Research Papers: Gas Turbines: Controls, Diagnostics, and Instrumentation

Experimental Investigation Into Thermal Behavior of Steam Turbine Components—Temperature Measurements With Optical Probes and Natural Cooling Analysis

[+] Author and Article Information
Gabriel Marinescu

e-mail: gabriel.marinescu@power.alstom.com

Wolfgang F. Mohr

e-mail: wolfgang.mohr@power.alstom.com

Andreas Ehrsam

e-mail: andreas.ehrsam@power.alstom.com

Paolo Ruffino

e-mail: paolo.ruffiono@power.alstom.com

Michael Sell

e-mail: michael.sell@power.alstom.com
Alstom, Power
Baden 5401, Switzerland

Contributed by the Controls, Diagnostics and Instrumentation Committee of ASME for publication in the JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER. Manuscript received August 31, 2013; final manuscript received September 10, 2013; published online November 1, 2013. Editor: David Wisler.

J. Eng. Gas Turbines Power 136(2), 021602 (Nov 01, 2013) (10 pages) Paper No: GTP-13-1334; doi: 10.1115/1.4025556 History: Received August 31, 2013; Revised September 10, 2013

The steam turbine cooldown has a significant impact on the cyclic fatigue life. A lower initial metal temperature after standstill results in a higher temperature difference to be overcome during the next start-up. Generally, lower initial metal temperatures result in higher start-up stress. In order to optimize steam turbines for cyclic operation, it is essential to fully understand natural cooling, which is especially challenging for rotors. This paper presents a first-in-time application of a 2D numerical procedure for the assessment of the thermal regime during natural cooling, including the rotors, casings, valves, and main pipes. The concept of the cooling calculation is to replace the fluid gross buoyancy during natural cooling by an equivalent fluid conductivity that gives the same thermal effect on the metal parts. The fluid equivalent conductivity is calculated based on experimental data. The turbine temperature was measured with pyrometric probes on the rotor and with standard thermocouples on inner and outer casings. The pyrometric probes were calibrated with standard temperature measurements on a thermo well, where the steam transmittance and the rotor metal transmissivity were measured.

Copyright © 2014 by ASME
Your Session has timed out. Please sign back in to continue.


