Matches in SemOpenAlex for { <https://semopenalex.org/work/W4387132541> ?p ?o ?g. }
Showing items 1 to 88 of
88
with 100 items per page.
- W4387132541 endingPage "11680" @default.
- W4387132541 startingPage "11650" @default.
- W4387132541 abstract "ABSTRACTRealizing the importance of the natural circulation loop (NCL), which is a passive heat transport device, an analytical study is undertaken to demonstrate the functioning of an NCL-based parabolic trough collector (PTC). Multiple validated analytical models were incorporated to evaluate the system performance. The parametric study involved variations in loop height, loop length, and solar radiation. The loop flow rate enhances by increasing its height or the receiver length. At maximum radiation, 1.3 kg/s flow rate was observed for loop geometry of 5 m height and 7.8 m length against 0.79 kg/s for 1 m height. The flow rate predicted for a 10 m length and 1 m height loop was 0.87 kg/s. Since instability rises with height and heat loss and receiver temperature increase with receiver length, a trade-off between the two is necessary to function NCL-based PTC properly. Otherside, though the higher heat output with an increase in the receiver length is evident, a noticeable drop in thermal efficiency (≈7%) during the peak hours of solar radiation is a matter of concern. Further, the outlet temperature was not affected by the loop height for the defined flow condition of the process fluid. Like in conventional PTC systems, the process fluid’s exit temperature or flow rate can also be maintained constant during a day operation by varying the flow condition. The proposed model can deliver ≈ 1500 liters of hot water in six hours with an average 68% thermal efficiency without external power, in contrast to the necessity of notable pumping power and associated overhead charges in conventional PTC. Further, the system’s stability was predicted using linear stability analysis, and stability maps were generated for different loop heights and found that as the loop height decreases, the unstable zone diminishes. Though the steady-state data points are in the unstable flow region, stable operation is expected by incorporating pertinent instability restraining technique, that is, loop tilt.KEYWORDS: NCL-based PTC1-D steady-state analysislinear stability analysisstability mapthermal analysis of PTC Highlights Efficacy of NCL-based PTC is demonstrated.Effect of geometrical and operational conditions of NCL on PTC performance is analyzed.Stability analysis of NCL and instability restraining method is suggested.NCL-based PTC model is proposed.Nomenclature A=Area (m2)Ar=Aspect ratio (Height/Width)Cp=Specific heat (J/kgK)D=Diameter (m)f=Friction factor (-)FR=Collector heat removal factor (-)F’=Collector efficiency factor (-)g=Acceleration due to gravity (m/s2)Grm=Modified Grashoff number Di3ρ2βgQHAμ3CpH=Loop height (m)h=Heat transfer coefficient (W/m2K)Ib=Beam radiation (W/m2)k=Thermal conductivity (W/mK)K=Flow losses (-)L=Length (m)m=Mass flow rate (kg/s)Num=Modified Nusselt number = 4LtUiDDckPr=Prandlt number (-)Q=Heat input (W)r=Radius (m)Re=Reynolds number (Dm/Aμ)s=Coordinate around the loop (m)Stm=Modified Stanton number = NumRessPrT=Temperature (K)U=Overall heat transfer coefficient (W/m2K)Greek symbols=β=Thermal expansion coefficient (K−1)/(orifice diameter/loop diameter)ρ=Density (kg/m3)/reflectivityµ=Absolute viscosity (kg/m.s)ωˉ=Dimensionless mass flow rate (m/mss)η=Efficiencyα=Absorptivityγ=Intercept factorτ=Transmissivityθˉ=Dimensionless temperature T−Ts(ΔTh)ssSubscripts=a=Aperture/ambientc=Cooler/covercl=Cold lege=Elboweff=Effectiveg=Glassh=Heaterhl=Hot legi=InnerL=Losso=Outer/opticalr=Receiver/Radiusss=Steady statet=Total/thermalu=UsefulAcronyms=CFD=Computational fluid dynamicsDNI=Direct normal irradianceHHHC=Horizontal heater horizontal coolerHTF=Heat transfer fluidNCL=Natural circulation loopNCS=Natural circulation systemNREL=National renewable energy laboratoryPTC=Parabolic trough collectorSPNCL=Single phase natural circulation loopVHVC=Vertical heater vertical coolerDisclosure statementNo potential conflict of interest was reported by the author(s).Additional informationNotes on contributorsNakul S.Nakul S. is Assistant professor in the Department of Mechanical and Industrial engineering, Manipal Accademy of higher education, Manipal India. His research interesrts include natural circulation flows, heat transfer, computational fluid dynamics and thermal mangement.Arunachala U. C.Arunachala U. C. is a Professor in the Department of Mechanical and Industrial Engineering at Manipal Institute of Technology, Manipal, India. He has more than 25 years of research and teaching experience. His research interests include analysis of solar thermal systems, thermal management of photovoltaic modules, stability analysis of natural circulation loops, thermosyphon heat transport systems, heat transfer augmentation of thermal systems and heat exchanger analysis." @default.
