CN109764909A - A system and method for monitoring the flow rate of exhaust gas and the composition of particulate matter - Google Patents

Abstract

The invention discloses a kind of discharge gas flow velocity and the monitoring system and methods of particulate matter component.The monitoring system includes two gas flow rate signal collectors, gas particles object laser induced breakdown spectroscopy signal picker, spectrometer and signal analysis module；Two gas flow rate signal collectors are parallelly mounted in flue along the axial direction of flue；Each gas flow rate signal collector is installed along flue diametrical direction, two gas flow rate signal collectors are connect with the signal analysis module, the gas particles object laser induced breakdown spectroscopy signal picker is installed in flue along the diameter of flue, the gas particles object laser induced breakdown spectroscopy signal picker is connect with the spectrometer by armored fiber optic, and the spectrometer is connect by data line with the signal analysis module.The present invention realizes the comprehensive on-line monitoring of gas flow rate and particulate matter component.

Description

A system and method for monitoring the flow rate of exhaust gas and the composition of particulate matter

technical field

The invention relates to the field of environmental monitoring, in particular to a system and method for monitoring the flow rate of exhaust gas and the composition of particulate matter.

Background technique

With the rapid development of society and economy, the waste gas, waste water and particulate matter released by industrial production have caused serious pollution to the natural environment, posing severe challenges to environmental protection and causing widespread concern around the world. The problem of particulate pollution is another important factor that leads to the deterioration of the modern living environment. Particulate pollution is air pollution caused by small solid particles in the air caused by industrial production. Particulate pollution often poses a serious threat to people's lives and health. Some of the small particles (PM2.5) can also enter the blood through the bronchi and alveoli, and the harmful heavy metals in them are dissolved in the blood, which is more harmful to human health. To achieve environmental governance, it is first necessary to monitor the total emission of polluting gases. In this process, real-time online monitoring of emission speed and gas concentration are two indispensable prerequisites. The flue gas flow rate measurement instrument based on optical method has the characteristics of non-intrusiveness, can be used in flue ducts with extreme conditions such as high temperature and explosive, and has strong anti-interference ability of environmental factors, and has been paid more and more attention in industrial monitoring. At present, the United States has realized the commercialization of optical flow meter, and OFS-2000 optical flow meter is a typical representative. The optical flow meter adopts the structure of single light source and double detectors, which can realize the effective measurement of flue gas flow rate. In addition, many researchers have also measured flue gas flow rates based on light flicker caused by random fluctuations in particle extinction properties. However, from the perspective of measurement principle, the above methods are all based on active irradiation measurement methods, which cannot realize comprehensive online monitoring of gas flow rate and particle composition. It has a certain degree of coaxiality, which brings great inconvenience to the actual installation and debugging of the instrument.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a monitoring system and method for the flow rate of the exhaust gas and the composition of the particulate matter, so as to realize the comprehensive online monitoring of the flow rate of the gas and the composition of the particulate matter, and avoid the inconvenience of actual installation and debugging.

For achieving the above object, the present invention provides the following scheme:

A monitoring system for exhaust gas flow rate and particle composition, the monitoring system includes two gas flow rate signal collectors, a gas particle laser-induced breakdown spectrum signal collector, a spectrometer and a signal analysis module;

The two gas flow rate signal collectors are installed in the flue in parallel along the axial direction of the flue; both of the gas flow rate signal collectors are connected to the signal analysis module, and the two gas flow rate signal collectors are used to obtain Two-channel flow velocity signals of the gas in the flue, and send the two-channel flow velocity signals to the signal analysis and processing module;

The gas particle laser-induced breakdown spectrum signal collector is installed in the flue along the diameter of the flue, the gas particle laser-induced breakdown spectrum signal collector and the spectrometer are connected through armored optical fibers, and the gas particle laser-induced breakdown The breakdown spectrum signal collector is used to acquire the particle laser-induced breakdown spectrum signal in the flue, and collect the particle laser-induced breakdown spectrum signal on the spectrometer;

The spectrometer is connected to the signal analysis module through a data line, and the spectrometer is used to analyze the laser-induced breakdown spectral signal of the particulate matter to obtain particle composition information, and send the particulate matter composition information to the signal analysis and processing module ;

The signal analysis and processing module is used to correlate the two flow velocity signals to obtain an associated signal, and to monitor the flow velocity of the gas in the flue on-line according to the correlated signal, and to monitor the particulate matter in the flue according to the particulate matter composition information. Conduct online monitoring.

