蒸汽发生器实验回路倒流特性仿真分析

Numerical Simulation and Analysis of Reverse Flow in Steam Generator Experiment Loop

针对立式倒U型管蒸汽发生器传热管内出现的倒流现象,基于RELAP5/MOD3.3程序,采用新的控制体划分方案对蒸汽发生器实验段进行建模,模拟实验回路中发生的倒流现象。通过与实验数据进行对比分析,验证建模方案的正确性。在此基础上,分析倒流现象对蒸汽发生器实验段流动传热的影响。结果表明:倒流现象发生在较短管内,对于单个U型管,倒流管的流量高于正流管。倒流发生后,系统进入相对稳定状态,但蒸汽发生器实验段的换热功率和进出口腔室负压降绝对值显著降低。

For the reverse flow phenomenon in the vertically inverted U-tube steam generators,a new node partition scheme was used to model the steam generator test section based on the system analysis code RELAP5/MOD3.3.The reverse flow phenomenon in the process of experiment was simulated in this paper.Compared with the experimental data,the correctness of the new scheme developed in this paper was verified.The results show that the reverse flow phenomenon occurs in the shorter U-tubes.For single U-tube,the mass flow rate of reverse flow is generally greater than that of normal flow U-tube.When the reverse flow occurs,the system will get into a relatively stable state.However,the negative pressure drop between the inlet and outlet plenums and the heat exchange of test section reduce significantly.