Title: Control of dynamic effects in small hydro with long hydraulic circuits

Authors: Helena Ramos, A. Betamio De Almeida

Addresses: Civil Engineering Department, Technical University of Lisbon–IST UTL, Lisbon 1049 001, Portugal. ' Civil Engineering Department, Technical University of Lisbon–IST UTL, Lisbon 1049 001, Portugal

Abstract: Lab tests in a long hydraulic circuit were developed to analyse hydrotransients induced by waterhammer effects under runaway conditions. The definition of suitable design criteria in hydraulic systems is of utmost importance and has become a priority for good design implementation. The dynamic behaviour of turbo-generators of small reaction turbines and the interaction with long hydraulic circuits are the major constraints for design criteria. In small reaction turbines, runaway conditions may cause significant discharge variations and consequently pressure fluctuations. A benchmark analysis based on the hydrodynamic behaviour of the system through computer simulations and experimental tests was developed. Specific unconventional protection devices were selected to control overpressures induced by runaway conditions in small hydropower systems with lesser environmental impacts. A spectral analysis was used in order to identify the influence of each type of disturbances in the system response.

Keywords: small hydro; small reaction turbines; runaway conditions; dynamic effects; protection devices; design criteria; long hydraulic circuits; hydrotransients; waterhammer; hydrodynamics; simulation.

DOI: 10.1504/IJGEI.2005.007077

International Journal of Global Energy Issues, 2005 Vol.24 No.1/2, pp.47 - 58

Published online: 24 May 2005 *

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