改进二甲醚燃料润滑性能的研究

Study on Lubricity Improver of Dimethyl Ether as the Fuel of Compression Ignition Engine

在国内首次研究了二甲醚(DME)燃料中加入不同种类和配比的润滑改进剂后两者的互溶特性、发动机排放性能的变化以及燃油系统偶件润滑性能和磨损的改进,从而为 DME发动机选择合适的燃料润滑改进剂提供重要依据.实验给出了3种润滑改进剂与DME的临界互溶温度曲线,可据此在不同季节和地区为DME发动机选择合适比例的不同润滑改进剂来使燃油系统获得足够润滑,同时保证润滑改进剂与 DME能完全互溶.实验结果表明:植物油作为润滑改进剂效果较好;DME中加入少量的润滑改进剂后不会使发动机的排放性能恶化.

The mutual solubility characteristics of dimethyl ether (DME) and different kinds and proportions of lubricity improvers were investigated. The improvement of the lubricating characteristics and the wear of the precision pairs of fuel system also was studied. At the same time, the change of the emission characteristics of engine operating on DME mixed with different lubricity improvers was analyzed. These three aspects are basic and critical for selecting the lubricity improver for DME powered compression ignition engine. It is found that vegetable oils are good improvers for improving the DME lubricity. In our experimental study, the curves of the critical mutual solubility temperatures between DME and three kinds of lubricity improvers were obtained. Thus, the different lubricity improvers with appropriate proportion at different ambient temperatures and seasons, in which the lubricity improver can absolutely dissolve into DME, can be selected for DME engine. The experiment result also shows that the emission characteristics of the engine are not worsened after adding small proportion lubricity improvers into DME.