Modelling NOx Reduction by Selective Catalytic Reduction (SCR) appropriate for Light-Duty Vehicles under Steady State and Transient Conditions

通过适用于稳态和瞬态条件下轻型车辆的选择性催化还原 (SCR) 进行 NOx 还原建模

• 批准号: EP/F036175/1
• 负责人: S Benjamin
• 金额: $ 41.27万
• 依托单位: Coventry University
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2008
• 资助国家: 英国
• 起止时间: 2008 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FF036175%2F1
• 关键词: Modelling; NOx; Reduction; Selective; Catalytic

Diesel engines offer the prospect of reducing emissions of carbon dioxide as they are inherently more thermodynamically efficient than petrol engines. However diesels produce higher emissions of nitrogen oxides (NOX) and particulates. Whilst technologies to deal with the latter are well advanced (particulate traps) the reduction of NOx emissions is more challenging. Whilst improvements in combustion and/or alternative fuels can lead to lower NOx emissions it is widely accepted that in order to meet EuroV and VI emission targets some form of after-treatment will be requiredCurrently there are two major after-treatment technologies under consideration: NOx traps and Selective Catalytic Reduction (SCR). SCR in the automotive context involves the catalytic reduction of NOx with urea/ammonia (NH3). A solution of urea (Adblue) is injected into the exhaust system where it is decomposed in NH3 which selectively reduces NOx over a catalyst. SCR was first commercialised on a heavy-duty diesel truck as recently as 2004 by Nissan. Studies have shown that SCR can achieve 90 % NOX conversion. In Europe, a number of heavy-duty vehicle manufacturers have chosen urea-SCR for meeting Euro IV and V standards and since 2003 the infrastructure for urea outlets within Europe has been steadily developing. Hence SCR could be used on light duty vehicles and passenger cars without major investments in the urea distribution system. The application to light-duty vehicles and passenger cars presents additional challenges. Their operational characteristics are quite different from heavy duty vehicles as they typically operate at high speed and low load with lower exhaust temperatures. Further, light duty vehicle homologation requires emissions compliance over drive cycles featuring significant transients. Urea injectors will be quite different operating with much lower flow rates. Amongst a number of important issues to be addressed will be the urea dosing strategy, the positioning of the injector and the type of the catalyst. Currently almost all prototype development work is conducted on engine test stands and chassis dynamometers. A mathematical model of an SCR system would facilitate the design of these light duty systems. It would allow design engineers to vary operating parameters and system design features prior to prototype testing. This would potentially save development time and costs whilst also providing systems with reduced emissions and better fuel economy. The development and validation of a light-duty SCR mathematical model is the main objective of this research proposal.

柴油发动机提供了减少二氧化碳排放的前景，因为它们本质上比汽油发动机更有效率。然而，柴油机产生更高的氮氧化物（NOX）和颗粒物排放。虽然处理后者的技术很先进（颗粒捕集器），但减少NOx排放更具挑战性。虽然燃烧和/或替代燃料的改进可以降低NOx排放，但人们普遍认为，为了满足欧V和VI排放目标，将需要某种形式的后处理。目前，正在考虑两种主要的后处理技术：NOx捕集器和选择性催化还原（SCR）。汽车领域中的SCR涉及用尿素/氨（NH3）催化还原NOx。尿素溶液（Adblue）被喷射到排气系统中，在排气系统中尿素被分解成NH3，NH3通过催化剂选择性地还原NOx。SCR最早于2004年由日产在重型柴油卡车上商业化。研究表明，SCR可以实现90%的NOx转化率。在欧洲，许多重型汽车制造商选择了尿素SCR以满足欧IV和欧V标准，自2003年以来，欧洲尿素出口的基础设施一直在稳步发展。因此，SCR可用于轻型车辆和乘用汽车，而无需对尿素分配系统进行重大投资。应用于轻型车辆和乘用汽车提出了额外的挑战。它们的操作特性与重型车辆完全不同，因为它们通常在高速和低负荷下运行，排气温度较低。此外，轻型车辆认证要求在具有显著瞬变的驱动循环上符合排放。尿素喷射器在低得多的流速下操作将是非常不同的。其中要解决的重要问题将是尿素定量策略，喷射器的定位和催化剂的类型。目前，几乎所有的原型开发工作都是在发动机试验台和底盘测功机上进行的。SCR系统的数学模型将有助于这些轻型系统的设计。它将允许设计工程师在原型测试之前改变操作参数和系统设计特征。这将潜在地节省开发时间和成本，同时还提供具有减少的排放和更好的燃料经济性的系统。开发和验证的轻型SCR的数学模型是本研究建议的主要目标。

项目成果

Report S5 Modelling SCR for light duty vehicles under steady & transient conditions

报告 S5 稳定状态下轻型车辆 SCR 建模

• 作者: S Benjamin (Author)

Tuning the Standard SCR Reaction Kinetics to Model NO Conversion in a Diesel Engine Exhaust SCR Catalyst System Under Steady State Conditions in 1D and 3D Geometries Using Ammonia Gas as the Reductant

使用氨气作为还原剂，在 1D 和 3D 几何形状的稳态条件下，调整标准 SCR 反应动力学来模拟柴油发动机排气 SCR 催化剂系统中的 NO 转化

• DOI: 10.4271/2012-01-1636
• 发表时间: 2012
• 作者: Benjamin S

Report S4 Modelling SCR for light duty vehicles under steady & transient conditions

报告 S4 稳定状态下轻型车辆 SCR 建模

• 作者: S Benjamin (Author)

Report S1 Modelling SCR for light duty vehicles under steady & transient conditions

报告 S1 稳定状态下轻型车辆 SCR 建模

• 作者: S Benjamin (Author)

Modelling of NOx Conversion in a 1D Diesel Engine Exhaust SCR Catalyst System under Transient Conditions Using Ammonia Gas as the Reductant

使用氨气作为还原剂的瞬态条件下一维柴油机排气 SCR 催化剂系统中 NOx 转化的建模

• DOI: 10.4271/2012-01-1743
• 发表时间: 2012
• 作者: Benjamin S