• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.37 no.3
• /
• pp.397-403
• /
• 2013

The demand for eco-friendly and higher fuel economy vehicles has helped develop eco-friendly and fuel-efficient vehicles such as hybrid vehicles. In a hybrid vehicle, the change in the battery charge after driving should be added to the fuel consumption as the equivalent fuel usage based on its own characteristics. Thus, the fuel efficiency of a hybrid vehicle cannot be improved simply by increasing the battery capacity. In this study, I attempt to improve the total fuel economy of a hybrid vehicle, including the equivalent fuel consumption, by modeling a fuel cell hybrid vehicle using Matlab Simulink, analyzing the usage zone of the fuel cell with the existing control strategy, and optimizing the power distribution of the battery and fuel cell in the main usage zone of the fuel cell.

• Journal of Environmental Science International
• /
• v.33 no.2
• /
• pp.161-168
• /
• 2024

This study was conducted to identify the pollutants generated by the fuel complex and to determine the health effects of the surrounding residents. In addition, based on the results of epidemiological surveys and health impact surveys of local residents, we analyze the distribution of patient groups and exposure characteristics according to the distance from the fuel complex boundary. Samples were collected from the briquette plant within the fuel complex and analyzed by SEM-EDXA, X-ray Fluorescence Spectrometer, and ICP. In addition, the distribution of patients and exposure characteristics were analyzed according to the distance from the fuel complex and yard boundaries. Analysis of briquette samples from the fuel complex showed that the average particle size was 10-30 ㎛, the shape was irregular, and SiO₂ accounted for more than 50%. It is believed that silica, which causes pneumoconiosis, may have been scattered into the air. In particular, there was a large distribution of 5 ㎛ particles that affect respiratory diseases. According to the analysis of the residential addresses and distribution of pneumoconiosis cases, many pneumoconiosis cases were located in the area between 200 and 500 meters from the boundary of the fuel complex. In addition, 28 pneumoconiosis cases were identified as a result of the epidemiological survey and health impact survey at the fuel complex. In detail, there were 8 cases of occupational pneumoconiosis, 6 cases of environmental pneumoconiosis, and 14 cases of occupational and environmental pneumoconiosis. The confirmed pneumoconiosis cases were located between 0.3 and 1.1 kilometers from the fuel complex. It was found that environmental pollutants generated by the fuel complex adversely affect the health of local residents. In particular, there are many cases of pneumoconiosis in the area between 200 and 500 meters from the boundary of the fuel complex, and this distance is considered to be the direct and indirect impact zone of the briquette plant.

• The KSFM Journal of Fluid Machinery
• /
• v.15 no.5
• /
• pp.11-19
• /
• 2012

The main function of fuel cell manifold is to render reactants distribution as uniform as possible into a fuel cell stack. The purpose of this study is to numerically investigate the effects of stack manifold design on reactants distribution within a fuel cell stack. Four manifold designs with different manifold entrance shapes (expansion or diffuser) and different values of the extra width between the cell outer channel and manifold side wall are considered and applied to the fuel cell stack consisting of 50 cells. Since the fuel cell stack geometry involves several millions of grid points for numerical calculations, a parallel computing methodology is employed to substantially reduce the computational time and overcome the memory requirement. The numerical simulations are carried out and calculated results clearly demonstrate that both the manifold entrance shape and extra width have a substantial influence on manifold performance, controlling the degree of flow separation and entrance length for fully developed flow in the manifold channel. Finally, we suggest the optimum design of fuel cell manifold based on the simulation results.

• Journal of ILASS-Korea
• /
• v.4 no.2
• /
• pp.19-32
• /
• 1999

The present study investigated the forms and behaviors of fuel during intake and compression process, and the initial flame stability in a lean burn engine modified as a single cylinder engine equipped with quartz windows for visualization. PLIF(Planar Laser Induced Fluorescence) method with KrF Excimer laser was used for measuring the fuel distributions. The principal design concept of the lean burn nin in this study is the axial stratification in the fuel distribution via fuel injection during intake process and different shapes of intake ports; helical and straight. The experiments showed that fuel flowed in as a vapor state in the early part of intake process and lots of this mixture mated down along the intake valve side cylinder wall, but in the latter part, a lot of fuel flowed in as a liquid state and this fuel stayed in the upper part of cylinder, after that the dense fuel cloud moved upward in the early of part compression process. It became clear that the fuel flowed in via straight port had a important role in the axial fuel stratification.

