JPH11311129A - Load controller of gasification compound power plant - Google Patents

Abstract

PROBLEM TO BE SOLVED: To favorably hold both of load and gas pressure controls in a gasification compound power plant comprising multiple system. SOLUTION: This plant is equipped with three units of gasified furnaces 1 and dedusters 4, two units of desulfurizers 6 and three gas turbine devices 30. A load controller is equipped with a general load control part 31 controlling the total output of the gas turbine 30 and a steam turbine 19 on the basis of the load setting value, a general gas pressure control part 32 constantly controlling gas pressure on the basis of the gas pressure setting value and a feedforward control part imparting this general gas pressure control part 32 with a feedforward signal favorably keeping the responsiveness of gas pressure control, respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an integrated gasification combined cycle power plant, and more particularly to a load control apparatus for a combined gasification combined cycle power plant including a plurality of gasification furnaces, a desulfurization unit, and a plurality of gas turbine units.

[0002]

2. Description of the Related Art The demand for effective use, diversification, and high efficiency of energy resources is becoming more and more important today, and accordingly, gasification plants for gasifying hydrocarbon fuels such as coal or petroleum residua have been developed. Combined gas power generation (hereinafter referred to as IGCC) configured with a combined power generation system
Is attracting attention. There are many favorable features of IGCC,
Good environmental compatibility and compatibility with a variety of coals and fuels is a unique feature. These IGCCs, which are expected to improve power generation efficiency in combination with the application of higher temperature gas turbines that exceed the current level, have higher expectations than before and are considered as one of the promising options for thermal power generation in the next century .

[0003] A typical IGCC plant comprises a gasifier for gasifying solid or liquid fuel, a gas purification facility for purifying the obtained gas, and a combined power generation system comprising a gas turbine, a waste heat recovery boiler, and a steam turbine. Is a large and complex plant. Various types of IGCC plants composed of various equipment have been proposed depending on the type of gasification furnace used and the type of gas purification equipment including dust removal equipment and desulfurization equipment. A gasification furnace for gasifying a liquid fuel such as oil using oxygen will be mainly described.

FIG. 5 shows the overall configuration of an IGCC plant. The gasified fuel supplied from the outside is converted into a gas (referred to as a crude gas with respect to a purified gas) in the gasification furnace 1. That is, gasification fuel enters the gasification furnace 1 from the gasification fuel control valve 2, and oxygen gas as an oxidant enters from the oxygen control valve 3. In the gasification furnace 1, a high-temperature crude gas (about 1000 ° C.) containing combustible gases CO and H2 is generated by the water gasification reaction.

[0005] Next, the generated crude gas enters a dust removing device 4 composed of a scrubber or the like, where fine particles such as ash contained in the crude gas are removed. Further, the crude gas is supplied to the gas cooler 5.
And cooled to a predetermined temperature. The cooled crude gas enters a desulfurization unit 6, which obtains a purified gas, where approximately several percent of the sulfur content in the crude gas is desulfurized.

[0006] The purified gas is supplied to the gas turbine device of the combined cycle system as fuel for the gas turbine. Fuel gas flows into the combustor 8 from the fuel control valve 7. In the combustor 8, the fuel gas is burned together with the combustion air from the compressor 9 to become a high-temperature combustion gas. This combustion gas enters the gas turbine 10 and expands to perform work. This work causes the generator 11 to rotate and generate an electrical output.

The combustion gas that has finished its work in the gas turbine 10 is kept at a high temperature (about 600 ° C.) and flows into the exhaust heat recovery boiler 12 as exhaust gas. Exhaust heat recovery boiler 12
Is provided with a superheater 13, an evaporator 14, and a economizer 15 along the flow of the exhaust gas, and the exhaust gas exchanges heat with steam or feed water. Due to this heat exchange, the exhaust gas has a low temperature (about 100 ° C)
And discharged through the chimney 16 into the atmosphere.

