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

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.