Abstract: A turbomachine assembly includes a number of circumferentially spaced rotor blades, a number V of circumferentially spaced guide vanes axially adjacent to the rotor blades, an annular chamber surrounding the rotor blades, and an intake and exhaust for receiving and discharging air that passes through the annular chamber. When the turbomachine is in operation, spinning mode tones are generated by the interaction of the rotor and guide vanes. These tones are minimized by selecting a number of vanes relative to the number of blades so that selected tones propagate axial to the intake and exhaust of the turbomachine. A sound absorptive material is then positioned so that the tones impinge upon it. Moreover, a tuned duct is positioned in the path of the remaining tones. The turning vanes, placed within the tuned duct, cancel the remaining tones travelling through the duct.

Abstract: The gas from combustion or gasification of fossil fuel contains flyash and other particulate. The flyash is separated from the gas in a plurality of standleg moving granular-bed filter modules. Each module includes a dipleg through which the bed media flows into the standleg. The bed media forms a first filter bed having an upper mass having a first frusto-conical surface in a frusto-conical member at the entrance to the standleg and a lower mass having a second frusto-conical surface of substantially greater area than the first surface after it passes through the standleg. A second filter media bed may be formed above the first filter media bed. The gas is fed tangentially into the module above the first surface. The flyash is captured on the first frusto-conical surface and within the bed mass. The processed gas flows out through the second frusto-conical surface and then through the second filter bed, if present.

Abstract: A semi-closed steam turbine power system and method of operation which employs a combustor which injects and combusts hydrogen fuel and oxygen oxidant in a stoichiometric ratio so that the primary by-product of the combustion process is H.sub.2 O. The system also includes a recuperator, fuel preheater, fuel heater, and condenser which enable a substantial portion of the steam in the system to be recycled.

Abstract: A recuperative steam cooled gas turbine in which steam used to cool the turbine section is subsequently introduced into the combustors, thereby recuperating the heat absorbed by the steam during cooling. The steam is generated in a heat recovery steam generator and then directed to a manifold within the turbine shell. From the manifold, the steam flows through passages formed within the interior of the vane by a baffle, thereby cooling the vane and heating the steam. The steam is then discharged from the vane into a chamber that collects the compressed air from the compressor. In the chamber, the heated steam mixes with the compressed air and the air/steam mixture then flows into the combustors, where it serves to reduce NOx generation from the combustors and increase power output from the turbine.

Abstract: A turbine blade has a cooling air flow path specifically directed toward cooling the platform portion of the blade root. Two cooling air passages are formed in the blade root platform just below its upper surface. Each passage extends radially outward from an inlet that receives a flow of cooling air and then extend axially along almost the entire length of the platform. Each passage also has an outlet formed in the downstream face of the platform that allows the cooling air to exit the platform and enter the hot gas flow path. The passages are formed in portions of the platform that overhang the shank portion of root.

Abstract: A combustor for burning a mixture of fuel and air in a rich combustion zone, in which the fuel bound nitrogen in converted to molecular nitrogen. The fuel rich combustion is followed by lean combustion. The products of combustion from the lean combustion are rapidly quenched so as to convert the fuel bound nitrogen to molecular nitrogen without forming NOx. The combustor has an air radial swirler that directs the air radially inward while swirling it in the circumferential direction and a radial fuel swirler that directs the fuel radially outward while swirling it in the same circumferential direction, thereby promoting vigorous mixing of the fuel and air. The air inlet has a variable flow area that is responsive to variations in the heating value of the fuel, which may be a coal-derived fuel gas. A diverging passage in the combustor in front of a bluff body causes the fuel/air mixture to recirculate with the rich combustion zone.

Abstract: A stationary vane assembly for a turbo-machine in which the vane is restrained against motion in the circumferential direction by first and second locking pins. The second locking pin extends radially through a turbine cylinder and engages a notch in a downstream support rail formed on the vane outer shroud. The first locking pin is affixed to the front radial flange of the cylinder and has a projection that extends into a notch in an upstream support rail formed on the outer shroud. An over-sized slot in the first locking pin allows the circumferential location at which the first locking pin is fixed to the cylinder to be adjusted, thereby ensuring that the first locking pin can be pre-loaded against the outer shroud notch at assembly in a manner that will allow it to restrain the motion of the vane.

Abstract: A gas turbine vane having an inner shroud that is cooled by a portion of the cooling air directed to a cavity between two adjacent rows of discs. A portion of the cooling air in the cavity flows through impingement plates and impinges on the inner surface of the inner shroud. Another portion of the cooling air flows through a passage in the leading edge of the inner shroud that has a pin fin array for enhanced cooling. The impingement plates form chambers that collect both the impingement air and the pin fin passage air and direct it through holes in the trailing edge of the inner shroud for cooling of the trailing edge. Longitudinal passages along the side of the inner shroud direct the cooling air from the pin fin passage tot the trailing edge.

Abstract: A method of determining the condition of a battery which backs up a real-time clock (RTC) when a main power supply fails or is disconnected, in a system which includes a controller having a volatile random access memory (VRAM) and a non-volatile random access memory (NVRAM). The method includes the steps of periodically storing the time value of the RTC in NVRAM, and periodically writing a predetermined data pattern in VRAM, while the main power supply adequately powers the real time clock. The method then includes the steps of detecting a power-down condition of the main power supply, and terminating the recording and writing steps when the detecting step detects power-down. Return of main power, or power-up, is then detected, with the data pattern stored in VRAM then being compared with the predetermined data pattern.

