空冷凝汽器积灰对机组出力影响的计算分析

富煤缺水地区空冷机组装机容量不断增加,而空冷凝汽器的积灰决定着机组能否安全高效运行,为此有必要研究积灰厚度与机组出力的关系。利用传热学以及换热器原理对积灰前后的换热系数进行推导计算,并根据某电厂330 MW机组的实际数据,给出传热系数随积灰厚度的变化关系,进而给出机组背压随积灰厚度的变化关系,最终得出积灰厚度对机组出力的影响程度。研究结果表明,对于330 MW机组,空冷凝汽器积灰1 mm时,机组出力会减少1.4%。

Computational Analysis on the Influence of Dust Accumulation of Air-Cooled Condenser on Unit Outputs

The dust accumulation of air-cooled condensers determines whether the unit can be operated with enough security and high efficiency. With the ever-increasing installed capacity of air-cooled units in the areas rich in coal but short of water resources, it is necessary to study the relationship between the thickness of dust accumulation and unit outputs. In this paper, the heat exchanging coefficient before and after dust accumulation is calculated by taking advantage of the heat transfer theory and the principle of heat exchanger. Combined with the operation data of one 330-MW unit of a power plant, the correlation between the heat exchanging coefficient/unit back pressure and the fouling thickness is derived. In this way the influence of dust thickness on the unit output is concluded. The results show that for 330-MW units, a mere 1mm thick layer of fouling will reduce the unit output by 1.4%.