小型LPG单一燃料发动机的试验研究

【作者】 魏鹏；

【导师】 周俊杰；

【作者基本信息】 大连理工大学 ， 动力机械及工程， 2003， 硕士

【摘要】 随着石油资源的不断开发以及对环境保护的要求，代用燃料发动机越来越受到人们的重视，其发展也越来越迅速。代用燃料的研究已成为发动机领域的重要研究方向。为了充分利用液化石油气（LPG）和天然气（NG）资源，保护环境，国家和地方政府制定了一系列政策鼓励开发燃气汽车，推进其产业化。因此，进行气体燃料发动机燃烧过程的基础理论研究和试验研究、开发低排放的燃气发动机是一项十分紧迫而有意义的课题。本文开展了基于小缸径柴油机的液化石油气（LPG）单一燃料发动机的设计和全面的试验研究工作。本文主要有两方面内容。其一，将一台2100柴油机改造成为缸内直接点火式LPG单一燃料发动机，并进行了一系列的台架试验研究。其二，针对液化石油气燃烧速度低，为改善其动力性、经济性、排放特性和提高功率，有必要提高液化石油气的燃烧速度。为此，设计了一种结构简单、改装方便的预燃烧系统，将小型柴油机改进设计为独具特色的预燃式LPG发动机，并进行了一系列台架试验。试验表明，该燃烧系统可大大加快燃烧速度，提高燃烧效率，有较好的动力性和排放特性，具有实用推广价值。对预燃式和缸内直接点火两种改装方案的试验结果进行了系统的性能对比分析，着重讨论了预燃室喷嘴直径和气道性能对发动机的影响。通过试验数据分析，得出一些对火花点火液化石油气发动机设计和应用具有指导意义的结论。更多还原

【Abstract】 The investigations on alternative fuels have become an important direction of engine technique. The central and local governments have worked out a series of policies for developing gas fuel vehicles and promoting its industrialization, in order to protect environment and fully use LPG and NG resources. Therefore, the basal and theory researches on combustion and development of gas engine with low exhaust emission are very pressing and significant. The design of LPG (liquefied petroleum gas) mono-fuel engine based on small bore diesel engine and comprehensive experimental investigations were made first in our country.This paper has two main contents. First, This paper carried on the transformation to one 2100 diesel engine, made it become a LPG mono-fuel SI dedicated engine，and carried on a series of experiments.Second, In order to improve its power, economy and emission, it is necessary to improve burning speed of LPG contraposing its low burning speed. For this reason, designed one structure simple, refit conveniently pre-combustion system, and a small-scale diesel engine was improved and designed into a pre-combustion LPG engine, having unique characteristic. Experiments indicate that this burning system can accelerate speed of burning greatly, raise combustion efficiency and have better power and emission characteristic. There is practical value of popularizing.Systematic engine performance contrast analyzing was carried out based on the two refit schemes’ results. And the impact on the engine of the spray nozzle’s diameter and of the port performance was discussed emphatically. Through analyzing the test data, drew out some directive and significant conclusion for SI LPG engine’s design and application.更多还原