• Journal of Advanced Marine Engineering and Technology
• /
• v.29 no.6
• /
• pp.628-636
• /
• 2005

In this paper. the effects of a WI(Water Injection) in the intake pipe for a 4-cylinder Dl(Direct Injection) diesel engine are investigated experimentally, The WI system was controlled by the duty cycle from the intake manifold's temperature and MAF(Manifold Air Flow) First. effect of EGR on NOx reduction was investigated. Then WI system was applied to reduce NOx As the results. we can make the NOx map and visualize the NOx results by variation of engine speed and engine load It was known that effect of WI system on NOx reduction without the EGR was better than the with EGR base engine except of low load and speed condition.

• Proceedings of the KSME Conference
• /
• 2003.04a
• /
• pp.2186-2191
• /
• 2003

This study is to investigate the effects of water induction through the air intake system on the characteristics of combustion and exhaust emissions in diesel engine. The effects of water induction through the air intake port were considered in IDI diesel engine in this study. The formation of NOx was significantly suppressed by decreasing the gas peak temperature during the initial combustion process because the water play a role as a heat sink during evaporating in the combustion chamber, but the smoke was slightly increased with increased water amount. Also, NOx significantly decreased with increase in water amount. A simultaneous reduction in smoke and NOx emissions can be obtained when water is injected into the combustion chamber by retarding the fuel injection timing more than without water injection.

• Transactions of Materials Processing
• /
• v.17 no.5
• /
• pp.337-342
• /
• 2008

The injection molding process has high accuracy and good reproducibility that are essential for mass production at low cost. Conventional molding processes typically use the water-based mold heating and air cooling methods. However, in the nano injection molding processes, this semi-active mold temperature control results in the several defects such as air-flow mark, non-fill, sticking and tearing, etc. In order to actively control temperature of the molds and effectively improve the quality of the molded products, the novel nano injection molding system, which uses active heating and cooling method, has been introduced. By using the Peltier devices, the temperature of locally adiabatic molds can be controlled dramatically and the quality of the molded patterns can be improved.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.4 no.4
• /
• pp.46-57
• /
• 1996

The direct injection stratified charge(DISC) engine enhances the fuel tolerance and the antiknock tendency. This enhanc3d antiknock tendency allows use of a higher compression ratio which results in higher thermal efficiency. But its actual utilization is prevented by high emission combustion time and wall quenching will be the main causes of increasing unburned hydrocarbons in DISC system. In order to solve this problem, small aount of hydrogen was added to the charging air or injected fuel. The effects of hydrogen addition were examined experimentally by radial fuel injection using a pancake-type constant volume bomb. In case of the hydrogen addition to the charge of air, the combustion the amount of hydrogen. In case of the hydrogen addition to the fuel, the combustion pressure was significantly increased.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.13 no.1
• /
• pp.28-35
• /
• 2005

Fuel injection rate of an injector is affected by various injection conditions such as injection duration, fuel temperature, injection pressure, and voltage in LPG liquid injection systems for either a port-fuel-injection(PFI) or a direct injection(DI) in a cylinder. Even fuel injection conditions are changed, the air-fuel ratio should be accurately controlled to educe exhaust emissions. In this study, correction factor for the fuel injection rate of an injector is derived from the density ratio and the pressure difference ratio. A voltage correction factor is researched from injection test results on an LPG liquid injection engine. A compensation method of the fuel injection rate is proposed for a fuel injection control system. The experimental results for the LPG liquid injection system in a SI-engine show that this system works well on experimental range of engine speed and load conditions. And the fuel injection rate is accurately controlled by the proposed compensation method.

