System for detecting concentration of gas in liquid

Abstract

The invention relates to a system for detecting the concentration of gas in liquid. The system comprises a liquid storage tank, a multi-wavelength laser, an optical fiber laser hydrophone and mobile equipment, the liquid storage tank is provided with a resonant cavity which is used for accommodating a liquid sample; the multi-wavelength laser is arranged opposite to the incident end of the liquid storage tank, and the multi-wavelength laser is used for emitting a laser beam to the liquid storage tank, so that gas in the liquid sample can absorb laser and generate a sound wave signal; the optical fiber laser hydrophone is arranged in the resonant cavity and is used for collecting sound wave signals and converting the sound wave signals into optical signals; the mobile equipment is in communication connection with the fiber laser hydrophone and is used for calculating according to the optical signal to obtain the concentration of the detected gas. Through cooperation of the multi-wavelength laser, the fiber laser hydrophone and the mobile device, degassing treatment does not need to be carried out on the liquid sample, and the gas concentration of the liquid sample can be directly measured.

Description

Technical Field

[0001] The invention relates to the technical field of gas detection, and in particular to a gas concentration detection system in liquid. Background Art

[0002] At present, gas detection is mainly based on photoacoustic spectroscopy gas detection technology. Photoacoustic spectroscopy gas detection technology requires liquid degassing before gas concentration detection. However, due to the large dispersion of gas-liquid separation and degassing, the detection results are also highly dispersed. Moreover, due to the long time taken for degassing, the real-time performance of online detection is greatly restricted. Summary of the invention

[0003] Based on the above description, the present invention provides a gas concentration detection system in liquid, aiming to solve the problems of long degassing time and large degassing dispersion during existing gas detection in liquid, resulting in large dispersion of detection results.

[0004] The technical solution of the present invention to solve the above technical problems is as follows: In a first aspect, a gas concentration detection system in a liquid comprises: A liquid storage tank having a resonant cavity, wherein the resonant cavity is used to contain a liquid sample; a multi-wavelength laser, arranged opposite to the incident end of the liquid storage tank, the multi-wavelength laser being used to emit a laser beam to the liquid storage tank, so that the gas in the liquid sample can absorb the laser and generate an acoustic wave signal; A fiber laser hydrophone is disposed in the resonant cavity, and is used to collect the acoustic wave signal and convert it into an optical signal; The mobile device is communicatively connected with the fiber laser hydrophone, and the mobile device is used to calculate according to the optical signal to obtain the concentration of the measured gas.

[0005] Based on the above technical solution, the present invention can also be improved as follows.

[0006] Furthermore, the resonant cavity is constructed in a horn shape.

[0007] Furthermore, it comprises a spatial light modulator, which is arranged between the multi-wavelength laser and the incident end of the liquid storage tank, and is used to modulate the laser beam.

[0008] Furthermore, a laser controller is included. The laser controller is electrically connected to the multi-wavelength laser, and the laser controller is used to control the multi-wavelength laser to emit the laser light beams of different wavelengths.

[0009] Furthermore, it comprises a conductivity sensor, the detection end of which passes through the bottom wall of the liquid storage tank and is inserted into the resonant cavity, the conductivity sensor is electrically connected to the mobile device, and the conductivity sensor is used to detect the conductivity of the liquid sample.

[0010] Furthermore, it includes a spectrometer, which is arranged opposite to the exit end of the liquid storage tank, and is electrically connected to the mobile device. The spectrometer is used to receive the laser light beam emitted from the liquid storage tank to generate a spectral image, and calculate the impurity content of the liquid sample based on the spectral image.

[0011] In a second aspect, a method for detecting gas in oil is provided. The method is applicable to the gas concentration detection system in liquid described in the first aspect, comprising: The multi-wavelength laser emits a laser beam to the liquid storage tank, which can cause the gas in the liquid sample to absorb the laser and generate an acoustic wave signal; The fiber laser hydrophone collects the acoustic wave signal and converts it into an optical signal; The mobile device calculates according to the optical signal to obtain the concentration of the measured gas.

[0012] Compared with the prior art, the technical solution of the present invention has the following beneficial technical effects: (1) The present invention uses a multi-wavelength laser, a fiber laser hydrophone and a mobile device to directly measure the gas concentration of the liquid sample without the need for degassing the liquid sample.

[0013] (2) The curved liquid storage tank wall in the horn-shaped resonant cavity of the present invention can enhance the resonance of the acoustic wave signal, while maximally reducing the noise when the laser beam passes through the liquid storage tank, thereby further improving the detection accuracy of the gas components to be measured in the liquid sample. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 A structural block diagram of a gas concentration detection system in liquid provided in an embodiment of the present invention; Figure 2 A comparison diagram of the acoustic wave signal test results of a horn-shaped resonant cavity and an I-shaped resonant cavity in an embodiment of the present invention; Figure 3 The figure is a comparison chart of the concentration test results of four transformer oils containing different concentrations of acetylene in the embodiment of the present invention.

