Experimental Study of Soot Nanoparticle Formation and Oxidation at Elevated Pressures

高压下烟灰纳米粒子形成和氧化的实验研究

• 批准号: 0651906
• 负责人: Alessandro Gomez
• 金额: $ 35.46万
• 依托单位: Yale University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-09-15 至 2011-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0651906&HistoricalAwards=false
• 关键词: Experimental; Study; Soot; Nanoparticle; Formation

Proposal Number: CBET-0651906 Principal Investigator: Gomez, Alessandro Affiliation: Yale UniversityProposal Title: Experimental Study of Soot Nanoparticle Formation and Oxidation at Elevated Pressures PUBLIC ABSTRACTThis research focuses on the fundamentals of soot nanoparticle formation at elevated pressures, a challenge because many practical systems operate at such conditions but few fundamental data are available there. Emission of soot particles from combustion systems has been a long-standing environmental problem because of the health effects associated with particulate matter and the polycyclic aromatic hydrocarbons adsorbed on their surfaces. Soot formation is also an issue of technical relevance for the potential engineering problems that may ensue; e.g., erosion of turbine blades. Despite considerable progress made in recent years, a fundamental understanding of soot formation in practical systems is still a daunting challenge. The present research examines soot formation of gaseous and liquid fuels in a counterflow burner operated at high pressures, up to 40 atm, that are relevant to practical applications such as gas turbines and engines. Fuels to be studied include ethylene, acetylene, heptane and toluene, a set of gaseous and liquid fuels with significantly different sooting propensities. One of the main difficulties of studying soot formation with these fuels is that they are very prone to soot, a problem that is exacerbated at high pressures. If the soot yield is too abundant, a number of experimental complications ensue that make it difficult to perform fundamental studies. A counterflow diffusion flame was selected as an optimal environment for the research because of the unparalleled level of control that it provides on the soot formation process, the suppression of buoyancy instabilities that typically plague co-flow flames at high pressures, and the opportunity of modeling the system in subsequent studies as one-dimensional. The flame is operated as a reactor in which the soot loading can be ?dialed? at will from the onset of the nucleation stage to significant surface growth and oxidation. As an additional novelty, by experimenting with a high diffusivity diluent such as helium, sufficiently thick flames can be stabilized, despite the high-pressure conditions, to enable the probing of the flame structure with adequate resolution. Particular emphasis is placed on the nanoparticle, early-nucleation stage. Chemical species are characterized that reflect the flame structure and participate in the growth process. Among impacts of the work, the effort is intended to yield a database for general use in validation of detailed computational models. Data sets will be made available on the web to allow convenient access to researchers for subsequent modeling. The research will also spill over into teaching and outreach activities. Soot research at high pressure does not lend itself easily to experimentation by inexperienced hands. However, with the supervision of graduate students and the PI, simple projects, such as on SEM/TEM analysis and data reduction software, will be tackled by undergraduate and upper high-school students.

提案编号：CBET-0651906项目负责人：Gomez， Alessandro合作院校：耶鲁大学提案标题：高压下烟尘纳米颗粒形成和氧化的实验研究公共摘要本研究重点研究高压下烟尘纳米颗粒形成的基本原理，这是一个挑战，因为许多实际系统在这种条件下运行，但很少有基础数据可用。燃烧系统的烟尘颗粒排放一直是一个长期存在的环境问题，因为颗粒物及其表面吸附的多环芳烃对健康有影响。烟尘的形成也是一个与可能随之而来的潜在工程问题相关的技术问题；例如，涡轮叶片的侵蚀。尽管近年来取得了相当大的进展，但对实际系统中烟灰形成的基本理解仍然是一个艰巨的挑战。目前的研究考察了在高达40atm的高压下运行的逆流燃烧器中气体和液体燃料的烟灰形成，这与燃气轮机和发动机等实际应用有关。研究的燃料包括乙烯、乙炔、庚烷和甲苯，这是一组气体和液体燃料，它们的熏烟倾向有显著不同。研究这些燃料形成烟灰的主要困难之一是它们很容易产生烟灰，这个问题在高压下会加剧。如果烟尘产量太大，就会出现一些实验上的复杂问题，使进行基础研究变得困难。选择逆流扩散火焰作为研究的最佳环境，是因为它对烟灰形成过程提供了无与伦比的控制水平，抑制了通常在高压下困扰共流火焰的浮力不稳定性，并且有机会在随后的研究中将系统建模为一维。火焰是作为一个反应器来操作的，其中的烟灰负荷可以被拨通。从随意开始的成核阶段到明显的表面生长和氧化。作为一个额外的创新，通过实验高扩散率的稀释剂，如氦，足够厚的火焰可以稳定，尽管高压条件下，使火焰结构的探测具有足够的分辨率。特别强调的是纳米颗粒，早期成核阶段。化学物质以反映火焰结构和参与生长过程为特征。在这项工作的影响中，努力的目的是产生一个数据库，用于验证详细的计算模型。数据集将在网络上提供，方便研究人员进行后续建模。这项研究还将扩展到教学和推广活动中。高压下的煤烟研究不容易让没有经验的人来做实验。然而，在研究生和项目负责人的指导下，简单的项目，如扫描电镜/透射电镜分析和数据简化软件，将由本科生和高中生完成。