JP2716668B2 - Gas turbine control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas turbine control device provided in a gas turbine using a low-pressure gas having a low calorific value, such as a blast furnace gas, as a main fuel. In addition, the present invention relates to a gas turbine control device having a mechanism for supplying an auxiliary fuel having a high calorific value.

[0002]

2. Description of the Related Art Blast furnace gas generated from a blast furnace is a combustible gas containing carbon monoxide. However, since its concentration is low, its calorific value is low, and it is difficult to burn at high pressure.
It was customary to use it as fuel for boilers that are relatively easy to burn.

[0003] In order to effectively use blast furnace gas, blast furnace gas is burned by a gas turbine, the exhaust gas is guided to a boiler, and steam generated by a cogeneration facility or a boiler is introduced into a steam turbine to generate electricity. In recent years, combined cycle power generation equipment that has increased the number of blast furnaces has been attracting attention as a method of effectively using blast furnace gas.

A gas having a low calorific value such as a blast furnace gas is generally generated as a by-product in a process such as a blast furnace or petroleum refining, and its components are not as stable as ordinary fuel. As a result, the calorific value changes, so that the calorific value decreases, so that the gas turbine cannot burn well and may blow out. For this purpose, a high calorific value auxiliary main fuel is added to the main fuel in advance so that the calorific value of the main fuel is kept high and the main fuel is processed so as to be easily combusted.

[0005] A gas turbine using a gas having a low calorific value such as a blast furnace gas as a fuel is disclosed, for example, in Japanese Patent Publication No. 5-83742. In the prior art disclosed in this publication, a low-calorie gas fuel as a main fuel supplied from a low-calorie gas fuel supply path and a high-calorie gas as an auxiliary fuel supplied from a high calorie gas fuel supply path are used. The mixed gas fuel is supplied to a combustor from a mixed gas fuel supply path including a gas fuel compressor, which is a main fuel compressor coaxially arranged with the gas turbine, and the gas turbine is operated. A steam is generated by high-temperature exhaust gas energy of a turbine, a steam turbine is operated, and a gas turbine of a combined cycle power generation that drives a gas turbine and a generator coaxially arranged with the steam turbine bypasses the gas fuel compressor. Connecting the high calorie gas fuel supply path and the mixed gas fuel supply path on the discharge side of the gas fuel compressor as described above. A part of the high-calorie gas fuel pressurized by the gas fuel compressor separately driven from the gas turbine provided in the bypass is mixed with the mixed gas fuel at the time of ignition and acceleration of the gas turbine. Is configured.

In the prior art, the main fuel having a low calorific value and the auxiliary main fuel having a high calorific value are mixed and compressed by a main fuel compressor and supplied to a combustor of a gas turbine. Therefore, a viscous substance is generated in the mixed main fuel due to the auxiliary fuel, and adheres to a stationary blade or a moving blade of the main fuel compressor. by this,
The operation of the main fuel compressor is hindered, and the continuous operation of the gas turbine cannot be performed. For this reason, cleaning and maintenance are required, which is troublesome, and the workability is poor.

To solve this problem, for example, Japanese Patent Laid-Open No.
Japanese Patent Application Publication No. 202767 discloses that a catalytic reaction tower for reforming a mixed main fuel by catalytic hydrogenation reaction is provided. According to the technique disclosed in this publication, a mixed gas is reformed by a contact reaction tower to prevent the generation of a viscous substance, and the mixture is guided to a main fuel compressor.

[0008]

In such a conventional technique, auxiliary fuel which is more expensive than the main fuel is always supplied at a constant rate. Even auxiliary fuel is consumed and costly. In addition, since the main fuel and the auxiliary fuel are mixed and guided to the combustor, the auxiliary fuel is also a gas (gas) with respect to the main fuel which is a gas (gas).
Needs to be In the prior art disclosed in Japanese Patent Publication No. 5-83742, a bypass is provided to stably control the gas turbine, and a main fuel compressor driven separately from the gas turbine is provided. Also, Japanese Patent Application Laid-Open No. H5-220276
In the prior art disclosed in Japanese Patent Application Publication No. 7-107, a contact reaction tower for reforming a mixed gas is required. As described above, the configuration becomes large, and a large space is required.

Accordingly, an object of the present invention is to provide a gas (gas)
A gas turbine control device is provided in which the auxiliary fuel is supplied only when the calorific value of the main fuel is reduced, and gas or liquid can be used as the auxiliary fuel, and the size of the configuration is prevented from increasing. That is.

[0010]

SUMMARY OF THE INVENTION The present invention comprises a main fuel supply for supplying main fuel to a combustor of a gas turbine, and a first flow control means interposed between the main fuel supply and the combustor. ,
An auxiliary fuel supply source for supplying auxiliary fuel to the combustor, a second flow rate control means interposed between the auxiliary fuel supply source and the combustor, an output detection means for detecting an output of the gas turbine, A load setting device for setting an output, a subtractor for obtaining a difference between a detection output by the output detection means and a load set by the load setting device, and a first flow rate control means for controlling the first flow rate so that the output of the subtractor becomes zero. Main heat calculation control means for controlling the heat quantity of the main fuel, an insufficient heat quantity calculation means for calculating an insufficient heat quantity given to the combustor of the main fuel when the heat value of the main fuel falls below a predetermined reference heat value, and an insufficient heat quantity calculation means And an auxiliary fuel calculation control means for controlling the second flow rate by the second flow rate control means so that the insufficient heat is supplied to the combustor in response to the output of the first fuel flow rate. Compress and compress A main fuel compressor to be supplied to the combustor of the bottle; a fuel recirculation line for branching a part of the main fuel discharged from the main fuel compressor and returning to the inlet of the main fuel compressor; and an inlet of the main fuel compressor A first flow rate adjusting means for controlling the flow rate of the main fuel, and a second flow rate adjusting means for controlling the flow rate of the main fuel returned to the inlet of the main fuel compressor by the fuel recirculation line and capable of being fully closed. The main fuel arithmetic control means includes a differential pressure transmitter that detects a differential pressure obtained by subtracting a gas pressure in a combustor provided in the gas turbine from a pressure at an outlet of the main fuel compressor, and supplies the differential pressure to a combustor of the gas turbine. A signal generator for generating a main fuel command signal for instructing the flow rate of the main fuel to be performed, and the main fuel compressor responding to the main fuel command signal, and the pressure from the outlet of the main fuel compressor corresponding to the flow rate represented by the main fuel command signal. Calculates the target value of the differential pressure obtained by subtracting the gas pressure in the combustor Control means for outputting a control signal indicating a flow rate of main fuel supplied to the combustor so that the detected differential pressure becomes the target value in response to outputs of the calculation means, the differential pressure transmitter and the calculation means And outputting a first flow rate set value representing the minimum flow rate in response to the control signal when the flow rate represented by the control signal is less than a predetermined minimum flow rate of the main fuel compressor. When the flow rate is equal to or more than the flow rate, a first flow rate set value corresponding to the control signal is output, and a first function generator for providing the output signal to the first flow rate adjusting means; When the flow rate is equal to or less than the minimum flow rate, the flow rate represented by the control signal is subtracted from the minimum flow rate, and a second flow rate set value representing the subtracted flow rate is output. When the flow rate represented by the control signal exceeds the minimum flow rate, the second flow rate For the adjustment means to be fully closed A second function generator for outputting a second flow rate set value and providing the second flow rate set value thus output to a second flow rate adjusting means.

The present invention also provides a main fuel supply source for supplying main fuel to a combustor of a gas turbine, a first flow control means interposed between the main fuel supply source and the combustor, An auxiliary fuel supply source to be supplied to the vessel, a second flow rate control means interposed between the auxiliary fuel supply source and the combustor, an output detection means for detecting an output of the gas turbine, and an output of the gas turbine. A load setting device, a subtractor for obtaining a difference between a detection output by the output detection device and a load set by the load setting device, and a main device for controlling the first flow rate by the first flow control device so that the output of the subtractor becomes zero. A fuel operation control unit, an under-heat amount operation unit that calculates an under-heat amount given to the combustor of the main fuel when the heat value of the main fuel falls below a predetermined reference heat amount, and a response to the output of the under-heat amount calculation unit. And that lack of heat Auxiliary fuel calculation control means for controlling the second flow rate by the second flow rate control means so as to be supplied to the combustor, wherein the first flow rate control means compresses the main fuel and supplies the compressed main fuel to the combustor of the gas turbine. Controls the main fuel compressor, the fuel recirculation line that branches off part of the main fuel discharged from the main fuel compressor and returns it to the inlet of the main fuel compressor, and the flow rate of the main fuel at the inlet of the main fuel compressor Main flow control means for controlling the flow rate of main fuel returned to the inlet of the main fuel compressor by the fuel recirculation line, and capable of being fully closed. Is a differential pressure transmitter that detects a differential pressure obtained by subtracting the pressure at the outlet of the air compressor provided in the gas turbine from the pressure at the outlet of the main fuel compressor, and the flow rate of the main fuel supplied to the combustor of the gas turbine. A signal generator for generating a main fuel command signal for commanding Calculating means for responding to the fuel command signal and calculating a target value of a differential pressure obtained by subtracting the pressure at the outlet of the air compressor from the pressure at the outlet of the main fuel compressor corresponding to the flow rate represented by the main fuel command signal; Control means for responding to the outputs of the differential pressure transmitter and the arithmetic means for outputting a control signal indicating the flow rate of the main fuel supplied to the combustor so that the detected differential pressure becomes the target value; and A first signal representing a minimum flow rate in response to the control signal when the flow rate represented by the control signal is less than a predetermined minimum flow rate of the main fuel compressor.
A first function generation unit that outputs a flow rate set value, outputs a first flow rate set value corresponding to the control signal when the flow rate represented by the control signal is equal to or greater than the minimum flow rate, and gives the output signal to the first flow rate adjusting unit. And in response to the control signal, subtracts the flow rate represented by the control signal from the minimum flow rate when the flow rate represented by the control signal is equal to or less than the minimum flow rate, and outputs a second flow rate set value representing the subtracted flow rate; When the flow rate indicated by the control signal exceeds the minimum flow rate, the second flow rate adjusting means is completely closed.
A second function generator for outputting a flow rate set value and providing the output second flow rate set value to a second flow rate adjusting means.

Further, the present invention provides a main fuel supply source for supplying a main fuel to a combustor of a gas turbine, a first flow control means interposed between the main fuel supply source and the combustor, and a method for burning an auxiliary fuel. An auxiliary fuel supply source to be supplied to the vessel, a second flow rate control means interposed between the auxiliary fuel supply source and the combustor, an output detection means for detecting an output of the gas turbine, and an output of the gas turbine. A load setting device, a subtractor for obtaining a difference between a detection output by the output detection device and a load set by the load setting device, and a main device for controlling the first flow rate by the first flow control device so that the output of the subtractor becomes zero. A fuel operation control unit, an under-heat amount operation unit that calculates an under-heat amount given to the combustor of the main fuel when the heat value of the main fuel falls below a predetermined reference heat amount, and a response to the output of the under-heat amount calculation unit. And that lack of heat Auxiliary fuel calculation control means for controlling the second flow rate by the second flow rate control means so as to be supplied to the combustor, wherein the first flow rate control means compresses the main fuel and supplies the compressed main fuel to the combustor of the gas turbine. Controls the main fuel compressor, the fuel recirculation line that branches off part of the main fuel discharged from the main fuel compressor and returns it to the inlet of the main fuel compressor, and the flow rate of the main fuel at the inlet of the main fuel compressor Main flow control means for controlling the flow rate of main fuel returned to the inlet of the main fuel compressor by the fuel recirculation line, and capable of being fully closed. A pressure transmitter for detecting the pressure at the outlet of the main fuel compressor, a signal generator for generating a main fuel command signal for commanding the flow rate of the main fuel supplied to the combustor of the gas turbine, and a main fuel command signal. In response to the flow rate indicated by the main fuel command signal. Calculating means for calculating a target value of the pressure at the outlet of the charge compressor, and main fuel supplied to the combustor in response to outputs of the pressure transmitter and the calculating means so that the detected pressure becomes the target value. Control means for outputting a control signal representing the flow rate of
When the flow rate represented by the control signal is less than a predetermined minimum flow rate of the main fuel compressor, a first flow rate set value representing the minimum flow rate is output, and when the flow rate represented by the control signal is equal to or more than the minimum flow rate, the control signal is output. Outputting the corresponding first flow rate set value,
A first function generator for providing the output signal to the first flow rate adjusting means; and, in response to the control signal, subtracting the flow rate represented by the control signal from the minimum flow rate when the flow rate represented by the control signal is equal to or less than the minimum flow rate. And outputting a second flow rate set value representing the subtracted flow rate, and outputting a second flow rate set value for fully closing the second flow rate adjusting means when the flow rate indicated by the control signal exceeds the minimum flow rate. The set second flow rate set value
A second function generator provided to the flow rate adjusting means.

The present invention also provides a main fuel supply source for supplying a main fuel to a combustor of a gas turbine, a first flow control means interposed between the main fuel supply source and the combustor, and a method for burning auxiliary fuel. An auxiliary fuel supply source to be supplied to the vessel, a second flow rate control means interposed between the auxiliary fuel supply source and the combustor, an output detection means for detecting an output of the gas turbine, and an output of the gas turbine. A load setting device, a subtractor for obtaining a difference between a detection output by the output detection device and a load set by the load setting device, and a main device for controlling the first flow rate by the first flow control device so that the output of the subtractor becomes zero. A fuel operation control unit, an under-heat amount operation unit for calculating an under-heat amount given to the combustor of the main fuel when the heat value of the main fuel falls below a predetermined reference heat amount, And that lack of heat Auxiliary fuel calculation control means for controlling the second flow rate by the second flow rate control means so as to be supplied to the combustor, wherein the first flow rate control means compresses the main fuel and supplies the compressed main fuel to the combustor of the gas turbine. Controls the main fuel compressor, the fuel recirculation line that branches off part of the main fuel discharged from the main fuel compressor and returns it to the inlet of the main fuel compressor, and the flow rate of the main fuel at the inlet of the main fuel compressor Main flow control means for controlling the flow rate of main fuel returned to the inlet of the main fuel compressor by the fuel recirculation line, and capable of being fully closed. A pressure transmitter for detecting the pressure at the outlet of the main fuel compressor, a signal generator for generating a main fuel command signal for commanding the flow rate of the main fuel supplied to the combustor of the gas turbine, and a main fuel command signal. In response to the flow rate indicated by the main fuel command signal. Calculating means for calculating a first target value of the pressure at the outlet of the charge compressor, and a first flow rate adjusting means responsive to the outputs of the pressure transmitter and the calculating means so that the detected pressure becomes the first target value. A first control means for controlling the pressure, a pressure deviation setter for outputting a pressure deviation signal representing a predetermined value, and a pressure represented by the first target value in response to the first target value and the pressure deviation signal of the pressure; An adder for adding a value represented by the pressure deviation signal and outputting a second target value of the pressure representing the pressure; and responding to outputs of a pressure transmitter and an adder, wherein the detected pressure is the second target value. And a second control means for controlling the second flow rate adjusting means so as to provide a gas turbine control device.

Further, the present invention provides a main fuel supply source for supplying a main fuel to a combustor of a gas turbine, a first flow control means interposed between the main fuel supply source and the combustor, and a method for burning an auxiliary fuel. An auxiliary fuel supply source to be supplied to the vessel, a second flow rate control means interposed between the auxiliary fuel supply source and the combustor, an output detection means for detecting an output of the gas turbine, and an output of the gas turbine. A load setting device, a subtractor for obtaining a difference between a detection output by the output detection device and a load set by the load setting device, and a main device for controlling the first flow rate by the first flow control device so that the output of the subtractor becomes zero. A fuel operation control unit, an under-heat amount operation unit that calculates an under-heat amount given to the combustor of the main fuel when the heat value of the main fuel falls below a predetermined reference heat amount, and a response to the output of the under-heat amount calculation unit. And that lack of heat Auxiliary fuel calculation control means for controlling the second flow rate by the second flow rate control means so as to be supplied to the combustor, wherein the first flow rate control means compresses the main fuel and supplies the compressed main fuel to the combustor of the gas turbine. Controls the main fuel compressor, the fuel recirculation line that branches off part of the main fuel discharged from the main fuel compressor and returns it to the inlet of the main fuel compressor, and the flow rate of the main fuel at the inlet of the main fuel compressor Main flow control means for controlling the flow rate of main fuel returned to the inlet of the main fuel compressor by the fuel recirculation line, and capable of being fully closed. Is a pressure transmitter that detects the pressure at the outlet of the main fuel compressor, a signal generator that generates a main fuel command signal that commands the flow rate of the main fuel supplied to the combustor of the gas turbine, and a main fuel command signal. The main fuel corresponding to the flow rate indicated by the main fuel command signal A calculating means for calculating a first target value of the pressure at the outlet of the compressor; and a first flow rate adjusting means responsive to outputs of the pressure transmitter and the calculating means so that the detected pressure becomes the first target value. A first control means for controlling, a detector for detecting an opening of the first flow rate adjusting means, and a flow rate of the main fuel to the main fuel compressor based on the detected opening in response to an output of the detector. A pressure deviation signal representing a positive value corresponding to the output of the detector is output when the flow rate is equal to or more than the predetermined minimum flow rate of the compressor, and the flow rate of the main fuel to the main fuel compressor based on the detected opening is less than the minimum flow rate. And a pressure deviation generator that outputs a pressure deviation signal representing zero when the pressure is greater than a first target value of the pressure and a value represented by the pressure deviation signal. An adder for adding and outputting a second target value of the pressure representing the pressure; And a second control means for controlling a second flow rate adjusting means so that the detected pressure becomes the second target value in response to an output from the adder.

Further, the present invention provides a main fuel supply source for supplying a main fuel to a combustor of a gas turbine, a first flow control means interposed between the main fuel supply source and the combustor, and a method for burning auxiliary fuel. An auxiliary fuel supply source to be supplied to the vessel, a second flow rate control means interposed between the auxiliary fuel supply source and the combustor, an output detection means for detecting an output of the gas turbine, and an output of the gas turbine. A load setting device, a subtractor for obtaining a difference between a detection output by the output detection device and a load set by the load setting device, and a main device for controlling the first flow rate by the first flow control device so that the output of the subtractor becomes zero. A fuel operation control unit, an under-heat amount operation unit that calculates an under-heat amount given to the combustor of the main fuel when the heat value of the main fuel falls below a predetermined reference heat amount, and a response to the output of the under-heat amount calculation unit. And that lack of heat Auxiliary fuel calculation control means for controlling the second flow rate by the second flow rate control means so as to be supplied to the combustor, wherein the first flow rate control means compresses the main fuel and supplies the compressed main fuel to the combustor of the gas turbine. Controls the main fuel compressor, the fuel recirculation line that branches off part of the main fuel discharged from the main fuel compressor and returns it to the inlet of the main fuel compressor, and the flow rate of the main fuel at the inlet of the main fuel compressor Main flow control means for controlling the flow rate of main fuel returned to the inlet of the main fuel compressor by the fuel recirculation line, and capable of being fully closed. Is a differential pressure transmitter that detects the differential pressure obtained by subtracting the gas pressure in the combustor provided in the gas turbine from the pressure at the outlet of the main fuel compressor, and the flow rate of the main fuel supplied to the combustor of the gas turbine. A signal generator for generating a main fuel command signal; Computing means for responding to the command signal and calculating a first target value of a differential pressure obtained by subtracting the gas pressure in the combustor from the pressure at the outlet of the main fuel compressor corresponding to the flow rate represented by the main fuel command signal; In response to the output of the differential pressure transmitter and the calculating means, the detected differential pressure
A first control means for controlling the first flow rate adjusting means to be a target value, a pressure deviation setter for outputting a pressure deviation signal representing a predetermined value, and a first target value and a pressure deviation signal for the differential pressure. Responding to the output of the adder for adding the differential pressure represented by the first target value and the value represented by the pressure deviation signal and outputting a second target value of the differential pressure; And a second control unit that controls the second flow rate adjusting unit so that the detected differential pressure becomes the second target value.
A gas turbine control device comprising a control unit.

