Abstract :
Hydropower plants play an important role in the growth of the renewable
energy sector. The main objective of the paper is to present, discuss and
assess critical parameters which may cause unacceptable water hammer
loads in hydropower plants. Water hammer is caused by flow disturbances
in a conduit from one steady state to another. It induces pressure rise or
drop in hydraulic systems, rotational speed variation in hydraulic
turbomachinery and level fluctuation in surge tanks and air chambers.
Design principles of water hammer control strategies (mitigation of excessive
loads) are outlined including operational scenarios (closing and opening laws),
surge control devices (flywheel, surge tank, regulating valve, air valve, etc.) or
redesign of the pipeline components. Water hammer models and solutions
are briefly discussed in the light of their capability. Case studies include
hydropower plants with long fluid conveying systems (open channels, tunnels)
and water hammer control devices (surge tank, regulating valve).
Keyword :
hydropower plant, water hammer control, surge tank, regulating valve, numerical analysis, field tests.