Jiahao Wang, Marco A.B. Zanoni, Tarek L. Rashwan, José L. Torero, Jason I. Gerhard
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引用次数: 0
Abstract
Applied smoldering has been demonstrated as an efficient waste-to-energy approach for low heating value/high moisture content combustible waste materials. Therefore, smoldering can be used to extract energy from wastes that are not amenable to traditional thermochemical routes (e.g., using flaming-based incinerators). Nevertheless, understanding the process of smoldering-driven drying and its relationship to ignition and quenching within these smoldering systems is critical to determine the viability and economic feasibility of this approach. These interlinked phenomena are not well-understood. To address this knowledge gap, this study developed new analytical methods with a previous validated numerical model to establish a comprehensive framework to better understand ignition and the associated drying process. These new models accurately resolve the coupling between downward water migration, water phase change, and smoldering propagation in space and time, revealing how drying defines ignition. The relationship between residual water saturation () and drying time to enable ignition () was determined analytically to unveil the fundamental relationships between these variables. represents a critical limiting water saturation for smoldering ignition, which was found to be solely dependent on material properties rather than operational conditions (e.g., initial water saturation or packing height). In contrast, , is the critical drying time that enables ignition, which was shown to be significantly influenced by system heat losses and operational parameters. Conditions such as a slender reactor design, insufficient thermal insulation, and low heater power can substantially extend the required drying period – and lead to ignition failure at critical conditions. Furthermore, a four-zone ignition region was established and used to characterize the requirements for smoldering ignition. Overall, this study untangles interlinked phenomena and supports researchers and engineers in better understanding drying and its influence on ignition within applied smoldering systems.
期刊介绍:
The Proceedings of the Combustion Institute contains forefront contributions in fundamentals and applications of combustion science. For more than 50 years, the Combustion Institute has served as the peak international society for dissemination of scientific and technical research in the combustion field. In addition to author submissions, the Proceedings of the Combustion Institute includes the Institute''s prestigious invited strategic and topical reviews that represent indispensable resources for emergent research in the field. All papers are subjected to rigorous peer review.
Research papers and invited topical reviews; Reaction Kinetics; Soot, PAH, and other large molecules; Diagnostics; Laminar Flames; Turbulent Flames; Heterogeneous Combustion; Spray and Droplet Combustion; Detonations, Explosions & Supersonic Combustion; Fire Research; Stationary Combustion Systems; IC Engine and Gas Turbine Combustion; New Technology Concepts
The electronic version of Proceedings of the Combustion Institute contains supplemental material such as reaction mechanisms, illustrating movies, and other data.