Comparing the Behavior of a Loop Heat Pipe With Different Elevations of the Capillary Evaporator

During the life tests required for the development of a loop heat pipe (LHP), the device must operate at different capillary evaporator elevations in order to compare its thermal behavior, specially related to the operation temperature. As an effort in developing LHPs for future space missions, a LHP was designed and tested for a system operating with acetone as the working fluid. Tests were performed for the LHP at horizontal position and with the capillary evaporator above and below the condenser. The experimental results show the operationability of the LHP tested at all situations, where the system presented reliable operation at power levels as low as 1 W. Tests with the capillary evaporator above and below the condenser also show the reliability of the LHP operation, showing higher operation temperatures with the evaporator above and lower operation temperatures with the evaporator below. The test results present the robust design of the LHP and its capability as a thermal control device for future space missions.