Numerical analysis of Miller-premixed charge compression ignition combustion on a dynamic φ—T map

Abstract

A variable valve timing mechanism has been applied in a high-speed direct injection diesel engine. The effective compression ratio ( εeff) is lowered by means of late intake valve closing, while keeping the expansion ratio constant. Premixed charge compression ignition (PCCI) combustion, adopting the Miller cycle, was experimentally realized and numerically analysed. Significant improvements in NO x (nitrogen oxides) and soot emissions were achieved for a wide range of engine speeds and loads frequently used in a transient mode test. The operating range of the Miller-PCCI combustion has been expanded up to an indicated mean effective pressure of 1.3 MPa.

The effects of early inlet valve closing and cylinder disablement on fuel economy and emissions of a direct injection diesel engine

“…This similarity of responses to both EIVC and LIVC timing changes is evident in other work [6e13], with some exceptions which may be attributable to the varying range of MAP (manifold absolute pressure), AFR (air to fuel ratio) and EGR rate settings examined in the different investigations. The influence of LIVC on in-cylinder conditions was investigated by Murata et al [11,14] through CFD (computational fluid dynamics) simulations. Plotting local states on an equivalence ratio-temperature map showed local peak values of temperature and equivalence ratio were lowered, moderating NO x and soot formation during combustion.…”

Suitability analysis of advanced diesel combustion concepts for emissions and noise control

“…This work is focused on the second solution, the PCCI combustion concept, which may provide significant reductions of NO x and soot emissions [19,20]. Furthermore, in this concept the mixture formation process, and hence the rate of heat release, can be controlled by the injection settings [21].…”

Improving the environmental performance of heavy-duty vehicles and engines: particular technologies

“…LTC has been receiving great attention in the heavy-duty diesel engine industry. LTC includes a variety of innovative and different pre-mixed combustion mechanisms discovered by many researchers, such as PCCI (Kanda et al, 2005(Kanda et al, , 2006Zhang et al, 2009;Murata et al, 2010), HCCI (Stanglmaier and Roberts, 1999;Epping et al, 2002;zhao et al, 2003;Cracknell et al, 2008;Schleyer, 2006;Zhao, 2007), premixed compression ignition (PCI), modulated kinetics (MK), Unibus, and reactivity controlled compression ignition (RCCI) (Reitz, 2010), etc. A common feature of LTC is to enhance the premixing of fuel and air and to keep combustion temperature low in order to simultaneously avoid no x and soot formations (De Ojeda et al, 2007Musculus et al, 2011).…”

“…In the SuperTruck program, variable IVC timing has been researched as one possible way of improving engine thermal efficiency to achieve flexible controls on engine compression ratio and low-temperature combustion timing (De Ojeda, 2010a, 2010b. In fact, the Miller cycle with early or late IVC timing has been always regarded as one of the very rare engine technologies that can simultaneously reduce no x and BSFC (Ke and Pucher, 1996;Clarke and Smith, 1997;Edwards et al, 1998;Millo et al, 2004;imperato et al, 2009;Yang et al, 2009Yang et al, , 2010Murata et al, 2010).…”