43 KB2871 KB33 KB199920252009Bergant, AntonKaradžić, UrošVukoslavčević, Petar12 straniletnik:55številka:6str. 369-380ISSN:0039-2480COBISSID:11066139URN:URN:NBN:SI:doc-WH8YKD2MenAssociation of Mechanical Engineers and Technicians of Slovenia et al.Zveza strojnih inženirjev in tehnikov Slovenije et al.Strojniški vestnikhidroelektrarnePeltonove turbinešobetrenjevodni udarA novel pelton turbine model for water hammer analysis|This paper presents a novel Pelton turbine model for water hammer analysis. Water hammer phenomena have been investigated in Perućica high-head hydropower plant (HPP), Montenegro. During its first phase of modernisation and refurbishment new distributors (needle valves) have been installed on the first two Pelton turbine units. Closure of the Pelton turbine distributors for the case of emergency shut-down and load rejection under governor control is modelled by two different closing laws i.e. the two-speed closing law and the law that considers actual (measured) needle stroke. Dissipation torques in turbine housing and shaft bearings are considered in the model. Stop procedure of the turbine unit is also investigated. Numerical results using the standard quasi-steady friction model and the convolution based unsteady friction model for different distributor closing laws are compared with the results of measurements. The agreement between computed and measured results is reasonable. It is shown that the effect of unsteady friction on water hammer events in Perućica HPP is of little importance (slow varying transients)Pričujoč prispevek prikazuje nov model peltonove turbine za analizo vodnega udara. Obravnavamo vodni udar v visokotlačni hidroelektrarni (HE) Perućica, Črna gora. V prvi fazi posodobitve in obnove so se zamenjale šobe (iglasti ventili) na prvih dveh peltonovih turbinah. Zapiranje šob peltonove turbine v pogojih hitre zapore in krmiljene razbremenitve stroja je modelirano z dvema različnima zakonoma zapiranja tj. dvohitrostnim zapiranjem in zapiranjem, ki upošteva dejanski (merjeni) gib igle. V modelu sta upoštevana disipacijska momenta v ohišju turbine in ležajih. Raziskana je tudi zaustavitev turbine. Rezultati izračunov z uporabo stalnega modela kapljevinskega trenja in konvolucijskega nestalnega modela trenja za različne zakone zapiranja šob so primerjani z rezultati meritev na izvedbi. Rezultati izračuna in meritev se dobro ujemajo. Pokazali smo, da je vpliv nestalnega kapljevinskega trenja med prehodnimi pojavi v HE Perućica zanemarljivo majhen (počasni prehodni pojavi)TEXTznanstveno časopisjejournalsSlovenian National E-content AggregatorNational and University Library of SloveniaUniverza v Ljubljani, Fakulteta za strojništvo