电控LPG缸内直接喷射技术应用于火花点火式发动机的研究

【作者】 卫忠星；

【导师】 何文华；

【作者基本信息】 浙江大学 ， 动力机械及工程， 2004， 硕士

【摘要】 本文在实验室环境下对液化石油气发动机采用电控缸内直接喷射方式进行了初步研究，主要涉及以下一些内容。 设计了一套适用于台架试验的电控缸内直接喷射LPG发动机的燃料供给系统，主要包括初级增压系统，高压产生装置，高压喷射系统三大部分。其中，液压式的燃料高压产生装置具有燃料适应性广，压力调节范围大，压力波动小，密封性好等优点。喷射器通过电控阀和柴油机喷嘴的组合使用实现。 介绍了台架试验环境下的LPG发动机的电控系统，对部分传感器电路和控制软件进行了改进设计。 开发了一套电容放电式的高能多次点火系统，将其应用到电控LPG发动机上，并进行了台架试验。试验结果表明，多次点火提高了点火可靠性，改善了HC和CO的排放，但对NO_x排放影响不大。 对所开发的电控缸内直接喷射LPG发动机，初步进行了整机性能的台架试验。与进气道气态喷射方式和进气道液态喷射方式相比，缸内直接喷射方式下的发动机动力性得到显著提高，但是排放性能变差。这说明，所开发的缸内直接喷射系统有待进一步完善。更多还原

【Abstract】 The paper studies the direct injection of electronic-controlled engine fueled with LPG(Liquefied Petroleum Gas) in the lab condition. The main contents are as follows:A fuel-supplying system for direct injection electronic-controlled engine fueled with LPG in the lab condition, including the primary pressure system, the high-pressure producing device and the injection system with high-pressure, has been developed. Hydraulic-pressure based high-pressure producing device has such advantages as wide fuel adaptability, wide pressure adjustability, little fluctuation of pressure, good seal performance, and etc. The nozzle is made up of the electronic-controlled valve and diesel nozzle.It is described that the electronic control system of the LPG engine under the lab condition. Some circuit of sensors and software are improved.The high energy and capacitor-discharging multi-time ignition system has been developed and applied to the electronic-controlled LPG engine. The experiment results indicate that the reliability of ignition has been improved, and the exhaust of HC and CO has been reduced. However, this ignition system has little influence on the emission of NOx.The experiment that tests the integral performance of the LPG engine of electronic-controlled direct injection has been carried out. Compared with the LPG engine of intake gaseous injection and intake liquid injection, the power performance of the LPG engine that works under the circumstance of direct injection is improved greatly, but the performance of emission becomes worse. It shows that the direct injection system developed needs further improvement.更多还原