Raabe J. Hydro power - the design, use, and function of hydromechanical, hydraulic, and electrical еquipment
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Table 2.3.2. Design data
of
Itaipu
[2.28;
2.271.
Number of sets: 18.
Hcsd rangc: 82,9 m- 126.7 m; output range: 400
MW-
540
MW:
rated output: 715
MU':
runner
tip diameter 8.75 m (this bcc;~use of the larger head is some\vhr~t smaller than in Grand Coulee \+lth
9,9
m). Largcst axial extension of runner 4.5 ni; rotational spceds 92.3 and 90.9 rpm Ibr
60
and
50
Hertz respectively. Runaway speed 175 rpm. Distance of adjacent sets 35 m. Diameter of spirai
inlet
10,5
m.
Alternators 18 765
MW
nominal output. Length of power house 900 m (this size takes
care of the 18 sets envisaged at first and 8 additional sets).
Catchment area for the plant: 820000 km2. Average discharge per year: 9070 m3/s.
Storage basin: Surface area: 1355 km2. Length: 200 km (this rather modest figure for a power plant
with 100
n~ head in contrast to Bratsk with 550 km results from the extraordinarily stcep slope of
0,16% over 60 km river length; for comparison
0,02%
on the Angara around Bratsk). Live storage
volume with 23 m level drop: 19 km3. Barrage: Length: 1643 m. Maximum crest
11e:ld: 170m.
(Taller than the towers of the cathedral of Cologne). Lateral rock dikes: Length:
2800
m. rnasimunl
height: 60
m,
lateral earth dikes: Length: 3700 m, maximum height: 30
In.
Type: Hollow gravit)
dam. Bottom outlet: Number: 8. total discharge 6000 mvs. Spillways: Number: 14, tlimension.
20 -20 n~, total discharge: 58000 m3/s (this is 45 times greater than the Danube has
on
at least
100 days before it
leaves West Germany). Penstocks: Number: 26, mean diameter: 12,2 m.
Civil engineering work: Excavation: Diversion channel (to be blasted in :he rocky underground):
12. 106 m3, for barrage: 2
-
lo6
m3, dikes: 3,8
-
lo6 m3, spillways: 14,7 lo6 m3, power house:
4,25. lo6 m3. Concrete (to be obtained by blasting the rocky ground at site): Barrage: 7.9
.
lo6 m3,
spillway:
0,75 lo6 m3, power house:
2
-
lo6
1n3,
total structure: 10.75
-
10'
m3.
Rock and eartk,:
Total volume of excavated rock: 3,4
-
lo6 m3, volumc of lateral rock filled dikes: 16,65 10" m3,
total volume of
earth filled dikes: 3,2. lo6 n13. Material for construction: Cement: 1.85
.
lo6 Mp,
sand: 4,3
lo6 m3, mixture of concrete: 8,6. lo6 m3. Reinforccrnent: 71 400 Mp.
length
of
the four large Siberian rivers Yenissei,
Ob,
Lena and Amoor. After the Zaire
(Congo), Brahmaputra, Yangtse and Parana, it is also the river with the largest harness-
able potential in the world.
Along the 1250 km of its upper course three plants are projected:
Chevelig, Seybinsk and
Ouyouk. For
thc following section of 900 km where its slope
is
still steep
(0,04
%),
three
plants are in service or being
developed.
1)
Sayano Shushensk under erection since
1963
(23,8
TWh);
2)
Mainsk probably under erection (3,4 TWh);
3)
Krasnoyarsk, in service
since
1978
(20,4 TWh)
[1.1].
These stations are remarkable also for their large installed output. Sayano Shushensk has
12
FT
with
222
m
head and a total rated output of 6360 MW (the fourth largest after Iiaipu, Guri
11
and Grand
Coulee
I-11-111).
They were built in the Leningrad Metal works (Leningradskij Metaliccskij
Zavod
=
LMZ) the greatest maker of hydro and steam turbines in the USSR. J)uring a visit to the
LMZ in Leningrad
(I
I years since his previous visit at which he saw the runner of Krasnoyarsk in
the
LMZ)
the author saw the model runner of Sayano Shushensk with about
600
nlm ol;trnost
diameter equipped with strain gauges for stress measurements. Simultaneous tests then had been
carried out on the model of the plant's ski jump spillway above the power house at the base of the
dam.
