JPH05163902A - Starting device of compound power generating plant - Google Patents

Abstract

PURPOSE:To reduce burden of an operator, and operate a plant softly. CONSTITUTION:It is judged whether a target operating condition can reach or not a target output from target operating condition and target output of the whole of a multishaft type combined cycle plant (a multishaft C/C plant) 17 which is set in setters 10, 11 by means of a target adjustor 12 on the basis of a variable output reange which is set according to the target operating condition beforehand. When possibility of reaching is judged affirmative, individual GT target output which is necessary for realizing set target is found out by a gas turbine (GT) target output calculator 13. In addition, the gas turbine GT, an exhaust heat recovery steam generator (HRSG) and a steam turbine required for starting and the order of their start are decided from the target operating condition set by a starting pattern setter 14 and a present condition of a multi-shaft C/C plant, and target steam pressure at the time of starting the HRSG is found out by a HRSG target steam pressure calculator 15, and the GT, the HRSG, and the ST are placed in starting-control by an automatic control device 16 on the basis of each parameter.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to one or more gas turbines (hereinafter abbreviated as GT), the same number of exhaust heat recovery steam generators (hereinafter abbreviated as HRSG) and one steam turbine (hereinafter abbreviated as GTR). And an abbreviated ST).

[0002]

2. Description of the Related Art FIG. 4 shows a conventional combined cycle power plant.
There is a multi-screw combined cycle plant (hereinafter referred to as a multi-screw C / C plant) as shown in FIG. This multi-axis C
The / C plant consists of two GT1-a, as shown in FIG.
GT1-b and generators 2-a, 2 driven by each GT
-B, two HRSGs 3-a, 3-b, one ST4 and a generator 5 driven by this ST.

Here, the exhaust gas from GT1-a and GT1-b passes through exhaust ducts 6-a and 6-b to HRSG3-.
In this HRSG, steam is generated by the heat of the exhaust gas. The steam generated in this HRSG passes through the high pressure main steam pipe 9 and the low pressure main steam pipe 10 to ST4.
Is driven to drive ST4. Exhaust duct 6-a,
Isolation dampers 7-a and 7-b are provided at 6-b, and the following two operation states are possible for each GT depending on the opening position of the damper. (1) A simple cycle (S / S) in which exhaust gas is allowed to escape through the bypass stacks 8-a and 8-b and the GT alone operates
C) Operation (2) Combining cycle (C) in which exhaust gas is passed through the HRSG 3-a and 3-b to generate steam and the steam is operated together with ST4
/ C) Driving

A multi-axis C / C plant as shown in FIG. 4 is composed of a plurality of constituent elements of GT and generator, HRSG, ST and generator, and is capable of various operating states. For example, in the example of FIG. 4, one GT / one S / C, two GTs S / C, one GT and ST C / C, one GT and ST C / C + GT1 S / C, two GT and ST C / C 5 are possible, and the possible range of the total output as a plant differs depending on each operating state. Also,
When the GT output changes during C / C operation, the amount of steam generated from the HRSG changes, and as a result, the ST output also changes.

Further, the pressure of each steam system is controlled by using the high pressure bypass valve 17 and the low pressure bypass valve 18 while allowing the steam generated at the time of starting the HRSG to escape to the condenser through the high pressure bypass system 15 and the low pressure bypass system 16. This pressure control must be coordinated with the amount of steam generated by the HRSG, that is, the output of the corresponding GT, or a stable steam system cannot be started. Also, when the second and subsequent HRSGs are started,
High-pressure steam header 11 and low-pressure steam header 1 already in operation
By controlling to match the pressure of 2, the HRS
Smoothly perform additional activation and in-service of G.

As described above, the multi-axis C / C is capable of various operating states, and the GT system and the HRSG and ST systems are related to each other. Need to be controlled in a coordinated manner.

[0007]

As described above, in the conventional multi-axis C / C plant starter, GT, HRSG, ST
Is controlled for each individual component of. Therefore, when starting the GT, it is necessary to perform an operation of determining the target output of the GT and the target steam pressure when starting the HRSG and setting the automatic starter, or the target output of the GT. The target steam pressure of the HRSG is set as a constant value and is built in the automatic starter, and the C / C plant is always started toward a constant target state and target output.

