Exergetic performance analysis on helically coiled tube heat exchanger-forecasting thermal conductivity of SiO2/EG nanofluid using ANN and RSM to examine effectiveness of using nanofluids

2021 ◽  
Author(s):  
Mashhour A. Alazwari ◽  
Nidal H. Abu-Hamdeh ◽  
Elias Mesfin Salilih
Keyword(s):  
Thermal Conductivity ◽  
Heat Exchanger ◽  
Performance Analysis ◽  
Coiled Tube ◽  
Tube Heat Exchanger ◽  
Helically Coiled Tube

Numerical Analysis of Heat Transfer on the Shell Side of a Helically Coiled Tube Heat Exchanger for Helium Applications

2021 ◽  
Vol 7 (2) ◽  
Author(s):  
Radomír Filip ◽  
Tomáš Melichar
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Numerical Model ◽  
Constant Heat Flux ◽  
Heat Fluxes ◽  
Heat Transfer Correlation ◽  
Shell Side ◽  
Coiled Tube ◽  
Tube Heat Exchanger ◽  
Helically Coiled Tube

Abstract A new heat transfer correlation for high temperature helium on the shell side of a helically coiled tube heat exchanger was derived with the use of computational fluid dynamics (CFD) tools. The use of suitable heat transfer correlations has an impact on the evaluation of performance of a heat exchanger in relation to the requirements for a sufficient heat transfer surface, which relates to material cost requirements; therefore, it is of high importance. A numerical model was validated with data measured using the helium cooler, which is part of an experimental channel located at the Research Center Řež (CVR) in the Czech Republic. The numerical model used for obtaining the heat transfer correlation assumes a constant heat flux on the wall of the helical coil. In total, 72 cases with varying inlet temperatures, velocities, and heat fluxes were simulated to obtain the heat transfer correlation. Furthermore, the effects of the flow rectifier within the channel regarding the heat transfer coefficient and pressure loss were discussed.

Effectiveness of a shell and helically coiled tube heat exchanger operated with gold nanofluids at low concentration: A multi-level factorial analysis

2020 ◽  
pp. 1-39
Author(s):  
Marina B. Fogaça ◽  
Daniele Toniolo Dias ◽  
Sergio L. Gómez ◽  
Jhon Jairo Ramirez Behainne ◽  
Rozane de Fátima Turchiello
Keyword(s):  
Heat Transfer ◽  
Gold Nanoparticles ◽  
Heat Exchanger ◽  
Volumetric Flow Rate ◽  
Working Fluid ◽  
Inlet Temperature ◽  
Coiled Tube ◽  
Tube Heat Exchanger ◽  
Helically Coiled Tube ◽  
Multi Level

Abstract This work assesses the thermal performance of gold nanofluids as cooling liquid in a shell and helically coiled tube (SHCT) heat exchanger built in bench-scale. Tests planned under a multi-level factorial experimental design were carried out to evaluate the effects caused by the volumetric fraction of the gold nanoparticles, the volumetric flow rate of the working fluid and the inlet temperature of the hot fluid (water) on the SHCT heat exchanger effectiveness. Spherical gold nanoparticles with mean diameter of 14±2 nm were produced from the Turkevich's method to be used in two concentrations of about 10-5 %vol. The heat transfer tests were performed at volumetric flow rates of 20, 30 and 40 L/h for both working fluids using heated water at inlet temperatures of 40, 50 and 60°C. Results showed that the less concentrated nanofluid was comparatively more efficient, suggesting the presence of a range of values of the gold concentration for the existence of an improvement on the effectiveness in the heat transfer.

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