Karady, G.G. “Conventional Power Generation”
The Electrical Engineering Handbook
Ed. Richard C. Dorf
Boca Raton: CRC Press LLC, 2000
59
Conventional Power
Generation
59.1 Introduction
59.2 Fossil Power Plants
Fuel Handling ? Boiler ? Turbine ? Generator ? Electric
System ? Condenser ? Stack and Ash Handling ? Cooling and
Feedwater System
59.3 Nuclear Power Plants
Pressurized Water Reactor ? Boiling-Water Reactor
59.4 Geothermal Power Plants
59.5 Hydroelectric Power Plants
59.1 Introduction
The electric energy demand of the world is continuously increasing, and most of the energy is generated by
conventional power plants, which remain the only cost-effective method for generating large quantities of energy.
Power plants utilize energy stored in the earth and convert it to electrical energy that is distributed and used
by customers. This process converts most of the energy into heat, which increases the entropy of the earth. In
this sense, power plants deplete the earth’s energy supply. Efficient operation becomes increasingly important
to conserve energy.
Typical energy sources used by power plants include fossil fuel (gas, oil, and coal), nuclear fuel (uranium),
geothermal energy (hot water, steam), and hydro energy (water falling through a head).
Around the turn of the century, the first fossil power plants used steam engines as the prime mover. These
plants were evolved to an 8- to 10-MW capacity, but increasing power demands resulted in the replacement
by a more efficient steam boiler–turbine arrangement. The first commercial steam turbine was introduced by
DeLaval in 1882. The boilers were developed from heating furnaces. Oil was the preferred and most widely
used fuel in the beginning. The oil shortage promoted coal-fired plants, but the adverse environmental effects
(sulfur dioxide generation, acid rain, dust pollution, etc.) curtailed their use in the late seventies. Presently the
most acceptable fuel is natural gas, which minimizes pollution and is available in large quantities. During the
next two decades, gas-fired power plants will dominate the electric industry.
The hydro plants’ ancestors are water wheels used for pumping stations, mill driving, etc. Water-driven
turbines were developed in the last century and used for generation of electricity since the beginning of their
commercial use. However, most of the sites that can be developed economically are currently being utilized.
No significant new development is expected in the United States in the near future.
Nuclear power plants appeared after the Second World War. The major development occurred during the
sixties; however, by the eighties environmental considerations stopped plant development in the United States
and slowed it down all over the world. Presently, the future of nuclear power generation is unclear, but the
abundance of nuclear fuel and the expected energy shortage in the early part of the next century may rejuvenate
nuclear development if safety issues can be resolved.
George G. Karady
Arizona State University
? 2000 by CRC Press LLC
Geothermal power plants are the product of the clean energy concept, although the small-scale, local
application of geothermal energy has a long history. Presently only a few plants are in operation. The potential
for further development is limited because of the unavailability of geothermal energy sites that can be developed
economically.
Typical technical data for different power plants is shown in Table 59.1.
59.2 Fossil Power Plants
The operational concept and major components of a fossil power plant are shown in Fig. 59.1.
Fuel Handling
The most frequently used fuels are oil, natural gas, and coal. Oil and gas are transported by rail, on ships, or
through pipelines. In the former case the gas is liquefied. Coal is transported by rail or ships if the plant is near
a river or the sea. The power plant requires several days of fuel reserve. Oil and gas are stored in large metal
tanks, and coal is kept in open yards. The temperature of the coal layer must be monitored to avoid self-ignition.
Oil is pumped and gas is fed to the burners of the boiler. Coal is pulverized in large mills, and the powder
is mixed with air and transported by air pressure, through pipes, to the burners. The coal transport from the
yard to the mills requires automated transporter belts, hoppers, and sometimes manually operated bulldozers.
Boiler
Two types of boilers are used in modern power plants: subcritical water-tube drum-type and supercritical once-
through type. The former operates around 2500 psi, which is under the water critical pressure of 3208.2 psi.
The latter operates above that pressure, at around 3500 psi. The superheated steam temperature is about 1000°F
(540°C) because of turbine temperature limitations.
