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발전소 Deaerator floor의 복사효과 저감을 위한 열유동 해석
김태권(Tae-Kwon Kim),하지수(Ji-Soo Ha),최용석(Yong-Seok Choi) 한국산학기술학회 2016 한국산학기술학회논문지 Vol.17 No.12
화력발전은 화석연료인 석탄을 연소시켜 얻은 열에너지로 물을 끓여 증기를 만들고 그 증기로 터빈을 운전시켜 터빈축에 연결된 발전기로 전기를 얻는 방식이다. 따라서 하절기에는 화력발전소 Deaerator의 표면온도는 70℃, Storage Tank의 표면온도는 67℃, 공기온도는 50℃를 상회한다. 이런 현상은 기기와 작업자에게 부적합한 영향을 끼친다. 특히, Deaerator와 Storage Tank에 인접해 있는 작업자는 복사열전달의 영향을 받아 더 높은 체감온도를 느끼게 된다. 따라서 본 논문에서는 전산해석을 통해 Deaerator 부근의 열유동 특성을 파악하고 단열재를 사용하였을 때와 복사차폐막을 사용하였을 때의 효과를 비교하여 최적의 냉각조건을 제시하였다. Case 1은 현재 발전소의 형상이고 Case 2는 Case 1에서 단열재를 추가로 사용한 형상이고 Case 3은 Case 1에서 복사차폐막을 사용한 형상이다. 유동은 벽면과 열원의 온도 차이에 의해 발생되었고 오른쪽 상단부에 고온의 공기가 포집된다. 온도 분포에서 작업자표면의 최대 온도를 비교해보면 단열재를 사용한 Case 2가 복사효과 저감에 가장 효율적인 것으로 나타났다. Steam power generation is used to produce electricity through a generator that is connected to a steam turbine. As a result, the surface temperature of the deaerator is 70℃during the summer season, the surface temperature of the storage tank is 67℃, and the air temperature is 50℃. This environment is inappropriate for workers and instruments. Workers adjacent to the deaerator and storage tank in particular feel higher temperatures because of the radiative heat transfer effect. Therefore, we optimized the cooling conditions by computational analysis. Case 1 is the current shape of the power plant, Case 2 has additional insulation, and Case 3 has a radiation shield. Flow is caused by a temperature difference between the heat sources in the wall, and hot air is trapped in the right upper end. Based on the temperature contours and the maximum temperature of the surfaces, Case 2 was found to be the most efficient for reducing radiative heat transfer effects.
Fault Detection and Diagnosis of the Deaerator Level Control System in Nuclear Power Plants
Kim Kyung Youn,Lee Yoon Joon Korean Nuclear Society 2004 Nuclear Engineering and Technology Vol.36 No.1
The deaerator of a power plant is one of feedwater heaters in the secondary system, and it is located above the feedwater pumps. The feedwater pumps take the water from the deaerator storage tank, and the net positive suction head(NSPH) should always be ensured. To secure the sufficient NPSH, the deaerator tank is equipped with the level control system of which level sensors are critical items. And it is necessary to ascertain the sensor state on-line. For this, a model-based fault detection and diagnosis(FDD) is introduced in this study. The dynamic control model is formulated from the relation of input-output flow rates and liquid-level of the deaerator storage tank. Then an adaptive state estimator is designed for the fault detection and diagnosis of sensors. The performance and effectiveness of the proposed FDD scheme are evaluated by applying the operation data of Yonggwang Units 3 & 4.
Experimental Heat and Mass Transfer Coefficients of a Two Stage Spray and Packed Bed Deaerator
( K. V. Suryanarayana ),( R. A. Bakar ),( Chang Sik Lee ),( D. M. Reddy Prasad ),( K. V. Sharma ) 한국액체미립화학회 2010 한국액체미립화학회 학술강연회 논문집 Vol.2010 No.-
Experiments are conducted to study the influence of mass flow rate on heat and mass transfer coefficients in a two stage deaerator consisting of a spray stage and packed bed combination. It has been observed that an increase in mass flow rate of water increases the heat transfer coefficients in both the stages of the deaerator, whereas the mass transfer coefficients increases in the first and decreases in the second stage. The heat transfer coefficient in the spray stage is 300 times greater than that obtained in the packed bed. The mass transfer coefficient decreased by 2 times in the second stage with increase in flow rate in the range of experiments conducted. It has been observed that oxygen can be reabsorbed by the outgoing feed water under certain conditions of flow.
