RT Journal Article
ID 6503dd4668f306d9
A1 Karadag, Refet
A1 Bulut, Husamettin
A1 Demirtas, Yunus
A1 Hilali, Ismail
T1 THERMAL ANALYSIS OF EARTH–AIR HEAT EXCHANGERS UNDER HEATING CONDITIONS AT A CONSTANT SURFACE TEMPERATURE
JF Heat Transfer Research
JO HTR
YR 2018
FD 2018-09-12
VO 49
IS 18
SP 1813
OP 1823
K1 earth energy
K1 earth–air heat exchanger
K1 heat transfer
K1 CFD
K1 constant surface temperature
AB Earth–air heat exchangers (EAHEs) are used for ventilation and air conditioning, taking advantage of the earth energy.
Many experimental, analytical, and numeritical researches of EAHEs have been made so far due to their promising applications. In this study, the thermal performance of an earth–air heat exchanger is investigated numerically and experimentally depending on heating conditions. The computational fluid dynamics simulation soft ware FLUENT is used in the analysis. Numerical solutions are obtained by using computational fluid dynamics (CFD) analysis under constant surface temperature boundary conditions. Computational analysis is conducted for different outside air temperatures, pipe surface temperatures, air velocities (ranging from 0.5 m/s to 5.5 m/s), and different pipe lengths of the EAHE. The numerical results obtained
at different outlet and inlet air temperatures and heat loads are compared with those measured experimentally under
Sanliurfa climatic conditions during winter season. The relation between the Nusselt and Reynolds numbers for the inner surfaces of the EAHE is analyzed by using numerical values, and the results are compared with the equations given in the literature. The maximum and mean deviations between the experimental and numerical results were equal to 30% and 15%, respectively. The results are acceptable, and there is agreement with the literature data, because the average deviation between the results of numerical solutions and equations given in the literature varies from 1.8% to 35% depending on the
length of the heat exchanger and flow Reynolds numbers.
PB Begell House
LK http://dl.begellhouse.com/journals/46784ef93dddff27,38ea29f07a631486,6503dd4668f306d9.html