JPH02298633A - Coal gasifying combined cycle power generation plant - Google Patents

Abstract

PURPOSE:To improve the controllability for gas pressure by making an output to follow a target value in response to a change of the target value of a generated output for holding the pressure constant while precedingly changing gas generation quantity in accordance with variation of the generated output in consideration of the quantity of gas to be necessary at the time when pressure difference is generated. CONSTITUTION:In the power generating plant in the title, having a gas turbine 9 using coal gas generated in a gasifying furnace 3 as a fuel and a steam turbine 15 using heat due to exhaust gas of a gas turbine, a generated output control unit (gas turbine control unit) 21 for controlling a fuel flow adjusting value 6 is provided in order to make the generated output to follow target value thereof by receiving the target value of the generated output. Besides, a pressure control unit (gasifying furnace control unit) 20 for controlling a slurry supply pump 2 and an oxygen flow adjusting valve 1 and holding gas pressure to a set value is provided. Furthermore, a gas flow setting unit (load control unit) 18 for predicting gas system pressure distribution change occurring due to change in gas flow at a time of changing the target value of the power generation output and calculating gas flow rate corresponding to the pressure distribution at the time is provided.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to a coal gasification combined cycle power generation plant, and particularly to an output/pressure control device section that controls the power generation output and generated gas pressure. This invention relates to a coal gasification combined cycle 112 plant that has been improved.

(Conventional technology) The coal gasification bind cycle gasifies coal, uses this gas as fuel gas to drive a gas turbine to operate a generator, and also recovers heat from the exhaust gas of the gas turbine. This is a cycle in which the steam turbine is driven by steam to operate the generator. This coal gasification combined cycle has been developed in recent years and has already been put into practical use because it has great advantages such as effective use of coal, ease of desulfurization, and superior environmental measures.

Figure 3 shows an outline of a coal gasification combined cycle power plant. lli as an oxidizing agent! 21
A is fed through an oxygen flow control valve 1, coal and water slabs are fed together through a slurry feed pump 2, and gasification is fed to 3. Note that some gasifiers 3 are of a type to which air is supplied as an oxidizing agent and pulverized coal is supplied instead of slurry.

Slurry or pulverized coal (hereinafter referred to as slurry) and oxygen or air as an oxidizing agent (hereinafter referred to as oxygen)
This means that a gasification reaction occurs in the gasifier 3, and high-temperature crude gas is generated. The crude gas generated in the gasifier 3 is sent to the gas cooler 4 and cooled to a temperature at which it can be processed at the gas purification installation a5. In the gas purification equipment 5, dedusting and desulfurization are performed, and the crude gas becomes clean gas and is passed through the fuel flow control valve 6.
is sent to the combustor 7 via the combustor 7. And compression f! It is mixed with compressed air sent from 18 and used for combustion. This combustion gas drives the gas turbine 9, which generates the
0 operation is performed.

On the other hand, a steam drum 11 is connected to the gas cooler 4 via a pipe 11a. In the gas cooler 4, water as a refrigerant is heated by heat exchange to become steam, and this steam is guided to the steam drum 11.

Furthermore, the exhaust gas from the gas turbine 9 is transferred to the exhaust heat recovery boiler 1.
2, where also steam is generated by heat exchange with water, and this steam is led to another steam drum 13. The steam generated in the gas cooler 4 and the steam generated in the exhaust heat recovery boiler 12 are combined by a steam pipe 13a, and sent to the steam turbine 15 via the steam control valve 14 to drive the steam turbine 15 and the power generation v116. do. In some cases, the steam turbine 15 and the gas turbine 9 are connected by a single shaft and share a single generator.

The power generation output of the coal gasification bind cycle power generation plant configured as described above is the sum of the power generation output by the gas turbine 9 and the power generation output by the steam turbine 15.

The power generation output of the gas turbine 9 is determined by the amount of fuel to be combusted. In addition, the power generation output of the steam turbine 15 is
It is determined by the heat possessed by the exhaust gas of the gas turbine 9 and the heat recovered from the gas cooler 4, and can be adjusted depending on the amount of fuel combusted by the gas turbine 9. That is, the load on the power plant can be increased or decreased by adjusting the flow rate of gas sent to the combustor 7 of the gas turbine 9 using the fuel flow ma control valve 6.

