• Plant Journal
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• v.15 no.3
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• pp.29-34
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• 2019

In the study, the effect of steam injection on syngas productivity was investigated under the constant operating conditions of gasifier oxygen load while the coal feed was fixed and the steam injection flow rate is changed in Taean IGCC plant. The maximum syngas average productivity was found to be at 80 % and 90 % of gasifier oxygen loads with the steam injection flow rate of 0.14 kg/s and 0.15 kg/s per coal burner. Through this study, the syngas productivity was changed by adjusting the steam injection amount and as the steam injection flow rate increased, the syngas productivity increased and then decreased again. The syngas productivity can be increased only by steam injection without supplying additional coal and it is considered that the syngas productivity has different characteristics depending on coal type. Thus it is recommended to operate the gasifier using Carbo-One coal with the steam injection flow rate of about 0.14 kg/s per coal burner when the gasifier oxygen load is 80 % ~ 90 %.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.68 no.1
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• pp.8-12
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• 2019

Combined Cycle Unit(CC) generates the primary power from the Gas Turbine(GT) and supplies the remaining heat of the GT to the Steam Turbine(ST) to generate the secondary power from the ST. It plays a major role in terms of energy efficiency and Load Frequency Control(LFC). Incremental Heat Rate(IHR) curves of economic dispatch(ED) of CC is applied differently by GT/ST combination. But It is practically difficult because of performance test by all combinations. This paper suggests a reasonable method for estimating IHR curves for partial combinations(1:1~(N-1):1) using IHR curves when operating with GT alone(1:0) and with all(N:1) combinations of CC.

• Proceedings of the KSME Conference
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• 2000.11b
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• pp.228-233
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• 2000

The Korean Next Generation Reactor(KNGR) is a Pressurized Water Reactor adopting direct vessel injection(DVI) to optimize the performance of emergency core cooling system(ECCS). In a certain accident, however, pressurized thermal shock(PTS) of the vessel due to the sudden contact with the injected cold water is expected. In this paper, an accident of Main Steam Line Break(MSLB) has been numerically investigated with direct vessel injections and an increased volume flow rate in some cold legs. Using FLUENT code, temperature distributions of the fluid in the downcomer and of reactor vessel including the core region have been calculated, together with the distribution of convective heat transfer coefficient(CHTC) at the cladding surface of the reactor vessel. The result shows that some parts of the core region of the reactor vessel have higher temperature gradient expressing higher thermal stress.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.39 no.3
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• pp.261-269
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• 2015

In this study, numerical analysis of curved channel steam-methanol reformer was conducted using the computational fluid dynamics (CFD) commercial code STAR-CCM. A pre-numerical analysis of reference model with a cylindrical channel reactor was performed to validate the combustion model of the CFD commercial code. The result of advance validation was in agreement with reference model over 95%. After completing the validation, a curved channel reactor was designed to determine the effects of shape and length of flow path on methanol conversion efficiency and generation of hydrogen. Numerical analysis of the curved-channel reformer was conducted under various flow rate ($10/15/20{\mu}l/min$). As a result, the characteristics of flow and mass transfer were confirmed in the cylindrical channel and curved channel reactor, and useful information about methanol conversion efficiency and hydrogen generation was obtained for various flow rate.

• Resources Recycling
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• v.18 no.2
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• pp.51-55
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• 2009

Sawdust and sewage sludge and PE gasification by high temperature steam of Brown gas have been performed in this study. Steam/carbon ratio has been changed from 1 to 5 and the effect of steam/carbon ratio on the produced gas concentrations, gasification rate and tar generation has been determined. Also, the temperature distribution in the gasification reactor has been studied. Highest combustible content in the produced gas is around 70vol% and $H_2$ shows highest content among the combustible compounds. However, the heating value of the produced gas and tar content have been reduced with increasing steam/carbon ratio.

