1. HYDRO-ELECTRIC POWER PLANT
Contents:
General arrangement of storage Type Hydro-Electric Project and its operation.
Essential feature or elements of Hydro-Electric power plant.
Site Selection for Hydro-Electric power plant.
Advantages of a Hydro-Electric power plant.
Disadvantage of a Hydro-Electric power plant.
Compression of Hydro-Electric power plant and steam power plant.
Problem- 3 no.

2. HYDRO-ELECTRIC POWER PLANT
General Arrangement of Storage Type Hydro-electric Project and it, s Operation.

3. HYDRO-ELECTRIC POWER PLANT
The basic requirement of a hydro-electric power station is a reservoir where large quantity of water is stored during flood season and used during dry season. the reservoir is generally built by constructing a dam across a river. The water from the reservoir is drawn by the fore bay through an open canal or turned. The water from the fore bay is supplied to the water prime mover through the penstock which is located at much lower level than the height of water in the reservoir. The water entering into the turbine rotates the turbine shaft and ultimately the generator shaft rotates ,it cuts the magnetic flux, and power produce. In hydro-electric plants the potential energy of water is converged into kinetic energy, first passing through the tunnel to the power house. The kinetic energy in the water turbines utilized to run the electric generator. This is the common principle of hydro-electric generation.

4. HYDRO-ELECTRIC POWER PLANT
Essential Feature or Element of Hydro-electric power plant
are as follows:
Reservoir
Dam
For eBay
Trash rack
Water way
Draft tube
Surge tank
Spill way
Power house
Prime movers

5. HYDRO-ELECTRIC POWER PLANT
1. Reservoir: The main purpose of the reservoir is to store the water during rainy season and supply the same during dray season.
2. Dam: The function of the dam is to increase the height of water level behind it which ultimately increases the reservoir capacity.
3. For eBay: It acts as a sort of regulating reservoir temporarily. Water is temporarily stored in the fore bay is the event of a rejection of load by the turbine and there is withdrawal of water from it when load increased.

6. HYDRO-ELECTRIC POWER PLANT
4. Trash Rack: The water intakes from the dam or from the fore bay is large and height of trash rack structure is more, mechanical cleaning is economical.
5. Water way: A water is used to carry water from the dam to power house. It includes canal, penstock or tunnel.
6. Draft tubes: It is an integral part of reaction turbine. The water after doing work on the turbine runner passes through the draft tube to the tail race . Draft tube is a metallic pipe or concrete tunnel having gradually increasing cross-sectional area towards outlet to ensure that as little energy as possible is left in water as it discharges into the tail-race.

7. HYDRO-ELECTRIC POWER PLANT
7. Surge tank: The surge tank controls the water when the load on the turbine decreases and supplies water the load on the turbine increases.
8. Spillway: Spillway is considered a safety valve for a dam. It must have the capacity to discharge major floods without damage to the dam and at the same time keeps the reservoir level below some predetermined maximum level.
9. Power house: The function of the power house is to support the hydraulic and electric equipment as well as protect this equipments
1o. Prime Movers: The main purpose of the prime movers is to convert the kinetic energy of water into mechanical energy to produce electric energy.

8. HYDRO-ELECTRIC POWER PLANT
Site selection for Hydro-electric power plant:
The various factors to be considered while selecting the site for
hydro-electric power plant are as follows:
water Available: Estimate should be made about the verge quantity of water available through the year also about maximum and minimum quantity of water available during the year. These factors are necessary to decide the capacity of the hydro-electric plant.
Storage of water: Water used in the hydro-electric power is mainly dependent on the rain and since the rainfall is not-regular through the year, therefore, it is essential store water to afford a uniform output.

9. HYDRO-ELECTRIC POWER PLANT
3. Heat of water: Water in large quantities and a sufficient heat should be available.
Distance from load centre: It is desirable that the power plant should be set up near the load centers..So that costs of erection of the transmission lines and their maintenance are low .
Accessibility: The site selection should have rail and road trans potation facility. The idle site will be one where the dam will have the largest catchment area to store water at a high heat and will be economical in construction.

10. HYDRO-ELECTRIC POWER PLANT
The various disadvantages of hydro-electric power plant are as
follows:-
The power produced by the plant depends upon the rainfall, if the rainfall is in time , the plant will function satisfactorily other wise not.
Hydro-electric plants are generally situated away from the load centers, Therefore ,the cost of transmission lines and losses in then will be more.
Initial cost of the plant is high.
It takes fairly long time for the creation of such plant.

