Development of a tunable diode laser absorption sensor for online monitoring of industrial gas total emissions based on optical scintillation cross-correlation technique

Abstract

We report the first application of gas total emission using a DFB diode laser for gas concentration measurements combined with two LEDs for gas velocity measurements. In situ gas total emissions and particle density measurements in an industrial pipeline using simultaneous tunable diode laser absorption spectroscopy (TDLAS) and optical scintillation cross-correlation technique (OSCC) are presented. Velocity mean values obtained are 7.59 m/s (OSCC, standard deviation is 1.37 m/s) and 8.20 m/s (Pitot tube, standard deviation is 1.47 m/s) in a steel plant pipeline for comparison. Our experiments demonstrate that the combined system of TDLAS and OSCC provides a new versatile tool for accurate measurements of total gas emissions.

Similarity Analysis for Time Series-Based 2D Temperature Measurement of Engine Exhaust Gas in TDLAT

“…Tunable diode laser absorption spectroscopy (TDLAS) is a measurement technique commonly used in a variety of applications recently as well as temperature and density of molecules in gas [15,16]. When a laser beam permeates an absorption medium, its intensity will be attenuated by the absorbing gas species.…”

Improvement of Concentration Inversion Model Based on Second Harmonic Valley Spacing in Wavelength Modulation Spectroscopy

“…In thermal power plants, in-situ real-time monitoring of carbon monoxide (CO) concentration is of great significance for energy saving and emission reduction. The tunable diode laser absorption spectroscopy (TDLAS) technology [1] is a technology that utilizes the tunable diode laser to scan the absorption line of the gas, thereby measuring various parameters such as concentration, temperature [7], flow velocity [8], and so on. In recent years, with the development and maturity of optoelectronic devices [2]- [6], this technology has been widely employed in atmospheric environment monitoring [9], industrial process control [10], combustion flow field diagnosis [11], and human breath detections [12], due to its advantages of high sensitivity, high selectivity, fast response speed, and in-situ real-time measurement.…”

Multi-Component and Multi-Point Trace Gas Sensing in Wavelength Modulation Spectroscopy Based on Wavelength Stabilization

“…Over the last few decades, tunable diode laser absorption spectroscopy (TDLAS) has been widely used in the trace gas detection in various fields, such as industrial production control [1], mine safety monitoring [2,3], combustion processes [4,5], Zongliang WANG et al: Multi-Component and Multi-Point Trace Gas Sensing in Wavelength Modulation Spectroscopy Based on Wavelength Stabilization 377 environmental monitoring [6,7], and explosive analysis. Moreover, owing to the well-known advantages of resistance to electromagnetic interference, low cost, and portability, TDLAS has been widely studied [8,9]. Among TDLAS techniques, the method that is often referred to as wavelength modulation spectroscopy (WMS) [10][11][12] is the most representative because of its high minimum detection limit (MDL) and sensitivity.…”