The penetration of intermittent wind and solar power to the grid network above manageable limits disrupts electrical power grids. Consequently, hydraulic turbines synchronized to the grid experience total load rejection and are forced to shut down immediately. The turbine runner accelerates to runaway speeds in a few seconds, inducing high-amplitude, unsteady pressure loading on the blades. This sometimes results in a failure of the turbine components. Moreover, the unsteady pressure loading significantly affects the operating life of the turbine runner. Transient measurements were carried out on a scale model of a Francis turbine prototype (specific speed = 0.27) during an emergency shutdown with a transition into total load rejection. A detailed analysis of variables such as the head, discharge, pressure at different locations including the runner blades, shaft torque, and the guide vane angular movements are performed. The maximum amplitudes of the unsteady pressure fluctuations in the turbine were observed under a runaway condition. The amplitudes were 2.1 and 2.6 times that of the pressure loading at the best efficiency point in the vaneless space and runner, respectively. Such high-amplitude, unsteady pressure pulsations can affect the operating life of the turbine.

References

References
1.
Trivedi
,
C.
,
Gandhi
,
B. K.
, and
Cervantes
,
M. J.
,
2013
, “
Effect of Transients on Francis Turbine Runner Life: A Review
,”
J. Hydraulic Res.
,
51
(
2
), pp.
121
132
.10.1080/00221686.2012.732971
2.
Deepak
,
A.
,
Roger
,
C-J.
, and
Gerald
,
J.
,
2011
, “
The Impact of Hydroelectric Power and Other Forms of Generation on Grid Frequency Stability for the WECC Region
,” HydroVision International, Sacramento, CA, July 19–22.
3.
Trivedi
,
C.
,
Cervantes
,
M. J.
,
Gandhi
,
B. K.
, and
Ole
,
D. G.
,
2013
, “
Pressure Measurements on a High Head Francis Turbine During Load Acceptance and Rejection
,”
J. Hydraulic Res.
,
52
(
2
), pp.
1
15
.10.1080/00221686.2013.854846
4.
Trivedi
,
C.
,
Cervantes
,
M. J.
,
Gandhi
,
B. K.
, and
Ole
,
D. G.
,
2014
, “
Experimental Investigations of Transient Pressure Variations in a High Head Model Francis Turbine During Start-Up and Shutdown
,”
J. Hydrodyn. Ser. B
,
26
(
2
), pp.
277
290
.10.1016/S1001-6058(14)60031-7
5.
Deschênes
,
C.
,
Fraser
,
R.
, and
Fau
,
J.-P.
,
2002
, “
New Trends in Turbine Modelling and New Ways of Partnership
,”
International Conference on Hydraulic Efficiency Measurement—IGHEM
, Toronto, Ontario, Canada, July 17–19, pp.
1
12
.
6.
Huth
,
H.-J.
,
2005
, “
Fatigue Design of Hydraulic Turbine Runners
,” Ph.D. thesis. Norwegian University of Science and Technology, NTNU, Trondheim, Norway.
7.
Nicolet
,
C.
,
2007
, “
Hydroacoustic Modelling and Numerical Simulation of Unsteady Operation of Hydroelectric Systems
,” Ph.D. thesis, No. 3751, École Polytechnique Fédérale de Lausanne (EPFL), Switzerland.
8.
Liu
,
S.
,
Zhou
,
D.
,
Liu
,
D.
,
Wu
,
Y.
, and
Nishi
,
M.
,
2010
, “
Runaway Transient Simulation of a Model Kaplan Turbine
,”
IOP Conf. Ser.: Earth Environ. Sci.
,
12
(
1
), p.
012073
.10.1088/1755-1315/12/1/012073
9.
Kolsek
,
T.
,
Duhovnik
,
J.
, and
Bergant
,
A.
,
2006
, “
Simulation of Unsteady Flow and Runner Rotation During Shut-Down of an Axial Water Turbine
,”
J. Hydraulic Res.
,
44
(
1
), pp.
