考虑漏空气因素的空冷凝汽器真空分析

Influences of Air Leakage on the Vacuum of Air-Cooled Condenser

凝汽器真空是影响机组安全、经济运行的一个重要指标。机组运行参数的变化会对凝汽器真空产生影响。而空冷凝汽器有庞大的真空体,在其运行过程中不可避免的要漏入空气,因此在空冷凝汽器真空的影响因素中不能忽视漏入空气因素。建立了考虑漏空气因素的空冷凝汽器真空的数学模型,采用数值计算的方法绘出了考虑漏空气时机组热负荷、管外污垢热阻、环境温度和空气流速等运行参数变化对空冷凝汽器真空的影响曲线,分析各运行参数对真空影响的剧烈程度,结果表明前3个参数对凝汽器真空影响较大,并且随漏入空气量的增多影响趋势增大。所建模型对空冷凝汽器的运行优化有一定参考价值。

The vacuum of condenser is an important index which influences safety and economic operation of the unit. The vacuum is affected by the change of operational parameters of the unit. Air leakage is inevitable while air-cooled condenser is running because of its huge vacuum body, and is one of factors which influence the vacuum of air-cooled condenser that can＇t be ingnored. A math model considering air leakage is established, curves are drawn to describe the influence of heat load, dirt thermal resistance outside the pipe, ambient temperature and velocity of the air on the vacuum of air-cooled condenser considering air leakage, how severe those operational parameters influence the vacuum is analysed, it is indicted that the more the air leak in, the larger contribution the three former parameters influence the vacuum. The model established has some reference to optirnal operation of aft-cooled condenser.