Forced circulation drum boiler with smoke temperature rising system

Abstract

The invention relates to a forced circulation drum boiler with a smoke temperature rising system. The forced circulation boiler comprises a boiler body, a steam drum, a boiler water pump, a coal economizer, an SCR reactor and an air pre-heater. An inlet of the boiler water pump is connected with the steam drum through a downcomer, an outlet of the boiler water pump is divided into two routes, one route is connected with a low water drum of the boiler body through an electric adjusting valve, and the other route is connected with a water feeding inlet pipe of the coal economizer through a second electric adjusting valve. The low water drum is connected with the steam drum through the water wall inside a boiler hearth. The smoke temperature rising system is applicable to subcritical and ultrahigh pressure forced circulation drum boilers, the SCR reactor can be made to run normally under the conditions / condition of low loads and / or low atmosphere temperature, and therefore the smoke emission quality of the subcritical and ultrahigh pressure forced circulation drum boilers under the conditions / condition of the low loads and / or the low atmosphere temperature can reach national standards.

Description

technical field [0001] The invention relates to a forced circulation drum boiler of a power plant, in particular to a method of increasing the inlet flue temperature of the SCR reactor of the original forced circulation drum boiler through the operation of the flue gas heating system to meet the low load of the boiler and / or the atmosphere Under low temperature conditions, the flue gas temperature at the inlet of the SCR reactor is too low to be put into use when the denitrification system of the forced circulation drum boiler needs to be increased. Background technique [0002] my country's energy structure is dominated by coal, and coal consumption will continue to grow. According to statistics, thermal power installed capacity accounts for more than 74% of my country's installed power generation capacity. For a long time to come, nitrogen oxide pollution caused by coal burning will be another important environmental problem after sulfur dioxide pollution. At the same tim...

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Problems solved by technology

[0008] The present invention aims to solve the technical problem that the SCR reactor cannot be put into operation under the condition of low load and / or low atmospheric temperature of the forced circulation drum boiler, and provides a forced circulation drum boiler with a flue gas heating system, through the The water system of the existing forced circulation drum boiler is modified, and the boiler water pump is used to transport part of the high-temperature saturated water to the water side inlet of the boiler economizer to mix with the feed water of the economizer to increase the temperature of the feed water of the economizer, thereby increasing The flue gas temperature at the outlet of the boiler economizer, so that the temperature reaches the applicable temperature for the SCR reactor to be put into operation

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