SOF Emissions Research Articles

Effect of post injection strategy on regulated exhaust emissions and particulate matter in a HSDI diesel engine

We investigate effects of post injection strategies on regular exhaust emissions and soot particulate matters on in-cylinder emission control. A trade-off relation indicates that CO and THC emissions increase as post injection timing delays, but NOx emission significantly decreases when crank angle intervals increase because of cylinder volume expansion and heat transfer. In PM emission, total particle concentration and particle size distributions indicate that, at early post injection timing, SOF emission is relatively low but soot emission is relatively large caused by high temperature and local lean oxygen conditions. As crank angle intervals increasing, soot emission decreases quickly and becomes insensitive to the post injection timing. When SOF emission has an obvious increasing trend, there is a lowest level for the PM emission at intermediate post injection timing. Moreover, variations for total particle concentration are similar with soot emission at different post injection strategies. Particle size distribution result illustrates that PS is insensitive to post injection timing at different post injection strategies.

Experimental Study of the Effects of Fuel Quality and Pollution Control Devices on SOF and PAHs Emissions in PM for HD Diesel Engine

The effects of fuel quality and pollution control devices on SOF and PAHs emissions in particle matter (PM) for China V heavy-duty (HD) diesel engine fueled with China III, China IV and China V diesel were studied by using soxhlet extraction technique and Gas Chromatography-Mass Spectroscopy (GC-MS) technique. Two engines used were equipped with Diesel Oxidation Convert (DOC)+Diesel Particulate Filter (DPF) and Select Catalytic Reduction (SCR) individually. It is found that the SOF mass fraction in PM rises remarkably and total PAHs concentration declines obviously with the improvement of diesel fuel from China III to China V. However, the 16 components of PAHs distribute similarly for three quality of diesel, the concentrationes of Flu、PA、Ant、FL、Pyr、BaA、CHR reduce obviously, especially Pyr decrease by 95.8%. Moreover, the pollution control device has important effects on SOF and PAHs emissions.

2217 水エマルジョン化およびエタノール添加による菜種油ディーゼル機関の排気性能(J16-2 燃料多様化と燃焼・化学反応制御(2),ジョイントセッション,21世紀地球環境革命の機械工学:人・マイクロナノ・エネルギー・環境)

In order to improve emissions from a diesel engine fuelled by rapeseed oil (SVO), this study investigated the effects of using water-emulsified (W-SVO) and ethanol-blended (E-SVO) rapeseed oil on emissions. Results show that SVO produces lower smoke compared with gas oil at high load despite of the increase of NO_x. Both W-SVO and E-SVO are effective to reduce both NO_x and particulate emissions at high load. In particular, W-SVO has a great effect on NO_x reduction with keeping low particulate emissions. However, W-SVO produces high HC and CO emissions at low load. SOF emission with SVO at low load cannot be sufficiently improved by using W-SVO and E-SVO due to high viscosity and high distillation temperature.

Modelling soot and SOF emissions from a diesel engine

Modelling of soot and SOF emissions from a typical European turbocharged diesel engine has been made. The model consists of a detailed kinetic mechanism with 472 reactions (120 chemical species) and data from the thermodynamic diagnostic procedure of the combustion process of the engine. The forward kinetic constants were obtained from literature and the background constants from a self-developed non-linear fitting routine based on the Marquardt algorithm. The dilution and mixing processes inside the engine are represented by a simple Wiebe function. The system of ordinary differential equations is solved with the Rosenbrock method for rigid systems and using the interpolating Lagrange polynomials to calculate the heat capacity of each species at the corresponding temperature. The kinetic model has been implemented in Digital Visual Fortran 6.0. The model has been executed for five different fuels and three mixtures of biodiesel and reference diesel operating under three diverse conditions from the European transient urban/extraurban Certification Cycle and the results of soot and SOF predicted are compared with experimental data.

Emission Characteristics of Unburnt HC and Particulate Matter from a Small DI Diesel Engine. 3rd Report. Effect of Fuel Properties.

