IMPACT OF GRAVITY FORCE ON HEAT TRANSFER CHARACTERISTICS OF VAPORDYNAMIC THERMOSYPHON

The two-phase vapordynamic thermosyphon (VDT) is an efficient heat transfer device. Closed vapordynamic evaporative-condensation heat transfer cycle is realized inside it. Vapor pressure acts as a driving force for returning the liquid phase of working fluid to the condenser. The original design of the condenser and the evaporator of the VDT allows to transfer heat flow in horizontal direction to large (10–20 meters) distance. VDT can be used in heat exchangers of heat pumps, heat and cold accumulators of alternative energy sources and secondary energy sources for utilization. This article presents results of the experimental study and shows VDT heat transfer capability depending on the conditions of its work. For this purpose following VDT parameters were determined for different values of heat load and various drops between the thermosyphon evaporator and its condenser: the operating range of heat loads, maximum allowable thermosyphon angle of inclination, dependence of thermal resistance on the transmitted heat flow. The scheme of VDT is described and the methodology of the study is presented. Experimental data allows to conclude that high heat-transfer device working efficiency is achievable with heat loads between 300 and 1500 W and with vertical inclination angles up to 85 degrees. 

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