Flow ratio calculation device, control device provided with same, gas turbine plant provided with said control device, flow ratio calculation method, and method for controlling fuel system

Patent metadata

Field	Value
Publication number	US-10612472-B2
Application number	US-201515325908-A
Country	US
Kind code	B2
Filing date	Jun 8, 2015
Priority date	Aug 6, 2014
Publication date	Apr 7, 2020
Grant date	Apr 7, 2020

Abstract

A flow ratio calculation device includes: a flow volume ratio computer that, using a predetermined relationship between a first parameter that can express a combustion state in a combustor and a flow volume ratio of fuels flowing through multiple fuel systems, is configured to find the flow volume ratio based on a value of the first parameter; a correction value computer configured to find a correction value of the flow volume ratio when a load of a gas turbine changes; a fluctuation sensor configured to sense fluctuations in a value correlated with the load of the gas turbine; and a corrector configured to correct the flow volume ratio found by the flow volume ratio computer with the correction value found by the correction value computer when a fluctuation in the value correlated with the load of the gas turbine is sensed by the fluctuation sensor.

First claim

The invention claimed is:

1. A flow ratio calculation device configured to be used in a gas turbine, the gas turbine including multiple fuel systems, a compressor configured to generate compressed air by compressing air, a combustor configured to generate a combustion gas by burning fuels from the multiple fuel systems in the compressed air, and a turbine configured to be driven by the combustion gas, the flow ratio calculation device being configured to calculate a flow volume ratio of the fuels in the multiple fuel systems, and the flow ratio calculation device comprising:
a flow volume ratio computer configured to receive a value of a first parameter among multiple parameters capable of expressing a combustion state in the combustor, and find the flow volume ratio based on the received value of the first parameter using a predetermined relationship between the first parameter and the flow volume ratio;
a correction value computer configured to find a correction value of the flow volume ratio corresponding to a load percentage indicating a current load with respect to a maximum load permitted for the gas turbine;
a fluctuation sensor configured to sense a fluctuation in a fuel flow volume command value specifying a total flow volume of the fuels supplied to the combustor; and
a corrector that, upon a fluctuation in the fuel flow volume command value being sensed by the fluctuation sensor, is configured to correct the flow volume ratio found by the flow volume ratio computer with the correction value found by the correction value computer.

2. The flow ratio calculation device according to claim 1 ,
wherein the correction value computer is configured to receive a value of a second parameter, among the multiple parameters, that is different from the first parameter, and find the correction value based on the received value of the second parameter using a predetermined relationship between the second parameter and the correction value, and
wherein the second parameter is the load percentage.

3. The flow ratio calculation device according to claim 2 ,
wherein:
the first parameter is an inlet temperature correlated value that is a value changing in correlation with changes in an inlet temperature of the combustion gas in the turbine or that is the inlet temperature.

4. The flow ratio calculation device according to claim 2 ,
wherein:
the correction value includes an increase correction value and a decrease correction value;
the correction value computer includes an increase time correction value computer configured to find the increase correction value based on the value of the second parameter when the fuel flow volume command value is increasing, using a predetermined increase time relationship between the second parameter and the increase correction value at a time when the fuel flow volume command value is increasing, and a decrease time correction value computer configured to find the decrease correction value based on the value of the second parameter when the fuel flow volume command value is decreasing, using a predetermined decrease time relationship between the second parameter and the decrease correction value at a time when the fuel flow volume command value is decreasing; and
the corrector is configured to correct the flow volume ratio found by the flow volume ratio computer with the increase correction value upon the fluctuation sensor sensing an increase in the fuel flow volume command value, and correct the flow volume ratio found by the flow volume ratio computer with the decrease correction value upon the fluctuation sensor sensing a decrease in the fuel flow volume command value.

5. The flow ratio calculation device according to claim 4 ,
wherein:
the combustor includes a pilot burner and a main burner configured to spray the fuels;
the gas turbine includes, as the multiple fuel systems, a pilot fuel system configured to supply a first of the fuels to the pilot burner and a main fuel system configured to supply a second of the fuels to the main burner;
the flow volume ratio includes a pilot fuel ratio that is a ratio of a flow volume of the first of the fuels relative to the total flow volume of the fuels supplied to the combustor from the multiple fuel systems; and
the correction value computer is configured to calculate the correction value so as to increase the pilot fuel ratio calculated by the flow volume ratio computer.

6. The flow ratio calculation device according to claim 5 ,
wherein, upon the fluctuation sensor sensing a decrease in the fuel flow volume command value, the corrector is configured to correct the pilot fuel ratio using the correction value found by the correction value computer so that the pilot fuel ratio calculated by the flow volume ratio computer increases.

7. The flow ratio calculation device according to claim 2 ,
wherein:
the combustor includes a pilot burner and a main burner configured to spray fuels;
the gas turbine includes, as the multiple fuel systems, a pilot fuel system configured to supply a first of the fuels to the pilot burner and a main fuel system configured to supply a second of the fuels to the main burner;
the flow volume ratio includes a pilot fuel ratio that is a ratio of a flow volume of the first of the fuels relative to the total flow volume of the fuels supplied to the combustor from the multiple fuel systems;
the correction value includes an increase correction value and a decrease correction value;
the correction value computer includes an increase time correction value computer configured to find the increase correction value based on the value of the second parameter when the fuel flow volume command value is increasing, using a predetermined increase time relationship between the second parameter and the increase correction value at a time when the fuel flow volume command value is increasing, and a decrease time correction value computer configured to find the decrease correction value based on the value of the second parameter when the fuel flow volume command value is decreasing, using a predetermined decrease time relationship between the second parameter and the decrease correction value at a time when the fuel flow volume command value is decreasing;
the corrector is configured to correct the flow volume ratio found by the flow volume ratio computer with the increase correction value upon the fluctuation sensor sensing an increase in the fuel flow volume command value, and correct the flow volume ratio found by the flow volume ratio computer with the decrease correction value upon the fluctuation sensor sensing a decrease in the fuel flow volume command value; and
the decrease time correction value computer is configured to calculate the decrease correction value such that the decrease correction value is greater than the increase correction value when the value of the second parameter is the same value.

8. The flow ratio calculation device according to claim 1 ,
wherein:
the combustor includes a pilot burner and a main burner configured to spray the fuels;
the gas turbine includes, as the multiple fuel systems, a pilot fuel system configured to supply a first of the fuels to the pilot burner and a main fuel system configured to supply a second of the fuels to the main burner; and
the flow volume ratio includes a pilot fuel ratio that is a ratio of a flow volume of the first of the fuels relative to the total flow volume of the fuels supplied to the combustor from the multiple fuel systems.

9. The flow ratio calculation device according to claim 1 ,
wherein:
the combustor includes a burner configured to spray a first of the fuels;
the gas turbine includes, as the multiple fuel systems, a burner fuel system configured to

Assignees

• Mitsubishi Hitachi Power Sys

Inventors

• Endo Yoji
• NAKAGAWA Jotaro
• Ochiai Yoshiaki

Classifications

• F05D2260/964

  counteracting thermoacoustic noise · CPC title

• F02C9/28 Primary

  Regulating systems responsive to plant or ambient parameters, e.g. temperature, pressure, rotor speed (F02C9/30 - F02C9/38, F02C9/44 take precedence) · CPC title

• F23R2900/00013

  Reducing thermo-acoustic vibrations by active means · CPC title

• F23N2237/02

  two or more burners · CPC title

• F23R3/36

  Supply of different fuels · CPC title