Abstract: A gas turbine combustor has homogenous air inflow by elimination of turbulence from the air, reducing combustion instability. A combustor 3 has, at its center, a pilot nozzle 8 and eight main nozzles 7 around the pilot nozzle 8. The air flows in around the individual nozzles 7 and 8 to the leading end of the combustor 3 so that it is used for combustion. An annular flow ring 20, having a semicirculat section, is disposed at the upstream end portion of a combustion cylinder 10, and a porous plate 50 and a surrounding rib 51 are disposed downstream of the flow ring 20. The air inflow is smoothly turned at first by the flow ring 20 and then straightened by the porous plate 50 so that the air flows without any disturbance around the individual nozzles 7 and 8 to the leading end, thereby reducing combustion instability.

Abstract: A split ring is disposed on an inner wall of a gas turbine casing. The split ring is composed of a plurality of split segments that are arranged on the inner wall of the casing in circumferential direction. A predetermined clearance is formed between the inner face of a split segment and the rotor blade tips. The split segments are arranged so that a predetermined circumferential clearance is formed between the split segments in order to allow the thermal expansion of the segments. A circumferential end face located upstream side of the segments with respect to the direction of the rotor blade rotation is connected to the inner face by a transition face having a surface formed as an inclined plane. The inclined plane prevents the swirl flow caused by the rotating rotor blade from impinging the upstream end face and, thereby, suppresses a temperature rise of the split segment at the upstream end face.

Abstract: A gas turbine moving blade is provided which prevents occurrence of cracks caused by thermal stresses due to temperature differences between a blade and a platform while the gas turbine is being stopped. During steady operation time of the moving blade, cooling air enters cooling passages to flow through other cooling passages for cooling the blade, and then to flow out of the blade. A recessed portion having a smooth curved surface is provided in the platform near a blade fitting portion on the blade trailing edge side. A fillet of the blade fitting portion on the blade trailing edge side has a curved surface with curvature larger than that of a conventional blade fitting portion. A hub slot below the fillet, for blowing air, has a cross sectional area larger than other slots of the blade trailing edge. A thermal barrier coating is applied to the blade surface.

Abstract: A split ring is disposed on an inner wall of a gas turbine casing. The split ring is composed of a plurality of split segments that are arranged on the inner wall of the casing in circumferential direction. A predetermined clearance is formed between the inner face of a split segment and the rotor blade tips. The split segments are arranged so that a predetermined circumferential clearance is formed between the split segments in order to allow the thermal expansion of the segments. A circumferential end face located upstream side of the segments with respect to the direction of the rotor blade rotation is connected to the inner face by a transition face having a surface formed as an inclined plane. The inclined plane prevents the swirl flow caused by the rotating rotor blade from impinging the upstream end face and, thereby, suppresses a temperature rise of the split segment at the upstream end face.

Abstract: Gas turbine starting method is improved to start operation with bleed valves being first throttled, then fully opened on the way and then fully closed at 90% speed, thereby fluid unstableness phenomenon is suppressed and starter motor power is reduced. While inlet guide vane (11) and variable stator vanes (C1 to C5) are set to predetermined opening from starting to rated speed, bleed valves (1, 2, 3) are set to predetermined opening until 52% speed for the bleed valve (1) and until 51% speed each for the bleed valves (2, 3), then the bleed valves (1, 2, 3) are fully opened until the speed exceeds 90%, when they are fully closed for rated operation. In the prior art, starting operation is done with bleed valves being first fully opened until the speed is elevated to 90% and then fully closed, but in the present invention, air discharged into ambient air in vain can be reduced and thereby starter motor power can be also reduced.

Abstract: Gas turbine moving blade is improved so as to prevent occurrence of cracks caused by thermal stresses due to temperature differences between blade and platform when gas turbine is stopped. In steady operation time of moving blade (20), cooling air (40 to 43) enters cooling passages (23 to 26) to flow through cooling passages (23a, 24a to 24c, 25a to 25c) for cooling the blade (20) to then flow out of the blade (20). Recessed portion (1) having smooth curved surface is provided in platform (22) near blade fitting portion on blade trailing edge side. Fillet (R) of the blade fitting portion on the blade trailing edge side is formed with curved surface having curvature larger than conventional case. Hub slot below the fillet (R) for blowing air is formed having slot cross sectional area larger than other slots of blade trailing edge. TBC is applied to blade (20) surface.

Abstract: An improved centrifugal fan in which a fan blade is supported by a main plate and a side plate and said main plate is connected to a rotation shaft, characterized in that between the rotation shaft and the main plate, there is interposed a doughnut-shaped connecting plate penetrated by the rotation shaft at the central part thereof, the connecting plate is fixed to the rotation shaft and to the main plate, at the inner and outer circumferential parts of the connecting plate, respectively, a plurality of through holes are provided in the inner and outer circumferential parts of the connecting plate in the circumferential directions, respectively, and slits are formed between each pair of two opposite through holes positioned obliquely with respect to the direction of radius of the connecting plate. Non-reversible displacement of the center of the fan blade is avoided which is a major factor in the vibration of the fan blade.