Emission Technology And Experimental Study Of Non-Road Diesel Engine In The Third Stage

Due to the increasing reduction of petrochemical energy and environmental pollution, energy saving and emission reduction has become a hot research topic in the field of internal combustion engine. The article researched a six cylinder vehicle diesel engine which produced in a well-known enterprise to the domestic, By optimizing the electric control and structure parameters, to meet the third stage of China’s non road emission limits, achieved efficient and clean combustion in diesel engine.Test in accordance with emission regulations(GB 20891-2014) in eight operating condition as the standard engine operation, researching of electronic control fuel injection parameters, cam profile, fuel injector parameters and combustion chamber shape influence on engine power, economy and emissions.Test results show that:With the delay of the main injection timing, NOx emission reduction, smoke and fuel consumption rise, the main injection timing at 2 to -3 degrees angle BTDC, the engine performance is balance. Pre injection interval angle in (35-30) degrees, the engine’s economy and emissions to achieve the best.With increasing the pre injection fuel mass, NOx slightly decreased, smoke slightly increased, the best range of (2～3) mg/str. There is or no pre spray on the NOx emission and smoke effect is more obvious, little impact on the fuel consumption. Turbocharged inter-cooled of intake is benifit to reduce fuel consumption, NOx and soot emissions.BOOST simulation results show that:The IVC at 47deg.CRA as the best optimization results. The EVO of the original machine is more reasonable, don’t change the EVO. The valve overlap angle of the original machine is 40deg.CRA (valve clearance 0.35/0.4mm). Increase the valve overlap angle, the BSFC is reduced and the inflation efficiency is improved.10 deg. CRA overlap angle increasing as optimization result.Test results also indicate that:comparison the camshafts of SF1 and SF2 performance, the camshaft of SF2 response is poor at low-speed, high speed performance is good, it suitable for speed change is small as the ship motor or generator. The new combustion chamber can reduce the NOx and smoke emission simultaneously, and the gas filling efficiency is slightly higher than the traditional shrinkage type combustion chamber, economy is better. Due to the cancellation of the combustion chamber structure, the highest temperature of the throat area, strength and cooling are improved, the reliability of the piston is significantly improved.