Biomass high-temperature flue gas gasification combination coal burning boiler and low-pollution combustion method thereof

Abstract

The invention belongs to the technical field of a coal burning boiler and particularly relates to a biomass high-temperature flue gas gasification combination coal burning boiler and a low-pollution combustion method thereof. Flue gas serving as a gasification agent enters a gasification furnace; a biomass to be gasified in a biomass bin also enters the gasification furnace; gasified biomass fuel gas enters a fuel gas purification chamber to be subjected to primary purification to remove H2S, HCl and oil tar impurities; after a pressure head of the purified biomass fuel gas is improved by a booster fan, the purified biomass fuel gas enters a fuel gas storage tank and then enters a hearth of the coal burning boiler by a fuel gas nozzle to be burnt; the content of the biomass in the total glue gas is in the range of 0 to 30 percent and the whole system can still operate stably. The use of the biomass effectively reduces discharge of CO2 and SO2. The high-temperature flue gas is used as a heat source to gasify the biomass so as to reduce the content of the oil tar in the biomass fuel gas. The generated biomass fuel gas has high CO2 concentration. The reducing effect of the fuel gas on NOX is far superior to that of the biomass solid on NOX. The NOX concentration is effectively reduced.

Description

technical field [0001] The invention belongs to the technical field of coal-fired boilers, and in particular relates to a biomass high-temperature flue gas gasification combined coal-fired boiler and a low-pollution combustion method thereof. Background technique [0002] Flue gas from coal-fired power plants is rich in CO 2 , SO 2 , NO X , CO 2 is the main greenhouse gas, and the extensive use of fossil fuels emits a large amount of CO 2 cause the Earth's temperature to rise, SO 2 and NO X Entering the atmosphere, causing acid rain and photochemical pollution, seriously damaging the ecological environment. Pulverized coal boiler units with a unit capacity of less than 100MW are facing policy pressure to be forced to close due to poor economy and large pollutant emissions. And biomass fuel due to its zero CO 2 emissions, SO 2 and NO X The emission is very low. As a renewable new energy source, the utilization of biomass fuel is being supported by policies. Biomass ...

AI Technical Summary

Problems solved by technology

But it may reduce boiler output, limit the type and proportion of biomass used

After all, pulverized coal and biomass are two fuels with different physical properties. Their ignition temperature, combustion time, and flow trajectory in the air are all different. The unified combustion after mixing is prone to combustion instability, flame center changes, and combustion efficiency. drop and other issues

Moreover, biomass is rich in alkali metals. After mixed combustion, due to the presence of alkali metals, the ash melting point decreases and sintered ash deposits increase, resulting in slagging tendencies on heating surfaces such as boiler water wall superheaters and reheaters and high-temperature corrosion tendencies of alkali metals. enhanced, and the corrosion problem of HCl is also very serious

NO in the exhaust flue gas under this combustion mode X higher concentrations of emissions

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