• 한국안전학회지
• /
• 제14권3호
• /
• pp.84-92
• /
• 1999

The effects of air velocity and excess air on combustion characteristics were studied in a fluidized bed combustor. The domestic low-grade anthracite coal with heating value of 2010 kcal/kg and the imported bituminous coal from Australia with heating value of 6520 kcal/kg were used as coal samples. The combustion characteristics of mixed fuels in a fluidized bed combustor could be interpreted by pressure fluctuation properties, ash distribution and gas emission. The properties of the pressure fluctuations, such as the standard deviation, cross-correlation function, dominant frequency and the power spectral density function, were obtained from the statistical analysis. From this study, the combustion region increased with increasing air velocity but decreased with excess air due to combustion characteristics of anthracite and bituminous coal.

• 한국연소학회:학술대회논문집
• /
• 한국연소학회 2004년도 제28회 KOSCO SYMPOSIUM 논문집
• /
• pp.165-172
• /
• 2004

Co-incineration of coal and wastewater sludge was r;erfonn:rl in a O.lMWth bench scale circulating fluidized bed combustor(CFBC) Sludge was received from a wastewater treatment plant in a dye industrial complex in Busan. Metropolis. Moisture content of received sludge was 80%. Coal and sludge mixture was prepared with weight ratio of 90/10, 85/15 and 80/20. Co-combustion characteristics of the coal and sludge mixture demonstrated stable combustion conditions. Component analysis, incineration characteristics, boiler performance was measured before and after the test and application for commercial 59MWth CFBC boiler. The release of hazardous components such as $SO_2$ and Cl was suppressed by the presence of inherent minerals of Ca, Na, K in coal and sludge mixture. Pre-drying was not essential but it was recommended for the benefits of manageability of sludge.

• Structural Engineering and Mechanics
• /
• 제60권6호
• /
• pp.923-937
• /
• 2016

The common prospect in diminishing mine-blast vibration is decreasing vibration with increasing distance. This paper indicates that, contrary to the general expectancy, vibration waves change their forms when they are travelling through the low velocity layer like coal and so-called guided waves moving the vibration waves to longer distances without decreasing their amplitudes. The reason for this unexpected vibration increase is the formation of guided waves in the coal bed which has low density and low seismic velocity with respect to the neighboring layers. The amplitudes of these guided waves, that are capable of traveling long distances depending on the seam thickness, are several times higher than that of the usual vibration waves. This phenomenon can many complaints from the residential areas very far away from the blasting sites. Thus, this unexpected behavior of the coal beds in the surface coal mines should also be considered in vibration minimization studies. This study developed a model to predict the effects of guided waves on the propagation ways of blast-induced vibrations. Therefore, vibration mitigation studies considering the nearby buildings can be focused on these target places.

• 한국수소및신에너지학회논문집
• /
• 제29권1호
• /
• pp.124-129
• /
• 2018

Methane is the cleanest fuel and supplies by many distributed type: liquefaction natural gas (LNG), compressed natural gas (CNG), and pipeline natural gas (PNG). Natural gas is mainly composed by methane and has been discovered in the oil and gas fields. Coal bed methane (CBM) is also one of them which reserved in coalbed. This significant new energy sources has emerge to convert an energy source, hydrogen and hydrogen-driven chemicals. For this CBM, this paper was written to analyze the geological analysis and reserves in Mongolian Tavan Tolgoi CBM coal mine and to examine the application field. This paper is mainly a preliminary feasibility report analyzing the business of Tavan Tolgoi CBM and its exploitable gas.

