Water feeding method used during unit starting

Abstract

The invention provides a water feeding method used during unit starting. The water feeding method comprises the steps that when the unit is started in a cold state (or a warm state), the unit is started without a condensate water pump, specifically, a deaerator does not perform water feeding using the condensate water pump, but performs water feeding using a boiler feedwater pump, and the condensate water pump is started until a condenser is vacuumized before a boiler is ignited; when the unit is started in the cold state (or the warm state), the unit is started without an electric feedwater pump, specifically, firstly, the boiler is subjected to water feeding using a deaerator pressurizing method, that is, a static pressure water feeding method; secondly, after adjacent furnace heating iscarried out, a front-arranged pump is used for feeding water; the condensate water pump is started; after the boiler is boosted, a steam pump is used for feeding the water; the rotation speed of a steam-driven feedwater pump is gradually accelerated; the unit starts steam source switching of middle and small steam turbines; when the unit is started in a thermal state (or an extreme thermal state), a high-pressure assisted steam source is directly used for charging the small steam turbine, and a steam-driven main feedwater pump is started to perform water feeding on a boiler steam dome; and the unit is started without the condensate water pump or the electric feedwater pump in the cold state, the unit is started without an electric pump in the thermal state for feeding the water, and the security and economy in the starting process of the unit are improved.

Description

technical field [0001] The invention belongs to the technical field of thermal power plant equipment design, and in particular relates to a water filling method when a unit is started. Background technique [0002] The design principle of the traditional unit water supply system is: start the condensate pump first when the unit starts, use the condensate pump to supply water to the deaerator, and use the electric water supply pump group as the working pump for boiler supply. After the unit load is greater than 90MW, as the load increases Put 1 or 2 sets of steam-driven feedwater pumps into operation, and withdraw from the electric pumps as backup pumps during normal operation when the load is greater than 180MW. It has the following problems: [0003] The power consumption rate of the plant is high. When the unit is started in a cold state, it takes 15 hours or even longer from starting the electric pump to a load of 180MW (that is, when the steam pump is turned on), and t...

AI Technical Summary

Problems solved by technology

Therefore, before the load of the unit is 180MW, if the electric pump fails and the steam-driven pump cannot be put into operation immediately, it will inevitably cause the boiler water supply to be interrupted, and the unit startup will be forced to stop