The numerical simulation is performed to investigate the thermal performance of supercritical carbon dioxide (sCO₂) in horizontal ribbed tubes at mass flux ranging from 200 kg/(m²·s) to 400 kg/(m²·s), heat flux, 20 kW/m² to 30 kW/m², pressure 8–9 MPa and inlet temperature 290–310 K. Three types of ribs were selected to investigate the effects of rib geometry, buoyancy and rib parameters on the thermal-hydraulic performance. The results indicated that the triangular ribbed tube (TRT) could significantly improve the heat transfer coefficient (HTC) and reduce the wall temperature. Nevertheless, circular ribbed tubes have the best performance from the performance evaluation criteria (PEC) viewpoint. Moreover, the rib configuration promotes the transition of the flow field from “flattened shape” to “U-shaped”, which improves the heat transfer. Finally, small rib size and medium pitch can further enhance supercritical CO₂ turbulent heat transfer.

通过数值模拟研究了超临界二氧化碳（sCO ₂）在水平肋管中的热性能，质量通量范围为200 kg /（m ² ·s）至400 kg /（m ² ·s），热通量， 20 千瓦/米²至 30 千瓦/米², 压力 8-9 MPa 和入口温度 290-310 K。选择了三种类型的加强筋来研究加强筋几何形状、浮力和加强筋参数对热工水力性能的影响。结果表明，三角肋管（TRT）可以显着提高传热系数（HTC），降低壁温。然而，从性能评估标准 (PEC) 的角度来看，圆形带肋管具有最佳性能。此外，肋条结构促进了流场从“扁平形”到“U形”的转变，从而改善了传热。最后，小肋尺寸和中等间距可以进一步增强超临界CO ₂湍流传热。