Optionally, the gas flow rate signal collector includes a detector, a detector driving module, a mirror frame, a first signal collection combined lens, a combined lens pressure ring, a collimating cavity, a dust-proof mirror, a dust-proof mirror pressure ring, and a method. orchid plate;

The dust-proof mirror is fixed in the collimation cavity through the dust-proof mirror pressure ring, and the infrared light emitted by the gas in the flue enters the collimation cavity through the dust-proof mirror;

One end of the collimation cavity is threadedly connected with the flange plate, the other end of the collimation cavity is connected with one end of the mirror frame, and the first signal collection combined lens is fixed on the combined lens through the combined lens pressure ring. Inside the mirror frame, the collimating cavity is used for collimating the infrared light, and the processed infrared light is irradiated on the first signal collecting and combining lens;

The other end of the mirror frame is threadedly connected to the detector; the detector driving module is connected to the detector through a power supply line, and the detector driving module supplies power to the detector through a power supply line; the detection The detector is connected to the signal analysis module through a data line; the first signal collection combination lens focuses the processed infrared light on the detector, and the detector converts the processed infrared light into The electrical signal is obtained to obtain the flow rate signal of the gas in the flue.

Optionally, the dust-proof mirror pressure ring is provided with a plurality of air outlet holes uniformly distributed along the circumferential direction of the dust-proof mirror pressure ring, and the dust-proof mirror pressure ring is also provided with purge gas inlet holes, The central axis of the air outlet and the mirror surface of the dust-proof mirror form an included angle of 10 degrees, a plurality of grooves are arranged on the side wall of the collimation cavity, and the position of the grooves is the same as that of the air-outlet of the dust-proof mirror pressure ring. The groove is communicated with the purge gas inlet hole, and the purge gas enters the groove through the purge gas inlet hole and flows out from the outlet hole.

Optionally, the monitoring system further includes a signal preprocessing module, the signal preprocessing module is respectively connected to the two gas flow rate signal collectors and the signal analysis module, and the signal preprocessing module is used to Filtering and amplifying the flow velocity signals of the two paths are performed to obtain two-path processed flow velocity signals.

Optionally, the gas particle laser-induced breakdown spectral signal collector includes a second signal collection combination lens, a semi-reflection lens and a laser focusing lens, and a lens barrel, and the semi-reflection and semi-lens is mounted on the In the middle position inside the lens barrel, the incident excitation beam is reflected by the half mirror and irradiated on the laser focusing combined lens;

The laser focusing combined lens is installed at one end inside the lens barrel, and the laser focusing combined lens focuses the reflected incident excitation beam in the flue to excite the particulate matter in the flue to obtain the particle laser-induced breakdown spectrum Signal;

The second signal collecting combined lens is installed at the other end inside the lens barrel, the other end of the lens barrel is connected to the spectrometer through the armored optical fiber, and the particle laser-induced breakdown spectral signal is passed through the After the laser focusing combined lens is collimated, it is irradiated on the second signal collecting combined lens through the semi-reflecting semi-lens, and the second signal collecting combined lens will process the laser-induced breakdown spectral signal of the particles after processing. collected into the spectrometer.

Optionally, the monitoring system further includes a laser;

The laser is arranged corresponding to the half mirror and the half mirror, and the laser is used for generating an incident excitation beam and irradiating the incident excitation beam on the half mirror mirror.

