Go to the main menu
Skip to content
Go to bottom
REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
Transactions of the Korean hydrogen and new energy society
Journal Basic Information
Journal DOI :
The Korean Hydrogen and New Energy Society
Editor in Chief :
Volume & Issues
Volume 23, Issue 6 - Dec 2012
Volume 23, Issue 5 - Oct 2012
Volume 23, Issue 4 - Aug 2012
Volume 23, Issue 3 - Jun 2012
Volume 23, Issue 2 - Apr 2012
Volume 23, Issue 1 - Feb 2012
Selecting the target year
Prediction of Bypass Flow Rate through Gas Diffusion Layer in PEMFC with Serpentine Flow Channels
Jeon, Se-Gye ; Kim, Kuoung-Youn ;
Transactions of the Korean hydrogen and new energy society, volume 23, issue 4, 2012, Pages 293~299
DOI : 10.7316/KHNES.2012.23.4.293
The serpentine flow channel is widely used in polymer electrolyte membrane fuel cells (PEMFCs) to prevent flooding phenomena because it effectively removes liquid water in the flow channel. The pressure drop between inlet and outlet increases as compared with straight channels due to minor losses associated with the corners of the turning configurations. This results in a strong pressure gradient between adjacent channels in specific regions, where some amount of reactant gas can be delivered to catalyst layers by convection through a gas diffusion layer (GDL). The enhancement of the convective flow in the GDL, so-called bypass flow, affects fuel cell performance since the bypass flow influences the reactant transport and thus its concentration over the active area. In the present paper, for the bipolar plate design, a simple analytic model has been proposed to predict the bypass flow in the serpentine type flow channels and validated with three-dimensional numerical simulation results.
Development and Demonstration of 150W Fuel Cell Propulsion System for Unmanned Aerial Vehicle (UAV)
Yang, Cheol-Nam ; Kim, Yang-Do ;
Transactions of the Korean hydrogen and new energy society, volume 23, issue 4, 2012, Pages 300~309
DOI : 10.7316/KHNES.2012.23.4.300
Long endurance is a key issue in the application of unmanned aerial vehicles. This study presents feasibility test results when fuel cell system as an alternative to the conventional engine is applied for the power of the UAV after the 150W fuel cell system is developed and packaged to the 1/4 scale super cub airplane. Fuel cell system is operated by dead-end method in the anode part and periodically purged to remove the water droplet in flow field during the operation. Oxygen in the air is supplied to the stack by the two air blowers. And fuel cell stack is water cooled by cooling circuit to dissipate the heat generated during the fuel cell operation. Weight balance is considered to integrate the stack and balance of plant (BOP) in package layout. In flight performance test, we demonstrated 4 times standalone take-off and landing. In the laboratory test simulating the flight condition to quantify the energy flow, the system is analyzed in detail. Sankey diagram shows that electric efficiency of the fuel cell system is 39.2%, heat loss 50.1%, parasitic loss 8.96%, and unreacted purged gas 1.67%, respectively compared to the total hydrogen input energy. Feasibility test results show that fuel cell system is high efficient and appropriate for the power of UAV.
Moisture Absorption Characteristics of Pt/Nafion Membrane for PEMFC Prepared by a Drying Process
Lee, Jae-Young ; Lee, Hong-Ki ;
Transactions of the Korean hydrogen and new energy society, volume 23, issue 4, 2012, Pages 310~315
DOI : 10.7316/KHNES.2012.23.4.310
A simple drying process was developed for the preparation of a Pt/Nafion self-humidifying membrane to be used for a proton-exchange membrane fuel cell (PEMFC). Platinum (II) bis (acetylacetonate),
was sublimed, penetrated into the surface of a Nafion film and then reduced to Pt nanoparticles simultaneously without any support of a reducing agent in a glass reactor at
for 15 min. The process was carried out in
atmosphere to prevent the oxidation of Pt nanoparticles at high temperature. The morphology and distribution of the Pt nanoparticles were observed by transmission electron microscopy (TEM) and energy dispersive spectroscopy (EDS), and we found that the average Pt particle size was ca. 3.7 nm, the penetration depth was ca.
. Almost all Pt nanoparticles were formed just beneath the surface and the number density decreased rapidly as the penetration depth increased. To estimate water absorption characteristics of the Nafion membranes, water uptake at an isothermal condition was measured by dynamic vapor sorption (DVS), and it was found that water uptake of the Pt/Nafion membrane was higher than that of the neat Nafion membrane.
