• Journal of Advanced Marine Engineering and Technology
• /
• v.36 no.4
• /
• pp.484-489
• /
• 2012

The objective of this work presented here was focused on analysis of particulate matter and nitrogen oxide characteristics in ESC test mode from heavy-duty diesel engine installed on-road vehicles applicable to prime propulsion engine for marine vessels. The authors confirmed that a large quantity particulate matter were emitted in high power density condition, nitrogen oxide characteristics were dependent on exhaust gas temperature. Particulate matters were reduced by 1/100~1/1,000 times in post DPF with test modes but filtration efficiency was decreased in the engine power fluctuation. In the case of the high speed and power condition, the exhaust level of particulate matters was increased according to increment of temperature of gas flowing into DPF. The orders of magnitude for particle concentration levels from the analysis of size distribution of particulate matters of test engine was different. Both emitting nano-sized particles below 100nm regardless of DPF and non-DPF.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.28 no.1
• /
• pp.52-58
• /
• 2004

To develop a low emission engine, it is necessary to obtain some better quality of automotive fuels. Sulfur in fuel is transformed to sulfate-laden PM as DOC is applied. Therefore, it necessary to provide low sulfur fuels before DOC is applied. According to the specification of test fuels, flash point, distillation 90％, cetane index are improved but viscosity is decreased in the process of desulfurization. Excessively reduced sulfur may cause to decrease lubricity of fuel and engine performance in fuel injection system. Therefore, this research was emphasized how the application of Bio-diesel affects on the emission characteristics and engine performance under the circumstance of ULSD and DOC.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.10 no.4
• /
• pp.77-84
• /
• 2002

For the purpose of obtaining a fundamental data which is needed to develope the port injection type charged LPLi engine system, we manufactured intake port injection system of liquid charging LPG and modified heavy duty single cylinder LPLi engine from heavy duty diesel engine. Engine output and emission characteristics were analyzed under variable air/fuel ratio and charging pressure. Since LPG is consisted of propane and butane, we investigated combustion characteristics using this two kinds of fuel. From the result of charging engine performance test, engine torque increase about 30% ∼ 40% with 0.3bar charging pressure. In low speed condition, as charging pressure increase, combustion stability improve ill lean bum condition, but, in high speed condition, combustion stability make worse in lean bum condition. We know that engine output decreased rapidly from the condition of air excess ratio 1.3. In addition, we measured emission characteristics under the lean bum and charging condition. From this experiment, we found that CO emission is out of the question in the range from stiochiometric to lean burn and charging condition, but charging pressure has influence on HC emission.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.18 no.5
• /
• pp.136-144
• /
• 2010

Exhaust gas recirculation (EGR) is an emission control technology allowing significant NOx emission reduction from light-and heavy duty diesel engines. The future EGR type, dual loop EGR, combining features of high pressure loop EGR and low pressure loop EGR, was developed and optimized by using a commercial engine simulation program, GT-POWER. Some variables were selected to control dual loop EGR system such as VGT (Variable Geometry Turbocharger)performance, especially turbo speed, flap valve opening diameter at the exhaust tail pipe, and EGR valve opening diameter. Applying the dual loop EGR system in the light-duty diesel engine might cause some problems, such as decrease of engine performance and increase of brake specific fuel consumption (BSFC). So proper EGR rate (or mass flow) control would be needed because there are trade-offs of two types of the EGR (HPL and LPL) features. In this study, a diesel engine under dual loop EGR system was optimized by using design of experiment (DoE). Some dominant variables were determined which had effects on torque, BSFC, NOx, and EGR rate. As a result, optimization was performed to compensate the torque and BSFC by controlling start of injection (SOI), injection mass and EGR valves, etc.

• Journal of Advanced Marine Engineering and Technology
• /
• v.24 no.6
• /
• pp.128-139
• /
• 2000

Environmental concerns and shortage of petroleum have promoted considerable interest in the use of alternate fuels in stationary diesel engine. In this study, a heavy-duty, intercooler-turbocharged 6-cylinder stationary diesel engine was converted into stationary gas engine fueled with propane or natural gas for the cogeneration plants. One of the most important factors in the combustion features of a stationary gas engine is the fuel composition and operating parameters in terms of compression ratio, spark advance, and engine loads. Experiments with different fuel gas and load conditions were carried out with combustion pressure analysis and NOx measurement. Combustion analysis based on P-$\theta$ diagrams was also investigated by means of combustion duration and cycle variation. Compression ratio is 10.0 and ignition timing is set by using the gasoline setting as a base line and advanced toward BTDC. The results show that fuel composition and spark advance have dominant effects on combustion and NOx characteristics at operating conditions.

