Sensitivity analysis and chemical reaction mechanism simplification of blast furnace gas in gas turbine combustor environment

2017 ◽  
Vol 31 (4) ◽  
pp. 2005-2014 ◽  
Author(s):  
Zhao Yang ◽  
Xiangsheng Li ◽  
Zhenping Feng ◽  
Lian Lu
Author(s):  
Le Cao ◽  
Eva Gutheil

In polar spring, tropospheric ozone depletion is related to the presence of halogen oxide concentrations in the atmospheric boundary layer. Halogen oxides such as BrO participate in an autocatalytic chemical reaction cycle, leading to the release of Br2 and BrCl from the fresh sea ice. The paper presents the identification of a detailed chemical reaction mechanism for the ozone depletion event, where bromine plays the major role. The heterogeneous reactions in the chemical reaction mechanism are studied in detail, and a sensitivity analysis is performed to identify the importance of each reaction in the mechanism. A skeletal reaction scheme is identified on the basis of the sensitivity analysis,. This skeletal chemical reaction mechanism then is used in a 3-D large eddy simulation (LES) with the Smagorinsky sub-grid model. The configuration studied includes a mountain located at the ground above which the ozone depletion is studied. In this situation, the height of the boundary layer varies, which greatly affects the ozone depletion event.


2011 ◽  
Vol 268-270 ◽  
pp. 172-177
Author(s):  
Hui Liu ◽  
Wen Zhong Chen ◽  
Ben Wen Li

Simplification of the detail reaction mechanism is critical to the numerical simulation of BFG (Blast Furnace Gas) combustion. The software CHEMKIN was used for solving a one-dimensional mathematical model of steady-state premixing combustion. By analyzing the effects of BFG’s basic species on the burning rate, the simplified reaction mechanism was obtained. Compared the results of simplified mechanism with that of detail mechanism, the consumed time of the former was less than 1 second but that of the latter was about 18 seconds. The differences between the molar fractions of BFG species which were computed by the two mechanisms were less than 0.4%. Therefore the reliability of the simplified reaction mechanism is verified.


Fluids ◽  
2020 ◽  
Vol 5 (3) ◽  
pp. 126 ◽  
Author(s):  
Kai Zhang ◽  
Ali Ghobadian ◽  
Jamshid M. Nouri

The scale-resolving simulation of a practical gas turbine combustor is performed using a partially premixed finite-rate chemistry combustion model. The combustion model assumes finite-rate chemistry by limiting the chemical reaction rate with flame speed. A comparison of the numerical results with the experimental temperature and species mole fraction clearly showed the superiority of the shear stress transport, K-omega, scale adaptive turbulence model (SSTKWSAS). The model outperforms large eddy simulation (LES) in the primary region of the combustor, probably for two reasons. First, the lower amount of mesh employed in the simulation for the industrial-size combustor does not fit the LES’s explicit mesh size dependency requirement, while it is sufficient for the SSTKWSAS simulation. Second, coupling the finite-rate chemistry method with the SSTKWSAS model provides a more reasonable rate of chemical reaction than that predicted by the fast chemistry method used in LES simulation. Other than comparing with the LES data available in the literature, the SSTKWSAS-predicted result is also compared comprehensively with that obtained from the model based on the unsteady Reynolds-averaged Navier–Stokes (URANS) simulation approach. The superiority of the SSTKWSAS model in resolving large eddies is highlighted. Overall, the present study emphasizes the effectiveness and efficiency of coupling a partially premixed combustion model with a scale-resolving simulation method in predicting a swirl-stabilized, multi-jets turbulent flame in a practical, complex gas turbine combustor configuration.


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