Abstract: A finned tube comprises a tube; and a fin strip having fins formed by forming slits of a predetermined length in a fin portion of a strip and at predetermined intervals, and a base portion in which no slit is formed, and wound around the tube so that the fins thereof extend substantially radially of the tube. The fins are twisted at a twist angle in the range of 2.degree. to 40.degree. to a contact line along which the base portion of the fin strip is in contact with the tube, and inclined at an inclination angle in the range of 2.degree. to 20.degree. to a straight line perpendicular to the axis of the tube. A heat exchanger is provided with a plurality of such finned tubes, and a heat recovery apparatus comprises such a heat exchanger disposed in a combustion gas passage.

Abstract: A heat exchanger apparatus has a hot-fluid casing and a cold-fluid casing which are separated from each other by a partition plate and through which a fluid of a higher temperature and a fluid of a lower temperature pass, respectively. The hot-fluid casing accommodates a plurality of heat transfer tubes charged with a heat medium and connected at their ends to respective headers so as to constitute an evaporator panel. The cold-fluid casing also accommodates a plurality of heat transfer tubes similar to that in the hot-fluid casing and connected at their ends to respective headers so as to constitute a condenser panel. The header on the medium outlet side of the evaporator panel and the header on the medium inlet side of the condenser panel are positioned substantially at the same level. The header on the medium outlet side of the condenser panel is disposed above the header on the medium inlet side of the evaporator panel and these headers are connected to each other through a connection pipe.

Abstract: A hybrid Rankine cycle system comprises a boiler in which water steam is generated, a steam turbine which is worked by the water steam from the boiler to drive a generator to obtain an electric power, an absorber condenser for introducing thereinto strong absorbent solution to absorb the water steam from the steam turbine to produce weak absorbent solution, and a pump for delivering the weak absorbent solution from the absorber condenser to the boiler. The weak absorbent solution is heated in the boiler to produce the strong absorbent solution to be fed to the absorber condenser and the water steam to be fed to the steam turbine.