# US 2016/0252017 A1 · Method for controlling the operation of a gas turbine with sequential combustion > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2016/0252017 A1 - Document ID: US20160252017A1 - Status: Published application - Kind: A1 - Application number: 15/006,480 - Filed: 2016-01-26 - Published: 2016-09-01 - Earliest claimed: 2015-02-26 - Applicants: ALSTOM Technology Ltd - Inventors: Andreas Jan Schesny; Pimin Schiessel; Piotr Siewert; Torsten Lüddecke; Rajeshwor Dhital - Web page: https://patentgrep.com/patent/US20160252017A1 ## CPC - F02C 7/057: Control or regulation (conjointly with fuel supply control F02C9/50, with nozzle area control F02K1/16) - F01D 21/003: {Arrangements for testing or measuring (for measuring vibrations G01H)} - F02C 3/14: characterised by the arrangement of the combustion chamber in the plant (combustion chambers per se F23R; F02C3/205 takes precedence) - F02C 6/003: {Gas-turbine plants with heaters between turbine stages} - F02C 7/042: having variable geometry - F02C 9/22: by adjusting turbine vanes - F02C 9/28: Regulating systems responsive to plant or ambient parameters, e.g. temperature, pressure, rotor speed (F02C9/30 - F02C9/38, F02C9/44 take precedence) - F02C 9/54: by throttling the working fluid, by adjusting vanes - F05D 2220/32: in gas turbines - F05D 2240/35: Combustors or associated equipment - F05D 2250/52: Outlet - F05D 2270/303: Temperature - F05D 2270/309: Rate of change of parameters - F02C: GAS-TURBINE PLANTS; AIR INTAKES FOR JET-PROPULSION PLANTS; CONTROLLING FUEL SUPPLY IN AIR-BREATHING JET-PROPULSION PLANTS (construction of turbines F01D; jet-propulsion plants F02K; construction of compressors or fans F04; generating combustion products of high pressure or high velocity F23R; using gas turbines in compression refrigeration plants F25B11/00) - F01D: NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES (machines or engines for liquids F03; non-positive displacement pumps F04D) - F05D: INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS ## Abstract A method for controlling the operation of a gas turbine with sequential combustion, which gas turbine comprises a compressor with variable inlet guide vanes (VIGV), a first combustor, a high-pressure turbine downstream of the first combustor, a second combustor downstream of the high-pressure turbine, and a low-pressure turbine downstream of the second combustor. ## Claims ### Claim 1 A method for controlling the operation of a gas turbine with sequential combustion, which gas turbine comprises a compressor with variable inlet guide vanes (VIGV), a first combustor, a high-pressure turbine Downstream of said first combustor, a second combustor downstream of said high-pressure turbine, and a low-pressure turbine downstream of said second combustor, said method comprising the steps of: verifying that the gas turbine operates under base load conditions; continuously measuring locally at various points the turbine outlet temperature TAT1 of the high-pressure turbine; averaging over the various local TAT1 measurement values to get an average TAT1 temperature (TAT1 AVG); controlling the operation of the first combustor in dependence of said average TAT1 temperature (TAT1 AVG); checking if at least one local TAT1 measurement value, which is higher than said average TAT1 temperature (TAT1 AVG), is increasing; adjusting said average TAT1 temperature (TAT1 AVG), if said at least one local TAT1 measurement value is increasing above a predetermined threshold value. ### Claim 2 (depends on 1) The method as claimed in claim 1, wherein said base load conditions comprise said variable inlet guide vanes (VIGV) to be open, a turbine inlet temperature (TIT1) of said first combustor being at a base load value, and a turbine inlet temperature (TIT2) of said second combustor being at a base load value. ### Claim 3 (depends on 1) The method as claimed in claim 1, wherein the moving average of a plurality of local TAT1 measurement values, which are higher than said average TAT1 temperature (TAT1 AVG), is checked, and said average TAT1 temperature (TAT1 AVG) is adjusted, if said moving average is increasing above a predetermined threshold value. ### Claim 4 (depends on 3) The method as claimed in claim 3, wherein the largest local TAT1 measurement value of said moving average is neglected. ### Claim 5 (depends on 3) The method as claimed in claim 3, wherein said moving average is evaluated on a time scale of 10 minutes or longer. ### Claim 6 (depends on 5) The method as claimed in claim 5, wherein said moving average is evaluated on a time scale of 20 minutes. ### Claim 7 (depends on 1) The method as claimed in claim 1, wherein said predetermined threshold value is at least 5 K above a local TAT1 reference value. ### Claim 8 (depends on 7) The method as claimed in claim 7, wherein said predetermined threshold value is 10 K above a local TAT1 reference value. ### Claim 9 (depends on 1) The method as claimed in claim 1, wherein said adjusting of the average TAT1 temperature (TAT1 AVG) is done by stepwise decreasing said average TAT1 temperature (TAT1 AVG) by a predetermined amount. ### Claim 10 (depends on 3) The method as claimed in claim 3, wherein the NOx content of the exhaust gases of the gas turbine is measured by NOx CEMS measuring means, and that said average TAT1 temperature (TAT1 AVG) is only adjusted, if in addition the moving average of the NOx CEMS emission measurement values is above a predetermined threshold value. ### Claim 11 (depends on 10) The method as claimed in claim 10, wherein said moving average of the NOx CEMS emission measurement values is evaluated on a time scale of 20 minutes, and said threshold value is at 80% of guaranteed NOx emission level. ### Claim 12 (depends on 10) The method as claimed in claim 10, wherein pressure pulsations are measured in said first combustor, and that said average TAT1 temperature (TAT1 AVG) is only adjusted, if in addition the low frequency part of said measured pressure pulsations, especially in the frequency band between 100 Hz and 150 Hz, are below a predetermined threshold value, of especially 30 mbar. ### Claim 13 (depends on 12) The method as claimed in claim 12, wherein said average TAT1 temperature (TAT1 AVG) is only adjusted, if all said adjustment criteria are fulfilled for a predetermined number of separate base load cycles and a predetermined time of operation. ### Claim 14 (depends on 13) The method as claimed in claim 13, wherein said predetermined number of separate base load cycles is at least 5, and that said predetermined time of operation is at least 120 minutes.