CN108956406A - A kind of smoke intensity detection optical system and its method - Google Patents

Abstract

The invention discloses a smoke detection optical system and a method thereof, belonging to the technical field of gas smoke detection. The system includes a light source part, a spectroscopic part and a detection part; the light source part includes a light-emitting element, a primary collimator, a converging lens and a secondary collimator arranged in sequence along the illumination direction; Accepting the light beam emitted by the light-emitting element and passing through the secondary collimating mirror, and the plurality of beam splitters can divide the light beam into multiple parallel beams; the detection part is used to receive the multiple parallel beams, and The spectra of the multiple parallel light beams are detected. In this method, the light source part is used to condense the light, and then the light is divided into multiple beams by the light splitting part, and finally the detection part detects the multiple beams of light to obtain a result. Through the combination of the collimating mirror, the converging lens and the spectroscopic mirror, the present invention increases the light intensity while reducing the secondary error caused by the spectroscopic separation, reaches the light intensity accepted by the detection end, and improves the detection accuracy.

Description

Optical system and method for smoke detection

technical field

The invention belongs to the technical field of gas smoke detection, and more specifically relates to a smoke detection optical system and a method thereof.

Background technique

With the development of the world economy, environmental pollution is becoming more and more serious, and the detection and treatment of air quality has become the focus of attention. The technology of using spectral characteristics to analyze atmospheric components has been widely used in the fields of atmospheric trace gas detection, industrial process control, and emission monitoring of urban pollution sources. Therefore, it is of great significance to develop devices that can accurately and real-time measure air gas concentrations.

In order to improve the detection sensitivity of absorption spectroscopy to low-concentration gases, increasing the length of the light beam passing through the gas sample is an effective method. Obviously, simply keeping the light source away from the detector so that the light beam passes through a very straight and long transmission-type gas sample cell will make the device bulky, complicated in alignment, and poor in shock resistance. A common and direct method is to increase the light passing through the gas to be measured. The optical path length, resulting in stronger absorption. Traditional long-range absorption cell designs mainly include: waveguide type, integrating sphere type, Chernin type and similar structures. Generally speaking, the design of this type of long-range absorption pool has the defect of low utilization of the effective area of the mirror surface, which makes it difficult to obtain a high number of reflections in a miniaturized structure. At the same time, the light-splitting structure of the air detection device also has a lot of room for improvement, and it is difficult to avoid the secondary error caused by the superimposition of different light-splitters in the existing light-splitting structure.

There are many solutions for gas component detection in the prior art. For example, the Chinese patent application number is: 201110098658.7, and the patent document published on November 23, 2011 discloses an online monitoring method for a motor vehicle exhaust monitoring system , including the following steps: Step A, measuring the background spectrum, ultraviolet channel reference spectrum, and infrared channel reference spectrum of the system; The exhaust emitted by the motor vehicle absorbs the ultraviolet light signal and infrared light signal, and calculates the exhaust gas composition according to the pre-stored background spectrum, ultraviolet channel reference spectrum and infrared channel reference spectrum. The solution monitors the content of the corresponding gas components in the exhaust of motor vehicles through two channels of ultraviolet and infrared, which can realize unattended automatic online monitoring, grasp the real exhaust emissions of motor vehicles during driving, and facilitate real-time monitoring of heavily polluting vehicles. Governance, the entire monitoring system has the advantages of online calibration, real-time, high monitoring efficiency, unattended, and continuous operation. However, it is specifically for the detection of motor vehicle exhaust components, and does not involve the detection of smoke concentration in the air, and it uses ultraviolet light and infrared light to penetrate the exhaust gas, which cannot be detected by ordinary light sources.

As another example, the Chinese patent application number is: 201310348019.0, and the publication date is: the patent document on November 27, 2013, which discloses an optical platform for a transmission opacimeter, which includes a fan, a detection pipeline, a gas chamber pipeline and The photoelectric detection unit, the two side walls of the fan and the detection pipe are respectively provided with a smoke inlet and an observation port. The photoelectric detection unit includes a support, a collimating lens, a converging lens and a photodiode. A branch airflow pipeline and a second branch airflow pipeline, the airflow inlet of the first branch airflow pipeline is connected to the outlet of the fan, the first branch airflow pipeline and the second branch airflow pipeline extend to the support, and are connected between the converging lens and the observation An air outlet is provided between the ports, and the air outlet is connected with a second branch air flow pipeline, and the second branch air flow pipeline is connected to the first branch air flow pipeline. Due to the formation of a stable airflow vortex near the surface of the collimating lens and the converging lens, this solution can effectively reduce the direct contact between the engine exhaust gas containing oil and gas and the surface of the lens, and the surface cleaning cycle can be greatly extended, and it is not used for smoke components. to test.

