Laminar Flame Speed and Ignition Delay Time Data for the Kinetic Modeling of Hydrogen and Syngas Fuel Blends

Abstract

Laminar flame speeds and ignition delay times have been measured for hydrogen and various compositions ofH2lCO (syngas) at elevated pressures and elevated temperatures. Two constant-volume cylindrical vessels were used to visualize the spherical growth of the flame through the use of a schlieren optical setup to measure the laminar flame speed of the mixture. Hydrogen experiments were peiformed at initial pressures up to lOatm and initial temperatures up to 443 K. A syngas composition of 50150 by volume was chosen to demonstrate the effect of carbon monoxide on H2-O2 chemical kinetics at standard temperature and pressures up to lOatm. All atmospheric mixtures were diluted with standard air, while all elevated-pressure experiments were diluted with a He:02 ratio of 7:1 to minimize instabilities. The laminar flame speed measurements of hydrogen and syngas are compared to available literature data over a wide range of equivalence ratios, where good agreement can be seen with several data sets. Additionally, an improved chemical kinetics model is shown for all conditions within the current study. The model and the data presented herein agree well, which demonstrates the continual, improved accuracy of the chemical kinetics model. A high-pressure shock tube was used to measure ignition delay times for several baseline compositions of syngas at three pressures across a wide range of temperatures. The compositions of syngas (H2/CO) by volume presented in this study included 80/20, 50150, 40/60, 20/80, and 10/90, all of which are compared to previously published ignition delay times from a hydrogen-oxygen mixture to demonstrate the effect of carbon monoxide addition. Generally, an increase in carbon monoxide increases the ignition delay time, but there does seem to be a pressure dependency. At low temperatures and pressures higher than about 12 atm, the ignition delay times appear to be indistinguishable with an increase in carbon monoxide. However, at high temperatures the relative composition of H2 and CO has a strong influence on ignition delay times. Model agreement is good across the range of the study, particularly at the elevated pressures.

An experimental and modeling study of propene oxidation. Part 2: Ignition delay time and flame speed measurements

“…The design and details of this vessel are explained in depth in Krejci et al [31]. In brief, the vessel has an internal diameter of 32 cm and a length of 28 cm.…”

“…Experimental data were collected using a high-speed camera (Photron Fastcam SA1.1) at 3,000 fps using a Z-type Schlieren setup with a Hg lamp light source [31]. The images were processed using a MATLAB-based edge-detection program.…”

Laminar Flame Characteristics of C1–C5 Primary Alcohol-Isooctane Blends at Elevated Temperature

“…The spark ignition and the chamber confinement are recognized to affect the accuracy of laminar flame speed measurements, therefore a flame radius of 8-22 mm was utilized to do the data processing. The total experimental uncertainty was evaluated according to the theory of Moffat et al [41] which has been widely adopted in previous studies [42][43][44]. It can be described as: …”

Research on Cellular Instabilities of Lean Premixed Syngas Flames under Various Hydrogen Fractions Using a Constant Volume Vessel

“…Figure 2 shows the measured laminar burning velocity of H 2 /CO/air mixtures compared with those of previous studies [42,[47][48][49][50][51][52]; all the data were measured with a spherically propagating flame at P u = 0.1 MPa and all data are in good agreement. This proves the correctness of the data obtained in this investigation.…”