Large Eddy Simulation of a laboratory-scale gas-assisted pulverized coal combustion chamber under oxy-fuel atmospheres using tabulated chemistry

Nicolai, Hendrik; Kuenne, G.; Schneider, Henning; Becker, Lukas; Hasse, Christian; Mare, Francesca di; Dreizler, Andreas; Janicka, J.

doi:10.1016/j.fuel.2020.117683

Cited by 25 publications

(11 citation statements)

References 58 publications

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“…To design predictive reactor networks, the entire flow structure of the chamber should be available. Therefore, additional information available from a LES−CFD simulation, 15 validated by the experimental data, is considered for building the network. Figure 3b depicts velocity fields indicated first by the contour color and streamlines and second by the averaged temperature distribution at the center plane extracted from the CFD results.…”

Section: Resultsmentioning

confidence: 99%

“…Both qualitative and quantitative agreements are obtained in regions where experimental data are available. 15 Additionally, local temperature distributions are available from the CFD simulation. This information is essential to determine the respective reactor temperatures inside the network.…”

Section: Resultsmentioning

confidence: 99%

“…To obtain an accurate description of the flow and temperature distribution inside the studied combustion chamber, a LES published in a previous study has been employed. 15 In this study, the three-dimensional (3D) finite volume code FASTEST was used for the LES study. The LES relies on the flamelet assumption to take into account detailed kinetics.…”

Section: Modeling and Numericsmentioning

confidence: 99%

“…Therefore, alternatives, such as flamelet-based models, which allow for the efficient representation of gas-phase detailed kinetics, have recently attracted attention, are already being successfully used for air conditions, 13,14 and have been recently extended for oxy-fuel conditions. 15 Nevertheless, these models also come with two main disadvantages: first, the cost of the typical simulations easily exceeds 1 × 10 6 central processing unit (CPU) hours, making this method unusable for repetitive engineering calculations. Second, while the global characteristics of the combustion process can be well-captured, minor species and pollutants, such as CO, which typically react on slower time scales, are difficult to predict using flamelet models.…”

Section: Introductionmentioning

confidence: 99%

“…However, the exceptionally high cost for solving the stiff system of equations associated with the large chemical mechanisms required to capture the complexity of chemical reactions prohibits the direct use of finite-rate chemistry in large-scale simulations. Therefore, alternatives, such as flamelet-based models, which allow for the efficient representation of gas-phase detailed kinetics, have recently attracted attention, are already being successfully used for air conditions, , and have been recently extended for oxy-fuel conditions . Nevertheless, these models also come with two main disadvantages: first, the cost of the typical simulations easily exceeds 1 × 10 6 central processing unit (CPU) hours, making this method unusable for repetitive engineering calculations.…”

Section: Introductionmentioning

confidence: 99%

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Development and Application of an Efficient Chemical Reactor Network Model for Oxy-fuel Combustion

et al. 2020

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The excessive computational cost of computational fluid dynamics (CFD) simulations of complex reactors is still a barrier to investigations using detailed chemical kinetics. Chemical rector network modeling is a promising tool for affordable numerical investigations of novel combustor technologies, such as oxy-fuel combustion, using directly coupled detailed chemical kinetics. In this work, a novel chemical reactor network solver, NetSMOKE, which is part of the OpenSMOKE++ suite, is presented and discussed. The numerical model employed, together with the relative solution method, is explained, also exploiting a combined sequential-modular and equation-oriented approach for solving the global system of equations. The novel solver was employed to build a chemical reactor network that represents the Technische Universitaẗ Darmstadt oxy-fuel burner using a reduced number of ideal reactors with directly coupled detailed kinetic models for the first time. On the basis of previously available CFD simulations and measurements, the complex flow is accurately characterized and discretized into macrozones, facilitating the development of a simplified reactor network. Carbon monoxide emissions were analyzed in detail, supported by sensitivity analysis with respect to the reactor temperatures. The sensitivity analysis revealed that the post-flame zone is crucial for the overall CO emission. Therefore, on the basis of the sensitivity analysis, an iterative approach for refining the reactor network model is developed. The increase in the number of ideal reactors in targeted areas of the system allows for significant improvements with respect to CO predictions. The chemical reactor network provides good agreement with the experimental data, requiring only a limited increase in the overall computational cost. The presented tool offers a computationally efficient strategy to investigate and predict the behavior of complex reactors, including the emission of pollutants in combustion devices, allowing for the employment of state-of-the-art, detailed chemical kinetic mechanisms available from the literature.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Modeling and Numericsmentioning

confidence: 99%