| 论文简介 |
Heat transfer performance of submerged jet impingement boiling over staggered micro-pin-finned
surfaces was investigated using air-dissolved FC-72. The dimension of the silicon chips is 10 10
0.5 mm3 (length width thickness) on staggered micro-pin-fins with four dimensions of 30 30
60 lm3, 50 50 60 lm3, 30 30 120 lm3 and 50 50 120 lm3 (width thickness height,
named S-PF30-60, S-PF50-60, S-PF30-120, and S-PF50-120) were fabricated by using the dry etching
technique. The effects of micro-pin-fins, jet-to-target distance (H = 3, 6, and 9 mm), and jet Reynolds
number (Re = 2853, 5707, and 8560) on jet impingement boiling heat transfer performance were
explored. For comparison, experiments with jet impinging on a smooth surface were also conducted.
The results showed that all micro-pin-finned surfaces show better heat transfer performance than that
of a smooth surface. The largest Nusselt number is 1367, corresponding to a heat transfer coefficient
of 26387Wm2K1 with S-PF30-120 at Re = 8560, H/d = 2, and q = 151Wcm2, which is approximately
twice the largest Nusselt number of Chip S. In the single-phase heat-transfer-dominant region, the
Nusselt number (Nu) is mainly influenced by several dimensionless numbers, including Reynolds number
(Re), boiling number (Bo), the ratio of jet-to-target distance to jet diameter (H/d), the ratio of micro-pinfinned
surface area to smooth surface area A/AS, and a dimensionless number corresponding to flow resistance
Dh/Lh. Correlations to predict Nu in both single-phase heat-transfer-dominant region and twophase
heat-transfer-dominant region for smooth and micro-pin-finned surfaces were proposed. The
results show that most data (96%) in the single-phase heat-transfer-dominant region and most data
(96%) in the two-phase heat-transfer-dominant region were predicted within ±13% and ±15%, respectively.
In addition, CHF correlations for smooth and micro-pin-finned surfaces were also proposed, and
most data (95%) are predicted within ±20% for a smooth surface and all the data within ±5% for the
micro-pin-finned surfaces. |
(创新港)
