CN111562055B - Infrared imaging and concentration detection device and method for methane gas leakage - Google Patents
Infrared imaging and concentration detection device and method for methane gas leakage Download PDFInfo
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Abstract
An infrared imaging and concentration detection device and method for methane gas leakage comprises an infrared thermal imager and a laser methane detection module. The thermal infrared imager is used for carrying out infrared imaging on a region to be monitored so as to find a methane gas leakage point; the laser methane detection module aligns according to the leakage points found by the infrared imaging and measures the methane concentration. And the laser methane detection module is embedded into the thermal infrared imager, the laser beam emission direction of the laser methane detection module is adjusted to be consistent with the optical axis direction of the thermal infrared imager, and the laser beam emission direction and the optical axis direction are communicated with each other to realize data interaction. The infrared thermal imaging technology for detecting the methane gas leakage is combined with the laser methane detection technology, the non-contact large-area rapid search of the methane leakage point and the methane gas concentration quantitative detection are realized, and the comprehensive detection with higher efficiency and more accurate quantification is realized compared with the existing single detection device.
Description
Technical Field
The invention relates to the field of gas detection, in particular to an infrared imaging and concentration detection device and method for methane gas leakage.
Background
In industries such as petrochemical industry and the like, a large number of methane gas storage or conveying equipment with complex structure exist, and effective monitoring on the leakage condition of the equipment is an important precondition for ensuring safety production. At present, contact type leakage detection equipment is widely adopted, and a sensor of the equipment can find the leakage condition only by contacting with a detection target gas. However, some of the leaks may be leaking, but most of the potential leaks have not yet leaked, so that an operator must personally check and detect each potential leak, which is inefficient and also poses a health safety hazard to inspection personnel. The infrared thermal imager developed for methane gas leakage detection makes up for the defects. The infrared absorption spectrum characteristic of methane gas is utilized, non-contact passive imaging detection is carried out on the wave band where the infrared absorption peak is located, and the methane gas can be found easily. The operating personnel can inspect many potential leakage sources simultaneously through the mode of large tracts of land formation of image observation outside safe distance, and the consuming time is short and need not to stop equipment operation, has also guaranteed operating personnel's personal safety when getting high-efficient accurate testing result. In the prior art, when methane gas leakage is detected, the leaked methane gas absorbs infrared radiation in the surrounding environment, an infrared imaging system collects changes of the infrared radiation of the methane gas, the infrared radiation is focused by an optical lens, infrared radiation in a required waveband is filtered out from incident light rays of complex spectrums of target and background infrared radiation by an infrared band-pass filter, finally the radiation is focused on a focal plane of an infrared detector, and then the infrared radiation is subjected to image enhancement processing by an infrared image acquisition processing module and is output to a liquid crystal display screen or a viewfinder. Thus, the invisible methane gas and the leakage position are displayed on a liquid crystal display or a viewfinder of the methane gas infrared imager clearly in real time.
The thermal infrared imager for detecting methane gas leakage has outstanding advantages, but the detection principle is based on the infrared absorption spectrum characteristic of target gas for imaging observation, so that the thermal infrared imager is mainly suitable for quickly detecting whether methane gas leakage occurs in a large area, and the high-precision quantitative detection of the concentration of leaked gas is difficult to realize. Therefore, accurate quantitative assessment of the severity of gas leakage is not easy to make using a thermal infrared imager.
At present, a laser methane detector can realize quantitative detection of non-contact methane gas concentration, and adopts an optical detection mode, an infrared spectroscopy measurement principle and a laser beam with unique absorption wavelength to methane molecules to realize leakage detection. The concentration of the methane gas at the position can be quickly measured only by aligning the laser methane detector at the position where the methane gas exists. For example, the prior patent CN108037129A discloses a method for detecting the methane concentration in a coal mine, which converts the gas concentration to be detected into a current signal by a laser gas detection component, transmits the current signal to a processor, compares the current signal with a set threshold value, and displays the gas concentration data. However, searching for leakage points is still inefficient when the device is used alone, and the actual leakage point can only be found by detecting all possible leakage points one by one.
Disclosure of Invention
The invention aims to provide an infrared imaging and concentration detection device and method for methane gas leakage, which combine an infrared thermal imaging technology for methane gas leakage detection with a laser methane detection technology, realize non-contact large-area rapid search of methane leakage points and quantitative detection of methane gas concentration, and realize more efficient and accurate quantitative comprehensive detection than the existing single detection device.