The Evaluation of Hydrogen Leakage Safety for the High Pressure Hydrogen System of Fuel Cell Vehicle
Kim, Hyun-Ki ; Choi, Young-Min ; Kim, Sang-Hyun ; Shim, Ji-Hyun ; Hwang, In-Chul ;
Transactions of the Korean hydrogen and new energy society, volume 23, issue 4, 2012, Pages 316~322
DOI : 10.7316/KHNES.2012.23.4.316
A fuel cell vehicle has the hydrogen detection sensors for checking the hydrogen leakage because it use hydrogen for its fuel and can't use a odorant to protect the fuel cell stack. To verify the hydrogen safety of leakage we select the high possible leak points of fittings in hydrogen storage system and test the leaking behavior at them. The hydrogen leakage flow rate is 10, 40, 118 NL/min and the criterion for maximum hydrogen leakage is based on allowing an equivalent release of combustion energy as permitted by gasoline vehicles in FMVSS301. There are total 18EA hydrogen leakage detection sensors installed in test system. we acquire the hydrogen leakage detection time and determine the ranking. Hydrogen leakage detection time decrease when hydrogen leakage flow rate increase. The minimum hydrogen leakage detection time is about 3 seconds when the flow rate is 118NL/min. In this study, we optimize hydrogen sensor position in fuel cell vehicle and verify the hydrogen leakage safety because there is no inflow inside the vehicle.
Model Based Hardware In the Loop Simulation of Thermal Management System for Performance Analysis of Proton Exchange Membrane Fuel Cell
Yun, Jin-Won ; Han, Jae-Young ; Kim, Kyung-Taek ; Yu, Sang-Seok ;
Transactions of the Korean hydrogen and new energy society, volume 23, issue 4, 2012, Pages 323~329
DOI : 10.7316/KHNES.2012.23.4.323
A thermal management system of a proton exchange membrane fuel cell is taken charge of controlling the temperature of fuel cell stack by rejection of electrochemically reacted heat. Two major components of thermal management system are heat exchanger and pump which determines required amount of heat. Since the performance and durability of PEMFC system is sensitive to the operating temperature and temperature distribution inside the stack, it is necessary to control the thermal management system properly under guidance of operating strategy. The control study of the thermal management system is able to be boosted up with hardware in the loop simulation which directly connects the plant simulation with real hardware components. In this study, the plant simulation of fuel cell stack has been developed and the simulation model is connected with virtual data acquisition system. And HIL simulator has been developed to control the coolant supply system for the study of PEMFC thermal management system. The virtual data acquisition system and the HIL simulator are developed under LabVIEWTM Platform and the Simulation interface toolkit integrates the fuel cell plant simulator with the virtual DAQ display and HIL simulator.
High Voltage Wiring System Evaluation Methode of FCEV (Fuel Cell Electric Vehicle)
Lim, Ji-Seon ; Lee, Jeong-Hun ; Lee, Hyo-Jeong ; Na, Joo-Ran ;
Transactions of the Korean hydrogen and new energy society, volume 23, issue 4, 2012, Pages 330~336
DOI : 10.7316/KHNES.2012.23.4.330
FCEV uses 250 ~ 450 V instead of using 12 V battery. High voltage vehicle can cause electric shock, fire and explosion accident. Therefore, it has potential factors that can cause hazard of safety for users. United states of America and Europe legislate regulations such as ECE R100, FMVSS 305 for regulating electrical safety during driving or after collision. The company manufacturing high voltage components must do advanced R&D about Method for improving and confirming the safety of high voltage. We develop the specific hardware components of high voltage wiring system for the power train system and power supply system of Hyundai Motors FCEV. This paper shows test method of insulative performance for securing the electrical safety of high voltage components such as power cable, connectors and buss-bar, and proposals the guide line value for human safety of FCEV according to the test result of our development components.
