锅炉烟气酸露点研究现状及展望

Review and prospect of researches on boilers’ flue gas acid dew point

烟气酸露点是设计锅炉排烟温度、防止低温腐蚀的重要参数。通过总结和分析烟气酸露点的影响因素,指出最直接的影响因素是烟气中SO3和水蒸气的体积分数及分压力。详细介绍了酸露点经验公式,总结了苏联经验公式的修正公式以及其他常用经验公式的应用条件、计算误差等,分析了各经验公式的优势与不足:苏联的经验公式考虑了灰分的影响,但不适合低硫分燃料;其他经验公式中SO3和H2SO4等烟气成分的体积分数及分压力测量困难,但应用范围较广泛。最后,基于目前的研究现状和不足,展望了未来酸露点测量与计算的方向:研究出更适合现场应用的测量设备及测量技术;结合不同的燃烧工况总结出更加精确、重现性好、适用性好的经验公式。

Flue gas acid dew point is an important parameter in setting boilers′ exhaust temperature and preventing lowtemperature corrosion.After considering the influencing factors of acid dew temperature(ADT)comprehensively,the volume fractions and partial pressures of SO3 and water vapor were considered to be the most direct influencing ones.After introducting empirical formulas for ADT,application conditions and calculation errors of modifier formulas for empirical formulas from the Soviet Union and other commonly-used empirical formulas were summarized. The pros and cons of each empirical formula were compared.The Soviet Union empirical formula that has considered the influence of ash is not suitable for low-sulfur fuels. The measurement of volume fractions and partial pressures of SO3 and H2 SO4 in flue gas brings difficulties to other empirical formulas which have a wider application range,though. In conclusion,the prospect for ADT measurement and calculation is given based on the status quo and shortages of current researches.And considering different combustion conditions,the empirical formulas with better accuracy,reproducibility and applicability are deduced.