Boiler thermal system and control method thereof

Abstract

The invention relates to a boiler thermal system and a control method thereof, and belongs to the technical field of thermal power generation. Part of superheated steam generated by a boiler superheater selectively enters a deaerator, a third high-pressure heater, a second high-pressure heater and a third high-pressure heater respectively after being subjected to temperature reduction and pressurereduction effect of a temperature reduction and pressure reduction device, the boiler heat is recycled by increasing the feed water temperature of a boiler, the inlet flue gas temperature of an SCR denitration device is increased, and the cold start speed of the boiler can be accelerated.

Description

technical field [0001] The invention relates to a boiler thermal system and a control method thereof, belonging to the technical field of thermal power generation. Background technique [0002] The boiler thermal system is a whole composed of boilers, steam turbines, water pumps, high-pressure heaters and other thermal power plant thermal equipment connected in a certain order by steam and water pipes. [0003] In the existing boiler thermal system, the superheated steam generated by the boiler is divided into two paths, one path directly enters the high-pressure cylinder of the steam turbine after doing work and expansion, and then enters the boiler reheater of the boiler after passing through the high-row check door; the other path steam It can enter the high-pressure bypass of the unit, and after decompression, it merges with the steam behind the high-row check door and enters the boiler reheater for reheating. The reheated steam enters the condenser or the air-cooled is...

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Problems solved by technology

When the unit is at a lower load or in the process of stopping, as the steam flow rate at the turbine inlet decreases, because there is no steam or the pressure and temperature parameters of the steam extraction ports of the steam turbine are too low, it cannot provide heating steam for the high-pressure heater and low-pressure heater. The feed water cannot be heated effectively, resulting in a low temperature of the feed water entering the boiler side, which affects the rapid startup of the boiler to some extent

On the other hand, the flue gas temperature at the inlet of the SCR denitrification device under low load of the boiler cannot meet the requirements of the SCR denitrification catalyst, which limits the normal operation of the SCR denitrification device and puts huge pressure on the units to meet the emission standards.

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