Oxygen-enriched combustion device of circulating fluidized bed and air supply method for oxygen-enriched combustion thereof

Abstract

An air supply method for oxygen-enriched combustion of a circulating fluidized bed comprises the steps of providing recirculating flue gas and oxygen for a fluidized bed body. The recirculating flue gas and the oxygen are led into the fluidized bed body respectively and then mixed. In addition, the recirculating flue gas and the oxygen are both preheated before entering the fluidized bed body. The invention also provides an oxygen-enriched combustion device of the circulating fluidized bed. According to the air supply method, the manner that the high temperature oxygen and the high temperature recirculating flue gas are not mixed before entering the fluidized bed body and are transported in respective pipes is adopted so as to prevent safety accidents during the conveying and mixing processes of the recirculating flue gas and the oxygen.

Description

technical field [0001] The invention relates to the technical field of circulating fluidized beds, and further relates to a circulating fluidized bed oxygen-enriched combustion device and an oxygen-enriched combustion air supply method thereof. Background technique [0002] With the development of human society and economy, the impact of energy production and consumption on the environment has become increasingly prominent. The greenhouse effect has become one of the most severe and far-reaching challenges faced by mankind. CO produced during the combustion of fossil fuels such as coal 2 important contribution to the greenhouse effect. Carbon dioxide capture and storage (CCUS) can be used to reduce CO 2 emissions. CCUS technology is mainly divided into three categories: pre-combustion capture, in-combustion capture and post-combustion capture. Oxygen-enriched combustion technology, as a CCUS technology in combustion, has many advantages such as low cost, easy scale, and...

AI Technical Summary

Problems solved by technology

However, in the high oxygen concentration circulating fluidized bed oxygen-enriched combustion system, if the air supply method of mixing the preheated oxygen and the recirculated flue gas is still used, and the mixed gas is transported through the pipeline and then injected into the furnace, there are serious safety issue

Because in the flue gas recirculation system, even if the bag filter is set up to remove dust from the recirculated flue gas, the flue gas still carries a small amount of carbon-containing particles with small particle sizes. If the preheated oxygen (about 180°C) and The preheated flue gas (about 200°C) is directly mixed and transported according to conventional methods, especially when the oxygen concentration in the mixed gas reaches 50% or higher, a small amount of carbon-containing particles carried in the recirculated flue gas encounters pure oxygen Afterwards, it is easy to catch fire and burn. Once the mixture gas pipeline burns, it will be a major safety accident, which not only endangers the equipment body, but also poses a threat to the safety of operating personnel.

[0007] At present, in order to ensure the safety of oxygen and recirculated flue gas in the process of mixing and transportation, oxygen and recirculated flue gas are usually not preheated, which greatly reduces the reasonable distribution of the boiler thermal system

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