JPH08121194A - Gas turbine control device - Google Patents

Abstract

(57) [Summary] [Purpose] For example, a low-pressure gas with a low calorific value, such as blast furnace gas, is effectively used as fuel for a gas turbine. [Configuration] Fuel gas is compressed by a fuel gas compressor 2 and supplied to a combustor 3b. There is a minimum flow rate in the fuel gas compressor 2, and when the fuel gas control signal X _f from the signal generator 50 of the gas turbine control device corresponds to less than the minimum flow rate, the first flow rate adjusting valve 6 causes the minimum flow rate. Fuel gas is supplied to the fuel gas compressor 2, the surplus fuel gas is controlled by the second flow rate adjusting valve 7, and is recirculated to the inlet of the fuel gas compressor 2 so that the fuel gas control signal X _f is at least the minimum flow rate. If so, fully close the second flow rate adjusting valve 7,
The fuel gas supply flow rate is controlled by the flow rate adjusting valve 6.

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 that uses, as a fuel, a low-pressure gas having a low calorific value generated from, for example, blast furnace gas.

[0002]

Blast furnace gas generated from a blast furnace is a combustible gas containing carbon monoxide, but its calorific value is low due to its low concentration and it is difficult to burn it at high pressure.
Conventionally, for example, as shown in Japanese Patent Publication No. 5-77926, it was customary to control the supply flow rate of blast furnace gas as a function of its temperature and use it as a fuel for a boiler that is relatively easy to burn.

On the other hand, in order to effectively use the blast furnace gas, a blast furnace gas is burned by a gas turbine, the exhaust gas is guided to a boiler, and steam generated in a cogeneration facility or a boiler for generating steam is supplied to a steam turbine. In recent years, combined cycle power generation equipment that has been introduced to further increase the amount of power generation has been attracting attention as an effective method for utilizing blast furnace gas.

Regarding a gas turbine using a gas having a low calorific value such as blast furnace gas, for example, Japanese Patent Publication No. 5-837.
No. 42 publication. In this conventional technique, a gas with a low calorific value and a gas with a high calorific value are mixed and guided to a combustor of a gas turbine, and only the gas with a low calorific value is not used as a fuel gas. . Another conventional technique using a gas having a low calorific value is disclosed in Japanese Patent Publication No. 5-78656. In this conventional technique, a plurality of heat storage heat exchangers are divided into first and second groups, one group burns B gas which is a blast furnace gas to store the heat, and the other group stores it. Utilizing the heat generated, the working gas is heated by heat exchange to drive the turbine, and every predetermined time cycle,
It is configured to switch the operation of each group. In such a conventional technique, since the working gas is heated by heat exchange, the thermal efficiency is poor as compared with the case of directly burning the fuel gas in the combustor.

FIG. 13 is a system diagram showing a cogeneration facility 60e using a gas turbine 3 that uses blast furnace gas as fuel. This cogeneration facility 60e
Is configured to supply only the gas having a low heating value to the combustor 36. The common rotary shaft 1 has a fuel gas compressor 2,
The gas turbine 3 and the generator 4 are connected. A boiler 5 for generating steam by heat of exhaust gas of the gas turbine 3 is provided on the downstream side in the gas flow direction of the gas turbine 3. The gas turbine 3 includes an air compressor 3a, a combustor 3b, and a turbine 3c. Further, the first fuel supply line 111 for supplying the fuel gas to the fuel gas compressor 2
A second fuel supply line 112 for supplying a fuel gas from the fuel gas compressor 2 to the combustor 3b of the gas turbine, and a second fuel supply line 112 branching from the first fuel supply line 111.
A fuel recirculation line 113 for returning the fuel gas to the inlet of the fuel gas compressor, and a first flow rate adjusting valve 6 as a first flow rate adjusting means interposed in the first fuel supply line 111,
A second flow rate adjusting valve 7 as a second flow rate adjusting means and a gas cooler 8 interposed in the fuel return conduit 113, and a gas turbine control circuit for controlling the first flow rate adjusting valve 6 and the second flow rate adjusting valve 7. And 10 are provided. The fuel gas compressor 2 and the fuel return line 11 of the first fuel supply line 111.
3 on the downstream side in the fuel gas supply direction from the connection point, and the fuel recirculation conduit 11 of the second fuel supply conduit 112.
A circulation loop including a portion on the upstream side in the fuel gas supply direction from a branch point where 3 is branched, a fuel recirculation pipe line 113, first and second flow rate adjusting valves 6 and 7, and a gas cooler 8. 8
0 is configured.

The fuel gas guided by the first fuel supply line 111 is supplied to the fuel gas compressor 2 and compressed.
The fuel gas compressed by the fuel gas compressor 2 is supplied to the combustor 3b via the second fuel supply conduit 112, compressed by the air compressor 3a, and combustor 3b via the air conduit 116.
It is mixed with the air supplied to and burned. The high-temperature gas after the combustion of the fuel gas is guided to the turbine 3c through the working gas pipe 115, expanded in the turbine 3c, drives the generator 4 to generate power, and after the pressure drops, the boiler 5 Be led to.

On the other hand, for the surplus which is a part of the fuel gas compressed by the fuel gas compressor 2, the second flow rate adjusting valve 7
Is recirculated to the first fuel supply conduit 111 via the fuel recirculation conduit 113 in which At this time, the fuel gas compressor 2
Since the fuel gas compressed in is high in temperature, it is cooled by the gas cooler 8. Since the fuel gas compressor 2 has the minimum flow rate, a circulation loop for recirculating the surplus fuel gas is required.

The steam generated in the boiler 5 is steam line 114.
Are supplied to various uses inside the factory such as steam turbines.

The output of the gas turbine 3 used for this equipment is controlled by a gas turbine control device 120 including a gas turbine control circuit 10 and first and second flow rate adjusting means 6, 7. Turbine control circuit 10
Operates the first flow rate adjusting valve 6 and the second flow rate adjusting valve 7,
It is performed by adjusting the flow rate of the fuel gas supplied to the combustor 3b.

FIG. 14 is a system diagram showing a conventional cogeneration facility 60f using a gas turbine which uses a fuel gas of high pressure and high calorific value as fuel. Compared with FIG. 13, there is no fuel gas compressor 2 for increasing the pressure of the fuel gas and the accompanying first flow rate adjusting valve 6, second flow rate adjusting valve 7 and gas cooler 8, and instead of the fuel gas combustor 3b is a configuration in which a flow rate adjusting valve 61 for adjusting the flow rate of the fuel gas in the fuel pipeline 117 supplied to 3b is provided. In the case of this conventional equipment, the gas turbine control circuit 1
01a and the flow rate adjusting valve 61, the gas turbine control device 101 operates the opening degree of the flow rate adjusting valve 61, and the combustor 3b.
The output of the gas turbine 3 is controlled by adjusting the flow rate of the fuel gas supplied to the.

FIG. 15 shows a conventional gas turbine controller 1.
2 is a system diagram showing a cogeneration facility 60f including 01. FIG. In the conventional gas turbine 3, the fuel gas control device for controlling the output is configured by the flow rate adjusting valve 61, and the configuration of the gas turbine control circuit 101a responds to the output from various detectors (not shown), Rotational speed / load control circuit 10a, gas temperature control circuit 10b, and start control circuit 10c, which output signals for instructing the flow rate of each of them, and these control circuits 10a, 10b, 10
It is customary to configure the signal generator 50 including a low-level signal selector 10d that selects a signal that commands the smallest flow rate of the fuel gas from the signals output from c. Such a conventional technique is disclosed in, for example, Japanese Patent Laid-Open No. 5-332.
No. 103 publication.

In this conventional technique, the rotation speed / load control circuit 10a calculates the fuel gas flow rate to be supplied to the gas turbine 3 for controlling the rotation speed of the rotating shaft 1 and the output of the generator 4. The gas temperature control circuit 10b calculates the range of the fuel gas flow rate such that the gas temperature at either or both of the inlet and the outlet of the turbine 3c does not exceed the allowable range. The startup control circuit 10c calculates the fuel gas flow rate required at startup. In this way, by selecting the signal corresponding to the smallest fuel gas flow rate from the calculated fuel gas flow rates by the low-level signal selector 10d, the output of the predetermined generator 4 is maintained,
When the gas temperature rises to a range that hinders the operation of the gas turbine 3, the fuel gas flow rate is correspondingly limited.
Further, it also has a function of smoothly starting the gas turbine 3 at the time of startup.

The control of the conventional gas turbine is established, and each of them includes the configuration shown in FIG. 8 although there are some differences depending on the characteristics of individual gas turbines. Another conventional technique is disclosed in, for example, Japanese Patent Publication No. 5-79818. In this conventional technique, a premixing chamber of fuel gas and compressed air is provided in the combustor to locally reduce the flame temperature.

Another conventional technique is disclosed in Japanese Patent Laid-Open No. 5-2027.
No. 67 publication. In this conventional technique, CO
A fuel gas containing a polymerization component such as G, various off-gases, and dienes such as LPG is catalytically hydrogenated and supplied to the combustor.

[0015]

In such conventional techniques (Japanese Patent Laid-Open No. 5-332103, Japanese Patent Publication No. 5-79818, and Japanese Patent Laid-Open No. 5-202767), a low-pressure blast furnace gas as shown in FIG. 13 is used as a fuel. Gas turbine control device 120
However, since it is necessary to control the flow rate of the fuel gas supplied to the gas turbine 3 by combining the first flow rate adjusting valve 6 and the second flow rate adjusting valve 7 having different characteristics, there is a problem that it is not possible.

As long as the first flow rate adjusting valve 6 of the fuel gas compressor 2 can continuously adjust the fuel gas flow rate from zero to the maximum flow rate, the conventional gas turbine control device 101 can handle it. However, in the fuel gas compressor 2, there is a minimum flow rate for preventing the destruction thereof, and it is customary that the flow rate cannot be made lower than that. Therefore, in order to reduce the fuel flow rate below the minimum flow rate of the fuel gas compressor 2, the flow rate of the fuel gas supplied to the fuel gas compressor 2 is set to the minimum flow rate by the first flow rate adjusting valve 6, and the second flow rate adjusting valve is set. 7
The fuel gas at a flow rate which becomes an excess in the first fuel supply line 1
Need to reflux to 11.

Therefore, in this type of gas turbine control device 120, the first flow rate adjusting valve 6 for controlling the flow rate of the fuel gas supplied to the fuel gas compressor 2 and the flow rate of the recirculating fuel gas are controlled. A control means for operating the second flow rate adjusting valve 7 is required. Further, the first flow rate adjusting valve 6
And, the second flow rate adjusting valve 7 needs to be operated in conjunction with each other in order to realize continuous adjustment of the flow rate of the fuel gas.

Therefore, an object of the present invention is low pressure,
In addition, a gas with a low calorific value can be used as a fuel, and the flow rate of the fuel can be adjusted steplessly, and a gas with a low calorific value at a low pressure, which has not been regarded as important in the past, can be effectively used as a fuel for a gas turbine. Another object of the present invention is to provide a gas turbine control device.

[0019]

