• Title/Summary/Keyword: unburned-carbon

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Flame Image Processing System for Combustion Condition Monitoring of Pulverized Coal Firing Boilers in Thermal Power Plant (발전용 미분탄 보일러의 연소 상태 감시를 위한 화염 영상 처리 시스템)

  • Baek, Woon-Bo;Shin, Jin-Ho
    • Journal of Institute of Control, Robotics and Systems
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    • v.12 no.11
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    • pp.1119-1123
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    • 2006
  • The flame image processing and analysis system has been investigated for the optimal pulverized coal firing of thermal power plant, especially for lower nitrogen oxide generation and more safe operation. We aimed at gaining the relationship between burner flame image information and emissions of nitrogen oxide and unburned carbon in furnace utilizing the flame image processing methods, by which we quantitatively determine the condition of combustion on the individual humors. Its feasibility test was undertaken with a pilot furnace for coal firing, through which the system was observed to be effective for the monitoring of the combustion condition of pulverized coal firing boilers.

The Flame Image Observation for Monitoring Management of Pulverized Coals Firings and its Feasibility Test to Boilers for Thermal Power Plant (미분탄 연소의 감시 관리를 위한 화염영상 감시 및 발전용 보일러 적용시험)

  • Baek, Woon-Bo
    • Journal of the Korean Society for Precision Engineering
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    • v.25 no.1
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    • pp.92-98
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    • 2008
  • The flame image observation and analysis has been investigated for combustion monitoring and management of the pulverized coal firing for thermal power plant, especially for lower nitrogen oxide generation and safer operation. We aimed at obtaining the relationship between burner flame image information and emissions of nitrogen oxide and unburned carbon in furnace utilizing the flame image processing methods, by which we quantitatively determine the conditions of combustion on the individual homers. Its feasibility test was undertaken with Samchonpo thermal power plant #4 unit which has 24 burners, through which the system was observed to be effective for evaluating the combustion conditions and continuous monitoring to prevent future loss of ignition.

Effects of fire on Vegetation and Soil nutrients in Mt. palgong (팔공산에서 식생과 토양에 미치는 산불의 영향)

  • Sim, Hak-Bo;Kim, Woen
    • The Korean Journal of Ecology
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    • v.21 no.5_1
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    • pp.465-473
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    • 1998
  • This study was carried out to investigate the developmental process of plant community during the secondary succession and changes of soil properties in the burned areas lapsed 28 years after the forest fire in Mt.Palgong. The forest fire occurred on March, 1969 and the red pine (pinus densiflora) forest and its floor vegetation were burned down. The results are summarized as follows: the floristic composition of burned and unburned areas were composed of 49 and 48 species of vascular plants, respectively. The dominant species based on SDR4 of the burned sites were Lespedeza maximowicxii(87.75), Carex humilis (62.94), Rhododendron schippenbachii(55.78) and Miscanthus sinensis var.purpurascens (51.94). In contrast, Pinus densiflora (81.17), Quercus serrata (53.58)m Carex humilis (53.11) and Miscanthus sinenis var. purpuracens (52.42) were dominant in the unburned area. The biological spectra showed the $H-D_1-R_5-e$ type in both areas. The indices of similarity (CCs) between the two areas were 0.80. Degree of succession (DS) was 734 in the burned area and 809 in the unburned area. The species diversity (H) and evenness indices (e) in the burned and unburned areas were 2.05, 2.13 and 0.53, 0.55, respectively. Dominance index (C) in the burned and unburned areas were 0.30 and 0.32, respectively. Soil properties such as soil pH, content of organic matter, total nitrogen, total carbon, exchangeable potassium, sodium, calcium, and magnesium in burned area were comparatively higher than those of unburned area. Monthly changes of soil properties were of little significance except for some cases. These results suggest that there was relationship between trend of vegetation recovery and the changes of soil properties after the forest fire. Mixed forestation of fire-resistant species and nitrogen fixation species will be effective for reforestation after the forest fire.

