Investigation on Uneven Flow Distribution in Triply Periodic Minimal Surface Heat Exchangers

The development in manufacturing engineering has made it possible to adopt the unique porous structure known as the triply periodic minimal surface to increase energy efficiency in a variety of energy-related sectors. With the unique morphological characteristics, triply periodic minimal surface exhibits remarkable mechanical strength and thermal performance, which makes it a potential candidate for compact, high-performance heat exchanger constructions. In this study, a theoretical model based on triply periodic minimal surface porous media is developed. Based on the hypothesis that the triply periodic minimal surface is isotropic and the heat transfer intensity of fluid and solid is uniform throughout the core of the heat exchanger, the simulation of the full-size heat exchanger is simplified by using a porous media model. The flow distribution characteristics of triply periodic minimal surface heat exchangers, as well as the effect mechanism of key factors, including the channel porosity, header configuration, the type of triply periodic minimal surface, the core length and Reynolds number on the flow distribution performance, are investigated. A dual-header configuration is proposed to improve the flow uniformity of triply periodic minimal surface heat exchangers. The results indicate that the flow distribution performance of triply periodic minimal surface based heat exchangers can be enhanced by the reduction of channel porosity. When the cold-side porosity is 0.7, the flow rate deviates from the mean value by 220% at its maximum for a Primitive heat exchanger. A dual-header configuration eliminates the columnar extreme high velocity space in the core and greatly reduces the “weak zone” of flow distribution, which improves the flow non-uniformity by 45–90% over the single-inlet headers. This paper provides data and theoretical support for the optimal design and practical application of the complex, high-performance triply periodic minimal surface based heat exchangers.