Investigation of saturated critical heat flux in a single, uniformly heated microchannel
- Laboratory of Heat and Mass Transfer (LTCM), Faculty of Engineering Science (STI), Ecole Polytechnique Federale de Lausanne (EPFL), CH-1015 Lausanne (Switzerland)
A series of tests have been performed to determine the saturated critical heat flux (CHF) in 0.5 and 0.8mm internal diameter microchannel tubes as a function of refrigerant mass velocity, heated length, saturation temperature and inlet liquid subcooling. The tested refrigerants were R-134a and R-245fa and the heated length of microchannel was varied between 20 and 70mm. The results show a strong dependence of CHF on mass velocity, heated length and microchannel diameter but no influence of liquid subcooling (2-15{sup o}C) was observed. The experimental results have been compared to the well-known CHF single-channel correlation of Y. Katto and H. Ohno [An improved version of the generalized correlation of critical heat flux for the forced convective boiling in uniformly heated vertical tubes, Int. J. Heat and Mass Transfer 27 (9) (1984) 1641-1648] and the multichannel correlation of W. Qu and I. Mudawar [Measurement and correlation of critical heat flux in two-phase microchannel heat sinks, Int. J. Heat and Mass Transfer 47 (2004) 2045-2059]. The comparison shows that the correlation of Katto-Ohno predicts microchannel data with a mean absolute error of 32.8% with only 41.2% of the data falling within a +/-15% error band. The correlation of Qu and Mudawar shows the same trends as the CHF data but significantly overpredicts them. Based on the present experimental data, a new microscale version of the Katto-Ohno correlation for the prediction of CHF during saturated boiling in microchannels has been proposed. (author)
- OSTI ID:
- 20770232
- Journal Information:
- Experimental Thermal and Fluid Science, Journal Name: Experimental Thermal and Fluid Science Journal Issue: 8 Vol. 30; ISSN 0894-1777; ISSN ETFSEO
- Country of Publication:
- United States
- Language:
- English
Similar Records
Survey of critical heat flux data for pool boiling of liquid metals and new correlations
Saturated critical heat flux in a multi-microchannel heat sink fed by a split flow system