• Journal of ILASS-Korea
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• v.23 no.1
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• pp.16-21
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• 2018

The current study has developed an in-house 3D FEM code in order to model thermoacoustic problems in a gas turbine combustion system and compared calculation results of main instability characteristics with measured ones from a lab-scale partially-premixed combustor. From the comparison of calculation results with the measured data, the current model could successfully capture the harmonic longitudinal instability frequencies and their spatial distributions of the acoustic field as well as the growth rate of self-excited modes.

• Bulletin of the Korean Chemical Society
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• v.28 no.1
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• pp.59-62
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• 2007

A quantitative analysis method of halogen elements in volatile organohalogen compounds was established by the Wickbold combustion pretreatment in an enclosed system and ion chromatography. The sample pretreatment parameters of Wickbold combustion were experimentally optimized, and using the determined optimal pretreatment parameters, the reproducibility was estimated by ion chromatography. As a comparison for real samples, NIST certified reference materials (CRMs) were analyzed for the recovery efficiency and reproducibility.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.11a
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• pp.93-97
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• 2010

The energy balance program which can balance the relations among energy, mass flow, pressure in the staged-combustion cycle of the liquid rocket engine has been developed. The modular approach has been chosen for the analysis; the engine cycle consists of the elements from the predefined component analysis program. The engine with the staged-combustion cycle has been decomposed into several principal component modules, such as a thruster chamber, turbopumps, turbines, supply system components and a pre-burner. The program has been verified with comparison of the results to the selected data of the space shuttle main engine.

• Proceedings of the KSME Conference
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• 2004.04a
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• pp.1280-1285
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• 2004

Microsystem technology has been applied to space technology and became one of the enabling technology by which low cost and high efficiency are achievable. Micro propulsion system is a key technology in the miniature satellite because micro satellite requires very small and precise thrust force for maneuvering and attitude control. In this paper research on micro solid propellant thruster is reported. Micro solid propellant thruster has four basic components; micro combustion chamber, micro nozzle, solid propellant and micro igniter. In this research igniter, solid propellant and combustion chamber are focused. Micro igniter was fabricated through typical micromachining and evaluated. The characteristic of solid propellant was investigated to observe burning characteristic and to obtain burning velocity. Change of thrust force and the amount of energy loss following scale down at micro combustion chamber were estimated by numerical simulation based on empirical data and through the calculation normalized specific impulses were compared to figure out the efficiency of combustion chamber.

• Proceedings of the KSME Conference
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• 2008.11b
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• pp.3169-3174
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• 2008

Future power plants will be required to adopt some type of carbon capture and storage (CCS) technologies to reduce their CO2 emissions. One of distinguished CCS techniques expected to resolve the green house effect is to apply the oxy-fuel combustion technique to power plant, and a lot of research/demonstration programs have been going on in the world. In this paper, CO2-capturing power plants based on gas turbine and oxy-fuel combustion are investigated over several types of configurations. As a prior step, simulation model for 500 MW-class combined cycle power plant was set and was used as a reference case. The efficiencies of several power plants was compared and the advantages and disadvanteges was investigated.

• Journal of the Korean Society for Precision Engineering
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• v.25 no.1
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• pp.92-98
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• 2008

The flame image observation and analysis has been investigated for combustion monitoring and management of the pulverized coal firing for thermal power plant, especially for lower nitrogen oxide generation and safer operation. We aimed at obtaining the relationship between burner flame image information and emissions of nitrogen oxide and unburned carbon in furnace utilizing the flame image processing methods, by which we quantitatively determine the conditions of combustion on the individual homers. Its feasibility test was undertaken with Samchonpo thermal power plant #4 unit which has 24 burners, through which the system was observed to be effective for evaluating the combustion conditions and continuous monitoring to prevent future loss of ignition.

• Journal of the Korean Society of Combustion
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• v.6 no.1
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• pp.14-19
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• 2001

Interests and importance of down-scale combustor is increasing with the emerging need for miniaturized power source which is now a bottleneck of micro system development. But in down scaled combustor increased heat loss compared to thermal energy generation inhibits the usability and application of the device, so as a preliminary work of down scaled combustor fabrication. Modeling tool for the device should be established, in this study modeling approach of closed vessel combustion phenomena that can express heat loss effect and resulting quenching is proposed and the result is compared with experiment data. From this model heat loss effect following combustor scale down can be further understood, and further more design parameter and analysis tool can be obtained.

• 한국연소학회:학술대회논문집
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• 2013.06a
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• pp.83-85
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• 2013

With an increase in the use of low rank coals in power plants, various operational issues were raised in the fuel storage and supply, combustion, boiler and flue gas treatment systems. In the fuel storage and supply system, the main issue is the self-heating propensity of low rank coals leading to spontaneous combustion in yard storage, transport and pulverization. This study evaluated the reactivity of various sub-bituminous and bituminous coals with oxygen at low temperatures by analyzing the temperature increase characteristics of coals under a constant flow rate of oxygen supply. The results were quantified to a self-heating index and the relation with the fuel properties were evaluated.

• Journal of the Korean Society of Mechanical Technology
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• v.13 no.4
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• pp.149-156
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• 2011

In case of domestic pyrolysis dry distillation gassification technology, it stays at the stage of its early introduction and development. Moreover, the companies possessed of this technology are limited to Japan and some countries in Europe, and domestic operative performance of this system is nominal, so there exist a lot of difficulties in securing its basic data. In addition, considering its operation and management, there happens a corrosion of metals by the production of corrosive gases in time of combustion of waste, and there arise a problem of occurrence of low temperature corrosion on exterior casing or gas ducts of a combustion chamber due to the high temperature corrosion around the burner of an incinerator, lowering the durability of an incinerator. Therefore, this study looked at the problems arising in time of incineration by understanding the characteristics of the pyrolysis dry distillation gassification incinerating facility, and did research on the improvement plan for durability of an incinerator for more economic, efficient waste incineration.

• Journal of ILASS-Korea
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• v.27 no.1
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• pp.36-41
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• 2022

In this study, the combustion instability characteristics according to the change in the hydrogen ratio in the fuel in the single nozzle system of the hydrogen-natural gas mixed gas turbine for power generation was analyzed using a three-dimensional finite element analysis-based Helmholtz solver. This combustor shows the instability characteristics in which mode transition occurs from a mode having a low amplitude near 70 Hz to a mode having a high amplitude of 250 Hz or higher as the hydrogen fraction in the fuel increases. The current modeling results are found to reasonably predict the main characteristics of the change in measured instability frequency and growth rate with the change in fuel composition.