CN105116528A - Scattering-type fire smoke detector and concentrator thereof - Google Patents

Abstract

The invention discloses a light concentrator for a scattering fire smoke detector, which comprises a light concentrator shell, the internal reflection surface of the light concentrator shell is a compound parabolic reflective surface, and light beams are arranged at the front and back ends of the light concentrator shell respectively. The entrance and the light exit. The light entrance includes an end light entrance and a side light entrance. The side light entrance is provided on the side of the concentrator shell and intersects with the end light entrance. The present invention also proposes a scattering type fire smoke detector, which collects scattered light from smoke particles in the optical detection chamber by using the light collector for the above scattering type fire smoke detector. In the present invention, the side light entrance is set on the concentrator, which increases the area of the light entrance, increases the range of receiving scattered light, and improves the ability of the concentrator to collect scattered light, thereby improving fire smoke detection detection sensitivity and detection accuracy.

Description

A diffuse fire smoke detector and its concentrator

technical field

The invention relates to the technical field of fire smoke detectors, in particular to a light collector for a diffuse fire smoke detector and a diffuse fire smoke detector using the light condenser.

Background technique

At present, the scattering-type fire smoke detector is a device that uses fire smoke particles to scatter light to detect fire. In the process of fire detection, when smoke particles and light interact, smoke particles can re-radiate the received light energy at the same wavelength, where re-radiation can occur in all directions, but the radiation intensity in different directions is also different, a phenomenon called scattering. In order to detect the existence of fire smoke, the light beam emitted by the light source can be irradiated on the smoke, and in the area outside the light path, the concentration of smoke can be determined by measuring the light energy generated by the scattering effect of smoke particles on light. This method is called scattering fire smoke detection method.

In the diffuse fire smoke detector, in order to eliminate the interference of external ambient light on the light-receiving element, the light-emitting element and the light-receiving element are generally installed in an optical darkroom, and smoke is allowed to enter in the optical darkroom while external light is not allowed to enter, so as to eliminate The purpose of external ambient light interference.

In the development process of the scattering fire smoke detector, since the scattering signal of the smoke particles is weak, the detection performance of the fire smoke detector can be improved by improving the ability of the light-receiving element to collect scattered light.

Chinese invention patent application CN101833840A discloses a forward/backward scattering composite point-type photoelectric smoke fire detector and its detection method; a condenser lens is used in the detector, but the field of view of the condenser lens is relatively small, And it will be limited by the scattering angle.

U.S. patent application US5764142 (Anderson and Tice1998) proposes to use a light-emitting element to emit a thinner laser beam to reduce the volume of the beam, and on this basis, use an algorithm to reduce false alarms; for the same concentration of smoke, using a thinner beam will inevitably reduce the scattering The intensity of light, in order to ensure the detection sensitivity, puts forward higher requirements on the ability of the photodetector to receive light energy.

Chinese invention patent application CN1662942A discloses a scattered light alarm. In order to increase the ability to identify fire smoke and interfering particles, forward and backward scattering is used. However, according to known principles, the light intensity of backward scattering is generally weaker than that of forward scattering. Therefore, it is necessary to strengthen the ability of the light receiver to collect scattered light in a certain way.

To sum up, in the existing scattering fire smoke detectors, the detection performance of fire smoke detectors is limited due to the poor ability of the light receiving element to collect scattered light, which has become an urgent problem to be solved by those skilled in the art. technical problem.

Contents of the invention

Based on the technical problems existing in the background technology, the present invention proposes a scattering type fire smoke detector and a concentrator thereof, which improves the ability to collect scattered light.

The present invention proposes a concentrator for a scattering type fire smoke detector, comprising a concentrator shell, the internal reflection surface of the concentrator shell is a compound parabolic reflective surface, and light beams are respectively arranged at the front and rear ends of the concentrator shell. The entrance and the light exit. The light entrance includes an end light entrance and a side light entrance. The side light entrance is provided on the side of the concentrator shell and intersects with the end light entrance.

