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Research Papers: Gas Turbines: Turbomachinery

Degradation of Aerodynamic Performance of an Intermediate-Pressure Steam Turbine Due to Erosion of Nozzle Guide Vanes and Rotor Blades

[+] Author and Article Information
Koichi Yonezawa

Civil Engineering Laboratory,
Central Research Institute of
Electric Power Industry,
1642,
Abiko 270-1194, Chiba, Japan
e-mail: koichi-y@criepi.denken.or.jp

Tomoki Kagayama

Graduate School of Engineering Science,
Osaka University,
1-3, Machikanayama-cho,
Toyonaka 560-8531, Osaka, Japan
e-mail: tomoki.kagayama@flow.me.es.osaka-u.ac.jp

Masahiro Takayasu

Graduate School of Engineering Science,
Osaka University,
1-3, Machikanayama-cho,
Toyonaka 560-8531, Osaka, Japan
e-mail: masahiro.takayasu@flow.me.es.osaka-u.ac.jp

Genki Nakai

Graduate School of Engineering Science,
Osaka University,
1-3, Machikanayama-cho,
Toyonaka 560-8531, Osaka, Japan
e-mail: genki_nakai@mhi.co.jp

Kazuyasu Sugiyama

Graduate School of Engineering Science,
Osaka University,
1-3, Machikanayama-cho,
Toyonaka 560-8531, Osaka, Japan
e-mail: Kazuyasu.sugiyama@flow.me.es.osaka-u.ac.jp

Katsuhiko Sugita

Tokyo Electric Power Company Holdings, Inc.,
4-1 Egasaki-cho, Tsurumiki-ku,
Yokohama 230-8510, Kanagawa, Japan
e-mail: sugita.katsuhiko@tepco.co.jp

Shuichi Umezawa

Tokyo Electric Power Company Holdings, Inc.,
4-1 Egasaki-cho, Tsurumiki-ku,
Yokohama 230-8510, Kanagawa, Japan
e-mail: umezawa.s@tepco.co.jp

1Corresponding author.

Contributed by the Turbomachinery Committee of ASME for publication in the JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER. Manuscript received December 5, 2017; final manuscript received April 25, 2018; published online September 14, 2018. Assoc. Editor: Klaus Dobbeling.

J. Eng. Gas Turbines Power 141(1), 012602 (Sep 14, 2018) (8 pages) Paper No: GTP-17-1646; doi: 10.1115/1.4040566 History: Received December 05, 2017; Revised April 25, 2018

Deteriorations of nozzle guide vanes (NGVs) and rotor blades of a steam turbine through a long-time operation usually decrease a thermal efficiency and a power output of the turbine. In this study, influences of blade deformations due to erosion are discussed. Experiments were carried out in order to validate numerical simulations using a commercial software ANSYS-cfx. The numerical results showed acceptable agreements with experimental results. Variation of flow characteristics in the first stage of the intermediate pressure steam turbine is examined using numerical simulations. Geometries of the NGVs and the rotor blades are measured using a 3D scanner during an overhaul. The old NGVs and the rotor blades, which were used in operation, were eroded through the operation. The erosion of the NGVs leaded to increase of the throat area of the nozzle. The numerical results showed that rotor inlet velocity through the old NGVs became smaller and the flow angle of attack to the rotor blade leading edge became smaller. Consequently, the rotor power decreased significantly. Influences of the flow angle of at the rotor inlet were examined by parametric calculations and results showed that the angle of attack was an important parameter to determine the rotor performance. In addition, the influence of the deformation of the rotor blade was examined. The results showed that the degradation of the rotor performance decreased in accordance with the decrease of blade surface area.

