Raabe J. Hydro power - the design, use, and function of hydromechanical, hydraulic, and electrical еquipment
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~hcrefore Tables 1.3.1 and 1.3.2 contain also this capacity and its development. The tables contain
also
the
load factor
rp,
as the portion of
full
load hours the plant makes in the average year.
From Table
1.3.2
it is seen that the installed capacity tends to be relatively larger in aieas
with
a low precipitation, e.g. Australia, or large catchment areas, e.g.
USSR,
USA,
or with
an
irregular hydrograph varying with time due to, snow fall, melting period or Inonsoon
(Spain, China, India). It will be smaller in regions with smaller storing facilities, more
continuous rainfall, smaller reliability of peak load demand on hydro power (Norway,
Canada). In general an increased capacity installed may lead to
a
smaller load factor
cp.
In
storage plants this factor may drop down to 0,l.
1.3.2.
Distribution
of
harnessed and harnessable potential
Table
1.3.3.
Countries with the biggest usable potential (estimate in 1974) from
Cotillort
[1.1] and their potential actually used in 1980 from the Yearbook of World Energy
Statistics, United Nations
[1.77].
-
Country
Usable potential
Used potential Percentage of
TWh
TWh
usable pot.
-
1
China
2
USSR
3
USA
4
Zaire
5 Canada
6
Brazil
7
Malaysia
8 Columbia
9
India
10
Burma
11 Vietnam and Laos
12 Argentina
13
Indonesia
14
Japan
15 Ecuador
16 New Guinea
17 Norway
18 Cameroon
19 Peru
20 Pakistan
21
Sweden
22
Mexico
23
Venezuela
24
Chile
25 Gaboon
26
Spain
27
France
28
Yugoslavia
Sum
Other
countries
T:tblc
1.3.3
diows thc distribulion of harncssccf and h:trncss;ihle porcntinl of thc
28
cnunlrics that pvsscs
S
1,5
'%
of' tlic harncssablc potcntinl
11.
From this
~t
is sccn,
tli;lt
the
I'coplc's Iicpi~tdic
ol'
Chinil, thc cv~i~itry with the largest harncs~blc potential
ill
thc
world of 1320 TWII, in 197.1 has h;irnessctl only
4.22
%
of this. According
to
Corillort's
cstirn;lto [].I]
wtli
growth rutcr of 14,2% up to
1985
and then
8?:,
China should have
liarnesscd roughly
26%
of
IJ
by tlic ycar
2000.
This would need the installation of ncnrly
4600
MW
per ycar of new hydro power, a figure that Chinese turbine makers cannot cope
with and that \\r:~tcr turbine riiakers of countries other than China shoulrl bc pr~pi~rctl for.
Table 1.3.2
2it.c~
an
idea of hyc!rc, power development
of
the aeturll lnain
producers
of
hydro
power during the period 1974 to
1980
according to Cotilloll [I.]] and
UNO
report
[1.77]. Assuming a nienn load lactor of
0,4,
it indicates in this decildc a mean annual
growth of
institlled capacity in hydro power
of
11
00
MW
for the whole world.
The following authors clcscribe this development in some countries, namely
Gnrsrkcl
[I .3] and
Gillette
11.20) in the
USA.
Borol.oi
[I .9] in
the
Soviet Unicn,
I.Veher
[1.21; 1.231 and
Goldst,rith
[I
,221 in
S:vitzerland,
S~llil
!
1
.j; 1.61 and
Koh
[1.24] in the Pcoplc's Rcpublie of Cliin~,
Fiill.striim
(1.251 and
.4rtgelin
[1.26] in Sweden,
,4al:o
[I
.27] in Finnland,
Mornrill
[I .28] in Pcru,
Orcrr~rns
[1.29] in Columbia,
Bicho~l
[1.30] in Francc.
L)o~~tcrcq
(1.311 in Spain,
Jegannthon
[1.32] and
Du!rtl
[1.33] in India, and
Giirz,
and
Schillrr
[1.1 I] in Austria [1.34].
Recently also small hydro power has gained interest, which is shown by the publications of
Golrbel
[I
.35],
Frnnc-oil
[I .36],
Clrinar
ar?d
Kolissel
[1.37],
Rouper
and
le Plonlb
[1.38],
Kiissler
[I .39],
Gortlon
Table
1.3.4.
