Constant NO.sub.x control for gas turbine
AssigneeDreser Industries, Inc.
InventorHarry A. Kidd
Life of this patent
Estimating the term…
Abstract
A method and apparatus for automatically maintaining gas turbine NO.sub.x emissions at a substantially constant level during all ambient conditions and for no load to full load fuel flows. The required water/fuel ratio is calculated for a substantially constant level of NO.sub.x emissions at the given operating conditions and, knowing the actual fuel flow to the gas turbine, a signal is generated representing the water metering valve position necessary to inject the proper water flow into the combustor to achieve the desired water/fuel ratio.
Claims10
A system for automatically maintaining substantially constant nitrogen oxide emissions from a gas turbine burning a gaseous or liquid fossil fuel injected through at least one fuel input valve by the use of variable quantities of water injected in the combustor through a water input valve, the system comprising:
- a. means for determining a corrected rotational speed, CGG, of said gas generator according to the formula ##EQU15## where AGG=the actual rotational speed of said gas generator, ##EQU16## the gas generator air inlet temperature correction factor, and T.sub.2 =compressor inlet temperature, and
- b. means coupled to said determining means for automatically varying the water/fuel ratio, WFR, by changing the volume of water input through said water valve to said gas generator with variation in load, inlet temperature and turbine speed according to the formula ##EQU17## where N.sub.1 =minimum corrected gas generator speed for WFR=0.0, N.sub.2 =(corrected gas generator speed for WFR=1.0)-N.sub.1 and K=constant thereby maintaining a substantially constant emission of oxides of nitrogen from said gas turbine.
A method for automatically maintaining substantially constant nitrogen oxide emissions from a gas turbine burning a gaseous or liquid fossil fuel injected through at least one fuel input valve by the use of variable quantities of water injected in the combustor through a water injected input valve, the method comprising the steps of:
- a. determining a corrected rotational speed, CGG, of said gas generator according to the formula ##EQU21## where AGG=the actual rotational speed of said gas gas generator, ##EQU22## the gas generator air temperature correction factor, and T.sub.2 =compressor inlet temperature, and
- b. automatically varying the water/fuel ratio, WFR, by changing the volume of water input to said gas generator with variation in load, inlet temperature and turbine speed according to the formula ##EQU23## where N.sub.1 =minimum corrected gas generator speed for WFR=0.0, N.sub.2 =(corrected gas generator rotational speed for WFR=1.0)-N.sub.1 and K=constant thereby maintaining a substantially constant emission of oxides of nitrogen from said gas turbine.
Dependencies are inferred from the claim text.