双流程凝汽器汽相流动与传热特性的准三维数值分析

Quasi-Three-Dimensional Numerical Analysis of Steam Flow and Heat Transfer Performance of a Two-Pass Power Plant Condenser

为了掌握大型电站凝汽器的三维汽相流动与传热特性,采用一种准三维数值计算方法对一台双流程凝汽器的汽相流动与传热特性进行了计算与分析.计算结果表明,由于冷却水温度沿冷却水流动方向的变化,第二流程管束的热负荷明显小于第一流程的,并使蒸汽流动产生侧向偏斜,导致流动与传热特性的恶化.在管束布置时,应当采取相应措施减小流场偏斜对凝汽器传热特性的影响.计算结果对凝汽器的合理设计具有重要作用.

To know well the behavior of three-dimensional steam flow and heat transfer in the condenser, a quasi three-dimensional program is adopted to analyse the steam flow field and the heat transfer performance of a two-pass power plant condenser numerically. The numerical results show that because of the temperature variation of cooling water along its flow direction the heat load of the second-pass tube bundle is lower than that of the first- pass tube bundle, which brings about the steam flow deflection and then the deterioration of heat transfer. Therefore, it is necessary to take suitable measures at the time of the tube bundle arrangement to alleviate the influence of flow deflection on the heat-transfer performance of the condenser. The computational results are helpful to the reasonable design of power plant condensers.