摘要
低温环境条件下,直接空冷系统冷却性能出色,但也面临空冷凝汽器翅片管束冻结的风险。揭示不同环境气象条件和系统运行模式下空冷系统性能变化规律,提出直接空冷系统防冻高效运行控制逻辑,对于机组的安全经济运行具有重要意义。以机组实现阻塞背压运行为目标,约束条件为管束出口凝结水状态,开发直接空冷系统控制逻辑。首先,当风机满转速运行且管束出口凝结水不过冷时,确定临界最高环境温度。其次,当风机停转且管束出口凝结水温度等于0℃时,确定临界最低环境温度。再次,以管束出口凝结水不过冷为约束条件,通过风机转速调节,实现直接空冷系统的高效运行。最后,通过数值模拟方法,对直接空冷系统防冻高效运行控制逻辑进行了算例验证。
At low ambient temperature,a direct dry cooling system presents excellent cooling performance,but the finned tube bundles may face the risk of freezing.It is of great significance for the safe and economic operation of a direct dry cooling system to reveal the performance variation under different environmental conditions and operating modes,and to develop the anti-freezing and energy-efficient operation controlling logic of the direct dry cooling system.The controlling logic was developed,focusing on the chocking back pressure of the turbine,and taking the state of condensate water at the outlet of bundles as the constraint.At first,when the axial flow fans operated at full speed and the condensate at the outlet of bundles remained saturated,the maximum critical ambient temperature was determined.Secondly,when the axial flow fans stopped running and the condensate temperature at the outlet of bundles was 0℃,the minimum critical ambient temperature can be obtained.Thirdly,the direct dry cooling system can operate with a high energy efficiency by adjusting the rotational speeds of the axial flow fans with the constraint that the condensate at the outlet of bundles was not overcooled.Finally,several cases of the direct dry cooling system were investigated,to verify the aforementioned controlling logic by means of numerical simulations.
作者
陈磊
侯一晨
王伟佳
孔艳强
杨立军
杜小泽
CHEN Lei;HOU Yichen;WANG Weijia;KONG Yanqiang;YANG Lijun;DU Xiaoze(Key Laboratory of Power Station Energy Transfer Conversion and System of Ministry of Education(School of Energy Power and Mechanical Engineering,North China Electric Power University),Changping District,Beijing 102206,China)
出处
《中国电机工程学报》
EI
CSCD
北大核心
2022年第13期4896-4906,共11页
Proceedings of the CSEE
基金
国家自然科学基金项目(52006070)。
关键词
直接空冷系统
防冻
高效运行控制逻辑
临界环境温度
轴流风机转速调节
数值模拟
direct dry cooling system
anti-freezing
controlling logic for efficient running
critical ambient temperature
rotational speed adjustment of axial flow fans
numerical simulation
