Diesel engines for rail traction locomotives -meeting the challanges of lower emission limits

摘要

Diesel engines play an important part in the running of a modern railway. Reliability and economy are always required but increasingly there is a requirement to decrease engine exhaust emissions. The smaller engines in use are similar to road transport engines and the technology developed in the road designs can be adapted for traction applications. For the larger engines used in locomotives the emission reduction is more difficult. This paper reviews existing emission reduction techniques and discusses the main options available to the large engine and locomotive designer. The test cycles used to certify railway engines are compared to road engines and a simplified comparison of the emissions produced by road and rail transport is described. Examples of the low NOx ( Oxides of Nitrogen ) locomotive engine build options available from MAN B&W Diesel Ltd, Paxman, are mentioned to provide an idea of the NOx emission levels available from modern large high speed diesel engines.