by Types of Water Turbines
There are mainly three types of water turbines that are used for power generation from water: impulse turbine, reaction turbine, and mixed-flow turbine. Each type has its own characteristics which make it suitable for different hydraulic conditions.
Impulse Turbine
Impulse turbines utilize the velocity or kinetic energy of water to move the runner blades. Water Turbine enters the turbine with high velocity but low pressure and leaves the turbine with low velocity but without giving up its full pressure head. Impulse turbines like Pelton wheel are best suited for installations having high head of water and low flow. They can achieve highest efficiencies of over 90%. However, they have a smaller operating range as compared to reaction turbines.
Reaction Turbine
In reaction turbines, the pressure energy of water is also utilized along with its kinetic energy in moving the runner blades. Water enters and leaves the turbine with changes in both pressure and velocity. Examples include Francis turbine and Kaplan turbine. Francis turbines are more efficient for medium heads with high discharge, while Kaplan turbines can operate efficiently over a wide range of heads and flows which makes them suitable for varying hydraulic conditions. Their maximum efficiency is slightly lower around 85-90%.
Mixed-Flow Turbine
Mixed-flow Water Turbine combine the working principles of both impulse and reaction turbines. Water enters the runner blades tangentially like in reaction turbines but leaves both tangentially and radially as in impulse turbines. They have the widest operation range and higher efficiency than impulse turbines, although slightly lower than reaction turbines. They can efficiently harness energy from varying flow conditions making them a good choice for small head hydro sites.
Advantages and Uses of Water Turbines
Environment Friendly: Water turbines produce no pollutants and have little emissions making them one of the cleanest renewable energy sources.
Reliability: With proper maintenance, water turbines can last for decades and keep generating power as long as there is flow of water.
Multiple Applications: Water turbines are used not just for electricity generation but also for irrigation, industrial processing and transportation.
Peak Load Management: Turbines help reduce peak demand on conventional grids and provide power during emergencies supplementing conventional power plants.
Small Scale Solutions: Mini/micro hydro systems use small turbines to generate electricity even at small dams and irrigation canals to power rural/remote locations.
Worldwide Usage: Globally, hydropower constitutes around 16% of total electricity generation with major developing regions still having huge untapped hydro potential. Key nations leading in hydro include China, Brazil, Canada, USA, Russia, India etc.
Emerging Technologies in Water Turbines
Crossflow Turbine: They combine the benefits of both impulse and reaction turbines and can harness water energies efficiently even at low heads below 3m. With twin runnes oriented perpendicular to the flow direction, their solid design also allows handling of sediment-laden waterstreams.
Tidal Turbines: These underwater turbines harnesses energy from tidal currents utilizing horizontally-axis or vertical-axis design. Emerging technologies are making them more efficient, durable and easy to install and maintain even in harsh marine environments.
Hydrokinetic Turbines: Similar to tidal turbines but optimized to tap energies from river/ocean currents, waves or temperature gradient between water layers. Developments in composite materials and power electronics are aiding their widespread commercial applications.
Fish-Friendly Turbines: Advanced designs minimize fish injury risks through features like mesh screens, wide blade spacing, reduced blade tips speeds. CFD modelling helps optimize turbine hydraulics to minimize ecological impacts on aquatic life.
Condition Monitoring Systems: Sensors, controls and data analytics are enhancing turbine monitoring, predictive maintenance, remote operations and lifetime performance. Automation solutions will boost hydropower capabilities and integration into smart grids.
These turbines have become highly efficient and versatile machines for hydropower generation. Constant R&D is further advancing turbine designs and support systems to achieve optimized energy extraction from various watercourses in a sustainable manner. With growing global focus on clean energy transition, hydropower backed by innovative water turbine technologies will surely play a major role in future energy mixes worldwide.
*Note:
1. Source: Coherent Market Insights, Public sources, Desk research
2. We have leveraged AI tools to mine information and compile it
