本論文探討管式復熱器管內及管外之熱液動分析，管外部份，考慮管排間的熱輻射效應以及工作流體性質，藉以評估復熱器管外之熱效率；管內部份，探討管內不同插入物在不同流速下的熱傳及壓降，插入物型式包括一字片、一字片打洞、三角柱、圓柱及三種螺旋片插入物(螺旋角度分別為α=15.3°、24.4°與34.3°)。

由數值結果可得知管內不同插入物的熱傳係數與單位管長壓降，與裸管比較的結果，一字片、一字片打洞、三角柱、圓柱、螺旋片-A (α=15.3°) 、螺旋片-B (α=24.4°) 與螺旋片-C (α=34.3°)的熱傳係數分別比裸管高5-16%、12-27%、3-16%、3-19%、6-32%、12-43%與25-61%；壓降則分別比裸管高90-140%、220-250%、130-160%、200-350%、130-170%、240-280%與290-330%。

由數值結果的平均熱傳係數與實驗結果比較，裸管，一字片、一字片打洞、三角柱、圓柱以及螺旋片-A (α=15.3°)與實驗誤差分別約在3.6%、4.1%、4.5%、6.9%、4.8%以及1.4%~8.5%以下。此外，使用螺旋片-A的面積縮減率可達到20%。

The thermal-hydraulic characteristics for both inside and outside tubes of a recuperator were discussed in this study. The radiation effect was considered between the tube wall and the working fluid for evaluating the outside tube performance. For inside tube, the heat transfer and pressure drop data for turbulent flow were discussed for different kinds of tube inserts including longitudinal strip inserts with and without holes and twisted-tape inserts with varied twist angle (α=15.3o, 24.4o and 34.3o).

Form the simulation results, it is found that the heat transfer coefficient of the tube bank with strip inserts, strip inserts with holes, triangular prism, circular cylinder and twisted-tape inserts of α=15.3o, 24.4o, and 34.3o are respectively 5-16%, 12-27%, 3-16%, 3-19%, 6-32%, 12-43% and 25-61% than those for tube bank without using inserts. And pressure drop are respectively 90-140%, 220-250%, 130-160%, 200-350%, 130-170%, 240-280% and 290-330% than those for tube bank without using inserts.

The numerical results of heat transfer coefficient for tube bank without using inserts, strip inserts without and with holes, triangular prism, circular cylinder, and twisted-tape inserts (α=15.3o) are respectively agreed with the experimental data within 3.6%, 4.1%, 4.5%, 6.9%, 4.8% and 8.5%. Furthermore, the results indicate that it is possible to obtain a reduction in area of approximately 20%.

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