Second-law analysis of TiO2-SiO2 binary nanofluids in shell-and-tube heat exchangers: Entropy generation and exergy efficiency

Second-law analysis of TiO2-SiO2 binary nanofluids in shell-and-tube heat exchangers: Entropy generation and exergy efficiency | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Second-law analysis of TiO 2 -SiO 2 binary nanofluids in shell-and-tube heat exchangers: Entropy generation and exergy efficiency Sukarman Sukarman, Budi Kristiawan, Eko Prasetya Budiana, Khoirudin Khoirudin, and 1 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8929390/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Shell-and-tube heat exchangers (STHE X ) are widely used in industry; however, first-law analysis alone cannot capture the energy degradation caused by irreversibility. This study experimentally evaluated the second-law performance of a parallel-flow, adiabatically insulated STHEX operated with TiO 2 –SiO 2 binary nanofluids dispersed in a monoethylene glycol–water mixture (MEG-40). The influences of the Reynolds number (500 ≤ Re ≤ 2222) and nanoparticle loading (0–3.0 vol.%) on the entropy generation, exergy destruction, and exergy efficiency were examined. Characterization confirmed a stable hybrid dispersion and nearly Newtonian behavior. Entropy generation and exergy destruction increased with Re and were dominated by tube-side processes. Entropy generation exhibited a nonmonotonic dependence on concentration, with intermediate loading (φ ≈ 1.75%) minimizing irreversibility, whereas a greater loading intensified viscous dissipation. The dimensionless exergy loss followed quadratic ε–Re correlations (R² = 99.5–99.6), consistently identifying φ ≈ 1.75% as the minimum irreversibility condition. However, the exergy efficiency was highest at φ = 3.0%. The results highlight that optimal nanofluid operation depends on the selected second-law metric, which requires a balance between heat-transfer enhancement and friction-induced irreversibility. Shell-and-tube heat exchangers Thermodynamic irreversibility Exergy analysis Entropy generation Second law efficiency Binary nanofluids Full Text Additional Declarations No competing interests reported. Supplementary Files SupplementaryAppendixA.docx Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-8929390","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":602539390,"identity":"6404bb7e-bb63-4703-9227-8fc632244ec7","order_by":0,"name":"Sukarman Sukarman","email":"","orcid":"","institution":"Sebelas Maret University","correspondingAuthor":false,"prefix":"","firstName":"Sukarman","middleName":"","lastName":"Sukarman","suffix":""},{"id":602539391,"identity":"b5b77be7-a002-4675-90da-a9fd4ccac9bc","order_by":1,"name":"Budi 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efficiency\u003c/p\u003e","fulltext":[],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":true,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":true,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Shell-and-tube heat exchangers, Thermodynamic irreversibility, Exergy analysis, Entropy generation, Second law efficiency, Binary nanofluids","lastPublishedDoi":"10.21203/rs.3.rs-8929390/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8929390/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eShell-and-tube heat exchangers (STHE\u003csub\u003eX\u003c/sub\u003e) are widely used in industry; however, first-law analysis alone cannot capture the energy degradation caused by irreversibility. This study experimentally evaluated the second-law performance of a parallel-flow, adiabatically insulated STHEX operated with TiO\u003csub\u003e2\u003c/sub\u003e\u0026ndash;SiO\u003csub\u003e2\u003c/sub\u003e binary nanofluids dispersed in a monoethylene glycol\u0026ndash;water mixture (MEG-40). The influences of the Reynolds number (500\u0026thinsp;\u0026le;\u0026thinsp;Re\u0026thinsp;\u0026le;\u0026thinsp;2222) and nanoparticle loading (0\u0026ndash;3.0 vol.%) on the entropy generation, exergy destruction, and exergy efficiency were examined. Characterization confirmed a stable hybrid dispersion and nearly Newtonian behavior. Entropy generation and exergy destruction increased with Re and were dominated by tube-side processes. Entropy generation exhibited a nonmonotonic dependence on concentration, with intermediate loading (φ\u0026thinsp;\u0026asymp;\u0026thinsp;1.75%) minimizing irreversibility, whereas a greater loading intensified viscous dissipation. The dimensionless exergy loss followed quadratic ε\u0026ndash;Re correlations (R\u0026sup2; = 99.5\u0026ndash;99.6), consistently identifying φ\u0026thinsp;\u0026asymp;\u0026thinsp;1.75% as the minimum irreversibility condition. However, the exergy efficiency was highest at φ\u0026thinsp;=\u0026thinsp;3.0%. The results highlight that optimal nanofluid operation depends on the selected second-law metric, which requires a balance between heat-transfer enhancement and friction-induced irreversibility.\u003c/p\u003e","manuscriptTitle":"Second-law analysis of TiO2-SiO2 binary nanofluids in shell-and-tube heat exchangers: Entropy generation and exergy efficiency","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-03-09 21:41:06","doi":"10.21203/rs.3.rs-8929390/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"9c736a6d-3370-4e1d-b634-e6df0238d04f","owner":[],"postedDate":"March 9th, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2026-03-29T18:54:29+00:00","versionOfRecord":[],"versionCreatedAt":"2026-03-09 21:41:06","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-8929390","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8929390","identity":"rs-8929390","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}