[0015] Description of reference numerals: 1. Liquid storage tank; 11. Resonant cavity; 2. Multi-wavelength laser; 3. Fiber laser hydrophone; 4. Mobile devices; 5. Spatial light modulator; 6. Laser controller; 7. Conductivity sensor; 8. Spectrometer. DETAILED DESCRIPTION

[0016] In order to facilitate the understanding of the present invention, the present invention will be described more fully below with reference to the relevant drawings. Embodiments of the present invention are given in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present invention more thorough and comprehensive.

[0017] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0018] It will be appreciated that spatial relationship terms such as "under," "beneath," "below," "under," "above," "above," etc., may be used herein to describe the relationship of an element or feature shown in the figures to other elements or features. It will be appreciated that, in addition to the orientations shown in the figures, spatial relationship terms also include different orientations of the device in use and operation. For example, if the device in the accompanying drawings is flipped, an element or feature described as "under other elements" or "under it" or "under it" will be oriented as being "above" the other elements or features. Thus, the exemplary terms "under" and "under" may include both upper and lower orientations. In addition, the device may also include additional orientations (e.g., rotated 90 degrees or other orientations), and the spatial descriptors used herein are interpreted accordingly.

[0019] When used herein, the singular forms "a", "an", and "said / the" may also include plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "include / comprise" or "have" etc. specify the presence of stated features, wholes, steps, operations, components, parts or combinations thereof, but do not exclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts or combinations thereof.

[0020] Reference Figure 1As shown, the present invention provides a technical solution: a gas concentration detection system in liquid, comprising a liquid storage tank 1, a multi-wavelength laser 2, a fiber laser hydrophone 3 and a mobile device 4; the liquid storage tank 1 has a resonant cavity 11, and the resonant cavity 11 is used to accommodate a liquid sample; the multi-wavelength laser 2 is arranged opposite to the incident end of the liquid storage tank 1, and the multi-wavelength laser 2 is used to emit a laser beam to the liquid storage tank 1, so that the gas in the liquid sample can absorb the laser and generate an acoustic wave signal; the fiber laser hydrophone 3 is arranged in the resonant cavity 11, and the fiber laser hydrophone 3 is used to collect the acoustic wave signal and convert it into an optical signal; the mobile device 4 is connected to the optical fiber laser hydrophone 3 for communication, and the mobile device 4 is used to calculate according to the optical signal to obtain the concentration of the measured gas.

[0021] Exemplarily, the mobile device 4 may be a computer or the like.

[0022] In this embodiment, by cooperating with the multi-wavelength laser 2, the fiber laser hydrophone 3 and the mobile device 4, the gas concentration of the liquid sample can be directly measured without degassing the liquid sample.

[0023] Reference Figure 1 As shown, in some embodiments, the resonant cavity 11 is constructed in a horn shape.

[0024] In this embodiment, the curved liquid storage tank wall in the resonant cavity 11 can enhance the resonance of the acoustic wave signal, while maximally reducing the noise of the laser beam passing through the liquid storage tank, further improving the detection accuracy of the gas component to be measured in the liquid sample.

[0025] Due to the large dispersion effect and light absorption effect in liquid samples. Figure 2 As shown, after the laser beam is incident, the traditional I-shaped resonant cavity 11 is affected by the dispersion effect and the light absorption effect, and the acoustic wave signal is not obvious. However, the horn-shaped resonant cavity 11 of the present invention has a strong acoustic wave signal under the influence of the dispersion effect and the light absorption effect.

[0026] Reference Figure 1 As shown, in some embodiments, a spatial light modulator 5 is included. The spatial light modulator 5 is disposed between the multi-wavelength laser 2 and the incident end of the liquid reservoir 1. The spatial light modulator 5 is used to modulate the laser beam.

[0027] In this embodiment, when the laser beam enters the spatial light modulator 5, the spatial light modulator 5 modulates the laser beam to control the phase and amplitude of the laser beam to obtain a high-resolution laser beam.

[0028] Reference Figure 1 As shown, in some embodiments, a laser controller 6 is included. The laser controller 6 is electrically connected to the multi-wavelength laser 2. The laser controller 6 is used to control the multi-wavelength laser 2 to emit laser beams of different wavelengths.

[0029] In this embodiment, the laser controller 6 controls the multi-wavelength laser 2 to emit laser beams of different wavelengths, thereby enabling detection of the concentrations of different gases.

[0030] Reference Figure 1 As shown, in some embodiments, a conductivity sensor 7 is included, the detection end of the conductivity sensor 7 passes through the bottom wall of the liquid storage tank 1 and is inserted into the resonant cavity 11, the conductivity sensor 7 is electrically connected to the mobile device 4, and the conductivity sensor 7 is used to detect the conductivity of the liquid sample.

