Start-up transients of a capillary pumped loop operating in reflux mode

This study investigates the start-up transients of a Capillary Pumped Loop (CPL) operating in reflux mode where the condenser is elevated above the evaporator. This configuration results in a constant tendency toward flooding of the evaporator wicks with subcooled working fluid from the condenser. Due to this condition, a larger amount of heater power must be applied to the evaporator pump to initiate boiling and clearing of the vapor passages as opposed to a start-up in a zero gravity environment where less vapor pressure is required to overcome the gravity induced pressure head.; The vapor/liquid interactions occurring in the vertically oriented reservoir are also examined.; Both a standard start-up employing only the evaporator pump heaters, and a contingency start-up utilizing the vapor line heaters for liquid clearing prior to the pump heater activation are investigated.