Experimentální výzkum sprchového chlazení horizontálně a vertikálně orientovaných povrchů

EXPERIMENTAL INVESTIGATION OF SPRAY COOLING OF HORIZONTALLY AND VERTICALLY ORIENTED SURFACES

článek ve sborníku ve WoS nebo Scopus

en

The spray cooling of stainless steel plates was studied using different orientations of the cooled surface. A 1.5 mm-thick test plate was moved vertically or horizontally with a velocity of 3 m/s. Experiments were conducted with mist nozzles oriented either vertically with the spray flowing down or horizontally. The water impingement density was between 0.93– 9.68 kg m2 s-1. It was found that the heat transfer coefficient is similar for horizontally and vertically down oriented nozzles within the surface temperature range of 700–900C. The vertically down spray yields a higher heat transfer coefficient for surface temperatures below 300 C. Furthermore, it was observed that the Leidenfrost temperature is slightly higher for vertically down spray for lower water impingement densities. This shift of the Leidenfrost temperature was not observed for higher water impingement densities.

Experimentálně bylo studováno sprchové chlazení 1,5 mm tlustých nerezových plechů pohybujících se rychlostí 3 m/s. Experimenty byly provedeny s vodovzdušnými tryskami orientovanými buď vertikálně nebo vodorovně. Hustota dopadající vody byla v rozmezí 0,93-9,68 kg/m2/s. Bylo zjištěno, že koeficient přestupu tepla je podobný pro vodorovně a svisle orientované trysky pro povrchové teploty 700 až 900C. Svisle orientované trysky měli vyšší součinitel prostupu tepla pro povrchové teploty pod 300 C. Dále bylo zjištěno, že Leidenfrostova teplota je mírně vyšší pro svisle orientované trysky s nižší hustotou dopadající vody. Tento posun Leidenfrostovi teploty nebyl pozorován pro velké hustoty dopadající vody.

The spray cooling of stainless steel plates was studied using different orientations of the cooled surface. A 1.5 mm-thick test plate was moved vertically or horizontally with a velocity of 3 m/s. Experiments were conducted with mist nozzles oriented either vertically with the spray flowing down or horizontally. The water impingement density was between 0.93– 9.68 kg m2 s-1. It was found that the heat transfer coefficient is similar for horizontally and vertically down oriented nozzles within the surface temperature range of 700–900C. The vertically down spray yields a higher heat transfer coefficient for surface temperatures below 300 C. Furthermore, it was observed that the Leidenfrost temperature is slightly higher for vertically down spray for lower water impingement densities. This shift of the Leidenfrost temperature was not observed for higher water impingement densities.

sprchové chlazení, orientace povrchu, přenos tepla

spray cooling, surface orientation, heat transfer

2013

15.05.2013

Tanger, s.r.o.

Ostrava

978-80-87294-41-3

Conference proceedings of 22nd Conference on metallurgy and materials

1

198–202

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