319
Chapter 9
Hydraulic Turbines
© Springer Science+Business Media Dordrecht 2015
E. Dick, Fundamentals of Turbomachines, Fluid Mechanics and Its Applications 109,
DOI 10.1007/978-94-017-9627-9_9
Abstract In this chapter, we discuss the different types of hydraulic turbines for
electric power plants. We analyse their main characteristics in order to understand
in which range of head and flow rate they can be used efficiently. We also discuss
bulb turbines for tidal energy plants and reversible pump-turbines for pumped storage plants.
9.1 Hydraulic Energy
Hydraulic energy becomes available by water flow between two places with a difference in altitude. Hydraulic turbines convert the gravitational potential energy in
mechanical energy. This mechanical energy is in practice merely used for electricity
generation. Natural altitude differences are very seldom just serviceable. In most
cases, a water reservoir is built by erecting a dam in a river. In high mountain areas,
a supply pipe connects the reservoir with a power station at a much lower altitude.
The available head then strongly exceeds the dam height. With most rivers, however, the power station can only be built within the dam or very near to it and the
available head is lower than the dam height. With plain rivers, the dam normally enables shipping traffic in combination with a lock system. Available heads may thus
strongly differ: from the 1000 m order to some few meters. It is obvious that lower
heads imply higher investment costs per unit of power. The minimal economically
applicable head is about 4–5 m.
River water originates from rain or snow at higher altitudes. This is caused by
water evaporation at lower altitudes, by rise and condensation in the colder atmosphere at higher altitudes. The energy source with this process is the sun. Hydraulic
energy is thus part of a thermal cycle using solar energy. Throughout the world
there is about 700.000 MW installed hydraulic power (2014). About 15 % of all
electricity is generated by means of hydraulic energy and about 25 % of the practically exploitable hydraulic energy potential is already in use. Most of the potential
is already used in Europe and North America. Notwithstanding some big plants in
Asia and South America, there still is a significant unused potential.
Hydraulic turbines may strongly vary in size. The typical power is 100–400 MW,
but there also exist 4–5 MW turbines and even much smaller ones. Hydraulic power
Chapter 9
Hydraulic Turbines
© Springer Science+Business Media Dordrecht 2015
E. Dick, Fundamentals of Turbomachines, Fluid Mechanics and Its Applications 109,
DOI 10.1007/978-94-017-9627-9_9
Abstract In this chapter, we discuss the different types of hydraulic turbines for
electric power plants. We analyse their main characteristics in order to understand
in which range of head and flow rate they can be used efficiently. We also discuss
bulb turbines for tidal energy plants and reversible pump-turbines for pumped storage plants.
9.1 Hydraulic Energy
Hydraulic energy becomes available by water flow between two places with a difference in altitude. Hydraulic turbines convert the gravitational potential energy in
mechanical energy. This mechanical energy is in practice merely used for electricity
generation. Natural altitude differences are very seldom just serviceable. In most
cases, a water reservoir is built by erecting a dam in a river. In high mountain areas,
a supply pipe connects the reservoir with a power station at a much lower altitude.
The available head then strongly exceeds the dam height. With most rivers, however, the power station can only be built within the dam or very near to it and the
available head is lower than the dam height. With plain rivers, the dam normally enables shipping traffic in combination with a lock system. Available heads may thus
strongly differ: from the 1000 m order to some few meters. It is obvious that lower
heads imply higher investment costs per unit of power. The minimal economically
applicable head is about 4–5 m.
River water originates from rain or snow at higher altitudes. This is caused by
water evaporation at lower altitudes, by rise and condensation in the colder atmosphere at higher altitudes. The energy source with this process is the sun. Hydraulic
energy is thus part of a thermal cycle using solar energy. Throughout the world
there is about 700.000 MW installed hydraulic power (2014). About 15 % of all
electricity is generated by means of hydraulic energy and about 25 % of the practically exploitable hydraulic energy potential is already in use. Most of the potential
is already used in Europe and North America. Notwithstanding some big plants in
Asia and South America, there still is a significant unused potential.
Hydraulic turbines may strongly vary in size. The typical power is 100–400 MW,
but there also exist 4–5 MW turbines and even much smaller ones. Hydraulic power