Contents of the invention

1. Problems to be solved

The invention provides an optical system for smoke detection, which aims to solve the problems of insufficient light intensity, low utilization rate of reflecting mirrors, large spectral error and the like in the existing way of using absorption spectrum to detect smoke concentration. The smoke detection optical system of the present invention, through the reasonable combination of the collimating mirror, the converging lens and the beam splitter, can increase the light intensity while reducing the secondary error caused by the light splitting, so as to enhance the strength of the light signal received by the detection end and improve the detection efficiency. precision.

The smoke detection optical system of the invention can be applied to the detection of the smoke concentration in the air, and provides a smoke concentration detection method, which can efficiently and accurately detect the smoke concentration.

2. Technical solution

In order to solve the above problems, the present invention adopts the following technical solutions.

An optical system for smoke detection, comprising a light source part, a light splitting part and a detection part; the light source part includes a light emitting element, a primary collimator, a converging lens and a secondary collimator, and the light splitting part includes multiple beam splitters; the The light emitting element, the primary collimating mirror, the converging lens and the secondary collimating mirror are sequentially arranged in the direction of illumination of the light emitting element; , and the plurality of beam splitters can equally divide the light beam into multiple parallel light beams; the detection part is used to receive the multiple parallel light beams and detect the spectrum of the multiple parallel light beams.

As a further improvement, the light source part also includes a light source support cylinder, a middle cylinder, and a lower cylinder connected end to end from top to bottom; The converging lens is arranged in the middle cylinder, and the secondary collimating mirror is arranged in the lower cylinder.

As a further improvement, a light source seat plate and a primary lens seat plate are installed up and down in the light source support cylinder; the light-emitting element array is installed on the light source seat plate, and its irradiation direction faces the side of the primary lens seat plate; the primary collimator is installed On the primary lens seat plate, each light-emitting element is aligned with a primary collimating mirror.

As a further improvement, the light-emitting elements are arranged in layers in a honeycomb shape, satisfying T=1+(n-1)*6, wherein: T is the number of light-emitting elements, and n is the number of layers in which the light-emitting elements are arranged.

As a further improvement, the lower end of the light source supporting cylinder is socket-connected to the upper end of the middle cylinder; the inner side of the lower end of the light source supporting cylinder is provided with a plurality of elastic buckles along the circumferential direction, and the inner side of the upper end of the middle cylinder is provided with The convex ring is clamped, and the elastic buckle can be clamped on the convex ring; at least one of the elastic buckles is provided with a paddle extending out of the light source support cylinder.

As a further improvement, a lens holder is installed in the middle cylinder; the outer circumference of the converging lens is sleeved in the elastic pressure ring, and supported on the support boss inside the lens holder; screwed on the lens holder The compression swivel at the upper end of the holder clamps the converging lens by squeezing the elastic pressure ring.

As a further improvement, a fine-tuning knob is threaded on the outer side of the middle cylinder, and a fine-tuning ring groove is provided on the inner side of the fine-tuning knob; After passing through the holes, the legs are supported in the fine-tuning ring groove of the fine-tuning knob.

As a further improvement, the beam splitter is installed in the beam splitter box below the lower cylinder; the upper end of the beam splitter box has a light inlet for light to enter, and its lower end has a hole for the beam split by the beam splitter to exit. Light aperture.

As a further improvement, a flue gas passage part is arranged between the spectroscopic part and the detection part; the flue gas passage part includes a flue gas box that can be passed by the light beam from the spectroscope to the detection part; The flue gas box in the direction of the light beam is opposite to the box walls on both sides, and a fan is installed on one side of the box wall, and air holes are opened on the other side of the box wall, or fans are installed on both sides of the box wall.

A smoke detection method, the steps of which include: firstly, the light-emitting element is powered on to emit light; then, the light emitted by the light-emitting element passes through a primary collimator to form a parallel beam, and the parallel light is focused and irradiated to a secondary collimator through a converging lens In the above, the parallel beam with larger diameter passes through the secondary collimator to form a parallel beam with smaller diameter; then, the parallel beam after passing through the secondary collimator is divided into multiple parallel beams with the same light intensity through the beam splitter; finally, multiple After the parallel light beam passes through the smoke to be detected, it is received by the detection part, and the spectrum is detected.

3. Beneficial effects

Compared with the prior art, the beneficial effects of the present invention are:

(1) The smoke detection optical system of the present invention, through the light-emitting element in the light source part, the primary collimating mirror, the converging lens and the secondary collimating mirror converge the light, and combine the beam splitter of the beam splitting part to divide the light into multiple parallel channels The light beam is detected by the detection part, which can obtain accurate air multi-component concentrations in real time, providing great help for the detection and treatment of air quality; for the light source part, the present invention overcomes the existing technical deficiencies and provides light-emitting elements, converging lenses and The high-power coaxial light source composed of collimating mirrors solves the problem that the light intensity of a single luminous tube is insufficient and the brightness is not enough, while the light emitted by multiple luminous tubes is not on the same axis and the light intensity is not enough.