According to the present invention, a fuel gas compressor for compressing fuel gas and supplying it to a combustor of a gas turbine and a part of the fuel gas discharged from the fuel gas compressor are branched. A fuel recirculation pipe returning to the inlet of the fuel gas compressor, a first flow rate adjusting means for controlling the flow rate of the fuel gas at the inlet of the fuel gas compressor, and the fuel recirculation pipe returning to the inlet of the fuel gas compressor. A second flow rate adjusting means for controlling the flow rate of the fuel gas so that the fuel gas can be fully closed; a signal generator for generating a fuel gas command signal for instructing the flow rate of the fuel gas supplied to the combustor of the gas turbine; In response to the command signal, when the flow rate represented by the fuel gas command signal is less than the predetermined minimum flow rate of the fuel gas compressor, the first flow rate set value representing the minimum flow rate is output, and the flow rate represented by the fuel gas command signal is If it is above the minimum flow rate A first function generator that outputs a first flow rate set value corresponding to the fuel gas command signal and gives the output signal to the first flow rate adjusting means; and a first function generator that responds to the fuel gas command signal When the flow rate represented is less than or equal to the minimum flow rate, the flow rate represented by the fuel gas command signal is subtracted from the minimum flow rate, and the second flow rate set value representing the subtracted flow rate is output, and the flow rate represented by the fuel gas command signal indicates the minimum flow rate. A second function generator that outputs a second flow rate set value for the second flow rate adjusting means to be fully closed when exceeding, and gives the second flow rate set value thus output to the second flow rate adjusting means. It is a gas turbine control device. Further, according to the present invention, a fuel gas compressor that compresses fuel gas and supplies it to a combustor of a gas turbine, and a part of the fuel gas discharged from the fuel gas compressor is branched and returned to the inlet of the fuel gas compressor. A fuel return line, a first flow rate adjusting means for controlling the flow rate of the fuel gas at the inlet of the fuel gas compressor, and a flow rate of the fuel gas returned to the inlet of the fuel gas compressor by the fuel return line, A second flow rate adjusting means 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 the gas turbine from a pressure at an outlet of the fuel gas compressor;
A signal generator that generates a fuel gas command signal that commands the flow rate of the fuel gas supplied to the combustor of the gas turbine, and a fuel gas compression unit that responds to the fuel gas command signal and that corresponds to the flow rate represented by the fuel gas command signal. In response to the output of the differential pressure transmitter and the calculation means for calculating the target value of the differential pressure obtained by subtracting the gas pressure in the combustor from the outlet pressure of the machine, the detected differential pressure is the target value. Control means for outputting a control signal indicating the flow rate of the fuel gas supplied to the combustor, and the flow rate indicated by the control signal in response to the control signal is less than a predetermined minimum flow rate of the fuel gas compressor. When the flow rate represented by the control signal is equal to or more than the minimum flow rate, the first flow rate set value corresponding to the control signal is output, and the output signal is 1
A first function generator for giving to the flow rate adjusting means, and a flow rate represented by the control signal is subtracted from the minimum flow rate when the flow rate represented by the control signal is less than or equal to the minimum flow rate in response to the control signal, and the subtracted flow rate is represented. The second flow rate set value is output, and when the flow rate represented by the control signal exceeds the minimum flow rate, the second flow rate setting value is output so that the second flow rate adjusting means is fully closed, and the second flow rate set value thus output. Is provided to the second flow rate adjusting means, and a second function generator is provided. Further, according to the present invention, a fuel gas compressor that compresses fuel gas and supplies it to a combustor of a gas turbine, and a part of the fuel gas discharged from the fuel gas compressor is branched and returned to the inlet of the fuel gas compressor. A fuel return line, a first flow rate adjusting means for controlling the flow rate of the fuel gas at the inlet of the fuel gas compressor, and a flow rate of the fuel gas returned to the inlet of the fuel gas compressor by the fuel return line, Second flow rate adjusting means capable of fully closing, a pressure transmitter for detecting the pressure at the outlet of the fuel gas compressor, and a fuel gas command signal for commanding the flow rate of the fuel gas supplied to the combustor of the gas turbine. A signal generator that operates in response to the fuel gas command signal and that calculates a target value of the pressure at the outlet of the fuel gas compressor corresponding to the flow rate represented by the fuel gas command signal; In response to the output of There a control means for outputting a control signal representative of the flow rate of the fuel gas supplied to the combustor such that the target value, in response to the control signal,
When the flow rate represented by the control signal is less than the predetermined minimum flow rate of the fuel gas compressor, the first flow rate set value representing the minimum flow rate is output, and when the flow rate represented by the control signal is the minimum flow rate or more, the control signal is output. A first flow rate setting value corresponding to the first flow rate setting value is output, and the output signal is given to the first flow rate adjusting means.
In response to the function generator and the control signal, when the flow rate represented by the control signal is less than or equal to the minimum flow rate, the flow rate represented by the control signal is subtracted from the minimum flow rate, and the second flow rate set value representing the subtracted flow rate is output. Then, when the flow rate indicated by the control signal exceeds the minimum flow rate, the second flow rate adjusting means outputs the second flow rate setting value so that the second flow rate adjusting means is fully closed, and the second flow rate setting value thus output is output to the second flow rate adjusting means. And a second function generator for providing the gas turbine controller. Further, according to the present invention, a fuel gas compressor that compresses fuel gas and supplies it to a combustor of a gas turbine, and a part of the fuel gas discharged from the fuel gas compressor is branched and returned to the inlet of the fuel gas compressor. A fuel recirculation line, a first flow rate adjusting means for controlling the flow rate of the fuel gas at the inlet of the fuel gas compressor, and a flow rate of the fuel gas returned to the inlet of the fuel gas compressor by the fuel recirculation line, Second flow rate adjusting means capable of fully closing, a pressure transmitter for detecting the pressure at the outlet of the fuel gas compressor, and a fuel gas command signal for commanding the flow rate of the fuel gas supplied to the combustor of the gas turbine. A signal generator for operating the fuel gas command signal, operating means for operating the first target value of the pressure at the outlet of the fuel gas compressor corresponding to the flow rate represented by the fuel gas command signal, the pressure transmitter and the operation. In response to output with means,
First control means for controlling the first flow rate adjusting means so that the detected pressure becomes the first target value, a pressure deviation setter for outputting a pressure deviation signal representing a predetermined value, and a first target value of pressure. In response to the pressure deviation signal and the pressure represented by the first target value,
The detected pressure is the second target value in response to the outputs of the adder that adds the value represented by the pressure deviation signal and outputs the second target value of the pressure that represents the pressure, and the pressure transmitter and the adder. And a second control means for controlling the second flow rate adjusting means so as to: Further, according to the present invention, a fuel gas compressor that compresses fuel gas and supplies it to a combustor of a gas turbine, and a part of the fuel gas discharged from the fuel gas compressor is branched and returned to the inlet of the fuel gas compressor. A fuel return line, a first flow rate adjusting means for controlling the flow rate of the fuel gas at the inlet of the fuel gas compressor, and a flow rate of the fuel gas returned to the inlet of the fuel gas compressor by the fuel return line, A second flow rate adjusting means capable of being fully closed, a pressure transmitter for detecting the pressure at the outlet of the fuel gas compressor, and a fuel gas command signal for commanding the flow rate of the fuel gas supplied to the combustor of the gas turbine. A signal generator, a calculation unit that responds to the fuel gas command signal, and calculates a first target value of the pressure at the outlet of the fuel gas compressor corresponding to the flow rate represented by the fuel gas command signal, a pressure transmitter, and a calculation unit. In response to the output with the above detection A first control means for controlling the first flow rate adjusting means so that the force reaches the first target value, a detector for detecting the opening degree of the first flow rate adjusting means, and a response to the output of the detector, When the flow rate of the fuel gas to the fuel gas compressor according to the detection opening is equal to or higher than a predetermined minimum flow rate of the fuel gas compressor, a pressure deviation signal representing a positive value corresponding to the output of the detector is output and the detection opening is performed. Pressure deviation generator for outputting a pressure deviation signal representing zero when the flow rate of the fuel gas to the fuel gas compressor is less than the minimum flow rate, and the pressure in response to the outputs of the calculation means and the pressure deviation generator. In response to the output of the pressure transmitter and the adder that adds the pressure represented by the first target value and the value represented by the pressure deviation signal and outputs the second target value of the pressure representing that pressure, The second flow rate adjusting means is controlled so that the detected pressure becomes the second target value. A gas turbine control device characterized by comprising a second control means. Further, according to the present invention, a fuel gas compressor that compresses fuel gas and supplies it to a combustor of a gas turbine, and a part of the fuel gas discharged from the fuel gas compressor is branched and returned to the inlet of the fuel gas compressor. A fuel return line, a first flow rate adjusting means for controlling the flow rate of the fuel gas at the inlet of the fuel gas compressor, and a flow rate of the fuel gas returned to the inlet of the fuel gas compressor by the fuel return line, A second flow rate adjusting means 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 the gas turbine from a pressure at an outlet of the fuel gas compressor, and a combustion of the gas turbine. A signal generator that generates a fuel gas command signal that commands the flow rate of the fuel gas supplied to the container,
Arithmetic means for responding to the fuel gas command signal and for computing a first target value of the differential pressure obtained by subtracting the gas pressure in the combustor from the pressure at the outlet of the fuel gas compressor corresponding to the flow rate represented by the fuel gas command signal. Responding to the outputs of the differential pressure transmitter and the computing means, the first control 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 that outputs a deviation signal and a first differential pressure
An adder that responds to the target value and the pressure deviation signal, adds the differential pressure represented by the first target value and the value represented by the pressure deviation signal, and outputs a second target value of the differential pressure, and a differential pressure transmitter. In response to the output of the adder and the second adder so that the detected differential pressure becomes the second target value.
It is a gas turbine control device characterized by including the 2nd control means which controls a flow control means. The present invention also provides
A fuel gas compressor that compresses the fuel gas and supplies it to the combustor of the gas turbine; and a fuel return line that branches a portion of the fuel gas discharged from the fuel gas compressor and returns it to the inlet of the fuel gas compressor. A first flow rate adjusting means for controlling the flow rate of the fuel gas at the inlet of the fuel gas compressor, and a flow rate of the fuel gas returned to the inlet of the fuel gas compressor by the fuel recirculation conduit, so that the fuel gas can be fully closed. The second flow rate adjusting means, 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 fuel gas compressor, and the combustor of the gas turbine are supplied. A signal generator that generates a fuel gas command signal that commands the flow rate of the fuel gas; and a combustor that responds to the fuel gas command signal and that corresponds to the flow rate represented by the fuel gas command signal from the outlet pressure of the fuel gas compressor. Subtract gas pressure in The first flow rate adjusting means is controlled so that the detected differential pressure becomes the first target value in response to the output of the differential pressure transmitter and the calculating means for calculating the first target value of the differential pressure. In response to an output of the first control means, a detector that detects the opening degree of the first flow rate adjusting means, and the detector,
When the flow rate of the fuel gas to the fuel gas compressor according to the detection opening is equal to or higher than the predetermined minimum flow rate of the fuel gas compressor, a pressure deviation signal representing a positive value corresponding to the output of the detector is output,
A pressure deviation generator that outputs a pressure deviation signal representing zero when the flow rate of the fuel gas to the fuel gas compressor according to the detected opening is less than the minimum flow rate; and the differential pressure calculation means and the pressure deviation generator. In response to the output, an adder that adds the differential pressure represented by the first target value of the differential pressure and the value represented by the pressure deviation signal, and outputs the second target value of the differential pressure that represents the differential pressure, and the differential pressure transmission And a second control means for controlling the second flow rate adjusting means so that the detected differential pressure becomes the second target value in response to the outputs of the adder and the adder. Is. Further, according to the present invention, a fuel gas compressor that compresses fuel gas and supplies it to a combustor of a gas turbine, and a part of the fuel gas discharged from the fuel gas compressor is branched and returned to the inlet of the fuel gas compressor. A fuel return line, a first flow rate adjusting means for controlling the flow rate of the fuel gas at the inlet of the fuel gas compressor, and a flow rate of the fuel gas returned to the inlet of the fuel gas compressor by the fuel return line, A second flow rate adjusting means capable of being fully closed; a differential pressure transmitter for detecting 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; A signal generator that generates a fuel gas command signal that commands the flow rate of the fuel gas supplied to the combustor, and an outlet of the fuel gas compressor that responds to the fuel gas command signal and that corresponds to the flow rate represented by the fuel gas command signal. Pressure from the air pressure In response to the output of the calculation means for calculating the target value of the differential pressure obtained by subtracting the pressure at the outlet of the machine and the differential pressure transmitter and the calculation means, the combustor is controlled so that the detected differential pressure becomes the target value. Control means for outputting a control signal representing the flow rate of the supplied fuel gas, and in response to this control signal, when the flow rate represented by the control signal is less than a predetermined minimum flow rate of the fuel gas compressor, it represents the minimum flow rate. A first flow rate setting value is output, a first flow rate setting value corresponding to the control signal is output when the flow rate represented by the control signal is equal to or more than the minimum flow rate, and the output signal is given to the first flow rate adjusting means. In response to the function generator and the control signal, when the flow rate represented by the control signal is less than or equal to the minimum flow rate, the flow rate represented by the control signal is subtracted from the minimum flow rate, and the second flow rate set value representing the subtracted flow rate is output. However, the flow rate represented by the control signal is maximum. A second function generator that outputs a second flow rate set value for fully closing the second flow rate adjusting means when the flow rate is exceeded, and gives the second flow rate setting value thus output to the second flow rate adjusting means. It is a gas turbine control device characterized in that. Further, according to the present invention, a fuel gas compressor that compresses fuel gas and supplies it to a combustor of a gas turbine, and a part of the fuel gas discharged from the fuel gas compressor is branched and returned to the inlet of the fuel gas compressor. A fuel recirculation line, a first flow rate adjusting means for controlling the flow rate of the fuel gas at the inlet of the fuel gas compressor, and a flow rate of the fuel gas returned to the inlet of the fuel gas compressor by the fuel recirculation line, A second flow rate adjusting means capable of being fully closed; a differential pressure transmitter for detecting 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; A signal generator that generates a fuel gas command signal that commands the flow rate of the fuel gas supplied to the combustor, and an outlet of the fuel gas compressor that responds to the fuel gas command signal and that corresponds to the flow rate represented by the fuel gas command signal. Pressure from the air pressure So that the detected differential pressure becomes the first target value in response to the output of the differential pressure transmitter and the calculation means for calculating the first target value of the differential pressure obtained by subtracting the pressure at the outlet of the machine. A first control means for controlling the first flow rate adjusting means, a pressure deviation setter for outputting a pressure deviation signal representing a predetermined value, a first target value of the differential pressure and a pressure deviation signal, and a first target In response to the output of the differential pressure transmitter and the adder that adds the differential pressure represented by the value and the value represented by the pressure deviation signal, and outputs the second target value of the differential pressure,
A gas turbine control device comprising: a second control unit that controls a second flow rate adjusting unit so that the detected differential pressure becomes the second target value. Further, according to the present invention, a fuel gas compressor that compresses fuel gas and supplies it to a combustor of a gas turbine, and a part of the fuel gas discharged from the fuel gas compressor is branched and returned to the inlet of the fuel gas compressor. A fuel return line, a first flow rate adjusting means for controlling the flow rate of the fuel gas at the inlet of the fuel gas compressor, and a flow rate of the fuel gas returned to the inlet of the fuel gas compressor by the fuel return line, A second flow rate adjusting means capable of being fully closed; a differential pressure transmitter for detecting 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; A signal generator that generates a fuel gas command signal that commands the flow rate of the fuel gas supplied to the combustor, and an outlet of the fuel gas compressor that responds to the fuel gas command signal and that corresponds to the flow rate represented by the fuel gas command signal. Pressure from the air pressure So that the detected differential pressure becomes the first target value in response to the output of the differential pressure transmitter and the calculation means for calculating the first target value of the differential pressure obtained by subtracting the pressure at the outlet of the machine. A first control means for controlling the first flow rate adjusting means, a detector for detecting the opening of the first flow rate adjusting means, and a fuel gas compressor according to the detected opening in response to the output of the detector. When the flow rate of the fuel gas is equal to or higher than a predetermined minimum flow rate of the fuel gas compressor, a pressure deviation signal representing a positive value corresponding to the output of the detector is output, and the fuel gas to the fuel gas compressor according to the detection opening is output. Of the first target value of the differential pressure in response to the output of the pressure deviation generator that outputs a pressure deviation signal representing zero when the flow rate of the pressure difference is less than the minimum flow rate, and the output of the differential pressure calculation means and the pressure deviation generator. The second target of the differential pressure representing the differential pressure is obtained by adding the differential pressure represented and the value represented by the pressure deviation signal. And second control means for controlling the second flow rate adjusting means in response to the outputs of the differential pressure transmitter and the adder so that the detected differential pressure becomes the second target value. It is a gas turbine control device characterized by including.

