System for increasing low-load feed water temperature of power station boiler

Abstract

The invention discloses a system for increasing the low-load feed water temperature of a power station boiler. A method for increasing the feed water temperature of the power station boiler comprises the following steps that under the low-load working condition of the boiler, the SCR (Selective Catalytic Reduction) flue gas temperature is lower than a temperature window required by a catalyst; a steam source of a first high-pressure heater of a unit regenerative system is changed into extracted steam of a boiler superheater system or a main steam pipeline from an original high-pressure cylinder, so that the pressure of steam entering the first high-pressure heater of the unit regenerative system is increased; the temperature of saturated steam corresponding to the steam inlet pressure rises due to rising of the steam inlet pressure of the first high-pressure heater of the unit regenerative system, so that the temperature of feed water at a first high-pressure heater outlet of the unit regenerative system rises, the temperature of the feed water entering a boiler economizer rises, and finally the temperature of flue gas entering an SCR reactor is increased; and thus, the purpose of low-load denitration of the boiler is achieved. The flue gas temperature at an inlet of the low-load SCR reactor of the boiler is increased, the activity of the SCR catalyst under the low load is guaranteed, and the technical range of low-load denitration of the boiler is widened.

Description

technical field [0001] The invention relates to the technical field of low-load denitrification of power plant boilers, in particular to a system for increasing the temperature of low-load feed water for power plant boilers. Background technique [0002] The energy structure dominated by coal and its utilization through direct combustion is one of the main causes of air pollution in our country. In order to ensure air quality, my country requires that all power plant boilers must adopt advanced pollutant control technology to control the total amount of pollutants discharged by the units, and implement stricter emission standards. [0003] For a long period of time in the future, it will be necessary to vigorously develop new energy sources, and the role of coal-fired units will gradually change from power generation to power grid peak regulation. The change of the function of the coal-fired unit will lead to the change of the operating parameters of the unit, and the coal-...

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Problems solved by technology

Although there are many low-load denitrification technologies at present, there are generally problems such as limited layout space, limited heating effect, high investment, and complex systems.

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