Progress on the Investigation of Coal-Water Slurry Fuel Combustion in a Medium Speed Diesel Engine: Part 2—Preliminary Full Load Test

Full load (186 kW/cyl) operation using CWS fuel at 1050 rpm has been achieved on a single-cylinder GE-7FDL test engine. No major changes in engine parameters were made. With normal inlet air conditions, 3–5 percent pilot diesel fuel, separately injected or stratified into the main coal charge, was used. Inlet air temperature had to be raised about 40°C if no pilot diesel fuel was used. The coal burnout was about 95 percent and the cycle efficiency was comparable to using diesel fuel. The NO_x and CO emissions were about 1/2 of those obtained normally with diesel fuel. The maximum heat release rate was higher than diesel fuel operation which resulted in higher maximum cylinder firing pressure. The combustion characteristic and its dependence on some fuel characteristics and inlet air parameters are discussed. Increasing coal burnout while limiting maximum cylinder firing pressure is the main objective of near future studies.