind the smoke particle; It is characterized in that: described light beam becomes the linearly polarized light of polarization direction perpendicular to the scattering reference plane after having passed through partially, and reenter and be incident upon smoke particle generation light scattering, be the scattered light intensity I of θ by measuring scattering angle
Sca(θ), and identical scattering angle θ go up the light intensity of polarization direction perpendicular to the scattered light of scattering reference plane
, two scattered light intensities
With I
ScaRatio (θ) is the depolarized rate δ P (θ) of characterizing particles essential characteristic; First δ P (θ) the maximal value δ P that records according to experiment in the depolarized rate of simulating atmospheric dust, loess dirt and water vapour particle on a certain scattering angle θ
1(θ), the minimum value δ P of δ P (θ) in the depolarized rate of the black smoke particle of normal heptane naked light, polyurethane naked light and the generation of diesel oil naked light
4(θ), and the depolarized rate of the grey smoke particle correspondence that cotton cord glows, the thermal decomposition of wood generates at δ P (θ) greater than δ P
2(θ) and less than δ P
3(θ), arrange out δ P
4(θ)〉δ P
3(θ)〉δ P
2(θ)〉δ P
1(θ); Measure the scope of determining each self-corresponding depolarized rate δ P (θ) value in dust and water vapour particle, grey smoke particle and the black smoke grain optical scattering process more by experiment, δ P (θ) value of these 3 types of particle correspondences is in the interval that does not overlap mutually, thereby according to the kind of depolarized rate δ P (θ) backstepping particle; If the depolarized rate value δ P (θ) that records is less than δ P
1(θ), judge that then it is dust or water vapour interference source particle, for depolarized rate at δ P
2(θ)～δ P
3Grey smoke particle (θ) and depolarized rate are greater than P
4Black smoke particle (θ) is according to scattered light intensity value I
Sca(θ), one-level, secondary and three grades of corresponding respectively smoke densities of sensitivity according to regulation in the 4.22.2.1 joint among the standard GB 4715-93 " spot-type smoke detector technical requirement and test method " are 0.5dB/m, 1.0dB/m and 2.0dB/m, setting threshold is judged whether breaking out of fire, thereby realizes the response sensitivity for variety classes smoke particle unanimity; Get described scattering angle θ at 30 °～100 °.
In the fire smoke particle light scattering process, the scattered light intensity on a certain scattering angle has reflected the concentration of smoke particle, and existing photoelectric smoke Detection Techniques utilize the size of scattered light intensity that smoke particle is surveyed just, thereby judge whether fire takes place.Yet because dust, water vapor interference source particle also have this scattering signatures that is similar to smoke particle, only can't discern what scattering took place by the size of scattered light intensity is fire smoke particle or interference source particle, is easy to generate wrong report.In addition, for various natural fire smoke particles, its physical parameter also has nothing in common with each other, as smoldering fire grey cigarette that generates and the black smoke that has the fireworks burning to generate, corresponding light scattering feature also exists than big-difference, therefore, existing photoelectric smoke detector is inconsistent for the response sensitivity of these smoke particles.According to Maxwell's electromagnetic scattering theory, comprise 3 information in the grain optical scattering process: light intensity, polarization and phase place, wherein scattered light intensity is a kind of comprehensive characteristics of various factors in the scattering process, composition, pattern and the size characteristic that can't specifically reflect scattering particles, polarization characteristic has then embodied the influence of these essential characteristic of particle, and be easier to obtain with respect to phase information, only need add upper polarizer and get final product.Wherein, this parameter of depolarized rate of scattered light can effectively be distinguished fire smoke particle and interference source particle, and different types of smoke particle.
The present invention reaches the purpose of identification fire smoke particle and interference source particle according to the size of the depolarized rate of particle scattered light, thereby get rid of the interference of dust, water vapor interference source particle to photoelectric smoke detector, reduce the rate of false alarm of detector, the while also can further be reduced the alarm threshold value of detector and be improved its response sensitivity.In addition, for different types of smoke particle,, adjust alarm threshold value, thereby realize all having identical response sensitivity with the black smoke particle, promptly reach the consistance of explorer response sensitivity for grey smoke particle according to the depolarized rate on its corresponding θ angle.
Description of drawings:
Fig. 1 is the schematic top plan view based on the photoelectric smoke fire hazard detecting method of depolarized rate;
Fig. 2 is the schematic side view based on the photoelectric smoke fire hazard detecting method of depolarized rate.
Embodiment:
Below in conjunction with description of drawings the specific embodiment of the present invention.