Optionally, the signal analysis module includes a computer and an acquisition card, and the acquisition card is respectively connected to the two gas flow rate signal collectors and the spectrometer through a data cable.

A monitoring method for exhaust gas flow rate and particulate matter composition, the monitoring method is applied to the monitoring system, and the monitoring method comprises the following steps:

Obtain two flow velocity signals;

Correlate the two flow velocity signals to obtain an associated signal, and perform online monitoring of the flow velocity of the gas in the flue according to the associated signal;

Get particle information;

On-line monitoring of the particulate matter in the flue is performed according to the particulate matter composition information.

Optionally, the two described flow velocity signals are correlated to obtain an associated signal, and the flow velocity of the gas in the flue is monitored online according to the correlated signal, specifically including:

Use the formula

Correlate the two flow velocity signals to obtain the correlated signals;

Among them, κ ₀ represents the spatial wave number in the flue, k represents the light wave number, v(z) represents the flow velocity, ρ represents the average distance between the two beams, τ represents the delay time, L represents the beam transmission distance, D _t and D _r respectively represent the transmit and receive apertures, J ₀ and J ₁ represent the zero- and first-order Bessel functions, respectively, and _Snl (κ ₀ ) represents the spectrum of the imaginary part of the refractive index.

Optionally, the online monitoring of the particulate matter in the flue according to the particulate matter composition information specifically includes:

Using the standard-free analysis method, using the formula Continuous on-line monitoring of the particulate matter composition in the flue;

in, represents the measured spectral line intensity of the s-th element; C _s represents the concentration of the s-th element; A _ji represents the transition probability of energy level j to energy level i; E _j represents the energy of excitation energy level j; g _j represents excitation The degeneracy of energy level j; F represents the experimental parameter; k represents the Boltzmann constant, U _s (T) represents the partition function, and T represents the plasma temperature.

According to the specific embodiments provided by the present invention, the present invention discloses the following technical effects:

The invention discloses a monitoring system and method for the flow rate of exhaust gas and the composition of particulate matter. The monitoring system obtains the flow velocity signals of the gas in the two flues in real time through two gas flow velocity signal collectors arranged in the flue, and correlates the two flow velocity signals through the signal analysis and processing module to obtain the correlated signals, And according to the correlated signal, the flow rate of the gas in the flue is monitored online, and the laser-induced breakdown spectral signal of the particulate matter in the flue is acquired by the gas particle laser-induced breakdown spectral signal collector arranged in the flue, and the spectrometer is used to measure the Laser analysis is used to obtain particle composition information, and through the signal analysis module, the particles in the flue are monitored online according to the particle composition information, so as to realize the comprehensive online monitoring of gas flow rate and particle composition, and the gas flow rate signal collector of the present invention The laser-induced breakdown spectrum signal collector of and gas particulate matter is directly fixed and installed inside the flue, so it is not necessary to drill the flue for installation every time it is detected, which avoids the inconvenience of actual installation and debugging.

Description of drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings required in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some of the present invention. In the embodiments, for those of ordinary skill in the art, other drawings can also be obtained according to these drawings without creative labor.

Fig. 1 is the structure diagram of the monitoring system of a kind of exhaust gas flow velocity and particulate matter composition provided by the present invention;

Fig. 2 is the structural diagram of the gas flow velocity signal collector provided by the present invention;

3 is a structural diagram of a gas particle laser-induced breakdown spectrum signal collector provided by the present invention;

FIG. 4 is a flow chart of a method for monitoring the flow rate of exhaust gas and the composition of particulate matter provided by the present invention.

Detailed ways

The purpose of the present invention is to provide a monitoring system and method for the flow rate of the exhaust gas and the composition of the particulate matter, so as to realize the comprehensive online monitoring of the flow rate of the gas and the composition of the particulate matter, and avoid the inconvenience of actual installation and debugging.

In order to make the above objects, features and advantages of the present invention more clearly understood, the invention will be described in further detail below with reference to the accompanying drawings and specific embodiments.

