Abstract:
Thermal performance of Earth Air Tunnel Heat Exchanger (EATHE) under steady operating conditions has been carried out considering in hot and dry region of Bangladesh using Computational Fluid Dynamics modeling. Effect of soil thermal conductivity and by changing air velocity operation of EATHE on thermal performance has been evaluated for different pipe length of EATHE using experimentally validated CFD. Simulation Results show that the steady thermal performance of EATHE is significantly dependent on thermal conductivity of the soil and velocity of air. Results show that the increase in flow velocity leads to change in thermal behavior of the pipe.
The effect of soil thermal conductivity of EATHE on thermal performance has been also carried out for different pipe length of EATHE using experimentally validated CFD simulation. Maximum air temperature drop of 15.6, 17.0 and 17.3 K are observed for soil thermal conductivities of 0.52, 2 and 4 W m1 K1 respectively for 60 meter pipe. The thickness of the soil annulus beyond which no significant rise in temperature of soil observed is equal to the pipe diameter.
Mainly in this paper, the effect soil thermal conductivity has been compared with different pipe length considering also the change in velocity of air. The optimization of pipe length has been also carried out from the experimental analysis based on validated CFD analysis.
