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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 5, Issue 2 - Sep 1996
Volume 5, Issue 1 - Mar 1996
Selecting the target year
Current Status and Future Tasks of Clean Coal Technologies in the Asia Pacific Region
Son, Jae-Ek ;
Journal of Energy Engineering, volume 5, issue 1, 1996, Pages 1~7
Coal consumption in Asia is projected to increase by about 1.3 billion tons over the 1993-2010 period. The expansion in coal consumption for electricity generation is the dominant factor in the large increase in coal consumption. Without effective control measures, the projected increase in coal consumption will have a serious impact on environmental effects of increased coal use in Asia. Thus, the introduction of appropriate CCTs is considered essential to achieving the twin goals of expanded use of coal decreased environmental impacts.
Thermal Performance Analysis of Combined Power Plant Using Coal Gas - Development of the Steady-state Model -
Journal of Energy Engineering, volume 5, issue 1, 1996, Pages 8~18
As a part of comprehensive IGCC process simulation, the thermal performance analysis was performed for coal gas firing combined power plant. The combined cycle analyzed consisted of il Texaco gasifier and a low temperature gas cleanup system for the gasification block and a GE 7FA gas turbine, a HRSG and steam turbine for the power block. A steady state simulator called ASPEN(Advanced System for Process Engineering) code was used to simulate IGCC processes. Composed IGCC configuration included air integration between ASU and gas turbine and steam integration between gasifier, gas clean up and steam turbine. The results showed 20% increase in terms of gas turbine power output(MWe) comparing with natural gas case based on same heat input. The results were compared with other study results which Bechtel Canada Inc. performed for Nova Scotia power plant in 1991 and the consistency was identified within two studies. As a result, the analysing method used in this study is verified as a sound tool for commercial IGCC process evaluation.
Transient Analysis of Pressure Behavior of Cryogenics in Closed Vessel
Journal of Energy Engineering, volume 5, issue 1, 1996, Pages 19~27
Self-pressurization of cylindrical container of cryogen is numerically analyzed. The container is axi-symmetric and heated from side wall with constant heat flux. Natural convection by external heat flux is studied numerically using finite difference method. Oxygen, nytrogen and hydrogen are working fluids in this paper. Liquid is considered incompressible fluid and vapor is assumed to behave as gas meeting with virial equation of gas. The Second virial coefficients of gas are obtained from Lennard-jones model. The important variables which have effects on self-pressurization are external heat flux, heat capacity of wall and initial ullage in container. The most important variable of them is external heat flux. The pressure rise calculated from the virial gas model is slightly different from that calculated using Ideal gas model for oxygen.
An Experimental Study on the Temperature Control For a Gas Engine Cogeneration System
Journal of Energy Engineering, volume 5, issue 1, 1996, Pages 28~33
This study was carried out find out the appropriate tuning method of PID controller for a package type gas engine cogeneration system in terms of stabilizing the engine coolant temperature and system heat balance. In order to acquire the proper parameters of the controller, a system transfer function was set as a first order plus dead time model and thereafter model parameters were determined by using several tuning methods. And, with determined values of parameters and the system transfer functions, optimal turning method was selected by simulating the process using MATLAB. From the experimental results, it was found that obtained PID gains made the system stable in various operating conditions.
A Comparative Study of the Cold Power Generation Systems for LNG Terminal
Journal of Energy Engineering, volume 5, issue 1, 1996, Pages 34~41
The heat of evaporation (cold energy) of LNG is the energy consumed in the production of LNG. This energy amounts to 14% of the NG. In Pyungtak LNG terminal, it is about 96 MW in 1993. In order to utilize the cold energy, the cold power generation systems are investigated: The Rankine cycle using the low temperature energy, the partial expansion cycle using the pressure energy, and the Linde process which is a combined cycle of the Rankine and the partial direct expansion cycle. The commercial simulator, ASPEN Plus, is used. The conceptual design data are obtained from the current facilities of the Pyungtak LNG terminal. The performances of three systems are evaluated. The amount of electric power ranges iron 3 MW to 6MW. The optimum energy efficiency is about 37%. The optimum design conditions are obtained for the partial direct expansion (PDE) cycle. The performance of the PDE cycle is supposed to be comparable to that of the Rankine cycle if the areas of the total heat exchanger of the both cycle are equal.
Performance Characteristics of CNG Vehicle at Various Compression Ratios
Journal of Energy Engineering, volume 5, issue 1, 1996, Pages 42~49
Natural gas is one of the promising alternative fuels for automotive vehicles, because it has lower exhaust emissions and better fuel economy characteristics than those of gasoline, and can be used in conventional gasoline engines without major modifications. In the present study, a conventional gasoline engine was modified to a CNG engine, which can be operated with CNG only, and an engine bench test was performed to calibrate the operating parameters of the engine such as air fuel ratio, spark advance, etc. at various operating conditions. The modified CNG engine, then, was installed on a commercial gasoline vehicle and a vehicle driving test on chassis dynamometer was performed to examine the fuel economy and exhaust emission characteristics. As a result, the prototype CNG vehicle showed lower exhaust emissions and better fuel economy characteristics, but slightly reduced brake horse power, compared to the gasoline vehicle.
