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발전용 보일러에 대한 다중영역분할 화로해석 기법의 활용성 연구
Baek, SeHyun,kim, Donggyu,Lee, Jang Ho 한국전력공사 2020 KEPCO Journal on electric power and energy Vol.6 No.4
본 연구에서는 화력 발전소 보일러에 대한 연소 및 열전달 해석을 위하여 화로 내부를 다중영역으로 나누고 각 영역에서 energy와 mass balance는 1차원으로 계산하고, 복사열전달은 3차원으로 계산하는 다중영역분할 화로해석 기법을 활용하였다. 그리고 적용 기법에 대한 신뢰성 검증을 위하여 국내 500 MW 급 석탄화력 보일러 화로에 대한 계산 값과 보일러 제작사의 설계 데이터를 비교하여 양호함을 확인하였고, 동일한 설비에 대한 CFD 해석과 비교한 결과 유사한 경향을 얻었다. 본 계산 기법은 CFD 화로해석 보다는 덜 상세하지만, 빠른 시간에 연료반응성, 화로형상 및 운전변수에 따른 특성을 계산할 수 있는 장점이 있으므로 발전소 현장에서의 설비감시진단 및 일일 연료/운전 계획 수립 등 활용성 측면에서 유용할 것으로 예상된다. In this study, a multi-zone furnace analysis method that couples a 1D energy and mass balance calculation with a 3D radiative heat transfer calculation is tested in order to verify its reliability. The calculated results for a domestic 500 MW capacity coal-fired boiler furnace were compared with the design data of the boiler manufacturer and CFD analysis, and a good agreement was achieved. Although this calculation method is less sophisticated than the CFD furnace analysis, it has an advantage in terms of calculation time while being able to provide the furnace behavior according to the fuel characteristics and operational variable changes. Therefore, it is expected to be useful for boiler operation diagnosis and daily fuel/operation planning.
Baek Sehyun,Lee Sungkyu,Lee Shin Young 한국사회복지학회 2022 Asian Social Work and Policy Review Vol.16 No.2
Using a nationally representative sample in Korea, this study examined the association of information and communication technology (ICT) utilization level and the life satisfaction of people with disabilities and the variations by disability type. Data were obtained from the second wave of the 2021 Survey on the Digital Divide, administered by the Korean National Information Society Agency (N = 2200 persons with disabilities). Study findings reveal that ICT utilization level has a significant association with the life satisfaction of people with disabilities, regardless of the disability type. In addition, the level of disability was related to the life satisfaction of people with physical disabilities only, while income was associated with the life satisfaction of people with physical disabilities and brain lesion disabilities. Based upon these results, this study discussed practical and policy implications for people with disabilities, particularly focusing on the methods to increase to increase the level of ICT utilization.
A Study on Repowering of Domestic Aged Coal-fired Power Plant
Baek, SeHyun,Kim, YoungJoo,Kim, HyunHee,Park, SangBin,Jang, JiHoon Korea Electric Power Corporation 2017 KEPCO Journal on electric power and energy Vol.3 No.1
Recently, the public opinion is growing that the main cause of greenhouse gas, fine dust and nitrogen oxide, sulfuric acid emission is coal-fired power plant, and now the decommission or conversion to other clean fuel is being demanded. However, it is a huge national loss to decommission coal-fired power plant with remaining life, and also simple fuel converting to natural gas will lead to drastic rise on power generating cost. Therefore, this study aims to provide the analysis result about the reduction effect of $CO_2$, environment emission, and to influence to power plant performance and facilities when repowering with adding gas turbine is applied to domestic aged coal-fired power plant.
A Feasibility Study on Adopting Sliding Pressure Operation for Drum Type Boiler
Baek, SeHyun,Kim, HyunHee,Park, SangBin,Kim, YoungJoo,Park, Hoyoung Korea Electric Power Corporation 2016 KEPCO Journal on electric power and energy Vol.2 No.3
In general, drum-type boilers are designed for base load duty and applied under constant pressure operation mode. Recently, however conditions often occur that even drum-type boilers have to operate at partial load conditions. A feasibility study on adopting the sliding pressure operation for drum-type boiler was conducted, and corresponding performance changes and effects on the equipment were analyzed by utilizing a process simulation model. As a result, the conclusion was reached that drum type boilers are able to adopt the sliding pressure operation and can improve of net efficiency at part load operation in spite of the Rankine cycle efficiency reduction due to the decreases in main steam pressure. Because of thank to improvement of high pressure turbine stage-1 internal efficiency and power savings of boiler feed water pump. The sliding pressure operation is advantageous in terms of stress level relief for boiler tube as well as maintaining the rating steam temperature at part load condition. However, cautions are required because the drum boilers have poor dynamic response characteristics which may get worse during the sliding pressure operation.
75 MWe급 중유 발전소 보일러에 대한 바이오중유 100% 전소 실증 연소실험 결과
백세현(Sehyun Baek),박호영(Hoyoung Park),김영주(Young Joo Kim),김태형(Tae Hyung Kim),김현희(Hyunhee Kim),고성호(Sung Ho Ko) 한국연소학회 2014 한국연소학회지 Vol.19 No.2
Bio fuel oil combustion experiments were successfully demonstrated at the 75 MWe oil-fired power plant without major equipment retrofit and 100% bio-fuel oil combustion was possible without big problems. The experimental data error correction was conducted and numerical model-based analysis technique was applied for the evaluation of the results. Incase of bio fuel oil combustion, heat absorption of radiative heat transfer section was reduced while convection section has opposite trend. The furnace exit gas temperature tends to rise slightly. Environment emissions such as NOx and SOx concentrations showed a tendency to decrease during the bio fuel oil combustion period. On the other hand, boiler efficiency was slightly underestimated.
100 MWe급 순산소연소 발전소 보일러계통 공정설계 및 운전변수 민감도 예측
백세현(Sehyun Baek),고성호(SungHo Ko) 한국연소학회 2013 한국연소학회지 Vol.18 No.4
The oxy-fuel combustion is CO₂ capture technology that uses mixture of pure O₂ and recirculated exhaust as oxidizer. Currently some Oxy-fuel power plants demonstration project is underway in worldwide. Meanwhile research project for converting 125 MWe Young-Dong power plant to 100 MWe oxy-fuel power plants is progress. In this paper, 1 D process analytical approach was applied for conducting process design and operating parameters sensitivity analysis for oxy-fuel combustion of Young-Dong power plant. As a result, appropriate gas recirculation rates was 74.3% that in order to maintain normal rating superheater, reheater steam temperature and boiler heat transfer patterns. And boiler efficiency 85.0%, CPU inlet CO₂ mole concentration 71.34% was predicted for retrofitted boiler. The oxygen concentration in the secondary recycle gas is predicted as 27.1%. Meanwhile the oxygen concentration 22.4% and moisture concentration 5.3% predicted for primary recycle gas. As the primary and secondary gas recirculation increases, then heat absorption of the reheater is tends to increases whereas superheater side is decreased, and also the efficiency is tends to decrease, according to results of sensitivity analysis for operating parameters. In addition, the ambient air ingression have a tendency to lead to decline of efficiency for boiler as well as decline of CO₂ purity of CPU inlet.