Embodiment 1:
Fig. 1 has provided the schematic top plan view of the photoelectric smoke sniffer based on depolarized rate of the present invention, and Fig. 2 is its schematic side view.Each optics in the present embodiment sniffer, electronic devices and components all are installed in the detection chamber 7 of an oblate cylindricality, this detection chamber can block external environment light, smoke particle can be entered smoothly, make chamber interior form optical dark room, the structure that for example can adopt one group of " V " shape thin slice to arrange as " dominoes " to form is as the sidewall of surveying chamber.As shown in Figure 1, detection chamber 7 inside in the bottom surface horizontal positioned, near light source 1 of left installed inside of surveying chamber 7, the center of circle in cylindrical detection chamber 7 rounded bottom surfaces of the beam alignment of light source 1 along continuous straight runs outgoing, this outgoing beam is incident to the particles 3 generation light scattering that enter in the detection chamber 7 after passing through the polarizer 2 with vertical direction optical axis, with the plane through this incident beam and level is scattering reference plane 8, the both sides up and down that are close to and are symmetrical in this scattering reference plane 8 install respectively two identical, first photelectric receiver 5 and second photelectric receiver 6 with identical scattering angle θ, these 2 photelectric receivers all nestle up surveys the inboard of chamber 7 and to the center of circle of the rounded bottom surface of quasi-cylindrical detection cavity chamber 7, i.e. particle scattering center; As shown in Figure 2, at the front end of first photelectric receiver 5 optical axis being installed is the inclined to one side device 4 of testing of vertical direction; The scattering reference plane 8 of described level also can be the arbitrary plane through incident beam; Get described scattering angle θ at 30 °～100 °.
The measured scattered light signal of photelectric receiver 5 among the present invention
The scattered light signal I measured with photelectric receiver 6
ScaRatio (θ) is the depolarized rate δ P (θ) of scattered light on this angle, and this value is as the criterion of distinguishing dust and water vapour particle, grey cigarette and black smoke particle.
The size of the scattered light intensity that photelectric receiver 6 is received has reflected the granule density that enters the detection chamber.Therefore, the scattered light intensity that is received by photelectric receiver 6 is aided with depolarized rate and discerns different types of particle, thereby provides the response output of normal, interference source or fire alarm.
The grain optical scattering signal is along with the increase of scattering angle θ, and its intensity reduces rapidly, and the scattering angle θ that adopts among the present invention guarantees that the measured signal of two photelectric receivers is enough big in 30～100 ° of scopes, make detection process reliable.In the present embodiment, the scattering angle θ of selection is 75 ° ± 5 °.
Measure by experiment, can simulate depolarized rate δ P (θ) minimum of atmospheric dust, loess dirt and water vapour particle, its maximal value is no more than δ P
1(θ), when θ is 75 ° ± 5 °, δ P
1(θ) value is about 0.15; Depolarized rate δ P (θ) maximum of the black smoke particle correspondence that normal heptane naked light, polyurethane naked light and diesel oil naked light generate, minimum value is not less than δ P
4(θ), when θ is 75 ° ± 5 °, δ P
4(θ) value is about 0.6; And the δ P (θ) of the grey smoke particle correspondence that cotton cord glows, the thermal decomposition of wood generates is placed in the middle, greater than δ P
2(θ) and less than δ P
3(θ), when θ is 75 ° ± 5 °, δ P
2(θ) value is about 0.25, δ P
2(θ) value is about 0.4.
When adopting the photoelectric smoke sniffer work based on depolarized rate of the present invention, operational testing as follows:
Enter as particle and to survey chamber generation light scattering and do the time spent, at first measure on the θ angle scattered light respectively in light intensity perpendicular to the component on the scattering plane by first photelectric receiver 5 and second photelectric receiver 6
With the total light intensity I of scattered light on the θ angle
Sca(θ), obtain on the θ angle
Ratio be depolarized rate δ P (θ).By this depolarized rate value, with δ P
1(θ), δ P
2(θ), δ P
3(θ) and δ P
4(θ) compare, thereby judge the type that enters detection chamber particle, then according to the photelectric receiver 6 scattered light signal intensity I of surveying
ScaSize (θ) is made corresponding judgement, and is specific as follows described:
(1) value of the depolarized rate δ P (θ) on the θ angle is less than depolarized rate δ P
1In the time of (θ), then judging and entering what survey chamber is dust or water vapor interference source particle, and according to the size of 6 receiving scattered light signal intensities of photelectric receiver, obtain entering the granule density of surveying chamber, whether final decision provides the fault-signal of " the interference source granule density is bigger ".