원전 탈기기 시스템의 수위 측정 센서의 고장 검출 및 진단
김봉석,이인수,이윤준,김경연,Kim, Bong-Seok,Lee, In-Soo,Lee, Yoon-Joon,Kim, Kyung-Youn 한국전기전자학회 2003 전기전자학회논문지 Vol.7 No.1
원전 탈기기 저장탱크의 기하학적 구조 및 정상 상태에서의 입출력 흐름율을 고려하여 동적 제어 모델을 설정하고, 적응 추정기를 이용하여 수위 측정 센서의 고장 검출 및 진단 기법을 제안하였다. 영광 3, 4호기의 실제 운전 데이터를 적용하여 제안된 고장 검출 및 진단 기법의 성능을 평가하고 타당성을 검증하였다. In this paper, dynamic control model is formulated by considering the geometrical structure of the deaerator storage tank in nuclear power plant and input-output flow rate at steady state, and we describe fault detection and diagnosis (FDD) scheme based on the adaptive estimator. The performance and effectiveness of the proposed FDD scheme are evaluated by applying real operating data obtained from the YOUNGKWANG 3 & 4 FSAR.
분사제트 온도변화에 따른 벽면충돌 현상에 대한 실험적 연구
최현훈(Hyeonhun Choi),우루노유미(Yumi Uruno),김상호(Sangho Kim),정재원(Jaewon Chung) 대한기계학회 2018 대한기계학회 춘추학술대회 Vol.2018 No.12
In order to remove dissolved oxygen and carbon dioxide from feedwater in power generation facilities, boilers and incinerators, deaerators are essential. In actual deaerator, temperature of spray is about 145°C and the surrounding temperature is about 177°C (steam temperature). It is necessary to analyze the temperature in order to improve the efficiency of deaerator. In this paper, splashed fraction and jet breakup according to the distance from nozzle were studied. Also, Liquid film shapes on the vertical wall are visualized and analyzed using highspeed camera. These were obtained at different temperature respectively. As temperature increases, ξ(splashed fraction) becomes smaller overall. Also, the value of ξ<SUB>max</SUB>(maximum of splashed fraction) decreases as the temperature increases. The Rayleigh regime, the first wind-induced regime, and the second wind-induced regime were confirmed by jet breakup images. The phenomenon that <SUB>max</SUB> decreased with increasing temperature was visualized and confirmed. It was confirmed that the diameter of the liquid film becomes larger as the temperature rises. That is, ξ decreases because droplets spread on the wall and the thickness of the liquid film becomes thinner. Therefore, when the temperature of water rises, ξ decreases. The results of this paper are used to increase the efficiency of actual deaerator and provide data for design and optimization.
급수계통 설비의 탈기기에 의한 부식방지 및 살균에 관한 연구
구남열(Nam Yeol Koo),서승일(Seung il Seo),하옥남(Yok Nam Ha) 대한설비공학회 2011 대한설비공학회 학술발표대회논문집 Vol.2011 No.7
Corrosion of water supply system due to the low of pH and dissolved oxygen mainly. Important thing is that corrosion occurs by inflow feed water pipe product of apartment house to each system of progression, supply water, compound waters. By inflowing the Fe²+, CU²+, ferrate freight etc. from boiler proper inside, corrosion is apt to be occurred in boiler body proper. There is method that use heating, vacuum, chemical method and separation film by deaeration method to prevent this corrosion. In this study, progression develops and manufactures and supplies all water pipe and equipment to anti-corrosion fundamentally in pressure tank of equipment that use service water of feed tank etc.. using and supply deaeration equipment. There is purpose of study in plan presentation for cost reduction economic income by this.
Nisheeth Kr. Prasad,A. S. Pathak,S. Kundu,K. Mondal 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.9
The effect of deaeration, Cl−ion content and strong oxidizer on the active behavior of the high phosphorus pig iron (HPPI)samples was studied in 3.5% NaCl and 1 N HNO3solutions. Deaerating the 3.5% NaCl solution could effectively shift thecorrosion potential of the HPPI below the protective potential of the steel in seawater [− 0.778 V vs saturated calomelelectrode (SCE)], which has not been observed in the freely aerated 3.5% NaCl solution. Both the Cl−ion content and thedeaerated conditions restrict the formation of the stable iron phosphate on the surface and promote the dissolution of the pigiron as soluble iron phosphate hydrate (FePO4·2H2O). However, in the case of the freely aerated nitric acid solution, evenwith deaeration, the HPPI samples have shown more noble behavior as compared to the mild steel due to the strong oxidizingnature of nitric acid and the formation of a stable iron phosphate on the surface.