On the other hand, the steam generated by the evaporator 14 enters the superheater 13 via the steam drum 17, becomes superheated steam there, and flows into the steam turbine 19 through the steam control valve 18. This steam expands and performs work in the steam turbine 19. This work causes the generator 20 to rotate, generating electrical output. The steam that has finished the work becomes low-temperature wet steam, flows into the condenser 21, and is cooled to be condensed. This condensate is extracted by a condensate pump (not shown),
Through the economizer 15 and is heated by the exhaust gas,
It is sent to the evaporator 14 and becomes vapor.

By the way, in the IGCC, an electric output is generated by the generators 11 and 20 as described above, and the power generation output is adjusted by adjusting the opening of the fuel control valve 7 of the gas turbine device and the steam control valve 18 of the steam turbine 19. Adjusted and done. Further, the gas pressure is increased by adjusting the opening of the gasification fuel control valve 2 of the gasification furnace 1 to change the gas generation amount,
The output of the gas turbine 10 can be changed even if the fuel flowing to the gas turbine 10 is increased or decreased secondarily.

Of these three types of power generation output adjustment, the steam control valve 18 has a large response delay in energy transmission in the exhaust heat recovery boiler 12 and the steam control valve 1
Since the overall efficiency is better when the opening 8 is fully opened and the operation is performed in the variable pressure state, the operation in which the opening is kept constant is preferred. For this reason, both the fuel control valve 7 and the gasified fuel control valve 2 respond to the load fluctuation, and are the main operation ends of the whole plant load control. The oxygen control valve 3 is automatically controlled in response to a command to the gasification fuel control valve 2.

By the way, the quality of the load control of the whole plant is based on how fast and stable the load response can be achieved, and even if a large load fluctuation occurs, the load can be stably followed. When this load change occurs, it is necessary to follow the change in load while keeping the parameters of the plant within an appropriate range so that the equipment is not restricted. As described above, the opening of the fuel control valve 7 and the gasification fuel control valve 2 is controlled with respect to the load fluctuation of the entire plant. The control targets are power generation output and gas pressure.

For example, the fluctuation in gas pressure is caused by an increase or decrease in pressure that occurs when an imbalance occurs between the amount of gas generated in the gasifier 1 and the amount of gas consumed in the gas turbine device. For this reason, it is important in control to suppress an increase or decrease in pressure, that is, to keep the gas pressure constant.

As described above, in the load control of the IGCC plant, the fuel flow rate of the gas turbine 10 is controlled based on the load command, or the gas generation amount of the gasifier 1 is controlled while keeping the fluctuation of the gas pressure within an allowable range. Control will be optimal.

By the way, when the control of the gas pressure becomes unsatisfactory, or when an excessive load fluctuation occurs and it becomes difficult for the control to follow this, the plant protects the equipment in the system by the operation of the following protection device. Can be avoided. That is, when the pressure signal from the pressure detector 23 that detects the gas pressure in the purified gas path exceeds the pressure upper limit set value, the flare valve 25 is opened by the flare pressure controller 24 and the gas flowing toward the combustor 8 is discharged. A part is released to the flare stack 26 to prevent a rise in gas pressure.

Conversely, when the gas pressure decreases, the fuel for the gas turbine device can be switched from the refined gas to the auxiliary fuel to avoid stopping the operation of the gas turbine 10. That is, when the gas pressure falls below the set value, a control device (not shown) operates to switch from the purified gas by the fuel control valve 7 to the auxiliary fuel by the auxiliary fuel control valve 27, and to continuously supply the fuel corresponding to the load. It is possible. In addition, the fuel control valve 7 is fully closed by this switching of the fuel.

[0016]

In the IGCC plant, the power generation output and the gas pressure, which are controlled variables, are controlled by the gasification fuel flow rate to the gasifier 1 (the oxygen flow rate is controlled in accordance with the gasification fuel). The most important point in achieving desired control is how to feed back the fuel flow to the gas turbine device. Basically, the following three methods can be considered for this control method.

That is, the first control method is called a gasifier lead method, and the gasifier 1 is controlled by controlling the power generation output corresponding to the turbine follower method of a general thermal power plant.
The amount of fuel supplied to the gas turbine is controlled, and the control of the gas pressure that changes with this operation is performed by adjusting the gas consumption of the gas turbine 10 by the fuel control valve 7 of the gas turbine device.

