# US 2010/0168980 A1 · Operating a turbine at baseload on cold fuel with hot fuel combustion hardware > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2010/0168980 A1 - Document ID: US20100168980A1 - Status: Published application - Kind: A1 - Application number: 12/347,384 - Filed: 2008-12-31 - Published: 2010-07-01 - Earliest claimed: 2008-12-31 - Assignees: General Electric Company - Inventors: Jason D. Fuller; Garth C. Frederick; John C. Maters; Douglas C. Morgan; Luls M. Flamand - Web page: https://patentgrep.com/patent/US20100168980A1 ## CPC - F02C 7/228: Dividing fuel between various burners - F02C 9/34: Joint control of separate flows to main and auxiliary burners - F02C 9/40: specially adapted to the use of a special fuel or a plurality of fuels - F23R 3/34: Feeding into different combustion zones - F23R 3/36: Supply of different fuels - F05D 2270/08: to produce clean exhaust gases - F05D 2270/09: to cope with emergencies - F05D 2270/31: Fuel schedule for stage combustors - F23N 2221/10: Analysing fuel properties, e.g. density, calorific - F23N 2241/20: Gas turbines - F23R 2900/00013: Reducing thermo-acoustic vibrations by active means - 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) - F23R: GENERATING COMBUSTION PRODUCTS OF HIGH PRESSURE OR HIGH VELOCITY, e.g. GAS-TURBINE COMBUSTION CHAMBERS (fluidised bed combustion apparatus specially adapted for operation at superatmospheric pressures F23C10/16) - F05D: INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS - F23N: REGULATING OR CONTROLLING COMBUSTION (control devices specially adapted for combustion apparatus in which combustion takes place in a fluidised bed of fuel or other particles F23C10/28; condition responsive controls for regulating combustion in domestic stoves with open fires for solid fuel F24B1/187) ## Abstract A method and algorithm are provided to operate a gas turbine at baseload in an emission compliant capable mode to avoid combustion dynamics while operating with cold fuel and hot fuel combustion hardware. The method includes performing a gas turbine operational sequence such as a startup to an emission compliant capable mode. A gas fuel temperature is measured. The gas turbine is operated in the emissions compliant capable mode according to a designated fuel split for avoiding combustion dynamics when a temperature for a gas fuel is below a designated value. A determination is made whether a modified wobbe index for the gas fuel is below an emissions compliant value. An alarm is activated if the modified wobbe index is below the emissions compliant value to notify the operator of a potential emissions shift. ## Claims ### Claim 1 A method to operate a gas turbine at high loads in an emission compliant capable mode to avoid combustion dynamics while operating with cold fuel and hot fuel combustion hardware, comprising: performing a gas turbine operational sequence; measuring a gas fuel temperature; operating the gas turbine in an emissions compliant capable mode according to a designated fuel split for avoiding combustion dynamics in an emission compliant capable mode when a temperature for a gas fuel is below a designated value; and heating the gas fuel temperature to at least the designated value, when possible. ### Claim 2 (depends on 1) The method to operate a gas turbine at high loadsin an emission compliant capable mode according to claim 1, wherein the designated fuel split includes a designated fuel split for a quaternary nozzle. ### Claim 3 (depends on 2) The method to operate a gas turbine at high loads in an emission compliant capablemode according to claim 2, futher comprising: adjusting the designated fuel split for the quaternary nozzle as a function of gas fuel temperature. ### Claim 4 (depends on 3) The method to operate a gas turbine at high loads in an emission compliant capable mode according to claim 3, further comprising: determining if a modified wobbe index for operation is within tolerance for emissions compliant operation. ### Claim 5 (depends on 4) The method to operate a gas turbine at high loads in an emission compliant capable mode according to claim 4, further comprising: alarming to inform operator if the modified wobbe index for operation is outside the tolerance for emission compliant operation. ### Claim 6 (depends on 1) The method to operate a gas turbine at high loads in an emission compliant capable mode according to claim 1, wherein the operational sequence is a gas turbine