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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 11, Issue 4 - Nov 2002
Volume 11, Issue 3 - Sep 2002
Volume 11, Issue 2 - Jun 2002
Volume 11, Issue 1 - Mar 2002
Selecting the target year
A Study on the Thermal Designs of 300 MW-Class IGCC Plant
Journal of Energy Engineering, volume 11, issue 2, 2002, Pages 81~89
IGCC (Integrated Coal Gasification Combined Cycle) is a technology that generates electric power using coal gasification and gasified fuel. Carbon conversion value of IGCC is higher and the influence on the environment is lower than the pulverized coal power plant. Especially, in the nations where the weight of fossil fuel for power generation is remarkably high like in Korea, IGCC stands out as an alternative plan to cope with sudden limitation for the emissions. In this paper, system design study for the commercial IGCC system which the introduction is imminent to Korea was performed. Two cases of entrained gasification process are adapted, one is FHR(full heat recovery) type IGCC system for high efficiency and the other is Quench type IGCC system for low cost. System simulations using common codes like AspenPlus were performed for each system. In the case of Quench system, system option study and sensitivity analysis of the air extraction rate was performed. Thermal performance result for the FHR system is 42.6% (HHV, Net) and for the quench system is 40% (HHV, net) when 75% air is extracted.
Effects of Swirl and Combustion Parameters on the Performance and Emission in a Turbocharged D.1. Diesel Engine
Journal of Energy Engineering, volume 11, issue 2, 2002, Pages 90~98
The effects of swirl and combustion parameters on the performance and emission in a turbo-charged D.I. diesel engine of the displacement 9.4L were studied experimentally in this paper. Generally the swirl in the combustion process of diesel engine promotes mixing of the injection fuel and the intake air. It is a major factor to improve the engine performance because the fuel consumption and NO
is trade-off according to the high temperature and high pressure of combustion gas in a turbocharged D.I. diesel engine, it's necessary to thinking over the intake and exhaust system, the design of combustion bowl and so on. In order to choose a turbocharger of appropriate capacity. As a result of steady flow test, when the swirl ratio is increased, the mean flow coefficient is decreased, whereas the gulf factor is increased. Also, through engine test its can be expected to meet performance and emissions by optimizing the main parameter's; the swirl ratio is 2.43, injection timing is BTDC 13
CA, compression ratio is 16, combustion bowl is re-entrant 5
, nozzle hole diameter is
0.28*6, turbocharger is GT40 model which are compressor A/R 0.58 and turbine A/R 1.19.
Numerical Analysis on Melting and Solidification of Pure Metals with Enthalpy-Porosity Model
Kim, Sin ; Chung, Bun-Jin ; Kim, Min-Chan ;
Journal of Energy Engineering, volume 11, issue 2, 2002, Pages 99~105
A finite volume numerical approach is developed and used to simulate convection-dominated melting and solidification problems. The present approach is based on the enthalpy-porosity method that is traditionally used to track the motion of the liquid-solid front and to obtain the temperature and velocity profiles in the liquid-phase. The enthalpy-porosity model treats the solid-phase as the porosity in all computational cells that are located on the solid-liquid interfacial boundary. Concerning the computational cells that are fully located in the solid side of the interfacial boundary, the zero value of the porosity severely suppresses the velocity vector to practically a non-existent value that could be set equal to zero. A comparative analysis with the previous numerical approaches is performed to demonstrate the improved features of the presented model. Results of a melting and solidification experiments are also used to assess and evaluate the performance of the model.
An Investigation on Quantity of Unused Energy Using Temperature Difference Energy as Heat Source and Its Availability
Journal of Energy Engineering, volume 11, issue 2, 2002, Pages 106~113
While the demand for energy has shown a sharp increase recently, the supply seems to be limited by the fact that the conventional fossil fuel energy or nuclear energy has its own environmental problems such as, for example, global warming or nuclear waste disposal. To overcome such limited supply of energy, the utilization of natural thermal energy such as river water and sea water as well as treated sewage can be a substantial supplement. The potential use of the unused energy has become more and more feasible these days as the heat pump technology has been advanced. In the present study, the unused energy reserves are estimated on regional and monthly basis for each resource based on the method developed here in order to establish the base data for its utilization. The potential use of the unused energy is also discussed.
