燃煤电厂超低排放的减排潜力及其PM2.5环境效益

燃煤机组在燃用低硫优质煤的基础上采用先进的大气污染控制技术设备,实施主要大气污染物的超低排放,在新建机组与改造机组上均是可行的。长三角、京津冀的燃煤电厂实施超低排放环保改造后,与现有燃煤电厂排放的污染物相比,SO₂、NO_x和烟尘以及烟尘中一次PM_2.5减排比例均在90%以上,SO₃减排幅度也达到70%左右。采用MM5+CULPUFF耦合模型,以江苏省为例,定量模拟研究了2012年江苏省火电厂排放的大气污染物对各地级市PM_2.5的影响,结果表明,对各市贡献的日均浓度最大值介于27.3~42.9 μg/m³,平均为35.28 μg/m³,其中二次PM_2.5占87.4%;实施超低排放后对各市贡献的日均浓度最大值介于6.2~12.5 μg/m³,平均为9.43 μg/m³,其中二次PM_2.5占91.7%。

Potential Capabilities of Pollutant Reduction and Environmental Benefits from Ultra-Low Emissions of Coal-Fired Power Plants

For those coal-fired generating units using low-sulfur coal with the advanced air pollutant control technologies and equipments applied, it is feasible to implement ultra-low emission technique of major air pollutant reductions no matter whether they are newly built or retrofitted units. Compared with the pollutant emissions of the existing coal-fired power plants in the Yangtze river delta and Beijing-Tianjin-Hebei region, the SO₂, NO_x, dust and primary PM_2.5 emissions of the corresponding power plants which would have ultra-low emission retrofit implemented will be reduced by more than 90% and the SO₃ emissions will be reduced by about 70%. Taking Jiangsu Province for example, the quantitive analysis on the PM_2.5 caused by air pollutant emissions of the power plants in the major cities of the province in 2012 is simulated with the MM5 and CULPUFF coupling model. The results show that the maximum contribution to the daily average concentration of the cities is between 27.3~42.9 μg/m³ with an average of 35.28 μg/m³, of which the secondary PM_2.5 accounts for 87.4%. After the implementation of ultra-low emission retrofit, the maximum contribution to the daily average concentration is between 6.2~12.5 g/m³, with an average of 9.43 μg/m³, of which, the secondary PM_2.5 accounts for 91.7%.