燃油锅炉燃烧过程SO2的生成与排放特征

燃料燃烧过程是大气污染物的重要来源之一，对人体健康、空气质量和气候变化产生非常重要的影响。以62台燃油锅炉（≤10.5 MW）的燃料特性分析数据和SO₂排放实测数据为基础，通过统计分析方法，研究了燃油燃烧过程中燃油硫含量S和过量空气系数α对硫的转化率、SO₂排放因子和排放浓度的影响，获得了基于燃料消耗量、燃料发热量的SO₂排放因子EF_C、EF_H以及SO₂标态折算浓度C′_SO2与硫含量S间的关联式。结果表明，在过量空气系数α＞1的燃油燃烧过程中，EF_C、EF_H、C′_SO2与燃油硫含量S呈现出显著的线性正相关性，而与过量空气系数α无关，其关系式分别为：EF_C=18.86602×S，EF_H=443.78751×S ，C′_SO2＝1 509.28337×S；硫转化率η和基于燃料硫含量的SO₂排放因子EF_S则与燃油硫含量S和过量空气系数α无关，其平均值分别为96.3％和1.93 kg/kg。

Generation and emission characteristics of SO2 from fuel oil combustion in boilers

The combustion of fuels in boilers is one of important sources of air pollutants. It has very impor-tant impacts on human health, air quality and climate changes. The impacts of sulphur contents of fuel oil and excess air coefficients on sulphur conversion rates, emission factors and emission concentrations of SO_2 were stud-ied by means of statistical analysis method and based on the fuel oil analysis data and the actual test data of SO_2 emissions from 62 oil-fired boilers in China,actual capacity of boilers≤ 10. 5 MW. Furthermore, the mathemati-cal relationships of SO_2 emission factors based on fuel consumption (EF_C) and fuel heating value(EF_H) ,and e-mission concentrations of SO_2( C'_(SO_2)) converted into standard state and excess air coefficient is 1. 2, with sulphur contents were obtained. The results indicate that in fuel oil combustion, excess air coefficients > 1, EF_C , EF_H , and C'_(SO_2) present a highly significant positive linear correlation with sulphur contents, and are independent of ex-cess air coefficients. These correlations are EF_C = 18.86602 × S, EF_H = 443.78751 × S, and C'_(SO_2) = 1 509. 28337 ×S, respectively. Sulphur conversion rates and emission factors based on sulphur content of fuel oil are independent of sulphur contents and excess air coefficients, and their average values are 96.3% and 1.93kg/kg, respectively.