A superheated steam temperature adjustment system and method suitable for scr low load operation

Abstract

The invention discloses a superheated steam temperature adjustment system and method suitable for operation under low load of SCR. The feed water heater before the inlet header of the boiler and various pipes and valves connected to the steam temperature adjustment system. The invention adjusts the steam flow rate from the low-temperature superheater by adjusting the valve opening of the bypass system, thereby using part of the superheated steam to heat the feed water at the inlet of the economizer, increasing the water temperature at the inlet of the economizer, and reducing the heat exchange of the economizer system To achieve the purpose of controlling the flue gas temperature at the outlet of the economizer, so that the temperature of the flue gas that cannot meet the SCR commissioning conditions under low load can meet the temperature requirements of the SCR commissioning. The invention solves the problem that the SCR denitrification system of the coal-fired power plant cannot be put into operation under low load, and ensures that the discharge of nitrogen oxides reaches the standard during the full-load operation of the power plant.

Description

technical field [0001] The invention relates to a technical method for low-load flue gas denitrification of coal-fired boilers, which belongs to the technical field of coal-fired boiler emission reduction, and specifically refers to a system and method for regulating superheated steam temperature suitable for SCR low-load operation. Background technique [0002] my country's coal-based energy source determines that my country's air pollution is characterized by soot-type pollution. my country's existing coal-fired power generation equipment has a high overall coal consumption for power generation and low energy utilization, which further aggravates the gas emissions and environmental pollution caused by coal combustion. At the same time, my country's coal-fired power plants started late in the control of nitrogen oxide emissions, resulting in a rapid increase in the total amount of nitrogen oxide emissions. After nitrogen oxides enter the atmosphere, under the action of sun...

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Problems solved by technology

[0005] The purpose of the present invention is to provide an existing coal-fired power plant boiler as the transformation object, aiming at the problem that the SCR denitrification system currently in operation cannot be put into operation under low load, and to provide a method to change the arrangement of water spraying and cooling of the existing superheater The system and method can not only adjust the superheated steam temperature, but also meet the purpose of SCR operation under low load, meet the current pollutant emission standards of thermal power plants, and meet the requirements of environmental protection

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