Thermal hydraulic performance analysis of a double tube bundle steam generator for a liquid metal reactor

In this study, thermal-hydraulic performance of a double tube bundle steam generator (DTBSG) using helically coiled tubes was analyzed numerically. For this purpose a one-dimensional thermal-hydraulic analysis computer program was developed.The DTBSG contains hot fluid and cold fluid tube bundles, a medium fluid and a pump for a medium fluid circulation in an SG. Heat is transferred from the hot side to the cold side through a medium fluid which fills the SG shell side. The fluids of the hot, cold and medium side are sodium, water/steam, lead–bismuth respectively. The assessment was made for four different types of the DTBSG at 200 MWt. It showed there is an optimum medium flow rate for each type and the separated bundle type have the best heat transfer efficiency (heat transfer rate per unit area) among the various DTBSG. However, it requires quite a large pumping power and the velocity of the medium fluid. The effect of a medium flow rate change is relatively small in the integrated bundle types while it is very large in the separated type.The developed program can be used for the optimum thermal design of a double tube bundle steam generator, which is one of the candidates for an Intermediate Heat Transport System (IHTS) simplification concept.

► Thermal-hydraulic performance of the double tube bundle steam generators was analyzed.
► A numerical method was used with considering properties variation and phase change.
► The separated types are about two times more efficient than the integrated types.
► The integrated types have good heat transfer rate even during small medium flow rate.