Exhaust steam waste heat recovering and supplying system of air-cooling units in large thermal power plants

An exhaust steam waste heat recovering and supplying system used for air-cooling units in large thermal power plants, in which the air-cooling units in large thermal power plants comprises a first steam turbine and a second steam turbine, and the first steam turbine and the second steam turbine respectively have a first turbine low-pressure cylinder and a second turbine low-pressure cylinder respectively connected with a first air-cooling member and a second air-cooling member via an exhaust pipe;

• wherein the exhaust steam waste heat recovering and supplying system comprises:
• a first exhaust steam extraction system and a second exhaust steam extraction system and corresponding first and second steam ejectors, first and second pre-condensers, and first and second steam ejector condensers thereof, in which turbine exhaust steam is extracted by using an exhaust steam extraction system;
• each of the two steam turbines has its own independent exhaust steam extraction system, in which the exhaust steam extraction system of each steam turbine is connected with the corresponding pre-condenser via an exhaust steam extraction pipeline, with a shell side of the pre-condenser being fed with the turbine exhaust steam and a water side being fed with return water of a heating network so that the return water of the heating network is heated by steam-water heat exchange;
• the exhaust steam extraction pipeline of each steam turbine is further connected with a suction steam inlet of the corresponding steam ejector, and a heating steam extraction pipe of the steam turbines is connected with motive steam inlets of the steam ejectors, so as to perform pressurization by using the exhaust steam extracted by the heating steam extraction pipe;
• and
• an exhaust port of each steam turbine is connected with the corresponding steam ejector condenser thereof, with a shell side of the steam ejector condenser being fed with the pressurized exhaust steam and a water side thereof being fed with the return water of the heating network so that the return water of the heating network is heated by the steam-water heat exchange.