<?xml version="1.0" encoding="UTF-8"?><OAI-PMH xmlns="http://www.openarchives.org/OAI/2.0/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/ http://www.openarchives.org/OAI/2.0/OAI-PMH.xsd"><responseDate>2026-10-29T23:44:41Z</responseDate><request verb="GetRecord" identifier="oai:bayburt-rdlopen.rawdatalibrary.net:bayburt/12080" metadataPrefix="oai_dc">https://bayburt-rdlopen.rawdatalibrary.net/oai/request</request><GetRecord><record><header><identifier>oai:bayburt-rdlopen.rawdatalibrary.net:bayburt/12080</identifier><datestamp>2026-10-29T19:42:08Z</datestamp><setSpec>openaire</setSpec><setSpec>driver</setSpec><setSpec>com_bayburt_10000</setSpec><setSpec>col_bayburt_10001</setSpec><setSpec>com_bayburt_10007</setSpec><setSpec>col_bayburt_10223</setSpec></header><metadata><oai_dc:dc xmlns:oai_dc="http://www.openarchives.org/OAI/2.0/oai_dc/" xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/oai_dc/ http://www.openarchives.org/OAI/2.0/oai_dc.xsd"><dc:title>Exergy analyses of two and three stage cryogenic cycles</dc:title><dc:creator>Atasbak, Musa</dc:creator><dc:creator>Keven, Arzu</dc:creator><dc:creator>Karaali, Rabi</dc:creator><dc:subject>cryogenic</dc:subject><dc:subject>exergy</dc:subject><dc:subject>local optimization</dc:subject><dc:description>Cryogenics has an important influence on industry and science. In this study, optimum working conditions are obtained by applying exergy analysis and local optimization methods to two- and three-stage vapor compression cascade cryogenic cycle. The first and second laws of thermodynamics, exergy analysis, and local optimization methods are applied to the two- and three-stage cascade cryogenic cycle. By considering the needs and demands, it is possible to create new cycles by adding new devices and/or new stages to these cycles. The results of the optimum operating conditions are obtained for the two- and three-stage vapor compression cascade cryogenic cycle. It is seen that to achieve high COP values and high efficiency; it is necessary to reduce the compression ratio of the compressor as much as the fluid allows. For the two-stage cycle, the minimum total work required for cryogenic cooling is around P 7 = 2,400 kPa. The COP value is 0.30 between P 7 = 2,400 and 2,800 kPa, and the maximum exergy efficiency is obtained around 0.235. It is seen operating the first-stage compressor at high pressures increases the total losses of the entire cycle from 7,500 to 18,550 kW. The increase in total exergy losses is around 247%, and operating the first-stage compressor at high pressures increases the exergy efficiency of the entire cycle. The increase in total exergy efficiency is around 160%. When the second-stage compressor is operated at low pressure, the COP value increases by 2%, the exergy efficiency increases by 20%, and the exergy losses decrease by around 40%.</dc:description><dc:publisher>Walter de Gruyter GmbH</dc:publisher><dc:date>2022</dc:date><dc:type>Article</dc:type><dc:identifier>https://rdlopen.rawdatalibrary.net/r/bayburt/12080</dc:identifier><dc:identifier>https://doi.org/10.1515/arh-2022-0134</dc:identifier><dc:identifier>1430-6395</dc:identifier><dc:language>en</dc:language><dc:relation>Applied Rheology</dc:relation><dc:rights>info:eu-repo/semantics/openAccess</dc:rights><dc:type>info:eu-repo/semantics/article</dc:type><dc:identifier>https://bayburt-rdlopen.rawdatalibrary.net/tr/items/bayburt/12080</dc:identifier></oai_dc:dc></metadata></record></GetRecord></OAI-PMH>