Further, the present invention provides a main fuel supply source for supplying a main fuel to a combustor of a gas turbine, a first flow control means interposed between the main fuel supply source and the combustor, and a method for burning an auxiliary fuel. An auxiliary fuel supply source to be supplied to the vessel, a second flow rate control means interposed between the auxiliary fuel supply source and the combustor, an output detection means for detecting an output of the gas turbine, and an output of the gas turbine. A load setting device, a subtractor for obtaining a difference between a detection output by the output detection device and a load set by the load setting device, and a main device for controlling the first flow rate by the first flow control device so that the output of the subtractor becomes zero. A fuel operation control unit, an under-heat amount operation unit that calculates an under-heat amount given to the combustor of the main fuel when the heat value of the main fuel falls below a predetermined reference heat amount, and a response to the output of the under-heat amount calculation unit. And that lack of heat Auxiliary fuel calculation control means for controlling the second flow rate by the second flow rate control means so as to be supplied to the combustor, wherein the first flow rate control means compresses the main fuel and supplies the compressed main fuel to the combustor of the gas turbine. Controls the main fuel compressor, the fuel recirculation line that branches off part of the main fuel discharged from the main fuel compressor and returns it to the inlet of the main fuel compressor, and the flow rate of the main fuel at the inlet of the main fuel compressor Main flow control means for controlling the flow rate of main fuel returned to the inlet of the main fuel compressor by the fuel recirculation line, and capable of being fully closed. Is a differential pressure transmitter that detects the differential pressure obtained by subtracting the gas pressure in the combustor provided in the gas turbine from the pressure at the outlet of the main fuel compressor, and the flow rate of the main fuel supplied to the combustor of the gas turbine. A signal generator for generating a main fuel command signal; Computing means for responding to the command signal and calculating a first target value of a differential pressure obtained by subtracting the gas pressure in the combustor from the pressure at the outlet of the main fuel compressor corresponding to the flow rate represented by the main fuel command signal; In response to the output of the differential pressure transmitter and the calculating means, the detected differential pressure
First control means for controlling the first flow rate adjusting means so as to attain a target value; a detector for detecting an opening of the first flow rate adjusting means; When the flow rate of the main fuel to the fuel compressor is equal to or more than a predetermined minimum flow rate of the main fuel compressor, the main fuel compressor outputs a pressure deviation signal representing a positive value corresponding to the output of the detector, and the main fuel compression based on the detected opening degree. A pressure deviation generator that outputs a pressure deviation signal representing zero when the flow rate of the main fuel to the machine is less than the minimum flow rate, and responding to the outputs of the differential pressure calculating means and the pressure deviation generator, The differential pressure represented by the first target value and the value represented by the pressure deviation signal are added,
An adder that outputs a second target value of the differential pressure representing the differential pressure;
And a second control means for controlling a second flow rate adjusting means in response to an output of the differential pressure transmitter and the adder so that the detected differential pressure becomes the second target value. It is a turbine control device.

Further, the present invention provides a main fuel supply source for supplying main fuel to a combustor of a gas turbine, a first flow control means interposed between the main fuel supply source and the combustor, An auxiliary fuel supply source to be supplied to the vessel, a second flow rate control means interposed between the auxiliary fuel supply source and the combustor, an output detection means for detecting an output of the gas turbine, and an output of the gas turbine. A load setting device, a subtractor for obtaining a difference between a detection output by the output detection device and a load set by the load setting device, and a main device for controlling the first flow rate by the first flow control device so that the output of the subtractor becomes zero. A fuel operation control unit, an under-heat amount operation unit for calculating an under-heat amount given to the combustor of the main fuel when the heat value of the main fuel falls below a predetermined reference heat amount, And that lack of heat Auxiliary fuel calculation control means for controlling the second flow rate by the second flow rate control means so as to be supplied to the combustor, wherein the first flow rate control means compresses the main fuel and supplies the compressed main fuel to the combustor of the gas turbine. Controls the main fuel compressor, the fuel recirculation line that branches off part of the main fuel discharged from the main fuel compressor and returns it to the inlet of the main fuel compressor, and the flow rate of the main fuel at the inlet of the main fuel compressor Main flow control means for controlling the flow rate of main fuel returned to the inlet of the main fuel compressor by the fuel recirculation line, and capable of being fully closed. Is a differential pressure transmitter that detects a differential pressure obtained by subtracting the pressure at the outlet of the air compressor provided in the gas turbine from the pressure at the outlet of the main fuel compressor, and the flow rate of the main fuel supplied to the combustor of the gas turbine. A signal generator for generating a main fuel command signal for commanding Calculating means for calculating a first target value of a differential pressure obtained by subtracting the pressure at the outlet of the air compressor from the pressure at the outlet of the main fuel compressor corresponding to the flow rate indicated by the main fuel command signal in response to the fuel command signal A first control means responsive to outputs of the differential pressure transmitter and the arithmetic means for controlling the first flow rate adjusting means so that the detected differential pressure becomes the first target value; and a pressure representing a predetermined value. A pressure deviation setter for outputting a deviation signal, and responding to a first target value and a pressure deviation signal of the differential pressure, adding a differential pressure represented by the first target value and a value represented by the pressure deviation signal, An adder that outputs a second target value of
A gas turbine, comprising: a second control means responsive to outputs of the differential pressure transmitter and the adder, for controlling a second flow rate adjusting means such that the detected differential pressure becomes the second target value. It is a control device.

The present invention also provides a main fuel supply source for supplying main fuel to a combustor of a gas turbine, a first flow control means interposed between the main fuel supply source and the combustor, and a method for burning auxiliary fuel. An auxiliary fuel supply source to be supplied to the vessel, a second flow rate control means interposed between the auxiliary fuel supply source and the combustor, an output detection means for detecting an output of the gas turbine, and an output of the gas turbine. A load setting device, a subtractor for obtaining a difference between a detection output by the output detection device and a load set by the load setting device, and a main device for controlling the first flow rate by the first flow control device so that the output of the subtractor becomes zero. A fuel operation control unit, an under-heat amount operation unit that calculates an under-heat amount given to the combustor of the main fuel when the heat value of the main fuel falls below a predetermined reference heat amount, and a response to the output of the under-heat amount calculation unit. And that lack of heat Auxiliary fuel calculation control means for controlling the second flow rate by the second flow rate control means so as to be supplied to the combustor, wherein the first flow rate control means compresses the main fuel and supplies the compressed main fuel to the combustor of the gas turbine. Controls the main fuel compressor, the fuel recirculation line that branches off part of the main fuel discharged from the main fuel compressor and returns it to the inlet of the main fuel compressor, and the flow rate of the main fuel at the inlet of the main fuel compressor Main flow control means for controlling the flow rate of main fuel returned to the inlet of the main fuel compressor by the fuel recirculation line, and capable of being fully closed. Is a differential pressure transmitter that detects a differential pressure obtained by subtracting the pressure at the outlet of the air compressor provided in the gas turbine from the pressure at the outlet of the main fuel compressor, and the flow rate of the main fuel supplied to the combustor of the gas turbine. A signal generator for generating a main fuel command signal for commanding Calculating means for calculating a first target value of a differential pressure obtained by subtracting the pressure at the outlet of the air compressor from the pressure at the outlet of the main fuel compressor corresponding to the flow rate indicated by the main fuel command signal in response to the fuel command signal And first control means for controlling the first flow rate adjusting means in response to the outputs of the differential pressure transmitter and the arithmetic means so that the detected differential pressure becomes the first target value; and the first flow rate adjusting means. A detector for detecting the opening of the main fuel compressor, wherein the detector responds to the output of the detector and detects a flow rate of the main fuel to the main fuel compressor based on the detected opening degree which is equal to or greater than a predetermined minimum flow rate of the main fuel compressor. A pressure deviation signal representing a positive value corresponding to the output of the above, and outputting a pressure deviation signal representing zero when the flow rate of the main fuel to the main fuel compressor based on the detected opening is less than the minimum flow rate. Response to the output of the deviation generator, the differential pressure calculating means and the pressure deviation generator. An adder for adding a differential pressure represented by a first target value of differential pressure and a value represented by a pressure deviation signal, and outputting a second target value of differential pressure representing the differential pressure; a differential pressure transmitter and an adder And a second control means for controlling a second flow rate adjusting means so that the detected differential pressure becomes the second target value in response to the output of the gas turbine control apparatus.

[0019]

According to the present invention, the main fuel is supplied from the main fuel supply source to the combustor, and its flow rate is determined by the output of the gas turbine detected by the output detecting means and the output of the gas turbine set by the load setting device. The first fuel flow control means is operated and controlled by the main fuel arithmetic control means so that the load coincides with the load. The auxiliary fuel is supplied from the auxiliary fuel supply source to the combustor, and the flow rate thereof is calculated by the insufficient heat amount calculating means, the insufficient heat amount of the gas turbine when the calorific value of the main fuel falls below a predetermined reference calorific value, The second flow control means is operated and controlled by the auxiliary fuel calculation control means so as to supply the insufficient heat. Accordingly, when the calorific value of the main fuel supplied to the combustor is reduced and the calorific value required for operating the gas turbine is insufficient, the auxiliary fuel is supplied so as to compensate for the insufficient calorific value.

Further, the flow rate of the main fuel guided to the main fuel compressor for compressing the main fuel is controlled by the first flow rate adjusting means, and a part of the gas discharged from the main fuel compressor is controlled by the fuel recirculation line. It is returned to the inlet of the compressor, and its flow rate is controlled by the second flow rate adjusting means. The differential pressure obtained by subtracting the gas pressure in the combustor from the pressure at the outlet of the main fuel compressor is output by the differential pressure transmitter, and the main fuel compression corresponding to the flow rate indicated by the main fuel command signal output from the signal generator The target value of the differential pressure between the pressure at the outlet of the machine and the gas pressure in the combustor is calculated by the calculating means, and a control signal indicating the main fuel flow rate such that the detected differential pressure becomes the target value is output by the control means. The control signal is provided to the first and second function generators, the first function generator provides a first flow rate set value corresponding to the control signal to the first flow rate adjusting means, and the second function generator The second flow rate set value corresponding to the control signal is provided to the second flow rate adjusting means. Accordingly, the supply flow rate of the main fuel supplied to the main fuel compressor in response to the control signal output from the control means is controlled by the first flow rate adjusting means, and the discharge rate from the main fuel compressor is controlled in response to the control signal. The flow rate of the recirculated gas is controlled by the second flow rate adjusting means. Accordingly, the combustor of the gas turbine is supplied with the main fuel at a stepless main fuel supply flow rate regardless of the minimum flow rate of the main fuel compressor, and for a gas turbine provided with a large main fuel compressor, The pressure at the outlet of the main fuel compressor can be controlled stably.

Further, according to the present invention, the flow rate of the main fuel guided to the main fuel compressor for compressing the main fuel is controlled by the first flow rate adjusting means, and a part of the gas discharged from the main fuel compressor is converted to the fuel. The fuel is returned to the inlet of the main fuel compressor by the return line, and its flow rate is controlled by the second flow rate adjusting means.
The differential pressure obtained by subtracting the pressure at the outlet of the air compressor provided in the gas turbine from the pressure at the outlet of the main fuel compressor is output by the differential pressure transmitter, and the flow rate represented by the main fuel command signal output from the signal generator The target value of the differential pressure between the pressure at the outlet of the main fuel compressor and the pressure at the outlet of the air compressor provided in the gas turbine is calculated by the differential pressure calculating means, and the detected differential pressure is controlled by the control means. A control signal representing the main fuel flow rate as a value is output by the control means,
The control signal is provided to first and second function generators,
The first function generator gives a first flow rate set value corresponding to the control signal to the first flow rate adjusting means, and the second function generator gives a second flow rate set value corresponding to the control signal to the second flow rate adjusting means. Given to. Accordingly, the supply flow rate of the main fuel supplied to the main fuel compressor in response to the control signal output from the control means is controlled by the first flow rate adjusting means, and the discharge rate from the main fuel compressor is controlled in response to the control signal. The flow rate of the recirculated gas is controlled by the second flow rate adjusting means. Accordingly, the combustor of the gas turbine is supplied with the main fuel at a stepless main fuel supply flow rate regardless of the minimum flow rate of the main fuel compressor, and for a gas turbine provided with a large main fuel compressor, The pressure at the outlet of the main fuel compressor can be controlled stably.

Further, according to the present invention, the flow rate of the main fuel guided to the main fuel compressor for compressing the main fuel is controlled by the first flow rate adjusting means, and a part of the gas discharged from the main fuel compressor is converted to the fuel. The fuel is returned to the inlet of the main fuel compressor by the return line, and its flow rate is controlled by the second flow rate adjusting means. The pressure at the outlet of the main fuel compressor is detected by the pressure transmitter, and a first target value of the pressure at the outlet of the main fuel compressor corresponding to the flow rate indicated by the main fuel command signal output from the signal generator is calculated by the calculating means. The control means outputs a control signal that is output and indicates a flow rate of the main fuel such that the detected pressure becomes the target value. The control signal is provided to first and second function transmitters, and the first function generator Gives the first flow rate set value corresponding to the control signal to the first flow rate adjusting means,
The function generator provides a second flow rate setting value corresponding to the control signal to the second flow rate adjusting means. Thereby, the supply flow rate of the fuel supplied to the main fuel compressor is controlled by the first flow rate adjusting means in accordance with the control signal output from the control means, and the supply flow rate of the fuel discharged from the main fuel compressor is controlled in accordance with the control signal. The flow rate of the recirculated gas is controlled by the second flow rate adjusting means. Therefore, the main fuel is supplied to the gas turbine combustor at a stepless main fuel supply flow rate regardless of the minimum flow rate of the main fuel compressor, and the main turbine is provided with a large main fuel compressor. The pressure at the outlet of the fuel compressor can be controlled stably.

Further, according to the present invention, the flow rate of the main fuel guided to the main fuel compressor for compressing the main fuel is controlled by the first flow rate adjusting means, and a part of the gas discharged from the main fuel compressor is used as the fuel. The fuel is returned to the inlet of the main fuel compressor by the return line, and its flow rate is controlled by the second flow rate adjusting means. The pressure of the main fuel is detected by the pressure transmitter, and the first target value of the pressure at the outlet of the main fuel compressor corresponding to the flow rate represented by the main fuel command signal output from the signal generator is output by the calculating means, The first flow control means is controlled by the first control means so that the detected pressure becomes the target value, a pressure deviation signal representing a predetermined value is outputted from the pressure deviation setting device, and the pressure represented by the first target value is outputted. And the value represented by the pressure deviation signal are added, a second target value of the pressure is output by the adder, and the second control means controls the second flow rate adjusting means so that the detected pressure becomes the target value. You. Accordingly, each flow control means is controlled by each control means, the supply flow rate of the main fuel supplied to the main fuel compressor is controlled by the first flow control means, and the gas discharged from the main fuel compressor is recirculated. The flow rate is controlled by the second flow rate adjusting means. Accordingly, the combustor of the gas turbine is supplied with the main fuel at a stepless main fuel supply flow rate regardless of the minimum flow rate of the main fuel compressor, and for a gas turbine provided with a large main fuel compressor, The pressure at the outlet of the main fuel compressor can be controlled stably.

Further, according to the present invention, the flow rate of the main fuel guided to the main fuel compressor for compressing the main fuel is controlled by the first flow rate adjusting means, and a part of the gas discharged from the main fuel compressor is used as the fuel. The fuel is returned to the inlet of the main fuel compressor by the return line, and its flow rate is controlled by the second flow rate adjusting means. The pressure at the outlet of the main fuel compressor is detected by the pressure transmitter, and the first target value of the pressure at the outlet of the main fuel compressor corresponding to the flow rate indicated by the main fuel command signal output from the signal generator is calculated by pressure calculation means. The first flow control means is controlled by the first control means so that the detected pressure becomes the first target value, and the opening of the first flow control means is detected by the detector. A pressure deviation signal is output by a pressure deviation generator in response to the pressure, and the pressure represented by the first target value and the value represented by the pressure deviation signal are added by an adder to output a second target value of the pressure; The second flow rate adjusting means is configured to control the second flow rate so that the detected pressure becomes the second target value.
It is controlled by pressure control means. Accordingly, each flow control means is controlled by each control means, the supply flow rate of the main fuel supplied to the main fuel compressor is controlled by the first flow control means, and the gas discharged from the main fuel compressor is recirculated. The flow rate is controlled by the second flow rate adjusting means.
Accordingly, the combustor of the gas turbine is supplied with the main fuel at a stepless main fuel supply flow rate regardless of the minimum flow rate of the main fuel compressor, and for a gas turbine provided with a large main fuel compressor, The pressure at the outlet of the main fuel compressor can be controlled stably.

Further, according to the present invention, the flow rate of the main fuel guided to the main fuel compressor for compressing the main fuel is controlled by the first flow rate adjusting means, and a part of the gas discharged from the main fuel compressor is used as the fuel. The fuel is returned to the inlet of the main fuel compressor by the return line, and its flow rate is controlled by the second flow rate adjusting means. The differential pressure obtained by subtracting the gas pressure in the combustor from the pressure at the outlet of the main fuel compressor is detected by the differential pressure transmitter, and the main fuel is output in accordance with the flow rate indicated by the main fuel command signal output from the signal generator. The first target value of the differential pressure obtained by subtracting the gas pressure in the combustor from the pressure at the outlet of the compressor is output by the calculating means, and the first control means controls the first differential value so that the detected differential pressure becomes the first target value. (1) The flow rate adjusting means is controlled, a pressure deviation signal representing a predetermined value is output from the pressure deviation setter, and the differential pressure represented by the first target value of the differential pressure and the value represented by the pressure deviation signal are added by an adder. The second target value of the differential pressure is output by the addition, and the second target value is set so that the detected differential pressure becomes the second target value.
The second flow rate adjusting means is controlled by the control means. As a result, each flow control means is controlled by each control means, and the supply flow rate of the main fuel supplied to the main fuel compressor is reduced to the first flow rate.
The flow rate of the discharge gas from the main fuel compressor is controlled by the flow rate adjusting means, and the flow rate of the discharged gas from the main fuel compressor is controlled by the second flow rate adjusting means. Accordingly, the combustor of the gas turbine is supplied with the main fuel at a stepless main fuel supply flow rate regardless of the minimum flow rate of the main fuel compressor, and for a gas turbine provided with a large main fuel compressor, The pressure at the outlet of the main fuel compressor can be controlled stably.

Further, according to the present invention, the flow rate of the main fuel guided to the main fuel compressor for compressing the main fuel is controlled by the first flow rate adjusting means, and a part of the gas discharged from the main fuel compressor is converted to the fuel. The fuel is returned to the inlet of the main fuel compressor by the return line, and its flow rate is controlled by the second flow rate adjusting means. The differential pressure obtained by subtracting the gas pressure in the combustor from the pressure at the outlet of the main fuel compressor is detected by the differential pressure transmitter, and the main fuel is output in accordance with the flow rate indicated by the main fuel command signal output from the signal generator. A target value of the differential pressure obtained by subtracting the gas pressure in the combustor from the pressure at the outlet of the compressor is output by the calculating means,
The first flow control means is controlled by the first control means so that the detected differential pressure becomes the first target value, and the opening of the first flow control means is detected by a detector. In response, a pressure deviation signal is output by the pressure deviation generator, and the differential pressure represented by the target value of the differential pressure and the value represented by the pressure deviation signal are added by the adder to output a second target value of the differential pressure. The second flow control valve is controlled by the second control means so that the detected differential pressure becomes the second target value. Thereby, each flow control means is controlled by each control means, the supply flow rate of the main fuel supplied to the main fuel compressor is controlled by the first flow control means, and the release flow rate of the discharge gas from the main fuel compressor is reduced. It is controlled by the first flow rate adjusting means. Accordingly, the combustor of the gas turbine is supplied with the main fuel at a stepless main fuel supply flow rate regardless of the minimum flow rate of the main fuel compressor, and for a gas turbine provided with a large main fuel compressor, The pressure at the outlet of the main fuel compressor can be controlled stably.