Abstract: Combined cycle power plants are disclosed that utilize a stream of compressed flue gas and fuel that has been passed through a reformer (a thermochemical recuperator) to increase its thermal and chemical value and, along with the output of an air compressor, is fed into the gas turbine combustor. In preferred embodiments the thermochemical recuperation and flue gas recirculation are incorporated into combined cycle power plants that utilize either two gas turbines or reheat gas turbines.

Abstract: A process of depositing layers of weld metal onto a ferrous NiMoV low alloy steel turbine component. During a deposition of a first layer of weld metal, low levels of amperage are used to prevent a dramatic increase in a level of hardness of a heat affected zone produced during the deposition of the first layer of weld metal. During a deposition of a second layer of weld metal, higher levels of amperage are used to temper the heat affected zone but not high enough to overtemper the HAZ.

Abstract: A gas turbine power plant in which a mixture of steam and compressed air, the mixture being primarily steam, is used to cool the rotating blades and stationary vanes in the turbine section. The air is bled from the compressor. The flow rate of steam that is mixed into the compressed air is adjusted so to maintain the pressure drop experienced by the compressed air as it flows to the turbine within a predetermined range. Consequently, the steam and air mixture has the same volumetric flow rate as if compressed air alone were being used. Thus, any sudden decrease in steam flow rate will automatically result in an offsetting increase in the flow of compressed air due to the decrease in the line pressure in the common line through which the air and steam flow to the turbine. Consequently, no control, isolation or check valves are utilized in the compressed air piping.

Abstract: A steam turbine having improved stationary parts in which a moisture removal slot is formed in a blade ring cylinder immediately upstream of the last row of rotating blades. The slot has a reduced width inlet throat portion and an enlarged manifold portion. The manifold portion of the slot distributes the moisture collected to a plurality of radially oriented discharge holes formed in the blade ring. The inlet throat serves to insolate the manifold from the swirling steam flowing through the turbine, thereby preventing entrainment of the moisture droplets into the steam flow. The blade ring encircles the tips of the last row of rotating blades and the outer flow guide is integrally formed on the blade ring. The steam turbine also has a new inner flow guide that matches a new last row of rotating blades. The new inner flow guide is attached to the existing inner flow guide by welds.

Abstract: A method of operating a gas turbine in which variations in power requirements are accomplished by varying the rate of steam injection into the combustor while maintaining the temperature of the fluid flowing to the turbine at a constant value. The steam injection flow rate is varied by varying the pressure in the evaporator of a HRSG that receives exhaust gas from the turbine. Preferably, the flow area of the turbine is increased so as to allow the use of especially high rates of steam injection.

Abstract: A gas turbine power plant having a heat recovery steam generator that generates steam at high and low pressures. The high pressure steam, which is superheated, is partially expanded in a steam turbine, thereby producing shaft power. All of the partially expanded steam is then combined with low pressure steam. The combined steam flow is superheated and then injected into the combustor of the gas turbine to increase power output and reduce NOx.

Abstract: A method of securely controlling direct memory access (DMA) in a microprocessor controlled system having a CPU on a CPU board which has an address/data bus connector for selectively connecting an expansion board to the CPU board, and a random access memory (RAM) on the CPU board having a specific address range which is accessible by a DMA device on the expansion board when the CPU board relinquishes control of the address/data bus to the DMA device in response to a bus access request.

Abstract: An apparatus for causing a portion of the compressed air from the compressor section of a gas turbine to bypass the combustor. The apparatus comprises a clamping ring and a rotating ring. The clamping ring joins the aft end of the combustor to the front end of a duct that directs the hot gas from the combustor to the turbine section. The rotating ring encircles the clamping ring. When the rotating ring is rotated into a first position, ports disposed in the rotating ring are aligned with ports in the clamping ring so that air can flow into the hot gas flowing between the combustor and the duct. However, the ports in the rotating ring are completely blocked by the clamping ring when the rotating ring is rotated into a second position and partially blocked when the rotating ring is rotated into intermediate positions. An actuating ring that encircles the combustion chamber controls the rotation of the rotating ring by means of an actuating rod that extends into the shell.

Abstract: A refrigeration unit, and method of operating same, having a compressor driven by a prime mover. The prime mover is selectively operable in either a continuous mode which includes heating and cooling cycles, or in start-stop cycling mode which includes cooling and null cycles, to control the temperature of a conditioned space relative to a predetermined set point temperature. In one embodiment, the cycle mode is operable only when the set point temperature is in a predetermined temperature range, the limits of which are selectable. The prime mover is operated in the continuous mode, notwithstanding the selection of the cycle mode, when the set point temperature is not within the temperature range authorized for cycle operation.

Abstract: A gas turbine power plant having a pressurized fluidized bed combustor and an external topping combustor. A cylindrical duct and a toroidal duct direct the flow of hot gas from the topping combustor and distribute it around the circumference of the turbine inlet. The walls of the duct are cooled by water or steam. The walls are formed by tubes, having cooling fluid passages formed therein, that extend between inlet and outlet manifolds. Elongated plate sections connect each tube to an adjacent tube so as to form a continuous gas barrier. If the walls are water cooled, the water that flows through the tubes for cooling is subsequently directed to a heat recovery steam generator, in which it is converted to steam for expansion in a steam turbine. If the walls are steam cooled, the steam is first generated in the heat recovery steam generator and then at least partially superheated by flowing through the walls.