Improving PM-NOx trade-off with paraffinic fuels: A study towards diesel engine optimization with HVO. (1st April 2020)

• Record Type: Journal Article
• Authors: Dimitriadis, Athanasios; Seljak, Tine; Vihar, Rok; Žvar Baškovič, Urban; Dimaratos, Athanasios; Bezergianni, Stella; Samaras, Zissis; Katrašnik, Tomaž
• Is Part Of: Fuel. Volume 265(2020)
• Publication Date: 2020-04-01
• Subjects: A/F ratio: Air Fuel ratio; -- CAD Crank Angle Degree; -- CD Combustion Duration; -- CI Compression Ignition (engine); -- CLD ChemiLuminescence Detector; -- CO Carbon Oxide; -- COV Coefficient of Variance; -- CRDI Common Rail Direct Injection; -- DOC Diesel Oxidation Catalyst; -- DOHC Double Over-Head Camshaft; -- DPF Diesel Particulate Filter; -- EGR Exhaust gas Recirculation; -- FAME Fatty Acids Methyl Ester; -- FID Flow Indicator Detector; -- GFM Gravimetric Filter Module; -- CFPP Cold Filter Plugging Point; -- H/C ratio Hydrogen to Carbon ratio; -- HC Hydrocarbons (total); -- HVO Hydrotreated Vegetable Oil; -- ID Ignition Delay -- IE Injector Energizing; -- IMEP Indicative Mean Effective Pressure; -- IMV Inlet Metering Valve; -- IP Injection Pressure; -- MIT Main Injection Timing; -- MSS Micro Soot Sensor; -- NOX Nitrogen Oxides; -- PIT Pilot Injection Timing; -- PM Particulate Matter; -- pmax Maximum cylinder pressure; -- RoHR Rate of Heat Release; -- SCR Selective Catalytic Reduction; -- SOC Start of Combustion; -- SOI Start of Injection; -- TDC Top Dead Center;; Renewable diesel -- HVO -- PM-NOx trade off -- Main injection timing -- Pilot injection timing -- Injection pressure; Fuel -- Periodicals; Coal -- Periodicals; Coal; Fuel; Periodicals; 662.6
• DOI: 10.1016/j.fuel.2019.116921
• Languages: English
• ISSNs: 0016-2361

Abstract

Highlights: At default settings HVO produce lower PM and HC emissions compared to petrodiesel. At default engine settings NOx emissions are similar for HVO and petrodiesel. MIT retardation with HVO results in lower PM and NOx compared to petrodiesel. Retardation of MIT is the optimum strategy for HVO fuel. Abstract: The current work investigates the impact of a paraffinic fuel on combustion and emissions of a diesel engine, examining alternative injection strategies for the full exploitation of the fuel characteristics. The paraffinic fuel used was the HVO (Hydrotreated Vegetable Oil) produced by Neste Oil with the brand name NEXBTL. The study was conducted on a light-duty turbocharged and aftercooled common-rail diesel engine, with both HVO and a conventional diesel fuel. Four steady-state operating points were examined, at low and medium engine speeds (1500 and 3000 rpm) and loads (35 and 100 Nm), typical of daily driving of a passenger car. The key contribution of the study is a comprehensive analysis of the phenomena influencing the crank angle resolved in-cylinder parameters, as well as interlinking the effects of different variations of injection pressure (default and 300 bar higher), pilot injection timing (default and ± 5°CA) and main injection timing (default and ± 2°CA) on gaseous emissions and particulate matter (PM). The findings have shown that at default engine settings the use of HVO results in up to 40% reduction of engine-out PM and HC emissions without appreciable changes in NOx emissions. The significant reduction of engine-out PM levels, facilitates the adoption of measures for NOx emissions limitation. The latter are reduced by up to 20% when the main injection timing is retarded (by 2° CA in the present study), while PM emissions are still kept well below the respective diesel fuel levels.