Further, according to the present invention, the flow rate of the main fuel guided to the main fuel compressor for compressing the main fuel is controlled by the first flow rate adjusting means, and a part of the gas discharged from the main fuel compressor is converted to the fuel. The fuel is returned to the inlet of the main fuel compressor by the return line, and its flow rate is controlled by the second flow rate adjusting means. The differential pressure obtained by subtracting the pressure at the outlet of the air compressor provided in the gas turbine from the pressure at the outlet of the main fuel compressor is detected by the differential pressure transmitter, and the flow rate represented by the main fuel command signal output from the signal generator The first target value of the differential pressure obtained by subtracting the pressure at the outlet of the air compressor provided in the gas turbine from the pressure at the outlet of the main fuel compressor from the pressure at the outlet of the main fuel compressor is output by the calculating means, and the detected differential pressure is equal to the first target value. The first flow control means is controlled by the first control means so as to be a target value, a pressure deviation signal representing a predetermined value is output from the pressure deviation setting device, and the differential pressure represented by the first target value of the differential pressure is output. The value represented by the pressure deviation signal is added by the adder to output a second target value of the differential pressure, and the second control means controls the second flow rate adjusting means so that the detected differential pressure becomes the second target value. Is controlled. Thereby, each flow control means is controlled by each control means, the supply flow rate of the main fuel supplied to the main fuel compressor is controlled by the first flow control means, and the release flow rate of the discharge gas from the main fuel compressor is reduced. It is controlled by the second flow rate adjusting means. Therefore, to the gas turbine combustor,
Regardless of the minimum flow rate of the main fuel compressor, the main fuel at a stepless main fuel supply flow rate is supplied, and the pressure at the outlet of the main fuel compressor is increased for a gas turbine provided with a large main fuel compressor. It can be controlled stably.

Further, according to the present invention, the flow rate of the main fuel guided to the main fuel compressor for compressing the main fuel is controlled by the first flow rate adjusting means, and a part of the gas discharged from the main fuel compressor is converted to the fuel. The fuel is returned to the inlet of the main fuel compressor by the return line, and its flow rate is controlled by the second flow rate adjusting means. The differential pressure obtained by subtracting the pressure at the outlet of the air compressor provided in the gas turbine from the pressure at the outlet of the main fuel compressor is detected by the differential pressure transmitter, and the flow rate represented by the main fuel command signal output from the signal generator The target value of the differential pressure obtained by subtracting the pressure at the outlet of the air compressor provided in the gas turbine from the pressure at the outlet of the main fuel compressor from the pressure at the outlet of the main fuel compressor is output by the calculation means, and the detected differential pressure is the first target value. The first to be
The first flow rate adjusting means is controlled by the control means, an opening of the first flow rate adjusting means is detected by a detector, and a pressure deviation signal is output by a pressure deviation generator in response to an output of the detector. The adder adds the differential pressure indicated by the target value of the differential pressure and the value indicated by the pressure deviation signal to output a second target value of the differential pressure, and the second target value is set so that the detected differential pressure becomes the second target value. The second control means controls the second flow control valve. Thereby, each flow control means is controlled by each control means, the supply flow rate of the main fuel supplied to the main fuel compressor is controlled by the first flow control means, and the release flow rate of the discharge gas from the main fuel compressor is reduced. It is controlled by the first flow rate adjusting means. Therefore, to the gas turbine combustor,
Regardless of the minimum flow rate of the main fuel compressor, the main fuel at a stepless main fuel supply flow rate is supplied, and the pressure at the outlet of the main fuel compressor is increased for a gas turbine provided with a large main fuel compressor. It can be controlled stably.

[0029]

FIG. 1 is a system diagram showing a configuration of a gas turbine control device on which the present invention is based. The gas turbine control device shown in FIG. 1 shows a configuration of a common part which is a premise of each embodiment described later. The gas turbine controller 120 supplies, for example, a blast furnace, which supplies a low-calorific fuel gas such as a blast furnace gas, which is a blast furnace top waste gas, to a combustor 3b provided in the gas turbine 3 described below. Main fuel supply 200 and main fuel supply 20
0 and first flow control means 2 interposed between combustor 3b
04, an auxiliary fuel supply source 201 realized by, for example, a storage tank or the like for supplying an auxiliary fuel which is a liquid fuel such as kerosene to the combustor 3b, and an auxiliary fuel supply source 2
01, an auxiliary fuel flow control valve 205 as a second flow control means interposed between the burner 3 and the combustor 3b, a calorific value measuring device 202 for measuring the calorific value of the main fuel, and an output of the gas turbine 3 which will be described later. It includes a power value detector 203 as output detection means for detecting the output of the generator 4, and a gas turbine control circuit 90 for controlling the main turbine and the auxiliary fuel to control the gas turbine 3.

In order to lead the main fuel supplied from the main fuel supply source 200 to the combustor 3b of the gas turbine 3, the main fuel is supplied to the main fuel compressor 2 by compressing and supplying the main fuel. And a second main fuel supply line 112 for guiding main fuel from the main fuel compressor 2 to the combustor 3b of the gas turbine 3.

Further, when blast furnace gas is used as the main fuel of the gas turbine 3, it is necessary to compress the blast furnace gas, so that the main fuel compressor 2 is used. The main fuel compressor 2 has a predetermined minimum flow rate, for example, a minimum flow rate for preventing the main fuel compressor 2 from causing an abnormality such as destruction. In order to smoothly control the gas turbine 3, the main fuel having a flow rate equal to or less than the minimum flow rate is supplied to the combustor 3b of the gas turbine 3.
The circulation loop 80 for circulating a part of the main fuel is provided.
The value 0 sets the main fuel flow rate control means 204 as the first flow rate control means, and controls the flow rate of the main fuel supplied to the combustor 3b as the first flow rate.

The first flow rate control means 204 is branched from the second main fuel supply line 112 to the first main fuel supply line 111.
Are connected to a fuel recirculation line 113 for returning a part of the main fuel discharged from the main fuel compressor 2 to an inlet of the main fuel compressor 2 and a first main fuel supply line 111, First flow control valve 6 for controlling the flow rate of main fuel of fuel compressor 2
And a second flow control valve 7 and a gas cooler 8 which are interposed in the fuel recirculation line 113 to control the flow rate of the main fuel recirculated to the inlet of the main fuel compressor 2 and can be fully closed. . A portion of the main fuel compressor 2, a portion of the first main fuel supply line 111 downstream of a connection point where the fuel recirculation line 113 is connected, and a portion of the second main fuel supply line 112. A portion upstream of the branch point where the fuel return line 113 branches in the main fuel supply direction; a fuel return line 113; first and second flow control valves 6 and 7, and a gas cooler 8 Constitutes the circulation loop 80, that is, the first flow control means 204.

An auxiliary fuel supply pipe 117 and an auxiliary fuel flow control means interposed in the auxiliary fuel supply pipe 117 for guiding the auxiliary fuel supplied from the auxiliary fuel supply source 201 to the combustor 3b. An auxiliary fuel flow control valve 205 is provided to control the flow rate of the auxiliary fuel, which is the second flow rate.

The calorific value measuring device 202 measures the calorific value of the main fuel in the first main fuel supply pipe 111 by actually burning the main fuel, raising the temperature of water by the generated heat, and measuring the temperature. The heat generation amount _Hm is detected by detecting the rise. As a result, the actual accurate calorific value H
_m can be detected and grasped. This calorific value measuring device 2
02 outputs a heating value signal representative of the detected calorific value H _m. Power value detector 203 detects the power value W _a which is generated by the generator 4 as the output of the generator 4, and outputs the generator output signal representative of the power value W _a.

[0035] Gas turbine control circuit 90, a load setting unit 206 for setting the output of the generator 4 (electric power value) as the output load of the gas turbine 3, the generator from the power value W _s represented by the output of the load setting unit 206 a subtracter 209 for subtracting the power value W _a representative of the output signal, a main fuel arithmetic control circuit 207 as a main fuel control means for controlling the flow rate of the main fuel by operating the main fuel flow rate control means 204, the gas turbine 3 And a supplementary fuel computation control circuit 208 as supplementary fuel control means for controlling the supplementary fuel flow rate by operating the supplementary fuel flow rate adjustment valve 205.

The load setting unit 206 is preset with a power value W _s which is a desired output to be obtained by the gas turbine 3 and outputs a load setting signal representing the power value W _s . The subtractor 209 outputs a load deviation signal representing the subtracted load deviation ΔW in response to the load setting signal and the generator output signal.

The main fuel arithmetic control circuit 207 includes a signal generator 50 for outputting a main fuel control signal as the fuel gas command signal for commanding the flow rate F _m of the main fuel, in response to the main fuel control signals, the later 1st flow rate adjusting valve 6 which is 1 flow rate adjusting means
The first opening command signal for commanding the valve opening _Xc to the first
Function generator 11 and, in response to the main fuel control signal, the second function providing a second opening command signal for commanding the valve opening degree X _v to the second flow rate control valve 7 is a second flow regulating means described later generated And a valve opening calculator 210 having the device 12. The signal generator 50 includes a rotation speed / load control circuit 10a, a gas temperature control circuit 10b, and a start control circuit 10c that respectively output signals for instructing the flow rate of the main fuel, and signals output from these control circuits 10a to 10c. And a low-level signal selector 10d for selecting a signal for instructing the smallest flow rate of the main fuel from the above.

The rotation speed / load control circuit 10a receives the output from the subtracter 209, and sets a main fuel for rotating the rotating shaft 1 described below at a predetermined rotation speed and keeping the output of the generator 4 described later constant. The gas temperature control circuit 10b outputs a signal instructing the flow rate of the working gas at one or both of an inlet and an outlet of the turbine 3c described later.
The start control circuit 10c outputs a signal for commanding a flow rate of the main fuel for supplying the fuel little by little, and outputs a signal for commanding a flow rate of the main fuel so that the flow rate does not exceed a certain value (for example, 1300 ° C.). . These control circuits 10b and 10c are supplied with signals from various detectors (not shown). By the signal generator 50 having such control circuits 10a to 10c and the low-order signal selector 10d,
When the output of the predetermined generator 4 is maintained and the temperature of the working gas rises to a temperature that hinders the operation of the gas turbine 3, the flow rate of the main fuel can be limited, and the gas turbine 3 can be smoothly operated even at the time of startup. It can be controlled to have a function of starting up.

Such a gas turbine control device 120
Is provided in a cogeneration facility 60 using the gas turbine 3 using blast furnace gas as fuel. In the cogeneration facility 60, a main fuel compressor 2, a gas turbine 3, and a generator 4 are connected to a common rotating shaft 1. A boiler (not shown) for generating steam by the heat of the exhaust gas of the gas turbine 3 is provided downstream in the gas flow direction of the gas turbine 3. Gas turbine 3
Is composed of an air compressor 3a, a combustor 3b, and a turbine 3c.

The main fuel supplied from the main fuel supply source 200 at a low pressure near the atmospheric pressure by the first main fuel supply line 111 is supplied to the main fuel compressor 2 and compressed. The flow rate of the main fuel supplied to the main fuel compressor is controlled by the first flow control valve 6. The main fuel compressed by the main fuel compressor 2 passes through the second main fuel supply line 112 to the combustor 3.
b, where it is mixed with air compressed by the air compressor 3a and burned. The main fuel is a blast furnace gas containing carbon monoxide gas. Further, when the calorific value of the main fuel decreases and there is a possibility that the operation of the gas turbine 3 is hindered, the auxiliary fuel is supplied and burned. The hot gas after combustion of the main fuel and auxiliary fuel is
_After expansion at _c , the generator 4 is driven to generate power, and after the pressure is reduced, it is led to the boiler. The steam generated by the boiler
For example, it is supplied to various uses inside a factory such as a steam turbine.

FIG. 2 is a cross-sectional view showing a simplified configuration near the combustor 3b shown in FIG. The combustor 3b has a combustion cylinder 3b1 in which fuel is burned. The main fuel is injected from the main fuel nozzle 3b2 into the combustion cylinder 3b1, and the auxiliary fuel is injected into the combustion cylinder 3b1 from the auxiliary fuel nozzle 3b5 coaxially inserted into the main fuel nozzle 3b2. The air is guided from the annular space 3b3 around the combustion cylinder 3b1 into the combustion cylinder 3b1 through a plurality of through holes 3b4 formed in the combustion cylinder 3b1. The main fuel is burned in the combustion tube 3b1, and the burned gas is guided to the turbine 3c.

A nozzle 3b2 for injecting the main fuel and a nozzle 3b5 for injecting the auxiliary fuel are separately provided, and the combustion chamber 3b1
The auxiliary fuel is configured to be injected separately into the fuel and burned at the same time, so that the auxiliary fuel is liquid to the gas (gas), such as blast furnace gas, for example, kerosene as in this embodiment. Etc. can be used. Therefore, the handling of the auxiliary fuel is easy, for example, the configuration of the equipment for storing the auxiliary fuel is simple, the manufacturing can be performed at low cost, and the cost can be reduced. In addition, even if a carbonized gas used for making coke by steaming coal is used as the auxiliary fuel, the main fuel and the carbonized gas that is the auxiliary fuel are not mixed, so the viscosity caused by the carbonized gas is not used. Substance formation can be prevented. Therefore, for example, it is possible to prevent the viscous substance from adhering to the stationary blade or the moving blade of the main fuel compressor 2 and causing a malfunction.

Referring to FIG. 1 again, the surplus part of the main fuel compressed by the main fuel compressor 2 is supplied to the fuel recirculation line 113 via the second flow rate control valve 7 by the fuel recirculation line 113. The fuel is guided to one main fuel supply pipe 111 and returned to the inlet of the main fuel compressor 2. At this time, since the main fuel compressed by the main fuel compressor 2 has a high temperature, it is cooled by the gas cooler 8. Thereby, it is possible to prevent the temperature of the main fuel from undesirably becoming high while recirculating. The second flow control valve 7 can be fully closed.

[0044] from the load setting unit 206, the load setting signal for commanding a desired output or power value W _s to be obtained by the generator 4 is output is supplied to the subtractor 209. On the other hand, from the power detection unit 203, the generator output signal representative of the power value W _a which is output or power generation of the generator 4 is output is provided to the subtractor 209. The subtractor 209 is responsive to the load setting signal and the generator output signal, the power value W _a representative from the power value W _s indicating the load setting signals generator output signal is subtracted, commanded by the load setting unit 206 Load deviation ΔW (= W _s ) which is a power value corresponding to the difference between the output of the generator and the actual output of the generator detected by the power detector 203.
A load deviation signal representing −W _a ) is output, and the load deviation signal is supplied to the rotation speed / load control circuit 10 a provided in the signal generator 50.

The rotation speed / load control circuit 10a is configured as shown in FIG. 3, for example, and responds to the load deviation signal given by the subtracter 209, performs proportional control by, for example, the input buffer 160, and controls by the integrator 161. The integral control is performed, the differential control is performed by the differential capacitor 162, and the calculation result of the integrator 161 and the differential capacitor
The calculation result of 62 is added by the adder 163, and a signal for commanding the flow rate of the main fuel is output. On the other hand, the gas temperature control circuit 10b and the startup control circuit 10c respond to signals given from various detectors (not shown) as described above, and perform, for example, the same proportional, integral, and differential operations as those of the rotational speed / load control circuit 10a. And the like, and outputs a signal for commanding the flow rate of the main fuel. The signals output from the rotation speed / load control circuit 10a, the gas temperature control circuit 10b, and the start control circuit 10c are given to the low-order signal selector 10d, and the low-order signal selector 10d commands the smallest flow rate among these. selects a signal to the main fuel control signal for commanding the main fuel flow rate F _m is output.

As described above, by performing control calculations such as proportional, integral, and derivative, minute fluctuations in the detection output are stably controlled without being constrained by the fluctuations, and the detection output is controlled. Control can be performed immediately in response to a large sudden change.

The main fuel control signal F _m outputted from the low signal selector 10d of the signal generator 50 is a signal representing the flow rate of the main fuel needed to operate the gas turbine at a predetermined output, the first Function generator 11 and second function generator 1
2 given.

FIG. 4 is a diagram showing a control function of the first function generator 11 provided in the gas turbine control device 120 shown in FIG. The horizontal axis represents the flow rate F _m of the main fuel represented by the main fuel control signal inputted to the first function generator 11, and the vertical axis, a first opening command output from the first function generator 11 5 shows a valve opening _Xc of the first flow rate adjusting means 6 represented by a signal.

In the first function generator 11, the main fuel control signal F
An operation represented by the following equation (1) is performed according to _m .

[0050]

(Equation 1)

Here, X _c is the valve opening of the first flow control valve 6, a _min is the valve opening corresponding to the minimum flow rate, and a
(F _m ) is a valve opening corresponding to the main fuel flow rate F _m specified by the main fuel control signal, and both are determined by the characteristics of the main fuel compressor 2. F _min is the main fuel compressor 2
Is the minimum flow rate. The minimum flow rate F _min is 5 which is the maximum flow rate.
It is about 0%.

Based on the equation (1), the flow rate F _m represented by the main fuel control signal is set to the minimum flow rate F _min of the main fuel compressor 2 for preventing the main fuel compressor 2 from being destroyed as described above.
If it is less than the minimum flow rate _Fmin , a first opening command signal representing the valve opening _Xc (= _amin ) of the first flow control valve 6 corresponding to the minimum flow rate _Fmin is output, and the flow rate F represented by the main fuel control signal is output. _{When m} is _{equal to} or greater than the minimum flow rate F _min , the valve opening X _c (= a (F _m )) corresponding to the flow rate F _m represented by the main fuel control signal.
Is output.

FIG. 5 is a diagram showing a control function of the second function generator 12 provided in the gas turbine control device 120 shown in FIG. The horizontal axis represents the main fuel flow rate F _m indicating the main fuel control signal inputted to the second function generator 12, and the vertical axis, a second flow rate which represents a second degree of opening command signal outputted from the function shows the valve opening X _v of the adjusting means 7.

The second function generator 12 performs an operation represented by the following equation (2) according to the main fuel control signal.

[0055]

(Equation 2)

Here, _Xv is the valve opening of the second flow control valve 7, _θmin is the valve opening corresponding to fully closed, and θ ( _Fmin- F
_m ) is a valve opening corresponding to the flow rate F _min -F _m , and both are values specified by the characteristics of the second flow control valve 7.

[0057] When the flow rate F _m indicating the main fuel control signal based on the formula (2) is less than the minimum flow rate F _min, the flow rate F obtained by subtracting the flow rate F _m indicating from the minimum flow rate F _min of the main fuel control signal valve opening corresponding to the _min -F _m X _v (= _θ
(F _min -F _m )), and when the flow rate F _m indicated by the main fuel control signal exceeds the minimum flow rate F _min , the second flow control valve 7 is fully closed X _v (= Θ _min )
Is output.

