초록 ▼

A system and method to reduce the gas fuel supply pressure requirements of a gas turbine, which results in an increased operability range and a reduction in gas turbine trips. According to the method, the gas turbine is allowed to start and operate at supply pressures determined as a function of amb

A system and method to reduce the gas fuel supply pressure requirements of a gas turbine, which results in an increased operability range and a reduction in gas turbine trips. According to the method, the gas turbine is allowed to start and operate at supply pressures determined as a function of ambient conditions and gas turbine compressor pressure ratio. This increases the operability window, and reduces or eliminates the need for gas fuel compressors.

대표청구항 ▼

What is claimed is: 1. A method of determining a fuel pressure reference for supply from a pressure control valve to a gas flow rate control valve of a plurality of fuel nozzles in a gas turbine combustor, comprising: determining a first required fuel pressure directly upstream of the fuel nozzles;

What is claimed is: 1. A method of determining a fuel pressure reference for supply from a pressure control valve to a gas flow rate control valve of a plurality of fuel nozzles in a gas turbine combustor, comprising: determining a first required fuel pressure directly upstream of the fuel nozzles; determining a minimum allowable pressure requirement upstream of the gas flow rate control valve based on said first required fuel pressure; and determining the fuel pressure reference for control of the pressure control valve based on said minimum allowable pressure requirement. 2. A method as in claim 1, wherein said minimum allowable pressure requirement is a minimum allowable fuel pressure to maintain choked operation of said gas flow rate control valve. 3. A method as in claim 1, wherein the fuel pressure reference is determined based on said minimum allowable pressure requirement, available supply pressure, and base load fuel pressure requirement. 4. A method as in claim 3, wherein said base load pressure requirement is based on a cold ambient day base load pressure requirement. 5. A method as in claim 3, wherein said base load pressure requirement is based on a cold ambient day base load pressure requirement that has been adjusted based on compressor inlet temperature. 6. A method as in claim 3, wherein the minimum allowable pressure requirement is determined based on said first required fuel pressure, a piping pressure drop between the gas flow rate control valve and the fuel nozzle, and a gas flow rate control valve pressure drop. 7. A method as in claim 1, wherein the minimum allowable pressure requirement is determined based on said first required fuel pressure, a piping pressure drop between the gas flow rate control valve and the fuel nozzle, and a gas flow rate control valve pressure drop. 8. A method as in claim 1, wherein said first required fuel pressure is selectively determined based compressor discharge pressure. 9. A method as in claim 8, wherein said first required fuel pressure, P4, is determined as for unchoked nozzle pressure ratios and as for choked nozzle pressure ratios, where M=Fuel flow, lb/sec Pcc=CPD--Combustor Pressure Drop Ae=Nozzle Effective Area g=Acceleration due to gravity, ft/sec2 k=specific heat ratio, CP/CV R=Universal gas constant, lbf.ft/lbm.R T=Fuel Temperature, degrees Rankine.