JP2007002703A - Gas turbine control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gas turbine control device capable of realizing the consistent operation by preventing surging of a compressor of a gas turbine and the overheat of the turbine. <P>SOLUTION: A pressure detector generates the first power generation command value so that the outlet pressure of a compressor does not exceed the predetermined reference. A temperature detector generates the second power generation command value so that the outlet temperature of a turbine does not exceed the predetermined reference. The minimum value is selected from the first power generation command value, the second power generation command value, and the third power generation command value for controlling the power generation during the normal operation, and the power generation output of a DC generator to be driven by the turbine is controlled by using the minimum value. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a technique for controlling a gas turbine.

  A gas turbine plant including a compressor that takes in and compresses air, a combustor that burns compressed air discharged from the compressor, and a turbine that converts energy of combustion gas taken from the combustor into torque is widely used. Electric power is generated using the torque generated by the turbine. When a DC generator is used for this power generation, the rotational speed can be controlled at all times by connecting to a system power supply via an inverter that converts DC to AC.

In Patent Document 1, in a fuel control method for a gas turbine in which at least two types of fuels are used and each fuel is exclusively burned or both are mixedly burned, There is described a fuel control method for a gas turbine, characterized in that control is performed such that the mixed combustion ratio is changed in accordance with a change in generator output while the flow rate of fuel is kept constant (see Patent Document 1).
JP-A-6-341330

An object of the present invention is to provide a gas turbine control device that controls the rotational speed so as to ensure stable operation of a gas turbine plant.
Another object of the present invention is to provide a gas turbine control device that prevents compressor surging.
Still another object of the present invention is to provide a gas turbine control device that prevents the temperature of the facility from exceeding an allowable value and becoming overheated.

  In the following, means for solving the problem will be described using the numbers used in [Best Mode for Carrying Out the Invention] in parentheses. These numbers are added to clarify the correspondence between the description of [Claims] and [Best Mode for Carrying Out the Invention]. However, these numbers should not be used to interpret the technical scope of the invention described in [Claims].

  A gas turbine control device according to the present invention is installed in a gas turbine plant including a combustor (8) that takes in and burns gas, and a turbine (6) that converts energy of the gas combusted in the combustor (8) into torque. The first power generation amount command value for generating the first power generation amount command value for detecting the thermodynamic state amount of the gas and controlling the output of the generator (10) that generates power by torque using the state amount A generation unit (28, 30), a second generation amount command value generation unit (32) that generates a second generation amount command value indicating a target value of the output of the generator (10), a first generation amount command value, The minimum value selection unit (36) for selecting the smallest value among the plurality of input command values including the second power generation amount command value as the power generation amount command value, and the generator (10) using the power generation amount command value And a control unit (36) for controlling the power generation output. The first power generation amount command value is, for example, a value indicating the power generation output of the generator. The second power generation amount command value is, for example, a value indicating the power generation output of the generator.

  In the gas turbine control device according to the present invention, the state quantity is the pressure on the outlet side of the compressor (2) that supplies gas to the combustor (8).

  The gas turbine control device according to the present invention detects the temperature on the outlet side of the turbine (6) and generates a third power generation amount command value for controlling the output of the generator (10) using the temperature. A quantity command value generation unit (30) is provided. The plurality of input command values include a third power generation amount command value. The third power generation amount command value is, for example, a value indicating the power generation output of the generator.

  In the gas turbine control device according to the present invention, the state quantity is the temperature at the outlet side of the turbine (6).

  The gas turbine control device according to the present invention includes a mixed combustion ratio control unit (20, 22, 24) that controls the ratio of the amount of main fuel and sub fuel supplied to the combustor (8).

  A gas turbine plant according to the present invention includes a compressor (2) that compresses gas, a combustor (8) that takes in and burns gas discharged from the compressor (2), and energy of the gas burned in the combustor (8). A turbine (6) that converts gas into torque and discharges the gas, and a first power generation amount command value for detecting the thermodynamic state quantity of the gas and controlling the output of the generator (10) that generates power based on the torque A first power generation amount command value generation unit (28, 30) that generates a state value using a state quantity, and a second power generation amount command value generation unit that generates a second power generation amount command value that indicates a target value of the output of the generator ( 32), a minimum value selection unit (36) for selecting the smallest value among the plurality of input command values including the first power generation amount command value and the second power generation amount command value, and the power generation amount The power generation output of the generator (10) is controlled using the command value. And a control unit (36).