In order to achieve the purpose, the invention adopts the following technical scheme:
the invention provides an infrared imaging and concentration detection device for methane gas leakage, which comprises a thermal infrared imager and a laser methane detection module, wherein the thermal infrared imager is connected with the laser methane detection module;
the thermal infrared imager is used for carrying out infrared imaging on a region to be monitored so as to find a methane gas leakage point;
the laser methane detection module is used for aligning according to the leakage points found by infrared imaging and measuring the methane concentration;
and the laser methane detection module is embedded into the thermal infrared imager, the laser beam emission direction of the laser methane detection module is adjusted to be consistent with the optical axis direction of the thermal infrared imager, and the laser beam emission direction and the optical axis direction are communicated with each other to realize data interaction.
Furthermore, the thermal infrared imager comprises an infrared focal plane detector, an infrared detector driver, an infrared image processor, a display unit and a communication unit;
the infrared image processor is respectively connected with the infrared focal plane detector, the infrared detector driver, the display unit and the communication unit, controls the infrared focal plane detector, the infrared detector driver, the display unit and the communication unit, and receives signals;
the infrared detector driver is connected with the infrared focal plane detector and is used for generating power supply voltage, bias voltage and driving time sequence signals required by the infrared detector, then collecting original infrared signals radiated by a target and transmitting the original infrared signals to the infrared image processor;
the infrared image processor carries out non-uniformity correction, image noise reduction, image enhancement, gray scale conversion and the like on the collected original infrared signals and then transmits the processed signals to the display unit.
Furthermore, the laser methane detection module comprises a processor, a laser methane signal acquisition and processing unit and a communication unit;
the processor is connected with the laser methane signal acquisition and processing unit and used for receiving and processing the signals of the laser methane signal acquisition and processing unit, carrying out corresponding signal processing and transmitting the processing result to the thermal infrared imager and/or the terminal equipment through the communication unit.
Furthermore, the laser methane detection module comprises a processor, a laser methane signal acquisition and processing unit and a communication unit;
the processor is connected with the laser methane signal acquisition and processing unit and used for receiving and processing the signals of the laser methane signal acquisition and processing unit, carrying out corresponding signal processing and transmitting the processing result to the thermal infrared imager and/or the terminal equipment through the communication unit;
the laser methane signal acquisition and processing unit comprises a trigger regulator, a laser driver, a laser and a photoelectric detector;
the trigger adjuster receives a detection state signal sent by the thermal infrared imager and/or the terminal equipment, and according to detection state information, the trigger adjuster sends an adjusting signal to the laser driver, adjusts the emitting direction of a laser beam of the laser to be consistent with the optical axis direction of the thermal infrared imager, and sends a trigger signal to the laser driver after adjustment is finished;
after receiving the trigger signal, the laser driver generates a modulation signal according to the detection state signal so as to modulate the output of the laser and drive the laser to emit laser with a target wavelength to a methane leakage point;
the photoelectric detector receives the reflected laser and converts the laser into a detection signal to be output;
the processor receives and processes signals of the laser methane signal acquisition and processing unit, and the processor receives detection signals output and converted by the photoelectric detector, wherein the detection signals comprise the absorption of methane gas to light intensity, and the intensity of the absorbed light and the intensity of original light are compared to calculate and obtain and output a methane gas concentration detection processing result.
Further, the laser methane detection module further comprises a temperature compensation unit;
the temperature compensation unit adopts the following temperature compensation formula:
wherein, TIMeasuring the temperature, T, for a thermal infrared imagerLMeasuring temperature for a laser methane detection module (T)L/TI)tempThe ratio of the temperature measured by the laser methane detection module after temperature compensation to the temperature measured by the thermal infrared imager is calculated, and alpha is a temperature compensation calculation coefficient, and the value depends on the characteristics of the laser methane detection module; and (3) carrying out temperature compensation on the temperature measured by the laser methane detection module according to the formula (1), and then obtaining the measured methane concentration value according to operation.
Further, the step of obtaining the measured methane concentration value according to the operation comprises the steps of extracting data of a gas spectrum absorption rate signal in the detection laser, and carrying out integral or fitting operation through an absorption line function to obtain the gas concentration; or modulating the laser emission wavelength to enable the gas spectrum absorption rate signal to be reflected on the fundamental frequency and the frequency multiplication of the modulation frequency, and calculating to obtain the gas concentration through non-odd signal harmonic amplitude analysis.
Furthermore, the device also comprises a power module, an acoustic alarm module and/or a display module;
the power supply module is used for providing power for the thermal infrared imager and the laser methane detection module;
the acoustic alarm module is used for giving out acoustic alarm when detecting that the concentration of methane and/or methane exceeds a preset threshold value;
the display module is used for displaying the detection result, and the detection result comprises whether the methane and/or the methane concentration value is detected.
