The invention discloses a self-
adaptive optimization control method for steam-driven induced draught fan guide vanes. The method mainly includes the following steps that (1) a plurality of auxiliary systems of a small
steam turbine are put in, the impulse starting condition of the small
steam turbine is preset, and a
turbine heating mode is started; (2) under the
turbine heating mode, in the period that a rotating speed R of the small
steam turbine on an induced draught fan is in continuing speed increasing, and the induced draught fan guide vanes control a
hearth negative pressure by adoptinga
closed loop control loop; (3) when the rotating speed of the small steam
turbine on the induced draught fan is increased to reach a rotating speed preset value, a rotating speed adjusting manner isstarted, and the
hearth negative pressure is controlled by adopting
closed loop control in the rotating speed adjusting manner; and (4) on the basis of the step (3), when the boiler
air volume or theload capacity rises, the guide vane opening degree Y is gradually increased to an opening degree set value in an opening manner, the induced draught fan guide vane
closed loop state is released, andthe induced draught fan guide vanes enter an open loop adjusting manner. According to the self-
adaptive optimization control method for the steam-driven induced draught fan guide vanes, the opening degree piecewise function f(x) corresponding to the optimal economical opening degree value Y0 of the guide vanes is gathered and solidified into a DCS, and it is achieved that the induced draught fan guide vanes control the
hearth negative pressure to be automatic in the whole process in a full-load stage of a unit.