What are hydraulic turbines, and where are they used?

Short Answer:

Hydraulic turbines are mechanical devices that convert the energy of flowing or falling water into mechanical energy, which is then used to generate electricity using a generator. These turbines rotate when water strikes their blades, producing rotational motion.

They are commonly used in hydroelectric power plants, especially near rivers, dams, or waterfalls, where there is a continuous water flow. Hydraulic turbines are essential for producing clean, renewable energy and are widely used in both small and large-scale power generation across the world.

Detailed Explanation:

Hydraulic turbines

Hydraulic turbines are machines designed to use the energy from moving water to perform work, usually in the form of electricity generation. They are a key component of hydroelectric power systems, where potential energy from water stored at a height (like in a dam) is converted into kinetic energy as water flows downward. This kinetic energy is captured by the turbine blades, causing them to spin. The rotational motion of the turbine shaft is then used to drive a generator, converting mechanical energy into electrical energy.

There are different types of hydraulic turbines, mainly classified based on how they extract energy from water. The most common types are:

  • Impulse Turbines: These turbines use high-velocity jets of water to strike the blades. The water hits the blades and then falls away. An example is the Pelton wheel. They are used in sites with high head (large height difference) and low flow.
  • Reaction Turbines: These operate with water flowing over and around the blades, causing pressure differences that spin the turbine. Examples include Francis and Kaplan turbines. These are suitable for low to medium head and higher flow conditions.

Hydraulic turbines are carefully selected based on the site conditions such as water flow rate, head (height difference), and power requirement. They are typically made of strong materials like stainless steel to withstand the constant force of water and resist corrosion.

Where they are used

Hydraulic turbines are mostly used in hydroelectric power plants to generate electricity. Their use depends on the availability of a water source and the possibility to create or use a natural height difference. Common places where they are used include:

  • Dams: Water stored in large reservoirs is released in a controlled way to spin turbines. This is the most common use.
  • Rivers: Small-scale turbines are sometimes installed in rivers with strong currents for decentralized power generation.
  • Waterfalls: Natural waterfalls provide the head required to drive impulse turbines.
  • Pumped Storage Plants: These use turbines in reverse during off-peak hours to pump water back up for reuse.

Apart from electricity production, hydraulic turbines are also used in some industrial processes where mechanical energy is required, though this is rare compared to power generation.

They are also eco-friendly compared to fossil fuel sources as they do not emit greenhouse gases. However, large hydro projects may affect aquatic life and local ecosystems, which is why proper planning and environmental assessment are essential before setting them up.

Conclusion:

Hydraulic turbines are vital machines that convert the energy from moving water into usable mechanical energy, mainly for generating electricity. They are used in hydroelectric power stations, dams, and rivers, contributing to renewable and sustainable energy generation. Their application is crucial for meeting global energy needs while reducing environmental pollution.