基于ADS1~3缩比模型的双孔蒸汽喷放冷凝传热系统程序计算与实验验证

System Code Calculation and Experimental Verification for Double-hole Steam Jet Condensation Heat Transfer Process Based on ADS1-3 Scaled Model

高温蒸汽在过冷水中喷放直接接触式冷凝是AP1000、CAP1400等三代先进压水堆一回路在事故超压情况下重要的降温降压途径。本文基于系统程序RELAP5、COSINE对饱和蒸汽通过双孔喷洒器喷入大容积过冷水中进行直接接触冷凝这一过程进行建模、计算、分析,获得高温蒸汽从喷口喷出后沿轴向的温度分布。同时开展蒸汽喷放冷凝可视化实验,采用热电偶矩阵和高速摄像机等对关键热工参数进行测量,以获得蒸汽汽羽的温度分布和喷放流型等,用于验证系统程序对蒸汽喷放冷凝过程模拟的准确性。结果表明,采用RELAP5程序基本能模拟简化条件下的ADS蒸汽喷放冷凝总体变化规律,模拟结果与实验结果相比平均误差为2.97%。此外,采用COSINE程序对喷放冷凝过程模型进行了进一步修正和改进,考虑水箱内整体流动对喷放特性的影响,模拟结果与实验结果吻合较好,平均误差为1.89%。但由于实际双孔喷放过程较为复杂,并且存在明显的三维特性,所以仍需对系统程序中相关冷凝传热模型进行完善,以更精确地模拟其局部冷凝特征。

The steam direct contact condensation of high-temperature steam in sub-cooled water is an important way to reduce the temperature and pressure in the primary circuit in the third generation of advanced pressurized water reactors such as AP1000 and CAP1400 in the event of accidental overpressure.Based on the system codes of RELAP5 and COSINE,the process of saturated steam injecting into large volume sub-cooled water through a double-hole nozzle was modeled,calculated and analyzed.The temperature distributions along the axial direction of the high-temperature steam ejected from the nozzle were obtained.At the same time,the visual experiments of steam jet condensation were performed.The thermocouple matrix and high-speed camera were used to measure the key thermal-hydraulic parameters to obtain the temperature distributions along the steam plume and the flow patterns of the steam jet,which were used to verify the accuracy of the system code to simulate the process of steam spraying and condensation.The results show that the system code RELAP5 can basically simulate the general trend of ADS steam condensation process under the simplified model.The average error of the simulation results is 2.97%compared with the experimental results.In addition,the COSINE code was used to further modify and improve the model of the spraying condensation process.Considering the influence of the overall flow in the water tank on the condensation characteristics,the simulation results fit well with the experimental results,with an average error of 1.89%.However,the actual double-hole spraying process is complex and has obvious three-dimensional characteristics,so the relevant condensation heat transfer model in the system code still needs to be further improved to simulate its local condensation characteristics more accurately.