Abstract

Thermal stratification is a well-known phenomenon in pressurizer surge line of pressurized water reactor. The pressurizer surge line has a complex geometry it runs down vertically and horizontally with varying slopes and curvatures connecting pressurizer with the hot leg of the primary loop. The significant thermal stratification is usually observed in horizontal sections of the pressurizer surge line during reactor starting up phase (heat up) from cold shut down condition. To study the thermal stratification phenomenon a simple horizontal pipe model is considered. The pressurizer surge line is typically a 250 to 350 mm diameter stainless steel pipe. The dimensions of horizontal pipe are selected on the basis of pressurizer surge line dimensions. The horizontal pipe model inner diameter is 305 mm with thickness of 33.5 mm and length of four diameters. The transient analysis is performed using commercially available software ANSYS CFX with three different turbulence models (K-E, RNG K-E and SST). The transient temperature distribution along the horizontal pipe with different turbulence models is represented in this study. The transient temperatures obtained vary with selection of different turbulence models. Among the three different turbulence models, KE turbulence model predicts the lowest top to bottom inner and outer wall surfaces temperature differences.

Keywords:

Pressurizer surge line, thermal stratification, turbulence models,

References

Competing interests

The authors have no competing interests.

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Copyright

The authors have no competing interests.