11. HYDRO-ELECTRIC POWER PLANT
Advantages of Hydro-electric power plant are as follows:-
Water is the cheapest reliable source of generation of generation of electric power because exits as a free gift of nature.
There are no ash disposal problems.
No fuel transpiration problem.
Its maintenance cost is low.
It requires less supervising staff.
Auxiliaries needed in the plant are less as compared to steam plant of equal size.
Running cost of the plant is low.
In addition to the power generation such are used for irrigation and flood control purpose also.

12. HYDRO-ELECTRIC POWER PLANT
Comparison of Hydro-electric power plant and steam- power plant:
The initial cost of a hydro-electric power plant is nearly twice or more as that of steam power plant of equal size.
It is easy to locate steam power plant near the load centre where as power generated by a hydro- power plant is to be transmitted over longer distance and hence at greater costs.
the efficiency of steam power plant drops as it gets older.
Steam power station can be operated as the demand of the load system where as power to be generated from hydro-plant is dependent on the quantity of water available in the storage.
The cost of transportation of fuel is quite high in case of steam power plant .
As compared of fuel is quite high in case of steam power plant.
as compared to steam power plant the hydro-electric generation is the cleanest and most simple way.

13. HYDRO-ELECTRIC POWER PLANT
FORMULA
Performance of water turbine,
P = wHQ/ (where P=power produced by a turbine)
P = ȠwɸH/ (where P= total power available)
Ns= N√P/H5/4
V = Ku√2gH = πDN/60
Where,
Q = Discharge (m3)
H = Net head (m)
W = unit weight of water
ɸ = Discharge(m3)
Ƞ = Turbine efficiency (%) ,

14. HYDRO-ELECTRIC POWER PLANT
Ns = specific speed
N = speed
V = Tangential velocity of the runner
Ku = speed ratio
D = Diameter of runner 
Note:
Pelton turbine = (Ns = )
Francis turbine = (Ns= )
Kaplan turbine = (Ns= )

15. HYDRO-ELECTRIC POWER PLANT
Problem: 1
A turbine develops Hp working under a head of 520m when
running at 400rpm. Calculate specific speed of the turbine. Specify
the type of turbine to be used.
Given,
P = 18,800 Hp
H = 520m
N = 400rpm
Required,
Ns = ?
What type of turbine used = ?
We know, Ns = (N √p) / H5/4 = (400 √18000) / 5205/4 = 21.6 i.e. the specific speed of the turbine is 21.6 and Ns = 21. i.e. the type of turbine to be used is pelton turbine (Answer).

16. HYDRO-ELECTRIC POWER PLANT.
Problem: 2
It is desired to built a hydro-electric power station across a river having
a discharge of liter/second. At a heat of 10m. Assume the
turbine efficiency 80% and speed ratio ku as Determine the
following-
Is it possible to use two turbine with a speed not less than 120 rpm and specific speed not more than 350 rpm.
Specify the type of runner that can be used. Also calculate the diameter of runner.
Given data,
ɸ = 30,000 liter/sec
H = 10m
Ƞ= 80% or 0.80
ku= 0.83
W = 1(for water)

17. HYDRO-ELECTRIC POWER PLANT
To find:
(a) Is it possible to use two turbine ?
When,
N ≥ 120
Ns ≤ 350
D = ?
(a) We know
P = (Ƞw ɸH) / 75
= (0.80 x 1 x 30,000 x 10) / 75
= HP
Again,
Ns = (N √P) / H5/4
= (120 √1600) / 105/4
= 270 r.p.m
i.e Ns = 270 r.p.m ( Ns≤350 rpm)
And, if Ns = 350
Ns= (N √p) / H5/ N = (Ns H5/4 ) / √1600
= (350 x 105/4) / √1600
= 155 r.p.m

18. HYDRO-ELECTRIC POWER PLANT
i.e. it is possible to use two turbines with a speed not less then
120 r.p.m and specific speed not more than 350 r.p.m (Answer).
(b) we know,
Ku√2gH = πDN/60
D = (60 x Ku√2gH) / πN
= (60 X 0.83 X √2 X 9.81 X 10) / (π X 120)
= 1.85m
i.e. the diameter of runner is 1.85 m (answer).

19. HYDRO-ELECTRIC POWER PLANT
Problem: 3 Calculate the specific speed of a turbine and suggest the types of turbine required for a river having a discharge of 250 liter/sec. with a available head of 50 meter. Assume efficiency of the turbine as 80% and speed 450 rpm.
We know
P = (ηwɸH) / 75
= (0.8 x 1 x 250 x 50) / 75
= hp
Ns = (N √p) / H5/4
= (450 √133.3) / (0.8)5/4
i.e. Ns= 39 (answer)
i.e. the required pelton turbine(Answer)
Given,
Q = 250 liter/sec
H = 50 m
Η = 80% or 0.8
N = 450 rpm
To find,
Ns = ?
Type of turbine = ?