Example 1

Embodiment 1 of the present invention provides a monitoring system for exhaust gas flow rate and particulate matter composition.

As shown in FIG. 1 , the monitoring system includes two gas flow rate signal collectors 1 , a gas particle laser-induced breakdown spectrum signal collector 2 , a spectrometer 3 and a signal analysis module 4 ; the two gas flow rate signal collectors 1 Installed in the flue in parallel along the axial direction of the flue; each of the gas flow rate signal collectors 1 is installed along the diameter direction of the flue, two of the gas flow rate signal collectors 1 are connected to the signal analysis module 4, and the two are connected to the signal analysis module 4. Each of the gas flow rate signal collectors 1 is used to acquire the flow rate signals of the gas in the two channels of flue gas, and send the two channels of the flow rate signals to the signal analysis and processing module; the gas particle laser-induced breakdown spectrum signal collector 2 is installed in the flue along the diameter of the flue, the gas particle laser-induced breakdown spectral signal collector 2 is connected with the spectrometer 3 through armored optical fibers, and the gas particle laser-induced breakdown spectral signal collector 2 is used for Acquire the laser-induced breakdown spectral signal of particulate matter in the flue, and collect the particulate matter laser-induced breakdown spectral signal on the spectrometer 3; the spectrometer 3 is connected to the signal analysis module 4 through a data cable, so The spectrometer 3 is used to analyze the laser-induced breakdown spectral signal of the particulate matter, obtain the particulate matter composition information, and send the particulate matter composition information to the signal analysis and processing module; the signal analysis and processing module is used to The flow velocity signals are correlated to obtain a correlated signal, and the flow velocity of the gas in the flue is monitored online according to the correlated signal, and the particulate matter in the flue is monitored online according to the particulate matter composition information. Specifically, the two gas flow rate signal collectors 1 are independent of each other and have identical technical parameters. Correlate the two flow velocity signals to obtain the correlated signals, and monitor the flow velocity of the gas in the flue on-line according to the correlated signals, which specifically includes performing cross-correlation calculation on the two flow velocity signals, and obtaining the flow rate from the upstream flow rate signal. The transit time from the gas flow rate signal collector to the downstream gas flow rate signal collector, and according to the distance between the two gas flow rate signal collectors, realizes continuous online monitoring of the gas flow rate in the flue.

The invention discloses a monitoring system and method for the flow rate of exhaust gas and the composition of particulate matter. The monitoring system obtains the flow velocity signals of the gas in the two flues in real time through two gas flow velocity signal collectors arranged in the flue, and correlates the two flow velocity signals through the signal analysis and processing module to obtain the correlated signals, And according to the correlated signal, the flow rate of the gas in the flue is monitored online, and the laser-induced breakdown spectral signal of the particulate matter in the flue is acquired by the gas particle laser-induced breakdown spectral signal collector arranged in the flue, and the spectrometer is used to measure the Laser analysis is used to obtain particle composition information, and through the signal analysis module, the particles in the flue are monitored online according to the particle composition information, so as to realize the comprehensive online monitoring of gas flow rate and particle composition, and the gas flow rate signal collector of the present invention The laser-induced breakdown spectrum signal collector of and gas particulate matter is directly fixed and installed inside the flue, so it is not necessary to drill the flue for installation every time it is detected, which avoids the inconvenience of actual installation and debugging.

Example 2

Embodiment 2 of the present invention is a preferred implementation of a monitoring system for exhaust gas flow rate and particulate matter composition.

