• 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.

• Proceedings of the KIEE Conference
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• 2004.11c
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• pp.535-537
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• 2004

The flame image processing and it's analysis system has been developed for optimal coal firing of thermal power plant, especially for reducing NOx and safe operations. We aimed at gaining the relationship between burner flame image, emissions of NOx and LOI(Loss on ignition) in furnace by utilizing the flame image processing methods. And the relationship determines quantitatively the conditions of combustion on the individual burners. The test was conducted on Samchonpo thermal power plant #4 unit(560MW) of KOSEP which has 24 burners. The system simplified the burner adjustment works in accordance with the real time trending of flame behavior like NOx profiles and unburned carbon profiles for individual burners. But, This kind of conventional method increases the cost as the number of burner are increased. Also there is a difficulty to measure exhausted gas of each burner because of measurement errors. This paper intends to propose the useful "Flame Monitoring System" that can find Low NOX and LOI at the upper furnace and to compare with the conventional System.

• The KSFM Journal of Fluid Machinery
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• v.2 no.1 s.2
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• pp.7-14
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• 1999

This simulation method is developed by using GateCycle code for the performance evaluation of the gas turbine in IGCC(Integrated Gasification Combined Cycle) power plant that uses clean coal gas fuel derived from coal gasification and gas clean-up processes and it is integrated with ASU(Air Separation Unit). In the present simulation method, thermodynamic calculation procedure is incorporated with compressor performance map and expander choking models for considering the off-design effects due to coal gas firing and ASU integration. With the clean coal gases produced through commercially available chemical processes, their compatibility as IGCC gas turbine fuel is investigated in the aspects the overall performance of the gas turbine system. The predictions by the present method show that the reduction of the air extraction from gas turbine to ASU results in a remarkable increase in the efficiency and net power of gas turbines, but it is accompanied with a shift of compressor operation point toward to surge limit. In addition, the present analysis results reveal the influence of compressor performance characteristics of gas turbine have to be carefully examined in designing the ASU integration process and evaluating the overall performance parameters of the gas turbine in IGCC Power plant.

• Journal of Power System Engineering
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• v.22 no.1
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• pp.79-86
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• 2018

Many countries have conducted extensive studies for biomass co-firing to enhance the durability of reactor on high-temperature corrosion. However, due to the complicated mechanisms of biomass co-firing, there have been limitations in accurately determining the current state of corrosion and predicting the potential risk of corrosion of power plant. In order to solve this issue, this study introduced Lab-scale corrosion system to analyze the corrosion characteristics of the A213 T91 material under the biomass co-firing conditions. The corrosion status of the samples was characterized using SEM/EDS analysis and mass loss measurement according to various biomass co-firing conditions such as corrosion temperature, $SO_2$ concentration, and corrosion time. As a result, the corrosion severity of A213 T91 material was gradually increased with the increase of $SO_2$ concentration in the reactor. When $SO_2$ concentration was changed from 0 ppm to 500 ppm, both corrosion severity and oxide layer thickness were proportionally increased by 15% and 130%, respectively. The minimum corrosion was observed when the corrosion temperature was $450^{\circ}C$. As the temperature was increased up to $650^{\circ}C$, the faster corrosion behavior of A213 T91 was observed. A213 T91 was observed to be more severely corroded by the effect of chlorine, resulting in faster corrosion rate and thicker oxide layer. Interestingly, corrosion resistance of A213 T91 tended to gradually decrease rather than increases as the oxide layer was formed. The results of this study is expected to provide necessary research data on boiler corrosion in biomass co-firing power plants.

• Journal of Energy Engineering
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• v.20 no.3
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• pp.231-235
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• 2011

Ligneous biomass such as wood pellet is characterized as carbon neutral which has no carbon dioxide emission ; additionally, it can be used as an alternative fuel by co-firing without additional plant reformation as well as for maintaining stability of fuel supply. We can develop CDM project while co-firing by using biomass into conventional coal fired thermal power plant with AM0085 CDM methodology, and it's possible to prove additionality as fuel cost per kWh is higher than bituminous. The study shows that the electricity by biomass can reduce green house emission by $0.6737tCO_2$ per MWh.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.35 no.9
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• pp.939-946
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• 2011