- W4387132541 created "2023-09-29" @default.
- W4387132541 creator A5046088853 @default.
- W4387132541 creator A5077133903 @default.
- W4387132541 date "2023-09-28" @default.
- W4387132541 modified "2023-10-18" @default.
- W4387132541 title "Efficacy of natural circulation loop based parabolic trough collector- An analytical approach" @default.
- W4387132541 cites W2009439412 @default.
- W4387132541 cites W2020583145 @default.
- W4387132541 cites W2029232927 @default.
- W4387132541 cites W2591570532 @default.
- W4387132541 cites W2616333350 @default.
- W4387132541 cites W2621171535 @default.
- W4387132541 cites W2794888736 @default.
- W4387132541 cites W2809276547 @default.
- W4387132541 cites W2884328405 @default.
- W4387132541 cites W2888640339 @default.
- W4387132541 cites W2907549389 @default.
- W4387132541 cites W2908643038 @default.
- W4387132541 cites W2946059398 @default.
- W4387132541 cites W2948333409 @default.
- W4387132541 cites W2953511199 @default.
- W4387132541 cites W2965558646 @default.
- W4387132541 cites W2998492208 @default.
- W4387132541 cites W3008485922 @default.
- W4387132541 cites W3018995068 @default.
- W4387132541 cites W3029123434 @default.
- W4387132541 cites W3200232021 @default.
- W4387132541 cites W3202646708 @default.
- W4387132541 cites W3203342467 @default.
- W4387132541 cites W4200370582 @default.
- W4387132541 cites W4224283846 @default.
- W4387132541 cites W4281390700 @default.
- W4387132541 cites W4309778758 @default.
- W4387132541 cites W4362719258 @default.
- W4387132541 doi "https://doi.org/10.1080/15567036.2023.2262415" @default.
- W4387132541 hasPublicationYear "2023" @default.
- W4387132541 type Work @default.
- W4387132541 citedByCount "0" @default.
- W4387132541 crossrefType "journal-article" @default.
- W4387132541 hasAuthorship W4387132541A5046088853 @default.
- W4387132541 hasAuthorship W4387132541A5077133903 @default.
- W4387132541 hasConcept C114614502 @default.
- W4387132541 hasConcept C121332964 @default.
- W4387132541 hasConcept C172120300 @default.
- W4387132541 hasConcept C184670325 @default.
- W4387132541 hasConcept C192562407 @default.
- W4387132541 hasConcept C204530211 @default.
- W4387132541 hasConcept C2779301550 @default.
- W4387132541 hasConcept C2780113671 @default.
- W4387132541 hasConcept C2781249646 @default.
- W4387132541 hasConcept C33923547 @default.
- W4387132541 hasConcept C39432304 @default.
- W4387132541 hasConcept C57879066 @default.
- W4387132541 hasConcept C97355855 @default.
- W4387132541 hasConceptScore W4387132541C114614502 @default.
- W4387132541 hasConceptScore W4387132541C121332964 @default.
- W4387132541 hasConceptScore W4387132541C172120300 @default.
- W4387132541 hasConceptScore W4387132541C184670325 @default.
- W4387132541 hasConceptScore W4387132541C192562407 @default.
- W4387132541 hasConceptScore W4387132541C204530211 @default.
- W4387132541 hasConceptScore W4387132541C2779301550 @default.
- W4387132541 hasConceptScore W4387132541C2780113671 @default.
- W4387132541 hasConceptScore W4387132541C2781249646 @default.
- W4387132541 hasConceptScore W4387132541C33923547 @default.
- W4387132541 hasConceptScore W4387132541C39432304 @default.
- W4387132541 hasConceptScore W4387132541C57879066 @default.
- W4387132541 hasConceptScore W4387132541C97355855 @default.
- W4387132541 hasIssue "4" @default.
- W4387132541 hasLocation W43871325411 @default.
- W4387132541 hasOpenAccess W4387132541 @default.
- W4387132541 hasPrimaryLocation W43871325411 @default.
- W4387132541 hasRelatedWork W2032427195 @default.
- W4387132541 hasRelatedWork W2062887893 @default.
- W4387132541 hasRelatedWork W2073981414 @default.
- W4387132541 hasRelatedWork W2094543730 @default.
- W4387132541 hasRelatedWork W2559833865 @default.
- W4387132541 hasRelatedWork W3033110448 @default.
- W4387132541 hasRelatedWork W3158249547 @default.
- W4387132541 hasRelatedWork W365379648 @default.
- W4387132541 hasRelatedWork W4200370582 @default.
- W4387132541 hasRelatedWork W4309103040 @default.
- W4387132541 hasVolume "45" @default.
- W4387132541 isParatext "false" @default.
- W4387132541 isRetracted "false" @default.
- W4387132541 workType "article" @default.