As shown in FIG. 2 , the gas flow rate signal collector 1 includes a detector 101 , a detector driving module 102 (not shown in FIG. 2 ), a mirror frame 103 , a first signal collection combined lens 104 , and a combined lens pressure ring 105 , collimating cavity 106, dust-proof mirror 107, dust-proof mirror pressure ring 108 and flange 109; the dust-proof mirror 107 is fixed in the collimation cavity 106 through the dust-proof mirror pressure ring 108, and inside the flue The infrared light emitted by the gas enters the collimation cavity 106 through the dust-proof mirror 107; one end of the collimation cavity 106 is screwed with the flange 109, and the other end of the collimation cavity 106 is connected with the One end of the mirror frame 103 is connected, the first signal collection combination lens 104 is fixed inside the mirror frame 103 through the first signal collection combination lens 105, and the collimation cavity 106 is used to carry out the infrared light. Collimation processing, the processed infrared light is irradiated on the first signal collecting combination lens 104; the other end of the mirror frame 103 is screwed with the detector 101; the detector driving module 102 is connected with the The detector 101 is connected through a power supply line, and the detector driving module 102 supplies power to the detector 101 through a power supply line; the detector 101 is connected with the signal analysis module 4 through a data line; the first signal collection The combined lens 104 focuses the processed infrared light onto the detector 101, and the detector 101 converts the processed infrared light into an electrical signal to obtain a flow rate signal of the gas in the flue. Further, both the mirror frame 103 and the collimating cavity 106 adopt a cylindrical structure, and the inner surfaces of the mirror frame 103 , the combined lens pressing ring 105 , the collimating cavity 106 and the dust-proof mirror pressing ring 108 are all roughened and blackened. , which can prevent various stray light from forming specular reflection in the cavity, which helps to improve the signal-to-noise ratio of collected signals. The detection range of the detector 101 is the mid-infrared band of 2.6-3.2 microns.

The dust-proof mirror pressure ring 108 is provided with a plurality of air outlet holes uniformly distributed along the circumferential direction of the dust-proof mirror pressure ring 108, and the dust-proof mirror pressure ring 108 is also provided with a purge gas inlet hole 110, The central axis of the air outlet and the mirror surface of the dust-proof mirror 107 form an included angle of 10 degrees. The side wall of the collimation cavity 106 is provided with a plurality of grooves, and the position of the grooves is the same as that of the dust-proof mirror pressure ring 108 The position of the air outlet hole corresponds to the position of the air outlet, the groove is communicated with the purge gas inlet hole 110, and the purge gas enters the groove through the purge gas inlet hole 110, and flows out from the air outlet hole. , play the role of purging the mirror surface, so that the system has a self-cleaning function, which is convenient for long-term stable acquisition of experimental data.

The monitoring system also includes a signal preprocessing module, which is respectively connected to the two gas flow rate signal collectors 1 and the signal analysis module 4, and the signal preprocessing module is used to The flow velocity signal is filtered and amplified to obtain two-way processed flow velocity signals.

As shown in FIG. 3 , the gas particle laser-induced breakdown spectral signal collector 2 includes a second signal collection combined lens 201 , a semi-reflective semi-lens 202 , a laser focusing combined lens 203 , and a lens barrel 204 . 202 is installed at the middle position inside the lens barrel 204 through the adjusting frame, and the incident excitation beam is reflected by the half mirror and half mirror 202 and irradiated on the laser focusing combined lens 203;

The laser focusing combined lens 203 is installed at one end inside the lens barrel 204, and the laser focusing combined lens 203 focuses the reflected incident excitation beam in the flue to excite the particulate matter in the flue to obtain the particle laser induction breakdown spectral signal;

The second signal collecting combination lens 201 is installed at the other end inside the lens barrel 204, and the other end of the lens barrel 204 is connected to the spectrometer 3 through the armored optical fiber, and the particle laser-induced breakdown spectroscopy After the signal is collimated by the laser focusing combined lens 203, it is irradiated on the second signal collecting combined lens 201 through the semi-reflective semi-mirror 202, and the second signal collecting combined lens 201 will process the processed The laser-induced breakdown spectroscopic signal of particulate matter is collected into the spectrometer 3 .

