空冷凝汽器U型翅片管水平布置间隙优化

Research on the Horizontal Arrangement Space and Optimization of U-finned Tube in Air-cooled Condenser

研究及优化空冷凝汽器U型翅片管的水平布置间隙,对火电站空冷岛的设计与运行具有重要意义。基于FLUENT软件,以空冷凝汽器U型翅片管束为研究对象,对不同翅片管水平布置间隙下空冷凝汽器U型翅片的换热及流动特性进行数值模拟及计算,得到了空冷凝汽器冷却空气对流换热平均努谢尔数和摩擦系数随雷诺数的变化规律,并采用最小二乘法拟合得到了相应的关联式。针对U型翅片的换热及流动特性提出两种优化方案,并进行比较分析。结果表明:当流动损失能量较小时,空冷翅片综合性能评价指标不能准确反应出空冷翅片管的综合性能,需通过空冷翅片换热量进行优化,由此得出空冷凝汽器U型翅片管的最佳水平布置间隙。

It is of great importance to investigate the horizontal arrangement space and its optimization of U-finned tube in air-cooled condenser of power plant for the designing and operation of air-cooled system. Based on the FLUNET software, the characteristics of the heat transfer and flow were simulated and calculated. The variations of mean Nusseh number （Nu） and friction coefficient （f） of air convection heat transfer with Reynolds number （Re） under the different horizontal arrangement spaces of U-finned tube in air-cooled condenser were obtained by calcula- tion, and the concerned correlations of flow and heat transfer were established by the least squares fitting. In connection with the characteristics of the flow and transfer heat of the U-finned tune, two optimization schemes were put forward, and the comparison was made between the schemes. It is concluded that the Comprehensive Performance Evaluation indicator （PEC） can not reflect comprehensive performance correctly when the flow loss of energy is less, and the U-finned tube should be optimized via the heat transfer, and by which, the optimal U-finned tube horizontal arrangement space is obtained.