Lenbr
who,
by
the way, spent some years in Sayano Shushensk in his Siberian exile, tried later to
make up for Russian backwardness by coining the slogan "Socialism is Soviet power plus
electrification", which now can be read in the interior of many power houses in the
USSR.
2)
Krasnoyarsk:
12
FTs
each of 507
MW
at 101 m rated head. These turbines (Fig. 10.3.2) which
have been in operation since 1978 also were made at the
LMZ
and were for a long time the most
Po\vcrful water turbines and well known for their advaliced cast-wclded construction, and for the
watcr coolccl rotor
;id
stiltor of the alt~i.li;it~r.
A
r;ithcr srn;tli ruallcr tip di;im~-tcr rcsi~ltcd in
n
ncarly hook-fornictl runner v;tnc tvith
;i
ratlicr thick and round i~osc
and
;in i~ilct ;~nglc of tically
90'.
Thc
runner
of
350
311,
\vcight, wclded together iroin cast stcel huh and sliroutl scctions with siilmps
for tlic
14
vancs, was trans~~ortctl by
;I
special ship via the Lenio c;~n;il, Ice Occa~i and 11pstrt:nrn the
lcwcr
course
of the Ycnissci. Contrary to thc usual rccommcn~::itions, tlic numbil. of gates is an
integer
multiple,
n;lmcly twicc tlic runner vane numbcr. This tog~thcr with tlic ratlicr blunt runncr
vanc inlet edge parallcl to the shaft may cause a noisy operation of the scts; wliicli was also reported.
Another fca:urc is that the wcldcd spiral casing has
2
intakes (Dwuchnaja spiralnaja kamara) which
should obviously
lower transportation weights, but also may rcducc radial forcc and
secondary
flow
in
thc volute casing.
The
wclded shaft of
2,3
m diameter has a water lubricated lowcr journal bearing.
The Mitchell thrust bcaring rated at
3400
tons is supported by
a
conical trunk
011
the head cover.
The gates are opcratcd by two pairs of oppositc plunger servomotors, mounted on the hezd cover,
[2.35].
The exploitation of the middle Yenissei is yet to be carried out. The deve1opmei;t of the
lower Yenissei (1250 km with
0,006% slope) has been made in two steps: Ossinov and
Igarka.
Speirking of the harnessable potential of the Yenissei proper, has excludcd its greatest
tributary the
P.n_gara. This famous and only outflow of the Haikal Lake has a length of
1850
km
ar.d
a
drop in level
of
378
m
between Baikal
and
its conflue~lce with the Yenissci.
The
average slopc
of
the Angara is 0,02%, but the dc?th of the valley permits
development at
three sites having 76 to 106
m
head and at four other sites
with
smaller
liead.
The
lint
plant in service is Irkutsk with
31
m
head and
8
KT
of
82,5
MW
each
with vibrating oil
hcads above the a1terna;ors. Irkutsk serves pertly as an outflow regrlla!or for tlic Iiuge
700
kni long
rescrvoir of thc Baikal
Lnkz.
In a typical Soviet manner the spillnays werc built here as by-pass
outlets around the semi-spiral casing
and dralt tube of cach machine and act during spillage a; a
head enlarger by virtue of the hydraulic jump then formed past the draft tube outlet (see Fig.
3.3.2).
This
Tacilitatcs also thz deflection of ice floes during the very cold (temperature drops down to
-
59'C)
and long lnstiriy winter in this region of nearly
0'
average temperature.
On account of the large
specific
heat of water, the heat insulation of the ice sheet and thc heat flow
from the
ictcrior of thc earth, all the great northwardly flowing Siberian streams crossing about
1500
km of perrna-frost-soil do not freeze completely even in winter time whilst at the river mouth
there ere zones with
-
17
-C
average temperature.
3)
Bratsk: This is thz
next
station in service downstream of Irkutsk with an annual
production of
22
TiVh. This was the greatest station output before the inauguration of
Churchill Falls in 1970. After commissioning Grand Coulee
III in 1979, La Grande
2
in
1980, Sayano Shushensk and Itaipil (between 1985 and 90) Bratsk then will be the fifth
larsest plant on the basis
of
annual energy production. With respect to its output of
4050
MW
Bratsk was the most powerful station from 1962 until 1968 when Krasnojarsk
started. Now
it
is the fourth largest after Krasnojarsk, Gran Coulee 1-12-111 and Churchill
Falls.
