A Detailed Study of Boost Pressure and Injection Timing on an RCCI Engine Map Fueled with Iso-Octane and N-Heptane Fuels

Abstract

By using two types of different fuels and changing the ratios of these fuels, Reactivity Controlled Compression Ignition Engine (RCCI) is able to provide a more effective control over combustion phase at different loads and speeds. In a typical RCCI engine which could be considered as a type of homogeneous charge compression ignition (HCCI) engine, a low reactive fuel is injected into the intake port and a high reactive fuel is directly injected into the combustion chamber. In this study, a multi-dimensional model coupled with chemical mechanism is developed to simulate an RCCI engine operation fueled with iso-octane as the low reactive fuel and n-heptane as the high reactive one. Initially, the engine map was derived using different quantities of total above-mentioned fuels at different ratios and then engine inappropriate operating points were detected and improved by changing intake air pressure and injection timing strategies. The improved criteria to extend engine map are ringing intensity limit, NOx formation standard and gross indicated efficiency. It was concluded that high ringing intensity and NOx formation can be reduced by increasing intake air pressure; also badfire and misfire points can get improved by retarding the injection timing.

Numerical Investigation of Ducted Fuel Injection Strategy for Soot Reduction in Compression Ignition Engine

“…There are two main approaches to controlling exhaust emissions. One of them is to reduce emissions by improving the combustion process (Fajri et al 2019;Mohan et al 2013), and the other approach is to prevent the release of harmful gases from the exhaust using an aftertreatment system (Brijesh and Sreedhara 2013). Exhaust aftertreatment methods for instance lean NOX-trap (LNT) and selective catalytic reduction (SCR) significantly increase the system complexity, weight, and cost (Lao et al 2020;Praveena and Martin 2018).…”

Mixture Formation Analysis for Diesel, n-Dodecane, RME, and HVO in Large-Scale Injector Nozzles

“…The International Energy Agency in 2017 reported that the global gasoline and diesel ICEs are growing up based on two different scenarios, firstly, up to 2045 based on the reference technology scenario and secondly, until 2030 based on the 2DS scenario, both indicate the importance of taking considerations in the current engines developments for future CO2 reduction [3]. More and more combustion strategies such as RCCI, HCCI, PCCI [4,5] as subparts of low-temperature combustion to dualfuel combustion [6] in addition to improvements in engine parts and calibrations such as in-cylinder size, piston shape, injector design, and fuel injection strategies have been and will be investigated in order to reduce fuel consumption and engine emission and therefore, to achieve CO2 reduction. Air/fuel mixture formation in diesel engines is a significant process influences engine performance and exhaust gas emission production, and accordingly, nozzle shapes, fuel properties, ambient and fuel pressures and temperatures, and spray propagation parameters including penetration length and cone angle are widely being studied to elucidate how mixture formation is affected and amended by these parameters [6][7][8][9][10][11][12][13].…”