However, it is difficult for the starter for a multi-axis C / C plant to coordinately control the plant as a whole so as to match the operating state and the total output targeted by the operator at the completion of plant startup.

That is, it is necessary for the operator to individually examine the target operating state, the target output of GT and the target steam pressure of HRSG necessary to realize the total output, and set them for each automatic starter. However, there is a problem in that the burden on the operator increases. In addition, if these target values are built into the automatic starter as constant values, it is not possible to set the target operating state and total output at the completion of plant startup to the values required by the operator, so the operation flexibility There is a problem such as lack of performance, or it is necessary to readjust the total output to a value required by an operator after completion of plant startup.

The present invention has been made to solve the above problems, and an object thereof is to provide a start-up control device for a combined cycle power plant that can reduce the burden on the operator and perform a flexible operation of the plant. There is

[0011]

The present invention takes the following means in order to achieve the above object.

The start control device for a combined cycle power plant according to the present invention is intended for a multi-shaft combined cycle plant including one or more gas turbines, the same number of exhaust heat recovery steam generators as the gas turbines, and one steam turbine. In the combined cycle power generation plan, the setting means for setting the target operating state and the target output of the entire multi-axis combined cycle plant, and the target operating state set by this setting means are set in advance according to the target operating state. Target determining means for determining whether or not the target output is reached based on the possible output range, and when this target determining means determines that the target operating state reaches the target output, it is set in the setting means at that time. A first calculation means for obtaining the target output of each gas turbine required to realize the target operating state and the target output The target operating state set in the setting means and the current state of the multi-shaft combined cycle plant are compared to determine the gas turbine, the exhaust heat recovery steam generator and the steam turbine required for startup, and the startup order thereof. Start-up pattern setting means, the target output of the gas turbine obtained by the first calculation means, and the start-up sequence of the exhaust-heat-recovery steam generator required for start-up determined by the start-up pattern setting means Second calculating means for obtaining a target steam pressure at the time of starting the generator, and these first calculating means
And second control means, and control means for starting and controlling the gas turbines, the exhaust heat recovery steam generator, and the steam turbine based on the parameters determined by the start pattern setting means.

[0013]

In the starter of the combined cycle power plant having such a configuration, when the operator sets the target operating state and the target output of the entire multi-axis combined cycle plant in the setting means, the target determining means determines the target operating state. It is determined whether or not the target output can be reached, and if the target output can be reached, the target operating state and target output at startup are determined for these targets. Further, the first calculation means determines the target output of each gas turbine required to realize the target output of the multi-shaft combined cycle plant for the gas turbine in the gas turbine target operating state, and the start pattern setting means Then, compare the set target operating state with the current plant state, the gas turbine required for startup,
While determining the exhaust heat recovery steam generator and steam turbine,
The start-up order is determined, and the second calculation means further determines the first
The target steam pressure of the exhaust heat recovery steam generator is determined based on the target output of the gas turbine determined by the calculation means and the starting sequence of the exhaust heat recovery steam generator determined by the activation pattern setting means. Then, the control means controls the start-up of each gas turbine, the exhaust heat recovery steam generator, and the steam turbine based on the parameters determined by the first and second calculation means and the start-up pattern setting means.

Therefore, the operator simply sets the target operating state and the target output of the entire multi-axis combined cycle plant in the setting means, and the flexible operation of the multi-axis combined cycle plant is automatically performed. The burden can be significantly reduced.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing an example of the configuration when the starter for a combined cycle power plant according to the present invention is applied to the multi-axis C / C plant shown in FIG. In FIG. 1, 10
Is a C / C target setter that sets the target output (MW) of the entire multi-axis C / C plant, 11 is a C / C target state setter that sets the target operating state of the multi-axis C / C plant, 12
Is the target output set by the C / C target setter 10 (M
W) A target determiner to which the signal S1 and the target state signal S2 set by the C / C target state setter 11 are input,
The target determiner 12 includes a memory that stores data indicating a possible output range determined according to the target operating state,
Based on the data, it is determined whether the target operating state can reach the target output.

