Consolidated nuclear steam generator

Claim 2

In a nuclear power generating system having separate flow paths for a primary and a secondary fluids the improvement comprising a plurality of modular heat exchanger units, each of said units having a steam header and a feedwater header spaced from each other, a pair of tube sheets spaced from each other and joined to individual headers to form a feedwater inlet chamber and a steam discharge chamber with said respective headers, a feedwater tube passing through said steam discharge chamber tube sheet and attached to said feedwater inlet tube sheet to establish fluid communication with said feedwater inlet chamber, a plurality of tubes establishing fluid communication between said feedwater inlet chamber and said steam discharge chamber, a concentrically disposed shroud that is spaced outwardly from said communicating feedwater tube, said shroud having ends received in said tube sheets, the primary and secondary flow paths being countercurrent relative to each other, each of said tubes in said plurality of tubes terminating in two ends, each of said ends being secured to a respective one of said tube sheets, a nuclear reactor pressure vessel enclosing said plurality of modular heat exchangers, and a feedwater inlet manifold penetrating said pressure vessel, said feedwater manifold being in fluid communication with more than one of said modular heat exchanger units through individual conduits to allow for thermal expansion and contraction of said units.

Claim 3

The system of claim 1 wherein portions adjacent to the ends of each of said tubes in said tube plurality are swaged to a reduced diameter relative to the diameter of the central portion of each of said tubes.

Claim 4

The system of claim 1 further comprising a steam outlet manifold, said steam manifold being in fluid communication with at least some of said modular heat exchanger steam discharge chambers.

Claim 5

In a nuclear power generating system having separate flow paths for a primary and a secondary fluids the improvement comprising a plurality of modular heat exchanger units, each of said units having a steam header and a feedwater header spaced from each other, a pair of tube sheets spaced from each other and joined to individual headers to form a feedwater inlet chamber and a steam discharge chamber with said respective headers, a feedwater tube passing through said steam discharge chamber to establish fluid communication with said feedwater inlet chamber, a plurality of tubes establishing fluid communication between said feedwater inlet chamber and said steam discharge chamber, a concentrically disposed shroud that is spaced outwardly from said communicating feedwater tube, said shroud having ends received in said tube sheets, the primary and secondary flow paths being countercurrent relative to each other, each of said tubes in said plurality of tubes terminating in two ends, each of said ends being secured to a respective one of said tube sheets, a nuclear reactor pressure vessel enclosing said plurality of modular heat exchangers, a feedwater inlet manifold penetrating said pressure vessel, said feedwater manifold being in fluid communication with more than one of said modular heat exchanger units through individual conduits to allow for thermal expansion and contraction of said units, and another feedwater inlet manifold penetrating said pressure vessel having a return bend outside said pressure vessel and establishing fluid communication between said feedwater manifolds.

Claim 6

In a nuclear power generating system having separate flow paths for a primary and a secondary fluids the improvement comprising a plurality of modular heat exchanger units, each of said units having a steam header and a feedwater header spaced from each other, a pair of tube sheets spaced from each other and joined to individual headers to form a feedwater inlet chamber and a steam discharge chamber with said respective headers, a feedwater tube passing through said steam discharge chamber to establish fluid communication with said feedwater inlet chamber, a plurality of tubes establishing fluid communication between said feedwater inlet chamber and said steam discharge chamber, a concentrically disposed shroud that is spaced outwardly from said communicating feedwater tube, said shroud having ends received in said tube sheets, the primary and secondary flow paths being countercurrent relative to each other, each of said tubes in said plurality of tubes terminating in two ends, each of said ends being secured to a respective one of said tube sheets, a nuclear reactor pressure vessel enclosing said plurality of modular heat exchangers, a feedwater inlet manifold penetrating said pressure vessel, said feedwater manifold being in fluid communication with more than one of said modular heat exchanger units through individual conduits to allow for thermal expansion and contraction of said units, and another feedwater inlet manifold penetrating said pressure vessel having a return bend outside said pressure vessel and establishing fluid communication between said feedwater manifolds.

Claim 7

The system according to claim 4 further comprising another steam outlet manifold, a return bend outside said pressure vessel and establishing fluid communication between said steam manifolds.