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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Critical heat flux in a 0.38 mm microchannel and actions for suppression of flow boiling instabilities

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Tibirica, Cristiano Bigonha [1] ; Czelusniak, Luiz Eduardo [1] ; Ribatski, Gherhardt [1]
Total Authors: 3
[1] Univ Sao Paulo, Escola Engn Sao Carlos, Dept Mech Engn, Heat Transfer Res Grp, Sao Carlos, SP - Brazil
Total Affiliations: 1
Document type: Journal article
Source: EXPERIMENTAL THERMAL AND FLUID SCIENCE; v. 67, n. SI, p. 48-56, OCT 2015.
Web of Science Citations: 15

This paper presents experimental results for critical heat flux in a 0.38 mm internal diameter tube during saturated flow boiling. Experiments were performed for refrigerant R134a flowing inside a horizontal stainless steel circular channel of 70 mm heated length, mass velocities ranging from 200 to 1400 kg/m(2) s, saturation temperature of 31 degrees C and critical heat fluxes up to 215 kW/m(2). A parametric study of the effect of mass velocity revealed the same trends observed in previous studies with 1.1 and 2.2 mm internal diameter tubes. In contrast, prediction methods that performed well in previous works for internal diameters higher than 1.00 mm failed to predict the data for the 0.38 mm tube. An investigation into the reasons for the failure of these methods revealed thermo-hydraulic instabilities are more pronounced for the 0.38 mm tube and actions to cancel these effects are required. Tests revealed that a saturated inlet vapor quality near 5% combined with a high inlet pressure drop could increase the critical heat flux up to 50% in comparison to the results without any control actions. Moreover, conventional CHF predictive methods from the literature provided a reasonable prediction of the results for the 0.38 mm tube when instability effects were minimized. (c) 2015 Elsevier Inc. All rights reserved. (AU)

FAPESP's process: 07/53950-5 - A theoretical and experimental study on flow boiling heat transfer and critical heat flux in microchannels
Grantee:Cristiano Bigonha Tibirica
Support type: Scholarships in Brazil - Doctorate
FAPESP's process: 14/01948-0 - Heat transfer and fluid flow in microscale
Grantee:Cristiano Bigonha Tibirica
Support type: Research Grants - Meeting - Abroad
FAPESP's process: 11/01372-3 - Study of two-phase flow and thermal instabilities during convective boiling in micro-scale channels
Grantee:Cristiano Bigonha Tibirica
Support type: Scholarships in Brazil - Post-Doctorate