• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.34 no.3
• /
• pp.269-274
• /
• 2010

As a preliminary study on a SOFC-GT hybrid system integrated a with coal-gasification system, the influence of the concentrations of $H_2$ and CO in syngas on the performance characteristics of the hybrid system is investigated. It is expected that the differences in the heating values of fuels with different compositions trigger the off-design operation of the gas turbine and result in different performance characteristics of the overall hybrid system. Syngas compositions are found to affect the SOFC performance. Performance of hybrid system with carbon monoxide is poorer than the case with hydrogen. In the case of part-load performance with syngas, performance degradation at part-load operating conditions with hydrogen is more dominant than the case with carbon monoxide.

• Korean Journal of Optics and Photonics
• /
• v.1 no.1
• /
• pp.33-39
• /
• 1990

By developing a computer simulation code for discharge excited KrF excimer laser, we analyzed mainly the effects of buffer gas for the $KrF^*$ formation. the $KrF^*$ relaxation. and the absorption of the laser radiation. The $KrF^*$ formation efficiency were found to be 7.5%, 19% and the $KrF^*$ relaxation kinetic reactions were found to be 45%, 30% at the charging voltage of 30 KV and He. Ne buffer gas. respectively. But the absorption of the 248 nm laser radiation were less than 10% by the buffer gas.er gas.

• Proceedings of the Korea Technology Innovation Society Conference
• /
• 2017.11a
• /
• pp.1473-1487
• /
• 2017

2017년 6월 19일 고리 원전 1호기 영구정지 기념식에서 문재인 대통령의 '탈원전' 선언을 계기로, 국내에서는 후쿠시마 원전 사고 이후 탈원전으로 복귀한 독일의 사례에 대한 관심이 고조되었다. 독일은 1986년 체르노빌 원전 사고 이후 탈원전에 대한 논의가 본격적으로 이루지면서 집권 정부의 성향과 사회 경제적 요인에 따라 "2000년 탈원전 선언 ${\rightarrow}$ 2010년 탈원전 보류 ${\rightarrow}$ 2011년 탈원전 복귀"의 결정 과정을 거쳤다. 이러한 정책 변화의 배경에는 간헐성의 재생에너지를 뒷받침(back-up)할 수 있는 자국의 풍부한 갈탄 매장량, 지리적으로 주변국과 연결된 전력망을 통해 전력을 상시 주고받을 수 있는 전력 수급 환경, 탈원전에 대한 정부 국민 산업계의 40여년에 걸친 합의형성 등 '독일 자국의 실정을 반영한 정책적 판단'이 자리하고 있다. 그럼에도 불구하고, 2011년 후쿠시마 원전 사고 직후 독일의 즉각적인 탈원전 복귀는 화석연료 사용의 증가로 인한 온실가스 배출량 증가, 재생에너지 보조금 증가 및 송전망 확대로 인한 전기요금 상승, 간헐성의 재생에너지로 인한 불안정한 전력 수급, 과잉 생산된 전력의 수출로 인한 주변국 전력계통 혼란 등의 문제를 초래하고 있다. 이에 본고에서는 독일의 탈원전 정책이 '어떤 정책결정 과정을 거쳤으며, 현실적으로 어떤 문제에 직면해 있는지'를 살펴보고 우리나라의 에너지 수급 현실을 반영한 정책적 시사점을 도출하고자 한다.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2007.11a
• /
• pp.350-353
• /
• 2007

In this study, the genetic algorithm has been used for the real-time defect diagnosis on the operation of the aircraft gas-turbine engine. The component elements of the gas-turbine engine for consideriation of the performance deterioration is consist of the compressor, the gas generation turbine and the power turbine, repectively. Compared to the on-design point on the sea-level condition, the learning data has been increased 200 times in case of the off-design conditions for the altitude, the flight mach number and the fuel consumption. Therefore, enormous learning time has been required for the satisfied convergence. The optimum division has been proposed to decrease learning time as well as to obtain high accuracy. As results, the RMS errors of the defect diagnosis using the genetic algorithm have been estimated under 5 %.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.47 no.12
• /
• pp.881-889
• /
• 2019

The pre-swirl system is the device that minimizes energy loss of turbine cooling airflow from the stationary parts into rotating parts. In this paper, an off-design analysis was conducted for the ambient air temperature and turbine load conditions. The discharge coefficient was constant for ambient air temperature and turbine load. However, adiabatic effectiveness was increased. This is due to the volume flow rate. The volume flow rate was increased at higher ambient temperature and higher turbine load. It means that the volume of cooling air was increased and the cooling performance of the air was improved. Consequently, adiabatic effectiveness increased by 30.46% at 100% turbine load compared to 20% turbine load. And increased by 18.42% at 55℃ ambient air temperature compared to -20℃ ambient air temperature.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.12 no.3
• /
• pp.60-67
• /
• 2008

In this study, the genetic algorithm has been used for the real-time defect diagnosis on the operation of the aircraft gas-turbine engine. The component elements of the gas-turbine engine for consideration of the performance deterioration consist of the compressor, the gas generation turbine and the power turbine. Compared to the on-design point, the teaming data has been increased 200 times in case off-design conditions for the altitude, the flight mach number and the fuel consumption. Therefore, enormous learning time has been required for the satisfied convergence. The optimal division has been proposed for learning time decrease as well as the high accuracy. As results, the RMS errors of the defect diagnosis using the genetic algorithm have been confirmed under 5 %.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.25 no.1
• /
• pp.12-18
• /
• 2021

In this study, the performance modeling of MT30 gas turbine engine is performed. The design point is determined, and the component performance maps to which the scaling technique is applied are generated using standard maps provided by the commercial program. Off-design point performance analysis is performed with the generated performance model, and this is compared with the performance deck data of the engine. It is confirmed that the data of the performance maps generated by the one-point scaling method had some errors from the performance deck data, and it is determined that correction is necessary to increase the accuracy of the performance model. Therefore, the off-design point analysis is performed by creating the correction performance model in a manner that obtains the scaling factors for each operating point(off-design point) according to the high pressure spool speed.

• Journal of Korea Foundry Society
• /
• v.8 no.3
• /
• pp.266-270
• /
• 1988

• Proceedings of the Korean Vacuum Society Conference
• /
• 1997.07a
• /
• pp.94-94
• /
• 1997

• Journal of Korea Foundry Society
• /
• v.43 no.5
• /
• pp.251-255
• /
• 2023