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Masiraidhi anoratidza zvinyorwa zvitatu pane siraidhi.Shandisa mabhatani ekumashure neanotevera kufamba nemumasiraidhi, kana mabhatani ekudzora masiraidhi ari kumagumo kuti ufambe nemumasiraidhi ega ega.
304 10 * 1mm Stainless simbi yakasungirirwa tubing muchina
Kukura: 3/4 inch, 1/2 inch, 1 inch, 3 inch, 2 inch
Unit Pipe Kureba: 6 metres
Simbi Giredhi: 201, 304 UYE 316
Giredhi: 201, 202, 304, 316, 304L, 316 L,
zvinhu: Stainless simbi
Chimiro: Chitsva
Stainless Simbi Tube Coil
Kukura: 3/4 inch, 1/2 inch, 1 inch, 3 inch, 2 inch
Unit Pipe Kureba: 6 metres
Simbi Giredhi: 201, 304 UYE 316
Giredhi: 201, 202, 304, 316, 304L, 316 L,
zvinhu: Stainless simbi
Chimiro: Chitsva
Covalent uye isina-covalent nanofluids yakaedzwa mumachubhu akatenderera akashongedzerwa akamonyoroka tepi ekuisa ane helix angles e45 ° uye 90 °.Nhamba yeReynolds yaiva 7000 ≤ Re ≤ 17000, iyo thermophysical properties yakaongororwa pa 308 K. Muenzaniso wepanyama unogadziriswa nenhamba uchishandisa maviri-parameter turbulent viscosity model (SST k-omega turbulence).Kuiswa (0.025 wt.%, 0.05 wt.%, uye 0.1 wt.%) ye nanofluids ZNP-SDBS@DV neZNP-COOH@DV zvakaonekwa mubasa.Madziro emachubhu akamonyoroka anopisa pakupisa kwe 330 K. Zvikamu zvitanhatu zvakatariswa muchidzidzo chezvino: kupisa kwekubuda, kupisa kweyekupisa, chiyero cheNusselt nhamba, coefficient of friction, pressure loss, uye maitiro ekuongorora maitiro.Muzviitiko zvose zviri zviviri (helix angle ye45 ° uye 90 °), ZNP-SDBS@DV nanofluid yakaratidza unhu hwepamusoro hwekushisa-hydraulic kupfuura ZNP-COOH @ DV, uye yakawedzera nekuwedzera chikamu chemazana, somuenzaniso, 0.025 wt., uye 0.05 wt.iri 1.19.% uye 1.26 - 0.1 wt.%.Mune ese ari maviri (helix angle 45 ° uye 90 °), kukosha kweiyo thermodynamic maitiro kana uchishandisa GNP-COOH@DW ndeye 1.02 ye0.025% wt., 1.05 ye0.05% wt.uye 1.02 ye0.1% wt.
Iyo yekupisa yekupisa ndeye thermodynamic mudziyo 1 unoshandiswa kutamisa kupisa panguva yekutonhora nekudziya.Thermal-hydraulic properties of the heat exchanger inovandudza kupisa kwekushisa coefficient uye kuderedza kushorwa kwemvura inoshanda.Nzira dzinoverengeka dzakagadzirwa kuvandudza kupisa kupisa, kusanganisira turbulence enhancers2,3,4,5,6,7,8,9,10,11 uye nanofluids12,13,14,15.Twisted tepi kuiswa ndiyo imwe yedzakanyanya kubudirira nzira dzekuvandudza kupisa kwekushisa mumagetsi ekupisa nekuda kwekureruka kwayo kwekugadzirisa uye yakaderera mutengo7,16.
Mukutevedzana kwezvidzidzo zvekuyedza uye zvemakomputa, iyo hydrothermal zvimiro zvemisanganiswa ye nanofluids uye kupisa kunopisa neakamonyoroka tepi kuiswa zvakadzidzwa.Mubasa rekuyedza, iyo hydrothermal zvimiro zveatatu akasiyana esimbi nanofluids (Ag@DW, Fe@DW uye Cu@DW) akadzidzwa mune tsono yakamonyoroka tepi (STT) heat exchanger17.Kuenzaniswa nebhesi pombi, kupisa kwekushisa kwe STT kunovandudzwa ne11% uye 67%.Iyo SST dhizaini ndiyo yakanakisa kubva kune yehupfumi maonero maererano nehunyanzvi neparameter α = β = 0.33.Mukuwedzera, kuwedzera kwe18.2% mu n kwakaonekwa neAg @ DW, kunyange zvazvo kuwedzera kukuru kwekurasikirwa kwekumanikidzwa kwaiva 8.5 chete%.Maitiro emuviri ekupisa kupisa uye kurasikirwa kwekumanikidza mumapombi akaomesesa ane uye asina akamoneredzwa turbulators akadzidzwa pachishandiswa nyonganyonga kuyerera kweAl2O3@DW nanofluid ine kumanikidzwa convection.Huwandu hweavhareji Nusselt nhamba (Nuavg) uye kurasikirwa kwekumanikidzwa kunoonekwa paRe = 20,000 apo coil pitch = 25 mm uye Al2O3@DW nanofluid 1.6 vol.%.Zvidzidzo zvemurabhoritari zvakaitwawo kuongorora kuchinjisa kupisa uye kuomerwa kurasikirwa maitiro egraphene oxide nanofluids (GO@DW) inoyerera nemumachubhu anenge denderedzwa ane WC inoiswa.Mhedzisiro yacho yakaratidza kuti 0.12 vol% -GO@DW yakawedzera convective kupisa kwekutamisa coefficient neinosvika 77%.Mune imwe ongororo yekuyedza, nanofluids (TiO2@DW) yakagadziridzwa kuti idzidze thermal-hydraulic maitiro emachubhu ane dimpled akaiswa akamonyoroka tepi inoiswa20.Iyo yakanyanya hydrothermal inoshanda ye1.258 yakagadziriswa uchishandisa 0.15 vol% -TiO2 @ DW yakaiswa mu45 ° yakatemerwa shafts ine twist factor ye3.0.Single-phase and two-phase (hybrid) simulation modhi inotarisa kuyerera uye kupisa kupisa kweCuO@DW nanofluids pane zvakasiyana-siyana solids concentrations (1–4% vol.