Abstract
Authors originally proposed a unique method to transport the low-quality exhaust heat downward in the gravitational direction with almost no additional power input for fluid circulation. This heat transport process was composed of the following cycle : (1) accumulation of high-pressure vapor in an evaporator vessel, (2) sudden flow generation by discharging the accumulated vapor, (3) condensation of a part of the discharged vapor in the downstream condenser, (4) return of the condensate to the evaporator by vapor-liquid two-phase flow via a low-pressure reservoir. In the present work, the instantaneous pressure drop of the upward returning vapor-liquid two-phase flow [process (4)] was estimated by using a mass conservation model proposed by the authors with the help of the Lockhart-Martinelli correlation. The estimation showed good agreement with the experimental result.
