Abstract: Aspects of the invention related to a system for providing advance notice of impending contact between a stationary component and a rotating component in a turbine engine. For example, the system can be used to warn of potential contact between a seal holder and a rotor disk in the compressor section of the engine. In one embodiment, a pad or other component can be provided on the stationary seal holder. If the seal holder and the rotor disk approach each other during operation, the pad can contact the rotor disk prior to actual contact between the seal holder and the rotor disk. An optical and/or an acoustic signal can be generated by such contact. The signals can be detected remotely from the point of contact by a signal detection device, thereby avoiding the need to pass wires through the compressor section.

Abstract: A pressure sensor (52) for a harsh environment such as the combustion chamber (58) of a gas turbine engine (50). The pressure sensor includes an acoustic waveguide (60) having a sensing portion (66) exposed to the combustion gas in the combustion chamber. Modulations in an acoustic signal passing through the acoustic waveguide are sensed and correlated to pressure fluctuations in the combustion gas. The sensing portion of the waveguide includes a core acoustic waveguide element (42) covered by a coating material (44). The coating material not only protects the core from the harsh environment, but it also improves the efficiency of the transfer of energy from the combustion gas into the waveguide because it provides a stepped transition from the acoustic impedance of the gas to the acoustic impedance of the core material. The protective coating may have a plurality of layers (46, 48) and/or it may include a graded material (78, 80) having an acoustic impedance value that varies across its depth.

Abstract: A pressure sensor (52) for a harsh environment such as the combustion chamber (58) of a gas turbine engine (50). The pressure sensor includes an acoustic waveguide (60) having a sensing portion (66) exposed to the combustion gas in the combustion chamber. Modulations in an acoustic signal passing through the acoustic waveguide are sensed and correlated to pressure fluctuations in the combustion gas. The sensing portion of the waveguide includes a core acoustic waveguide element (42) covered by a coating material (44). The coating material not only protects the core from the harsh environment, but it also improves the efficiency of the transfer of energy from the combustion gas into the waveguide because it provides a stepped transition from the acoustic impedance of the gas to the acoustic impedance of the core material. The protective coating may have a plurality of layers (46, 48) and/or it may include a graded material (78, 80) having an acoustic impedance value that varies across its depth.

Abstract: A combustion turbine with a secondary combustor is provided. The secondary combustor is disposed within the turbine assembly of the combustion turbine. The secondary combustor assembly is structured to maintain the working gas at a working temperature within the turbine assembly. The secondary combustor assembly re-heats the working gas by injecting a combustible gas into the working gas. The secondary combustor assembly includes a plurality of openings disposed among the vanes and/or blades in the turbine assembly which are coupled to a combustible gas source. As the combustible gas is injected into the working gas, the combustible gas will auto-ignite. That is, the combustible gas will combust without the need for an igniter or pre-existing flame. Combustion of the combustible gas in the turbine assembly re-heats the working gas.

Abstract: A combustion turbine with a secondary combustor is provided. The secondary combustor is disposed within the turbine assembly of the combustion turbine. The secondary combustor assembly is structured to maintain the working gas at a working temperature within the turbine assembly. The secondary combustor assembly re-heats the working gas by injecting a combustible gas into the working gas. The secondary combustor assembly includes a plurality of openings disposed among the vanes and/or blades in the turbine assembly which are coupled to a combustible gas source. As the combustible gas is injected into the working gas, the combustible gas will auto-ignite. That is, the combustible gas will combust without the need for an igniter or pre-existing flame. Combustion of the combustible gas in the turbine assembly re-heats the working gas.

Abstract: A combustion turbine which produces a reduced amount of NOx is provided. The combustion turbine reduces the amount of NOx produced by utilizing a secondary combustor. By using a secondary combustor the working gas of the combustion turbine does not need to be heated above 2500° F., the temperature at which a substantial amount of NOx begins to form, until the working gas is entering the turbine assembly. The secondary combustor assembly heats the working gas by injecting a combustible gas, or compressed air if the primary combustor produces a fuel rich working gas, into the elevated temperature working gas. This gas combusts and heats the working gas adjacent to the beginning of the turbine assembly. Because the working gas is not raised above 2500° F. until it is about to enter the turbine assembly, the time during which NOx is formed is reduced.

Abstract: A high-voltage winding for core-form power transformers is disclosed that uses two different conductor configurations within a single coil to minimize eddy current losses. The winding includes a first elongated conductor bundle formed from a plurality of thin enamel coated conductor ribbons arranged in side by side relation. A plurality of second elongated conductor bundles are each formed from at least one bundle section having a multiplicity of elongated insulated conductor strands arranged in side by side relation. Each of the conductor strands is less than 40 mils thick. The coil includes a top end section, a body section and a bottom end section. The body section is spirally wound with the first conductor bundle. The top and bottom end sections are wound with the second conductor bundles. In windings that include tap connectors, the tap section is also wound with one of the second conductor bundles.