Experimental and computational study of a lean burn natural gas engine

Turbocharged diesel engine used for electric generator was converted to run on natural gas. Modifications of the engine included engine head, piston, spark ignition set, fuel delivery system and intake system. During laboratory tests the performance maps of the gas engine were taken at 1500rpm. The following measurements were performed: • Composition of exhaustgases (NO" CO, C02 etc.); • Temperatureof exhaustgases; • Pressure in combustionchamber; • Fuel consumption; • Electric power producedby generator. Computations of combustion process in gas engine were made with the use of KJVA3V computer code. Several ignitionangles and equivalence ratioswere considered in the study. Results of computations include: • Temperaturedistribution in combustion chamber; • Pressure distribution in combustion chamber; • NO, emissionconcentration; • CO2 and CO emissions; • OHconcentrationdistribution in combustion chamber; • Velocity and turbulence kineticenergy field in combustionchamber; • Overall indicatedpressureand temperature of the cycle. All calculation were performedfor originalenginecombustion chamber geometry.