129
137
.10.1080/00221686.2006.9521668
10.
Brekke
,
H.
,
Jacob
,
T.
,
Leyland
,
B.
, and
Pejovic
,
S.
,
2003
, “
Transient Problems During Load Rejection
,” Masjed-E-Soleymn Panel Experts Mission, Nov. 18–25.
11.
Nicolet
,
C.
,
Alligne
,
S.
,
Bergant
,
A.
, and
Avellan
,
F.
,
2011
, “
Parametric Study of Water Column Separation in Francis Pump-Turbine Draft Tube
,” SHF: Pumped Storage Powerplants, Lyon, Nov. 23–24.
12.
Pejovic
,
S.
,
Karney
,
B.
, and
Zhang
,
Q.
,
2004
, “
Water Column Separation in Long Tailrace Tunnel
,”
Hydroturbo 2004, International Conference on Hydro-Power Engineering
, Brno, Czech Republic, Oct. 18–22.
13.
Ramos
,
H.
, and
Almedia
,
B.
,
2001
, “
Dynamic Orifice Model on Water Hammer Analysis of High or Medium Heads of Small Hydro Power Schemes
,”
J. Hydraul. Res.
,
39
(
4
), pp.
429
436
.10.1080/00221680109499847
14.
Grunde
,
O.
,
Torbjørn
,
N.
, and
Bjarne
,
B.
,
2012
, “
Stability Limits of Reversible-Pump Turbines in Turbine Mode of Operation and Measurements of Unstable Characteristics
,”
ASME J. Fluids Eng.
,
134
(
11
), p.
111202
.10.1115/1.4007589
15.
Hasmatuchi
,
V.
,
Farhat
,
M.
,
Roth
,
S.
,
Botero
,
F.
, and
Avellan
,
F.
,
2011
, “
Experimental Evidence of Rotating Stall in a Pump-Turbine at Off-Design Conditions in Generating Mode
,”
ASME J. Fluids Eng.
,
133
(
5
), p.
051104
.10.1115/1.4004088
16.
Gagnon
,
M.
, and
Leonard
,
F.
,
2013
, “
Transient Response and Life Assessment: Case Studies on the Load Rejection of Two Hydroelectric Turbines
,”
Surveillance 7, International Conference
, Institute of Technology of Chartres, France, Oct. 29–30.
17.
Widmer
,
C.
,
Staubli
,
T.
, and
Ledergerber
,
N.
,
2011
, “
Unstable Characteristics and Rotating Stall in Turbine Brake Operation of Pump-Turbines
,”
ASME J. Fluids Eng.
,
133
(
4
), p.
041101
.10.1115/1.4003874
18.
Brekke
,
H.
,
2010
, “
A Review on Oscillatory Problems in Francis Turbine
,” New Trends in Technologies: Devices, Computer, Communication and Industrial Systems, Sciyo, pp.
217
232
, available online at http://cdn.intechweb.org/pdfs/12284.pdf
19.
Gagnon
,
M.
,
Tahan
,
S. A.
,
Bocher
,
P.
, and
Thibault
,
D.
,
2010
, “
Impact of Startup Scheme on Francis Runner Life Expectancy
,”
IOP Conf. Ser.: Earth Environ. Sci.
,
12
(
1
), p.
012107
.
20.
Nicolle
,
J.-F. M.
, and
Giroux
,
A.-M.
,
2012
, “
Transient CFD Simulation of a Francis Turbine Startup
,”
26th IAHR Symposium on Hydraulic Machinery and Systems
, Beijing, China, Aug. 19–23.
21.
Tsukamoto
,
H.
, and
Ohashi
,
H.
,
1982
, “
Transient Characteristics of a Centrifugal Pump During Starting Period
,”
ASME J. Fluids Eng.
,
104
(
1
), pp.
6
13
.10.1115/1.3240859
22.