Also the high voltage transmission of
500
kV
built with the assistance of Savoisiennc (France) was
the
first of this type. The
220
MW
FTs once were amongst the most powerfill, consisting of
icteg-ally cast runner hdvcs, bolted together on site with welded shzft,
and
having 14 runner vanes.
The
rescrvoir
oi
Bratsk with a capacity of
169
km3
remains however the largest artificial lake located
in the
midst of the nearly everlasting virgin needle forest of Siberia, the so-called Taiga.
It is closed
by
a
1500 m long and 110 m high gravity dam with a
400
m
long power house
on its
base (Fig 3.4.49). Owing to the time taken to fill the reservoir, energy production
of Bratsk started with
a
llalf filled basin. This caused
a
rather r,oisy stalling cavitation in
the midst of the rotor channel, which was eliminated by injecting air at the rotor vane's
inlet edge
12.361-
A
symbol of Soviet power, "victory of men over nature in concrete, the New Jerusalem
song of the poet Yevtushenko, the shop window of Siberia. Bratsk has been all of these
for the pioneers
of
its period of construction" says Heudrick Smitll [2.37]. But now other
giants have appeared.
In
the north of Bratsk begins the perma-frost soil. In this zone such work as tunnelling and digging
the foundation of dams and buildings becomes extremely difficult. Any larger construction in the
course of time melts the upper layer of
tlie soil by heat transfer, destabilizing its foundation. Such
troubles were envisaged at the northern sites of the Angara like Ust
llim and Bougatchany, the first
of which is being put to work the second probably yet under erection.
2.3.5.
The
Volga
(USSR,
European part)
With its length (3700 km) its catchment area (1 385 000 km2) and its average discharge
(8000
m3/s), this is the twelveth river in catchment area and the fifteenth in length [1.1].
Its slope within the harnessed section varies between 0,012 and 0,002%. With a mean
value of
0,04
%
it is one tenth of that of the Columbia. Its development will be made by
nine barrage power plants with heads between 11 and 24 m
of
which two remain up to
the moment only as projects. Its actual annual output is
29,5 TWh at 7100
MW
installed
.
capacity and its final values will be 393 TWh and 10270
MW.
The plant "22nd Congress" at Volgograd (formerly Stalinsrad) with a head
of
23 m is
the third low head plant
(H
<
30 m) in annual output (11,l TWh). The reservoir of
Kouibishev is the second largest artificial lake in surface area (6450 km2).
Inaugurated in 1960 with its 22 KTs of
1
16
M
W
and 9,4 m runner diameter, the 22nd Co~~gress plant
has had for a long time the largest Soviet manufactured huge
KTs with the largest runner diameter.
In
Western
KT
plants the runner diameter is only up to 8,4 m, e.g. in the
4
-
70
MW
plant "Asch-
ach", Danube, Austria. The actual largest runner diameter in the
world of a KT is 11,3 m at the
Chinese
Changjiang plant Gezhouba
(P
=
2
-
178
hlW,
rated head
18
m, maximum head 27
m).
These machines are similar to Western design (e.g., runner servomotor with movable cylinder under-
neath the blades) and operate smoothly. Moreover Gezhouba has KT sets with
10,3
In
runner.
The original Volga plants were provided with fish passes about 9 m in length in its
casings, to enable the migration at spawning time of the big Volga sturgeon, the Beluga
(Accipenser huso), which reached a length of
9
m [2.38]. This is the producer of the Beluga
Malasol (mildly salted) Caviar, a valuable export for foreign currency. But now, when the
size of runners has grown up to
9
m the Beluga when ready to spawn is reduced to 2
m.
(Note animals inversely proportional to machines!)
2.3.6.
The
Zambesi
(Zimbabwe, Mozambique,
Africa)
The Zambesi has the third largest catchment area (1 330000 km2) and discharge
(3500
rn3/s) in Africa, and is the forth longest there (2660 km). Its catchment area is at
rather high altitude half
of
its course being above 500 m. But it lies also in an area with
26% less rainfall than the Russian Angara, namely 2,81/s/km2. Downstream of the
steeply inclined reach following the Victoria Falls
(0,16% along 250 km) it has a mean
slope larger than
0,04
%
.
