• Journal of Energy Engineering
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• v.20 no.4
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• pp.330-337
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• 2011

In these days, the gas or kerosene boiler was usually used as heating system. This study was carried out to investigate the merits of X-L pipe boiler with electric heat line that was specially manufactured. The electric heat line was inserted into inside of X-L pipe and voltage was impressed to electric heat line and, as a result, temperature of X-L pipe filled with heat medium was increased. As changing the number of electric heat line and voltage, the characteristics of X-L pipe boiler and its mechanism on heat generation were studied. Furthermore, the economical efficiency was evaluated by comparing heating cost of X-L pipe boiler with those of kerosene boiler and natural gas boiler, respectively. As the results, it was confirmed that heating cost of X-L pipe boiler was showed as 28% of kerosene boiler and 58% of natural gas boiler.

• KEPCO Journal on Electric Power and Energy
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• v.8 no.2
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• pp.93-96
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• 2022

The boiler tubes of thermal power plants are exposed to harsh environment of high temperature and high pressure, and the deterioration state of materials rapidly increases. In particular, parent material and welds of the materials used are subjected to a temperature change and various constraints, resulting in deformation and its growth, resulting in frequent leakage accidents caused by tube failure. The power plant checks the integrity of boiler tubes through non-destructive testing as it may act as huge costs loss and limitation of power supply during power station shutdown period due to boiler tube leakage. However, the current non-destructive testing is extremely limited in the field to detect micro cracks. In this study, the ability of metal magnetic memory technique to detect flaws of size that are difficult to inspect by the visual or general non-destructive methods was verified in the early stage of their occurrence.

• Korean Chemical Engineering Research
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• v.44 no.5
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• pp.489-497
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• 2006

The economical efficiency of conversion of the PC (pulverized coal) firing boiler to the CFB (circulating fluidized bed) boiler which used Koran anthracite as fuel was evaluated. The economic feasibility study was also carried out with regard to maintenance of the existing PC boiler. The sensitivity of economical efficiency with variation of the electric power and coal industry and the policy of government was analyzed and compared. As a results of the evaluation, the economical efficiency of maintenance of the existing PC boiler was higher than that of conversion to the CFB boiler because of the special policy of the government for Korean anthracite. However, the conversion to the CFB boiler was more economically attractive from a point of view of effective use of energy resources and future electric power industry. Additionally, the fund support for electric power industry using Korean anthracite would be effective as changing the policy of the government.

• KEPCO Journal on Electric Power and Energy
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• v.2 no.3
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• pp.403-407
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• 2016

In general, drum-type boilers are designed for base load duty and applied under constant pressure operation mode. Recently, however conditions often occur that even drum-type boilers have to operate at partial load conditions. A feasibility study on adopting the sliding pressure operation for drum-type boiler was conducted, and corresponding performance changes and effects on the equipment were analyzed by utilizing a process simulation model. As a result, the conclusion was reached that drum type boilers are able to adopt the sliding pressure operation and can improve of net efficiency at part load operation in spite of the Rankine cycle efficiency reduction due to the decreases in main steam pressure. Because of thank to improvement of high pressure turbine stage-1 internal efficiency and power savings of boiler feed water pump. The sliding pressure operation is advantageous in terms of stress level relief for boiler tube as well as maintaining the rating steam temperature at part load condition. However, cautions are required because the drum boilers have poor dynamic response characteristics which may get worse during the sliding pressure operation.

• KEPCO Journal on Electric Power and Energy
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• v.1 no.1
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• pp.93-97
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• 2015

The combustion tests for Korean anthracite-bituminous coal blend were carried out in the 200 MW utility boiler. The burning characteristics of the blend were studied with a thermogravimetric analyzer (TGA). From the observation of TGA burning profiles, it was found that the presence of bituminous coal in the blend appeared to enhance the reactivity of anthracite in the higher temperature region, indicating certain interactions between the two coals. The plant test showed the boiler operation was reasonably stable with somewhat poor combustion efficiency, and some modification of the combustion environment in the furnace is necessitate for the further stable plant operation.

• Journal of the Korean Society of Mechanical Technology
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• v.13 no.3
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• pp.81-85
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• 2011

The night time electric cost is cheaper due to electric supply and demand policy in Korea from 1985. Currently about 900,000 customers are using night time electric heating boilers and this causes shift of peak demand time to night in winter and increase of deficit spending. To solve this problem, replacing night time electric heating boiler by air-source heat pump using night time electricity has been proposed. An air-source heat pump can provide efficient heating equipment especially in a warm climate. For estimating the night time electric heat pump COP(Coefficient of Performance), Korean Standard KS C 9306:2010 and European Standard EN-14511:2004 is available. SCOP(Seasonal COP) using European weather bin data is also calculated. SCOP is not available yet but European Committee for Standardization will establish a standard in the near future. The evaluation result show that the replacing night time electric heating boiler by heat pump can be possible.

• KEPCO Journal on Electric Power and Energy
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• v.6 no.4
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• pp.427-432
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• 2020

In this study, a multi-zone furnace analysis method that couples a 1D energy and mass balance calculation with a 3D radiative heat transfer calculation is tested in order to verify its reliability. The calculated results for a domestic 500 MW capacity coal-fired boiler furnace were compared with the design data of the boiler manufacturer and CFD analysis, and a good agreement was achieved. Although this calculation method is less sophisticated than the CFD furnace analysis, it has an advantage in terms of calculation time while being able to provide the furnace behavior according to the fuel characteristics and operational variable changes. Therefore, it is expected to be useful for boiler operation diagnosis and daily fuel/operation planning.

• JOURNAL OF ELECTRICAL WORLD
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• no.6 s.66
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• pp.26-31
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• 1982

• KEPCO Journal on Electric Power and Energy
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• v.4 no.1
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• pp.25-31
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• 2018

A boiler system transforms water to pressured supercritical steam which drives the running of the turbine to rotate in the generator to produce electricity in power plants. Materials for building the tube system face challenges from high temperature creep damage, thermal fatigue/expansion, fireside and steam corrosion, etc. A database on the creep resistance strength and steam oxidation of the materials is important to the long-term reliable operation of the boiler system. Generally, the ferritic steels, i.e., grade 1, grade 2, grade 9, and X20, are extensively used as the superheater (SH) and reheater (RH) in supercritical (SC) and ultra supercritcal (USC) power plants. Currently, advanced austenitic steel, such as TP347H (FG), Super304H and HR3C, are beginning to replace the traditional ferritic steels as they allow an increase in steam temperature to meet the demands for increased plant efficiency. The purpose of this paper is to provide the state-of-the-art knowledge on boiler tube materials, including the strengthening, metallurgy, property/microstructural degradation, oxidation, and oxidation property improvement and then describe the modern microstructural characterization methods to assess and control the properties of these alloys. The paper covers the limited experience and experiment results with the alloys and presents important information on microstructural strengthening, degradation, and oxidation mechanisms.

• Proceedings of the KIEE Conference
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• 2000.07b
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• pp.778-780
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• 2000

Due to the long time operation of the thermal power plant boiler. the load redistribution of the sling rods is occurred. To enlarge the sincerity of the boiler. measuring and adjusting the actual load of the sung rods is required. The original targets were reached from the 1-year-study. Survey related to the load distribution system for the boiler, systematic design of the hydraulic unit and hydro cylinder, detailed design of the hydraulic unit and hydro cylinder.