Solution Selection in Geothermal Heat Pipes

Abstract

Steady heat pipe solutions with capillarity and conduction effects included are considered. Phase plane trajectories of temperature vs. saturation typically approach zero capillarity solutions, one liquid-dominated and one vapor-dominated. The way in which choice of boundary conditions selects from these solutions is studied. Comparisons with previous work on the effect of upstreaming on solution selection are made. Implications for actual geothermal reservoirs are that liquid-dominated counterflow is typically selected when saturation and temperature are fised at the top of the counterflow region, and vapor-dominated counterflow is typically selected when temperature and saturation are at the bottom.