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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 12, Issue 4 - Nov 2003
Volume 12, Issue 3 - Sep 2003
Volume 12, Issue 2 - Jun 2003
Volume 12, Issue 1 - Feb 2003
Selecting the target year
The Figures for the Alstom Power Pressurized Fluidized Bed Combustion Combined Cycle System
Journal of Energy Engineering, volume 12, issue 1, 2003, Pages 1~10
Pressurized fluidized bed combustion unit is operated at pressures of 1~1.5 MPa with combustion temperatures of 850~87
. The pressurized coal combustion system heats steam, in conventional heat transfer tubing, and produces a hot gas supplied to a gas turbine. Gas cleaning is a vital aspect of the system, as is the ability of the turbine to cope with some residual solids. The need to pressurize the feed coal, limestone and combustion air, and to depressurize the flue gases and the ash removal system introduces some significant operating complications. The proportion of power coming from the steam : gas turbines is approximately 80:20%. Pressurized fluidized bed combustion and generation by the combined cycle route involves unique control considerations, as the combustor and gas turbine have to be properly matched through the whole operating range. The gas turbines are rather special, in that the maximum gas temperature available from the FBC is limited by ash fusion characteristics. As no ash softening should take place, the maximum gas temperature is around 90
. As a result a high pressure ratio gas turbine with compression intercooling is used. This is to offset the effects of the relatively low temperature at the turbine inlet.
A Numerical Analysis on Transient Fuel temperatures in a Military Aircraft under Non-operating Ground Static Condition
Journal of Energy Engineering, volume 12, issue 1, 2003, Pages 11~16
A numerical study was performed on the transient fuel temperatures of a military aircraft stationed under non-operating static condition. Numerical calculation was peformed by an explicit method using modified Dufort-Frankel scheme. It was assumed that the non-operating aircraft is subjected to repeated daily cycles of air temperature with the solar radiation and wind speed corresponding to the 1 % hot day ambient condition. And, the aircraft was assumed to be in turbulent flow. The convective heat transfer coefficient for turbulent flow on the flat plate suggested by Eckert was employed to calculate heat transfer between the aircraft surface and the ambience. The energy conservation equation on fuel was used as governing equation for this analysis. As a result of this analysis, the wing tank temperature showed the highest temperature and the largest rate of temperature changes among fuel tanks. The results of this analysis could be used as initial foe] temperatures for analysis of the transient fuel temperatures in various flight missions. Also, this analysis method could be used to analysis and design of an aircraft thermal energy management system.
A fundamental Study on the Manufacturing and Operating Characteristics of a Small Scale CPL Heat Pipe
Journal of Energy Engineering, volume 12, issue 1, 2003, Pages 17~22
The present study was conducted to obtain the fundamental knowledge on the manufacturing and operating characteristics of a small scale CPL (Capillary Pumped Loop) heat pipe. CPL heat pipes are able to transfer heat effectively at any orientation in a gravitational field over long distances. An experimental model with an evaporator of a circular plate shape was designed and manufactured and its operating performances were tested. A Bronze powder sintered metal plate of 3 mm thick and
50 mm was used as wick and ethanol was used as working fluid. An experimental apparatus was set up to ascertain the operating conditions oi CPL at different heat load and an surrounding temperature at the condenser was maintained about 13
Vibration Analysis of Rotary Specimen Rack (RSR) in a Still Fluid and Stress Analysis of Clamp Part of RSR
Journal of Energy Engineering, volume 12, issue 1, 2003, Pages 23~28
In this paper, in-air and in-water vibration characteristics of Rotary Specimen Rack (RSR) are estimated through 3D finite element modeling by using ANSYS software. Added mass is calculated by using Blevins' equation. To confirm the reasonability of the results presented in this study, obtained results are compared to those of using a theoretical equation. It is confirmed that in-water natural frequencies of the RSR are lower than in-air ones due to the added mass effect of the fluid. Also, to design clamp which needs to fix RSR, Von-Mises stress and displacement of RSR to clamp pressure are calculated.
A Study on the Generation and Transmission of a Pressure Wave Induced by Rapid Heating of Compressible Fluid
Journal of Energy Engineering, volume 12, issue 1, 2003, Pages 29~34
Thermo-acoustic waves can be generated in a compressible fluid by rapid heating and cooling near the boundary walls. These phenomena are very important mechanism of heat transfer in the space environment in which natural convection does not exist. In this study, the generation and transmission characteristics of thermo-acoustic waves in an air filled enclosure with rapid wall heating are studied numerically. The governing equations were discretized using control volume method, and were solved using PISO algorithm and second-order upwind scheme. For the stable solution time step were considered as t=1
order, and grids are 50
800. The induced thermo-acoustic wave propagates through the fluid until it decays due to viscous and heat dissipation. The wave showed sharp front shape and decreased with long tail.