%)21.Kunyanya kupisa kwekupisa kwechubhu inopinzwa nematepi imwe yakamonyoroka ndeye 2.18, uye chubhu inoiswa nematepi maviri akamonyoroka pasi pemamiriro akafanana ndeye 2.04 (mbiri-yechikamu modhi, Re = 36,000 uye 4 vol.%).Iyo isiri-Newtonian turbulent nanofluid kuyerera kwecarboxymethyl cellulose (CMC) uye copper oxide (CuO) mumapaipi makuru nemapombi ane akamonyoroka ekuisa akaongororwa.Nuavg inoratidza kuvandudzwa kwe16.1% (yepombi huru) uye 60% (yepombi yakavharidzirwa ine reshiyo ye (H/D = 5)).Kazhinji, reshiyo yakadzikira-kune-ribhoni inoguma nekwepamusoro coefficient of friction.Muchidzidzo chekuedza, mhedzisiro yemapombi ane tepi yakamonyoroka (TT) uye makoiri (VC) pamidziyo yekupisa kupisa uye friction coefficient yakadzidzwa uchishandisa CuO@DW nanofluids.Kushandisa 0.3 vol.% -CuO @ DW paRe = 20,000 inoita kuti zvikwanise kuwedzera kupisa kwekushisa muVK-2 pombi kusvika kuhuwandu hwehuwandu hwe44.45%.Pamusoro pezvo, kana uchishandisa tambo yakamonyoroka uye coil inoisa pasi peiyo muganhu mamiriro, iyo coefficient yefriction inowedzera nezvinhu zve1.17 uye 1.19 zvichienzaniswa neDW.Kazhinji, kupisa kwemafuta e nanofluids akaiswa mumakoiri kuri nani pane iyo nanofluids inopinzwa muwaya dzakasungwa.Hunhu hwevhoriyamu hwemhirizhonga (MWCNT@DW) nanofluid kuyerera kwakadzidzwa mukati mechubhu yakachinjika yakaiswa muwaya inotenderera.Thermal performance parameters yaive> 1 yezviitiko zvese, zvichiratidza kuti kusanganiswa kwenanofluidics necoil kuisa kunonatsiridza kupisa kupisa pasina kushandisa pombi simba.Abstract-Iyo hydrothermal hunhu hwepombi mbiri yekupisa yekupisa ine dzakasiyana siyana dzakagadzirwa neyakamonyoroka-yakamonyoroka V-shaped tepi (VcTT) dzakadzidzwa pasi pemamiriro emhirizhonga yekuyerera kweAl2O3 + TiO2@DW nanofluid.Kuenzaniswa neDW mumabhesi machubhu, Nuavg ine kuvandudzwa kwakakura kwe132% uye friction coefficient inosvika 55%.Pamusoro pezvo, simba resimba reAl2O3 + TiO2 @ DW nanocomposite mune maviri-pombi kupisa exchanger26 yakakurukurwa.Muchidzidzo chavo, vakaona kuti kushandiswa kweAl2O3 + TiO2@DW uye TT kwakavandudza kushanda kwesimba zvichienzaniswa neDW.Mu concentric tubular heat exchangers neVcTT turbulators, Singh naSarkar27 vakashandisa phase shanduko zvinhu (PCM), vakaparadzirwa single/nanocomposite nanofluids (Al2O3@DW ine PCM uye Al2O3 + PCM).Vakataura kuti kupisa kwekushisa uye kurasikirwa kwekumanikidzwa kunowedzera sezvo twist coefficient inoderera uye nanoparticle concentration inowedzera.Iyo yakakura V-notch kudzika chinhu kana diki hupamhi chinhu chinogona kupa hukuru hwekupisa kupisa uye kurasikirwa kwekumanikidza.Mukuwedzera, graphene-platinum (Gr-Pt) yakashandiswa kuongorora kupisa, kukwesha, uye yakazara entropy generation rate mumachubhu ane 2-TT28 inoisa.Ongororo yavo yakaratidza kuti chikamu chidiki che (Gr-Pt) chakaderedza zvakanyanya kupisa entropy chizvarwa kana ichienzaniswa neyakakura frictional entropy development.Yakasanganiswa Al2O3 @ MgO nanofluids uye conical WC inogona kuonekwa semusanganiswa wakanaka, sezvo kuwedzera kwehuwandu (h / Δp) kunogona kuvandudza kushanda kwehydrothermal ye-two-tube heat exchanger 29.Muenzaniso wenhamba unoshandiswa kuongorora kuchengetedza kwesimba uye kushanda kwezvakatipoteredza kwevanotsinhanisa kupisa nemhando dzakasiyana-siyana dzezvikamu zvitatu zvakasanganiswa nanofluids (THNF) (Al2O3 + graphene + MWCNT) yakamiswa muDW30.Pamusana pePerformance Evaluation Criteria (PEC) muhuwandu hwe1.42-2.35, musanganiswa weDepressed Twisted Turbulizer Insert (DTTI) uye (Al2O3 + Graphene + MWCNT) inodiwa.
Kusvika ikozvino, kutarisisa kushoma kwakabhadharwa kune basa re covalent uye risiri-covalent functionalization mu hydrodynamic kuyerera mumvura inopisa.Chinangwa chaicho chechidzidzo ichi chaiva chekuenzanisa maitiro e-thermal-hydraulic e nanofluids (ZNP-SDBS@DV) uye (ZNP-COOH@DV) mumatepi akaiswa akamonyoroka ane helix angles ye45 ° uye 90 °.Iyo thermophysical properties yakayerwa paTin = 308 K. Muchiitiko ichi, zvikamu zvitatu zvehuwandu zvakatorwa mukuenzanisa, zvakadai se (0.025 wt.%, 0.05 wt.% uye 0.1 wt.%).Iyo shear stress transfer mu 3D turbulent flow model (SST k-ω) inoshandiswa kugadzirisa thermal-hydraulic maitiro.Nokudaro, chidzidzo ichi chinopa mupiro wakakosha pakudzidza kwezvinhu zvakanaka (kupisa kupisa) uye zvinhu zvisina kunaka (kuderedza kudonha pakurwisana), kuratidza maitiro e-thermal-hydraulic uye optimization yemvura chaiyo yekushanda mumagetsi akadaro einjiniya.
