Experimental study and optimization of friction factor and heat transfer in the fin and tube heat exchanger using nanofl
- PDF / 3,099,744 Bytes
- 12 Pages / 595.276 x 790.866 pts Page_size
- 39 Downloads / 209 Views
ORIGINAL ARTICLE
Experimental study and optimization of friction factor and heat transfer in the fin and tube heat exchanger using nanofluid Hassan Hajabdollahi1 · Mohammad Shafiey Dehaj1 Received: 20 September 2020 / Accepted: 30 October 2020 © King Abdulaziz City for Science and Technology 2020
Abstract In the present research, friction factor and Nusselt number in tube side of a fin-and-tube heat exchanger are experimentally determined. Two kinds of nanofluids including Al2O3 and CuO water-based are used and experimental results are performed for three nanoparticle volumetric concentrations (PVC) for the Reynolds number between 3000 and 15,000. The results show that both friction factor and Nusselt number enhance in the case of nanofluid as working fluid in comparison to the water and this increment is higher in the CuO nanofluid. In the Al2O3 nanofluid at Re = 3000, 1.92%, 15.08% and 22.46% enhancements in the Nusselt number are observed compared with the base fluid for PVC = 0.025, 0.050 and 0.075, respectively. The mentioned improvements for CuO nanofluid are obtained 10.89%, 35.50% and 46.11%, respectively. In addition, at Re = 3000, 15.27%, 9.64% and 13.80% increases in friction factor are observed for Al2O3 nanofluid compared with base fluid, respectively, for PVC = 0.025, 0.050 and 0.075. The mentioned increases for CuO nanofluid are obtained 7.71%, 13.97% and 19.59%, respectively. Then, correlations for friction factor and Nusselt number are derived with adequate accuracy. Finally, the optimization of this kind of heat exchanger is performed in presence of nanoparticles and their results are presented. Keywords Fin and tube heat exchanger · Al2O3 nanofluid · CuO nanofluid · Nusselt number · Friction factor · Optimization List of symbols Atot Total heat transfer surface (m2 ) Cmin Minimum of Ch and Cc (W∕K) Cmax Maximum of Ch and Cc (W∕K) C* Heat capacity rate ratio (−) cp Specific heat capacity (kJ/kg K) dnp Average size of nanoparticle (nm) Dh Hydraulic diameter (m) f Friction factor (−) G Mass flux (kg∕m2 s) h Convection heat transfer coefficient (W∕m2 K) j Colburn factor (−) kf Fluid thermal conductivity (W∕m2 K) ṁ Mass flow rate (kg/s) NTU Number of transfer units (−) Nu Nusselt number (−) Pr Prandtl number (−) PVC Particle volumetric concentration (%) * Mohammad Shafiey Dehaj [email protected] 1
Q Rate of heat transfer (kW) Qmax Maximum rate of heat transfer (kW) Re Reynolds number (−) St Stanton number (−) U Overall heat transfer coefficient (W∕m2 K) V Heat exchanger volume ( m3) v Fluid velocity (m/s) Greek abbreviations ΔP Pressure drop (kPa) 𝜀 Effectiveness (−) 𝜂o Fin overall efficiency (−) 𝜇 Viscosity (Pa s) 𝜌 Density ( kg∕m3) 𝜙 Particle volumetric concentration (%) Subscript bf Fluid fin Fin side nf Nanofluid np Nanoparticle o Outside tube Tube side
Department of Mechanical Engineering, Faculty of Engineering, Vali-e-Asr University of Rafsanjan, Rafsanjan, Iran
13
Vol.:(0123456789)
Applied Nanoscience
Introduction Generally, there are
Data Loading...
