Patent application number | Description | Published |
20090145137 | TRANSITION DUCT ASSEMBLY - A transition duct assembly with a thermally free aft frame and mounting system for use in a gas turbine engine are disclosed. The aft frame is capable of adjusting to thermal gradients while the mounting system provides for at least transverse movement of the transition duct during engine assembly. The mounting system also provides a means for raising the natural frequency of the transition duct outside of the engine's dynamic excitation ranges. | 06-11-2009 |
20090145983 | GAS TURBINE FUEL NOZZLE HAVING IMPROVED THERMAL CAPABILITY - Embodiments for minimizing relative thermal growth within a fuel nozzle of a gas turbine combustor are disclosed. Fuel nozzle configurations are provided in which a heating fluid is provided to one or more passages in a fuel nozzle from feed holes in the fuel nozzle base. The heating fluid passes through the fuel nozzle, thereby raising the operating temperature of portions of the fuel nozzle to reduce differences in thermal gradients within the fuel nozzle. Various fuel nozzle configurations and passageway geometries are also disclosed. | 06-11-2009 |
20090188255 | COMBUSTOR END CAP ASSEMBLY - A combustor end cap assembly having an improved cooling configuration is disclosed. Embodiments of the present invention are directed towards an apparatus and method for cooling an effusion plate of the combustor end cap assembly. The combustor end cap assembly also incorporates an impingement plate having a plurality of cooling holes with the impingement plate positioned a predetermined distance from the effusion plate. The cooling fluid passes through the impingement plate and is directed towards and onto the effusion plate for cooling of the effusion plate. | 07-30-2009 |
20090188258 | ALTERING A NATURAL FREQUENCY OF A GAS TURBINE TRANSITION DUCT - A transition duct having a thermally free aft frame and being capable of adjusting the natural frequency is disclosed. The aft frame is capable of permitting movement due to thermal gradients with the transition duct. The transition duct utilizes a spring plate located adjacent to an aft mounting bracket, where the spring plate, based on its thickness can either increase or decrease a frequency of the transition duct. Such an arrangement ensures that the transition duct natural frequency does not coincide with or cross other critical engine and/or combustor frequencies. | 07-30-2009 |
20100300108 | STABILIZING A GAS TURBINE ENGINE VIA INCREMENTAL TUNING - An auto-tune controller and tuning process implemented thereby for measuring and tuning the combustion dynamics and emissions of a GT engine, relative to predetermined upper limits, are provided. Initially, the tuning process includes monitoring the combustion dynamics of a plurality of combustors and emissions for a plurality of conditions. Upon determination that one or more of the conditions exceeds a predetermined upper limit, a fuel flow split to a fuel circuit on all of the combustors on the engine is adjusted by a predetermined amount. The control system continues to monitor the combustion dynamics and to recursively adjust the fuel flow split by the predetermined amount until the combustion dynamics and/or emissions are operating within a prescribed range of the GT engine. | 12-02-2010 |
20110265487 | Dynamically Auto-Tuning a Gas Turbine Engine - Tuning processes implemented by an auto-tune controller are provided for measuring and adjusting the combustion dynamics and the emission composition of a gas turbine (GT) engine via a tuning process. Initially, the tuning process includes monitoring parameters, such as combustion dynamics and emission composition. Upon determining that one or more of the monitored parameters exceed a critical value, these “out-of-tune” parameters are compared to a scanning order table. Upon comparison, the first out-of-tune parameter that is matched within the scanning order table is addressed. The first out-of-tune parameter is then plotted as overlaid slopes on respective graphs, where the graph represents a fuel-flow split. Typically, the slopes are plotted as a particular out-of-tune parameter against a particular fuel-flow split. The slopes for each graph are considered together by taking into account the combined impact on each out-of-tune parameter when a fuel-flow split is selected for adjustment. | 11-03-2011 |
20110270502 | EMPLOYING FUEL PROPERTIES TO AUTO-TUNE A GAS TURBINE ENGINE - A tuning process is provided for monitoring fuel properties of a fuel being consumed by a gas turbine (GT) engine, and for dynamically tuning the GT engine as a function of changes to the monitored fuel properties. Initially, readings are taken from the GT engine during a reference calibration, or commissioning, and utilized to calculate an initial-pressure-drop reference value. The tuning process during commercial operation takes post-calibration readings from the GT engine to calculate a fuel property parameter, which represents a heating value of the fuel. Specifically, the fuel property parameter is calculated by deriving a corrected-pressure-drop dynamic value as a function of pressure and temperature readings of the fuel at a point upstream of a combustor and pressure drops across fuel nozzles that introduce the fuel into the combustor, and solving a ratio of the dynamic value and the reference value. | 11-03-2011 |
