GAS TURBINE CONTROL METHOD AND DEVICE

• US 20110004390A1
• Filed: 04/10/2009
• Published: 01/06/2011
• Est. Priority Date: 09/29/2008
• Status: Active Grant

• Current Assignee: Mitsubishi Power Limited (Mitsubishi Heavy Industries, Ltd.)
• Original Assignee: Mitsubishi Heavy Industries, Ltd.
• Inventors: Toyama, Kozo, Nomura, Masumi
• Granted Patent: US 8,406,978 B2
• Time in Patent Office: Days
• US Class Current: 701/100
• CPC Class Codes: F02C 9/28 Regulating systems responsive to plant or ambient parameters, e.g. temperature, pressure, rotor speed F02C9/30 - F02C9/38, F02C9/44 take precedence
• CPC Class Codes: F02C 9/34 Joint control of separate flows to main and auxiliary burners
• CPC Class Codes: F02C 9/50 with control of working fluid flow
• CPC Class Codes: F05D 2270/44 active, predictive, or anticipative

Abstract

Provided is a gas turbine control method and control device whereby a design performance and an operating state based on ideal fuel flow rate and air flow rate simulated at the time of designing can be maintained by preventing an operation deviated from an operating condition that is based on ideal fuel flow rate and air flow rate simulated by initial design values, in a gas turbine control method designed to search optimal operating conditions automatically using control inputs such as a pilot ratio. The gas turbine controller comprises a second database that stores load sensitivity, i.e. the correlation between the load amount of a gas turbine and control inputs such as a fuel flow rate, air flow rate, pilot fuel ratio, and top hat fuel ratio in the gas turbine, wherein the amount of load variation for at least one of control inputs, a fuel flow rate or an air flow rate supplied to a combustor is predicted according to operational conditions obtained by searching using the load sensitivity, regulation is made according to the prediction results, and the regulation results are stored in the second database.

Claims

1. A gas turbine control method, provided with a gas turbine comprising:

a plurality of combustors, and

a first database that memorizes an optimal operation condition as to each combustor; and

the gas turbine control method is used for adjusting at least one of a fuel flow rate toward the combustor and an airflow rate toward the combustor in response to the optimal operation condition,

in a manner that the optimal operation condition is searched by fluctuating at least one of the fuel flow rate and the airflow rate, while combustion vibrations are not occurring, and

in a manner that the memory contents of the first database are renewed with the data as to the optimal operation condition that is obtained by the searching;

wherein,

a second database is provided in which load sensitivity coefficients, which show a correlation between the actuating variables such as the fuel flow rate, the airflow rate, a pilot ratio and a top-hat ratio of the gas turbine, and a gas turbine power output, are memorized;

a load increment change in response to actuating variables of at least one of the fuel flow rate toward the combustor and the airflow rate toward the combustor is estimated according to the optimal operation conditions obtained by the searching by use of the load sensitivity coefficients; and

at least one of the fuel flow rate and the airflow rate is adjusted on the basis of the estimation results, and the contents of the first database are renewed according to the results of the adjustments.

2. The gas turbine control method according to claim 1, wherein

the load sensitivity coefficients are calculated on the basis of the actuating variables, operation status signals and a gas turbine load while the gas turbine is being operated, in which the actuating variables includes the airflow rate, the pilot ratio and the top-hat ratio, and the operation status signals includes atmosphere conditions and the gas turbine load, and

the calculated load sensitivity coefficients are memorized and renewed in a second database.

3. A gas turbine control device, provided with a gas turbine having a plurality of combustors and a first database that memorizes an optimal operation condition as to each combustor, and a correction amount determining means for performing a search control for the purpose of adjusting at least one of a fuel flow rate toward the combustor and an airflow rate toward the combustor in response to the optimal operation condition;

in a manner that the optimal operation condition is searched by fluctuating at least one of the fuel flow rate and the airflow rate, while combustion vibrations are not occurring, and

in a manner that the memory contents of the first database are renewed with the data as to the optimal operation condition that is obtained by the searching;

wherein,

a second database is provided in which load sensitivity coefficients, which show a correlation between the actuating variables such as the fuel flow rate, the airflow rate, a pilot ratio and a top-hat ratio of the gas turbine, and a gas turbine power output, are memorized;

the correction amount determining means estimates a load increment change in response to actuating variables of at least one of the fuel flow rate toward the combustor and the airflow rate toward the combustor by use of the load sensitivity coefficients that are memorized in the second database, in response to the optimal operation condition obtained by fluctuating at least one of the fuel flow rate and the airflow rate during the search control; and

at least one of the fuel flow rate and the airflow rate is adjusted on the basis of the estimation results, thereby the contents of the first database are renewed according to the results of the adjustments.

4. A gas turbine control device having a gas turbine comprising a plurality of combustors and a first database that memorizes an optimal operation condition as to each combustor, and a correction amount determining means for performing a search control for the purpose of adjusting at least one of a fuel flow rate toward the combustor and an airflow rate toward the combustor in response to the optimal operation condition;

in a manner that the optimal operation condition is searched by fluctuating at least one of the fuel flow rate and the airflow rate, while combustion vibrations are not occurring, and

in a manner that the memory contents of the first database are renewed with the data as to the optimal operation condition that is obtained by the searching;

wherein the gas turbine control device further comprising;

a sensitivity analyzing means for calculating load sensitivity coefficients, which show a correlation between the actuating variables such as the fuel flow rate, the airflow rate, a pilot ratio and a top-hat ratio of the gas turbine, and a gas turbine power output; and

a second database in which the load sensitivity coefficients calculated by the sensitivity analyzing means are memorized,

further wherein

the correction amount determining means estimates a load increment change in response to actuating variables of at least one of the fuel flow rate toward the combustor and the airflow rate toward the combustor by use of the load sensitivity coefficients calculated by the sensitivity analyzing means or the load sensitivity coefficients that are memorized in the second database, in response to the optimal operation condition obtained by fluctuating at least one of the fuel flow rate and the airflow rate during the search control; and

at least one of the fuel flow rate and the airflow rate is adjusted on the basis of the estimation results, thereby the contents of the first database are renewed according to the results of the adjustments.