Autoignition Chemistry of Gasoline Surrogates Relevant to HCCI Operating Conditions

与 HCCI 操作条件相关的汽油替代物的自燃化学

• 批准号: 0932559
• 负责人: Chih-Jen Sung
• 金额: $ 30万
• 依托单位: University of Connecticut
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-01 至 2013-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0932559&HistoricalAwards=false
• 关键词: Autoignition; Chemistry; Gasoline; Surrogates; Relevant

0932559SungHomogeneous charge compression ignition (HCCI) combustion has received much attention during the past few years as a cost-effective means of increasing the fuel economy of gasoline engines. HCCI engines offer the potential for 10 to 15% improvement in fuel economy and dramatic reductions in NOx emissions as compared to today's conventional SI engines. While the potential benefits of HCCI combustion are great, this combustion mode has several practical development issues that must be solved before it can be implemented. One of the goals of this project is to develop surrogate fuels made from a small number (less than 10) of pure hydrocarbon components that closely mimics the global ignition characteristics of gasoline at conditions representative of HCCI combustion. The use of surrogate fuels is a viable approach to make the development of chemical kinetic mechanisms for practical fuels tractable. This proposed research aims to conduct kinetic investigation of surrogate fuels relevant to HCCI operating conditions and provide benchmark experimental data of high fidelity that will be used to validate the predictive capability of chemical kinetic models.The main focus of this three-year program will be to experimentally determine the ignition characteristics of neat and blended components for gasoline surrogate fuels using a uniquely designed rapid compression machine. Experimental conditions will cover the compressed pressures of 10-50 bar and charge temperatures of 650-1100 K. Based on the measured pressure traces, information about the delay times of the first and second stage ignition, heat release associated with the first stage ignition, and the fuel burning rate can be obtained. The neat fuel components of interest include n-heptane, iso-octane, toluene, 1-pentene, and methylcyclohexane, while experiments will be also conducted using research-grade gasoline. Experimental efforts will first focus on the investigations of each of these five components in neat form over a range of pressures, temperatures, air-to-fuel ratios, and dilution levels. Subsequently, these neat hydrocarbons will be blended into test fuels, including binary, ternary, and higher-order blends, which will be evaluated to determine if the ignition characteristics match that of a fully blended gasoline.With the availability of benchmark experimental data in a well-defined configuration, the fuel kinetics can be systematically studied, which represents an important step towards the development of robust detailed and reduced chemical mechanisms for gasoline surrogate fuels. For comprehensive kinetic modeling, literature experimental data from shock tubes, flow reactors, and flames will also be included and considered. It is recognized that the kinetics of these neat fuels is rather complex and not yet properly understood. Significant advances in terms of the availability of critical experimental data and kinetic understandings are expected from this proposed work.This research program will provide an invaluable experimental database and chemical kinetic models for gasoline surrogate fuels. These results are critical for the development of successful HCCI engines. Enhanced understanding of gasoline surrogate fuels through this research will help in overcoming R&D barriers to the development of HCCI engines by making reliable predictions and explorations through numerical simulations. Estimates show that if HCCI technology can be successfully implemented starting from year 2010, large savings in the US demand for gasoline in the transportation sector are possible. Furthermore, the research conducted will directly contribute to an improvement in the learning experience of undergraduate and graduate students. With active participation in cutting-edge combustion research, talented students can be attracted to retain in science/engineering areas and be well prepared to meet challenges in the field of clean and efficient energy utilization.

均质充量压缩着火(HCCI)燃烧作为提高汽油机燃油经济性的一种经济有效的手段，在过去的几年里受到了广泛的关注。与当今的传统喷气发动机相比，均质压燃发动机的燃油经济性有可能提高10%到15%，NOx排放也会大幅减少。虽然均质压燃燃烧的潜在效益很大，但这种燃烧模式在实施之前必须解决几个实际发展问题。该项目的目标之一是开发由少量(少于10种)纯碳氢化合物组分制成的替代燃料，这种燃料在代表均质压燃燃烧的条件下非常接近汽油的全球点火特性。使用替代燃料是一种可行的方法，可以使开发实用燃料的化学动力学机制变得容易。这项拟议的研究旨在对与HCCI操作条件相关的替代燃料进行动力学研究，并提供高保真的基准实验数据，用于验证化学动力学模型的预测能力。这项为期三年的计划的主要重点将是使用独特设计的快速压缩设备，通过实验确定汽油替代燃料的整齐和混合组分的点火特性。实验条件包括压缩压力为10-50bar，装药温度为650-1100K。根据测量的压力轨迹，可以得到一段点火和二段点火的延迟时间、与一段点火有关的放热以及燃料的燃速。令人感兴趣的纯燃料成分包括正庚烷、异辛烷、甲苯、1-戊烯和甲基环己烷，同时还将使用研究级汽油进行实验。实验工作将首先集中于在不同的压力、温度、空燃比和稀释程度范围内以整齐的形式研究这五种成分。随后，这些整齐的碳氢化合物将被混合到测试燃料中，包括二元、三元和更高阶混合燃料，将进行评估，以确定其点火特性是否与完全混合的汽油匹配。有了明确配置的基准实验数据，燃料动力学可以被系统地研究，这代表着朝着开发健壮、详细和简化的汽油替代燃料的化学机理迈出了重要的一步。对于全面的动力学建模，还将包括和考虑来自激波管、流动反应堆和火焰的文献实验数据。人们认识到，这些清洁燃料的动力学相当复杂，还没有得到适当的理解。这项拟议的工作有望在关键实验数据的可用性和动力学理解方面取得重大进展。该研究计划将为汽油替代燃料提供一个宝贵的实验数据库和化学动力学模型。这些结果对于开发成功的均质压燃发动机是至关重要的。通过这项研究加深了对汽油替代燃料的了解，通过数值模拟做出可靠的预测和探索，将有助于克服研发障碍，促进HCCI发动机的发展。估计表明，如果HCCI技术能够从2010年开始成功实施，美国对运输部门的汽油需求将有可能大幅节省。此外，所进行的研究将直接有助于改善本科生和研究生的学习体验。通过积极参与尖端燃烧研究，可以吸引有才华的学生留在科学/工程领域，并为迎接清洁和高效能源利用领域的挑战做好准备。