Streltsova Y. Characteristics of metallic porous materials: the effect on heat transfer in heat pipes of chemical and energy purpose

The dissertation is devoted to the investigation of two types of metal porous materials, which can be used as capillary structures of heat pipes - monofibrous and composite fibrous-powder structures. The dependences for engineering calculations of frame thermal conductivity for monofibrous and composite materials were obtained after the experiments of heat conduction processes in metallic porous materials. Multi-factor dependence for calculations of temperature difference of the water boiling beginning on metallic porous surfaces was proposed on the basis of the experimental studies of boiling in free water flow. The obtained experimental data allowed to compare the real values of heat transfer coefficients with the data obtained by the model of boiling on porous surfaces (the KPI model) specified in the dissertation. As a result of model elaboration, It became possible to bring the calculated values obtained by the experiments to the model calculated values and to confirm the adequacy of the model. It was refined the method of internal thermal resistance determining in heat pipes with metal porous structures by the application of the KPI model. The cycle of experimental studies of heat pipes with monofibrous and composite capillary structures showed, that in horizontal position heat pipes with composite structures do not concede with the main characteristics (maximum heat transfer capacity and thermal resistance) to the heat pipes with monofibrous capillary structures. In addition, maximum heat transfer capacity of composite heat pipes has higher values, than the same one of mono-fibrous pipes, when working against the forces of gravity.