EXPERIMENTAL INVESTIGATION OF HEAT EXCHANGE IN COOLING THE SURFACE BY A SYSTEM OF SUBMERGED DIELECTRIC-LIQUID JETS

Heat exchange on a heat-stressed surface and the critical heat fl ow from it in the process of cooling this surface by a system of distributed impact submerged microjets of a dielectric liquid, depending on the velocity of these jets, were investigated experimentally for the case where the initial subcooling of the liquid in the jets to the saturation temperature comprises 40 ± 2^o C. The experiments were conducted for 36 jets of the HFE-7100 dielectric liquid with an initial diameter of 174 μm, outfl owing from the nozzles positioned at a distance of 1 mm from a cooling surface. It was established that the heat transfer coeffi cients of this surface and the critical heat fl ow from it are determined by the velocity of the jets, acting on the surface, and the initial subcooling of the cooling liquid, and that they are much larger than those in the case of pool boiling of the cooling liquid on the surface and in the case of its cooling by a single jet of a liquid with a small subcooling to the saturation temperature.
Heat exchange on a heat-stressed surface and the critical heat fl ow from it in the process of cooling this surface by a system of distributed impact submerged microjets of a dielectric liquid, depending on the velocity of these jets, were investigated experimentally for the case where the initial subcooling of the liquid in the jets to the saturation temperature comprises 40 ± 2^o C. The experiments were conducted for 36 jets of the HFE-7100 dielectric liquid with an initial diameter of 174 μm, outfl owing from the nozzles positioned at a distance of 1 mm from a cooling surface. It was established that the heat transfer coeffi cients of this surface and the critical heat fl ow from it are determined by the velocity of the jets, acting on the surface, and the initial subcooling of the cooling liquid, and that they are much larger than those in the case of pool boiling of the cooling liquid on the surface and in the case of its cooling by a single jet of a liquid with a small subcooling to the saturation temperature.
Author:  A. S. Shamirzaev, A. S. Mordovskii, V. V. Kuznetsov
Keywords:  impact microjets, subcooled boiling, dielectric liquid, heat transfer, critical heat fl ow
Page:  1129