Tsukamoto
,
H.
,
Hata
,
S.
,
Matsunga
,
S.
, and
Yoneda
,
H.
,
1986
, “
Transient Characteristics of a Centrifugal Pump During Stopping Period
,”
ASME J. Fluids Eng.
,
108
(
4
), pp.
392
399
.10.1115/1.3242594
23.
Dazin
,
A.
,
Caignaert
,
G.
, and
Bois
,
G.
,
2007
, “
Transient Behavior of Turbomachineries: Applications to Radial Flow Pump Startups
,”
ASME J. Fluids Eng.
,
129
(
11
), pp.
1436
1444
.10.1115/1.2776963
24.
Rodriguez
,
C. G.
,
Egusquiza
,
E.
, and
Santos
,
I. F.
,
2007
, “
Frequencies in the Vibration Induced by the Rotor Stator Interaction in a Centrifugal Pump Turbine
,”
ASME J. Fluids Eng.
,
129
(
11
), pp.
1428
1435
.10.1115/1.2786489
25.
Arpe
,
J.
,
Nicolet
,
C.
, and
Avellan
,
F.
,
2009
, “
Experimental Evidence of Hydroacoustic Pressure Waves in a Francis Turbine Elbow Draft Tube for Low Discharge Conditions
,”
ASME J. Fluids Eng.
,
131
(
8
), p.
081102
.10.1115/1.3155944
26.
Bosioc
,
A. I.
,
Susan-Resiga
,
R.
,
Muntean
,
S.
, and
Tănasă
,
C.
,
2012
, “
Unsteady Pressure Analysis of Swirling Flow With Vortex Rope and Axial Water Injection in a Discharge Cone
,”
ASME J. Fluids Eng.
,
134
(
8
), p.
081104
.10.1115/1.4007074
27.
Nilsson
,
O.
, and
Sjelvgren
,
D.
,
1997
, “
Hydro Unit Start-Up Costs and Their Impact on the Short Term Scheduling Strategies of Swedish Power Producers
,”
IEEE Trans. Power Syst.
,
12
(
1
), pp.
38
44
.10.1109/59.574921
28.
Bakken
,
B. H.
, and
Bjørkvoll
,
T.
,
2002
, “
Hydropower Unit Start-Up Costs
,”
Power Engineering Society Summer Meeting
, Chicago, IL, July 25. pp.
1522
1527
.
29.
Keck
,
H.
, and
Sick
,
M.
,
2008
, “
Thirty Years of Numerical Flow Simulation in Hydraulic Turbomachines
,”
Acta Mech.
,
201
(1–4), pp.
211
229
.10.1007/s00707-008-0060-4
30.
Hutton
,
S. P.
,
1954
, “
Component Losses in Kaplan Turbines and the Prediction of Efficiency From Model Tests
,”
Proc. of the Institution of Mechanical Engineers
, pp.
168
743
.
31.
Osterwalder
,
J.
,
1978
, “
Efficiency Scale-Up for Hydraulic Turbo-Machines With Due Consideration of Surface Roughness
,”
J. Hydraul. Res.
,
16
(
1
), pp.
55
76
.10.1080/00221687809499632
32.
Ida
,
T.
,
1989
, “
Analysis of Scale Effects on Performance Characteristics of Hydraulic Turbines
,”
J. Hydraul. Res.
,
27
(
6
), pp.
809
831
.10.1080/00221688909499109
33.
Dorfler
,
P. K.
,
2009
, “
Evaluating 1D Models for Vortex-Induced Pulsation in Francis Turbines
,”
3rd IAHR International Meeting of the Workgroup on Cavitation and Dynamic Problems in Hydraulic Machinery and Systems
, Brno, Czech Republic, Oct. 14–16.
34.
Dorfler
,
P. K.
,
Keller
,
M.
, and
Braun
,
O.
,
2010
, “
Francis Full-Load Surge Mechanism Identified by Unsteady 2-Phase CFD
,”
IOP Conf. Series: Earth Environ. Sci.