20130255276 | Transition Duct Mounting System - The present invention is directed to a mounting system for a gas turbine transition duct. The mounting system includes a generally C-shaped mounting bracket having a generally radially extending first portion, an arc-shaped second portion, and a generally radially extending third portion. Each of the first portion and third portion includes a spherical bearing and the second portion has a plurality of sets of mounting holes. In another embodiment of the present invention, a gas turbine transition duct is provided having a panel assembly, an aft frame secured to the panel assembly and a mounting system for securing the transition duct to a turbine inlet. The panel assembly includes two formed sheets of metal secured together along axial seams. The panel assembly is secured to an aft frame that is capable of expanding in the circumferential direction due to thermal growth. The mounting system comprises a generally C-shaped mounting bracket having a generally radially extending first portion, an arc-shaped second portion, and a generally radially extending third portion. Each of the first portion and third portion includes a spherical bearing and the second portion has a plurality of sets of mounting holes. | 10-03-2013 |
20140090389 | VARIABLE LENGTH COMBUSTOR DOME EXTENSION FOR IMPROVED OPERABILITY - The present invention discloses a novel apparatus and method for operating a gas turbine combustor having a structural configuration proximate a pilot region of the combustor which seeks to minimize the onset of thermo acoustic dynamics. The pilot region of the combustor includes a generally cylindrical extension having an outlet end with an irregular profile which incorporates asymmetries into the system so as to destroy any coherent structures. | 04-03-2014 |
20140090390 | FLAMESHEET COMBUSTOR DOME - The present invention discloses a novel apparatus and way for controlling a velocity of a fuel-air mixture entering a gas turbine combustion system. The apparatus comprises a hemispherical dome assembly which directs a fuel-air mixture along a portion of the outer wall of a combustion liner and turns the fuel-air mixture to enter the combustion liner in a manner coaxial to the combustor axis and radially outward of a pilot fuel nozzle so as to regulate the velocity of the fuel-air mixture. | 04-03-2014 |
20140090396 | COMBUSTOR WITH RADIALLY STAGED PREMIXED PILOT FOR IMPROVED - The present invention discloses a novel apparatus and method for a mixing fuel and air in a gas turbine combustion system. The mixer helps to mix fuel and air while being able to selectively increase the fuel flow to a shear to a shear layer of a pilot flame in order to reduce polluting emissions. The mixer directs a flow of air radially inward into the combustion system and includes two sets of fuel injectors within each radially-oriented vane. A first plurality of fuel injectors operate independent of a second plurality of fuel injectors and the second plurality of fuel injectors are positioned to selectively modulate the fuel flow to the shear layer of the resulting pilot flame. | 04-03-2014 |
20140196461 | DETECTING FLASHBACK BY MONITORING ENGINE-DYNAMIC SPIKES - A tuning process is provided for dynamically tuning a gas-turbine (GT) engine to correct for flashback events without directly measuring occurrences of the flashback events at the GT engine. Initially, readings are taken that measure low-frequency dynamics at the GT engine. A determination of whether flashback criteria are met by an instantaneous signal that quantifies a detected spike within the measured low-frequency dynamics is carried out, where the flashback criteria include the following: identifying the spike overcomes a multiple of an average of the low-frequency dynamics measured over a predefined period of time; and identifying the spike overcomes a preestablished minimum amplitude. Upon the spike meeting the flashback criteria, a count is added to a running record of spikes, which is compared to an alarm limit. If the alarm limit is triggered, action(s) are invoked to address the flashback events, such as adjusting fuel-flow splits of the GT engine. | 07-17-2014 |