In thermal power generation companies, the recycling of refined ash (LOI < 6%) obtained from a PC-firing furnace is beneficial for the companies, e.g., it can be used for making lightweight aggregates. However, ash having a high LOI, which cannot be reused, is still buried in the ground. To obtain refined ash, the re-burning of high-LOI ash (LOI > 6%) in a PC-firing furnace can be an alternative. In this study, a numerical analysis was performed to demonstrate the effects of ash re-burning. An experimental constant value was decided by TGA (thermo-gravimetric analysis), and a DTF (drop-tube furnace) was used in the experiment for calculating the combustion of ash. On the basis of the trajectory of the moving particles of coal and ash, it was concluded that supplying ash near the burner, which is located high above the ground, is appropriate. On the basis of numerical results, it was concluded that an ash supply rate of 6 ton/h is suitable for combustion, without affecting the PC-firing boiler.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.40 no.1
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• pp.31-37
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• 2016

Co-firing of biomass with coal is a promising combustion technology in a coal-fired power plant. However, it still requires verifications to apply co-firing in an actual boiler. In this study, data from the Thermogravimetric analyzer(TGA) and Drop tube furnace(DTF) were used to obtain the combustion characteristics of biomass when co-firing with coal. The combustion characteristics were verified using experimental results including reactivity from the TGA and Unburned carbon(UBC) data from the DTF. The experiment also analyzed with the variation of the biomass blending ratio and biomass particle size. It was determined that increasing the biomass blending ratio resulted in incomplete chemical reactions due to insufficient oxygen levels because of the rapid initial combustion characteristics of the biomass. Thus, the optimum blending condition of the biomass based on the results of this study was found to be 5 while oxygen enrichment reduced the increase of UBC that occurred during combustion of blended biomass and coal.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2005.05a
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• pp.385-390
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• 2005

This paper provided a counter measures against the troubles and accidents that are likely to take place in the power plant using hydrogen gas as a coolant for the cooling system of the generator. Because of the extremely wide flammability limits of hydrogen in comparison to the other flammable gases, the safety measures against the hydrogen accidents is very important to ensure the normal operation of electric-power facility. This study's purpose was a presentation of standard model of safety management of hydrogen equipments in the coal firing power plant such as following items: 1) providing the technical prevention manual of the hydrogen explosions and hydrogen fires occurring in the cooling system of power generator; 2) the selection of explosion-proof equipments in terms of the risk level of operating environment; 3) the establishment of regulations and counter measures, such as the incorporation of gas leakage alarm device, for preventing the accidents from arising; 4) the establishment of safety management system to ensure the normal operation of the power plant.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.4
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• pp.272-277
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• 2009

Three dimensional numerical analysis for the coal fired boiler has been performed to investigate the effect of yaw angle variation of the secondary air nozzles on the combustion characteristics and NOx emission. It was found that the prediction gives a good agreement with plant data. The increase in yaw angle up to $20^{\circ}$ have results in the decrease in NOx emission at furnace exit and recirculation flow intensity, together with the increase of unburned carbon in ash. It also has been recognized the remarkably change in configuration of fire ball with increase in yaw angle. The results from this study would be valuable in the case of the combustion modification of the corner firing coal-fired utility boiler.

• 유체기계공업학회:학술대회논문집
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• 1998.12a
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• pp.209-214
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• 1998

A thermodynamic simulation method is developed for the process design and the performance evaluation of the gas turbine in IGCC power plant. The present study adopts four clean coal gases derived from four different coal gasification and gas clean-up processes as IGCC gas turbine fuel, and considers the integration design condition of the gas turbine with ASU(Air Separation Unit). In addition, the present simulation method includes compressor performance map and expander choking models for considering the off-design effects due to coal gas firing and ASU integration. The present prediction results show that the efficiency and the net power of the IGCC gas turbines are seperior to those of the natural gas fired one but they are decreased with the air extraction from gas turbine to ASU. The operation point of the IGCC gas turbine compressor is shifted to the higher pressure ratio condition far from the design point by reducing the air extraction ratio. The exhaust gas of the IGCC gas turbine has more abundant wast heat for the heat recovery steam generator than that of the natural gas fired gas turbine.