燃料润滑性研究三十年

THIRTY YEARS OF RESEARCH ON FUEL LUBRICITY

回顾了液体燃料润滑性研究的历史。航空喷气燃料和柴油的润滑性研究经历了相同的曲折过程。燃料炼制深度的大大增加导致燃料泵在使用中出现了问题 ,于是发展了测试方法来研究磨损机理 ,然后采用添加剂技术来解决润滑性问题。目前 ,从表面上看 ,这两类燃料的润滑问题似乎己经解决 ,但深层次的润滑问题尚需进一步研究。第三类燃料——汽油正面临着相似的局面。由于在轿车上广泛采用电控汽油喷射系统 ,增加了汽油的工作压力 ,并且要符合越来越严的环保法规对汽车排放的要求和对汽油组成的限制 ,使得汽油的润滑性逐步下降 ,已出现油泵磨损失效的迹象。为防患于未然 。

The history of fuel lubricity research was briefly reviewed There is a similar cycle of events for both aviation and diesel fuel including a significant increase in severity of refinement followed by consequent service problems, the development of fuel lubricity test methods, a study of wear mechanisms and, eventually, solutions based largely on additive technology But unlike aviation kerosene, no major lubricity problems were encountered in use of diesel fuels until late 1980s probably due to higher naturally occurring lubricity agents added In the late 1980s and early 1990s to solve the problem of environment pollution concerned with the toxic emissions from diesel engines led to large reductions in the level of sulphur and aromatics in diesel fuels and development of the so called “reformulated diesel fuels” Almost as soon as reformulated diesel fuels were introduced, fuel pump failures occurred Since then, considerable efforts have been paid to investigate the lubricity of low sulphur diesel fuels These investigations concerned with analyzing the nature of field tests, studying on wear mechanisms and finally, searching for an appropriate solution of the low lubricity in both gasoline and diesel fuels appeared to have been resolved Today gasoline lubrication is facing two substantial changes One involves wider adoption of direct injection (DI) gasoline engine, which will necessitate quite high pressure gasoline pumps The other concerns with the impact of environmental regulations to compositional constraints on fuel lubricity In anticipation of a similar cycle taking place with gasoline fuels the author of this paper began to systematically investigate the friction/wear behavior of gasoline and the relationship between composition and lubricity three years ago The BL(Boundary lubrication) and EHD (Elastohydrodynamic) behaviors of gasoline fuels will be discussed in successive papers