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Small Hydropower Plants
Published in Getu Hailu, Michal Varchola, Peter Hlbocan, Design of Hydrodynamic Machines, 2022
Getu Hailu, Michal Varchola, Peter Hlbocan
A penstock transports water from the intake to the turbine. Different materials can be used for penstock, including flexible hoses, pipes made of steel/iron, and concrete. Depending on the size, penstocks can be simply laid on the ground or anchored. For larger penstocks the anchor blocks resist the thrust of the penstock. In some cases, expansion joints are needed. This depends on the temperature variation of the location and operation of the turbine (continuous or interrupted). Some of the criteria for penstock material selection are: ground conditions, site accessibility, weight, jointing system, and cost (ESHA 2004). Pipe material and size determine hydraulic losses. Smooth pipes made of plastics will minimize frictional losses. Small-diameter pipes will cause high velocity, hence high frictional losses. With increasing pipe diameter, the frictional losses decrease; however the cost will increase. Selection of penstock material requires careful hydraulic and economic analysis. Selection of the wall thickness of the penstock is usually based on the maximum internal pressure, including transient surge pressures (ESHA 2004).
Hydroelectric power development
Published in P. Novak, A.I.B. Moffat, C. Nalluri, R. Narayanan, Hydraulic Structures, 2017
P. Novak, A.I.B. Moffat, C. Nalluri, R. Narayanan
The penstocks are pipes of large diameter, usually of steel or concrete, used for conveying water from the source (reservoir or forebay) to the power house. They are usually high-pressure pipelines designed to withstand stresses developed because of static and waterhammer pressures created by sudden changes in power demands (i.e. valve closures and openings according to power rejection and demand). The provision of such a high-pressure line is very uneconomical if it is too long, in which case it can be divided into two parts, a long low-pressure conveyance (tunnel) followed by short high-pressure pipeline (penstock) close to the turbine unit, separated by a surge chamber which absorbs the waterham-mer pressure rises and converts them into mass oscillations.
Fabrication and Erection of Steel Structure and Penstock
Published in Suchintya Kumar Sur, A Practical Guide to Construction of Hydropower Facilities, 2019
A penstock is a high pressure tunnel made of steel which connects the turbine scroll case with the surge shaft. The penstock shall be hydraucally efficient and structurally prepared to withstand the high pressure of the water head to prevent accidents. The penstock can be fabricated from many types of materials but steel is found to be the most friendly and suitable material for its strength and flexibility.
Hydraulic load-bearing mechanism in rib-strengthened steel bifurcation structures of hydroelectric power plants: Numerical simulation
Published in Mechanics Based Design of Structures and Machines, 2023
Lei Hu, Qi-Ling Zhang, Chang-Zheng Shi, He-Gao Wu
A hydroelectric system in a hydroelectric power plant (HPP) utilizes water resources to convert hydroenergy into electricity. Major components of a hydroelectric system include intakes, a penstock works and powerhouses. A penstock works is a conduit that provides water to hydroelectric power turbines. Penstocks fabricated of steel are typically employed to withstand internal water pressure (IWP) and resist buckling from external pressure when they are dewatered for inspection and maintenance (Valdeolivas and Mosquera 2015; El-Sawy 2013). For low head HPPs, exposed-to-air steel penstocks are commonly used for ease of installation, inspection and maintenance. For high head HPPs, a steel penstock is usually placed in reinforced concrete (Su et al. 2017) or underground in rock with backfilled concrete (Zhang et al. 2019).