(2) The smoke detection optical system of the present invention, in terms of smoke detection, adopts a novel light-splitting structure that reduces the secondary error caused by the superimposition of different light-splitting sheets of the existing light-splitting structure, thereby achieving the maximum value received by the final receiving end. The purpose of high optical signal intensity and small error.

(3) The smoke detection optical system of the present invention can be applied to the detection of smoke concentration in the air, and provides a detection method of smoke concentration, which can detect smoke concentration efficiently and accurately.

Description of drawings

Fig. 1 is a front sectional view of the smoke detection optical system of the present invention;

Fig. 2 is a left view of the smoke detection optical system of the present invention;

Fig. 3 is a three-dimensional structural view of the light source part in the smoke detection optical system of the present invention;

Fig. 4 is a front sectional view of the light source part in the smoke detection optical system of the present invention;

Fig. 5 is a view of the connection structure of the light source seat plate and the primary lens seat plate in the light source part;

Fig. 6 is a front structural view of the light source support cylinder in the smoke detection optical system of the present invention;

Fig. 7 is the sectional view of A-A among Fig. 6;

Fig. 8 is a three-dimensional structural view of the middle barrel in the smoke detection optical system of the present invention;

Fig. 9 is a front sectional view of the middle cylinder in the smoke detection optical system of the present invention;

Fig. 10 is a view of the installation structure of the converging lens in the smoke detection optical system of the present invention;

Fig. 11 is a three-dimensional structural view of the connecting ring in the smoke detection optical system of the present invention;

Fig. 12 is a front sectional view of the lower cylinder in the smoke detection optical system of the present invention;

Fig. 13 is a three-dimensional mechanism view of the connector in the smoke detection optical system of the present invention viewed from the upper side;

Fig. 14 is a three-dimensional mechanism view of the connector in the smoke detection optical system of the present invention viewed from the lower side;

Fig. 15 is a three-dimensional structural view of half of the spectroscope box in the spectroscopic part of the smoke detection optical system of the present invention;

Fig. 16 is a schematic diagram of light splitting in the beam splitter box of the light splitting part;

Figure 17 shows the honeycomb arrangement of light sources in the light source part;

Fig. 18 is a schematic diagram showing the principle of light concentrating and light splitting in the smoke detection optical system of the present invention;

Fig. 19 is a schematic diagram of the arrangement of beam splitters in the beam splitting part to split light.

The labels in the accompanying drawings represent respectively:

100. Light source part; 110. Light emitting element; 111. Light source seat plate; 112. Positioning sleeve; 113. Positioning screw; 120. Primary collimating mirror; 121. Primary lens seat plate; 130. Converging lens; 131. Lens clamping Device; 1311, thread section; 1312, support boss; 1313, leg; 132, compression screw; 1321, screw hole; 133, fine-tuning knob; 1331, fine-tuning ring groove; 134, elastic pressure ring; 140, Secondary collimating mirror; 141, secondary lens seat plate; 150, light source support cylinder; 151, light source pressure ring; 152, collimating mirror pressure ring; 153, socket section; 154, elastic buckle; ;156, paddle; 157, paddle hole; 158, cover section; 159, protrusion; 160, middle cylinder; 161, sleeve boss; 165, card slot; 170, lower cylinder; 171, connecting ring sleeve; 172, elastic washer; 173, positioning convex ring; 174, clamping block; 175, positioning ring groove; 176, positioning boss; 177, 178, embedded ring groove; 180, connector; 181, positioning slot hole; 182, light hole; 183, clip block; 184, guide bar; 185, fixed seat; 186, bolt hole; cover;

200, beam splitter; 210, beam splitter box; 220, beam splitter support; 230, light entrance hole; 240, light exit hole; 250, guide groove;

300. Detection part; 310. Photoelectric sensor;

400, the flue gas channel part; 410, the flue gas box; 411, the air hole; 420, the fan.

Detailed ways

In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "length", "upper", "lower", "top", "bottom", "inner" and "outer" are based on the attached The orientation or positional relationship shown in the figure is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be construed as a reference to this invention. Invention Limitations.

In addition, the terms "primary" and "secondary" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of indicated technical features. Thus, the features defined as "primary" and "secondary" may explicitly or implicitly include one or more of these features. In the description of the present invention, unless otherwise specified, "plurality" means two or more.

In the description of the present invention, it should be noted that unless otherwise specified and limited, the terms "installation", "connection", "connection" and "fixation" should be understood in a broad sense, for example, it can be a fixed connection, or It can be a detachable connection or an integral connection; it can be a mechanical connection; it can be a direct connection or an indirect connection through an intermediary, and it can be an internal communication between two components. Those of ordinary skill in the art can understand the specific meanings of the above terms in the present invention in specific situations.

