Khairnasov S. Scientific and technological fundamentals of aluminium grooved heat pipes creation for the energy-saving systems

Thesis is devoted to solving the scientific and applied problem of creation of the the aluminium grooved heat pipes with constant thermal resistance for energy-saving systems, executing the functions of heat transport and thermal stabilization, and of determination of their thermal performances in a wide temperature range at ground application. Influencing factors on the heat transfer intensity in evaporation, boiling and condensation modes of aluminium grooved heat pipes were identified. The mechanisms of hydraulic processes influence on the values of heat transfer coefficients are defined and analyzed. The experimental results of heat transfer and visualization of transport processes in the evaporation zone of aluminum grooved heat pipes were presented. Different types of heat transfer modes were revealed as well as their dependence on the various heat carriers, the geometry of the grooves forming capillary structure and their effective length, and the level of heat input. Patterns of the stationary and nonstationary temperature field formation in aluminium grooved heat pipes were identified. Obtained generalized formulas allow to calculate: heat transfer coefficients in the evaporation and condensation zones of aluminum grooves heat pipes filled with ammonia, acetone and pentane; their thermal resistance, maximum heat transfer ability and the limiting density of heat flow at any their location relatively gravity force. Optimal filling factor of aluminium grooved heat pipes were determined. New designs of energy-saving equipment based on aluminum grooved heat pipes: solar thermal and photovoltaics-thermal collectors, heat exchangers, thermal stabilization systems of electronics and LED lighting equipment, which work without energy consumption and provide high value of their effectiveness at temperature range from -40 to +210 Celsius degree, are proposed and verified.