Parametric Study of to Design an Earth to Air Heat Exchanger with Experimental Validation

Geothermal energy uses an air ground exchanger to cool buildings with minimum of energy. The outlet air coming from this exchanger can be directly used for space cooling if its temperature is low enough. In this study we try to evaluate the profile of ground temperature to decide of the depth to bury the exchanger. Through modeling and experimentation, we try to evaluate the performance of a horizontal pipe used for cooling, for this finite differential method which consists on dividing the length of the exchanger on multiple equal segments and by the knowledge of initial and boundary conditions the profile of the air temperature is that carry out. The authors conclude that many parameters influence the performance of earth to air exchanger such as the nature of the ground, the ground depth diameter of the duct and the throughput flow

Simulation of Night Cooling Through Natural cross Ventilation using ANSYS (Fluent)

In this study, we carried out a numerical simulation using CFD code “Fluent 14.0” to quantify night ventilation due to convective and radiative phenomena with well-defined boundary conditions. The configuration is an open square cavity. Top & bottom walls are adiabatic, however, vertical walls represent the left/interior wall and right/external wall provided with a top and a bottom opening, at Tcold & Thot temperatures, respectively. The computational domain is two-dimensional with open boundary conditions of the local Bernoulli type. The fluid is incompressible with Boussinesq's approximation and flow regime is stationary turbulent with k-ε RNG model on a 200 * 240 mesh refined near the walls, (ΔT = 10 °C). The obtained results allowed flow dynamics & thermal characterization as well as cooling integral quantities calculation. Introduction of surface emissivity influences heat transfer via active walls and increases (decreases) the lower (upper) passive wall temperature, while no effect was noted on the dynamics

Simulation of Night Cooling Through Natural Cross Ventilation using ANSYS (Fluent)

In this study, we carried out a numerical simulation using CFD code “Fluent 14.0” to quantify night ventilation due to convective and radiative phenomena with well-defined boundary conditions. The configuration is an open square cavity. Top & bottom walls are adiabatic, however, vertical walls represent the left/interior wall and right/external wall provided with a top and a bottom opening, at Tcold & Thot temperatures, respectively. The computational domain is two-dimensional with open boundary conditions of the local Bernoulli type. The fluid is incompressible with Boussinesq's approximation and flow regime is stationary turbulent with k-ε RNG model on a 200 * 240 mesh refined near the walls, RaH = 1.43 X 1010 (ΔT = 10 °C). The obtained results allowed flow dynamics & thermal characterization as well as cooling integral quantities calculation. Introduction of surface emissivity influences heat transfer via active walls and increases (decreases) the lower (upper) passive wall temperature, while no effect was noted on the dynamics