Series flow through reheater hairpins improves efficiency - HP steam of reactor passes through longer hairpin bank thence inner rank

摘要

In a vapour reheater as used to reheat the HP/LP steam of a nuclear power station, where the vapour to be reheated is outside the hairpin tubes tubes and the high temp. vapour (steam) is inside the tubes, the hot vapour flows first through the longer outer tubes of the hairpin tube bundle and then, in series, through the inner thermally lighter loaded hairpins. Used with a vapour (steam) reheater as used on BWR, PWR reactors to reheat the steam after the HP or LP turbines. Results in redn. of the risk of reflux of condensate in outer tubes due to higher heat transfer loading on these outer tubes, partic. during sudden increase in flow on the LP side.