In a further embodiment, there is a predetermined angle between the plane where the side light entrance is located and the central axis of the concentrator housing; preferably, the predetermined angle is less than or equal to the maximum concentrating angle of the concentrator.

In a further embodiment, the intersection point where the plane where the side light entrance is located and the central axis of the concentrator housing intersects is located between the front and rear ends of the concentrator housing.

In a further embodiment, there is a predetermined distance between the light entrance position at which the side light entrance is closest to the light exit and the light exit.

In a further embodiment, the end face light entrance is an arc entrance, the light exit is a circular exit, and the circle where the end face light entrance is located and the light exit circle are concentric circles perpendicular to the central axis of the concentrator housing.

In a further embodiment, the internal reflective surface of the concentrator shell is a compound parabolic reflective surface formed by using two symmetrically arranged parabolas to rotate around their symmetrical axes according to the CPC principle of the compound parabolic concentrator;

Preferably, the focus of the two parabolas falls on the light exit of the concentrator housing.

In a further embodiment, the internal reflective surface of the concentrator housing is coated with a reflective coating;

Preferably, the reflective properties of the reflective coating are designed according to the wavelength of the scattered light to increase the reflectivity of the reflective coating.

The present invention proposes a scattering type fire smoke detector, comprising: a detector housing, a light source, a light concentrator, and an optical receiving element, wherein the light concentrator adopts the above light concentrator for a scattering type fire smoke detector;

There is an optical detection cavity inside the detector housing. The light source, light collector, and optical receiving element are installed in the optical detection cavity of the detector housing. The light source is used to emit light beams into the optical detection cavity. For the scattered light of smoke particles in the cavity, the optical receiving element is arranged at the optical exit position of the concentrator.

In a further embodiment, the concentrator includes a first concentrator for collecting forward scattered light of smoke particles, the first concentrator is located on the first side of the illuminating beam, and the central axis of the first concentrator is aligned with the direction of the illuminating beam. The first included angle θfront≤θ1max, where θ1max is the maximum focusing angle of the first concentrator;

Preferably, the plane where the side light entrance of the first concentrator is located is arranged parallel to the illumination beam, and there is a first preset distance between the plane where the side light entrance of the first concentrator is located and the edge of the illumination beam;

Preferably, the projected straight line of the central axis of the first concentrator on the plane where the side light entrance is located, the normal of the projected straight line and the central axis of the illuminating light beam are located on the same plane.

In a further embodiment, the concentrator includes a second concentrator for collecting backscattered light from the smoke particles, the second concentrator is located on the second side of the illuminating beam, and the central axis of the second concentrator is aligned with the direction of the illuminating beam. The second included angle θback≤90°+θ2max, where θ2max is the maximum focusing angle of the second concentrator;

Preferably, the plane where the side light entrance of the second concentrator is located is perpendicular to the illumination beam, and there is a second preset distance between the end light entrance of the second concentrator and the edge of the illumination beam;

Preferably, the side light entrance of the second concentrator is set toward the outgoing direction of the illuminating light beam;

Preferably, the projected straight line of the central axis of the second concentrator on the plane where the side light entrance is located, the normal of the projected straight line and the central axis of the illuminating light beam are located on the same plane.

In the concentrator for scattering fire smoke detectors disclosed by the present invention, the internal reflection surface of the concentrator shell is a compound parabolic reflective surface, and the front and rear ends of the concentrator shell are respectively provided with a light entrance and a light exit, and the light entrance It includes an end light entrance and a side light entrance. The side light entrance is set on the side of the concentrator shell and intersects with the end light entrance. By opening the side light entrance on the side of the concentrator shell, the area of the light entrance is increased, the range of receiving scattered light is increased, and the ability of the condenser to collect scattered light is improved, thereby improving the performance of the fire smoke detector. Detection sensitivity and detection accuracy.

Description of drawings

Fig. 1 is a schematic structural view of a concentrator for a diffuse fire smoke detector in an embodiment of the present invention.