The present invention will be further described below in conjunction with specific embodiments and accompanying drawings.

Example

As shown in Figures 1 and 2, this embodiment provides a smoke detection optical system, which mainly uses optical principles to detect smoke concentration. It is mainly composed of four parts, namely a light source part 100, a spectroscopic part 200, The flue gas passage part 400 and the detection part 300. Wherein, the light source part 100 is mainly used for converging the more scattered and weaker light emitted by the light source to form a more concentrated and stronger light beam to increase the light intensity of the light source; the light splitting part 200 is used for converging the light source part 100 The light beam is divided into multiple light beams with basically the same light intensity; the flue gas channel part 400 can pass through the flue gas, and the passing flue gas can be passed by the multiple light beams separated by the light splitting part 200, so that the flue gas can absorb part of the light; The detection part 300 is used to receive the light beam passing through the smoke, and detect the absorption spectrum to perform smoke detection. The whole system is a unified whole formed by the organic combination of the above four parts. The mechanism and connection relationship of each part and how to carry out smoke detection will be described in detail below.

As shown in FIGS. 3 and 4 , the light source part 100 includes a light emitting element 110 , a primary collimator 120 , a converging lens 130 , a secondary collimator 140 , a light source support cylinder 150 , a middle cylinder 160 and a lower cylinder 170 . Wherein, the light emitting element 110, the primary collimating mirror 120, the converging lens 130 and the secondary collimating mirror 140 are arranged sequentially in the light direction of the light emitting element 110, and are arranged sequentially from the direction of the drawing, that is, the up and down direction; the light source supporting cylinder 150, the middle The cylinder 160 and the lower cylinder 170 are connected end to end in order from top to bottom, and the light emitting element 110 and the primary collimator 120 are arranged in the light source support cylinder 150 in the up and down direction, the converging lens 130 is arranged in the middle cylinder 160, and the secondary collimator The straight mirror 140 is disposed in the lower cylinder 170 . The combination of the light source support cylinder 150, the middle cylinder body 160 and the lower cylinder body 170 forms a relatively closed space inside them, that is, the channel for light convergence to avoid the influence of external light. In order to achieve a better sealing effect, the light source support cylinder The upper end of 150 is also screwed with a screw cap 190 , and the electric circuit of the light emitting element 110 can pass through the screw cap 190 for connection.

4 to 7, the light source support tube 150 is installed with a light source seat plate 111 and a primary lens seat plate 121 up and down; the array of light emitting elements 110 is installed on the light source seat plate 111, and its irradiation direction faces the side of the primary lens seat plate 121; The primary collimating mirror 120 is mounted on the primary lens seat plate 121 , and each light emitting element 110 is aligned with one primary collimating mirror 120 , so that the light emitted by the light emitting element 110 passes through the primary collimating mirror 120 to form a parallel beam. For the stable and reliable installation structure of the light source seat plate 111 and the primary lens seat plate 121 in the light source support cylinder 150, the light source seat plate 111 is set in the light source pressing ring 151, and the primary lens seat plate 121 is set in the collimating mirror pressing ring 152. The light source pressure ring 151 and the collimator mirror pressure ring 152 are made of rubber, nylon and other elastic materials, which are elastic and can be evenly clamped from around the board, and the middle part of the light source support tube 150 has an inwardly protruding step, and the light source pressure ring 151 and the collimating mirror pressure ring 152 are supported up and down on the step surface of this step, and a spacer ring is placed between the two.

Simultaneously, the upper end of the light source supporting cylinder 150 is a covering section 158, which has internal threads, and the lower end of the screw cap 190 has external threads, and the lower end of the screw cap 190 is screwed into the covering section 158 of the light source supporting cylinder 150, and can be pressed against the pressure of the light source. On the upper end surface of the ring 151, the light source pressure ring 151 and the collimator mirror pressure ring 152 can radially expand and contract, and the light source seat plate 111 and the primary lens seat plate 121 can be pressed reliably. The inner surface of the light source pressure ring 151, that is, the contact surface with the light source seat plate 111, and the inner surface of the collimator mirror pressure ring 152, that is, the contact surface with the primary lens seat plate 121, are evenly opened along the circumferential direction. It is beneficial to the radial expansion and contraction of the light source pressure ring 151 and the collimator mirror pressure ring 152 . In addition, in order to ensure that the parallel distance between the pressing light source seat plate 111 and the primary lens seat plate 121 remains unchanged, a plurality of positioning sleeves 112 are arranged along the circumferential direction between the two, and by passing through the pressing light source seat from top to bottom respectively, The positioning screws 113 of the plate 111 and the primary lens seat plate 121 are screwed into the positioning sleeve 112 to securely fix the light source seat plate 111 , the primary lens seat plate 121 and the positioning sleeve 112 .