Iyo yekutanga dhizaini pombi yakatsetseka (L = 900 mm uye Dh = 20 mm).Yakaiswa yakamonyoroka tepi zviyero (kureba = 20 mm, ukobvu = 0.5 mm, chimiro = 30 mm).Muchiitiko ichi, kureba, upamhi, uye sitiroko ye spiral profile yaive 20 mm, 0.5 mm, uye 30 mm, zvichiteerana.Matepi akamonyoroka anorerekera pa45° uye 90°.Zvinwiwa zvakasiyana-siyana zvinoshanda zvakadai seDW, non-covalent nanofluids (GNF-SDBS@DW) uye covalent nanofluids (GNF-COOH@DW) paTin = 308 K, matatu akasiyana misa yakawanda uye nhamba dzakasiyana dzeReynolds.Miedzo yakaitwa mukati mekupisa.Rusvingo rwekunze rwe spiral chubhu yaipiswa patembiricha yepasi pe 330 K kuti iedze ma parameter ekuvandudza kupisa kupisa.
Pamusoro pemuonde.1 schematically inoratidza yakamonyoroka tepi yekuisa chubhu ine inoshanda muganho mamiriro uye meshed nzvimbo.Sezvambotaurwa, velocity uye kumanikidza muganho mamiriro anoshanda kune inopinza uye yekubuda zvikamu zvehelix.Pakupisa kwepamusoro kwepamusoro, mamiriro asina kutsika anoiswa pamadziro epombi.Ikozvino nhamba yekufananidza inoshandisa kudzvinyirira-based solution.Panguva imwecheteyo, chirongwa (ANSYS FLUENT 2020R1) chinoshandiswa kushandura chikamu chekusiyanisa equation (PDE) kuita hurongwa hwe algebraic equations uchishandisa nzira ye finite volume (FMM).Yechipiri-yekurongeka SIMPLE nzira (semi-yakajeka nzira ye sequential pressure-dependent equations) ine chekuita nevelocity-pressure.Zvinofanira kusimbiswa kuti kusanganiswa kwezvisaririra zvehuwandu, simba, uye simba equation ishoma pane 103 uye 106, zvichiteerana.
p Dhiagiramu yezvikamu zvemuviri uye computational: (a) helix angle 90 °, (b) helix angle 45 °, (c) hapana helical blade.
A homogeneous modhi inoshandiswa kutsanangura maitiro e nanofluids.Nekubatanidza nanomaterials mu base fluid (DW), mvura inoenderera ine yakanakisa yekupisa zvinhu inoumbwa.Panyaya iyi, tembiricha uye velocity ye base fluid uye nanomaterial zvine kukosha kwakafanana.Nekuda kwedzidziso nefungidziro dziri pamusoro, kuyerera kwechikamu chimwe kunoshanda muchidzidzo ichi.Zvidzidzo zvakawanda zvakaratidza kushanda uye kushandiswa kwemaitiro ega-chikamu chenanofluidic flow31,32.
Kuyerera kwenanofluids kunofanirwa kunge kuri kweNewtonian mhirizhonga, isingachinjiki uye yakamira.Basa rekudzvanya nekudziisa viscous hazvina basa muchidzidzo ichi.Mukuwedzera, kuwanda kwemadziro emukati nekunze kwepombi haafungi.Naizvozvo, huwandu, kukurumidza, uye simba rekuchengetedza equations inotsanangura iyo yekupisa modhi inogona kuratidzwa seinotevera:
apo \(\ overrightarrow{V}\) ndiyo inoreva velocity vector, Keff = K + Kt ndiyo inoshanda yekupisa conductivity yecovalent uye noncovalent nanofluids, uye ε ndiyo chiyero chekuparara kwesimba.Kushanda kwe thermophysical properties ye nanofluids, kusanganisira density (ρ), viscosity (μ), chaiyo yekupisa simba (Cp) uye thermal conductivity (k), inoratidzwa patafura, yakayerwa panguva yekuongorora patembiricha ye308 K1 payakashandiswa. mune izvi simulators.
Nhamba dzekuenzanisa kwemhirizhonga nanofluid inoyerera mumachubhu akajairika uye eTT akaitwa paReynolds nhamba 7000 ≤ Re ≤ 17000. Izvi zvifananidzi uye convective kupisa kupisa coefficients zvakaongororwa uchishandisa Mentor's κ-ω turbulence model ye shear average stress transfer (Sturynold) modhi Navier-Stokes, inowanzoshandiswa mukutsvaga kweaerodynamic.Mukuwedzera, iyo modhi inoshanda isina madziro basa uye yakarurama pedyo nemadziro 35,36.(SST) κ-ω inotonga maequation eiyo turbulence modhi ndeaya anotevera:
uko \(S\) ndiko kukosha kweiyo strain rate, uye \(y\) ndiyo chinhambwe kuenda kunzvimbo iri pedyo.Zvichakadaro, \({\ alpha}_{1}\), \({\ alpha}_{2}\), \({\beta}_{1}\), \({\beta}_{ 2 }\), \({\beta}^{*}\), \({\sigma}_{{k}_{1}}\), \({\sigma}_{{k}_{ 2) }}\), \({\sigma}_{{\omega}_{1}}\) uye \({\sigma}_{{\omega}_{2}}\) zvinoreva mhando dzese dzinogara dziripo.F1 uye F2 mabasa akasanganiswa.Cherechedza: F1 = 1 mumuganhu wemuganhu, 0 mukuyerera kuri kuuya.
