Abstract: In this paper, the operation conditions of Venturi scrubbers in nuclear power plants is simulated with a CFD numerical simulation method. The influence of the change of air flow velocity and system pressure on the ejection volume was analyzed. Combined with the experiment method, the influence of the ejection capacity of the Venturi scrubber on iodine removal efficiency was discussed, and some guiding suggestions for the discharge conditions of the containment filtration and discharge system of a nuclear power plant were put forward. The results show that increasing air flow velocity can increase the injection amount, and the injection amount presents an approximate linear growth relationship. Meanwhile, the pressure difference between the inside and outside of the suction tube presents an approximate parabola law. The iodine removal efficiency of the system is consistent with the increasing trend of the injection amount in the initial stage, and then tends to be stable after the injection amount reaches a certain level. In order to ensure a high iodine removal efficiency, the exhaust air flow of the system should be kept above 3 300 m³/h. In the range of 0.1 to 0.5 MPa system pressure, the iodine removal efficiency can be maintained at a high level. The increase of pressure is helpful to the increase of ejection capacity, and the increase is more obvious in the high flow area.

Key words: containment, Venturi scrubber, numerical simulation, performance of iodine removal