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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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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 27, Issue 4 - Aug 2016
Volume 27, Issue 3 - Jun 2016
Volume 27, Issue 2 - Apr 2016
Volume 27, Issue 1 - Feb 2016
Selecting the target year
Study on the Design Parameters of a Heat Exchange Steam Reformer (HESR) using CFD
YANG, CHANUK ; LEE, YULHO ; PARK, SANGHYUN ; YANG, CHOONGMO ; PARK, SUNGJIN ;
Transactions of the Korean hydrogen and new energy society, volume 27, issue 1, 2016, Pages 1~12
DOI : 10.7316/KHNES.2016.27.1.001
In this study, CFD model for a Heat Exchange Steam Reformer (HESR) used for a 10kW SOFC system is developed for the design optimization of the HESR. The model is used to explore the effect of design parameters on the performance of the HESR. In the HESR, heat is delivered from the hot gas channel to the fuel channel to supply the heat required for the fuel reforming. In the fuel channel where the fuel is reformed, thermo-fluid dynamics, heat transfer, and chemical reaction are considered to predict the performance of the reformer. The model is validated with experimental data within 2~3% error. The validated model is used for the parametric study of the HESR design. Channel length, channel diameter, and flow direction are selected as the design parameters. The effects of the HESR design parameters on the outlet temperature, outlet H2 mole fraction, and pressure drop across the reformer are presented using the model.
Effects of Solubility of SO
Gas on Continuous Bunsen Reaction using HI
KIM, JONGSEOK ; PARK, CHUSIK ; KANG, KYOUNGSOO ; JEONG, SEONGUK ; CHO, WON CHUL ; KIM, YOUNG HO ; BAE, KI KWANG ;
Transactions of the Korean hydrogen and new energy society, volume 27, issue 1, 2016, Pages 13~21
DOI : 10.7316/KHNES.2016.27.1.013
The Sulfur-Iodine thermochemical hydrogen production process (SI process) consists of the Bunsen reaction section, the
decomposition section, and the HI decomposition section. The
) could be recycled to Bunsen reaction section from the HI decomposition section in the operation of the integrated SI process. The phase separation characteristic of the Bunsen reaction using the
solution was similar to that of
system. On the other hands, the amount of produced
phase was small. To investigate the effects of
solubility on Bunsen reaction, the continuous Bunsen reaction was performed at variation of the amounts of
gas. Also, it was carried out to make sure of the effects of partial pressure of
in the condition of 3bar of
atmosphere. As the results, the characteristic of Bunsen reaction was improved with increasing the amounts and solubility of
gas. The concentration of Bunsen products was changed by reverse Bunsen reaction and evaporation of HI after 12 h.
Dehydriding Performance in a Depleted Uranium Bed
KOO, DAESEO ; KIM, YEANJIN ; YUN, SEI-HUN ; CHUNG, HONGSUK ;
Transactions of the Korean hydrogen and new energy society, volume 27, issue 1, 2016, Pages 22~28
DOI : 10.7316/KHNES.2016.27.1.022
It is necessary to store and supply hydrogen isotopes for Tokamak operation. A storage and delivery system (SDS) is used for storing hydrogen isotopes as a metal hydride form. We designed and fabricated a depleted uranium (DU) bed to store hydrogen isotopes. The rapid storage of hydrogen isotopes is very important not only for safety reasons but also for the economic design and operation of the SDS. The delivery rate at the desorption temperatures without the operation of a dry pump was analyzed in comparison with that with the operation of the dry pump. The effect of the initial desorption temperatures on the dehydriding of the DU without the operation of the dry pump was measured. The effect of the initial desorption temperatures on the dehydriding of DU with the operation of the dry pump was also measured and analyzed. The primary pressure on the desorption temperatures without the operation of the dry pump was analyzed in comparison with that with the operation of the dry pump. The temperature gradient of the coil heater and the primary vessel was also analyzed. Our results will be used to develop pilot scale hydrogen isotope processes. It was confirmed that dehydriding of a medium-scale DU bed has enabled without the operation of the dry pump.
Numerical Study on Flow Distribution in PEMFC with Metal foam Bipolar Plate
SONG, MYEONGHO ; KIM, KYOUNGYOUN ;
Transactions of the Korean hydrogen and new energy society, volume 27, issue 1, 2016, Pages 29~35
DOI : 10.7316/KHNES.2016.27.1.029
It is important to uniformly supply the fuel gas into the reaction activity area in polymer electrolyte membrane fuel cell (PEMFC). Recent studies have shown that the cell performance can be significantly improved by employing metal foam gas distributor as compared with the conventional bipolar plate types. The metal foam gas distributor has been reported to be more efficient to fuel transport. In this study, three-dimensional computational fluid dynamics (CFD) simulations have been performed to examine the effects of metal foam flow field design on the fuel supply to the reaction site. Darcy`s law is used for the flow in the porous media. By solving additional advection equation for fluid particle trajectory, the gas transport has been visualized and examined for various geometrical configuration of metal foam gas distributor.
