Steam separator, nuclear power generation plant, and boiler apparatus

A nuclear power generation plant using a boiling-water reactor, said nuclear power generation plant comprising:

• a reactor pressure vessel;
• a plurality of fuel rod assemblies, disposed within said reactor pressure vessel, through which a coolant flows;
• a shroud surrounding said plurality of fuel rod assemblies, wherein a two-phase liquid-vapor flow comprising a liquid-phase component and a vapor-phase component is created as said coolant flows within said plurality of fuel rod assemblies, said shroud including a shroud head at an upper end thereof;
• and
• a separator/injector erected above said shroud head said separator/injector comprising:
• a two-phase flow accelerator nozzle having an inlet portion opening toward the interior of said shroud and an outlet portion positioned higher than said inlet portion, said accelerator nozzle accelerating said two-phase liquid-vapor flow, which is generated in said shroud and flows into said inlet portion, and discharging the same from said outlet portion;
• a liquid-phase capture means connected to said outlet portion of said two-phase flow accelerator nozzle and having a guide wall formed as an inverted U-shape curve, so that said two-phase flow, which is discharged from said outlet portion of said two-phase flow accelerator nozzle, is guided along a wall surface of said guide wall, said liquid-phase capture means imparting centrifugal forces to said vapor-phase component and said liquid-phase component to separate said liquid-phase component from said vapor-phase component, wherein a difference in centrifugal forces imparted to said vapor-phase component and said liquid-phase component of said two-phase flow while said two-phase flow is guided along said guide wall causes said liquid-phase component to be guided along the wall surface of said guide wall and be captured, whereas said vapor-phase component is separated from said guide wall;
• and
• a diffuser into which said liquid-phase component captured by said liquid-phase capture means is allowed to flow, said diffuser increasing the pressure of said liquid-phase component as said liquid-phase component flows therethrough, and discharging said liquid-phase component from an outlet side thereof.

A nuclear power generation plant using a pressurized-water reactor, wherein said nuclear power generation plant comprises:

• a steam generator comprising a heat exchanger formed of heat-exchange pipes having inlets and outlets for a primary coolant, a lower casing surrounding said heat exchanger, and an upper casing connected to said lower casing and having a steam outlet for supplying steam to a turbine;
• a fuel rod assembly;
• a reactor container communicating with said steam generator and surrounding said primary coolant and said fuel rod assembly;
• and
• a separator/injector provided above said lower casing, wherein said separator/injector comprises:
• a two-phase flow accelerator nozzle having an inlet portion opening toward the interior of said lower casing and an outlet portion positioned higher than said inlet portion, said accelerator nozzle accelerating a two-phase flow of said primary coolant that flows into an interior portion thereof from said inlet portion and discharging the same from said outlet portion, said two-phase flow comprising a vapor-phase component and a liquid-phase component;
• a liquid-phase capture means connected to said outlet portion of said two-phase flow accelerator nozzle and having a guide wall formed as an inverted U-shape curve, so that said two-phase flow, which is discharged from said outlet portion of said two-phase flow accelerator nozzle, is guided along a wall surface of said guide wall, said liquid-phase capture means imparting centrifugal forces to said vapor-phase component and said liquid-phase component to separate said liquid-phase component from said vapor-phase component, wherein a difference in centrifugal forces imparted to said vapor-phase component and said liquid-phase component of said two-phase flow while said two-phase flow is guided along said guide wall causes said liquid-phase component to be guided along the wall surface of said guide wall and be captured, whereas said vapor-phase component is separated from said guide wall;
• and
• a diffuser into which said liquid-phase component captured by said liquid-phase capture means is allowed to flow, said diffuser increasing the pressure of said liquid-phase component as said liquid-phase component flows therethrough, and discharging said liquid-phase component from an outlet side thereof.

A boiler apparatus comprising:

• a heat exchanger comprising heat-transfer tubes;
• a combustor that heats said heat-transfer tubes;
• a pressure vessel surrounding said heat-transfer tubes and said combustor;
• a recirculation pump that recirculates a fluid flowing through said pressure vessel;
• and
• a separator/injector provided above said heat-transfer tubes said separator/injector comprising:
• a two-phase flow accelerator nozzle having an inlet portion opening toward the interior of said pressure vessel and an outlet portion positioned higher than said inlet portion, said accelerator nozzle accelerating a two-phase liquid-vapor flow flowing into said inlet portion thereof from said heat exchanger, and discharging the same from said outlet portion, said two-phase flow comprising a vapor-phase component and a liquid-phase component;
• a liquid-phase capture means connected to said outlet portion of said two-phase flow accelerator nozzle and having a guide wall formed as an inverted U-shape curve, so that said two-phase flow, which is discharged from said outlet portion of said two-phase flow accelerator nozzle, is guided along a wall surface of said guide wall, said liquid-phase capture means imparting centrifugal forces to said vapor-phase component and said liquid-phase component to separate said liquid-phase component from said vapor-phase component, wherein a difference in centrifugal forces imparted to said vapor-phase component and said liquid-phase component of said two-phase flow while said two-phase flow is guided along said guide wall causes said liquid-phase component to be guided along the wall surface of said guide wall and be captured, whereas said vapor-phase component is separated from said guide wall;
• and
• a diffuser into which said liquid-phase component captured by said liquid-phase capture means is allowed to flow, said diffuser increasing the pressure of said liquid-phase component as said liquid-phase component flows therethrough, and discharging said liquid-phase component from an outlet side thereof.