Recent studies have shown that in a prewarming, respectively, warm-keeping operation of a steam turbine, the blades and vanes transport most of the heat to the thick-walled casing and rotor. Thereby, a thermal bottle-neck arises at the connection between the blade root and the rotor. The thermal contact resistance (TCR) at these interfaces affects the temperature distribution and thus the thermal stresses in the rotor. The present paper introduces an experimental setup, which is designed to quantify the TCR at the blade-rotor-connection of a steam turbine. An uncertainty analysis is presented, which proves that the average measurement uncertainties are less than one percent. The experiments especially focus on the investigation of the contact pressure, which is a function of the rotational speed. Therefore, the results of several steady-state measurements under atmospheric and evacuated atmosphere using a high temperature-resistant chromium-molybdenum steel are presented. For the evaluation of the TCR, a numerical model of the specimen is developed in addition to a simplified 1D approach. The results show a significantly increasing TCR with decreasing contact pressure, respectively, rotational speed.

References

References
1.
Toebben
,
D.
,
Luczynski
,
P.
,
Diefenthal
,
M.
,
Wirsum
,
M.
,
Reitschmidt
,
S.
,
Mohr
,
W.
, and
Helbig
,
K.
,
2017
, “
Numerical Investigation of Heat Transfer and Flow Phenomena in an IP Steam Turbine in Warm-Keeping Operation With Hot Air
,”
ASME
Paper No. GT2017-63555.
2.
Pusch
,
D.
,
Voigt
,
M.
,
Vogeler
,
K.
,
Dumstorff
,
P.
, and
Almstedt
,
H.
,
2016
, “
Setup, Validation and Probabilistic Robustness Estimation of a Model for Prediction of LCF in Steam Turbine Rotors
,”
ASME
Paper No. GT2016-57321.
3.
Fenech
,
H.
, and
Rohsenow
,
W. M.
,
1963
, “
Prediction of Thermal Conductance of Metallic Surfaces in Contact
,”
ASME J. Heat Transfer
,
85
(
1
), pp.
15
24
.
4.
Mikic
,
B. B.
, and
Rohsenow
,
W. M.
,
1966
, “
Thermal Contact Resistance
,” Massachusetts Institute of Technology, Cambridge, MA, Technical Report No. 4542-41.
5.
Yovanovich
,
M. M.
, and
Fenech
,
H.
,
1966
, “
Thermal Contact Conductance of Nominally Flat Rough Surfaces in a Vacuum Environment
,”
Thermophys. Temp. Control Spacecr. Entry Veh.
, pp. 773–794.
6.
Cooper
,
M. G.
,
Mikic
,
B. B.
, and
Yovanovich
,
M. M.
,
1969
, “
Thermal Contact Conductance
,”
Int. J. Heat Mass Transfer
,
12
, pp. 279–300.
7.
Yovanovich
,
M. M.
,
2005
, “
Four Decades of Research on Thermal Contact, Gap, and Joint Resistance in Microelectronics
,”
IEEE Trans. Compon. Packaging Technol.
,
28
(2), pp. 182–206.
8.
Madhusudana
,
C. V.
,
2014
,
Thermal Contact Conductance
(Mechanical Engineering Series),
2nd ed.
,
Springer
,
Cham, Switzerland
.
9.
Burghold
,
E. M.
,
Frekers
,
Y.
, and
Kneer
,
R.
,
2015
, “
Determination of Time-Dependent Thermal Contact Conductance Through IR-Thermography
,”
Int. J. Therm. Sci.
,
98
, pp. 148–155.https://doi.org/10.1016/j.ijthermalsci.2015.07.009
10.
Ustinov
,
V.
,
Kneer
,
R.
,
Al-Sibai
,
F.
,
Schulz
,
S.
, and
El-Magd
,
E.
,
2010
, “
Influence of Surface Roughness on Contact Heat Transfer
,”
ASME
Paper No. IHTC14-22288.
11.
Ustinov
,
V.
,
Schulz
,
S.
,
Kneer
,
R.
, and
El-Magd
,
E.
,
2011
, “
Model Development for the Contact Pressure Dependent Heat Transfer
,”
Motortechnische Zeitschrift: MTZ
, Springer Automotive Media, München, Germany.
12.
Mar
,
J.
,
Litovsky
,
E.
, and
Kleiman
,
J.
,
2008
, “
Modeling and Database Development of Conductive and Apparent Thermal Conductivity of Moist Insulation Materials
,”
J. Building Phys.
,
32
(1), pp. 9–30.https://doi.org/10.1177/1744259108092001
13.
Working Group 1,
2008
, “
Evaluation of Measurement Data—Guide to the Expression of Uncertainty in Measurement
,” Joint Committee for Guides in Metrology (JCGM), Technical Report No. JCGM 100:2008.
14.
DIN Deutsches Institut fuer Normung e. V, 2013, “
Thermoelemente-Teil 1: Thermospannungen und Grenzabweichungen
,” DKE Deutsche Kommission Elektrotechnik Elektronik Informationstechnik im DIN und VDE, Technical Report No. IEC60584-1:2013, DIN EN 60584-1.
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