Numerical investigation of protection measures against water hammer in the Yesilvadi hydropower plant

Thesis Type: Postgraduate

Institution Of The Thesis: Orta Doğu Teknik Üniversitesi, Faculty of Engineering, Department of Civil Engineering, Turkey

Approval Date: 2013


Supervisor: ZAFER BOZKUŞ


The purpose of this thesis is to analyze protection measures against water hammer numerically and compare the results with measured field data of Yesilvadi HEPP project. Pressure relief valves are used as protective measure against water hammer in Yesilvadi HEPP project formulation. The hydropower system is investigated numerically with software, Bentley HAMMER, which uses method of characteristics for solving nonlinear equations of transient flow. Yesilvadi HEPP project is analyzed for load rejection, instant load rejection, load acceptance and load variation scenarios for three different cases which are system without a protection measure, the existing system including pressure relief valves, and system as if including a surge tank instead of pressure relief valves against water hammer. The pressure variations at the inlets of turbines, maximum and minimum hydraulic grade lines of the water transmission line and rotational speed of turbines are computed and compared with measured data for these three different cases. Eventually, the effectiveness of protection measures are compared and some suggestions are made for appropriate operation of existing pressure relief valves to either diminish or decrease the effects of water hammer in Yesilvadi HEPP project.