Abstract: A condenser is provided with a heat exchanger which is rotated in an airtight cylindrical vessel filled with a fluid to be condensed. The rotated heat exchanger has a structure almost similar to a rotor of a steam turbine, namely, has a structure formed of plural pairs of hollow blades arranged individually opposite to each other on both sidewalls of an elongated rectangular hollow axle rotated in the fluid to be condensed, all of those hollows being communicated with each other, so as to circulate a coolant therethrough. As a result, the fluid to be condensed always uniformly contacts with the coolant through surfaces of the blades with an extremely high performance of condensation.

Abstract: An oceano-thermosteric power plant is provided with plural evaporators and plural condensers, alternate parts of which are not operated at night and in winter on light load and hence a high efficiency heat exchange can be maintained. During the period that selected condensers and evaporators are not in service, excess cold water from the out-of-service condensers is circulated through the out-of-service evaporators in the opposite direction and hence the filth deposited inside the out-of-service evaporators can be washed away.