• Title/Summary/Keyword: pulverized coal combustion

Search Result 124, Processing Time 0.027 seconds

The Strength and Characteristic of PCC Bottom Ash (석탄재의 강도 특성에 관하여)

  • Shin, Sanguok;Sanjeev, Kumar;Jung, Teuok;Shin, Bangwoong
    • Journal of the Korean GEO-environmental Society
    • /
    • v.8 no.2
    • /
    • pp.57-63
    • /
    • 2007
  • Coal combustion by-product (CCB) bottom ash, obtained from burning of pulverized coal, has physical properties which are similar to that of natural sand with particle sizes ranging from fine gravel to fine sand. Several studies have been completed to utilize pulverized coal combustion (PCC) bottom ash as a partial or full replacement of fine aggregate in cement concrete products. The objectives of this study were to develop air-entrained concrete composites using PCC bottom ash from burning of Illinois coal and to demonstrate the use of these composites on real-world projects. The results obtained show that the compressive, splitting-tensile, and flexural strengths of concrete composites is slightly lower than that of conventional concrete are early curing ages. However, after 60 days of curing, the strength of concrete composites is either equal to or slightly higher than that of an equivalent conventional concrete. The concrete composites showed lower resistance to chloride ion penetrability than that of an equivalent conventional concrete at early curing ages. However, after 28 days of curing, concrete composites showed better resistance to chloride ion penetrability compared to that of an equivalent conventional concrete.

  • PDF

An Analysis of the Demand Expansion Options for the Domestic Anthracite Coal (국내 무연탄의 수요개발 가능성 분석)

  • 최기련;강희정
    • Journal of Energy Engineering
    • /
    • v.1 no.1
    • /
    • pp.102-110
    • /
    • 1992
  • The determination of production level of the domestic anthracite coal is an important issue in the national energy strategy. It is also closely related to the energy mix scenarios in the future. The objective of the paper is to discuss and analyze the options of expanding anthracite coal demand in the utility sector. The observed options are including; (1) New pulverized system of the 200 and 500 MW level, (2) Atmospheric Fluidized Bed Combustion (AFBC), and (3) Pressurized Fluidized Bed Combustion (PFBC). Special emphasis is placed on the considerations in estimating the effects on the electric system costs and government subsidies when the options are introduced in the utility sector.

  • PDF

Influence of Biomass Co-firing on a Domestic Pulverized Coal Power Plant In Terms of CO2 Abatement and Economical Feasibility (다양한 바이오매스 혼소시 국내 미분탄화력에 미치는 이산화탄소 감축 및 경제성 영향 분석)

  • Kim, Taehyun;Yang, Won
    • Journal of the Korean Society of Combustion
    • /
    • v.22 no.1
    • /
    • pp.14-22
    • /
    • 2017
  • Co-firing of renewable fuel in coal fired boilers is an attractive option to mitigate $CO_2$ emissions, since it is a relatively low cost option for efficiently converting renewable fuel to electricity by adding biomass as partial substitute of coal. However, it would cause reducing plant efficiency and operational flexibility, and increasing operation and capital cost associated with handling and firing equipment of renewable fuels. The aim of this study is to investigate the effects of biomass co-firing on $CO_2$ emission and capital/operating cost. Wood pellet, PKS (palm kernel shell), EFB (empty fruit bunch) and sludge are considered as renewable fuels for co-firing with coal. Several approaches by the co-firing ratio are chosen from previous plant demonstrations and commercial co-firing operation, and they are evaluated and discussed for $CO_2$ reduction and cost estimation.

Analysis of Air Distribution in the Windbox System of the Utility Boiler (보일러 Windbox내 공기공급 계통의 유량분포 해석)

  • Park, Ho-Young;Kim, Sung-Chul
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
    • /
    • v.20 no.9
    • /
    • pp.581-589
    • /
    • 2008
  • The pulverized coal combustion behavior in the utility boiler is very complex since so many physical and chemical processes happen in it, simultaneously. The mixing of pulverized coal with combustion air plays an important role in achieving the efficient combustion and stable boiler operation. The distribution of combustion air supplied to the furnace through the windbox damper system has not been clearly known since the individual measurements of air flow for each air nozzle were not possible, yet. The present study describes the CFD modelling of windbox damper system and aims to obtain the air flow rates and pressure loss coefficients across the present five damper systems, respectively. The one dimensional flow network model has been also established to get air flow distributions across the windbox damper, and applied to the actual plant operation condition. Compared with the designed air flow distribution, the modelled one gives a reasonable agreement. For the actual plant operation, the predicted air flow distribution at each air nozzle is differed with the designed data and strongly affected by the individual opening angle.

A Study of Chemical Properties and Fusibility of Korean Anthracite Coal Ash (국내 무연탄회의 화학조성 및 용융특성에 관한 연구)

  • Park, Cheol-Woo;Lee, See-Hoon;Shon, Eung-Kwon
    • Analytical Science and Technology
    • /
    • v.5 no.4
    • /
    • pp.433-441
    • /
    • 1992
  • Chemical composition and fusibility of coal ash were measured for 23 Korean anthracite coals. The relationship between chemical properties and fusion temperature of coal ash was investigated. The slagging and fouling in firing the pulverized coal for boiler was assessed for the coal samples. It was found that most ashes contained more than 80% of $SiO_2$ and $Al_2O_3$ whereas less than 1% of $Na_2O$. And also fusion temperature of ashes occured relatively higher for Korean coals. Therefore it can be predictable that the slagging and fouling formation has a little problem in a pulverized coal firing system. A base/acid ratio did show a good correlation with fusion temperature for these coal ashes.

