Influence of fuel injection timing and trade-off study on the RCCI engine characteristics of Jatropha oil-diesel blend under 1-pentanol dual-fuel strategies

Influence of injection strategies on ignition patterns of RCCI combustion engine fuelled with hydrogen enriched natural gas

The depletion of fossil fuel and the concerns for harmful emissions and global warming has instigated researchers to use alternative fuels. Hydrogen (H2) and natural gas (NG) are attractive fuels for internal combustion engines. The dual-fuel combustion strategy is promising to reduce emissions with efficient engine operation. The concern for using NG in this strategy is the lower efficiency at low load conditions and the emission of exhaust gases like carbon monoxide and unburnt hydrocarbon. Mixing fuel with a wide flammability limit and a faster burning rate with NG is an effective method to compensate for the limitations of using NG alone. Hydrogen (H2) is the best fuel added with NG to cover NG limitations. This study investigates the in-cylinder combustion phenomenon of reactivity-controlled compression ignition (RCCI) engines using hydrogen-added NG as a low-reactive fuel (H2 addition to NG on a 5% energy basis) and diesel as a highly reactive fuel. The numerical study was done on a 2.44 L heavy-duty engine using CONVERGE CFD code. Three low, mid, and high load conditions were analyzed in six stages by varying the diesel injection timing from -11 to -21 O after top dead centre (ATDC). The H2 addition to NG had shown deficient harmful emissions generation like carbon monoxide (CO) and unburnt hydrocarbon with marginal NOx generation. At low load conditions, the maximum imep was achieved at the advanced injection timing of -21OATDC, but with the increase in load, the optimum timing was retarded. The diesel injection timing varied the optimum performance of the engine for these three load conditions.

Multi-objective optimisation of engine characteristics of an RCCI diesel engine powered with Jatropha/1-pentanol blend: a Taguchi-fuzzy approach

Researchers are examining the possibilities for alternative fuel research as a fossil fuel replacement in light of global energy insecurity and other urgent challenges like global warming, severe emissions, and growing industrialization. This research uses 1-pentanol as a low reactivity fuel and Jatropha biodiesel as a high reactivity fuel to explore the reactivity-controlled compression ignition engine characteristics. A water-cooled single-cylinder engine is used in an experiment with varied loads of 25%, 50%, and 75% at a constant speed of 2000 rpm to examine the effects of operational parameters (i.e., (23 bTDC, 25 bTDC, and 27 bTDC) and (400 bar, 500 bar, and 600 bar)). The fuzzy-based Taguchi approach predicts operational parameters, including fuel injection time, fuel injection pressure, and engine load. Utilizing this ideal model, one may increase brake thermal efficiency and braking power while minimizing unburned hydrocarbon and nitrogen oxide emissions. An L20 orthogonal array is used to analyze the effects of various variables on an engine running on B20/1-pentanol fuel, including engine load, fuel injection timing, and fuel injection pressure. Multiple models are generated and verified with the use of experimental findings. Compared to other operating parameters, for reducing oxides of nitrogen, hydrocarbons, and brake-specific energy consumption maximally, engine load of 75%, FIP of 400 bar, and FIT of 23 bTDC are optimal based on the greatest MPCI value of 0.802.