Note that if the inlet pressure of the gas turbine fuel flow control valve 6 drops too much, there will be no pressure difference with the combustor 7, making it easier for the fuel flow control valve 6 to fully open, deteriorating the fil controllability. will no longer be supplied. Moreover, if the pressure rises too much, there is a risk that it will exceed the design pressure of the equipment, and it will be necessary to release the pressure to the outside. Therefore, the pressure of the generated gas is maintained within a certain range, and a stable gas supply to the combustor 7 of the gas turbine 9 is achieved. Efforts will be made to stabilize the operation of J equipment and ensure the safety of each piece of equipment. Specifically, by increasing or decreasing the amount of oxygen and slurry supplied to the gasifier 3, the amount of generated gas can be increased or decreased, and the amount of gas consumed by the gas turbine 9 can be adjusted by changing the fuel flow @
It is increased or decreased by operating the control valve 6. The pressure of the gas in the gas system from the gasifier 3 to the gas turbine 9 is determined by the amount of gas remaining in the system, so the gas pressure is determined by the amount of oxygen, slurry supply, and consumption in the gas turbine. It can be adjusted by changing the amount etc. Generally, the output and gas pressure of a coal gasification combined cycle power plant are controlled so as to maintain the gas pressure at a set value and to make the power generation output follow a target output value.

FIG. 4 shows a power generation output/gas pressure control device in a conventional coal gasification fuel oil power generation plant. The rate of change of the output target value 19 is limited by a rate of change limiter 29 so that the rate of change is within the rate of change set by the rate of change upper limit setter 30, and that value is further limited by an output lower limit setter 31 and an output upper limit setter 32. The upper and lower limits are limited by the high value selector 33 and the low value selector 34 so that it falls within the set range, resulting in the output J command value 35. The power generation output signals of the generators 10.16 of the gas turbine 9 and the steam turbine 15 are added to each other by an adder 23, and this and the output command Vi35 are compared and calculated by the adjustment calculator 24, and then the output signal is sent to the first sub-loop controller 27. sent to. In addition, steam turbines, generators,
In the case where the gas turbines are connected by a single shaft and the steam turbine and the gas turbine generator are both connected to form one unit, the following operation is performed in the same manner using only the output signal of the generator. The gas pressure is detected by the pressure transmitter 22, and the detected gas pressure and the pressure setting value set by the pressure setting device 26 are compared and calculated by the adjustment calculator 25 and sent to the second sub-loop υ control device 28. . Adjustment performance fjZ2/1.2
Although the P■ controller having proportional + integral action is applied to No. 5, the same applies to a controller having only proportional action or proportional + integral and sufficient differential action.

Furthermore, although not shown, a correction signal may be added to the output command value due to deviation of the power system frequency from the reference value.

The first and second subloop control devices 27 and 28 are the gasifier control device 20 or the gas turbine control device 21 in FIG.
Either. When the first sub-loop 1, 11111 necking 27 is the gas turbine control device 21, the second
The subloop control device 28 is the gasifier control device 20, and at this time, the control wave C1 result regarding the load is sent to the gas turbine control device 21. Therefore, a command signal is generated to the fuel Rffi control valve 6 of the gas turbine, and based on this command, the fuel in the gas turbine 9 is adjusted or decreased to change the power generation output. On the other hand, the result of the pressure control is sent to the gas furnace υ1 controller 20, where a command signal is created for the slurry supply pump 2 and the oxygen flow control valve 1, and based on this command, gasification is performed. The amount of slurry and oxygen introduced into the furnace 3 is adjusted to change the gas pressure.

The mode in which the load control device 18 and the first and second sub-loop control devices 27 and 28 configured in this manner are combined is based on the mode in which the power generation output is mainly changed.
This is called gas turbine lead mode.

Figure 5 shows the control device in gas turbine lead mode.
A modified example is shown. That is, the function generator 37 generates a feedforward signal to the gasifier controller 20 using the power generation command value 35, and this signal and the signal from the adjustment operator 25 are added by the adder 23. Chemical furnace control device 20
It generates the command value. Generally function generator 37
In this case, a signal is created based on the steady relationship of the gasifier output with respect to a certain power generation output, and when the power generation command value 35 or the power generation output 36 changes, the signal is generated so that the gasifier output is followed in advance. The command value to the chemical furnace control device 20 changes. Corrections due to changes in gas pressure are then applied from the adjustment calculator 25 to correct deviations in gas pressure.

