Impact of Hydrogen and Carbon Monoxide on Lean Premixed Hydrocarbon Flames

氢气和一氧化碳对贫预混烃火焰的影响

• 批准号: 0074428
• 负责人: Gregory Jackson
• 金额: $ 28.07万
• 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: 2000
• 资助国家: 美国
• 起止时间: 2000-09-01 至 2004-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0074428&HistoricalAwards=false
• 关键词: Impact; Hydrogen; Carbon; Monoxide; Lean

The objectives of this study are (1) to characterize experimentally stretched, lean, premixed flames under laminar and mildly turbulent conditions using particle thermometry and laser-induced fluorescence; (2) to assess enhancement of flame stability and lean-burning limits in premixed hydrocarbon (methane or propane) flames by addition of hydrogen or hydrogen/carbon monoxide mixtures; (3) to develop and validate reduced mechanisms to predict flame behavior (including extinction) of methane/ hydrogen/ carbon monoxide fuel mixtures; and (4) to develop analytical understanding of how multicomponent fuels with different Lewis numbers impact flame stability. The experimental studies and subsequent validation of numerical models rely detailed characterization of counterflow, opposed-jet, premixed flames. Independent variation of the hydrogen and carbon-monoxide concentrations in the fuel feed offer a new mean of exploring and influencing the chemical pathways in lean, premixed hydrocarbon combustion, in particular near extinction. To measure extinction conditions in the counterflow flames, flow fields are probed with laser Doppler velocimetry and temperature fields are measured by observing emissions from micron-size particles with a sensitive infrared camera. Laser-induced fluorescence (LIF) along the flame centerline probes flame structure through measurements of hydroxyl and formaldehyde fluorescence signals. Previous studies have shown that small amounts of hydrogen in the fuel stream can substantially extend the stability limits of stretched, premixed flames, suggesting that this may be a way to enhance the operability of lean, premixed, dry, low-NOx combustion systems. Such systems are used for space heating, power generation, and other industrial applications. This concept is further explored in this study.

这项研究的目标是（1）表征在层流下进行实验拉伸，瘦弱的预混合火焰，并使用颗粒温度计和激光诱导的荧光来表征轻度湍流的条件； （2）通过添加氢或氢/碳一氧化碳的混合物来评估预混合碳氢化合物（甲烷或丙烷）火焰中的火焰稳定性和瘦燃烧极限的增强； （3）开发和验证减少的机制，以预测甲烷/氢/一氧化碳燃料混合物的火焰行为（包括灭绝）； （4）对多组分燃料的分析理解具有不同的路易数量影响火焰稳定性。 实验研究和随后的数值模型验证依赖于反流，相反的，预混合的火焰的详细表征。 燃料饲料中氢和碳氧化氧化物浓度的独立变化为探索和影响化学途径的新均值提供了瘦的，预混合的碳氢化合物燃烧，尤其是接近灭绝。 为了测量逆流火焰中的灭绝条件，通过激光多普勒速度测定仪探测流场和温度场，通过观察来自微米大小的粒子的排放量，用敏感的红外摄像头来测量。 激光诱导的荧光（LIF）沿火焰中心线探针通过测量羟基和甲醛荧光信号来探测火焰结构。 先前的研究表明，燃油流中的少量氢可以大大扩展伸展的，预混合的火焰的稳定性极限，这表明这可能是增强瘦，预混合，干燥，低诺克斯燃烧系统的可操作性的一种方法。 此类系统用于供暖，发电和其他工业应用。 这项研究进一步探讨了这个概念。