• 플랜트 저널
• /
• 제14권2호
• /
• pp.33-38
• /
• 2018

본 연구에서는 순환유동층보일러의 베드가 과열되어 층 물질의 소결이 발생하고 노 내 유동물질에 의해 보일러튜브가 마모 되는 것을 최소화하기 위하여, 노 하부 베드의 층 물질량 조정을 통한 베드 온도 변화를 실험적으로 연구하였다. 실험은 300MW급 순환유동층보일러인 여수화력 2호기를 대상으로 하였으며 터빈출력, 석탄소비량, 공기량 등을 고정한 상태에서 층 물질 양을 감소시켜 베드 압력을 설계값 4.5KPa에서 2.5KPa까지 감소시켰다. 결론적으로 층 물질 양을 적정하게 줄이면 베드 온도가 저하 되나, 지속적으로 저하되지 않는 것을 확인 하였으며, 베드 압력 3.0KPa, 즉 베드 물질량 110 톤을 변곡점으로 하여 베드 온도는 상승하기 시작하였다. 층 물질량이 충분히 많은 상태에서, 층 물질량이 감소되면 베드 온도는 저하되며, 층 물질량이 적정량 보다 적으면 노 내 유동물질의 순환량 감소로 베드 온도는 상승함을 알 수 있었다. 또한 유동층보일러에서 베드 온도 변화는 단순히 층 물질의 양 뿐만 아니라, 보일러 용량 및 연료의 성상 등에 따라 변화 추이가 매우 다양하게 나타난다는 것을 알 수 있었다.

• 에너지공학
• /
• 제5권2호
• /
• pp.138-145
• /
• 1996

The particulate collection at high temperature and high pressure (HTHP) is important on the advanced coal power generation system not only to improve the thermal efficiency of the system, but also to prevent the gas turbine from erosion and to meet the emission limits of the effluent gas. The specifications for particulate collection in those systems such as Integrated Coal Gasification Combined Cycle (IGCC) and Pressurized Fluidized Bed Combustion (PFBC) require the absolutely high collection efficiency and reliability. Advanced cyclone, granular bed filter, electrostatic precipitator, and ceramic filter have been developed for particulate collection on the advanced coal power generation system. However, rigid ceramic filters and granular bed filter among them show the best potential. The current technology of these collectors was evaluated in this paper. The experienced problems of these systems on performance, materials, and mechanical design were investigated. Ceramic candle filters has the best potential for IGCC at this moment because it has nearly the highest efficiency comparing with other filtering systems and has accumulated many reliable design data resulted from many field experiences.

• 에너지공학
• /
• 제1권1호
• /
• 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.

• 한국수소및신에너지학회논문집
• /
• 제29권1호
• /
• pp.130-137
• /
• 2018

Now discusses the potential use and applications of coal bed methane (CBM) in various industries. One of the options for gas monetization is gas to power (GTP), sometimes called gas to wire (GTW). Electric power can be an intermediate product, such as in the case of mineral refining in which electricity is used to refine bauxite into aluminum; or it can be an end product that is distributed into a large utility power grid. For stranded gas, away from the regional markets, the integration of the ammonia and urea plants makes commercial sense. These new applications, if established, could lead to a surge in demand for methanol plants.

• 한국수소및신에너지학회논문집
• /
• 제30권5호
• /
• pp.436-447
• /
• 2019

The circulating fluidized bed boiler has an advantage that can burn a variety of fuels from low-grade fuel to coal. In this study, for the design of a circulating fluidized bed boiler using wood pellets, a circulating fluidized bed combustion test device using no external heater was manufactured and used. According to the increase of co-combustion rate with wood pellet, combustion fraction and heat flux by combustor height were measured and pollutant emission characteristics were analyzed. In terms of combustibility, the effect on primary and secondary air ratio were also studied. In addition, as a result of analysis of the effect of corrosive nanoparticles on the combustion of coal with wood pellets, it was confirmed that coal is mostly composed of Ca and S, whereas wood pellets are mostly composed of K, Cl, and Na.

• 한국연소학회:학술대회논문집
• /
• 한국연소학회 2004년도 제28회 KOSCO SYMPOSIUM 논문집
• /
• pp.141-148
• /
• 2004

Coal combustion in an iron ore sintering bed is a key parameter that determines quality of the sintered ores and productivity of the process. In this study, effects of the different types of coal coke and anthracite - on the combustion in the iron ore sintering bed are investigated by modeling and experiment. Fuel characteristics of coke and anthracite are observed through a few basic analysis and thermo-gravimetric analysis. It was found that coke has a higher reactivity than anthracite due to the difference of surface area and density. Those characteristics are reflected to the 1-D unsteady simulation of the iron ore sintering bed. Calculation results show that different reactivity of the fuel can affect the bed combustion, which implies the further investigation should be performed for obtaining optimal combustion conditions in the sintering bed.