A Study of Alkali Metal Vapor Adsorption Behavior by Using Pressurized Reactor
Journal of Energy Engineering, volume 11, issue 2, 2002, Pages 114~121
Alkali metal compounds existed in original coal or sorbents are exhausted as vapor or small particle at the outlet of combustor when operating PFBC power plant. These compounds can be removed with dust removal equipment, but total generation efficiency will be decreased because of lower operating temperature of dust removal equipment. Alkali metal contained in vapor phase is initially deposited onto turbine blade results in serious corrosion. The concentration of alkali vapor in the PFBC flue gas is 20∼40 ppm which is dependent on mineral characteristics and composition as well as operating condition of PFBC. However, the allowance limit of alkali metal vapor is assigned as less than 50 ppb for gas turbine when coal or oil is used as fuel. Therefore, alkali metal vapor in PFBC or IGCC process should be removed by solid sorbents to prevent corrosion of turbine blade and improve plant efficiency. In the present investigation, powder of Bauxite, Kaolinite and Limestone is used in the preparation of cylinder-type pellet which is inserted into the pressurized alkali removal reactor for the alkali absorption experiment. Experimental results showed that the alkali removal efficiency in the order of Bauxite, Kaolinite and Limestone. Alkali vapor removal efficiency is related with reaction temperature, porosity of pellet and alkali vapor concentration of flue gas.
Evaluation of the SWR′s Early Pressure Variations in the KALIMER IHTS
Journal of Energy Engineering, volume 11, issue 2, 2002, Pages 122~129
The analytical models and algorithm of the SPIKE code, which has been developed by KAERI's KALIMER team to investigate the sodium-water reaction phenomena in the liquid metal reactor, were introduced with its verification calculation results. The sodium water reaction of KALIMER IHTS was evaluated. Early stage of the sodium-water reaction consists of wave and mass transfer regimes. The pressure variations were independent of specific design features in the wave transfer regime. However in the mass transfer regime, the pressure variations were strongly dependent on cover gas volume and rupture disk set pressure. The early stage SWR analysis showed that the KALIMER IHTS with an appropriate cover gas volume and rupture disk set pressure had enough margin to its design pressure.
The Performance Analysis of a Return Air Bypass Air Conditioning System by a Simulator Experiment
Journal of Energy Engineering, volume 11, issue 2, 2002, Pages 130~135
Bypass air conditioning systems are divided into three types; outdoor air bypass, mixed air bypass and return air bypass system. Among bypass air conditioning systems, a return air bypass system is more effective than other two systems because it doesn't induce unconditioned outdoor air into conditioned room. The numerical study on the bypass air conditioning system shows this system can maintain indoor RH(Relative Humidity) less than a conventional CAV (Constant Air Volume) air conditioning system by adjusting face and bypass dampers at part load. A simulator was built to compare results of a numerical experiment and those of a simulator experiment. The results of the simulator experiment was nearly same as those of the numerical experiment; when a design sensible load (the ratio of sensible load to total sensible load) was 70 percent (at this time, RSHF=0.7), indoor relative humidity (in case of both numerical experiments and simulator experiments) was maintained below 60% specified by ASHRAE STANDARD 62-1999. The bypass air conditioning system is expected to be applied to many buildings where the Percentage of latent loads or air change tate is high.
Preparation and Reactivity of ZnO-Al
Desulfurization Sorbents for Removal H
Journal of Energy Engineering, volume 11, issue 2, 2002, Pages 136~141
Advanced zinc-based sorbents, ZA, for Hot Gas Desulfurization (HGD) process in Integrated Gasification Combined Cycle (IGCC) systems were formulated with
as support to enhance the reactivity and their reactive characteristics was also investigated in this study. Changes in the physical and chemical properties of the sorbents based on both the mole ratios of ZnO/Al
and the calcination temperatures were examined by a XRD. The results obtained in our desulfurization-regeneration cycle tests demonstrated that degradation of sorbents due to the heat generation could be improved through the optimization of the
contents and of the calcination temperatures. From the durability study it is concluded that the prepared ZA sorbents with additives have the desirable features for HGD.
