导　　师： 黄震

学科专业： 080703

授予学位： 硕士

作　　者： ;

机构地区： 上海交通大学

摘　　要： 能源和环境是当今世界普遍关注的两大问题。人类的生产和生活不断的消耗地球上的化石能源,汽车工业的发展和汽车保有量的增加,不仅加快了有限能源的消耗,更对全球的环境造成了污染。氢以其来源广泛型、可再生性、清洁性等特点作为汽车发动机燃料具有很多的优势,是具有广阔前景的替代能源之一。因此,系统深入地研究氢和含氢燃料发动机的燃烧和排放特性有重要的意义。 本文论述了氢燃料发动机的混合气形成方式,研究了氢燃料发动机异常燃烧现象和抑制技术,分析了NOx排放的形成机理和影响因素,对国内外相关研究进展和成果进行深入的了解。 建立了适用于氢燃料的发动机台架,试验研究纯氢燃料发动机的燃烧与排放特性。考察点火提前角、过量空气系数对缸压、放热率、峰值压力、燃烧持续期和NOx排放的影响。在氢燃料发动机研究的基础上,进一步试验研究不同比例天然气掺氢的燃烧和排放特性。 试验结果表明:纯氢燃料燃烧快,燃烧持续期短,缸压和放热率升高率大且峰值较高。λ=1.1时,峰值压力为4.3MPa,燃烧持续期为12°CA。氢燃料的稀燃界限宽,过量空气系数λ=3时,峰值压力降低到1.7MPa,NOx排放趋于零。天然气掺氢可以改善天然气燃烧特性,拓展天然气的稀燃极限。在相同工况下,掺氢30/%的混合气燃烧持续期比天然气缩短20°CA,但峰值压力和NOx排放增加,可以通过稀燃和优化点火提前角来降低峰值压力和NOx排放。掺氢30/%的混合气可以在λ=1.857时稳定的工作,此时峰值压力降低到1.57MPa,NOx的排放小于50ppm。 Energy and Environment are two major issues in the world. Production and human life continually consume fossil fuels on the earth. With the development of automobile industry and vehicle population, pollution and shortage of energy are aggravated. Hydrogen is a promising substitute for fossil fuels because it has many advantages, such as multiple sources, renewable, clean, and so on. Therefore, studies on engine performance and emissions fueled with hydrogen are of great significance on the development of hydrogen engine. The thesis discussed different hydrogen-fuel engine mixture formations, abnormal combustion phenomena and suppression techniques, analyzed NOx formation mechanism and influencing factors. Relevant researches were also studied in this paper. Testing apparatus which was suitable for hydrogen fuel was set up. Performance and emissions of hydrogen engine were investigated. Based on experimental study of hydrogen engine above, effects of addition of hydrogen to natural gas on engine performance and emissions were investigated. Results show that for pure hydrogen fuel, combustion duration is short and cylinder pressure and heat release rate increase sharply due to fast flame propagation velocity of hydrogen. Peak values of cylinder pressure and heat release rate are high. Atλ=1.1, peak pressure is 4.3MPa, and combustion duration is 12°CA. Hydrogen engine has wide lean burn limit. Atλ=3, peak pressure is reduced to 1.7MPa and NOx concentration is approximately zero. Addition of hydrogen to natural gas is an effect way to enhance combustion of natural gas. At the same conditions, combustion duration of natural gas blended with 30/%vol hydrogen is 20°CA less than that of natural gas. Peak pressure and NOx concentration increase as addition of hydrogen to natural gas, but it can be reduced by lean burn and optimizing ignition timing. Natural gas blended with 30/%vol hydrogen can work stably atλ=1.857. Peak pressure is reduced to 1.57MPa and NOx concentration is less than 50ppm due to exte

关 键 词： 氢燃料发动机 天然气掺氢 点火提前角 过量空气系数 稀燃 燃烧 排放

领　　域： [动力工程及工程热物理]