Cool Pool Diffusion Flames

酷池扩散火焰

• 批准号: 2243560
• 负责人: Peter Sunderland
• 金额: $ 36万
• 依托单位: University of Maryland, College Park
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-06-15 至 2026-05-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2243560&HistoricalAwards=false
• 关键词: Cool; Pool; Diffusion; Flames

Most of the engines that power land, air, and sea transportation have low thermal efficiencies and consume nonrenewable fuels. A newly discovered class of flames, called cool diffusion flames, could contribute to dramatic increases in these efficiencies – from upper thirties to sixty per cent – and accelerate the adoption of renewable fuels. These flames could also improve the understanding of wildland fire spread and smoldering mechanisms. Cool diffusion flames were discovered in 2012 aboard the International Space Station. They have unusually low temperatures between 500 – 1000 K, compared to 2000 K for traditional flames. Their discovery has already resulted in an improved understanding of ignition, but further progress has been impeded by the high cost and complexity of the experimental facilities required. This project will reduce this cost by developing a novel facility that burns fuel pools in cool flame mode. It will also improve the understanding of cool diffusion flames by performing detailed measurements and comparing them with computational simulations.The first objective of this project is to develop new ways to observe cool diffusion flames above pools of liquid fuels bounded above by a heated ceiling. This will enable any laboratory to build such a facility inexpensively. Many liquid fuels will be considered, including pure hydrocarbons, traditional transportation fuels, and renewable bio-derived fuels. It is unknown which of these fuels can burn in air as cool diffusion flames, and at what temperatures and mixture fractions. It is also unknown whether they may support slightly hotter flames, called warm diffusion flames, and whether they can exist without an external heat source. The second objective will be to characterize the flame details, namely, the flame temperatures, compositions, burning rates, and emissions. The third objective will be to perform autoignition simulations with Cantera software using various chemical kinetics models and to compare the predictions with the measurements. These simulations will fill gaps in the measurements and help evaluate and develop models of cool flame chemistry. The broader impacts of this project include improving engine efficiency, increasing the use of renewable fuels, and involving graduate students and undergraduates from diverse backgrounds.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

为陆地、空中和海上运输提供动力的大多数发动机热效率较低，而且消耗的是不可再生燃料。一种新发现的火焰，称为冷扩散火焰，可能有助于大幅提高这些效率--从30%以上提高到60%--并加快可再生燃料的采用。这些火焰还可以提高对荒地火灾传播和阴燃机理的理解。2012年，国际空间站上发现了冷扩散火焰。它们的温度在500-1000K之间，与传统火焰的2000K相比，它们的温度非常低。他们的发现已经改善了人们对点火的理解，但由于所需实验设备的高昂成本和复杂性，进一步的进展受到了阻碍。该项目将通过开发一种在冷火焰模式下燃烧燃料池的新型设施来降低这一成本。它还将通过进行详细的测量并将其与计算模拟进行比较来提高对冷扩散火焰的理解。该项目的第一个目标是开发新的方法来观察被加热天花板包围的液体燃料池上方的冷扩散火焰。这将使任何实验室都能以低廉的成本建造这样的设施。许多液体燃料将被考虑，包括纯烃、传统运输燃料和可再生生物衍生燃料。目前尚不清楚这些燃料中的哪些可以在空气中以冷扩散火焰的形式燃烧，以及在什么温度和混合分数下燃烧。也不知道它们是否会支持稍微热一些的火焰，也就是所谓的热扩散火焰，以及它们是否可以在没有外部热源的情况下存在。第二个目标是描述火焰的细节，即火焰温度、成分、燃烧速率和排放。第三个目标是用Cantera软件使用各种化学动力学模型进行自燃模拟，并将预测与测量结果进行比较。这些模拟将填补测量方面的空白，并有助于评估和开发冷火焰化学模型。该项目的更广泛的影响包括提高发动机效率，增加可再生燃料的使用，以及涉及来自不同背景的研究生和本科生。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。