Development of New Procedures for Rating the Ignition Quality of Fuels for Diesel Engines

摘要

The ignition delay times of 42 different fuels were measured in a constant voulume combustion bomb. The measurements were performed at three different initial air temperatures using fuels ranging from the primary reference fuels for cetane rating to complex mixtures of coal-derived liquids. A single-cylinder, variable compression-ratio, direct-injection diesel engine was designed and constructed to study the ignition quality of 17 of the 42 fuels. The total ignition delay times in the bomb were studied in the context of providing a means for rating the ignition quality of the fuels. Fuel ignition quality rating schemes are discussed, including one based on the current cetane number scale as well as one based on a new scale which includes a measure of the sensitivity of the various fuels to the air temperature. The ignition delay times in the engine have been measured as functions of the engine speed, load, and compression rato. Keywords: Centane, Variable, Compression, Ratio combustion, Bomb, Fuels, Ignition.