• Applied Chemistry for Engineering
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• v.23 no.3
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• pp.333-338
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• 2012

To verify the utilization of fluff refuse derived fuel (RDF) as energy source, the combustion charateristic has been studied by an experimental combustion furnace under various temperatures. The characteristics of flue gas, dust and residue from fluff RDF combustion has been analyzed and compared with those of pelletized RDF. From this work, it was found that the incomplete combustion of fluff RDF was greater than that of pelletized RDF because the combustion reaction rate of fluff RDF was faster than that of pelletized RDF, and oxgen concentration in fluff RDF combustion decreased rapidly. It was also found that carbon monoxide concentration of flue gas from fluff RDF combustion increased with combustion temperature because the oxygen consumption and the incomplete combustion increased. Therefore, it is felt that the combustion operation conditions of fluff RDF should be carefully determined.

• Journal of the Korean Society for Precision Engineering
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• v.29 no.11
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• pp.1178-1182
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• 2012

The organic linings at flue gas desulfurization systems (FGD system) in power plant have the excellent chemical properties but, lose the anticorrosive properties according to the aging with environment conditions. The properties of the organic linings depend on the manufacturing company. Therefore, the basic properties of organic linings for the preestimate of life time should be examined by conducting the aging and the bond strength test according to temperature. The pre-aging samples were compared with the post-aging samples. The temperature conditions of the aging process were 70, 150 and $200^{\circ}C$. The bond strength was calculated and the cross sections of fracture surface were examined by optical microscope and SEM. The $T_g$ was examined by DSC, DTA and TGA.

• Journal of the Korean Institute of Gas
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• v.22 no.3
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• pp.7-12
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• 2018

Thermal NOx is generated in a high temperature environment in a combustion facilities. Exhaust gas recirculation method is widely used among various methods for reducing nitrogen oxides in combustion devices. In the present study, the computational fluid dynamic analysis was accomplished to elucidate the cold flow characteristics in the flue gas recirculation burner with both outlets opening. Because the reciculation pipes is installed toward the tangential direction, the swirling flow is formulated in the burner and the phenomenon of the reverse flow creation is detected at the center area of circular burner. We are confirmed that this is the similar trend with the burner with one side outlet closed. From the present study, it was seen that the recirculated inflow from both recirculated burner outlets increased by about 5% compared to the burner with one side outlet opening. At the outlet located at the exhaust gas recirculation pipe inlet(gas exit 1), the inlet flow was formed in the entire region. At the opposite outlet(gas exit 2), the total flow was discharged, but the center part of the burner was observed to have a reverse flow. The flow rate at the gas exit 2 was 3 ~ 5 times larger than the flow rate at the gas exit 1.

• Journal of the Korean Society of Combustion
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• v.22 no.4
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• pp.35-42
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• 2017

This case covers the issues related to the operation problem, cause analysis and improvement cases of the FGD that employed the non-leakage type GGH in coal-fired power plant for the first time in Korea. In the Cooler, there was a main problem that the tube is damaged by the ash cutting due to the high velocity of flue gas in the duct and by the weak wear resistance of material. In the Reheater, there was a main problem that the tube was corroded due to chlorine and sulfur in the circumstance of the low temperature. In order to solve those problems, we have improved the Reheater tube and tube fins by coating enamel to reduce corrosion rate.

• Journal of Energy Engineering
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• v.29 no.3
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• pp.7-17
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• 2020

Heat recovery steam generator(HRSG) generate steam using the high-temperature exhaust energy of gas turbines. Structures of HRSG are damaged by flow induced vibration of flue gas in some cases. In order to evaluate fatigue life to predict damage to a structure, a vibration analysis caused from flue gas should be used to derive the Power Spectral Density(PSD). However, it is very difficult to experimentally derive the vibrations generated by the exhaust gas form of gas turbines, which is very fast and complex. It was able to establish a way to identify vibration characteristics depending on the location of the structure by using high computing resources, large eddy simulation (LES). Random vibration analysis through these vibration characteristics(PSD) can evaluate the fatigue life of a structure.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.11
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• pp.1977-1983
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• 2000