• Journal of Electrochemical Science and Technology
• /
• v.8 no.4
• /
• pp.331-337
• /
• 2017

A simple strategy is proposed herein for attaining uniform current distribution in direct methanol fuel cells by varying the catalyst loading over the electrode. In order to use the same total catalyst amount for a serpentine flow field, three spatial variation types of catalyst loading were selected: enhancing the cathode catalyst loading (i) near the cathode outlet, (ii) near the cathode inlet, and (iii) near the lateral areas. These variations in catalyst loading are shown to improve the homogeneity of the current distribution, particularly at lower currents and lower air-flow rates. Among these three variations, increased loading near the lateral areas was shown to contribute most to achieving a homogenous current distribution. The mechanism underlying each catalyst loading variation method is different; very high catalyst-loading is shown to decrease the homogeneity of the distribution, which may be caused by water management in the thick catalyst layer thereof.

• Journal of Energy Engineering
• /
• v.24 no.4
• /
• pp.33-41
• /
• 2015

Dimethyl ether (DME) can be used as a clean diesel alternative fuel due to the high cetane number and low emission, it can also be applied to automotive fuel as a blended liquefied petroleum gas (LPG) because physical properties are similar to those of LPG. In this study, feasibility test of LPG vehicle using blended DME-LPG fuel was investigated. Three types of fuel supply such as LPLi (Liquid phase LPG injection), LPGi (Liquid phase gas injection) and mixer type were selected to consider the LPG fuel-injection system. The performance characteristics of LPG vehicle were examined by using LPG and blended DME-LPG fuel in order to compare the exhaust emissions (CO, THC, $NO_X$) and fuel economy. The emissions and fuel economy of DME-LPG blend fuel were comparable to those of LPG with increasing driving distance.

• Journal of Power System Engineering
• /
• v.15 no.1
• /
• pp.5-10
• /
• 2011

The spatial fuel vapor distribution of the homogeneous charge by a 6-hole injector was examined in a optically accessed single cylinder direct injection spark ignition(DISI) engine. The effects of in-cylinder charge motion, and fuel injection pressure, and coolant temperature were investigated using a planar LIF (Laser Induced Fluorescence) technique. It was confirmed that the in-cylinder tumble flow played a little more effective role in the spatial fuel vapor distribution than the swirl flow during the compression stroke at 10 mm and 2 mm planes under cylinder head gasket and the increased fuel injection pressure activated spatial distributions of the fuel vapor. In additions, richer mixtures were concentrated around the cylinder wall by the increase of the coolant temperature.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.21 no.9
• /
• pp.1198-1206
• /
• 1997

The flow characteristics of an intermittent fuel injection into a stationary ambient air were investigated using gasoline. The measurements were made by two-channel, air cooling type Phase Doppler Anemometer(PDA) system (DANTEC, 750 MW). And a pintle type injector of MPI (Multi-point Port Injection) system was utilized as a fuel injector. The PDA receiver optic was set up in a 60.deg. C forward scatter arrangement to obtain the optimum scattering signal of fuel droplets. The data were obtained by synchronizing PDA system with the fuel injection period, and the axial and radial velocity and turbulent components of fuel droplets were mainly measured for the analysis of temporal and spatial distribution depending upon the fuel injection pressures.

• Transactions of the Korean hydrogen and new energy society
• /
• v.29 no.3
• /
• pp.299-305
• /
• 2018

The domestic label fuel economy measurement method is the same as the North American measurement method. The results of two test modes (city [FTP-75 mode], highway [HWFET mode]) are calculated to be equivalent to the final fuel economy value calculated as the result of five test modes reflecting various environmental conditions and driving patterns 5-cycle correction formula is used. In this study, we tried to find out that the difference between the domestic label fuel economy of the vehicle and the real road fuel economy felt by the driver compared to the new vehicle condition as the mileage increases. Using domestic label fuel economy measurement method, Four gasoline vehicles and four diesel vehicles were tested for the fuel economy of a new vehicle with a mileage of 150 km or less and domestic fuel economy test $6,500{\pm}1,000km$ durability condition and 15,000 km durability. It is confirmed that the certain portion (6,500 km endurance vehicle) The increase in mileage did not affect the fuel economy or the emission gas significantly, indicating that vehicle durability was limited.

• International Journal of Automotive Technology
• /
• v.7 no.4
• /
• pp.493-500
• /
• 2006

Investigation on the fuel adhering on a wall was carried out experimentally to clarify the characteristics of impinging diesel sprays. Diesel sprays were injected into a high-pressure chamber of cold state and impinged to a wall having various impingement distances and ambient pressures. Photographs of both the fuel film and the post-impingement spray were taken through a transparent wall. Adhered fuel mass on a wall was measured by means of dividing into two types of fuel state: the fuel film itself; and sparsely adhered fuel droplets. Adhering fuel ratio was predicted and further the distribution of fuel mass for impinging diesel spray was analyzed as a function of time. As result, with an increase of the ambient pressure, both the maximum fuel film diameter and the adhered fuel ratio decreased. Based on some assumptions, the adhering fuel mass increased rapidly until the fuel film diameter approached the maximum value, and then increased comparatively gradually.