Method and device for methane gas mass interface identification and adjustable range laser remote measurement of methane concentration

Abstract

The method and device for methane air mass interface identification and adjustable range laser remote measurement of methane concentration of the present invention relate to the field of gas detection and analysis, and are composed of an STM32 controller, a laser drive circuit, a laser temperature control circuit, a photoelectric detection circuit, and a phase-locked demodulation circuit. , three-dimensional space laser measurement tracker and built-in wind speed sensor, the STM32 controller is respectively connected with the laser drive circuit, laser temperature control circuit, phase-locked demodulation circuit and three-dimensional space laser measurement tracker circuit; the photoelectric detection circuit and phase-locked demodulation Circuit connection. The invention has fast measurement speed, response time of ms level, high measurement sensitivity, reaching ppm level, maximum detection distance of 100 meters, and one-time detection of 30 meters long range, which improves detection efficiency; The high dust and strong corrosive gas environment under test has no effect on the measurement results; and the remote detection function enables the detection of places that cannot be reached or are difficult to reach.

Description

technical field [0001] The invention relates to the field of gas detection and analysis, in particular to a method and device for methane air mass interface identification and adjustable range laser remote measurement of methane concentration. Background technique [0002] According to the principle of gas detection, methane gas detection methods can be divided into the following categories: gas-sensing detection method, gas chromatography detection method, optical interference detection method, differential detection method, tunable semiconductor laser absorption spectroscopy detection method, etc. Explanation: the problem of gas sensing detection method is that the detection performance is closely related to the production and process of sensitive components, and the detection results are also affected by environmental factors such as the temperature of the detection site. The detection response speed is slow, the components are easy to be poisoned and the service life is ...

AI Technical Summary

Problems solved by technology

[0002] According to the principle of gas detection, methane gas detection methods can be divided into the following categories: gas-sensing detection method, gas chromatography detection method, optical interference detection method, differential detection method, tunable semiconductor laser absorption spectroscopy detection method, etc. Explanation: the problem of gas sensing detection method is that the detection performance is closely related to the production and process of sensitive components, and the detection results are also affected by environmental factors such as the temperature of the detection site

The detection response speed is slow, the components are easy to be poisoned and the service life is short; the gas chromatography requires the qualitative data of the pure chromatogram of the analyte, and it is difficult to make a qualitative analysis of the mixture with unknown components. Additional reactions may occur during the adoption process, and the response time Long, unable to perform real-time measurement, complex measurement system, unable to achieve online measurement, only single-point monitoring, unable to reflect the overall situation of the measured environment; optical interferometry is difficult to achieve remote measurement, narrow linear range, poor long-term stability, and requires post-processing Processing; the tunable diode laser gas spectrum absorption detection method puts forward high requirements on the laser, which requires a wide tunable range of the light source, high frequency stability, high precision in temperature tuning and current tuning control, and a complex light source drive circuit. At the same time, lasers are more expensive

[0003] Most of the gas detectors used for methane produced by Hans in the United States and the 32A methane gas detector produced by Tokyo Gas Company in Japan now have large errors in the measurement of column density and concentration values ​​by users, and the false alarm rate At the same time, the handheld device is connected to the chassis through a rigid connection tube, which is easy to break during use; the latter has a relatively short measurement distance, and the working environment temperature must be above zero degrees Celsius to work normally, which limits its use. Dynamic response Slow, battery life can not exceed 1 hour

[0004] The most important thing is that domestic and foreign methane gas laser detection instruments and equipment mostly use the methane air mass column density value measured by TDLAS technology, and its unit is ppm.m. This result cannot display the current concentration of methane air mass in real time, and there is a big Bias, which is a major flaw in current measuring instruments

Images