A system for deriving 100% quality steam for steam assisted gravity drainage (SAGD) injection or other applications features a once through steam generator (OTSG), a steam-water separator connected downstream of the OTSG's radiant tubes to separate steam and water from a two-phase flow received therefrom, superheater tubes installed in the convection section and connected to a steam outlet of the steam-water separator in downstream relation thereto to receive and heat dried steam therefrom to a superheated state, and a desuperheater connected downstream of the superheater tubes to receive the superheated steam therefrom and use same to vaporize blowdown water from the steam-water separator, whereby the vaporized blowdown water and the superheated steam collectively form a superheated steam output for the intended application, typically after additional separation of solid particles therefrom for optimal steam quality.

A steam supply system having a wet steam source and a steam separator disposed to separated wet steam into dry saturated steam and a saturated condensate. The dry saturated steam is heated in a superheater to produce superheated steam, while the saturated condensate is cooled in a subcooler to produced subcooled condensate with a target temperature selected to prevent immediate evaporation of the subcooled condensate when mixed with the superheated steam. The subcooled condensate is sprayed into a stream of superheated steam using spray nozzles and gradually evaporates downstream of the spray nozzles to produce process steam of a desired % quality. A cooling fluid passing through the subcooler is utilized to cool the saturated condensate. The flow rate of the cooling fluid through the subcooler can be utilized to achieve process steam of a desired % quality.

A steam supply system having a wet steam source and a steam separator disposed to separated wet steam into dry saturated steam and a saturated condensate. The dry saturated steam is heated in a superheater to produce superheated steam, while the saturated condensate is cooled in a subcooler to produced subcooled condensate with a target temperature selected to prevent immediate evaporation of the subcooled condensate when mixed with the superheated steam. The subcooled condensate is sprayed into a stream of superheated steam using spray nozzles and gradually evaporates downstream of the spray nozzles to produce process steam of a desired % quality. A cooling fluid passing through the subcooler is utilized to cool the saturated condensate. The flow rate of the cooling fluid through the subcooler can be utilized to achieve process steam of a desired % quality.

A steam-temperature control device for a gas- and steam turbine plant, including a feed water line, a feed-water control valve located in the feed water line and a water injection line which branches off from the feed water line upstream of the feed-water control valve in the flow direction of said water and which opens into an injection cooler is provided. The steam-temperature control device is characterized in that a pre-heating device for the injection water is connected in the water injection line. A method for controlling the steam temperature in a gas- and steam turbine plant is also provided.

The present application provides a combined cycle system. The combined cycle system may include a heat recovery steam generator, a feedwater source positioned upstream of the heat recovery steam generator, a desuperheater positioned downstream of the heat recovery steam generator, a first extraction from the heat recovery steam generator to the desuperheater, and a second extraction from upstream of the heat recovery steam generator to the desuperheater.

A multi-cone, multi-stage spray nozzle includes a nozzle body, a valve stem with a first valve head, and a second valve head attached to the first valve head. The first valve stem is biased into a closed position against a valve seat of the nozzle body by a bias device. The second valve head is continuously open. Upon the application of a first fluid pressure, which is less than a threshold fluid pressure, the bias device maintains the valve stem in the closed position while the second valve head is continuously open. And upon the application of a second fluid pressure, which is at least as great as the threshold fluid pressure, the valve stem moves to an open position while the second valve head remains continuously open.

A multi-cone, multi-stage spray nozzle includes a nozzle body and outer and inner valve stems. The nozzle body defines an outer valve seat disposed at its distal end. The outer valve stem is slidably disposed in the nozzle body. The inner valve stem is slidably disposed in the outer valve stem. The inner valve stem occupies an open position and the outer valve stem occupies a closed position upon the application of a first pressure on the distal ends of the inner and outer valve stems. And, the inner and outer valve stems both occupy open positions upon the application of a second pressure that is greater than the first pressure on the distal ends of the inner and outer valve stems.

The present disclosure introduces a nozzle apparatus and method. In one embodiment, a spray nozzle apparatus is described. The spray nozzle apparatus includes a plurality of flow channels formed by the combination of a: sprayhead, a major element, and a minor element. The sprayhead may have a plurality of holes. The major element is retained within the sprayhead by a nozzle nut and spring, allowing a first annular gap to form between the sprayhead and the major element. The minor element is retained within the major element by a second nozzle nut and second spring, allowing a second annular gap to form between the major element and the minor element. The minor element may have an axial hole. Other embodiments also are described.

A steam assisted ring style desuperheater includes a ring body defining an axial flow path and one or more spray nozzles extending through a wall of the ring body. Each of the nozzles is connected to a separate cooling water manifold and atomizing steam manifold to conduct cooling water and atomizing steam separate from each other through the spray nozzle to an injection point. An atomizing head of each nozzle combines the cooling water and atomizing steam to form a spraywater cloud that is injected radially into the axial flow path. The spray nozzles include one or more flow passage inserts that define separate first and second fluid flow paths for conducting the cooling water and the atomizing steam separately through the spray nozzle.

The present disclosure introduces a nozzle apparatus and method. In one embodiment, a spray nozzle apparatus is described. The spray nozzle apparatus includes a plurality of flow channels formed by the combination of a: sprayhead, a major element, and a minor element. The sprayhead may have a plurality of holes. The major element is retained within the sprayhead by a nozzle nut and spring, allowing a first annular gap to form between the sprayhead and the major element. The minor element is retained within the major element by a second nozzle nut and second spring, allowing a second annular gap to form between the major element and the minor element. The minor element may have an axial hole. Other embodiments also are described.