Performance Prediction of Heat Regenerators with using Spheres: Relation between Heat Transfer and Pressure Drop
Journal of Energy Engineering, volume 12, issue 1, 2003, Pages 35~41
Heat regenerator occupied by regenerative materials improves thermal efficiency of regenerative combustion system through the recovery of heat of exhaust gaset. By using one-dimensional two-phase fluid dynamics model, the unsteady thermal flow of heat regenerator with spherical particles, was numerically simulated to evaluate the heat transfer and pressure drop and thereby to suggest the parameter for designing heat regenerator. It takes about 7 hours for the steady state of the flow field in regenerator, in which heat absorption of regenerative particle is concurrent with the same magnitude of heat desorption. The regenerative particle experiences small temperature fluctuation below 10 K during the reversing process. The performance of thermal flow in heat regenerator varies with inlet velocity of exhaust gas and air, configuration of regenerator (cross-sectional area and length) and diameter of regenerative particle. As the gas velocity increases, the heat transfer between gas and particle enhances and with the increase the pressure losses. As particle diameter decreases, the air is preheated higher and the exhaust gases are cooled more with the increase of pressure losses.
Optimal Control of Voltage and Reactive Power in Local Area Using Genetic Algorithm
Journal of Energy Engineering, volume 12, issue 1, 2003, Pages 42~48
In system planing and operation, voltage and reactive power control is very important. The voltage deviation and system losses can be reduced through control of reactive power sources. In general, there are several different reactive power sources, we used switched shunt capacitor to improve the voltage profile and to reduce system losses. Since there are many switched shunt capacitors in power system, so it if necessary to coordinate these switched shunt capacitors. In this study, Genetic Algorithm (GA) is used to find optimal coordination of switched shunt capacitors in a local area of power system. In case study, the effectiveness of the proposed method is demonstrated in KEPCO's power system. The simulation is performed by PSS/E and the results of simulation are compared with sensitivity method.
Experimental Study on the Characteristics of Vacuum Residue Gasification in an Entrained-flow Gasifier
Journal of Energy Engineering, volume 12, issue 1, 2003, Pages 49~57
Approx. 200.000 bpd vacuum residue oil is produced from oil refineries in Korea, and is supplied to use asphalt, high sulfur fuel oil and for upgrading at the residue hydro-desulfurization unit. Vacuum residue oil has high energy content, however its high sulfur content and high concentration of heavy metals represent improper low grade fuel. To meet growing demand for effective utilization of vacuum residue oil from refineries, recently some of the oil refinery industries in Korea, such as SK oil refinery and LG Caltex refinery, have already proceeded feasibility study to construct 435~500 MWe IGCC power plant and hydrogen production facilities. Recently, KIER (Korea Institute of Energy Research) are studying on the Vacuum Residue gasification process using an oxygen-blown entrained-flow gasifier. The experiment runs were evaluated under the reaction temperature: 1.100~l,25
, reaction pressure: 1~6 kg/
G, oxygen/V.R ratio: 0.8~0.9 and steam/V.R ratio: 0.4~0.5. Experimental results show the syngas composition (CO+H
): 85~93%, syngas flow rate: 50~l10 Nm
/hr, heating value: 2,300~3,000 k㎈/Nm
, carbon conversion: 65~92, cold gas efficiency: 60~70%. Also equilibrium modeling was used to predict the vacuum residue gasification process and the predicted values were compared reasonably well with experimental data.
Syngas Concentration and Efficiency in Heavy Residual Oil Gasification with 1 Ton/Day-Class Entrained-Bed Reactor
Journal of Energy Engineering, volume 12, issue 1, 2003, Pages 58~64
With the 1 ton/day-class entrained-bed gasification system, heavy residual oil from local refinery was gasified at the operating conditions of 1,000~1,20
in order to determine the variation of syngas composition, carbon conversion, and cold gas efficiency. Produced syngas consists of mainly CO, H
, and the methane concentrations. Results yielded a maximum syngas composition of 45% H
and 26%, CO at the 31 kg/hr feeding condition. The maximum carbon conversion and cold gas efficiency were 87% and 68%, respectively at the feeding conditions of 20 kg/hr and oxygen/feed ratio of 1.2. When oxygen feeding amount that is one of the most important operating parameter in gasification was increased, concentration of hydrogen in the syngas is greatly increased comparing to the concentration of CO and
. The temperature exhibited about 11
raise while oxygen/feed ratio changed from 0.6 to 1.2. Methane concentration showed enhanced dropping rate with increase in gasifier temperature and the useful relationship between the gasifier temperature and methane concentration existed such that it can be employed as an indirect measure of inside gasifier temperature.