(2) value of the depolarized rate δ P (θ) on the θ angle is greater than depolarized rate δ P
2(θ) and less than depolarized rate δ P
3In the time of (θ), then judging and entering what survey chamber is the grey smoke particle that is generated by smoldering fire, and this grey smoke particle is bigger at the scattered light intensity of forward angle, therefore, and according to 6 receiving scattered light signal intensities of photelectric receiver I
ScaSize (θ), obtain entering the smoke particle concentration of surveying chamber, one-level, secondary and three grades of corresponding respectively smoke densities of sensitivity according to regulation in the joint of the 4.22.2.1 among the standard GB 4715-93 " spot-type smoke detector technical requirement and test method " are 0.5dB/m, 1.0dB/m and 2.0dB/m, set alarm threshold value, whether decision provides the signal of " fire alarm " and starts fire-fighting fire-extinguishing equipment.
(3) value of the depolarized rate δ P (θ) on the θ angle is greater than depolarized rate δ P
4In the time of (θ), then judging and entering what survey chamber is by the black smoke particle that has fireworks to generate, this grey smoke particle the scattered light intensity of forward angle relatively a little less than, therefore, according to 6 receiving scattered light signal intensities of photelectric receiver I
ScaSize (θ), one-level, secondary and three grades of corresponding respectively smoke densities of sensitivity according to regulation in the joint of the 4.22.2.1 among the standard GB 4715-93 " spot-type smoke detector technical requirement and test method " are 0.5dB/m, 1.0dB/m and 2.0dB/m, set alarm threshold value, judge the signal that whether provides " fire alarm " and start fire-fighting fire-extinguishing equipment.
By above analysis as seen,, utilize this important parameter of depolarized rate of reflection scattering particles essential characteristic, judge to enter the particle type of surveying chamber, get rid of the interference source particle, avoid the generation of reporting by mistake based on the photoelectric smoke Detection Techniques of depolarized rate.In addition,, adjust corresponding alarm threshold value, make the response sensitivity unanimity of this photoelectric smoke detector for the variety classes smoke particle by identification for the variety classes smoke particle.What this technology was utilized is the interior scattered lights of 30 ° ~ 100 ° stronger scopes of signal, has avoided adopting at 130 ° of later faint back scattering light signals, thereby has realized more reliably and exactly fire alarm.
Claims (3)
1, a kind of photoelectric smoke sniffer based on depolarized rate, comprise, light beam in light source (1) outgoing is incident on a certain scattering angle of smoke particle (3) the back generation light scattering in the cylindrical detection chamber (7), is provided with strong first photelectric receiver (5) of receiving scattered light; It is characterized in that: establish described light source (1) along continuous straight runs outgoing beam, be incident to smoke particle (3) before earlier through the polarizer (2), with the plane through this light beam and level is scattering reference plane (8), on reception plane (9) perpendicular to this scattering reference plane (8), the both sides up and down that are close to and are symmetrical in this scattering reference plane (8) install respectively two identical, first photelectric receiver (5) and second photelectric receiver (6) with identical scattering angle, and be the particle scattering center to the center of circle in the rounded bottom surface of quasi-cylindrical detection cavity chamber (7) all; Install one at the front end of first photelectric receiver (5) or second photelectric receiver (6) and test inclined to one side device (4); The described polarizer (2) and the direction of optic axis of testing inclined to one side device (4) are all perpendicular to scattering reference plane (8).
2,, be characterised in that the plane of described scattering reference plane (8) for the level of process incident beam according to claim 1 based on the photoelectric smoke sniffer of depolarized rate.