Distribution and development of harnessed potential referred to har-
liessatle potential over the large geographic zones ot' the world [].I].
Zone I-Iarnessablc Harnessed
%
of
a
1-larncsscd
O/u
of
a
I
larnesscd
%
of
a
potentiill potential potential potential
a
b
c
d
e
f
g
TWh TWh 1974
TWh 1985 TWh 2000
Europe
\i.iihout
USSR
700 402,3 65
%
520 73
%
560
SO
%
USSR
1100 132 12
%
230 21
%
550 50
%
C~reznland
65
0 0
?
?
?
?
Canada 535]i235 212.5
39,246
'W\
5"0}53?4 900 73
%
USA 700 304 43,5% 353,6
50
%
Japan
130
82,3
63,4
%
117
.90
%
117 90
%
China I320
35
2,6
%
153 11
%
350 26,5
%
Latin
America
Africa
Asia with-
out Japan,
China and
Siberia
Oceania
and
Australia
and Penma11 [1.40],
Kijzg
[1.41] and
Colillon
[1.42]. For more information about small hydro poHer
scc cap.
3.5.
In this contcxt Nair's paper on the \ievclopment potential for low head hydro
is
of
interest [1.43], and the paper of Warnick on the hydro potential of irrigation schemes [I..W]. The
of hydrograph arid flow duration line is discussed by Tomasi~lo [1.45] and
Plnre
[1.46]. In
this connection also Press's book (1.471 dealing with electronic computation in hydrology and his
tables
for the solution of such problems [1.49] and the computer program for a river development
presented by Murry and Wrissbeck [1.48] are of interest.
Table 1.3.4 shows according to
Cotillon
[1.1] the developement of hydro power in 1974,
1985 and 2000 over the large geographic zones.
Table 1.3.5 from
[1.1] and [1.77] refers to the annual electric energy production
H
to the
total electric energy production
E
in 1974 and 1980 for the most important countries
with
Table 1.3.5. Hydro electric annual energy production
H
referred to total energy produc-
tion
E
of the most important countries with respect to
H
in 1974 [1.1] and in 1980 [1.77].
State
H
(TWh)
E
(TWh)
HIE
(%)
1974 1980
1974 1980 1974 1980
-
--
Canada
USA
USSR
Brazil
Japan
Norway
France
Sweden
China
Italy
India
Switzerland
Spain
Austria
Yugoslavia
North Korea
West Germany
Australia
New
Zealand
Mexico
Finland
Argentina
Venezuela
Columbia
Mozambique
Turkey
Pakistan
Egypt
Zambia
Portugal
Peru
Chile
Grcat Britain
Czechoslovakia
Zim
b;t
b~vc
7~irc
rcspcct
to
11.
Citing the r;~tio
11,/1:
of this tablc
in
brackets. the l'ollowing countries are
saturated
in
11.
Thcir
hrlrncsscd
potc~~tiiil ncnrly cqu;~ls thcir ii;~i-nsssnble potcntinl:
Switzcr1;lncl (0,70), Fr;:nce (0,27), Italy (0,26), Spain (0,25).
Thc followirig col~ntries show a continuoos growth in hydro
power:
(HIE
=
0,993, Sweden (0,64),
Austria (0,69), Yugodavii1(0,48), Finland (0,4 I), I'ortugal(0,53),
USSR
(0.14). India (0,4), China (O,tS),
Hra1i1(0,92), hlcxico (0.25). Venczucln (0,47), Columbia (0,67), Chilc (0.64). .Argentine (0,37), Australia
(0,18), Canada (0.6Y), Peru (0,78), Pakistan (0,651, Mozambique (0,96), Zimbabwe (0,89), Zaire (0,31),
Turk ev (0,49).
Thc followin_e countries have a very low water power
HIE:
Denmark
(I-IIE
=
0.001) Hungary (0,00S),
Bclgium (0,011). German Dem~cratic Republic (0,014), Great Britain (0,OlS). Czechoslovakia (0,07),
Federal Republic of Germany (0,05), Bulgaria (0,097), Ireland (0,lO).
