Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1740654 | Progress in Nuclear Energy | 2014 | 6 Pages |
Abstract
The volumetrically heated packed bed has been widely utilized in modern industry, however, no research on the bubble behaviors in forced convection subcooled boiling was studied. To study the bubble behaviors in the volumetrically heated packed bed, here electromagnetic induction heating method was used to heat oxidized carbon steel balls adopted to stack packed bed, while water was utilized as the refrigerant in the experiment. Bubble behaviors were observed by a high speed camera for particle diameter varying from 8 mm to 12 mm, mass flux varying from 29.3 kg mâ2 sâ1 to 84.2 kg mâ2 sâ1, heat flux varying from 14.5 kW mâ2 to 50 kW mâ2, inlet pressure varying from 0.116 MPa to 0.125 MPa, inlet subcooling varying from 7 k to 9.2 k and porosity = 0.39. Obtained flow visualization images were analyzed. The experimental results indicated that the bubbles were blocked by steel balls and easily attached to the surface of balls, then slipped along the surface of steel balls. There was “regrowth phenomenon” in the packed bed and generated bubbles repeated growth several times in the lifetime. The nucleate boiling was firstly observed in the contact surface. Structures of contact surface had great impacts on the bubble shapes, departure diameter and frequency.
Keywords
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Physical Sciences and Engineering
Energy
Energy Engineering and Power Technology
Authors
Guangzhan Xu, Zhongning Sun, Xianke Meng, Xiaoning Zhang,