[0058] Referring again to FIG. 1, by using thus the two function generators 11, 12 are set, the main representative of the minimum flow rate F _min than the flow rate F _m of the main fuel compressor 2 The fuel control signal is supplied to the first and second function generators 11, 12
, The first flow control valve 6 is controlled to supply a flow rate corresponding to the minimum flow rate F _min to the main fuel compressor 2, and the second flow control valve 7 controls the minimum flow rate F _min
Is controlled so as to reflux the main fuel control signal fuel return line 113 the flow the flow rate F _m by subtracting represented by the. Thus the main fuel of said minimum flow rate F _min is supplied to the main fuel compressor 2 is discharged from the main fuel compressor 2, F _min -F _m by a fuel return line 113 where the second flow rate control valve 7 is interposed since the main fuel flow rate represented by the recirculated to the inlet led of the main fuel compressor 2 to the first main fuel supply conduit 111, supply main fuel flow rate F _m of the difference in the combustor 3b of the gas turbine 3 Is done.

Meanwhile, the main fuel control for signal flow F when _m exceeds the minimum flow rate F _min of the main fuel compressor 2 second flow rate control valve 7 representing the is fully closed theta _min, the first flow rate regulation valve 6 the main fuel flow rate F _m indicating the main fuel control signal controlled by the is supplied to the combustor 3b of the gas turbine 3.

By controlling the first flow control valve 6 and the second flow control valve 7 in this way, the main fuel compressor can be used for a gas turbine using low pressure and low heat generation gas such as blast furnace gas as fuel. In step 2, the main fuel flow rate can be adjusted and controlled steplessly so that the main fuel flow rate equal to or less than the minimum flow rate can be supplied. Therefore, regardless of the minimum flow rate of the main fuel compressor 2, the gas turbine 3 can be controlled in a stable state, and the power generation output can be kept constant.

The flow rate of the main fuel guided to the main fuel compressor 2 for compressing the main fuel is controlled by a first flow control valve 6, and a part of the main fuel discharged from the main fuel compressor 2 is supplied to the fuel recirculation pipe. The flow is returned to the inlet of the main fuel compressor 2 by the passage 113, and its flow rate is controlled by the second flow control valve 7. The main fuel control signal output from the signal generator 50 is provided to the first function generator 11 and the second function generator 12, and the first function generator 11 generates a first opening command corresponding to the main fuel control signal. gives a signal to the first flow regulating valve 6, the second function generator 12 provides a second opening command signal corresponding to the main fuel control signal F _m in the second flow regulating valve 7. As a result, the flow rate of the main fuel gas supplied to the main fuel compressor 2 in response to the main fuel control signal output from the signal generator 50 is reduced to the first level.
The flow rate of the main fuel discharged from the main fuel compressor 2 in response to the main fuel control signal is controlled by the second flow rate control valve 7. Accordingly, the main fuel having a stepless flow rate is supplied to the combustor 3b of the gas turbine 3 regardless of the minimum flow rate of the main fuel compressor 2.

Accordingly, regardless of the minimum flow rate of the main fuel compressor 2, the gas turbine 3 can be controlled from the minimum output to the maximum output, and the gas having a low pressure and a low calorific value, which requires the main fuel compressor 2, For example, blast furnace gas or the like can be effectively used as fuel for the gas turbine 3.

FIG. 6 is a flowchart for explaining the control operation for controlling the auxiliary fuel. At step n1, the control of the auxiliary fuel is started. In step n2, the load setting signal output from the load setting device 206 and the heat generation signal output from the heat generation amount measuring device 202 are converted into the insufficient heat amount calculation circuit 2.
Given 20, in response to the load setting signal and heating value signal, the main fuel is the reference flow rate F _s when having a reference calorific value H _s is calculated by the equation (3).

F _s = F (W _s ) (3) FIG. 7 is a diagram showing a function of the equation (3). The horizontal axis represents the power value represented by the load setting signal W _s applied to this function, the vertical axis corresponds to the setting load when the main fuel is calculated by the function has a reference calorific value H _s This shows the flow rate of the main fuel. This function is a linear function of the flow rate, i.e. the reference flow rate F _s of the main fuel when the power value W _s and a main fuel that has been set by the load setting unit 206 has a reference calorific value H _s. The intercept of this function, that is, the intersection with the vertical axis, is positive, and its value is F _s 1, which is almost zero. In equation (3), the calculation is performed based on a function as shown in FIG.

The function on the right side of the equation (3), that is, the function F (W _s ) shown in FIG. 7 is a function determined based on the characteristics of the gas turbine 3, and based on this function, the load setting signal W
flow rate F _s of the main fuel corresponding to _s is calculated. Then the heating value H _m of the main fuel is derived in step n3. The calorific value _Hm is given by the output of the calorific value measuring device 202. Then, the calorific value H _m of the reference calorific value H _s and the main fuel is compared at step n4. If it is determined that the calorific value H _m of the main fuel is less than the reference calorific value H _s, the process proceeds to the control of step n5. In step n5, the insufficient heat amount _Er of the gas turbine is calculated by the equation (4).

[0066] When _{E r = F s · (H} s -H m) ... H s ≧ H m ... (4) in the calculation of the equation (4) based on the equation (3), measuring the amount of heat generated reference When the calorific value is less than the calorific value, a calorific value corresponding to a value obtained by subtracting the measured calorific value from the reference calorific value is calculated. The signal indicating the insufficient heat amount _Er is supplied to the auxiliary fuel calculation control means 208.

In step n6, the auxiliary fuel control arithmetic circuit 208 calculates the amount of insufficient heat E _r , that is, based on equation (4).
Flow rate F _a of the auxiliary fuel corresponding to insufficient heat is calculated by the equation (5).

[0068]

(Equation 3)

[0069] Here, H _a is the heating value of the auxiliary fuel that has been set in advance, the calorific value is known. In step n7, based on equation (5), the valve opening theta _a supplementary fuel flow control valve 205, which corresponds to the flow rate of the auxiliary fuel is calculated.

Θ _a = θ (F _a ) (6) where θ (F _a ) is a function for calculating the valve opening degree θ _a of the auxiliary fuel flow rate adjustment valve 205 corresponding to the flow rate of the auxiliary fuel. This function is determined based on the characteristics of the auxiliary fuel flow control valve 205. Performed in order calculations as described above, a result of calculation by Equation (6), that the third opening command signal for commanding the valve opening theta _a supplementary fuel flow control valve 205 to the auxiliary fuel flow rate adjusting valve 205 Given, step n8
The control is terminated.

[0071] Thus, by the auxiliary fuel based on an operation of the above is supplied to the combustor 3b, even calorific value H _m of the main fuel is decreased, when the main fuel of the reference calorific value H _s was charged Can be given to the gas turbine 3. On the other hand, when the heating value H _m of the main fuel is determined to exceed the reference calorific value H _s in step n4, the step n9
Is transferred to control. In step n9, the amount of insufficient heat is set to zero by the following equation (7).

E _r = 0... H _s <H _m (7) The value of the insufficient heat amount _Er calculated by the equation (7) becomes 0, and a signal representing _Er = 0 is the auxiliary fuel calculation control means. 208
At step n10, the auxiliary fuel flow control valve 2
At 05, a third opening degree command signal for fully closing is supplied to the auxiliary fuel flow control valve 205, and the control is ended in step n8.

[0073] FIG. 8 (1) is a diagram showing an example of changes in the calorific value H _m of the main fuel, FIG. 8 (2) shows the transition of insufficient heat E _r at that time. If the calorific value of the main fuel is constant, the gas turbine 3 can be smoothly controlled with the above configuration. However, blast furnace gas is used as the main fuel, and the calorific value of this blast furnace gas is unstable. For example, as shown in FIG.
T1 to, and as later t2, if the flame is at a preset reference calorific value H _m above order not disappear blown in heating value H _m are for example the combustor 3b of the main fuel from the gas turbine 3 can be operated to obtain a sufficient amount of heat for obtaining the output (power value) set by the load setting unit 206. In contrast, when the heating value H _m of the main fuel as before time t1 after t2 is lowered to a value less than the reference calorific value H _s, as shown in FIG. 8 (2), the amount of heat is insufficient. In such a state, the gas turbine 3 cannot be operated smoothly, and for example, blowout may occur as described above.

[0074] For this, when the calorific value H _m of the main fuel is lower than the reference calorific value H _s to prevent a blowout of the foregoing, in order to operate smoothly the gas turbine 3, the auxiliary Fuel is supplied from an auxiliary fuel supply 201.
The flow rate is controlled by operating the auxiliary fuel flow control valve 205 by the auxiliary fuel operation control circuit 208.

Therefore, when the calorific value of the main fuel is reduced by performing the calculations represented by the equations (3) to (7) by the insufficient heat quantity calculation means 220 and the auxiliary fuel calculation control circuit 208, Auxiliary fuel is supplied to the combustor 3b so that the amount of heat corresponding to the amount of heat obtained when has the reference calorific value is supplied to the gas turbine 3, and the calorific value of the main fuel exceeds the reference calorific value That is, the supply of the auxiliary fuel is automatically stopped. As a result, the expensive auxiliary fuel is supplied only when the calorific value of the main fuel is reduced and the smooth operation of the gas turbine 3 may be hindered, so that the consumption of the auxiliary fuel is minimized. Cost can be reduced. of course,
The gas turbine 3 is controlled smoothly.

FIG. 9 shows a cogeneration facility 65 having a gas turbine controller 125 according to one embodiment of the present invention.
FIG. 2 is a system diagram showing a part of the configuration. The gas turbine control device 125 of this embodiment includes a main fuel arithmetic control circuit 207a.
A gas turbine control circuit 95 having The main fuel operation control circuit 207a determines the second main pressure, which is the pressure at the outlet of the main fuel compressor 2, based on the main fuel control signal output from the low-level signal selector 10d of the signal generator 50 and the characteristics of the gas turbine 3. A main fuel flow / differential pressure converter 21 which is a calculation means for calculating a differential pressure target value ΔP obtained by subtracting the gas pressure in the combustor 3b of the gas turbine 3 from the pressure of the main fuel in the fuel supply line 112; The target value ΔP of the differential pressure and the differential pressure P represented by the differential pressure signal output from the differential pressure transmitter 22 described later.
comparing the _f -P _c, detected differential pressure P _f represented by this differential pressure signal -
And a differential pressure control means 23 for outputting a control signal indicating a flow rate of the main fuel supplied to the combustor 3b so that _Pc becomes the target value. In this embodiment, the second
From the pressure of the main fuel in the main fuel supply line 112, the combustor 3
The differential pressure transmitter 22 for detecting a differential pressure obtained by subtracting the gas pressure in b is provided. Other parts having the same configuration as the gas turbine control device 120 shown in FIGS.
The same reference numerals are given and the description is omitted.

The differential pressure transmitter 22 guides the main fuel from the main fuel compressor 2 to the second combustor 3 b of the gas turbine 3.
In the main fuel supply line 112, for example, the position 30 shown in FIG.
1 pressure P _f and the space where the fuel in the combustor 3b is burned,
That is, the position 30 shown in FIG.
Detecting a second gas pressure P _c, Searching for the differential pressure P _f -P _c, and outputs it to the differential pressure control means 23.

[0078] Here, is expressed by the following equation (8) between the pressure P _f of the main fuel in the second main fuel supply conduit 112, the pressure P _c in the combustion cylinder 3b1 of the combustor 3b The relationship holds.

P _f −P _c > 0 (8) FIG. 10 is a diagram showing a control function of the main fuel flow rate / differential pressure converter 21 provided in the gas turbine control device 125 of this embodiment. The horizontal axis, the main fuel flow rate / signal input to the differential pressure transducer 21, indicates the flow rate F _m of the main fuel represented by the main fuel control signal in the present embodiment, the vertical axis, the main fuel flow rate /
A signal output from the differential pressure converter 21, a target value ΔP of the differential pressure obtained by subtracting the gas pressure of the combustor 3b of the gas turbine 3 from the pressure of the main fuel in the second main fuel supply pipe 112 in this embodiment. Show.

The main fuel flow / differential pressure converter 21 determines the second main fuel supply line 11 in the following procedure from the flow rate represented by the main fuel command signal output from the low-order signal selector 10d of the signal generator.
Then, a target value ΔP of a differential pressure between the main fuel pressure _Pf and the pressure _Pc in the combustor 3b is calculated. Flow rate G _f of the main fuel supplied to the gas turbine 3 are generally the second main fuel supply conduit 1
It is well known that determined by the pressure P _c of the main fuel in the pressure P _f and the combustor 3b in 12. Its relationship to the main fuel flow rate G _f and the differential pressure P _f -P _c is given by the following equation (9).

G _f = C · √ (P _f −P _c ) (9) Here, the coefficient C is a constant determined by the gas turbine. According to this relational expression, a differential pressure for calculating the flow rate _Gf of the main fuel to a value corresponding to the main fuel control signal is calculated as follows.

[0082]

(Equation 4)

[0083] Equation (10) based on the second main fuel supply conduit corresponding to the flow rate F _m of the main fuel represented by the main fuel control signal 1
12 from the pressure of the main fuel in the gas turbine combustor 3b
Calculates the target value ΔP of the differential pressure obtained by subtracting the gas pressure in
A signal representing the target value ΔP is output.

Referring again to FIG. 9, the control means 23
Wherein the target value ΔP of the differential pressure given by (10), from the main fuel pressure P _f of the second main fuel supply conduit 112 represented by the differential pressure signal outputted from the differential pressure transmitter 22. in the combustor 3b comparing the detected differential pressure P _f -P _c obtained by subtracting the gas pressure P _c, proportional, integral, and controls operation such as differentiation, the control signal first
It is provided to the function generator 11 and the second function generator 12. In the control unit 23, when the detected differential pressure P _f -P _c is less than the target value [Delta] P, as an output control signal, the flow rate B of increasing the flow rate than the flow rate F _m indicating the main fuel control signal emits signals representative of, increasing the supply main fuel flow to the gas turbine 3, when the detected differential pressure P _f -P _c conversely exceeds the target value, the control signal, the supply main fuel to the gas turbine 3 flow Decrease. Although the control signal is input instead of the main fuel control signal, the first function generator 1
1, the second function generator 12, the first flow control valve 6, and the second
The function of the flow control valve 7 is the same as that shown in FIGS.

The control means 23 is realized by, for example, a proportional-integral-differential circuit (abbreviated as PID circuit). Moreover, in this way to detect a pressure difference obtained by subtracting the gas pressure P _c in the combustor 3b from the pressure P _f of the main fuel of the second main fuel supply conduit 112, compared with a target value ΔP of the differential pressure By performing calculations and controlling the first flow control valve 6 and the second flow control valve 7, even if the main fuel compressor 2 is large and has a large capacity, the first flow control valve 6 In addition, a delay in controlling the flow rate of the main fuel by the second flow control valve 7 can be eliminated, and stable control of the gas turbine 3 can be performed.

The flow rate of the main fuel guided to the main fuel compressor 2 for compressing the main fuel is controlled by a first flow control valve 6, and a part of the main fuel discharged from the main fuel compressor 2 is supplied to the fuel recirculation pipe. The flow is returned to the inlet of the main fuel compressor 2 by the passage 113, and its flow rate is controlled by the second flow control valve 7. The differential pressure obtained by subtracting the gas pressure in the combustor 3 b from the pressure at the outlet of the main fuel compressor 2 is output by the differential pressure transmitter 22, and the flow rate F _m represented by the main fuel control signal output from the signal transmitter 50. The target value ΔP of the pressure difference between the pressure at the outlet of the main fuel compressor 2 and the gas pressure in the combustor 3b corresponding to the above is calculated by the main fuel flow / differential pressure converter 21 and the detected differential pressure P _f −P _The control means 23 outputs a control signal indicating the flow rate B of the main fuel such that _c becomes the target value ΔP, and this control signal is given to the first and second function generators 11 and 12, and the first function generator 11 is the first signal corresponding to the control signal B
The opening command signal is given to the first flow control valve 6, and the second function generator 12 outputs the second opening command signal corresponding to the control signal to the second flow control valve 6.
It is given to the flow control valve 7.

As a result, the flow rate of the main fuel supplied to the main fuel compressor 2 in response to the control signal output from the control means 23 is controlled by the first flow control valve 6, and the main flow rate is controlled in response to the control signal. The recirculated flow rate of the gas discharged from the fuel compressor 2 is controlled by the second flow control valve 7. Therefore, the main fuel is supplied to the combustor 3b of the gas turbine 3 at a stepless flow rate regardless of the minimum flow rate of the main fuel compressor 2, and the gas turbine 3 provided with the large main fuel compressor 2 Thus, the outlet pressure of the main fuel compressor 2 can be controlled stably.

Further, regardless of the minimum flow rate of the main fuel compressor 2, the gas turbine 3 can be controlled from the minimum output to the maximum output, and has a low pressure requiring a compression process by the main fuel compressor 2 and a low calorific value. Can be effectively used as fuel for the gas turbine. Detection differential pressure P _f -P _c by the control means 23 is supplied to the first and second function generators 11 and 12 control signals representative of the flow rate B of the main fuel so that the target value ΔP is output, the control signal The first and second opening command signals corresponding to the first and second flow control valves 6 and 6
Therefore, even if the main fuel compressor 2 is large and has a large capacity, the control of the gas turbine 3 can be performed without delay.

[0089] In this embodiment as described above, the differential pressure transmitter 22, a pressure difference obtained by subtracting the pressure P _c in the combustor 3b from the pressure P _f of the main fuel in the second main fuel supply conduit 112 It is configured to detect. However, the combustor 3b
Since the inside is at a high temperature, it is difficult to detect the pressure. Therefore, as another embodiment of the present invention, as shown by a virtual line in FIG. the pressure P _f of the main fuel at the position 301 shown in FIG. 2 of the fuel supply conduit 112, the air in the position 303 shown in FIG. 2 in the air line 116 for guiding the compressed air to the combustor 3b from the air compressor 3a it may be provided comprised differential pressure transmitter 22a to detect a differential pressure obtained by subtracting the pressure P _a.

The flow rate of the main fuel guided to the main fuel compressor 2 for compressing the main fuel is controlled by the first flow control valve 6 so that a part of the gas discharged from the main fuel compressor 2 is recirculated. The flow is returned to the inlet of the main fuel compressor 2 by the pipe line 113, and the recirculated flow is controlled by the second flow control valve 7. The pressure P _a pressure difference obtained by subtracting P _f -P _a differential pressure transmitter 22a of the outlet of the main fuel compressor 2 of the air compressor 3a provided in the gas turbine 3 from the pressure P _f of the outlet
Output by the pressure of the outlet of the signal transmitter 50 main fuel compressor 2 corresponding to the flow rate F _m indicating the main fuel command signal outputted from the outlet of the pressure P _f and the air compressor 3a provided in the gas turbine P target value of the differential pressure between _a main fuel flow rate /
The calculated differential pressure P _f −
The control means 23 outputs a control signal indicating the flow rate of the main fuel such that Pa becomes _a target value.
And the second function generators 11 and 12. The first function generator 11 supplies a first opening command signal corresponding to the control signal to the first flow rate control valve 6, and the second function generator 12 A second opening command signal corresponding to the control signal is provided to the second flow control valve 7.

As a result, the flow rate of the main fuel supplied to the main fuel compressor 2 in response to the control signal B output from the control means 23 is controlled by the first flow control valve 6, and in response to the control signal B Thus, the recirculated flow rate of the gas discharged from the main fuel compressor 2 is controlled by the second flow control valve 7. Therefore, the combustor 3b of the gas turbine 3 is supplied with the main fuel at a stepless flow rate irrespective of the minimum flow rate of the main fuel compressor 2, and the gas turbine 3 provided with the large main fuel compressor 2 The control can be performed by changing the pressure at the outlet of the main fuel compressor 2.