,
12
(
1
), p.
012026
.10.1088/1755-1315/12/1/012026
35.
Alligne
,
S.
,
Maruzewski
,
P.
,
Dinh
,
T.
,
Wang
,
B.
,
Fedorov
,
A.
,
Iosfin
,
J.
, and
Avellan
,
F.
,
2010
, “
Prediction of a Francis Turbine Prototype Full Load Instability From Investigations on the Reduced Scale Model
,”
IOP Conf. Series: Earth Environ. Sci.
,
12
(
1
), p.
012025
.10.1088/1755-1315/12/1/012025
36.
IEC 60193: 1999-11, “
Hydraulic Turbines, Storage Pumps and Pump-Turbines—Model Acceptance Tests
,” International Electrotechnical Commission, Geneva, Switzerland.
37.
Dorfler
,
P.
,
Sick
,
M.
, and
Coutu
,
A.
,
2013
,
Flow-Induced Pulsation and Vibration in Hydroelectric Machinery
,
1st ed.
,
Springer
,
New York
.
38.
Hasmatuchi
,
V.
,
2012
, “
Hydrodynamics of a Pump-Turbine Operating at Off-Design Conditions in Generating Mode
,” Ph.D. thesis, No. 5373, École Polytechnique Fédérale De Lausanne, Switzerland.
39.
Jacob
,
T.
,
1993
, “
Evaluation sur Modele Reduit et Prediction la Stabilite de Fonctionnement des Turbines Francis
,” Ph.D. thesis, No. 1146, Departement de Mecanique, Ecole Polytechnique Federale de Lausanne, Lausanne, Switzerland.
40.
Trivedi
,
C.
,
Cervantes
,
M. J.
,
Gandhi
,
B. K.
, and
Ole
,
D. G.
,
2013
, “
Experimental and Numerical Studies for a High Head Francis Turbine at Several Operating Points
,”
ASME J. Fluids Eng.
,
135
(
11
), p.
111102
.10.1115/1.4024805
41.
IEC 60041: 1991-11, “
Field Acceptance Tests to Determine the Hydraulic Performance of Hydraulic Turbines, Storage Pumps and Pump-Turbines
,” 3rd ed., International Electrotechnical Commission, Geneva, Switzerland.
42.
IEC 545: 1976, “
Guide for Commissioning, Operation and Maintenance of Hydraulic Turbines
,” International Electrotechnical Commission, Geneva, Switzerland.
43.
IEC 60308: 2005-01, “
Hydraulic Turbines-Testing of Control Systems
,” International Electrotechnical Commission, Geneva, Switzerland.
44.
IEC 61362: 1998-03, “
Guide to Specification of Hydraulic Turbine Control Systems
,” 1st ed., International Electrotechnical Commission, Geneva, Switzerland.
45.
IEC 60994: 1991-01, “
Guide for Field Measurement of Vibrations and Pulsations in Hydraulic Machines (Turbines, Storage Pumps and Pump-Turbines)
,” 1st ed., International Electrotechnical Commission, Geneva, Switzerland.
46.
ASME PTC 18-2011, “
Hydraulic Turbines and Pump-Turbines, Performance Test Codes
,” ASME, NY.
47.
Ciocan
,
G. D.
,
Iliescu
,
M. S.
,
Vu
,
T. C.
,
Nennemann
,
B.
, and
Avellan
,
F.
,
2007
, ”
Experimental Study and Numerical Simulation of the FLINDT Draft Tube Rotating Vortex
,”
ASME J. Fluids Eng.
,
129
(
2
), pp.
146
158
.10.1115/1.2409332
48.
Benjamin
,
T.
,
1962
, “
Theory of the Vortex Breakdown Phenomenon
,”
J. Fluid Mech.
,
14
(
4
), pp.
593
629
.10.1017/S0022112062001482
You do not currently have access to this content.