Fig. 2 is a schematic design diagram of a concentrator for a diffuse fire smoke detector in an embodiment of the present invention.

Fig. 3 is a schematic structural diagram of a compound parabolic concentrator CPC in the prior art.

Fig. 4 is a schematic diagram of the optical simulation of the scattered light collection effect of the concentrator for the diffuse fire smoke detector in the embodiment of the present invention and the compound parabolic concentrator CPC in the prior art by the optical simulation software TracePro.

Fig. 5 is the reflection of the scattered light collection effect of the radiant energy collector in the photodetector with the coating reflector disclosed by the light collector for the scattering type fire smoke detector in the embodiment of the present invention and the photodetector with the coating reflector disclosed by the optical simulation software TracePro Schematic of the optical simulation.

FIG. 6 is the optical simulation comparison result of FIG. 5 .

Fig. 7 is a schematic structural diagram of a diffuse fire smoke detector in an embodiment of the present invention.

FIG. 8 is a schematic diagram of optical simulation of the scattered light collection effect of the scattering fire smoke detector in the embodiment of the present invention and the scattering fire smoke detector in the prior art by the optical simulation software TracePro.

Detailed ways

As shown in FIG. 1 , FIG. 1 is a schematic structural diagram of a light concentrator for a scattering fire smoke detector in an embodiment of the present invention.

With reference to Fig. 1, the concentrator of a kind of scattering type fire smoke detector that the embodiment of the present invention proposes, comprises concentrator housing, and the internal reflection surface of concentrator housing is compound parabolic reflective surface, is set on concentrator housing There are a light entrance 1 and a light exit 2, wherein the light entrance 1 includes an end light entrance 1A and a side light entrance 1B, the end light entrance 1A is set at the first end of the concentrator housing, and the side light entrance 1B is opened at the concentrator housing and the side light entrance 1B intersects with the end light entrance 1A, and the light exit 2 is set at the second end of the concentrator housing.

In this embodiment, the internal reflective surface of the concentrator housing is a compound parabolic reflective surface designed according to the principle of a compound parabolic concentrator CPC (Compound Parabolic Concentrator).

Referring to Figure 2, in the design process of the compound parabolic concentrator CPC, the parabola A rotates around its focus F1 counterclockwise by an angle θmax, and the parabola B rotates around its focus F2 clockwise by an angle θmax, so that the focus of the parabola A F1 falls on the lower endpoint of parabola B, and the focus F2 of parabola B falls on the lower endpoint of parabola A. Axis 1' and axis 1 are the axes of symmetry before and after the rotation of parabola A respectively, axes 2' and 2 are the axes of symmetry before and after the rotation of parabola B respectively, parabola segments F1C and F2D are symmetrical about the Y axis and rotate around the Y axis to form a three-dimensional composite The structures of the parabolic concentrator CPC and the compound parabolic concentrator CPC are shown in FIG. 3 , and a light entrance 1' and a light exit 2' are respectively provided at both ends of the CPC.

In the compound parabolic concentrator CPC obtained through the above rotation, CD is the diameter of the light entrance of the CPC, F1F2 is the diameter of the light exit of the CPC, the circular plane where F1F2 is located is the focal plane of the CPC, and θmax is the maximum focusing angle of the CPC. The angle θi between the incident light and the Y axis is defined as the light incident angle. When θi>θmax, the incident light is reflected by the CPC and exits from the light entrance. When θi<θmax, the incident light converges at the light exit after one reflection. F1F2, so that all the light energy of θi<θmax is collected on the light exit.

According to the basic principle of scattering fire smoke detection, if there are smoke particles on the path of the irradiation beam, the irradiation beam will be scattered on the smoke particles to produce scattered light, and the scattered light will be scattered in the direction of the irradiation beam. In order to improve the ability of the light collector to collect scattered light, light inlets can be added to the light collector along the traveling direction of the irradiating light beam, thereby improving the ability of the light collector to collect scattered light. Based on the compound parabolic concentrator CPC, comprehensively considering the collection effect of scattered light and the processing difficulty of the concentrator, a plane is selected to intersect the side of the compound parabolic concentrator CPC during the design process of the concentrator, and the cut is made based on this plane A part of the side of the light concentrator, so that an entrance for scattered light is formed on the side of the light concentrator, that is, a side light entrance for collecting scattered light.

