基于CFD的开式循环凝汽器内固液两相冲蚀特性研究

Research on Solid-liquid Two-phase Erosion Characteristics of Open-circuit Condenser Based on CFD

凝汽器性能的优劣对机组的经济性影响很大,冲蚀泄漏是造成凝汽器性能下降的一个重要原因,对采用开式循环的凝汽器,水流挟沙是冲蚀凝汽器的主要原因,因此揭示泥沙冲蚀规律对于预防以及处理泄漏问题非常有帮助。实际中凝汽器设备庞大,完整的模拟计算计算机目前难以实现,且复杂环境下在线监测技术不成熟。为此,在保证流动符合实际的情况下建立凝汽器简化模型,用计算流体力学(computational fluid dynamics,CFD)对挟沙水流在凝汽器中的冲蚀进行数值模拟计算,基于CFD解分析凝汽器入水室和冷却水管的磨损特性并给予解释。

The performance of condenser has a great impact on the economy of the steam turbine, and leakage caused by erosion is one of the most important reasons which lead to deteriorate the performance of condenser . Sediment laden flow is the main reason that causes leakage of condensers in open-cycle condensers. Therefore, revealing the law of sediment erosion is very helpful for preventing and dealing with leakage problems. We know that the volume of condenser is so huge that it is impossible to make a complete simulation calculation by computer at present, and online monitoring technology can not be used well to give a correct data. Therefore, this paper established a simplified model of the condenser to ensure that the internal flow of the cooling water pipe is in line with that of the actual situation. Computational fluid dynamics (CFD) is used to perform the numerical simulation calculations of erosion in the condenser caused by sediment laden flow. Based on the CFD solution, the wear characteristics of condenser inlet and cooling water pipes were analyzed and explained.