The second aspect of the present invention provides an infrared imaging and concentration detection method for methane gas leakage, which uses the aforementioned infrared imaging and concentration detection apparatus for methane gas leakage to perform detection, and includes the following steps:
carrying out on-site infrared imaging on the area to be detected by using a thermal infrared imager, and finding whether a methane gas leakage point exists according to an imaging result;
if the methane gas leakage point exists, the laser methane detection module is started to obtain the methane gas concentration of the leakage point;
the laser methane detection module sends the obtained methane gas concentration to the thermal infrared imager through a communication unit;
the thermal infrared imager identifies methane gas concentration at a leak area on an infrared imaging picture.
Further, the step of obtaining the methane gas concentration of the leak point further comprises the step of temperature compensation:
the following temperature compensation formula is adopted:
wherein, TIMeasuring the temperature, T, for a thermal infrared imagerLMeasuring temperature for a laser methane detection module (T)L/TI)tempThe ratio of the temperature measured by the laser methane detection module after temperature compensation to the temperature measured by the thermal infrared imager is calculated, and alpha is a temperature compensation calculation coefficient, and the value depends on the characteristics of the laser methane detection module;
and (3) carrying out temperature compensation on the temperature measured by the laser methane detection module according to the formula (1), and then obtaining the measured methane concentration value according to operation.
Further, the step of obtaining the measured methane concentration value according to the operation comprises the steps of extracting data of a gas spectrum absorption rate signal in the detection laser, and carrying out integral or fitting operation through an absorption line function to obtain the gas concentration; or modulating the laser emission wavelength to enable the gas spectrum absorption rate signal to be reflected on the fundamental frequency and the frequency multiplication of the modulation frequency, and calculating to obtain the gas concentration through non-odd signal harmonic amplitude analysis.
Further, the method also comprises the steps of sound and light alarm and/or result display;
when the methane and/or the methane concentration is detected to exceed a preset threshold value, an audible and visual alarm is given;
displaying the detection result; the detection result includes whether methane and/or a methane concentration value is detected.
In summary, the present invention provides an infrared imaging and concentration detection apparatus and method for methane gas leakage, which have the following beneficial effects:
(1) the infrared thermal imaging technology can detect a large-area window through an infrared thermal imager so as to judge whether natural gas leaks in the window, and the specific gas leakage points are visually displayed in real time, so that the leakage position and the leakage amount are clear at a glance; meanwhile, infrared signals received by the thermal infrared imager are not affected by photoelectric noise and the concentration and optical path of a leakage source to be detected, and are observed simultaneously in a large range, so that methane leakage points can be identified and positioned quickly and accurately, the detection time is greatly shortened, and the working efficiency is greatly improved. In addition, by adopting a non-contact passive imaging principle and matching a telephoto lens, a detector can safely work far away from a gas leakage place.
(2) The laser methane detection technology carries out remote non-contact measurement on methane leakage points through a laser methane detection module, accurate methane gas concentration information can be obtained, the measurement error is small in range and large in range, the response speed is high, the sensitivity is high, under the condition of no failure sensitivity, the time resolution can be in the ms magnitude, the high monochromaticity of laser enables the measurement process to have no cross interference, the measurement result is accurate and reliable, the detection power consumption is low, and the target monitoring of continuous real-time methane concentration on the detection site can be realized.
(3) The infrared thermal imaging technology and the laser methane detection technology are combined for detecting methane gas leakage, non-contact large-area rapid search of methane leakage points and methane gas concentration quantitative detection is achieved, and more efficient and accurate quantitative comprehensive detection is achieved compared with the existing single detection device.
(4) The laser methane detection module provided by the invention takes the temperature obtained by the thermal infrared imager as a reference value, adopts a temperature compensation algorithm, and calculates a temperature compensation coefficient according to the characteristics and the absorption line function of the laser methane detection module, so as to eliminate the influence of the temperature on the measurement precision of the methane concentration and improve the measurement precision of the methane concentration.