Optionally, the monitoring system further includes a laser;

The laser is disposed correspondingly to the half mirror half mirror 202 , and the laser is used for generating an incident excitation beam and irradiating the incident excitation beam onto the half mirror half mirror 202 . The incident excitation beam emitted by the laser is reflected by the semi-reflecting semi-lens 202 and then the propagation direction is turned 90 degrees, and is focused on a certain point in the flue by the laser focusing combined lens 203 . When the aerosol flows through the laser focus point with the flue gas, it is excited and forms a plasma. Its radiation spectrum (particle laser-induced breakdown spectral signal) is focused by the laser focusing combined lens 203, the semi-reverse semi-mirror 202, and then focused by the second signal collecting combined lens 201, and then introduced into the spectrometer 3 by the armored fiber. The spectrometer 3 transmits the spectral signal (particulate matter composition information) to the signal analysis module 4 for processing through the data line (3). The laser is a pulsed laser with a wavelength of 532 nm.

Optionally, the signal analysis module 4 includes a computer and an acquisition card, and the acquisition card is respectively connected to the two gas flow rate signal collectors 1 and the spectrometer 2 through data lines.

Example 3

Embodiment 3 of the present invention provides a method for monitoring the flow rate of exhaust gas and the composition of particulate matter.

As shown in Figure 4, the monitoring method is applied to the monitoring system, and the monitoring method includes the following steps:

Step 401, acquire two flow velocity signals; Step 402, correlate the two flow velocity signals to obtain an associated signal, and perform online monitoring of the flow velocity of the gas in the flue according to the correlated signal; Step 403, acquire the laser-induced impact of particulate matter. Penetration spectral signal; Step 404, online monitoring of particulate matter components in the flue according to the particulate matter laser-induced breakdown spectral signal.

Example 4

Embodiment 4 of the present invention provides a preferred embodiment of a monitoring method for exhaust gas flow rate and particulate matter composition.

Step 402, associating the two flow velocity signals to obtain an associated signal, and monitoring the flow velocity of the gas in the flue on-line according to the associated signal, which specifically includes: using the formula

Correlate the two flow velocity signals to obtain the correlated signal; wherein, κ ₀ represents the spatial wave number in the flue, k represents the light wave number, v(z) represents the flow velocity, ρ represents the average distance between the two beams, and τ represents the delay Time, L represents the beam travel distance, D _t and _Dr represent the transmit and receive apertures, respectively, J ₀ and J ₁ represent the zero- and first-order Bessel functions, respectively, and _Snl (κ ₀ ) represents the spectrum of the imaginary part of the refractive index. The measured flow rate is an arithmetic mean value over the optical path, so it is easier to calculate the flue gas emissions than an OFS flow meter. For example, for maximum cross-correlation, the delay time satisfies the condition From this, the average flow velocity can be calculated.

Step 404, the on-line monitoring of the particulate matter composition in the flue according to the particulate matter laser-induced breakdown spectral signal, specifically includes: adopting a standard-free analysis method, using the formula Continuous online monitoring of the particulate matter composition in the flue; wherein, represents the measured spectral line intensity of the s-th element; C _s represents the concentration of the s-th element; A _ji represents the transition probability of energy level j to energy level i; E _j represents the energy of excitation energy level j; g _j represents excitation The degeneracy of energy level j; F represents the experimental parameter; k represents the Boltzmann constant, U _s (T) represents the partition function, and T represents the plasma temperature. Spectral parameters E _j , g _j and A _ji can be found from NIST, and F, T and C _s can be obtained from experiments. Definition: x=E _j , Get the composition and concentration of the corresponding element:

According to the specific embodiments provided by the present invention, the present invention discloses the following technical effects:

1. The present invention is based on laser-induced breakdown spectroscopy (LIBS technology) and comprehensive measurement of particulate matter composition and flue gas flow rate of flue gas infrared radiation, combining LIBS technology with flue gas infrared radiation detection technology, combined with standard-free analysis method and mutual Relevant calculation to realize online monitoring of particulate matter composition and flue gas flow rate in flue;