20140200721 | Stabilizing A Gas Turbine Engine Via Incremental Tuning During Transients - Methods and systems are provided for automatically tuning a combustor of a gas turbine engine during a transient period, such as when a state of the gas turbine engine is changing. Once it has been determined whether the state of the gas turbine engine is changing, it is then determined whether a lean blowout is imminent, which is based conditions being monitored. A stability bias is applied to the system if either the state is changing or if lean blowout is imminent until the lean blowout is no longer determined to be imminent. The stability bias monitors operating conditions of the gas turbine engine and determines when one of the operating conditions has overcome a threshold value. Once a threshold value is overcome, a fuel flow fraction is adjusted by a predefined increment. The application of the stability bias is gradually terminated once it is determined that the lean blowout is no longer imminent. | 07-17-2014 |
20140277789 | DYNAMIC TUNING OF A GAS TURBINE ENGINE TO DETECT AND PREVENT LEAN BLOWOUT - A method for tuning a combustor of a gas turbine engine based on one or more monitored operating conditions is provided. One or more operating conditions of the gas turbine engine are monitored. The monitored operating conditions may include, for example, a low frequency tone, a high frequency tone, and a ratio of the low frequency tone to the high frequency tone. It is determined whether the ratio of the low frequency tone to the high frequency tone is within a first predefined normal range. If the ratio of the low frequency tone to the high frequency tone is within the first predefined normal range, a determination is made not to tune the gas turbine engine. But, if the ratio of the low frequency tone to the high frequency tone is not within the first predefined normal range, a determination is made to tune the gas turbine engine. | 09-18-2014 |
20140277790 | ENSURING NON-EXCESSIVE VARIATION OF GRADIENTS IN AUTO-TUNING A GAS TURBINE ENGINE - Methods are provided for ensuring non-excessive variation of a gradient of an applied split bias versus firing temperature of a gas turbine engine. It is determined that an incremental split bias step is to be taken, and a current firing temperature of the gas turbine engine is identified on a graph. A first difference between a split schedule and an applied schedule gradient is calculated using lower firing temperatures than the current firing temperature, and a second difference is calculated using higher firing temperatures. If the first difference exceeds a predetermined limit, the incremental split bias step is not allowed at a lower firing temperature, and similarly, if the second difference exceeds a predetermined limit, the incremental split bias step is not allowed at a higher firing temperature. | 09-18-2014 |
20150075172 | FLAMESHEET COMBUSTOR CONTOURED LINER - The present invention discloses a novel apparatus and way for reducing the recirculation zone at the inlet end of a combustor. The recirculation zone is reduced by altering the geometry of the inlet end through a tapering of the liner wall thickness and a tapering of the thermal barrier coating to reduce the bluff body effect at the combustion liner inlet end. | 03-19-2015 |
Patent application number | Description | Published |
20090069583 | ETHYLENE OXIDE PRODUCTION USING FIXED MODERATOR CONCENTRATION - A method for controlling ethylene oxidation uses ethylene and oxygen, in conjunction with a silver based catalyst, a moderator and a co-moderator, to form ethylene oxide. When controlling the ethylene oxidation reaction, the moderator concentration is maintained constant within a comparatively narrow operative concentration range and the co-moderator concentration is varied within a comparatively wider operative concentration range, to optimize a catalyst property such as the catalyst activity and/or the catalyst selectivity. | 03-12-2009 |
20090082584 | PROCESS FOR INITIATING A HIGHLY SELECTIVE ETHYLENE OXIDE CATALYST - A process for initiating a highly selective ethylene oxide catalyst is provided in which the highly selective ethylene oxide catalyst is operated first as a ‘standard’ Ag-based catalyst (e.g., a catalyst that contains only silver and alkali metal, especially cesium). Moreover, the inventive initiation procedure is more efficient when the concentration of carbon dioxide in the feed is higher than 6 vol. %, and even more efficient when the concentration of carbon dioxide in the feed is higher than 10 vol. %, of the feed mixture during the initiation period. | 03-26-2009 |
20090277305 | RECOVERY OF RHENIUM - The present invention relates to a method for recovering rhenium from an ethylene oxide catalyst containing rhenium and at least silver on a solid support, wherein at least a substantial portion of the rhenium present in the catalyst is extracted by intimate contact of the catalyst with one or more polar non-acidic organic solvents substantially free of water such that a rhenium-containing solution is formed containing the polar non-acidic organic solvent and extracted rhenium, the polar non-acidic organic solvent containing one or more oxygen, nitrogen, and/or halogen atoms in its molecular structure. | 11-12-2009 |