startup. ### Claim 7 (depends on 1) The method adapted to allow a gas turbine to operate at high loads in an emission compliant capable mode according to claim 1, wherein the operational sequence is a response to a loss of fuel temperature control. ### Claim 8 (depends on 3) The method adapted to allow a gas turbine to operate at high loads in an emission compliant capable mode according to claim 3, wherein the designated split for the quaternary nozzle is reduced in response to reduced gas fuel temperature. ### Claim 9 (depends on 3) The method adapted to allow a gas turbine to operate at high loads in an emission compliant capable mode according to claim 3, wherein the designated split for the quaternary nozzle employs a split bias and curve developed from field data operational experience. ### Claim 10 An algorithm whose technical effect is to allow a gas turbine operating under an emission compliant capable mode at high loads to avoid combustion dynamics while operating with cold gas fuel and hot fuel combustion hardware, comprising: disabling interlocks, in a control system for the gas turbine, preventing mode transitions with cold gas fuel from an initial startup mode to an emissions compliant capable mode at baseload operation; and scheduling a quaternary fuel split to mitigate combustion dynamics at high loads in an emission compliant capable mode based on gas fuel temperature. ### Claim 11 (depends on 10) The algorithm according to claim 10, further comprising: calculating a modified wobbe index for the cold gas fuel; and determining whether the modified wobbe index for the cold gas fuel is within tolerance for emissions compliant operation. ### Claim 12 (depends on 11) The algorithm according to claim 11, further comprising: initiating an alarm function adapted to alert an operator to a modified wobbe index out of range for the emissions compliant mode. ### Claim 13 (depends on 10) The algorithm according to claim 10, the step of scheduling a quaternary fuel split comprising: reducing the quaternary fuel split as gas fuel temperature is reduced. ### Claim 14 (depends on 10) The algorithm according to claim 10, the step of scheduling a quaternary fuel split comprising: biasing the quaternary fuel split from the nominal fuel split. ### Claim 15 (depends on 10) The algorithm according to claim 10, the step of disabling interlocks comprising: at least one of bypassing a raise inhibit signal to allow loading on cold fuel and bypassing a modified wobbe index requirement to allow mode 4 fuel transfer with cold fuel. ### Claim 16 (depends on 10) The algorithm according to claim 10, further comprising: initiating a prefill for quaternary fuel schedule prior to shifting to the emissions compliant capable mode. ### Claim 17 A gas turbine control system adapted to allow a gas turbine with an emission compliant capable mode to avoid combustion dynamics while operating with cold fuel and hot fuel combustion hardware, comprising: a gas turbine operational sequence including interlocks adapted to prevent mode transitions, from an initial startup mode to an emission compliant capable mode at baseload, while operating with cold gas fuel; a gas fuel temperature measurement; an algorithm whose technical effect is to disable interlocks adapted to prevent mode transitions with cold gas fuel from an initial startup mode to an emissions compliant capable mode at baseload operation; and a schedule for a quaternary fuel split to mitigate combustion dynamics at high loads in an emission compliant capable mode based on gas fuel temperature. ### Claim 18 (depends on 17) The gas turbine control system according to claim 17, further comprising: a calculation of a modified wobbe index for gas turbine; a determination whether the calculation of the modified wobbe index for the gas turbine falls within emission compliant tolerances; and an alarm adapted to alert an operator when the modified wobbe index falls outside emission compliant tolerances to alert them of potential emissions out of compliance ### Claim 19 (depends on 17) The gas turbine control system according to claim 17, a schedule for a quaternary fuel split further comprising: a designated fuel split schedule bias for the quaternary nozzle as a function of gas fuel temperature. ### Claim 20 (depends on 19) The gas turbine control system according to claim 19, a schedule for a quaternary fuel split further comprising: a decrease in the quaternary fuel split as gas temperature decreases.