SCR(selective catalytic reduction) pilot plant for reduction of the nitrogen oxides using diesel oil as a reductant was installed at the NG(natural gas) fired combined cycle and the activity of Pt(0.3%)/Zeolite catalyst was studied in real flue gas condition according to the amount of reductant. reaction temperature and space velocity. NOx conversion gradually increased with increasing the diesel oil concentration up to C/N ratio 5.5(C/N ratio: the ratio of the number of carbon atom to the number of NOx molecules included in the flue gas). Increasing the reaction temperature. NOx conversion increased and reached a maximum conversion of 50% at $190^{\circ}C$. NOx conversion did not changed with increasing the space velocity up to 18,500/hr and then gradually decreased. These results reveal the potential for diesel oil as a reductant for de-NOx SCR process.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.34 no.5
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• pp.465-469
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• 2010

Air heater used in power plant helps increase the thermal efficiency of the boiler by recovering the heat from the boiler flue gas and thus preventing the loss of useful heat. This study investigates the effect of preventive maintenance on the performance of the air heater in a power plant. Performance indexes for the air heater are calculated to observe the changes in the performance and operation status of the air heater before and after preventive maintenance. The major performance indexes considered are temperature efficiency of the flue gas side, air leakage rate, heat recovery rate, heat transmission rate, and heat capacity ratio. The performance of the air heater is evaluated before and after preventive maintenance; our results show that all the abovementioned performance indexes are improved after the maintenance.

• Journal of Energy Engineering
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• v.15 no.3 s.47
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• pp.188-193
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• 2006

This paper intends to present theoretical study and its application result of the way of the temperature distribution embodiment through the production of subdivided nod's temperature from the average, maximum and minimum temperature following acoustic speed measurement with a set of acoustic speed meters at the arbitrary section in the furnace. By measuring the acoustic speed between the speed meters, flue gas temperature field can be determined. Then Subdivided arbitrary grid's temperatures can be infered out of surrounding nod's temperature distribution, and finally the entire grid's temperature distribution will be found. In this article, theoretical background, related system setup. and real application result are examined and discussed.

• Journal of the Korean Society of Combustion
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• v.8 no.4
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• pp.9-14
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• 2003

High temperature air combustion technology has been utilized by using preheated air over 1100 K and excessive exhaust gas recirculation. Numerical analysis was performed to investigate the combustion characteristics with high temperature deficient oxygen air combustion by adopting a counterflow as a model problem accounting for detailed chemical kinetics. Methane($CH_4$) was used as a test fuel and calculated oxidizer conditions were low temperature high oxygen (300K, $X_{O2}=0.21$) and high temperature low oxygen (1300K, $X_{O2}=0.04$) conditions. The latter case showed that the flame temperature is lower than the former case and its profile showed monotonic decrease from oxidizer to fuel side, without having local maximum flame temperature at high stretch rate. Also, heat release rate was one order lower and it has one peak profile because of low oxygen concentration and heat release rate integral is almost same for stretch rate. High temperature low oxygen air combustion shows low NO emission characteristics.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.23 no.11
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• pp.1464-1472
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• 1999

Design and operation of $1MW_{th}$ pulverized coal combustion testing facility are described. Also the influence of air staging on NOx emission and burnout of coal flames was investigated in this facility. The test facility consisted of coal feeding system, firing system and flue gas treatment system. A top-fired externally air staging burner was adopted in order to avoid influence of gravity on the coal particles and for easy maintenance. Distribution of temperature and chemical species concentration of coal flames could be measured in vertical pass of furnace. Main fuel was pulverized (83.4% less than $80{\mu}m$) Australian high bituminous coal. From variety of test conditions, overall excess air ratio was selected at 1.2(20% excess air). Tho study showed that increasing the staged air resulted in lower NOx omission, and it was suggested to be more than 40% of the total combustion air for the substantial NOx reduction. Sufficient burnout was not achievable when NOx emission was less than 500ppm. Also, the amount of core air did not influence tho NOx reduction.