The aim of this paper is to present, discuss and assess case studies of refurbished and new hydropower schemes with complex water conveyance systems. Modern hydraulic transient analysis approach, control strategies and modeling are outlined. Hydraulic transients are flow disturbances caused by a change from one steady state to another. Transients can disturb overall operation of the plant and damage the system components. Parameters that define the extent of the analysis, modelling and solution methods are covered. Detailed transient analysis was performed using commercial software package SIMSEN that includes a number of hydraulic and electrical components. The pakage incorporates standard steady state skin friction model. The paper concludes with one case study of refurbished (Doblar 1 HPP) and one case study of a new hydro powerplant (Toro 3). Computational results agree well with the measured results. For relatively slow transients the steady state skin friction model is appropriate.
F.18 Transfer of new know-how to direct users (seminars, fora, conferences)
COBISS.SI-ID: 13827867This paper reviews critical water hammer parameters as they are presented in official hydropower standards and guidelines. A particular emphasize is given to a number of IEC standards and guidelines that are used worldwide. The paper critically assesses water hammer control strategies including operational scenarios (closing and opening laws), surge control devices (surge tank, pressure regulating valve, flywheel, etc.), redesign of the water conveyance system components (tunnel, penstock), or limitation of operating conditions (limited operating range) that are variably covered in standards and guidelines. Little information is given on industrial water hammer models and solutions elsewhere. These are briefly introduced and discussed in the light of capability (simple versus complex systems), availability of expertise (in house and/or commercial) and uncertainty. The paper concludes with an interesting water hammer case study referencing the rules and recommendations from existing hydropower standards and guidelines in a view of effective water hammer control. Recommendations are given for further work on development of a special guideline on water hammer (hydraulic transients) in hydropower plants. The guideline should consider steady- and unsteady friction models too.
F.31 Development of standards
COBISS.SI-ID: 13745947