Drawings
FIG. 1 is a schematic structural diagram of an infrared imaging and concentration detection apparatus for methane gas leakage according to an embodiment of the present invention;
FIG. 2 is a schematic structural diagram of a thermal infrared imager according to an embodiment of the invention;
FIG. 3 is a schematic structural diagram of a laser methane detection module according to an embodiment of the present invention;
FIG. 4 is a schematic structural diagram of a laser methane signal acquisition and processing unit according to an embodiment of the present invention;
FIG. 5 is a schematic flow chart of a method for infrared imaging and concentration detection of methane gas leakage according to an embodiment of the present invention;
fig. 6 is a schematic flow chart of a method for infrared imaging and concentration detection of methane gas leakage according to another embodiment of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in further detail with reference to the accompanying drawings in conjunction with the following detailed description. It should be understood that the description is intended to be exemplary only, and is not intended to limit the scope of the present invention. Moreover, in the following description, descriptions of well-known structures and techniques are omitted so as to not unnecessarily obscure the concepts of the present invention.
A first aspect of the present invention provides an infrared imaging and concentration detection apparatus for methane gas leakage, as shown in fig. 1, including an infrared thermal imager and a laser methane detection module. The thermal infrared imager is used for carrying out infrared imaging on a region to be monitored so as to find a methane gas leakage point; and the laser methane detection module is aligned according to the leakage points found by the infrared imaging and measures the methane concentration. The laser methane detection module is embedded into the thermal infrared imager, the laser beam emission direction of the laser methane detection module is adjusted to be consistent with the optical axis direction of the thermal infrared imager, and the laser beam emission direction and the optical axis direction are communicated with each other to realize data interaction. Specifically, the communication can be performed in a serial port or bluetooth mode.
Further, as shown in a dashed box in fig. 1, the detection device further comprises a power module, an audible and visual alarm module and/or a display module. The power supply module is used for providing power for the thermal infrared imager and the laser methane detection module; the sound-light alarm module is used for giving out sound-light alarm when detecting that the concentration of the methane and/or the methane exceeds a preset threshold value; the display module is used for displaying the detection result, wherein the detection result comprises whether the methane and/or the methane concentration value is detected.
Furthermore, the thermal infrared imager is manufactured by adopting an infrared spectrum absorption principle, and molecules of polyatomic gas have more mechanical degrees of freedom, so that rotation and vibration transition motion of atoms are easy to occur. According to the frequency of transition, molecules of some gases can easily absorb photon energy with a specific infrared band, such as 3.2-3.4 um wavelength, so that the molecules generate atomic motion, and infrared radiation energy passing through the gases is absorbed and weakened. When infrared light of a specific wave band passes through a certain gas, if the frequency of the infrared light is consistent with the motion frequency of gas molecules, the gas absorbs the radiant energy of the infrared light to generate selective energy level transition, wherein the frequency of the infrared light with the strongest energy level transition is the characteristic frequency of the gas molecules. The leaking gas absorbs a portion of the energy that would have been available to reach the thermal infrared imager from its background radiation, thereby visually distinguishing regions with gas from regions without gas in the infrared image.
The thermal infrared imager for detecting methane gas is designed based on the principle, and comprises an infrared focal plane detector, an infrared detector driver, an infrared image processor, a display unit and a communication unit, as shown in FIG. 2. The infrared image processor is respectively connected with the infrared focal plane detector, the infrared detector driver, the display unit and the communication unit, controls the infrared focal plane detector, the infrared detector driver, the display unit and the communication unit, and receives signals. The infrared detector driver is connected with the infrared focal plane detector and used for generating power supply voltage, bias voltage and driving time sequence signals required by the infrared detector, then acquiring original infrared signals radiated by a target and transmitting the original infrared signals to the infrared image processor, wherein if methane gas exists in a target window, the acquired original infrared signals are original infrared signals absorbed by the methane gas. The infrared image processor carries out non-uniformity correction, image noise reduction, image enhancement, gray level conversion and other processing on the collected original infrared signals and then transmits the processed infrared signals to the display unit, and the processed data mainly comprises the area and the position of a methane leakage point in infrared imaging.
Further, as shown in fig. 3, the laser methane detection module includes a processor, a laser methane signal acquisition processing unit, and a communication unit. The processor is connected with the laser methane signal acquisition and processing unit and used for receiving and processing the signals of the laser methane signal acquisition and processing unit, carrying out corresponding signal processing and transmitting the processing result to the thermal infrared imager and/or the terminal equipment through the communication unit.
Further, as shown in fig. 4, the laser methane signal collecting and processing unit includes a processor, a laser methane signal collecting and processing unit, and a communication unit; the processor is connected with the laser methane signal acquisition and processing unit and used for receiving and processing the signals of the laser methane signal acquisition and processing unit, carrying out corresponding signal processing and transmitting the processing result to the thermal infrared imager and/or the terminal equipment through the communication unit.
