A Study of Methane and Hydrogen Ignition Delay Times in CO2 at High Pressures Near 40 atm

2018 ◽  
Author(s):  
Samuel Barak ◽  
Erik M. Ninnemann ◽  
Sneha Neupane ◽  
Frank Barnes ◽  
Subith Vasu
Keyword(s):  
Ignition Delay ◽  
High Pressures ◽  
Ignition Delay Times ◽  
Delay Times ◽  
Hydrogen Ignition

Ignition Delay Times of Syngas and Methane in sCO2 Diluted Mixtures for Direct-Fired Cycles

2019 ◽  
Author(s):  
Samuel Barak ◽  
Owen Pryor ◽  
Erik Ninnemann ◽  
Sneha Neupane ◽  
Xijia Lu ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Ignition Delay ◽  
High Pressures ◽  
Chemical Kinetic ◽  
Time Data ◽  
Fuel Loading ◽  
Supercritical Regime ◽  
Reflected Shock ◽  
Ignition Delay Times ◽  
Delay Times

Abstract In this study, a shock tube is used to investigate combustion tendencies of several fuel mixtures under high carbon dioxide dilution and high fuel loading. Individual mixtures of oxy-syngas and oxy-methane fuels were added to CO2 bath gas environments and ignition delay time data was recorded. Reflected shock pressures maxed around 100 atm, which is above the critical pressure of carbon dioxide in to the supercritical regime. In total, five mixtures were investigated within a temperature range of 1050–1350K. Ignition delay times of all mixtures were compared with predictions of two leading chemical kinetic computer mechanisms for accuracy. The mixtures included four oxy-syngas and one oxy-methane combinations. The experimental data tended to show good agreement with the predictions of literature models for the methane mixture. For all syngas mixtures though the models performed reasonably well at some conditions, predictions were not able to accurately capture the overall behavior. For this reason, there is a need to further investigate the discrepancies in predictions. Additionally, more data must be collected at high pressures to fully understand the chemical kinetic behavior of these mixtures to enable the supercritical CO2 power cycle development.

scholarly journals The influence of n -butanol blending on the ignition delay times of gasoline and its surrogate at high pressures

Fuel ◽  
2017 ◽  
Vol 187 ◽  
pp. 211-219 ◽  
Author(s):  
Edirin Agbro ◽  
Alison S. Tomlin ◽  
Malcolm Lawes ◽  
Sungwoo Park ◽  
S. Mani Sarathy
Keyword(s):  
Ignition Delay ◽  
High Pressures ◽  
Ignition Delay Times ◽  
Delay Times

Ignition delay times of methane and hydrogen highly diluted in carbon dioxide at high pressures up to 300 atm

2019 ◽  
Vol 37 (4) ◽  
pp. 4555-4562 ◽  
Author(s):  
Jiankun Shao ◽  
Rishav Choudhary ◽  
David F. Davidson ◽  
Ronald K. Hanson ◽  
Samuel Barak ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Ignition Delay ◽  
High Pressures ◽  
Ignition Delay Times ◽  
Delay Times

Ignition Delay Times of Oxy-Syngas and Oxy-Methane in Supercritical CO2 Mixtures for Direct-Fired Cycles

2020 ◽  
Vol 142 (2) ◽  
Author(s):  
Samuel Barak ◽  
Owen Pryor ◽  
Erik Ninnemann ◽  
Sneha Neupane ◽  
Subith Vasu ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Ignition Delay ◽  
Supercritical Co2 ◽  
High Pressures ◽  
High Efficiency ◽  
Predictive Accuracy ◽  
Chemical Kinetic ◽  
Reflected Shock ◽  
Ignition Delay Times ◽  
Delay Times