  • PDF

On the Improvement of the Combustibility of Waste Plastics used in Blast Furnace

  • Ban, Bong-Chan;Choi, Jin-Shik;Kim, Dong-Su
    • Proceedings of the IEEK Conference
    • /
    • 2001.10a
    • /
    • pp.751-754
    • /
    • 2001
  • A possibility of using waste plastics as a source of secondary fuel in blast furnace has been of recent interest. The success of this process, however, will be critically dependent upon the optimization of operating systems. for instance, the supply of waste plastics must be reliable as well as economically attractive compared with conventional secondary fuels such as heavy oil, natural gas and pulverized coal. In this work, we put special importance on the improvement of the combustibility of waste plastics as a way to enhance energy efficiency in blast furnace. As experimental variables to approach this target, the effects of plastic particle size, blast temperature, and the level of oxygen enrichment were investigated using a custom-made blast model designed to simulate a real furnace. Lastly, the combustion efficiency of the mixture of waste plastics and pulverized coal was tested. The observations made from these experiments led us to the conclusion that with the increase of both blast temperature and the level of oxygen enrichment, and with the decrease of particle size, the combustibility of waste PE could be improved at a given distance from tuyere. Also it was found that the efficiency of coal combustion decreased with the addition of plastics; however, the combustion efficiency of mixture could be comparable at longer distance from tuyere.

  • PDF

Review: Utilization of Coal Bottom Ash for Concrete and Mortar (총설: 콘크리트 및 모르타르를 위한 석탄 바텀애시의 활용)

  • Kim, Hyeong-Ki
    • Journal of the Korean Recycled Construction Resources Institute
    • /
    • v.8 no.3
    • /
    • pp.333-348
    • /
    • 2020
  • The present review dealt with the state-of-art on utilization of coal bottom ash in cement-based concrete and mortar. Two types of bottom ashes generated from pulverized coal combustion and circulating fluidized-bed combustion systems have been considered. The production process, chemical and physical characteristics of both ashes, and the methodology of utilization in various cement composites are summarized. The effect of bottom ash on various properties of concrete, such as workability, strength, and durability, were reviewed from the literature. In addition, the environmental and economic aspects of utilizing bottom ash in concrete are analyzed to explore the perspectives of bottom ash utilization, and through this, the future of the utilization was considered. The effect of bottom ash on the performance of concrete and mortar was greatly depended on the condition, pretreatment, and processing of the ash. Additional processing such as crushing might contribute to stimulating the utilization in this field. In particular, if economic support is possible in terms of policy, utilization rate is expected to be improved.

Study on Pneumatic Transport for Pulverized coal Combustion (미분탄 연소를 위한 공기압 수송에 관한 연구)

  • Oh, C.S.;Choi, B.S.;Hong, S.S.;Hwang, K.S.
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
    • /
    • v.4 no.4
    • /
    • pp.299-305
    • /
    • 1992
  • Saltation occurs in horizontal flow of solid and gas when the carrier gas velocity is small enough to permit enough to settling of the solid particles within the transport line. So we should examine the pneumatic flow system to lessen the unbured carbon in the power plant. In this paper the saltation velocity was studied on the various solid flow rate in the constant pipe diameter and on the various temperatures of the flow gas. The air velocity in the power plant transport lines was also surveyed in order to compare with the saltation velocity. As the solid flow rate increased in the constant diameter, saltation velocity increased and as the temperater of the flow gas inereased in the transport line, saltation velocity also increased.

  • PDF

Numerical Study on the Devolatilization models of Pulverized Coal in DTF (DTF 내 미분탄 휘발화 모델에 관한 수치적 연구)

  • Kim, Jin-Nam;Kim, Ho-Young
    • 한국연소학회:학술대회논문집
    • /
    • 2002.11a
    • /
    • pp.173-184
    • /
    • 2002
  • In order to evaluate the devolatilization models of pulverized coal, various devolatilization models are examined for the numerical analysis of Drop Tube Furnace.The results of analysis are compared with the experimental results. A numerical study was conducted to explore the sensitivities of the predictions to variation of the model parameters. It helps to elucidate the source of the discrepancies. Three different wall temperature conditions of the DTF, 1100, 1300 and $1500^{\circ}C$ were considered in this analysis. Two fuels are U.S.A. Alaska coal and Australia Drayton coal. The results of analysis with constant rate model, single kinetic rate model and two competing rate modes well presented fast volatile matter release in the early devolatilization. However, in the latter devolatilization they did not coincide with experimental results which presented tardy volatile matter release on account of pyrolysis of high molecular substance. On the other hand, the results of analysis with DAEM(Distribute Activation Energy Model) coincided with experiment al results in overall devolatilization.

  • PDF