ADVANTAGE OF THE INVENTION According to this invention, the gas turbine control apparatus which controls a rotation speed so that the stable driving | operation of a gas turbine plant is ensured is provided.
Furthermore, according to the present invention, a gas turbine control device that prevents surging of a compressor is provided.
Furthermore, according to this invention, the gas turbine control apparatus which prevents that the temperature of an installation exceeds an allowable value and will be in an overheated state is provided.

  Hereinafter, a gas turbine control device according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a configuration diagram of a gas turbine plant to which the gas turbine control device is applied.

  The gas turbine plant includes a compressor 2. The compressor 2 is connected to the turbine 6 via the shaft 4. The turbine 6 is further connected to the DC generator 10 via the shaft 4. The outlet of the gas passage of the compressor 2 is connected to the inlet of the combustor 8. The outlet of the combustor 8 is connected to the inlet of the turbine 6.

  A main fuel supply system 12 and a sub fuel supply system 14 are connected to the combustor 8. The main fuel supply system 12 includes a main fuel control valve 16 that controls the flow rate of the main fuel. The sub fuel supply system 14 includes a sub fuel control valve 18 that controls the flow rate of the sub fuel.

  The gas turbine plant further detects the rotational speed of the shaft 4 that couples the turbine 6 and the DC generator 10, and uses the rotational speed to generate a fuel supply amount command value for controlling the fuel supply amount. A rotation speed detector and a controller 26 for output. The fuel supply amount command value is input to the multiplier 22 and the non-inverting input terminal (+ side) of the subtractor 24. The multiplier 22 receives a mixed combustion ratio setting value (a value between 0 and 1) output from the mixed combustion ratio setting unit 20. The output of the multiplier 22 is input to the inverting input terminal (− side) of the subtractor 24. The output of the multiplier 22 is further input as an opening command value to a control device provided in the main fuel control valve 16. The output of the subtracter 24 is input as an opening degree command value to a control device provided in the sub fuel control valve 18.

  On the outlet side of the compressor 2, a pressure detector and a controller 28 for detecting pressure are provided. The pressure detector and controller 28 generates and outputs a first power generation amount command value using the detected pressure. The first power generation amount command value is determined so as to prevent the compressor 2 from surging. On the outlet side of the turbine 6, a temperature detector and a controller 30 for detecting temperature are provided. The temperature detector and the controller 30 generate and output a third power generation amount command value using the detected temperature. The third power generation amount command value is determined so as to prevent the turbine 6 and its downstream equipment from overheating beyond the allowable value.

  The output of the pressure detector and controller 28 and the output of the temperature detector and controller 30 are input to the minimum value selector 34. The minimum value selection unit 34 is further connected to a power generation amount setting unit 32 that outputs a second power generation amount command value that is a value set according to the required power supply amount. The minimum value selection unit 34 inputs the first power generation amount command value, the third power generation amount command value, and the second power generation amount command value, detects the minimum value among them, and outputs it as the power generation amount command value.

  The power generation amount command value output from the minimum value selection unit 34 is input to the control circuit 36. The control circuit 36 controls the output set value of the current or voltage of the inverter 36 that controls the DC generator 10 using the power generation amount command value.

  Next, operation | movement of a gas turbine plant provided with the above structure is demonstrated. During operation of the gas turbine plant, the rotational speed detector and controller 26 generates and outputs a fuel supply amount command value F in response to the rotational speed of the shaft 4. The co-firing ratio setting unit 20 generates and outputs a co-firing ratio setting value α indicating the mixing ratio of the main fuel and the sub fuel based on the input information. The multiplier 22 outputs a main fuel opening command value αF. The main fuel control valve 16 is controlled so that the opening degree is αF. The subtractor 24 outputs the sub fuel opening command value (1-α) F. The sub fuel control valve 18 is controlled so that the opening degree becomes (1-α) F. The main fuel supply system 12 and / or the sub fuel supply system 14 supply fuel to the combustor 8. The gas turbine control device in the present embodiment is suitably applied to a gas turbine plant that performs such mixed combustion of fuel.

