WO2022267286A1 - 一种气体检测装置 - Google Patents

一种气体检测装置 Download PDF

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Publication number
WO2022267286A1
WO2022267286A1 PCT/CN2021/126886 CN2021126886W WO2022267286A1 WO 2022267286 A1 WO2022267286 A1 WO 2022267286A1 CN 2021126886 W CN2021126886 W CN 2021126886W WO 2022267286 A1 WO2022267286 A1 WO 2022267286A1
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WIPO (PCT)
Prior art keywords
gas
laser
detection device
photoacoustic
photoacoustic cell
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PCT/CN2021/126886
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English (en)
French (fr)
Inventor
周福升
廖建平
王邸博
高帆
卓然
陈宇飞
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南方电网科学研究院有限责任公司
中国南方电网有限责任公司超高压输电公司检修试验中心
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Publication of WO2022267286A1 publication Critical patent/WO2022267286A1/zh

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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
    • G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
    • G01N21/1702—Systems in which incident light is modified in accordance with the properties of the material investigated with opto-acoustic detection, e.g. for gases or analysing solids
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N29/00—Investigating or analysing materials by the use of ultrasonic, sonic or infrasonic waves; Visualisation of the interior of objects by transmitting ultrasonic or sonic waves through the object
    • G01N29/02—Analysing fluids
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N29/00—Investigating or analysing materials by the use of ultrasonic, sonic or infrasonic waves; Visualisation of the interior of objects by transmitting ultrasonic or sonic waves through the object
    • G01N29/22—Details, e.g. general constructional or apparatus details
    • G01N29/222—Constructional or flow details for analysing fluids