When the combination of the load control device ¥118, the gasifier control device 20, and the gas turbine control device 21 is reversed to the above, that is, the first subloop control device 27 is the gasifier a, 11 In device 20 , and the second probe 1
When the 1 control device 28 is the gas turbine control device 21, the 1III 111 calculation result for the load is sent to the gasifier 1-1 gasifier 20, where the slurry feed pump 2 and the oxygen flow ffi control valve 1 are command signal is obtained,
The amounts of slurry and oxygen introduced into the gasifier 3 are adjusted. On the other hand, the control calculation result regarding the pressure is sent to the gas turbine control device 21 and converted into a command signal to the fuel flow ffi control valve 6, which works to adjust the amount of fuel in the gas turbine to keep the pressure constant. In this case, when trying to increase the load, first increase the amount of slurry and oxygen input into the gasifier 3. As a result, the gas pressure in the system tends to increase, but this is suppressed by consuming fuel in the gas turbine, thereby increasing the power generation output under constant pressure conditions. A mode in which such a-control is performed is called a gasifier lead mode.

These control systems are based on conventional thermal power plant control systems (turbine lead and boiler lead, respectively). Coal gasification combined cycle power generation plants have dynamic characteristics as described below due to the characteristics of the blunt equipment, and the above-mentioned aJI
There are problems with using your method as is. First, we will explain the dynamic characteristics of a coal gasification combined cycle power plant and problems with conventional control based on this.

As mentioned above, one gas line in a coal gasification bind cycle power generation plant includes a gasifier 3 and a gas cooler 4.
, a gas purification facility 5, a gas turbine fuel flow control valve 6, and a gas turbine w1 combustion control valve 7. FIG. 6 shows the relationship between the volume of these shells and the gas pressure. Although the gasifier 3 to gas cooler 4 occupies most of the volume, the gas pressure loss is small, and although the gas purification equipment 5 occupies a small volume, the gas pressure loss in this area is large. The pressure of the gas is increased from gas cooler 4 onward to fuel flow I.
! It is measured up to the inlet of the i control valve 6 and is used for υ1, but here it will be explained assuming that it is measured midway through the gas purification equipment 5.

The relationship between changes in power generation output and gas pressure will be explained with reference to FIG. 6. plan! When ・ is in a steady state and the power generation output is large, the pressure loss becomes large because there is a lot of gas being diverted, and the pressure is a-b-c- from the gasifier to the fuel flow control valve.
It becomes like d. When the power generation output is small in steady state, the gas flow m is small, so the pressure loss is small and the pressure is a b
1c 1-d. Since the pressure is controlled at point C (C1), this point C (C1) is fixed during steady state. Now, if the power generation output is increased by increasing the amount of gas m consumed by the gas turbine and the gas generated by the gasifier at the same rate from a state where the power generation output is small, the amount of gas generated and the amount consumed will be balanced. Therefore, the pressure changes due to the increase in pressure loss due to the increase in flow rate, and a - b -
From cl-dl state a -b c s d
3, the pressure at the pressure detection point and before the fuel flow control valve 6 decreases significantly. In order to increase the pressure at the pressure detection point from this state to the set value, since gas pressure and gas density have the same relationship, if we consider the vertical axis of the figure to be gas density instead of pressure, we can obtain a -b-c-d
It can be seen that flat gas corresponding to the concave volume of -d -c -bl-al must be further generated from the gasifier 3.

Conversely, if the power generation output is reduced by reducing the amount of gas consumed by the gas turbine and the amount of gas generated by the gasifier at the same rate from a state where the power generation output is high, the amount of gas consumed and the amount of gas generated will be balanced. Because of this, the pressure is ili! Due to the decrease in pressure loss due to the decrease in ffi, the state changes from a-b-c-d to a.
-b-c2-d2, and the pressure at the pressure detection point and in front of the fuel flow control valve increases significantly. In order to lower the pressure at the pressure detection point to the set value from this state, a-
It can be seen that the same gas corresponding to the area surrounded by b-C-d-d-C-bl-81 must be reduced.

Strictly speaking, in the above explanation, due to the gas accumulation effect of the gas purification equipment, the above-mentioned increase/decrease period of gas is alleviated a little, but
Basically, the situation is as described above.

As is clear from the above explanation, in order to keep the gas pressure at the pressure detection point constant, it is necessary not only to maintain the gas generated in the gasifier at the same ratio as the gas m consumed by the gas turbine, but also to maintain the gas pressure at the gas turbine. The gap between gases must be adjusted due to density changes.

