The effect of the geometric parameters to the thermal-hydraulic dimensioning of a H-type finned tube heat exchanger
Kakko, Markku (2017)
2017
Ympäristö- ja energiatekniikka
Teknis-luonnontieteellinen tiedekunta - Faculty of Natural Sciences
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Hyväksymispäivämäärä
2017-11-08
Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi:tty-201710252051
https://urn.fi/URN:NBN:fi:tty-201710252051
Tiivistelmä
The effect of the geometrical parameters of the in-line H-type finned tube to the heat exchanger dimensioning was studied in this Master's thesis. As the flow field around tubes and fins does not anneal to simple analytical solutions, computational fluid dynamics (CFD) was extensively used in this thesis to calculate heat transfer and pressure drop for different finned tube geometries. The calculation method was found to be in line with the validation experiment.
The data from CFD solution was reduced into a non-dimensional form as Reynolds number based correlations of the Nusselt and Euler numbers and fin efficiency. Additionally, universal correlations for all geometrical parameters were developed for the Nusselt number, Colburn j-factor, Euler number, Fanning friction factor and fin efficiency which are given in the appendices.
With the correlations from the CFD solutions, a thermal-hydraulic dimensioning was made for all CFD cases for equal heat transfer rate and pressure drop. The cases were then compared to the reference geometry to get insight on the effect of the geometric parameters in the heat exchanger core mass, volume and approximate manufacturing welding work for a given conductance and pressure drop requirement. The fin pitch was found to have the highest effect on all performance parameters while the tube pitches and fin thickness was found to be the next important geometric parameters. The least important geometric parameters were the gap between fins and the slit width of the fin.
The data from CFD solution was reduced into a non-dimensional form as Reynolds number based correlations of the Nusselt and Euler numbers and fin efficiency. Additionally, universal correlations for all geometrical parameters were developed for the Nusselt number, Colburn j-factor, Euler number, Fanning friction factor and fin efficiency which are given in the appendices.
With the correlations from the CFD solutions, a thermal-hydraulic dimensioning was made for all CFD cases for equal heat transfer rate and pressure drop. The cases were then compared to the reference geometry to get insight on the effect of the geometric parameters in the heat exchanger core mass, volume and approximate manufacturing welding work for a given conductance and pressure drop requirement. The fin pitch was found to have the highest effect on all performance parameters while the tube pitches and fin thickness was found to be the next important geometric parameters. The least important geometric parameters were the gap between fins and the slit width of the fin.