Performance evaluation parameters inoshandiswa kudzidza mhirizhonga convective heat transfer, covalent uye non-covalent nanofluid kuyerera, semuenzaniso31:
Muchirevo chechinyorwa chino, (\(\ rho\)), (\(v\)), (\({D}_{h}\))) uye (\(\mu\)) anoshandiswa kureva density, fluid velocity. , hydraulic dhayamita uye dynamic viscosity.(\({C}_{p}\, \mathrm{u}\, k\)) - chaiyo yekupisa simba uye thermal conductivity yemvura inoyerera.Zvakare, (\(\dot{m}\)) inoreva kuyerera kwehuwandu, uye (\({T}_{out}-{T}_{in}\)) zvinoreva kusiyana kwetembiricha yekupinza nekubuda.(NFs) inoreva covalent, non-covalent nanofluids, uye (DW) inoreva mvura yakasvibiswa (base fluid).\({A}_{s} = \pi DL\), \({\ overline{T}_{f}=\frac{\left({T}_{kunze}-{T}_{mu }\kurudyi)}{2}\) uye \({\ overline{T}_{w}=\sum \frac{{T}_{w}}{n}\).
Thermophysical properties of the base fluid (DW), non-covalent nanofluid (GNF-SDBS @ DW), uye covalent nanofluid (GNF-COOH @ DW) yakatorwa kubva mumabhuku akabudiswa (zvidzidzo zvekuedza), Sn = 308 K, se inoratidzwa muTable 134. Muchiitiko chekuedza kuwana non-covalent (GNP-SDBS@DW) nanofluid ine uwandu hunozivikanwa kubva muzana, mamwe magiramu ekutanga GNPs akatanga kuyerwa pachiyero chedigital.Huremu hwehuremu hweSDBS/native GNP ndeye (0.5:1) yakayerwa muDW.Panyaya iyi, covalent (COOH-GNP@DW) nanofluids akagadzirwa nekuwedzera carboxyl mapoka pamusoro peGNP vachishandisa yakasimba acidic medium ine vhoriyamu reshiyo (1:3) yeHNO3 neH2SO4.Covalent uye isina-covalent nanofluids yakamiswa muDW pazvikamu zvitatu zvakasiyana zvehuremu senge 0.025 wt%, 0.05 wt%.uye 0.1% yehuwandu.
Mesh kuzvimiririra bvunzo dzakaitwa munzvimbo ina dzakasiyana dzemakomputa kuti ive nechokwadi chekuti mesh saizi haikanganisi simulation.Panyaya ye45 ° torsion pombi, nhamba yezvikamu zvine saizi ye1.75 mm ndeye 249,033, nhamba yezvikamu zvine saizi ye2 mm ndeye 307,969, nhamba yezvikamu zvine saizi ye2.25 mm i421,406, uye nhamba yezvikamu. ine saizi yeyuniti 2 .5 mm 564 940 zvakateerana.Pamusoro pezvo, mumuenzaniso wepombi yakamonyoroka ye90°, huwandu hwezvinhu zvine saizi ye 1.75 mm i245,531, huwandu hwezvinhu zvine saizi ye 2 mm ndeye 311,584, huwandu hwezvinhu zvine saizi ye 2.25 mm 422,708, uye huwandu hwezvinhu zvine saizi ye2.5 mm inoteedzana 573,826.Kurongeka kwekuverenga kwenzvimbo yekushisa senge (Tout, htc, uye Nuavg) kunowedzera sezvo huwandu hwezvinhu hunodzikira.Panguva imwecheteyo, iko kurongeka kweiyo friction coefficient uye kudonha kwekumanikidza kwakaratidza maitiro akasiyana zvachose (Fig. 2).Giridhi (2) yakashandiswa senzvimbo huru yegridi yekuongorora iyo thermal-hydraulic maitiro mune yakafananidzirwa kesi.
Kuedza kutamisa kupisa uye kudonhedza kudonhedza kuita kwakazvimiririra kune mesh uchishandisa mapeya eDW machubhu akamonyoroka pa45 ° uye 90 °.
Ikozvino manhamba mhedzisiro yakave yakasimbiswa yekushanda kwekupisa uye friction coefficient uchishandisa inozivikanwa empirical correlations uye equation seDittus-Belter, Petukhov, Gnelinsky, Notter-Rouse uye Blasius.Kuenzanisa kwakaitwa pasi pemamiriro ezvinhu 7000≤Re≤17000.Maererano nomuonde.3, avhareji uye mukuru zvikanganiso pakati simulation zvabuda uye kupisa kutamisa equation 4.050 uye 5.490% (Dittus-Belter), 9.736 uye 11.33% (Petukhov), 4.007 uye 7.483% (Gnelinsky), uye 3.883% uye 4. Nott-Belter).Rose).Muchiitiko ichi, zvikanganiso zveavhareji uye zvakanyanya pakati pemhedzisiro yekufananidza uye friction coefficient equation ndeye 7.346% uye 8.039% (Blasius) uye 8.117% uye 9.002% (Petukhov), zvichiteerana.
Kuchinjisa kupisa uye hydrodynamic zvimiro zveDW panhamba dzakasiyana dzeReynolds uchishandisa manhamba ekuverenga uye empirical correlations.
Ichi chikamu chinokurukura kupisa kwemafuta evasina-covalent (LNP-SDBS) uye covalent (LNP-COOH) aqueous nanofluids pazvikamu zvitatu zvakasiyana-siyana zvehuwandu uye nhamba dzeReynolds semavhareji maererano ne base fluid (DW).Mageometri maviri ebhandi rinopisa rinopisa (helix angle 45 ° uye 90 °) inokurukurwa nokuda kwe7000 ≤ Re ≤ 17000. Mumuonde.4 inoratidza avhareji yetembiricha pakubuda kwenanofluid kupinda mumvura yepasi (DW) (\(\frac{{{T}_{out}}_{NFs}}{{T}_{out}}_{ DW } } \) ) pa (0.025% wt., 0.05% wt. uye 0.1% wt.).(\(\frac{{{T}_{out}}_{NFs}}{{{T}_{out}}_{DW}}\)) inogara iri pasi pe1,zvinoreva kuti tembiricha yekubuda nayo is non-covalent (VNP-SDBS) uye covalent (VNP-COOH) nanofluids iri pazasi tembiricha pakubuda kweiyo base fluid.Kudzikisira kwakaderera uye kwepamusoro kwaive 0.1 wt%-COOH@GNPs uye 0.1 wt%-SDBS@GNPs, zvichiteerana.Chiitiko ichi chinokonzerwa nekuwedzera kwenhamba yeReynolds pachikamu chinoramba chiripo, izvo zvinotungamirira kukuchinja kwezvinhu zve nanofluid (kureva, density uye dynamic viscosity).