A typical subcritical water-tube drum-type boiler has an inverted-U shape. On the bottom of the rising part
is the furnace where the fuel is burned. The walls of the furnace are covered by water pipes. The drum and the
superheater are at the top of the boiler. The falling part of the U houses the reheaters, economizer (water
heater), and air preheater, which is supplied by the forced-draft fan. The induced-draft fan forces the flue gases
out of the system and sends them up the stack, which is located behind the boiler. A flow diagram of the drum-
type boiler is shown in Fig. 59.2. The steam generator has three major systems: fuel, air-flue gas, and water-steam.
Fuel System. Fuel is mixed with air and injected into the furnace through burners. The burners are equipped
with nozzles, which are supplied by preheated air and carefully designed to assure the optimum air-fuel mix.
The fuel mix is ignited by oil or gas torches. The furnace temperature is around 3000°F.
Air-Flue Gas System. Ambient air is driven by the forced-draft fan through the air preheater, which is heated
by the high-temperature (600°F) flue gases. The air is mixed with fuel in the burners and enters into the furnace,
where it supports the fuel burning. The hot combustion flue gas generates steam and flows through the boiler
FIGURE 59.1 Major components of a fossil power plant.
? 2000 by CRC Press LLC
? 2000 by CRC Press LLC
T
ABLE 59.1
P
o
w
e
r Plant T
e
c
hnical Data
Capitaliz
ed C
o
nstr
u
ction
Equi
valent
Equi
valent
C
ost
Gener
a
tion
T
y
pical
Plant
C
ost,
L
e
ad T
ime,
H
eat
Rat
e,
F
u
el
C
ost,
F
o
r
c
ed
Sc
heduled
O&M Fix
ed,
V
ar
iable
T
y
pe
MW S
i
z
e
$/kW
Y
ears
B
tu/kW
h
$/MBtu
F
uel T
y
pe
Outage
Rat
e
Outage Rat
e
$/kW/y
ear
$/MW
h
N
u
clear
1200
2400
10
10,400
1.25
U
r
anium
20
15
25
8
P
u
l
v
er
iz
ed c
o
al
st
eam
500
1400
6
9,900
2.25
C
o
al
12
12
20
5
A
t
mospher
i
c
fluidiz
ed bed
400
1400
6
9,800
2.25
C
o
al
14
12
17
6
Gas tur
b
ine
100
350
2
11,200
4.00
N
at.
gas
7
7
1
5
C
o
mbined-cy
cle
300
600
4
7,800
4.00
N
at.
gas
8
8
9
3
C
o
al-gasification
c
o
mbined-cy
cle
300
1500
6
9,500
2.25
C
o
al
12
10
25
4
P
umped st
or
age
h
y
dr
o
300
1200
6
—
—
5
5
5
2
Con
v
ent
i
onal
h
y
dr
o
300
1700
6
—
—
3
4
5
2
to heat the superheater, reheaters, economizer, etc. Induced-draft fans, located between the boiler and the stack,
increase the flow and send the 300°F flue gases to the atmosphere through the stack.
Water-Steam System. Large pumps drive the feedwater through the high-pressure heaters and the economizer,
which further increases the water temperature (400–500°F). The former is heated by steam removed from the
turbine; the latter is heated by the flue gases. The preheated water is fed to the steam drum. Insulated tubes,
called downcomers, are located outside the furnace and lead the water to a header. The header distributes the
hot water among the risers. These are water tubes that line the furnace walls. The water tubes are heated by
the combustion gases through both convection and radiation. The steam generated in these tubes flows to the
drum, where it is separated from the water. Circulation is maintained by the density difference between the
water in the downcomer and the water tubes. Saturated steam, collected in the drum, flows through the
superheater. The superheater increases the steam temperature to about 1000°F. Dry superheated steam drives
the high-pressure turbine. The exhaust from the high-pressure turbine goes to the reheater, which again
increases the steam temperature. The reheated steam drives the low-pressure turbine.
The typical supercritical once-through-type boiler concept is shown
in Fig. 59.3.
