Investigation of waterhammer problems in the penstocks of small hydropower plants

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Tezin Türü: Yüksek Lisans

Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Mühendislik Fakültesi, İnşaat Mühendisliği Bölümü, Türkiye

Tezin Onay Tarihi: 2010

Öğrenci: MELİH ÇALAMAK

Danışman: ZAFER BOZKUŞ

Özet:

Waterhammer is an unsteady hydraulic problem which is commonly found in closed conduits of hydropower plants, water distribution networks and liquid pipeline systems. Due to either a malfunction of the system or inadequate operation conditions, pipeline may collapse or burst erratically resulting in substantial damages, and human losses in some cases. In this thesis, time dependent flow situations in the penstocks of small hydropower plants are investigated. A software, HAMMER, that utilizes method of characteristics for solving nonlinear differential equations of transient flow is used in the study. In two case studies, various operation conditions such as load rejection, load acceptance and instant load rejection are studied. The parameters and situations affecting pressure and turbine speed rises are investigated. Computed and available measured values are found to be very close. Also, differences between waterhammer responses of the Francis and Pelton turbines are revealed. Finally, specific protective measures are suggested to either diminish and/or avoid the harmful effects of waterhammer problems in small hydropower plants.