2. The present invention uses an optical method for measurement, which is a non-access measurement, does not affect the particle concentration in the flue and the distribution state of the flue gas flow rate, and can ensure the authenticity of the measurement results;

3. The present invention uses the infrared radiation of the flue gas flow as the light source to measure the flue gas flow rate, which is installed on one side and does not require an external light source;

4. The on-line monitoring of particulate matter components adopts a pulsed laser with a wavelength of 532 nm, and its wavelength does not overlap with the wavelength range of the infrared radiation of the flue gas flow, so it will not interfere with the radiation signal.

The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments, and the same and similar parts between the various embodiments can be referred to each other. For the system disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant part can be referred to the description of the method.

The principles and implementations of the invention are described herein by using specific examples. The descriptions of the above embodiments are only used to help understand the method and the core idea of the present invention, and the described embodiments are only a part of the embodiments of the present invention. , rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present invention.

Claims (10)

1. A monitoring system for the flow rate of exhaust gas and the particulate matter components is characterized by comprising two gas flow rate signal collectors, a gas particulate matter laser-induced breakdown spectroscopy signal collector, a spectrometer and a signal analysis module;

the two gas flow velocity signal collectors are arranged in the flue in parallel along the axial direction of the flue; the two gas flow velocity signal collectors are connected with the signal analysis module and used for acquiring flow velocity signals of gas in the two paths of flues and sending the two paths of flow velocity signals to the signal analysis processing module;

the gas particulate laser induced breakdown spectrum signal collector is arranged in the flue along the diameter of the flue, the gas particulate laser induced breakdown spectrum signal collector is connected with the spectrograph through an armored optical fiber, and the gas particulate laser induced breakdown spectrum signal collector is used for acquiring a particulate laser induced breakdown spectrum signal in the flue and collecting the particulate laser induced breakdown spectrum signal on the spectrograph;

the spectrometer is connected with the signal analysis module through a data line and is used for analyzing the particle laser induced breakdown spectrum signal, obtaining particle component information and sending the particle component information to the signal analysis processing module;

the signal analysis processing module is used for correlating the two paths of flow speed signals to obtain correlated signals, carrying out on-line monitoring on the flow speed of gas in the flue according to the correlated signals, and carrying out on-line monitoring on the particles in the flue according to the particle component information.

2. The system for monitoring the flow rate of exhaust gas and the composition of particulate matter of claim 1, wherein the gas flow rate signal collector comprises a detector, a detector driving module, a mirror holder, a first signal collecting combination lens, a combination lens clamping ring, a collimating cavity, a dust-proof mirror clamping ring and a flange;

the dust-proof mirror is fixed in the collimation cavity through the dust-proof mirror pressing ring, and infrared light emitted by gas in the flue enters the collimation cavity through the dust-proof mirror;

one end of the collimation cavity is in threaded connection with the flange plate, the other end of the collimation cavity is connected with one end of the mirror bracket, the first signal collection combined lens is fixed inside the mirror bracket through the combined lens press ring, the collimation cavity is used for collimating the infrared light, and the processed infrared light irradiates the first signal collection combined lens;

the other end of the mirror bracket is in threaded connection with the detector; the detector driving module is connected with the detector through a power supply line, and supplies power to the detector through the power supply line; the detector is connected with the signal analysis module through a data line; and the first signal collecting combined lens focuses the processed infrared light onto the detector, and the detector converts the processed infrared light into an electric signal to obtain a flow velocity signal of the gas in the flue.

3. The system for monitoring the flow rate of the exhaust gas and the particle content according to claim 2, wherein a plurality of air outlets are formed in the dustproof mirror pressing ring and are circumferentially and uniformly distributed on the dustproof mirror pressing ring, a purging gas inlet is further formed in the dustproof mirror pressing ring, a 10-degree included angle is formed between the central axis of each air outlet and the surface of the dustproof mirror, a plurality of grooves are formed in the side wall of the collimating cavity, the positions of the grooves correspond to the positions of the air outlets of the dustproof mirror pressing ring, the grooves are communicated with the purging gas inlet, and purging gas enters the grooves through the purging gas inlet and flows out of the air outlets.

