直接空冷系统轴流风机群运行特性分析

掌握直接空冷系统轴流风机群运行特性，对于电站空冷系统的优化设计和高效运行有重要意义。该文在2台风机并联运行的基础上，绘制并联风机的性能曲线，获得叶片安装角对并联风机运行特性的影响。通过引入集群因子，得到轴流风机群的性能曲线、空冷管束的阻力特性及空冷系统的工作点。结果表明，空冷系统风机群每台风机的流量介于风机并联运行和单台风机独立运行之间。风机群性能不仅取决于每台风机的性能，还与风机群的数量和布置方式有关。随空冷系统容量增加，风机群非线性效应增加。在一定程度上揭示出空冷系统传热面积随机组容量非线性放大效应的机理，为空冷系统设计提供了理论依据。

Operation Performance Analysis of Axial Flow Fan Cluster in Direct Air-cooled System

It is of importance to investigate the operation performance of axial flow fan cluster for the optimal designing and economic running of direct air-cooled system in power plant. Based on the parallel running of two axial flow fans, the performance diagram of parallel axial flow fans was drawn. The influence of stagger angle of axial flow fan upon the operation performance of parallel running was obtained. The cluster factor was introduced and the performance diagram of axial flow fan cluster, the resistance characteristics of the fin-tube banks of air-cooled condenser as well as the working point of the direct air-cooled system were presented. The results show that the flow rate of each fan of the fan cluster is between that of each fan of the parallel running fans and that of individual fan. The performance of the axial flow fan cluster depends not only on the performance of each fan, but also on the number and array way of the fans. The non-linear effect becomes more remarkable with the air-cooled system capacity increasing. It explains the non-linear enlargement of the heat transfer area of air-cooled system with the capacity of the air-cooled unit increasing to some extent and can be used as one of the theoretical bases of the air-cooled system designing.