Numerical estimation of heat transfer characteristics for two-row plate-finned tube heat exchangers with experimental data

2015 ◽  
Vol 52 (5) ◽  
pp. 969-979 ◽  
Author(s):  
Han-Taw Chen ◽  
Chih-Han Lu ◽  
Yao-Sheng Huang ◽  
Kuo-Chi Liu
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Heat Exchangers ◽  
Finned Tube ◽  
Numerical Estimation ◽  
Heat Transfer Characteristics ◽  
Transfer Characteristics

Numerical Investigation of Heat Transfer Characteristics of Different Nanoparticles Using Modified Eulerian-Eulerian Model

2020 ◽  
Author(s):  
Muzafar Hussain ◽  
Shahbaz Tahir
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Heat Exchangers ◽  
Single Phase ◽  
Reynolds Numbers ◽  
Operating Conditions ◽  
Phase Model ◽  
Heat Transfer Characteristics ◽  
Eulerian Model ◽  
Transfer Characteristics

Abstract Nanofluids are widely adopted nowadays to enhance the heat transfer characteristics in the solar applications because of their excellent thermophysical properties. In this paper, a modified Eulerian-Eulerian model recently developed based on experiments was validated numerically to account for the deviations from the experimental data. The modified Eulerian-Eulerian model is compared with the single-phase model, Eulerian-Eulerian models for TiO2-water at different operating conditions and deviation from the experimental data for each of the model was documented. However, the modified Eulerian-Eulerian model gave much closer results when compared to the experimental data. For the further extension of work, the modified Eulerian-Eulerian model was applied to different nanofluids in order to investigate their heat transfer characteristics. Three different nanoparticles were investigated namely Cu, MgO, and Ag and their heat transfer characteristics is calculated based on the modified Eulerian-Eulerian model as well as the single-phase model for the comparison. For lower values of Reynolds numbers, the average heat transfer coefficient was almost identical for both models with small percentage of error but for higher Reynolds numbers, the deviation got larger. Therefore, single-phase model is not appropriate for higher Reynolds numbers and modified Eulerian-Eulerian model should be used to accurately predict the heat transfer characteristics of the nanofluids at higher Reynolds numbers. From the analysis it is found that the Ag-water nanofluid have the highest heat transfer characteristics among others and can be employed in the solar heat exchangers to enhance the heat transfer characteristics and to further improve the efficiency.

Flow and Thermal Characteristics Analysis of Plate–Finned Tube and Annular–Finned Tube Heat Exchangers fo In–Line and Staggered Configurations

2020 ◽  
Vol 22 (4) ◽  
pp. 1407-1418
Author(s):  
Shadman Sakib ◽  
Abdullah Al-Faruk
Keyword(s):  
Heat Transfer ◽  
Flow Rate ◽  
Heat Exchangers ◽  
Air Flow ◽  
Thermal Characteristics ◽  
Finned Tube ◽  
Air Flow Rate ◽  
Heat Transfer Characteristics ◽  
Transfer Characteristics ◽  
Exit Temperature

AbstractAs the effective selection of fin can greatly enhance the performance of heat exchanger, heat transfer and pressure drop performance on the air-side of annular and rectangular finned tube heat exchangers were numerically investigated. Two types of tube arrangement (in-line and staggered alignment) were examined for 6 different air flow rate for both the heat exchangers using computational fluid dynamics software package ANSYS FLUENT. Renormalization group theory (RNG) based k-ε turbulence model was employed to handle the unsteady three-dimensional flow and the conjugate heat transfer characteristics. The exit temperature were determined from the simulated results and then the LMTD, heat transfer rate and air-side heat transfer coefficient were calculated. The numerical flow visualization results revealed few important aspects, such as, the development boundary layers between the fins, the formation of the horseshoe vortex system, and the local variations of the velocity and temperature on the fin geometries. The result shows that as the air flow rate increased the exit temperature decreased but the overall heat transfer increased. Staggered configuration shows higher heat transfer characteristics over the in-line configuration. The rectangular finned tube shows 17 to 24% improvement in heat transfer over the annular finned tube.

Sign in / Sign up

Export Citation Format

Share Document