Cooling system for condensing the exhaust steam of steam turbine plants,

Abstract

A cooling system for condensing the exhaust steam of steam turbine plants, particularly of power plants, comprises a mixing condenser connected to the outflow of the steam turbine, a dry cooling tower connected to the cooling water circuit of the mixing condenser, and a wet cooling apparatus provided inside the cooling tower. Although wet cooling apparatus seem to be suitable to additionally increase the cooling performance of the cooling tower and, thereby, its effective operation even in case of exceptionally high ambient temperatures, the air exiting from them is cooler than the air flowing in through the main heat exchangers of the cooling tower and, therefore, the draft of the latter suffers deterioration when the two air streams mix one with the other. It means that the effectiveness of complementary cooling is may be impaired. Such difficulty is eliminated by locating the wet cooling apparatus at least partly in a box for conducting cooling air from the ambient into the cooling tower, the box being arranged inside the cooling tower and encompassing a dry surface heat exchanger provided after the wet cooling apparatus as regards the flow direction of cooling air. The air exiting from the wet cooling apparatus becomes warmed up while traversing the dry surface heat exchanger and, thus, does not diminish the draft of the cooling tower when mixing with the air flowing in through the main heat exchangers of the latter.