面向灵活性发电的燃煤机组大气排放特性分析

随着可再生能源发电在电网中占比逐年增加，越来越多的燃煤机组参与灵活性发电。为了弄清灵活性发电燃煤机组的大气排放特性，以某亚临界600 MW和300 MW机组为例，通过对运行数据进行回归分析，获得了机组在启动、正常调峰和深度调峰阶段的CO₂、NO_x、SO₂和粉尘的排放特性。结果表明：正常调峰阶段，随着机组负荷下降，煤耗和CO₂排放因子逐渐增大，净烟气NO_x排放因子先减小后增大，SO₂排放因子略有下降；粉尘排放因子略有上升；深度调峰阶段，随机组负荷的进一步降低煤耗和CO₂排放因子明显增大，净烟气NO_x和粉尘排放因子迅速增大，SO₂排放因子继续下降；启动过程净烟气NO_x和粉尘排放因子明显高于调峰工况，SO₂排放因子略小于调峰工况。另外，调峰过程中较高的升降负荷率使得原烟气NO_x、SO₂排放因子明显增大，净烟气粉尘排放因子明显增大。

Air Emissions Characteristics of Coal-Fired Power Unit for Flexibility Generation

With the increasing share of renewable energy in power system, more and more coal-fired power units participate flexibility generation. For clarifying the air emission characteristics of flexibility generation, the operation history data of two subcritical coal-fired power units (600 MW and 300 MW) are used for regression analysis. In normal cyclic operation, power ramping-down will lead to a little increase in coal consumption rate and CO₂ emissions factor. Meanwhile, the NO_x emissions factor will decrease firstly and then increase when ramping down and the amplitude of variation is little in clean flue gas. The SO₂ emissions factor will decrease a little while dust factor will increase a little when ramping down. In deep cycling operation, the increase in coal consumption rate and CO₂ emissions factor will be much larger, while the NO_x and dust emissions factors will increase substantially when SO₂ emissions factor continues to decrease in clean flue gas. In start-up process, the NO_x and dust emissions are much larger while SO₂ emissions are slightly smaller than regular operating conditions. In addition, larger ramping rate has remarkable impact on NO_x and SO₂ in untreated flue gas and on dust in clean flue gas in deep cycling conditions.