直接空冷枝状排汽管道系统内导流装置的优化设计

Optimized Design of the Flow Guiding Device for a Direct Air-cooled Branch-shaped Exhaust-steam Piping System

对德国基伊埃(GEA)公司发明专利——枝状直接空冷排汽管道系统进行研究。建立某2×600MW机组直接空冷排汽管道内湿蒸气两相流动和传热的数学模型;利用数值传热学软件Fluent对典型汽轮机工况下的排汽状况进行了数值模拟;对二维管道内湿蒸气速度场、温度场和两相场的模拟、分析和研究。模拟结果表明:专利提出的简单几何原则分流方法,无法实现排汽的均匀分配。针对不同形式的直接空冷枝状排汽管道系统应进行详细的优化设计,并提出了枝状排汽管道系统导流装置的基本设计原则。

Studied was an invention patent of German GEA Energyietechnik Gmbh-a direct air-cooled branch-shaped exhaust steam piping system, and established was a mathematical model for the wet steam two-phase flow and heat transfer in a direct air-cooled exhaust steam pipeline of a 2×600 MW unit. By employing the numerical heat transfer software Fluent, the authors have conducted a numerical simulation of the exhaust steam situation under typical steam turbine operating conditions. Through a simulation, they have also analyzed and studied the wet steam velocity field, temperature field and two-phase field in a two-dimensional pipeline. The simulation results show that the flow division method according to the simple geometrical principles proposed in the invention patent is incapable of realizing a uniform distribution of the exhaust steam. In view of this, depending on the direct air-cooled branch-shaped piping system in different forms, a detailed optimized design should be conducted. Moreover, the basic design principles of the flow guiding device for the system in question were also given.