Definitions

  • the invention relates to the technical field of gas detection, in particular to a gas detection device.
  • Gas detection technology has a wide range of applications in modern society, such as the determination of harmful gas content in the air, the concentration detection of ozone and biogas in agricultural production, the concentration detection of special gases in chemical and medical fields, etc. Gas is inseparable from gas detection technology.
  • the photoacoustic gas detection device based on photoacoustic spectroscopy technology is a high-precision trace technology for gas detection by converting the light energy absorbed by the gas to be measured into acoustic wave energy.
  • the modulated laser is irradiated on the gas molecules to be measured, the gas molecules will absorb at the absorption line, transition from the ground state to the excited state, and then return to the ground state through collision relaxation, during which the light energy is converted into internal energy. And the temperature rises, which in turn leads to pressure changes.
  • the laser light source is modulated at the frequency of the sound wave band, a periodically changing pressure wave, that is, a sound wave, will be generated.
  • the concentration information of the gas to be measured can be retrieved.
  • the inventors have found through research that the photoacoustic signal in the photoacoustic detection in the existing infrared photoacoustic gas detection device is weak, which leads to low detection accuracy.
  • the invention provides a gas detection device to solve the technical problem that the photoacoustic signal of the photoacoustic gas detection device in the prior art is weak.
  • the invention can enhance the optical path of gas absorption, thereby improving the detection accuracy of gas.
  • the gas detection device includes a laser generating module, a photoacoustic cell, and a processor;
  • the wavelength control end of the laser generating module is connected to the processor;
  • One side of the photoacoustic pool is provided with a first reflective prism, and the other side is provided with a second reflective prism, and the incident beam of the laser generating module travels back and forth between the first reflective prism and the second reflective prism Reflecting to form multiple reflected light beams passing through the photoacoustic cell; wherein, the light exit surface of the first reflective prism is smaller than the reflective surface of the second reflective prism;
  • the gas to be measured in the photoacoustic cell reacts with the reflected light beam to generate an acoustic signal, and converts the acoustic signal into an electrical signal and transmits it to the processor.
  • the laser generator, the first reflective prism and the second reflective prism are sequentially arranged at intervals, and the light emitting surface of the first reflective prism is opposite to and parallel to the reflective surface of the second reflective prism.
  • the first reflecting mirror is an isosceles right-angle prism with a side length of 20 mm
  • the second reflection mirror is an isosceles right-angle prism with a side length of 14 mm.
  • the processor includes a lock-in amplifier, a function generator, an adder and a PC;
  • the electrical signal input end of the lock-in amplifier is connected to the electrical signal output end of the photoacoustic cell, and the photoacoustic signal output end of the lock-in amplifier is connected to the PC; the sawtooth signal output end of the function generator Connect the modulation control terminal of the lock-in amplifier;
  • the sine wave output end of the lock-in amplifier is connected to the first input end of the adder, the high-level voltage signal output end of the function generator is connected to the second input end of the adder, and the adder's The output end is connected to the wavelength regulation end of the laser generating module.
  • the photoacoustic cell includes an air chamber, an acoustic resonator disposed in the cavity of the air chamber, an acoustic-electric converter disposed in the middle of the bottom of the air chamber, and first buffers symmetrically disposed on both sides of the acoustic resonator.
  • the air chamber and the second buffer air chamber are two optical lenses fixed on both sides of the air chamber; the first buffer air chamber is provided with an air inlet connected with the first buffer air chamber, and the second The second buffer air chamber is provided with an air outlet communicating with the second buffer air chamber.
  • the optical lens is a BaF2 plane mirror.
  • the gas detection device further includes a laser amplification module connected to the laser generation module, and the laser amplification module is used to enhance the infrared laser source emitted by the laser generation module.
  • the laser amplification module includes an erbium-doped fiber amplifier
  • the erbium-doped fiber amplifier includes a preamplifier, a first optical filter, a power amplifier and a second optical filter, and the signal output of the preamplifier is connected to The input end of the first optical filter, the output end of the first optical filter are connected to the signal input end of the power amplifier, and the signal output end of the power amplifier is connected to the second optical filter.
  • the gas detection device further includes:
  • a nitrogen cylinder connected to the second flow controller
  • a first solenoid valve connected between the gas bottle to be tested and the first flow controller
  • a second solenoid valve connected between the nitrogen cylinder and the second flow controller.
  • the gas detection device provided by the present invention includes a laser generation module, a photoacoustic cell, and a processor, and the wavelength control end of the laser generation module is connected to the The processor is connected so that the processor modulates the laser wavelength emitted by the laser generating module, and one side of the photoacoustic pool is provided with a first reflective prism, and the other side is provided with a second reflective prism, so The incident light beam of the laser generating module is reflected back and forth between the first reflective prism and the second reflective prism to form multiple reflected light beams passing through the photoacoustic cell, the gas to be measured in the photoacoustic cell and multiple The reflected light beam reacts to generate an acoustic signal, and the acoustic signal is converted into an electrical signal by the photoacoustic cell and transmitted to the processor, and the processor processes the electrical signal to obtain the component detection of the gas to be measured As a result, since