• Proceedings of the KSME Conference
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• 2007.05b
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• pp.3236-3240
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• 2007

This paper describes the results of steam turbine performance tests. The objectives of performance test is to exactly evaluate the degradation(decrease in performance) of the coal-fired steam turbine generator in order to provide plant information to help performance engineers identify problems, improve performance, and make economic decisions about scheduling maintenance and optimizing operation. To achieve these goals, the periodic thermal performance tests have been carried out since the initial operation period, 1997. We made the calculation program and guidelines for the tests and developed the performance index of the turbine cycle on the basis of the ASME PTC. By comparing the performance changes throughout the whole operation period, we confirmed the performance reliabilities of the turbine and its conditions.

• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.794-797
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• 2009

중소형 폐기물 소각설비의 폐열보일러에서 생산되는 10 $kg/cm^2$미만의 저압증기를 이용한 증기터빈발전에서 증기의 건도를 높이이 위한 증기 전처리가 필수적이며, 건도를 증가시킨 증기를 이용하여 발전실험을 하였다. 본 연구에 적용된 증기터빈발전기는 마이크로 축류식 증기터빈으로 배압식을 채택하였으며, 증기터빈에 공급되는 증기압력의 증가에 따라 증기공급량, 발전량이 증가하였으며, 이에 따른 발전 효율은 설비의 효율에 따라 변하였다. 또한, 배압식 증기터빈의 경우, 공급.배기측의 증기 압력의 차이가 증가함에 따라 발전을 위한 증기 소비율이 감소하고 발전 효율이 증가함을 볼 수 있었다.

• Proceedings of the KSME Conference
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• 2001.06d
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• pp.726-731
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• 2001

A thermal design software is developed for the heat recovery steam generator(HRSG) of combined cogeneration systems. The heat transfer is calculated by using the element method to account for the varying thermal properties across the heat transfer elements. The circulation balance is computed for the evaporator to accurately estimate the steam generation rate and to check the proper circulation of the boiler water through the tubes. The software developed can be used to simulate HRSG systems with various combinations of auxiliary burner, wall superheater, superheater, reheater, evaporator, and economizer. Systems with several different combinations of the system components are successfully tested. And it is concluded that the developed software can be used for the design of heat recovery steam generators with various combinations of heat transfer components.

• 한국태양에너지학회:학술대회논문집
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• 2009.11a
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• pp.74-79
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• 2009

The generation of electric power and plant facilities have been attempting to improve energy efficiency with many efforts as those being basis of our country's economy. In particular, the CHP(Combined Heat Power plant) system, is producing the electricity and process steam, has generally been using for the cogeneration plants. When CHP system operates, the steam has to maintain the high temperature and high pressure in order to have high efficiency of electric power production as much as possible. In addition, the exhausted steam from the turbine has to reform proper temperature to use the needed process. The major purpose of desuperheater is that the superheated steam changes into the saturated steam because it is more efficient and suitable for using the process, furthermore, it is more convenient and stable regarding the process temperature control. The design of the desuperheater obtained through the experiment and preceding analysis. This paper is verified by analysis that water spray nozzle(${\Phi}$=28mm) shows the best ability under the real power plant condition.

• Resources Recycling
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• v.16 no.6
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• pp.28-33
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• 2007

Coal is the most abundant energy source and deposited in every area of world. Combustion process with lower efficiency has been mainly used. Therefore, implementation of more efficient technologies, involving gasification, combined cycles and fuel cells, would be a key issue in the plans for more efficient power generation. In these technologies, gasification has been studied for decades. However, coal gasification to high value combustible gas such as hydrogen and carbon monoxide is focused again due to high oil price. The gaseous product, called syngas, can be effectively utilized in a variety of ways ranging from electricity production to chemical industry (as feedstock). In this study, coal gasification with ultra high temperature steam has been performed. The effect of steam/carbon ratio on the produced gas concentrations, gasification rate and additional products like tar, ammonia and cyan compounds has been determined.