The
slope is even 0,07% over the 250 km long reach
now
suemerged by the reservoir of
Cabora Bassa. There are two large barrages: Kariba (125
m
crest height) in Zimbabwe
(forrnzrly
R
11odcsi:i) and Cabora Bassa
(1
60
m crest height) in Mo;:ambicluc forming two
of
the Iargcst artilicial storiigc basills in volu~nc, surface area and Icngth, n;l~ncly:
Karibri:
160
km',
5180
km2. 280
krn.
Cnbora Bassa:
60
kmJ, 2700 kn12, 250
km
[I.1].
The Ilarncssablc potential
of
the Zambcsi (130 TWh)
is
of
the same orclcr as that of the
Yenissci
(140
TW
h)
because
of
its highly elevated area. But the devclopme~lt
of
these
resoitrces has n~~rnci-ous political problems.
The
Cabora Bassa station which is shown in Fig.
3.4.55,
and whose energy
is
mainly
exported to the South
African Republic, has to date been constructed in its first phase
only
(power house on the southern river bank) with
5
sets
of
415
MW
resulting in
a
capacity
of
2075
k1W.
The rated discharge is 1974
m3/s
(average discharge there
2750 m3/s).
Hencc the spillway
of
the ski jump type is to operate nearly continuously. The
18
TWh annual output is the largest in the southern hemisphere and Africa. The specific
initial cost in
1974
was
180
US$/kW.
The Francis turbines (FT) of the first phase were assigned to a French G~rmiin syndicate (Neyrpic
Grennhle, France
and
J.
,\I.
C'oich,
Hcidcnheirn Fed. Rep. of Germany). They
arc,
by their rated
oulput of
415
b1W.
the most powerful turbines ever built in
s
Wcst Gcrnian workshop. At
a
rated
head of
113.5
m,
thcir runncr diameter of
6,56
m is rclativcly small. This results in a runner weight
of
165
Mp, modest cc.nlparcd with the
1GOO
hlp of its alternator rotor (see
Fig.
3.4.16).
N-
t\trthclcss
..,
these \\eights and dimensions were beyond the transportation f:icilitics in Mozam-
biqirc. Therefore the runner made in the workshop of a European firm, was split along a plane
cormal to thc axis (see Fis.
2.3.6).
The upper vaned part was integrally cast with thc' hub from
stainless steel
117?/o chrome,
4%
nickel). The shroud was welded from integrally cast pieces made
of
stainlcss stcel (13O/0 chrom,
14%
nickcl). The lower part of thc runner vanes was cast from the
satns
htainless steel as the shroud.
Fig.
2.3.6.
4
I5
XI
W
Francis runner of CaSora Bass?. Zambezi, Mozambique, Africa, on two column
lathe in Voith \vorks. Heidcnheim, West Germany, split into two halves for transporting. Note flaps
to retain good
iilignrncnt. Runner: weight
165
tons, throat diameter
(scc
also Fig.
3.4.16) 6,56
m.
Designed and n~anuf;tctured in close collaboration by
J.
M.
Voith, l-leidenheim Wcst Germany and
Neyrpic, Grenoblc. France. (Photograph courtesy
J.
M.
Voith, Heidenheim, West Germany).
After linishing,
it
\vns welded to the shroud. For assembly bcfore and after transport. the vnnc at thc
joint of both scctions were equipped with flaps. latcr removed. The welding of the
t\\a
hnlves
of
the
runner on site was followed by static balance and finish. Normalizing rvns not required.
Because of the long distance of 1400 km to the main consumer in Pretoria (South African
~epublic) a high voltage DC transmission of 1000 kV was provided, based on thyristor
technique. Strictly speaking, a DC of
1000 kV has
+
500 kV against earth.
On
account of the cost of converters at both
ends
of the
line
the application cif
DC
trans~nission is
only economical
lor
lines longer than
500
km without an intermediate consEn1er. Therefore the
transmission of Cabora Rassa can be considered as typical for the further developmsn: of ri.ater
power
in
remote areas
[2.39;
2.401.
2.3.7.
The
Danube
In harnessed potential (43 TWh), length (2850 km), average discharge at its mouth
(6400m3/s), the Danube ranks second in Europe, behind the
Voles (for comparison:
Rhine,
14,7 TWh, 1300 km, 2200 m3/s). Its harnessed potential is about 30
TWh.
1:s
catchment area is 817 000
km2
(only 133
%
of the Amazone's).
