EAGER: Investigating Super-Heated Urea for NOx Reduction for Low Temperature Combustion Engine Application

EAGER：研究过热尿素在低温内燃机应用中减少氮氧化物的效果

• 批准号: 1840883
• 负责人: Albert Ratner
• 金额: $ 6万
• 依托单位: University of Iowa
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-09-15 至 2019-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1840883&HistoricalAwards=false
• 关键词: EAGER; Investigating; Super; Heated; Urea

Nitrogen oxide (NOx) is one of the major pollutants from diesel engines and has its own well-documented health and environmental impacts. Serious efforts have been devoted to reducing them through exhaust clean-up and combustion optimization. Interestingly, there are often trade-offs between efficiency and pollution. This project will develop and demonstrate a greatly improved exhaust after-treatment methodology for NOx reduction, particularly for engines operating at low-temperature combustion regimes. The specific focus will be on developing and testing a novel system for low-cost NOx reduction by super-heating the diesel exhaust fluid (DEF) currently used on diesel engines. The project will not only open up new areas of research, but also directly impact engine combustion and energy efficiency.NOx has become an important problem because the increased focus on fuel economy has driven engines to burn less fuel and consequently operate at a lower temperature condition. Such low-temperature operations have led to colder exhaust, with hybrid systems that turn the engine on and off only exacerbating this problem. Additionally, the inability to mitigate high levels of NOx has limited the operational window for diesel engines. This project will investigate non-equilibrium NOx reduction through injection of super-heated urea into an engine exhaust stream. Central to this idea is the steep rise of NOx reduction capacities of commercial diesel exhaust fluid (DEF), urea with water, with rising temperature because of higher chemical reaction rates. The new system uses microwave heating of the urea (to 1200 K) prior to injection to make it much more reactive, with experimentally proven NOx reduction of up to 96% for such temperatures in commercial boilers. Experimental testing will be used to measure the exhaust composition for various urea injection cases while computer modeling will be employed to extract the chemical reaction rates that correspond to experimentally observed behaviors.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.

氮氧化物（NOx）是柴油发动机的主要污染物之一，对健康和环境的影响已得到充分证明。通过废气净化和燃烧优化，已经做出了认真的努力来减少它们。有趣的是，效率和污染之间往往存在权衡。该项目将开发和展示一种大大改进的废气后处理方法，用于减少NOx，特别是用于在低温燃烧状态下运行的发动机。具体的重点将是开发和测试一种新的系统，通过过热柴油发动机上目前使用的柴油机排气处理液（DEF）来降低低成本的NOx。该项目不仅将开辟新的研究领域，还将直接影响发动机的燃烧和能源效率。由于对燃油经济性的日益关注，促使发动机燃烧更少的燃油，从而在更低的温度条件下运行，NOx已成为一个重要问题。这种低温操作导致了更冷的排气，而混合动力系统打开和关闭发动机只会加剧这个问题。此外，无法减轻高水平的NOx限制了柴油发动机的操作窗口。本项目将研究通过向发动机废气流中喷射过热尿素来减少非平衡氮氧化物。这个想法的核心是商业柴油机排气处理液（DEF）的NOx还原能力的急剧上升，尿素与水，随着温度的升高，因为更高的化学反应速率。新系统在注入之前使用微波加热尿素（至1200 K），使其更具反应性，实验证明，在商业锅炉的这种温度下，NOx减少高达96%。实验测试将用于测量各种尿素喷射情况下的排气成分，而计算机建模将用于提取与实验观察到的行为相对应的化学反应速率。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。