Steam turbine generating heating system with double running modes

The invention provides a steam turbine generating heating system with double running modes. The steam turbine electric heating system comprises a generator, a first coupler, a low-pressure rotor, a second coupler, a high- and medium-pressure rotor, a condenser and a low-pressure cylinder flow portion. The low-pressure rotor comprises a pure coagulating rotor and a backpressure heating rotor. The high- and medium-pressure rotor of a steam turbine is connected with one end of the low-pressure rotor through the second coupler, and the other end thereof is connected with the generator through the second coupler to perform generating heating. In an off-heating season, the pure coagulating rotor serves as the low-pressure rotor, and a system is operated in a coagulating mode; in a heating season, the pure coagulating rotor is replaced by the back pressure heating rotor, and the system is operated in a backpressure mode. The steam turbine generating heating system with the double running modes is characterized in that flow grade of the pure coagulating rotor is of 2X6, while flow grade of the back pressure heating rotor which is a one-piece-forged centerless rotor is of 2X4.