空冷机组换热单元计算及风速场对机组的影响分析.docVIP

摘 要 在我国火力发电厂一般采用湿冷系统对机组进行冷却，此方法受水源限制较大，近几年来随着空冷技术日趋成熟，空冷技术受到广大缺水地区的电站的欢迎。本文首先介绍了空冷机组的发展过程，叙述了直接空冷系统与间接空冷系统的工作原理，并从结构、性能、特点、运行特性等方面对直接空冷和间接空冷系统进行对比、分析。其次详细分析直接空冷的特点，重点介绍了风速场对直接空冷系统的影响以及今后的发展方向。最后，对600MW直接空冷机组进行热力工况的计算，在此基础上，对直接空冷系统凝汽器压力变工况计算数学分析，得到直接空冷系统运行经济性的影响因素，以及对凝汽器压力的影响规律，并利用Visual Basic软件绘制出直接空冷凝汽器压力随迎风速度、排汽热负荷、环境气温变化的特性曲线，从而为提高直接空冷凝汽器的性能提供了有力的依据。 关键词：直接空冷；特性曲线；变工况；间接空冷；效率—传热单元数（） Abstract Generally the wet cold system are used in thermal power plant our country to carry on cooling to the unit, this method was limited by water source, in the last few years is day by day mature along with air-cooled technology, air-cooled the technology receives generally by lacks the water area the power plant welcome. This article first introduced air-cooled units developing process, narrated direct air-cooled systematic and the indirect air-cooled system principle of work, and from aspect and so on structure, performance, characteristic, movement characteristic to is direct air-cooled and the indirect air-cooled system carries on the contrast, the analysis .Next multianalysis direct air-cooled characteristic, introduced with emphasis the wind field will guard against to the direct air-cooled system influence as well as the next development approaches. Finally, the long-lived direct air-cooled unit carries on the thermal energy operating mode the computation, in this foundation, changes the operating mode computational mathematics analysis to the direct air-cooled system water recovery condenser pressure, obtains the direct air-cooled system movement efficient influence factor, as well as to the water recovery condenser pressure influence rule, and software draws up the direct air-cooled water recovery condenser pressure using Visual Basic along with against the wind the speed, the exhaust hot load, the environment temperature change characteristic curve, thus has provided the powerful basis for the enhancement direct air-cooled water recovery condenser performance. Keywo