Development of a New On-line state Estimation Method in PEMFC using Parameter Estimation
YOO, SEUNGRYEOL ; CHOI, DONGHEE ;
Transactions of the Korean hydrogen and new energy society, volume 27, issue 1, 2016, Pages 36~41
DOI : 10.7316/KHNES.2016.27.1.036
The development need of new renewable energy is more and more important to resolve exhaustion of chemical fuels and environmental pollution. Polymer electrolyte membrane fuel cell has been widely studied to the extent that it can be used commercially. But there are many problems to be solved. One of them is to enhance the stability of fuel cell stacks. This paper proposes a new fault diagnosis method using Least Square Method (LSM) which is one of parameter estimation methods. The proposed method extracts equivalent circuit parameters from on-line measurements. Parameters of the circuit are estimated according to normal and abnormal states using simulation. The variation of parameters estimated in each states enables the estimation of state in fuel cells. Thus the LSM presented can be a suitable on-line parameter estimation method in PEMFC.
An Experimental Study on the Natural Convection Heat Transfer of Air-cooling PEMFC in a Enclosure
LEE, JUNSIK ; KIM, SEUNGGON ; SOHN, YOUNGJUN ;
Transactions of the Korean hydrogen and new energy society, volume 27, issue 1, 2016, Pages 42~48
DOI : 10.7316/KHNES.2016.27.1.042
This study presents an experiment investigation on natural convection heat transfer of air-cooling Proton exchange membrane fuel cells (PEMFCs) in a enclosure system for unmanned aerial vehicles (UAVs). Considered are replacing fuel cell stack with Aluminum block for heat generating inside a enclosure chamber. The volume ratio of fuel cell stack and chamber for simulation to the actual size of aerial vehicle is 1 to 15. The parameters considered for experimental study are the environmental temperature range from
and the block heat input of 10 W, 20 W and 30 W. Effect of the thermal conductivity of the block and power level on heat transfer in the chamber are investigated. Experimental results illustrate the temperature rise at various locations inside the chamber as dependent upon heat input of fuel cell stack and environmental temperature. From the results, dimensionless correlation in natural convection was proposed with Nusselt number and Rayleigh number for designing air-cooling PEMFC powered high altitude long endurance (HALE) UAV.
Optimization of Operating Conditions for a 10 kW SOFC System
LEE, YULHO ; YANG, CHANUK ; YANG, CHOONGMO ; PARK, SANGHYUN ; PARK, SUNGJIN ;
Transactions of the Korean hydrogen and new energy society, volume 27, issue 1, 2016, Pages 49~62
DOI : 10.7316/KHNES.2016.27.1.049
In this study, a solid oxide fuel cell (SOFC) system model including balance of plant (BOP) for building electric power generation is developed to study the effect of operating conditions on the system efficiency and power output. SOFC system modeled in this study consists of three heat-exchangers, an external reformer, burner, and two blowers. A detailed computational cell model including internal reforming reaction is developed for a planer SOFC stack which is operated at intermediate temperature (IT). The BOP models including an external reformer, heat-exchangers, a burner, blowers, pipes are developed to predict the gas temperature, pressure drops and flow rate at every component in the system. The SOFC stack model and BOP models are integrate to estimate the effect of operating parameters on the performance of the system. In this study, the design of experiment (DOE) is used to compare the effects of fuel flow rate, air flow rate, air temperature, current density, and recycle ratio of anode off gas on the system efficiency and power output.
Oxidation of Ash Free Coal from Lignite and Anthracite Coals in a Molten Carbonate Fuel Cell
LEE, SANGWOO ; KIM, YUJEONG ; KIM, TAEKYUN ; LEE, KIJEONG ; LEE, CHOONGGON ;
Transactions of the Korean hydrogen and new energy society, volume 27, issue 1, 2016, Pages 63~70
DOI : 10.7316/KHNES.2016.27.1.063
In this study, ash free coals(AFCs) were produced with lignite and anthracite coals in a microwave. The AFCs were analyzed with proximate analysis, fourier transform infrared spectrometry (FTIR), X-ray diffraction analysis, and thermogravimetric analysis (TGA). The extraction yields of the AFCs were 16.4 wt%, 7.6 wt% at lignite and anthracite coal, respectively. The chemical and physical properties of the AFCs were similar regardless of the original coal types. Oxidation behavior of the AFCs was investigated by supplying a mixture of 3g of AFC and 3g of electrolyte into the coin-type molten carbonate fuel cell (MCFC). For the evaluation of AFC fuel performance, electrochemical analysis of the steady-state polarization and step-chronopotentiometry were conducted based on the standard hydrogen fuel (69 mol%
, 17 mol%
, 14 mol%
). The AFCs showed similar electrochemical oxidation behaviors regardless of the original coal types. The overvoltage of the AFCs was larger than the hydrogen fuel, although OCV of the AFCs was higher.