For the convenience of expression, the description in this paragraph is simplified. In Fig. 2, in the condenser F1CDF2, the entrance of the original light is CD, the selection plane EF intersects with the condenser F1CDF2, and the EDF part is the excised part. The new light entrance is CEF; compared with the original light entrance CD, the new light entrance CEF can collect more scattered beams in the direction of the irradiating light. In Fig. 2, the forward scattered light rays L1, L2 and L3 scattered by the smoke particles, the light L1 can be reflected once from the compound parabolic reflector and then guided to the light exit F1F2, while the light rays L2 and L3 can be directly irradiated to the light outlet F1F2, so that the optical receiving element installed on the light outlet F1F2 can collect more scattered light, thereby enhancing the collection ability of the scattered light of the light collector.

According to the above analysis, in the concentrator for scattering fire smoke detectors of this embodiment, the internal reflective surface of the concentrator housing is a compound parabolic reflective surface, and the light entrances include end face light entrances and side light entrances, and the side light entrances It is set on the side of the concentrator shell and intersects with the light entrance of the end face. In this way, in the process of collecting scattered light, more scattered light can be collected by opening the side light entrance on the side of the concentrator shell, thereby improving the concentration. The ability of an optical device to collect scattered light.

In Fig. 1, for the convenience of expression and explanation, the compound parabolic reflector is used as a reference in the concentrator shell, and the end close to the parabolic focus is defined as the rear end of the concentrator, and the end far away from the parabolic focus is defined as the concentrator. The front end of the light collector; according to the above arrangement, the light entrance is set at the front end of the light collector shell, the light exit is set at the rear end of the light condenser shell, and the side light entrance is set at the side of the light condenser shell and intersects with the end light light entrance; The inner reflective surface of the concentrator shell and the outer wall surface are combined at the side light entrance, and the outer wall faces the inner reflective surface to approach to form a light entrance front edge that gradually becomes thinner from outside to inside at the light entrance.

In the specific design process, the internal reflection surface of the concentrator shell is a compound parabolic reflector. In order to collect more scattered light and improve the ability of the concentrator to collect scattered light, the maximum concentration of the concentrator is rationally designed. Parameters such as the angle, the radius of the light entrance, the radius of the light exit, and the specific position of the side light entrance on the concentrator shell can significantly improve the ability of the concentrator to collect scattered light.

In a further embodiment, referring to FIG. 1 , the end surface light entrance 1A is an arc entrance, and the light exit is a circular exit 2. The circle where the end surface light entrance 1A is located is a concentric circle with the light exit 2, and the concentric circle is perpendicular to the concentric circle. The central axis Y of the optics housing.

In a specific embodiment, the focal points F1 and F2 of the parabola at both ends can be set to fall on the light exit of the concentrator shell, that is, the light exit is on the focal plane of the compound paraboloid reflective surface, and the diameter of the light exit is F1F2, of course, in In the actual application process, the light exit can be set at the front end or the rear end of the focal plane, which needs to be designed according to the process parameters and optical parameters of the actual application.

In a further embodiment, referring to FIG. 1 , the side light entrances on the concentrator housing are on the same plane, and there is a predetermined angle θ between the plane where the side light entrances are located and the central axis of the concentrator housing. The angle θ is less than or equal to the maximum condensing angle θmax of the concentrator; for example, if the maximum condensing angle θmax of the concentrator is designed to be 35°, the above-mentioned included angle θ can be set between 30° and 35°.

In a further embodiment, based on the fact that there is a predetermined angle θ between the plane where the side light entrance is located and the central axis of the concentrator housing, that is to say, the plane where the side light entrance is located intersects the central axis of the concentrator housing. , as shown in Figure 1, the intersection point of the two can be set between the front and rear ends of the concentrator shell, that is, the intersection point of the two falls inside the concentrator shell, or the intersection point of the two can also be set On the outside of the concentrator housing in front of the end face light exit.