Reaction Characteristics of WGS Catalyst for SEWGS Process in a Pressurized Fluidized Bed Reactor
Kim, Ha-Na ; Lee, Dong-Ho ; Lee, Seung-Yong ; Hwang, Taek-Sung ; Ryu, Ho-Jung ;
Transactions of the Korean hydrogen and new energy society, volume 23, issue 4, 2012, Pages 337~345
DOI : 10.7316/KHNES.2012.23.4.337
To check effects of operating variables on reaction characteristics of WGS catalyst for SEWGS process, water gas shift reaction tests were carried out in a pressurized fluidized bed reactor using ShiftMax210 catalyst and sand(as a substitute for
absorbent) as bed materials. Simulated syngas(mixed with
) was used as a reactant gas. Operating temperature was
and operating pressure was 20 bar. WGS catalyst content, steam/CO ratio, gas velocity, and syngas concentration were considered as experimental variables. CO conversion increased as the catalyst content and steam/CO ratio increased. CO conversion at fluidized bed condition was higher than that of fixed bed condition. However, CO conversion were maintained almost same value within the fluidized bed condition. CO conversion decreased as the syngas concentration increased. The optimum operation condition was confirmed and long time water gas shift reaction test up to 24 hours at the optimum operating conditions was carried out.
A Study of Methane Oxidation over Transition Metal (TM)/CeO
(TM=Ni, Co, Cu, Fe)
Ahn, Ki-Yong ; Chung, Yong-Chae ; Lee, Jong-Ho ;
Transactions of the Korean hydrogen and new energy society, volume 23, issue 4, 2012, Pages 346~352
DOI : 10.7316/KHNES.2012.23.4.346
The properties of methane oxidation were studied in this research over transition metal containing
, TM=Ni, Co, Cu, Fe) with TM content of 5 wt. % at atmospheric pressure. The characteristics of catalysts were investigated by various characterization techniques, including XRD, GC, SEM and EPMA analyses. The catalytic tests were carried out in a fixed Rmix ratio of 1.5 (
) in a fixed-bed reactor operating isothermally at atmospheric pressure. Only the Ni/
catalysts showed syngas production above
via typical partial oxidation reaction whereas other catalysts induced complete oxidation resulting in the production of
in whole reaction temperature range. From the quantitative analysis on carbon deposition after catalytic tests, Cu/
was found to show the highest resistance on carbon deposition. Therefore Cu can be proposed as an efficient catalyst element which can be combined with a conventional Ni-based SOFC anode to enhance the carbon tolerance.
Electrochemical Characteristics of Porous Modified Silicon Impregnated with Metal as Anode Materials for Lithium Secondary Batteries
Jang, Eun-Jung ; Jeon, Bup-Ju ;
Transactions of the Korean hydrogen and new energy society, volume 23, issue 4, 2012, Pages 353~363
DOI : 10.7316/KHNES.2012.23.4.353
The relationship between the diffusivity and electrochemical characteristics of lithium secondary battery with the modified Si anode material prepared in HF/
solution was investigated. The crystallographic structure and images of the modified porous Si and modified Si/Cu was examined using the X-ray diffraction, BET and SEM. To examine the effect of metal composite and pore size distribution according to chemical etching on the electrochemical characterization, the electrodes for half cells were prepared with the modified Si, modified Si/Cu, and modified Si/Cu annealed with
. Our results showed that the chemical diffusivity of lithium ions was related to structure and resistance of Si/Cu composite anode material. The lithium diffusivity in modified silicon compound calculated from the CV was at the range of
. The effects of modified silicon structure and resistance on the cycling efficiency were significant.
Measurements on Transient Mixing Concentrations of Two Fuel Oils using a Quantitative Flow Visualization Technique
Yum, Joo-Ho ; Doh, Deog-Hee ; Cho, Gyeong-Rae ; Min, Seong-Ki ; Kim, Myung-Ho ; Ryu, Gyong-Won ;
Transactions of the Korean hydrogen and new energy society, volume 23, issue 4, 2012, Pages 364~372
DOI : 10.7316/KHNES.2012.23.4.364
Transient mixing states of two different fuel oils, dimethylformamide (DMF) oil and JetA1 oil, were investigated by using a color image processing and a neural network. A tank (
) was filled with JetA1 oil. The DMF oil was filled at a top tank, and was mixed with the JetA1 oil in the tank mixing tank via a sudden opening which was performed by nitrogen gas with 1.9 bar. An impeller was rotated with 700 rpm for mixing enhancements of the two fuel oils. To visualize the mixing state of the DMF oil with the JetA1 oil, the DMF oil was coated with Rhodamine B whose color was red. A LCD monitor was used for uniform illumination. The color changes of the DMF oil were captured by a camcoder and the images were transferred to a host computer for quantifying the information of color changes. The color images of two mixed oils were captured with the camcoder. The R, G, B color information of the captured images was used to quantify the concentration of the DMF oil. To quantify the concentration of the DMF oil in the JetA1 oil, a calibration of color-to-concentration was carried out before the main experiment was done. Transient mixing states of DMF oil with the JetA1 oil since after the sudden infiltration were quantified and characterized with the constructed visualization technique.