This will be explained in Section 7 regarding the case of changing the power generation output.
This will be explained with reference to the figure and ff18 diagram. The power generation output, gas generation m and consumption m in a steady state have a linear relationship as shown in Figure 'I57. Of the gas generated in the gasifier, a very small amount is consumed outside of the gas turbine, or is used for de-1iI! Strictly speaking, the generated gas flow rate and the consumed gas flow meter are not the same, but the difference is small so it can be ignored.

An explanation will be given of when the power generation output changes with reference to FIG.

As shown in the power generation output shown in Fig. 8, when the consumption amount of the gas turbine is changed in order to change the output, as explained in Fig. 6, as the gas flow M changes, the pressure horn loss also changes. In order to keep the gas pressure constant, extra gas must be generated in the gasifier in response to the loss of pressure. For this reason, it is desirable that the gas flow rate generated in the gasifier changes to the large flow 1 side as shown by the constant chain line when changing.

Conventional power generation output/pressure control devices do not have a configuration that directly reflects the current customer's output command value to the gas generator in the gasifier 3, that is, the gasifier control device 20. do not have. In other words, with general gas turbine lead and gasifier lead control, the output and pressure are controlled independently as described above, and the gas other furnace fl is controlled according to the power generation output.
An output command value to the llJ headpiece 20 has not been created.

Furthermore, regarding the advance command from the output command value at the time of gas turbine lead shown in FIG. Increases and decreases in gas generation during transient periods are not considered. Therefore, when increasing the power generation output, the fuel consumption i11. :JJ - As a preceding element, the output command value is output to the gas other furnace υIll device, but in this case, as explained using Fig. 6,
Since it only has the effect of balancing the power generation gas flow and the consumption gas flow, the gas pressure will be low Ti. When the gas pressure decreases in this way, the pressure control adjustment calculator 25
changes the output and increases the command value to the gasifier υ1n device, thereby increasing the gas flow in the gasifier and restoring the pressure.

(Problems to be Solved by the Invention) As described above, in the conventional coal gasification combined nacre power generation plant, the power generation output and gas pressure are all
The equipment is configured to understand the transient characteristics of the blunt.

The present invention was made in view of these f and r circumstances,
The purpose of the present invention is to provide a coal gasification combined cycle power plant that can improve controllability during transient times.

(Structure of the Invention) (Means for Solving the Problems) The present invention provides a coal gasification combined system having a gas turbine that uses coal gas generated in a gasifier as fuel, and a steam turbine that uses heat from gas turbine exhaust gas. The cycle power generation bran has a power generation output/gas pressure 1.IIυp device that controls the power generation output and gas pressure, and this power generation output/gas pressure control device receives the power generation output target value and controls the power generation output and gas pressure.
), a power generation output υ control section that makes the power generation output follow the I5 value, a pressure horn control ti1 section that maintains the gas pressure at the set value, and tII! from each of these control sections. an output section that outputs a control signal sound signal as a command value to the turbine and gasifier;
A system that predicts changes in the pressure distribution of the gas system caused by changes in the gas flow m when the power generation output target value changes, calculates the gas flow rate corresponding to the pressure distribution, and changes the gas flow rate at a certain time. The feature is that it is equipped with a flow rate setting section.

(Function) According to the present invention, when the power generation output target value changes,
Gas turbine according to the difference between the actual power generation output! +11
A command value for the i device is created. Not only the command value based on the difference from the set pressure value, but also the predicted value of the gas flow rate required due to the change in the power generation output target value is added to the gasifier, and this added value is given as the command.

(Embodiment) Hereinafter, as a practical example of the present invention, a gas turbine having a υ control device using a lead will be described with reference to FIG. Incidentally, since the general structure of the cycle is the same as that of the conventional one, FIG. 3 will be used as is for explaining the embodiment.

The output target value 19 is input to a function generator 39, which generates an estimated value of the gas cooler pressure when the target value is reached. The pressure difference between this estimated value and the pressure transmitter 50 that measures the pressure of the gas cooler is multiplied by a coefficient in the proportional calculator 41, and the required gas skewer is calculated based on the pressure difference until the power generation output reaches the target value. be done. This suspension is divided by the time opening that the boat should achieve to determine the gas flow rate per hour.

This gas flow rate and the gas flow rate determined by the function generator 37 as the steady state gas flow rate based on the output command value 35 are added by the adder 47, and the proportional calculator 51 adds the gas flow rate to the gas flow rate determined by the function generator 37 as the gas flow rate in the steady state. II
III' is converted into a command value for the fi position and sent to the second subloop t, If tll device 28 (here, the gasifier control device).

