Study Of Particle Emissions From GDI Engine

From the perspective of fuel quality, the paper studied the effect of particles of GDI engine, which engine use gasline fuel, toluene additive of polycyclic aromatic fuel and ethanol additive of oxygenated fuel.1、In the idle condition, particle number concentration distribution of GDI engine is Kernel mode unimodal distribution. In other condition, the number concentration of total particles increased first and then decreased while the load increased, and the number concentration of total particles became smallest while the engine speed is economic speed. The removal of volatile organic compounds only can decrease the number concentration of particles and it can not change the particle number concentration distribution. The primary carbon particles of GDI engine are surrounded with clear carbon shell, and the average primary carbon particle size becomes smaller while the load becomes larger. The average primary carbon particle size becomes larger while the engine speed becomes larger. The oxidation activity of particulate GDI engine decreases with the increase of load. The content of PAHs in particulate matter increased significantly with the increase of load because low and medium molecular weight PAHs have large increasing contribution.2、When GDI engine use 10% toluene additive fuel, the total amount of particulate matter concentration trends change under load characteristics and speed characteristics. And the total amount of particulate matter concentration will increase under the increasing load or speed. And under the high load and speed, the total amount of particulate matter concentration will increase much more. In the situation of GDI engine using 10% toluene additive fuel, the basic carbon granule will together more closely, and the average grain diameter of the basic carbon granule will decrease when the engine speed increases. And under the low load, the oxidative activity of the particles will increase when the GDI engine use 10% toluene additive fuel. And in all working condition, the mass concentration of PAHs in the particles will increase greatly when the GDI engine use 10% toluene additive fuel.3、When GDI engine use 10% ethanol additive fuel, the total amount of particulate matter concentration trends change under load characteristics and speed characteristics. And the total amount of particulate matter concentration will increase under the increasing load or speed. But under the medium load, the total amount of particulate matter concentration will decrease greatly. In the situation of GDI engine using 10% ethanol additive fuel, the inner core of the basic carbon granule has loose structure, and the size of the basic carbon granule will change in the large range. And in all working condition, the oxidative activity of the particles will increase when the GDI engine use 10% ethanol additive fuel. And the ethanol has great effect on the PAHs production.