Study on heat transfer and flow resistance characteristics of cracking furnace tube by axial width of opening combination rotor blade.

• Novel opening combination rotor blade is proposed to enhance heat transfer effect. • The effect of opening combination rotor blade is optimized for overall performance improvement. • Enhanced heat transfer is revealed by field synergy principle. • The characteristics of opening combination rotor blade are revealed by numerical simulation. • The applicable conditions of heat transfer strategies are determined. Based on the passive enhanced heat transfer mechanism, this paper proposes the new opening combination rotor blade, which aims to improve heat and mass transfer performance by changing internal structure of cracking furnace tube, thus achieving efficient production of ethylene. Through mathematical modeling and simulation of heat transfer properties of opening combination rotor blade, heat transfer performance and fluid flow characteristics of ordinary rotor blade tubes and opening combination rotor blade with axial widths of W (W = 0.25 R, 0.5 R, 0.75 R) are analyzed using field synergy principle and comprehensive heat transfer evaluation coefficient (PEC).The results demonstrate that the Nusselt number of opening combination rotor blade is 19%-23% lower than that of ordinary rotor blade. The resistance coefficient of opening combination rotor blade with axial width of 0.25 R is significantly lower by 33%-43%. Opening combination rotor blade with axial width of 0.25 R has a significantly lower resistance coefficient of 72%-78%. Its PEC value is between 1.23–1.28 with significantly improved overall heat transfer performance. In summary, opening combination rotor blade with axial width of 0.25 R has the most significant heat transfer effect and has a high reference significance for engineering design. [Display omitted] [ABSTRACT FROM AUTHOR]