• Title/Summary/Keyword: Flue-gas temperature

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The Study of Optimized Combustion Tuning for Fossil Power Plant (발전보일러의 최적연소조정에 대한 실험적 연구)

  • Jung, Jae-Jin;Song, Jung-Il
    • 한국태양에너지학회:학술대회논문집
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    • 2009.04a
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    • pp.102-108
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    • 2009
  • Fossil power plants firing lower grade coals or equipped with modified system for NOx controls 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. In order to develop a on-line combustion tuning system, field test was conducted at operating power boiler. During the field test the exhaust gases' $O_2$, NOx and CO was monitored by using a spatially distributed monitoring grid located in the boiler's high temperature vestibule and upper convective back-pass 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. using these monitored information we can improving combustion at every point within the furnace, therefore the boiler can operate at reduced excess $O_2$ and gas temperature deviation, reduced furnace exit gas temperature levels while also reducing localized hot spots, corrosive gas conditions, slag or clinker formation and UBC. Benefits include improving efficiency, reducing NOx emissions, increasing output and maximizing availability. Discussion concerning the reduction of greenhouse gases is prevalent in the world. When taking a practical approach to addressing this problem, the best way and short-term solution to reduce greenhouse gases on coal-fired power plants is to improve efficiency. From this point of view the real time optimized combustion tuning approach is the most effective and implemented with minimal cost.

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The Study of Optimized Combustion Tuning Method for Fossil Power Plant (발전용 보일러의 최적연소조정기법에 대한 실험적 연구)

  • Jung, Jae-Jin;Song, Jung-Il
    • Journal of the Korean Solar Energy Society
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    • v.29 no.5
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    • pp.45-52
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    • 2009
  • Fossil power plants firing lower grade coals or equipped with modified system for $NO_x$ controls 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. In order to develop a on-line combustion tuning system, field test was conducted at operating power boiler. During the field test the exhaust gases' $O_2,\;NO_x$ and CO was monitored by using a spatially distributed monitoring grid located in the boiler's high temperature vestibule and upper convective rear pass 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. using these monitored information we can improving combustion at every point within the furnace, therefore the boiler can operate at reduced excess $O_2$ and gas temperature deviation, reduced furnace exit gas temperature levels while also reducing localized hot spots, corrosive gas conditions, slag or clinker formation and UBC. Benefits include improving efficiency, reducing $NO_x$ emissions, increasing output and maximizing availability. Discussion concerning the reduction of greenhouse gases is prevalent in the world. When taking a practical approach to addressing this problem, the best way and short-term solution to reduce greenhouse gases on coal-fired power plants is to improve efficiency. From this point of view the real time optimized combustion tuning approach is the most effective and implemented with minimal cost.

Comparison of Pyrolysis Patterns of Different Tobacco Leaves by Double-Shot Pyrolysis-GC/MSD Method

  • Lee, Chang-Gook;Lee, Jae-Gon;Jang, Hee-Jin;Kwon, Young-Ju;Lee, Jang-Mi;Kwag, Jae-Jin;Kim, Soo-Ho;Sung, Yong-Joo;Shin, Chang-Ho;Kim, Kun-Soo;Rhee, Moon-Soo
    • Journal of the Korean Society of Tobacco Science
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    • v.30 no.2
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    • pp.94-102
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    • 2008
  • In this paper, we describe our study on the characterization of tobacco leaves by their pyrolysis patterns. Two kinds of tobacco leaves were pyrolyzed and analyzed by Double-Shot Pyrolysis-Gas Chromatography/Mass Spectroscopy (Py-GC/MS) methods. Three grades of Korean flue-cured tobacco leafsuch as B1O, AB3O, CD3L and burley tobacco leaves such as B1T, AB3T, CD3W were pyrolyzed with six discrete but stepwise heating temperature ranges, those are from 100$^{\circ}C$ to 150$^{\circ}C$, 150$^{\circ}C$ to 200$^{\circ}C$, 200$^{\circ}C$ to 250$^{\circ}C$, 250$^{\circ}C$ to 300$^{\circ}C$, 300$^{\circ}C$ to 350$^{\circ}C$ and finally from 350$^{\circ}C$ to 400$^{\circ}C$. Using the resultant 52 pyrolytic components identified in the programs as components, principal component analysis (PCA) showed statistical classification between flue-cured and burley tobacco lamina. Among six pyrolysis temperature ranges, the best discrimination was achieved at the temperature range from 250$^{\circ}C$ to 300$^{\circ}C$ and from 300$^{\circ}C$ to 350$^{\circ}C$.