• Proceedings of the KSME Conference
• /
• 2008.11b
• /
• pp.3019-3025
• /
• 2008

An experimental study was performed to assess the effect of diesel and JP-8 aviation fuel on the spray characteristics, performance and emissions in a single cylinder optical diesel engine. Both fuels were injected via an 8-hole solenoid-driven injector in a common-rail injection system. For better understanding of spray development, the macroscopic images were captured with high speed camera, offered evidences for the results of performance and emissions. From macroscopic spray images, the spray tip penetration of JP-8 shorter than that of diesel while spray angle of JP-8 was wider than that of diesel. It indicates that the vaporization of JP-8 is superior to that of diesel. The lower cetane number of JP-8 resulted in increased portion of premixed combustion. The IMEP with JP-8 is lower than that of diesel-fueled engine. Especially, using JP-8 has a potential for reducing soot.

• Environmental Engineering Research
• /
• v.20 no.4
• /
• pp.397-402
• /
• 2015

SCR has been popularly approved as one of the most effective means for NOx emission control in heavy-duty and medium-duty vehicles currently. However, high urea dosing would lead to ammonia slip. And $NH_3$ sensor for vehicle emission applications has not been popularly used in real applications. This paper presents experimental studies on the diesel engine urea-SCR system by using a double NOx sensor system that is arranged in the downstream of the SCR catalyst based on ammonia cross-sensitivity. It was shown that the NOx conversion efficiency rised as $NH_3/NOx$ increases and the ammonia slip started from the $NH_3/NOx$ equal to 1.4. The increase of temperature caused high improvement of the SCR reaction rate while the space velocity had no obvious change. The ammonia slip was in advance as catalyst temperature or space velocity increase and the ammonia storage reduced as catalyst temperature or space velocity increase. The NOx real-time conversion efficiency rised as the ammonia accumulative storage increase and reached the maximum value gradually.

• Journal of Korean Society for Atmospheric Environment
• /
• v.26 no.5
• /
• pp.499-506
• /
• 2010

Recently, a great deal of attention have been directed to the use of alternative fuels as a means to reduce vehicular emissions. As one of the promising alternative fuels, bio-diesel has advantages of a wide adaptability without retrofit of diesel engine. It is also effective enough to reduce CO, THC, $SO_x$, polycyclic aromatic hydrocarbons (PAHs) and PM. In this study, we investigated the emission characteristics of biofuels between different operating conditions, i.e., engine speed (1,400 rpm and 2,300 rpm), engine load (10% and 100%), bio-diesel blending (BD0, BD5 and BD20), and recirculation (EGR) rate of exhaust gas (0% and 20%). Relative performance of the system was evaluated mainly for the greenhouse gases ($CH_4$, $N_2O$ and $CO_2$). In addition, emission characteristics of ND-13 mode were also tested against both greenhouse gases and other airborne pollutants under emission regulation. The relative composition of bio-diesel has shown fairly clear effects on the emission quantities of CO, THC, and PM emission, although it was not on $NO_x$ and greenhouse gases. EGR rate has shown trade-off characteristics between $NO_x$ and PM.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.7 no.6
• /
• pp.998-1003
• /
• 2006

In this research, engine performance and emission characteristics of a 12,000cc heavy duty diesel engine was investigated by the application of GTL and ULSD fuels. The test was conducted at several engine speeds and loads under a single mode and a ESC mode. GTL fuel proves that it can be applicable to vehicles without engine modification.

• Proceedings of the KSME Conference
• /
• 2008.11b
• /
• pp.3085-3089
• /
• 2008

In order to reduce NOx and Soot emissions simultaneously, characteristics of diesel spray and combustion were investigated by numerical simulation with StarCD in this paper. This work focuses on effect of Spin Injection. A simulation model of combustion, spray and emissions is developed for heavy duty marine diesel engine application. Simulation is performed with change of spray angle between first and second directions at fixed engine speed, injection timing, injection duration and etc. The results show that Spin Spray Injection method can reduce NOx emission. And the results show that the 1st injection considerably interfere with 2nd injection characteristics.