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ISSN Online: 2379-1748

9th Thermal and Fluids Engineering Conference (TFEC)
April, 21-24, 2024, Corvallis, OR, USA

OPTIMIZATION OF EARTH-AIR HEAT EXCHANGERS WITH TWISTED TAPES FOR PASSIVE COOLING

Get access (open in a dialog) pages 1213-1222
DOI: 10.1615/TFEC2024.csb.050463

要約

As global energy consumption continues to rise, the use of Earth-air heat exchangers during the summer is gaining popularity as a means of passive cooling to save energy and reduce the cooling load of buildings. This study focuses on assessing the effectiveness of integrating twists into Earth-air heat exchanger pipes through numerical simulations conducted using ANSYS Fluent. Four different sizes of twists, along with three rotation rates, were selected to investigate their impact on the thermal performance of the heat exchanger and airflow patterns. The studied heat exchanger is combined with a solar chimney to introduce cold air into the building, taking advantage of buoyancy-driven flow generated within the solar chimney. The findings reveal that integrating larger twists with higher rotation rates increases the Nusselt number by up to 260%, while their impact on the flow rate is the opposite due to increased friction loss. The study revealed that increasing the rotation rate induced a helical flow pattern in the air, leading to enhanced vortices and higher heat transfer rates. Turbulent kinetic energy also increased with the addition of twists and higher rotation rates, further highlighting the benefits of integrating twists in the Earth-air heat exchangers. The optimal twist geometry can reduce the heat exchanger's length by 60%, all while maintaining the desired standard airflow.