By giving the gas to be generated in the gasifier 3 when changing the power generation output as a command value to the gasifier controller 20 in the flow rate state shown in FIG. 8, the gas pressure in the gas turbine lead mode can be adjusted. Improve controllability.

6 and 8, as explained in detail, when changing the power generation output, the gas r that should be generated in the gasifier
is changed to the steady state gas flow rate in consideration of the change in pressure at the pressure detection point due to a change in pressure of 1.

Power generation output target lit! Change rate limiter 2 so that when +9 changes, the change rate is within the change rate set by change rate setting value 30.
The rate of change is limited in step 9, and the lower limit value of the output set by the lower limit setter 31 is compared with the high 1I11 selector 33, and a signal that is equal to or higher than the lower limit of the output is selected. Furthermore, the upper limit value of the output − set by the upper limit setter 32 and the low! Ti
The selected value is compared with the selector 34 and becomes below the upper limit of the output, which becomes the output command value 35.

The signals from the gas turbine generator 10 and the steam turbine generator 16 are then added together to form the plant output signal 36.
is required. The adjustment calculator 24 issues an output command! f135
and the blunt output 36 are compared to create a command value for the gas turbine control device 420 (the first Y-probe interrogator 27 in FIG. 1). The adjustment calculator 24 is
If the power generation output command value 35 is higher than the output signal 36, a command value is generated to the gas turbine control device to increase the output.

A change signal for one power generation output target value is sent to a separate function generator 39.
The predicted value of the gas cooler pressure when the target value is reached is determined at step A. This and the signal from the pressure transmitter 50, which is a measurement of the existing pressure in the gas cooler, are connected to the reducer 4.
The pressure difference is obtained by cutting off at 0. From this pressure difference, the gas R required for the pressure change is determined by the proportional calculator 41.

The difference between the power generation output target value 19 and the power generation output 1h value 35 is determined by the subtractor 42. The result of this reduction is absolutelylllllI
is output as This power generation output difference is divided by J: by the rate of change determined by the change 5t-4 setting 2S30 in the divider 43, and the time during which the change takes place is determined.

In this case, the signal generator 45 sets the shortest change time, and the t5 value selector 33 compares it with the σ result of the divider 43 to select the longer one. With this change time, the proportional performer 4
By dividing the gas load obtained in step 4 using the divider 46,
Gas FItEi per hour is determined. This is the gas flow rate for generating the necessary gas due to the pressure difference caused by the change in output.

Furthermore, the amount of gas generated in a steady state commensurate with the gas consumption of the gas turbine is determined by the function generator 37 from the power generation output 1st generation value 35.
The command values of the two gases *a are added by the adder 47. This is the proportional generator 51 and the gasifier υII
II device 2 (here, the second slope t, II l
It is converted as a command value to the IT equipment 28).

The gas pressure at the pressure 111 control detection point measured by the pressure transmitter 22 and the signal from the pressure setting device 26 are compared in the adjustment calculator 25 to generate a signal to maintain the pressure at the set value. Ru. This signal and the signal from the proportional calculator 51 generated by the ye electric ratio output target command value are combined into the adder 48.
is added, and becomes the Iε command value for the gasifier υ11Il device.

When the target value of the power generation output changes, the output port e'Afi'f
Based on the signal 19, a function generator 39 generates an expected value of the gas cooler pressure when the target value is reached. The difference between the measured value of the existing pressure obtained from the pressure transmitter 350 17 is determined. Since pressure and gas density have a nearly linear relationship, the proportional meter q device 41 determines the amount of gas required based on the pressure horn difference. This is expressed by the following relationship. In the case of a perfect gas, the formula PV=mRT (P: pressure, m: molar ffi, R: gas constant) ■=volume, ■=hot water temperature holds, so from this, the molar value for the difference ΔP between the two pressures is The difference Δm in m is determined by the following formula.

P V = m 1RT P2v-m2RT ΔPV-ΔmRT Since the composition and temperature of the gas are approximately constant, everything other than ΔP may be approximately constant in the right sword of the above equation.

Also, since the left side b can be regarded as ω instead of Φ, ΔW = becomes ΔP (ΔW: Gas Hatake, ΔP: pressure difference), and when changing the power generation output to the target value, the pressure difference becomes J:
Then, mΔW of the required gas is determined.

Power generation output l] The time required for the output to change is determined by dividing the difference between the reference level 19 and the output command value 35 by the output change rate.