P.ccording
to
the cstimate of a West German firm the degrce of exploitation expressed by the ratio
of installed
hydro power to installable power has actually a world mean value of 8,6
%,
of which 62
%
iirc in thc open market. For the individual regions of the wor!d this exploitation degrce reads as
follows: Europe
39,9%. Asia 5,5%, Africa 0,8
%,
Latin Amcrica 3,9%, North America 26,5%,
Australia, Oceania 4,6
%.
1.4.
IIydroelectricity,
its
development
1.4.1.
Past
and
future
of hydro power
in
the context of other power
Table
1.4.1
shows the development
of
primary energy, electricity and hydroelect~icity
consurfiption
du~.ing
the past 60 years and its prcdictio:~ for the nest
15
years on the base
of
a
5% growth rate within the worlci. In this context the ton equivalent of
coal
TE
-
30CO
kLVh
is
used under an assumption
of
33%
efficiency
of
the
generating cycle
a11d
using pit coal.
Hence
thcre h2s been durinz :he past 60 years
a
population growth of2,45 times, a growth of primary
cncrgy consumption of
8.55
times, a growth of prodl~ced electricity of 60 times, a growth of
h\droelect;icity produced of
28
times, a growth of kWh consumption per inhabitant pcr year by a
facror cf
24,!
and a growth of energy consumption per inhabitant per year by
a
factor 3,46. This
shows a
strong de:.c!opmen: over the ivhole world combined with a sl~ift towards electricity con-
s~iilptio~~, bee [1.1].
Table
1.4.1.
Development of primary energy, electricity and hydroelectricity consump-
tion
of
the world L~etween
1925
and 2000.
From
Cotilloil
[l.
11.
Item Unit 1925 1950 1963
1974
1985 2000
Primary energy
e
Produced electricity
E
Ele
Hydroelectricity
H
HIE
H,'e
=
IJjE
-
E/e
World population
kWh per inhabitant
TEC per inhabitant
lo9
TEC
!09
TEC
TWh
Yo
TWh
Yo
%
1
o6
k
Whjinh
TEC/inh
1.4.2.
Cost
and
social problems due
to
electrification
Table 1.4.1 reveals the availability of nearly 5000 kwh annually in every man's hand in
2000. According to the tests of occupational physiologists, the average male worker
between 25 and 45 years of age may perfoin during the 8 working hours of a day a
continuous output of 50
W.
Hence the annual work over 220 working days, the West
German year, becomes
W=
50 8
-
220
-
10-
=
88 kwh. The corresponding female
worker may perform 66% of this work. Assume the duration of the remaining average
life to be 40 years, during which only 50% of the specific work mentioned above is
performed, and imagine the population to consist only of 30% of blue collar workers.
Hence the average work
per inhabitant and year is
W=
88 [(0,5
+
0,66
-
0.5) (0,33
+
0,3
.
0,66)] 0,3
=
14,s kwh. This is for the year 2000 a fraction of 14,5/5000
=
11345
of what is offered per inhabitant by the electric grid. Imagine 345 workers are then
available for every person from birth to death by a mere touch of an electric switch.
Following an undesirable but convenient trend, it
may be imagined, that in the year 2000
two thirds of electric energy are used for heating, especially in the chemical industry.
Hence the average person in 2000 has roughly "only" 115 men available as mechanical
helpers. Obviously this is a key for understanding the wealth produced in an electrified
world.
For a drastic example of the cheapness of electricity, assume a consumption of 8800 kwh per
inhabitant per year, a figure some of the developed states have at present. Maintaining this figure
needs the installation of
1
kW continuously available per inhabitant. The blue collar working
population is possibly 25% of the whole. Electricity may be supplied by thermal power plants
with
a load factor of 0,5. Thus the monetary equivalent for a working inhabitant would be that of
8
installed
kW.
30% of this might produce mechanical work.
Assume that the first and fuel cost per year are raised by the sale of energy. Hence in the above plant.
an electricity rate of
0,04 US $/kwh would result in an annual cost of 1400
US
%.
This figure is to
be
compared with the annual wages of 800 blue collar workers as equivalent to the 4
-
8800 kwh.
Assuming now an annual salary of
9000
US% for the blue collar labour, this yields 800 9000/140(!
=
5140 times more than the total cost of !he equivalent electric energy. Moreover electricity creates
wealth made otherwise by 5140 workers. This procedure leads on the one hand to the production
of things never done in the era before electrification.