The laser methane signal acquisition and processing unit comprises a trigger regulator, a laser driver, a laser and a photoelectric detector; the trigger adjuster receives a detection state signal sent by the thermal infrared imager and/or the terminal equipment, and according to detection state information, the trigger adjuster sends an adjusting signal to the laser driver, adjusts the emitting direction of a laser beam of the laser to be consistent with the optical axis direction of the thermal infrared imager, and sends a trigger signal to the laser driver after adjustment is finished; after receiving the trigger signal, the laser driver generates a modulation signal according to the detection state signal so as to modulate the output of the laser and drive the laser to emit laser with a target wavelength to a methane leakage point; and the photoelectric detector receives the reflected laser and converts the laser into a detection signal to be output.
The processor receives and processes signals of the laser methane signal acquisition and processing unit, wherein the signals include detection signals output and converted by the photoelectric detector, detection state signals transmitted by the thermal infrared imager and/or the terminal equipment through the communication unit, the detection signals include spectral line intensity P (T) of methane gas to strong absorption, and the detection signals include absorption distance S and infrared temperature TIAnd comparing the spectral line intensity P (T) of the absorbed light and the original light, calculating by combining the absorption distance S and the absorption line function to obtain the methane gas concentration, and outputting a detection result.
Further, the laser may be an adjustable diode laser, which is used as a detection light source, and the temperature and intensity of the laser are controlled by a laser driver, so as to adjust the light intensity and the central wavelength of the laser output by the laser.
Further, emitting the laser signal at the target wavelength includes obtaining a gas absorption line of methane using a single narrow band laser frequency sweep within a methane gas characteristic wavelength range. The laser is modulated, and the emission wavelength can cover the absorption peak of the gas to be detected, so that the laser is adjusted according to the molecular spectral characteristics, and the detection can be effective on active molecules with absorption in infrared, thereby meeting the measurement requirements of other components or mixed multiple components.
The detection laser emitted by the laser penetrates into the methane gas to be detected, part of light can be absorbed by the gas, the absorption proportion depends on the wavelength of the laser penetrating into the methane gas to be detected, the laser penetrating through the gas reaches a reflector and is reflected back to part of laser through the reflector, the part of laser penetrates back into the methane gas to be detected again and is received by the photoelectric detector and converted into detection signals to be output, and the processor calculates the output detection signals to obtain the concentration of the methane gas and outputs detection results.
Further, according to the lambert beer law, the gas concentration and the spectral line intensity have a negative correlation proportional relationship, the temperature is a single variable of the spectral line intensity, the error of the temperature value can highly influence the accuracy of the measured value, and generally, the working environment of methane detection is complex, and the temperature change is large, so that the laser methane detection module further comprises a temperature compensation unit, and the temperature compensation unit adopts the following temperature compensation formula:
wherein, TIMeasuring the temperature, T, for a thermal infrared imagerLMeasuring temperature for a laser methane detection module (T)L/TI)tempThe ratio of the temperature measured by the laser methane detection module after temperature compensation to the temperature measured by the thermal infrared imager is calculated, and alpha is a temperature compensation calculation coefficient, and the value depends on the characteristics of the laser methane detection module; and (3) carrying out temperature compensation on the temperature measured by the laser methane detection module according to the formula (1), and then obtaining the measured methane concentration value according to operation.
Further, the step of obtaining the measured methane concentration value according to the operation comprises the steps of extracting data of a gas spectrum absorption rate signal in the detection laser, and carrying out integral or fitting operation through an absorption line function to obtain the gas concentration; or modulating the laser emission wavelength to enable the gas spectrum absorption rate signal to be reflected on the fundamental frequency and the frequency multiplication of the modulation frequency, and calculating to obtain the gas concentration through non-odd signal harmonic amplitude analysis.
A second aspect of the present invention provides an infrared imaging and concentration detection method for methane gas leakage, which uses the aforementioned infrared imaging and concentration detection apparatus for methane gas leakage for detection, as shown in fig. 5, and includes the following steps:
and S100, carrying out on-site infrared imaging on the area to be detected by using a thermal infrared imager, and finding whether a methane gas leakage point exists according to an imaging result. If no methane gas leakage point exists, the detection is finished.
Step S200, if a methane gas leakage point exists, a laser methane detection module is started to obtain the methane gas concentration of the leakage point;
step S300, the laser methane detection module sends the obtained methane gas concentration to the thermal infrared imager through a communication unit;
and S400, identifying the concentration of the methane gas at a leakage point area on an infrared imaging picture by the thermal infrared imager.
