Penstock refers to the pipeline that transfers water to the hydraulic turbine from the reservoir or hydropower station leveling structure (forebay or surge chamber). It is an important part of hydropower station, characterized by steep slope, large internal water pressure, close to the power house, and bearing the hydrodynamic pressure of water hammer. Therefore, it is also called high pressure pipe or high pressure water pipe.
The function of pressure water pipeline is to transport water energy. It can be said that the penstock is equivalent to the “artery” of hydropower station.
1、 Structural form of penstock
According to different structures, materials, pipe layout and surrounding media, the structural forms of penstocks are different.
（1） Dam penstock
1. Buried pipe in dam
The penstocks buried in the concrete of the dam body are called embedded pipes in the dam. Steel pipes are often used. The layout forms include inclined, horizontal and vertical shafts
2. Penstock behind dam
The installation of buried pipes in the dam has great interference with the dam construction, and affects the dam strength. Therefore, the steel pipe can be arranged on the downstream dam slope after passing through the upper dam body to become the dam back pipe.
（2） Surface penstock
The penstock of the diversion type ground powerhouse is usually laid in the open air along the ridge line of the mountain slope to form the ground penstock, which is called the open pipe or the open penstock.
According to different pipe materials, there are usually two types:
1. Steel pipe
2. Reinforced concrete pipe
（3） Underground penstock
When the topographical and geological conditions are not suitable for open pipe layout or the power station is arranged underground, the penstock is often arranged below the ground to become an underground penstock. There are two types of underground penstocks: buried pipe and backfilled pipe.
2、 Water supply mode from penstock to turbine
1. Separate water supply: one penstock only supplies water to one unit, that is, single pipe single unit water supply.
2. Combined water supply: a main pipe supplies water to all units of the power station after the end bifurcates.
3. Grouped water supply
Each main pipe will supply water to two or more units after branching at the end, that is, multiple pipes and multiple units.
Whether joint water supply or group water supply is adopted, the number of units connected to each water pipe should not exceed 4.
3、 Water inlet mode of penstock entering hydropower house
The axis of the penstock and the relative direction of the plant can be arranged in a positive, lateral or oblique direction.
Post time: Oct-17-2022
