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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
Journal of Energy Engineering
Journal Basic Information
Journal DOI :
The Korea Society for Energy Engineering
Editor in Chief :
Volume & Issues
Volume 18, Issue 4 - Dec 2009
Volume 18, Issue 3 - Sep 2009
Volume 18, Issue 2 - Jun 2009
Volume 18, Issue 1 - Feb 2009
Selecting the target year
Transient features of natural convection in nanofluid
Chang, Byong-Hoon ;
Journal of Energy Engineering, volume 18, issue 1, 2009, Pages 1~8
This paper reports the experimental study of natural convection heat transfer with
-water nanofluid. Experimental apparatus was a cylindrical enclosure with adjustable fluid layer thickness, and the aspect ratio was varied between 10.9 and 30.4. Heat transfer coefficients seemed to have reached a steady value within 30 minutes as the case with pure water. But, decrease in heat transfer coefficient continued for over
hours for inclination angle of
, and oscillation in heat transfer was observed for certain inclination angles and aspect ratios for over 10 hours. Oscillation shape and period depended on the aspect ratio and inclination angle. For example, the oscillation period for
was more than twice that for
. The maximum Nusselt number occurred at the inclination angle of
, and the minimum occurred at
for Rayleigh number less than 1.E5. However the present results were obtained with aggregated nanofluid and would be devoid of generalities.
The distribution of activation energy and frequency factor for coal pyrolysis and char-air reaction
Park, Ho-Young ; Kim, Young-Joo ;
Journal of Energy Engineering, volume 18, issue 1, 2009, Pages 9~16
The experimental work has been carried out for the study of pyrolysis and char-air reaction of five coals used in Y power station in Korea. For five coals, the characteristics of pyrolyis and char reaction have been investigated with TGA, and their kinetic parameters were obtained and compared each other. The order of pyrolysis rate for five coals were as follows : Peabody, Flame, MIP, Indominco, Elk valley. The behavior of char - air reaction for five coal chars have been successfully described by the grain model. The rate of char-air reaction gave the maximum value for Flame coal char, on the while Elk valley coal char had the minimum value. For the reaction temperature over 1,000K, Flame coal char - air reaction was very fast compared with other coal chars.
Control of Water Heat Recovery Chiller Using Split Condenser Templifier Application
Cho, Haeng-Muk ; Mahmud, Iqbal ;
Journal of Energy Engineering, volume 18, issue 1, 2009, Pages 17~21
By using the heat recovery of water-cooled chillers, it is possible to reduce the energy operating costs positively and at the same time it could fulfill the heating re-heat air conditioning system as well as the hot water requirements. Basically templifiers are designed to economically to turn the waste heat into useful heat. Waste heat is extracted from a fluid stream by cooling it in the evaporator, the compressor amplifies the temperature of the heat and the condenser delivers the heat to heating loads such as space heating, kitchens and domestic hot water. Design of higher water temperature requirements and split condenser heat recovery chiller system (using of templifiers) produced hotter condenser water approximately up to
and control the entire heat recovery system.
The Effects of Gas and Electric Demand according to Construction of Industrial CHP in the Korea
Kim, Yong-Ha ; Woo, Sung-Min ; Back, Bum-Min ; Yeon, Jun-Hee ;
Journal of Energy Engineering, volume 18, issue 1, 2009, Pages 22~30
Recently, energy efficiency is important in Korea. This paper reviews shadow amount to perform economic analysis for CHP that converts existing equipment in industrial area. It is verified that shadow amount analyze effects of gas and electric demand.
Simulation for the Fuel Economy and the Emission of Diesel Hybrid Electric Vehicle
Han, Sung-Bin ; Chang, Yong-Hoon ; Suh, Buhm-Joo ; Chung, Yon-Jong ;
Journal of Energy Engineering, volume 18, issue 1, 2009, Pages 31~36
There are several types of environment friendly vehicle being developed by auto manufactures. HEV (Hybrid Electric Vehicle) is most applicable one among them in actuality. HEV has two power sources, one is an internal combustion engine, the other one is an electric device. The HEV is developed for reducing fuel consumption and emissions. We selected the diesel engine as a main power source of HEV. The tests were carried out under different driving cycles which was CBDBUS (Central Business Driving Bus Schedule) and HWFET (Highway Fuel Economy Test). This research presents a simulation for the fuel economy and the emission of heavy diesel hybrid vehicle according to the SHEV (Serial Hybrid Electric Vehicle), PHEV (Parallel Hybrid Electric Vehicle), Plug-in SHEV and plug-in PHEV.
