ABSTRACT
The spontaneous combustion of coal storage piles and gangue piles in coal mines has been resulting in significant resource waste and serious environmental pollution. To solve spontaneous combustion problems, the use of gravity heat pipes to extract internal heat from piles of coal has been proposed. In this paper, a method for selecting the optimum working medium for a heat pipe is presented. In addition, an experimental system was set up to study a gravity heat pipe’s heat extraction rate, and a gravity heat pipe heat dissipation experiment was conducted. The experimental results showed that compared with using ethanol or hexane as the working medium, a methanol gravity heat pipe had the highest efficiency and provided the fastest cooling rate.