This research attempted to analyze a triple-tube heat exchanger (TTHE) fitted with innovative crimped-spiral ribs to enhance thermal efficiency. The crimped-spiral rib was placed on the top of the internal tube, and the water–alumina nanofluid was employed as the hot fluid within the ribbed side, whereas the two other fluids were pure water. The numerical solutions were performed through the two-phase mixture method, while the turbulent flow was modeled via the Reynolds Stress Model (RSM). The overall heat transfer coefficient (U), heat transfer rate, effectiveness, and performance index enhanced remarkably by using the nanofluid. The greatest increment in the U and effectiveness reached around 44.91 and 41 %, respectively, by the increment of the volume fraction by 0.02. The crimp intensity had an appreciable contribution to the thermal performance. The main mechanism was stronger swirl flow generated by the crimped-spiral rib that yielded boundary layer destruction. The heat transfer capability was increased via the rib pitch decrement and rib height increment. The performance index showed great values even at low volume fractions, which manifested the great merit of the implemented refinements. The thermal attributes were investigated at the first of the result section and then, the hydraulic characteristics were researched.

这项研究试图分析配有创新的卷曲螺旋肋的三管式换热器（TTHE），以提高热效率。卷曲的螺旋肋位于内管的顶部，水-氧化铝纳米流体用作肋侧的热流体，而其他两种流体是纯水。数值解通过两相混合法进行，而湍流则通过雷诺应力模型（RSM）进行建模。通过使用纳米流体，总传热系数（U），传热速率，有效性和性能指标显着提高。U中最大的增量体积分数增加0.02时，有效性分别达到44.91％和41％。压接强度对热性能有明显的贡献。主要机制是卷曲的螺旋肋产生的较强的旋流，导致边界层破坏。通过肋间距的减小和肋高度的增加来提高传热能力。即使在体积分数较低的情况下，性能指标也显示出很高的价值，这体现了实施改进的巨大优势。在结果部分的第一部分研究了热学特性，然后研究了水力特性。