The Role of Government to Supply Fuel Cell Electric Vehicle in Korea and Japan
SON, MINHEE ; NAM, SUKWOO ; KIM, KYUNGNAM ;
Transactions of the Korean hydrogen and new energy society, volume 27, issue 1, 2016, Pages 71~82
DOI : 10.7316/KHNES.2016.27.1.071
A fuel cell electric vehicle (FCEV) could be an alternative solution to gasoline powered vehicles. The Korean and Japanese governments have played the midwifery role in the development of the FCEV industry. This study explores the difference in policy goals for FCEV between the two countries. Koreans recognized that FCEV was innovative technology and put forward the notion of technology pre-occupancy. Whereas, the Japanese government discovered that FCEV was one way to apply hydrogen mechanisms, so they identified the supply of hydrogen as one of the industries of interest, and have played the demiurge role. This study suggests that the role of government is to introduce eco-friendly vehicles, using the cases of Korean and Japanese governments, who introduced FCEV to the world first.
Performance Analysis of Absorbent for Post-combustion CO
Capture by Regeneration
KIL, TAEHYOUNG ; LEE, DONGHO ; JO, SUNGHO ; YI, CHANGKEUN ; PARK, YEONGSEONG ; RYU, HOJUNG ;
Transactions of the Korean hydrogen and new energy society, volume 27, issue 1, 2016, Pages 83~94
DOI : 10.7316/KHNES.2016.27.1.083
Performance of absorbent for post-combustion
capture was measured and discussed. Fully saturated fresh absorbent (P2-15F) and absorbents sampled from absorption and regeneration reactor of continuous
capture process, P2-15A, P2-15R, respectively, were used as representative absorbents. Small scale fluidized bed reactor (0.05 m I.D., 0.8 m high) which can measure exhaust gas concentration and weight change simultaneously was used to analyze regeneration characteristics for those absorbents. Exhausted moles of
were measured with increasing temperature.
ratio and working capacity were determined and discussed to confirm reason of reactivity decay after continuous operation. Moreover, possibility of side reaction was checked based on the
mole ratio. Finally, suitable regeneration temperature range was confirmed based on the trend of working capacity with temperature.
The Effect of CBB(CaO·BaO·B
) Addition on the Physical Properties and Oxygen Transfer Reactivity of NiO-based Oxygen Carriers for Chemical Looping Combustion
BAEK, JEOM-IN ; JO, HYUNGEUN ; EOM, TAEHYOUNG ; LEE, JOONGBEOM ; RYU, HO-JUNG ;
Transactions of the Korean hydrogen and new energy society, volume 27, issue 1, 2016, Pages 95~105
DOI : 10.7316/KHNES.2016.27.1.095
Spray-dried NiO-based oxygen carriers developed for chemical looping combustion required high calcination temperatures above
to obtain high mechanical strength applicable to circulating fluidized-bed process. In this study, the effect of CBB (
) addition, as a binder, on the physical properties and oxygen transfer reactivity of spray-dried NiO-based oxygen carriers was investigated. CBB addition resulted in several positive effects such as reduction of calcination temperature and increase in oxygen transfer capacity and porosity. However, oxygen transfer rate was considerably decreased. This was more apparent when a higher amount of CBB was added and MgO was added together. From the experimental results, it is concluded that CBB added NiO-based oxygen carriers are not suitable for chemical looping combustion and a new method to reduce calcination temperature while maintaining high oxygen transfer rate of NiO-based oxygen carriers should be found out.