The second control system is called a gas turbine reed system, and corresponds to the turbine reed system of a general thermal power plant. The fuel consumption of the gas turbine 10 is controlled by controlling the power generation output. Adjust with 7,
The control of the gas pressure is performed by adjusting the command value of the supply amount of the gasified fuel to the gasification furnace 1.

FIGS. 6 and 7 show examples of the first and second control methods. Each of these two control methods has its own characteristics. That is, in the gasification furnace lead system shown in FIG. 6, the opening degree changes to the gasification fuel / oxygen supply valve 28 due to the change in the power generation output command, and the amount of fuel input to the gasification furnace 1 increases. Although the pressure rises, there is a large delay in the change in pressure at the gas turbine inlet, and it takes time before the power generation output increases. However, as for the gas pressure in the system, the operation of the gas turbine fuel control valve 29 is quick, and the gas pressure is controlled to almost the target value.

On the other hand, in the gas turbine reed system shown in FIG. 7, the opening degree of the gas turbine fuel control valve 29 changes first due to a change in the power generation output command, and the gas consumption in the gas turbine device increases. That is, the power generation output follows the command at high speed. However, the gas pressure drops significantly. Since both the gasification process and the gas purification process are delayed with respect to the increase in the gasification fuel to the gasification furnace 1, the change in the gas pressure increases in proportion to the load change width of the power generation output command.
By the way, these two control methods are described in
No. 10 discloses this in detail.

In addition to the gas turbine lead system and the gasifier lead system, there is a system called a cooperative control system. In this system, as shown in FIG. 8, in addition to the gas turbine reed system, a feedforward signal generated based on a load command is given to the gasification process to increase the opening degree of the gasification fuel / oxygen supply valve 28. And gasifier 1
This makes it possible to improve the delay in increasing the gas pressure, which is a drawback of the gas turbine reed system. This method is described in a paper entitled "Examination of Load Followability of Integrated Coal Gasification Combined Cycle Power Plant" (Goto and Nagata et al., IEEJ Transactions, Vol. 110, No. 10, 1990).

According to this emphasis control method, since the load followability is also kept good, it is possible to approach the optimum control, and it will become the main control method in the future IGCC plant during normal operation. Is believed to be something.

However, the IGCC plant is required to increase the output per plant in the future, and it is expected that a plurality of combined power generation plants will need to constitute one plant. in this case,
The gasification furnace 1 and the desulfurization unit 6 are not necessarily limited to one gasification furnace in one combined power plant as described above because of the limitation of the capacity of a single unit or the possibility of purifying a large amount of gas with one unit. No combination of one and one desulfurizer 6 is performed.

For example, in order to increase the overall cost of the plant, only the desulfurization unit 6 is constituted by one or two lines, and the remaining gasification furnace 1 and the gas turbine unit are constituted by a plurality of lines, and the inlet of the desulfurization unit 6 is provided. It is expected that a merging using a gas header or a branching of the gas path to a plurality of gas turbine devices at the outlet of the desulfurization device 6 will be planned.

[0025] Even in an IGCC plant in which the equipment configuration is multi-system, it is necessary to respond to a load command from the central power supply command center as one plant. Therefore, in load control, it is necessary that a plurality of combined cycle power plants respond to the load command given to the plant in question, respectively. Further, for example, when three gasification furnaces are used, even if a load fluctuates, the gas pressure must be maintained at a constant value according to the pressure set value in any of the gasification furnaces. Furthermore, it is necessary to apply the above-described feedforward control method to gas pressure control in a preferable manner.

However, none of the conventional load control devices can meet these demands in a multi-line IGCC plant.

An object of the present invention is to provide an IGC composed of multiple streams.
It is an object of the present invention to provide a load control device capable of maintaining good load control and gas pressure control in a C plant.