On
the other hand it feeds a growing number
of people in the less productive service sector.
1.4.3.
The
future of hydroelectricity
As shown in Table 1.4.1, hydroelectricity
H
referred to total electricity
E
is slowly de-
creasing from 20% to 14% in the period of 1980 to 2000. During this period
H
has
reached a nearly constant portion
of
5,5
%
of primary energy. This has something to do
with the rising transfer of heating by fuel to electric heating.
It is seen from the above table that the annual energy
prodsction of hydroelectricity
should rise during the period of 1974 to 2000 by 2500
TWh. With an average load factor
of
cp
=
0,5 this would mean that the hydro turbine manufacturers of the worla need to
enlarge their workshops for the production of machines with an output of 570000
MW.
What this means may be highlighted by the fact that in the foregoing 15 years from 1970
to 1985 hydro power production has been increased by
1100 TWh, namely, less than half
the value it will increase over the following 15 years.
Certain problenls arising from this may be eliminated when the fabrication of large hydroturbines
is transferred from the workshop to the site. But nevertheless large machine tools and transportation
21
faciliiivs
II~~I~I
I7r: ~.rrov~tlctl Tor tl~is incrt:n:;c.
Sornz
ccntrcs of _er;~vity
or
wiltcr powcr like South
Anicrica
ni;ly i~i:,ists
II:;II
;I
lit~nlc intluslly
:or
w;ilcl
Ootvcr cil~~i~;ltcl?t
is
crcctcd in llicir own
countries.
I1u1 [his cill)
hc
i1011c only with tlic cunlrr\\~ctl llelp
of
dcvclopcd cin~ntrics.
Sirlcc the not Iii~rncsscd potcntinl is ortcll
in
ai.c;\s
Iiavitig ~~citl~cr powcr
dcmriiitl
nor
po!itical stability, thc dcvclopmelit
or
large schcnle$ there sulTers milinly fl-om
a
lack
of
obvious
utility
and
immediate
profit.
1.5.
Hydro
power,
its
actual
dimcosions,
developme~~t
ond
features
1.5.1.
The
larcest structures
found
in
hydro power at present
111
Table
1.5.1
the figures
of
some important feattires of thc largest water power plants in
the world
are mentioned.
Table
1.5.1.
Some
important [eatures
of
the wurld's l;~l-gest hydro power plants.
Frorn
CcriNotz
[1.1].
Tlle highest dams in scr3;icc (crest height)
Nsurek in T~dshigiskan near Tashkcnt
(USSR):
cart11 danl
317
m
Grandc Dixence (Switi.crla~iii near Rllone vallcy) grality danl
255
m
hlauvoisin (Switzerlantlj arc11
dam
236
m
Daniel Johnson dam (klanicouagan
5,
Canada), rnulliple arch
dam
220
m
Greatest stor;ige capacities
Tarbela on ladus (P:tkistali), earth tlsm
142 hm3
Fort Peck
(USA)
96
hn3
-
The :ligllest hcads harnesscd fur water power
Rcisseck (Austria) 1772
m
Grand Dixcncc (Sw:tzcrland) 1748
m
Porrillon (France)
1420
m
-
---
'The
largest man-built storage lakes
-
in total capacity
Bratsk
(Angnrn. Siberia, IJSSR) 5500 kin2 surfac2
Aswan (Egypt,
fdil)
3900
km?
surface
Karibn (lillodcsia, Ziimbesi) 5180
km2
Akosombo (Ghana, Vo!t:i) 8470
km2
Manicouagan
5
(Canada. \4anicouagan)
Luchia Gorgc. (Hoangho, Chir.a) Barrage with
2
13 m
--
in surface
Akosombo on Volta
Kouibichev on
Volga
Bratsk
For comparison:
Lake
of Geneva
--
-
-
The most productive power plants (In service or undcr crcction')
-
In
!he
world
ltrtipu (Parani, Brazil)
1-(3
2
(La
Grande.
Canada)'
Churchill Falls (Cliurchill, Canada)
-.
Sayano Suchcnsk (Yenissei, USSR)'
Bratsk
(Xng;~r;~, USSR)
Tucuri (Tocnntins,
Brazil)'
U3t
Ilim (Angara, USSR)'
Production
70
'TWh
38.8 TWh
34.4
TWh
344
TWh
23 TWh
2
1,5
'TWh
2
1.9 T'Nh
Table
1
S.1.