Further, the step of obtaining the methane gas concentration of the leak point in step S200 further includes a step of temperature compensation:
the following temperature compensation formula is adopted:
wherein, TIMeasuring the temperature, T, for a thermal infrared imagerLMeasuring temperature for a laser methane detection module (T)L/TI)tempThe ratio of the temperature measured by the laser methane detection module after temperature compensation to the temperature measured by the thermal infrared imager is calculated, and alpha is a temperature compensation calculation coefficient, and the value depends on the characteristics of the laser methane detection module; and (3) carrying out temperature compensation on the temperature measured by the laser methane detection module according to the formula (1), and then obtaining the measured methane concentration value according to operation.
Further, as shown in fig. 6, a step S500 of alarming sound and light and/or displaying the result is included;
when the methane and/or the methane concentration is detected to exceed a preset threshold value, an audible and visual alarm is given; displaying the detection result; the detection result includes whether methane and/or a methane concentration value is detected.
In summary, the invention provides an infrared imaging and concentration detection device and method for methane gas leakage, and the device comprises an infrared thermal imager and a laser methane detection module; the thermal infrared imager is used for carrying out infrared imaging on a region to be monitored so as to find a methane gas leakage point; the laser methane detection module is used for aligning according to the leakage points found by the infrared imaging and measuring the methane concentration; and the laser methane detection module is embedded into the thermal infrared imager, the laser beam emission direction of the laser methane detection module is adjusted to be consistent with the optical axis direction of the thermal infrared imager, and the laser beam emission direction and the optical axis direction are communicated with each other to realize data interaction. The infrared thermal imaging technology for detecting the methane gas leakage is combined with the laser methane detection technology, the non-contact large-area rapid search of the methane leakage point and the methane gas concentration quantitative detection are realized, and the comprehensive detection with higher efficiency and more accurate quantification is realized compared with the existing single detection device.
It is to be understood that the above-described embodiments of the present invention are merely illustrative of or explaining the principles of the invention and are not to be construed as limiting the invention. Therefore, any modification, equivalent replacement, improvement and the like made without departing from the spirit and scope of the present invention should be included in the protection scope of the present invention. Further, it is intended that the appended claims cover all such variations and modifications as fall within the scope and boundaries of the appended claims or the equivalents of such scope and boundaries.
Claims (6)
1. An infrared imaging and concentration detection device for methane gas leakage is characterized by comprising a thermal infrared imager and a laser methane detection module;
the thermal infrared imager is used for carrying out infrared imaging on a region to be monitored so as to find a methane gas leakage point;
if the methane gas leakage point exists, a laser methane detection module is started;
the laser methane detection module is used for aligning according to the leakage points found by the infrared imaging and measuring the methane concentration;
embedding the laser methane detection module in the thermal infrared imager, adjusting the laser beam emission direction of the laser methane detection module to be consistent with the optical axis direction of the thermal infrared imager, and communicating the laser beam emission direction and the optical axis direction of the thermal infrared imager to realize data interaction;
the laser methane detection module comprises a processor, a laser methane signal acquisition and processing unit and a communication unit;
the processor is connected with the laser methane signal acquisition and processing unit and used for receiving and processing the signals of the laser methane signal acquisition and processing unit, carrying out corresponding signal processing and transmitting the processing result to the thermal infrared imager and/or the terminal equipment through the communication unit;
the laser methane signal acquisition and processing unit comprises a trigger regulator, a laser driver, a laser and a photoelectric detector;
the trigger adjuster receives a detection state signal sent by the thermal infrared imager and/or the terminal equipment, and according to detection state information, the trigger adjuster sends an adjusting signal to the laser driver, adjusts the emitting direction of a laser beam of the laser to be consistent with the optical axis direction of the thermal infrared imager, and sends a trigger signal to the laser driver after adjustment is finished;
after receiving the trigger signal, the laser driver generates a modulation signal according to the detection state signal so as to modulate the output of the laser and drive the laser to emit laser with a target wavelength to a methane leakage point;
the photoelectric detector receives the reflected laser and converts the laser into a detection signal to be output;
the processor receives and processes signals of the laser methane signal acquisition and processing unit, the signals comprise detection signals output and converted by the photoelectric detector, the detection signals comprise the light intensity absorption of methane gas, and the intensity of the absorbed light and the intensity of original light are compared to calculate and obtain and output a methane gas concentration detection processing result;
the laser methane detection module also comprises a temperature compensation unit;
the temperature compensation unit adopts the following temperature compensation formula:
wherein, TIMeasuring the temperature, T, for a thermal infrared imagerLMeasuring temperature for a laser methane detection module (T)L/TI)tempThe ratio of the temperature measured by the laser methane detection module after temperature compensation to the temperature measured by the thermal infrared imager is calculated, and alpha is a temperature compensation calculation coefficient, and the value depends on the characteristics of the laser methane detection module; laser methane detection module according to the formula (1)The block measures the temperature for temperature compensation, and then obtains the measured methane concentration value according to the operation.
