Thermal analysis of cooled supercritical steam turbine components

Kosman, Wojciech

doi:10.1016/j.energy.2009.05.033

Cited by 28 publications

(11 citation statements)

References 1 publication

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“…As a result of concerns related to the environmental impact from pollutants and greenhouse gas, the power industry has had to improve thermal efficiency by developing ultra-supercritical (USC) combustion technology, which has led to elevated steam temperatures and continuously increasing demand being placed on their components' performance [1]. The harsher working conditions exert extra stress on all moving parts, demanding higher reliability with much-enhanced mechanical properties for all components [2,3]. Steam turbine rotors are one of the most critical and highly stressed parts in steam turbines, experiencing centrifugal force, torsional force and bending stress.…”

Section: Introductionmentioning

confidence: 99%

Characterization on the Microstructure Evolution and Toughness of TIG Weld Metal of 25Cr2Ni2MoV Steel after Post Weld Heat Treatment

Liu

Cai

Yang

et al. 2018

Metals

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The microstructure and toughness of tungsten inert gas (TIG) backing weld parts in low-pressure steam turbine welded rotors contribute significantly to the total toughness of the weld metal. In this study, the microstructure evolution and toughness of TIG weld metal of 25Cr2Ni2MoV steel low-pressure steam turbine welded rotor under different post-weld heat treatment (PWHT) conditions are investigated. The fractography and microstructure of weld metal after PWHT are characterized by optical microscope, SEM, and TEM, respectively. The Charpy impact test is carried out to evaluate the toughness of the weld. The optical microscope and SEM results indicate that the as-welded sample is composed of granular bainite, acicular ferrite and blocky martensite/austenite (M-A) constituent. After PWHT at 580 • C, the blocky M-A decomposes into ferrite and carbides. Both the number and size of precipitated carbides increase with holding time. The impact test results show that the toughness decreases dramatically after PWHT and further decreases with holding time at 580 • C. The precipitated carbides are identified as M 23 C 6 carbides by TEM, which leads to the dramatic decrease in the toughness of TIG weld metal of 25Cr2Ni2MoV steel.

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Section: Introductionmentioning

confidence: 99%

Characterization on the Microstructure Evolution and Toughness of TIG Weld Metal of 25Cr2Ni2MoV Steel after Post Weld Heat Treatment

Liu

Cai

Yang

et al. 2018

Metals

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“…In order to meet the increasing challenge to reduce CO 2 emission, ultra-spercritical (USC) coal fired power plants with higher efficiency are developed [1][2][3]. By increasing the steam temperature and pressure entering into the turbines, the efficiency can be improved significantly [4]. And hence, the materials with more excellent creep property and oxidation resistance are required to adapt to such kind of severe service conditions.…”

Section: Introductionmentioning

confidence: 99%

Creep behavior and microstructure evaluation of welded joint in dissimilar modified 9Cr–1Mo steels

Liu

et al. 2015

Materials Science and Engineering: A

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“…Thermal stresses on steam turbine rotors are largest in any place where there is a mechanical stress concentrator or a non-uniform temperature distribution [4][5][6][7]. There are three reasons to investigate the behavior of thermal stresses in steam turbine rotors: (1) the frequent startups caused by a deregulated power generation market, (2) the use of higher steam temperature to increase the power generation capacity and (3) the remaining useful life evaluation of old steam turbine rotors which continue in operation.…”

Section: Introductionmentioning

confidence: 99%

Effect of Rotor Diameter on the Thermal Stresses of a Turbine Rotor Model

Dávalos

García

Urquiza

et al. 2016

International Journal of Turbo &Amp; Jet-Engines

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Thermal stresses in a simplified steam turbine rotor model during a cold startup are analyzed using finite element analysis (FEA). In order to validate the numerical model, an experimental array is developed in which a hollow cylinder is heated with hot air in the external surface. At the thick wall of the cylinder, temperature distribution is measured in real time, while at the same time an algorithm computes thermal stresses. Additional computational fluid dynamics (CFD) calculations are made to obtain magnitudes of velocity and pressure in order to compute convective heat transfer coefficient. The experimental results show good agreement with the FEA computations. To evaluate the effect of rotor diameter size, FEA computations with variation in external and internal diameters are performed. Results show that thermal stresses are proportional to rotor diameter size. Also, zones of higher stress concentration are found in the external and internal surfaces of the rotor.

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Thermal analysis of cooled supercritical steam turbine components

Cited by 28 publications

References 1 publication

Characterization on the Microstructure Evolution and Toughness of TIG Weld Metal of 25Cr2Ni2MoV Steel after Post Weld Heat Treatment

Characterization on the Microstructure Evolution and Toughness of TIG Weld Metal of 25Cr2Ni2MoV Steel after Post Weld Heat Treatment

Creep behavior and microstructure evaluation of welded joint in dissimilar modified 9Cr–1Mo steels

Effect of Rotor Diameter on the Thermal Stresses of a Turbine Rotor Model

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