[0028]

In order to achieve the above object, the invention according to claim 1 comprises a plurality of gasification furnaces for gasifying a gasified fuel, a plurality of gasification furnaces, and a plurality of dust removal units. In a combined gasification combined cycle power plant comprising a plurality of gas turbine devices, a device and a desulfurization device, and a combustion gas is obtained by burning a purified gas and generating an electric output by expanding in each gas turbine. An overall load control unit that controls the total output of the plant and the output of each gas turbine of the gas turbine device based on the load command, and controls the pressure of the purified gas to the gas turbine device and the flow rate of the gasified fuel supplied to each gasifier. An integrated gas pressure control unit, and a feedforward control unit that gives a fuel request generated based on the load command to the integrated gas pressure control as a feedforward signal. That.

In the load control device having the above-described configuration, a plurality of gas turbine devices can respectively handle corresponding outputs in response to a load command given as one plant. Further, even if the load fluctuates in the plant, it becomes possible to maintain the gas pressure between the plurality of gasifiers at a constant value according to the pressure set value. Further, since the feedforward signal is added to the fuel demand command, the responsiveness in the gas pressure control can be maintained well.

Further, according to a second aspect of the present invention, a centralized load controller outputs a load request signal based on a deviation between a load set value and a detected entire plant output signal. The gas turbine controller includes a plurality of gas turbine controllers that output a control signal for determining an opening degree of a fuel control valve of each gas turbine device based on a deviation from a gas turbine output signal.

In the load control device having the above-described configuration, a plurality of gas turbine devices can respectively handle outputs corresponding to a load command given as one plant by the general load controller and each gas turbine controller. .

Further, according to a third aspect of the present invention, a general gas pressure controller outputs a fuel request signal based on a deviation between a gas pressure set value and a detected gas pressure signal, and a fuel request signal. A plurality of gasifier controllers that output a control signal for determining the opening of the gasification fuel control valve and the oxygen control valve of each gasifier based on the deviation between the gasification fuel flow rate signal and the gasification fuel flow rate signal. It is assumed that.

In the load control device having the above configuration, even when a load fluctuation occurs in the plant by the general gas pressure controller and the respective gasifier controllers, the gas pressure between the plurality of gasifiers is controlled in accordance with the pressure set value. It can be kept constant.

According to a fourth aspect of the present invention, the gasifier controller outputs a control signal to the gasification fuel control valve and the oxygen control valve based on the difference between the fuel request signal and the gasification fuel flow rate signal. Instead, the control signal is output based on the deviation between the fuel request signal and the gasification furnace generated gas flow rate signal.

In the load control device having the above configuration, even when a load fluctuation occurs in the plant by the general gas pressure controller and the respective gasifier controllers, the gas pressure between the plurality of gasifiers is controlled in accordance with the pressure set value. It can be kept constant.

Further, in the invention according to claim 5, the feedforward control section calculates a required fuel flow rate based on a load set value given from the general load control section and outputs the calculated fuel flow rate as a feedforward signal to the general gas pressure control section. It is characterized by comprising a computing unit that performs the following.

In the load control device having the above configuration, the feedforward signal given from the arithmetic unit is added to the fuel request command, so that the response in the gas pressure control can be maintained well.

Further, the invention according to claim 6 is characterized in that the general load control unit includes a gain correction circuit for changing the control gain of the general load controller according to the number of operating gas turbine devices.

In the load control device having the above configuration, the gain can be changed by the gain correction circuit according to the number of operating gas turbine devices, and the load controllability can be improved.

Further, the invention according to claim 7 is provided with a gain correction circuit for changing the control gain of the general gas pressure controller according to the number of gasifiers operated by the general gas pressure control unit.

In the load control device having the above configuration, the gain can be changed by the gain correction circuit in accordance with the number of operating gasifiers, so that the gas pressure controllability can be improved.

[0042]

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, the IGCC plant has three gasifiers 1, a dust remover 4 and a gas cooler 5.
And two desulfurization devices 6. Further, the combined power generation system includes three gas turbine devices 30. Each of the three gas turbine devices 30 is provided with the fuel control valve 7 in an independent gas path.

