A method for installing a heat recovery steam generator (1) with a plurality of pre-assembled modules (10) includes arranging a pre-assembled module (10) at an installation site. The pre-assembled module (10) includes a functional unit of the heat recovery steam generator (1) housed in a casing structure (12). The casing structure (12) includes a top casing (12a), a bottom casing (12b) and a side casing (12c). An open side (15) is defined opposite to the side casing (12c). The module (10) is arranged horizontally at the installation site with the open side (15) facing downward and the side casing (12c) facing upward. The method includes attaching a structural steel (13) to the side casing (12c) in a horizontal position without lifting the module (10). The module (10) with the attached structural steel (13) is lifted to a vertical position and secured to a foundation (60). Also described is a method for pre-assembling the module (10) and a method for transporting the pre-assembled module (10) to the installation site.

In the case of a method for the heat treatment of erected, preferably large-area tube wall regions or tube wall segments, in particular of a diaphragm wall, of a steam generator, in particular of a power plant, in the installed state, it is sought to provide a solution which permits the use of steel types which are more problematic with regard to power plant operation with elevated steam parameters, in particular the steels T23 and T24, in the erection of steam generators. This is achieved in that the tube wall regions or tube wall segments for heat treatment are subjected, in the installed state in the steam generator, and in particular over a large area, to a stress-relief annealing process.

In the case of a method for the heat treatment of erected, preferably large-area tube wall regions or tube wall segments, in particular of a diaphragm wall, of a steam generator, in particular of a power plant, in the installed state, it is sought to provide a solution which permits the use of steel types which are more problematic with regard to power plant operation with elevated steam parameters, in particular the steels T23 and T24, in the erection of steam generators. This is achieved in that the tube wall regions or tube wall segments for heat treatment are subjected, in the installed state in the steam generator, and in particular over a large area, to a stress-relief annealing process.

A method for improving effectiveness of a steam generator system includes providing air to an air preheater in excess of that required for combustion of fuel and providing the air at a mass flow such that the air preheater has a cold end metal temperature that is no less than a water dew point temperature in the air preheater and such that the cold end metal temperature is less than a sulfuric acid dew point temperature. The method includes mitigating SO.sub.3 in the flue gas which is discharged directly from the air preheater to a particulate removal system and then directly into a flue gas desulfurization system. Flue gas reheat air is fed from the air preheater to heat the flue gas prior to entering a discharge stack to raise the temperature of the flue gas to mitigate visible plume exiting and to mitigate corrosion in the discharge stack.

A method for improving effectiveness of a steam generator system includes providing air to an air preheater in excess of that required for combustion of fuel and providing the air at a mass flow such that the air preheater has a cold end metal temperature that is no less than a water dew point temperature in the air preheater and such that the cold end metal temperature is less than a sulfuric acid dew point temperature. The method includes mitigating SO.sub.3 in the flue gas which is discharged directly from the air preheater to a particulate removal system and then directly into a flue gas desulfurization system. Flue gas reheat air is fed from the air preheater to heat the flue gas prior to entering a discharge stack to raise the temperature of the flue gas to mitigate visible plume exiting and to mitigate corrosion in the discharge stack.

A power plant is suggested with an additional heat transfer between the flue gas that flows through a flue gas line (5) and the feed-water in a feed-water line (19). The claimed arrangement of the first heat exchanger (13) upstream and adjacent to a precipitator (7) leads to a reduced space demand and optimizes dust precipitation as well as the pressure drop of the flue gas.

A multi-tube inspection system with a reel having a plurality of cameras is placed in the upper header. Each camera is attached to its own lead line and has a light source. An inspector, located in the upper header, aligns each camera with a tube and then operates the reel to simultaneously lower the cameras through their respective tube. As the cameras pass through the tubes, they capture a video image of the interior length of the tube. The video image is stored and relayed to a control center where additional inspectors can review the video image of the interior of the tube. Each video is identified and tied back to the tube in a data base. If a defect is identified, the tube can be taken out of service (blocked off) or scheduled for cleaning. Once cleaned, the tube is then reinspected.

A multi-tube inspection system with a reel having a plurality of cameras is placed in the upper header. Each camera is attached to its own lead line and has a light source. An inspector, located in the upper header, aligns each camera with a tube and then operates the reel to simultaneously lower the cameras through their respective tube. As the cameras pass through the tubes, they capture a video image of the interior length of the tube. The video image is stored and relayed to a control center where additional inspectors can review the video image of the interior of the tube. Each video is identified and tied back to the tube in a data base. If a defect is identified, the tube can be taken out of service (blocked off) or scheduled for cleaning. Once cleaned, the tube is then reinspected.

A steam dispersion system including insulation is disclosed. The steam dispersion system may include a steam dispersion tube with at least one opening defined on an outer surface of the steam dispersion tube and a hollow interior. The insulation covers at least a portion of the steam dispersion tube, the insulation defining an opening aligned with the opening of the steam dispersion tube, wherein the insulation meets 25/50 flame/smoke indexes for UL723/ASTM E-84 and has a thermal conductivity less than about 0.35 Watts/mK (2.4 inhr/ft2 deg F.). A nozzle defining a throughhole may be placed within the opening of the steam dispersion tube, the throughhole being in fluid communication with the hollow interior of the steam dispersion tube to provide a steam exit.

A steam dispersion system including insulation is disclosed. The steam dispersion system may include a steam dispersion tube with at least one opening defined on an outer surface of the steam dispersion tube and a hollow interior. The insulation covers at least a portion of the steam dispersion tube, the insulation defining an opening aligned with the opening of the steam dispersion tube, wherein the insulation meets 25/50 flame/smoke indexes for UL723/ASTM E-84 and has a thermal conductivity less than about 0.35 Watts/mK (2.4 inhr/ft2 deg F.). A nozzle defining a throughhole may be placed within the opening of the steam dispersion tube, the throughhole being in fluid communication with the hollow interior of the steam dispersion tube to provide a steam exit.