In a further embodiment, on the concentrator housing, the side light entrance intersects the end surface light entrance, when the intersection of the plane where the side light entrance is located and the central axis of the concentrator housing is between the front and rear ends of the concentrator housing, The central angle of the arc where the light entrance of the end face is located is greater than 0° and less than 180°.

In a further embodiment, referring to FIG. 1 , there is a predetermined distance between the light entrance position at which the side light entrance is closest to the light exit and the light exit, and the plane where the side light entrance is located does not intersect the light exit.

In the above embodiments, the concentrator housing can be made of reflective metal, or the concentrator housing can be made of plastic coated with a reflective coating. During the design of the reflective coating, the wavelength of the scattered light can be To design the reflective properties of the reflective coating to increase the reflectivity of the reflective coating for the scattered light beam of this wavelength.

In a specific embodiment, in the compound parabolic reflective surface of the concentrator housing, the maximum focusing angle is 35°, the focal length is 4.72 mm, the focal point lateral displacement is 3 mm, and the front end length is 27 mm. The light entrance of the concentrator in this embodiment includes an end face light entrance and a side light entrance, the angle between the plane where the side light entrance is located and the central axis Y of the concentrator housing is 32°, and the plane where the side light entrance is located and the concentrator housing The intersection coordinates of the central axis Y of 21.5mm. By setting the side light entrance, the area of the light entrance is increased, the range of receiving scattered light is increased, and the ability of the light collector to collect scattered light is improved.

Next, the optical simulation comparative analysis of the scattered light collection ability of the concentrator for the diffuse fire smoke detector in this embodiment is carried out by using the optical simulation software TracePro.

As shown in Fig. 4, by TracePro software, optical simulation is carried out to the scattered light collection effect of the diffuser type fire smoke detector concentrator (Fig. 4A) in the embodiment of the present invention and the composite parabolic concentrator CPC (Fig. 4B) in the prior art . In the optical simulation process, a group of parallel rays is used to simulate the light scattered by smoke particles. It can be seen from the light density of the light exit in Fig. 4 that compared with the prior art CPC (Fig. 4B), the concentrating The detector (Fig. 4A) can receive more scattered light from smoke particles.

As shown in Fig. 5, by TracePro software, the light collector (Fig. 5A) used in the scattering type fire smoke detector in the embodiment of the present invention and the radiant energy collector (Fig. Figure 5B) performs an optical simulation of the scattered light collection effect. Since the manufacturing difficulty and volume are relatively similar, it is of practical significance to compare the two models.

Assuming that the reflectance of the inner surface of the concentrator and the radiant energy collector is 100%, that is, specular reflection, the light exit area of the light concentrator and the radiant energy collector is the same, and the optical receiving element arranged at the light exit has the same area of light The surface absorption rate of the receiving surface and the light receiving surface is 100%, that is, the incident light is completely absorbed. During the optical simulation process, 10,000 rays of light are emitted through the surface light source, and the rays are emitted perpendicular to the light-emitting surface. Some of the rays will be reflected by the concentrator and irradiated on the light receiving surface, and some of the rays will be directly irradiated to the light receiving surface through the concentrator. face. By comparing the amount of light received on the light receiving surface of the optical receiving element, the collection effect of the light concentrator and the radiation energy collector on scattered light can be compared.

As shown in Figure 6, according to the relationship between the amount of incident light and the scattering angle of the light concentrator on the light receiving surface under different scattering angles, it can be seen that the collection effect of the light concentrator on scattered light in this embodiment It is better than the radiation energy collector disclosed in the invention patent application CN1191361A in collecting effect on scattered light.

