• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.20 no.7
• /
• pp.25-32
• /
• 2021

In the previous study, a study was conducted to improve the exhaust gas intake efficiency by improving the existing soot measurement probe in the shape and angle of the exhaust port. As a result, it can be seen that the smoke measurement performance according to the shape and angle is improved. In previous studies, the performance of the soot probe was not confirmed for the Korean KD 147 mode, which has a low suction flow rate and a long inspection time. So, we would like to confirm the improvement of the smoke probe performance of the Korean KD 147 mode, which is close to the actual driving conditions. The probe used in this study is another type of probe, and has a circular ring shape instead of a rib and variable center position unit, so the probe center hole is located close to the center of the exhaust pipe.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2017.05a
• /
• pp.1068-1071
• /
• 2017

The turbine exhaust system consists of a turbine flange, heat exchanger, exhaust duct and thrust nozzle. Heat exchanger is used for the launch vehicle because of the advantage of reducing the weight of the helium gas and the storage tank by using the heat exchanger pressurization method compared to the cold gas pressurizing method. Since the gas generator is combusted in fuel-rich condition, the soot is contained in the combustion gas. Hence, the heat exchanger should be designed considering the reduction of the heat exchange efficiency due to the soot effect. In addition, the uncertainty of the heat exchange calculation and the evaluation of the influence of the combustion gas soot on the heat exchange can not be completely calculated, so the design requirements must include a structure that can guarantee and control the temperature of the heat exchanger outlet. In this paper, it is described that the component allocation, the design method considering the manufacture of internal structure, the advantages of new concept of nozzle design.

• Proceedings of the KSME Conference
• /
• 2003.11a
• /
• pp.390-395
• /
• 2003

The effect of recirculated exhaust gas on exhaust emissions under four kinds of nozzle tip with the different fuel consumption rate are experimentally investigated by using an once-through boiler with FGR system. The purpose of this study is to develop the FGR control system for reducing NOx in a boiler. Intake and exhaust oxygen concentrations, and equivalence ratio are applied to discuss the effect of FGR rate on exhaust emissions at various fuel consumption rates. It is found that NOx emissions are decreased, while soot emissions are increased owing to the drop of intake and exhaust oxygen concentrations, and the rise of equivalence ratio as FGR rates are elevated.

• International Journal of Automotive Technology
• /
• v.8 no.2
• /
• pp.165-177
• /
• 2007

Predictions of diesel particulate filtration are typically made by modeling of a particle collection, and providing particle trapping levels in terms of a pressure drop. In the present study, a series of single channel diesel particulate filter (DPF) experiments are conducted, the pressure traces are inversely analyzed and essential filtration parameters are deducted for model closure. A DPF filtration model is formulated with a non-linear description of soot cake regression. Dependence of soot cake porosity, packing density, permeability, and soot density in filter walls on convective-diffusive particle transportation is examined. Sensitivity analysis was conducted on model parameters, relevant to the mode of transition. Soot cake porosity and soot packing density show low degrees of dispersion with respect to the Peclet number and have asymptotes at 0.97 and $70\;kg/m^3$, respectively, at high Peclet number. Soot density in the filter wall, which is inversely proportional to filter wall Peclet number, controls the filtration mode transition but exerts no influence on termination pressure drop. The percolation constant greatly alters the extent of pressure drop, but is insensitive to volumetric flow rate or temperature of exhaust gas at fixed operation mode.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.17 no.3
• /
• pp.163-170
• /
• 2016

Regulations for the exhaust gas of diesel vehicles are being strengthened every year. Recently, diesel emission regulations for HC, CO, NOx, and particulate matter (PM) have been subject to very strict standards. In the future, the regulation of PM is expected to become stricter. Accordingly, diesel particulate filters (DPFs) have been applied to most diesel vehicles for PM reduction. With increasing engine mileage, ash and soot from the engine exhaust gas accumulate inside the DPF. This accumulation can damage the DPF or degrade engine performance. Therefore, efficient cleaning of the DPF is critical for the maintenance of the engine. If the DPF is well managed through regular cleaning, it can improve the power and fuel economy of the engine and reduce maintenance costs. Therefore, this study was performed to develop a high-efficiency cleaning method for DPFs and an apparatus that can more effectively clean out the accumulated ash and soot.