[0031] In this embodiment, the conductivity sensor 7 is used to measure the current and voltage of the liquid sample to calculate the conductivity or resistivity, and finally the conductive performance related parameters of the liquid sample are obtained through the mobile device 4, thereby realizing multifunctional detection.

[0032] Reference Figure 1 As shown, in some embodiments, a spectrometer 8 is included, which is arranged opposite to the output end of the liquid storage tank 1, and the spectrometer 8 is electrically connected to the mobile device 4. The spectrometer 8 is used to receive the laser beam emitted from the liquid storage tank 1 to generate a spectral image, and calculate the impurity content of the liquid sample based on the spectral image.

[0033] In this embodiment, the spectrometer 8 is used to detect impurities in the liquid sample, which can help the user to timely understand the status of the liquid sample, prevent potential problems from occurring, and improve production efficiency and quality control level.

[0034] The present invention was used to test four transformer oils containing different concentrations of acetylene. The concentration of acetylene in the oil was increased from 25 ml / L to 100 ml / L. During the test, the ambient temperature was about 25°C and the pressure in the reservoir was kept at standard atmospheric pressure. The relationship between the concentration of acetylene and the intensity of the acoustic wave signal is shown in Figure 3 As shown. Obviously, with the increase of acetylene concentration, the intensity of the acoustic wave signal also gradually increases.

[0035] The present invention provides a technical solution: a method for detecting gas in oil, which is applicable to the above-mentioned gas concentration detection system in liquid, and comprises the following steps: S1, a multi-wavelength laser 2 emits a laser beam to a liquid reservoir 1, which enables the gas in the liquid sample to absorb the laser and generate an acoustic wave signal; S2, the fiber laser hydrophone 3 collects the acoustic wave signal and converts it into an optical signal; S3, the mobile device 4 calculates according to the optical signal to obtain the concentration of the measured gas.

[0036] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A gas concentration detection system in liquid, characterized in that: include: A liquid storage tank (1) having a resonant cavity (11), wherein the resonant cavity (11) is used to contain a liquid sample; A multi-wavelength laser (2) is arranged opposite to the incident end of the liquid storage tank (1), and the multi-wavelength laser (2) is used to emit a laser beam to the liquid storage tank (1), so that the gas in the liquid sample can absorb the laser and generate an acoustic wave signal; A fiber laser hydrophone (3) is disposed in the resonant cavity (11), and the fiber laser hydrophone (3) is used to collect the sound wave signal and convert it into an optical signal; A mobile device (4) is communicatively connected to the optical fiber laser hydrophone (3), and the mobile device (4) is used to calculate based on the optical signal to obtain the concentration of the measured gas.

2. A gas concentration detection system in liquid according to claim 1, characterized in that: The resonance cavity (11) is constructed in a horn shape.

3. A gas concentration detection system in liquid according to claim 1, characterized in that: It comprises a spatial light modulator (5), wherein the spatial light modulator (5) is arranged between the multi-wavelength laser (2) and the incident end of the liquid storage tank (1), and the spatial light modulator (5) is used to modulate the laser light beam.

4. A gas concentration detection system in liquid according to claim 1, characterized in that: It comprises a laser controller (6), the laser controller (6) is electrically connected to the multi-wavelength laser (2), and the laser controller (6) is used to control the multi-wavelength laser (2) to emit laser light beams of different wavelengths.

5. A gas concentration detection system in liquid according to claim 1, characterized in that: The device comprises a conductivity sensor (7), wherein a detection end of the conductivity sensor (7) penetrates the bottom wall of the liquid storage tank (1) and is inserted into the resonant cavity (11), the conductivity sensor (7) is electrically connected to the mobile device (4), and the conductivity sensor (7) is used to detect the conductivity of the liquid sample.

6. A gas concentration detection system in liquid according to claim 1, characterized in that: The device comprises a spectrometer (8), the spectrometer (8) being arranged opposite to the exit end of the liquid storage tank (1), the spectrometer (8) being electrically connected to the mobile device (4), the spectrometer (8) being used to receive the laser beam emitted by the liquid storage tank (1) to generate a spectral image, and to calculate the impurity content of the liquid sample based on the spectral image.

7. A method for detecting gas in oil, characterized in that: The gas detection method is applicable to a gas concentration detection system in liquid according to any one of claims 1 to 6, comprising: The multi-wavelength laser (2) emits a laser beam to the liquid storage tank (1), so that the gas in the liquid sample absorbs the laser and generates an acoustic wave signal; The optical fiber laser hydrophone (3) collects the acoustic wave signal and converts it into an optical signal; The mobile device (4) calculates according to the optical signal to obtain the concentration of the measured gas.

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