HEAT EXCHANGE IN THE HEATING ZONE OF ALUMINUM GROOVED HEAT PIPES

At the present time, autonomous closed two-phase heat transfer systems - heat pipes (TT) are increasingly used in the systems for ensuring the thermal regimes of some space and ground vehicles. When developing and using such devices, it is necessary to solve the issue of optimizing the characteristics of these systems, which is most realistic to do on the basis of experiments conducted in working conditions. One of the important characteristics is the intensity of heat exchange in the heating zone of the heat pipe during its operation. The article presents the results of experimental studies of heat transfer in the heating zone for different working fluids on the internal developed surface in the form of an Ω-shaped capillary structure of an aluminum heat pipe operating in thermosiphon mode, i.e. the pipe was located vertically, the heating zone was located below. The experiments were carried out on experimental samples of aluminum heat pipes in the range of supplied heat fluxes from 0.1·104 W/m2 to 1.4·104 W/m2 and temperatures of the saturated steam of the working fluid from +30°C to +90°C. The research results are compared with the literature data on the heat exchange of these investigated working fluids on smooth surfaces in conditions of a large volume, and the criterion dependence of the calculation of the intensity of heat exchange for these conditions is obtained.