Performance Characteristics of Potassium Heat Pipe Loaded with Argon

Abstract

T h e influence of inert gas on performance characteristics of liquid metal heat pipe was experimentally studied over a wide range of gas loading. In this experiment, potassium was used as a working fluid and argon was loaded in the heat pipe. T h e loading amount of argon ranged in initial pressure 10-2-102Torr a t room temperature. As the results, the followings became evident.During a start-up, an axial heat flux of the heat pipe is reduced from that corresponding to the sonic vapor flow by the presence of inert gas accumulating in the condenser section. In the region of high initial gas pressure, an over-all thermal conductance of the heat pipe can be described with the model due to "flat-front", but, with decreasing initial gas pressure, the over-all thermal conductance deviates from the theoretical values obtained from the flat-front model and approaches to that corresponding to the sonic vapor flow. Also, the over-all thermal conductance is influenced by the effect of the gravitational force on the wick pcmping ability of the heat pipe and the decrease of the thermal conductance depends on the initial gas pressure.

Review of reactor conceptual design and thermal hydraulic characteristics for heat pipe in nuclear systems

“…Matsushita (1975) found that the condensation heat transfer coefficient of the HP decreases significantly with the increase of non-condensable gas content in the tube, and a 5% volume fraction of non-condensable gas can reduce the steam condensation rate by 20% and affect the liquid working fluid reflux. Fukuzawa and Fujiie (1978) found that too much non-condensable gas would build up at the end of the HP's condensing section, leading to a sharp temperature drop there. As the power increased, the drop shifted further into the condensing section, and the gas had less effect.…”