Many reports, related to the effects of fuel properties on exhaust emissions in DI diesel engines, have been published. It is reported that decreasing of high boiling point fraction, aromatic hydrocarbon and sulfur contents in fuel are effective to reduce PM emissions. However, the effectiveness of these properties differs from researcher to researcher, may be due to the difference in engine specifications. Especially in small DI diesel engines, the fuel properties have significant influence on PM emissions, since much fuel impinges on the combustion chamber walls. To clarify the effect of fuel properties on PM emission in a small DI diesel engine, we investigated the changes of emission characteristics using some paraffinic hydrocarbon fuels with different boiling point. Moreover, the changes in exhaust emissions by the addition of aromatic hydrocarbon to paraffinic, naphthenic and diesel fuel were investigated. The results showed that the amount of SOF when using low boiling point paraffinic fuels decreases to about one tenth of that of diese1 fuel. Blending of the aromatic hydrocarbon with the base fuel of diesel or olefin causes increased amount of SOF emission, but there is no change when the base fuel is para ffin. However, the dry Soot is increased regardless of the base fuel when blending the aromatic hydrocarbon.

99/01513 Fuel composition effects on SOF and PAH exhaust emissions from DI diesel engines : Hori, S. and Narusawa, K. Soc. Automot. Eng., [Spec. Publ.] SP, 1998, 1328, 65–72

99/01513 Fuel composition effects on SOF and PAH exhaust emissions from DI diesel engines : Hori, S. and Narusawa, K. Soc. Automot. Eng., [Spec. Publ.] SP, 1998, 1328, 65–72

98/01611 Effects of diesel fuel composition on SOF and PAH exhaust emissions: Hori, S. et al. JSAE Rev., 1997, 18, (3), 255–261

98/01611 Effects of diesel fuel composition on SOF and PAH exhaust emissions: Hori, S. et al. JSAE Rev., 1997, 18, (3), 255–261

Effects of Fuel Properties on Exhaust Emission from DI Diesel Engine.

Exhaust emissions (HC, CO, NO x , PM, and PAH (polycyclic aromatic hydrocarbons in PM)) from a commercial DI diesel engine were measured for petroleum-derived fuels with a wide range of fuel properties. Fuel properties such as cetane number, aromatic content and type, and distillation temperature were adjusted to be independent from each other. The test results showed that total aromatic content was the controlling factor for NO x emission, and PM emission mainly depended on polycyclic aromatic content in the fuel. The increases in PM emission with increase in aromatics was mainly caused by the increase in SOF emission. Both of NO x and PM emissions were seldom affected by cetane number and 90% distillation temperature. Therefore, chemical characteristics of fuel are the controlling factor for NO x and PM emission, not the physical properties. The amount of sulfate in PM proportionally increased with increase in sulfur content of fuel. PAH emission was evaluated by analyzing SOF using a high performance liquid chromatography with a chemiluminesence detector. Also, the PAH highly depended on aromatic content, and the emission characteristics caused by aromatics was quite similar to PM emission.

Improvement of SOF emission in a small direct injection diesel engine

Improvement of SOF emission in a small direct injection diesel engine

Effects of diesel fuel composition on SOF and PAH exhaust emissions

Experiments were performed with a six cylinder test engine using both ordinary diesel fuel and synthetic diesel fuel, which has simple hydrocarbon components and no aromatics or sulfur content. SOF is extracted from the particulate sample, then GC and GC-MS analyses were carried out. By comparing the results obtained, the role of high boiling point components in diesel fuel on SOF emission was observed. Further, by adding an artificial sulfur-containing compound and pyrene, which is a four ring polynuclear-aromatic-hydrocarbon (PAH), into the synthetic fuel, the effect of PAH content in fuel on PAH emission in SOF and the increase of SOF with increased sulfur content in fuel, were observed.

Improvement of SOF emission in a small direct injection diesel engine Tatsuhito Kaimai (Kitami Inst. of Tech. MS), Hideyuki Tsunemoto, Hiromi Ishitani (Kitami Inst. of Tech.)