Mifananidzo 5 uye 6 inoratidza avhareji yekupisa kupisa maitiro e nanofluid kune base fluid (DW) pa (0.025 wt.%, 0.05 wt.% uye 0.1 wt.%).Avhareji yekupisa kupisa zvivakwa zvinogara zvakakura kupfuura 1, zvinoreva kuti kupisa kwekutamisa zvivakwa zve-non-covalent (LNP-SDBS) uye covalent (LNP-COOH) nanofluids inowedzerwa kana ichienzaniswa neiyo base fluid.0.1 wt%-COOH@GNPs uye 0.1 wt%-SDBS@GNPs vakawana pfuma yakaderera uye yepamusoro-soro, zvichiteerana.Kana iyo nhamba yeReynolds ichiwedzera nekuda kwekunyanya kusanganiswa kwemvura uye mhirizhonga mupombi 1, mashandiro ekutamisa kupisa anovandudza.Fluids kuburikidza nemakapu madiki anosvika pakakwirira, zvichikonzera kutetepa velocity/kupisa muganhu wemuganho, izvo zvinowedzera mwero wekutamisa kupisa.Kuwedzera mamwe nanoparticles kune base fluid inogona kuva nemhedzisiro yakanaka uye yakaipa.Zvibereko zvinokonzeresa zvinosanganisira kuwedzera nanoparticle kudhumhana, favourite fluid thermal conductivity zvinodiwa, uye kuwedzera kupisa kwekufambisa.
Kutamisa kupisa kwecoefficient ye nanofluid kune base fluid zvichienderana nenhamba yaReynolds ye45° uye 90° machubhu.
Panguva imwecheteyo, mhedzisiro yakaipa ndeyekuwedzera kweiyo dynamic viscosity ye nanofluid, iyo inoderedza kufamba kweiyo nanofluid, nokudaro kuderedza avhareji Nusselt nhamba (Nuavg).Kuwedzera kupisa kwekupisa kwenanofluids (ZNP-SDBS@DW) uye (ZNP-COOH@DW) kunofanirwa kuve nekuda kweBrownian motion uye microconvection yegraphene nanoparticles yakamiswa muDW37.Thermal conductivity ye nanofluid (ZNP-COOH@DV) yakakwirira kudarika iyo nanofluid (ZNP-SDBS@DV) nemvura yakasvibiswa.Kuwedzera mamwe nanomaterials kune base fluid inowedzera yavo yekupisa conductivity (Table 1)38.
Mufananidzo wechinomwe unoratidza avhareji yekoefficient yekukweshana kwenanofluids ine base fluid (DW) (f(NFs)/f(DW)) muhuwandu muzana (0.025%, 0.05% uye 0.1%).Avhareji ye friction coefficient inogara iri ≈1, zvichireva kuti non-covalent (GNF-SDBS@DW) uye covalent (GNF-COOH@DW) nanofluids ane friction coefficient yakafanana neye base fluid.Chiyereso chekupisa chine nzvimbo shoma chinoita kuti chivhare kuyerera uye chinowedzera kuyerera kwekuyerera1.Chaizvoizvo, iyo coefficient of friction inowedzera zvishoma nekuwedzera chikamu chechikamu che nanofluid.Kurasika kwepamusoro kwefriction kunokonzerwa nekuwedzera dynamic viscosity ye nanofluid uye kuwedzera kweshear stress pamusoro pepamusoro nepamusoro pezana ye nanographene mu base fluid.Tafura (1) inoratidza kuti dynamic viscosity ye nanofluid (ZNP-SDBS@DV) yakakwirira kudarika iyo nanofluid (ZNP-COOH@DV) pahuremu humwe chete, hunobatanidzwa nekuwedzera kwepamusoro pemigumisiro.mashandiro anoshanda pane isina-covalent nanofluid.
Pamusoro pemuonde.8 inoratidza nanofluid ichienzaniswa nebase fluid (DW) (\(\frac{{\Delta P}_{NFs}}{{\Delta P}_{DW}}\)) pa (0.025%, 0.05% uye 0.1% )Iyo isiri-covalent (GNPs-SDBS@DW) nanofluid yakaratidza yakakwira avhareji yekumanikidzwa kurasikirwa, uye nekuwedzera kwehuwandu muzana kusvika 2.04% ye0.025% wt., 2.46% ye0.05% wt.uye 3.44% ye0.1% wt.nekesi yekuwedzera (helix angle 45 ° uye 90 °).Zvichakadaro, iyo nanofluid (GNPs-COOH@DW) yakaratidza kuderera kwevhareji yekurasikirwa, kuwedzera kubva ku1.31% pa 0.025% wt.kusvika ku1.65% pa 0.05% wt.Ivhareji yekurasikirwa kwe0.05 wt.% -COOH@NP uye 0.1 wt.% -COOH@NP ndeye 1.65%.Sezvinoonekwa, kudonha kwekumanikidza kunowedzera nekuwedzera Re nhamba muzviitiko zvese.Kuwedzera kudonhedza kudonhedza pakakwirira Re tsika kunoratidzwa nekutsamira kwakananga pakuyerera kwevhoriyamu.Nokudaro, nhamba yepamusoro yeRe muchubhu inotungamirira kune kuderera kwepamusoro, izvo zvinoda kuwedzera kwepombi simba39,40.Mukuwedzera, kurasikirwa kwekumanikidzika kwakakwirira nekuda kwepamusoro-soro yeeddies uye mhirizhonga inokonzerwa nepamusoro penzvimbo, iyo inowedzera kupindirana kwekumanikidzwa uye inertia masimba mumuganhu wemuganhu1.