Continuation
Krasnoyarsk (Yenissei, USSR)
Grand Coulee I-11-111 (Columbia,
USA)
Bogoutchany (Angara, USSR)'
Cabora-Bassa (Zambezi, Mozambique)
Yacyreta-Apipe (Parana, Argentine)'
LG
4
(La Grande, Canada)'
Niagara (St. Lawrence, USA)
Cornwall (St. Lawrence, USA-Canada)
-
In Europe
Iron Gate (Danube, Rumania, Yugoslavia)
Volgograd (Now
XXIl th Congress) (Volga, USSR)
Kouibichev (Now Lenin) (Volga, USSR)
Saratov (Volga, USSR)
Dnieprostroy (Now Dniepro) (Dniepr, USSR)
-
In Spain
Aldeadavila (Douro-International, Portugal, Spain)
-
In France
Donzire (Rhbne)
The most powerful plants (In service or under erection')
-
In
the world
Sanxia (Three-Gorges) (Yangtse, PR China)
Itaipi! (Parani, Brazil)
Guri (Caroni, Venezuela)
Grand Coulee (Columbia, USA)
+
Sayano Suchensk (Yenissei, USSR)'
Krasnoyarsk (Yenissei, USSR)
LG
2
(La Grande, Canada)'
Churchill Falls (Churchill, Canada)
Ust
Ilim (Angara, USSR)
Bratsk (Angara, USSR)
Bougatchany (Angara, USSR)
Paulo Afonso
I-11-111-IV (Siio Francisco, Brazil)
Tucuri (Tocantins, Brazil)
John Day (Columbia, USA)
Nurek (Vakhsh, USSR, Tadchikistan)
Revelstoke (Canada, Rocky Mountains)'
Ilha Solteira (Parani, Brazil)
XXIl th Congress, ex Volgograd (Volga, USSR)
ChicoasCn (Grijalva)'
Cabora Bassa
(Zambeli, Mozambique)
-
In Europe
XXII
th Congress, late Volgograd (Volga, USSR)
Lenin, ex Kouibichev (Volga, USSR)
Iron Gate (Danube, Rumania, Yugoslavia)
Saratov (Volga, USSR)
-
In Spain
Aldeadavila (Duero-International, Spain-Portugal)
-
In Federal Republic of Germany
Wehr (Ternary pumped storage plant)
-
In France
Roselend
Genissiat
Mont-Cenis
Kance (Tidal power plant)
20,4
TWh
20,3
TWh
19,8
TWh
18 TWh
18 TWh
14,3
TWh
14,2
TWh
14
TWh
1
1,4
TWh
11 TWh
.
11
TWh
7
TWh
3,G
TWh
2,4
TWh
2,l TWh
Planncd value
1.5.2.
Survey
of historical
development
Hydro power as the prodirction of hydroclcctricity startcd in 1880 by
a
small
DC
generating
plant
in Wisconsi~l
USA.
But
it
began on a large modern scale, when cconom-
ical transmission of high voltage
AC
was initiated in the Frankfurt exhibition in IS91 (see
preface).
Corner stones of turbine development may be seen in the inventions of
Fourneyrorr
1527
(centrifugal reaction turbine),
Howd
1837 (cetitripetal reaction turbine),
Henscllel
1837
(axial reaction turbine,
draft
tube),
Boydcn
1848 (diffuser),
Frcrncis
1848 (Lowell experi-
ments on Howd turbine),
Fitlk
1855 (adjustable guide vane),
Swairz
1569 (radial axial
rehction runner),
Voitll
1573
(Francis
turbine with adjustable gate) mainly made with
Iespect to the semi axial or
Francis
turbine.
For the impulse turbine this was done mainly by
Girard
1863 (axial tangential action
turbine),
IJelton
1880 (bucket jet action turbine),
Breuer
1890 (needle valve) and
Abner
Ooble
1900 (bucket cutout). For the cross-flow turbine the essential inventions have been
made by
Micl~ell
1903,
Banki
1918 and
Ossherger
1922.
