Spatially resolved broadband absorption spectroscopy measurements of temperature and multiple species (NH, OH, NO, and NH3) in atmospheric-pressure premixed ammonia/methane/air flames

A mid‐infrared laser absorption sensor for calibration‐free measurement of nitric oxide in laminar premixed methane/ammonia cofired flames

“…The simulated results based on the Okafor mechanism were in good agreement with the measured value while the other two simulation results were much higher than the experimental measurements. Note that, experimental data by in situ broadband ultraviolet absorption measurements were also presented for comparisons, 37 as illustrated in Figure 7D. Our ex situ measurement results agree considerably well with in situ measurement results, indicating the additional minimally intrusive properties of our developed sensor.…”

“…(A) Representative measured absorption profiles along with the best Voigt‐fitting profiles for high‐temperature gas mixtures sampled from flames; (B) measured and simulated nitric oxide (NO) concentration as a function of height above the burner (HAB) under flame condition of Ф = 0.8 and X NH3 = 0.6 with different fuel mixture rate, and Ф = 1.1 and X NH3 = 0.2; (C) measured and simulated NO concentration at HAB = 12 mm under flame condition of Ф = 0.8 with different NH 3 blending ratios; (D) comparisons of the measured NO cencentration and the data from literature ( Ф = 0.9, X NH3 = 0.3, and Ф = 1.0, X NH3 = 0.3) 37 …”

“…The modeling was conducted using the "Premixed Laminar Burner-Stabilized Stagnation Flame" module of the Chemkin package and the chemical mechanisms include GRI 3.0, 34 Tian and Cronstein 35 and Okafor mechanism. 36 37 tendency of NO when the fuel mixture increase was successfully captured by both our developed sensor and the kinetic modeling. For a fixed equivalence ratio of 0.8 and blending ratio of 0.6 at different flow rate of fuel mixtures (6-9 cm/s), the modeling results were in good agreement within measured results within 5%.…”

Ppb-Level Ammonia Sensor for Exhaled Breath Diagnosis Based on UV-DOAS Combined with Spectral Reconstruction Fitting Neural Network

“…Nonetheless, research is still underway to address the problem of high working temperatures and to pursue a lower detection limit. On the other hand, NH 3 sensors based on optical methods mainly include gas sensors based on laser absorption spectroscopy, − gas sensors based on photoacoustic spectroscopy, gas sensors based on quartz tuning fork laser spectroscopy, gas sensors based on Fourier transform infrared spectroscopy (FTIR), and gas sensors based on ultraviolet absorption spectroscopy. − Among them, laser absorption spectroscopy-based sensors have been used for the detection of ultratrace gases due to their advantages of damage-free sample and rapid response time. However, it is challenging to avoid the interference caused by other components in EB and to further improve the measurement accuracy in the exhaled breath environment because the components of EB are complex and the concentration of breath NH 3 reaches the ppb level.…”