Heat transfer enhancement of gradient Laguerre-Voronoi porous receiver through pore-scale method

• Single and gradient Laguerre-Voronoi porous receivers (GLVPR) were generated. • A pore-scale method was used to investigate the thermal performance of the GLVPRs. • A smaller cell diameter and increased porosity enhance thermal efficiency. • Cell diameter has a greater effect on thermal efficiency than porosity. • A gradient design with a step-increase in cell diameter performs better overall. Laguerre-Voronoi porous structures represent an advanced typology of Voronoi that more effectively balances unordered and periodic porous designs than the original Voronoi typology, thereby yielding improved thermal performance. A single Laguerre-Voronoi porous receiver (SLVPR), featuring hundreds of uniform cells, has been developed, along with a gradient Laguerre-Voronoi porous receiver (GLVPR) created by combining two SLVPR components in the axial direction. The heat transfer process has been investigated utilizing a pore-scale method in conjunction with experimental measurements. Results indicate that the impact of cell diameter on thermal efficiency is more significant than that of porosity, with the SLV6-0.24 achieving the highest thermal efficiency among the five SLVPRs. Conversely, the friction factor and overall performance are influenced more by porosity than by cell diameter. The SLV7-0.20 exhibits the lowest friction factor and the highest overall performance among the SLVPRs. The thermal efficiency and friction factor of the GLVPR are situated between those of the two components. The GLVPR can attain optimal overall performance by modulating the length ratio of these two components, with GLV30-40 achieving the best overall performance. Furthermore, reducing the inlet solid temperature is identified as the most effective method for enhancing the thermal efficiency of the LVPRs, as the re-radiative loss is three to four times greater than the reflective loss. The optimized GLVPR introduces a novel developmental trajectory for high-temperature solar receivers compatible with advanced power cycles.