The Danube comes from the confluence
of
the two small rivers Brez and Brigacl~ Ilvhich
have their sources in the German Black Forest)
st
an altitude of 680
m
near Dn~~zu-
eschingen (Federal Republic of Germany). It starts passing the Jura mountains at T'utt-
lingen where at low water it seeps completely into the ground then feedins the catchment
area of the Rhine by the Ache at Lake Constance (altitude 390 m). Throush its passage
through the Jura (about 200 km long) it continues ;o lose water up to
its
confluence
piqt
with thc Iller near U:m. In consequence of the seepage into Jurassic ground, the first
269 km long reach of the German Danube with its available head of 335
m
cannot be
economically exploited. This is reflected by the small installed capacity of only
7
h4W
along this reach.
Here the
Iller, its first Alpine tributary has
a
much larger discharge than the Danube.
Hence any effective harnessing of the Danube starts from here at an altitude of
477
m.
Over the next 378 km of the German and finally the mixed German-Austrian
sectian up
to Jochenstein, the Danube has a mean slope of 0,045
%
and
a
drop i!l level of
175.2
m.
A
cascade of 24!4 power stations with an annual output of 2,64 TWh and an installable
capacity of 430
MW
is planned along this reach. 19
!4
stations are already ir, service.
In the following Austrian and finally mixed Austrian and Czechoslovakian
seciion of
330
km
length the Danube has a mean slope of 0,043
%
and a drop in level of
149
m.
12
power stations are planned with an annual output of
14,6 TWh and an installable capa-
city of 2402 MW. To date
3%
of them, namely Jochenstein
(by
72
of its production),
Aschach and
Wallsee Mitterkirchen and Ybbs Persenbeug are equipped xith vertical
shaft Kaplan
turbines and the residual plants with bulb turbines. Altogether they have
an annual production of
8,75 TWh and an installed capacity of 1450
MW.
In the following mixed Czechoslovakian-Hungarian section the river's slope falls to
0,006
%.
Therefore any passage of the Danube at low water beconles difficult.
To
improve
the navigability, the river is diverted
into
a
142 km long channel.
A
drop in level of 51 m
is used by 2 channel power
stations now under erection: Gabcikovo and Nagymaros with
an installed capacity of 850
h4\V
and an annual output of 3.98 TWh.
The following Yugoslav section
of
the mean Danube of 436
km
length with an average
slope of 0,00624 and a drop in level of 27 m will be used by the plant Novi
Sad
with
i.5
-1'\\'Ii
;ill;!
!'
-
3FO
k\'<.
;I(I.LYI~~
priijcctcd.
111
the next nlixe<i Run~;rni:t~t ;~r;d Y11gc;slnv
i'c'c;~o!i
of
II!~
I;~C;I~I
l);~~li~l>~. 40:!
krl~
long, the drnp in lcvel
is
42.5
m,
and tllc slopc riscs
l~cc';~\io~:;~~l'
!o
:).O.:
",,
:I[
II~C
site
of
the Ir~n G;~tc
I
(Yugoslitvia's Djc.1-cl;lp, Rum;lni:~'s
!'ortc i;crilt:). 'i'lic
Ir-011
(;;tic
I
~>l;tnt, cquippcd with vertical sli3!;1 liaplali turbines, has
'ncc.11 c)pcr:i!ing sincc
1070.
'l'hc Iron Gate
11
plant equipped wirh bulb turbines, is now
UIICICT
crcciio~l.
T'hc
folloi\.111g
4Si)
k111
long
mixcil Yugoslav, Buigarian
and
Rumanian scction with
a
level
drop of21
rn
\\-ili
havc
3
pl~ints ecli~ippcd with bulb turbines o;lly projected, with
9.2
TWh
annil::~l ou!put ;111d I30U
IMM'
installed capacity altogether,
[2.41].
The Inst secliot~ cannot
be
harnes~cci.
11
burdcrs
on
the
USSR.
-rIl~'sit~
of-
the
11-or;
Gats-
1
[2.42]
with
an
al~nual output of
11,4
TWh
ancl ;In ins!a!led
ctlpilcii~
:>f
2140
31\V.
is
tile
biggest river powcr
plant
in Europe with
the
world's most
powe;iu:
K;i;2ian
!i~l'bincs
of
1%
MW
unit output.
This
turb~nc
i-.,I.
a
runncr dlumctcr of
9,5
m.
It is
the
3rd largest in thc world lrftcr thc Chinese
Gc/hoab.~
t~:r!:~nc\
I
I
I.?
rn)
and thc Russian Sarntov
turbines
(10,3
m).
