Hostname: page-component-78c5997874-g7gxr Total loading time: 0 Render date: 2024-11-17T04:18:25.137Z Has data issue: false hasContentIssue false

An Experimental Study on the Effects of Nozzle and Surface Geometry in FC-72 Jet Cooling

Published online by Cambridge University Press:  22 March 2012

L.-H. Chien*
Affiliation:
Department of Energy and Refrigerating Air-Conditioning Engineering, National Taipei University of Technology, Taipei, Taiwan 10608, R.O.C.
T.-L. Wu
Affiliation:
Foundation of Taiwan Industry Service, Taipei, Taiwan 10684, R.O.C.
*
*Corresponding author ([email protected])
Get access

Abstract

In this study, a spray cooling device for electronic components was investigated. Dielectric fuid (FC-72) was sprayed at 50°C through five nozzles (4.243mm spacing). The nozzles are of diameters 0.17, 0.23 or 0.41mm. Volume flow rate varied from 24.5 to 99.1ml/min. Two grooved surfaces and a smooth surface were tested, and the heated area was 12 × 12mm2. The larger nozzles yielded greater heat transfer coefficients at high heat fluxes (300 ∼ 600kW/m2). However, smaller nozzles result in greater dry-out heat fluxes and greater heat transfer coefficients at heat flux < 300kW/m2. The C4 surface, having parallel grooves of 0.4mm depth, improved the spray cooling performance by up to 80% as compared with the smooth suface. Its thermal resistance is 0.11 ∼ 0.12K/W at 99.1ml/min flow rate, in the range of 85 ∼ 130W heat input. A new correlation of spray cooling, accounting for the contributions of nucleate boiling and spray convection, is proposed. For data of FC-72 in the range of Re = 856 ∼ 6188, Bo = 0.19 ∼ 5.70, We = 25.2 ∼ 3541.3, the predicted h-values agree with experimental data of the smooth surface within ±25%.

Type
Articles
Copyright
Copyright © The Society of Theoretical and Applied Mechanics, R.O.C. 2012

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1. Fabbri, M. and Dhir, V., “Optimized Heat Transfer for High Power Electronic Cooling Using Arrays of Microjets,” Journal of Heat Transfer, 127, pp. 760769 (2005).CrossRefGoogle Scholar
2. Estes, K. A. and Mudawar, I., “Correlation of Sauter Mean Diameter and Critical Heat Flux for Spray Cooling of Small Surfaces,” International Journal of Heat and Mass Transfer, 38, pp. 29852996 (1995).CrossRefGoogle Scholar
3. Lin, L. and Ponnappan, R., “Heat Transfer Characteristics of Spray Cooling in a Closed Loop,” International Journal of Heat and Mass Transfer, 46, pp. 37373746 (2003).CrossRefGoogle Scholar
4. Horacek, B., Kim, J. and Kiger, K., “Spray Cooling Using Multiple Nozzles: Visualization and Wall Heat Transfer Measurements,” IEEE Transactions on Device and Materials Reliability, 4, pp. 614625 (2004).CrossRefGoogle Scholar
5. Horacek, B., Kiger, K. T. and Kim, J., “Single Nozzle Spray Cooling Heat Transfer Mechanisms,” International Journal of Heat and Mass Transfer, 48, pp. 14251438 (2005).CrossRefGoogle Scholar
6. Hsieh, C.-C. and Yao, S.-C., “Evaporative Heat Transfer Characteristics of a Water Spray on Micro-Structured Silicon Surfaces,” International Journal of Heat and Mass Transfer, 49, pp. 962974 (2006).CrossRefGoogle Scholar
7. Silk., E. A., Kim, J. and Kiger, K., “Spray Cooling of Enhanced Surfaces: Impact of Structured Surface Geometry and Spray Axis Inclination,” International Journal of Heat and Mass Transfer, 49, pp. 49104920 (2006).CrossRefGoogle Scholar
8. Li, C.-Y. and Garimella, S. V., “Prandtl-Number Effects and Generalized Correlations for Confined and Submerged Jet Impingement,” International Journal of Heat and Mass Transfer, 44, pp. 34713480 (2001).CrossRefGoogle Scholar
9. Ma, C. F. and Bergles, A. E., “Jet Impingement Nucleate Boiling,” International Journal of Heat and Mass Transfer, 29, pp. 481499 (1986).CrossRefGoogle Scholar
10. Meyer, M. T., Mudawar, I., Boyack, C. E. and Hale, C. A., “Single-Phase and Two-Phase Cooling with an Array of Rectangular Jets,” International Journal of Heat and Mass Transfer, 49, pp. 1729 (2006).CrossRefGoogle Scholar
11. Chien, L.-H., Wu, T. L. and Lee, S.-C., “A Study of Spray-Impingement Cooling on Smooth and Pin-Finned Surfaces Using FC-72,” Journal of Enhanced Heat Transfer, 18, pp. 375387 (2011).CrossRefGoogle Scholar
12. Wu, T.-L., “A Study of Falling Film Evaporation on Finned Surfaces in Electronic Cooling System,” M.S. thesis, Department of Energy and Refrigerating Air-conditioning Engr., National Taipei University of Technology, Taipei, Taiwan (2008).Google Scholar
13. Royne, A. and Dey, C., “Effect of Nozzle Geometry on Pressure Drop and Heat Transfer in Submerged Jet Arrays,” International Journal of Heat and Mass Transfer, 49, pp. 800804 (2006).CrossRefGoogle Scholar
14. Chien, L.-H. and Cheng, C.-H., “A Predictive Model of Falling Film Evaporation with Bubble Nucleation on Horizontal Tubes,” Journal of HVAC & R Research, 12, pp. 6987 (2006).CrossRefGoogle Scholar
15. Chien, L.-H. and Lee, S.-C., “An Experimental Study of Pool Boiling on Pin-Finned and Straight-Finned Surfaces on an Inclined Plate in FC-72,” Journal of Enhanced Heat Transfer, 18, pp. 322324 (2011).Google Scholar