A steam generator for converting a fluid to steam includes a combustion chamber for receiving a combustion fuel into the combustion chamber. A steam chamber surrounds and is heated by the combustion chamber to a temperature exceeding a vaporization temperature of the fluid. A heat exchanging chamber surrounds and is heated by residual heat of the steam chamber. A preheating coil is disposed within the heat exchanging chamber and has a fluid inlet for receiving the fluid under pressure into the preheating coil for preheating the fluid within the heat exchanging chamber. An injector communicates with the preheating coil and the steam chamber for injecting a controlled flow of the preheated fluid under pressure into the steam chamber where it flashes to steam and is super-heated to the temperature of the steam chamber. A steam outlet conveys the super-heated steam externally of the steam generator.

Disclosed is: A casing of a heat recovery steam generator has a sidewall, and heat exchanger coil located therein capable of exchanging heat from hot exhaust gas flow into the casing, with a gap between the end of the coil and a sidewall. A baffle system for closing the gap after the coil is installed in the casing comprises a mount attached to the coil near the gap, and a baffle plate associated with the mount and movably supported thereby. The configuration of the mount and baffle plate are such to allow the baffle plate to be capable of moving from a retracted position withdrawn from the sidewall, to an extended position closing the gap. A retainer can hold the plate in the retracted position. The retainer can release, for example, by being temperature sensitive. The mount can have a support that engages the coil.

The erosion-prone sections of the tubes in a circulating fluidized bed boiler are provided with a locally thickened sidewall without forming discontinuities on the outer surface of the tubes. This can be accomplished, for example, by replacing the erosion prone portion of the tube with a section having a smaller inside diameter, but the same outside diameter, or by replacing the erosion prone portion of the tube with a section having a thicker sidewall, but the same inside diameter, and smoothing over the outside discontinuity with an alloy coating. A useful alloy coating is also disclosed which can be used for this and other applications.

The erosion-prone sections of the tubes in a circulating fluidized bed boiler are provided with a locally thickened sidewall without forming discontinuities on the outer surface of the tubes. This can be accomplished, for example, by replacing the erosion prone portion of the tube with a section having a smaller inside diameter, but the same outside diameter, or by replacing the erosion prone portion of the tube with a section having a thicker sidewall, but the same inside diameter, and smoothing over the outside discontinuity with an alloy coating. A useful alloy coating is also disclosed which can be used for this and other applications.

A superheater (e.g., a radiant superheater or a convention superheater) may include carbon nanotubes. A superheater may be arranged to, for example, hang at an upper portion of a furnace of a boiler. The superheater may be substantially planar and may include a first vertical pass, a first connection pass, a second vertical pass, a third vertical pass, a second connection pass, and a fourth vertical pass. Each vertical pass may include an upper end and a lower end. The vertical passes may be connected in series, so that steam to be superheated enters at the upper end of the first vertical pass and flows through the first vertical pass and from the lower end of the first vertical pass via the first connection pass to the lower end of the second vertical pass and through the second vertical pass and from the upper end of the second vertical pass to the upper end of the third vertical pass and through the third vertical pass and from the lower end of the third vertical pass via the second connection pass to the lower end of the fourth vertical pass and through the fourth vertical pass, to be discharged from the upper end of the fourth vertical pass. The first connection pass may be arranged below the second connection pass so as to shield the second connection pass from radiation from the lower portion of the furnace.

A system includes a radiant syngas cooler which receives and cools syngas generated in a gasifier. The radiant syngas cooler includes an outer shell of the radiant syngas cooler defining an annular space of the radiant syngas cooler and a heat exchange tube of the radiant syngas cooler positioned within the annular space and configured to flow a cooling medium. The heat exchange tube is configured to enable heat exchange between the syngas and the cooling medium to cool the syngas. The radiant syngas cooler includes a downcomer tube of the radiant syngas cooler which supplies the cooling medium to the heat exchange tube, where the downcomer tube includes a downflow portion positioned outside of the annular space of the radiant syngas cooler. The downflow portion is fluidly coupled to a header, and the header fluidly couples the downcomer tube to the heat exchange tube.

A steam generator is provided. The steam generator has a combustion chamber having a peripheral wall formed at least partially from gas-proof, welded steam generator pipes, at least two additional inner walls formed at least partially from additional steam generator pipes which are arranged inside the combustion chamber. The inner walls are connected one behind the other on the flow medium side by an intermediate collector. The steam generator has a high service life and is reliable. The flow medium on the inlet of the inner wall upstream of the intermediate collector has a lower temperature than that of the flow medium on an inlet of the peripheral wall.

A steam generator is provided. The steam generator has a combustion chamber having a peripheral wall formed at least partially from gas-proof, welded steam generator pipes, at least two additional inner walls formed at least partially from additional steam generator pipes which are arranged inside the combustion chamber. The inner walls are connected one behind the other on the flow medium side by an intermediate collector. The steam generator has a high service life and is reliable. The flow medium on the inlet of the inner wall upstream of the intermediate collector has a lower temperature than that of the flow medium on an inlet of the peripheral wall.

Embodiments of the invention provide a water-cooled column formed by side walls connected together to define an enclosed space, each side wall is formed of a water-cooled membrane wall, a working medium is passed through a tube of the water-cooled membrane wall from bottom to top, the water-cooled column comprising: a lower part having a cross section reduced segment, which has a cross section gradually reduced in a direction from bottom to top; and an upper part, wherein the upper part connects with the cross section reduced segment at a connection position, and a cross sectional area of the cross section reduced segment at the connection position is identical to a cross sectional area of the upper part at the connection position. Embodiments of the invention also provide a furnace for defining a reaction space, which comprises a water-cooled column defined as above disposed along a vertical direction therein.

Embodiments of the invention provide a water-cooled column formed by side walls connected together to define an enclosed space, each side wall is formed of a water-cooled membrane wall, a working medium is passed through a tube of the water-cooled membrane wall from bottom to top, the water-cooled column comprising: a lower part having a cross section reduced segment, which has a cross section gradually reduced in a direction from bottom to top; and an upper part, wherein the upper part connects with the cross section reduced segment at a connection position, and a cross sectional area of the cross section reduced segment at the connection position is identical to a cross sectional area of the upper part at the connection position. Embodiments of the invention also provide a furnace for defining a reaction space, which comprises a water-cooled column defined as above disposed along a vertical direction therein.