Analiza energije prelite vode v hidroelektrarni zaradi prevelikega pretoka reke

ROGELJ, VILI (author), Čepin, Marko (mentor)

Namen diplomske naloge je prikazati variabilnost električne energije iz hidroelektrarne skozi leta in oceniti količine energije, ki jih izgubimo zaradi prelivanja vode, ki je posledica neenakosti pretokov na primerih hidroelektrarne Tolmin in Mesto. Najprej je podan opis hidroelektrarne s poudarkom na tipih turbin in njihovih izkoristkih v odvisnosti od pretoka vode. Vsaka turbina je dimenzionirana na nek nazivni pretok. To je zelo pomemben podatek za ocenjevanje izgubljene energije, ki se prelije zaradi višjega pretoka reke od nazivnega. Če je pretok reke manjši ali enak nazivnemu pretoku turbine, je v elektrarni z eno turbino vsa voda lahko speljana skozi turbino in hidroelektrarna izkorišča celoten potencial vode, zato se takrat voda ne preliva mimo. Če je pretok reke večji od nazivnega pretoka turbine, je v elektrarni z eno turbino nazivni pretok speljan skozi turbino, preostala voda pa prelita steče mimo. Posledica prevelikega pretoka je prelita voda, ki se zlije mimo elektrarne in predstavlja nek del energije, ki je elektrarna ni izkoristila. Na primeru hidroelektrarne Tolmin se izkaže, da se v primeru ene turbine 70 % celotne energije vode pred elektrarno zlije mimo turbine, na primeru hidroelektrarne Mesto pa je ta podatek 80 %. Ker se zdi, da je energije prelite vode veliko, smo predpostavili, da v elektrarno dodamo eno ali celo dve dodatni turbini. S tem bi se količine prelite vode in posledično količina izgubljene energije zmanjšala. Hkrati pa bi se povečala količina proizvedene električne energije. Na primeru hidroelektrarne Tolmin se izkaže, da se količina izgubljene energije zaradi prelite vode zmanjša iz 70 % na 30 % celotne energije, na primeru hidroelektrarne Mesto pa iz 80 % na 60 %, torej samo za skromnih 20 %. Pri hidroelektrarni Tolmin bi se najverjetneje splačala dodatna turbina, saj se ocenjene izgube konkretno zmanjšajo. To pri hidroelektrarni Mesto to ne drži, ker ima reka Idrijca ogromno razliko med minimalnimi in maksimalnimi pretoki in se dodatna turbina ekonomsko ne bi splačala.

• Language: Slovenian
• Keywords: hidroelektrarna, pretok, energija
• Work type: Bachelor thesis/paper
• Organization: FE - Faculty of Electrical Engineering
• Year: 2022
• PID: 20.500.12556/RUL-139924
• COBISS.SI-ID: 120731139
• Publication date in RUL: 08.09.2022

Secondary language

• Language: English
• Title: Analysis of the energy of overflow water in a hydroelectric power plant due to excessive river flow

Abstract

The purpose of the diploma thesis is to show the variability of electricity from hydroelectric power plants over the years and to estimate the amount of energy lost due to water overflow, which is a result of the inequality of flows in the cases of the Tolmin and Mesto hydroelectric power plants. First, a description of the hydroelectric power plant is given with an emphasis on the types of turbines and their efficiencies depending on the flow of water. Each turbine is dimensioned for a certain nominal flow. This is a very important piece of information for estimating the lost energy that spills over due to a higher than rated river flow. If the flow of the river is less than or equal to the rated flow of the turbine, in a power plant with one turbine, all the water can be passed through the turbine and the hydroelectric plant uses the full potential of the water, so then the water does not overflow. If the flow of the river is greater than the rated flow of the turbine, in a power plant with one turbine, the rated flow is passed through the turbine, and the remaining water flows past the overflow. The result of excessive flow is overflowing water that flows past the power plant and represents a part of the energy that the power plant did not use. In the case of the Tolmin hydroelectric power plant, it turns out that in the case of one turbine, 70% of the total water energy flows past the turbine in front of the power plant, while in the case of the Mesto hydroelectric power plant, this data is 80%. Since it seems that there is a lot of energy in the overflowing water, we have planned to add one or even two additional turbines to the power plant. This would reduce the amount of spilled water and consequently the amount of lost energy. At the same time, the amount of electricity produced would increase. In the case of the Tolmin hydroelectric power plants, it turns out that the amount of lost energy due to upstream water is reduced from 70% to 30% of the total energy, and in the case of the Mesto hydroelectric power plants, from 80% to 60%, i.e. only by a modest 20%. At the Tolmin hydroelectric power plants, an additional turbine would most likely be worthwhile, as the estimated losses were concretely reduced. This is not the case with the Mesto hydroelectric plant, because the Idrijca river has a huge difference between the minimum and maximum flows and an additional turbine would not be economically worthwhile.

• Keywords: hydroelectric power plant, flow, energy