The feedwater enters through the economizer to the boiler, which
consists of riser tubes that line the furnace wall. All the water is converted
to steam and fed directly to the superheater. The latter increases the steam
temperature above the critical temperature of the water and drives the
turbine. The construction of these steam generators is more expensive
than the drum-type units but has a higher operating efficiency.
Turbine
The turbine converts the heat energy of the steam into mechanical energy.
Modern power plants usually use one high-pressure and one or two lower-
pressure turbines. A typical turbine arrangement is shown in Fig. 59.4.
The figure shows that only one bearing is between each of the
machines. The shafts are connected to form a tandem compound steam
turbine unit. High-pressure steam enters the high-pressure turbine to flow through and drive the turbine. The
exhaust is reheated in the boiler and returned to the lower-pressure units. Both the rotor and the stationary
part of the turbine have blades. The length of the blades increases from the steam entrance to the exhaust.
FIGURE 59.2 Flow diagram of a typical drum-type steam boiler.
Header
Air
Water Tubes
(Risers)
Steam
Drum
Freewater
Regulator
Downcomer
Reheater
To High-Pressure Turbine
Attemperators
Superheater
Saturated Steam
Pr
imar
y
Secondar
y
To Low-Pressure Turbine
From High-
Pressure Turbine
Forced
Draft Fan
Air Preheater
Feedwater
from
High-Pressure
Feedwater
Heater
Air
Induced-
Draft Fan
Flue Gas
to Stack
Water
Air
Economizer
Fuel
FIGURE 59.3 Concept of once-
through-type steam generator.
? 2000 by CRC Press LLC
Figure 59.5 shows the blade arrangement of an impulse-type turbine. Steam enters through nozzles and flows
through the first set of moving rotor blades. The following stationary blades change the direction of the flow
and direct the steam into the next set of moving blades. The nozzles increase the steam speed and reduce
pressure, as shown in the figure. The impact of the high-speed steam, generated by the change of direction and
speed in the moving blades, drives the turbine.
The reaction-type turbine has nonsymmetrical blades arranged like those shown in Fig. 59.5. The blade shape
assures that the pressure continually drops through all rows of blades, but steam velocity decreases in the moving
blades and increases in the stationary blades.
Generator
The generator converts mechanical energy from the turbines into electrical energy. The major components of
the generator are the frame, stator core and winding, rotor and winding, bearings, and cooling system.
Figure 59.6 shows the cross section of a modern hydrogen-cooled generator.
The stator has a laminated and slotted silicon steel iron core. The stacked core is clamped and held together
by insulated axial through bolts. The stator winding is placed in the slots and consists of a copper-strand
configuration with woven glass insulation between the strands and mica flakes, mica mat, or mica paper ground-
wall insulation. To avoid insulation damage caused by vibration, the groundwall insulation is reinforced by
asphalt, epoxy-impregnated fiberglass, or Dacron. The largest machine stator is Y-connected and has two coils
per phase, connected in parallel. Most frequently, the stator is hydrogen-cooled; however, small units may be
air-cooled and very large units may be water-cooled.
FIGURE 59.4 Large tandem compound steam turbine. (Source: M.M. El-Wakil, Power Plant Technology, New York:
McGraw-Hill, 1984, p. 210. With permission.)
FIGURE 59.5 Velocity and pressure variation in an impulse turbine.
? 2000 by CRC Press LLC
The solid steel rotor has slots milled along the axis. The multiturn, copper rotor winding is placed in the
slots and cooled by hydrogen. Cooling is enhanced by subslots and axial cooling passages. The rotor winding
is restrained by wedges inserted in the slots.
The rotor winding is supplied by dc current, either directly by a brushless excitation system or through
collector rings. The rotor is supported by bearings at both ends. The non-drive-end bearing is insulated to
avoid shaft current generated by stray magnetic fields. The hydrogen is cooled by a hydrogen-to-water heat
exchanger mounted on the generator or installed in a closed-loop cooling system.
The dc current of the rotor generates a rotating magnetic field that induces an ac voltage in the stator winding.
This voltage drives current through the load and supplies the electrical energy.