Further, regardless of the minimum flow rate of the main fuel compressor 2, the gas turbine 3 can be controlled from the lowest output to the highest output. Can be effectively used as fuel for the gas turbine 3. Further, the control means 23 outputs a control signal indicating the flow rate of the main fuel so that the detected differential pressure becomes the target value, and outputs the first and second function generators 1.
Since the first and second opening command signals corresponding to the control signals are supplied to the first and second flow control valves 6 and 7, the main fuel compressor 2 is large and has a large capacity. However, the control of the gas turbine 3 can be performed stably without delay. Incidentally, the pressure P _a of the air in the air duct 116, and the gas pressure P _c in the combustor 3b, so substantially matched, performed even using a differential pressure transmitting device 22a as the shown in FIG. 9 The same effect as the example can be obtained.

FIG. 11 is a system diagram showing a partial configuration of a cogeneration facility 66 having a gas turbine controller 126 according to another embodiment of the present invention. A gas turbine control device 126 of this embodiment, the second main fuel supply pipe based on the characteristics of the flow rate F _m, and a gas turbine 3 represents the main fuel control signal output from the low signal selector 10d of the signal generator 50 A main fuel flow / pressure converter 24 which is a calculating means for calculating a target value P _f1 of the gas pressure in the passage 112 and outputting a signal representing the value; a target value P _f1 of the pressure; comparing the detected pressure P _f representing the pressure signal output from the oscillator 25, the detected pressure P _f is calculated the main fuel flow rate such as to coincide with the target value P _f1, each function generates a control signal A gas turbine control circuit 96 having a main fuel operation control circuit 207b including the control means 26 provided to the units 11 and 12 is provided. Further, the pressure Pf of the main fuel in the second fuel line 112 is detected, and the pressure _Pf is detected.
A pressure transmitter 25 that outputs a pressure signal representing _f is provided. The other portions having the same configuration as the embodiment shown in FIG. 9 are denoted by the same reference numerals, and description thereof will be omitted.

FIG. 12 is a diagram showing a control function of the main fuel flow / pressure converter 24 provided in the gas turbine controller 126 of this embodiment. The horizontal axis, the signal input to the main fuel flow rate / pressure transducer 24, indicates the main fuel flow rate F _m indicating the main fuel control signal in the present embodiment, the signal ordinate, which is output from this function, the The target value of the pressure in the second main fuel supply line 112 represented by the signal representing the target value P _f1 of the pressure in the embodiment is shown.

[0095] Generally the gas turbine 3, since the characteristics thereof are given in advance is customary, the pressure P _a at the outlet of the air compressor 3a (F _m) are known, the target value P _f1 of the pressure mainly It is given in accordance with the flow rate F _m representing the fuel control signal. When this target value of the pressure is represented by _Pa (F _m ), it is represented by Expression (11).

[0096]

(Equation 5)

The main fuel flow rate / pressure converter 24 calculates the above equation (11) and outputs a signal representing the target value P _f1 of the pressure of the second main fuel supply line 112.

[0098] expression based on (11), the second main fuel supply conduit 11 corresponding to the main fuel flow rate F _m indicating the main fuel control signal
A target value P _f1 of the pressure of the main fuel in 2 is calculated, and a signal representing the value is output.

The control means 26 receives a signal from the main fuel flow / pressure converter 24 and outputs a signal from the pressure transmitter 25 for detecting the pressure of the main fuel in the second main fuel supply line 112 from the target value P _f1 represented by the signal. detected pressure P _f representing the pressure signal output is subtracted by the subtractor 55 is inputted a signal representing the value, proportional to the value represented by this signal, integration, performs control operation such as differentiation, the operation result D Is output.
This control signal is provided to first and second function generators 11 and 12. Operations are performed by the first and second function generators 11 and 12 based on the functions shown in FIGS.
First and second valve opening command signals to be supplied to the first and second flow control valves 6 and 7 are output. The control means 26
Is, for example, a proportional-integral-differential circuit (abbreviated PID circuit)
It is realized by such as.

The flow rate of the main fuel guided to the main fuel compressor 2 for compressing the main fuel is controlled by a first flow control valve 6 so that a part of the gas discharged from the main fuel compressor 2 is 113 returns to the inlet of the main fuel compressor 2,
The flow rate is controlled by the second flow control valve 7. The pressure P _{f at} the outlet of the main fuel compressor 2 is determined by the pressure transmitter 25.
Is detected, and a target value P _f1 of the pressure at the outlet of the main fuel compressor 2 corresponding to the flow rate F _m represented by the main fuel control signal output from the signal generator 50 is output by the main fuel flow / pressure converter 24. , the detected pressure P _f is control signal representative of the flow rate D of the main fuel such that the target value P _f1 is output by the control means 26, the control signal the first and second function generator 1
1 and 12, the first function generator 11 supplies a first opening command signal corresponding to the control signal to the first flow control valve 6, and the second function generator 12 generates a first opening command signal corresponding to the control signal. A second opening command signal is given to the second flow control valve 7.

As a result, the flow rate of the main fuel guided to the main fuel compressor 2 in accordance with the control signal output from the control means 26 is controlled by the first flow control valve 6, and the main fuel flow is controlled in accordance with the control signal. The recirculated flow rate of the main fuel discharged from the compressor 2 is controlled by the second flow control valve 7. Accordingly, the combustor 3 b of the gas turbine 3 is supplied with the main fuel at a stepless flow rate regardless of the minimum flow rate of the main fuel compressor 2, and is supplied to the gas turbine 3 having the large main fuel compressor 2. Thus, the pressure at the outlet of the main fuel compressor 2 can be controlled stably.

Therefore, regardless of the minimum flow rate of the main fuel compressor 2, the gas turbine 3 can be controlled from the minimum output to the maximum output, and has a low pressure requiring a compression process by the main fuel compressor 2 and a low calorific value. The gas can be effectively used as the main fuel of the gas turbine 3.

Further, since the first and second opening degree command signals in response to the control signal from the control means 26 are given to the first and second flow control valves 6, 7, the main fuel compressor 2 is large, Even if the capacity is large, stable control of the gas turbine 3 can be performed without delay. As described above, the gas turbine control device 126 can obtain the same effect as the embodiment shown in FIG.

In the configuration of the embodiment shown in FIGS. 9 and 11, the first flow control valve 6 and the second flow control valve are controlled by the combination of the first function generator 11 and the second function generator 12. Although the control signal for detecting and controlling the differential pressure or pressure is introduced, the control signal for detecting and controlling this differential pressure or pressure is used. It is possible to easily realize the division of the signal given to the first flow control valve 6 and the second flow control valve 7.

FIG. 13 is a system diagram showing a configuration of a part of a cogeneration equipment 67 including a gas turbine control device 127 according to still another embodiment of the present invention. The main fuel calculation control circuit 20 of the gas turbine control circuit 97 of the present embodiment
7c includes a first control means 26a for operating the first flow control valve 6 of the main fuel compressor 2 and a second control flow of the second flow control valve 7, instead of the pressure control means 26 of the embodiment shown in FIG. A second control means 26b for performing an operation is provided. Further, a pressure deviation setter 27 for outputting a pressure deviation signal representing a predetermined value dP1 is provided. The first control means 26 a outputs a command signal to the first function generator 11 in response to the output of the main fuel flow / pressure converter 24 and the pressure signal of the pressure transmitter 25. The first target value P _f1 of the pressure second pressure control 26b is represented by the output of the main fuel flow rate / pressure transducer 24, adds the pressure deviation dP1 is a value representing the pressure deviation signal output from the pressure deviation setter 27 The second function generator 12 responds to the signal indicating the pressure and the pressure signal output from the pressure transmitter 25.
Output command signal to The other portions having the same configuration as the embodiment shown in FIG. 11 are denoted by the same reference numerals, and description thereof will be omitted.

[0106] The first control unit 26a is a pressure P _f represented by the pressure signal output from the pressure transmitter 25 from the first target value P _f1 of the pressure represented by the signal output from the main fuel flow rate / pressure transducer 24 Responds to a signal representing the value subtracted by the subtractor 55, and performs control operations such as proportional, integral, and derivative,
Target value of pressure detected pressure P _f of the main fuel of the second main fuel supply conduit 112 is commanded by the main fuel flow rate / pressure transducer 24 P
_The flow rate is calculated so as to be _f1 and given to the first function generator 11. The first pressure control means 26a is, for example, proportional-
This is realized by an integration-differential circuit (abbreviated as PID circuit).

[0107] The second control unit 26b is pressure deviation representing a pressure deviation signal output from the main fuel flow rate / pressure transducer 24 pressure deviation setter 27 to the target value P _f1 of the pressure output from dP1
Is subtracted from the second target value P _f2 of the pressure indicated by the signal output from the adder 28 by the subtractor 55a, and the detected pressure P _f indicated by the pressure signal output from the pressure transmitter 25 is subtracted. in response to a signal representative of the proportional, integral, and controls operation such as differentiation, represented by the signal pressure P _f of the main fuel of the second main fuel supply conduit 112 is output from the main fuel flow rate / pressure transducer 24 the second function generator calculates the flow rate to the target value P _f1 becomes pressure P _f2 obtained by adding the pressure deviation dP1 12
Give to. The second pressure control means 26b is realized by, for example, a proportional-integral-differential circuit (abbreviated PID circuit).

Therefore, while the first control means 26a controls the first flow control valve 6 and controls the main fuel pressure in the second main fuel supply line 112, The pressure of the main fuel is maintained at a target value P _f1 represented by the signal output from the main fuel flow / pressure converter 24. The second target value P _f2 of the pressure is increased by the pressure deviation dP 1, and as a result, the second control means 26 b increases the pressure of the second main fuel supply line 112 by the second control means 26 b. The flow control valve 7 is fully closed.

When the target value P _f1 output from the main fuel flow / pressure converter 24 decreases and the valve opening of the first flow control valve 6 reaches the minimum opening corresponding to the minimum flow, the first pressure The control means 26a cannot reduce the flow rate of the main fuel supplied by the main fuel compressor 2, and the pressure of the main fuel in the second main fuel supply line 112 is output from the main fuel flow / pressure converter 24. Becomes larger than the target value P _f1 represented by the signal. When the pressure of the main fuel in the second main fuel supply line 112 becomes larger than the second target value P _f2 of the pressure indicated by the signal supplied to the second control means 26b, the second flow control valve 7 starts operating.

When the flow rate of the main fuel discharged from the main fuel compressor 2 exceeds the flow rate of the main fuel supplied to the gas turbine 3, the pressure of the main fuel in the second main fuel supply pipe 112 increases, and The first flow control valve 6 is operated by the first control means 26a so as to reduce the flow rate of the main fuel, and attempts to maintain the pressure of the second main fuel supply line 112. When the first flow control valve 6 reaches the minimum opening corresponding to the minimum flow rate of the main fuel compressor 2, the flow rate of the main fuel can no longer be reduced,
Pressure P _f of the main fuel of the second main fuel supply conduit is increased.
Pressure P _f of the main fuel of the second main fuel supply conduit 112 is the second
When the target value _Pf2 is exceeded, the second control means 26b operates the second flow rate control valve 7 to return the surplus main fuel flow rate to the first main fuel supply pipe 111, and to the inlet of the main fuel compressor 2 Bring to reflux. Although the pressure of the main fuel in the second main fuel supply line rises by the pressure deviation, the control is shifted from the control by the first flow control valve 6 to the control by the second flow control valve 7.

With the above operation, the pressure control for changing the valve opening of the first flow control valve 6 by the first control means 26a and the pressure for changing the valve opening of the second flow control valve 7 by the second control means 26b are performed. The control can be switched in accordance with the pressure of the main fuel in the second main fuel supply line 112.

The flow rate of the main fuel guided to the main fuel compressor 2 for compressing the main fuel is controlled by the first flow control valve 6,
A part of the main fuel discharged from the main fuel compressor 2 is returned to the inlet of the main fuel compressor 2 by the fuel recirculation line 113, and the flow rate is controlled by the second flow control valve 7. It is detected pressure of the main fuel by the pressure transmitter 25, a first target value of the pressure at the outlet of the main fuel compressor 2 corresponding to the flow rate represented by the main fuel control signal F _m outputted from the signal generator 50 The first flow control valve 6 is controlled by the first control means 26a so that the detected pressure is outputted by the main fuel flow-pressure converter 24 and the detected pressure becomes the first target value. The pressure deviation signal dP1 is output, the pressure represented by the first target value is added to the value represented by the pressure deviation signal, and the sum is output as a second target value of the pressure by the adder 28, and the detected pressure becomes the second target value. The second control means 2 so that
The second flow control valve 7 is controlled by 6b.

Thus, the control means 26a, 26b
The flow control means 6 and 7 are controlled by the first flow control valve 6, the flow rate of the main fuel supplied to the main fuel compressor 2 is controlled by the first flow control valve 6, and the gas discharged from the main fuel compressor 2 is recirculated. The flow rate is controlled by the second flow control valve 7.
Therefore, the main fuel is supplied to the combustor 3b of the gas turbine 3 at a stepless flow rate regardless of the minimum flow rate of the main fuel compressor 2, and the gas turbine 3 provided with the large main fuel compressor 2 Thus, the pressure at the outlet of the main fuel compressor 2 can be controlled stably.

Therefore, regardless of the minimum flow rate of the main fuel compressor 2, the gas turbine 3 can be controlled from the minimum output to the maximum output, and the gas having a low pressure and a low calorific value that requires the main fuel compressor 2 is supplied to the gas turbine. It can be effectively used as the main fuel of the turbine 3.

Further, since the first flow control valve 6 is controlled by the first control means 26a and the second flow control valve 7 is controlled by the second control means 26b, the main fuel compressor 2 is large and large. Even with the capacity, the control of the gas turbine 3 can be stably performed without delay in the control. As described above, the gas turbine control device 127
The same effect as the embodiment shown in FIG. 12 can be obtained.

FIG. 14 is a system diagram showing a partial configuration of a cogeneration facility 68 having a gas turbine control device 128 according to still another embodiment of the present invention. The gas turbine control device 128 of this embodiment includes the first flow control valve 6
Opening detector 29 as a detector for detecting the valve opening a of the valve
And the pressure deviation setting device 27 of the embodiment shown in FIG.
A pressure deviation generator 27 that outputs a pressure deviation signal representing a pressure deviation that is a value that changes in accordance with the valve opening a of the first flow control valve 6.
and a gas turbine control circuit 98 having a main fuel operation control circuit 207d including a. The other portions having the same configuration as the embodiment shown in FIG. 13 are denoted by the same reference numerals, and description thereof will be omitted.

An opening signal a representing the opening of the first flow control valve 6 is supplied from the opening detector 29 to the pressure deviation generator 27a.

FIG. 15 is a diagram showing a control function of the pressure deviation generator 27a provided in the gas turbine control device 128 of this embodiment.

The horizontal axis indicates the valve opening a of the first flow control valve 6 represented by the opening signal input to the pressure deviation generator 27a, and the vertical axis is output from the pressure deviation generator 27a. The pressure deviation dP2 represented by the pressure deviation signal is shown. In this case, the pressure deviation generator 27a may be set as in the following equation (12).

[0120]

(Equation 6)

Here, dP2 is a pressure deviation represented by a signal output from the pressure deviation generator 27a, k is a constant given in advance,
a is a valve opening of the first flow rate adjusting means 6. a _min is the first
This is a valve opening corresponding to the minimum flow rate of the flow control valve 6, and can be given in advance.

Based on the equation (12), when the valve opening indicated by the opening signal a is equal to or greater than the valve opening a _min corresponding to the minimum flow rate, the pressure corresponding to the valve opening indicated by the opening signal a is determined. A signal representing the deviation k (a-a _min ) is outputted, and a signal representing zero is outputted when the valve opening represented by the opening signal a is smaller than the valve opening a _min corresponding to the minimum flow rate F _min .

In the embodiment shown in FIG. 13, since a constant value is given as the pressure deviation signal, the control shifts from the first flow control valve 6 to the second flow control valve 7 or in the opposite direction. Sometimes, the main fuel pressure in the second main fuel supply line 112 changes by the pressure deviation.

In this embodiment, in response to an opening signal indicating the detected opening a of the first flow control valve 6 output from the opening detector 29, the opening of the first flow control valve 6 is reduced to the minimum opening. In the above case, the pressure deviation dP2 corresponding to the detected opening a represented by the opening signal.
(= K (a-a _min )), and a pressure deviation generator 27a for outputting a signal representing zero when the opening is smaller than the minimum opening is provided. The output is provided to adder 28.

As a result, when the first flow control valve 6 maintains a sufficient opening degree, a signal representing a positive value is output from the pressure deviation generator 27a, and the second control means 26b
Controls the second flow control valve 7 for increasing the pressure of the main fuel in the second main fuel supply line 112 to be fully closed. When the valve opening of the first flow control valve 6 becomes less than the minimum opening, the output of the pressure deviation generator 27a becomes a signal indicating zero, and the first
The second supply line 11 is set to the same pressure target value as the control means 26a.
Pressure control means 26 so as to maintain the pressure of the main fuel in
b adjusts the opening of the second flow control valve 7. Therefore, the control is shifted from the control by the first pressure control means 26a for controlling the first flow control valve 6 without changing the main fuel pressure to the control by the second pressure control means 26b for controlling the second flow control valve 7. .

The flow rate of the main fuel guided to the main fuel compressor 2 for compressing the main fuel is controlled by the first flow control valve 6, and a part of the main fuel discharged from the main fuel compressor 2 is supplied to the fuel recirculation pipe. The flow is returned to the inlet of the main fuel compressor 2 by the passage 113, and its flow rate is controlled by the second flow control valve 7. It detects the pressure at the outlet of the main fuel compressor 2 by the pressure transmitter 25, a first pressure at the outlet of the main fuel compressor 2 corresponding to the flow rate represented by the main fuel control signal F _m outputted from the signal generator 50 Is output by the main fuel flow / pressure converter 24, and the first flow control valve 6 is controlled by the first control means 26a so that the detected pressure becomes the first target value. The opening of the first flow control valve 6 is detected by an opening detector 29, and a pressure deviation signal is output by a pressure deviation generator 27a in response to the output of the opening detector 29, and represents a first target value. The pressure and the value represented by the pressure deviation signal are added by the adder 28 to output a second target value of the pressure. Is controlled by As a result, the flow control means 6 and 7 are controlled by the control means 26a and 26b, the supply flow rate of the main fuel supplied to the main fuel compressor 2 is controlled by the first flow control valve 6, and the main fuel compressor The recirculated flow rate of the main fuel discharged from 2 is controlled by the second flow control valve 7. Therefore, in the combustor 3b of the gas turbine 3, the main fuel is supplied at a stepless flow rate regardless of the minimum flow rate of the main fuel compressor 2, and the gas turbine 3 provided with the large main fuel compressor 2 Thus, the output at the outlet of the main fuel compressor 2 can be stabilized and controlled.

Therefore, regardless of the minimum flow rate of the main fuel compressor 2, the gas turbine 3 can be controlled from the lowest output to the highest output. It can be effectively used as the main fuel of the gas turbine 3.

The first flow control valve 6 is controlled by the first control means 26a, and the second flow control valve 7 is controlled by the second control means 26b. Thus, even if the main fuel compressor 2 is large and has a large capacity, stable control of the gas turbine 3 can be performed without delay.

Thus, the gas turbine control device 128
Can obtain the same effects as those of the embodiment shown in FIGS.

[0130] FIG. 16 (1) shows an example of changes in the pressure P _f of the second main fuel supply conduit 112 which is controlled by the gas turbine control device 127 and 128 of the embodiment shown in FIGS. 13 and 14, FIG. 16 (2) shows the transition of the valve opening X _c (= a) of the first flow control valve 6 at that time, and FIG.
(3) is the valve opening X _v (=
FIG. 9 is a diagram showing a transition of θ).

