Transient response of a gas-controlled heat pipe

The paper presents a combined analytical and experimental investigation of the transient response of a gascontrolled heat pipe with an absorption gas reservoir. A mathematical model which considers the heat conduction in the condenser wall, the overall vapor core temperature, the diffusion of the vapor-gas interface, and the absorption of the control gas in the working fluid/wick structure matrix of the reservoir is developed for analysis. Experimental evaluation of the heat-pipe performance is made with methanol as a working fluid and ammonia and nitrogen as control gases. The combination of ammonia and methanol is considered for the soluble gas absorption reservoir, while nitrogen and methanol is considered for the standard gas reservoir. The performance of the two is compared. It has been observed that, to a limited extent, the performance can be improved by the absorption gas reservoir. Both theoretical and experimental results exhibit the same features of the performance of the heat pipe.