Effect of Intake Charge Temperature on Combustion and Emissions Characteristics in a Natural Gas-Diesel Reactivity Controlled Compression Ignition Engine

Abstract

Partially premixed dual fuel strategy has been suggested as a new strategy for Compression Ignition (CI) engines because it could be effective for simultaneous reduction in NOx and soot exhaust emission accompanied. This strategy uses premixed low reactivity fuel as main fuel and advanced injection of high reactivity fuel as pilot fuel to reach a Reactivity Controlled Compression Ignition (RCCI) in CI engines. The current paper presents results from a study about NG-Diesel RCCI combustion with variable intake charge temperature in a CI engine. The results from the developed CFD model with a reduced chemical kinetic mechanism verify that the model can simulate the in-cylinder process, accurately. Based on the results, intake temperature impact the engine operation at RCCI combustion, significantly. The high intake temperature could result in advanced combustion phasing and higher ringing intensity (RI) as well as enhanced combustion efficiency. It is due combustion improvement with higher heat release rate (HRR) and peak in-cylinder pressure. On the other hand, the results revealed that RCCI combustion in low intake temperature causes great HC and CO emissions accompanied with low NOx emission in part load condition.