It
was dzsigncd
by
LMZ
:I.er:!ri~rati~1,1~ n~cl,lllcc.\I\~j labod
=
1-cningrad hlctal Works).
1
hrec
of
the
6
Rumaoian units were
iclb:lc;~tcd
:n
rt~t.
KC>I!:I
LVorhs
I.
Rumsnia. According to the author's im~rcssion :hc turbines
t-ig,
2.3.7.
Lo~igitudinal sccrion
of
the power house and Kaplan turbir~c set at
the
Iron
Gate,
D.lnubc. RLII~I,II;I;~.
i'l!s~~i;~\.iit
(owner
6
sels Kumanian Atate power board,
6
sets Yugoslavian state
r
1.
H
-
2
1.6
to
35.46
ni:
11
:=
7
1.5
rpm;
P,
=
178
hl
W;
12
sets
dcsigned
by
1-eningrad
rnc1~11 \\nrhs
(l.\IZ1.
3
SC~S
n~an:~fnc*urcd
by
Rcsitn Works. Runlania (Drawing courtesy Resita
\\'orl,s.
R
urn~nir~).
62
operate
rather smoothly, but some of thc Rumanian units suffered badly from cnvitation pittins after
one year of full load opcr:ttion, sec Fig. 10.2.7.
The power houses on each river
bank
each have
6
vertical shaft sets with Kaplan turbines
of
6
runner
blades
[2.42],
(see
Fig.
2.3.7
and Table
2.3.3).
Table
2.3.3.
Data of
the
Iron Gate plant (Rumania, Yugoslavia).
Mechnnical
equipmolf:
Designed by
LMZ
Leningrad.
3
sets machined at Resita Works Rumania.
The power house on each river bank has each 6
vcrtical sets with Kaplanturbines each with
6
runner
vanes.
largest net head
35,46 m
.
rated head 27,16 m
smallest head
21,6 m
head for
tcmporary operation 10- 18m
rated discharge 732 m3/s
rated
output 178 MW
rotational speed
71,5 rpm
ruaaway speed 180 rpm
guaranteed efficiency 94
%
runner tip diameter 9,5 m
total weight 1400 t
control system oil pressure 40 bar
maximum crane capacity
2.400+2-160t
Generators (three phase,
50
Hz)
rated output 190
MVA
voltage 15,75 kV
power factor 0,9
guaranteed efficiency 98,2
%
total weight 1300 t
transformer voltages
15,751220
kV
and 220/400
kV
Spillway:
14
Double hook sluice gates for discharging 15 500 m3/s width 25 n~ height 14,s
m.
Volume
620000 m3 concrete,
separalion abutment thickness:
7
m.
Maximum width:
440
m. Maximum height 60,60 m.
Barrage:
Type: Gravity dam. Length of whole barrage inclusive of power house 1100
m.
Power house type: Tall hall. Number: 2. Length 210 m. Maximum height inclusive draft tubes:
84,2 m
Storage basin
:
Maximum length: approximately 200 km (backwater reaching upstream of Belgrad).
Inundated area
101
km2.
Reconstructed roads: 160 km.
Reconstructed railroads:
24
km.
Historical sites such as the table of
Trajan, the city of the Island Ada Kaleh have been conserved
in a museum.
Volumes:
Excavation cf alluvial soil
18 000 000 m3
Rock excavations 5 000 000 m3
Concrete simple reinforced
3 200 000
m3
Earth dam
5 000 000 m3
Rock dam
2
500 000 m3
Electromechanic equipment 68 000 t
Costs at European level
395 million
US$
*)
From
a special issue
on
the
Iron
Gate
Plant
of
the
Resita
Works.
Rumania.
A
rcmarkablc fc;l~urc of this plant is the rather large ilrca of 101
km'
of m;~inly ar;rblc ant1 iiillilbit~d
lalid. wii~ch
\\>as
in[tndatctl
by
darnm~ng the D;lnubc. New
IIOIISCS
Ii;~d to be bltilt f<>r
32
931
pcrso~is,
160
km
roads.
2.1
km ritilroad lines mainly
in
tunncls
arid
on bridges,
and
7
I~;~rbol~rs
1i;rtl
to be
rcconstruc-tctl. 18% of thc tot;ll co~t of
395
millions of
US
$
h;~d
to
be
k.r;~ikl
for indcmnilic;~tion alld
ground acquisition. On the Dunubc see also I2.46 to 2.491.
