DBPapers
DOI: 10.5593/SGEM2015/B41/S17.018

CONSIDERATIONS ON THE EXPERIMENTAL TESTING MEANS OF AXIAL HYDRAULIC TURBINE MODELS

T.C. Popescu, R. Radoi, M. Blejan, S. Nicolae
Friday 25 September 2015 by Libadmin2015

References: 15th International Multidisciplinary Scientific GeoConference SGEM 2015, www.sgem.org, SGEM2015 Conference Proceedings, ISBN 978-619-7105-38-4 / ISSN 1314-2704, June 18-24, 2015, Book4, 137-144 pp

ABSTRACT
For an effective use of the energy potential of watercourses an important link is represented by the means of experimental testing of the equipment which is representative for hydropower plants – the hydraulic turbines. Developing these turbines begins with a rough design, based on differential equations of ideal fluid movement, and continues with successive stages of performance testing under laboratory conditions, on reduced-scale models. Based on geometric, kinematic and dynamic similarity, conclusions drawn from the functioning of the model will be also valid for the real equipment, using for this different similarity criteria.
The aim of this paperwork is expressing opinions on the developing of a modern stand for experimental tests upon scale models for a type of kinetic turbine: the axial hydraulic turbines, which can be installed on the water stream, in locations that do not use dams or other facilities for water accumulation. The stand developed by the authors allows both study on water flow around hydrodynamic profiles and experimental determination of mechanical and energy characteristics, of mechanical torque and rotation speed variation at the shaft of the tested turbine model, depending on the load and flow rate. There are described the main technical performance of the stand and the main types of tests that can be conducted on it.
Water speed adjustment on stand is achieved by varying the rotation speed of three centrifugal electric pumps. The automation system of the stand includes three frequency inverters, which power the electric pumps of the pumping group, flow directional control valve, fitted to the discharge pipe of the pumping group, water speed sensor, Pitot tube type, installed in the testing/viewing section, magnetic particle adjustable brake, which provides the load of the tested turbine, torque and speed transducer, which allows the measurement of torque and speed values in the tested turbine.
Monitoring, control and data acquisition for the automation equipment are provided by a SCADA system, made up of a PLC, a personal computer (PC), an RS-485 serial bus between the PLC and the frequency sensors and inverters, an Ethernet bus between the PLC and PC, the database server, and also the software applications running on the PLC and PC.
The application running on PC allows us to control the pumping group and the electrically controlled brake, to monitor and acquire data from the transducers installed along the water tunnel, and also to record them in a database, in order to further process them.

Keywords: experimental test stand; scale models; axial hydraulic turbines.