2. The infrared imaging and concentration detection device for methane gas leakage according to claim 1, wherein the thermal infrared imager comprises an infrared focal plane detector, an infrared detector driver, an infrared image processor, a display unit, and a communication unit;
the infrared image processor is respectively connected with the infrared focal plane detector, the infrared detector driver, the display unit and the communication unit, controls the infrared focal plane detector, the infrared detector driver, the display unit and the communication unit, and receives signals;
the infrared detector driver is connected with the infrared focal plane detector and is used for generating power supply voltage, bias voltage and driving time sequence signals required by the infrared focal plane detector, then collecting original infrared signals radiated by a target and transmitting the original infrared signals to the infrared image processor;
the infrared image processor carries out non-uniformity correction, image noise reduction, image enhancement and gray scale conversion on the collected original infrared signals and then transmits the signals to the display unit,
the communication unit is connected with the laser methane detection module, and the infrared image processor processes the acquired original infrared signals and transmits detection state signals of the original infrared signals through the communication unit.
3. The infrared imaging and concentration detection device for methane gas leakage according to claim 2, wherein the operation comprises obtaining the measured methane concentration value according to an operation comprising extracting data of a gas spectral absorption rate signal in the detection laser, and performing an integration or fitting operation by an absorption line function to obtain the gas concentration; or modulating the laser emission wavelength to enable the gas spectrum absorption rate signal to be reflected on the fundamental frequency and the frequency multiplication of the modulation frequency, and calculating to obtain the gas concentration through non-odd signal harmonic amplitude analysis.
4. The infrared imaging and concentration detection device for methane gas leakage according to any one of claims 1-3, characterized by further comprising a power supply module, an audible and visual alarm module and/or a display module;
the power supply module is used for providing power for the thermal infrared imager and the laser methane detection module;
the sound-light alarm module is used for giving out sound-light alarm when detecting that the concentration of the methane and/or the methane exceeds a preset threshold value;
the display module is used for displaying the detection result; the detection result includes whether methane and/or a methane concentration value is detected.
5. An infrared imaging and concentration detection method for methane gas leakage, which is characterized in that the infrared imaging and concentration detection device for methane gas leakage of any one of claims 1-4 is used for detection, and comprises the following steps:
carrying out on-site infrared imaging on the area to be detected by using a thermal infrared imager, and finding whether a methane gas leakage point exists according to an imaging result;
if the methane gas leakage point exists, the laser methane detection module is started to obtain the methane gas concentration of the leakage point;
the laser methane detection module sends the obtained methane gas concentration to the thermal infrared imager through a communication unit;
the infrared thermal imager marks the concentration of methane gas at a leakage point area on an infrared imaging picture;
the step of obtaining the methane gas concentration of the leak point further comprises the step of temperature compensation:
the following temperature compensation formula is adopted:
wherein, TIMeasuring the temperature, T, for a thermal infrared imagerLMeasuring temperature for a laser methane detection module (T)L/TI)tempThe ratio of the temperature measured by the laser methane detection module after temperature compensation to the temperature measured by the thermal infrared imager is calculated, and alpha is a temperature compensation calculation coefficient, and the value depends on the characteristics of the laser methane detection module; according to the formula (1), the temperature compensation is carried out on the temperature measured by the laser methane detection module, then the measured methane concentration value is obtained according to the operation,
further, the step of obtaining the measured methane concentration value according to the operation comprises the steps of extracting data of a gas spectrum absorption rate signal in the detection laser, and carrying out integral or fitting operation through an absorption line function to obtain the gas concentration; or modulating the laser emission wavelength to enable the gas spectrum absorption rate signal to be reflected on the fundamental frequency and the frequency multiplication of the modulation frequency, and calculating to obtain the gas concentration through non-odd signal harmonic amplitude analysis.
6. The infrared imaging and concentration detection method for methane gas leakage according to claim 5, characterized by further comprising the steps of acoustic alarm and/or displaying the result;
when detecting that the concentration of methane and/or methane exceeds a preset threshold value, sounding an alarm;
displaying the detection result; the detection result includes whether methane and/or a methane concentration value is detected.