  • Fig. 1 is a structural block diagram of a gas detection device provided by an embodiment of the present invention
  • Fig. 2 is a structural diagram of a photoacoustic pool provided by an embodiment of the present invention
  • Fig. 3 is a partial structural block diagram of a gas detection device provided by an implementation mode in an embodiment of the present invention.
  • Fig. 4 is a partial structural block diagram of a gas detection device provided in another implementation manner in the embodiment of the present invention.
  • Laser generating module ; 2. Photoacoustic pool; 21. First reflective prism; 22. Second reflective prism; 201. Gas chamber; 202. Acoustic-electric converter; 203. Acoustic resonator; 1 buffer air chamber; 205, the second buffer air chamber; 206, optical lens; 207, air inlet; 208, air outlet; 3, processor; 31, lock-in amplifier; 32, function generator; 33, adder ; 34, PC; 4, gas mixing chamber; 5, the first flow controller; 6, the second flow controller; 7, the gas bottle to be tested; 8, the nitrogen bottle; 2. Solenoid valve; 11. Laser amplification module; 111. Preamplifier; 112. First optical filter; 113. Power amplifier; 114. Second optical filter.
  • Fig. 1 is a structural block diagram of a gas detection device provided by an embodiment of the present invention.
  • the gas detection device provided by the embodiment of the present invention includes a laser generating module 1, a photoacoustic cell 2, and a processor 3;
  • the wavelength control end of the laser generating module 1 is connected to the processor 3;
  • One side of the photoacoustic cell 2 is provided with a first reflective prism 21, and the other side is provided with a second reflective prism 22, and the incident light beam of the laser generating module 1 passes between the first reflective prism 21 and the second reflective prism Reflecting back and forth between the reflective prisms 22 to form multiple reflected light beams passing through the photoacoustic pool 2; wherein, the light-emitting surface of the first reflective prism 21 is smaller than the reflective surface of the second reflective prism 22;
  • the gas to be measured in the photoacoustic cell 2 reacts with the reflected beam to generate an acoustic signal, and converts the acoustic signal into an electrical signal and transmits it to the processor 3 .
  • the processor 3 is used to modulate the wavelength of light, convert the acoustic signal into an electrical signal, and convert the electrical signal into a photoacoustic signal of the gas to be measured by processing the electrical signal, and then pass through the Photoacoustic signal processing can obtain the component detection results of the gas to be measured.
  • the laser generating module 1 is used to emit an infrared light source to form an incident beam
  • the processor is connected to the laser generating module 1 so that the processor 3 can control the infrared laser source emitted by the laser generating module 1
  • the wavelength is modulated to improve the detection sensitivity.
  • the incident light beam is incident on the photoacoustic cell, since the first reflective prism 21 is provided on one side of the photoacoustic cell 2, and the second reflective prism 22 is provided on the other side, so that the incident light beam is in the photoacoustic cell.
  • the back and forth reflection between the first reflective prism 21 and the second reflective prism 22 forms multi-path reflected light beams passing through the photoacoustic cell 2, thereby enhancing the photoacoustic effect of the gas to be measured and the multi-path reflected light beams.
  • the acoustic signal is obtained by completing the photoacoustic effect of the gas to be measured in the photoacoustic cell 2, and the acoustic signal is processed by the processor to obtain the component detection result of the gas to be measured.
  • the laser generator 1, the first reflective prism 21 and the second reflective prism 22 are sequentially arranged at intervals, and the light-emitting surface of the first reflective prism 21 and the second reflective prism
  • the reflective surfaces of the two reflective prisms 22 are opposite and arranged in parallel.
  • the first reflective prism 21 is located on a side close to the laser generating module 1, and the light-emitting surface of the first reflective prism 21 is opposite to the reflective surface of the second reflective prism 22, The light can be reflected back and forth between the first reflective prism 21 and the second reflective prism 22 multiple times.
  • the first reflecting mirror 21 is an isosceles right-angle prism with a side length of 20 mm
  • the second reflection mirror 22 is an isosceles right-angle prism with a side length of 14 mm.
  • the incident light beam initially passes through the photoacoustic cell 2 and is incident on the upper surface of the light-emitting surface of the second reflector 22 (at this time, the incident light beam and the The included angle between the light-emitting surfaces of the second reflecting mirror 22 is 45 degrees), and is reflected on the upper surface of the light-emitting surface of the second reflecting mirror 22 to form reflected light, which is incident on the second reflecting light again.
  • the lower surface of the light-emitting surface of the mirror 22 (according to the reflection principle of light), and after the reflection of the lower surface of the light-emitting surface, the first reflected light beam is incident on the reflecting surface of the first reflective prism 21 through the photoacoustic pool the lower surface of the reflective surface of the first reflective mirror 21, and the reflected light is obtained by reflection on the lower surface of the reflective surface of the first reflective mirror 21, and the reflected light is incident on the upper surface of the reflective surface of the first reflective mirror 21 again, and