Referring to FIG. 13, FIG. 14 and FIG.
When controlled by the gas turbine control device 127 of the embodiment shown in FIG. 13, the pressure deviation given from the pressure deviation setting device 27 is constant (dP1), and the first target value P _f1 and the second target value of the pressure are set. There is a constant difference from P _f2 , that is, a difference by the pressure deviation dP 1. From the time t0, including the time t1 at which the first flow control valve 6 starts to gradually reduce the opening thereof, and the first pressure of the pressure output from the main fuel flow / pressure converter 24 until the time t2 when the minimum opening is reached. The target value P _f1 is the first
When the opening is equal to or more than the minimum opening of the flow control valve 6, the second flow control valve 7 controls the pressure of the main fuel in the second main fuel supply pipe 112 by an amount corresponding to the pressure deviation dP1. In order to operate so as to increase P _f , the pressure P _f is controlled by the operation of the first flow control valve 6, and the target value P of the pressure is set.
_It is kept at _f1 (see 70 in FIG. 16 (1)).

The target value P _{f1 of the} pressure decreases, and the valve opening X _c (= a) of the first flow control valve 6 decreases (FIG. 16).
(Refer to 71 in (2))). At time t2 or later when the pressure value becomes equal to or less than the minimum flow rate (minimum opening a _min ) that can be controlled by the first flow rate control valve 6, the first flow rate control valve 6 is used.
Is controlled to the minimum opening (see 72 in FIG. 16).

On the other hand, the second flow control valve 7 attempts to increase the main fuel pressure P _f2 in the second main fuel supply pipe 112 by the pressure deviation dP1 as described above. During this time, the state in which the first flow control valve 6 is controlled to the minimum opening degree and the second flow control valve 7 is fully closed continues, and the pressure P _f
Rise (see 73 in FIG. 16).

[0134] The second main fuel pressure P _f of the main fuel supply conduit 112 after time t3 to reach the target value of the second pressure _{P f2 (= P f1 + dP1} ), the valve opening degree X _v is substantially constant Including the time t4 after which the holding is started, the second flow control valve 7
(3) Opened as shown by the broken line 75 in
Pressure P _f of the main fuel of the main fuel supply conduit 112 is maintained at the target value of the second pressure _{P f2 (= P f1 + dP1} ).

As described above, the second main fuel supply line 112
Pressure P _f of the main fuel of the inner varies only pressure deviation dP1 minutes, is shifted from the first flow control valve 6 to the control by the second flow rate control valve 7. When the target value P _{f1 of the} pressure gradually increases, the operation is reversed, but the control is shifted from the second flow control valve 7 to the control by the first flow control valve 6.

When controlled by the gas turbine controller 128 of the embodiment shown in FIG. 14, the pressure deviation generator 27a
The pressure deviation dP2 represented by the pressure deviation signal output from is given by the above equation (12), and changes according to the detected opening a of the first flow control valve 6. The pressure deviation dP2 is a positive value between the time t0 and the time t2 when the detected opening a is equal to or more than the minimum opening a _min , and after the time t2 when the detected opening a becomes smaller than the minimum opening a _min. , Zero. Accordingly, the second target value P _f2 of the pressure in which the pressure deviation dP2 is added to the first target value P _f1 of the pressure corresponds to the detected opening a, and the time t2 at which the detected opening a becomes the minimum opening a _min. Thereafter, the pressure becomes equal to the target value P _f1 (see the two-dot chain line 76 in FIG. 16A).

From time t0 to time t0 when the target pressure value P _f1 corresponds to the opening of the first flow control valve 6 which is equal to or greater than the minimum opening a _min.
In the period up to 2, the second flow control valve 7 controls the second main fuel supply line 112 by an amount corresponding to the pressure deviation dP2 which is a positive value.
To operate to increase the pressure P _f of the main fuel of the pressure P _f of the main fuel in the second main fuel supply conduit 112, first
The pressure is controlled by the operation of the flow regulating valve 6, and is maintained at the target value _{Pf1 of the} pressure (see 70 in FIG. 16A).

The target value P _{f1 of the} pressure decreases, and the opening degree of the first flow control valve 6 decreases (71 in FIG. 16 (2)).
After the time t2 when the detected opening a becomes equal to or less than the minimum opening a _min , the first flow control valve 6 is controlled to the minimum opening (see 72 in FIG. 16 (2)).

As described above, the target value P _f2 of the second value becomes equal to the target value P _{f1 of the} pressure after time t2 when the detected opening a becomes the minimum opening a _min . Thus, the second flow rate control valve 7 is operated the pressure P _f of the main fuel of said second main fuel supply conduit 112 so as to maintain the P _f1. The detected opening a
After time t2 at which the minimum opening a _min is reached, the second flow control valve 7 is opened (see 77 in FIG. 16 (3)).

Accordingly, while the pressure P _f of the main fuel in the second main fuel supply line 112 is kept constant (P _f1 ), the first
The flow is shifted from the flow control valve 6 to the control by the second flow control valve 7. Even when the target value P _{f1 of the} pressure gradually increases, the pressure P _f is kept constant and the control is shifted from the second flow control valve 7 to the control by the first flow control valve 6.

In the above embodiments, the gas turbine control circuits 95 to 98 provided in the gas turbine control devices 125 to 128 are configured as an integrated control circuit. In addition to being able to be configured by combining individual control devices, some or all of the functions can be realized as internal operations of the electronic computer.

It is also possible to obtain a gas turbine control circuit having substantially the same function as that of the above embodiment by changing the combination of these. For example, in the embodiment shown in FIG. 13 and the embodiment shown in FIG. 14, the control means 26a and 26b for controlling based on two pressures are used.
Instead of 6a and 26b, control means 23 for controlling based on the differential pressure as shown in the embodiment shown in FIG. 9 may be used. In this case, first and second control means 23a, 23 (not shown)
b. Two control means are provided.

In the case of such a configuration, the flow rate of the main fuel guided to the main fuel compressor 2 for compressing the main fuel is controlled by the first flow control valve 6, and the flow rate of the gas discharged from the main fuel compressor 2 is reduced. The part is returned to the inlet of the main fuel compressor 2 by the fuel recirculation line 113, and its flow rate is controlled by the second flow control valve 7. The differential pressure obtained by subtracting the gas pressure in the combustor 3 b from the pressure at the outlet of the main fuel compressor 2 is a differential pressure transmitter 22.
It is detected by a first pressure difference obtained by subtracting the gas pressure in the combustor 3b from the outputted main fuel control signal F pressure at the outlet of the main fuel compressor 2 in response to the flow rate represented by _m from a signal generator 50 The target value is output by the main fuel flow / differential pressure converter 21 and the first flow control valve 6 is controlled by the first control means 23a.
Is controlled, a pressure deviation signal representing a predetermined value is output from the pressure deviation setting unit 27, and the differential pressure represented by the first target value of the differential pressure and the value represented by the pressure deviation signal are added by the adder 28. , Is output as a second target value of the differential pressure, and the second control means 23b outputs the second target value so that the detected differential pressure becomes the second target value.
The flow control valve 7 is controlled.

Thus, the control means 23a, 23b
By controlling the respective flow control valves 6 and 7, the flow rate of the main fuel supplied to the main fuel compressor 2 is controlled by the first flow control valve 6 and the gas discharged from the main fuel compressor 2 is recirculated. Is controlled by the second flow control valve 7.
Accordingly, the combustor 3b of the gas turbine 3 is supplied with the main fuel at a stepless flow rate irrespective of the minimum flow rate of the main fuel compressor 2, and the gas turbine having a large main fuel compressor is provided. The pressure at the outlet of the main fuel compressor 2 can be controlled stably.

Therefore, regardless of the minimum flow rate of the main fuel compressor, the gas turbine 3 can be controlled from the minimum output to the maximum output, and the low pressure and low heat generation gas required for the main fuel compressor 2 is supplied to the gas turbine. It can be effectively used as the main fuel of the turbine 3.

Further, since the first flow control valve 6 is controlled by the first control means and the second flow control valve 7 is controlled by the second control means, the main fuel compressor is large and has a large capacity. Even if the control is not delayed, the gas turbine 3 can always be controlled stably.

Further, the flow rate of the main fuel guided to the main fuel compressor 2 for compressing the main fuel is controlled by the first flow control valve 6, and a part of the gas discharged from the main fuel compressor 2 is supplied to the fuel recirculation pipe. The flow is returned to the inlet of the main fuel compressor 2 by the passage 113, and its flow rate is controlled by the second flow control valve 7.
The differential pressure obtained by subtracting the gas pressure in the combustor 3 b from the pressure at the outlet of the main fuel compressor 2 is detected by the differential pressure transmitter 22, and the flow rate F _m represented by the main fuel control signal output from the signal generator 50. In response to the above, the first target value of the differential pressure obtained by subtracting the gas pressure in the combustor 3b from the pressure at the outlet of the main fuel compressor 2 is output by the main fuel flow / differential pressure converter 21 and the detected differential pressure is The first flow control valve 6 is controlled by the first control means 23a so as to attain one target value, and how the first flow control valve 6 is controlled is detected by the opening degree detector 29. , A pressure deviation signal is output by the pressure deviation generator 27a, and the differential pressure represented by the first target value and the value represented by the pressure deviation signal are added by the adder 28 to obtain the second target value of the differential pressure. Is output and the second pressure is set so that the detected differential pressure becomes the second target value. The second flow rate control valve 7 is controlled by the control unit 23b.

Thus, the control means 23a, 23b
The flow control valves 6 and 7 are controlled by the first flow control valve 6, and the flow rate of the main fuel supplied to the main fuel compressor is controlled by the first flow control valve 6 so that the gas discharged from the main fuel compressor 2 is recirculated. Is controlled by the second flow control valve 7. Therefore, the main fuel at a stepless flow rate is supplied to the combustor 3b of the gas turbine 3 irrespective of the minimum flow rate of the main fuel compressor 2, and the gas turbine provided with a large main fuel compressor has: The pressure at the outlet of the main fuel compressor can be controlled stably.

Therefore, regardless of the final flow rate of the main fuel compressor 2, the gas turbine 3 can be controlled from the minimum output to the maximum output, and the low pressure and low heat generation gas required for the main fuel compressor 2 can be supplied. It can be effectively used as the main fuel of the gas turbine 3.

Further, since the first flow control valve 6 is controlled by the first control means 23a and the second flow control valve 7 is controlled by the second control means 23b, the main fuel compressor 2 is large and large. Even if it is a capacity, the control of the gas turbine 3 can always be stably performed without delay.

When the control means 23 is used, the second
The second main fuel supply line 112 is replaced with a pressure difference between the main fuel pressure in the main fuel supply line 112 and the gas pressure in the combustor 3b.
The same effect can be obtained by using any one of the pressure difference between the pressure of the main fuel inside and the pressure at the outlet of the air compressor 3a.

In such a configuration, the flow rate of the main fuel guided to the main fuel compressor 2 for compressing the main fuel is controlled by the first flow control valve 6, and the flow rate of the gas discharged from the main fuel compressor 2 is reduced. The part is returned to the inlet of the main fuel compressor 2 by the fuel recirculation line 113, and its flow rate is controlled by the second flow control valve 7. Subtraction differential pressure of the pressure at the outlet of the main fuel compressor 2 of the air compressor 3a of the pressure at the outlet is detected by the differential pressure transmitting device 22a, represented by the main fuel control signal F _m outputted from the signal generator 50 The first target value of the differential pressure obtained by subtracting the pressure at the outlet of the air compressor 3a from the pressure at the outlet of the main fuel compressor 2 corresponding to the flow rate is the main fuel flow / differential pressure converter 21.
The first flow control valve 23 is controlled by the first control means 23a, a pressure deviation signal representing a predetermined value is outputted from the pressure deviation setter 27, and the differential pressure represented by the first target value of the differential pressure is outputted. And the value represented by the pressure deviation signal are added by the adder 28 and output as a second target value of the differential pressure, and the second control means 23b adjusts the second flow rate so that the detected differential pressure becomes the second target value. Valve 7 is controlled.

Thus, each of the control means 23a, 23b
By controlling the respective flow control valves 6 and 7, the flow rate of the main fuel supplied to the main fuel compressor 2 is controlled by the first flow control valve 6 and the gas discharged from the main fuel compressor 2 is recirculated. Is controlled by the second flow control valve 7.
Accordingly, the main fuel having a stepless main fuel supply flow rate is supplied to the combustor 3b of the gas turbine 3 irrespective of the minimum flow rate of the main fuel compressor 2, and the gas turbine is provided with a large-sized main fuel compressor. In contrast, the pressure at the outlet of the main fuel compressor 2 can be controlled stably.

Therefore, regardless of the minimum flow rate of the main fuel compressor, the gas turbine 3 can be controlled from the minimum output to the maximum output, and the low-pressure and low-heat-generation gas required for the main fuel compressor 2 is supplied to the gas turbine. It can be effectively used as the main fuel of the turbine 3.

Further, since the first flow control valve 6 is controlled by the first control means and the second flow control valve 7 is controlled by the second control means, the main fuel compressor is large and has a large capacity. Even if the control is not delayed, the gas turbine 3 can always be controlled stably.

Further, the flow rate of the main fuel guided to the main fuel compressor 2 for compressing the main fuel is controlled by the first flow control valve 6, and a part of the gas discharged from the main fuel compressor 2 is supplied to the fuel recirculation pipe. The flow is returned to the inlet of the main fuel compressor 2 by the passage 113, and its flow rate is controlled by the second flow control valve 7.
Differential pressure of the outlet of the main fuel compressor 2 of the air compressor 3a of the pressure at the outlet is subtracted is detected by the differential pressure transmitting device 22a, represented by the fuel gas control signal F _m outputted from the signal generator 50 A first target value of the differential pressure obtained by subtracting the pressure at the outlet of the air compressor 3a from the pressure at the outlet of the main fuel compressor 2 corresponding to the flow rate is output by the main fuel flow / differential pressure converter 21, and the detected differential pressure The first control means 2 so that
The first flow control valve 6 is controlled by 3a, and how the first flow control valve 6 is controlled is detected by an opening degree detector 29. In response to the output of the detector 29, a pressure deviation signal is generated. The differential pressure output by the deviation generator 27a and represented by the first target value and the value represented by the pressure deviation signal are added to the adder 28.
Is added to output a second target value of the differential pressure, and the second flow control valve 7 is controlled by the second control means 23b so that the detected differential pressure becomes the second target value. by this,
Each of the flow control means 6, 6 is controlled by the control means 23a, 23b.
7 is controlled, the flow rate of the main fuel supplied to the main fuel compressor 2 is controlled by the first flow control valve 6, and the recirculated flow rate of the gas discharged from the main fuel compressor 2 is controlled by the second flow control valve. 7. Therefore, the gas turbine 3
Of the main fuel compressor is supplied to the combustor 3b at a stepless flow rate irrespective of the minimum flow rate of the main fuel compressor 2 and the gas turbine provided with the large main fuel compressor is The outlet pressure can be controlled stably.

Therefore, regardless of the minimum flow rate of the main fuel compressor 2, the gas turbine 3 can be controlled from the lowest output to the highest output, and the gas having a low pressure and a low calorific value that requires the main fuel compressor 2 can be supplied. It can be effectively used as the main fuel of the gas turbine 3.

Further, since the first flow control valve 6 is controlled by the first control means 23a and the second flow control valve 7 is controlled by the second control means 23b, the main fuel compressor 2 is large and large. Even if it is a capacity, the control of the gas turbine 3 can always be stably performed without delay.

The differential pressure transmitters 22 and 22a for detecting these differential pressures include a transmitter for detecting the pressure of the main fuel in the second main fuel supply line 112 and a gas transmitter in the combustor 3b. It may be constituted by a combination of a transmitter for detecting pressure or a transmitter for detecting pressure at the outlet of the air compressor 3a, and a subtractor for calculating a difference between pressures represented by signals output from these transmitters. .

Further, as a normal gas turbine control device, a rotation speed / load control 10a, a gas temperature control 10b, a start control 10c, and a low signal selector 10 shown in the present invention.
It is clear that some combinations of d may be omitted depending on the type of gas turbine, and other elements may be added as necessary.

In the above-described embodiment, the main fuel compressor 2 is provided on the same rotary shaft 1 as the air compressor 3a and the turbine 3c of the gas turbine, and is driven by its power. It may be driven by power. Further, as shown by a virtual line K in FIG. 14, a gas gear may be interposed to drive the air compressor 3a of the gas turbine with the rotation speed increased or decreased.

Further, as another embodiment of the present invention, the first function generator and the second function generator do not have to consider only the main fuel flow rate but can realize a predetermined main fuel flow rate. The set values of the first flow control valve 6 and the second flow control valve 7 may be set in advance. In the above-described embodiment, the main fuel flow supplied to the main fuel compressor 2 is controlled by the first flow control valve 6. hand,
A mechanism for changing the angle of the stationary blade of the main fuel compressor 2 may be provided, or another mechanism for controlling the flow rate may be provided.

Further, in the above-described embodiment, the second flow rate regulating valve 7 is used which can be fully closed. However, as another embodiment of the present invention, the second flow rate regulating valve 7 which cannot be fully closed is used. The two-flow regulating valve 7 and an on-off valve that can be fully closed may be provided in series.

In the above embodiment, the target value of the pressure difference is
Although calculated based on the main fuel control signal and the characteristics of the gas turbine, another embodiment of the present invention is to control the gas turbine 3 by detecting the pressure at the outlet of the air compressor 3a using a detector. It may be.

[0165]

As described above, according to the present invention, the main fuel supplied from the main fuel supply source includes the output of the gas turbine detected by the output detection means and the output of the gas turbine set by the load setting device. Is controlled by operating the first flow rate control means by the main fuel arithmetic control means so that the values of the first and second flow rate control means are equal. The auxiliary fuel supplied from the auxiliary fuel supply source is supplied to the second fuel flow control means by the auxiliary fuel calculation control means so as to replenish the insufficient heat quantity calculated by the insufficient heat quantity calculation means when the calorific value of the main fuel decreases. Is operated and controlled. Thus, the auxiliary fuel is supplied only when the calorific value of the main fuel is reduced, the output of the gas turbine is reduced, or the operation of the gas turbine may be hindered. Therefore, the gas turbine can be operated in the most economical state by effectively using the expensive auxiliary fuel without wasting it.

Further, the supply flow rate of the fuel supplied to the fuel gas compressor is controlled by the first flow rate adjusting means in response to a control signal output from the control means, and the fuel gas compressor discharges in response to the control signal. The flow rate of the gas to be returned to the inlet of the fuel gas compressor is controlled by the second flow rate adjusting means, and the fuel gas is continuously supplied to the combustor of the gas turbine regardless of the minimum flow rate of the fuel gas compressor. Since the flow rate of the fuel gas is supplied, the gas turbine can be controlled from the minimum output to the maximum output regardless of the minimum flow rate of the fuel gas compressor, and the pressure is low and low, which requires the compression processing by the fuel gas compressor. The calorific value gas can be used effectively as gas turbine fuel.

A differential pressure obtained by subtracting the gas pressure in the combustor from the pressure at the outlet of the fuel gas compressor is detected by a differential pressure transmitter, and the gas pressure in the combustor is determined from the pressure at the outlet of the fuel gas compressor. The target value of the subtracted differential pressure is calculated by the calculating means, and the control means outputs a fuel gas flow rate such that the detected differential pressure becomes the target value as a control signal, which is given to the first and second function generators. Since the first and second flow rate set values corresponding to the signals are given to the first and second flow rate adjusting means, even if the fuel gas compressor is large and has a large capacity, the control is not delayed and the gas is not delayed. The stable control of the turbine can be performed.

