Experiment to Determine the Effects of Adding Water Vapor to Diesel Engine Intake Air on Engine Performance, Combustion and Exhaust Pollutants

This study examined the emission and performance factors of a diesel engine by sending varied ratios of ultrasonic cold-water vapor to the intake air through the intake manifold. An evaporator was used to complete this operation. The engine is a modified air-cooled, two-cylinder, four-stroke diesel engine with a compression ratio of 17:1. The engine operated on three different mixtures of diesel and biodiesel fuels under three various load conditions. Intake air humidity/fuel ratio ranged from 0 to 73%. The findings from the experiment showed that increases in humidity, CO, and HC emissions initially caused a decrease and later an increase.  Keywords: Cold water vapor; Injection advance; Diesel engine; Evaporator; Emission