概率2—距离空间

PERFORMENCE RESEARCH OH COTTONOIL AS AN ALTERNATIVE TO DIESEL FUEL

中文摘要:

      本文研究了直喷式柴油机燃用棉籽油时的性能。通过燃油加温对喷雾特性、燃烧特性、和工作特性的影响及燃油加温前后EMA循环试验所得到的喷嘴积炭状况对比,表明了燃油加温的措施促进燃油雾化,改善燃烧,减轻不完全燃烧倾向,提高热效率,减轻喷嘴积炭,从而能提高发动机的耐久性。本文还分析了加温的机理,并揭示了积炭形成的机理。 文中考察了供油提前角、喷油压力及燃油温度对发动机性能的影响,并用二次正交回归设计的方法建立了热效率与它们之间的数学模型,用优化的方法得到了柴油机燃用50/50混合油时的最佳调整,试验结果说明:用回收

英文摘要:

      The problems involved for using vegetable fuel as an alternative to diesel fuel are(1) carbon or gum deposits on chamber, injection nozzle tips and injector coking, (2) serious contamination of the lubricating oil and (3) the difficulty for starting the engine.The carbon and gum deposits mainly caused by the high viscosity of the vegetable fuels which is more than ten times as high as that of the diesel fuel. The high viscosity leads to poor atomization and inefficient combustion of the fuel. Also residues of partly combusted fuel remained in the engine to form deposits or to contaminate the lubricating oil.The purposes of the research are to change the properties of vegetable fuel throuhh heating the fuel as the main measure, to improve the poor atomization and imcompletcd combustion of the fuel and furthermore to reduce the deposits and lubricating oil coutamination of the D.I.engine.The paper analyzed the improvement on tne properties of injection, atomization, combustion performance of the D.I.engine by heating the fuel.The E.M.A.Test Cycle have been conducted with both heated (80℃) and no heated (20℃) oils.The result is that the method to heat oil is feasible in reducing deposits accumlating in the combustion chamber and on the injection nozzle tips was observed when heated fuel was used. The E.M.A.Test Cycle provided a promising result that heated fuel could improve the duribility of the D.I.engine.By the way of experimental design of regression analysis,this research established a mathematic model between the specific consumption of the fuel and the injection advance angle, injection pressure and fuel temperature. The potimum solution obtained are injection advance angle: 27°, injection pressure: 175kg/cm² and temperature: 80℃. The results indicate that it is effective to use the exhausted heat of engine to heat the vegetable oil to increase the duribility of engine.