Electric System
Energy generated by the power plant supplies the electric network through transmission lines. The power plant
operation requires auxiliary power to operate mills, pumps, etc. The auxiliary power requirement is approxi-
mately 10 to 15%.
Smaller generators are directly connected in parallel using a busbar. Each generator is protected by a circuit
breaker. The power plant auxiliary system is supplied from the same busbar. The transmission lines are
connected to the generator bus, either directly or through a transformer.
The larger generators are unit-connected. In this arrangement the generator is directly connected, without
a circuit breaker, to the main transformer. A conceptual one-line diagram is shown in Fig. 59.7. The generator
supplies main and auxiliary transformers without circuit breakers. The units are connected in parallel at the
high-voltage side of the main transformers by a busbar. The transmission lines are also supplied from this bus.
Circuit breakers are installed at the secondary side of the main and auxiliary transformer. The application of
generator circuit breaker is not economical in the case of large generators. Because of the generator’s large
short-circuit current, special expensive circuit breakers are required. However, the transformers reduce the
short-circuit current and permit the use of standard circuit breakers at the secondary side. The disconnect
switches permit visual observation of the off state and are needed for maintenance of the circuit breakers.
FIGURE 59.6 Direct hydrogen-inner-cooled generator. (Source: R.W. Beckwith, Westinghouse Power Systems Marketing
Training Guide on Large Electric Generators, Pittsburgh: Westinghouse Electric Corp. 1979, p. 54. With permission.)
? 2000 by CRC Press LLC
Condenser
The condenser condenses turbine exhaust steam to water, which is pumped back to the steam generator through
various water heaters. The condensation produces a vacuum, which is necessary to exhaust the steam from the
turbine. The condenser is a shell-and-tube heat exchanger, where steam condenses on water-cooled tubes. Cold
water is obtained from the cooling towers or other cooling systems. The condensed water is fed through a
deaerator, which removes absorbed gases from the water. Next, the gas-free water is mixed with the feedwater
and returned to the boiler. The gases absorbed in the water may cause corrosion (oxygen) and increase condenser
pressure, adversely affecting efficiency. Older plants use a separate deaerator heater, while deaerators in modern
plants are usually integrated in the condensor, where injected steam jets produce pressure drop and remove
absorbed gases.
Stack and Ash Handling
The stack is designed to disperse gases into the atmosphere without disturbing the environment. This requires
sufficient stack height, which assists the fans in removing gases from the boiler through natural convection.
The gases contain both solid particles and harmful chemicals. Solid particles, like dust, are removed from the
flue gas by electrostatic precipitators or bag-house filters. Harmful sulfur dioxide is eliminated by scrubbers.
The most common is the lime/limestone scrubbing process.
Coal-fired power plants generate a significant amount of ash. The disposition of the ash causes environmental
problems. Several systems have been developed in past decades. Large ash particles are collected by a water-
filled ash hopper, located at the bottom of the furnace. Fly ash is removed by filters, then mixed with water.
Both systems produce sludge that is pumped to a clay-lined pond where water evaporates and the ash fills
disposal sites. The clay lining prevents intrusion of groundwater into the pond.
Cooling and Feedwater System
The condenser is cooled by cold water. The open-loop system obtains the water from a river or sea, if the power
plant location permits it. The closed-loop system utilizes cooling towers, spray ponds, or spray canals. In the
case of spray ponds or canals, the water is pumped through nozzles, which generate fine sprays. Evaporation
cools the water sprays as they fall back into the pond. Several different types of cooling towers have been
developed. The most frequently used is the wet cooling tower, where the hot water is sprayed on top of a
latticework of horizontal bars. The water drifts downward and is cooled, through evaporation, by the air, which
is forced by fans or natural draft upward.
The power plant loses a small fraction of the water through leakage. The feedwater system replaces this lost
water. Replacement water has to be free from absorbed gases, chemicals, etc., because the impurities cause
severe corrosion in the turbines and boiler. The water treatment system purifies replacement water by pretreat-
ment, which includes filtering, chlorination, demineralization, condensation, polishing. These complicated
chemical processes result in a corrosion-free high-quality feedwater.
