电站空冷技术:研究现状及建议

Air Cooling Technology for Power Stations:Research Progress and Perspectives

空冷技术能够在电站冷端利用空气完成换热冷却,相比湿冷技术在节水、降耗、减排及降本方面具有独特优势。从系统设计与运行优化的角度出发,综述了直接空冷和间接空冷两大类空冷技术的研究进展。设计优化方面,换热器(凝汽器和散热器)的流动换热特性已获得广泛研究,相关优化一般从几何结构、位置布局等角度开展,然而目前凝汽器研究对象多局限于翅片管,针对管束整体的优化研究比较缺乏,散热器研究则需更全面地考虑几何参数的影响等;另外,由于风机(群)直接决定凝汽器的进气流量,其气动特性和集群效应研究成为重点,目前已形成多种分区方法和运行控制策略实施调优,但优化方案的经济性分析研究还有待深入。运行优化方面,为了削弱环境效应对空冷系统的负面影响,可以通过加装导流板等改善流场以扩展风的正向效应、开发控制预测模型进行防冻调控或设计防冻装置优化传热、设计开发各类清洗系统进行除垢等。当前研究在换热器设计优化的精度、广度和各类环境效应作用机理方面仍有进步空间,未来研究方向还包括新能源电站应用空冷的适应性分析,运用人工智能技术进行换热器设计、性能预测等。

Air cooling technology,which uses air at the cold end of the power station to complete heat exchanger cooling,has unique advantages in water saving,consumption reduction,emission reduction and cost reduction compared with wet cooling technology.From the perspective of system design and operation optimization,the research progress of two types of air cooling technologies,direct and indirect air cooling,is reviewed.In terms of design optimization,the flow heat transfer characteristics of heat exchangers(condensers and radiators)have been extensively studied,and the relevant optimizations are generally carried out from the perspectives of geometric structure,position layout,etc.,but at present,the research objects of condensers are mostly limited to finned tubes,and there is a lack of optimization research on the overall tube bundle,and research on the radiators needs to consider the influence of geometric parameters more comprehensively.In addition,since the fan(group)directly determines the inlet flow rate of the condenser,its aerodynamic characteristics and cluster effect have become the focus of research,and a variety of zoning methods and operation control strategies have been formed to implement tuning,but the economic analysis and research of the optimization scheme needs to be further carried out.In terms of operation optimization,in order to weaken the negative impact of environmental effects on the air cooling system,the flow field can be improved by installing deflectors to expand the positive effect of wind,developing control prediction models for antifreeze control or designing antifreeze devices to optimize heat transfer,and designing and developing various cleaning systems for descaling.At present,there is still room for improvement in research on the accuracy and breadth of heat exchanger design optimization and the mechanism of various environmental effects,and future research directions include the adaptability analysis of air cooling in the application of new energy power stations,and the use of artificial intelligence technology for heat exchanger design and performance prediction.