The IGCC plant has a load control device comprising the following means. That is, based on the load set value a given to the plant, the gas turbine device 30
As a function of controlling the total output of the steam turbine 19, a general load control unit 31 is provided. The general load control unit 31 is provided with the gas turbine output signals b and c of each gas turbine device 30 as feedback signals.
In addition, the overall load control unit 31 includes each gas turbine device 30.
Gas turbine output signals b, c, d of the steam turbine 1
The total plant output signal f, which is obtained by adding the turbine output signal e of No. 9 to the turbine output signal e, is provided as a feedback signal.

In the overall load control unit 31, a deviation from the load set value a is obtained by an overall load controller described later, and the output is given to the gas turbine controllers of the gas turbine units 30 to control the fuel adjustment of the gas turbine units 30, respectively. A control signal for determining the opening of the valve 7 is output.

Further, a general gas pressure control unit 32 is provided as a function of controlling the gas pressure to be constant based on the gas pressure set value g of the plant. A gas pressure signal h detected by a pressure detector 33 at the outlet of the desulfurization device 6 is given to the general gas pressure control unit 32 as a feedback signal. The integrated gas pressure control unit 32 is supplied with gasification fuel flow rate signals i, j, and k detected by the flow rate detectors 34a, 34b, and 34c at the gasification furnace 1 as feedback signals.

In the general gas pressure control unit 32, a deviation from the gas pressure set value g is obtained by a general gas pressure controller described later, and its output is given to the gasification furnace controller of each gasification furnace 1, and each gasification furnace is controlled. 1 gasification fuel control valve 2
And a control signal for determining the opening degree of the oxygen control valve 3 is output.

Further, there is provided a feed-forward control unit for maintaining good response of the gas pressure control. That is,
The computing unit 35 is provided with a load set value a given to the overall load control unit 31 as an input, and a required fuel flow rate is calculated. The fuel flow rate request is given to the general gas pressure controller 32 as a feedforward signal l.

FIG. 2 shows details of the general load control unit 31, the general gas pressure control unit 32, and the feedforward control unit. The overall load controller 31 includes an overall load controller 36 and a controller 37. The overall load controller 36 calculates a deviation between the load setting value a of the plant and the total plant output signal f, and outputs a load request signal to each gas turbine controller 37 so that the deviation becomes zero.

The gas turbine controller 37 calculates a deviation between the applied load request signal and the gas turbine output signals b, c, d, and sends an opening control signal to each fuel control valve 7 so that the deviation becomes zero. Output to Further, the overall load control unit 31 includes a gain correction circuit 38. The gain correction circuit 38 can change the control gain of the general load controller 36 according to the number of operating gas turbines. That is, when one or two gas turbine devices 30 are operating, the gas turbine device 30 can be used to maintain a large gain to improve load controllability.

The general gas pressure controller 32 includes a general gas pressure controller 39, an adder 40, and a gasification furnace controller 41. The general gas pressure controller 39 calculates a deviation between the gas pressure set value g and the gas pressure signal h, and adds the fuel request signal to the adder 40 so that the deviation becomes zero.
Is output to each gasification furnace controller 41 via.

Further, each of the gasifier controllers 4
1 is a given fuel demand signal and gasification fuel flow rate signal i,
A deviation from j and k is calculated, and an opening control signal is output to each gasification fuel control valve 2 and oxygen control valve 3 so that the deviation becomes zero. Further, the overall gas pressure control unit 32 includes a gain correction circuit 42. The gain correction circuit 42 controls the overall gas pressure controller 39 according to the number of operating gasifiers 1.
Can be changed. That is, 1
When one or two gasifiers 1 are in operation, the gain is kept large to improve the gas pressure controllability.