A Study on the Stratified Combustion and Stability of a Direct Injection LPG Engine
LEE, MINHO ; KIM, KIHO ; HA, JONGHAN ;
Transactions of the Korean hydrogen and new energy society, volume 27, issue 1, 2016, Pages 106~113
DOI : 10.7316/KHNES.2016.27.1.106
Lean burn engine, classified into port injection and direct injection, is recognized as a promising way to meet better fuel economy. Especially, LPG direct injection engine is becoming increasingly popular due to their potential for improved fuel economy and emissions. Also, LPDi engine has the advantages of higher power output, higher thermal efficiency, higher EGR tolerance due to the operation characteristics of increased volumetric efficiency, compression ratio and ultra-lean combustion scheme. However, LPDi engine has many difficulties to be solved, such as complexity of injection control mode (fuel injection timing, injection rate), fuel injection pressure, spark timing, unburned hydrocarbon and restricted power. This study is investigated to the influence of spark timing, fuel injection position and fuel injection rate on the combustion stability of LPDi engine. Piston shape is constituted the bowl type piston. The characteristics of combustion is analyzed with the variations of spark timing, fuel injection position and fuel injection rate (early injection, late injection) in a LPDi engine.
A Study on Generating efficiency of the Double Acting Stirling Engine/Generator
PARK, SEONGJE ; KO, JUNSEOK ; HONG, YONGJU ; KIM, HYOBONG ; YEOM, HANKIL ; IN, SEHWAN ;
Transactions of the Korean hydrogen and new energy society, volume 27, issue 1, 2016, Pages 114~120
DOI : 10.7316/KHNES.2016.27.1.114
This paper describes generating efficiency characteristics of the double acting Stirling engine/generator for domestic small-scale CHP (Combined Heat and Power) system. In small distributed generation applications, Stirling engine has competition from fuel cell, microturbine and etc. In order to be economical in the applications, a long life with minimum maintenance is generally required. Free piston Stirling engine (FPSE) has no crank and rotating parts to generate lateral forces and require lubrication. Double acting Stirling engine/generator has one displacer and two power piston which are supported by flexure springs. Two power pistons oscillate with symmetric displacement and are connected with moving magnet type linear generators for power generation from PV work. In experiments, 1 kW class double acting free piston Stirling engine/generator is fabricated and tested. Heat is supplied to hot end of engine by the combustion of natural gas and converted to electric power by linear generators which are assembled with power pistons. The electric parameters such as voltage, current and phase are measured with for variable flow rate of fuel gas. Especially, generating efficiency of FPSE is measured with three different measurement methods. Generating efficiency of the double acting Stirling engine/alternator is about 24%.
Evaluation for the Numerical Model of a Micro-Bubble Pump
LEE, SANG-MOON ; JANG, CHOON-MAN ;
Transactions of the Korean hydrogen and new energy society, volume 27, issue 1, 2016, Pages 121~126
DOI : 10.7316/KHNES.2016.27.1.121
Hydraulic performance of a micro-bubble pump has been analyzed by numerical simulation and experimental measurements. Flow recirculation apparatus between the pump inlet and outlet reserviors has been adopted to measure pump performance according to flow conditions sequentially. To analyze three-dimensional flow field in the micro-bubble pump, general analysis code, CFX, is employed. SST turbulence model is employed to estimate the eddy viscosity and compared the pump performance to k-
model. Unstructured grids are used to represent a composite grid system including blade, casing and inlet casing. It is found that the numerical model used in the present study is effective to evaluate the pump performance. From the numerical simulation, low velocity region due to pressure loss is decreased where pump efficiency has maximum value. Detailed flow field inside the micro-bubble pump is also analyzed and compared.
Developments of a Cross-Correlation Calculation Algorithm for Gas Temperature Distributions Based on TDLAS
CHOI, DOOWON ; KIM, KWANGNAM ; CHO, GYONGRAE ; SHIM, JOONHWAN ; KIM, DONGHYUK ; DEGUCHI, YOSHIHIRO ; DOH, DEOGHEE ;
Transactions of the Korean hydrogen and new energy society, volume 27, issue 1, 2016, Pages 127~134
DOI : 10.7316/KHNES.2016.27.1.127
Most of reconstruction algorithms for the calculation of temperature distributions in CT (computed tomography)-TDLAS (tunable diode laser absorption spectroscopy) are based upon two-line thermometry method. This method gives unstable calculation convergence due to signal noise, bias error, and signal mis-matches. In this study, a new reconstruction algorithm based on cross-correlation for temperature calculation is proposed. The patterns of the optical signals at all wave lengths were used to reconstruct the temperature distribution. Numerical test has been made using phantom temperature distributions. Using these phantom temperature data, absorption spectra for all wave lengths were constructed, and these spectra were regarded as the signals that would be obtained in an actual experiments. Using these virtually generated experimental signals, temperature distribution was once again reconstructed, and was compared with those of the original phantom data. Calculation errors obtained by the newly proposed algorithm were slightly large at high temperatures with small errors at low temperature.