Reference numeral 13 is a target output (MW) signal S1 set by the C / C target setting unit 10, a target state signal S2 set by the C / C target state setting unit 11, and a judgment made by the target judging unit 12. GT to which the completion signal S3 is input
In the target output calculator, the GT target output calculator 13 calculates the target output of each GT required to realize the target output in the target operating state.

Reference numeral 14 is a start pattern setting device to which the target state signal S2 set by the C / C target state setting device 11 and the plant state signal S7 from the multi-axis C / C plant 17 are input. The device 14 compares the target operating state with the current plant state to determine the GT, HRSG, ST that need to be started and the starting order of each.

Reference numeral 15 denotes an HRSG target steam pressure calculator to which the GT target output signal S4 obtained by the GT target output calculator 13 and the activation pattern command signal S5 determined by the activation pattern setter 14 are input. The computer calculates the target steam pressure at the time of starting the HRSG from the GT target output and the starting sequence of the HRSG that requires starting.

Further, 16 is a GT target output signal S4 obtained by the GT target output calculator 13, a start pattern command signal S5 determined by the start pattern setter 14, and an HR obtained by the HRSG target steam pressure calculator 15.
The SG target steam pressure signal S6 is inputted to the automation control device, and the automation control device 16 has GT target output, GT and H
The start control of the multi-axis C / C plant 17 is performed based on the parameters of the RSG and ST activation patterns and the HRSG target steam pressure.

When the target judging unit 12 judges that the target operating condition cannot reach the target output, the target judging unit 18 inputs a target correction guidance signal from the target judging unit 12, and C
/ C target state setter 11 and C / C target output setter 1
This is guidance for correcting and changing the set value set to 0. Next, the operation of the starter for the multi-axis C / C plant configured as described above will be described.

First, the operator sets the C / C target setter 10
Set the target output for the entire multi-axis C / C plant to
Further, the target operating state of the multi-axis C / C plant is set in the C / C target state setting device 11. In this case, the target operating state is the following eight types of operating states in a multi-axis C / C plant having a configuration as shown in FIG. 4, so one of them can be selected as the target operating state. Set. (1) GT1-a S / C operation (2) GT1-b S / C operation (3) GT1-a and GT1-b S / C operation (4) GT1-a, ST S / C operation (5) GT1 -B, ST S / C operation (6) GT1-a, ST S / C operation + GT1-b S
/ C operation (7) GT1-b, ST S / C operation + GT1-a S
/ C operation (8) GT1-a, GT1-b, ST S / C operation

Such target output and target operating state are C / C target setter 10 and C / C target state setter 11.
Is set to the target judging device 12 and the C / C target output signal S1
When the C / C target state signal S2 is input, data indicating a possible output range determined according to the target operating state is read from a memory (not shown), and the target operating state set based on the data is read. It is determined whether the output is reachable. FIG. 2 shows possible output ranges in the above-mentioned target operating states (1) to (8) stored in the memory. In this case, the possible output range is a function of atmospheric temperature.

If the determination result of the target determiner 13 can reach the target output, the target output signal S1 and the target state signal S2 at that time are determined as the target for the next start, and the determination completion signal S3 is obtained. Is output. If the result of determination is that the target output cannot be reached, a target correction guidance signal is output to the guidance 18 and C /
C target state setting device 11 and C / C target output setting device 10
Prompt to change the setting value of. After the setting values are changed, the target determiner 12 again performs the same process as above. The above routine is repeated until the determination completion signal S3 is satisfied and the target operating state and target output at the time of plant startup are determined.

Next, the GT target output computer 13 receives the target output signal S1 and the target state signal S2 from the C / C target setting device 10 and the C / C target state setting device 11, and the judgment completion signal S3 from the target judging device 12. When input, the GT target output calculator 13 calculates the target output as the target output signal S1 as each target output required to realize the C / C operating state given by the target state signal, and the GT target output signal S4 Output as. In this case, the output of ST is determined by the output of GT and the steam generation amount of HRSG determined by it. Therefore, the target output of each GT is determined, and the plant is started based on the target output. It is possible to reach the target output.

