基于空气预热器漏风率偏差的排烟温度影响研究

Influence Study Exhaust Temperature Based on the Air Leakage Rate of Deviation of Air Preheater

空气预热器的漏风对排烟温度和锅炉效率影响较大,准确的进行定量分析空气预热器不同部位漏风率变化对排烟温度的影响对于火电机组的运行维护和节能降耗具有重要意义。通过分析空气预热器不同部位的漏风对换热的影响机理,基于能量平衡原理推导出了不同部位漏风率变化对排烟温度影响的计算表达式,并以300 MW机组为例,计算了2个不同工况下空气预热器热端漏风率和冷端漏风率变化对排烟温度的影响。计算结果表明,随着热冷端漏风率变化的增大,对排烟温度的影响也在增大,并且热端漏风率变化对排烟温度的影响要大于冷端漏风率变化对排烟温度的影响。此研究可为定量分析空气预热器漏风率变化对锅炉效率和发电标准煤耗率的影响奠定理论基础。

Accurate quantitative analysis of influence on leakage rate change at different positions of the air preheater to exhaust temperature is of great significance for the operation of the thermal power unit maintenance and energy consumption. Heat transfer influence mechanism in different parts of the air preheater was analyzed in the paper, exhaust temperature calculation formula on the impact of different parts of the leakage rate change of air preheater was derived based on the principle of energy balance, taking a 300 mw unit as an example, the influence of exhaust temperature of two different working conditions on the change of hot end air leakage rate and cold end leakage rate was calculated. The results show that the exhaust temperature change increases with the increase of hot cold end leakage rate changes, and the influence of exhaust temperature on hot end leakage rate change is greater than the old end. This research can lay a theoretical foundation for the quantitative analysis of power generation standard coal consumption rate and boiler efficiency change on the air preheater leakage rate change.