Kazhinji, maitiro ekuongorora maitiro (PEC) yeasina-covalent (VNP-SDBS@DW) uye covalent (VNP-COOH @ DW) nanofluids inoratidzwa muFig.9. Nanofluid (ZNP-SDBS@DV) yakaratidza huwandu hwePEC hwepamusoro pane (ZNP-COOH@DV) muzviitiko zvose (helix angle 45 ° uye 90 °) uye yakavandudzwa nekuwedzera chikamu chikuru, semuenzaniso, 0.025 wt.%.iri 1.17, 0.05 wt.% iri 1.19 uye 0.1 wt.% i1.26.Zvichakadaro, iyo PEC yakakosha kushandisa nanofluids (GNPs-COOH@DW) yaive 1.02 ye0.025 wt%, 1.05 ye0.05 wt%, 1.05 ye0.1 wt%.muzviitiko zvose (helix angle 45 ° uye 90 °).1.02.Sezvo mutemo, nekuwedzera kwenhamba yeReynolds, iyo thermal-hydraulic performance inoderera zvakanyanya.Sezvo nhamba yeReynolds inowedzera, kuderera kwe-thermal-hydraulic performance coefficient yakarongeka yakabatana nekuwedzera kwe (NuNFs / NuDW) uye kuderera kwe (fNFs / fDW).
Hydrothermal zvimiro zvenanofluids zvine chekuita nemvura yepasi zvichienderana nenhamba dzeReynolds dzemachubhu ane 45° uye 90° angles.
Ichi chikamu chinokurukura nezve thermal properties yemvura (DW), non-covalent (VNP-SDBS@DW), uye covalent (VNP-COOH@DW) nanofluids pazvikamu zvitatu zvakasiyana-siyana uye nhamba dzeReynolds.Maviri akamonerwa bhandi kupisa anochinjanisa geometries akatariswa mumhando 7000 ≤ Re ≤ 17000 maererano nemapombi akajairwa (helix angles 45 ° uye 90 °) kuongorora avhareji yekupisa-hydraulic kuita.Pamusoro pemuonde.10 inoratidza tembiricha yemvura uye nanofluids panobuda seavhareji uchishandisa (helix angle 45° uye 90°) papombi yakajairika (\(\frac{{{T}_{out}}_{Twisted}}{{ {T} _{kunze}_{Regular}}\)).Non-covalent (GNP-SDBS@DW) uye covalent (GNP-COOH@DW) nanofluids ine zvikamu zvitatu zvakasiyana-siyana zvehuremu zvakadai se0.025 wt%, 0.05 wt% uye 0.1 wt%.Sezvinoratidzwa mufig.11, kukosha kweavhareji yetembiricha yekubuda (\(\frac{{{T}_{out}}_{Twisted}}{{{T}_{out}}_{Plain}}\)) > 1, zvichiratidza kuti (45° uye 90° helix angle) tembiricha iri panobuda mupombi inopisa yakakosha kupfuura yepombi yakajairwa, nekuda kwekunyanya mhirizhonga uye kusanganiswa kuri nani kwemvura.Uye zvakare, tembiricha yekubuda kweDW, isina-covalent uye covalent nanofluids yakadzikira nekuwedzera Reynolds nhamba.Iyo base fluid (DW) ine yakanyanya kureba yekubuda tembiricha.Zvichakadaro, kukosha kwakaderera kunoreva 0.1 wt% -SDBS@GNPs.Non-covalent (GNPs-SDBS@DW) nanofluids yakaratidza yakaderera avhareji tembiricha yekubuda zvichienzaniswa necovalent (GNPs-COOH@DW) nanofluids.Sezvo tepi yakamonyoroka ichiita kuti nzvimbo yekuyerera iwedzere kusanganiswa, iyo iri padyo-yemadziro kupisa flux inogona nyore kupfuura nemumvura, ichiwedzera kupisa kwese.Iyo yakaderera twist-to-tepi reshiyo inokonzeresa kupinda kuri nani uye saka zvirinani kutamisa kupisa.Kune rumwe rutivi, zvinogona kuonekwa kuti tepi yakakungurutswa inochengetedza yakadzika tembiricha pamadziro, izvo zvinowedzera Nuavg.Kune yakamonyoroka tepi yekuisa, iyo yepamusoro Nuavg kukosha inoratidza yakagadziridzwa convective kupisa kutamisa mukati mechubhu22.Nekuda kwekuwedzera kuyerera nzira uye kuwedzera kusanganisa uye mhirizhonga, nguva yekugara inowedzera, zvichikonzera kuwedzera kwekushisa kwemvura painobuda41.
Reynolds nhamba dzeakasiyana-siyana nanofluid zvine chekuita nekubuda kwekushisa kwemachubhu akajairwa (45° uye 90° helix angles).
Heat transfer coefficients (45° uye 90° helix angle) maringe nenhamba dzeReynolds dzenanofluid dzakasiyana zvichienzaniswa nemachubhu akajairwa.
Nzira huru yekusimudzira yakavharidzirwa tepi kupisa kutengesa ndeyotevera: 1. Kuderedza hydraulic dhayamita yehutu hunopisa hunoita kuti kuwedzere kuyerera kwevelocity uye curvature, izvo zvinowedzera kuwedzera shear stress pamadziro uye inokurudzira kufamba kwechipiri.2. Pamusana pekuvhara tepi inoputika, kukurumidza pamadziro epombi kunowedzera, uye kuwanda kwemuganhu wemuganhu kunoderera.3. Kuyerera kwespiral kuseri kwebhanhire rakamonyoroka kunotungamirira kukuwedzera kwekukurumidza.4. Induced vortices inovandudza kusanganiswa kwemvura pakati pepakati nepedyo-masvingo ekuyerera42.Pamusoro pemuonde.11 uye fig.12 inoratidza kupisa kwekushisa kweDW uye nanofluids, semuenzaniso (kupisa kuchinjisa coefficient uye avhareji Nusselt nhamba) seavhareji uchishandisa twisted tepi yekuisa machubhu kana ichienzaniswa neyakajairwa machubhu.Non-covalent (GNP-SDBS@DW) uye covalent (GNP-COOH@DW) nanofluids ine zvikamu zvitatu zvakasiyana-siyana zvehuremu zvakadai se0.025 wt%, 0.05 wt% uye 0.1 wt%.Mune zvese zvinopisa kupisa (45 ° uye 90 ° helix angle) avhareji yekupisa kupisa kuita ndeye> 1, ichiratidza kuvandudzwa kweyekupisa coefficient uye avhareji nhamba yeNusselt ine machubhu akakomberedzwa zvichienzaniswa neakajairika machubhu.Non-covalent (GNPs-SDBS@DW) nanofluids yakaratidza yakakwira avhareji yekupisa kupisa kunatsiridza pane covalent (GNPs-COOH@DW) nanofluids.PaRe = 900, iyo 0.1 wt% kunatsiridza mukupisa kwekuita -SDBS@GNPs kune maviri ekupisa kupisa (45 ° uye 90 ° helix angle) yaive yepamusoro-soro ine kukosha kwe1.90.Izvi zvinoreva kuti yunifomu yeTP mhedzisiro inonyanya kukosha kune yakaderera fluid velocities (nhamba yeReynolds) 43 uye kuwedzera mhirizhonga yakanyanya.Nekuda kwekuiswa kwemavortices akawanda, kupisa kweyekupisa coefficient uye avhareji Nusselt nhamba yeTT machubhu yakakwirira kupfuura yakajairwa machubhu, zvichikonzera mutete wemuganhu.Kuvepo kweHP kunowedzera kuwanda kwemhirizhonga, kusanganiswa kwemvura inoshanda inoyerera uye kuwedzeredzwa kwekutamisa kupisa kuenzaniswa nemapaipi epasi (pasina kuisa tepi yakamonyoroka)21.
