A penstock in a hydropower plant is a long pipe or channel that carries water from the reservoir to the hydroelectric power stations specifically to the turbines. It is considered to be an important constituent of the hydropower plant working by ensuring the direct and clean flow of water to the turbine by removing the debris and other unwanted materials by the attached filters at the ends of the pipe.
Depending upon the size of the power plant the length and circumference of the penstock also varies. A regular inspection of the pipe ensures identification and fixes any problems like cracks, holes, and splits in the penstock preventing possible catastrophic events in the built dams.
Role of Penstock in Hydropower Plant
Penstock usually consists of a gate like structure called sluice which is opened or closed depending upon the amount of water required to regulate the hydropower plant. The flow of the water in a hydroelectric power station is based on the turbine’s operation and if turbines are non-functioning, then the flow is nil. Apart from being used in hydropower plants, it is also utilized for its functions in an irrigation dam or a mine tailing dam construction.
Proper precautions should be taken when the sources of water are polluted in a hydroelectric system by cleaning the penstocks using hot water, manual methods or by coating it with an antifouling solution.
Also See: What is Hydraulic Head in Hydroelectric Powerplant?
Location of Penstocks
The location of the penstock route should be properly laid out by considering the following mentioned parameters which ensures the cost of construction is minimized and friction produced is also reduced:
- Accessibility: The installation of the penstock should be done in areas where disturbance is less, and maintenance could be done easily.
- Soil conditions: The conditions of the soil should be checked before incorporating pipelines to ensure no rock outcrops are present, which might hinder the flow of water.
- Gradient: The pipeline is best laid out on a downward gradient and an air relief valve is required at a local high point, and a drain valve is required at the local low point.
- Obstructions: These can be natural such as trees, rivers, and streams on the other hand various man-made structures like buildings, roadways, and highways also create disturbances in the penstock functioning.
Also Read: What is Pondage in Hydropower Plant?
Materials used in Penstock Valve
Penstocks in hydropower plant are usually found to be made up of steel because of its strong and durable nature but there have been various new alternative materials available in the market depending upon the specific requirements
- PVC (polyvinyl chloride)
- Polyethylene
- FRE (fiber reinforced epoxy)
- Transite (asbestos cement).
Uses of Penstocks in Hdropower Plant
Majorly penstocks in hydropower plant are used in a system where water needs to be channelized from a far-off source to the area of utilization such as in a water management system which could be:
- Surface water drainage
- Foul water sewers.
It is created to regulate the flow of water from the source as per the requirement of the hydropower plant or irrigation dam for which it has been used by filtering the debris. The pressure on the turbine is also maintained by penstock.
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