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为改善奥托循环发动机的效率,开发了一种辅助催化点火和燃烧系统。该系统的特征是采用涡流充量的稀混合气、显著提高压缩比和应用催化预燃室。长期以来,稀混合气燃烧已成为汽油机开发中最重要的趋势之一。要在全负荷时实现稀混合气燃烧,必须在燃烧室内引入强涡流,并提高压缩比。采用由主燃室和预燃室组成的燃烧系统是实现稀均质混合气燃烧的一种可行方法。预燃室和主燃室具有相同的稀均质混合气,预燃室中还有一个催化镶圈,靠它保持足够高的温度,以确保催化反应和主充量的火焰点燃。该燃烧系统在一台改造成奥托循环的Ford FSD425型2.5L4缸柴油机上进行了试验。原发动机的喷油器由小型预燃室替代。每个预燃室中装有催化镶圈和火花塞。发动机改造后的几何压缩比ε=16,并保持了原发动机的高涡流比。经过初步试验和一系列成功改进后,发动机开始处于最佳工作状态。改造成奥托循环的发动机达到了原机的功率(4000r/min时46.5kW)和燃油消耗率(2100r/min时245g/kW·h)。发动机运行了300h以上。带催化镶圈的小型预燃室大大改善了燃烧特性,因而有可能以稀混合气、高压缩比和高效率运行。试验发现,催化点火既可以与火花点燃并用,也可以用作独立的点火源。与纯火花点燃相比,这两种方式均能提高燃油经济性和降低CO、HC、NO_x排放。
To improve the efficiency of Otto cycle engines, a co-catalyst ignition and combustion system was developed. The system is characterized by a lean mixture of swirling charge, significantly increasing the compression ratio and application of the catalytic preburner. For a long time, lean burn combustion has become one of the most important trends in the development of gasoline engines. To achieve lean burn at full load, strong vortices must be introduced into the combustion chamber and the compression ratio increased. The use of a combustion system consisting of a primary combustion chamber and a pre-combustion chamber is a viable method for achieving a homogeneous, homogeneous mixture combustion. The pre-combustion chamber and the main combustion chamber have the same homogeneous, homogeneous mixture. The pre-combustion chamber also has a catalytic ring, which is maintained at a sufficiently high temperature to ensure that the catalytic reaction and main charge flame are ignited. The combustion system was tested on a Ford FSD425 2.5L 4-cylinder diesel engine modified to Otto cycle. The original engine injector is replaced by a small pre-combustion chamber. Each pre-combustion chamber fitted with a catalytic ring and spark plug. After the transformation of the engine geometric compression ratio ε = 16, and maintain the original engine high vortex ratio. After a preliminary test and a series of successful improvements, the engine started in the best working condition. The engine converted to Otto cycle reached the original engine power (46.5kW at 4000r / min) and fuel consumption (245g / kWh at 2100r / min). The engine is running for more than 300h. Small pre-combustion chamber with catalytic ring greatly improves the combustion characteristics, it is possible to lean mixture, high compression ratio and high efficiency operation. The test found that the catalytic ignition can be used with spark ignition and can also be used as an independent ignition source. Both of these approaches increase fuel economy and reduce emissions of CO, HC, NOx compared to pure spark ignition.