• 한국안전학회지
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• 제19권4호
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• pp.14-19
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• 2004

Boiler is a hazardous equipment to have potential explosion ail the time. And not only it has malfunction at explosion. it lead to people death but also secondary accident such as explosion and fire. Therefore, this equipment should not be broken for keeping its own function. And also, high level of safety should be kept in the process of the use not to be malfunctioned. A large scale of accident due to boiler explosion can be preventive in advance. Boiler fracture is occurred by instant expansion (approximately 1700 time) from quick evaporation of rater in boiler, due to pressure decrease in boiler Emitting energy from it is tremendous and it is so dangerous because of its high temperature. Secondary explosion such as fire is also a main hazard occurring at fuel supply place. If any devices with high pressure is broken, then not only boiler vessel but also components of it are spread with high speed, causing secondary accident. This study is to analyze integrally accident cause of fire and flue tube boiler to have occurred pressure fracture actually, to show countermeasures to prevent accident loss from the fire and flue tube boiler.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2009년도 추계학술발표대회 논문집
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• pp.259-264
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• 2009

Most of the fossil power plants firing lower grade coals are challenged with maintaining good combustion conditions while maximizing generation and minimizing emissions. In many cases significant derate, availability losses and increase in unburned carbon levels can be attributed to poor combustion conditions as a result of poorly controlled local fuel and air distribution within the boiler furnace. The poor combustion conditions are directly related to the gas flow deviation in upper furnace and convection tube-bank but a less reported issue related to in large-scale oppose wall fired boilers. In order to develop a on-line combustion monitoring system and suggest an alternative heat flux estimation method at tube bank, which is very useful information for boiler design tool and blower optimizing system, field test was conducted at operating power boiler. During the field test the exhaust gases' temperature and tube metal temperature were monitored by using a spatially distributed sensors grid which located in the boiler's high temperature vestibule region. At these locations. the flue gas flow is still significantly stratified, and air in-leakage is minimal which enables tracing of poor combustion zones to specific burners and over-fire air ports. Test results showed that the flue gas monitoring method is more proper than metal temperature distribution monitoring for real time combustion monitoring because tube metal temp. distribution monitoring method is related to so many variables such as flue gas, internal flow unbalance, spray etc., Heat flux estimation at the tube bank with flue gas temp. and metal temp. data can be alternative method when tube drilling type sensor can't able to use.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 추계학술대회
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• pp.1686-1691
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• 2004

The effect of recirculated exhaust gas on performance and exhaust emissions with FGR rate are investigated by using a natural circulation, pressurized draft and water tube boiler with FGR system operating at several boiler loads and over fire air(OFA) damper openings. The purpose of this study is to apply the FGR system to a power plant boiler for reducing $NO_{x}$ emissions. To activate the combustion, the suction damper of two stage combustion system installed in the upper side of wind box is opened by handling the lever between $0^{\circ}$ and $90^{\circ}$ , and the OFA with 0 to 20% into the flame is supplied, as the combustion air supplied to burner is reduced. It is found that the fuel consumption rate divided by evaporation rate does not show an obvious tendency to increase or decrease with rising the FOR rate, and $NO_{x}$ emissions are decreased, at the same OF A damper opening, as FOR rates are elevated and boiler loads are dropped.

• 대한기계학회논문집B
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• 제40권4호
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• pp.263-273
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• 2016

자연순환식 압입 송풍식 수관보일러에 FGR시스템을 설치하여 보일러 부하 및 공기량 댐퍼개도를 파라미터로 해서 FGR률에 따른 성능 및 배기 배출물에 미치는 재순환 배기의 영향을 조사하였다. 본 연구의 목적은 $NO_x$ 배출물을 저감시키기 위하여 동력플랜트 보일러에 FGR시스템을 적용하는 것이다. 연소를 활성화시키기 위해 0 ~ 20%의 연소용 공기를 화염 내에 공급한다. 공기상자 상부에 설치된 2단 연소시스템의 흡입댐퍼를 $0^{\circ}{\sim}90^{\circ}$ 사이에서 레버를 조작하여 열면, 버너로 공급되는 연소용 공기가 변화된다. 증발률당의 연료소비율은 FGR률의 증가에 따라 증가 혹은 감소의 명확한 경향을 나타내지 않았고, 동일 공기량 댐퍼개도에서는 FGR률이 증가할수록, 또한, 보일러 부하가 감소할수록 $NO_x$ 배출물이 감소되었다. 매연 배출물은 전기 집진기에서 86.7%의 포집효율로 매연이 제거되었기 때문에, 보일러 부하, 공기량 댐퍼 개도 및 FGR률의 운전조건에 관계없이 극소량의 매연이 배출되었다.