The Effects of Spot Pricing for the Change of the Electric Power Demand Based the Demand Elasticity
Journal of Energy Engineering, volume 11, issue 2, 2002, Pages 142~148
The variations of real time electric price in competitive electricity markets have influence on electric power demands of the consumers. Residential, commercial, and industrial consumers with different characteristics cause the different price elasticity of the demand due to changing the pattern of consumption. Therefore, this paper analyze the effects of spot pricing for the change of the electric power demand based on the demand elasticity of each loads in competitive electricity market.
Viscosity of Coal Slags under Gasification Conditions
Journal of Energy Engineering, volume 11, issue 2, 2002, Pages 149~159
In the entrained flow gasifiers, the slag viscosity is an important parameter determining the operation conditions. The slag viscosities of 9 coals, which were selected and tested as possible gasification feedstock in Korea, were measured in a high temperature slag viscometer under gasification conditions. The type and size of crystalline phases that were known to affect the slag viscosity behavior were also determined. The slag samples were obtained from the IEA dry-feed gasifier. The slags of Alaska Usibelli, Curragh, Kideco, Adaro, Denisovsky, Baiduri and Drayton coals showed the behavior of crystalline slags, while those of Datong and Cypurus glassy slags. When a recommended minimum operating temperature was arbitrarily defined as
for glassy slags and
for crystalline slags, the Drayton slag required the lowest temperature, while Denisovsky slag required the highest. All the slags contained C
from the refractory. The crystalline slags with
at around 132
contained large anorthites as the major crystalline phase that would have caused the rapid inrease in viscosity. Denisovsky slag contained many pores which were formed by
Influence of Compression Ratio on Engine Performance in Heavy-duty LPG Single-cylinder Engine
Journal of Energy Engineering, volume 11, issue 2, 2002, Pages 160~165
The heavy-duty LPG-fueled single cylinder engine was designed and developed as a fundamental equipment for analyzing combustion processes and emission performances. The cylinder head and the piston crown were modified to fire the LPG in the engine. The flywheel was also fabricated to minimize the vibration of the single cylinder engine. The size of bore and stroke of the tested engine are 130 mm and 140 mm, respectively. Compression ratios were varied 8 to 9 with different piston crown shapes. The developed single cylinder engine operates at 1,000 rpm for this work. The major conclusions of this work are; (1) the power of the developed engine was peaked at the condition of equivalence ratio 1.0 at three different compression ratios; (2) the power is slightly increased with the increase of compression ratio; (3) the optimum ignition timing is retarded with the increase of compression ratio ranged 2 to 10 crank angle.
Chemical Reactions in the Coal-Methane-Air Flame
Journal of Energy Engineering, volume 11, issue 2, 2002, Pages 166~177
The present study is described of the flame structure of one-dimensional, flat, premixed, laminar, coal-air flame with some addition of methane for the flame stability. A low pressure burner operating at a combustion pressure of 0.3 arm was employed in order to extend the reaction zone. Predicted results from the models considered in the present study are compared with experimental results. Comparisons are included gas temperatures, species concentrations, char analysis and measured burning velocity. Among the models, Model II
-d, which specified devolatilization rate constants and a char surface area factor S=4, resulted in good agreement within the present experimental ranges. The results of char analysis suggest that the extent of the reaction occurring on the panicle might be underestimated in the model so that the char surface area should be increased. A value of 4 for this factor was given by sensitivity analysis of change in char surface area. Again, model II
-d gave satisfactory predictions of burning velocities over most of the experimental range studied. It has been clearly shown that the particle diameter appreciably affects the rates of devolatilisation and char oxidation through the effects of thermal lag and volumetric reactive surface area, consequently laminar burning velocity.ity.
Early Fuel Evaporator Effects on Cold Driveability of Automobile
Journal of Energy Engineering, volume 11, issue 2, 2002, Pages 178~185
The object of this paper is to investigate the effects of early fuel evaporators on cold driveability of gasoline passenger cars. Experiment has been carried out for the assessment cold start performance and cold driveability. And fuel consumption rate, emission and cylinder pressure were measured. On the base of combustion pressure of cylinder, rate of heat release, cumulative heat release amount and burned mass fraction are evaluated. The results show that fuel consumption rate is increased by 17.7%, monoxide and hydrocarbon were reduced by 23% and by 45% respectively, fluctuations of indicated mean effective pressure and maximum combustion pressure were increased by 4∼6%, fuel consumption rate per power was improved by 0.2∼2.3%. These are caused by the fact maximum heat release period and main combustion period are getting short.