When the target state signal S2 from the C / C target state setter 11 and the plant state signal S7 from the multi-axis C / C plant 17 are input to the start pattern setter 14, the start pattern setter 14 Then, the start operation is required by comparing the target operating state with the current plant state.
T, HRSG, ST and multiple GTs, and HRS
When the activation of G is necessary, the order is determined. For example, when the current plant state is the stop state and the above-mentioned operating state (8) is set as the C / C target operating state, GT1-a, GT1-b, HRSG3-a, HR
It is necessary to start SG3-b and ST4, in which GT
1-a, GT1-b are activated in this order, and HRSG is H
It is decided to start in the order of RSG3-a and HRSG3-b. These determination results are output as the activation pattern command signal S5 in the following form, for example. (A) GT1-a start-up phase ON (b) GT1-b start-up phase ON (c) HRSG3-a 1st unit start-up phase ON (d) HRSG3-b second unit start-up phase ON (e) ST start-up phase ON ( f) GT1-a priority start ON

Where (a), (b) and (e) are G
It indicates that T1-a, GT1-b, and ST are activated.
(C) is the first HRSG3-a, (d) is HRSG3
-B Indicates that it is started as the second device. Also, (f)
Indicates that of the two GTs, GT1-a is activated first.

In this way, each GT in the GT target output computer 13
The target output of T is calculated, and the start pattern setter 14
When the starting pattern is determined by, the GT target output signal S4 and the starting pattern command signal S5 output from them are taken into the HRSG target steam pressure calculator 15.
The HRSG target steam pressure calculator 15 calculates the target steam pressure of each HRSG activated based on these signals, and outputs the HRSG target steam pressure signal S6.

In this case, for the HRSG (HRSG3-a in the above example) designated to be activated as the first HRSG by the activation pattern signal S5, the corresponding GT as shown in FIG. (In the above example, GT
By providing the target steam pressure as a function of the target output of 3-a), stable HRSG start and ST start can be performed.

For the HRSG (HRSG3-b in the above example) designated to be activated as the second HRSG by the activation pattern command signal S5, the ST operation is performed by the first HRSG. By calculating the steam pressure header when the second unit HRSG is in service and setting it as the target pressure of the second unit HRSG, the pressure fluctuation during in-service of the second unit HRSG can be reduced.

Further, when there are three or more HRSGs, the target steam pressure of the third and subsequent HRSGs is similarly calculated as the target pressure by activating the steam header pressure before activating the HRSG.

Although the target steam pressure has been described as one type in the above description, when the two systems of the high pressure main steam pipe 9 and the low pressure main steam pipe 10 are provided as in the HRSG shown in FIG. The calculation must be performed for each of the high pressure system and the low pressure system, and the method is the same as above.

The GT target output signal S4, the start pattern command signal S5 and the HRSG target steam pressure signal S6 output from the GT target output calculator 13, the start pattern setter 14 and the HRSG target steam pressure calculator 15 are automatically controlled. When input to the device 16, the automation control device 16 follows the activation pattern given by the activation pattern command signal S5 to determine the GT output given by the GT target output signal S4 and the HRSG vapor pressure given by the HRSG target vapor pressure signal S6. Multi-axis C / using each parameter
The C plant 17 is started.

As a result, the multi-axis C / C plant 17 is changed to C / C
C / C in the operating state set in the C target state setter 11.
The target output setter 10 can be activated toward a state where the output set by the target output setter 10 is generated.

As described above, in this embodiment, the multi-axis C /
It becomes possible to automatically start each part of the plant in cooperation with each other so that the operating condition and the total output targeted by the operator of the C plant as a whole match.

Therefore, complicated GT output settings, individual HRSG steam pressure settings, etc., made by the operator,
No operation is required, and the burden on the operator can be reduced. In addition, since the plant can be started up toward the operating state and total output set by the operator, the plant can be operated flexibly, and it is necessary to reset the total output of the plant after the completion of plant startup. Also disappears. Next, another embodiment of the present invention will be described.

