Abstract: A system for detecting spark in an igniter for a gas turbine engine. An igniter generates a plasma, or spark, somewhat similar to an automotive spark plug. In the invention, an inductive pick-up is positioned adjacent the igniter, to detect current pulses in the igniter, to thereby infer the presence of spark. The pick-up can take the form of a coil embedded in a mounting bracket which is used to fasten the igniter to the engine.

Abstract: A system for detecting spark in an igniter for a gas turbine engine. An igniter generates a plasma, or spark, somewhat similar to an automotive spark plug. In the invention, an inductive pick-up is positioned adjacent the igniter, to detect current pulses in the igniter, to thereby infer the presence of spark. The signal produced is small, and requires amplification. However, the environment is hot, often exceeding 400 degrees F. The invention utilizes an amplifier composed of passive components, in the form of an RLC circuit.

Abstract: A system for detecting spark in an igniter for a gas turbine engine. An igniter generates a plasma, or spark, somewhat similar to an automotive spark plug. In the invention, an inductive pick-up is positioned adjacent the igniter, to detect current pulses in the igniter, to thereby infer the presence of spark. The Inventors have found that this approach is effective, despite the fact that the inductor is surrounded by grounded shielding intended to suppress rf interference, and to protect personnel from high voltages present. The shielding is intended to block the very signals which the invention detects.

Abstract: An igniter for a gas turbine engine. An igniter generates a plasma, or spark, somewhat similar to an automotive spark plug. In the invention, an auxiliary electrode is provided, which is embedded in and covered by a solid insulator. During initial phases of operation, no part of the plasma generated contacts the auxiliary electrode. However, eventually, the covering insulation is eroded by the plasma, and the auxiliary electrode becomes exposed and available as a return path for the plasma. The igniter is constructed so that, when this erosion occurs, the lifetime of the igniter is near its end. Detection of this erosion, as by detecting the new current in the auxiliary ground electrode, indicates the approaching end-of-lifetime.

Abstract: An igniter for a gas turbine engine. An igniter generates a plasma, or spark, somewhat similar to an automotive spark plug. In the invention, an inductive pick-up is used to detect current which produces the spark, the thereby infer the presence of spark. Further, the sensor is located directly adjacent the igniter, in a hot environment, often exceeding 400 F.

Abstract: An industrial gas turbine engine includes in serial flow relationship a first compressor, a second compressor, a combustor, a first turbine, and a second turbine. The first compressor and the second turbine are fixedly joined together by a first shaft, and a turbine rear frame having a hub is disposed downstream of the second turbine for rotatably supporting the first shaft. A balance piston is fixedly joined to the first shaft, and means for channeling a fluid first to the balance piston for balancing thrust force on the first shaft and then to the turbine rear frame for heating the hub are provided. The apparatus is effective for carrying out a method including channeling a fluid first to the balance piston for thrust balancing the first shaft and then channeling the fluid to the tubine rear frame for heating the frame hub.

Abstract: An industrial gas turbine engine includes in serial flow relationship a first compressor, a second compressor, a combustor, a first turbine, and a second turbine. The first compressor and the second turbine are fixedly joined together by a first shaft, and a turbine rear frame having a hub is disposed downstream of the second turbine for rotatably supporting the first shaft. A balance piston is fixedly joined to the first shaft, and means for channeling a fluid first to the balance piston for balancing thrust force on the first shaft and then to the turbine rear frame for heating the hub are provided. The apparatus is effective for carrying out a method including channeling a fluid first to the balance piston for thrust balancing the first shaft and then channeling the fluid to the turbine rear frame for heating the frame hub.