When the gas flow FF1G-ΔW/T is obtained by dividing the gas amount ΔW by the time T using the divider 46, the gas flow rate ff1G-ΔW/T is obtained, which is required due to the change in pressure loss when the power generation output 1lll11 target value changes The amount of gas is changed by V as the output changes, resulting in a gas flow rate.

Furthermore, the steady-state value of the gas flow m to be generated in the gasifier is determined by the function generator 37 with respect to the existing power generation command value 35,
This and the gas flow 1 found earlier! By adding 1G with the adder 47, the gas flow rate required when the power generation output changes can be determined.

The relationship between the gas flow rate generated in the gasifier and the command value of the gasifier control device (here, the second Zabloop control device 28) also shows that the gas flow rate and the coal consumption M change linearly. From this, it can be determined using the proportional meter G1''551.

The difference in the control pressure at the detection point is obtained as a correction value to the command value to the gasifier i/J m device by the pressure iIi+control (here, the adjusting bell 25). To this, proportional calculation core 5
1 and the output J are added by adding ^48, and the gasifier control device (
Here, it is sent to the second sub-loop in+ device 28).

In this way, when the power generation output target value changes, the pressure of the pressure transmitter 22 changes from the set value 26. Since the gas Cf1t to be generated in the gasifier is given to the III device in advance as a command 11fl, including the pressure loss, the IllI when the Rm output changes
The pressure change at point IIll becomes small.

FIG. 2 shows, as another embodiment of the present invention, a υ control configuration in the gasifier lead mode. The amount of generated gas predicted by the change in the power generation output port jfA value is added to the signal from the adjustment calculator 24, and is used as a command value to the gasifier control device 221 (here, the first sub-117 control device 27). Also,
The gas turbine il+ 10 B Fi performs a pressure test.

In this embodiment as well, similarly to the above-described embodiment, by giving a command value to the gas other furnace control tIl device in advance, it is possible to improve the followability of the power generation output to the target value.

In addition, in the description of the above embodiment, the pressure transmitter 50 was described as a device that measures the pressure in the gas cooler section.
The measurement position n is not limited to the gas cooler section, but can be arbitrarily selected as long as it has a small pressure loss and occupies a large volume as shown in FIG.

Further, although the Jl output command signal 35 is used for comparison with the power generation output target value and for measuring the total gas flow N during steady state, the same effect as described above can be achieved by using the power generation output signal 36.

〔Effect of the invention〕

As described above, according to the present invention, in addition to the conventional function of keeping the pressure constant by making the output follow the target value in response to changes in the target power generation output value, Since the amount of gas generated can be changed in advance according to changes in the power generation output, taking into account the effects of This has the excellent effect of allowing stable plant operation.

[Brief explanation of the drawing]

FIG. 1 shows one embodiment of the present invention, and is a functional block diagram of a load control VT system in a power generation plant, and FIG. 2 shows another embodiment of the present invention. A functional block diagram showing an example, Fig. 3 is a configuration diagram showing a coal gasification combined nacre power generation blunt, Fig. 4 is a functional block diagram showing a conventional example, and Fig. 5 is a vR function block showing another conventional example. Figure 6 shows the relationship between pressure and volume in the gas system, Figure 7 shows the relationship between power generation output and amount of gas generated, and Figure 8 shows the change in the gas raw material when the lightning output changes. FIG. 3... Gasifier, 9... Gas turbine, 10...
Generator, 15... Steam turbine, 16... Generator,
18...; Load control II device (gas flow setting section), 2
0... Gas other furnace IIJ control device (pressure control section), 21.
...Gas turbine III device (power generation 1)), 22...Gas pressure transmitter, 27.28...Ploop control iI+ device (output part). Applicant's agent: Hisashi Hata Figure 1 Figure 2 Figure 4 Figure 5 Figure 6

Claims (1)

[Claims] In a coal gasification combined cycle power plant that has a gas turbine that uses coal gas generated in a gasifier as fuel and a steam turbine that uses heat from gas turbine exhaust gas, power generation output and gas that control power generation output and gas pressure This power generation output/gas pressure control device includes a power generation output control section that receives a power generation output target value and makes the power generation output follow the target value, and a pressure control section that maintains the gas pressure at the set value. , an output section that outputs control signals from these control sections as command values to the gas turbine and gasifier, and an output section that outputs control signals from these control sections as command values to the gas turbine and gasifier; A coal gasification combined cycle power generation plant characterized by comprising a gas flow rate setting unit that predicts changes, calculates a gas flow rate corresponding to the pressure distribution, and changes the gas flow rate within a certain period of time.