Laboratory Research on Hydraulic Losses on SHP Inlet Channel Trash Racks

cris.virtual.author-orcid0000-0003-0344-585X
cris.virtual.author-orcid0000-0003-3999-7250
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cris.virtualsource.author-orcidff7a36ab-d209-401b-822d-12191685f04a
cris.virtualsource.author-orcide32458cb-9a33-41e8-9c1a-a373b123c233
cris.virtualsource.author-orcid#PLACEHOLDER_PARENT_METADATA_VALUE#
dc.abstract.enThere is currently a growing trend towards renewable energy sources, which are characterised by a guaranteed power supply and low failure rate. Hydropower plants (small or large) are an example of such a source. They supply a total of 16% of the world’s electricity. The advantages of a small hydropower plant include the relatively simple construction process and the lack of need for upstream water storage. SHPs are one of the most cost-effective and environmentally friendly energy technologies, which is why they are steadily increasing in popularity. One of the important components of SHPs are the trash racks in the inlet channels. Their main purpose is to catch debris and other elements carried downstream and to prevent these pollutants from reaching the turbine units. They can also protect migrating ichthyofauna such as larger fish. If trash racks are installed in the inlet channel, hydraulic losses are to be expected due to the reduction in the flow cross-section through the racks (bars) themselves and through the accumulation of debris and various types of trash on these racks. Energy losses on the trash racks affect the financial aspect of SHP investments. This paper presents the results of laboratory tests on trash racks for SHPs by taking into account the different shapes of the bars used, their number and spacing, and the angles of the trash racks to estimate the hydraulic losses on the trash racks. The measured values of hydraulic losses Δh on the trash racks varied according to the type of trash racks, the density of the bars in the cross-section, and the angle of the trash racks from the horizontal, reaching the highest values on the trash racks with angle bars (AB). They were almost eight times greater than those recorded on cylindrical-bar (CB) trash racks, although they involved different angles. It was shown that the discrepancy in the magnitude of losses on trash racks can be large, even for the same type of trash racks. It depends significantly on the design (shape and bar spacing) of the trash racks and the way the trash racks are installed. Depending on the inclination angle, the increase in energy losses reached 70% for angle bars, 60% for flat-bar trash racks, and almost 40% for cylindrical bars. The values of energy loss as well as the loss coefficient β varied non-linearly for the different bar types depending on the angle of inclination of the gratings, and the degree of this non-linearity depended on the type of bars and the blockage ratio of the section. The presented research results can be useful both during the design and the operation of an SHP.
dc.affiliationWydział Inżynierii Środowiska i Inżynierii Mechanicznej
dc.affiliation.instituteKatedra Inżynierii Wodnej i Sanitarnej
dc.affiliation.instituteKatedra Budownictwa i Geoinżynierii
dc.contributor.authorWalczak, Natalia
dc.contributor.authorWalczak, Zbigniew
dc.contributor.authorTymiński, Tomasz
dc.date.access2026-02-09
dc.date.accessioned2026-02-26T07:43:48Z
dc.date.available2026-02-26T07:43:48Z
dc.date.copyright2022-10-14
dc.date.issued2022
dc.description.abstract<jats:p>There is currently a growing trend towards renewable energy sources, which are characterised by a guaranteed power supply and low failure rate. Hydropower plants (small or large) are an example of such a source. They supply a total of 16% of the world’s electricity. The advantages of a small hydropower plant include the relatively simple construction process and the lack of need for upstream water storage. SHPs are one of the most cost-effective and environmentally friendly energy technologies, which is why they are steadily increasing in popularity. One of the important components of SHPs are the trash racks in the inlet channels. Their main purpose is to catch debris and other elements carried downstream and to prevent these pollutants from reaching the turbine units. They can also protect migrating ichthyofauna such as larger fish. If trash racks are installed in the inlet channel, hydraulic losses are to be expected due to the reduction in the flow cross-section through the racks (bars) themselves and through the accumulation of debris and various types of trash on these racks. Energy losses on the trash racks affect the financial aspect of SHP investments. This paper presents the results of laboratory tests on trash racks for SHPs by taking into account the different shapes of the bars used, their number and spacing, and the angles of the trash racks to estimate the hydraulic losses on the trash racks. The measured values of hydraulic losses Δh on the trash racks varied according to the type of trash racks, the density of the bars in the cross-section, and the angle of the trash racks from the horizontal, reaching the highest values on the trash racks with angle bars (AB). They were almost eight times greater than those recorded on cylindrical-bar (CB) trash racks, although they involved different angles. It was shown that the discrepancy in the magnitude of losses on trash racks can be large, even for the same type of trash racks. It depends significantly on the design (shape and bar spacing) of the trash racks and the way the trash racks are installed. Depending on the inclination angle, the increase in energy losses reached 70% for angle bars, 60% for flat-bar trash racks, and almost 40% for cylindrical bars. The values of energy loss as well as the loss coefficient β varied non-linearly for the different bar types depending on the angle of inclination of the gratings, and the degree of this non-linearity depended on the type of bars and the blockage ratio of the section. The presented research results can be useful both during the design and the operation of an SHP.</jats:p>
dc.description.accesstimeat_publication
dc.description.bibliographyil., bibliogr.
dc.description.financepublication_nocost
dc.description.financecost0,00
dc.description.if3,2
dc.description.number20
dc.description.points140
dc.description.versionfinal_published
dc.description.volume15
dc.identifier.doi10.3390/en15207602
dc.identifier.issn1996-1073
dc.identifier.urihttps://sciencerep.up.poznan.pl/handle/item/7472
dc.identifier.weblinkhttps://www.mdpi.com/1996-1073/15/20/7602
dc.languageen
dc.relation.ispartofEnergies
dc.relation.pagesart. 7602
dc.rightsCC-BY
dc.sciencecloudnosend
dc.share.typeOPEN_JOURNAL
dc.subject.enhead loss
dc.subject.enenergy loss coefficient
dc.subject.ensmall hydropower plant
dc.subject.enSHP
dc.subject.enrenewable energy sources
dc.subject.enSHP trash racks
dc.titleLaboratory Research on Hydraulic Losses on SHP Inlet Channel Trash Racks
dc.title.volumeSpecial Issue Green Energy - Modern Digital Techniques)
dc.typeJournalArticle
dspace.entity.typePublication
oaire.citation.issue20
oaire.citation.volume15