Further, according to the present invention, the supply flow rate of the fuel supplied to the fuel gas compressor in response to the control signal output from the control means is controlled by the first flow rate adjusting means, and in response to the control signal, The flow rate of the gas discharged from the fuel gas compressor to be recirculated to the inlet of the fuel gas compressor is controlled by the second flow rate adjusting means, and is supplied to the combustor of the gas turbine regardless of the minimum flow rate of the fuel gas compressor. Since the fuel gas is supplied at a gradual fuel gas supply flow rate, the gas turbine can be controlled from the minimum output to the maximum output regardless of the minimum flow rate of the fuel gas compressor, and the pressure is low, requiring the fuel gas compressor. In addition, a gas having a low calorific value can be effectively used as fuel for a gas turbine.

Further, a differential pressure obtained by subtracting the pressure at the outlet of the air compressor provided in the gas turbine from the pressure at the outlet of the fuel gas compressor is detected by the differential pressure transmitter, and the gas pressure is detected from the pressure at the outlet of the fuel gas compressor. The target value of the differential pressure obtained by subtracting the pressure at the outlet of the air compressor provided in the turbine is calculated by the calculating means, and the control means outputs a fuel gas flow rate at which the detected differential pressure becomes the target value as a control signal. 1
And the first and second flow rate setting values corresponding to the control signal are output to the first and second flow rate adjusting means, so that the fuel gas compressor is large and has a large capacity. Even if there is, stable control of the gas turbine can be performed without delay.

Further, according to the present invention, the supply flow rate of the fuel supplied to the fuel gas compressor in response to the control signal output from the control means is controlled by the first flow rate adjustment means,
The flow rate of the gas discharged from the fuel gas compressor in response to the control signal, which is recirculated to the inlet of the fuel gas compressor, is controlled by the second flow rate adjusting means.
Since the fuel gas is supplied at a stepless fuel gas supply flow rate regardless of the minimum flow rate of the fuel gas compressor, the gas turbine can be controlled from the minimum output to the maximum output regardless of the minimum flow rate of the fuel gas compressor, A gas having a low pressure and a low calorific value that requires a fuel gas compressor can be effectively used as fuel for a gas turbine.

Further, the pressure at the outlet of the fuel gas compressor is detected by the pressure transmitter, and the target value of the pressure at the outlet of the fuel gas compressor is calculated by the calculating means so that the detected pressure becomes the target value. A signal representing the flow rate is output as a control signal by the control means and is provided to the first and second function oscillators, and the first and second flow rate set values in response to the control signal are provided to the first and second flow rate adjusting means. Therefore, even if the fuel gas compressor is large and has a large capacity, stable control of the gas turbine can be performed without delay.

Further, according to the present invention, the supply flow rate of the fuel supplied to the fuel gas compressor by the first control means is reduced to the first flow rate.
The flow rate of the gas discharged from the fuel gas compressor by the second control means is controlled by controlling the flow rate adjusting means, and the flow rate of the gas discharged from the fuel gas compressor to the inlet of the fuel gas compressor is controlled by controlling the second flow rate adjusting means. However, the fuel gas having a stepless fuel gas supply flow rate is supplied to the combustor of the gas turbine regardless of the minimum flow rate of the fuel gas compressor, so that the gas turbine is operated regardless of the minimum flow rate of the fuel gas compressor. The gas can be controlled from a minimum output to a maximum output, and a low-pressure and low-calorific value gas that requires a fuel gas compressor can be effectively used as fuel for a gas turbine.

Further, the pressure at the outlet of the fuel gas compressor is detected by the pressure transmitter, and a first target value of the pressure at the outlet of the fuel gas compressor is calculated by the calculating means. Thus, the first flow control means is controlled by the first control means, a predetermined value is output from the pressure deviation setter as a pressure deviation signal, and the value represented by the pressure deviation signal is added to the first target value of the pressure. A signal representing the second target value of the pressure is output by the compressor, and the second flow control means is controlled by the second control means so that the detected pressure becomes the target value. Thus, even if the capacity is large, stable control of the gas turbine can be performed without delay.

Furthermore, according to the present invention, the supply flow rate of the fuel supplied to the fuel gas compressor by the first control means is controlled to the first flow rate.
The flow rate of the gas discharged from the fuel gas compressor by the second control means is controlled by controlling the flow rate adjusting means, and the flow rate of the gas discharged from the fuel gas compressor to the inlet of the fuel gas compressor is controlled by controlling the second flow rate adjusting means. However, the fuel gas having a stepless fuel gas supply flow rate is supplied to the combustor of the gas turbine regardless of the minimum flow rate of the fuel gas compressor, so that the gas turbine is operated regardless of the minimum flow rate of the fuel gas compressor. The gas can be controlled from a minimum output to a maximum output, and a low-pressure and low-calorific value gas that requires a fuel gas compressor can be effectively used as fuel for a gas turbine.

Further, the pressure at the outlet of the fuel gas compressor is detected by the pressure transmitter, and the first target value of the pressure at the outlet of the fuel gas compressor is calculated by the calculating means, so that the detected pressure becomes the target value. The first flow control means is controlled by the first control means, the opening of the first flow control means is detected by a detector, and a pressure deviation signal is output by the pressure deviation generator in accordance with the output of the detector. Then, the value represented by the pressure deviation signal is added to the first target value by the adder and output as a second target value of the pressure, and the second control means controls the second flow rate adjusting means so that the detected pressure becomes the target value. Therefore, even if the fuel gas compressor is large and has a large capacity, stable control of the gas turbine can be performed without delay.

Further, according to the present invention, the supply flow rate of the fuel supplied to the fuel gas compressor by the first control means is reduced to the first flow rate.
The flow rate of the gas discharged from the fuel gas compressor by the second control means is controlled by controlling the flow rate adjusting means, and the flow rate of the gas discharged from the fuel gas compressor to the inlet of the fuel gas compressor is controlled by controlling the second flow rate adjusting means. However, the fuel gas having a stepless fuel gas supply flow rate is supplied to the combustor of the gas turbine regardless of the minimum flow rate of the fuel gas compressor, so that the gas turbine is operated regardless of the minimum flow rate of the fuel gas compressor. The gas can be controlled from a minimum output to a maximum output, and a low-pressure and low-calorific value gas that requires a fuel gas compressor can be effectively used as fuel for a gas turbine.

The differential pressure obtained by subtracting the gas pressure in the combustor from the pressure at the outlet of the fuel gas compressor is detected by the differential pressure transmitter, and the gas pressure in the combustor is determined from the pressure at the outlet of the fuel gas compressor. The first target value of the subtracted differential pressure is calculated by the calculating means, the first flow control means is controlled by the first control means so that the detected differential pressure becomes the target value, and the predetermined value is obtained from the pressure deviation set value device. Output as a pressure deviation signal, a value represented by the pressure deviation signal is added to the first target value of the differential pressure by an adder and output as a second target value of the differential pressure, and the detected differential pressure becomes the target value. Since the second flow control means is controlled by the second control means, even if the fuel gas compressor is large and has a large capacity, control is not delayed, and
The gas turbine can always be controlled stably.

Further, according to the present invention, the supply flow rate of the fuel supplied to the fuel gas compressor by the first control means is equal to the first flow rate.
The flow rate of the gas discharged from the fuel gas compressor by the second control means is controlled by controlling the flow rate adjusting means, and the flow rate of the gas discharged from the fuel gas compressor to the inlet of the fuel gas compressor is controlled by controlling the second flow rate adjusting means. However, the fuel gas having a stepless fuel gas supply flow rate is supplied to the combustor of the gas turbine regardless of the minimum flow rate of the fuel gas compressor, so that the gas turbine is operated regardless of the minimum flow rate of the fuel gas compressor. The gas can be controlled from a minimum output to a maximum output, and a low-pressure and low-calorific value gas that requires a fuel gas compressor can be effectively used as fuel for a gas turbine.

The differential pressure obtained by subtracting the gas pressure in the combustor from the pressure at the outlet of the fuel gas compressor is detected by the differential pressure transmitter, and the gas pressure in the combustor is subtracted from the pressure at the outlet of the fuel gas compressor. The first target value of the determined differential pressure is calculated by the calculating means, the first control means controls the first flow rate adjusting means so that the detected differential pressure becomes the target value, and the opening of the first flow rate adjusting means is detected. A pressure deviation signal is output by a pressure deviation generator in response to the output of the detector, and a value represented by the pressure deviation signal is added to a first target value of the differential pressure by an adder, thereby obtaining a differential pressure signal. Is output as the second target value, and the second flow rate adjusting means is controlled by the second differential pressure control means so that the detected differential pressure becomes the target value. Therefore, the fuel gas compressor is large and has a large capacity. Even if there is, without delay control It can be performed always stable control of the gas turbine.

Furthermore, according to the present invention, the supply flow rate of the fuel supplied to the fuel gas compressor by the first control means is controlled to the first flow rate.
The flow rate of the gas discharged from the fuel gas compressor by the second control means is controlled by controlling the flow rate adjusting means, and the flow rate of the gas discharged from the fuel gas compressor to the inlet of the fuel gas compressor is controlled by controlling the second flow rate adjusting means. However, the fuel gas having a stepless fuel gas supply flow rate is supplied to the combustor of the gas turbine regardless of the minimum flow rate of the fuel gas compressor, so that the gas turbine is operated regardless of the minimum flow rate of the fuel gas compressor. The gas can be controlled from a minimum output to a maximum output, and a low-pressure and low-calorific value gas that requires a fuel gas compressor can be effectively used as fuel for a gas turbine.

Further, a differential pressure obtained by subtracting the pressure at the outlet of the air compressor provided in the gas turbine from the pressure at the outlet of the fuel gas compressor is detected by the differential pressure transmitter, and the gas pressure is detected from the pressure at the outlet of the fuel gas compressor. The first target value of the differential pressure obtained by subtracting the pressure at the outlet of the air compressor provided in the turbine is calculated by the calculating means, and the first target value is set so that the detected differential pressure becomes the target value.
The first flow rate adjusting means is controlled by the control means, and a predetermined value is output from the pressure deviation setting device as a pressure deviation signal,
The value represented by the pressure deviation signal is added to the first target value of the differential pressure by an adder and output as a second target value of the differential pressure, and the second control means controls the second control unit so that the detected differential pressure becomes the target value. Since the two flow rate adjusting means is controlled, even if the fuel gas compressor is large and has a large capacity, the control of the gas turbine can be constantly performed without delay in control.

Further, according to the present invention, the supply flow rate of the fuel supplied to the fuel gas compressor by the first control means is reduced to the first flow rate.
The flow rate of the gas discharged from the fuel gas compressor by the second control means is controlled by controlling the flow rate adjusting means, and the flow rate of the gas discharged from the fuel gas compressor to the inlet of the fuel gas compressor is controlled by controlling the second flow rate adjusting means. However, the fuel gas having a stepless fuel gas supply flow rate is supplied to the combustor of the gas turbine regardless of the minimum flow rate of the fuel gas compressor, so that the gas turbine is operated regardless of the minimum flow rate of the fuel gas compressor. The gas can be controlled from a minimum output to a maximum output, and a low-pressure and low-calorific value gas that requires a fuel gas compressor can be effectively used as fuel for a gas turbine.

A differential pressure obtained by subtracting the pressure at the outlet of the air compressor provided in the gas turbine from the pressure at the outlet of the fuel gas compressor is detected by a differential pressure transmitter. The first target value of the differential pressure obtained by subtracting the pressure at the outlet of the air compressor provided in the first calculating means is calculated by the calculating means, and the first flow rate adjusting means is controlled by the first control means so that the detected differential pressure becomes the target value. , The first
The opening of the flow rate adjusting means is detected by a detector, and a pressure deviation signal is output by a pressure deviation generator corresponding to the output of the detector, and the value represented by the pressure deviation signal is used as the first target value of the differential pressure. The sum is output by the adder and output as a second target value of the differential pressure, and the second flow rate adjusting means is controlled by the second differential pressure control means so that the detected differential pressure becomes the target value. Even when the gas turbine is large and has a large capacity, stable control of the gas turbine can always be performed without delay.

[Brief description of the drawings]

FIG. 1 is a system diagram showing a configuration of a gas turbine control device as a premise of the present invention.

FIG. 2 is a simplified cross-sectional view showing a configuration near a combustor 3b shown in FIG.

FIG. 3 is a circuit diagram of a rotation speed / load control circuit shown in FIG. 1;

FIG. 4 is a diagram showing a control function of a first function generator 11;

FIG. 5 is a diagram showing a control function of a second function generator 12.

FIG. 6 is a flowchart illustrating a control operation for controlling auxiliary fuel.

FIG. 7 is a diagram showing a function of Expression (3).

8 (1) is a diagram showing an example of changes in the calorific value H _m of the main fuel, (2) is a diagram showing the transition of insufficient heat E _r at that time.

FIG. 9 shows a gas turbine control device 12 according to an embodiment of the present invention.
FIG. 6 is a system diagram showing a configuration of a part of a cogeneration facility 65 provided with a cogeneration apparatus 5.

10 is a diagram showing a control function of a main fuel flow rate / differential pressure converter 21 shown in FIG.

FIG. 11 is a system diagram illustrating a partial configuration of a cogeneration facility 66 including a gas turbine control device 126 according to another embodiment of the present invention.

12 is a diagram showing a control function of a main fuel flow / pressure converter 24 shown in FIG.

FIG. 13 is a system diagram showing a configuration of a part of a cogeneration facility 67 including a gas turbine control device 127 according to still another embodiment of the present invention.

FIG. 14 is a system diagram showing a configuration of a part of a cogeneration facility 68 including a gas turbine control device 128 according to still another embodiment of the present invention.

FIG. 15 is a diagram showing a control function of a pressure deviation generator 27a shown in FIG.

FIG. 16 (1) is a diagram showing an example of a change in the pressure in the second fuel supply pipe 112, and FIG. 16 (2) is a diagram showing an example of a change in the valve opening of the first flow control valve 6 corresponding thereto. FIG.
(3) is a diagram showing an example of a change in the valve opening degree of the second flow control valve 7 corresponding thereto.

[Explanation of symbols]

2 Main fuel compressor 3 Gas turbine 3a Air compressor 3b Combustor 3c Turbine 4 Generator 6 First flow control valve 7 Second flow control valve 10a Rotation speed / load control circuit 10b Gas temperature control circuit 10c Start control circuit 10d Low Signal selector 11 First function generator 12 Second function generator 21 Main fuel flow / differential pressure converter 22 Differential pressure transmitter 23, 23a, 23b, 26, 26a, 26b Control means 24 Main fuel flow / pressure converter Reference Signs List 25 pressure transmitter 27 pressure deviation setter 27a pressure deviation generator 28 adder 29 opening detector 50 signal generator 60, 65-68 cogeneration equipment 90, 95-98 gas turbine control circuit 120, 125-128 gas turbine Control device 200 Main fuel supply source 201 Auxiliary fuel supply source 202 Heating value measuring device 203 Power value detector 2 4 the first flow control means 205 the auxiliary fuel flow rate adjusting valve 206 load setter 207,207a~207d main fuel arithmetic control circuit 208 auxiliary fuel arithmetic control circuit 209 subtractor 210 valve opening setter 220 missing heat quantity calculation circuit

Continuation of front page (72) Inventor Masakazu Hayashi 3-1-1 Higashi Kawasaki-cho, Chuo-ku, Kobe-shi, Hyogo Kawasaki Heavy Industries, Ltd. Kobe Plant (56) References JP-A-63-143339 (JP, A) JP-A-6-146928 (JP, A) JP-A-62-13739 (JP, A) JP-B-6-3148 (JP, B2) JP-B-61-30134 (JP, B2)

Claims (9)