On the other hand, the feedforward signal 1 calculated by the calculator 35 according to the load set value a given from the general load control unit 31 is added to the fuel request signal which is the output of the general gas pressure controller 39 in the adder 40. It is configured to:

This embodiment has the above configuration.
Based on the plant load target value from the central power supply command center or the like, a ramp-shaped load set value a having a certain load change rate that is permitted by the plant is given to the overall load control unit 31. The integrated load controller 36 compares this load set value a with the plant total output signal f, and outputs a load request signal taking into account a gain determined by the number of operating gas turbines to each gas turbine controller 37. Each of the gas turbine controllers 37 compares the load request signal with the gas turbine output signals b, c, and d, and outputs an opening control signal for determining the amount of fuel to be supplied to each gas turbine device 30 to each fuel control valve 7. . As a result, the output of each gas turbine device 30 changes based on the given load set value a, and each can take charge of a corresponding output.

On the other hand, the gas pressure in the system is kept constant as follows. The reverse operation occurs in the system due to the fluctuation of the gas pressure when the load command increases and when the load command decreases. Here, the case where the load command increases will be described as an example. The control operation in the case of decrease is reversed.

When the gas turbine load increases, the fuel control valve 7 opens, and at this time, the gas pressure decreases. The general gas pressure controller 39 of the general gas pressure control unit 32 operates by the fluctuation of the pressure. The gas pressure signal h detected by the pressure detector 33 decreases, and the deviation from the gas pressure set value g increases. The fuel request signal from the general gas pressure controller 39 increases, and the feedforward signal 1 from the calculator 35 for calculating the fuel flow rate from the load set value a is added to the fuel request signal by the adder 40. A fuel request signal obtained by adding the feedforward signal 1 is output to each gasification furnace controller 41, and the opening control signal for determining the input gasification fuel amount is calculated by comparing with the gasification fuel flow rate signals i, j, and k. It is output to the fuel gas control valve 2 and the oxygen control valve 3.

At this time, the fuel demand signal to which the feed forward signal 1 is added and the gasification fuel flow rate signals i, j, k
A large deviation occurs between the gaseous fuel control valve 2 and the oxygen control valve 3 by the opening control signal, so that the gasified fuel and the oxygen control the gasified fuel control valve 2 and the oxygen control valve 3 respectively. And flows into the gasifier 1. As a result, more gasified fuel can enter the gasification process in each gasification furnace 1, and a larger amount of fuel can be supplied to each gas turbine device 30 through the purification process by each dust removal device 4 and desulfurization device 6. It becomes possible to supply.

The gas pressure signal h given to the general gas pressure controller 39 is based on the pressure detector 3 provided in the desulfurization unit 6.
Instead of 3, a gas pressure signal detected by a pressure detector disposed at the inlet of the desulfurizer 6 may be used.

In a plant in which a header is provided at the outlet of the gasifier 1, a pressure detector may be provided at the outlet of the gasifier 1, and the output may be used as a feedback signal.

As described above, according to the present embodiment, a plurality of gas turbine devices 30 can respectively handle corresponding outputs in response to a load command given as one plant. Further, even if a load fluctuation occurs in the plant, the gas pressure among the plurality of gasifiers 1 can be maintained at a constant value according to the pressure set value. Further, since the feedforward signal is added to the fuel demand command, the responsiveness in the gas pressure control can be maintained well.

Further, another embodiment of the present invention will be described. In the above-described embodiment, the feedback signal to be given to the gasification furnace controller 41 of the integrated gas pressure control unit 32 and serving as a guide of the output of each gasification furnace 1 uses the gasification fuel flow rate signals i, j, and k. As shown in FIG. 3, it is possible to use the generated gas flow rate signals m, n, and o detected by the flow rate detectors 43a, 43b, and 43c.

Incidentally, an oxygen flow rate signal to the gasifier 1 may be used in place of the generated gas flow rate signals m, n, and o of the present embodiment.

In this embodiment, the same effects as in the above embodiment can be obtained.

Further, another embodiment will be described. FIG.
In, an adder 44 is provided on the output side of each gasification furnace controller 41, and the feedforward signal 1 from the calculator 35 is added to the output of the gasification furnace controller 41.

Also in this embodiment, since the feedforward signal 1 is added or subtracted, the opening control signals for the gasification fuel control valve 2 and the oxygen control valve 3 change accordingly, and the gas pressure control is performed. Responsiveness can be kept better.

