600MW机组“Y型”排汽管道系统内湿蒸汽的数值研究

Numerical Investigation on Wet Steam in Y-type Exhausted Duct of a 600MW Power Unit

对德国基伊埃(GEA)公司发明专利——"Y型"(枝状)直接空冷排汽管道进行数值研究。建立华电宁夏灵武一期2×600MW机组直接空冷排汽管道内湿蒸汽两相流动和传热的数学模型。利用计算流体力学软件FLU-ENT,对典型汽轮机工况下的排汽状况进行了数值模拟。对二维管道内湿蒸汽速度场、温度场和两相场的模拟、分析和研究,为直接空冷排汽管道系统的优化设计提供帮助。模拟结果表明:在汽轮机典型工况下,水蒸汽流经各蒸汽分配管的压降约为高位布置方式水蒸汽压降的1/3,且流量分配更均匀。

The numerical research on Y-type （treelike shape） direct air cooling exhausted pipe, which is the invention patent of German GEA Energietechnik GmbH, is carried out. The mathematic model for two-phase flow and heat transfer of wet steam in direct air cooling exhausted duet for Huadian Lingwu the first stage 2 × 600MW power generating unit in China is constructed. Using the numerical heat transfer （NHT） software called FLUENT, the exhausted steam condition under typical steam turbine modes is simulated. The simulating results, including the flowing field, temperature field and twophase field of wet steam in 2-dimensional duct are analyzed and studied. It offers good help for the optimal design of air cooling exhausted duct system. The simulation results show that under typical operational parameters of steam turbine, the pressure drop of Y-type pipe configuration is approximately 1/3 of that of the high position pipe configuration, and the flow distribution are more even.