An Investigation of Performance Characteristics of A Biogas-Fueled Motorcycle Engine
Huynh, Thanh Cong ; Chiem, Tran Lam ; Vu, Thi Kim Chau ;
Transactions of the Korean hydrogen and new energy society, volume 23, issue 4, 2012, Pages 373~381
DOI : 10.7316/KHNES.2012.23.4.373
To determine the performance characteristics of motorcycle engine using biogas for practical use, the intake system of a 110 cc motorcycle engine is properly modified to operate with biogas as a fuel. Biogas is a potentially renewable fuel for replacing gasoline in future, but it has high percentage of
that could lead to slow the burning rate of biogas-air mixture and cause instability in combustion. Thus, the performance characteristics of biogas-fueled motorcycle engines could be different from those of gasoline motorcycle engines. In this paper, the important parameters of performance characteristics (such as: power output, thermal efficiency, fuel consumption, exhaust emission,
) of biogas-fueled motorcycle engine are studied and estimated with change of engine speed and load. The obtained results when operating with biogas are used to compare with that of gasoline fuel under the same operating conditions. Engine speed in the experimental is changed from 1500 rpm (idle-mode) up to 3500 rpm by a step of 500 rpm. Engine load is changed from zero to maximum load with the help of an exciting voltage device from generator-type dynamometer. The experimental results show that the tested engine operated with richer biogas-air mixture than that of gasoline-air mixture under the same test conditions. Biogas-fueled engine gives a higher fuel consumption and lower thermal efficiency under the same power output. Brake thermal efficiency of biogas engine is found to be about 3% lower than gasoline-fueled motorcycle engine for whole range of speed. Exhaust emission of biogas-fueled motorcycle engine (such as: CO, HC) is found to be lower than the limitation level of the emission standards of Vietnam for motorcycle engines (CO <4.5% HC <1200 ppm).
Performance Analysis of a Combined Power Cycle Utilizing Low-Temperature Heat Source and LNG Cold Energy
Kim, Kyoung-Hoon ; Oh, Jae-Hyeong ; Ko, Hyung-Jong ;
Transactions of the Korean hydrogen and new energy society, volume 23, issue 4, 2012, Pages 382~389
DOI : 10.7316/KHNES.2012.23.4.382
Power generation cycle using ammonia-water mixture as working fluid has attracted much attention because of its ability to efficiently convert low-temperature heat source into useful work. If an ammonia-water power cycle is combined with a power cycle using liquefied natural gas (LNG), the conversion efficiency could be further improved owing to the cold energy of LNG at
. In this work parametric study is carried out on the thermodynamic performance of a power cycle consisted of an ammonia-water Rankine cycle as an upper cycle and a LNG cycle as a bottom cycle. As a driving energy the combined cycle utilizes a low-temperature heat source in the form of sensible heat. The effects on the system performance of the system parameters such as ammonia concentration (
), turbine 1 inlet pressure (
) and temperature (
), and condenser outlet temperature (
) are extensively investigated. Calculation results show that thermal efficiency increases with the increase of
and the decrease of
, while its dependence on
has a downward convex shape. The changes of net work generation with respect to
are roughly linear.
Effects of Electrolyte Concentration on Growth of Dendritic Zinc in Aqueous Solutions
Shin, Kyung-Hee ; Jung, Kyu-Nam ; Yoon, Su-Keun ; Yeon, Sun-Hwa ; Shim, Joon-Mok ; Joen, Jae-Deok ; Jin, Chang-Soo ; Kim, Yang-Soo ; Park, Kyoung-Soo ; Jeong, Soon-Ki ;
Transactions of the Korean hydrogen and new energy society, volume 23, issue 4, 2012, Pages 390~396
DOI : 10.7316/KHNES.2012.23.4.390
In order to understand the nature of dendritic zinc growth, electrochemical zinc redox reaction on nickel plate was investigated in aqueous solutions containing different concentrations, 0.2, 0.1 and 0.02
(M), of zinc sulfate (
) or zinc chloride (
). Zinc ion was efficiently reduced and oxidized on nickel in the high-concentration (0.2 M) solution, whereas relatively poor efficiency was obtained from the other low-concentration solutions (0,1 and 0.02 M). Cyclic voltammetry (CV) analysis revealed that the 0.2 M electrolyte solution decomposes at more positive potentials than the 0.1 and the 0.02 M solutions. These results suggested that the concentration of electrolyte solution and anion would be an important factor that suppresses the reaction of the zinc dendrite formation. Scanning Electron Microscopy (SEM) data revealed that the shape of dendritic zinc and its growing behavior were also influenced by electrolyte concentration.