[0020]

According to the present invention, the flow rate of the fuel gas introduced into the fuel gas compressor for compressing the fuel gas is controlled by the first flow rate adjusting means, and a part of the gas discharged from the fuel gas compressor is recirculated to the fuel. It is returned to the inlet of the fuel gas compressor by a pipe, and its flow rate is controlled by the second flow rate adjusting means. The fuel gas command signal output from the signal generator is the first
The first function generator supplies the first flow rate setting value corresponding to the fuel gas command signal to the first flow rate adjusting means, and the second function generator supplies the fuel gas. The second flow rate setting value corresponding to the command signal is given to the second flow rate adjusting means. Thereby, 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 the fuel gas command signal output from the signal generator,
The recirculated flow rate of the gas discharged from the fuel gas compressor in response to the fuel gas command signal is controlled by the second flow rate adjusting means. Therefore, the fuel gas of the 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.

According to the invention, the flow rate of the fuel gas introduced into the fuel gas compressor for compressing the fuel gas is controlled by the first flow rate adjusting means, and a part of the gas discharged from the fuel gas compressor is fuel. It is returned to the inlet of the fuel gas compressor by the reflux pipe, 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 output pressure of the fuel gas compressor is output by the differential pressure transmitter, and the fuel gas compression corresponding to the flow rate indicated by the fuel gas command signal output from the signal generator. The target value of the differential pressure between the outlet pressure of the machine and the gas pressure in the combustor is calculated by the differential pressure calculating means, and the control signal representing the fuel gas flow rate by which the detected differential pressure becomes the target value is set by the control means. This control signal is output and provided to the first and second function generators, and the first function generator outputs the first flow rate set value corresponding to the control signal as the first flow rate setting value.
The second function generator supplies the second flow rate setting value corresponding to the control signal to the second flow rate adjusting means. Thus, the supply flow rate of the fuel gas supplied to the fuel gas compressor is controlled by the first flow rate adjusting means in response to the control signal output from the control means, and the fuel gas is discharged from the fuel gas compressor in response to the control signal. The recirculated flow rate of the generated gas is controlled by the second flow rate adjusting means. Therefore, regardless of the minimum flow rate of the fuel gas compressor, the fuel gas of the stepless fuel gas supply flow rate is supplied to the combustor of the gas turbine, and with respect to the gas turbine provided with the large-sized fuel gas compressor, It is possible to stabilize and control the pressure at the outlet of the fuel gas compressor.

Further, according to the invention, the flow rate of the fuel gas introduced into the fuel gas compressor for compressing the fuel gas is controlled by the first flow rate adjusting means, and a part of the gas discharged from the fuel gas compressor is fuel. It is returned to the inlet of the fuel gas compressor by the reflux pipe, and its flow rate is controlled by the second flow rate adjusting means. The pressure transmitter detects the pressure at the outlet of the fuel gas compressor, and the calculation means determines the first target value of the pressure at the outlet of the fuel gas compressor corresponding to the flow rate represented by the fuel gas command signal output from the signal generator. A control signal, which is output and represents the flow rate of the fuel gas such that the detected pressure becomes the target value, is output by the control means, and the control signal is given to the first and second function transmitters, and the first function generator. Gives the first flow rate setting value corresponding to the control signal to the first flow rate adjusting means, and the second function generator gives the 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 fuel gas compressor is controlled by the first flow rate adjusting means in response to the control signal output from the control means, and is discharged from the fuel gas compressor in response to the control signal. The flow rate of the recirculated gas is controlled by the second flow rate adjusting means. Therefore, regardless of the minimum flow rate of the fuel gas compressor, the fuel gas of the stepless fuel gas supply flow rate is supplied to the combustor of the gas turbine, and the fuel gas is supplied to the gas turbine equipped with a large fuel gas compressor. The pressure at the outlet of the gas compressor can be stabilized and controlled.

Further, according to the invention, the flow rate of the fuel gas guided to the fuel gas compressor for compressing the fuel gas is controlled by the first flow rate adjusting means, and a part of the gas discharged from the fuel gas compressor is fuel. It is returned to the inlet of the fuel gas compressor by the reflux pipe, and its flow rate is controlled by the second flow rate adjusting means. The pressure of the fuel gas is detected by the pressure transmitter, and the first pressure of the outlet of the fuel gas compressor corresponding to the flow rate represented by the fuel gas command signal output from the signal generator is detected.
The target value is output by the calculating means, the first flow rate adjusting means is controlled by the first control means so that the detected pressure becomes the target value, and a pressure deviation signal representing a predetermined value is output from the pressure deviation set value device. Then, the pressure represented by the first target value and the value represented by the pressure deviation signal are added, and the second target value of the pressure is output by the adder, and the second control is performed so that the detected pressure becomes the target value. The second flow rate adjusting means is controlled by the means. As a result, the flow rate adjusting means is controlled by the control means, the supply flow rate of the fuel gas supplied to the fuel gas compressor is controlled by the first flow rate adjusting means, and the gas discharged from the fuel gas compressor is recirculated. The flow rate to be controlled is controlled by the second flow rate adjusting means. Therefore, regardless of the minimum flow rate of the fuel gas compressor, the fuel gas of the stepless fuel gas supply flow rate is supplied to the combustor of the gas turbine, and with respect to the gas turbine provided with the large-sized fuel gas compressor, It is possible to stabilize and control the pressure at the outlet of the fuel gas compressor.

Further, according to the invention, the flow rate of the fuel gas introduced into the fuel gas compressor for compressing the fuel gas is controlled by the first flow rate adjusting means, and a part of the gas discharged from the fuel gas compressor is fuel. It is returned to the inlet of the fuel gas compressor by the reflux pipe, and its flow rate is controlled by the second flow rate adjusting means. 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 corresponding to the flow rate represented by the fuel gas command signal output from the signal generator is the pressure calculation means. Is output by the first control means so that the detected pressure becomes the first target value, the opening of the first flow rate adjusting means is detected by the detector, and the output of the detector In response to, the pressure deviation signal is output by the pressure deviation generator, the pressure represented by the first target value and the value represented by the pressure deviation signal are added by the adder, and the second target value of pressure is output.
The second flow rate adjusting means is controlled by the second pressure control means so that the detected pressure becomes the second target value. As a result, the flow rate adjusting means is controlled by the control means, the supply flow rate of the fuel gas supplied to the fuel gas compressor is controlled by the first flow rate adjusting means, and the gas discharged from the fuel gas compressor is recirculated. The flow rate to be controlled is controlled by the second flow rate adjusting means. Therefore, regardless of the minimum flow rate of the fuel gas compressor, the fuel gas of the stepless fuel gas supply flow rate is supplied to the combustor of the gas turbine, and with respect to the gas turbine provided with the large-sized fuel gas compressor, It is possible to stabilize and control the pressure at the outlet of the fuel gas compressor.

Further, according to the present invention, the flow rate of the fuel gas introduced into the fuel gas compressor for compressing the fuel gas is controlled by the first flow rate adjusting means, and a part of the gas discharged from the fuel gas compressor is fuel. It is returned to the inlet of the fuel gas compressor by the reflux pipe, 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 outlet pressure of the fuel gas compressor is detected by the differential pressure transmitter, and the fuel gas corresponding to the flow rate indicated by the fuel gas command signal output from the signal generator is output. A 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 computing means, and the first control means sets the detected differential pressure to the first target value. The first flow rate adjusting means is controlled, the pressure deviation setting unit outputs a pressure deviation signal representing a predetermined value, 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. The second target value of the differential pressure is added and output, and the second flow rate adjusting means is controlled by the second control means so that the detected differential pressure becomes the second target value. As a result, the flow rate adjusting means is controlled by the control means, the supply flow rate of the fuel gas supplied to the fuel gas compressor is controlled by the first flow rate adjusting means, and the escape flow rate of the discharge gas from the fuel gas compressor is controlled. It is controlled by the second flow rate adjusting means. Therefore, regardless of the minimum flow rate of the fuel gas compressor, the fuel gas of the stepless fuel gas supply flow rate is supplied to the combustor of the gas turbine, and with respect to the gas turbine provided with the large-sized fuel gas compressor, It is possible to stabilize and control the pressure at the outlet of the fuel gas compressor.

Further, according to the invention, the flow rate of the fuel gas guided to the fuel gas compressor for compressing the fuel gas is controlled by the first flow rate adjusting means, and a part of the gas discharged from the fuel gas compressor is fuel. It is returned to the inlet of the fuel gas compressor by the reflux pipe, 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 outlet pressure of the fuel gas compressor is detected by the differential pressure transmitter, and the fuel gas corresponding to the flow rate indicated by the fuel gas command signal output from the signal generator is output. The 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 calculation means, and the first flow rate is controlled by the first control means so that the detected differential pressure becomes the first target value. The adjusting means is controlled, a detector detects how the first flow adjusting means is controlled, and in response to the output of the detector, a pressure deviation signal is output by the pressure deviation generator, and the difference The differential pressure represented by the target value of the pressure and the value represented by the pressure deviation signal are added by the adder to output the second target value of the differential pressure,
The second control means controls the second flow rate adjusting valve so that the detected differential pressure becomes the second target value. As a result, the flow rate adjusting means is controlled by the control means, the supply flow rate of the fuel gas supplied to the fuel gas compressor is controlled by the first flow rate adjusting means, and the escape flow rate of the discharge gas from the fuel gas compressor is controlled. It is controlled by the first flow rate adjusting means. Therefore, regardless of the minimum flow rate of the fuel gas compressor, the fuel gas of the stepless fuel gas supply flow rate is supplied to the combustor of the gas turbine, and with respect to the gas turbine provided with the large-sized fuel gas compressor, It is possible to stabilize and control the pressure at the outlet of the fuel gas compressor.

Further, according to the present invention, the flow rate of the fuel gas introduced into the fuel gas compressor for compressing the fuel gas is controlled by the first flow rate adjusting means, and a part of the gas discharged from the fuel gas compressor is fuel. It is returned to the inlet of the fuel gas compressor by the reflux pipe, 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 output pressure of the fuel gas compressor is output by the differential pressure transmitter, and the flow rate represented by the fuel gas command signal output from the signal generator. The target value of the differential pressure between the outlet pressure of the fuel gas compressor and the outlet pressure of the air compressor provided in the gas turbine is calculated by the differential pressure calculating means, and the detected differential pressure is calculated by the differential pressure control means. Is output by the control means, and the control signal is output to the first and second function generators, and the first function generator corresponds to the control signal. The first flow rate setting value is given to the first flow rate adjusting means, and the second function generator is given the second flow rate setting value corresponding to the control signal to the second flow rate adjusting means. by this,
The supply flow rate of the fuel gas 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 the gas discharged from the fuel gas compressor in response to the control signal. The recirculated flow rate of is controlled by the second flow rate adjusting means. Therefore, regardless of the minimum flow rate of the fuel gas compressor, the fuel gas of the stepless fuel gas supply flow rate is supplied to the combustor of the gas turbine, and to the gas turbine equipped with a large-sized fuel gas compressor,
It is possible to stabilize and control the pressure at the outlet of the fuel gas compressor.

Further, according to the invention, the flow rate of the fuel gas introduced into the fuel gas compressor for compressing the fuel gas is controlled by the first flow rate adjusting means, and a part of the gas discharged from the fuel gas compressor is fuel. It is returned to the inlet of the fuel gas compressor by the reflux pipe, 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 installed in the gas turbine from the pressure at the outlet of the fuel gas compressor is detected by the differential pressure transmitter, and the flow rate represented by the fuel gas 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 fuel gas compressor is output by the calculating means, and the detected differential pressure is the first differential pressure. The first flow rate adjusting means is controlled by the first control means to reach the target value, and a pressure deviation signal representing a predetermined value is output from the pressure deviation setter to obtain the differential pressure represented by the first target value of the differential pressure. The value represented by the pressure deviation signal is added by the adder to output the 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 control means controls each flow rate adjusting means, the supply flow rate of the fuel gas supplied to the fuel gas compressor is controlled by the first flow rate adjusting means, and the escape flow rate of the discharge gas from the fuel gas compressor is controlled. Second
It is controlled by the flow rate adjusting means. Therefore, regardless of the minimum flow rate of the fuel gas compressor, the fuel gas of the stepless fuel gas supply flow rate is supplied to the combustor of the gas turbine,
Further, for a gas turbine equipped with a large-sized fuel gas compressor, the pressure at the outlet of the fuel gas compressor can be controlled stably.

Further, according to the invention, the flow rate of the fuel gas guided to the fuel gas compressor for compressing the fuel gas is controlled by the first flow rate adjusting means, and a part of the gas discharged from the fuel gas compressor is fuel. It is returned to the inlet of the fuel gas compressor by the reflux pipe, 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 installed in the gas turbine from the pressure at the outlet of the fuel gas compressor is detected by the differential pressure transmitter, and the flow rate represented by the fuel gas 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 fuel gas compressor is output by the calculating means, and the detected differential pressure is the first target value. The first control means controls the first flow rate adjusting means so that the opening degree of the first flow rate adjusting means is detected by the detector, and the pressure deviation signal generates the pressure deviation in response to the output of the detector. Output by the adder, the differential pressure represented by the target value of the differential pressure and the value represented by the pressure deviation signal are added by an adder to output a second target value of the differential pressure, and the detected differential pressure is the second target. Second control so that the value becomes The second flow rate control valve is controlled by the stage. As a result, the flow rate adjusting means is controlled by the control means, the supply flow rate of the fuel gas supplied to the fuel gas compressor is controlled by the first flow rate adjusting means, and the escape flow rate of the discharge gas from the fuel gas compressor is controlled. It is controlled by the first flow rate adjusting means. Therefore, regardless of the minimum flow rate of the fuel gas compressor, the fuel gas of the stepless fuel gas supply flow rate is supplied to the combustor of the gas turbine, and with respect to the gas turbine provided with the large-sized fuel gas compressor, It is possible to stabilize and control the pressure at the outlet of the fuel gas compressor.