Avhareji yenhamba yeNusselt (helix angle 45° uye 90°) maringe nenhamba yeReynolds yemananofluid akasiyana zvichienzaniswa nemachubhu akajairika.
Figure 13 ne 14 inoratidza avhareji coefficient of friction (\(\frac{{f}_{Twisted}}{{f}_{Plain}}\)) uye kurasikirwa kwesimba (\(\frac{{\Delta P} _ {Twisted}}{{\Delta P}_{Plain}}\}} ingangoita 45° uye 90° papombi dzemazuva ose dzinoshandisa DW nanofluids, (GNPs-SDBS@DW) uye (GNPs-COOH@DW) ion exchanger ine ( 0.025 wt %, 0.05 wt % uye 0.1 wt %). { {f}_{Plain} }\)) uye kurasikirwa kwesimba (\(\frac{{\Delta P}_{Twisted}}{{\Delta P }_{Plain}}\}) kudzikira., friction coefficient uye pressure loss yakakwira pazasi Reynolds manhamba Avhareji yefriction coefficient uye pressure loss iri pakati pe3.78 and 3.12 Avhareji ye friction coefficient and pressure loss inoratidza kuti (45° helix angle uye 90°) heat exchanger inodhura zvakapetwa katatu kudarika mapaipi emazuva ose.Pamusoro pezvo, kana mvura inoshanda ichiyerera nekumhanya kwepamusoro, coefficient of friction inodzikira.Dambudziko rinovapo nekuti nhamba yeReynolds painowedzera, ukobvu hwemuganhu wemuganhu. inoderera, izvo zvinoita kuti kuderera kwekuita kwesimba viscosity panzvimbo yakakanganiswa, kuderera kwevelocity gradients uye shear stresss uye, nokudaro, kuderera kwehuwandu hwe friction21.Iyo yakagadziridzwa inovharira mhedzisiro nekuda kwekuvapo kweTT uye yakawedzera swirl inoguma yakakwira zvakanyanya kurasikirwa kwekumanikidzwa kwemapaipi eTT ane heterogeneous pane mapaipi epasi.Mukuwedzera, kune zvose zviri zviviri pombi yepasi uye TT pombi, zvinogona kuonekwa kuti kudonha kwemhepo kunowedzera nekumhanya kwemvura inoshanda43.
Coefficient of friction (45° uye 90° helix angle) maringe nenhamba yeReynolds yemananofluid akasiyana zvichienzaniswa nemachubhu akajairwa.
Kurasikirwa kwepressure (45° uye 90° helix angle) sebasa renhamba yeReynolds kune akasiyana nanofluids ane hukama nechubhu yakajairwa.
Muchidimbu, Mufananidzo 15 unoratidza maitiro ekuongorora maitiro (PEC) ekuchinjanisa kupisa ne45° uye 90° angles zvichienzaniswa nemachubhu asina kujeka (\(\frac{{PEC}_{Twisted}}{{PEC}_{Plain}}} \ ) ) mu (0.025 wt.%, 0.05 wt.% uye 0.1 wt.%) vachishandisa DV, (VNP-SDBS@DV) uye covalent (VNP-COOH@DV) nanofluids.Hukoshi (\(\frac{{PEC}_{Twisted}}{{PEC}_{Plain}}\)) > 1 mune ese ari maviri (45° uye 90° helix angle) muchichinjisa chekupisa.Pamusoro pezvo, (\(\frac{{PEC}_{Twisted}}{{PEC}_{Plain}}\)) inosvika pakukosha kwayo paRe = 11,000.The 90° heat exchanger inoratidza kuwedzera kudiki mu (\ (\frac{{PEC}_{Twisted}}{{PEC}_{Plain}}\)) zvichienzaniswa ne45° heat exchanger., PaRe = 11,000 0.1 wt%-GNPs@SDBS inomiririra pamusoro (\(\frac{{PEC}_{Twisted}}{{PEC}_{Plain}}\)) kukosha, semuenzaniso 1.25 ye45° kona yekupisa uye 1.27 ye90 ° kona yekupisa kupisa.Ihombe kudarika imwe pazvikamu zvose zvezvikamu zvakawanda, izvo zvinoratidza kuti mapaipi ane mapepi akamonyoroka anopinza ari pamusoro pemapombi akajairwa.Zvinonzwisisika, iyo yakagadziridzwa kupisa kupisa kwakapihwa nematepi kuiswa kwakakonzera kuwedzera kukuru kwekukakavadzana kurasikirwa22.
Kushanda maitiro eiyo Reynolds nhamba yeakasiyana nanofluid maererano nemachubhu akajairwa (45 ° uye 90 ° helix angle).
