Distributed TDLAS (Tunable Diode Laser Absorption Spectroscopy) gas detection system and method

Abstract

The invention discloses a distributed TDLAS (Tunable Diode Laser Absorption Spectroscopy) gas detection system and a distributed TDLAS gas detection method. The gas detection system comprises a laser emitting, converting and receiving part, a testing and analyzing device, an optical path switching device and no less than two measuring air chambers, wherein the optical path switching device is used for introducing incident laser light from the laser emitting, converting and receiving part into the optical path of a specified measuring air chamber in the measuring air chambers according to a command from the testing and analyzing device; gas to be detected can be introduced into the measuring air chambers, incident laser light is reflected repeatedly in the measuring air chambers and is absorbed by target gas to form transmitted laser light which is reflected back into the optical path switching device; the optical path switching device is used for introducing transmitted laser light received from the specified measuring air chamber into the laser emitting, converting and receiving part. Thus, the target gas concentration of each measuring air chamber can be detected by configuring a plurality of measuring air chambers at different positions in one set of TDLAS gas detection system, the comprehensive cost of the TDLAS gas detection system is reduced, and the use efficiency of the system is increased.

Description

technical field [0001] The application belongs to the technical field of gas concentration measurement, and in particular relates to a distributed TDLAS gas detection system and method. Background technique [0002] As a method for measuring gas concentration values, TDLAS (Tunable Diode Laser Absorption Spectroscopy) measurement method is a non-contact measurement method in which photodetectors and other components are not in contact with the gas being analyzed . [0003] When using the TDLAS measurement method to measure the concentration of gas, the incident laser light whose wavelength is modulated according to a certain frequency f is introduced into the measuring gas chamber containing one or more target gases to be analyzed, and the gas sensing and measuring device is used to measure the concentration of the gas. A photoelectric sensing device detects the optical power of the transmitted laser light that has passed through the gas and returned. The gas to be measure...

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Problems solved by technology

[0004] When the existing TDLAS detection system detects the target gas concentration in each measurement gas chamber, each measurement gas chamber needs to be equipped with a complete set of TDLAS gas detection system corresponding to the measurement gas chamber; relative to the measurement gas chamber, the laser emits Much more expensive than the conversion receiving part and the test and analysis setup

[0005] Therefore, based on the above reasons, the existing TDLAS gas detection system not only has low efficiency in the use of laser emitting and converting receiving parts and testing and analysis devices, but also needs to be equipped with the same number of gas concentrations in order to achieve gas concentration detection at multiple measurement positions. TDLAS gas detection system, which makes the purchase and use costs and equipment maintenance costs relatively high, TDLAS detection system is difficult to popularize and apply

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