What are the types of hydraulic turbines?
There are two main types of hydro turbines: impulse and reaction. The type of hydropower turbine selected for a project is based on the height of standing water—referred to as “head”—and the flow, or volume of water, at the site. Other deciding factors include how deep the turbine must be set, efficiency, and cost.
What type of turbine is Kaplan turbine?
A Kaplan turbine is basically a propeller with adjustable blades inside a tube. It is an axial-flow turbine, which means that the flow direction does not change as it crosses the rotor. Figure 1 shows a simplified Kaplan turbine.
What type of turbine is Francis turbine?
The Francis turbine is a type of water turbine that was developed by James B. Francis in Lowell, Massachusetts. It is an inward-flow reaction turbine that combines radial and axial flow concepts. Francis turbines are the most common water turbine in use today.
What are four types of turbines?
While turbines can be classed as either impulse or reaction according to the way they function, there are four broad types of turbines categorized according to the fluid that supplies the driving force: steam, gas, water, or wind.
Which turbine has highest speed?
Francis turbine
How turbines are classified?
Reaction turbines are classified as Francis (mixed flow) or axial flow. Axial flow turbines are available with both fixed blades (Propeller) and variable pitch blades (Kaplan).
What is turbines and its types?
There are 3 main types of impulse turbine in use: the Pelton, the Turgo, and the Crossflow turbine. The two main types of reaction turbine are the propeller turbine (with Kaplan variant) and the Francis turbine. The reverse Archimedes Screw and the overshot waterwheel are both gravity turbines.
What is impulse turbine give example?
Artwork: A Pelton water wheel is an example of an impulse turbine. It spins as one or more high-pressure water jets (blue), controlled by a valve (green), fire into the buckets around the edge of the wheel (red).
Which turbine is used for high head?
Hydropower Turbines
| Hydropower Turbine Type | Typical Site Characteristics |
|---|---|
| Kaplan turbine | Low to medium heads (1.5 – 20 metres) Medium to high flows (3 m3/s – 30 m3/s) For higher flows multiple turbines can be used. |
| Pelton/Turgo turbine | High heads (greater than 25 metres) Lower flows (0.01 m3/s – 0.5 m3/s) |
What is the head of a turbine?
Head is the change in water levels between the hydro intake and the hydro discharge point. It is a vertical height measured in metres. The two diagrams below show how the head would be measured on a typical ‘low head’ and a typical ‘high head’ site.
Why Pelton turbine is used for high head?
These turbines are generally used for sites with heads greater than 300 meters. The water in a Pelton turbine is moving quickly (high velocity head, figure 2) and the turbine extracts energy from the water by slowing the water down, which makes this an impulse turbine.
Which turbine is used for low head?
propeller turbines
Which turbine is used for low head and high discharge?
What is the specific speed of turbine?
The specific speed value for a turbine is the speed of a geometrically similar turbine which would produce unit power (one kilowatt) under unit head (one meter). The specific speed of a turbine is given by the manufacturer (along with other ratings) and will always refer to the point of maximum efficiency.
Is propeller a turbine?
The Propeller Turbine is an inward flow reaction turbine, similar to a Kaplan design, but with fixed blades. It is a very common turbine and works best with high flow rates. Its moving part (runner) is a propeller, similar to those that push ships and submarines through water.
What is the difference between propeller and turbine?
Aircraft propellers are designed to move high velocity air and avoid the turbulence by moving out of the way. Wind turbines use blade pitch to adjust the rotation speed and the generated power. In aircraft, blade pitch is usually described as “coarse” for a coarser angle, and “fine” for a finer.
What is the difference between propeller and Kaplan turbine?
The Kaplan is of the propeller type, similar to an airplane propeller. The difference between the Propeller and Kaplan turbines is that the Propeller turbine has fixed runner blades while the Kaplan turbine has adjustable runner blades. It is a pure axial flow turbine uses basic aerofoil theory.
What is impulse turbine?
The impulse turbine is the simplest type of turbine. It consists of a row of nozzles followed by a row of blades. The gas is expanded in the nozzle, converting the high thermal energy into kinetic energy.
What is the principle of impulse turbine?
Impulse turbine works on the basic principle of impulse. When the jet of water strikes at the turbine blade with full of its speed, it generates a large force which used to rotate the turbine. The force is depends on the time interval and velocity of jet strikes the blades.
What are the three types of turbine blades?
Turbine blades are classified into three types: Impulse, reaction, and impulse-reaction. ducts as turbine blades. Turbine engines can use two types of compressors: Axial flow or centrifugal flow.
What is the principle of turbine?
Wind turbines operate on a simple principle. The energy in the wind turns two or three propeller-like blades around a rotor. The rotor is connected to the main shaft, which spins a generator to create electricity.
What is the main function of a turbine?
A turbine is a steam-powered machine that causes a shaft—a rotating rod that transmits power or motion from the turbine—to produce electricity through movement.
Why it is called reaction turbine?
The nozzle-guide vanes only guide the flow for the rotors. The turbine is driven by the reaction force resulting from the acceleration of gases through the converging blade passage and, hence, the name.
Do wind turbines generate AC or DC?
The generator in a wind turbine produces alternating current (AC) electricity. Some turbines drive an AC/AC converter—which converts the AC to direct current (DC) with a rectifier and then back to AC with an inverter—in order to match the frequency and phase of the grid.
Why do wind turbines have 3 blades?
Having fewer blades reduces drag. But two-bladed turbines will wobble when they turn to face the wind. With three blades, the angular momentum stays constant because when one blade is up, the other two are pointing at an angle. So the turbine can rotate into the wind smoothly.
Is a generator AC or DC?
Uses & Design Differences An AC generator creates an alternating current that periodically reverses direction. But in a DC generator, a direct current flows in one direction. In an AC generator, the coil through which current flows is fixed and the magnet usually moves.
What are the two types of wind turbines?
There are two basic types of wind turbines:
- Horizontal-axis turbines.
- Vertical-axis turbines.
Why is HAWT better than VAWT?
An Archimedes turbine may be the compromise between VAWT and HAWT. More maintenance – While a VAWT has fewer components that can wear and require repair, the forces acting on the machine are more turbulent than those on a HAWT. When a HAWT is pointed in the right direction, the blades are also pitched optimally.
What are 3 disadvantages of wind energy?
Various Disadvantages of Wind Energy
- The wind is inconsistent.
- Wind turbines involve high upfront capital investment.
- Wind turbines have a visual impact.
- May reduce the local bird population.
- Wind turbines are prone to noise disturbances.
- Installation can take up a significant portion of land.
- Wind turbines can be a safety hazard.
What are the disadvantages of vertical axis wind turbines?
The challenges brought by disadvantages of vertical axis wind turbines
- Less Rotation Efficiency.
- Lower Available Wind Speed.
- Component Wear-down.
- Less Efficiency.
- Self-Starting Mechanism.