Packed bed combustion of biomass/liquid mixture combustion

该提案包括两个独立的主题，都侧重于固体和液体生物燃料的燃烧。生物质燃料的填充床燃烧：木材和其他固体生物质燃料作为“碳中性”能源正变得越来越有吸引力。填充床-相对较大的燃料块在炉排上，空气从下面进入-是最常见的燃烧或气化这些燃料的方法，但由于其复杂性，它比大多数其他燃烧过程更不为人所知。该提案继续开发木材和其他生物质燃料的炉排燃烧的计算模型，并通过实验对这些模型进行测试，其总体目标是为设计和操作提供数值工具。所开发的模型和知识将支持利用木材废料和其他固体生物质作为能源；它们也将与密切相关的垃圾焚烧过程高度相关。液体混合燃烧：目前有多种液体生物燃料可供使用或正在开发中，包括酒精、生物柴油和由木材、农业废物和其他原料制成的生物质热解油（“生物油”）。使用这些燃料的燃烧器和发动机的设计和操作需要详细的液滴和喷雾蒸发和燃烧行为的计算模型。然而，大多数液体生物燃料是复杂的混合物，含有数百种不同的成分，太多了，无法在计算机模拟中单独建模。该项目继续研究“连续热力学”技术，通过概率密度函数而不是单个物种来表示复杂的混合物，这使得液滴燃烧模型可以模拟燃料的化学成分和蒸馏行为，而无需过多的计算。该提案将该技术应用于木材热解油和其他生物质基替代液体燃料。

This proposal comprises two separate themes, both focussed on combustion of solid and liquid bio-fuels.1. Packed Bed Combustion of Biomass Fuels: Wood and other solid biomass fuels are becoming increasingly attractive as "carbon neutral" energy resources. The packed bed - relatively large pieces of fuel on a grate, with air admission from below - is the most common means of burning or gasifying these fuels, but because of its complexity it is less well understood than most other combustion processes. This proposal continues the development of computational models for the grate combustion of wood and other biomass fuels and the testing of these models by experiments, with the overall objective of providing numerical tools for design and operation. The models and knowledge developed will support the use of wood wastes and other solid biomass as energy resources; they will also be highly relevant to the closely related process of trash incineration.2. Liquid Mixture Combustion: A wide range of liquid biofuels is currently available or under development, including alcohols, biodiesel, and biomass pyrolysis oil ("bio-oil") made from wood, agricultural wastes, and other feedstocks. Design and operation of combustors and engines using these fuels requires detailed computational models of their evaporation and combustion behaviour as droplets and sprays. However, most liquid bio-fuels are complex mixtures with hundreds of different components, far too many to model individually in computer simulations. This project continues work on the "continuous thermodynamics" technique of representing complex mixtures by probability density functions instead of individual species, which allows models for liquid droplet combustion to simulate the chemical composition and distillation behaviour of fuels without excessive computation. The proposal applies this technique to wood pyrolysis oils and other biomass-based alternative liquid fuels.