Self-adaptive optimization control method for steam-driven induced draught fan guide vanes

Abstract

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.

Description

technical field [0001] The invention relates to the technical field of self-adaptation of a steam-driven induced draft fan, in particular to an adaptive optimization control method for a guide vane of a steam-driven induced draft fan. Background technique [0002] With the increasing capacity of domestic fuel-fired power plants, the conventional design of domestic coal-fired generating set induced draft fans are all driven by electric motors. Difficulties, the increase in motor capacity will lead to increased power consumption and large starting current of the motor, which will cause a large increase in investment costs. There have also been cases in many power plants in the market that the bus voltage dropped due to the excessive starting current of the induced draft fan, which caused the equipment to trip. [0003] The conventional design is to optimize the design of the induced draft fan and the desulfurization booster fan. If the combination of the booster fan and the i...

AI Technical Summary

Problems solved by technology

Since the two adjustment methods of the guide vane of the induced draft fan and the speed of the small steam turbine both act on the same adjustment object—the negative pressure of the furnace, it is easy to have a coupling phenomenon in the automatic control, so that the adjustment quality cannot be effectively guaranteed

In this existing control loop, when the speed of the small steam turbine adjusts the negative pressure of the furnace, the guide vane of the induced draft fan is adjusted. Although this mode reduces the difficulty of automatic adjustment, the manual opening of the guide vane of the induced fan cannot guarantee the economical efficiency of the small steam turbine of the induced draft fan. sex to the max

Images