How does the Hydro-Electric Power Plant work?
The Hydroelectric power plant utilizes the potential energy of water put away in a dam worked across a body of water. The potential energy of the water is utilized to run the water turbine to which the electric generator is coupled.
The mechanical energy accessible at the shaft of the turbine is changed over into electrical energy through the generator.
Structure of a Hydro-Electric Power Plant
Water reservoir:
Consistent accessibility of water is the fundamental need for a hydroelectric plant. Water gathered from catchment territory during the rainy season is kept in the reservoir. The water surface in the storage reservoir is known as head race.
Dam:
The dam functions in increasing the water level behind it, which increases the reservoir capacity as a whole. The dam helps in increasing the working head of the power plant.
Spillway:
Water in the dam after a specific level in the supply floods through spillway without permitting the increment in water level in the reservoir during the rainy season.
Pressing tunnel:
It conveys water from the reservoir to the surge tank.
Penstock;
Water from the surge tank is taken to the turbine through penstocks, comprised of built-up steel or concrete pipe.
Surge tank:
There is an unexpected increment of pressing factor in the penstock because of abrupt backflow of water, as a burden on the turbine is decreased. The unexpected ascent of pressing factor in the penstock is known as water hammer.
The flood tank is presented between the dam and the force to be reckoned with to keep in lessening the unexpected ascent of pressing factor in the penstock. In any case, penstock will be harmed by the water hammer.
Water turbine:
Water through the penstock goes into the turbine through a channel valve. Prime engines which are in like manner use are Pelton turbine, Francis turbine and kalpan turbine. The possible energy of water entering the turbine is changed over into mechanical energy.
The mechanical energy accessible at the turbine shaft is utilized to run the electric generator. The water is then released through the draft tube.
Draft tube:
It is associated with the power source of the turbine. It permits the turbine to be set over the tailrace level.
Tailrace:
Tailrace is a water approach to lead the water released from the turbine to the waterway. The water held in the tailrace is called the tailrace water level.
Step-up transformer:
It can raise the voltage produced at the generator terminal before communicating with the force buyers.
Powerhouse
The powerhouse obliges the turbine, generator, transformer and control room.
Classes of hydro-power plants
Hydro-plants are classified by the head of water under which they work.
At the point when the working head of water surpasses 70 meters, the plant is known as a “high head power plant”. Peloton turbine is utilized as the main player in such force plants.
At the point when the head of water range is from 15 to 70 meters then the force plant is known as “medium head plant”. It utilizes a francis turbine.
At the point when the head is under 15 meters the plant is named as “low head plant”. It utilizes Francis or Kaplan turbine as the main player.
Benefits of hydro-electric force plants
- Water is an inexhaustible wellspring of energy. Water which is the working liquid is neither burned-through nor changed over into something different.
- Water is the least expensive wellspring of energy since it exists as an unconditional presence of nature. The energizes required for warm, diesel and atomic plants are expendable and costly.
- There are no debris dispensable issues as in the event of a nuclear energy station.
- Hydro-plant doesn’t represent the issue of air contamination on account of warm plant or radiation dangers as on account of the atomic plant.
- Variable burdens don’t influence the proficiency on account of a hydro-plant.
- The life of hydro-plant is extremely long (1 or 2 centuries) contrasted with the warm plant ( 3 with forty years). This is because the hydro-plants work at climatic temperature, though warm plants work at extremely high temperature (around 500 to 800’c).
- Hydro plants give extra advantages like water system, flood control, fishery and amusement.
- The water stockpiling of hydro-plant can likewise be utilized for homegrown water supply.
- Assistants required for the hydro-plant are less contrasted with a warm plant of equivalent limit.
- It requires less directing staff.
- Support cost is low.
Hindrances of hydro-electric force plant:
- Hydro-plants are for the most part arranged away from the heap habitats. Thus long transmission lines are needed for the conveyance of force. This builds the expense of transmission lines and transmission misfortunes. Yet, a warm plant can be situated close to the heap community, accordingly, the transmission cost and transmission misfortunes are impressively diminished.
- The force delivered by hydro-plant relies on the amount of water which thus is subject to precipitation. The dry year influences the hydropower age significantly.
- The introductory expense of the plant is high.
- Erection of hydro-plant (development of dam) normally takes a significant period.
Reference: eeguide.com
