600MW直接空冷机组补水方式探讨

Discussions on the Making-up Mode of Water for 600 MW Direct Air Cooling Unit

凝结水溶解氧量是表征凝结水水质的重要指标之一。它直接影响机组的经济性和安全性。国内目前还没有针对空冷机组的凝结水溶氧指标,暂时只能沿用湿冷机组的控制值。目前我国已投产的直接空冷机组,普遍存在凝结水溶氧量偏大的问题。文章分析了凝结水溶解氧量的存在机理和影响因素,介绍了3种补水方式,即凝结水补水到主凝结水箱、补水管路接至空冷凝汽器、直接空冷系统的补水到汽轮机的主排汽管道,并对此3种补水方式的优缺点进行了对比。提出了控制凝结水溶氧量偏大应采取的措施。

The dissolved oxygen in the condensate is one of the important indexes characterizing the quality of condeusate,which affects the economics and safety of units directly. There isn＇t dissolved oxygen index of condensate in accordance with the air cooling unit presently at home,hence it is the only way to continually use the controlled value for the wet cooling unit temporarily. As viewed from the direct air cooling units having been put into operation,the dissolved oxygen in the condensate is universally on the high side. This article analyzes the mechanism and factors of dissohed oxygen existing in the eondeusate,introduces three malting-up modes of water（the make-up water of condensate is supplied into the main condensate tank,the make-up water pipe is connected directly to the air cooling condenser,and the make-up water of direct air cooling system is supplied to the main. exhaust pipe of steam turbine）,conducts the comparisons of merits and demerits,of the three making-up modes,and puts forward the measures which should be taken to control the higher dissolved oxygen in the condensate for the references of design,operation and maintenance.