Fcr axial turbines
Kaplan
in 1313 made the decisive step (adjustable runner vane),
f~llowed by
Fisclrer
together with Escher Wyss in 1936 (bulb turbine, turbine with rim
generator),
Gibrat
in 1942 (tidal power turbine) and again Escher Wyss 1875 (Straflo
turbine). Further historical hints are given by
Raabe
[1.50] and
rMoser
[1.51].
Pumped storage was started by Sulzer Brothers in 1891 (ternary set), followed by Escher
Wyss 1930 (axial pumpt urbine) and Voi
th 1934 (radial pumpturbine).
The devclopn~enr of modern water turbines and storage pumps cannot be separated from thc Rames
of rvorld reknowned firms engaged in this work. To mention only a few: Sulzer Escher Wyss
(S\vitzerland);
J.
M.
Voith, Heicienheirn (Federal Republic Germany); Neyrpic, Grenoble (France);
Hydro~rt, hlil:ino (Italj); Allis Chaimers, Ivlilwaukee, Wisc. (USA), Ateliers de Constructions
3lkchanique
tic
Vevey (Sv~iizer!anti), Tampella Tampere (Finland), Ossberger Weissenburg
(F.
R.
German:), Kal-!stads hlekaniska LVerkstadcn Kristineham (Sweden), Dominion Engineering hlont-
real (Canada),
Lh1Z
Leningrad (ESSR), Voest Alpine Linr (Austria), Mitsubishi and Hitachi Works
(Japan).
Kvacrccr Rrugg (Norway),
P
ndritz Graz (Austria), Litostroj Lubljana (Yugoslavia), Resita
Works (Rumania), !jarbin Gcncrator Works (China), Blansko Works [Czechoslovakia), Heavy
Indian Electric, Hardware (India), Boving, London and Mc Lellan, Newcastle upon
Tyne, both
England.
.
The development of heavy electric and high voltage equipment has been stimulated by the inventions
of
Siema~s
(3C
dynamo by residual magnetism),
Hejiter
von
AIteneck
(drum armature),
Ferraris
(induction n~otor),
Brow11
(oil insulated heavy current transformer) and
Dolivo vorr Dobro~olsky
(three phase induction motor and high voltage power transmission) in connection with enterprises
like Siemens. AEG, BBC, Westinghouse, Edison, Alsthom, General Electric, ASEA, Fuji Electric and
Toshiba.
To this should be added the progress made in high voltage transmission. After the
initiative of Oskar
von Miller and Deprez in 1868 this was started on an industrial scale
by Dolivo von Dobrovolsky in
1891
with
a voltage of 15
kV
and rezched in the years
1906,1920, 1930,1960,1968, 1972 and 1983 the levels of 100,200,360,500,735,1000 and
1200
kV,
respectively bath the last with
DC
transmission.
A lively impression of how fast development of hydro power goes foreward can be obtained by the
development in Brazil during
1963
to
1971,
where the mean growth rate was
12,6%
with extreme
values of
27%
in
1969
and
2,4%
in
1966.
At the moment this development stagnates.
1.5.3.
The
features of water power plants
These are listed in Table
1.5.2.
It may be added to this table, that the initia!
cost
especially
of
low head plants may be much higher than those in thermal power
plants.
Nevertheless,
the present value of total cost, including also those of fuel, is in general lower in
a
water
power plant.
Table
1.5.2.
The features of water power plants.
-
-
--
-
Advantages Disadvantages
-
-
-
-
-
-
-
-
-
From the technical point of view
Excellent availability if cavitation pitting is kept within Number of
favourable sites limited aild
limits by sufficient submergence. Technology simple and
only occurring in some countries. Sites
proven. Long useful life. Short
time requirements of of interest more and more distantly
starting and loading, if pressure surges are kept within
located from the consumer centres due
limits by adequate devices. Thermal phenomena re- to progress in power transmission tech-
stricted to bearings and generator. High efficiency.
niques. Cavitation, water hammer.
From the economical point of view
Small operating, maintenance and replacement costs
(10
High initial investments especially for
to
15%
of the financial charges) even if the annual reve- low head plants in comparison to ther-
nues from them are retained (profit due to inflation).
mal
power plants but not more than
Harnessable as base and peak load energy. Resources are
that of a nuclear power plant, particul-
gratuitously renewed. May contribute to the advantages
arly when the cost of removal of waste
of other
fie!ds: agriculture (irrigation, reduction of inun-
material and environmental
protectior,
dated areas) navigation, mastering of inundations, zones against darnmage are included.
of leisure, drinking water reservoirs.