Ruffino, P., and Mohr, W., 2012, “Experimental Investigation Into Thermal Behavior of Steam Turbine Components: Part 1—Temperature Measurements With Optical Probes,” ASME Paper No. GT2012-68703. [CrossRef]
Dobler, T., Haffner, K., and Evers Wolfgang, 1998, “Optic Pyrometer for Gas Turbines,” U. S, Patent No. 6,109,783.
Kempe, A., Schlamp, S., Rösgen, T., and Haffner, K., 2006, “Optical Tip-Clearance Probe for Harsh Environments,” The XVIII Symposium on Measuring Techniques in Turbomachinery, Thessaloniki, Greece, September 21–22.
Kirby, P. J., Zachary, R. E., and Ruiz, F., 1986, “Infrared Thermometry for Control and Monitoring of Industrial Gas Turbines,” ASME Paper No. 86-GT-267.
Phelan, R., Lynch, M., Donegan, J. F., and Weldon, V., 2003, “Absorption Line Shift With Temperature and Pressure Impact on Laser-Diode-Based H2O Sensing at 1.393 μm,” Appl. Opt., 42, pp. 4968–4974. [CrossRef] [PubMed]
Smith, K. M., Ptashnik, I., Newnham, D. A., and Shine, K. P., 2004, “Absorption by Water Vapour in the 1 to 2 μm Region,” J. Quant. Spec. Radiat. Transfer, 83, pp. 735–749. [CrossRef]
Rothman, L. S., Jacquemart, D., Barbe, A., Chris Benner, D., Birk, M., Brown, L. R., Carleer, M. R., Chackerian, Jr.C., Chance, K., Coudert, L. H., Dana, V., Devi, V. M., Flaud, J.-M., Gamache, R. R., Goldman, A., Hartmann, J.-M., Jucks, K. W., Maki, A. G., Mandin, J.-Y., Massie, S. T., Orphal, J., Perrin, A., Rinsland, C. P., Smith, M. A. H., Tennyson, J., Tolchenov, R. N., Toth, R. A., Vander Auwera, J., Varanasi, P., and Wagner, G., 2005, “The HITRAN 2004 Molecular Spectroscopic Database,” J. Quant. Spectrosc. Radiat. Transfer, 96, pp. 139–204. [CrossRef]
Dicke, R. H., 1953, “The Effect of Collisions Upon the Doppler Width of Spectral Lines,” Phys. Rev., 89, pp. 472–473. [CrossRef]
Galatry, L., 1961, “Simultaneous Effect of Doppler and Foreign Gas Broadening of Spectral Lines,” Phys. Rev., 122, pp. 1218–1223. [CrossRef]
Goldstein, R., 1964, “Quantitative Spectroscopic Studies on the Infrared Absorption,” Ph.D. thesis, Caltech, Pasadena, CA.
Rieker, G., Liu, X., Li, H., Jeffries, J., and Hanson, R., 2007, “Measurement of Near-IR Water Vapor Absorption at High Pressure and Temperature,” Appl. Phys.B87, pp. 169–178. [CrossRef]
Nagali, V., Herbon, J. T., Horning, D. C., Davidson, D. F., and Hanson, R. K., 1999, “Shock-Tube Study of High-Pressure H2O Spectroscopy,” Appl. Opt., 38(33), pp. 6942–6950. [CrossRef] [PubMed]
SpectralCalc, 2013, “High-Resolution Spectral Modeling,” GATS, Inc., Newport News, VA, www.spectralcalc.com
Marinescu, G., and Ehrsam, A., 2012, “Experimental Investigation Into Thermal Behavior of Steam Turbine Components: Part 2—Natural Cooling of Steam Turbines and the Impact on LCF Life,” ASME Paper No. GT2012-68759. [CrossRef]
Spelling, J., Jöcker, M., and Martin, A., 2011, “Thermal Modeling of a Solar Steam Turbine With a Focus on Start-Up Time Reduction,” ASME Paper No. GT2011-45686. [CrossRef]


Grahic Jump Location
Fig. 1

IP steam turbine instrumentation

Grahic Jump Location
Fig. 2

The IP steam turbine arrangement

Grahic Jump Location
Fig. 3

(a) Flexible pyrometric probe as used in gas turbine applications. (b) The measurement chain as used for the in-house developed pyrometer.

Grahic Jump Location
Fig. 4

The USC autoclave. On the left the full view, on the right the detail of the box.

Grahic Jump Location
Fig. 5

The steam transmittance at 20 bar and 600 °C. The calculated curve using the HITRAN database [13], the low resolution data of Goldstein [10], and our experimental results from the FTIR spectrometer.

Grahic Jump Location
Fig. 6

Effect of purging on the lenses contamination in a real steam turbine (left not purged, right purged)

Grahic Jump Location
Fig. 7

Rotor temperature measured at optical probes OT1, OT2, and OT3

Grahic Jump Location
Fig. 8

Inner and outer casing temperatures measured at T11.1, T24.1, Tm33, and Tm42

Grahic Jump Location
Fig. 9

Thermal boundary conditions to simulate the steam ingestion

Grahic Jump Location
Fig. 10

Meshed model for natural cooling analysis

Grahic Jump Location
Fig. 11

Base load. Initial condition for natural cooling.

Grahic Jump Location
Fig. 12

The iterative process

Grahic Jump Location
Fig. 13

The overconductivity function K(T)

Grahic Jump Location
Fig. 14

The “thickness” property

Grahic Jump Location
Fig. 15

Calculated and measured temperature at T11.1

Grahic Jump Location
Fig. 16

Calculated and measured temperature at Tm33

Grahic Jump Location
Fig. 17

Calculated and measured temperature at OT1

Grahic Jump Location
Fig. 18

Temperature distribution at 2 h after natural cooling start

Grahic Jump Location
Fig. 19

Temperature distribution at 10 h after natural cooling start

Grahic Jump Location
Fig. 20

Impact of the ambient temperature

Grahic Jump Location
Fig. 21

Impact of the different parameters on the rotor temperature at OT1



Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In