The light source 110 can be selected as the light source as required, for example, it can be an incandescent light source, a fluorescent light source, an energy-saving light source, or an LED light source. Here, an LED light-emitting tube is preferred. It should be noted that, for the use of LED light-emitting tubes as light sources, this embodiment optimizes the arrangement of the light-emitting elements 110. As shown in the schematic diagram of Figure 17, the light-emitting elements 110 are arranged in layers in a honeycomb shape, satisfying T 1+(n-1)*6, wherein: T is the number of light-emitting elements 110, n is the number of layers of light-emitting elements 110, that is, there is only one LED light-emitting tube in the center, and the center connection of the LED light-emitting tubes in the outer layer Both form a regular hexagon. Of course, the arrangement form of the primary collimating mirror 120 on the primary lens seat plate 121 corresponds to that of the light-emitting element 110, so that the light emitted by the light-emitting element 110 passes through the primary collimating mirror 120 to form a large range of parallel light beams, which are vertically emitted. to the converging lens 130.

For the installation structure of the converging lens 130 in the middle cylinder 160, as shown in Figure 4, Figure 8, Figure 9 and Figure 10, a lens holder 131 is installed in the middle cylinder 160, and the convergence lens 130 is installed in this lens holder 131 on. In order to stabilize and reliably fix the converging lens 130, the outer circumference of the converging lens 130 is sleeved in the elastic pressure ring 134, and is supported on the support boss 1312 inside the lens holder 131; meanwhile, the upper end of the lens holder 131 is screwed with The compression screw sleeve 132 has a spinning screw hole 1321 in the middle of the lower end surface of the compression screw sleeve 132, and the upper threaded section 1311 of the lens holder 131 is screwed into the spinning screw hole 1321 of the compression screw sleeve 132, and is pressed The lower end of the screw sleeve 132 can contact and press the elastic pressure ring 134 to clamp the converging lens 130 . The graph of the converging lens 130 faces downward, so that the vertically incident parallel light beams can be converged into a strong light spot.

In particular, it should be noted that, in order to enable the secondary collimator 140 to be positioned above the focal point of the converging lens 130 and receive the strong light spot converged by the converging lens 130, a fine-tuning knob 133 is threaded on the outer side of the middle cylinder 160 in this embodiment. , the inner surface of the fine-tuning knob 133 is provided with a fine-tuning ring groove 1331; the leg 1313 on the outer peripheral surface of the lens holder 131 passes through the leg hole 164 provided on the middle cylinder 160 and is supported on the fine-tuning ring groove 1331 of the fine-tuning knob 133 Therefore, turning the fine-tuning knob 133 can adjust the position of the converging lens 130 up and down, that is, adjusting the distance between the converging lens 130 and the secondary collimator 140, so that focusing can be achieved when changing different converging lenses 130 . The foot hole 164 has a relatively large space so as to avoid the foot 1313 when the position of the converging lens 130 is adjusted.

The lower end of the light source support cylinder 150 is socket-connected to the upper end of the middle cylinder body 160 , that is, the socket section 153 at the lower end of the light source support cylinder 150 is matched with the socket boss 161 at the upper end of the middle cylinder body 160 . Regarding the connection reliability of this socket structure, as shown in Figure 4, Figure 6, Figure 7, Figure 8 and Figure 9, the inner side of the light source support cylinder 150 near the lower end is provided with a plurality of elastic buckles 154 along the circumferential direction, and the middle cylinder The inner side of the upper end of the body 160 is provided with a clamping protruding ring 162, and the clamping head 155 of the elastic buckle 154 can be clamped on the clamping protruding ring 162, and both the clamping protruding ring 162 and the clamping head 155 have a rounded triangle cross section, In order to snap together or separate from each other. At the same time, at least one elastic buckle 154 is provided with a pick 156 protruding out of the light source support tube 150 from the pick hole 157 opened on the light source support tube 150, so that the light source support tube 150 and the middle cylinder 160 are separated when necessary. , the paddle 156 can be moved downward, and the elastic buckle 154 can swing toward the center of the light source support cylinder 150, so that the clamp head 155 can be disengaged from the locking convex ring 162, and the separation can be performed. In addition, in order to facilitate positioning, a protrusion 159 is provided on the inner side of the lower end of the light source support cylinder 150 , and a notch 163 matching the protrusion 159 is provided on the outer side corresponding to the upper end of the middle cylinder 160 .

For the installation structure of the secondary collimating mirror 140 in the lower cylinder 170, as shown in Figure 4 and Figure 12, the lower cylinder 170 has an embedded ring groove 178 in which the secondary lens seat plate 141 is installed, and the secondary The collimating mirror 140 is installed at the center of the secondary lens seat plate 141 for fixing. The light beam passing through the secondary collimator 140 has a small irradiation range, that is, a light beam with a relatively small diameter and strong light intensity.