FIGURE 59.7 Conceptual one-line diagram for a unit-connected generator.
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59.3 Nuclear Power Plants
More than 500 nuclear power plants operate around the world. Close to 300 operate pressurized water reactors
(PWRs), more than 100 are built with boiling-water reactors (BWRs), about 50 use gas-cooled reactors, and
the rest are heavy-water reactors. In addition a few fast breeder reactors are in operation. These reactors are
built for better utilization of uranium fuel. The modern nuclear plant size varies from 100 to 1200 MW.
Pressurized Water Reactor
The general arrangement of a power plant with a PWR is shown in Fig. 59.8(A).
The reactor heats the water from about 550 to about 650°F. High pressure, at about 2235 psi, prevents
boiling. Pressure is maintained by a pressurizer, and the water is circulated by a pump through a heat exchanger.
The heat exchanger evaporates the feedwater and generates steam, which supplies a system similar to a con-
ventional power plant. The advantage of this two-loop system is the separation of the potentially radioactive
reactor cooling fluid from the water-steam system.
The reactor core consists of fuel and control rods. Grids hold both the control and fuel rods. The fuel rods
are inserted in the grid following a predetermined pattern. The fuel elements are Zircaloy-clad rods filled with
UO
2
pellets. The control rods are made of a silver (80%), cadmium (5%), and indium (15%) alloy protected
by stainless steel. The reactor operation is controlled by the position of the rods. In addition, control rods are
used to shut down the reactor. The rods are released and fall in the core when emergency shutdown is required.
Cooling water enters the reactor from the bottom, flows through the core, and is heated by nuclear fission.
Boiling-Water Reactor
In the BWR shown in Fig. 59.8(B), the pressure is low, about 1000 psi. The nuclear reaction heats the water
directly to evaporate it and produce wet steam at about 545°F. The remaining water is recirculated and mixed
with feedwater. The steam drives a turbine that typically rotates at 1800 rpm. The rest of the plant is similar
to a conventional power plant. A typical reactor arrangement is shown in Fig. 59.9. The figure shows all the
major components of a reactor. The fuel and control rod assembly is located in the lower part. The steam
separators are above the core, and the steam dryers are at the top of the reactor. The reactor is enclosed by a
concrete dome.
59.4 Geothermal Power Plants
The solid crust of the earth is an average of 20 mil (32 km) deep. Under the solid crust is the molten mass, the
magma. The heat stored in the magma is the source of geothermal energy. The hot molten magma comes close
to the surface at certain points in the earth and produces volcanoes, hot springs, and geysers. These are the
signs of a possible geothermal site. Three forms of geothermal energy are considered for development.
FIGURE 59.8 (A) Power plant with PWR; (B) power plant with BWR.
? 2000 by CRC Press LLC
Hydrothermal Source. This is the most developed source. Power plants, up to a capacity of 2000 MW, are
in operation worldwide. Heat from the magma is conducted upward by the rocks. The groundwater drifts down
through the cracks and fissures to form reservoirs when water-impermeable solid rock bed is present. The water
in this reservoir is heated by the heat from the magma. Depending on the distance from the magma and rock
configuration, steam, hot pressurized water, or the mixture of the two are generated. Signs of these underwater
reservoirs include hot springs and geysers. The reservoir is tapped by a well, which brings the steam-water
mixture to the surface to produce energy. The geothermal power plant concept is illustrated in Fig. 59.10.
The hot water and steam mixture is fed into a separator. If the steam content is high, a centrifugal separator
is used to remove the water and other particles. The obtained steam drives a turbine. The typical pressure is
FIGURE 59.9 Typical BWR reactor arrangement. (Source: Courtesy of General Electric Company.)
FIGURE 59.10 Concept of a geothermal power plant.
? 2000 by CRC Press LLC
around 100 psi and the temperature is around 400°F (200°C). If the water content is high, the water-steam
mixture is led through a flashed-steam system where the expansion generates a better quality of steam and
separates the steam from the water. The water is returned to the ground, the steam drives the turbine. Typically
the steam entering the turbine has a temperature of 120 to 150°C and a pressure of 30 to 40 psi.
