回转式空气预热器漏风对大容量锅炉热效率的影响探讨

Discussion on the influence of air leakage of rotary air preheater on the thermal efficiency of large capacity boiler

根据ASME标准讨论了回转式空气预热器漏风率对大容量电站锅炉热效率的影响,分析了冷端径向漏风和热端径向漏风对锅炉热效率的影响,用实际案例进行了详细的理论计算。计算表明:空预器热端径向漏风每增加1%,锅炉热效率降低约0.043%。空预器漏风率3.5%时对锅炉热效率的影响略大于排烟温度升高1℃对锅炉热效率的影响。因此,空预器性能对锅炉热效率影响应考虑排烟温度和漏风率。

According to the performance calculation of ASME standard, the influence of air leakage rate of rotary air preheater on the thermal efficiency of large capacity utility boiler is discussed.The influence of cold end radial air leakage and hot end radial air leakage on the thermal efficiency of boiler is analyzed.The theoretical calculation is carried out in detail with a practical case.The calculation shows that the thermal efficiency of the boiler decreases about 0.043% with every 1% increase of the radial air leakage at the hot end of the air preheater.When the air leakage rate of the air preheater is 3.5%, the influence on the thermal efficiency of the boiler is slightly greater than that when the exhaust gas temperature rises by 1℃.Therefore, the influence of air preheater performance on boiler thermal efficiency should first consider the exhaust gas temperature of air preheater, and then the air leakage of air preheater.