A Numerical Study of the 3-D Flow in the Primary Calcinator of Porcelain
Journal of Energy Engineering, volume 5, issue 1, 1996, Pages 50~55
A numerical simulation on a primary calcinator of porcelain was performed with using Fluent to calculate the heat efficiency by studying velocity vector and temperature profile according to variables such as the location of outlet and porcelain. Control-Volume based Finite Difference Method and Up-wind scheme are used for discretization of differential equation. SIMPLEC Algorithm and standard k-
turbulent model are selected to resolve the pressure-velocity coupling and the turbulent. The result of simulation showed that the whole velocity vector field in a calcinator was varied greatly according to the location of outlet. But the whole temperature profile at each zone was still high regardless of the location of outlet because of the radiation. But the temperature of a case with a outlet at sidepart of preheating or cooling zone was little high compared to the case with a outlet on the top of preheating zone. The velocity vector field and temperature profile in a calcinator were almost not affected by the location of porcelain, but the temperature inside a porcelain was much affected according to the place where it was located. The heat efficiency in a calcinator was 44.6% and the gas temperature in the outlet was about 1000 K.
The Removal Characteristics of Cs
from Aqueous Wastes by Ultrafiltration in Combination with Chemical Treatment Techniques(II)
Journal of Energy Engineering, volume 5, issue 1, 1996, Pages 56~64
The objective of this investigation is to establish the rejection characteristics of caesium and cobalt from radioactive liquid waste by chemical/ultrafiltration process. An extensive experimental investigation was conducted with inactive caesium and cobalt ions, utilizing ultrafiltration stirred cell. Caesium and cobalt could be effectively removed from waste solution using copper ferrocyanide and polyarcylic acid(PAA). The rejection dependence of the caesium was found to be a function of caesiun to potassium copper ferrocyanide feed molar ratio. The binding behavior of caesium on K
, particles was explained in terms of a Langmuir adsorption isotherm. When Cs/K
molar ratio was 1.5, the removal of caesium was the most efficient. The rejection efficiency of cobalt is dependent upon various parameters such as pH, cobalt concentration and PAA concentration. The rejection behavior of cobalt was explained in term of a equilibrium model taking into account the reaction between the ligand group, the proton and the cobalt ion. At the conditions of PAA/Co ratio of 2 and pH of 5.6, the removal of cobalt was over 90%. Also, the effect of chemical addition sequence for the simultaneously removal of caesiun and cobalt was discussed.
Decomposition Reaction of Methanol over Ni-Cu/SiO
Journal of Energy Engineering, volume 5, issue 1, 1996, Pages 65~71
Decomposition reaction of methanol was conducted on Ni-Cu/SiO
catalysts with several variables. Variables used in this study are S.V(Space Velocity), partial pressure of methanol, reaction temperature, and composition rate of Ni-Cu. The range of S.V is 10,000-30,000h
-1/, the temperature range is 150-400
and values of Cu/(Ni＋Cu) are 0, 0.25, 0.5, 0.75, and 1. Over Ni/SiO
, and Ni-Cu/SiO
, the conversion rate of decomposition reaction of methanol arrived at 100% with increasing of temperature. At this time the selectivity of CO on Ni/SiO
, was suddenly decreased, but on Ni-Cu/SiO
, it was still sustained highly. The main products of reaction were CO and H
, and by-products were CO
A Study on the Effect of Controllers in Small Signal Stability of Power Systems
Journal of Energy Engineering, volume 5, issue 1, 1996, Pages 72~79
The effect of controllers-Exciter, Power System Stabilizer, and Static Var Compensator-in one machine infinite bus system is investigated in this paper. The structure of generator state matrix with controllers is represented, while the Static Var Compensator is installed in generator terminal bus. Eigen-value analysis is performed and the effects of controllers to the dominant eigenvalue in one machine infinite bus system are represented by first order eigenvalue sensitivity coefficients while the operating conditions of the system are varied. Optimization of controller parameters using first order eigenvalue sensitivity coefficients is performed by the Simplex Method. It is proved that exciter control is the most efficient method to improve stability of the system and the effect of Static Var Compensator is small, in the case of one machine infinite bus system.
Hydrogenation of Naphthalene in a Tubing Bomb Microreactor
Journal of Energy Engineering, volume 5, issue 1, 1996, Pages 80~86
Naphthalene hydrogenation reaction was performed as a model reaction for coal liquefaction. Product distributions of tetralin and decalin are sensitive to reaction temperature and hydrogen pressure. At 380
, hydrogenation reaction using sulfided pellet catalysts gives poor reproducibility and several experimental methods are tried to examine its cause. It was inferred that H
S had, most possibly, a great effect on this phenomena and the effect of H
S was systematically investigated at 250
. It is possible that the intermediate hydroaromatic compound (tetralin) is maximized by changing the partial pressure of H
S. It was identified that the partial pressure of H
S could be another important factor in addition to the reaction time and temperature in coal liquefaction using sulfided catalysts.
A Study on Dynamic Optimization of Time-Of-Use Electricity Rates
Journal of Energy Engineering, volume 5, issue 1, 1996, Pages 87~92
This paper formulates dynamic optimization model for Time-Of-Use Rates when a electric power system consists of three generators and a rating period is divided into three sub-periods. We use Pontryagin's Maximum Principle to derive optimal price and investment policy. Particularly the cross-price elasticities of demand are considered in the objective function. We get the following results. First, the price is equal to short-run marginal cost when the capacity is sufficient. However, if the capacity constraint is active, the capacity cost is included in the price. Therefore it is equal to the long-run marginal cost. Second, The length of rating period affects allocation of capacity cost for each price. Third, the capacity investment in dynamic optimization is proportional to the demand growth rate of electricity. However the scale of investment is affected by not only its own demand growth rate but also that of other rating period.