[0030]

1 is a system diagram showing a partial configuration of a cogeneration facility 60 including a gas turbine controller 120 according to an embodiment of the present invention.

The gas turbine controller 120 of this embodiment
Are a rotation speed / load control circuit 10a and a gas temperature control circuit 10 which respectively output signals instructing the flow rate of the fuel gas.
b and start control circuit 10c, and these control circuits 10
Low-level signal selector 1 for selecting a signal instructing the smallest flow rate of fuel gas from the signals output from a to 10c
And a 0d, a signal generator 50 for outputting a fuel gas control signal X _f is a fuel gas command signal, in response to the fuel gas control signal X _f, the first flow rate regulation is the first flow rate regulation means described later The valve 6 has a first opening command signal X, which is the first flow rate setting value.
_a first function generator 11 for providing _c and a fuel gas control signal X
_In response to _f , the second flow rate adjusting valve 7, which is the second flow rate adjusting means described later, sends the second opening degree command signal X _v, which is the second flow rate setting value.
And a gas turbine control circuit 10 including a second function generator 12 for

The rotation speed / load control circuit 10a outputs a signal for instructing the flow rate of the fuel gas for keeping the rotation shaft 1 described below at a predetermined rotation speed and keeping the output of the generator 4 described below constant. In the gas temperature control circuit 10b, the temperature of the working gas at either or both of the inlet and the outlet of the turbine 3c, which will be described later, has a constant value (1300 in this embodiment).
(° C) or higher), and outputs a signal instructing the flow rate of the fuel gas so that the temperature does not exceed 10 ° C.).
Signals are supplied to these control circuits 10a to 10c from various detectors (not shown). Such a control circuit 1
When the signal generator 50 having 0a to 10c and the low-order signal selector 10d maintains the predetermined output of the generator 4 and the temperature of the working gas rises to a temperature that hinders the operation of the gas turbine 3, The flow rate can be limited, and the gas turbine 3 can be controlled so as to have a function to smoothly start up even at the time of startup.

The gas turbine control unit 120 also branches the fuel gas compressor 2 for compressing the fuel gas and supplying it to the combustor 3b of the gas turbine 3 and a part of the fuel gas discharged from the fuel gas compressor 2. The fuel recirculation line 113 for returning to the inlet of the fuel gas compressor 2, the first flow rate adjusting valve 6 as the first flow rate adjusting means for controlling the flow rate of the fuel gas at the inlet of the fuel gas compressor 2, and the fuel recirculation. The flow rate of the fuel gas returned to the inlet of the fuel gas compressor 2 is controlled by the pipe 113,
It includes a second flow rate adjusting valve 7 as a second flow rate adjusting means capable of being fully closed.

The gas turbine control device 120 is provided in a cogeneration facility 60 using the gas turbine 3 that uses blast furnace gas as fuel. A fuel gas compressor 2, a gas turbine 3, and a generator 4 are connected to a common rotary shaft 1 of the cogeneration facility 60.
A boiler (not shown) for generating steam by the heat of the exhaust gas of the gas turbine 3 is provided on the downstream side in the gas flow direction of the gas turbine 3. The gas turbine 3 includes an air compressor 3a, a combustor 3b, and a turbine 3c. When the blast furnace gas is used as the fuel for the gas turbine 3, the fuel gas compressor 2 is used because it is necessary to compress the blast furnace gas. The fuel gas compressor 2 has a predetermined minimum flow rate, for example, a minimum flow rate at which the fuel gas compressor 2 does not cause an abnormality such as breakage. A circulation loop 80 is required to supply the fuel gas having a flow rate less than or equal to the minimum flow rate to the combustor 3b of the gas turbine 3, and the first fuel supply pipeline 111 for supplying the fuel gas to the fuel gas compressor 2 is provided. Fuel gas compressor 2 to gas turbine 3
Second fuel supply line 1 for supplying fuel gas to the combustor 3b of
12, a fuel recirculation conduit 113 branched from the second fuel supply conduit and connected to the first fuel supply conduit 111 to recirculate the fuel gas to the inlet of the fuel gas compressor 2, and a first fuel supply conduit A first flow rate adjusting valve 6 as a first flow rate adjusting means interposed in 111, a second flow rate adjusting valve 7 as a second flow rate adjusting means interposed in the fuel return conduit 113, and a gas cooler 8 are provided. To be A portion of the first fuel supply line 111 on the downstream side in the fuel gas supply direction from the connection point where the fuel return line 113 of the first fuel supply line 111 is connected, and a fuel return line of the second fuel supply line 112. The pipe 113 includes a portion upstream of the branch point where the pipe 113 is branched in the fuel gas supply direction, the fuel return pipe 113, the first and second flow rate adjusting valves 6 and 7, and the gas cooler 8 for circulation. A loop 80 is constructed.

The fuel gas supplied from the blast furnace at atmospheric pressure is supplied to the fuel gas compressor 2 and compressed by the first fuel supply line 111. The flow rate of the fuel gas supplied to the fuel gas compressor is controlled by the first flow rate adjusting valve 6. The fuel gas compressed by the fuel gas compressor 2 is introduced into the combustor 3b via the second fuel supply pipe line 112, where it is mixed with the air compressed by the air compressor 3a and burned. The fuel gas is blast furnace gas containing carbon monoxide gas. The high-temperature gas after the combustion of the fuel gas is expanded by the turbine 3c, drives the generator 4 to generate power, and is reduced in pressure before being guided to the boiler. The steam generated in the boiler is supplied to various uses inside the factory such as a steam turbine.

On the other hand, for the surplus which is a part of the fuel gas compressed by the fuel gas compressor 2, the second flow rate adjusting valve 7
Through the fuel recirculation pipe line 113 to the first fuel supply pipe line 111 and is recirculated to the inlet of the fuel gas compressor 2. At this time, since the fuel gas compressed by the fuel gas compressor 2 has a high temperature, it is cooled by the gas cooler 8.
With this, it is possible to prevent the fuel gas from becoming undesirably high in temperature while repeating the recirculation. The second flow rate adjusting valve 7 can be fully closed.

Others of Cogeneration Facility 60 Cogeneration facility 60e described in FIG.
The same reference numerals are given to portions having the same configuration as, and description thereof will be omitted.

In FIG. 1, the fuel gas control signal X _f output from the low-order signal selector 10d of the signal generator 50 is
It is a signal representing the flow rate of fuel gas required to operate the gas turbine at a predetermined output, and is given to the first function generator 11 and the second function generator 12.

FIG. 2 is a diagram showing the control function of the first function generator 11 provided in the gas turbine control system 120 of this embodiment. The horizontal axis represents the flow rate of the fuel gas represented by the signal (fuel gas control signal X _f in this embodiment) input to the first function generator 11, and the vertical axis represents the output from the first function generator 11. The valve opening of the first flow rate adjusting means 6 represented by the signal (first opening command signal _Xc in this embodiment) is shown.

The first function generator 11 performs the operation represented by the following equation (1) according to the fuel gas control signal X _f .

[0041]

[Equation 1]

Here, X _c is a first opening command signal which commands the valve opening of the first flow rate adjusting valve 6, a _min is a signal which commands the valve opening corresponding to the minimum flow rate, and a _min (X _f ) is a signal for commanding the valve opening corresponding to the fuel gas flow rate specified by the fuel gas control signal X _f , and both are determined by the characteristics of the fuel gas compressor 2. X _min is a signal that commands a valve opening corresponding to the minimum flow rate of the fuel gas compressor 2. The minimum flow rate X _min is about 50% of the maximum flow rate.

Based on equation (1), the fuel gas control signal X
_When the flow rate represented by _f is less than the minimum flow rate X _min of the fuel gas compressor 2 for preventing the destruction of the fuel gas compressor 2 as described above, for example, the first flow rate adjustment corresponding to the minimum flow rate X _min. When the first opening command signal _Xc (= a _min ) indicating the valve opening of the valve 6 is output and the flow rate represented by the fuel gas control signal X _f is _{equal to} or more than the minimum flow rate X _min , the fuel gas control signal X The first that represents the valve opening corresponding to the flow rate that _f represents
An opening command signal _Xc (= a ( _Xf )) is output.

FIG. 3 is a diagram showing the control function of the second function generator 12 provided in the gas turbine controller 120 of this embodiment. The horizontal axis represents the fuel gas flow rate represented by the signal (fuel gas control signal X _f in this embodiment) input to the second function generator 12, and the vertical axis represents the signal output from this function (this embodiment). In the example, the valve opening of the second flow rate adjusting means 7 represented by the second opening command signal X _v ) is shown.

The second function generator 12 performs the calculation represented by the following equation (2) according to the fuel gas control signal X _f .

[0046]

[Equation 2]

Here, X _v is the second flow rate to the second flow rate adjusting valve 7.
The opening command signal, θ _min is a signal corresponding to full closing, θ _min
(X _min −X _f ) is a signal that commands a valve opening corresponding to the flow rate X _min −X _f , and is a value defined by the characteristics of the second flow rate adjusting valve 7.

Based on equation (2), the fuel gas control signal X _f
When the flow rate represented by is less than the minimum flow rate X _min ,
Second indicating a valve opening degree corresponding to the flow rate X _min -X _f obtained by subtracting the flow rate representing the said minimum flow rate X _min of the fuel gas control signal X _f
When the opening command signal X _v (= θ (X _min −X _f )) is output and the flow rate represented by the fuel gas control signal X _f exceeds the minimum flow rate X _min , the second flow rate adjusting valve 7 is fully closed. Output a second opening command signal X _v (= θ _min ).

Referring again to FIG. 1, by using the two function generators 11 and 12 set in this way, the fuel gas control signal X representing the flow rate of the fuel gas compressor 2 which is less than the minimum flow rate is obtained. _{At f} , the flow rate adjusting means 6 is controlled so as to supply the fuel gas compressor 2 with a flow rate corresponding to the minimum flow rate X _min . When the flow rate represented by the fuel gas control signal _Xf is less than or equal to the minimum flow rate, the second flow rate adjusting valve 7 causes the fuel recirculation conduit to recirculate the flow rate obtained by subtracting the flow rate represented by the fuel gas control signal _Xf from the minimum flow rate. Controlled as. Therefore, the fuel gas having the flow rate represented by the minimum flow rate X _min is supplied to the fuel gas compressor 2 and the fuel gas compressor 2
The fuel gas having a flow rate represented by X _min −X _f is guided to the first fuel supply pipe line 111 by the fuel recirculation pipe line 113 in which the second flow rate adjusting valve 7 is interposed and is introduced to the inlet of the fuel gas compressor 2. Since it is recirculated, the fuel gas flow rate represented by the difference X _f is supplied to the combustor 3 b of the gas turbine 3.

Furthermore, when the flow rate represented by the fuel gas control signal X _f exceeds the minimum flow rate of the fuel gas compressor 2, the second flow rate adjusting valve 7 is fully closed, so that the fuel controlled by the first flow rate adjusting valve 6 is controlled. The flow rate of the fuel gas represented by the gas control signal _Xf is supplied to the combustor 3b of the gas turbine 3.

By controlling the first flow rate adjusting valve 6 and the second flow rate adjusting valve 7 in this way, a fuel gas compressor is used for a gas turbine that uses a low-pressure gas with a low heating value such as blast furnace gas as a fuel. The flow rate of the fuel gas can be continuously adjusted and controlled so that the fuel gas flow rate of 2 or less can be supplied. Therefore, regardless of the minimum flow rate of the fuel gas compressor 2, the gas turbine 3
Can be controlled in a stable state, and the power generation output can be made constant.

FIG. 4 shows a cogeneration system 6 including a gas turbine controller 121 according to another embodiment of the present invention.
It is a systematic diagram which shows the structure of a part of 0a. The gas turbine control device 121 of the present embodiment uses the fuel gas control signal X _f output from the low-level signal selector 10 d of the signal generator 50 and the characteristics of the gas turbine 3 as the pressure at the outlet of the fuel gas compressor. Fuel gas flow rate-differential pressure converter 21 which is a calculating means for calculating a target value ΔP of the differential pressure obtained by subtracting the gas pressure in the combustor 3b of the gas turbine from the pressure of the fuel gas in the second fuel supply pipeline 112. And the target value ΔP of the differential pressure
Of the fuel gas supplied to the combustor 3b so that the detected differential pressure represented by the differential pressure signal A becomes the target value. A gas turbine control circuit 10e including a differential pressure control means 23 that outputs a control signal indicating a flow rate is provided.
Further, the control means 23 is provided with the differential pressure transmitter 22 for detecting a differential pressure obtained by subtracting the gas pressure in the combustor 3b from the pressure of the fuel gas in the second fuel supply line 112. The other parts having the same configuration are denoted by the same reference numerals, and the description thereof will be omitted.

FIG. 5 is a diagram showing a simplified structure of the vicinity of the combustor 3b of this embodiment. The combustor 3b has a combustion tube 3b1 in which fuel is combusted. The fuel gas is the nozzle 3b
2 is injected into the combustion cylinder 3 from the annular space 3b3 around the combustion cylinder 3b1 and is introduced into the combustion cylinder 3b1 through a plurality of through holes 3b4 formed in the combustion cylinder 3b1. The fuel gas is burned in the combustion cylinder 3b1, and the burned gas is guided to the turbine 3c.

The differential pressure transmitter 22 is the fuel gas compressor 2
Pressure P _f in the second fuel supply conduit 112 that guides the fuel gas from the fuel gas to the combustor 3b of the gas turbine 3 and the gas pressure P _c in the space where the fuel of the combustor 3b is burned, that is, the combustion cylinder 3b1. detecting the door, Searching for the differential pressure P _f -P _c, and outputs it to the differential pressure control means 23.

Here, the following equation is established between the pressure P _f of the fuel gas in the second fuel supply conduit 112 and the pressure P _c in the combustion tube 3b1 of the combustor 3b.