Improvement of SOF emission in a small direct injection diesel engine Tatsuhito Kaimai (Kitami Inst. of Tech. MS), Hideyuki Tsunemoto, Hiromi Ishitani (Kitami Inst. of Tech.)

ディーゼル機関の排出未燃炭化水素に及ぼすリエントラント燃焼室の影響

The effects of re-entrant combustion chambers on emissions of particulates and unburned hydrocarbons were investigated in a high speed small direct-injection diesel engine. From our study, it has been already suggested that the fuel or the fuel-air mixture can become an important origin of unburned hydrocarbon emissions when they intrude into the narrow space between the piston and the cylinder head. In this work, especially noticing this point, the trends of THC and SOF were examined changing the injection timing and the top clearance.The results show that the re-entrant combustion chamber reduces THC emissions, but increases SOF emissions compared with the deep bowl chamber at the advanced injection timing. On the other hand, at the late injection timing, THC and SOF are simultaneously reduced. When the injection timing and the top clearance are optimized for the re-entrant combustion chamber, it is possible to reduce not only smoke and NOx but also THC and SOF.

Influence of the Molecular Structure of Hydrocarbon Fuels on Diesel Exhaust Emissions.

The influence of the molecular structure of hydrocarbon fuels on soot, SOF, and NOx emissions from a diesel engine was analyzed while ignition lag and other physical fuel properties were kept constant. Mixtures of normal paraffin (n-tetradecane) and isoparaffin (heptamethylnonane) were used as a base fuel and one of 5 kinds of hydrocarbons including mono-aromatic, diaromatic, and non-aromatic was added. The aromatic compound content varied in the range of 0∼60 vol% for the mono-aromatic fuel and 0∼40 vol% for the diaromatic fuels. The experimental results showed that regardless of the molecular structure of the fuel, both particulate and NOx emissions increased linearly with the C/H atomic ratio of fuels under constant ignition lag. The increase in particulate emissions with C/H atomic ratio was caused by increase in the amount of dry soot. SOF, THC, and BSEC were not very much affected by the C/H atomic ratio and molecular structure of the fuels. The fuel properties discussed here showed similar results both in DI and IDI engines.

Lighter organic particulates in diesel exhaust.

Lighter organic particulates emitted from a high-speed four-cycle DI diesel engine at various loads for commercial diesel fuels and some blended fuels have been studied under steady operating conditions. Emissions of lubricating oil, fuel fractions, and combustion products in the lighter organic fraction have been evaluated by chemical analysis using a gas chromatograph and a mass spectrometer. Furthermore, flow reactor experiments under atmospheric pressure were conducted to simulated the effects of temperature on forming particulates in the engine cylinder. The fractions having higher boiling points than 300°C are hot fully decomposed even at flow-reactor temperatures of 880°C. Side-chained two-ring compounds which are the major aromatic component in commercial fuel rapidly decompose to yield a polymerized substance at much lower temperatures than other fuels. This explains the dependence of SOF emission on load and fuel property.

Diesel Emissions Reduction Using a Catalyst and Water Scrubber for Underground Mine Applications

BS 6680 requires the efficiency of coalmine diesel engine exhaust pollution-reduction devices to be determined. The efficiency of an Englehard PTX catalyst and water scubber for both particulate and gaseous emissions reduction was determined using a 533 cc single-cylinder Petter AVI direct injection diesel engine. The separate and combined influence of the two exhaust devices was determined. The water scrubber acted as aflame trap as well as an exhaust particulate trap. The catalyst gave a substantial reduction in CO and UHC gaseous emissions and particulate SOF emissions for exhaust temperatures above 250°C. However, the high MW particulate SOF, including the PAH, had a 70 per cent reduction for catalyst temperatures as low as 200°C. The water scrubber was the dominant particulate removal device, although the catalyst removal efficiency was significant for temperatures above 250° C. The scrubber also had a significant influence on the reduction in NOx emissions, with a 30 per cent removal at high exhaust temperatures.