A comparative study of lean burn and exhaust gas recirculation in an HCNG-fueled heavy-duty engine

摘要: Abstract Two dilution strategies, exhaust gas recirculation (EGR) with a stoichiometric mixture and excess air lean mixture, were investigated for an 11 L, 6-cylinder H2-blended compressed natural (HCNG) engine. The engine was operated at 1260 rpm 50% of maximum load (575 Nm) brake torque each strategy. To evaluate the EGR approach, combustion mode varied, to mode, ratio varied. rate flammability limit constrained by stability. employed compare effect on performance emission levels under identical both modes. thermal efficiencies lower than those combustion, owing higher pumping loss speed. total hydrocarbon emissions only when speed relatively slow, due mixing caused active combustion. As increased in decrease NOx slowed compared mode. lowest level engine-out observed