A Low-NOx High-Efficiency Engine System for Alternative Fuels by Mean of Ultra-Lean Homogeneous-Charge Premixed Combustion

采用超稀薄均质预混燃烧的低氮氧化物高效替代燃料发动机系统

基本信息

批准号：
07555071
负责人：
IKEGAMI Makoto
金额：
$ 9.66万
依托单位：
KYOTO UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (A)
财政年份：
1995
资助国家：
日本
起止时间：
1995 至 1996
项目状态：
已结题

项目摘要

This study aims at the establishment of the high-efficiency low-NOx engine for alternative fuels at lean homogeneous-charge combustion. The contents of the present study are summarized as follows :1.Lean limits of homogeneous premixture were investigated in a spark-ignition engine fueled by naturalgas and LPG,and the factors for determining the limit and the method for extending it were shown.2.Experiments for a variety of engine types and sizes at lean-burning operations show that a homogeneous mixture allows much more reduction of the exhaust NOx concentration than a heterogeneous mixture. In addition, the histories of temperature and NO concentration were calculated using a thermodynamic model based on the measured rates of heat release for the mixture having different degrees of heterogeneity. It was shown that a lean-burn engine with a more homogeneous mixture is desirable, and that much reduction of NO may be achieved once the burnt gas is artificially mixed during combustion to … More make the burnt zone more uniform.3.Real-time measurement of exhaust gas emissions in a lean-burn gas engine was carried out by using Fourier transform infrared spectroscopy analyzer. From the measured results, it was shown that not only unburnt HC but also combustion-generated HC increase in lean combustion. Furthermore, the characteristics of exhaust emissions under a cold start condition were measured, and high concentrations of HCs were detected just after the firing operation, whereas NOx gradually increases from the start.4.A three-dimensional model for the combustion process and NO formation in a homogeneous-charge engine was established based on a submodel for flame development. Computations carried out for different conditions gave a good reproduction of the entire combustion process. The spatial profiles of heat-release rates, the flame temperature and the NO concentration were investigated to clarify the mechanism of NO formation with special attention to mixing of heat and mass in the combustion process. Less

这项研究旨在建立高效低诺克斯发动机，以替代均质均匀电荷组合。本研究的内容总结如下：1。在由天然加斯和液化石油气加油的火花点火引擎中研究了同质预混合的局限性，并显示了确定限制的因素和扩展方法的因素。22。exprimimimimimimimimimiment for a Explimimiment for a Enter gly允许同型混合物的浓度多于繁聚的混合物，使杂交的混合物多样性更高，而杂交混合物则更多地重新定型。混合物。此外，使用热力学模型基于具有不同程度异质性的混合物的热量释放速率来计算温度史和无浓度。结果表明，希望具有更均匀混合物的瘦燃烧发动机是可取的，并且一旦在组合过程中人工混合燃烧气体后，就可以实现NO的大量降低。3.Real燃烧区更加均匀。从测得的结果中可以看出，不仅没有燃烧的HC，而且还结合了瘦肉组合的HC组合。此外，测量了冷启动条件下排气排放的特征，并在发射操作后检测到高浓度的HCS，而NOx从开始时逐渐增加。4。混合过程中的三维模型，并且基于用于火焰开发的子模型而建立了同型充电发动机中的三维组合。针对不同条件进行的计算可以很好地再现整个混合过程。研究了热释速率，火焰温度和无浓度的空间曲线，以阐明无形成的机制，并特别注意混合过程中热和质量的混合。较少的