The Relation of Combustion Phases and Emissions of ULSD & HFO in a Common-Rail HSDI Diesel Engine

The Relation of Combustion Phases and Emissions of ULSD & HFO in a Common-Rail HSDI Diesel Engine

Type	Journal Article
Author	Hayder A. Dhahad Mohammed A. Abdulhadi
Author	Ekhlas M. Alfayyadh
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Abstract	This study investigates the effect of combustion phase ( premixed and diffusion phases ) duration on the emissions emitted from a high speed direct injection (HSDI) diesel engine fueled with heavy fuel oil and run at a constant speed ( 1500 rpm ) with single injection strategy at constant fuel injection pressure ( 1200 bar ) and varying fuel injection timings ( - 12, - 9, - 6, - 3,0 ) ATDC , for two loads( 2.5 and 5 bars ) BMEP . The obtained results were compared with those obtained when the engine run at the same conditions but with ultra - low sulfur diesel fuel (ULSD). In - cylinder pressure was measured and analyzed using (LABVIWE) program. calculation program specially written in (MATLAB) software was used to extract the apparent heat release rate, the ignition delay, combustion duration and specify the amount of heat released during the premixed and diffusion combustion phases (premixed burn fraction PMBF) and ( diffusion burn fraction DBF) . Emission measurements included; NOx , CO, THC and smoke number (SN). Study results showed that ULSD generate higher NOx due to higher combustion temperature, while, HFO generate higher soot, CO and THC. Measurements and calculations indicated that ignition delay of ULSD was shorter than that of HFO, which means less PMBF. This conflicting effect is probably due to the advanced start of combustion (SOC) leading to higher combustion temperature inside the combustion chamber with ULSD and the difficulty of heavy fuel atomization and incomplete combustion of the heavy components for the heavy fuel
Publication	International Journal of Scientific & Engineering Research
Volume	Volume 5, Issue 7
Date	July 2014