To provide an energy conversion device capable of converting
primary energy into
secondary energy.SOLUTION: An energy conversion device 1 comprises: a
liquid tank 11 in which liquid 10 is stored; a plurality of gas receiving parts 12 provided in the
liquid tank 11 in a vertical direction, and capable of rotating or moving up and down; a
nozzle 13 that ejects compressed gas from below the gas receiving part 12 located at the lower part in the
liquid tank 11; a
gas cylinder 14 that stores compressed gas as a
primary energy source and sends the compressed gas to the
nozzle 13; output means 3 that outputs the
kinetic energy of rotation or upward movement generated in the gas receiving part 12 by
buoyancy generated by the gas receiving part 12 receiving the compressed gas ejected from the
nozzle 13, to the outside of the liquid tank 11 as
secondary energy; and a
recovery device 4 that returns gas from the liquid tank 11 to the
gas cylinder 14.SELECTED DRAWING: Figure 1