1. Field of the Invention
The invention relates to tools and methods for inspecting and validating internal circumferential minimal dimensions and coaxial alignment of combustion turbine combustor igniter ports, including prior to installation of a combustor into an engine, so that an igniter is insertable into the igniter port during subsequent engine assembly.
2. Description of the Prior Art
Known combustion turbine engines entrain and ignite atomized fuel within a flow of compressor supplied air passing through the combustor section. Hot combustion gasses thereafter are directed into a turbine section, where they convert heat energy into mechanical work by spinning shaft mounted turbine blades. Some known combustion turbine engines utilize combustor baskets having outer and inner combustor shrouds nested along a combustor centerline axis that envelop one or more air swirlers, a fuel injector for introducing atomized fuel into the combustor and an igniter that ignites the atomized fuel. The igniter is retained within an igniter port coupled to the inner and outer combustor shrouds at a port angle defined by an igniter port centerline axis and the combustor centerline axis. The igniter port includes a tubular guide tube and a tubular igniter boss that are concentrically aligned along the igniter port centerline axis. The guide tube has a proximal guide tube axial end that is coupled to and outwardly projects from the outer shroud and a guide tube inner circumferential profile having a first minimum dimension specification. The igniter boss has a proximal boss axial end that is coupled to and projects outwardly from the inner shroud, a distal boss axial end proximal the guide tube proximal end and an igniter boss inner circumferential profile having a second minimum dimension specification.
An igniter port constructed within nominal inner circumferential dimensions and axial alignment specifications allows insertion of an igniter therein without mechanical binding or interference fit. Additionally, an igniter port is oriented at a specified port angle for alignment of the igniter within the combustor. In the past, combustors, including igniter ports have been assembled outside of and subsequently installed in the turbine engine combustion section. The igniter was inserted and installed into the igniter port after the combustor installation within the engine. If, after installation of the combustor into the turbine engine, it was discovered that the igniter could not be inserted into the igniter port and/or that clearance between the two components was not sufficient and/or that the port angle was not within design specifications, the combustor had to be removed from the engine. Then the igniter port physical dimensions and/or alignment concentricity/angle had to be remediated before the combustor could be placed in service in an engine, ready to receive an igniter. Removal, remediation of igniter ports and reinstallation of remediated combustors in turbine engines wastes service time and effort as well as causes service delays. Often the combustors are replaced rather than remediated, which adds shipping delays until the replacement combustors arrive at the field site.