Flue gas circulation system for improving combustion characteristics and thermal characteristics of pulverized coal fired boiler

Abstract

Disclosed in the present application is a flue gas circulation system for improving combustion characteristics and thermal characteristics of a pulverized coal fired boiler. The flue gas circulation system comprises a plurality of circulation flue gas leading-out ports provided in a hearth outlet flue of a boiler, wherein the circulation flue gas leading-out ports are connected to a circulation flue gas leading-out main pipe by means of a circulation flue gas leading-out pipeline; the circulation flue gas leading-out main pipe is connected to a circulation flue gas leading-in main pipe; the circulation flue gas leading-in main pipe is connected to a circulation flue gas leading-in pipeline; and the circulation flue gas leading-in pipeline is connected to a hearth. Flue gas in a flue is introduced into the hearth through the circulation flue gas leading-out ports, thereby achieving flue gas circulation; and at the same time, the problems such as clinkering or overtemperature of a heating surface of a pulverized coal fired boiler of a power station, high-temperature corrosion of a water-cooled wall, burning loss of a combustor, incapability of reaching a design value of steam temperature, and high concentration of nitrogen oxides at an outlet of the hearth can be solved or ameliorated.

Dependencies are inferred from the claim text.