Determination of conversion relations for the use of small hydrodynamic pumps in reverse turbine operation
Czech University of Life Sciences in Prague, Faculty of Engineering, Kamýcká 129, CZ16521, Praha 6, Czech Republic
In small-scale hydropower, hydrodynamic pumps used in reverse mode are an important economical alternative to conventional water turbines. Efficient utilisation of these devices however requires taking into account all the specifics of the reverse pump operation and optimise the pump design for maximum utilisation of the hydro-technical potential of the deployment site. The article compares existing conversion models, describes initial theoretical assumptions and determines new conversion relations for the design of pumps as turbines (PAT) for the lowest power and specific speed category. The validity of the conversion relations is experimentally verified on a hydraulic test circuit with a radial centrifugal pump tested in both pump and turbine operation modes. The results of the verification of the new conversion relations proved better correspondence to reality within this category of machines than that reported by the previously used conversion models.