Combustion Characteristics of a Turbulent Non-premixed Flame Using High Preheated Air (고온 예열 공기에 의한 난류 비예혼합 화염의 연소 특성)

  • Kwark, Ji-Hyun;Jeon, Chung-Hwan;Chang, Young-June
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.27 no.5
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    • pp.561-568
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    • 2003
  • An experiment using high preheated air in a turbulent non-premixed flame was performed to investigate the effects of high preheated air on the combustion characteristics. Combustion using high preheated and diluted air with flue gas is a new technology which enables NO emission to be reduced. In this study, Na was used as diluent and propane as fuel. Combustion characteristics, especially the distributions of the flame temperature, NO concentration and OH radical intensity were examined under the condition of 300 K, 600 K, 1000 K in terms of the combustion air temperature, and also under the condition of the dilution level from 21% to 13% in terms of oxygen concentration. As the preheated air temperature increased, it appeared that the flame length became shorter, maximum flame temperature increased, the reaction region moved to upstream, and NO concentration increased, but the flame temperature's fluctuation was reduced. In opposite, it was shown with decrement of oxygen concentration at the maximum temperature that both maximum value and the gradient of the flame temperature decreased, and NO emission also decreased considerably, but its fluctuation became larger, being inclined to be unstable.

Combustion Characteristics of Coal and Wood Biomass Co-Firing on the Pulverized Coal Combustion Furnace (목질계 바이오매스와 유연탄의 혼합 연소특성에 관한 연구)

  • Kim, Sung-Chul;Lee, Hyun-Dong;Kim, Jae-Gwan
    • 한국연소학회:학술대회논문집
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    • 2006.10a
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    • pp.293-298
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    • 2006
  • There are many researches in progress on co-firing of coal and biomass to reduce carbon dioxide produced from the coal consumption. This study carried out 200 Kg/h combustion test furnace by mixing coal with timber. Coal was mixed with domestic and imported-wood around 10% to 20% based on input energy. For the mixed fuel, combustion temperature, unburned carbon and the composition of flue gas were analyzed. In addition, the tendency of slagging and fouling was examined using a probe. According to the result of the experiment, combustion temperature was depended on the kind of wood and mixing ratio. The unburned carbon loss was higher with increase of wood biomass mixing ratio, as a result, the total heat loss of furnace was slightly increased. The emission of NOx and SOx were decreased by $3{\sim}20%$ and $21{\sim}60%$ respectively. There are no difference of slagging and fouling tendency between biomass co-firing and coal burning only.

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Study on Low Temperature Pyrolysis of Woody Biomass to Produce High-Calorie Torrefied Fuel (고열량 반탄화 연료 생산을 위한 목질계 바이오매스 저온열분해 방법에 대한 연구)

  • Lee, Changyeop;Kwon, Minjun;Kim, Daehae;Kim, Sewon
    • 한국연소학회:학술대회논문집
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    • 2014.11a
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    • pp.263-263
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    • 2014
  • Low temperature pyrolysis of woody biomass has been conducted to produce highcalorie torrefied fuel. In this experiment, to maximize the energy efficiency in heat transfer, flue gas is directly used for heat source in the torrefier. To accomplish the oxygen free environment in the torrefaction reactor, a burner has been developed and it can be runned with fuel rich state. An inner central axis rotating type of reactor was applied in experiment. To use the calorific gases produced from torrefier, another burner is developed to combust them.

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Energy recovery characteristics by combustion of pulverized fuel made from food waste (음식물쓰레기로부터 제조한 분체연료의 연소에 의한 에너지회수 특성)

  • Kim, Sang-Guk;Kwon, Hyo-Lee
    • 한국신재생에너지학회:학술대회논문집
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    • 2009.11a
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    • pp.329-330
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    • 2009
  • Food waste contains almost no heavy metals and high fuel ratio 0.14-0.17 that makes it a good candidate for solid fuel. Thermogravimetric analysis showed that volatile matter volatilizes at $200-400^{\circ}C$, and ignition temperature is $460^{\circ}C$. Combustion efficiency measured from energy balance before and after combustion was over 99%. Pulverized fuel made from food waste is a new and renewable energy which contribute to low carbon green economic growth.

