Abstract: Apparatus (10) controls net thrust in a steam turbine (T) in response to changes in the operating condition of the turbine. The turbine includes a thrust bearing (B) positioned between low and intermediate pressure sections (LP, IP) of the turbine and a high pressure section (HP) thereof. Sensors (14) for sense thrust loads on the thrust bearing. A number of control valve (CV1-CV4) are used to balance pressures occurring at locations within the high pressure section of the turbine. A controller (16) is responsive to the sensors sensing a change within the turbine indicative of a significant change in net thrust to energize one or more of the control valves and to adjust the pressure within the high pressure section of the turbine so to maintain net thrust within an acceptable range of thrust values.

Abstract: A system (10) controlling operation of a steam turbine (T). Sensors (12) measure dynamic pressure level variations in a stage (S1-Sn) of the turbine. A signal (Ps) from a sensor is converted to a frequency based signal (Fs). A comparator (16) compares the pressure levels at various frequencies as represented by the frequency based signal (Fs) to a matrix of limiting values including both alarm and trip signal limits. The control system provides an alarm to an operator of the steam turbine if the comparison indicates that an alarm limit has been exceeded, or takes the steam turbine off line, if a trip signal limit has been exceeded. This is done to prevent damage to the steam turbine. However, the control system maintains the steam turbine in operation if no aeromechanical disturbances or instabilities, as sensed by the sensors, has occurred.

Abstract: A system (10) controlling operation of a steam turbine (T). Sensors (12) measure dynamic pressure level variations in a stage (S1-Sn) of the turbine. A signal (Ps) from a sensor is converted to a frequency based signal (Fs). A comparator (16) compares the pressure levels at various frequencies as represented by the frequency based signal (Fs) to a matrix of limiting values including both alarm and trip signal limits. The control system provides an alarm to an operator of the steam turbine if the comparison indicates that an alarm limit has been exceeded, or takes the steam turbine off line, if a trip signal limit has been exceeded. This is done to prevent damage to the steam turbine. However, the control system maintains the steam turbine in operation if no aeromechanical disturbances or instabilities, as sensed by the sensors, has occurred.

Abstract: Apparatus (10) controls net thrust in a steam turbine (T) in response to changes in the operating condition of the turbine. The turbine includes a thrust bearing (B) positioned between low and intermediate pressure sections (LP, IP) of the turbine and a high pressure section (HP) thereof. Sensors (14) for sense thrust loads on the thrust bearing. A number of control valve (CV1-CV4) are used to balance pressures occurring at locations within the high pressure section of the turbine. A controller (16) is responsive to the sensors sensing a change within the turbine indicative of a significant change in net thrust to energize one or more of the control valves and to adjust the pressure within the high pressure section of the turbine so to maintain net thrust within an acceptable range of thrust values.

Abstract: A nozzle configuration and control methodology adapted to provide a compact means for configuring and operating an industrial gas turbine on either gaseous or liquid fuel while utilizing fuel staging to achieve very low emissions. More specifically, the outer fuel nozzles are used for delivery of a portion of the premix gaseous fuel and all liquid fuel, but not diffusion gaseous fuel. Water injection for emissions control on liquid fuel and atomizing air for the liquid fuel are also supplied entirely by the outer fuel nozzles. The central fuel nozzle is thus used for the supply of both premix gaseous fuel and all diffusion gaseous fuel. The disclosed configuration reduces the number of required fluid passages thus simplifying the endcover structure while enabling fuel staging to achieve very low emissions on gaseous fuel.

Abstract: A nozzle configuration and control methodology adapted to provide a compact means for configuring and operating an industrial gas turbine on either gaseous or liquid fuel while utilizing fuel staging to achieve very low emissions. More specifically, the outer fuel nozzles are used for delivery of a portion of the premix gaseous fuel and all liquid fuel, but not diffusion gaseous fuel. Water injection for emissions control on liquid fuel and atomizing air for the liquid fuel are also supplied entirely by the outer fuel nozzles. The central fuel nozzle is thus used for the supply of both premix gaseous fuel and all diffusion gaseous fuel. The disclosed configuration reduces the number of required fluid passages thus simplifying the endcover structure while enabling fuel staging to achieve very low emissions on gaseous fuel.

Abstract: A nozzle configuration and control methodology adapted to provide a compact means for configuring and operating an industrial gas turbine on either gaseous or liquid fuel while utilizing fuel staging to achieve very low emissions. More specifically, the outer fuel nozzles are used for delivery of a portion of the premix gaseous fuel and all liquid fuel, but not diffusion gaseous fuel. Water injection for emissions control on liquid fuel and atomizing air for the liquid fuel are also supplied entirely by the outer fuel nozzles. The central fuel nozzle is thus used for the supply of both premix gaseous fuel and all diffusion gaseous fuel. The disclosed configuration reduces the number of required fluid passages thus simplifying the endcover structure while enabling fuel staging to achieve very low emissions on gaseous fuel.

Abstract: An actual Wobbe Index is calculated for a turbine and compared to a reference Wobbe Index. By comparing the actual and reference Wobbe Indices and recognizing that the reference Wobbe Index has acceptable combustion dynamics, a measure of the combustion dynamics of the operating turbine can be obtained. To lower the possibility of combustion dynamics, causing combustor distress, a feedback signal is provided to change the temperature of the fuel gas provided the combustor. Since the Wobbe Index is a function of temperature and fuel composition, the variation in temperature can be effected to change the Wobbe Index to a reference Wobbe Index having known low combustion dynamics.

Abstract: A method for detecting flashback events in gas turbine is disclosed. The method employs periodic reference point checks to determine whether or not flashback damage has occurred. The method relies on the repeatability of exhaust profile and NOx as functions of precise turbine conditions. In combination with experience-based limits, changes in these values are used to determine if a flashback has occurred, even days later.

Abstract: In a gas turbine having a transition region between a combustor and turbine stage including a transition piece duct extending between a combustor liner and the turbine stage; an impingement sleeve surrounding the transition piece, the impingement sleeve having a plurality of apertures therein; and a compressor diffuser directing compressor discharge air into the transition region, an improvement wherein the diffuser includes a pair of outer walls flaring outwardly in a direction of compressor discharge air flow; and a pair of baffles within a flow area defined by the pair of outer diffuser walls which divide the flow area into three discrete flow passages. One passage has a substantially radial flow component; a second passage has both radial and axial flow components; and a third passage has a substantially axial flow component.

Abstract: An inlet air heating system for a gas turbine comprising a main air inlet; ducting leading from the main inlet to an inlet of the gas turbine; a manifold located adjacent the inlet for feeding intermediate temperature air into the ducting; a conduit connected to the inlet air manifold, the conduit having an ambient air inlet and connected to a compressor bleed air conduit, downstream of the ambient air inlet; and one or more eductors in the conduit through which the bleed air flows to entrain the ambient air into the conduit through the ambient air inlet and to mix the bleed air and ambient air for introduction into the ducting through the manifold.

Abstract: Embodiments of this invention include devices for removing particles, such as the fly ash from gaseous effluent produced by the combustion of pulverized coal, comprising arrays of ceramic rods that are contained within a housing having ingress and egress openings for the effluent. The rods are so oriented as to create tortuous paths for the effluent and thereby effectively render the rods in the aggregate into an impact separator. The rods are made from material which exhibits electrical resistance such that when the are sufficiently energized electrically, ash accumulated thereon liquefies or otherwise looses its adhesive strength, releasing such accumulations which then, by gravity and/or the drag forces of the gas stream separate from the rods for subsequent collection and removal.