Three-Dimensional Combustion Modeling in Municipal Solid-Waste Incinerator
| Autor: | Kang-Shin Chen, J. C. Lou, Y. J. Tsai |
|---|---|
| Rok vydání: | 1999 |
| Předmět: |
Engineering
Environmental Engineering Waste management Turbulence business.industry Nuclear engineering Mixing (process engineering) Combustion Methane Incineration Reaction rate chemistry.chemical_compound chemistry Environmental Chemistry Combustion chamber business General Environmental Science Civil and Structural Engineering Waste disposal |
| Zdroj: | Journal of Environmental Engineering. 125:166-174 |
| ISSN: | 1943-7870 0733-9372 |
| DOI: | 10.1061/(asce)0733-9372(1999)125:2(166) |
| Popis: | The impetus from public concerns and stringent emission standards requires optimization of the design and operation of incinerators. Consequently, if the burning process within the combustion chamber can be well characterized and modeled, then performance improvements and cost savings of new and existing systems can be realized. Three-dimensional flame structures and mixing behaviors of turbulent burning flows in a municipal solid-waste incinerator are investigated by finite-element simulation. The modified {kappa}-{var_epsilon} turbulence model together with wall functions was adopted. Devolatilization of solid wastes was simulated by gaseous methane (CH{sub 4}) nonuniformly distributed along the inclined grate. The combustion process was considered as two-step stoichiometric reactions when primary underfire air entered and mixed with methane gas in the first combustion chamber. The mixing-controlled eddy-dissipation model was employed for predicting the reaction rates of CH{sub 4}, O{sub 2}, CO{sub 2}, and CO. Results show that the grate is covered by cone-shaped flames that are bent and aligned with the flow directions. Additional mixing in the second combustion chamber can enhance the oxidation and can be improved by provision of more excess air or by the injection of secondary overfire air. Combustion efficiency up to 99.97% and an exit temperature around 1,100--1,300 K canmore » be achieved at 100--150% excess air. Reasonable agreements are achieved between numerical predictions and available in-situ measurements.« less |
| Databáze: | OpenAIRE |
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