P _f −P _c > 0 (3) FIG. 6 is a diagram showing a control function of the fuel gas flow rate-differential pressure converter 21 provided in the gas turbine control device 121 of the present embodiment. The horizontal axis represents the fuel gas flow rate-differential pressure converter 21.
Shows the flow rate of the fuel gas represented by the signal (fuel gas control signal X _f in this embodiment) input to the ordinate, and the vertical axis represents the signal output from this function (the target value Δ of the differential pressure in this embodiment).
The target value of the differential pressure obtained by subtracting the gas pressure of the combustor 3b of the gas turbine from the pressure of the fuel gas in the second fuel supply line 112 represented by the signal (P) is shown.

The fuel gas flow rate-differential pressure converter 21 uses the fuel gas command signal _Xf output from the low-level signal selector 10d of the signal generator to determine the fuel gas pressure in the second fuel supply line 112 in the following procedure. A target value ΔP of the differential pressure between P _f and the pressure P _c in the combustor 3b is calculated. The flow rate G _f of the fuel gas supplied to the gas turbine 3 is generally the second fuel supply line 112.
It is well known that it depends on the pressure P _f of the fuel gas inside and the pressure P _c inside the combustor 3b. Relationship between the fuel gas flow rate G _f and the differential pressure P _f -P _c is given by the following equation (4).

G _f = C · √ (P _f −P _c ) ... (4) Here, the coefficient C is a constant determined by the gas turbine. According to this relational expression, when the differential pressure for making the fuel gas flow rate a value corresponding to the fuel gas control signal X _f is calculated,
It looks like this:

[0059]

(Equation 3)

Based on equation (5), the fuel gas control signal X
Second fuel supply line 1 corresponding to the flow rate of fuel gas represented by _f
Combustor 3b of gas turbine from fuel gas pressure in 12
The target value of the differential pressure is calculated by subtracting the internal gas pressure from the internal pressure, and a signal representing the target value is output.

Referring again to FIG. 4, in the differential pressure control means 23, the differential pressure target value ΔP given by the equation (5) and the differential pressure signal A output from the differential pressure transmitter 22 are expressed. 2 Compare the detected differential pressure P _f −P _c obtained by subtracting the gas pressure P _c in the combustor 3b from the fuel gas pressure P _{f in} the fuel supply line 112,
Control operations such as proportionality, integration, and differentiation are performed, and the control signal B is given to the first function generator 11 and the second function generator 12. In this control calculation, when the detected differential pressure P _f −P _c is less than the target value ΔP, as the control signal B to be output,
When the flow rate of the fuel gas supplied to the gas turbine 3 is increased by giving an instruction to increase the flow rate than the flow rate represented by the fuel gas control signal X _f , and conversely the detected differential pressure exceeds the target value, the control signal B is used. , Reduce the flow rate of the fuel gas supplied to the gas turbine 3. Although the control signal B is input instead of the fuel gas control signal X _f , the first function generator 1
1, second function generator 12, first flow rate adjusting valve 6 and second
The function of the flow rate adjusting valve 7 is the same as that of the embodiment shown in FIG.

The differential pressure control means 23 is, for example, proportional-
It is realized by an integration-differentiation circuit (abbreviated as PID circuit). Such a gas turbine control device 121 of this embodiment
Can obtain the same effect as the gas turbine control device 120 of the embodiment shown in FIG. In addition, the second
The differential pressure obtained by subtracting the gas pressure P _c in the combustor 3b from the pressure P _f of the fuel gas in the fuel supply line 112 is detected and compared with the target value ΔP of the differential pressure to perform a calculation and By controlling the flow rate adjusting valve 6 and the second flow rate adjusting valve 7, even if the fuel gas compressor 2 is large and has a large capacity, the first flow rate adjusting valve 6 and the second flow rate adjusting valve 7 are used. The delay of the control of the flow rate of the fuel gas can be eliminated, and stable control of the gas turbine can be performed.

With reference to FIGS. 4, 5 and 6, in the embodiment shown in FIGS. 4 to 6, the differential pressure transmitter 22 burns from the pressure P _f of the fuel gas in the second fuel supply line 112. Bowl 3b
Although it is configured to detect the differential pressure obtained by subtracting the internal pressure P _c , it is difficult to detect the pressure inside the combustor 3b, and therefore it is difficult to detect the pressure. Therefore, as another embodiment of the present invention, Instead of the differential pressure transmitter 22, as shown by a virtual line,
From the pressure P _f of the fuel gas in the second fuel supply line 112,
The differential pressure transmitter 22a configured to detect the differential pressure obtained by subtracting the pressure P _a of the air in the air pipeline 116 that guides the compressed air from the air compressor 3a serving as the outlet of the air compressor 3a to the combustor 3b. May be provided. Air pipeline 116
Since the pressure of the internal air and the gas pressure in the combustor 3b substantially match, the same effect as the embodiment shown in FIGS. 4 to 6 can be obtained even if the differential pressure transmitter 22a is used as described above. be able to.

FIG. 7 shows a cogeneration system 6 including a gas turbine controller 122 according to another embodiment of the present invention.
It is a systematic diagram which shows the structure of a part of 0b. In the gas turbine control device 122 of the present embodiment, the second fuel supply pipeline is based on the flow rate represented by the fuel gas control signal X _f output from the low signal selector 10 d of the signal generator 50 and the characteristics of the gas turbine 3. A fuel gas flow rate-pressure converter 24 which is a calculating means for calculating a target value P _f1 of the gas pressure in 112 and outputting a signal representing the value; and a target value P _{f1 of the} pressure.
A pressure signal E output from a pressure transmitter 25, which will be described later, is compared with the pressure signal E to calculate a fuel gas flow rate such that the detected pressure matches the target value P _f1 . There is provided a gas turbine control circuit 10f configured to include a control means 26 for supplying the gas turbines 11 and 12.
Further, the pressure transmitter 2 that detects the pressure P _f of the fuel gas in the second fuel line 112 and outputs the pressure signal E representing the pressure.
5 are provided. The other parts having the same configuration are denoted by the same reference numerals, and the description thereof will be omitted.

FIG. 8 is a diagram showing a control function of the fuel gas flow rate-pressure converter 24 provided in the gas turbine controller 122 of this embodiment. The horizontal axis represents the fuel gas flow rate represented by the signal (fuel gas control signal _Xf in this embodiment) input to the fuel gas flow rate-pressure converter 24, and the vertical axis represents the signal output from this function ( In the present embodiment, the second fuel supply line 1 represented by the signal representing the target pressure value P _f1 )
The target value of the pressure in 12 is shown.

In general, since the characteristic of the gas turbine 3 is usually given in advance, the outlet pressure P _a (X _f ) of the air compressor 3a is known, and the target value P _{f1 of the} pressure is the fuel gas. It is given according to the control signal X _f . When the target value of this pressure is represented by P _a (X _f ), it is represented as in equation (6).

[0067]

[Equation 4]

In the fuel gas flow rate-pressure converter 24, the equation (6) is calculated and a signal representing the target value P _f1 of the pressure in the second fuel supply line 112 is output.

Based on the equation (6), the fuel gas control signal X
Second fuel supply line 11 corresponding to the fuel gas flow rate indicated by _f
A target value P _f1 of the fuel gas pressure in 2 is calculated, and a signal representing the value is output.

The control means 26 outputs from the pressure transmitter 25 which detects the target value P _f1 represented by the signal output from the fuel gas flow rate-pressure converter 24 and the pressure of the fuel gas in the second fuel supply line 112. The detected pressure represented by the pressure signal E is compared by the comparator 55, the signal representing the value is input, the control computation such as proportional, integral, and differential is performed on the value represented by this signal, and the control signal D is output. To do. This control signal D is given to the first and second function generators 11 and 12. First
The first and second valve opening commands given to the first and second flow rate adjusting valves 6 and 7 are calculated by the second function generators 11 and 12 based on the functions shown in FIGS. The signals X _c and X _v are output. The control means 26 is realized by, for example, a proportional-integral-differential circuit (abbreviated as PID circuit). Such a gas turbine control device 12
2 can obtain the same effect as that of the embodiment shown in FIG.

In the configuration of the embodiment shown in FIGS. 1 to 8, the control signal is generated by the combination of the first function generator 11 and the second function generator 12 with the first flow rate adjusting valve 6 and the second flow rate. Although the command signal given to the adjusting valve 7 was output, even if a control means for detecting and controlling the differential pressure or pressure is introduced, the control means for detecting and controlling this differential pressure or pressure is used. Thus, it is possible to easily realize the division of the signals given to the first flow rate adjusting valve 6 and the second flow rate adjusting valve 7.

FIG. 9 is a system diagram showing a part of the construction of a cogeneration system 60c including a gas turbine controller 123 according to still another embodiment of the present invention. The gas turbine control circuit 10g of this embodiment includes the pressure control means 26, the first and second function generators 11 of the embodiment shown in FIG.
Instead of 12, the first control means 26a for operating the first flow rate adjusting valve 6 of the fuel gas compressor 2 and the second control means 26b for operating the second flow rate adjusting valve 7 are provided. A pressure deviation setter that outputs a pressure deviation signal dP1 that represents a predetermined value is also provided. The first control means 26a responds to the output of the fuel gas flow rate-pressure converter 24 and the pressure signal E of the pressure transmitter 25, and outputs the first opening command signal _Xc to the first flow rate adjusting valve 6. The second pressure control 26b is the first of the pressures represented by the output of the fuel gas flow rate-pressure converter 24.
In response to a signal representing a pressure obtained by adding a pressure deviation dP1 which is a value represented by the pressure deviation signal output from the pressure deviation setter 27 to the target value P _f1 and a pressure signal E output from the pressure transmitter 25, The second opening degree command signal _Xv is output to the second flow rate adjusting valve 7. The other parts having the same configuration are denoted by the same reference numerals, and the description thereof will be omitted.

The first control means 26a controls the first target value P _f1 of the pressure represented by the signal output from the fuel gas flow rate-pressure converter 24 and the pressure represented by the pressure signal E output from the pressure transmitter 25. In response to a signal representing the value subtracted by the subtractor 55, control calculation such as proportional, integral, and differential is performed, and the detected pressure P _f of the fuel gas in the second fuel supply pipe 112 is the fuel gas flow rate-pressure converter. Target value P of pressure commanded in 24
The first opening command signal X is sent to the first flow rate adjusting valve 6 so that it becomes _f1.
Output _c and. The first pressure control means 26a is realized by, for example, a proportional-integral-differential circuit (abbreviated as PID circuit).

The second control means 26b controls the pressure deviation dP represented by the pressure deviation signal output from the pressure deviation setting unit 27 to the target value P _{f1 of the} pressure output from the fuel gas flow rate-pressure converter 24.
The second target value P _f2 of the pressure represented by the signal output from the adder 28 by adding 1 and the detected pressure represented by the pressure signal E output from the pressure transmitter 25 are subtracted by the subtractor 55a, The fuel gas pressure P _{f of} the second fuel supply line 112 is represented by the signal output from the fuel gas flow rate-pressure converter 24 in response to the signal representing the value, by performing control calculations such as proportional, integral, and differential. The opening degree of the second flow rate adjusting valve 7 is adjusted by outputting the second opening degree command signal so that the pressure value becomes the target value P _f1 plus the pressure deviation dP1. Controls the flow rate of the fuel gas that is returned to the. The second pressure control means 26b is realized by, for example, a proportional-integral-differential circuit (abbreviated as PID circuit).

The first control means 26a is the first flow rate adjusting valve 6
Is controlled to control the fuel gas pressure in the second fuel supply line 112, the pressure of the fuel gas in the second fuel supply line 112 is a signal output from the fuel gas flow rate-pressure converter 24. _Is maintained at the target value P _f1 . Second target value P of pressure
_{In f2,} the target value of the pressure increases by the pressure deviation dP1, and as a result, the second control means 26b fully closes the second flow rate adjusting valve 7 in order to increase the pressure in the second fuel supply line 112. Will be done.

When the target value P _f1 output from the fuel gas flow rate-pressure converter 24 decreases and the valve opening degree of the first flow rate adjusting valve 6 reaches the minimum opening degree corresponding to the minimum flow rate, the first The pressure control means 26a cannot reduce the flow rate of the fuel gas supplied by the fuel gas compressor 2, and the pressure of the fuel gas in the second fuel supply conduit 112 is output from the fuel gas flow rate-pressure converter 24. _Is larger than the target value P _f1 represented by the signal. When the pressure of the fuel gas in the second fuel supply line 112 becomes larger than the second target value _Pf2 of the pressure represented by the signal given to the second control means 26b, the second flow rate adjusting valve 7 starts to operate.

When the flow rate of the fuel gas discharged from the fuel gas compressor 2 exceeds the flow rate of the fuel gas supplied to the gas turbine, the pressure of the fuel gas in the second fuel supply line 112 rises and the first pressure control is performed. The first flow rate adjusting valve 6 by 26a
Works in the direction of decreasing the flow rate, and the second fuel supply line 112
Trying to maintain the pressure. When the first flow rate adjusting valve 6 reaches the minimum opening degree corresponding to the front minimum flow rate of the fuel gas compressor 2,
The fuel flow rate cannot be reduced any further, and the fuel gas pressure P _f in the second fuel supply line increases. When the pressure of the fuel gas pressure P _f in the second fuel supply line exceeds the second target value P _f2 , the second control means 26b starts to operate and the second flow rate adjusting valve 7
To open the excess fuel gas flow rate to the first fuel supply line 1
It returns to 11 and is recirculated to the inlet of the fuel gas compressor 2. Although the pressure of the fuel gas in the second fuel supply pipe increases by the pressure deviation, the control by the first flow rate adjusting valve 6 shifts to the control by the second flow rate adjusting valve 7.

By the above operation, the first pressure control means 26
The pressure control for changing the valve opening degree of the first flow rate adjusting valve 6 by a and the pressure control for changing the valve opening degree of the second flow rate adjusting valve 7 by the second pressure control means 26b are performed by the second fuel supply line 11.
It can be switched according to the pressure of the fuel gas in 2. Such a gas turbine control device 123 can obtain the same effects as those of the embodiment shown in FIGS.