3, a kind of photoelectric smoke fire hazard detecting method based on depolarized rate comprises and measures the scattered light intensity be incident to the light beam on scattering angle θ behind the smoke particle; It is characterized in that: described light beam becomes the linearly polarized light of polarization direction perpendicular to the scattering reference plane after having passed through partially, and reenter and be incident upon smoke particle generation light scattering, be the scattered light intensity I of θ by measuring scattering angle
Sca(θ), and identical scattering angle θ go up the light intensity of polarization direction perpendicular to the scattered light of scattering reference plane
(θ), two scattered light intensities
(θ) and I
ScaRatio (θ) is the depolarized rate δ P (θ) of characterizing particles essential characteristic; First δ P (θ) the maximal value δ P that records according to experiment in the depolarized rate of simulating atmospheric dust, loess dirt and water vapour particle on a certain scattering angle θ
1(θ), the minimum value δ P of δ P (θ) in the depolarized rate of the black smoke particle of normal heptane naked light, polyurethane naked light and the generation of diesel oil naked light
4(θ), and the depolarized rate of the grey smoke particle correspondence that cotton cord glows, the thermal decomposition of wood generates at δ P (θ) greater than δ P
2(θ) and less than δ P
3(θ), arrange out δ P
4(θ)〉δ P
3(θ)〉δ P
2(θ)〉δ P
1(θ); Measure the scope of determining each self-corresponding depolarized rate δ P (θ) value in dust and water vapour particle, grey smoke particle and the black smoke grain optical scattering process more by experiment, this dust δ P (θ) value corresponding with water vapour particle, grey smoke particle and black smoke particle be in the interval that does not overlap mutually, thereby according to the kind of depolarized rate δ P (θ) backstepping particle; If the depolarized rate value δ P (θ) that records is less than δ P
1(θ), judge that then it is dust or water vapour interference source particle, for depolarized rate at δ P
2(θ)～δ P
3Grey smoke particle (θ) and depolarized rate are greater than the black smoke particle of P4 (θ), according to scattered light intensity value I
Sca(θ), one-level, secondary and three grades of corresponding respectively smoke densities of sensitivity according to regulation in the 4.22.2.1 joint among the standard GB 4715-93 " spot-type smoke detector technical requirement and test method " are 0.5dB/m, 1.0dB/m and 2.0dB/m, setting threshold is judged whether breaking out of fire, thereby realizes the response sensitivity for variety classes smoke particle unanimity; Get described scattering angle θ at 30 °～100 °.
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| CNB2006100971913A CN100511304C (en) | 2006-10-31 | 2006-10-31 | Photoelectric smoke sensing fire detecting method and apparatus based on depolarization rate |
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| CNB2006100971913A CN100511304C (en) | 2006-10-31 | 2006-10-31 | Photoelectric smoke sensing fire detecting method and apparatus based on depolarization rate |
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| CN100511304C true CN100511304C (en) | 2009-07-08 |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101763708B (en) * | 2009-12-28 | 2012-01-18 | 公安部沈阳消防研究所 | Wind pipe smoke-sensing fire detector |
| US9851291B2 (en) | 2016-05-02 | 2017-12-26 | Hamilton Associates, Inc. | Realtime optical method and system for detecting and classifying biological and non-biological particles |
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| CN102967542B (en) * | 2012-12-10 | 2019-05-10 | 乐志明 | A kind of method and device for identifying, measuring smoke particle |
| CN107564234B (en) * | 2017-09-15 | 2019-09-13 | 华中科技大学 | A kind of equalizer response is black, white cigarette fire detecting method and system |
| CN108205867B (en) * | 2017-12-25 | 2021-03-09 | 中国科学技术大学 | Early fire smoke detection method with interference particle recognition capability |
| CN110009864A (en) * | 2019-04-19 | 2019-07-12 | 汉威科技集团股份有限公司 | A kind of vertical multi-pass two-way dispersion smoke sensing detector labyrinth |
| CN109979155A (en) * | 2019-04-19 | 2019-07-05 | 汉威科技集团股份有限公司 | A kind of smoke detection labyrinth |
| CN116665397B (en) * | 2023-08-01 | 2023-09-26 | 中国科学技术大学 | Fire smoke alarm method and alarm device, alarm and readable storage medium |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1089048A (en) * | 1992-05-28 | 1994-07-06 | 能美防灾株式会社 | The sensitivity measuring apparatus that is used for fire detector |
| CN200963473Y (en) * | 2006-10-31 | 2007-10-24 | 中国科学技术大学 | Photoelectric smoke-sensitive fire detecting device based on depolarization rate |
-
2006
- 2006-10-31 CN CNB2006100971913A patent/CN100511304C/en not_active Expired - Fee Related
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1089048A (en) * | 1992-05-28 | 1994-07-06 | 能美防灾株式会社 | The sensitivity measuring apparatus that is used for fire detector |
| CN200963473Y (en) * | 2006-10-31 | 2007-10-24 | 中国科学技术大学 | Photoelectric smoke-sensitive fire detecting device based on depolarization rate |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101763708B (en) * | 2009-12-28 | 2012-01-18 | 公安部沈阳消防研究所 | Wind pipe smoke-sensing fire detector |
| US9851291B2 (en) | 2016-05-02 | 2017-12-26 | Hamilton Associates, Inc. | Realtime optical method and system for detecting and classifying biological and non-biological particles |
| US10908064B2 (en) | 2016-05-02 | 2021-02-02 | Hamilton Associates, Inc. | Realtime optical method and system for detecting and classifying biological and non-biological particles |
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| Publication number | Publication date |
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| CN1949285A (en) | 2007-04-18 |
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