Effect of velocity and pressure on performance of a full-scale SG steam separator package

Abstract

Steam separator package including swirl-vane separator, gravity and dryer is crucial for supplying the qualified steam for the turbines in nuclear steam generator (SG). In this paper, steam-water experiments are carried out to study the separation efficiency, moisture carryover (MCO) and pressure loss of a full-scale SG steam separator package of the GEN-III advanced PWR. The system pressure ranges from 2 to 6 MPa and the superficial velocities of the steam jg and water jl are 1.47–5.91 m/s and 0.18–1.05 m/s, respectively. At rated pressure of 6 MPa, the results indicate that the separation efficiency of swirl-vane separator is insensitive to jg at low jl but decreases with jg at high jl. Generally, a larger jl causes a higher efficiency. Nevertheless, both the influence of jg and jl on the separation efficiency of gravity and dryer is minor. The MCO of swirl-vane separator and gravity decreases with jg increasing or jl decreasing whereas the residual wetness at dryer exit exhibits minor change with jg and jl. The pressure loss of swirl-vane separator increases with both jg and jl increasing while it increases gradually with jg but shows slight change with jl in the dryer. Overall, a higher pressure leads to a lower separation efficiency of swirl-vane separator and gravity but a higher dryer efficiency, a lower MCO and a higher-pressure loss of the whole separator package. Considering the effect of velocity and pressure, empirical correlations are proposed to predict the performance of swirl vanes, which are the key components for the separation performance and pressure loss.