  The fuel burns in the combustor 8 and becomes combustion gas. The combustion gas is supplied to the turbine 6 and drives the turbine 6. The temperature detector and controller 30 detects the temperature on the outlet side of the turbine 6, generates a third power generation amount command value, and transmits it to the minimum value selector 34. The compressor 2 is rotated by the torque generated by the gas turbine. The compressor 2 takes in air, compresses it, and discharges it. The pressure detector and controller 28 detects the pressure at the outlet of the compressor, generates a first power generation amount command value, and transmits it to the minimum value selector 34. The discharged air is supplied to the combustor 8.

  The power generation amount setting unit 32 generates and outputs a second power generation amount command value that is a value set according to the required power supply amount. The minimum value selector 34 selects and outputs the minimum value among the first power generation amount command value, the third power generation amount command value, and the second power generation amount command value. During normal operation, the second power generation amount command value is minimum, and the minimum value selection unit 34 outputs the second power generation amount command value as the power generation amount command value. The control circuit 36 controls the rotational speed of the DC generator 10 based on the power generation amount command value input from the minimum value selection unit input 34.

  If the outlet pressure of the compressor 2 exceeds a predetermined reference, surging may occur. When the reference is reached, the first power generation amount command value is smaller than the second power generation amount command value. The minimum value selector 34 selects and outputs the first power generation amount command value as the power generation amount command value. The control circuit 36 controls the rotational speed of the DC generator 10 based on the power generation amount command value. As a result, occurrence of surging is prevented.

  When the outlet temperature of the turbine 6 exceeds a predetermined reference, there is a possibility that an overheat state occurs. When the standard is reached, the third power generation amount command value is smaller than the second power generation amount command value. The minimum value selector 34 selects and outputs the third power generation amount command as the power generation amount command value. The control circuit 36 controls the rotational speed of the DC generator 10 based on the power generation amount command value. As a result, overheating is prevented and high temperature damage of the equipment is automatically prevented.

FIG. 1 shows the configuration of a turbine plant.

Explanation of symbols

DESCRIPTION OF SYMBOLS 2 ... Compressor 4 ... Shaft 6 ... Turbine 8 ... Combustor 10 ... DC generator 12 ... Main fuel supply system 14 ... Sub fuel supply system 16 ... Main fuel control valve 18 ... Sub fuel control valve 20 ... Mixed combustion ratio setting part 22 ... Multiplier 24 ... Subtractor 26 ... Rotation speed detector and controller 28 ... Pressure detector and controller 30 ... Temperature detector and controller 32 ... Power generation amount setting unit 34 ... Minimum value selection unit 36 ... Control circuit

Claims (6)

Installed in a gas turbine plant including a combustor that takes in and burns gas and a turbine that converts energy of the gas combusted in the combustor into torque, detects a thermodynamic state quantity of the gas, and detects the torque A first power generation amount command value generation unit that generates a first power generation amount command value for controlling the output of the generator that generates power by using the state quantity;
A second power generation amount command value generation unit that generates a second power generation amount command value indicating a target value of the output of the generator;
A minimum value selection unit that selects the smallest value among a plurality of input command values including the first power generation amount command value and the second power generation amount command value as a power generation amount command value;
A gas turbine control device comprising: a control unit that controls the power generation output of the power generator using the power generation amount command value. A gas turbine control device according to claim 1,
The state quantity is a pressure on an outlet side of a compressor that supplies the gas to the combustor. A gas turbine control device according to claim 2, comprising:
And a third power generation amount command value generation unit that detects a temperature on the outlet side of the turbine and generates a third power generation amount command value for controlling the output of the generator using the temperature.
The plurality of input command values include the third power generation amount command value. A gas turbine control device according to claim 1,
The state quantity is a temperature at an outlet side of the turbine. A gas turbine control device according to any one of claims 1 to 4,
A gas turbine control device further comprising: a mixed combustion ratio control unit that controls a ratio of a supply amount of the main fuel and the sub fuel supplied to the combustor. A compressor for compressing the gas;
A combustor that takes in and burns the gas discharged from the compressor;
A turbine for converting the energy of the gas burned in the combustor into torque and discharging the gas;
First power generation amount command value generation using the state amount to generate a first power generation amount command value for detecting a thermodynamic state amount of the gas and controlling an output of a generator that generates power by the torque And
A second power generation amount command value generation unit that generates a second power generation amount command value indicating a target value of the output of the generator;
A minimum value selection unit that selects the smallest value among a plurality of input command values including the first power generation amount command value and the second power generation amount command value as a power generation amount command value;
A gas turbine plant comprising: a control unit that controls a power generation output of the generator using the power generation amount command value.

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