Abstract: The invention provides an ion sensor for use in a fuel nozzle of a gas turbine combustor and other combustor surfaces that uses thin-film coatings to form both the dielectric and electrode layer of the ion sensor and methods to provide an electrical connection to the electrode layer. The dielectric layer electrically insulates the sensor from the combustor surface, which is typically grounded. The electrode layer, typically a metallic material capable of withstanding high temperatures in the combustion environment without delamination from the dielectric layer, is applied over the dielectric layer and forms the ion-sensing electrode. A wire protrudes through the dielectric layer to connect to the electrode layer and provides for the ion-sensing electrode to be controlled outside of the combustion zone (e.g., to a control module for signal processing).

Abstract: An apparatus and method to sense the onset of combustion stability is presented. An electrode is positioned in a turbine combustion chamber such that the electrode is exposed to gases in the combustion chamber. The electrode may be integrated with an igniter. A control module applies a voltage potential to the electrode and detects a combustion ionization signal and determines if there is an oscillation in the combustion ionization signal indicative of the occurrence of combustion stability or the onset of combustion instability. The control module broadcasts a notice if the parameters indicate the combustion process is at the onset of combustion instability or broadcasts an alarm signal if the parameters indicate the combustion process is instable. Combustion parameters are adjusted to drive the combustion process towards stability.

Abstract: An apparatus and method to detect combustion conditions using ion signals for use in a feedback control of a diesel engine is presented. The apparatus is a spark plug type of sensor or a sensor integrated with a fuel injector. The spark plug type of sensor is used to provide a cold start mechanism combined with an ion sensing device.