Mid-infrared laser measurement system and method for engine combustion process monitoring

Abstract

The invention discloses a mid-infrared laser measurement system and method for engine combustion process monitoring. The measurement system comprises a laser device and detectors, the laser device cantransmit mid-infrared laser within a specific wavelength range, and the mid-infrared laser is absorbed by engine combustion flames. Particularly, the laser transmitted by the laser device is dividedinto two beams by a beam splitter, one beam of laser passes a laser calibration device and is measured by the first detector and used for calibrating wavelengths generated by the laser device, the other beam of laser is absorbed by carbon dioxide gas generated by combustion, measured by the second detector and acquired by a data acquisition system, and concentration information of carbon dioxide can be acquired by processing, so that the combustion efficiency of an engine is acquired. According to the system, background absorption interference of the carbon dioxide in an environment is omittedwithin the selected laser wavelength range, the carbon dioxide is obviously absorbed in the high-temperature environment, interference of other combustion products such as water molecules and intermediates is omitted, and high measurement accuracy of the combustion efficiency of the engine can be achieved.

Description

technical field [0001] The invention relates to the field of optical detection, in particular to the application of TDLAS technology in the field of engine high-temperature combustion process monitoring. Background technique [0002] In engine development, in order to judge the combustion efficiency and operating status of the engine, and predict the change trend of combustion performance, the high-temperature gas at the engine outlet can be measured, and key combustion parameters such as the concentration of combustion products, temperature, and heat flux density can be monitored, so as to determine the combustion performance of the engine. to evaluate. Products of engine combustion, such as water vapor H 2 O, carbon oxide COx (mainly CO 2 and CO), nitrogen oxides NOx (mainly NO 2 and NO) etc. can reflect the combustion efficiency of the combustion chamber. Therefore, the combustion diagnosis of the combustion chamber (exhaust exhaust) of the engine, especially the real...

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Problems solved by technology

[0004] However, the environment of the engine is harsh during operation, there is strong noise and vibration, the unburned low-viscosity aviation kerosene and the soot generated limit the sensitivity of the TDLAS probe; due to the reduction of the absorption intensity of water molecules in the near-infrared band, the absorption The signal is not obvious, and the water vapor in the air also absorbs at room temperature, which makes it difficult to obtain an accurate baseline, so that the accuracy of the calculation of the absorption coefficient cannot be guaranteed

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