2.4.
Exceptio~lal sites
2.4.1.
Churchill
Falls
(Churchill
River,
Labrador,
Canada)
Nearly the wholc plateau of Labrador is drained by the Churchill River. At a distance
of
300
km from its mouth
it
eats into the plateau over 35 km as a deep gorse with
il
mean
slope of
0,9'%.
This contains tlie Churchill Falls with a drop of
75
m. For this latitude
the precipitation is remarkably high (20 I/s/km2).
According to
Corillo,~
[I.
I] for this catchment area of
79
000 km2 only the Italian Po has a greater
figure
namely
22
Ils/km2. The mean discharge
(1600
m3/s) is modest.
In
drop of Icvel along tlie
developed river section (323 m) the Columbia, Parani and Angara arc nearly equal.
The discharge and spillway operation of the Churchill Falls is nearly completely regu-
lated by numerous lakes of glacial origin regrouped into one lake of nearly five times the
original surface area by the construction of small earth-filled
dikcs of 10
In
average crest
hcisht and a total length of
64
km. U~lder this the Smallwood reservoir
(25
300 hm3) can
be
distinguished, mainly constructed to divert the drainage of many of these original lakes
from the Goosebay river system into the Churchill. The exploitation of the available head
of
323
m
is made by one single power station. The energy production started in 1970.
With its
anr?ual output (34.5 TWh), Churchill Falls headed until 1982 all the power
stations
in
the lvorld. Now La G~.ande
2
heads with 35,8 TWh. Work has also stzrted on
another deveiopment, Gull Island (1800
M
W,
12
TWh)
200
km downstream of Churchill
Fa!ls.
In the words of
Corillo~t
jl.11
the high head of 312 m, the elevated precipitation rate, the
nearly complete regulation of the discharge by one tremendous reservoir, the topographic
conditions which reduce nearly all
?he civil engineering work of storing and
collection
render Churchill Falls an exceptional site 12.431.
-
Data of site: Annual precipitation 765 mm. Temperatures: Range
-
48°C
to 30°C. avcrage
annual
-
4
-C. Topography: 396 m to 580
m
altitudes. Hills rise 150 m above thc plateau Icvel.
Watzr level lo\\tr Churchill River gorge at
power
site
129
m. Vegetntion: Shallew muskeg and
irregular spruce forest. Surface Geology: Irregular deposit of silty sand, gravel and boulders
in
random thickness up to
12
m.
-
Data
of
plant: Dikes: Number
88.
average height 9
m.
maximum height 36
in.
longest 6041 m total
vol~~mc
~f
material used 20
-
lo6 1n3, largest volume of
a
single dam 1,95
.
10%'. Reservoirs:
Smallwood
and
OssoLmanuan with
65
000
km2
surface,
31
100
hm3 storage volun~e, 6510 m3/s dis-
cli.~rge capacity.
58
SO0 m3 concrete.
-
Power installations: Gross head
323
m,
11
units with
=
47.5
MW.
Vertical
FT,
spiral
casing
embedded in concrete without shut off valve
on
the inlet except for the gate at the
penstock intake (see Fig.
2.4.1).
Wicket gates operated by a pair of servomotors opposite
each other on the pit wall. Thrust bearing supported by conical trunk on head cover. Two
journal
bzarinss. Runners from Dominion Engineering with vane leading inlet edges
parallel to the shaft. from Marine Engineering (licensee of Neyrpic) with dihcdral angle
to cut more smoothly the wakes past the gates.
Fig.
2.4.1.
Schematic 1ongitudin:ll section of plant and power house Churchill Falls, Churchill K,r,cr,
Labrador, Canada (owncr Churchill Falls corp.)
11
sets with FTs designed
by
Neyrpic Grcnoble,
France and manufactured
by
hliirinc Engineering Canada and Dominion Engll;ccring,
H
=
3
I:!
m,
n
=
200
rpm,
P
=
483
MW.
(Drawing from I'ublic relation office Churchill Falls
Co.)
According to tests carried out by Nctsch, the design with inlet edges parallel to the shaft is noisy
[2.44].
