Present work proposed an eccentric tube-in-tube helically coiled heat exchanger (TTHC), used in Aero engine turbine film cooling which can precool compressed air more efficiently. The supercritical n-decane (3 MPa) at inner tube is used to precool the compressed air at annulus channel. The effects of mass flow rate, eccentric angle (ϕ) and eccentric ratio (e) of the inner tube on flow and heat transfer performance are investigated systematically by the RNG $k-\epsilon$numerical model. The results showed that the Nusselt number (Nu_a) of concentric and eccentric TTHC (ϕ = 0°, e = 0.4) was 1.15 and 1.19 times of that for straight concentric tube-in-tube heat exchanger, respectively. The synergy effect at annulus side for the eccentric TTHC is more strengthened than the concentric one. When eccentric angle(ϕ) increased from 0° to 180° (e = 0.4), the Nu_a and f_a decreased by 20% and 3%, and the performance evaluation factor (PEF_a) decreased 10%. Moreover, when eccentric ratio (e) increased from 0 to 0.8 (ϕ = 0°), the Nu_a and the PEF_a increased by 10.7% and 14%. Therefore, the optimal geometric parameters in eccentric TTHC can be selected as ϕ = 0°, e = 0.8.

目前的工作提出了一种偏心管中管螺旋盘管换热器（TTHC），用于航空发动机涡轮薄膜冷却，可以更有效地预冷压缩空气。内管的超临界正癸烷（3 MPa）用于预冷环形通道的压缩空气。RNG系统地研究了质量流量、内管偏心角（ϕ）和偏心比（e）对流动和传热性能的影响$克-\epsilon$数值模型。结果表明，同心和偏心TTHC（φ= 0°，e  =0.4）的努塞尔数（Nu _a）分别是直管式同心管换热器的1.15和1.19倍。偏心TTHC在环面侧的协同效应比同心TTHC更强。当偏心角( ϕ )从0°增加到180°( e  =0.4)时，Nu _a和f _{a 分别}下降20%和3%，性能评价因子( PEF _a )下降10%。此外，当偏心比 ( e ) 从 0 增加到 0.8 ( ϕ =0°)，Nu _a和PEF _{a 分别}增加了 10.7% 和 14%。因此，偏心TTHC中的最佳几何参数可以选择为φ  =0°，e  =0.8。