Appendix A inoratidza streamlines ye45° uye 90° heat exchangers paRe = 7000 uchishandisa DW, 0.1 wt%-GNP-SDBS@DW uye 0.1 wt%-GNP-COOH@DW.Iyo mitsetse mundege inochinjika ndiyo inonyanya kushamisa mhedzisiro yeakamonyoroka ribhoni inoiswa pane huru inoyerera.Kushandiswa kwe45 ° uye 90 ° kupisa kunopisa kunoratidza kuti velocity munzvimbo iri pedyo-yemadziro inenge yakafanana.Zvichakadaro, Appendix B inoratidza velocity contours ye45° uye 90° heat exchangers paRe = 7000 uchishandisa DW, 0.1 wt%-GNP-SDBS@DW uye 0.1 wt%-GNP-COOH@DW.Zvishwe zvevelocity zviri munzvimbo nhatu dzakasiyana (zvidimbu), semuenzaniso, Plain-1 (P1 = -30mm), Plain-4 (P4 = 60mm) uye Plain-7 (P7 = 150mm).Kuyerera kwevelocity pedyo nemadziro epombi ndiko kwakadzikira uye manyawi emvura anowedzera akananga pakati pepombi.Uye zvakare, kana uchipfuura nepamhepo duct, nzvimbo yakaderera velocities pedyo nemadziro inowedzera.Izvi zvinokonzerwa nekukura kweiyo hydrodynamic boundary layer, iyo inowedzera kuwanda kwenzvimbo yakaderera-velocity pedyo nemadziro.Uye zvakare, kuwedzera iyo nhamba yeReynolds kunowedzera iyo yakazara velocity mwero mumativi ese emuchinjiko, nekudaro ichidzikisa ukobvu hwenzvimbo yakaderera velocity muchiteshi39.
Covalently uye asiri-covalently functionalized graphene nanosheets akaongororwa mune akamonyoroka tepi anoisa ane helix angles e45 ° uye 90 °.Mutsinhanisi wekupisa unogadziriswa nenhamba uchishandisa SST k-omega turbulence model pa7000 ≤ Re ≤ 17000. Thermophysical properties inoverengwa paTin = 308 K. Panguva imwe chete kupisa rusvingo rwechubhu yakamonyoroka pane imwe nguva tembiricha ye330 K. COOH@DV) yakaderedzwa muhuwandu hutatu, semuenzaniso (0.025 wt.%, 0.05 wt.% uye 0.1 wt.%).Chidzidzo chezvino chakatarisa zvinhu zvitanhatu zvikuru: tembiricha yekubuda, kupisa kweyekupisa coefficient, avhareji Nusselt nhamba, coefficient of friction, pressure kurasikirwa, uye maitiro ekuongorora maitiro.Hezvino izvo zvakawanikwa zvakanyanya:
Avhareji tembiricha yekubuda kunze (\({{T}_{out}}_{Nanofluids}\)/\({{T}_{out}}_{Basefluid}\)) inogara iri pasi pe1, zvichireva kuti non-spread Tembiricha yekubuda kwevalence (ZNP-SDBS@DV) uye covalent (ZNP-COOH@DV) nanofluids yakadzikira pane yemvura yepasi.Zvichakadaro, avhareji tembiricha yekubuda (\({{T}_{out}}_{Twisted}\)/\({{T}_{kunze}}_{Plain}\)) kukosha> 1, zvichiratidza chokwadi chekuti (45° uye 90° helix angle) tembiricha yekubuda nayo yakakwira kupfuura nemachubhu akajairwa.
Muzviitiko zvese izvi, avhareji kukosha kwekupisa kwekutamisa zvivakwa (nanofluid / base fluid) uye (yakamonyoroka chubhu/yakajairika chubhu) inogara ichiratidza> 1.Non-covalent (GNPs-SDBS@DW) nanofluids yakaratidza yakakwira avhareji yekuwedzera mukupisa kupisa, zvinoenderana necovalent (GNPs-COOH@DW) nanofluids.
Avhareji yefriction coefficient (\({f}_{Nanofluids}/{f}_{Basefluid}\)) ye-non-covalent (VNP-SDBS@DW) uye covalent (VNP-COOH@DW) nanofluids inogara iri ≈1 .friction of non-covalent (ZNP-SDBS@DV) uye covalent (ZNP-COOH@DV) nanofluids (\({f}_{Twisted}/{f}_{Plain}\)) nguva dzose > 3.
Muzviitiko zvese zviri zviviri (45° uye 90° helix angle), iyo nanofluids (GNPs-SDBS@DW) yairatidza kumusoro (\({\Delta P}_{Nanofluids}/{\Delta P}_{Basefluid}\)) 0.025 wt .% ye2.04%, 0.05 wt.% ye2.46% uye 0.1 wt.% ye3.44%.Zvichakadaro, (GNPs-COOH@DW) nanofluids yakaratidza yakaderera (\({\Delta P}_{Nanofluids}/{\Delta P}_{Basefluid}\)) kubva pa1.31% ye0.025 wt.% kusvika 1.65% iri 0.05 % nekurema.Pamusoro pezvo, avhareji yekurasikirwa kwekumanikidza (\({\Delta P}_{Twisted}/{\Delta P}_{Plain}\) ye-non-covalent (GNPs-SDBS@DW) uye covalent (GNPs-COOH@DW) ))) nanofluids nguva dzose >3.
Muzviitiko zvese zviri zviviri (45° uye 90° helix angles), iyo nanofluids (GNPs-SDBS@DW) yairatidza yakakwirira (\({PEC}_{Nanofluids}/{PEC} _{Basefluid}\)) @DW kukosha) , semuenzaniso 0.025 wt.% - 1.17, 0.05 wt.% - 1.19, 0.1 wt.% - 1.26.Pakadai, kukosha kwe(\({PEC}_{Nanofluids}/{PEC}_{Basefluid}\)) uchishandisa (GNPs-COOH@DW) nanofluids i1.02 ye0.025 wt.%, 1.05 ye0 , 05 wt.% uye 1.02 ndeye 0.1% nehuremu.Pamusoro pezvo, paRe = 11,000, 0.1 wt%-GNPs@SDBS yakaratidza hunhu hwepamusoro (\({PEC}_{Twisted}/{PEC}_{Plain}\)), senge 1.25 ye45° helix angle. uye 90° helix angle 1.27.
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Nguva yekutumira: Mar-17-2023