Abstract The direct-fired supercritical CO2 (sCO2) cycles promise high efficiency and reduced emissions while enabling complete carbon capture. However, there is a severe lack of fundamental combustion kinetics knowledge required for the development and operation of these cycles, which operate at high pressures and with high CO2 dilution. Experiments at these conditions are very challenging and costly. In this study, a shock tube was used to investigate the auto-ignition tendencies of several mixtures under high carbon dioxide dilution and high fuel loading. Individual mixtures of oxy-syngas and oxy-methane fuels were added to CO2 bath gas environments and ignition delay time data were recorded. Reflected shock pressures neared 100 atm, above the critical pressure of carbon dioxide into the supercritical regime. In total, five mixtures were investigated with a pressure range of 70–100 atm and a temperature range of 1050–1350 K. Measured ignition delay times of all mixtures were compared with two leading chemical kinetic mechanisms for their predictive accuracy. The mixtures included four oxy-syngas and one oxy-methane compositions. The literature mechanisms tended to show good agreement with the data for the methane mixture, while these models were not able to accurately capture all behavior for syngas mixtures tested in this study. For this reason, there is a need to further investigate the discrepancies. To the best of our knowledge, we report the first ignition data for the selected mixtures at these conditions. Current work also highlights the need for further work at high pressures to fully understand the chemical kinetic behavior of these mixtures to enable the sCO2 power cycle development.

A Reduced Kinetic Mechanism for Oxy/Methane sCO2 Combustor Simulations

2018 ◽  
Author(s):  
K. R. V. Manikantachari ◽  
Ladislav Vesely ◽  
Scott Martin ◽  
Jose O. Bobren-Diaz ◽  
Subith Vasu
Keyword(s):  
Ignition Delay ◽  
Ignition Delay Time ◽  
High Pressures ◽  
Fluid Dynamic ◽  
Kinetic Mechanism ◽  
Flux Analysis ◽  
Analysis Method ◽  
Stirred Reactor ◽  
Ignition Delay Times ◽  
Delay Times

Reduced mechanisms are needed for use with computational fluid dynamic codes (CFD) utilized in the design of combustors. Typically, the reduced mechanisms are created from the detailed mechanisms which contain numerous species and reactions that are computationally difficult to handle using most CFD codes. Recently, it has been shown that the detailed Aramco 2.0 mechanism well predicted the available experimental data at high pressures and in high-CO2 diluted methane mixtures. Further, a 23-species gas-phase mechanism is derived from the detailed Aramco 2.0 mechanism by path-flux-analysis method (PFA) by using CHEM-RC. It is identified that the reaction CH4+HO2⇔ CH3+H2O2 is very crucial in predicting the ignition delay times under current conditions. Further, it is inferred that species C2H3 and CH3OH are very important in predicting the ignition delay time of lean sCO2 methane mixtures. Also, the 23-species mechanism presented in this work is performing on par with the detailed Aramco 2.0 mechanism in-terms of simulating ignition delay times, perfectly-stirred-reactor estimates under various CO2 dilutions and equivalence ratios, and prediction of turbulence chemistry interactions. It is observed that the choice of equation-of-state has no significant impact on the ignition delay times of supercritical CH4/O2/CO2 mixtures but it influences supercritical H2/O2/CO2 mixtures considered in this work.

Ignition delay times in lean n-hexane–air mixture at high pressures

2004 ◽  
Vol 136 (1-2) ◽  
pp. 257-259 ◽  
Author(s):  
V.P. Zhukov ◽  
V.A. Sechenov ◽  
A.Yu. Starikovskii
Keyword(s):  
Ignition Delay ◽  
High Pressures ◽  
Ignition Delay Times ◽  
Delay Times

Ignition delay times of low alkylfurans at high pressures using a rapid compression machine

2017 ◽  
Vol 36 (1) ◽  
pp. 323-332 ◽  
Author(s):  
Nan Xu ◽  
Yingtao Wu ◽  
Chenglong Tang ◽  
Peng Zhang ◽  
Xin He ◽  
...  
Keyword(s):  
Ignition Delay ◽  
High Pressures ◽  
Rapid Compression Machine ◽  
Ignition Delay Times ◽  
Delay Times ◽  
Rapid Compression
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