In the concentrator for scattering fire smoke detectors disclosed in this embodiment, the light entrance of the concentrator includes an end light entrance and a side light entrance, and the side light entrance is provided on the side of the concentrator shell and intersects with the end light entrance. By opening a side light entrance on the side of the concentrator shell, the area of the light entrance is increased, and the range of receiving scattered light is increased, thereby improving the ability of the light collector to collect scattered light.

Based on the light concentrator for the scattering fire smoke detector proposed in this embodiment, the embodiment of the present invention also proposes a light concentrator for the scattering fire smoke detector by applying the above light concentrator.

As shown in FIG. 7 , FIG. 7 is a schematic structural diagram of a scattering fire smoke detector in an embodiment of the present invention.

Referring to Fig. 7, a diffused fire smoke detector proposed by an embodiment of the present invention includes: a detector housing 10, a light source 11, a concentrator and an optical receiving element, wherein the concentrator adopts the above-mentioned diffused fire smoke detector Condenser for the detector; the accommodating cavity inside the detector housing 10 forms an optical detection cavity, the light source 11, the light collector, and the optical receiving element are installed in the optical detection cavity of the detector housing 10, and the light source 11 is used for The light beam K is emitted into the optical detection chamber, the condenser is used to collect the scattered light of the smoke particles in the optical detection chamber, and the optical receiving element is arranged at the optical outlet of the condenser to receive the scattered light and output a signal.

During the detection process, the air enters the optical detection chamber of the detector, and the irradiating light beam encounters smoke particles in the air during the traveling process and is scattered, for example, forward scattered light and back scattered light are generated, and the scattered light is emitted from the condenser The end light entrance and the side light entrance enter the concentrator, are reflected by the compound parabolic reflective surface inside the concentrator, and then emit from the light exit of the concentrator, and then guided to the optical receiving element to absorb the scattered light.

Referring to Fig. 7, in a further embodiment, the concentrator includes a first concentrator 12, the first concentrator 12 is used to collect the forward scattered light of smoke particles, the first concentrator 12 can be called forward scattered light Concentrator, the first concentrator 12 is located on the first side of the illuminating light beam K.

The first included angle θfront≤θ1max between the central axis of the first concentrator and the illuminating beam, where θ1max is the maximum converging angle of the first concentrator and θ1max=35°, the central axis of the first concentrator in the figure The included angle ∠AOC between AA' and the irradiation beam CC' is θfront, ∠AOC=32°.

The plane where the side light entrance of the first concentrator is located is arranged parallel to the irradiation beam, that is, the angle between the plane where the side light entrance is located and the central axis of the first concentrator is θfront, and in the figure the plane where the side light entrance is located and the first concentrator The included angle of the central axis AA' is 32°.

There is a first preset distance between the plane where the side light entrance of the first concentrator is located and the edge of the illuminating beam; under the condition that the illuminating beam is guaranteed not to enter the first concentrator, the side light entrance can be infinitely close The irradiating light beam, specifically, the above-mentioned first preset distance is 4mm.

The projection line of the central axis of the first concentrator on the plane where the side light entrance is located, the normal of the projection line and the central axis of the illuminating light beam are located on the same plane.

According to the above-mentioned design of the first concentrator, it is beneficial to enhance the ability of the first concentrator to collect small-angle forward scattered light, and can quantitatively determine the receiving angle of the first concentrator for forward scattered light, thereby avoiding The first concentrator receives backscattered light.

Referring to Fig. 7, in a further embodiment, the concentrator includes a second concentrator 13, the second concentrator 13 is used to collect the backscattered light of the smoke particles, and the second concentrator 13 can be called backscattered light. Condenser, the second concentrator 13 is located on the second side of the illuminating beam K, and the side light entrance of the second concentrator 13 is set toward the outgoing direction of the illuminating beam K (with reference to the second concentrator).

The second included angle θback≤90°+θ2max between the central axis of the second concentrator and the illumination beam, where θ2max is the maximum converging angle of the second concentrator and θ1max=35°, the second concentrator in the figure The included angle ∠BOC between the central axis BB' and the irradiation beam CC' is θback, ∠BOC=90°+32°=122°.

