共查询到17条相似文献,搜索用时 234 毫秒
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对船舶柴油机油劣化规律进行模拟氧化试验和船舶行驶试验研究,运用红外光谱和理化指标分析所取样品的酸值、碱值、闪点、氧化值等.结果表明,模拟样品和跟踪样品随着氧化时间和航程的增加,呈黏度增加、酸值升高、碱值降低,氧化值、硝化值增大的变质趋势,且理化指标和红外指标有很好的相关性.模拟氧化试验和跟踪取样的样品的红外和理化数据变化一致,因此可以用模拟试验的数据来预测实际样品的衰变.应用模拟氧化试验可以快速研究柴油机油的劣化规律,采取红外和理化相结合的方法能够评价柴油机油的质量变化程度,实现按质换油. 相似文献
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《机械科学与技术》2015,(12):1919-1923
以一台车用4缸汽油压缩天然气(CNG)两用燃料发动机为研究对象进行噪声源识别,测试工况为怠速工况、最大转矩工况与最大功率工况。首先测试发动机的1 m声压级,定位噪声最大的端面为发动机前端,再使用基于波束形成技术的声阵列系统对发动机前端和进气侧进行分析,分析结果表明汽油与CNG燃料主要噪声频段均位于1 000~2 000 Hz,进而识别出主要噪声源为链壳,通过振动测试验证了噪声源,并对两种燃料的噪声源特点进行了比较。研究表明波束形成技术在噪声源识别中具有快捷、直观的优点;两用燃料发动机CNG燃料怠速噪声较汽油燃料各对应面大5~7 d B,250 Hz以下的燃烧噪声是主要成因。 相似文献
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CNG/汽油两用燃料发动机油清净分散性试验研究 总被引:1,自引:1,他引:0
按CNG/汽油两用燃料发动机对机油清净分散性能要求,选择了几种清净分散剂,通过试验考察了基础油与添加剂的感受性,采用均匀设计分析了几种添加剂之间的复配性能。试验结果表明:几种添加剂的最佳配比为T104∶T106∶T151∶T152=2∶3∶5∶5。 相似文献
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为使发动机能够正常运转,选用的润滑油应具有以下的良好性能。 (1)良好的抗高温性能:发动机在工作过程中,大部分润滑油处在高温下。润滑油通过燃烧、氧化、分解等变化,生成积炭、不溶物等,使其老化、变质,失去了润滑作用。因此,润滑油要有良好的热氧化稳定 相似文献
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二烷基二硫代氨基甲酸钼(MoDTC)的减摩效果与其在润滑油中的含量直接相关,为探索快速准确的润滑油新油和在用油中MoDTC含量的检测方法,采用红外光谱分析MoDTC在成品发动机油和减速箱油中的吸收峰特征。选取波数为1 515 cm-1的吸收峰为定量基准,分别用差谱法和直接趋势法建立发动机油和减速箱油中MoDTC含量的测定方法。该方法回归曲线相关系数高,计算误差小。用建立的方法考察发动机油中MoDTC在四球试验时的消耗情况,结果发现MoDTC的消耗趋势与四球试验摩擦因数和磨斑直径的变化趋势有很好的对应关系,验证了该方法对检测新油和在用油中的MoDTC含量均有很好的效果。 相似文献
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A. B. Vipper 《Lubrication Science》1995,8(1):73-83
During oxidation of an engine oil under laboratory conditions, and testing in a single-cylinder gasoline engine, it has been found that oil ageing depends on the copper content, in particular the oil-soluble copper salt content. The latter considerably intensifies engine oil oxidation, loss in bearing weight, and piston deposit formation. Several regularities in the oil ageing process were found. It was noted that interaction of copper naphthenate with zinc dithiophosphate essentially influences this process. 相似文献
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Yu Liu Yong Dong J. K. Yeom S. S. Chung 《Journal of Mechanical Science and Technology》2012,26(11):3673-3679
In this paper, the radical induced (RI) ignition method was applied into a compressed natural gas (CNG) engine to achieve rapid bulk combustion. The experimental RI-CNG engine was modified from a diesel engine. The combustion chamber of the modified diesel engine was divided into a sub-chamber and a main-chamber. The sub-chamber is physically separated from the main-chamber above the piston and is connected to the main-chamber via several passage holes. CNG is injected into the sub-chamber during the intake stroke and then ignited before the top dead center (TDC) by a spark plug. As the ignition occurs in the sub-chamber, the pressure rises, forcing the gases which contain a number of active radicals out into the main-chamber to ignite the unburned mixture. The purpose of this paper is to study the engine operating limit and the combustion characteristics of the RI-CNG engine. The engine operating limit was accessed with different engine speeds and injection timings. The obtained data including the coefficient of variation (COV), brake specific fuel consumption (BSFC), mass fraction burned and emissions were analyzed. 相似文献