Experimental and numerical analysis of a wind tower with run around heat exchanger

This study proposes the integration of a run around heat exchanger within a passive ventilation wind tower to provide heating, cooling, and thermal energy recovery on a seasonal basis. A field trial of the system was conducted at a test site in Sheffield, UK, with the results recorded through experimental testing used to validate a numerical model. The numerical model was developed through the commercial computational fluid dynamics program ANSYS and was used to investigate the performance of the proposed system under a range of boundary conditions. The minimum volumetric flow rate through the wind tower was 0.09 m3/s at an inlet velocity of 1 m/s for a heat exchanger model featuring three rows of pipes. Fresh air temperature was increased by 4.14 °C and reduced by 4.36 °C when the temperature difference between the fresh air and water flowing through the heat exchanger was 27 °C. The difference in water temperature between the inlet and outlet of the heat exchanger was 6.15 °C for both heating and cooling simulations at the same temperature difference, equivalent to 2 kW of thermal energy recovery.