US 11,236,676 B2Granted

Humid air turbine

AssigneeMitsubishi Power, Ltd.

InventorsYasushi Iwai, Hidefumi Araki, Takuya Takeda

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Abstract

The invention aims to shorten the time required for start-up and prevent excessive increases in the heat loads on turbine blades. A humid air turbine includes a compressor; a combustor; a turbine; an exhaust heat recovery unit for recovering the heat of turbine exhaust gas to generate high-temperature moisture; a fuel supply system having a fuel flow rate control valve; an exhaust temperature acquiring unit for acquiring a temperature of the exhaust discharged while the turbine is driven; a combustion gas moisture ratio calculating section for calculating a ratio of moisture contained in combustion gas; an exhaust temperature upper limit calculating section for setting an exhaust temperature upper limit based on the combustion gas moisture ratio and the pressure ratio; an exhaust temperature difference calculating section for calculating the difference between the exhaust temperature upper limit and the exhaust temperature; a fuel flow rate command value calculating section for calculating a fuel flow rate command value using the exhaust temperature difference; and a control command value output section for outputting a command signal to the fuel flow rate control valve based on the command value selected by a fuel flow rate command value selecting section.

Claims12

Dependent claims

A humid air turbine comprising:

a compressor for compressing air to generate compressed air;
a moisture system for supplying moisture to intake air of the compressor or the compressed air generated by the compressor;
a combustor for mixing humid air generated by supplying the moisture to the intake air, or to the compressed air with a fuel, and combusting the mixture to generate combustion gas;
a fuel supply system, having a fuel flow rate control valve, for supplying the fuel to the combustor;
a turbine rotationally driven by the combustion gas supplied from the combustor;
a sensor configured to acquire an exhaust temperature that is a temperature of exhaust discharged while the turbine is driven;
and a controller configured to perform steps of:
calculating a pressure ratio of the compressor based on a discharge pressure and an intake pressure;
acquiring a combustion gas moisture ratio that is a ratio of moisture contained in the combustion gas based on a moisture supply amount and an intake flow rate;
calculating an upper limit for the exhaust temperature based on the combustion gas moisture ratio and the pressure ratio using a functional relation of an exhaust temperature upper limit to the pressure ratio of the compressor that is obtained in advance from a limiting value for a combustion gas temperature that changes according to the combustion gas moisture ratio and temperature constraints of an exhaust gas duct;
and outputting a command signal to the fuel flow rate control valve using a fuel flow rate command value calculated based on a difference between the exhaust temperature upper limit and the exhaust temperature, wherein the upper limit for the exhaust temperature is variable value that varies with the combustion gas moisture ratio and the pressure ratio.

8 more elements

A method for controlling a humid air turbine, comprising:

compressing, using a compressor, air to generate compressed air;
supplying, using a moisture system, moisture to intake air of the compressor or the compressed air generated by the compressor;
mixing, using a combustor, humid air generated by supplying the moisture to the intake air or the compressed air with a fuel and combusting the mixture to generate combustion gas;
supplying, using a fuel supply system having a fuel flow rate control valve, the fuel to the combustor;
rotationally driving a turbine by the combustion gas supplied from the combustor;
acquiring, using a sensor, an exhaust temperature that is a temperature of exhaust discharged while the turbine is driven;
and using a controller:
calculating a pressure ratio of the compressor based on a discharge pressure and an intake pressure;
acquiring a combustion gas moisture ratio that is a ratio of moisture contained in the combustion gas based on a moisture supply amount and an intake flow rate;
calculating an upper limit for the exhaust temperature based on the combustion gas moisture ratio and the pressure ratio using a functional relation of an exhaust temperature upper limit to the pressure ratio of the compressor that is obtained in advance from a limiting value for a combustion gas temperature that changes according to the combustion gas moisture ratio and temperature constraints of an exhaust gas duct;
and outputting a command signal to the fuel flow rate control valve using a fuel flow rate command value calculated based on a difference between the exhaust temperature upper limit and the exhaust temperature, wherein the upper limit for the exhaust temperature is variable value that varies with the combustion gas moisture ratio and the pressure ratio.

8 more elements

Dependencies are inferred from the claim text.

Facts

Application: 15/882,263Filed 29 Jan 2018
Priority: JP JP2017-0193486 Feb 2017
Published: US 2018/0223737 A19 Aug 2018
Granted: 1 Feb 2022
Term ends: Not estimatedThe source records don’t support an estimate.

Classification18 codes

F02C 7/26
Features, components parts, details or accessories, not provided for in, or of interest apart form groups F02C1/00 - F02C6/00; Air intakes for…:…
F01D 17/085
Responsive to condition of working-fluid, e.g. pressure: to temperature
F02C 3/04
Gas-turbine plants characterised by the use of combustion products as the working fluid: having a turbine driving a compressor
F02C 3/305
Adding water, steam or other fluids for influencing combustion, e.g. to obtain cleaner exhaust gases: increasing the power, speed, torque or…