For the stable and reliable connection of the middle cylindrical body 160 and the lower cylindrical body 170, they are detachably connected through the connecting ring 171 set on the outside. As shown in Figure 4, Figure 11 and Figure 12, an elastic washer 172 is placed between the lower end surface of the middle cylinder 160 and the upper end surface of the lower cylinder 170; The outer peripheral surface of the upper end of the lower cylinder body 170 is provided with a positioning ring groove 175; the inner side of the corresponding connecting ring sleeve 171 is provided with a positioning convex ring 173 that can be snapped into the positioning ring groove 175 at the lower end, and the inner side of the corresponding connecting ring sleeve 171 is provided at the upper end. snap into the block 174 of the slot 165 . It is worth noting that the clamping slot 165 is formed by connecting the clamping vertical slot and the clamping horizontal slot, and the clamping vertical slot leads to the lower end surface of the middle cylinder 160 . When the middle cylindrical body 160 is connected with the lower cylindrical body 170, the block 174 of the connecting ring sleeve 171 first enters into the vertical groove, and then the connecting ring sleeve 171 is rotated so that the blocking block 174 enters the clamping horizontal groove to be fastened. During this process, the elastic washer 172 is compressed, so that the middle cylinder 160 and the lower cylinder 170 are connected stably and reliably. In addition, an escape groove 177 is also provided on the inner side of the upper end of the lower cylinder body 170 to avoid the expansion and contraction of the elastic gasket 172 at the junction of the middle cylinder body 160 and the lower cylinder body 170; There is a positioning boss 176, which can cooperate with the positioning groove on the inner side of the lower end of the connecting ring sleeve 171.

It can be seen from the above that the light source part 100 converges the light through the combination of the light emitting element 110, the primary collimating mirror 120, the converging lens 130 and the secondary collimating mirror 140 to form a high-power coaxial beam. The concentrating principle is shown in Figure 18 Show. The structure of the light source part 100 overcomes the shortcomings of the existing technology, and solves the problem that the light intensity of a single luminous tube is insufficient and the brightness is not enough, while the light emitted by multiple luminous tubes is not on the same axis and the light intensity is not enough.

As shown in Fig. 1, Fig. 2, Fig. 15 and Fig. 16, the spectroscopic part 200 comprises a spectroscopic box 210 positioned below the lower cylindrical body 170 and a plurality of spectroscopic mirrors installed in the spectroscopic box 210, the spectroscopic mirror is arranged at an acceptable The light beam emitted by the light-emitting element 110 passes through the secondary collimating mirror 140 , and the beam splitters can divide the light beam into multiple parallel beams. The spectroscopic box 210 is composed of two half-cabinets, and the side surfaces of the two half-cabinets are correspondingly provided with a spectroscopic mirror support 220. After the two half-cabinets are combined, the spectroscopic mirror is supported on the two spectroscopic mirror supports. Between 220. The light splitting box 210 also forms a closed space to avoid the impact of external light on the light incident by the light source part 100. Its upper end face offers a light entrance hole 230 for the light entering through the secondary collimating mirror 140, and its lower end It has a light exit hole 240 through which the light beam split by the beam splitter exits.

The number of light beams split by the beam splitter 200 is determined by the requirements. In this embodiment, it is divided into 8 beams with substantially the same light intensity. The specific beam splitting method is related to the arrangement of the beam splitters in the beam splitter box 210 . Figure 16 provides a spectroscopic form, which is composed of 14 spectroscopic lenses, which are divided into three rows from top to bottom, and all the spectroscopic lens surfaces are at 45° to the horizontal direction. Wherein, the first row has 4 dichroic mirrors, the two dichroic mirrors at both ends are total reflection mirrors, and the middle two are semi-transparent and semi-reflective mirrors, and the light incident from the light inlet 230 first hits a total reflection mirror ; The second row has 2 dichroic mirrors, a total reflection mirror and a semi-transparent mirror; the third row has 8 dichroic mirrors, 4 total reflection mirrors and 4 semi-transparent mirrors are arranged alternately. The 8 light exit holes 240 at the bottom of the beam splitting box 210 correspond to the 8 light splitter mirrors in the third row respectively, and the 8 split beams of light are emitted from the 8 light exit holes 240 .

