In order to enhance the combustion characteristics and transient operations of heavy diesel (HD), the high cetane number palm biodiesel was blended by 5%, 10%, 15%, and 20%. Respectively the steady state and transient performance were investigated. The engine performance and exhaust emissions were tested under cold start and acceleration condition. The study of fuel properties on engine steady combustion characteristics and transient operations will be helpful to evaluate the fuel characteristics and the suitability for use.
The experimental results showed that the heavy diesel blending with 15% biodiesel (HBD-15) would have less knocking pressure, better fuel consumption, and higher engine output power under steady state test. The NOx exhaust emissions of HBD-15 were 26.66% less than HD’s exhaust and 11.79% lower than the super diesel’s (SD) exhaust and the smoke emissions were reduced about 40%~ 60% by adding biodiesel into heavy diesel. Under transient operation tests, the cold start performance and free acceleration smoke has excellent performance for HBD-15, the load acceleration performance of heavy diesel with 5% and 10% biodiesel had short acceleration time and about 30%~ 80% lower smoke emission than HD’s.