In the above embodiment, the HRSG target steam pressure calculator 15 calculates the HRSG target steam pressure according to the GT target output signal S4 as shown in FIG.
In the case of a plant having an isolation damper 7 and a bypass stack 8 as shown in Fig. 4, it is also possible to start the steam system by opening the isolation damper and communicating the exhaust gas to the HRSG after the start of the GT is completed. Is.

In such a case, the GT output value immediately before the activation of the HRSG (immediately before the closing operation of the isolation damper) is measured, and based on this, the HRSG is calculated by the same function as in FIG.
By calculating the target steam pressure, more reliable starting control becomes possible.

In the above embodiment, the HRSG target steam pressure calculator 15 uses the function shown in FIG.
Although the target steam pressure was calculated, if the HRSG was stopped by banking at the time of the previous stop and the time since the stop has not passed so much, the residual pressure of the steam in the HRSG may be higher than the pressure target value obtained from FIG. obtain. In such a case, if the pressure target value obtained from FIG. 3 is simply used, the pressure control set values of the high pressure bypass valve 17 and the low pressure bypass valve 18 become HR.
The steam pressure becomes lower than that in SG, and as a result, these bypass valves are opened, and a part of the stored steam energy is discarded to the condenser by viking stop.

In such a case, the higher of the residual pressure of steam in the HRSG and the pressure target value obtained from FIG. 3 is selected, and this is used as the final pressure target value. The energy loss as described above can be prevented.

Further, in the above embodiment, the multi-axis C / shown in FIG.
The case of applying to C plant was described, but GT, H
The same application as described above can be applied to the case where there is one RSG, or when there are three or more RSGs.

In the multi-axis C / C plant shown in FIG. 4, the isolation dampers 7-a and 7-b can be operated in two ways for each GT. -B and bypass stacks 8-a and 8-b are eliminated, and GT exhaust gas is always HRSG.
It can also be configured to be guided to. In that case, there is no case of S / C operation, and only C / C operation is possible, but it can be applied to such a multi-axis C / C plant as described above.

[0043]

As described above, according to the present invention, it is possible to provide a starter for a combined cycle power plant that can reduce the burden on the operator and can flexibly operate the plant.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a starter for a combined cycle power plant according to the present invention.

FIG. 2 is a diagram showing a relationship between an operating state of a multi-axis C / C stored in a memory of a target determiner and an outputtable range in the embodiment.

FIG. 3 is a diagram showing a function for determining the target pressure of the first HRSG stored in the HRSG target vapor pressure calculator in the embodiment.

FIG. 4 is a configuration diagram showing an example of a multi-axis C / C plant to which the present invention is applied.

[Explanation of symbols]

10 ... C / C target setting device, 11 ... C / C target state setting device, 12 ... target judging device, 13 ... GT target output calculator, 14 ... starting pattern setting device, 15 ... HRSG target steam Pressure calculator, 16 ... Automatic control device, 17 ...
Multi-axis C / C plant, 18 ... Guidance.

Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display area F22B 1/18 E 7715-3L

Claims (1)

[Claims] 1. A multi-cycle power generation plan for a multi-axis combined cycle plant comprising one or more gas turbines, the same number of exhaust heat recovery steam generators as the gas turbines, and one steam turbine. Setting means for setting the target operating state and the target output of the whole type combined cycle plant, and the target operating state set by this setting means is set as the target output based on the possible output range previously determined according to the target operating state. Target determining means for determining whether or not to reach, and when the target determining state determines that the target operating state reaches the target output, the target operating state and the target output set in the setting means at that time are realized. First computing means for obtaining the target output of each gas turbine required for the Start-up pattern setting means for comparing the states of the multi-shaft combined cycle plant to determine a gas turbine, an exhaust heat recovery steam generator and a steam turbine required for start-up, and to determine the start-up order thereof;
The target steam pressure at the time of starting the exhaust heat recovery steam generator from the starting order of the exhaust heat recovery steam generator required for the start determined by the target output of the gas turbine obtained by the calculation means and the starting pattern setting means Starting control of each of the gas turbines, the exhaust heat recovery steam generator, and the steam turbine is performed based on the second calculating means to be obtained and each of the parameters determined by the first and second calculating means and the starting pattern setting means. A starting device for a combined cycle power plant comprising a control means.