• Journal of Biosystems Engineering
• /
• v.35 no.3
• /
• pp.163-168
• /
• 2010

With income growth and "well-being" trends, sales of corn has been increased recently. Corns are processed at processing facilities on the main production site. Corn processing steps include removing bract, steaming, vacuum packing, and storing. To replace manual corn bract removing, some bract removing machines were imported and used. However, the machines were abandoned shortly, because of high damaging ratio of corns. In this research, factors of successful bract removing was studied with rotating rollers and air-injection nozzles to develop corn bract removing system. The test device was composed of a cylindrical roller, an air spray nozzle, a regulator, and a motor. Designing factors were roller type, diameter of air spraying nozzle, spraying angle, and spraying pressure. The measured factors were bract removing rate and damaging rate. It was found that optimum cylindrical roller surface shape was cylindrical roller and linear grove roller. This roller shape produced lowest damaging rate. Test results of the efficacy of preprocessing showed that the air spraying after preprocessing produced highest performance. The rotational speed and inclination of the roller didn't affect the bract removing performance. Optimum injection angle of the air jet nozzle was $70^{\circ}$. To increase bract removing rate and to reduce corn damage, required injection pressure and injection nozzle diameter were decided to less than 0.4 MPa and 2.5 mm, respectively. More than 3 times of nozzle passing produced good bract removing performance and there were no significant difference between the number of passing times.

• Journal of Advanced Marine Engineering and Technology
• /
• v.28 no.3
• /
• pp.457-465
• /
• 2004

Environmental protection on the ocean has been interested and nowadays the International Maritime Organization(IMO) has advanced on the prevention of air pollution from ships. This study presents the performance and the emission characteristics of 4 stroke marine diesel engines for generation application in D2 cycle(IMO mode). The effects of important operating parameters, such as intake air pressure. intake air temperature and maximum combustion pressure on NOx emissions were also described. Emissions measurement and calculation are processed according to IMO Technical Code. The results show that the maximum combustion pressure by fuel injection timing control and intake air temperature has strong influence on NOx emission production. But NOx emission is not affected by intake air pressure and exhaust gas back pressure.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2017.05a
• /
• pp.236-237
• /
• 2017

This study discusses the development of waterproofing layer jet-spray nozzle that forms a three-dimensional air cell. This nozzle has an air flow generation mechanism in the air groove of the attachment cell part located at the end of the injection nozzle. Since the air grooves also function as an air curtain, the airborne particles generated when the waterproof material is sprayed is effectively blocked. In the past, spraying of the waterproof material through the high pressure was possible, but this technology allows stable injection due to the static agitation method, and various problems caused by particle generation has been (damages to neighboring areas, economic loss, etc.) minimized.

• Journal of ILASS-Korea
• /
• v.3 no.4
• /
• pp.16-24
• /
• 1998

The fuel injection type, in the gasoline engines of atomization of fuel droplet and its distribution hae influenced directly on the decision of engine performance and harmful emission. In this paper, atomization characteristics of fuel spray is investigated with microscopic visualization system. Particle motion analysis system is used to measure the SMD from fuel spray of air-assisted injector by initial factors such as temperature of ambient air and air-assisted pressure. As air-assist pressure and ambientair temperature increase, the SMD is decreased, and its variation is more stable.

• Journal of ILASS-Korea
• /
• v.12 no.2
• /
• pp.115-122
• /
• 2007

The spray characteristics and drop size measurements have been experimentally studied in liquid jets injected into subsonic crossflow. With water as fuel injection velocity, injection angle and atomize. internal flows were varied to provide of jet operation conditions. The injector internal flow was classified as three modes such as a non-cavitation flow, cavitation, and hydraulic flip flows. Pulsed Shadowgraph Photography measurement was used to determine the spatial distribution of the spray droplet diameter in a subsonic crossflow of air. And this study also obtains the SMD (Sauter Mean Diameters) distribution by using Planar Liquid Laser Induced Fluorescence technique. The objectives of this research are get a droplet distributions and drop size measurements of each condition and compare with the other flow effects. As the result, This research has been showned that droplet size were spatially dependent on air-stream velocity, fuel injection velocity, injection angle effects, and normalized distance from the injector exit length(x/d, y/d). There are also different droplet size characteristics between cavitation, hydraulic flip and the non-cavitation flows.