FIG. 10 is a system diagram showing a part of the construction of a cogeneration system 60d including a gas turbine controller 124 according to still another embodiment of the present invention.

In the gas turbine controller 124 of this embodiment, the opening detector 29 as a detector for detecting the valve opening a of the first flow rate adjusting means 6 and the pressure deviation setting of the embodiment shown in FIG. The gas turbine control circuit 1 including a pressure deviation generator 27a that outputs a pressure deviation signal that represents a pressure deviation that is a value that changes corresponding to the valve opening degree a of the first flow rate adjusting valve 6 instead of the device 27.
0b is provided. The same reference numerals are attached to the other parts having the same configuration.

From the opening detector 29, an opening signal a representing the opening of the first flow rate adjusting valve 6 is given to the pressure deviation generator 27a.

FIG. 11 is a diagram showing a control function of the pressure deviation generator 27a provided in the gas turbine controller 124 of this embodiment.

The horizontal axis represents the valve opening of the first flow rate adjusting valve 6 represented by the signal (opening signal a in this embodiment) input to the pressure deviation generator 27a, and the vertical axis represents the pressure deviation. The pressure deviation dP2 represented by the signal (pressure deviation signal in this embodiment) output from the generator 27a is shown. In this case, the pressure deviation generator 27a may be set according to the following equation (7).

[0084]

(Equation 5)

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

Based on equation (7), when the valve opening represented by the opening signal a is greater than or equal to the valve opening a _min corresponding to the minimum flow rate, the pressure corresponding to the valve opening represented by the opening signal a is calculated. Deviation k
A signal representing (a−a _min ) is output, and a signal representing zero is output when the valve opening represented by the opening signal a is less than the valve opening a _min corresponding to the minimum flow rate X _min .

In the embodiment shown in FIG. 9, since a constant value is given as the pressure deviation signal, the control shifts from the first flow rate adjusting valve 6 to the second flow rate adjusting valve 7 or in the opposite direction. At times, the fuel gas pressure in the second fuel supply line 112 changes by the pressure deviation.

When the opening degree of the first flow rate adjusting valve 6 is equal to or larger than the minimum opening degree in response to the opening degree signal a indicating the valve opening degree of the first flow rate adjusting valve 6 outputted from the opening degree detector 29, A pressure deviation generator 27a that outputs a signal representing the pressure deviation k (a-a _min ) corresponding to the valve opening represented by the signal a and outputs a signal representing zero when the opening is less than the minimum opening is used. An output of the pressure deviation generator 27a is provided to the adder 28.

As a result, when the first flow rate adjusting valve 6 maintains a sufficient opening, the pressure deviation generator 27a outputs a signal representing a positive value, and the second control means 26b.
Controls the second flow rate adjusting valve 7 for increasing the pressure of the fuel gas in the second fuel supply line 112 so as to be fully closed. When the valve opening of the first flow rate adjusting 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 pipeline 11 is set to the target value of the same pressure as the control means 26a.
2nd pressure control means 2 so that the pressure of the fuel gas in 2 may be maintained
6b adjusts the opening degree of the second flow rate adjusting valve 7. For this reason,
The first flow rate adjusting valve 6 without changing the fuel gas pressure
From the control by the first pressure control means 26a for controlling the
The control shifts to the control by the second pressure control means 26b that controls the flow rate adjusting valve 7.

FIG. 12 (1) shows an example of the transition of the pressure P _{f in} the second fuel supply line 112 controlled by the gas turbine control devices 123, 124 of the embodiment shown in FIGS. 9 and 10. 12 (2) shows the transition of the valve opening degree X _c (= a) of the first flow rate adjusting valve 6 at that time, and FIG.
FIG. 4 is a diagram showing a transition of the valve opening degree X _v (= θ) of the second flow rate adjusting valve 7 at that time.

With reference to FIGS. 9, 10 and 12, when controlled by the gas turbine controller 123 of the embodiment shown in FIG. 9, the pressure deviation signal E output from the pressure deviation setter 27 is constant. (DP1), and there is a constant difference between the first target value P _f1 and the second target value P _f2 of the pressure, that is, a difference corresponding to the pressure deviation dP1. From time t0, including the time t1 at which the first flow rate adjusting valve 6 gradually starts to decrease its opening, the first pressure output from the fuel gas flow rate-pressure converter 24 until time t2 when the minimum opening is reached. When the target value P _f1 corresponds to the opening of the first flow rate adjusting valve 6 which is equal to or larger than the minimum opening degree, the second flow rate adjusting valve 7 controls the second fuel supply line by an amount corresponding to the pressure deviation dP1. Since the fuel gas 112 operates to increase the pressure P _f of the fuel gas, the pressure P _f is controlled by the operation of the first flow rate adjusting valve 6 and is maintained at the target value P _{f1 of the} pressure (FIG. 12 ( 70 in 1)).

The target value P _{f1 of} pressure becomes small, and the valve opening a of the first flow rate adjusting valve 6 becomes small (7 in FIG. 12 (2)).
1), and eventually becomes a pressure value corresponding to the minimum flow rate (minimum opening) that can be controlled by the first flow rate adjusting valve 6 or less t2
After that, the first flow rate adjusting valve 6 is controlled to the minimum opening degree (see 72 in FIG. 12).

On the other hand, the second flow rate adjusting valve 7 tries to increase the pressure P _f2 of the fuel gas in the second fuel supply line 112 by the pressure deviation dP1 as described above, so that the time t2 to t3. , The state where the first flow rate adjusting valve 6 is controlled to the minimum opening degree and the second flow rate adjusting valve 7 is fully closed continues, and the pressure P _f
Rises (see 73 in FIG. 12).

After the time t3 when the pressure P _f of the fuel gas in the second fuel supply line 112 reaches the second pressure target value P _f2 (P _f2 = P _f1 + dP1 in the embodiment shown in FIG. 5), The second flow rate adjusting valve 7 is opened as shown by a broken line 75 in FIG. 7C including the time t4 after which the opening degree X _v starts to be kept substantially constant, and the inside of the second fuel supply pipe line 112 is opened. The fuel gas pressure P _f is the second target pressure value P _f2 (= P _f1
+ DP1).

As described above, the pressure P _f of the fuel gas in the second fuel supply line 112 changes by the pressure deviation dP,
The control is shifted from the first flow rate adjusting valve 6 to the control by the second flow rate adjusting valve 7. When the target value P _{f1 of} pressure gradually increases, the operation is reversed, but the control is shifted from the second flow rate adjusting valve 7 to the control by the first flow rate adjusting valve 6.

When controlled by the gas turbine controller 124 of the embodiment shown in FIG. 10, the pressure deviation transmitter 27a.
The pressure deviation dP2 represented by the pressure deviation signal E output from
It is given by the above equation (7) and changes depending on the valve opening degree of the first flow rate adjusting valve 6. The pressure deviation dP2 is a positive value between the time t0 and the time t2 when the valve opening is equal to or more than the minimum opening, and the time t when the valve opening becomes the minimum opening corresponding to the minimum flow rate.
After 2 is zero. Therefore, the first target value P of pressure
The second target value P of pressure at which the pressure deviation dP2 is added to _f1
f2 corresponds to the valve opening, and the time t at which the valve opening becomes the minimum opening
After that, it becomes equal to the target pressure value P _f1 (Fig. 12 (1)).
(See the two-dot chain line 76 in the figure).

During the period from time t0 to time t2 when the target pressure value P _f1 corresponds to the minimum opening of the first flow rate adjusting valve 6 or more, the second flow rate adjusting valve 7 has a positive value. Pressure deviation d
To operate by an amount corresponding to P2 so as to increase the pressure P _f of the fuel gas in the second fuel supply conduit 112, the pressure P _f of the fuel gas in the second fuel supply conduit 112, the first flow rate regulation Controlled by the operation of the valve 6, said pressure target value P _f1
Is maintained (see 70 in FIG. 12 (1)).

The target value P _{f1 of} pressure becomes small, and the valve opening of the first flow rate adjusting valve 6 becomes small (71 in FIG. 12 (2)).
), Time t2 at which the valve opening is equal to or smaller than the minimum opening
After that, the first flow rate adjusting valve 6 is controlled to the minimum opening (see FIG.
72 in 2 (2)).

The target value P _f2 of the second value becomes equal to the target value P _{f1 of} pressure after the time t2 when the valve opening becomes the minimum opening as described above. As a result, the second flow rate adjusting valve 7
Is the pressure P of the fuel gas in the second fuel supply line 112.
_Operates to keep _f at P _f1 . After the time t2 when the valve opening becomes the minimum opening, the second flow rate adjusting valve 7 is opened (see 77 in FIG. 12 (3)).

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

In the above embodiments, the gas turbine control circuits 10, 10e, 10f, 10 provided in the gas turbine control devices 120, 121, 122, 123, 124 are provided.
Although g and 10h are configured as an integrated control circuit, as another embodiment of the present invention, both can be configured by combining individual control devices, and some or all of the functions thereof can be implemented by an electronic computer. It can be realized as an internal calculation.

Further, it is possible to obtain a gas turbine control circuit having substantially the same function as in the above embodiment by changing the combination of these. For example, in the embodiment shown in FIG. 9 and the embodiment shown in FIG. 10, the control means 26a, 26b for controlling based on two pressures are used.
Instead of a and 26b, the control means 23 for controlling based on the differential pressure as shown in the embodiment shown in FIG. 4 may be used.

Further, when the control means 23 is used, the second
The pressure difference between the fuel gas pressure in the fuel supply line 112 and the gas pressure in the combustor 3b or the pressure difference between the fuel gas pressure in the second fuel supply line 112 and the outlet pressure of the air compressor 3a. Whichever is used, the same effect can be obtained. Further, the differential pressure transmitter 22 for detecting these differential pressures,
A transmitter for detecting the pressure of the fuel gas in the second fuel supply line 112, a transmitter for detecting the gas pressure in the combustor 3b or a transmitter for detecting the pressure at the outlet of the air compressor 3a, and It may be configured by a combination of subtractors that calculate a pressure difference represented by a signal output from the transmitter.

The rotation speed / load control 10a, the gas temperature control 10b, the start control 10c and the low level signal selector 10 shown in the present invention as a normal gas turbine control device.
It is obvious that the combination of d may be partially omitted depending on the model of the gas turbine, and other elements may be added if necessary.

Further, in the above-described embodiment, the fuel gas 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, but it is, for example, a motor or the like. It may be driven by power. Also, the virtual line K in FIG.
A gear may be interposed between the air compressor 3a and the air compressor 3a of the gas turbine so that the rotation speed is increased or decreased to drive the air compressor 3a.

As another embodiment of the present invention, the first function generator and the second function generator do not simply consider only the fuel gas flow rate, but can realize a predetermined fuel gas flow rate. The set values of the first flow rate adjusting valve 6 and the second flow rate adjusting valve 2 may be set in advance. Further, although the flow rate of the fuel gas supplied to the fuel gas compressor 2 is controlled by the first flow rate adjusting valve 6 in the above-described embodiment, as another embodiment of the present invention, the first flow rate adjusting valve 6 is replaced. Thus, a mechanism for changing the angle of the stationary blades of the fuel gas compressor 2 may be provided, or another mechanism for controlling the flow rate may be provided. As another embodiment of the present invention, instead of the second flow rate adjusting valve 7, a mechanism for controlling another flow rate may be provided.

Further, although the second flow rate adjusting valve 7 which can be fully closed is used in the above-mentioned embodiment, as the other embodiment of the present invention, the second flow adjusting valve 7 which cannot be fully closed is used. The two flow rate adjusting valve 7 and the on-off valve that can be fully closed may be provided in series.

Although the target pressure value is calculated based on the fuel gas control signal X _f and the characteristics of the gas turbine in the above-described embodiment, as another embodiment of the present invention, the pressure at the outlet of the air compressor 3a is calculated. May be detected using a detector to control the gas turbine 3.

[0109]

As described above, according to the present invention, the supply flow rate of the fuel gas supplied to the fuel gas compressor in response to the fuel gas command signal output from the signal generator is controlled by the first flow rate adjusting means. The flow rate of the gas discharged from the fuel gas compressor in response to the fuel gas command signal is recirculated to the inlet of the fuel gas compressor and is controlled by the second flow rate adjusting means to the combustor of the gas turbine. Since the fuel gas of stepless fuel gas supply flow rate is supplied 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. Thus, a low-pressure gas requiring a fuel gas compressor and having a low calorific value can be effectively used as a fuel for a gas turbine.

According to the 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, which is recirculated to the inlet of the fuel gas compressor, is controlled by the second flow rate adjusting means, and is not 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 in a stepwise 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 low pressure required for the fuel gas compressor. Moreover, the gas having a low calorific value can be effectively used as the fuel for the gas turbine.

Further, 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 target value of the subtracted differential pressure is calculated by the calculation means, and the fuel gas flow rate such that the detected differential pressure becomes the target value is output by the control means as a control signal and given to the first and second function generators for control. Since the first and second flow rate setting 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, control is not delayed and the gas is not delayed. 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 is controlled by the first flow rate adjusting means in response to the control signal output from the control means,
The flow rate of the gas discharged from the fuel gas compressor in response to the control signal and flowing back to the inlet of the fuel gas compressor is controlled by the second flow rate adjusting means, and to the combustor of the gas turbine,
Since the fuel gas of the stepless fuel gas supply flow rate is supplied 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. It is possible to effectively use a low-pressure gas that requires a fuel gas compressor and has a low calorific value as a fuel for a gas turbine.