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The study of geopolymer utilization of reclaimed ash by using magnetic separation method (자력선별법을 이용한 화력 발전소 매립회의 지오폴리머 원료화 연구)

  • Kim, Kangduk
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.27 no.5
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    • pp.249-255
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    • 2017
  • Using a magnetic separation process, pond ash generated in thermoelectric power plants was separated into magnetic materials and nonmagnetic materials in order to make it into a raw material of geopolymers and unburned carbon; screening characteristics according to the particle sizes and magnet strength levels of the pond ash were observed. Based on the results of magnetic separation into fine particle (0.15~0.84 mm) and rough particle (0.84~2.4 mm) pond ash using 3000 G magnets, the weight fraction and ignition loss of nonmagnetic materials were found to be higher than those of magnetic materials, regardless of the particle size. In the case of fine particle pond ash, when the magnet strength was increased from 3000 G to 10000 G, even those materials that were weakly magnetic were separated into magnetic materials, leading to drastic increases in the weight fraction of magnetic materials, such that the ignition loss accounted for 66.9 % (22.8 wt%) of the entire ignition loss of 32.6 wt%, despite of the low ignition loss. Based on the results of measurement of the compressive strength levels of geopolymers made of magnetic-separated rough particle pond ash, the compressive strength of geopolymers made of magnetic materials containing small amounts of unburned carbon was found to be 20 MPa.

Characteristics of UBC and NOx Emission in Air Staging Combustion (공기 다단 연소 기법 적용에 따른 미연탄소분 및 질소산화물 배출특성)

  • Kim, Jeong Woo;Lim, Ho;Go, Young Gun;Jeon, Chung Hwan
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.40 no.10
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    • pp.637-644
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    • 2016
  • The purpose of this study is to understand the characteristics of unburned carbon (UBC) and NOx emissions for pulverized coal when air staging combustion is applied. A two-staged drop tube furnace capable of applying air staging combustion was designed and installed. The combustion of sub-bituminous (Tanito) has been investigated. UBC and the NOx concentration were measured under various temperatures and stoichiometric ratios in unstaged and staged combustion. As a result, UBC decreased and the NOx concentration increased with an increase in stoichiometric ratio and temperature. In particular, the NOx reduction mechanism was activated when the temperature in the fuel rich zone increased. Both UBC and the NOx concentration decreased as the temperature increased in the fuel rich zone. A high NOx reduction effect was obtained, compared to the UBC increase, when the air staging technique was applied.

Study on the Unburned Carbon and NOx emission of High Moisture Coal (고수분탄의 건조에 따른 미연분 및 NOx 배출 특성에 관한 연구)

  • Ahn, Seok-Gi;Kim, Jung-Woo;Kim, Gyu-Bo;Lee, Si-Hyun;Jeon, Chung-Hwan
    • Journal of Energy Engineering
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    • v.25 no.4
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    • pp.53-61
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    • 2016
  • Unburned Carbon(UBC) and NOx emissions from High-moisture coal and Dried coal were investigated in Drop Tube Furnace(DTF). When the same amount of the High-moisture coal and Dried coal were oxidized in DTF, the results show that UBC and NOx emissions of Dried coal case is higher than High-moisture coal case. As the moisture in coal decreases from 40% to 10%, the average gas temperature increases but the moisture concentration in DTF decreases. As the wall temperature increases from $900^{\circ}C$ to $1500^{\circ}C$, the UBC decreases and NOx emissions increases. Especially, the difference for UBC between High-moisture coal and Dried coal decreases with increasing wall temperature.

Determination of Air Fuel Ratio According to Fuel Composition (II) -Compensation of Unburned Gas Concentration in Eltinge Chart- (연료 조성에 따른 공연비 산정 (II) -Eltinge 차트에서 미연 성분의 보상-)

  • Ohm, In-Yong;Park, Chan-Jun
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.27 no.11
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    • pp.1563-1571
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    • 2003
  • This paper is the second part of several companion papers which compare the method of Air-fuel ratio(AFR) determination. In the previous paper, Eltinge chart was applied to the arbitrary fuel composition and the charts for gasoline, diesel, methanol, M85, liquefied petroleum gas(LPG), natural gas(NG), propane and butane were illustrated. In Eltinge chart, however, unburned hydrocarbon (UHC) is not used for determination of AFR. For improving accuracy, Eltinge suggested UHC compensation after the AFR reading in the chart. This compensation reduced the difference between real and reading value. In the compensation, however, the correction of oxygen and carbon dioxide is uncertain and there might be a mistake in conversion of UHC reading value. Therefore, the error is overestimated comparing with Spindt one which is most widely used. In addition, there is no comparison of the value with other useful methods. In this paper, the compensation of unburned HC was performed in Eltinge chart and the compensated value was compared with Spindts formula over wide range of AFR. The objects of investigating fuel are gasoline, methanol, NG and LPG. The result shows that Eltinge and Spindt method is flawlessly compatible and the difference between the two methods is under 0.3% in a λrange from 0.9 to 1.7. The method fur debugging instrumentation error is also presented.