EXTERNAL COMBUSTION ENGINE

摘要

PROBLEM TO BE SOLVED: To improve accuracy in leakage detection of a working fluid in an external combustion engine which converts displacement of a liquid part of the working fluid caused by a volume change of the working fluid into mechanical energy and outputs the energy.SOLUTION: An external combustion engine includes: an auxiliary vessel 16 in which a working fluid 12 in a liquid state and a gas 18 are filled; a communication pipe 17 which communicates the inside of the auxiliary vessel 16 with the inside of a main vessel 11; a water level sensor 22 which detects a liquid surface position of the working fluid 12 in the auxiliary vessel 16; and a leakage determining means 20a which determines whether or not leakage occurs in the working fluid 12 in response to a detection value by the water level sensor 22. In a communication pipe 17, a cross-sectional area in a displacement orthogonal direction, orthogonal to a displacement direction of a liquid part of the working fluid 12, is smaller than a cross-sectional area in a displacement orthogonal direction in the main vessel 11. The leakage determining means 20a determines leakage of the working fluid 12 when the detected value by the water level sensor 22 is lower than a predetermined lower limit position.