CN-121978017-A - Multi-component photoacoustic gas detection device and method based on photoluminescent material

CN121978017ACN 121978017 ACN121978017 ACN 121978017ACN-121978017-A

Abstract

The invention discloses a multi-component photoacoustic gas detection device and method based on a photoluminescent material, and relates to the technical field of gas detection. Through designing a novel photoacoustic cell with multiple photoluminescent material coatings on the inner surface in a spin-coating mode, and matching with a single radiation light source and a two-dimensional optical adjusting device, the function of generating multiple characteristic wavelength lights through excitation of the single light source is achieved, and online, real-time and multi-component trace gas detection is achieved through combination of a photoacoustic spectrum technology. The invention realizes single light source, multicomponent and high sensitivity on-line detection, and has simplified system structure and low cost.

Inventors

YIN XUKUN
LIU ZIQI
YANG XIU
GENG XIAO
Zhao Tianbai
YU QIWEN
ZHANG DACHENG

Assignees

西安电子科技大学

Dates

Publication Date: 20260505
Application Date: 20260130

Claims (10)

1. A multi-component photoacoustic gas detection device based on photoluminescent materials is characterized by comprising a radiation light source, a two-dimensional optical adjusting device (1) and a photoacoustic spectrum gas sensing device (2), wherein, The radiation light source and two-dimensional optical adjusting device (1) comprises a laser modulating device (3), a radiation light source (4) and a two-dimensional optical adjusting frame (5), wherein the radiation light source (4) is used for outputting an excitation light beam, the laser modulating device (3) is used for modulating the intensity of the excitation light beam, and the two-dimensional optical adjusting frame (5) is used for adjusting the incidence angle of the excitation light beam; the photoacoustic spectrum gas sensing device (2) comprises a photoacoustic cell (7), an acoustic sensor (8) and a signal processing unit, wherein at least two photoluminescent material coatings are arranged on the inner surface of the photoacoustic cell (7); After the incidence angle of the excitation light beam output by the radiation light source (4) is adjusted by the two-dimensional optical adjusting frame (5), one photoluminescence material coating on the inner surface of the photoacoustic cell (7) is selectively irradiated, the currently irradiated photoluminescence material coating is excited to generate characteristic wavelength light, the characteristic wavelength light is used for exciting corresponding trace gas to generate a photoacoustic signal, the acoustic sensor (8) is used for detecting the photoacoustic signal, and the signal processing unit is used for processing the photoacoustic signal and inverting the concentration of the trace gas.
2. A photoluminescent material based multicomponent photoacoustic gas detection device according to claim 1, characterized in that the laser modulation means (3) modulate the frequency of the excitation beam to be equal to the acoustic resonance frequency of the photoacoustic cell (7).
3. A photoluminescent material based multicomponent photoacoustic gas detection device according to claim 1, characterized in that the output band of the radiation source (4) covers the effective absorption band of all photoluminescent material coatings.
4. A photoluminescent material based multicomponent photoacoustic gas detection device according to claim 1, wherein the two-dimensional optical adjustment frame (5) is used to adjust the pitch angle and azimuth angle of the excitation beam with respect to the photoacoustic cell (7) axis.
5. A photoluminescent material based multicomponent photoacoustic gas detection device according to claim 1, wherein the photoluminescent material coating is coated on the inner walls of the photoacoustic cell (7) forming an annular structure; At least two photoluminescent material coatings are alternately arranged along the axial direction of the photoacoustic cell (7), and a space is arranged between adjacent coatings, wherein the width of the space is 1-3 mm; The photoluminescent material coating layer has a width of 3-10 mm and a thickness of 10-100 μm.
6. The photoluminescence material-based multicomponent photoacoustic gas detection device of claim 1, wherein the photoacoustic cell (7) is one of a circular straight-cavity, elliptical, multi-resonant cavity, T-shaped, circular ring-shaped, or spherical structure.
7. The photoluminescence material based multicomponent photoacoustic gas detection device according to claim 1, wherein the acoustic sensor (8) is a microphone or a tuning fork quartz crystal.
8. The photoluminescence material-based multicomponent photoacoustic gas detection device according to claim 1, wherein the signal processing unit comprises a lock-in amplifier (11), a data acquisition card (12) and a computer (13) connected in sequence, wherein the lock-in amplifier (11) is connected with the acoustic sensor (8).
9. A method of photoluminescence material based multicomponent photoacoustic gas detection, suitable for use in a photoluminescence material based multicomponent photoacoustic gas detection apparatus according to any one of claims 1 to 8, said method comprising: introducing a gas to be tested containing various trace gases into the photoacoustic cell; controlling the two-dimensional optical adjusting frame to change the incidence angle of an excitation light beam output by the radiation light source, and sequentially exciting different photoluminescent material coatings; detecting photoacoustic signals generated by excitation of each photoluminescent material coating; and inverting to obtain the concentration of each trace gas based on the intensity and phase information of the photoacoustic signals.
10. The method of photoluminescence material based multicomponent photoacoustic gas detection of claim 9, wherein the step of inverting the concentration of the trace gas comprises: calculating the absorption coefficient of trace gas to characteristic wavelength light according to the intensity of the detected photoacoustic signal, wherein ; In the formula, In order to detect the intensity of the photoacoustic signal, Is a constant of the photoacoustic cell, For the intensity of the light of the characteristic wavelength, An effective band of radiant light generated by absorption of the photoluminescent material for the trace gas, Is the absorption coefficient of trace gases for characteristic wavelengths of light, Is the included angle between the excitation light beam and the axis of the photoacoustic cell; Inverting to obtain the concentration of the trace gas according to the absorption coefficient of the trace gas to the light with characteristic wavelength, wherein ; In the formula, In the form of the concentration of the trace gas, Is the absorption cross section of trace gases at a characteristic wavelength.

