New extended eddy dissipation concept model for flameless combustion in furnaces
| Autor: | Xu Huang, Dirk Roekaerts, Erik Salazar-Herran, Koldo Martin-Eskudero, Naiara Romero-Anton, Hesheng Bao |
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| Rok vydání: | 2020 |
| Předmět: |
Work (thermodynamics)
Constant coefficients Materials science 020209 energy General Chemical Engineering General Physics and Astronomy Energy Engineering and Power Technology 02 engineering and technology Computational fluid dynamics Combustion Flameless combustion Reaction rate 020401 chemical engineering 0202 electrical engineering electronic engineering information engineering 0204 chemical engineering NOx business.industry Eddy Dissipation Concept Lab-scale furnace General Chemistry Mechanics Dissipation Flamelet Generation Manifold Damköhler numbers Fuel Technology MILD combustion CFD business |
| Zdroj: | Combustion and Flame, 220 |
| ISSN: | 0010-2180 |
| DOI: | 10.1016/j.combustflame.2020.06.025 |
| Popis: | Flameless combustion, also called MILD combustion (Moderate or Intense Low Oxygen Dilution), is a technology that reduces NOx emissions and improves combustion efficiency. Appropriate turbulence-chemistry interaction models are needed to address this combustion regime via computational modelling. Following a similar analysis to that used in the Extended EDC model (E-EDC), the purpose of the present work is to develop and test a Novel Extended Eddy Dissipation Concept model (NE-EDC) to be better able to predict flameless combustion. In the E-EDC and NE-EDC models, in order to consider the influence of the dilution on the reaction rate and temperature, the coefficients are considered to be space dependent as a function of the local Reynolds and Damköhler numbers. A comparative study of four models is carried out: the E-EDC and NE-EDC models, the EDC model with specific, fixed values of the model coefficients optimized for the current application, and the Flamelet Generated Manifold (FGM) model with pure fuel and air as boundary conditions for flamelet generation. The models are validated using experimental data of the Delft Lab Scale furnace (9 kW) burning Natural Gas (T = 446 K) and preheated air (T = 886 K) injected via separate jets, at an overall equivalence ratio of 0.8. among the considered models, the NE-EDC results show the best agreement with experimental data, with a slight improvement over the E-EDC model and a significant improvement over the EDC model with tuned constant coefficients and the FGM model. |
| Databáze: | OpenAIRE |
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