火电站直接空冷凝汽器设计及校核计算和性能分析

掌握火电站直接空冷凝汽器的设计和校核计算方法并进行性能分析,对于提高我国直接空冷机组的设计和运行水平具有重要意义。以600MW机组直接空冷凝汽器为例,在传热理论模型分析的基础上,分别对其设计和校核计算过程进行了讨论,对直接空冷凝汽器性能影响因素进行了分析,对性能变化规律进行了研究。结果表明直接空冷凝汽器的设计过程要综合考虑气象条件尤其是环境大风的影响、换热要求和空冷电站的平面布局,而校核计算则需充分考虑凝汽器积灰的影响,并建立汽轮机背压和凝汽器积灰厚度之间的关系,为凝汽器清洗提供理论依据。冷却空气流量、凝汽器凝结蒸汽量、空冷凝汽器积灰会显著影响空冷凝汽器的性能,进而影响汽轮机背压,影响机组运行的经济性。

Designing and Verifying Calculations and Performance Analysis for Direct Air-cooled Steam Condensers in Power Plant

It is of great importance to investigate the designing and verifying calculations as well as the performance of direct air-cooled steam condensers in power plant. Based on a typical direct air-cooled condenser of a 600MW unit, the designing and verifying process are discussed and the performance affecting factors and changing rules are analyzed by the heat transfer model of direct air-cooled condensers. The results show that the designing of direct air-cooled condensers should take the weather conditions especially the natural wind, heat transfer demands and the power plant layout into account. The verifying calculations should setup the correlation between the exhaust steam pressure and the dust accumulation on direct air-cooled condenser, which is useful for condenser cleaning. The exhaust steam pressure and the economy of the unit as well as the heat transfer performance of direct air-cooled condensers are affected by the cooling air flow rate, exhaust saturated steam flow rate and the dust accumulation.