  • the reflection of the upper surface of the reflection surface of the first reflection mirror 2 forms a second reflection light beam that is incident on the lower surface of the light exit surface of the second reflection prism 22 through the photoacoustic pool and reflected to the exit light of the second reflection prism 22.
  • the third reflected beam is obtained after the upper surface of the surface, and the third reflected beam is emitted after passing through the photoacoustic pool 2, and finally forms 4 channels of infrared light acting on the photoacoustic pool 2. Therefore, compared with the common single infrared laser light path, the embodiment of the present invention can provide multiple infrared light paths, greatly increasing the power of the light.
  • the processor includes a lock-in amplifier 31, a function generator 32, an adder 33 and a PC 34;
  • the electrical signal input end of the lock-in amplifier 31 is connected to the electrical signal output end of the photoacoustic cell 2, and the photoacoustic signal output end of the lock-in amplifier 31 is connected to the PC 34; the function generator 32 The sawtooth signal output end is connected to the modulation control end of the lock-in amplifier 31;
  • the sine wave output end of the lock-in amplifier 31 is connected to the first input end of the adder 33, and the high-level voltage signal output end of the function generator 32 is connected to the second input end of the adder 33, so The output terminal of the adder 33 is connected to the wavelength control terminal of the laser generating module 1 .
  • the function generator 32 is used to provide a sawtooth signal and a high-level voltage signal, the modulation control terminal of the lock-in amplifier 31 and the sawtooth signal output terminal of the function generator 32, To make the high-level voltage signal produced by the function generator 32 act on the lock-in amplifier 31, and trigger the lock-in amplifier 31 to demodulate the second harmonic to obtain a sine wave whose frequency is equal to the Half of the resonant frequency of the photoacoustic cell, and by setting the adder 33 to superimpose the sine wave signal and the sawtooth wave signal, the superimposed signal acts on the laser generating module 1, thereby playing the role of modulating the laser wavelength .
  • FIG. 2 is a structural diagram of a photoacoustic cell provided by an embodiment of the present invention.
  • the photoacoustic cell 2 includes a gas chamber 201, an acoustic resonator 203 disposed in the inner chamber of the gas chamber, an acoustic-electric converter 202 disposed in the middle of the bottom of the gas chamber, and a symmetrical
  • the first buffer air chamber 204 and the second buffer air chamber 205 arranged on both sides of the acoustic resonator, and two optical lenses 206 fixed at both ends of the air chamber 201;
  • the first buffer air chamber 204 is provided with
  • the first buffer air chamber 204 is connected with an air inlet 207
  • the second buffer air chamber 205 is provided with an air outlet 208 connected with the second buffer air chamber 205 .
  • optical lenses 206 are arranged at both ends of the air chamber 201 , specifically, the optical lenses 206 are closely attached to the left and right sides of the air chamber 201 to enhance light perspective.
  • the acoustic-electric conversion module is a microphone.
  • the optical lens 206 is a BaF2 plane mirror.
  • a BaF2 plane mirror is used as the optical lens 206, which has the beneficial effect of having a light transmittance of more than 90% for infrared light with a wavelength below 10 ⁇ m.
  • the gas detection device further includes a laser amplification module 11 connected to the laser generation module, and the laser amplification module 11 is used to enhance the laser generation module emits an infrared laser source.
  • the laser amplification module 11 includes an erbium-doped fiber amplifier
  • the erbium-doped fiber amplifier includes a preamplifier 111, a first optical filter 112, a power amplifier 113 and a second optical filter 114, and the preamplifier
  • the signal output end of 111 is connected to the input end of the first optical filter 112
  • the output end of the first optical filter 112 is connected to the signal input end of the power amplifier 113
  • the signal output end of the power amplifier 113 is connected to The second optical filter 114 .
  • the laser amplification module 11 in order to further enhance the infrared light emitted by the laser generating module, the laser amplification module 11 is provided, the preamplifier 111 first amplifies the input signal, and then amplifies the current through the power amplifier 113 .
  • the gas detection device further includes:
  • a gas mixing chamber 4 connected to the gas inlet 207;
  • a first flow controller 5 and a second flow controller 6 connected to both sides of the gas mixing chamber 4;
  • the gas bottle 7 to be tested connected with the first flow controller
  • a nitrogen cylinder 8 connected with the second flow controller
  • a first solenoid valve 9 connected between the gas cylinder 7 to be tested and the first flow controller 5;
  • a second solenoid valve 10 connected between the nitrogen cylinder 8 and the second flow controller 6 .
  • a test gas bottle 7 is provided to store the test gas, and the nitrogen gas provided in the nitrogen bottle 8 is used to scrub the photoacoustic cell 2 before the experiment starts.
  • S1 open the first solenoid valve, and repeatedly inject N 2 for several times to scrub the photoacoustic pool.
  • the gas to be measured enters the photoacoustic cell, and the air inlet and the gas outlet of the photoacoustic cell are closed.
  • the laser wavelength is modulated by sending signals from the function generator and the phase-locked generator.
  • the laser light emitted by the laser enters the photoacoustic cell and the gas to be measured in the photoacoustic cell undergoes a photoacoustic action, causing the pressure in the photoacoustic cell to change.
  • the electrical conversion module converts the acoustic signal into an electrical signal.
  • the lock-in amplifier receives the electrical signal from the acoustic-electric conversion module, and converts it into a photoacoustic signal related to the gas concentration.
  • the PC receives the photoacoustic signal and calculates the volume fraction to be measured through inversion of the amplitude of the net photoacoustic signal, so as to realize the quantitative detection of the gas component to be measured.