• Journal of Advanced Marine Engineering and Technology
• /
• v.26 no.3
• /
• pp.307-312
• /
• 2002

A study on the exhaust emissions of marine diesel engine with various fuel injection timing is performed experimentally .In this paper, fuel injection timing is changed from BTDC $14^{\circ}$ to $20^{\circ}$ by $2^{\circ}$ intervals, the experiments are performed at engine speed 1800rpm and from load 0% to 100% by 25% intervals, and main measured parameters are fuel consumption rate, Soot, NOx, HC and CO emissions etc. The obtained conclusions are as follows (1) Specific fuel consumption is indicated the least value at BTDC $18^{\circ}$ of fuel injection timing and it is increased in case of leading the injection timing. (2) Soot emission is decreased in case of leading fuel injection timing and it is increased in the form of convex downwards with increasing the load. (3) NOx emission is increased in case of leading fuel injection timing and it is increased in the form of straight line nearly with increasing the load. (4) HC and CO emissions are decreased in case of leading fuel injection timing and they are changed in the form of convex downwards with increasing the load.

• Proceedings of the Korean Society of Marine Engineers Conference
• /
• 2001.11a
• /
• pp.50-56
• /
• 2001

A study on the exhaust emissions of diesel engine with various fuel injection timing is peformed experimentally. In this paper, fuel injection timing is changed from BTDC $14^{\circ}$ to $20^{\circ}$ by $2^{\circ}$ intervals, the experiments are performed at engine speed 1800rpm and from load 25% to 100% by 25% intervals, and main measured parameters are fuel consumption rate, Soot, NOx. HC and CO emissions etc. The obtained conclusions are as follows (1) Specific fuel consumption is indicated the least value at BTDC $18^{\circ}$ of fuel injection timing and it is increased in case of leading the injection timing. (2) Soot emission is decreased in case of leading fuel injection timing and it is increased in the form of convex downwards with increasing the load. (3) $NO_x$ emission is increased in case of leading fuel injection timing and it is increased in the form of straight line nearly with increasing the load. (4) HC and CO emissions are decreased in case of leading fuel injection timing and they are changed in the form of convex downwards with increasing the load.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2003.07b
• /
• pp.1139-1142
• /
• 2003

NOx, Soot and other exhausted components already became a dangerous state as principal materials of the air pollution. Therefore, the exhausted regulations are getting strict in the many countries. In this paper, reduction characteristic of NOx, Soot and CO from diesel engine are investigated, when MF plasma-EGR hybride system is put to the diesel engine. NOx is decreased in all measured load and applied voltage to plasma renter However Soot is increased as increasing EGR rate and it is decreased as increasing applied voltage.

• Journal of the Korean Ceramic Society
• /
• v.45 no.9
• /
• pp.497-506
• /
• 2008

The long time of twenty years has passed since Diesel Particulate Filter (DPF) was proposed before the practical use. The main factors that DPF has been put to practical use in this time, are the same time proposal of the evaluation method of SiC porous materials linked to he performance on the vehicle, and that the nature of thermal shock required for the soot regeneration (combustion of soot) in the DPF is different from the conventional requirement for the rather rapid thermal shock. For the requirements, these includ demonstrating utmost the characteristic of SiC's high thermal conductivity, and overcoming the difficulty of thermal expansion of SiC-DPF by dividing the filter into segments binding with the cement of lower Young's modulus, and the innovation of technology around the diesel exhaust system such as Common-Rail system. As the results of these, the cumulative shipments of SiC-DPF have reached about 5 million, and it goes at no claim in the market.

• Transactions of the Korean Society of Machine Tool Engineers
• /
• v.13 no.3
• /
• pp.98-103
• /
• 2004

Diesel engine offers superior fuel consumption than gasoline engine of equivalent capacity. For this reason, diesel engines are widely used in heavy duty transport applications. Specially, it has been many years that exhaust gases from gasoline automobile rather than from diesel is the major object concerned by Korea and other countries, and it is strongly required on the reduction techniques on harmful NOx, Soot, CO, He. Thus, this paper focused on the emission reduction and target for this paper is heavy-duty diesel engine equipped with power filter such as wet type air cleaner. In this paper, the performance, exhaust emissions(CO, THC, NOx, Soot) and noise of heavy-duty diesel engine were measured at maximum load condition and the range of 1,000∼2,200rpm. The smoke was measured at FAS(Free Accel Smoke) test mode.