Refine Your Search

Search Results

Viewing 1 to 7 of 7
Technical Paper

Optimization of Exhaust Pipe Injection Conditions for Diesel Oxidation

2007-10-29
2007-01-3998
In a Diesel Oxidation Catalyst (DOC) and Catalyzed Soot Filter (CSF) system, the DOC is used to oxidize additional fuel injected into the cylinder and/or exhaust pipe in order to increase the CSF's inlet temperature during soot regeneration. The catalyst's hydrocarbon (HC) oxidation performance is known to be strongly affected by the HC species present and the catalyst design. However, the engine operating conditions and additive fuel supply parameters also affect the oxidation performance of DOCs, but the effects of these variables have been insufficiently examined. Therefore, in this study, the oxidation performance of a DOC was examined in experiments in which both exhaust gas recirculation (EGR) levels and exhaust pipe injection parameters were varied. The results were then analyzed and optimal conditions were identified using modeFRONTIER.
Technical Paper

Detailed Analysis of Particulate Matter Emitted from Biofueled Diesel Combustion with High EGR

2009-04-20
2009-01-0483
Difference of engine combustion characteristics, species and amount of exhaust gas and PM (particulate matter consisted of SOF and Soot and Ash), and especially PM oxidation characteristics were studied when diesel fuel or bio-fuel, here PME (palm oil methyl ester) as an example, was used as a fuel. The fueling rate was adjusted to obtain the same torque for both fuels and engine was operated under several range of EGR (Exhaust Gas Recirculation) ratio. Under such conditions, PME showed shorter ignition delay time and lower R.H.R (rate of heat release) under 0-40% EGR ratio. With respect to engine exhaust gas species, CO, NO, THC and HCHO, CH3CHO concentration was almost the same when the EGR ratio is higher than 35% (Intake-Air/Fuel: A/F=20). However, PME also showed lower exhaust gas emission when the EGR ratio is higher than 30%.
Technical Paper

Experimental Study on Unregulated Emission Characteristics of Turbocharged DI Diesel Engine with Common Rail Fuel Injection System

2003-10-27
2003-01-3158
In this study, we selected four unregulated emissions species, formaldehyde, benzene, 1,3-butadiene and benzo[a]pyrene to research the emission characteristics of these unregulated components experimentally. The engine used was a water-cooled, 8-liter, 6-cylinder, 4-stroke-cycle, turbocharged DI diesel engine with a common rail fuel injection system manufactured for the use of medium-duty trucks, and the fuel used was JIS second-class light gas oil, which is commercially available as diesel fuel. The results of experiments indicate as follows: formaldehyde tends to be emitted under the low load condition, while 1,3-butadiene is emitted at the low engine speed. This is believed to be because 1,3-butadiene decomposes in a short time, and the exhaust gas stays much longer in a cylinder under the low speed condition than under the high engine speed one. Benzene is emitted under the low load condition, as it is easily oxidized in high temperature.
Technical Paper

Developments of the Reduced Chemical Reaction Scheme for Multi-Component Gasoline Fuel

2015-09-01
2015-01-1808
The reduced chemical reaction scheme which can take the effect of major fuel components on auto ignition timing into account has been developed. This reaction scheme was based on the reduced reaction mechanism for the primary reference fuels (PRF) proposed by Tsurushima [1] with 33 species and 38 reactions. Some pre-exponential factors were modified by using Particle Swarm Optimization to match the ignition delay time versus reciprocal temperature which was calculated by the detailed scheme with 2,301 species and 11,116 elementary chemical reactions. The result using the present reaction scheme shows good agreements with that using the detailed scheme for the effects of EGR, fuel components, and radical species on the ignition timing under homogeneous charge compression ignition combustion (HCCI) conditions.
Journal Article

Detailed Diesel Combustion and Soot Formation Analysis with Improved Wall Model Using Large Eddy Simulation

2015-11-17
2015-32-0715
A mixed time-scale subgrid large eddy simulation was used to simulate mixture formation, combustion and soot formation under the influence of turbulence during diesel engine combustion. To account for the effects of engine wall heat transfer on combustion, the KIVA code's standard wall model was replaced to accommodate more realistic boundary conditions. This were carried out by implementing the non-isothermal wall model of Angelberger et al. with modifications and incorporating the log law from Pope's method to account for the wall surface roughness. Soot and NOx emissions predicted with the new model are compared to experimental data acquired under various EGR conditions.
Technical Paper

The Effect of Intake, Injection Parameters and Fuel Properties on Diesel Combustion and Emissions

2003-05-19
2003-01-1793
To improve urban air pollution, stringent emissions regulations for heavy-duty diesel engines have been proposed and will become effective in Japan, the EU, and the United States in a few years. To comply with such future regulations, it is critical to investigate the effects of intake and injection parameters and fuel properties on engine performance, efficiency and emissions characteristics, associated with the use of aftertreatment systems. An experimental study was carried out to identify such effects. In addition, the KIVA-3 code was used to gain insight into cylinder events. The results showed improvements in NOx-Smoke and BSFC trade-offs at high-pressure injection in conjunction with EGR and supercharging.
Technical Paper

A Numerical Study on Combustion and Exhaust Gas Emissions Characteristics of a Dual Fuel Natural Gas Engine Using a Multi-Dimensional Model Combined With Detailed Kinetics

2002-05-06
2002-01-1750
A numerical study was carried out to investigate combustion characteristics of a dual-fuel gas diesel engine, using a multi-dimensional model combined with detailed chemical kinetics, including 43 chemical species and 173 elementary reactions. In calculations, the effects of initial temperature, EGR ratios on ignition, and combustion were examined. The results indicated EGR combined with intake preheating can favorably reduced NOx and THC emissions simultaneously. This can be explained by the fact that combustion mechanism is changed from flame propagation to HCCl like combustion.
X