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Abstract

一种气体检测装置，包括激光发生模块（1）、光声池（2）、处理器（3），激光发生模块（1）的波长调控端与处理器（3）连接，以使得处理器（3）对激光发生模块（1）发出的激光波长进行调制，且光声池（2）的一侧设有第一反射棱镜（21），另一侧设有第二反射棱镜（22），激光发生模块（1）的入射光束在第一反射棱镜（21）和第二反射棱镜（22）之间往返反射，形成经过光声池（2）的多路反射光束，光声池（2）的待测气体与多路反射光束反应产生声信号，并通过光声池（2）将声信号转换为电信号传输至处理器（3），由于在光声池（2）的两侧分别设有第一反射棱镜（21）和第二反射棱镜（22），从而形成多路红外光束，有利于光声池（2）中光的吸收，从而增强光声池（2）的光的功率，进而提高气体组分的检测精度。

Description

一种气体检测装置 技术领域
本发明涉及气体检测技术领域，尤其涉及一种气体检测装置。
背景技术
气体检测技术在现代社会中有着广泛的应用，如空气中有害气体含量的测定，农业生产中的臭氧、沼气的浓度检测，化工、医学领域中的特殊气体的浓度检测等，上述所涉及到的气体都离不开气体检测技术。
基于光声光谱技术的光声气体检测装置是通过将待测气体吸收的光能转换为声波能量从而对气体进行检测的高精度痕量技术。经过调制的激光照射到待测气体分子上时，气体分子会在其吸收谱线处产生吸收从基态跃迁到激发态，然后通过碰撞弛豫回到基态，在此过程中光能转化为内能并使温度升高，进而导致压力变化，如果激光光源以声波波段的频率进行调制，则会产生周期变化的压力波，即声波。用声学传感器探测到这个声学信号，就可反演出待测气体的浓度信息。
但是，发明人经过研究发现，现有的红外光声气体检测装置中的光声检测中的光声信号较弱，进而导致检测的精度较低。
发明内容
本发明提供了一种气体检测装置，以解决现有技术的光声气体检测装置的光声信号较弱的技术问题，本发明能够增强气体吸收的光程，进而提高气体的检测精度。
本发明提供的气体检测装置，包括激光发生模块、光声池、处理器；
所述激光发生模块的波长调控端与所述处理器连接；
所述光声池的一侧设有第一反射棱镜，另一侧设有第二反射棱镜，所述激光 发生模块的入射光束在所述第一反射棱镜和所述第二反射棱镜之间往返反射，形成经过所述光声池的多路反射光束；其中，所述第一反射棱镜的出光面小于所述第二反射棱镜的反射面；
所述光声池的待测气体与所述反射光束反应产生声信号，并将所述声信号转换为电信号传输至所述处理器。
优选的，所述激光发生装置、所述第一反射棱镜与所述第二反射棱镜依次间隔设置，所述第一反射棱镜的出光面与所述第二反射棱镜的反射面相对且平行设置。
优选的，所述第一反射镜为腰边长为20mm的等腰直角棱镜，所述第二反射镜为腰边长14mm的等腰直角棱镜。
优选的，所述处理器包括锁相放大器、函数发生器、加法器以及PC机；
所述锁相放大器的电信号输入端连接所述光声池的电信号输出端，所述锁相放大器的光声信号输出端连接所述PC机；所述函数发生器的锯齿波信号输出端连接所述锁相放大器的调制控制端；
所述锁相放大器的正弦波输出端连接所述加法器的第一输入端，所述函数发生器的高电平电压信号输出端连接所述加法器的第二输入端，所述加法器的输出端连接所述激光发生模块的波长调控端。
优选的，所述光声池包括气室、设置在气室内腔的声谐振器、设置在所述气室底部中间的声电转换器、对称设置在所述声谐振器两侧的第一缓冲气室和第二缓冲气室，固定在所述气室两侧的2个光透镜；所述第一缓冲气室设置有与所述第一缓冲气室相贯通的进气口，所述第二缓冲气室设置有与所述第二缓冲气室相贯通的出气口。
优选的，所述光透镜为BaF2平面镜。
优选的，所述气体检测装置还包括与所述激光发生模块连接的激光放大模块，所述激光放大模块用于增强所述激光发生模块发射出的红外激光源。
优选的，所述激光放大模块包括掺铒光纤放大器，所述掺铒光纤放大器包括前置放大器、第一光过滤器、功率放大器和第二光过滤器，所述前置放大器的信号输出端连接所述第一光过滤器的输入端，所述第一光过滤器的输出端连接所述功率放大器的信号输入端，所述功率放大器的信号输出端连接所述第二光滤器。
优选的，所述气体检测装置，还包括：
与所述进气口连接的气体混合室；
连接在所述气体混合室两侧的第一流量控制器和第二流量控制器；
与所述第一流量控制器连接的待测气体瓶；
与所述第二流量控制器连接的氮气瓶；
连接在所述待测气体瓶和所述第一流量控制器之间的第一电磁阀；
连接在所述氮气瓶和所述第二流量控制器之间的第二电磁阀。
与现有技术相比，本发明提供的气体检测装置具有以下有益效果：本发明提供的气体检测装置包括激光发生模块、光声池、处理器，所述激光发生模块的波长调控端与所述处理器连接，以使得所述处理器对所述激光发生模块发出的激光波长进行调制，且所述光声池的一侧设有第一反射棱镜，另一侧设有第二反射棱镜，所述激光发生模块的入射光束在所述第一反射棱镜和所述第二反射棱镜之间往返反射，形成经过所述光声池的多路反射光束，所述光声池的待测气体与多路所述反射光束反应产生声信号，并通过光声池将所述声信号转换为电信号传输至所述处理器，该处理器通过对所述电信号处理，得到待测气体的组分检测结果，由于本发明在光声池的两侧分别设有第一反射棱镜和第二反射棱镜，从而形成多路红外光，有利于光声池中光的吸收，从而增强光声池的光的功率，进而提高气体组分的检测精度。
附图说明
图1是本发明实施例提供的气体检测装置的结构框图；
图2是本发明实施例提供的光声池的结构图；
图3是本发明实施例中一种实施方式提供的气体检测装置的部分结构框图；
图4是本发明实施例中另一种实施方式提供的气体检测装置的部分结构框图；
图中，1、激光发生模块；2、光声池；21、第一反射棱镜；22、第二反射棱镜；201、气室；202、声电转换器；203、声谐振器；204、第一缓冲气室；205、第二缓冲气室；206、光透镜；207、进气口；208、出气口；3、处理器；31、锁相放大器；32、函数发生器；33、加法器；34、PC机；4、气体混合室；5、第一流量控制器；6、第二流量控制器；7、待测气体瓶；8、氮气瓶；9、第一电磁阀；10、第二电磁阀；11、激光放大模块；111、前置放大器；112、第一光过滤器；113、功率放大器；114、第二光过滤器。
具体实施方式
下面将结合本发明实施例中的附图，对本发明实施例中的技术方案进行清楚、完整地描述，显然，所描述的实施例仅仅是本发明一部分实施例，而不是全部的实施例。基于本发明中的实施例，本领域普通技术人员在没有作出创造性劳动前提下所获得的所有其他实施例，都属于本发明保护的范围。
参见图1，图1是本发明实施例提供的气体检测装置的结构框图。本发明实施例提供的气体检测装包括激光发生模块1、光声池2、处理器3；
所述激光发生模块1的波长调控端与所述处理器3连接；
所述光声池2的一侧设有第一反射棱镜21，另一侧设有第二反射棱镜22，所述激光发生模块1的入射光束在所述第一反射棱镜21和所述第二反射棱镜22之间往返反射，形成经过所述光声池2的多路反射光束；其中，所述第一反射棱镜21的出光面小于所述第二反射棱镜22的反射面；