20110152549 | PROCESS FOR INITIATING A HIGHLY SELECTIVE ETHYLENE OXIDE CATALYST - A start-up process for epoxidation of ethylene is provided. The process includes initiating an epoxidation reaction by reacting a feed gas composition in the presence of an epoxidation catalyst at a first temperature of about 180° C. to about 210° C. The first temperature is increased to a second temperature of about 230° C. to about 290° C., over a time period of about 6 hours to about 50 hours, while simultaneously adding a sufficient concentration of moderator so that the amount of moderator adsorbed on the catalyst after achieving the second temperature is from about 10 to about 50 g/m | 06-23-2011 |
20110281724 | METHOD FOR MAKING A HIGHLY SELECTIVE ETHYLENE OXIDE CATALYST - A process for the preparation of a catalyst useful for the vapor phase production of ethylene oxide from ethylene and oxygen comprising providing a catalyst precursor comprising an inert support having a catalytically effective amount of a silver containing compound, a promoting amount of an alkali metal containing compound, and a promoting amount of a transition metal containing compound disposed thereon; calcining the catalyst precursor to convert the silver in the silver containing compound to metallic silver by heating the catalyst precursor to form a catalyst; and curing the catalyst in an inert gas atmosphere at temperatures of about 250° C. to about 600° C. for a period of about 1 hour to 200 hours. | 11-17-2011 |
20130006002 | PROCESS FOR PREPARATION OF A CATALYST CARRIER - This invention relates to catalyst carriers to be used as supports for metal and metal oxide catalyst components of use in a variety of chemical reactions. More specifically, the invention provides a process of formulating a low surface area alpha alumina carrier that is suitable as a support for silver and the use of such catalyst in chemical reactions, especially the epoxidation of ethylene to ethylene oxide. A precursor for a catalyst support comprises an admixture of an alpha alumina and/or a transition alumina; a binder; and either a solid blowing agent which expands, or propels a gas upon the application of sufficient heat, and optionally contains talc and/or water soluble titanium compound. | 01-03-2013 |
20140343306 | CARRIER TREATMENT TO IMPROVE CATALYTIC PERFORMANCE OF AN ETHYLENE OXIDE CATALYST - A method for lowering the sodium content of different carriers which may have different physical properties as well as varying degrees of sodium is provided. The method, which lowers the sodium content from the surface, subsurface as well as the binding layer of the carrier, includes contacting a carrier with water. A rinse solution is recovered from the contacting. The rinse solution includes leached sodium from the carrier. The sodium content in the rinse solution is then determined. The contacting, recovering and determining are repeated until a steady state in the sodium content is achieved. | 11-20-2014 |
20140343307 | CARRIER FOR ETHYLENE OXIDE CATALYSTS - A carrier for an ethylene epoxidation catalyst is provided that includes an alumina first component and a mixed metal oxide of alumina second component. The mixed metal oxide of alumina second component comprises a corundum lattice structure having a plurality of O—Al—O bonds, wherein an Al atom of at least one O—Al—O bond of the plurality of O—Al—O bonds, but not all of the plurality of O—Al—O bonds, is replaced with a divalent or trivalent transition metal selected from the group consisting of scandium (Sc), titanium (Ti), vanadium (V), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni) copper (Cu), and zinc (Zn). A catalyst containing the carrier, as well as a process for the epoxidation of ethylene using the catalyst are also disclosed. | 11-20-2014 |
20140343308 | SILVER-BASED ETHYLENE OXIDE CATALYST HAVING REDUCED SODIUM CONTENT - A silver-based ethylene oxide catalyst that can be used in the vapor phase conversion of ethylene to ethylene oxide in the presence of oxygen is provided that includes a carrier; a catalytic effective amount of silver; and a promoting amount of at least one promoter, wherein the catalyst has a surface sodium content of 100 ppm or less. | 11-20-2014 |
20150057150 | METHOD FOR MAKING A HIGHLY SELECTIVE ETHYLENE OXIDE CATALYST - A process for the preparation of a catalyst useful for the vapor phase production of ethylene oxide from ethylene and oxygen comprising providing a catalyst precursor comprising an inert support having a catalytically effective amount of a silver containing compound, a promoting amount of an alkali metal containing compound, and a promoting amount of a transition metal containing compound disposed thereon; calcining the catalyst precursor to convert the silver in the silver containing compound to metallic silver by heating the catalyst precursor to form a catalyst; and curing the catalyst in an inert gas atmosphere at temperatures of about 250° C. to about 600° C. for a period of about 1 hour to 200 hours. | 02-26-2015 |