Influence of emulsified fuel combustion on soot formation process

乳化燃料燃烧对碳烟形成过程的影响

• 批准号: 10650906
• 负责人: YOSHIMOTO Yasufumi
• 金额: $ 0.83万
• 依托单位: Niigata Institute of Technology
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1998
• 资助国家: 日本
• 起止时间: 1998 至 1999
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10650906/
• 关键词: Diesel Engine; Model Chamber; Water Addition; Emulsified Fuel; Particulate Matter; Smoke; Nitrogen Oxides; 乳化燃焼; ディーゼル燃焼; 燃焼凍結

It is difficult to achieve simultaneous reductions in soot and nitrogen oxides (Nox) emitted from diesel engines because of the trade-off relation. Water addition is effective to reduce Nox emissions without deterioration in the combustion performance. It is unclear, however, how the water addition influences the soot and particulate emissions. First, experiments were carried out to determine the formation characteristics of smoke emissions using actual diesel engines fueled with water-in-oil emulsified fuels. The experimental parameters with two types of base fuel (gas oil and biodiesel, fuel transesterified from vegetable oil), EGR (exhaust gas recirculation), and water addition were investigated. Compared with water free fuels, the smoke density of the emulsified fuels reduced remarkably at all operating conditions.To examine the formation process of particulate, experiments using a model chamber were made. It is possible to simulate diesel combustion and a model chamber simulating constant volume combustion was employed. The experimental apparatus consisted of five parts : a modified combustion chamber of the diesel engine, a vessel for high temperature and high pressure air, a rupture system with a needle cutter driven by a solenoid, a vessel to contain expanded gas, and a system for single injections of diesel fuel. A thin steel plate is used to partition the combustion chamber and the gas expansion vessel. In the combustion process the thin plate is ruptured by the needle cutter and the combustion reaction stops immediately, because the burnt gas expands in an extremely short time. The preliminary combustion experiments were conducted at atmospheric conditions with an initial air pressure of 2MPa and 450℃, and the ignition delay was longer than with actual engines. The apparatus will need improvements to obtain more precise data.

由于权衡关系，很难同时减少从柴油发动机中发出的烟灰和氮氧化物（NOX）。在不确定组成性能的情况下，加水可以有效减少NOx排放。但是，尚不清楚水的添加如何影响烟灰和特定的排放。首先，进行了实验，以使用用油中乳化燃料燃料的实际柴油发动机来确定烟气排放的形成特征。研究了具有两种类型的碱性燃料（气体油和生物柴油，植物油进行了燃料），EGR（排气再循环）和添加水的实验参数。与无水燃料相比，乳化燃料的烟雾密度在所有工作条件下都大大降低。要检查特殊性的形成过程，使用模型室进行了实验。可以模拟柴油燃烧，并采用模型室模拟恒定体积组合。实验设备由五个部分组成：柴油发动机的改良燃烧室，用于高温和高压空气的容器，由螺线管驱动的针切割机的破裂系统，包含膨胀气体的容器以及用于柴油燃料的单个注射的系统。薄钢板用于分区燃烧室和气体膨胀容器。在燃烧过程中，薄板被针切器破裂，混合物反应立即停止，因为燃烧的气体在极短的时间内膨胀。初始气压为2MPA和450℃，在大气条件下进行了初步混合实验，并且点火延迟比实际发动机更长。该设备将需要改进以获得更精确的数据。