Figure 19 shows another arrangement of spectroscopic mirrors, which are also divided into three rows in the direction of normal incident light. Among them, the first row has 4 beam-splitting lenses, a total reflection lens and 3 semi-transparent mirrors; the second row has 5 beam-splitting lenses, 2 total reflection lenses at both ends and 3 semi-transparent mirrors in the middle ; The third row has 2 dichroic lenses, a total reflection lens and a semi-transparent and half-reflective lens. Other arrangements of beam splitters are also possible, as long as the number and intensity requirements of the split beams can be met. This kind of beam splitting structure only uses a semi-transparent and semi-reflective beam splitting lens, which reduces the difficulty of coating and the secondary error caused by the existing beam splitting structure, and improves the accuracy of optical signals. The light beam becomes 8 channels of light through the beam splitter, and the light intensity of each channel is one-eighth of the output light of the light source, which strengthens the light intensity of each channel, and increases the light intensity of the gas detected to make the optical signal received by the receiving end more efficient. Obviously, the accuracy of the final optical signal is improved.

In order to organically combine the light source part 100 and the light splitting part 200 into one body, they are connected through a connector 180 . As shown in Figures 13 and 14, the main body of the connector 180 is a disc-shaped structure, and its upper end surface is provided with a positioning slot 181, and the lower end of the lower cylinder 170 is positioned in the positioning slot 181; the center of the connector 180 is provided with Through the light hole 182, the light hole 182 is coaxial with the secondary collimator 140, and its diameter will be greater than the diameter of the secondary collimator 140, so that the light passing through the secondary collimator 140 can all pass through. The light hole 182, meanwhile, the light through hole 182 is coaxial and equal to the light entrance hole 230, and the light beams can all be injected into the beam splitting box 210. The outer peripheral surface of the connector 180 is provided with a fixed seat 185, and both ends of the fixed seat 185 are provided with bolt holes 186, and the two ends of the connector 180 and the light splitting box 210 are connected by bolts screwed into the bolt holes 186 on the fixed seat 185. half-box connections. More importantly, a pair of clamping blocks 183 are arranged side by side on the lower end surface of the connector 180, and a pair of guide bars 184 are provided on the opposite inner sides of the pair of clamping blocks 183; The outer surface is provided with a guide groove 250 matched with the guide bar 184, so that the two half-casings are clamped in the middle by a pair of clamping blocks 183, and are positioned through the cooperation of the guide bar 184 and the guide groove 250, while The fixing seat 185 can fix them, and the structural design is flexible and ingenious.

As shown in FIG. 1 and FIG. 2 , the flue gas channel part 400 is arranged between the spectroscopic part 200 and the detection part 300 , that is, it is under the spectroscopic box 210 as seen from the figure. The flue gas channel part 400 includes a flue gas box 410 that can be passed by the light beam from the spectroscopic mirror to the detection part 300 , and the upper side of the flue gas box 410 is provided with a through hole corresponding to the light exit hole 240 of the spectroscopic box 210 , so that light can enter the smoke box 410 . The inner space of the flue gas box 410 is a channel for the flue gas. On the opposite side walls of the flue gas box 410 parallel to the beam direction, a fan 420 is installed on one side of the box wall, and a fan 420 is installed on the other side of the box wall. The air hole 411, so that when the fan 420 is activated, the smoke to be measured can be sucked into the smoke box 410 and passed through by the light beam. Of course, the fans 420 can also be installed on the opposite sides of the smoke box 410, which requires the same wind direction. Of course, it is not necessary to use the fan 420 to suck the flue gas into the flue gas box 410 , other existing ways to make the flue gas pass through the flue gas box 410 are also available, such as a blower, direct introduction of the flue gas, and the like.

The detection part 300 is used to receive the multiple parallel light beams and detect the spectra of the multiple parallel light beams, and it is mainly composed of a photoelectric sensor 310, a spectrometer and a display. Wherein, the photoelectric sensor 310 is installed at the bottom of the flue gas box 410 and corresponds to the light exit hole 240 of the spectroscopic box 210 , so that the light beam passing through the flue gas box 410 can be received by the photoelectric sensor 310 . The spectrometer analyzes the light signal received by the photoelectric sensor 310, inverts the smoke concentration in the air according to the light absorption spectrum, and the display is connected to the spectrometer and displays the detection result.

The structural principle of the smoke detection optical system has been described in detail above, and this system is used to detect the smoke concentration below. The specific operation steps are as follows:

First, select the LED light-emitting tube as the light-emitting element 110, and adopt green light as the light source, and the LED light-emitting tube is powered on to emit green light; then, according to the focal length of the converging lens 130, turn the fine-tuning knob 133 to adjust the up and down position of the converging lens 130 Make the focus just fall on the mirror surface of the secondary collimator 140; then, the light emitted by the light-emitting element 110 passes through the primary collimator 120 to form a parallel beam, and then the parallel light is focused and irradiated on the secondary collimator 140 through the converging lens 130 , the parallel beam with a larger diameter passes through the secondary collimating mirror 140 to form a parallel beam with a smaller diameter; moreover, the parallel beam passing through the secondary collimating mirror 140 is divided into multiple parallel beams with the same light intensity through the beam splitter; finally , multiple parallel light beams are received by the detection part 300 after passing through the smoke to be detected, and the spectrum is detected to obtain the result.