The plane where the side light entrance of the second concentrator is located is perpendicular to the irradiation beam, that is, the angle between the plane where the side light entrance is located and the central axis of the second concentrator is θback-90°, the plane where the side light entrance is located and the second The included angle of the central axis BB' of the concentrator is 122°-90°=32°

There is a second preset distance between the end light entrance of the second concentrator and the edge of the irradiated beam; under the condition that the front end of the concentrator will not block the irradiated beam, the end light entrance of the second concentrator can be infinitely close to The irradiating light beam, specifically, the above-mentioned second preset distance is 1.6mm.

The projection line of the central axis of the second concentrator on the plane where the side light entrance is located, the normal of the projection line and the central axis of the illuminating light beam are located on the same plane.

According to the above-mentioned design of the second concentrator, it is beneficial to enhance the ability of the second concentrator to collect backscattered light, and can quantitatively determine the range of receiving angles of the second concentrator for backscattered light, and can also avoid the second Two concentrators receive forward scattered light.

In the following, the optical simulation comparative analysis of the scattered light collection capabilities of the diffuse fire smoke detector in this embodiment and the diffuse fire smoke detector in the prior art is carried out by optical simulation software TracePro.

Referring to Fig. 8, Fig. 8A is the simulation result of the light data received by the forward scatter concentrator in the detector of this embodiment, Fig. 8B is the simulation result of the light data received by the backscatter concentrator in this embodiment, and Fig. 8C is the current The simulation result of the light data received by the forward scatter concentrator in the prior art detector, Fig. 8D is the simulation result of the light data received by the back scatter concentrator in the prior art detector, where the numbers in the figure are the light concentrators The number of rays received by the ray exit.

The diffuse fire smoke detector of the present embodiment adopts the concentrator shown in Fig. 1, and the diffuse fire smoke detector of the prior art adopts the concentrator shown in Fig. 3, and light is concentrated in two detectors devices have the same mounting position. In the detector of this embodiment, the forward scatter concentrator has a side light entrance and the plane where the side light entrance is located is arranged parallel to the illumination beam, so the forward scatter concentrator will not block the illumination beam; Under the premise that the central concentrator is installed in the same position, the concentrator in the detector of the prior art will irradiate the light beam and produce occlusion, therefore, the forward scattering concentrator is truncated in Fig. 8C and Fig. 8D; for the backward Diffuse concentrators do not obstruct the illuminating beam and require no exceptions.

In the optical simulation process, a section of cylindrical side surface is used as the light emitted by the surface light source to simulate the light scattered by smoke particles. In Figure 8, 10,000 light rays are emitted through the surface light source, and the field angle distribution of the light is Lambertian luminous field type .

In Figure 8A and Figure 8C, according to the distribution range and light density of the light, it can be seen that compared with the detector of the prior art, the forward scattering concentrator of the detector of this embodiment can receive a wider range of light And more light, and the forward scattering concentrator has a filtering effect on the received light, that is, the light received by the forward scattering concentrator is all forward scattering light.

In Fig. 8B and Fig. 8D, according to the light distribution range and light density, it can be seen that compared with the detector of the prior art, the amount of light received by the backscatter concentrator of the detector of this embodiment is less, However, the light received by the backscatter concentrator of the detector in this embodiment is all backscattered light, and the backscatter concentrator has a significant light screening effect; in the detector of the prior art, although the backscatter The scattering concentrator receives more light, but part of the light is forward scattered light, which is not conducive to the design of detection algorithm and the improvement of detection accuracy and detection sensitivity.

In the scattering-type fire smoke detector proposed in this embodiment, by adopting the light collector for the above-mentioned scattering-type fire smoke detector, the ability of the light collector to collect scattered light is improved, the amount of scattered light received by the optical receiving element is increased, and the The signal level of the optical receiving element is improved, and the signal-to-noise ratio is increased, thereby improving the detection sensitivity and detection accuracy of the fire smoke detector.

