Automatic paralleling method and device for steam-driven induced draft fans of thermal power generating unit

Abstract

The invention discloses an automatic paralleling method and device for steam-driven induced draft fans of a thermal power generating unit. The method comprises the steps of: determining whether automatic paralleling of steam-driven induced draft fans is required according to unit load; when automatic paralleling of steam-driven induced draft fans is required, controlling stationary blades of an electrically-driven induced draft fan to automatically track and maintain stable furnace draft of the thermal power generating unit, carrying out a paralleling operation to the steam-driven induced draft fan A and the steam-driven induced draft fan B in the thermal power generating unit in order, adjusting the steam-driven induced draft fan A and the steam-driven induced draft fan B to be identical in rotating speed and stationary blade opening, and controlling the stationary blades of the steam-driven induced draft fan A and the steam-driven induced draft fan B to automatically track the furnace draft. The device comprises an automatic paralleling trigger unit, an automatic control unit for the electrically-driven induced draft fan, a first paralleling operation control unit, a second paralleling operation control unit, a synchronous operation control unit for the steam-driven induced draft fans, all of which completely correspond to the method. The automatic paralleling method and device for the steam-driven induced draft fans of the thermal power generating unit allow decrease of fan paralleling time, reduction of manual operation, and reduction of risks of stalling and surging during fan paralleling.

Description

technical field [0001] The invention mainly relates to the field of thermal power plants using steam-driven induced draft fans, and in particular to a method and device for automatic paralleling of steam-driven induced draft fans for thermal power generating sets. Background technique [0002] At present, the capacity of thermal power generation units is gradually increasing, the number of boiler tail equipment is increasing, the resistance is increasing, and the capacity of boiler induced draft fans is also gradually increasing. Boiler induced draft fans have become one of the most power-consuming equipment in power plants. The increase in the capacity of the induced draft fan brings a series of problems. The starting current of the fan is too large, which leads to a decrease in the voltage level of the power plant; the load of the unit varies widely, and the efficiency of the fan cannot work in the high-efficiency area. At present, the use of steam-driven induced draft fan...

AI Technical Summary

Problems solved by technology

[0004] However, there may be a deep peak-shaving problem after the thermal power generation unit is running, and the steam-driven induced draft fan needs to be frequently paralleled and separated.

At present, the juxtaposition and decoupling of steam induced draft fans are realized manually by the DCS system. The existing thermal power plants using steam induced draft fans need to manually parallelize and decouple the steam induced draft fans frequently when starting and stopping or when the load changes, and the operation is cumbersome. , The defect of long time consumption, and if the operation is improper, it may cause the steam-driven induced draft fan to stall

Once the steam-driven induced draft fan stalls, if it is coupled with the pipeline system, it will generate surge. Surge is a very bad operating condition. When surge occurs, the flow rate and total pressure of the fan will have a large cycle. Sexual vibration, which makes it difficult for the thermal power unit to run stably, or even shut down in an emergency. The surge will cause great damage to the fan body and may cause fatigue damage to the fan blades.

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