The turbine drives a conventional generator. The typical rating is in the 20- to 100-MW range. The exhaust
steam is condensed in a direct-contact condenser. A part of the obtained water is reinjected into the ground.
The rest of the water is fed into a cooling tower to provide cold water to the condenser.
Major problems with geothermal power plants are the minerals and noncondensable gases in the water. The
minerals make the water highly corrosive, and the separated gases cause air pollution. An additional problem
is noise pollution. The centrifugal separator and blowdowns require noise dampers and silencers.
Petrothermal Source. Some fields have only hot rocks under the surface. Utilization of this petrothermal
source requires pumping surface water through a well in a constructed hole to a reservoir. The hot water is
then recovered through another well. The problem is the formation of a reservoir. The U.S. government is
studying practical uses of petrothermal sources.
Geopressured Source. In deep underground holes (8000 to 30,000 ft) a mixture of pressurized water and
natural gas, like methane, may sometimes be found. These geopressured sources promise power generation
through the combustion of methane and the direct recovery of heat from the water. The geopressured method
is currently in an experimental stage, with operating pilot plants.
59.5 Hydroelectric Power Plants
Hydroelectric power plants convert energy produced by a water head into electric energy. A typical hydroelectric
power plant arrangement is shown in Fig. 59.11.
The head is produced by building a dam across a river, which forms the upper-level reservoir. In the case of
low head, the water forming the reservoir is fed to the turbine through the intake channel or the turbine is
integrated in the dam. The latter arrangement is shown in Fig. 59.11(A). Penstock tubes or tunnels are used
for medium- [Fig. 59.11(B)] and high-head plants (Fig. 59.12). The spillway regulates the excess water by
opening gates at the bottom of the dam or permitting overflow on the spillway section of the dam. The water
discharged from the turbine flows to the lower or tail water reservoir, which is usually a continuation of the
original water channel.
High-Head Plants. High-head plants (Fig. 59.12) are built with impulse turbines, where the head-generated
water pressure is converted into velocity by nozzles and the high-velocity water jets drive the turbine runner.
FIGURE 59.11 Hydroelectric power plant arrangement. (A) Low-head plant, (B) medium-head plant.
Power
House
Power
House
Power
House
Forebay
Canal
Gate House
Water Level
Canal Wall
Control Gates
Dam and
Spillway
Canal
Intake
Gates
Head
Water
Head
Water
Penstocks
Tail
Water
Tail
Water
Control
Gates
Dam and
Spillway
AB
? 2000 by CRC Press LLC
Low- and Medium-Head Plants. Low- and medium-head installations (Fig. 59.11) are built with reaction-
type turbines, where the water pressure is mostly converted to velocity in the turbine. The two basic classes of
reaction turbines are the propeller or Kaplan type, mostly used for low-head plants, and the Francis type, mostly
used for medium-head plants. The cross section of a typical low-head Kaplan turbine is shown in Fig. 59.13.
The vertical shaft turbine and generator are supported by a thrust bearing immersed in oil. The generator
is in the upper, watertight chamber. The turbine runner has 4 to 10 propeller types, and adjustable pitch blades.
The blades are regulated from 5 to 35 degrees by an oil-pressure-operated servo mechanism. The water is evenly
distributed along the periphery of the runner by a concrete spiral case and regulated by adjustable wicket blades.
The water is discharged from the turbine through an elbow-shaped draft tube. The conical profile of the tube
reduces the water speed from the discharge speed of 10–30 ft/s to 1 ft/s to increase turbine efficiency.
