Measurement, prediction, and analysis of effective thermal conductivity of powder beds enhanced by periodic open cellular structure

Abstract

Powder beds are widely utilized in various industrial fields. However, the inherent properties of the particles limit their heat transfer performance. One of the most promising solutions to enhance heat transfer is the addition of periodic open cellular structure (POCS) to form packed POCS. However, the effective thermal conductivity (ETC) of packed POCS has been rarely explored. This study aims to enhance the heat transfer performance of powder beds by integrating POCS and establish a predictive framework for their ETC. In this study, the ETC of the powder beds, POCS, and packed POCS was measured. The modified Zehner–Schlünder–Damköhler (ZSD) model was adopted to predict the ETC of the powder beds. A prediction formula for ETC of packed POCS was developed based on the ZSD model. The effects of particle properties on the thermal conductivity of both powder beds and packed POCS were investigated. Results revealed that an increase in solid thermal conductivity (k_s) enhanced heat transfer within both powder beds and packed POCS. Reductions in porosity (ε) and packing density (ε_packing) enhanced heat transfer within powder beds and packed POCS, respectively. Particle diameter (D_p) had a negligible impact on ETC. POCS has the potential to significantly enhance heat transfer in the powder beds, and the incorporation of POCS into powder beds increased ETC by 2–5 times. In addition, the ETC of packed POCS was accurately predicted using the prediction formula (maximum relative error ≤ 5.7 %).