流动不均匀性对核电机组再热器换热的影响  

Influence of Flow Inhomogeneity on Heat Transfer in Reheaters of Nuclear Power Units

作　　者：鹿纯彬 邢天阳 朱小良[1] 胥建群[1] LU Chunbin;XING Tianyang;ZHU Xiaoliang;XU Jianqun(School of Energy and Environment,Southeast University,Nanjing 211189,China)

机构地区：[1]东南大学能源与环境学院,南京211189

出　　处：《动力工程学报》2024年第11期1696-1703,共8页Journal of Chinese Society of Power Engineering

基　　金：核反应堆系统设计重点实验室基金资助项目(HT-WDZC-02-2020007)。

摘　　要：再热器是核电机组中用于提高汽轮机功率并减少零部件腐蚀的关键设备,其壳程蒸汽轴向流动不均匀性对机组效率与安全有重要影响。对此,首先建立再热器的一维分布数值与仿真模型,进行不同工况的稳态验证与流量阶跃动态准确性验证。考虑到再热器内循环蒸汽分布沿管长方向有较强的流动不均匀性,对不同流量偏差系数下再热器管内外蒸汽的流动与换热进行了仿真研究。结果表明:额定工况下,循环蒸汽出口温度的变化与流量分布成反比,随着流量偏差系数增大,温度分布越不均匀;各管段再热蒸汽出口焓值与干度受到的影响较小,同时流量偏差系数越大,再热管束出口出现过冷现象的概率下降;设备低功率运行导致再热管束出口更易出现过冷现象,流动不均匀性的影响增大。Reheaters are key equipment in nuclear power units used to increase turbine power and reduce component corrosion,and the shell-stream steam axial flow inhomogeneity has a significant impact on efficiency and safety of the units.In this regard,a one-dimensional distribution numerical and simulation model of the reheater was firstly established to verify the steady state and the accuracy of the flow step dynamics under different operating conditions.Considering that the distribution of steam circulating in the reheater had a strong flow inhomogeneity along the tube length,the flow and heat transfer of steam inside and outside reheater tubes were simulated under different flow deviation coefficients.Results show that under the rated condition,the change of circulating steam outlet temperature is inversely proportional to the flow distribution,and as the flow deviation coefficient increases,the temperature distribution becomes more uneven;the outlet enthalpy and dryness of reheat steam in each tube section are less affected,but the probability of subcooling at the outlet of reheat bundle decreases with the increase of flow deviation coefficient.In addition,the low power operation of equipment makes the outlet of reheat bundle more susceptible to subcooling,and the influence of flow inhomogeneity increases.

关 键 词：再热器 流动不均匀性 一维分布 温度 干度 

分 类 号：TL353[核科学技术—核技术及应用]