Hyun Gu Roh

Combustion and Emission Characteristics of 4 Cylinder Common-Rail DI Diesel Engine with Biodiesel Blended Fuel

, Soot 을 나타내었다. Abstract: This paper describes the effects of biodiesel blended fuel on the engine combustion and emission characteristics in a four cylinder CRDI(Common-rail direct injection) diesel engine. In this work, the biodiesel-diesel blended fuel(20% of biodiesel and 80% of ULSD(ultra low sulfur diesel) by volume ratio, BD20) and ULSD fuel are used under the various injection pressures and engine speeds. The experimental results of BD20 and ULSD fuel show that NOX emissions were increased and soot emissions were decreased with the increase of injection pressure. In particular, NOX emissions were slightly increased for the BD20 fuel, however, soot emissions were significantly reduced compared to the ULSD fuel. When the engine speed is increased from 1000rpm to 2000rpm, NOX emissions are decreased at all tested conditions, and soot emissions are largely increased at lower injection pressure.

Impact of DME as an Oxygenated Alternative Fuel on Combustion and Emissions Reduction in a Transportation Vehicle at Low Load Condition

AbstractThis study investigates the impact of dimethyl ether (DME) on the combustion and exhaust emission characteristics at low engine load operating and pilot injection conditions in a four-cylinder diesel engine that was modified for DME application. The combustion characteristics were analyzed based on the combustion pressure, the rate of heat release, the accumulated heat release, and the premixed combustion characteristics. The emission characteristics were analyzed through the analysis of the nitrogen oxides (NOx), soot, hydrocarbon (HC), and carbon monoxide (CO). The heat release amount per unit crank angle in DME combustion is higher than that in diesel combustion in a pilot injected combustion mode. The accumulated heat release of DME during the main combustion is higher than that of diesel fuel. The pilot injection combustion of DME fuel started earlier than single-injection combustion does. The advanced pilot injection timing caused a decrease of premixed combustion duration and a retardation ...

An Experimental Study of Two-Stage Combustion Strategy on Combustion and Emission Characteristics in a Diesel Engine Fueled With Biodiesel Blends

This study describes the effects of two-stage combustion (TSC) strategy on combustion and emission characteristics in 4 cylinder common-rail direct injection (CRDI) diesel engine fueled with biodiesel blends. In the present work, to investigate the combustion and emission characteristics, the experiments were performed under various injection pressures, first injection quantity and first injection timing of TSC strategy at constant engine speed and engine load. In addition, conventional diesel fuel (ULSD) was used to compare with biodiesel blends.The experimental results show that combustion of biodiesel blends is stable for various test conditions regardless of blending ratio, and indicated specific fuel consumption (ISFC) was increased as biodiesel blending ratio increased. In the emission characteristics, biodiesel blends generated lower indicated specific nitrogen oxides (IS-NOx) and indicated specific soot (IS-Soot) emissions compared to those of ULSD when the first injection quantity increased.Copyright

Fuel Properties and Emission Characteristics of Dimethyl Ether in a Diesel Engine

The purpose of this article is to provide the physicochemical properties and characteristics of exhaust emissions from a DME-fueled diesel engine. Fundamental properties of DME are described and compared with the properties of the conventional diesel fuel. In addition, the applicability of DME fuel is presented in terms of its potentials as an alternative fuel for compression ignition engines. The exhaust emission characteristics of a DME-fueled engine are described using experimental results of different DME and diesel blends. The most important properties of DME are the presence of oxygen in the fuel molecule, lower ignition temperature, and high cetane number. The kinematic viscosity of DME is significantly lower than that of diesel. However, low lower hating value (LHV), low viscosity, and low lubricity are some of the major disadvantages of DME. The bulk modulus of DME is about 1/3 compared to diesel fuel. Spray tip penetration of DME is found to be shorter than that of diesel. Also, the Sauter mean diameter (SMD) distribution of the DME spray is found to be much smaller than that of diesel. Emission characteristics of different DME and diesel blends are investigated, which shows low soot, CO, and other hydrocarbon emissions.

Comparative investigation of emissions and combustion characteristics between ethanol-biodiesel-diesel blends and diesel fuel in a passenger car diesel engine

This study investigated the comparison of emissions and performance characteristics between ethanol-biodiesel-diesel blends and diesel fuel in a passenger car diesel engine. In order to analyse the effect of ethanol-biodiesel blends, the combustion and emission reduction characteristics of a four-cylinder diesel engine with common-rail direct injection system were investigated under the various injection and blended ratios. The experimental results showed that the combustion pressure of ethanol-biodiesel-diesel blended fuels slightly increased than that of convention diesel fuel at higher load condition, while the coefficient of variance of the combustion pressure (COVimep) showed almost the similar values. Under low-load conditions, the effects of ethanol-biodiesel blending to conventional diesel fuel on exhaust emissions showed that brake specific CO emission (BS-CO) and BS-HC emissions remarkably increased while BS-NOx emissions decreased as ethanol blending ratio increased. Under high load conditions, BS-CO, BS-HC and BS-NOx emissions slightly increased as ethanol blending ratio increased. On the other hand, the BS-Soot emissions were reduced by more than 50% in all conditions. [Received: October 16, 2015; Accepted: June 8, 2016]