所述光声池2的待测气体与所述反射光束反应产生声信号，并将所述声信号转换为电信号传输至所述处理器3。
在本发明实施例中，所述处理器3用于调制光的波长，并将声信号转换为电 信号，并通过对所述电信号处理转换为待测气体的光声信号，再经所述光声信号处理即可得到待测气体的组分检测结果。
即，所述激光发生模块1用于发射红外光源形成入射光束，所述处理器与所述激光发生模块1连接，以使得所述处理器3能够对所述激光发生模块1发出的红外激光源的波长进行调制，进而提高检测的灵敏度。其中，所述入射光束入射至所述光声池，由于所述光声池2的一侧设有第一反射棱镜21，另一侧设有第二反射棱镜22，使得所述入射光束在所述第一反射棱镜21和所述第二反射棱镜22之间往返反射，形成经过所述光声池2的多路反射光束，从而增强了待测气体与多路反射光束的光声作用，有利用提高光声池中光的功率。通过在所述光声池2中完成待测气体的光声效应得到声信号，并通过所述处理器处3理所述声信号，进而得到待测气体的组分检测结果。
在一种可选的实施方式中，所述激光发生装置1、所述第一反射棱镜21与所述第二反射棱镜22依次间隔设置，所述第一反射棱镜21的出光面与所述第二反射棱镜22的反射面相对且平行设置。
在本发明实施例中，所述第一反射棱镜21位于靠近所述激光发生模块1的一侧，所述第一反射棱镜21的出光面与所述第二反射棱镜22的反射面相对设置，使得光能够在所述第一反射棱镜21和所述第二反射棱镜22多次来回反射。
在一种可选的实施方式中，所述第一反射镜21为腰边长为20mm的等腰直角棱镜，所述第二反射镜22为腰边长14mm的等腰直角棱镜。
具体的，在一种实施方式中，参见图2，所述入射光束在开始时经过所述光声池2入射到所述第二反射镜22的出光面的上表面(此时入射光束与所述第二反射镜22的出光面之间的夹角为45度)，并在所述第二反射镜22的出光面的上表面反射形成反射光，该反射光再次入射到所述第二反射镜22的出光面的下表面(根据光的反射原理)，并在所述出光面的下表面反射后形成第一反射光束经过所述光声池入射到所述第一反射棱镜21的反射面的下表面，并通过在所述 第一反射镜21的反射面的下表面后反射得到反射光，该反射光再次入射至所述第一反射镜21的反射面的上表面，并在所述第一反射镜2的反射面的上表面反射形成第二反射光束经过所述光声池入射至所述第二反射棱镜22的出光面的下表面并反射至所述第二反射棱镜22的出光面的上表面后得到第三反射光束，所述第三反射光束经过所述光声池2后射出，最终形成作用于所述光声池2的4路红外光。因此，相较于普通的单路红外激光光路，本发明实施例能够提供多路红外光，极大增加了光的功率。
在一种可选的实施方式中，所述处理器包括锁相放大器31、函数发生器32、加法器33以及PC机34；
所述锁相放大器31的电信号输入端连接所述光声池2的电信号输出端，所述锁相放大器31的光声信号输出端连接所述PC机34；所述函数发生器32的锯齿波信号输出端连接所述锁相放大器31的调制控制端；
所述锁相放大器31的正弦波输出端连接所述加法器33的第一输入端，所述函数发生器32的高电平电压信号输出端连接所述加法器33的第二输入端，所述加法器33的输出端连接所述激光发生模块1的波长调控端。
在本发明实施例中，所述函数发生器32用于提供锯齿波信号和高电平电压信号，所述锁相放大器31的调制控制端与所述函数发生器32的锯齿波信号输出端，以使得所述函数发生器32产生的高电平电压信号作用于所述锁相放大器31，并触发所述锁相放大器31解调二次谐波，得到正弦波，该正弦波的频率等于所述光声池谐振频率的一半，并通过设置所述加法器33将该正弦波信号与锯齿波信号叠加，得到叠加后的信号作用于所述激光发生模块1，从而起到调制激光波长的作用。
参见图2，图2是本发明实施例提供的光声池的结构图。在本发明实施例的一种实施方式中，所述光声池2包括气室201、设置在气室内腔的声谐振器203、设置在所述气室底部中间的声电转换器202、对称设置在所述声谐振器两侧的第 一缓冲气室204和第二缓冲气室205，固定在所述气室201两端的2个光透镜206；所述第一缓冲气室204设置有与所述第一缓冲气室204相贯通的进气口207，所述第二缓冲气室205设置有与所述第二缓冲气室205相贯通的出气口208。
在本发明实施例中，通过在所述气室201两端设置光透镜206，具体的，所述光透镜206紧贴在所述气室201的左右两侧，以增强光的透视率。
具体的，所述声电转换模块为麦克风。
在一种可选的实施方式中，所述光透镜206为BaF2平面镜。
在本发明实施例中，采用BaF2平面镜作为光透镜206，其对于波长10μm以下的红外光具有光透过率达90％以上的有益效果。
参见图3，在本发明实施例的一种实施方式中，所述气体检测装置还包括与所述激光发生模块连接的激光放大模块11，所述激光放大模块11用于增强所述激光发生模块发射出的红外激光源。
进一步的，所述激光放大模块11包括掺铒光纤放大器，所述掺铒光纤放大器包括前置放大器111、第一光过滤器112、功率放大器113和第二光过滤器114，所述前置放大器111的信号输出端连接所述第一光过滤器112的输入端，所述第一光过滤器112的输出端连接所述功率放大器113的信号输入端，所述功率放大器113的信号输出端连接所述第二光滤器114。
在本发明实施例中，为了进一步增强所述激光发生模块发出的红外光，设置有所述激光放大模块11，所述前置放大器111先放大输入的信号，再通过所述功率放大器113放大电流。
进一步，参见图4，在本发明实施例的一种实施方式中，所述气体检测装置还包括：
与所述进气口207连接的气体混合室4；
连接在所述气体混合室4两侧的第一流量控制器5和第二流量控制器6；
与所述第一流量控制器连接的待测气体瓶7；
与所述第二流量控制器连接的氮气瓶8；
连接在所述待测气体瓶7和所述第一流量控制器5之间的第一电磁阀9；
连接在所述氮气瓶8和所述第二流量控制器6之间的第二电磁阀10。
在本发明实施例中，设置有待测气体瓶7存储待测气体，并通过设置在氮气瓶8中的氮气，以在实验开始前对所述光声池2进行洗气处理。
基于本发明实施例提供的气体检测装置，提供以下实验流程，包括步骤S1到步骤S6：
S1，打开第一电磁阀，重复通入多次N 2对光声池进行洗气处理。
S2，打开第二电磁阀，根据实验要求设置两个流量控制器的参数，配置出一定浓度的待测气体。
S3，待测气体进入光声池，关闭光声池的进气口与出气口。
S4，通过函数发生器和锁相发生器发出信号进行激光波长的调制，激光器发出的激光进入光声池与光声池中的待测气体发生光声作用使光声池中气压发生变化，声电转换模块把声信号转化为电信号。
S5，锁相放大器接收来自声电转换模块的电信号，并转换为有关气体浓度的光声信号。
S6，PC机接收光声信号通过净光声信号幅值反演计算出待测的体积分数，实现待测气体组分的定量检测。
以上所述是本发明的优选实施方式，应当指出，对于本技术领域的普通技术人员来说，在不脱离本发明原理的前提下，还可以做出若干改进和润饰，这些改进和润饰也视为本发明的保护范围。