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References

Dikunchak, S. , 1992, “Performance Deterioration in Industrial Gas Turbine,” ASME J. Eng. Gas Turbines Power, 114(2), pp. 161–168. [CrossRef]
Spina, P. R. , 2002, “Gas Turbine Performance Prediction by Using Generalized Performance Curves of Compressor and Turbine Stages,” ASME Paper No. GT2002-30275.
Kurz, R. , Brun, K. , and Wollie, M. , 2009, “Degradation Effects on Industrial Gas Turbines,” ASME J. Eng. Gas Turbines Power, 131(6), p. 062401. [CrossRef]
Morini, M. , Pinelli, M. , Spina, P. R. , and Venturini, M. , 2010, “Influence of Blade Deterioration on Compressor and Turbine Performance,” ASME J. Eng. Gas Turbines Power, 132(3), p. 032401. [CrossRef]
Wang, S.-S. , Mao, J.-R. , Liu, G.-W. , and Feng, Z.-P. , 2010, “Performance Deterioration of the Governing Stage Nozzle Caused by Solid Particle Erosion in the Steam Turbine,” Proc. Inst. Mech. Eng., Part A, 224(2), pp. 279–292. [CrossRef]
Edwards, R. , Asghar, A. , Woodason, R. , LaViolette, M. , Goni Boulama, K. , and Allan, W. D. E. , 2012, “Numerical Investigation of the Influence of Real World Blade Profile Variations on the Aerodynamic Performance of Transonic Nozzle Guide Vanes,” ASME J. Turbomach., 134(2), p. 021014. [CrossRef]
Bouchard, D. , Asghar, A. , LaViolette, M. , Allan, W. D. E. , and Woodason, R. , 2014, “Experimental Evaluation of Service-Exposed Nozzle Guide Vane Damage in a Rolls Royce A-250 Gas Turbine,” ASME J. Eng. Gas Turbines Power, 136(10), p. 102601. [CrossRef]
Yonezawa, K. , Nakai, G. , Kagayama, T. , Sugiyama, K. , Sugita, K. , and Umezawa, S. , 2016, “Influences of Deteriorations of Stators and Rotors of a Gas Turbine,” Asian Congress on Gas Turbines (ACGT), Mumbai, India, Nov. 14–16, No. ACGT2016-48.
Yonezawa, K. , Nakai, G. , Kagayama, T. , Sugiyama, K. , Sugita, K. , and Umezawa, S. , 2017, “A Numerical Investigation of Aerodynamic Characteristics of a Deteriorated Gas Turbine,” ASME Paper No. POWER-ICOPE2017-3444.
Yun, I. Y. , Park, I. Y. , and Song, S. J. , 2005, “Performance Degradation Due to Blade Surface Roughness in a Single-Stage Axial Turbine,” ASME J. Turbomach., 127(1), pp. 137–143. [CrossRef]
Menter, F. R. , 1994, “Two-Equation Eddy-Viscosity Turbulence Models for Engineering Applications,” AIAA J., 32(8), pp. 1598–1605. [CrossRef]
Belamri, T. , Galpin, P. , Braune, A. , and Cornelius, C. , 2005, “CFD Analysis of a 15 Stage Axial Compressor—Part I: Method,” ASME Paper No. GT2005-68261.

Figures

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Fig. 1

Cross-sectional contour of NGVs (top) and rotor blades (bottom) at midspan

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Fig. 2

Cross-sectional contour of rotor blades at midspan. Entire contour (top) and magnification around the leading edge (bottom).

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Fig. 3

Computational mesh for calculation with NGVs and rotor blade

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Fig. 4

Test section of two-dimensional cascade experimental apparatus

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Fig. 5

Computational mesh for experimental model

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Fig. 6

Total pressure distribution downstream of the cascade

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Fig. 7

Blade surface pressure distribution. New blade model (top) and old blade model (bottom) are shown.

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Fig. 8

Total pressure distribution downstream of the NGV

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Fig. 9

Pressure distribution and relative velocity vector field around the rotor blade at 50% blade span (new rotor blade with old NGV upstream of the rotor)

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Fig. 10

Blade leading edge angle and relative flow angle distribution in spanwise direction. Definition of each angle (top) and spanwise distributions (bottom).

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Fig. 11

Rotor inlet Mach number versus angle of attack

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Fig. 12

Stage loading coefficient versus angle of attack. Entire of rotor blade (top) and in each segment (bottom) are shown.

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Fig. 13

Velocity coefficient versus angle of attack. Entire of rotor blade (top) and in each segment (bottom) are shown.

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Fig. 14

Streamlines in meridional plane. Case B (top) and the case with the old NGV (bottom) are shown.

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Fig. 15

Stage loading coefficient versus degree of blade erosion

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Fig. 16

Velocity coefficient versus degree of blade erosion

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Fig. 17

Pressure distribution and relative velocity vector field at 50% blade span. New blade (left) and old blade (right) are shown.

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