scholarly journals Planar Laser-Induced Fluorescence and Chemiluminescence Analyses of CO2-Argon-Steam Oxyfuel (CARSOXY) Combustion

Energies ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 263
Author(s):  
Odi Fawwaz Alrebei ◽  
Abdulkarem I. Amhamed ◽  
Syed Mashruk ◽  
Phil Bowen ◽  
Agustin Valera Medina

Strict regulations and acts have been imposed to limit NOx and carbon emissions. The power generation industry has resorted to innovative techniques to overcome such a low level of tolerance. Amongst those in the literature, CO2-argon-steam oxyfuel (CARSOXY) gas turbines have theoretically been proven to offer an economically sustainable solution while retaining high efficiency. Although theoretical studies have characterized CARSOXY, no experimental evidence has been provided in the literature. Therefore, this paper attempts to experimentally assess CARSOXY in comparison to a CH4/air flame. OH* chemiluminescence integrated with OH Planar Laser-Induced Fluorescence (PLIF) imaging has been utilized to study flame stability and flame geometry (i.e., the area of highest heat intensity (AOH¯Max center of highest heat intensity (COH¯Max)) over a range of working fluid Reynolds’ numbers and oxidizing equivalence ratios. In addition, the standard deviation of heat release fluctuations (σOH*/OH¯) has been utilized as the base-criteria to compare the stability performance of CARSOXY to CH4/air combustion. Moreover, turbulence-chemistry interactions have been described using Damköhler numbers and by plotting Borghi regime diagrams. This paper suggests a modified numerical approach to estimate Damköhler numbers and plot regime diagrams for non-premixed combustion by utilizing the Buckingham π theorem based on experimental observations and results. CARSOXY flames showed lower flame intensity than that of the CH4/air flame throughout the entire Re interval by approximately 16%, indicating higher heat release. The Damköhler numbers of the CARSOXY flame were also greater than those of the CH4/air flame in all conditions, indicating more uniform CARSOXY flames. It was found that the tendency of the CARSOXY flame of approaching the concentrated reaction zone is greater than that of the CH4/air flame.

2018 ◽  
Vol 10 (3) ◽  
pp. 185-210 ◽  
Author(s):  
Ruoyang Yuan ◽  
James Kariuki ◽  
Epaminondas Mastorakos

Various characteristics of swirling spray flames of ethanol, n-heptane, n-decane, and n-dodecane have been measured at conditions far from and close to blow-off using phase Doppler anemometry and OH* chemiluminescence, OH-planar laser-induced fluorescence, and Mie scattering at 5 kHz. The blow-off transient has also been examined. The OH* showed that the two main heat release regions lie around the spray jet at the inner recirculation zone and along the outer shear layer between the inner recirculation zone and the annular air jet. The heat release region is shortened and more attached as the flame approached blow-off. Mie images and phase Doppler anemometry data showed a wider dispersion of the ethanol spray compared to the other fuels. Similar spatial distributions of the Sauter mean diameter were observed for the four fuels for identical flow conditions, with the Sauter mean diameter value increasing with decreasing fuel volatility, but with the exception of significant presence of droplets in the nominally hollow cone for the ethanol spray. The OH-planar laser-induced fluorescence measurements showed an intermittent lift-off from the corner of the bluff body and the average lift-off height decreased with increasing air velocity, with less extinction along the inner flame branch especially for the heavier fuels. At the blow-off conditions, local extinctions appeared at both flame branches. The blow-off process followed a gradual reduction of the size of the flame, with the less volatile fuels showing a more severe flame area reduction compared to the condition far from blow-off. The average blow-off duration, [Formula: see text], calculated from the evolution of the area-integrated OH* signal, was a few tens of milliseconds and for all conditions investigated the ratio [Formula: see text] /( D/ UB) was around 11, but with large scatter. The measurements provide useful information for validation of combustion models focusing on local and global extinction.


2018 ◽  
Vol 26 (14) ◽  
pp. 18105 ◽  
Author(s):  
Ulrich Retzer ◽  
Rongchao Pan ◽  
Thomas Werblinski ◽  
Franz J. T. Huber ◽  
Mikhail N. Slipchenko ◽  
...  

2000 ◽  
Author(s):  
T. Muruganandam ◽  
Srihari Lakshmi ◽  
A. Ramesh ◽  
S. Viswamurthy ◽  
R. Sujith ◽  
...  

Sensors ◽  
2021 ◽  
Vol 21 (8) ◽  
pp. 2607
Author(s):  
Siying Chen ◽  
Yuanyuan Chen ◽  
Yinchao Zhang ◽  
Pan Guo ◽  
He Chen ◽  
...  

Although it is quite challenging to image and analyze the spatial distribution of bioaerosols in a confined space, a three-dimensional (3D) modeling system based on the planar laser-induced fluorescence (PLIF) technique is proposed in this paper, which is designed to analyze the temporal and spatial variations of bioaerosol particles in a confined chamber. The system employs a continuous planar laser source to excite the fluoresce, and a scientific complementary metal oxide semiconductor (sCMOS) camera to capture images of 2048 × 2048 pixels at a frame rate of 12 Hz. While a sliding platform is moving back and forth on the track, a set of images are captured at different positions for 3D reconstruction. In this system, the 3D reconstruction is limited to a maximum measurement volume of about 50 cm × 29.7 cm × 42 cm, with a spatial resolution of about 0.58 mm × 0.82 mm × 8.33 mm, and a temporal resolution of 5 s. Experiments were carried out to detect the PLIF signals from fluorescein aerosols in the chamber, and then 3D reconstruction was used to visualize and analyze the diffusion of aerosol particles. The results prove that the system can be applied to clearly reconstruct the 3D distribution and record the diffusion process of aerosol particles in a confined space.


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