The compact design. thc el:~stic response of its stationary welded parts to wakes past the spiral
tongue, stay and guide vanes, and
thcn cut by the runner vanes, the concentration of losses on a
cylinder of about
6
m
diameter. first
or
all due to vortex generation. these altogether
create
such a
noise in the turbine pit,
that
tllc usc of
ear
plugs is imperative and hence a special noise, caused
by
damage, is hidden from the human eilr.
Other details are the gatc lcvcrs with brcitki~~g bolts. This is a rather risky device in a turbine with
no shut
off
valve with such a long
penstock.
The obvious saving of this omission has been balanced
by the planning
staff against thc possihlc d;lmsge under
a
sudden load rejection, simultaneous
reaction of breaking bolts and subsel~ucnt runaway.
The
bottom of the elbow draft tubc is
3
tinlcs thc runner throat diameter underneath the throat to
prevent
the entrance of air from the sllrpC cll:~n~bcr downstream by a level drop under a sudden load
decrease. The
whole machine is
a
very co~lIp;~ct dcsign. Pertinent data see Table
2.4.1.
Elevation
see
Fig.
10.3.3.
Energy transmission: By transfc~rmcrs
in
two
stages from
15
to
220
kV
in underground
transformers
and then
by
tr;\nsfdrtilcrs
in
the
outdoor switch yard up to
735
kV
for the
1200
km distance to the next corlsutilcr.
In
urlpopul~lted areas the towers have only one
abutment on the earth kept
in
t~prigflt
pclsition
by anchored cables.
-
Townsite: The remote
area
necdcd lllc
~rcction
of
a
townsite with an airport offering
a regular
air service to Montreal,
1100
di~(il11(.
The
permanent town site, which was
T'ablc
2.4.1.
Dcsign
data
of Cliurchill F:~lls
po\vc.r
plant.*)
Turbines: <;enerators:
Rated net head 312 m Itatcd capiicity 500
000
kVA
Ratcd output 483
MW
Rated voltagc 15
kV
Rated speed 200 rpm I'owcr f;~ctor (ovcrcscitcd)
0,95
Runaway speed 330
rpm
Synclironous
reactance
100
%
Scroll case inlet diameter 4,45 m Transient re:lctancc 33
%
Runner inlet dinmeter 5,82 m Jncrtia constant 3.47 min
Runncr throat diameter 4,30 m ltotor diamcter 9,ll m
Runner weight
77,l t Rotor wciglit 576 t
Total weight
907,O t Stzitor core depth 2,98
m
Total weight 1020
t
Penstocks:
Number:
1
I.
Length 426 m. Internal diameter-concrete lined: 6,l
rn.
Internal diameter
-
steel
lined: 4,45 m.
Powerhous:::
Maximum length: 296
m.
Maximum width: 24,7
m.
Maximum hcight: 45,l m.
Surge chamber:
Length: 233
m.
Width (varying): 12,2 to 19,s m. Height: 45,l
m.
Ven! shaft:
Diameter:
6,l m. Depth: 253 m.
Tailrace tunnels (unlined):
Number:
2.
Width: 13,7 m. Height: 18.3 m. Average length:
1692
m.
Trltnsformer gallery:
Length: 261 m. Width:
15,2
m.
Height: 11,9
m.
Cable shafts:
Nuinber
6.
Interi~al diameter: 2.13 m. Average depth: 264
m.
*)
From a special publication of
the
Churchill
Falls Labrador Corporation,
New
Foundland, Canada.
utilized
by
construction stan initially, provides housing, shopping, medical
and
security
ser~ices for the residents. Accommodation is provided. For the population
and
the public
a
conservation programme was implemented to preserve and protect the natural cnviron-
ment.
Penrtanent residents number about 900.
Of
these one third are for the maintainance of thc access
roads, the roads to the airport and the airport itself, another third arc employed in plant operation.
The remaining third are employed in the service sector and on the
plant as white collar workers. It
seems advisable to operate in
such
a
remote area even
a
highly automated plant with a staff of white
collar men capable of operating the plant by themselves
in
an emergency.
-
Financing: Cost estimates established the capital required to complete the development at
936
-
lo6
US
S.
To meet this requirement the largest fi~~ancial assistance ever undertaken for
a
single
industrial enterprise was negotiated.
2.4.2.
Inga
(Zaire,
Congo)
Africa
Due to its second largest catchment area
(3
800
000
km2)
the rather high altitude
of
this
area
even'in its lower course and the high precipitation
(30
I/s/km2) the Zaire (Congo) has
the
largest harnessable potential
(700
TWh).