二甲醚/甲醇均质压燃的燃烧特性

为开究二甲醚/甲醇均质压燃的燃烧特性，在单缸发动机上进行了二甲影甲醇均质压燃的试验研究．结果表明，随二甲醚浓度增加，主燃烧时刻提前，燃烧持续期缩短，放热率峰值升高；随甲醇浓度增加，低温反应变得不明显，主燃烧时刻推迟，燃烧持续期延长，因此通过调节2种燃料浓度可以有效控制均质压燃燃烧过程．在均质压燃正常燃烧范围内，燃烧效率和指示热效率随二甲醚浓度的增加而提高，随甲醇浓度的增加而降低，通过采用较浓的二甲醚可以获得比较高的指示热效率值，试验中在较高负荷采用高浓度二甲醚时，指示热效率达到48％．

Combustion Characteristics of Dimethyl Ether/Methanol Fueled Homogeneous Charge Compression Ignition Engine

An experiment on homogeneous charge compression ignition (HCCI) with dimethyl ether (DME) / methanol dual fuel was carried out on a single cylinder engine to investigate the combustion characteristics. The results indicated with increased DME, the main combustion timing was advanced, the main combustion duration reduced and the peak of heat release rate increased. While with increased methanol, the low temperature heat release became smaller, the main combustion timing was retarded and the combustion duration prolonged. By regulating the concentrations of DME and methanol, the HCCI combustion process can be controlled effectively. Under normal HCCI combustion, both the combustion efficiency and the indicated thermal efficiency rose with increased DME, and reduced with increased methanol. With rich DME supply under normal combustion, an optimal indicated thermal efficiency can be obtained, e. g. , at a fairly high load, an indicated efficiency of about 48% was available when more DME was fueled.