o:1536 Povećanje energetske efikasnosti malih hidroelektrana Increasing the energy efficiency of small hydropower plants : doctoral dissertation sr REZIME:U disertaciji su analizirane mogućnosti povećanja energetske efikasnostimalih hidroelektrana. Fokus je na rešavanju problema: (i) niske efikasnostiproizvodnje električne energije pri protocima koji su manji od granice do kojeproizvođač garantuje efikasnost turbine i (ii) neefikasnog izdvajanjasedimenata usled nejednakih protoka kroz komore višekomornih taložnika.Drugi problem se rešava originalnom metodologijom, koja predstavljanadgradnju tradicionalnog korišćenja CFD i analitičkih modela. U njenojprimeni leži najveći naučni doprinos, u koji spadaju: metoda iterativnog traženja optimalnog tehničkog rešenjakorišćenjem CFD i pomoćnog analitičkog modela, koji služi kao vodiljasloženog i tromog modela ka optimalnoj geometriji, metoda određivanja lokalnih otpora složenih geometrijskih oblika savišedimenzionalnom strujnom slikom korišćenjem CFD simulacija,regresione analize i posredne validacije, primena savremenih računarskih alata na projektovanje, optimizaciju,modeliranje i rekonstrukciju MHE, i originalno rešenje za istovremeno izjednačavanje i umirenje protoka uulaznoj zoni višekomornih taložnika.Nabrojani rezultati su primenjeni na dve elektrane sa instalisanim snagama1,220 MW i 1,327 MW, koje rade u linijski spregnutom sistemu sa zajedničkimvodozahvatom, i rezultirale su tehničkim rešenjima za: određivanje optimalne konfiguracije pri postojećim uslovima (brutopad, turbine, prečnici cevovoda) korišćenjem nove(ih) turbina inezavisnog ili spregnutog rada kaskadnih derivacionih MHE-a, izjednačavanje protoka i umirenje struja (prigušenje turbulencija)ugradnjom usmerivača u ulaznoj zoni višekomornih taložnika, i izjednačavanje protoka i umirenje struja korišćenjem tablastihzatvarača i umirujućih šipki na ulazima komora taložnika.Rešavanjem (i) problema povećana je EE obe elektrane za 4.8%, dok se rešavanjem(ii) problema smanjuju gubici nastali u eksploataciji za 8%. Rezultatidisertacije su primenjivi na svim postojećim i novoprojektovanim MHE-ma sabočnim vodozahvatima, dok predložene metodologije prevazilaze oblast MHEa. ABSTRACT:The core of the dissertation is to improve energy efficiency of small hydropowerplants (SHPPs). The focus is to solve the problems of (1) decreased electricityproduction during low water flows and (2) inadequate functioning of multi-chambersettling basins because of an uneven flow distribution among the chambers. The latterproblem has been solved by an original methodology, which is an upgrade on thetraditional usage of CFD and analytical models. The methodology is among thescientific contributions that are: a method for the iterative finding of a technical solution by the use of a CFDand an ancillary analytical model, which is a guide for a complex and slow CFDmodel towards an optimal geometry; a method for the determination of local pressure drops (minor losses) forcomplex geometrical shapes with multi-dimensional flow patterns using: CFDsimulations, regression analysis, and indirect validation; the application of modern software for the design, optimization, modeling, andmodernization of SHHPs. a novel solution for simultaneous equalization of flows among the chambers ofa multi-chamber settling basin and the dissipation of turbulent kinetic energy.These results were implemented on a case study, which includes two cascade SHPPswith a common side water intake and nominal installed capacities of 1.220 MW and1.327 MW. The solving of both problems resulted in technical solutions for: the determination of an optimal configuration under existing conditions (grosshead, turbine types, pipeline diameters) by the use of new turbine(s) andindependent or coupled operation of two run-of-the-river SHPPs; the equalization of flows among the chambers of a multi-chamber settling basinand the dissipation of turbulent kinetic energy by the use of: (a) pillars withvanes in a common inlet zone and (b) sluice gates with tranquilizing racks.The solution of the (1) problem increased the electricity production by 4.8% and thesolution of the (2) problem reduced the total loss by 8%. The results are applicable toall new and existing SHPPs with side water intakes, whereas the developedmethodologies exceed the field of SHPPs. - 91552100 77591305 91552101 8580 2022-10-18T12:00:02.053Z 45 no 46 Miloš, 1990- Nikolić 68556553 2021 63 mentor Rade, 1975- Karamarković 26143847 2021 63 član komisije Ivan, 1977- Božić 12918887 2021 63 član komisije Dušan, 1970- Gordić 13546599 2021 63 član komisije Aleksandar, 1966- Jovović 12716903 2021 V, 194 lista 21115823 http://phaidrakg.kg.ac.rs/o:1536 no yes 12 2022-10-18T12:00:02.320Z 70 male hidroelektrane, energetska efikasnost, taložnici, CFDmodeliranje, matematičko modeliranje, turbulentno strujanje, regulacijaprotoka, optimizacija, regresiona analiza small hydropower plants, energy efficiency, settling basin, CFDmodeling, mathematical modeling, turbulent flow, flow control, optimization,regression analysis 621.311.21:620.92(043.3) 1738 34A04 2021