Effects of Non-Uniform Circumferential Heating and Inclination on Critical Heat Flux in Smooth Round Tubes

Abstract:

Experimental investigation of the critical heat flux (CHF) in smooth round tubes with circumferentially variable heating was carried out. The riser tubes with 0, 20, 90-degree inclinations from the horizontal were electrically heated. The measurements were carried out for pressure between 13 and 21MPa, mass flux between 600 and 900kg/m2s. The peak-to average heat flux ratio was amounted to 1.6. CHF data of uniform heating were also tested. The test results show that the initial CHF is always observed at location of peak heat flux in vertical tubes with non-uniform heating. In horizontal and inclined tubes with side-heating the transit from a top to side initial indication of CHF occurs by increasing the mass flux and the pressure to certain values. The Initial CHF of non-uniformly heated tubes is fairly agreement with the values of uniformly heated tubes.

• Periodical: Applied Mechanics and Materials (Volumes 291-294)
• Pages: 1657-1660
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.291-294.1657
• Online since: February 2013
• Authors: Zhi Hong Hu, Ting Kuan Chen
• Keywords: Critical Heat Flux, Inclined Tube, Non-Uniform Circumferential Heating, Round Smooth Tube, Upward Flow

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