A Study on the Optimal Bilateral Heat Transaction of CHP considering the Operation Modes
Kim, Yong-Ha ; Woo, Sung-Min ; Back, Bum-Min ; Lee, Pyong-Ho ; Kim, Young-Gil ;
Journal of Energy Engineering, volume 18, issue 1, 2009, Pages 37~48
Recently, the significance of Green-Energy led by low-carbon Green-Development is increasing as well in Korea. Among them, the most practical solution is the cogeneration which performs the best energy efficiency. This paper addresses the two of RCS(Regional Cogeneration System) connecting heat each other. It is conducted to quantitatively evaluate algorithm that optimally operate the heat transaction considering various operating modes. The proposed method is tested using the real system. Through the case studies, it is verified that the proposed algorithm of heat transaction can evaluate availability.
Study on Hydrogen Embrittlement for API 5L X65 Steel Using Small Punch Test I : Base Metal
Jang, Sang-Yup ; Yoon, Kee-Bong ;
Journal of Energy Engineering, volume 18, issue 1, 2009, Pages 49~55
Occurrence of hydrogen embrittlement could be one of the main obstacles for using structural equipment under hydrogen environment. It is required to develop assessment methods of hydrogen embrittlement for the metals used in production, storage, transmission and application utilities of hydrogen. The most probable method of hydrogen mass transmission is using existing natural gas pipeline. Base or weld part of the pipeline can be damaged by mixed gas of hydrogen in the pipeline. In this study small punch (SP) testing was employed to evaluate the hydrogen embrittlement behavior for a line pipe steel (API X65) with electrochemically hydrogen charged specimens. Results showed that the SP test can be a good candidate test method for hydrogen damage evaluation method. Strength of steel is known to be decreased with the level of hydrogen charging. However, for API X65 steel base metal need in this study, the effect of hydrogen to strength was not significant. It can be negligible regardless of the hydrogen contents in the steel. With this test different strength levels with various hydrogen charging conditions were observed. It can also be anticipated that more sensitive evaluation of material behavior be obtainable by the SP test method.
Study on Hydrogen Embrittlement for API 5L X65 Steel Using Small Punch Test II : Weld Metal
Jang, Sang-Yup ; Yoon, Kee-Bong ;
Journal of Energy Engineering, volume 18, issue 1, 2009, Pages 56~62
With weld metal of X65 steel, hydrogen was charged by electro-chemical method and mechanical behavior such as strength was measured by the small punch test. The weld metal was more sensitive to hydrogen charging than the case of base metal. The small punch (SP) strength was decreased as the hydrogen contents increased. Magnitude of strength decrease was dependent on current density, temperature, charging time. Current density and charging time have significant effect on the mechanical properties but temperature of electrolyte has limited effect. Fractured surfaces of the tested specimens were observed by SEM (scanning electron microscope). In the hydrogen charged specimens cleavage fracture were observed, which is consistent with the SP test results. Since the testing procedure for studying hydrogen embrittlement proposed in this study has shown good reproducibility of test results, the proposed method can be assumed to be a reliable test procedure. Using the electrochemical charging and the small punch test, the change of SP strength for X65 weld metal due to hydrogen embritlement could be evaluated sensitively.
Development of Safety Climate Measuring Software Tool
Baek, Jong-Bae ; Ko, Jae-Wook ;
Journal of Energy Engineering, volume 18, issue 1, 2009, Pages 63~68
The safety culture of an organization is very complex and hard to study, but it is possible to examine norms that make up the culture. This paper describes of a Process Safety Management (PSM) climate assessment tool developed in high risk industry such as chemical industries. The main purpose is to develop measuring software tool behaviors by examining their nature and strength and by analysing underlying factors that offer explanations for attitudinal differences. We reviewed the current techniques and literatures available to assess safety climate and culture, conducted focus group interviews and discussions. Based on the reviews and focus group, PSM climate assessment questionnaires and an online application program were developed. A pilot assessment was done at a chemical plant in Korea and the safety climate profile was completed. It was suggested to have a constant feedback from different sectors of industry to improve the application.
Characteristics Analysis of Exhaust Emission according to Fuels at CVS-75 Mode
Han, Sung-Bin ; Kim, Yong-Tae ; Lee, Ho-Kil ; Kang, Jung-Ho ; Jeong, Jae-U ; Chun, Yon-Jong ;
Journal of Energy Engineering, volume 18, issue 1, 2009, Pages 69~73
The regulations for exhaust emission from vehicles have become much more stringent in recent years. These more stringent regulations require vehicle manufacturers to develop alternative fuels that reduce exhaust emission. This research is to analyze the characteristics of exhaust gas emission of same level vehicles that use gasoline, diesel, and LPG fuels. As for the test mode, we used the CVS-75 mode, which is the driving mode of the current domestic and North American emissions. The characteristics of the exhaust gas emitted under this driving condition was studied. We examined the emissions of THC, CO, and NOx of vehicles that use gasoline, diesel, and LPG fuels. As a result, vehicle exhaust gas emissions increased 9.8 % for vehicles using gasoline and it decreased 12.2 % for diesel-powered vehicles compared to vehicles using LPG fuel. Using gasoline and LPG fuel in the CVS-mode, over 80 % of THC and CO emission was produced for the cold start Phase 1.