What is the basic requirements of hydroelectric power station MCQS?
Availability of water, large catchment area and rocky land are primary requirements for site selection of hydroelectric power plant. Explanation: Potential energy of large quantity of stored water is used by hydroelectric power plant to generate electrical energy.
What is the gross head of hydroelectric power station?
Gross head of a hydroelectric power plant is given by the O (A) height of the water level in the river where the storage is provided. (B) height of the water level in the river where the tail race is provided. (C) difference of height of the water level between the level in the storage and tail race.
Which turbine is used for medium head?
Hydropower Turbines
| Hydropower Turbine Type | Typical Site Characteristics |
|---|---|
| Crossflow turbine | Low to medium heads (2 – 40 metres) Low to medium flows (0.1 – 5 m3/s) |
| 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. |
How do I choose a hydropower turbine?
Following are the factors affecting selection of hydraulic turbines : Head. Specific speed….
- Head.
- Specific speed.
- Rotational speed.
- Efficiency of turbine.
- Cavitation.
- Disposition of turbine shaft.
- Part-load operation.
How are turbines selected?
Selecting the appropriate type of turbine depends primarily on available head and less so on available flow rate. The three primary types of turbines are: the Pelton turbine, for high heads; the Francis turbine, for low to medium heads; and the Kaplan turbine for a wide range of heads (see Figure 2.3a below).
What is unit speed of turbine?
The unit speed is the speed of the turbine operating under one meter head. Mathematically, unit speed, The unit discharge is the discharge through a turbine when the head on the turbine is unity. Mathematically, unit discharge, The unit power is the power developed by a turbine when the head on the turbine is unity.
What is the unit of specific speed of turbine?
Turbine specific speed 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).
Is specific speed of turbine is dimensionless?
For turbines, the values of N , P and H , and for pumps and compressors, the values of N , Q and H are usually quoted for which the machines run at maximum efficiency. The name specific speed for these expressions has a little justification. The specific speed is, therefore, not a dimensionless quantity.
Which of the following is an impulse turbine?
Explanation: Pelton Wheel Turbine is an example of impulse Turbine.
What is specific speed and unit quantities?
UNIT AND SPECIFIC QUANTITY. In order to predict the behavior of a turbine working under varying conditions of head, speed, and power, recourse has been made to the concept and unit The unit quantities give the speed, discharge and power for a particular turbine under a head of 1m assuming the same efficiency.
Which type of centrifugal pump is most suitable for high flow and low head application?
Radial discharge pumps are suitable for sites with low flow and high head and axial discharge pumps are suitable for high flow and low head sites.
How do you calculate the speed of a centrifugal pump?
We must divide N by 9.55 to convert to radians/second. Q must be divided by 449 to convert to ft3/second and H must be multiplied by 32.2. The result tells us that to convert from U.S. units to dimensionless values requires that the U.S. values for NS be divided by 2,735.
What is pump speed?
Rotational speed (also called speed, or speed of rotation) can be quantified as the number of revolutions a rotating system makes within a defined period of time. The unit used for rotational speed is s–1 (rev/s); pump speed is generally given in min–1 (rpm).
What is H in pump?
Total head (H) [Htx]– This is the measure of energy increase, per unit weight of liquid, imparted to the liquid by the pump, and is the difference between total discharge head and total suction head.
What will happen when we increase the RPM of a centrifugal pump?
Pump efficiency also increases with pump rotational speed, especially high speeds. The increase is not as pronounced at 3,600 rpm and below. Specific speed also affects head-capacity curve shape. Low specific speeds (500 to 1,500) produce flat curves.