Influence of flue gas recirculation on the performance of incinerator-waste heat boiler and NOx emission in a 500 t/d waste-to-energy plant

摘要

The flue gas composition and the flue gas temperature at outlet of the economizer were tested, and the influence of flue gas recirculation (FGR) on the efficiency of the incinerator-waste heat boiler and NOx emission in a waste incineration power plant with a waste disposal capacity of 500 t/d was explored experimentally. The results indicate that the largest proportion of the total heat loss is the exhaust heat loss under different loads, and the next is the heat loss of slag. Within the test range, the efficiency of the incinerator-waste heat boiler increases from 80.26% to 80.42% as the ratio of the recirculating flue gas increases from 0 to 16.43%. The oxygen content in the flue gas and FGR have significant influence on NOx emissions. The NOx concentration at outlet of the economizer increases from 209.54 mg/m~3 to 307.30 mg/m~3, that is an increase of 46.65%, when the oxygen content at outlet of the economizer increases from 4.52% to 8.00%. Compared with the shutdown of FGR system, the NOx concentration at outlet of the economizer decreases from 209.54 mg/m~3 to 126.15 mg/m~3 when the FGR valve is fully opened. The results have important reference significance for the design of incinerator-waste heat boiler and the optimal operation of power plant.