• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2004년도 춘계 학술발표대회 개요집
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• pp.324-326
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• 2004

l2wt%Cr Steel has been applied on turbine bucket and nozzle partition material of power plant. Turbine bucket and nozzle get damaged by solid particle within steam, therefore they are protected by surface treatments such as ion nitriding, boriding and chrome carbide HVOF spray coating. In this study, solid particle erosion(SPE) characteristics after these surface treatments are examined at operating temperature 540$^{\circ}C$ and 590$^{\circ}C$ of fossil power plant and the mechanism of damage was studied. Erosion of 12wt%Cr steel is originated by micro cutting and that of boriding and chrome carbide HVOF spray is originated by these mechanism - repeating collision, crack initiation and propagation. As the results of SPE test at 540$^{\circ}C$ and 30$^{\circ}$ impact angle that is the most commonly occurred in power plant, Boriding had the best SPE -resistance property, Cr$_2$C$_3$-25(Ni20Cr) HVOF spayed and ion nitrided samples were also better than bare metals(l2wt%Cr Steels). At 590$^{\circ}C$ and 30$^{\circ}$ impact angle, Boriding had also the most superior characteristic and HVOF spay sample was better than bare metal.

• Journal of Electrical Engineering and Technology
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• 제6권3호
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• pp.423-430
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• 2011

Multi-input multi-output (MIMO) dynamic matrix control (DMC) technique is applied to control steam temperatures in a large-scale ultrasupercritical once-through boiler-turbine system. Specifically, four output variables (i.e., outlet temperatures of platen superheater, finish superheater, primary reheater, and finish reheater) are controlled using four input variables (i.e., two spray valves, bypass valve, and damper). The step-response matrix for the MIMO DMC is constructed using the four input and the four output variables. Online optimization is performed for the MIMO DMC using the model predictive control technique. The MIMO DMC controller is implemented in a full-scope power plant simulator with satisfactory performance.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 심포지엄 논문집 정보 및 제어부문
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• pp.223-224
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• 2008

초초임계압 화력발전 제어계통 설계와 관련하여 보일러 제어시스템의 기본 요건인 제어전략을 구현하기 위해 현재 표준화력 500MW 제어시스템과 제어로직을 기반으로 1000MW급에서 필요로 하는 새로운 구조의 제어에 요구되는 제어전략에 대해 각종 제어 운전 모드의 구성과 각 운전 모드에서의 제어전략을 개발하고 있다. 최신제어시스템에서 중요하게 취급되는 자동 플랜트 제어(Automatic Plant Control, APE)의 각종 제어전략 구성에 중점을 두고 있으며 Unit Master Control, Boiler Master Control, Turbine blaster Control, Throttle Pressure Control, Fuel/Air Master Control, Forced Draft Fan Control, Induced Draft Fan Control, Primary Air Fan, Feed Water Master Control, Super Heater/Reheater Steam Temp Control 등의 제어전략을 논하고, 실제 프로세스 응단특성 파악을 위해 국내 신규발전소를 방문하여 수집한 프로세스 응답시험 결과와 특성을 분석하고 USC에 적용하기위한 보일러 제어전략에 대해 논하고자 한다.

• KEPCO Journal on Electric Power and Energy
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• 제4권1호
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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.