Effect of thermal-hydraulic parameters and pH on the corrosion product deposition in steam generator based on CFD

The deposition of corrosion products in the primary circuit of a pressurized water reactors is known to have an adverse impact on reactor system’s performance, which can cause localized corrosion. They can also impede the flow of coolant, or in severe cases block the tube channels. Besides, the deposits have a lower thermal conductivity than the structural materials, which may increase the thermal resistance, thus reducing heat transfer efficiency. Despite the presence of a considerable amount of corrosion products in steam generators, research on the deposition of corrosion products within is still insufficient. A comprehensive 3-D model of thermal–hydraulic and chemical processes was used to investigate the factors affecting the deposition of corrosion products in a steam generator. For the purpose of determine the deposition distribution along the heat transfer tube, the tube was separated into 11 main nodes based on the equal temperature differences according to the thermal–hydraulic data calculated. The simulation results indicate that the deposition thickness is sensitive to coolant temperature, flow velocity and pH value, and it was shown that higher temperature(from 560 K to 600 K decreasing 9.31 %), pH value (from 6.5 to 8.0 decreasing 9.92 %) and lower flow velocity (from 5 m/s to 20 m/s increasing 8.13 %)was effective for reducing the corrosion product deposition due to the physicochemical properties of the coolant and the turbulent flow, while working pressure has less influence on it(from 6 MPa to 15 MPa increasing only 1.03 %).