Hydrogen Fermentation of the Galactose-Glucose Mixture
Cheon, Hyo-Chang ; Kim, Sang-Youn ;
Transactions of the Korean hydrogen and new energy society, volume 23, issue 4, 2012, Pages 397~403
DOI : 10.7316/KHNES.2012.23.4.397
Galactose, an isomer of glucose with an opposite hydroxyl group at the 4-carbon, is a major fermentable sugar in various promising feedstock for hydrogen production including red algal biomass. In this study, hydrogen production characteristics of galactose-glucose mixture were investigated using batch fermentation experiments with heat-treated digester sludge as inoclua. Galactose showed a hydogen yield compatible with glucose. However, more complicated metabolic steps for galactose utilization caused a slower hydrogen production rate. The existence of glucose aggravated the hydrogen production rate, which would result from the regulation of galactose-utilizing enzymes by glucose. Hydrogen produciton rate at galactose to glucose ratio of 8:2 or 6:4 was 67% of the production rate for galactose and 33% for glucose, which could need approximately 1.5 and 3 times longer hydraulic retention time than galacgtose only condition and glucose only condition, respectively, in continuous fermentation. Hydrogen production rate, Hydrogen yield, and organic acid production at galactose to glucose ratio of 8:2 or 6:4 were 0.14 mL H2/mL/hr, 0.78 mol
/mol sugar, and 11.89 g COD/L, respectively. Galactose-rich biomass could be usable for hydogen fermenation, however, the fermentation time should be allowed enough.
A Numerical Simulation for the Spring Hardness of a Free Piston Linear Engine
Hung, Nguyenba ; Oh, Yong-Il ; Park, Kyu-El ; Lim, Ock-Taeck ;
Transactions of the Korean hydrogen and new energy society, volume 23, issue 4, 2012, Pages 404~411
DOI : 10.7316/KHNES.2012.23.4.404
This research numerically analyses the effects of the damping device on the operation characteristics of a free piston linear engine. In this paper, the free piston linear engine uses spring as a damping device. The investigated parameter is spring hardness which is varied at 0.5, 1, 2.9, and 14.7 N/mm. The effects of spring hardness on the dynamic characteristic, thermodynamic characteristic and electric power of the engine are investigated. Beside, the equivalent ratio is also changed to provide more information for this study. The simulation results show that, by increasing spring hardness from 0.5 to 14.7 N/mm, all of parameters related to dynamic characteristic such as piston velocity, acceleration, displacement, and frequency increase accordingly. Beside, the peak pressure in the cylinder and electric power are also increased when increasing spring hardness. The tendency is also observed at varied equivalent ratios.
Effects of Hydrogen in SNG on Gas Turbine Combustion Characteristics
Park, Se-Ik ; Kim, Ui-Sik ; Chung, Jae-Hwa ; Hong, Jin-Pyo ; Kim, Sung-Chul ; Cha, Dong-Jin ;
Transactions of the Korean hydrogen and new energy society, volume 23, issue 4, 2012, Pages 412~419
DOI : 10.7316/KHNES.2012.23.4.412
Increasing demand for natural gas and higher natural gas prices in the recent decades have led many people to pursue unconventional methods of natural gas production. POSCO-Gwangyang synthetic natural gas (SNG) project was launched in 2010. As the market price of natural gas goes up, the increase of its price gets more sensitive due to the high cost of transportation and liquefaction. This project can make the SNG economically viable. In parallel with this project, KEPCO (Korea Electric Power Corporation) joined in launching the SNG Quality Standard Bureau along with KOGAS (Korea Gas Corporation), POSCO and so on. KEPCO Research Institute is in charge of SNG fueled gas turbine combustion test. In this research, several combustion tests were conducted to find out the effect of hydrogen contents in SNG on gas turbine combustion. The hydrogen in synthetic natural gas did not affect on gas turbine combustion characteristics which are turbine inlet temperature including pattern factor and emission performance. However, flame stable region in
-Air flow rate map was shifted to the lean condition due to autocatalytic effect of hydrogen.