硕士论文-济南公交燃气汽车改造及应用研究.pdf

山东大学
硕士学位论文
济南公交燃气汽车改造及应用研究
姓名:张小鹏
申请学位级别:硕士
专业:车辆工程
旨导教师:程勇
20070915
山东大学硕士论文
摘要
近年来,天然气汽车技术迅猛发展,这不仅有利于降低对环境的污染,还
能够调整我国的能源结构,缓解能源紧张状况。本文在公交公司汽油CNG两
用燃料汽车研究的基础上,分析了汽油/CNG两用燃料汽车存在的缺陷,介绍
和回顾了柴油/CNG双燃料及天然气单燃料公交汽车的改装应用技术。
介绍了柴油/CNG双燃料公交汽车的改装及应用技术,根据目前双燃料汽车
存在低速控油量较大的缺点,论文设计了一油量限制器,该油量限制器基于喷
油泵调速器的工作原理,采用简单机械装置,实现了引燃油量全工况精确控制。
为了保证天然气混合的均匀性,使发动机工况过渡平稳,论文设计了天然气混
气装置,该混气装置由混合器、混合器座、天然气控制阀、旁通空气阀等组成。
为了实现不同工况下,公交汽车能够以不同的燃烧方式运行,还对操纵系统进
行了改装,改装后的操纵系统由联动杠杆装置、压缩空气气路装置、电控电路
装置组成。该操作系统简单可靠,使用性能良好。改装后,对汽车进行了台架
试验、道路试验等研究,改装前后汽车的动力性、排放性及经济性等参数对比
结果表明,改装后的柴油CNG公交车动力性得到了提高,排放明显降低,而经
济性和原车相比略有降低,车辆运行效果良好。并对该型公交车进行了推广应
用
介绍和回顾了CJ6922客车及JK6800客车改装为天然气单燃料汽车的技术
天然气单燃料车辆的改装过程中,主要是进行发动机的匹配。因此,在进行改
装时,首先根据原车发动机类型,选择了几种认为可以匹配的发动机,然后分
别对这几种发动机进行匹配试验,最后根据匹配试验结果的对比分析,最终确
定性能较好的发动机作为改装匹配发动机。对改装后的发动机的可靠性、安全
性、经济性的试验表明,改装后的天然气単燃料发动机比原车有更好的经济性、
动力性、排放性和可靠性。认为单燃料天然气公交车具有更好的发展前景,可
以进行更广的推广使用。
根据多年从事公交汽车改装及应用的经验,制定了适于济南市公交公司的
改装及使用安全规范,该规范从一定程度上改善了改装后公交汽车的运行安全
性
山东大学硕士论文
就实际运行过程中可能出现的故障进行了分析,并总结了排除故障的方
法,提高了故障车辆的维修效率
关键词:柴油/CNG双燃料发动机;天然气发动机;动力性与燃料消耗;排
放特性
山东大学硕士论文
ABSTRACT
Compressed natural gas(CNG)has been used as a fuel for internal combustion
engines for decades. Developing CNG engine which can meet more strict emission
regulations and can improve the oil security of China becomes more and more
important. Jinan public transport company has studied CNG engines for several
years. This paper mainly introduces the revamping technology of the diesel/CNG
engines and the single fuel CNG engines based on the disadvantages of the bi-fuel
eIne。
At first, this paper introduces the revamping technology of the diesel/CNG
engines. For most dual-fuel engines can't control the oil quantity well at low speed,
this paper designs an oil limiter. This limiter can control the injection quantity
accurately according to the operating principle of the speed controller. In order to
mix the CNG fuel homogeneously, this paper designs one CNG mix unit. This unit
is composed by a mixer, a mixer plate, a CNG controlling valve and a by-pass
valve. In order to adjust different conditions, the buses should operate on differen
combustion modes. Thus this paper revamps the control system which concludes
the lever linkage, the air compression system and the electric control system. This
control system operates simply performances well. After revamping, this paper
tested the engines dynamic, exhaust and economy performances. The result shows
hat the dynamic performance was increased and the exhaust was decreased
unambiguously. The economy performance was cqual or a lit higher than the
prototype engine. Based on the good performances of the revamping engine, the
public transport company popularized this type diesel/CNG engine
Secondly, this paper introduced the revamping technology of the CJ6922 and
the K6800 buses to single fuel CNG engine. In the revamping process, the crisis
technology is matching proper engines to the buses. This paper first selects several
engines to match the buses and tested these engines'performances. By comparing
these engines' dynamic, exhaust and economy performances, this paper
determined the best engines to the CJ6922 and the J