Description

Multi-component photoacoustic gas detection device and method based on photoluminescent material Technical Field The invention belongs to the technical field of gas detection, and particularly relates to a multi-component photoacoustic gas detection device and method based on a photoluminescent material. Background Trace gas detection techniques based on spectroscopy are largely classified into direct absorption spectroscopy techniques (such as tunable laser absorption spectroscopy (TDLAS)) and indirect absorption spectroscopy techniques (such as photoacoustic spectroscopy (PAS)) according to the principle of detection of their interaction with a gas. The photoacoustic spectroscopy technology inverts the concentration by detecting an acoustic signal generated after the gas absorbs the light energy, has the comprehensive advantages of compact structure, high sensitivity, strong selectivity, quick response, support of online real-time monitoring and the like, and becomes an important development direction in the field of trace gas detection. In a photoacoustic spectroscopy system, the choice of radiation source directly affects system performance and feasibility. The existing light sources are mainly divided into incoherent light sources (such as broadband continuous light sources) and coherent light sources (such as near infrared and mid-infrared lasers). To achieve detection of a multi-component gas, the system typically needs to have radiation capability that covers multiple characteristic absorption bands, typically by using multiple lasers, or by employing a single broadband light source in combination with filtering or spectroscopy components. However, the main flow schemes are all faced with obvious limitations that although the middle infrared laser has high absorption line intensity, the middle infrared laser has high cost and huge volume, water cooling and even liquid nitrogen cooling are often needed, so that the system is complex and high in energy consumption, the near infrared laser has weak absorption line intensity and limits the further improvement of detection sensitivity despite the relatively low volume and cost, and the scheme of combining a broadband continuous light source with a narrow-band filter often has the problems of low optical power, large system volume, poor signal to noise ratio and the like, so that the requirement of high-sensitivity trace detection is difficult to meet. Therefore, the current multi-component gas detection technology based on photoacoustic spectroscopy still faces multiple contradictions such as complex light source system, high cost, large power consumption or limited sensitivity while pursuing high sensitivity, high selectivity and online real-time monitoring capability. Particularly when a single radiation light source is used for detecting the multi-component gas, the simplification of the system structure and the optimization of the detection performance are often difficult to achieve. Disclosure of Invention In order to solve the problems in the prior art, the invention provides a multi-component photoacoustic gas detection device and method based on photoluminescent materials. The technical problems to be solved by the invention are realized by the following technical scheme: the invention provides a multi-component photoacoustic gas detection device based on a photoluminescent material, which comprises a radiation light source, a two-dimensional optical adjusting device and a photoacoustic spectrum gas sensing device, wherein, The radiation light source and the two-dimensional optical adjusting device comprise a laser modulating device, a radiation light source and a two-dimensional optical adjusting frame, wherein the radiation light source is used for outputting an excitation light beam, the laser modulating device is used for modulating the intensity of the excitation light beam, and the two-dimensional optical adjusting frame is used for adjusting the incident angle of the excitation light beam; the photoacoustic spectrum gas sensing device comprises a photoacoustic cell, an acoustic sensor and a signal processing unit, wherein at least two photoluminescent material coatings are arranged on the inner surface of the photoacoustic cell; After the incidence angle of the excitation light beam output by the radiation light source is adjusted by the two-dimensional optical adjusting frame, one photoluminescence material coating on the inner surface of the photoacoustic cell is selectively irradiated, the currently irradiated photoluminescence material coating is excited to generate characteristic wavelength light, the characteristic wavelength light is used for exciting corresponding trace gas to generate a photoacoustic signal, the acoustic sensor is used for detecting the photoacoustic signal, and the signal processing unit is used for processing the photoacoustic signal and inverting the concentration of the trace gas. The invention also provides a