Hydrogenerators. The hydrogenerator is a low-speed (100 to 360 rpm) salient-pole machine with a vertical
shaft. A typical number of poles is from 20 to 72. They are mounted on a pole spider, which is a welded, spoked
wheel. The spider is mounted on the forged steel shaft. The poles are built with a laminated iron core and
stranded copper winding. Damper bars are built in the pole faces. The stator is built with slotted, laminated
iron core that is supported by a welded steel frame. Windings are made of stranded conductors insulated
between the turns by fiberglass or Dacron-glass. The ground insulation is multiple layers of mica tape impreg-
nated by epoxy or polyester resins. The older machines use asphalt and mica tape insulation, which is sensitive
to corona-discharge-caused insulation deterioration. Direct water cooling is used for very large machines, while
the smaller ones are air- or hydrogen-cooled. Some machines use forced-air cooling with an air-to-water heat
exchanger. A braking system is installed in larger machines to stop the generator rapidly and to avoid damage
to the thrust.
FIGURE 59.12 Hydroelectric power plant arrangement, high-head plant.
Tail
Water
Head Water
Elevation
Penstock
Penstock
Surge
Tank
Surge
Tank
Dam and
Spillway
Power
House
Rock
Tunnel
Tunnel
Pipe Line
Pipe Line
Pipe Line
Intake
Tower
Intake
Tower
Head
Water
? 2000 by CRC Press LLC
Defining Terms
Boiler: A steam generator which converts the chemical energy stored in the fuel (coal, gas, etc.) to thermal
energy by burning. The heat evaporates the feedwater and generates high-pressure steam.
Economizer: A heat exchanger which increases the feedwater temperature. It is heated by the flue gases.
Fuel: Thermal power plants use coal, natural gas, and oil as a fuel, which is burned in the boiler. Nuclear
power plants use uranium as a fuel.
Penstock: A water tube which feeds the turbine. It is used when the slope is too steep for using an open canal.
Reactor: A container where the nuclear reaction takes place. The reactor converts the nuclear energy to heat.
Superheater: A heat exchanger which increases the steam temperature to about 1000°F. It is heated by the
flue gases.
Surge tank: An empty vessel which is located at the top of the penstock. It is used to store water surge when
the turbine valve is suddenly closed.
References
A.J. Ellis, “Using geothermal energy for power,” Power, 123(10), October 1979.
M.M. El-Wakil, Power Plant Technology, New York: McGraw-Hill, 1984.
A.V. Nero, A Guidebook to Nuclear Reactors, Berkeley: University of California Press Ltd., 1979.
J. Weisman and L.E. Eckart, Modern Power Plant Engineering, Englewood Cliffs, N.J.: Prentice-Hall, 1985.
Further Information
Other recommended publications include the “Power Plant Electrical References Series,” published by EPRI,
which consists of several books dealing with power plant electrical system design. A good source of information
on the latest developments is Power magazine, which regularly publishes articles on power plants.
Additional books include the following:
S. Glasstone and M.C. Edlund, The Elements of Nuclear Reactor Theory, New York: Van Nostrand, 1952, p. 416.
G. Murphy, Elements of Nuclear Engineering, New York: Wiley, 1961.
FIGURE 59.13 Typical low-head hydroplant with Kaplan turbine.
Wicket Gate
Draft Tube
Runner
Gate
Generator
Govenor Cabinet
Power House
Cranes
Head
Water
Tail
Water
Gate
? 2000 by CRC Press LLC
M.A. Schultz, Control of Nuclear Reactors and Power Plants, New York: McGraw-Hill, 1955.
R.H. Shannon, Handbook of Coal-Based Electric Power Generation, Park Ridge, N.J.: Noyes, 1982, p. 372.
E.J.G. Singer, Combustion: Fossil Power Systems, Windsor, Conn.: Combustion Engineering, Inc., 1981.
B.G.A. Skrotzki and W.A. Vopat, Power Station Engineering and Economy, New York: McGraw-Hill, 1960.
M.J. Steinberg and T.H. Smith, Economy Loading of Power Plants and Electric Systems, New York: Wiley, 1943,
p. 203.
Various, Electric Generation: Steam Stations, B.G.A. Skrotzki, Ed., New York: McGraw-Hill, 1970, p. 403.
Various, Steam, New York: Babcock & Wilcox, 1972.
Various, Steam: Its Generation and Use, New York: Babcock & Wilcox, 1978.
? 2000 by CRC Press LLC
