Investigation on the heat discharge performance of a bioinspired latent heat exchanger with leaf-like fins

Abstract

The low energy efficiency of phase-change thermal storage technologies leads to slow progress in promoting sustainable energy. To address this, here constructs a creative leaf-like fin and designs a bioinspired latent heat exchanger (LHE) using phase change materials (PCMs). A two-dimensional model of solidification processes considering natural convection is developed and solved numerically. The phase-change behaviors and dynamic thermal characteristics of different LHEs are investigated. Moreover, material selections and operating conditions of LHEs are studied, focusing on their effects on discharge performance. The results imply that the innovative leaf-like fin strengthens discharge performance. Compared to conventional LHEs, bioinspired LHEs shorten complete solidification time by 41.6% and increase average discharge power by 69.9%. Since the solidification procedure is driven by heat-conduction, the temperature stratification is only apparent in the early stage, while the solid–liquid phase interface and temperature distribution are almost axisymmetric for most solidification processes. For material selections, aluminum is recommended based on the trade-off between cost and thermal enhancement gain, and Stearic acid has apparent advantages in achieving satisfactory heat discharge performance for PCMs selected in this paper. Moreover, the lower temperature of the heat transport fluid facilitates the discharge rate enhancement for practical engineering.