Which turbine operates at low discharge rate and high head?
Table of Contents
- 1 Which turbine operates at low discharge rate and high head?
- 2 Which turbine is used for low head and low discharge?
- 3 Is used to control discharge in Pelton turbine?
- 4 Which turbine is used in low head plants?
- 5 Why Pelton turbine has high efficiency?
- 6 Is reaction turbine is suitable for low discharge?
Which turbine operates at low discharge rate and high head?
Pelton turbine
Pelton turbine – Low discharge and high head. Francis turbine – Medium discharge and medium head.
Which turbine is used for low head and low discharge?
Reaction turbines are generally used for sites with lower head and higher flows and are the most common type currently used in the United States. The two most common types of reaction turbines are Propeller (including Kaplan) and Francis. Kinetic turbines are also a type of reaction turbine.
Why is Pelton used at 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.
Why do impulse turbine needs high head and low flow rate?
They are suitable for high head and low flow rates. Impulse turbines work based on the change of velocity vectors, that is, the potential energy of the water (or other sources of fluid, e.g., steam) depending on the height of the waterfall is converted into kinetic energy by one or more nozzles.
Is used to control discharge in Pelton turbine?
The spear/needle controls the flow of water through the nozzle and thus the amount of force exerted upon the wheel. Not all Pelton wheels have a spear or needle. The spear adjuster can be operated manually, electrically or hydraulically.
Which turbine is used in low head plants?
Venturi turbines can be used at low heads (1.5–5 metres) and medium to high flows (1m3/s–20 m3/s). Multiple turbines can be installed in parallel.
Which turbine is used for low heads and large quantities of flow?
7.3. 1.2. 2 Kaplan turbine
| Parameters | Pelton turbine | Kaplan turbine |
|---|---|---|
| Flow type | Axial flow turbine | Axial flow turbine |
| Number of vanes and buckets | Wheel with 20–40 buckets | Impeller with 4–8 vanes |
| Head requires | Very high head (above 300–400 m) | Low head (below 100 m) |
| Flow rate | Low flow rate | Very large flow rate |
Is the Pelton impulse turbine a low pressure high flow rate or a high pressure low flow rate device?
The Pelton turbine is generally used where a high head of water is available and the flow rate is relatively low. For large hydropower plants, they are normally used when a head height of more than 450 m is available but they can be used for heads a low as 200 m.
Why Pelton turbine has high efficiency?
Pelton’s paddle geometry was designed so that when the rim ran at half the speed of the water jet, the water left the wheel with very little speed; thus his design extracted almost all of the water’s impulse energy—which made for a very efficient turbine.
Is reaction turbine is suitable for low discharge?
Railways Question. i) Reaction Turbine: A turbine for which both pressure energy and kinetic energy is available at the inlet is a reaction turbine. E.g. Francis Turbine, Kaplan Turbine and Propeller Turbine. They are useful for low head and high discharge.
Which turbine works at low speed Mcq?
Specific speed of Pelton turbine is lowest. Speed of Kaplan turbine is 2 to 3 times more than that of Francis turbine. Explanation: During load variation it is necessary to maintain the speed of the alternator constant.