Effect of Water Injection on Emission Characteristics of a Turbocharged Diesel Engine

The diesel engine is a very common source of small-scale power generation. While diesel engines are efficient with low carbon monoxide and hydrocarbon emissions, they have high nitrous oxide emissions. One approach to reduce the formation of nitrous oxides is by introducing water in the diesel engine system. The present paper is a study of effects on performance of direct water injection in the cylinder during the compression stroke and humidifying air prior to its entry to the engine by use of suitable models for various processes. It is observed that nitrous oxide concentrations are substantially reduced by both direct water injection as well as by use of humidified air. Use of humid air however also increases the power output of the engine with a minor loss in efficiency.