Claims (9)

  1. 一种气体检测装置，其特征在于，包括激光发生模块、光声池、处理器；
    所述激光发生模块的波长调控端与所述处理器连接；
    所述光声池的一侧设有第一反射棱镜，另一侧设有第二反射棱镜，所述激光发生模块的入射光束在所述第一反射棱镜和所述第二反射棱镜之间往返反射，形成经过所述光声池的多路反射光束；其中，所述第一反射棱镜的出光面小于所述第二反射棱镜的反射面；
    所述光声池的待测气体与所述反射光束反应产生声信号，并将所述声信号转换为电信号传输至所述处理器。
  2. 如权利要求1所述的气体检测装置，其特征在于，所述激光发生装置、所述第一反射棱镜与所述第二反射棱镜依次间隔设置，且所述第一反射棱镜的出光面与所述第二反射棱镜的反射面相对且平行设置。
  3. 如权利要求1所述的气体检测装置，其特征在于，所述第一反射镜为腰边长20mm的等腰直角棱镜，所述第二反射镜为腰边长14mm的等腰直角棱镜。
  4. 如权利要求1所述的气体检测装置，其特征在于，所述处理器包括锁相放大器、函数发生器、加法器以及PC机；
    所述锁相放大器的电信号输入端连接所述光声池的电信号输出端，所述锁相放大器的光声信号输出端连接所述PC机；
    所述函数发生器的锯齿波信号输出端连接所述锁相放大器的调制控制端；所述锁相放大器的正弦波输出端连接所述加法器的第一输入端，所述函数发生器的高电平电压信号输出端连接所述加法器的第二输入端，所述加法器的输出端连接所述激光发生模块的波长调控端。
  5. 如权利要求1所述的气体检测装置，其特征在于，所述光声池包括气室、设置在气室内腔的声谐振器、设置在所述气室底部中间的声电转换器、对称设置在所述声谐振器两侧的第一缓冲气室和第二缓冲气室，固定在所述气室两侧的2个光透镜；所述第一缓冲气室设置有与所述第一缓冲气室相贯通的进气口，所述第二缓冲气室设置有与所述第二缓冲气室相贯通的出气口。
  6. 如权利要求5所述的的气体检测装置，其特征在于，所述光透镜为BaF2平面镜。
  7. 如权利要求1所述的气体检测装置，其特征在于，还包括：
    与所述激光发生模块连接的激光放大模块，所述激光放大模块用于增强所述激光发生模块发射出的红外激光源。
  8. 如权利要求7所述的气体检测装置，其特征在于，所述激光放大模块包括掺铒光纤放大器，所述掺铒光纤放大器包括前置放大器、第一光过滤器、功率放大器和第二光过滤器，所述前置放大器的信号输出端连接所述第一光过滤器的输入端，所述第一光过滤器的输出端连接所述功率放大器的信号输入端，所述功率放大器的信号输出端连接所述第二光滤器。
  9. 如权利要求2所述的气体检测装置，其特征在于，还包括：
    与所述进气口连接的气体混合室；
    连接在所述气体混合室两侧的第一流量控制器和第二流量控制器；
    与所述第一流量控制器连接的待测气体瓶；
    与所述第二流量控制器连接的氮气瓶；
    连接在所述待测气体瓶和所述第一流量控制器之间的第一电磁阀；
    连接在所述氮气瓶和所述第二流量控制器之间的第二电磁阀。
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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN116577279A (zh) * 2023-07-14 2023-08-11 深圳市智多兴投控科技有限公司 高精度多组分温室气体自动化实时监测系统及方法