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Families Citing this family (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114323111A (en) * | 2020-10-10 | 2022-04-12 | 中国石油天然气集团有限公司 | Methane emission monitoring system and method for oil-gas field development |
| CN112304900B (en) * | 2020-10-23 | 2022-12-20 | 西安智光物联科技有限公司 | Shoulder-back type absorption spectrum methane detector |
| CN112782118B (en) * | 2020-12-24 | 2024-01-05 | 中国科学院合肥物质科学研究院 | Multichannel methane leakage optical telemetry device and measurement method |
| CN113029997A (en) * | 2021-04-27 | 2021-06-25 | 深圳市利拓光电有限公司 | Methane concentration detection system and method |
| CN113757570B (en) * | 2021-07-28 | 2023-05-05 | 北京市燃气集团有限责任公司 | Methane leakage detection device for natural gas pipeline |
| CN113670628A (en) * | 2021-08-31 | 2021-11-19 | 国电投周口燃气热电有限公司 | Gas turbine set intelligent safety monitoring system based on ZYNQ7020 |
| CN114279964A (en) * | 2021-12-29 | 2022-04-05 | 数量级(上海)信息技术有限公司 | Laser methane leakage monitor and methane leakage monitoring method |
| CN114414526A (en) * | 2021-12-31 | 2022-04-29 | 北京无线电计量测试研究所 | Mobile terminal for methane detection, methane detection system and methane detection method |
| CN115015149B (en) * | 2022-05-05 | 2023-11-17 | 汉威科技集团股份有限公司 | Laser infrared gas concentration detection method and system based on dynamic absorption line |
| CN117516811A (en) * | 2023-10-09 | 2024-02-06 | 南京智谱科技有限公司 | Gas leakage monitoring system, method and device and inspection device |
| CN117516812A (en) * | 2023-10-09 | 2024-02-06 | 南京智谱科技有限公司 | Gas leakage monitoring system, method and device |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101122540A (en) * | 2007-09-12 | 2008-02-13 | 上海天陇电力科技发展有限公司 | Laser imaging SF6 leakage positioning device |
| WO2017197521A1 (en) * | 2016-05-18 | 2017-11-23 | Lineriders Inc. | Apparatus and methodologies for leak detection using gas and infrared thermography |
| CN110470615A (en) * | 2019-08-26 | 2019-11-19 | 北京环境特性研究所 | A kind of chemical gas concentration monitoring method and system |
Family Cites Families (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101619807A (en) * | 2009-07-24 | 2010-01-06 | 中国科学院上海技术物理研究所 | System and method for monitoring airborne natural gas line leakage |
| CN202886278U (en) * | 2012-03-30 | 2013-04-17 | 北京惟泰安全设备有限公司 | Laser gas remote telemetering device with visible image positioning and recording function |
| CN104697716A (en) * | 2013-12-09 | 2015-06-10 | 山东长运光电科技有限公司 | Methane leak detection infrared imager |
| CN104091415B (en) * | 2014-07-27 | 2016-08-17 | 北京航星网讯技术股份有限公司 | A kind of laser methane gas leak detection method with camera function and device |
| CN104122054A (en) * | 2014-07-27 | 2014-10-29 | 北京航星网讯技术股份有限公司 | Infrared thermal imaging type laser gas leak detection method and apparatus |
| IL244775B (en) * | 2016-03-27 | 2018-01-31 | Opgal Optronic Ind Ltd | Combined gas leakage detection and quantification |
| US10386260B2 (en) * | 2017-03-07 | 2019-08-20 | Accenture Global Solutions Limited | Leak detection for fluid distribution networks using hyperspectral imaging |
| CN109030374A (en) * | 2018-08-16 | 2018-12-18 | 上海禾赛光电科技有限公司 | Data managing method and data management terminal for laser gas detector |
| CN110231308B (en) * | 2019-08-05 | 2019-11-19 | 南京南智芯光科技有限公司 | A kind of active illumination gas imaging detection method and system |
-
2020
- 2020-05-22 CN CN202010443190.XA patent/CN111562055B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101122540A (en) * | 2007-09-12 | 2008-02-13 | 上海天陇电力科技发展有限公司 | Laser imaging SF6 leakage positioning device |
| WO2017197521A1 (en) * | 2016-05-18 | 2017-11-23 | Lineriders Inc. | Apparatus and methodologies for leak detection using gas and infrared thermography |
| CN110470615A (en) * | 2019-08-26 | 2019-11-19 | 北京环境特性研究所 | A kind of chemical gas concentration monitoring method and system |
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