Thanks to the partnership between OFEN, Sulzer Pumps, EIG and HEVS important improvements for the determination of performance of pumps as turbines and for the use of small variable speed generators in small power plants have been done.
The method proposed is based on the determination of a model which computes the total head losses in pump operation with the help of the pump geometry. Then, this model is applied to determine the characteristics in turbine operation.
The pump model has been divided in elements connected in series and in parallel from the inlet to the exit of the pump. The calculation of hydraulic losses in each element (friction losses, bend losses, gradual expansion and contraction, sudden expansion or contraction) has been performed and the sum of those gives the total head losses through the pump.
For this project, 5 pump geometries have been used in order to verify the model. As a result, the model of losses allows a prediction of the head at the best efficiency point (BEP) in pump operation with a shift between 4 and 5 %.
In turbine operation, by comparing the turbine characteristics predicted and the experimental data, a shift from 2 to 5% is observed at the BEP.
A software programmed in Excel has been developed and it is available for free use (from the Swiss Small Hydropower Programme, www.smallhydro.ch, please write to
pl@smallhydro.ch).Auftragnehmer/Contractant/Contraente/Contractor:
Autorschaft/Auteurs/Autori/Authors:
Dubas,Michel
Biner,Hans-Peter