[0065]

As described above, according to the present invention, 1
In response to a load command given as a plant, a plurality of gas turbine devices can each take charge of a corresponding output. Further, even if a load fluctuation occurs in the plant, the gas pressure can be maintained at a constant value between the plurality of gasifiers according to the pressure set value. Further, since the feedforward signal is added to the fuel demand command, the responsiveness in the gas pressure control can be maintained well.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a load control device for an integrated gasification combined cycle power plant according to the present invention.

FIG. 2 is a block diagram showing details of a general load control unit and a general gas pressure control unit shown in FIG. 1;

FIG. 3 is a block diagram showing another embodiment of the present invention.

FIG. 4 is a block diagram showing another embodiment of the present invention.

FIG. 5 is a system diagram showing an example of a conventional integrated gasification combined cycle power plant.

FIG. 6 is a block diagram showing an example of a conventional plant load control system using a gasifier lead system.

FIG. 7 is a block diagram showing an example of a conventional plant load control system using a gas turbine lead system.

FIG. 8 is a block diagram showing an example of a plant load control method using a conventional cooperative control method.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 gasification furnace 2 gasification fuel control valve 6 desulfurization device 7 fuel control valve 30 gas turbine device 31 general load control unit 32 general gas pressure control unit 35 computing unit 36 general load controller 37 gas turbine controller 39 general gas pressure controller 41 gas Furnace controller

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI F02C 9/40 F02C 9/40 Z

Claims (7)

[Claims] 1. A plurality of gasifiers for gasifying a gasified fuel, a plurality of dust removers and a desulfurizer for purifying a produced gas, and a combustion gas obtained by burning a purified gas; In a gasification combined cycle power plant comprising a plurality of gas turbine devices, which expands in each gas turbine to generate an electric output, based on a load command, the total plant output and each gas turbine output of the gas turbine device And a general gas pressure control unit for controlling the pressure of the purified gas to the gas turbine device and the flow rate of the gasified fuel supplied to each gasifier, and a fuel generated based on the load command. A load control device for a combined gasification combined cycle power plant, comprising: a feedforward control unit that gives a request to the integrated gas pressure control as a feedforward signal. 2. An integrated load controller, wherein the integrated load control unit outputs a load request signal based on a deviation between a load set value and a detected entire plant output signal, and a load control signal between the load request signal and each gas turbine output signal. The load of a combined gasification combined cycle plant according to claim 1, further comprising a plurality of gas turbine controllers that output a control signal for determining an opening of a fuel control valve of each of the gas turbine devices based on the deviation. Control device. 3. A general gas pressure controller, wherein the general gas pressure control unit outputs a fuel request signal based on a deviation between a gas pressure set value and a detected gas pressure signal, a fuel request signal and a gasified fuel flow signal. A plurality of gasification furnace controllers for outputting a control signal for determining the degree of opening of the gasification fuel control valve and the oxygen control valve of each gasification furnace based on a deviation from the gasification furnace. A load control device for an integrated gasification combined cycle plant as described in the above. 4. The method according to claim 1, wherein the gasification furnace controller outputs a control signal to the gasification fuel control valve and the oxygen control valve based on a deviation between the fuel request signal and the gasification fuel flow rate signal. 4. The load control device for an integrated gasification combined cycle plant according to claim 3, wherein a control signal is output based on a deviation between the signal and a gasification furnace generated gas flow rate signal. 5. An arithmetic unit for calculating a required fuel flow rate based on a load set value provided from the general load control unit, and outputting the calculated fuel flow rate as a feed forward signal to the general gas pressure control unit. The load control device for an integrated gasification combined cycle plant according to claim 1, further comprising: 6. The integrated gasification combined cycle system according to claim 2, further comprising a gain correction circuit that changes a control gain of the general load controller according to the number of the gas turbine devices operated by the general load control unit. Plant load controller. 7. The gain control circuit according to claim 3, further comprising: a gain correction circuit for changing a control gain of said general gas pressure controller according to the number of said gasifiers in operation of said general gas pressure controller. Load control device for combined gasification combined cycle plant.