Further, the pressure transmitter detects the pressure at the outlet of the fuel gas compressor, the target value of the outlet pressure of the fuel gas compressor is calculated by the calculating means, and the detected pressure becomes the target value of the fuel gas. A signal representing the flow rate is output as a control signal by the control means and is given to the first and second function transmitters, and the first and second flow rate set values in response to the control signal are given 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 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 the first
It is controlled by controlling the flow rate adjusting means, and the flow rate of the gas discharged from the fuel gas compressor and returned to the inlet of the fuel gas compressor is controlled by controlling the second flow rate adjusting means. Since the fuel gas of the 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, the gas turbine is operated regardless of the minimum flow rate of the fuel gas compressor. It is possible to control from the minimum output to the maximum output, and it is possible to effectively use a low-pressure gas that requires a fuel gas compressor and has a low calorific value as fuel for a gas turbine.

Further, the pressure at the outlet of the fuel gas compressor is detected by the pressure transmitter, the first target value of the pressure at the outlet of the fuel gas compressor is calculated by the calculating means, and the detected pressure becomes the first target value. As described above, the first control means controls the first flow rate adjusting means, a predetermined value is output as a pressure deviation signal from the pressure deviation set value device, and the value represented by the pressure deviation signal is set as the first target value of pressure. Since the signal indicating the second target value of the pressure is added by the adder and the second flow rate adjusting means is controlled by the second control means so that the detected pressure becomes the target value, the fuel gas compressor is large. Therefore, even if the capacity is large, stable control of the gas turbine can be 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 the first
It is controlled by controlling the flow rate adjusting means, and the flow rate of the gas discharged from the fuel gas compressor and returned to the inlet of the fuel gas compressor is controlled by controlling the second flow rate adjusting means. Since the fuel gas of the 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, the gas turbine is operated regardless of the minimum flow rate of the fuel gas compressor. It is possible to control from the minimum output to the maximum output, and it is possible to effectively use a low-pressure gas that requires a fuel gas compressor and has a low calorific value as fuel for a gas turbine.

Further, the pressure at the outlet of the fuel gas compressor is detected by the pressure transmitter, the first target value of the pressure at the outlet of the fuel gas compressor is calculated by the calculating means, and the detected pressure becomes the target value. The first control means controls the first flow rate adjusting means, the opening degree of the first flow rate adjusting means is detected by the detector, and the pressure deviation signal is output by the pressure deviation generator corresponding to 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 the 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 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 the first
It is controlled by controlling the flow rate adjusting means, and the flow rate of the gas discharged from the fuel gas compressor and returned to the inlet of the fuel gas compressor is controlled by controlling the second flow rate adjusting means. Since the fuel gas of the 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, the gas turbine is operated regardless of the minimum flow rate of the fuel gas compressor. It is possible to control from the minimum output to the maximum output, and it is possible to effectively use a low-pressure gas that requires a fuel gas compressor and has a low calorific value as fuel for a gas turbine.

Further, 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 rate adjusting means is controlled by the first control means so that the detected differential pressure becomes the target value, and a predetermined value is set from the pressure deviation set value device. A pressure deviation signal is output, and 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 so that the detected differential pressure becomes the target value. Since the second control means controls the second flow rate adjusting means, the control is not delayed even if the fuel gas compressor is large and has a large capacity.
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 the first
It is controlled by controlling the flow rate adjusting means, and the flow rate of the gas discharged from the fuel gas compressor and returned to the inlet of the fuel gas compressor is controlled by controlling the second flow rate adjusting means. Since the fuel gas of the 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, the gas turbine is operated regardless of the minimum flow rate of the fuel gas compressor. It is possible to control from the minimum output to the maximum output, and it is possible to effectively use a low-pressure gas that requires a fuel gas compressor and has a low calorific value as fuel for a gas turbine.

Further, the differential pressure obtained by subtracting the gas pressure in the combustor from the outlet pressure of the fuel gas compressor is detected by the differential pressure transmitter, and the gas pressure in the combustor is subtracted from the outlet pressure of the fuel gas compressor. The first target value of the differential pressure thus calculated is calculated by the calculation means, the first flow rate adjusting means is controlled by the first control means so that the detected differential pressure becomes the target value, and the opening degree of the first flow rate adjusting means is detected. Is detected by the pressure detector, and a pressure deviation signal corresponding to the output of the detector is output by the pressure deviation generator. The value represented by the pressure deviation signal is added by the adder to the first target value of the differential pressure to obtain the differential pressure. Is output as a second target value of the fuel gas compressor 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 if there is, control will not be delayed It can be performed always stable control of the gas turbine.

Further, according to the present invention, 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 the control signal output from the control means,
The flow rate of the gas discharged from the fuel gas compressor in response to the control signal and flowing back to the inlet of the fuel gas compressor is controlled by the second flow rate adjusting means, and to the combustor of the gas turbine,
Since the fuel gas of the stepless fuel gas supply flow rate is supplied 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. It is possible to effectively use a low-pressure gas that requires a fuel gas compressor and has a low calorific value as a fuel for a gas turbine.

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 fuel gas compressor is detected by the differential pressure transmitter, and the pressure at the outlet of the fuel gas compressor is changed to the gas pressure. 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 calculation means, and the fuel gas flow rate such that the detected differential pressure becomes the target value is output as the control signal by the control means. 1
And the second and third function generators, 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. Therefore, the fuel gas compressor is large in size and large in capacity. Even if there is, it is possible to perform stable control of the gas turbine without delaying 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 the first
It is controlled by controlling the flow rate adjusting means, and the flow rate of the gas discharged from the fuel gas compressor and returned to the inlet of the fuel gas compressor is controlled by controlling the second flow rate adjusting means. Since the fuel gas of the 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, the gas turbine is operated regardless of the minimum flow rate of the fuel gas compressor. It is possible to control from the minimum output to the maximum output, and it is possible to effectively use a low-pressure gas that requires a fuel gas compressor and has a low calorific value 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 pressure at the outlet of the fuel gas compressor is detected. 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 differential pressure is set so that the detected differential pressure becomes the target value.
The control means controls the first flow rate adjusting means, a predetermined value is output from the pressure deviation set value device as a pressure deviation signal, and the value represented by the pressure deviation signal is added to the first target value of the differential pressure by an adder. Is output as a second target value of the differential pressure, and the second flow rate adjusting means is controlled by the second control means so that the detected differential pressure becomes the target value. Therefore, the fuel gas compressor has a large size and a large capacity. Even if so, it is possible to always perform stable control of the gas turbine without delaying 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 the first
It is controlled by controlling the flow rate adjusting means, and the flow rate of the gas discharged from the fuel gas compressor and returned to the inlet of the fuel gas compressor is controlled by controlling the second flow rate adjusting means. Since the fuel gas of the 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, the gas turbine is operated regardless of the minimum flow rate of the fuel gas compressor. It is possible to control from the minimum output to the maximum output, and it is possible to effectively use a low-pressure gas that requires a fuel gas compressor and has a low calorific value as fuel for a gas turbine.

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 fuel gas compressor is detected by the differential pressure transmitter, and the pressure at the outlet of the fuel gas compressor is detected. The first target value of the differential pressure obtained by subtracting the pressure at the outlet of the air compressor provided in the is calculated by the calculating means, and the first control means controls the first flow rate adjusting means so that the detected differential pressure becomes the target value. , The first
The opening degree of the flow rate adjusting means is detected by the detector, the pressure deviation signal is output by the pressure deviation generator corresponding to the output of the detector, and the value represented by the pressure deviation signal is set as the first target value of the differential pressure. Since the second differential pressure control means controls the second flow rate adjusting means so that the differential pressure is added as a second target value of the differential pressure and is output as the second target value of the differential pressure, the second differential pressure control means controls the fuel gas compressor. Even if the gas turbine has a large size and a large capacity, the control is not delayed and the gas turbine can always be stably controlled.

[Brief description of drawings]

FIG. 1 is a gas turbine controller 12 according to an embodiment of the present invention.
It is a systematic diagram which shows a part of cogeneration facility 60 provided with 0.

FIG. 2 is a diagram showing a control function of a first function generator 11.

FIG. 3 is a diagram showing a control function of a second function generator 12.

FIG. 4 is a gas turbine control device 1 according to another embodiment of the present invention.
21 is a system diagram showing a part of a cogeneration facility 60a.

FIG. 5 is a simplified view showing the vicinity of a combustor 3b.

FIG. 6 is a diagram showing a control function of the fuel gas flow rate-differential pressure converter 11.

FIG. 7 is a system diagram showing a part of a cogeneration facility 60b including a gas turbine control device 122 according to still another embodiment of the present invention.

FIG. 8 is a diagram showing a control function of a fuel gas flow rate-differential pressure converter 24.

FIG. 9 is a system diagram showing a part of a cogeneration facility 60c including a gas turbine control device 123 according to still another embodiment of the present invention.

FIG. 10 is a cogeneration facility 60d including a gas turbine controller 124 according to still another embodiment of the present invention.
It is a systematic diagram showing a part of.

FIG. 11 is a diagram showing a control function of a pressure deviation generator 27a.

FIG. 12 (1) shows the transition of the pressure P _f of the fuel gas in the second fuel supply conduit 112 controlled by the gas turbine control devices 123, 124 of the embodiment shown in FIGS. 9 and 10, ( 2) shows the transition of the valve opening degree X _c (= a) of the first flow rate adjusting valve 6 at that time, and (3) shows the valve opening degree X _v (= θ) of the second flow rate adjusting valve 7 at that time. It is a figure which shows the transition of.

FIG. 13 is a system diagram showing a cogeneration facility 60e using a gas turbine 3 that uses blast furnace gas as fuel.

FIG. 14 is a system diagram showing a conventional cogeneration facility using a gas turbine 3 that uses fuel gas having a high pressure and a high calorific value as a fuel.

FIG. 15 is a system diagram showing a part of a cogeneration facility 60f including a conventional gas turbine control device 101.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 rotary shaft 2 fuel gas compressor 3 gas turbine 3a air compressor 3b combustor 3c turbine 4 generator 5 boiler 6 first flow rate adjusting valve 7 second flow rate adjusting valve 8 cooler 10, 10e, 10f, 10g, 10h, 10i Gas turbine control circuit 10a Rotation speed / load control circuit 10b Gas temperature control circuit 10c Start control circuit 10d Low-level signal selector 11 First function generator 12 Second function generator 21 Fuel flow rate-differential pressure converter 22 Difference Pressure transmitter 23, 26, 26a, 26b Control means 24 Fuel gas flow rate-pressure converter 25 Pressure transmitter 27 Pressure deviation setter 27a Pressure deviation generator 28 Adder 29 Opening transmitter 50 Signal generator 60, 60a, 60b, 60c, 60d, 60e, 60
f Cogeneration facility 61 Flow control valve 80 Circulation loop 120, 121, 122, 123, 124 Gas turbine control device

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display area F02C 9/48

Claims (10)