4. The system according to claim 1, further comprising a signal preprocessing module, wherein the signal preprocessing module is respectively connected to the two gas flow rate signal collectors and the signal analysis module, and is configured to filter and amplify the two flow rate signals to obtain two processed flow rate signals.

5. The system for monitoring the flow rate of the exhaust gas and the composition of particulate matters according to claim 1, wherein the laser-induced breakdown spectrum signal collector for the gas particulate matters comprises a second signal collecting combined lens, a semi-reflecting and semi-transmitting lens, a laser focusing combined lens and a lens barrel, wherein the semi-reflecting and semi-transmitting lens is mounted at the middle position inside the lens barrel through an adjusting frame, and an incident excitation beam is reflected by the semi-reflecting and semi-transmitting lens and irradiates the laser focusing combined lens;

the laser focusing combined lens is arranged at one end inside the lens barrel and focuses the reflected incident excitation beam in the flue to excite the particles in the flue so as to obtain a particle laser induced breakdown spectrum signal;

the second signal collecting combined lens is arranged at the other end inside the lens barrel, the other end of the lens barrel is connected with the spectrometer through the armored optical fiber, the particulate laser induced breakdown spectrum signal is collimated by the laser focusing combined lens and then passes through the semi-reflecting and semi-transparent lens to be irradiated onto the second signal collecting combined lens, and the second signal collecting combined lens collects the processed particulate laser induced breakdown spectrum signal to the spectrometer.

6. An exhaust gas flow rate and particulate matter composition monitoring system according to claim 5, further comprising a laser;

the laser device is arranged corresponding to the semi-reflecting and semi-transmitting mirror and used for generating incident excitation beams and irradiating the incident excitation beams onto the semi-reflecting and semi-transmitting mirror.

7. The system according to claim 1, wherein the signal analysis module comprises a computer and an acquisition card, and the acquisition card is connected to the two gas flow rate signal collectors and the spectrometer via data lines.

8. A monitoring method of an exhaust gas flow rate and a particulate matter component, which is applied to the monitoring system according to any one of claims 1 to 7, the monitoring method comprising the steps of:

acquiring two flow velocity signals;

correlating the two flow rate signals to obtain correlated signals, and carrying out online monitoring on the flow rate of the gas in the flue according to the correlated signals;

acquiring particle composition information;

and carrying out on-line monitoring on the particles in the flue according to the particle component information.

9. The method according to claim 8, wherein the correlating the two flow rate signals to obtain a correlated signal, and the online monitoring of the flow rate of the gas in the flue according to the correlated signal comprises:

using formulas Correlating the two paths of flow speed signals to obtain correlated signals;

wherein, κ₀Representing the number of spatial waves in the flue, k representing the number of optical waves, v (z) representing the flow velocity, p representing the average distance between two beams, τ representing the delay time, L representing the beam propagation distance, D_tAnd D_rRespectively representing transmit and receive apertures, J₀And J₁Representing zero and first order Bessel functions, S, respectively_nl(κ₀) A spectrum representing the imaginary part of the refractive index.

10. The method according to claim 8, wherein the online monitoring of the particulate matter in the flue according to the particulate matter component information comprises:

using a nonstandard analysis method using a formulaContinuously monitoring the particulate matter components in the flue on line;

wherein,represents the measured spectral line intensity of the s-th element; c_sDenotes the concentration of the s-th element, A_jiRepresenting the probability of the transition of the energy level j to the energy level i; e_jRepresents the energy of excitation level j; g_jRepresents the degeneracy of the excitation level j; f represents an experimental parameter; k represents Boltzmann constant, U_s(T) represents the partition function, and T represents the plasma temperature.