(57) [Claims] 1. A main fuel supply source for supplying main fuel to a combustor of a gas turbine, a first flow control means interposed between the main fuel supply source and the combustor, and an auxiliary fuel to the combustor Auxiliary fuel supply source, second flow control means interposed between the auxiliary fuel supply source and the combustor, output detection means for detecting the output of the gas turbine, and load setting device for setting the output of the gas turbine A subtractor for obtaining a difference between a detection output from the output detection means and a load set by the load setting device; and a main fuel calculation control for controlling a first flow rate by the first flow control means so that an output of the subtractor becomes zero. Means for calculating the amount of insufficient heat given to the combustor of the main fuel when the calorific value of the main fuel falls below a predetermined reference calorific value; and The lack of heat is the combustor Auxiliary fuel calculation control means for controlling the second flow rate by the second flow rate control means so as to be supplied to the fuel tank. The first flow rate control means compresses the main fuel and supplies the main fuel to the combustor of the gas turbine. A compressor, a fuel recirculation line for branching a part of the main fuel discharged from the main fuel compressor and returning it to an inlet of the main fuel compressor, and a second fuel flow control device for controlling a flow rate of the main fuel at an inlet of the main fuel compressor. 1) a flow rate adjusting means, and a second flow rate adjusting means which controls a flow rate of the main fuel returned to an inlet of the main fuel compressor by the fuel recirculation line and is capable of being fully closed. A differential pressure transmitter for detecting a differential pressure obtained by subtracting a gas pressure in a combustor provided in a gas turbine from a pressure at an outlet of a main fuel compressor, and instructing a flow rate of a main fuel supplied to a combustor of the gas turbine. A signal generator for generating a main fuel command signal, and a main fuel Calculating means for calculating a target value of the differential pressure obtained by subtracting the gas pressure in the combustor from the pressure at the outlet of the main fuel compressor corresponding to the flow rate indicated by the main fuel command signal in response to the command signal; Control means for responding to the outputs of the transmitter and the arithmetic means, for outputting a control signal indicating the flow rate of the main fuel supplied to the combustor so that the detected differential pressure becomes the target value; In response, when the flow rate represented by the control signal is less than a predetermined minimum flow rate of the main fuel compressor, a first flow rate set value representing the minimum flow rate is output, and when the flow rate represented by the control signal is greater than or equal to the minimum flow rate, A first function generator for outputting a first flow rate set value corresponding to the control signal and providing the output signal to the first flow rate adjusting means; and a flow rate responsive to the control signal and represented by the control signal being equal to or less than the minimum flow rate When the minimum flow rate from the control signal The flow rate represented by the control signal is subtracted, and a second flow rate set value representing the subtracted flow rate is output. When the flow rate represented by the control signal exceeds the minimum flow rate, the second flow rate set value for fully closing the second flow rate adjusting means is set. And a second function generator for outputting the output second flow rate set value to the second flow rate adjusting means. 2. A main fuel supply source for supplying a main fuel to a combustor of a gas turbine, a first flow control means interposed between the main fuel supply source and the combustor, and an auxiliary fuel to the combustor Auxiliary fuel supply source, second flow control means interposed between the auxiliary fuel supply source and the combustor, output detection means for detecting the output of the gas turbine, and load setting device for setting the output of the gas turbine A subtractor for obtaining a difference between a detection output from the output detection means and a load set by the load setting device; and a main fuel calculation control for controlling a first flow rate by the first flow control means so that an output of the subtractor becomes zero. Means for calculating the amount of insufficient heat given to the combustor of the main fuel when the calorific value of the main fuel falls below a predetermined reference calorific value; and The lack of heat is the combustor Auxiliary fuel calculation control means for controlling the second flow rate by the second flow rate control means so as to be supplied to the fuel tank. The first flow rate control means compresses the main fuel and supplies the main fuel to the combustor of the gas turbine. A compressor, a fuel recirculation line for branching a part of the main fuel discharged from the main fuel compressor and returning it to an inlet of the main fuel compressor, and a second fuel flow control device for controlling a flow rate of the main fuel at an inlet of the main fuel compressor. (1) a flow rate adjusting means, and a second flow rate adjusting means that controls a flow rate of the main fuel returned to an inlet of the main fuel compressor by the fuel recirculation line and is capable of being fully closed. A differential pressure transmitter that detects the differential pressure obtained by subtracting the pressure at the outlet of the air compressor provided in the gas turbine from the pressure at the outlet of the main fuel compressor, and instructs the flow rate of the main fuel supplied to the combustor of the gas turbine. A signal generator for generating a main fuel command signal Calculating means for calculating a target value of a differential pressure obtained by subtracting the pressure at the outlet of the air compressor from the pressure at the outlet of the main fuel compressor corresponding to the flow rate represented by the main fuel command signal, Control means responsive to outputs of the differential pressure transmitter and the arithmetic means for outputting a control signal indicating a flow rate of the main fuel supplied to the combustor so that the detected differential pressure becomes the target value; In response to the signal, when the flow rate represented by the control signal is less than a predetermined minimum flow rate of the main fuel compressor, a first flow rate set value representing the minimum flow rate is output, and the flow rate represented by the control signal is equal to or greater than the minimum flow rate. A first function generator for outputting a first flow rate set value corresponding to the control signal, and providing the output signal to the first flow rate adjusting means; and a flow rate responsive to the control signal, wherein the flow rate represented by the control signal is the minimum value. When the flow rate is below the minimum flow rate The flow rate represented by the control signal is subtracted, and a second flow rate set value representing the subtracted flow rate is output. When the flow rate represented by the control signal exceeds the minimum flow rate, the second flow rate for completely closing the second flow rate adjusting means is set. A second function generator for outputting a set value and providing the second flow rate set value thus output to the second flow rate adjusting means. 3. A main fuel supply source for supplying main fuel to a combustor of a gas turbine, first flow control means interposed between the main fuel supply source and the combustor, and auxiliary fuel to the combustor. Auxiliary fuel supply source, second flow control means interposed between the auxiliary fuel supply source and the combustor, output detection means for detecting the output of the gas turbine, and load setting device for setting the output of the gas turbine A subtractor for obtaining a difference between a detection output from the output detection means and a load set by the load setting device; and a main fuel calculation control for controlling a first flow rate by the first flow control means so that an output of the subtractor becomes zero. Means for calculating the amount of insufficient heat given to the combustor of the main fuel when the calorific value of the main fuel falls below a predetermined reference calorific value; and The lack of heat is the combustor Auxiliary fuel calculation control means for controlling the second flow rate by the second flow rate control means so as to be supplied to the fuel tank. The first flow rate control means compresses the main fuel and supplies the main fuel to the combustor of the gas turbine. A compressor, a fuel recirculation line for branching a part of the main fuel discharged from the main fuel compressor and returning it to an inlet of the main fuel compressor, and a second fuel flow control device for controlling a flow rate of the main fuel at an inlet of the main fuel compressor. (1) a flow rate adjusting means, and a second flow rate adjusting means that controls a flow rate of the main fuel returned to an inlet of the main fuel compressor by the fuel recirculation line and is capable of being fully closed. A pressure transmitter that detects the pressure at the outlet of the main fuel compressor, a signal generator that generates a main fuel command signal that commands the flow rate of the main fuel supplied to the gas turbine combustor, and responds to the main fuel command signal The main fuel corresponding to the flow rate indicated by the main fuel command signal Calculating means for calculating a target value of the pressure at the outlet of the compressor; and, in response to outputs of the pressure transmitter and the calculating means, the main fuel supplied to the combustor so that the detected pressure becomes the target value. A control means for outputting a control signal representing the flow rate; and a first flow rate setting value representing the minimum flow rate when the flow rate represented by the control signal is less than a predetermined minimum flow rate of the main fuel compressor in response to the control signal. A first function generator for outputting a first flow rate set value corresponding to the control signal when the flow rate represented by the control signal is equal to or greater than the minimum flow rate, and providing the output signal to the first flow rate adjusting means; In response to the signal, when the flow rate represented by the control signal is equal to or less than the minimum flow rate, the flow rate represented by the control signal is subtracted from the minimum flow rate, and a second flow rate set value representing the subtracted flow rate is output, and the control signal is represented. Flow rate exceeds minimum flow rate A second function generator for outputting the second flow rate set value for the second flow rate adjusting means to be fully closed, and providing the output second flow rate set value to the second flow rate adjusting means. Gas turbine control device. 4. A main fuel supply source for supplying main fuel to a combustor of a gas turbine, a first flow control means interposed between the main fuel supply source and the combustor, and an auxiliary fuel for supplying to the combustor Auxiliary fuel supply source, second flow control means interposed between the auxiliary fuel supply source and the combustor, output detection means for detecting the output of the gas turbine, and load setting device for setting the output of the gas turbine A subtractor for obtaining a difference between a detection output from the output detection means and a load set by the load setting device; and a main fuel calculation control for controlling a first flow rate by the first flow control means so that an output of the subtractor becomes zero. Means for calculating the amount of insufficient heat given to the combustor of the main fuel when the calorific value of the main fuel falls below a predetermined reference calorific value; and The lack of heat is the combustor Auxiliary fuel calculation control means for controlling the second flow rate by the second flow rate control means so as to be supplied to the fuel tank. The first flow rate control means compresses the main fuel and supplies the main fuel to the combustor of the gas turbine. A compressor, a fuel recirculation line for branching a part of the main fuel discharged from the main fuel compressor and returning it to an inlet of the main fuel compressor, and a second fuel flow control device for controlling a flow rate of the main fuel at an inlet of the main fuel compressor. (1) a flow rate adjusting means, and a second flow rate adjusting means that controls a flow rate of the main fuel returned to an inlet of the main fuel compressor by the fuel recirculation line and is capable of being fully closed. A pressure transmitter that detects the pressure at the outlet of the main fuel compressor, a signal generator that generates a main fuel command signal that commands the flow rate of the main fuel supplied to the gas turbine combustor, and responds to the main fuel command signal The main fuel corresponding to the flow rate indicated by the main fuel command signal Calculating means for calculating a first target value of the pressure at the outlet of the compressor; and a first flow rate adjusting means responsive to outputs of the pressure transmitter and the calculating means so that the detected pressure becomes the first target value. A first control means for controlling; a pressure deviation setter for outputting a pressure deviation signal representing a predetermined value; and a pressure represented by the first target value in response to the first target value of the pressure and the pressure deviation signal; An adder that adds a value represented by the deviation signal and outputs a second target value of the pressure representing the pressure; and an output of the pressure transmitter and the adder, wherein the detected pressure is equal to the second target value. And a second control means for controlling the second flow rate adjusting means. 5. A main fuel supply source for supplying main fuel to a combustor of a gas turbine, a first flow control means interposed between the main fuel supply source and the combustor, and an auxiliary fuel to the combustor. Auxiliary fuel supply source, second flow control means interposed between the auxiliary fuel supply source and the combustor, output detection means for detecting the output of the gas turbine, and load setting device for setting the output of the gas turbine A subtractor for obtaining a difference between a detection output from the output detection means and a load set by the load setting device; and a main fuel calculation control for controlling a first flow rate by the first flow control means so that an output of the subtractor becomes zero. Means for calculating the amount of insufficient heat given to the combustor of the main fuel when the calorific value of the main fuel falls below a predetermined reference calorific value; and The lack of heat is the combustor Auxiliary fuel calculation control means for controlling the second flow rate by the second flow rate control means so as to be supplied to the fuel tank. The first flow rate control means compresses the main fuel and supplies the main fuel to the combustor of the gas turbine. A compressor, a fuel recirculation line for branching a part of the main fuel discharged from the main fuel compressor and returning it to an inlet of the main fuel compressor, and a second fuel flow control device for controlling a flow rate of the main fuel at an inlet of the main fuel compressor. (1) a flow rate adjusting means, and a second flow rate adjusting means that controls a flow rate of the main fuel returned to an inlet of the main fuel compressor by the fuel recirculation line and is capable of being fully closed. A pressure transmitter that detects the pressure at the outlet of the main fuel compressor, a signal generator that generates a main fuel command signal that commands the flow rate of the main fuel supplied to the combustor of the gas turbine, and a signal generator that responds to the main fuel command signal. , The main fuel corresponding to the flow rate represented by the main fuel command signal Calculating means for calculating a first target value of the pressure at the outlet of the compressor; and a first flow rate adjusting means responsive to the outputs of the pressure transmitter and the calculating means so that the detected pressure becomes the first target value. A first control means for controlling; a detector for detecting an opening of the first flow rate adjusting means; a flow rate of the main fuel to the main fuel compressor based on the detected opening in response to an output of the detector. A pressure deviation signal representing a positive value corresponding to the output of the detector is output when the flow rate is equal to or more than a predetermined minimum flow rate of the compressor, and the flow rate of the main fuel to the main fuel compressor based on the detected opening is less than the minimum flow rate. And a pressure deviation generator that outputs a pressure deviation signal representing zero when the pressure is greater than a first value of the pressure in response to the output of the calculating means and the pressure deviation generator.
An adder for adding the pressure represented by the target value and the value represented by the pressure deviation signal and outputting a second target value of the pressure representing the pressure; and responding to the outputs of the pressure transmitter and the adder, And a second control means for controlling the second flow rate adjusting means so as to attain the second target value. 6. A main fuel supply source for supplying a main fuel to a combustor of a gas turbine, a first flow control means interposed between the main fuel supply source and the combustor, and an auxiliary fuel for the combustor Auxiliary fuel supply source, second flow control means interposed between the auxiliary fuel supply source and the combustor, output detection means for detecting the output of the gas turbine, and load setting device for setting the output of the gas turbine A subtractor for obtaining a difference between a detection output from the output detection means and a load set by the load setting device; and a main fuel calculation control for controlling a first flow rate by the first flow control means so that an output of the subtractor becomes zero. Means for calculating the amount of insufficient heat given to the combustor of the main fuel when the calorific value of the main fuel falls below a predetermined reference calorific value; and The lack of heat is the combustor Auxiliary fuel calculation control means for controlling the second flow rate by the second flow rate control means so as to be supplied to the fuel tank. The first flow rate control means compresses the main fuel and supplies the main fuel to the combustor of the gas turbine. A compressor, a fuel recirculation line for branching a part of the main fuel discharged from the main fuel compressor and returning it to an inlet of the main fuel compressor, and a second fuel flow control device for controlling a flow rate of the main fuel at an inlet of the main fuel compressor. (1) a flow rate adjusting means, and a second flow rate adjusting means that controls a flow rate of the main fuel returned to an inlet of the main fuel compressor by the fuel recirculation line and is capable of being fully closed. A differential pressure transmitter that detects a differential pressure obtained by subtracting a gas pressure in a combustor provided in a gas turbine from a pressure at an outlet of a main fuel compressor, and instructs a flow rate of a main fuel supplied to a combustor of the gas turbine. A signal generator for generating a main fuel command signal, and a main fuel Calculating means for calculating a first target value of a differential pressure obtained by subtracting the gas pressure in the combustor from the pressure at the outlet of the main fuel compressor corresponding to the flow rate represented by the main fuel command signal in response to the command signal; First control means for controlling the first flow rate adjusting means so that the detected differential pressure becomes the first target value in response to the outputs of the differential pressure transmitter and the arithmetic means; and a pressure deviation signal representing a predetermined value. A pressure deviation setting device that outputs the differential pressure, and responds to the first target value of the differential pressure and the pressure deviation signal, adds the differential pressure represented by the first target value, and the value represented by the pressure deviation signal, (2) an adder for outputting a target value; and a second control means for controlling a second flow rate adjusting means in response to outputs of the differential pressure transmitter and the adder so that the detected differential pressure becomes the second target value. And a gas turbine control device. 7. A main fuel supply source for supplying main fuel to a combustor of a gas turbine, a first flow control means interposed between the main fuel supply source and the combustor, and an auxiliary fuel for supplying to the combustor Auxiliary fuel supply source, second flow control means interposed between the auxiliary fuel supply source and the combustor, output detection means for detecting the output of the gas turbine, and load setting device for setting the output of the gas turbine A subtractor for obtaining a difference between a detection output from the output detection means and a load set by the load setting device; and a main fuel calculation control for controlling a first flow rate by the first flow control means so that an output of the subtractor becomes zero. Means for calculating the amount of insufficient heat given to the combustor of the main fuel when the calorific value of the main fuel falls below a predetermined reference calorific value; and The lack of heat is the combustor Auxiliary fuel calculation control means for controlling the second flow rate by the second flow rate control means so as to be supplied to the fuel tank. The first flow rate control means compresses the main fuel and supplies the main fuel to the combustor of the gas turbine. A compressor, a fuel recirculation line for branching a part of the main fuel discharged from the main fuel compressor and returning it to an inlet of the main fuel compressor, and a second fuel flow control device for controlling a flow rate of the main fuel at an inlet of the main fuel compressor. (1) a flow rate adjusting means, and a second flow rate adjusting means that controls a flow rate of the main fuel returned to an inlet of the main fuel compressor by the fuel recirculation line and is capable of being fully closed. A differential pressure transmitter that detects a differential pressure obtained by subtracting a gas pressure in a combustor provided in a gas turbine from a pressure at an outlet of a main fuel compressor, and instructs a flow rate of a main fuel supplied to a combustor of the gas turbine. A signal generator for generating a main fuel command signal, and a main fuel Calculating means for calculating a first target value of a differential pressure obtained by subtracting the gas pressure in the combustor from the pressure at the outlet of the main fuel compressor corresponding to the flow rate represented by the main fuel command signal in response to the command signal; First control means for controlling the first flow rate adjusting means in response to the outputs of the differential pressure transmitter and the arithmetic means so that the detected differential pressure becomes the first target value; and opening of the first flow rate adjusting means. And a detector for detecting the degree, in response to the output of the detector, the output of the detector when the flow rate of the main fuel to the main fuel compressor by the detected opening is equal to or more than the predetermined minimum flow rate of the main fuel compressor. A pressure deviation generator that outputs a pressure deviation signal representing a corresponding positive value and outputs a pressure deviation signal representing zero when the flow rate of the main fuel to the main fuel compressor based on the detected opening is less than the minimum flow rate. Responding to the outputs of the differential pressure calculating means and the pressure deviation generator, The adder adds the differential pressure represented by the target value and the value represented by the pressure deviation signal and outputs a second target value of the differential pressure representing the differential pressure, and responds to the outputs of the differential pressure transmitter and the adder. And a second control means for controlling a second flow rate adjusting means so that the detected differential pressure becomes the second target value. 8. A main fuel supply source for supplying main fuel to a combustor of a gas turbine, first flow control means interposed between the main fuel supply source and the combustor, and auxiliary fuel to the combustor. Auxiliary fuel supply source, second flow control means interposed between the auxiliary fuel supply source and the combustor, output detection means for detecting the output of the gas turbine, and load setting device for setting the output of the gas turbine A subtractor for obtaining a difference between a detection output from the output detection means and a load set by the load setting device; and a main fuel calculation control for controlling a first flow rate by the first flow control means so that an output of the subtractor becomes zero. Means for calculating the amount of insufficient heat given to the combustor of the main fuel when the calorific value of the main fuel falls below a predetermined reference calorific value; and The lack of heat is the combustor Auxiliary fuel calculation control means for controlling the second flow rate by the second flow rate control means so as to be supplied to the fuel tank. The first flow rate control means compresses the main fuel and supplies the main fuel to the combustor of the gas turbine. A compressor, a fuel recirculation line for branching a part of the main fuel discharged from the main fuel compressor and returning it to an inlet of the main fuel compressor, and a second fuel flow control device for controlling a flow rate of the main fuel at an inlet of the main fuel compressor. (1) a flow rate adjusting means, and a second flow rate adjusting means that controls a flow rate of the main fuel returned to an inlet of the main fuel compressor by the fuel recirculation line and is capable of being fully closed. A differential pressure transmitter that detects the differential pressure obtained by subtracting the pressure at the outlet of the air compressor provided in the gas turbine from the pressure at the outlet of the main fuel compressor, and instructs the flow rate of the main fuel supplied to the combustor of the gas turbine. A signal generator for generating a main fuel command signal Calculating means for calculating a first target value of a differential pressure obtained by subtracting the pressure at the outlet of the air compressor from the pressure at the outlet of the main fuel compressor corresponding to the flow rate indicated by the main fuel command signal in response to the fuel command signal A first control means responsive to outputs of the differential pressure transmitter and the arithmetic means for controlling the first flow rate adjusting means so that the detected differential pressure becomes the first target value; and a pressure representing a predetermined value. A pressure deviation setter for outputting a deviation signal; a differential pressure represented by the first target value and a value represented by the pressure deviation signal in response to the first target value of the differential pressure and the pressure deviation signal; An adder that outputs a second target value of the second and a second control unit that controls a second flow rate adjusting unit in response to outputs of the differential pressure transmitter and the adder so that the detected differential pressure becomes the second target value. A gas turbine control device, comprising: a control unit. 9. A main fuel supply source for supplying main fuel to a combustor of a gas turbine, first flow control means interposed between the main fuel supply source and the combustor, and auxiliary fuel for supplying to the combustor Auxiliary fuel supply source, second flow control means interposed between the auxiliary fuel supply source and the combustor, output detection means for detecting the output of the gas turbine, and load setting device for setting the output of the gas turbine A subtractor for obtaining a difference between a detection output from the output detection means and a load set by the load setting device; and a main fuel calculation control for controlling a first flow rate by the first flow control means so that an output of the subtractor becomes zero. Means for calculating the amount of insufficient heat given to the combustor of the main fuel when the calorific value of the main fuel falls below a predetermined reference calorific value; and The lack of heat is the combustor Auxiliary fuel calculation control means for controlling the second flow rate by the second flow rate control means so as to be supplied to the fuel tank. The first flow rate control means compresses the main fuel and supplies the main fuel to the combustor of the gas turbine. A compressor, a fuel recirculation line for branching a part of the main fuel discharged from the main fuel compressor and returning it to an inlet of the main fuel compressor, and a second fuel flow control device for controlling a flow rate of the main fuel at an inlet of the main fuel compressor. (1) a flow rate adjusting means, and a second flow rate adjusting means that controls a flow rate of the main fuel returned to an inlet of the main fuel compressor by the fuel recirculation line and is capable of being fully closed. A differential pressure transmitter that detects the differential pressure obtained by subtracting the pressure at the outlet of the air compressor provided in the gas turbine from the pressure at the outlet of the main fuel compressor, and instructs the flow rate of the main fuel supplied to the combustor of the gas turbine. A signal generator for generating a main fuel command signal Calculating means for calculating a first target value of a differential pressure obtained by subtracting the pressure at the outlet of the air compressor from the pressure at the outlet of the main fuel compressor corresponding to the flow rate indicated by the main fuel command signal in response to the fuel command signal A first control means responsive to an output of the differential pressure transmitter and the arithmetic means for controlling the first flow rate adjusting means so that the detected differential pressure becomes the first target value; and the first flow rate adjusting means. A detector that detects the opening of the main fuel compressor in response to the output of the detector, and the flow rate of the main fuel to the main fuel compressor based on the detected opening is equal to or greater than a predetermined minimum flow rate of the main fuel compressor. A pressure deviation signal representing a positive value corresponding to the output of the above, and outputting a pressure deviation signal representing zero when the flow rate of the main fuel to the main fuel compressor based on the detected opening is less than the minimum flow rate. A deviation generator, responsive to outputs of the differential pressure calculating means and the pressure deviation generator An adder for adding a differential pressure represented by a first target value of differential pressure and a value represented by a pressure deviation signal, and outputting a second target value of differential pressure representing the differential pressure; a differential pressure transmitter and an adder And a second control means for controlling a second flow rate adjusting means so that the detected differential pressure becomes the second target value in response to the output of the gas turbine control apparatus.