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Evaluation of self-heating propensity and its relation with fuel properties of various coals (다양한 탄종별 자체발열 특성과 물성의 비교 분석)

  • Kim, Jungsoo;Lee, Yongwoon;Im, Hyeon Soo;Park, Hoyoung;Ryu, Changkook
    • 한국연소학회:학술대회논문집
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    • 2013.06a
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    • pp.83-85
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    • 2013
  • With an increase in the use of low rank coals in power plants, various operational issues were raised in the fuel storage and supply, combustion, boiler and flue gas treatment systems. In the fuel storage and supply system, the main issue is the self-heating propensity of low rank coals leading to spontaneous combustion in yard storage, transport and pulverization. This study evaluated the reactivity of various sub-bituminous and bituminous coals with oxygen at low temperatures by analyzing the temperature increase characteristics of coals under a constant flow rate of oxygen supply. The results were quantified to a self-heating index and the relation with the fuel properties were evaluated.

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Studies on the Combustion of Anthracite (I). Combustion of Carbon Monoxide and the Furface (無燃炭 燃燒에 關한 硏究 (第 1 報). 一酸化炭素 燃燒反應 및 燃燒裝置)

  • Shin Byoung Sik;Shin Sei Kun
    • Journal of the Korean Chemical Society
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    • v.19 no.3
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    • pp.186-192
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    • 1975
  • In the course of anthracite briquet combustion, air draft is usually controlled to continue burning of definite amount of briquet in the conventional hollow clay cylinder with air inlet hole open for given time, so that a large amount of CO tends to be produced. Therefore, it is necessary to establish an improved combustion process to depress the yielding rate of CO and for this purpose, we performed a basic experiment in which combustion rate of CO was measured in the mixture of $N_2, O_2 $and CO gas with or without the presence charcoal at the various temperature. The observed results showed that the burning temperature of CO is about 680${\sim}700^{\circ}C$, further burning rate of it was increased with increasing the amount of draft. From these facts, longer combustion time and low CO generation are thus contradictory to each other and it has been long desired to make those two compatible somehow. The purpose of the present investigation lies in designing an effective new briquet stove to meet the above requirements. The essential feature of the new briquet stove consisted in the use of two hollow iron cylinders with different inside diameter. A cylindrical air jacket thus formed served as a path through which small amount of secondary air run from the bottom of the stove to the upper vent holes. Heat exchange occurred between the upgoing secondary air and the burning briquet, which lowered the combustion temperature of the briquet. The results observed were selfevident as anticipated. It was confirmed that the combustion time was increased tolerably due to the heat loss from the combustion zone and that CO in the flue gas was reoxidized at the upper portion of the stove by the upgoing hot secondary air. By this reoxidation reaction the concentration of CO in the flue gas was found to be about 1/20 of that in case the conventional clay cylinder was used as briquet jacket.

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Removal of S $O_{2}$ and NO by Dry Sorbent(II) - Efficiency of Cu-Ce and Cu-7Al - (건식법에 의한 이산화황과 산화질소의 제거(II) - Cu-Ce 및 Cu-7Al의 효율 -)

  • 신창섭
    • Journal of Korean Society for Atmospheric Environment
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    • v.9 no.4
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    • pp.288-294
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    • 1993
  • Flue gas control systems for small-scale combustors must be designed to provide highly effective removal of three criteria pollutants (S $O_{2}$, N $O_{x}$ and particulate matter), and must be safe, reliable and small. These requirements make dry, regenerative clean-up process particularly attractive and this paper describes a new concept for integrated pollutant control : a filter comprised of layered, gas permeable membranes that act as an S $O_{2}$ sorbant, a N $O_{x}$ reduction catalyst and a particulate filter. A mixed metal oxide sorbent, Cu-Ce was used as a sorbent/catalyst and the activity was compared with Cu-7Al. The S $O_{2}$ removal eficiency of Cu-Ce was increased with temperature increase up to 500$^{\circ}$C and the catalytic activity for NO was higher than that of Cu-7Al. By the sulfation of Cu-Ce, the reduction activity was increased at the temperature higher than 350$^{\circ}$C. The regeneration of Cu-Ce was very fast and some amount of elemental sulfar was found.

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