A method for operating a forced-flow steam generator constructed as a waste-heat steam generator having a pre-heater, including pre-heater heating surfaces, and having an evaporator including evaporator heating surfaces connected downstream on the flow medium side of the pre-heater heating surfaces. A device for adjusting a feed water mass flow has a set point for the feed water mass flow. During the creation of the set point for the feed water mass flow, a waste-heat flow transferred to a fluid in the evaporator heating surfaces is determined, and mass storage and energy storage in the fluid in the evaporator heating surfaces is detected during non-steady-state plant operation. A behaviour over time of a mass storage in the evaporator is coupled with a behaviour over time of a mass storage in the pre-heater, wherein scaling is carried out with a ratio of the density changes in the evaporator and pre-heater.

Disclosed is a Once-Through Steam Generator (OTSG) coil (52) and method, comprising a plurality of vertically arranged serpentine conduits (90) in a horizontal heat recovery steam generator (HRSG) that replaces a traditional natural circulation HP evaporator for producing super-critical steam. The OTSG comprises a lower equalization header system (130) that promotes system stability in multiple operating conditions. The equalization header allows a partial flow of fluid from the lower serpentine curved flow path (120) through an equalization conduit (125) into the equalization header (130) Disclosed also are: a flow restriction device in serpentine conduits; drainage structure from serpentine conduits through the equalization header, a drainage expansion section to accommodate stresses, and drainage bypass connections; and flow through serpentine conduits in upstream and downstream directions, mixed flow directions and longitudinally staggered directions.

A method for operating a forced-flow steam generator constructed as a waste-heat steam generator having a pre-heater, including pre-heater heating surfaces, and having an evaporator including evaporator heating surfaces connected downstream on the flow medium side of the pre-heater heating surfaces. A device for adjusting a feed water mass flow has a set point for the feed water mass flow. During the creation of the set point for the feed water mass flow, a waste-heat flow transferred to a fluid in the evaporator heating surfaces is determined, and mass storage and energy storage in the fluid in the evaporator heating surfaces is detected during non-steady-state plant operation. A behaviour over time of a mass storage in the evaporator is coupled with a behaviour over time of a mass storage in the pre-heater, wherein scaling is carried out with a ratio of the density changes in the evaporator and pre-heater

Disclosed is a Once-Through Steam Generator (OTSG) coil (52) and method, comprising a plurality of vertically arranged serpentine conduits (90) in a horizontal heat recovery steam generator (HRSG) that replaces a traditional natural circulation HP evaporator for producing supercritical steam. The OTSG comprises a lower equalization header system (130) that promotes system stability in multiple operating conditions. The equalization header allows a partial flow of fluid from the lower serpentine curved flow path (120) through an equalization conduit (125) into the equalization header (130) Disclosed also are: a flow restriction device in serpentine conduits; drainage structure from serpentine conduits through the equalization header, a drainage expansion section to accommodate stresses, and drainage bypass connections; and flow through serpentine conduits in upstream and downstream directions, mixed flow directions and longitudinally staggered directions.

A heat transfer tube for a boiler, an interior of the heat transfer tube having a supercritical pressure and being configured to have a heating medium flow therethrough, includes: a groove portion defined on an inner circumferential surface and having a spiral shape extending continuously toward a tube axis direction; and a rib portion extending continuously and protruding inward in a radial direction by the groove portion of the spiral shape. In a cross section taken along the tube axis direction, a width of the groove portion in the tube axis direction is defined as Wg, a height of the rib portion in the radial direction is defined as Hr and a tube outer diameter is defined as D, and the width Wg of the groove portion, the height Hr of the rib portion, and the tube outer diameter D satisfy Wg/(Hr.Math.D)>0.40.

An evaporator includes an introducing portion that introduces a heat source gas from a heat source gas pipe, a heat source gas passage through which the heat source gas introduced from the introducing portion flows, a heating portion that is disposed in the heat source gas passage and at which a working fluid is heated by the heat source gas, an increasing portion at which a cross-sectional area of the heat source gas passage gradually increases from an upstream side towards a downstream side in the heat source gas passage, and a flow regulating plate that is disposed on an upstream side from the heating portion in the heat source gas passage and that has a plurality of holes which allow the heat source gas to pass through the plurality of holes.

A supercritical steam generator includes a downdraft furnace enclosure, a hopper tunnel, and a convection pass enclosure, with the hopper tunnel joining the downdraft furnace enclosure and convection pass enclosure together. Flue gas passes down through the downdraft furnace enclosure through the hopper tunnel and up through the convection pass enclosure. This structure permits the outlet steam terminals, which provide access to the resultant supercritical steam and/or reheat steam, to be located at a base of the steam generator rather than at the top of the steam generator as with conventional boilers. This reduces the length of the steam leads from the steam generator to a steam turbine that produces electricity using the supercritical steam.

A steam generator apparatus for generating steam from a feedwater inlet stream including impurities is disclosed. The apparatus includes a tubing circuit in communication with an inlet for receiving the feedwater stream, the tubing circuit having a substantially unrifled bore defined by a metal wall, and a heat source operable to deliver a heat flux to the feedwater stream through the metal wall of the tubing circuit, the heat flux being operable to cause evaporation of feedwater within the tubing circuit and to produce an outlet stream at an outlet of the tubing circuit, the outlet stream includes a steam portion and liquid phase portion, the steam portion being greater than about 80% of the outlet stream by mass, the steam portion providing sufficient cooling of the metal wall to maintain a wall temperature at less than a threshold temperature associated with safe operation of the steam generator apparatus.

The instant disclosure provides a method of generating steam for the recovery of hydrocarbon from a hydrocarbon producing system including (i) generating supercritical steam from water; (ii) converting the supercritical steam to a subcritical steam; and (iii) injecting the subcritical steam into the system.

An evaporator includes an introducing portion that introduces a heat source gas from a heat source gas pipe, a heat source gas passage through which the heat source gas introduced from the introducing portion flows, a heating portion that is disposed in the heat source gas passage and at which a working fluid is heated by the heat source gas, an increasing portion at which a cross-sectional area of the heat source gas passage gradually increases from an upstream side towards a downstream side in the heat source gas passage, and a flow regulating plate that is disposed on an upstream side from the heating portion in the heat source gas passage and that has a plurality of holes which allow the heat source gas to pass through the plurality of holes.