An investigation on the particulate number and size distributions over the whole engine map from an optimized combustion strategy combining RCCI and dual-fuel diesel-gasoline. (15th May 2017)

• Record Type: Journal Article
• Authors: Benajes, Jesús; García, Antonio; Monsalve-Serrano, Javier; Boronat, Vicente
• Is Part Of: Energy conversion and management. Volume 140(2017)
• Page Start: 98
• Page End: 108
• Publication Date: 2017-05-15
• Subjects: Reactivity controlled compression ignition -- Dual-fuel combustion -- Dual-mode -- EURO VI emissions -- Efficiency -- Engine map; AIM Aerosol Instrument Manager -- ASTM American Society of Testing and Materials -- ATDC after top dead center -- BDC bottom dead center -- CAD crank angle degree -- CA10 crank angle of 10% heat release -- CA50 crank angle at 50% heat release -- CDC conventional diesel combustion -- CO carbon monoxide -- CO2 carbon dioxide -- COV coefficient of variation -- CPC condensation particle counter -- CR compression ratio -- DMA Differential Mobility Analyzer -- DMDF dual-mode dual-fuel -- DOC diesel oxidation catalyst -- DPF diesel particulate filter -- ECU electronic control unit -- EGR exhaust gas recirculation -- EVO exhaust valve open -- FSN Filter Smoke Number -- GF gasoline fraction -- HC hydrocarbons -- HCCI homogeneous charge compression ignition -- IMEP indicated mean effective pressure -- IVC intake valve close -- IVO intake valve open -- LTC low temperature combustion -- MCE multi cylinder engine -- NOx nitrogen oxides -- ON octane number -- PFI port fuel injection -- PPC partially premixed charge -- PSD particle size distribution -- PRR pressure rise rate -- RCCI reactivity controlled compression ignition -- RoHR Rate of Heat Release -- SCE single cylinder engine -- SCR selective catalytic reduction -- SMPS scanning mobility particle sizer -- SOC start of combustion -- SOF soluble organic fraction; Direct energy conversion -- Periodicals; Energy storage -- Periodicals; Energy transfer -- Periodicals; Énergie -- Conversion directe -- Périodiques; Direct energy conversion; Periodicals; 621.3105
• DOI: 10.1016/j.enconman.2017.02.073
• Languages: English
• ISSNs: 0196-8904

Abstract

Highlights: Optimized dual-mode dual-fuel strategy to cover the whole engine map. High coherence between smoke and total particles number for diffusive dual-fuel mode. Fully premixed RCCI regime dominated by small particles of 30 nm diameter peak. Highly premixed RCCI mode has a transitional behavior with two particle diameter peaks. Abstract: Literature demonstrates that, for premixed low temperature combustion concepts, particulate matter cannot be directly extrapolated from soot emissions measurements, as typically done for conventional diesel combustion. This is because the particulate matter from low temperature combustion has low fraction of carbonaceous compounds and great amount of soluble organic fraction, which is not captured by the smoke measurement techniques such as the optical reflectometry. By this reason, the study of the particulate matter characteristics from this combustion techniques requires using specific equipment. The aim of the current work is to gain understanding on the particulate matter characteristics from the dual-mode dual-fuel combustion, which is an optimized combustion strategy that combines fully and highly premixed RCCI regimes at low and medium loads, and switches to dual-fuel diffusion combustion at full load. The study was performed over the whole engine map, using a 15.3:1 compression ratio medium-duty EURO VI diesel engine. In particular, the particulate number and size distributions were sampled using a scanning mobility particle sizer and a condensation particle counter, which allow measuring the size distribution and total number of particles from 5 to 250 nm. Results demonstrate that the fully premixed RCCI combustion is dominated by small particles (less than 30 nm in mobility diameter), the dual-fuel diffusion mode is dominated by larger particles (around 100 nm in mobility diameter) showing more diesel-like particle size distributions, and the highly premixed reactivity controlled compression ignition regime shows a transitional particle size distribution with two peaks of mobility diameters around 20 and 80 nm.