The examples described in the present invention are only to describe the preferred implementation of the present invention, and are not intended to limit the concept and scope of the present invention. Variations and improvements should fall within the protection scope of the present invention.

Claims (10)

1. A smoke detection optical system, comprising a light source part (100), a spectroscopic part (200) and a detection part (300); the light source part (100) includes a light emitting element (110), and the spectroscopic part (200) includes multiple A beam splitter, characterized in that: the light source part (100) also includes a primary collimator (120), a converging lens (130) and a secondary collimator (140), the light emitting element (110), primary collimator A straight mirror (120), a converging lens (130) and a secondary collimating mirror (140) are sequentially arranged on the illumination direction of the light emitting element (110); And through the light beam of the secondary collimating mirror (140), and the plurality of beam splitters can divide the light beam into multiple parallel light beams; the detection part (300) is used to receive the multiple parallel light beams , and detect the spectra of the multiple parallel beams. 2. A smoke detection optical system according to claim 1, characterized in that: the light source part (100) further comprises a light source support cylinder (150), a middle cylinder (160) connected end to end from top to bottom ) and the lower cylinder (170); the light-emitting element (110) and the primary collimator (120) are arranged in the light source support cylinder (150) in the up and down direction, and the converging lens (130) is arranged in the middle cylinder (160 ), the secondary collimating mirror (140) is arranged in the lower cylinder (170). 3. A smoke detection optical system according to claim 2, characterized in that: a light source seat plate (111) and a primary lens seat plate (121) are installed up and down in the light source support cylinder (150); The element (110) array is installed on the light source seat plate (111), and its irradiation direction faces the primary lens seat plate (121) side; the primary collimating mirror (120) is installed on the primary lens seat plate (121), and each light The element (110) is aligned with a primary collimating mirror (120). 4. A smoke detection optical system according to claim 3, characterized in that: the light-emitting elements (110) are arranged in layers in a honeycomb shape, satisfying T=1+(n-1)*6, wherein: T is the number of light emitting elements (110), and n is the number of layers arranged by the light emitting elements (110). 5. A smoke detection optical system according to claim 2, 3 or 4, characterized in that: the lower end of the light source support cylinder (150) is socketed and connected to the upper end of the middle cylinder (160); The inner side of the lower end of the light source support cylinder (150) is provided with a plurality of elastic buckles (154) along the circumferential direction, and the inner side of the upper end of the middle cylinder (160) is provided with a snap ring (162), and the elastic buckles (154) It can be clamped on the clamping convex ring (162); at least one of the elastic clamps (154) is provided with a pick (156) extending out of the light source support cylinder (150). 6. A smoke detection optical system according to claim 2, characterized in that: a lens holder (131) is installed in the middle cylinder (160); In the pressure ring (134), and supported on the support boss (1312) inside the lens holder (131); The converging lens (130) is clamped by squeezing said elastic retainer ring (134). 7. A smoke detection optical system according to claim 6, characterized in that: a fine-tuning knob (133) is threaded on the outer side of the middle cylinder (160), and a fine-tuning knob (133) is provided on the inner surface of the fine-tuning knob (133). There is a fine-tuning ring groove (1331); the legs (1313) on the outer peripheral surface of the lens holder (131) pass through the leg holes (164) provided on the middle cylinder (160) and are supported on the fine-tuning In the fine adjustment ring groove (1331) of the knob (133). 8. A smoke detection optical system according to claim 2, characterized in that: the beam splitter is installed in the beam splitting box (210) below the lower cylinder (170); the beam splitting box ( The upper end of 210) has a light entrance hole (230) for light to enter, and its lower end has a light exit hole (240) for the light beam split by the beam splitter to exit. 9. A smoke detection optical system according to claim 1 or 8, characterized in that: a smoke channel part (400) is set between the spectroscopic part (200) and the detection part (300); The gas channel part (400) includes a smoke box (410) that can be passed by the light beam from the beam splitter to the detection part (300); On both sides of the box wall, a fan (420) is installed on one side of the box wall, and air holes (411) are set on the other side box wall, or fans (420) are installed on both sides of the box wall. 10. A smoke detection method, the steps comprising: first, the light-emitting element (110) is powered on to emit light; then, the light emitted by the light-emitting element (110) passes through a collimating mirror (120) to form a parallel beam, and the parallel light is again Focusing on the secondary collimating mirror (140) through the converging lens (130), the parallel beam with a larger diameter passes through the secondary collimating mirror (140) to form a parallel beam with a smaller diameter; then, passes through the secondary collimating mirror The parallel light beam of (140) is divided into multiple parallel light beams with the same light intensity by a beam splitter; finally, the multiple parallel light beams pass through the smoke to be detected and are received by the detection part (300), and the spectrum is detected.