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* Cited by examiner, † Cited by third party
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CN114166757A (zh) * 2021-12-08 2022-03-11 国网江苏省电力有限公司检修分公司 一种多功能混合气体光声检测装置及方法
CN116089802A (zh) * 2023-04-07 2023-05-09 南方电网科学研究院有限责任公司 一种应用于光声光谱检测系统的噪声信号处理方法及装置

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20110214481A1 (en) * 2010-03-02 2011-09-08 Li-Cor, Inc. Method and apparatus for the photo-acoustic identification and quantification of analyte species in a gaseous or liquid medium
WO2014090518A1 (de) * 2012-12-14 2014-06-19 Avl List Gmbh Fotoakustische messzelle
CN104792703A (zh) * 2015-03-17 2015-07-22 浙江省计量科学研究院 基于激光多次反射光声光谱技术的气溶胶光学吸收系数检测装置
CN207114412U (zh) * 2017-08-31 2018-03-16 浙江朗松智能电力设备有限公司 一种搭配全反射棱镜组增加光程的光声池结构
CN109975241A (zh) * 2019-02-27 2019-07-05 哈尔滨工业大学 一种角反射增强光声光谱式痕量气体探测装置及方法
CN209911225U (zh) * 2019-01-09 2020-01-07 南方电网科学研究院有限责任公司 一种co和co2痕量检测装置

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101498690B (zh) * 2009-02-19 2010-12-01 上海交通大学 在线式电力变压器故障监测系统
CN101514960A (zh) * 2009-03-23 2009-08-26 吉林市中准仪表开发有限责任公司 基于光声光谱技术的sf6检测系统
CN201497702U (zh) * 2009-08-12 2010-06-02 南京信息工程大学 智能式室内气体甲醛浓度测量仪
CN104251819A (zh) * 2013-06-26 2014-12-31 中南大学 一种基于红外光源的光声光谱气体检测装置
CN104198433A (zh) * 2014-09-14 2014-12-10 中国科学院合肥物质科学研究院 一种激光吸收光谱技术在线检测人体呼吸标识性气体浓度的装置及方法
CN109115688B (zh) * 2018-09-10 2020-11-03 大连理工大学 一种光纤遥测式多功能气体听漏仪器及方法
CN112834430B (zh) * 2020-12-31 2022-05-31 山西大学 一种基于光声池声脉冲激励的气体检测装置及方法

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20110214481A1 (en) * 2010-03-02 2011-09-08 Li-Cor, Inc. Method and apparatus for the photo-acoustic identification and quantification of analyte species in a gaseous or liquid medium
WO2014090518A1 (de) * 2012-12-14 2014-06-19 Avl List Gmbh Fotoakustische messzelle
CN104792703A (zh) * 2015-03-17 2015-07-22 浙江省计量科学研究院 基于激光多次反射光声光谱技术的气溶胶光学吸收系数检测装置
CN207114412U (zh) * 2017-08-31 2018-03-16 浙江朗松智能电力设备有限公司 一种搭配全反射棱镜组增加光程的光声池结构
CN209911225U (zh) * 2019-01-09 2020-01-07 南方电网科学研究院有限责任公司 一种co和co2痕量检测装置
CN109975241A (zh) * 2019-02-27 2019-07-05 哈尔滨工业大学 一种角反射增强光声光谱式痕量气体探测装置及方法

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN116577279A (zh) * 2023-07-14 2023-08-11 深圳市智多兴投控科技有限公司 高精度多组分温室气体自动化实时监测系统及方法

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