Reaction Mechanism Reduction for Ozone-Enhanced CH4/Air Combustion by a Combination of Directed Relation Graph with Error Propagation, Sensitivity Analysis and Quasi-Steady State Assumption

Abstract

In this study, an 18-steps, 22-species reduced global mechanism for ozone-enhanced CH 4 /air combustion processes was derived by coupling GRI-Mech 3.0 and a sub-mechanism for ozone decomposition. Three methods, namely, direct relation graphics with error propagation, (DRGRP), sensitivity analysis (SA), and quasi-steady-state assumption (QSSA), were used to downsize the detailed mechanism to the global mechanism. The verification of the accuracy of the skeletal mechanism in predicting the laminar flame speeds and distribution of the critical components showed that that the major species and the laminar flame speeds are well predicted by the skeletal mechanism. However, the pollutant NO was predicated inaccurately due to the precursors for generating NO were removed as redundant components. The laminar flame speeds calculated by the global mechanism fit the experimental data well. The comparisons of simulated results between the detailed mechanism and global mechanism were investigated and showed that the global mechanism could accurately predict the major and intermediate species and significantly reduced the time cost by 72%.

Gas‐phase kinetic of boron carbide chemical vapor deposition using BCl3+CH4+H2 mixture

“…The sensitivity coefficients, λ i,j , are used to identify the reactions that significantly impact the production of desired species. It can be estimated using Equation ( 8) 29 :…”

“…The sensitivity coefficients, λ i,j , are used to identify the reactions that significantly impact the production of desired species. It can be estimated using Equation () 29 : $$\begin{equation}{\lambda _{ij}} = \frac{{\ln {C_j}}}{{\ln {r_i}}} = \frac{{\partial {C_j}}}{{\partial {r_i}}}\frac{{{r_i}}}{{{C_j}}}\end{equation}$$ C j is the concentration of species, j and r i are the reaction rate of i th reaction. Reactions with a significant value of λ ij are likely to produce highly reactive radicals and enhance the overall reactivity and vice versa.…”

Usage of Converter Gas as a Substitute Fuel for a Tunnel Furnace in Steelworks

“…Finally, they validated this mechanism by several experiments and found that the developed skeletal mechanism could reproduce the results from the detailed mechanism. The DRGASA method was also confirmed as a successful tool for mechanism reduction by Liu et al [ 29 ]. Skeletal mechanisms developed using the reduction method should only be used for those applications and boundary conditions for which they were created, as discussed by Liu et al [ 29 ] and Zhao et al [ 30 ].…”

“…The DRGASA method was also confirmed as a successful tool for mechanism reduction by Liu et al [ 29 ]. Skeletal mechanisms developed using the reduction method should only be used for those applications and boundary conditions for which they were created, as discussed by Liu et al [ 29 ] and Zhao et al [ 30 ]. However, it often happens that a skeletal mechanism developed on the basis of simple applications can be used for more complex simulations and still has satisfactory accuracy.…”