[Claims] 1. A fuel gas compressor for compressing fuel gas and supplying it to a combustor of a gas turbine, and a part of fuel gas discharged from the fuel gas compressor is branched and returned to the inlet of the fuel gas compressor. A fuel recirculation line and a first part for controlling the flow rate of the fuel gas at the inlet of the fuel gas compressor
A flow rate adjusting means, a second flow rate adjusting means capable of fully closing the flow rate of the fuel gas returned to the inlet of the fuel gas compressor by the fuel recirculation conduit, and a fuel supplied to the combustor of the gas turbine. A signal generator that generates a fuel gas command signal that commands the flow rate of gas, and a minimum value when the flow rate indicated by the fuel gas command signal is less than the predetermined minimum flow rate of the fuel gas compressor in response to the fuel gas command signal. A first flow rate set value indicating the flow rate is output, and when the flow rate indicated by the fuel gas command signal is equal to or greater than the minimum flow rate, the first flow rate set value corresponding to the fuel gas command signal is output, and the output signal is the first First to give to flow rate adjusting means
A function generator, which responds to the fuel gas command signal, subtracts the flow rate represented by the fuel gas command signal from the minimum flow rate when the flow rate represented by the fuel gas command signal is less than or equal to the minimum flow rate, and represents the subtracted flow rate. 2 flow rate set value is output, and when the flow rate represented by the fuel gas command signal exceeds the minimum flow rate, the second flow rate setting value is output so that the second flow rate adjusting means is fully closed. And a second function generator which supplies the second function to the second flow rate adjusting means. 2. A fuel gas compressor for compressing fuel gas and supplying it to a combustor of a gas turbine, and a part of the fuel gas discharged from the fuel gas compressor is branched and returned to the inlet of the fuel gas compressor. A fuel recirculation line and a first part for controlling the flow rate of the fuel gas at the inlet of the fuel gas compressor
Flow rate adjusting means, second flow rate adjusting means for controlling the flow rate of the fuel gas returned to the inlet of the fuel gas compressor by the fuel recirculation pipe line, and fully closing the fuel gas; A differential pressure transmitter that detects the differential pressure obtained by subtracting the gas pressure in the combustor provided in the turbine, and a signal generator that generates a fuel gas command signal that commands the flow rate of the fuel gas supplied to the combustor of the gas turbine. And a calculation unit that responds to the fuel gas command signal and calculates a target value of the differential pressure obtained by subtracting the gas pressure in the combustor from the pressure at the outlet of the fuel gas compressor corresponding to the flow rate represented by the fuel gas command signal. And a control unit that outputs a control signal indicating the flow rate of the fuel gas supplied to the combustor so that the detected differential pressure becomes the target value, in response to the outputs of the differential pressure transmitter and the calculation unit, In response to this control signal, When the flow rate represented by the control signal is less than the predetermined minimum flow rate of the fuel gas compressor, the first flow rate set value representing the minimum flow rate is output, and when the flow rate represented by the control signal is the minimum flow rate or more, the control signal is added to the control signal. A first function generator that outputs a corresponding first flow rate set value and outputs the output signal to the first flow rate adjusting means; and when the flow rate represented by the control signal is less than or equal to the minimum flow rate in response to the control signal. A flow rate represented by the control signal is subtracted from the minimum flow rate, a second flow rate set value representing the subtracted flow rate is output, and the second flow rate adjusting means is fully closed when the flow rate represented by the control signal exceeds the minimum flow rate. And a second function generator which outputs a second flow rate set value and gives the second flow rate set value thus output to the second flow rate adjusting means. 3. A fuel gas compressor for compressing fuel gas and supplying it to a combustor of a gas turbine, and a part of the fuel gas discharged from the fuel gas compressor is branched and returned to the inlet of the fuel gas compressor. A fuel recirculation line and a first part for controlling the flow rate of the fuel gas at the inlet of the fuel gas compressor
Flow rate adjusting means, second flow rate adjusting means for controlling the flow rate of the fuel gas returned to the inlet of the fuel gas compressor by the fuel recirculation pipe line, and detecting the pressure at the outlet of the fuel gas compressor Pressure transmitter, a signal generator that generates a fuel gas command signal that commands the flow rate of the fuel gas supplied to the combustor of the gas turbine, and a flow rate that the fuel gas command signal represents in response to the fuel gas command signal. Corresponding to the calculation means for calculating the target value of the pressure at the outlet of the fuel gas compressor, and in response to the outputs of the pressure transmitter and the calculation means, the detected pressure is supplied to the combustor so as to reach the target value. A control means for outputting a control signal representative of the flow rate of the fuel gas, and a first means for responding to the control signal, wherein the flow rate represented by the control signal is less than a predetermined minimum flow rate of the fuel gas compressor. 1 flow rate setting A first function generator which outputs a 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 more than the minimum flow rate, and gives the output signal to the first flow rate adjusting means. In response to the control signal, when the flow rate represented by the control signal is less than or equal to the minimum flow rate, the flow rate represented by the control signal is subtracted from the minimum flow rate, and the second flow rate set value representing the subtracted flow rate is output, When the flow rate represented by exceeds the minimum flow rate, the second flow rate adjusting means outputs the second flow rate setting value for fully closing, and the second function which gives the second flow rate setting value thus output to the second flow rate adjusting means. A gas turbine control device comprising: a generator. 4. A fuel gas compressor for compressing fuel gas and supplying it to a combustor of a gas turbine, and a part of the fuel gas discharged from the fuel gas compressor is branched and returned to the inlet of the fuel gas compressor. A fuel recirculation line and a first part for controlling the flow rate of the fuel gas at the inlet of the fuel gas compressor
Flow rate adjusting means, second flow rate adjusting means for controlling the flow rate of the fuel gas returned to the inlet of the fuel gas compressor by the fuel recirculation pipe line, and detecting the pressure at the outlet of the fuel gas compressor Pressure transmitter, a signal generator that generates a fuel gas command signal that commands the flow rate of the fuel gas supplied to the combustor of the gas turbine, and a flow rate that the fuel gas command signal represents in response to the fuel gas command signal. Corresponding to the calculation means for calculating the first target value of the pressure at the outlet of the fuel gas compressor, and in response to the outputs of the pressure transmitter and the calculation means, the detected pressure becomes the first target value. No. 1 first control means for controlling the flow rate adjusting means, a pressure deviation setter for outputting a pressure deviation signal representing a predetermined value, a first target value of pressure and a pressure deviation signal Add the pressure indicated and the value indicated by the pressure deviation signal Then, in response to the outputs of the adder that outputs the second target value of the pressure that represents the pressure, and the output of the pressure transmitter and the adder, the second flow rate adjusting means so that the detected pressure becomes the second target value. And a second control means for controlling the gas turbine control device. 5. A fuel gas compressor that compresses fuel gas and supplies it to a combustor of a gas turbine, and a part of the fuel gas discharged from the fuel gas compressor is branched and returned to the inlet of the fuel gas compressor. A fuel recirculation line and a first part for controlling the flow rate of the fuel gas at the inlet of the fuel gas compressor
Flow rate adjusting means, second flow rate adjusting means for controlling the flow rate of the fuel gas returned to the inlet of the fuel gas compressor by the fuel recirculation pipe line, and detecting the pressure at the outlet of the fuel gas compressor Pressure generator, a signal generator that generates a fuel gas command signal that commands the flow rate of the fuel gas supplied to the combustor of the gas turbine, and a fuel gas command signal that responds to the fuel gas command signal. A calculating means for calculating a first target value of the pressure at the outlet of the corresponding fuel gas compressor; and a first means for responding to the outputs of the pressure transmitter and the calculating means so that the detected pressure becomes the first target value. First control means for controlling the flow rate adjusting means, a detector for detecting the opening degree of the first flow rate adjusting means, and a fuel gas to the fuel gas compressor depending on the detected opening degree in response to the output of the detector. Flow rate predetermined for fuel gas compressor 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 higher than the minimum flow rate, and zero is output when the flow rate of the fuel gas to the fuel gas compressor according to the detection opening is less than the minimum flow rate. A pressure deviation generator that outputs a pressure deviation signal that represents the first pressure of the pressure
An adder that adds the pressure represented by the target value and the value represented by the pressure deviation signal and outputs a second target value of the pressure representing that pressure, and the detected pressure in response to the outputs of the pressure transmitter and the adder. And a second control means for controlling the second flow rate adjusting means so that the second target value becomes the second target value. 6. A fuel gas compressor for compressing fuel gas and supplying it to a combustor of a gas turbine, and a part of fuel gas discharged from the fuel gas compressor is branched and returned to the inlet of the fuel gas compressor. A fuel recirculation line and a first part for controlling the flow rate of the fuel gas at the inlet of the fuel gas compressor
Flow rate adjusting means, second flow rate adjusting means for controlling the flow rate of the fuel gas returned to the inlet of the fuel gas compressor by the fuel recirculation pipe line, and fully closing the fuel gas; A differential pressure transmitter that detects the differential pressure obtained by subtracting the gas pressure in the combustor provided in the turbine, and a signal generator that generates a fuel gas command signal that commands the flow rate of the fuel gas supplied to the combustor of the gas turbine. And responding to the fuel gas command signal, calculating a first target value of the differential pressure obtained by subtracting the gas pressure in the combustor from the pressure at the outlet of the fuel gas compressor corresponding to the flow rate represented by the fuel gas command signal. Calculating means, first control means for controlling the first flow rate adjusting means in response to the outputs of the differential pressure transmitter and the calculating means, so that the detected differential pressure becomes the first target value, and a predetermined value Pressure deviation that outputs the indicated pressure deviation signal Responsive to the first target value of the differential pressure and the pressure deviation signal, the differential pressure represented by the first target value and the value represented by the pressure deviation signal are added, and the second target value of the differential pressure is output. And a second control means for controlling the second flow rate adjusting means so that the detected differential pressure becomes the second target value in response to the outputs of the differential pressure transmitter and the adder. A characteristic gas turbine control device. 7. A fuel gas compressor for compressing fuel gas and supplying it to a combustor of a gas turbine, and a part of the fuel gas discharged from the fuel gas compressor is branched and returned to the inlet of the fuel gas compressor. A fuel recirculation line and a first part for controlling the flow rate of the fuel gas at the inlet of the fuel gas compressor
Flow rate adjusting means, second flow rate adjusting means for controlling the flow rate of the fuel gas returned to the inlet of the fuel gas compressor by the fuel recirculation pipe line, and fully closing the fuel gas; A differential pressure transmitter that detects the differential pressure obtained by subtracting the gas pressure in the combustor provided in the turbine, and a signal generator that generates a fuel gas command signal that commands the flow rate of the fuel gas supplied to the combustor of the gas turbine. And responding to the fuel gas command signal, calculating a first target value of the differential pressure obtained by subtracting the gas pressure in the combustor from the pressure at the outlet of the fuel gas compressor corresponding to the flow rate represented by the fuel gas command signal. Calculating means; first control means for controlling the first flow rate adjusting means in response to the outputs of the differential pressure transmitter and the calculating means, so that the detected differential pressure becomes the first target value; and the first flow rate. With a detector that detects the opening of the adjusting means In response to the output of the detector, a pressure that represents a positive value corresponding to the output of the detector when the flow rate of the fuel gas to the fuel gas compressor depending on the detection opening is equal to or more than a predetermined minimum flow rate of the fuel gas compressor. A pressure deviation generator that outputs a deviation signal and outputs a pressure deviation signal representing zero when the flow rate of the fuel gas to the fuel gas compressor according to the detected opening is less than the minimum flow rate; In response to the output from the pressure deviation generator, the differential pressure represented by the first target value of the differential pressure and the value represented by the pressure deviation signal are added, and the second target value of the differential pressure representing the differential pressure is output. And a second control means for controlling the second flow rate adjusting means so that the detected differential pressure becomes the second target value in response to the outputs of the differential pressure transmitter and the adder. Gas turbine control device. 8. A fuel gas compressor for compressing fuel gas to be supplied to a combustor of a gas turbine, and a part of fuel gas discharged from the fuel gas compressor is branched and returned to an inlet of the fuel gas compressor. A fuel recirculation line and a first part for controlling the flow rate of the fuel gas at the inlet of the fuel gas compressor
Flow rate adjusting means, second flow rate adjusting means for controlling the flow rate of the fuel gas returned to the inlet of the fuel gas compressor by the fuel recirculation pipe line, and fully closing the fuel gas; A differential pressure transmitter that detects the differential pressure obtained by subtracting the pressure at the outlet of the air compressor installed in the turbine, and a signal generator that generates a fuel gas command signal that commands the flow rate of the fuel gas supplied to the combustor of the gas turbine. And a target value of the differential pressure in response to the fuel gas command signal and subtracting the pressure at the outlet of the air compressor from the pressure at the outlet of the fuel gas compressor corresponding to the flow rate represented by the fuel gas command signal. Control means for responding to the outputs of the differential pressure transmitter and the computing means, and for outputting a control signal indicating the flow rate of the fuel gas supplied to the combustor so that the detected differential pressure becomes the target value. And this control signal In response, when the flow rate represented by the control signal is less than the predetermined minimum flow rate of the fuel gas compressor, the first flow rate set value representing the minimum flow rate is output, and when the flow rate represented by the control signal is the minimum flow rate or more, A first function generator which outputs a first flow rate set value corresponding to the control signal and gives the output signal to the first flow rate adjusting means; and a flow rate which is responsive to the control signal and which is represented by the control signal is equal to or less than the minimum flow rate. When the flow rate represented by the control signal is subtracted from the minimum flow rate, a second flow rate set value representing the subtracted flow rate is output, and when the flow rate represented by the control signal exceeds the minimum flow rate, the second flow rate adjusting means is fully closed. And a second function generator which outputs a second flow rate setting value for the above, and gives the second flow rate setting value thus output to the second flow rate adjusting means. 9. A fuel gas compressor for compressing fuel gas and supplying it to a combustor of a gas turbine, and a part of fuel gas discharged from the fuel gas compressor is branched and returned to the inlet of the fuel gas compressor. A fuel recirculation line and a first part for controlling the flow rate of the fuel gas at the inlet of the fuel gas compressor
Flow rate adjusting means, second flow rate adjusting means for controlling the flow rate of the fuel gas returned to the inlet of the fuel gas compressor by the fuel recirculation pipe line, and fully closing the fuel gas; A differential pressure transmitter that detects the differential pressure obtained by subtracting the pressure at the outlet of the air compressor installed in the turbine, and a signal generator that generates a fuel gas command signal that commands the flow rate of the fuel gas supplied to the combustor of the gas turbine. And a first target value of the differential pressure in response to the fuel gas command signal, which is obtained by subtracting the pressure at the outlet of the air compressor from the pressure at the outlet of the fuel gas compressor corresponding to the flow rate represented by the fuel gas command signal. Calculating means for calculating, first control means for controlling the first flow rate adjusting means in response to the outputs of the differential pressure transmitter and the calculating means, so that the detected differential pressure becomes the first target value; Outputs the pressure deviation signal that represents the value In response to the pressure deviation setter, the first target value of the differential pressure and the pressure deviation signal, the differential pressure represented by the first target value and the value represented by the pressure deviation signal are added to obtain the second target value of the differential pressure. And a second control means that responds to the outputs of the differential pressure transmitter and the adder and controls the second flow rate adjusting means so that the detected differential pressure becomes the second target value. A gas turbine control device characterized by the above. 10. A fuel gas compressor for compressing fuel gas and supplying it to a combustor of a gas turbine, and a part of fuel gas discharged from the fuel gas compressor is branched and returned to the inlet of the fuel gas compressor. A fuel recirculation line and a first part for controlling the flow rate of the fuel gas at the inlet of the fuel gas compressor
Flow rate adjusting means, second flow rate adjusting means for controlling the flow rate of the fuel gas returned to the inlet of the fuel gas compressor by the fuel recirculation pipe line, and fully closing the fuel gas; A differential pressure transmitter that detects the differential pressure obtained by subtracting the pressure at the outlet of the air compressor installed in the turbine, and a signal generator that generates a fuel gas command signal that commands the flow rate of the fuel gas supplied to the combustor of the gas turbine. And a first target value of the differential pressure in response to the fuel gas command signal, which is obtained by subtracting the pressure at the outlet of the air compressor from the pressure at the outlet of the fuel gas compressor corresponding to the flow rate represented by the fuel gas command signal. Calculating means for calculating; 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 calculating means; 1 Detecting the opening of the flow rate adjusting means And a positive response corresponding to the output of the detector in response to the output of the detector, when the flow rate of the fuel gas to the fuel gas compressor according to the detected opening is equal to or greater than the predetermined minimum flow rate of the fuel gas compressor. A pressure deviation generator that outputs a pressure deviation signal that represents the value of, and that outputs a pressure deviation signal that represents zero when the flow rate of the fuel gas to the fuel gas compressor according to the detected opening is less than the minimum flow rate, In response to the outputs of the differential pressure calculation means and the pressure deviation generator, the differential pressure represented by the first target value of the differential pressure and the value represented by the pressure deviation signal are added, and the second target of the differential pressure representing the differential pressure is added. An adder which outputs a value, and a second control means which responds to the outputs of the differential pressure transmitter and the adder and controls the second flow rate adjusting means so that the detected differential pressure becomes the second target value. A gas turbine control device comprising: