To improve the thermal efficiency of S-CO₂ solar receivers while ensuring pressure resistance and thermal safety, a new type of solar receiver based on the TPMS (Triply Periodic Minimal Surface) structure - Primitive - is proposed, which possesses unique body absorption characteristics and excellent pressure-bearing capacity. Along with the Zigzag and Straight structures, their internal flow heat transfer and stress distribution characteristics are investigated through CFD simulations. The results show that the Primitive has significant heat transfer advantages: its \(\bar{f}\)  is the smallest, and based on the Straight, PEC_Primitive is 2-2.8 times higher than PEC_Zigzag, and it effectively reduces the maximum wall temperature. The maximum thermal stresses of all three structures are less than the material yield stress, but the Primitive has relatively high stresses at the cell junctions. This is related to its special curvature structure.
 

Flow and heat transfer,direct solar receiver,supercritical CO2,triply periodic minimal surface,thermal stress