The above is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto, any person familiar with the technical field within the technical scope disclosed in the present invention, according to the technical solution of the present invention Any equivalent replacement or change of the inventive concepts thereof shall fall within the protection scope of the present invention.

Claims (10)

1. a scatter-type fire smog detector condenser, comprise concentrator shell, the internal reflection surface of concentrator shell is compound parabolic reflecting surface, light entrance and light outlet is respectively equipped with in the rear and front end of concentrator shell, it is characterized in that, light entrance comprises end face light entrance and side light entrance, and side light entrance is opened in the side of concentrator shell and crossing with end face light entrance.

2. scatter-type fire smog detector condenser according to claim 1, is characterized in that, has predetermined angle between side light entrance place plane and the central axis of concentrator shell; Preferably, described predetermined angle is less than or equal to the maximum condensing angle of condenser.

3. scatter-type fire smog detector condenser according to claim 2, is characterized in that, the plane intersection point crossing with the central axis of concentrator shell in light entrance place, side is between the rear and front end of concentrator shell.

4. the scatter-type fire smog detector condenser according to any one of claim 1-3, is characterized in that, side light entrance distance light exports between nearest light entrance position and light outlet has preset distance.

5. the scatter-type fire smog detector condenser according to any one of claim 1-4, it is characterized in that, end face light entrance is circular arc entrance, light outlet is round exit, and end face light entrance place circle and the circle of light outlet are the concentric circles of the central axis perpendicular to concentrator shell.

6. the scatter-type fire smog detector condenser according to any one of claim 1-5, it is characterized in that, the internal reflection surface of concentrator shell is the compound parabolic reflecting surface adopting the two sections of para-curves be arranged symmetrically with to rotate around its axis of symmetry according to compound parabolic concentrator CPC principle and formed;

Preferably, two sections of parabolical focuses drop on the light outlet of concentrator shell.

7. the scatter-type fire smog detector condenser according to any one of claim 1-6, is characterized in that, be coated with reflectance coating at the internal reflection surface of concentrator shell;

Preferably, the reflectivity of reflectance coating is improved according to the reflection characteristic design of wavelength to reflectance coating of scattered light.

8. a scatter-type fire smog detector, is characterized in that, comprising: detector housing, light source, condenser, optical receiver component, and wherein, condenser adopts the scatter-type fire smog detector condenser according to any one of claim 1-7;

Detector housing inside has optical detection chamber, light source, condenser, optical receiver component are arranged in the optical detection chamber of detector housing, light source is used for sending illumination beam in optical detection chamber, condenser is for collecting the scattered beam of smoke particle in optical detection chamber, and optical receiver component is located at the optical outlet position of condenser.

9. scatter-type fire smog detector according to claim 8, it is characterized in that, condenser comprises the first condenser for collecting the forward scattering light of smoke particle, first condenser is positioned at the first side of illumination beam, the central axis of the first condenser and the first angle theta front of illumination beam≤θ 1max, wherein θ 1max is the maximum condensing angle of the first condenser;

Preferably, the side light entrance place plane of the first condenser and illumination beam are arranged in parallel, and have the first predeterminable range between the side light entrance place plane of the first condenser and illumination beam edge;

Preferably, the first condenser central axis side light entrance the central axis of projection straight line in the plane, the normal of projection straight line and illumination beam in the same plane.

10. scatter-type fire smog detector according to claim 8 or claim 9, it is characterized in that, condenser comprises the second condenser for collecting the back scattering light of smoke particle, second condenser is positioned at the second side of illumination beam, the central axis of the second condenser and the second angle theta back≤90 of illumination beam °+θ 2max, wherein θ 2max is the maximum condensing angle of the second condenser;

Preferably, the side light entrance place plane of the second condenser and illumination beam are arranged vertically, and have the second predeterminable range between the end face light entrance of the second condenser and illumination beam edge;

Preferably, the side light entrance of the second condenser is arranged in the exit direction of illumination beam;

Preferably, the second condenser central axis side light entrance the central axis of projection straight line in the plane, the normal of projection straight line and illumination beam in the same plane.