Indemnification for submerged land.
The access to the site may open also the road for the Rebuilding of roads railroads and
development and exploitation of other wealth. townships occasionally
subnerged.
It may permit access to new countries for their improve-
ment.
From the ecological and social point of view
No air pollution.
Inundations of the reservoirs. Displa-
No thermal pollution of water.
cement of population. Loss of arable
(Contrary to many thermal power plants).
land by growing salination. Spreading
of tropical diseases (Bilharziosis).
Fsci-
litating sedimentation upstream and
erosion downstream of a barrage.
lnterrrupting the aquatic food chain.
Possible induction of landslide and
earthquake at high head. Black out of
long transmission lines by pressure
groups may undermine social order.
1.6.
Survey
of
types
of
hydro
power
plants
1.6.1.
Plants
for
conversion of liydraulic primary energy
1.6.1.1.
Genersl remarks on conversion of primary energy
In these plants primary energy in the form of water potential obtained from river,
depression, gas washer and tidal power plants is converted
inta electric energy.
In gcncri~l
;i
I~ydraulic ni;ichinc conve~.ts thc availxblc
spec.i;lc
energy of fluid into -.vork
done
by
tllc hi1,ift
work
(but
also
OII
a snli~~lcr sc;i!c into
wastc
Ilcat)
and
hencc
into t'lcctric
encrgy
between
tlte te~rnirials of its genet-a:or. Strictly spc;rki~lg this available energy is thc
difierclice
c,f
totill enthalpy txtween inlet
I1
and exit
I
of thc r.~achir,c an3 I-cierred to the
unit mass of the fluid according to
Ai,
=
A
(p/~
+
e
-k
glt
+
c2!2)f1,
(1
.6
-
1)
where
A
indicates the
difference
of the valucs in the brackcts between the pressure flange
(11)
and
thc
suction
flange
(I)
of thc mncl~ine. Their location depends on the type of
machine
as
shown
in
Table
1.6.1.
The valiics or
y
and
c
arc understood as mass-flow-
averaged at the respective cross sections
I1
and
I.
Table 1.6.1. Localization of cross section
I1
and
I
with regard to machine type and
according
to
the rules of t.he international clectric cornmision
(IEC).
Machine type Section
I1
Section
I
Rcaction type with
adrnis-
sion through open Ilurne Intake of cnamber Draft tube exit
Ditto with admission by
seini spiral casing Intake of semi spiral Ditto
Ditto with
iitimission by
full spiral casing
Inlet flange of spiral case Ditto
impulse
cjr cross flow type
Before jet needle,
Past turbine
chamber,
or inlet valve
or on contact
poifit
of jet circle and jet
centre line
111 the above
p
is the pre5sure,
q
the density and hence
P/Q
the specific positive displace-
ment work,
t!
the specific internal energy.
c2/2
the specific kinetic energy and
gh
the
spccific potential energy per unit mass of fluid resulting from its height
h
above
a
reference
altitude, and
g
ihe giavitatior~al acceleration.
In
gencral the difference of specific kinetic energy
cz/2
is relatively small, excep?ing the inre case of
a
free s!ream or rapids ~urbine using only
cr/2
by diffusing the flow in a river rapid. lrl low head
plants the term
dglr
is rslaiively large, in high head plants the rcrm
dy/g
is relatively large compared
with the residual terms.
Excepting gas purification plants, the pressure
tern1
dp/~
has its origin in
a
difference of altitudes
..?;I
between head and tail water levels and hence in !he gravity field of the earth:y Inay vanish, e.g.
i-i
a space missile. In a rocket, accelerated by
6,
-
b
must be added vectorially to
g.
1.6.1.2.
River
power
plants
.
Here the higher potential energy of water
gh
at an arbitrary station of the river compared
with another station downstream
thz same river, with its lower elevation
Ir
above sea
level, is used. This difference in level
of
both the stations is a consequence of the slope
of
river level to overcome wall friction on the river bed and the dissipation of adjacent
turbulent flow laminae.
This potential
enei-gy
gll
is utilized by retarding the flow by means
of
a bar-age. Thus the
dissipation of
the river and hence the gradient of its slope decrease. This enables the