Heat Transfer during Boiling in a Thin Layer of Dielectric Liquid HFE-7100 on Capillary-Porous Coatings

The paper presents an experimental study of heat transfer during boiling on capillary-porous coatings with different thermal conductivity in horizontal layers of dielectric liquid HFE-7100. Samples of stainless steel and bronze coatings were produced using additive 3D printing technology using selective laser melting/sintering. Using high-speed thermographic imaging, the mechanisms of heat transfer intensification during boiling and the dynamics of crisis phenomena in a thin layer of HFE-7100 dielectric liquid were studied. It is shown that due to the activation of active vaporization nuclei of a larger range of sizes on a capillary-porous coating made of stainless steel, a higher intensification of heat transfer during boiling is achieved than on a bronze coating. It has been established that during the development of crisis phenomena, the speed of propagation of the drying front boundary along the channels of 2D modulated capillary-porous coatings is approximately twice as large as in the transverse direction.