135MW机组枝状排汽管道系统内湿蒸汽的数值研究

Numerical Investigation on Wet Steam Inside the Tree-branch Shape Exhausted Duct of a 135MW Power Unit

对德国基伊埃(GEA)公司发明专利——枝状(Y型)直接空冷排汽管道技术进行数值研究。建立神华阳光2×135MW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FLUENT,对典型汽轮机工况下的排汽状况进行了数值模拟。结果表明:在设计方案下,水蒸汽在各分配管的流量分配均匀,流动压降较低。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。

The numerical research on tree-branch shape （Y-type） direct air cooling exhausted pipe technology, 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 duct for ShenHua YangGuang 2 × 135MW 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 results show that under the design scheme, the flow dividing for steam distribution manifolds are quite equal, and the flowing pressure drop of steam is low. The simulating results, including the flowing field, temperature field and two-phase 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.