A gas turbine system includes an exhaust processing system that may process exhaust gas generated by a gas turbine engine, the exhaust processing system includes an exhaust diffuser that may receive the exhaust gas from a turbine of the gas turbine engine and having an annular passage disposed between an inner annular wall and an outer annular wall, and an air injection assembly disposed within the exhaust diffuser. The air injection assembly includes one or more air injection conduits disposed within the annular passage of the exhaust diffuser and including fluid injection holes that may direct a cooling fluid into a first mixing region of the exhaust diffuser.

Disclosed is an exhaust duct (1) for a gas turbine engine (50), comprising a silencer section (12). At least two plate-shaped silencer baffles (20) are provided inside the silencer section (12). At least one of the plate-shaped silencer baffles is configured as a heat exchange device in that it comprises at least one internal cavity (22) suitable for receiving a heat exchange fluid and leakproof with respect to the interior of the exhaust duct, wherein the at least one internal cavity is fluidly connected to the outside of the exhaust duct at an inlet port and an outlet port (23, 24). This device is useful for recuperating exhaust heat from exhaust gases of the gas turbine engine without the expense and additional space required for providing a heat recovery steam generator.

An emissions control system for a gas turbine system includes a reducing agent supply, at least one sensor, at least one valve, and a controller. The reducing agent supply has one or more conduits configured to couple to one or more fluid pathways of the gas turbine system, which are fluidly coupled to a flow path of an exhaust gas from a combustor through a turbine of the gas turbine system. The at least one sensor is configured to obtain a feedback of one or more parameters of the gas turbine system, which are indicative of a visibility of emissions of the exhaust gas. The at least one valve is coupled to the reducing agent supply. The controller is communicatively coupled to the at least one sensor and the at least one valve, such that, in response to the feedback, the controller adjusts the at least one valve to adjust a flow of the reducing agent to reduce the visibility of the emissions of the exhaust gas.

A gas turbine engine system is equipped with a tempering system for a selective catalyst reduction system. The subject tempering system for a selective catalyst reduction system comprises a tempering compartment equipped with a plurality of relatively high temperature environment self-supporting pipes, and optionally, a plurality of flow vanes.

An auxiliary power unit that can reduce a flow loss of gas includes: a compressor, a combustion chamber, a turbine, a turbine outlet, and a bypass duct, wherein the turbine outlet comprises an exhaust diffuser and a guide portion, wherein the bypass duct connects the compressor with the guide portion, wherein the guide portion is a channel for an air or gas and is extended radially from an outer circumferential surface of the exhaust diffuser and communicates with an inside of the exhaust diffuser via an opening, and wherein the exhaust diffuser has a first portion adjacent to a front end of the opening and a second portion adjacent to a rear end of the opening, and a radius of the second portion is larger than a radius of the first portion so that there is formed a step difference between the first portion and the second portion.

An exhaust energy recovery system (EERS) and associated methods for an engine are disclosed. An embodiment of an EERS, for example, includes an inlet duct that is configured to divert exhaust gas from an exhaust duct of the engine into the recovery system and an outlet duct configured to return the exhaust gas to the exhaust duct downstream of the inlet duct. The recovery system is configured to heat components or fluids associated with engine to operating temperatures. The recovery system may be part of a mobile power system that is mounted to a single trailer and includes an engine and a power unit such as a high pressure pump or generator mounted to the trailer. Methods of operating and purging recovery systems are also disclosed.

A compact heat exchanger is disclosed for re-circulating bleed air from a combustor into an inlet and/or exhaust of a gas turbine engine. In an embodiment, the heat exchanger may comprise a plurality of airfoils with internal passages that receive bleed air. The bleed air may be forced through outlets in one or a plurality of concentric passages from the internal passage of each airfoil to an internal cavity of each airfoil, and out of micro-holes within a trailing surface of the airfoil. This enables bleed air to be mixed with gas flowing through the airfoils, in close proximity to the compressor or turbine of the gas turbine engine, while providing acoustic noise suppression and low thermal mixing stratification.

An exhaust duct for a fossil fuel powered engine includes an exhaust gas passage, a cooling fluid passage, a mixing device for mixing cooling fluid with the hot exhaust gas and a selective catalytic reduction catalyst for removing nitrogen oxides arranged in the exhaust gas passage. The mixing device has a mixing chamber with a first wall and an opposed second wall, the first and second wall arranged upstream of the selective catalytic reduction catalyst in the exhaust gas passage and extending over the cross-sectional area of the exhaust gas passage, both walls perforated by through holes, wherein through holes of the first wall are connected with through holes of the second wall in pairs by pipes extending through the mixing chamber, the pipes perforated by at least one hole into the mixing chamber and the cooling fluid passage ending into the mixing chamber.

An emission reduction system for a combined cycle power plant including a gas turbine and heat recovery steam generator (HRSG) can comprise a stationary emission converter in fluid communication with and disposed upstream of the HRSG, and a diversion system operably coupled to an exhaust passage of the gas turbine, the exhaust passage defining an exhaust path for exhaust gas of the gas turbine through the heat recovery steam generator, the diversion system operable to define a primary exhaust path excluding the stationary emission converter and a start-up exhaust path including the stationary emission converter.

An exhaust control damper system for a power plant includes a frame configured to be fluidly coupled in an exhaust flow path from a gas turbine (GT) system to a heat recovery system. The damper system includes at least two sets of louvered dampers in the frame and collectively covering the exhaust flow path. Each set of louvered dampers includes a plurality of blades collectively angularly positionable in one of: a fully open position, a fully closed position, and a partially open position. An air insertion system is coupled to the frame and configured to insert an airflow into the exhaust flow path to control the exhaust temperature entering the heat recovery system. The sets of louvered dampers can be modulated independently to control exhaust flow distribution and mass flow to the heat recovery system.