Investigation of additively manufactured triply periodic minimal surfaces as an air-to-air heat exchanger

Abstract

Additive manufacturing provides freedom of production and design of geometries that cannot be produced with traditional methods. Therefore high-efficiency and innovative heat exchanger designs can be produced with 3D printer technology efficaciously. Heat recovery ventilation devices, which meet the indoor air quality requirements with high thermal efficiency, allow heat recovery between the exhaust air and fresh air with the help of the recuperator, which is an air-to-air heat exchanger. In this study, the production processes of triply periodic minimal surfaces (TPMS) with the additive manufacturing method and their performance as an air-to-air heat exchanger are examined. Triply periodic minimal surfaces are three-dimensional and infinite surface geometries that can be expressed with continuous trigonometric functions, forming two separate non-intersecting spaces for fluids. The surface geometry derived from the trigonometric function can be arranged to provide heat transfer between two unmixed fluids at different temperatures. In this study, Schwarz-D, Schwarz-P and Shoen's gyroid geometries are investigated as triply periodic minimal surfaces. During the production of these geometries processes, parameters such as wall and layer thicknesses and printing temperature were changed to achieve the lowest possible wall thickness (0.16mm) with the 3D printer used. The performance of triply periodic minimal surface geometries as air-to-air heat exchangers are determined experimentally in a crossflow experimental setup.