A gas turbine generally includes, in serial flow order, an inlet system, a compressor, a combustion section and a turbine. Various exhaust gas related components may be disposed downstream from an outlet of the turbine including but not limited to an exhaust gas diffuser, an exhaust plenum, a bypass stack, a diverter damper, or a heat recovery steam generator (HRSG), among others. The exhaust gas diffuser defines a flow path for routing relatively hot combustion gases away from the turbine. The hot combustion gases may then be routed through the various outer exhaust gas related components.
The exhaust gas diffuser is typically formed by an outer casing or shell and multiple liner panels that are coupled to an inner surface of the outer casing and that define an outer flow boundary of the flow path. In order to reduce the temperature of the outer casing, insulation, usually in the form of fiber batts, is packed between the inner surface of the outer casing and an outer surface of each liner panel.
The liner panels are typically coupled to supports that are welded to the inner surface of the casing. These connections are subject to stress from various sources, such as movement of the liner panels relative to the outer casing. Such relative movement may be caused by vibration of the panel and/or differing thermal growth rates of the liner panels and the outer casing, among others. Over time, this may potentially lead to liner panel buckling, other deformation, cracking, and/or disengagement of the panel(s) from the coupling.
When a liner panel as described above is in need of maintenance or replacement, the entire liner panel must be removed, which requires significant labor and expense.