Start control device, start control method and start control program

Abstract

To complete start control in accordance with fixed time schedule regardless of an operating state of a combined cycle plant.SOLUTION: This disclosure relates to a start control device for starting a combined cycle plant including a gas turbine and a steam turbine. The device acquires a stand-by load of the combined cycle plant at start of steam supply of the steam turbine and a target load at the completion of the start of the combined cycle plant, and sets a load change rate for increasing a load of the combined cycle plant from the stand-by load to the target load for a preset fixed required time on the basis of the stand-by load. The load of the combined cycle plant from the start of the steam supply to the completion of the start is controlled on the basis of the load change rate.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to a startup control device, a startup control method, and a startup control program. [Background technology]

[0002] A combined cycle plant is known that improves energy efficiency by combining a gas turbine and a steam turbine. In the combined cycle plant, steam is generated by recovering exhaust heat from the gas turbine (e.g., heat contained in the exhaust gas of the gas turbine) using, for example, a heat recovery boiler. The steam generated in the heat recovery boiler is supplied to the steam turbine, and the steam turbine is driven using the exhaust heat from the gas turbine.

[0003] When starting up this type of combined cycle plant, each element constituting the plant is controlled in sequence according to a startup control sequence. In this startup control sequence, the gas turbine is started first, and the rotation speed of the gas turbine is increased to a reference rotation speed (e.g., rated rotation speed), and then a predetermined load is applied, so that the exhaust gas temperature of the gas turbine gradually increases. At this time, the load of the combined cycle plant is maintained at a constant standby load until the exhaust gas temperature of the gas turbine is sufficiently increased so that the heat recovery steam generator can supply generated steam to the steam turbine. Then, when the steam turbine is in a state where it can be supplied with steam, steam supply to the steam turbine is started, and the rotation speed of the steam turbine gradually increases. After the rotation speed of the steam turbine reaches the reference rotation speed (e.g., rated rotation speed), the load of the combined cycle plant also gradually increases. When the load of the combined cycle plant reaches a preset target load (e.g., 50%), the startup control sequence of the combined cycle plant is completed, and the plant transitions to normal operation.

[0004] For example, Patent Document 1 discloses that, with regard to startup control of such a combined cycle plant, the load change rate when controlling the load of the combined cycle plant to increase so as to reach a target load is made variable depending on the operating state of the combined cycle plant. This document particularly discloses that the load change rate is variably set so that the startup time is shortened as the control parameters at startup are closer to the control parameters at startup completion. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2015-90132 A Summary of the Invention [Problem to be solved by the invention]

[0006] In the above-mentioned startup control sequence of the combined cycle plant, after the rotational speed of the gas turbine reaches a reference rotational speed (e.g., a rated rotational speed), the load of the combined cycle plant is maintained at a constant standby load until the supply of steam to the steam turbine can be started. This standby load may be changed depending on the atmospheric temperature (or outside air temperature) or the steam turbine rotor temperature in order to establish a steam condition at the start of the steam turbine (e.g., a condition in which a mismatch between the inlet steam temperature of the steam turbine and the steam turbine rotor temperature is equal to or less than a permissible value). Therefore, if the load change rate after the start of steam supply to the steam turbine is constant, the time required for the load of the combined cycle plant to reach the target load changes depending on the magnitude of the standby load, and as a result, the startup completion time of the combined cycle plant (the time required for the load of the combined cycle plant to reach the target load from the start of the gas turbine) changes. In this way, if the startup completion time changes depending on the operating state of the combined cycle plant, it is difficult to meet the user's desire to always operate the plant on the same time schedule.

[0007] In the above Patent Document 1, the load change rate is made variable depending on the operating state of the combined cycle plant, but there is no disclosure about setting the load change rate so as to complete startup control on a fixed time schedule regardless of the operating state of the combined cycle plant.

[0008] At least one embodiment of the present disclosure has been made in consideration of the above-mentioned circumstances, and aims to provide a startup control device, a startup control method, and a startup control program that are capable of completing startup control on a fixed time schedule regardless of the operating state of a combined cycle plant. [Means for solving the problem]

[0009] In order to solve the above problem, a start-up control device according to at least one embodiment of the present disclosure includes: 1. A startup control device for starting up a combined cycle plant including a gas turbine and a steam turbine that can be driven by steam generated by exhaust heat of the gas turbine, comprising: a standby load acquisition unit for acquiring a standby load of the combined cycle plant at a time when steam supply to the steam turbine starts; a target load acquisition unit for acquiring a target load of the combined cycle plant at the time of completion of startup of the combined cycle plant; a load change rate setting unit for setting a load change rate for increasing a load of the combined cycle plant from the standby load to the target load within a predetermined constant required time based on the standby load; a load control unit for controlling the load of the combined cycle plant from the start of the steam supply to the completion of the startup based on the load change rate; Equipped with.

[0010] In order to solve the above problem, the startup control method according to at least one embodiment of the present disclosure includes: 1. A startup control method for starting up a combined cycle plant including a gas turbine and a steam turbine that can be driven by steam generated by exhaust heat of the gas turbine, comprising: acquiring a standby load of the combined cycle plant at a time when steam supply to the steam turbine is started; acquiring a target load of the combined cycle plant at the time of completion of start-up of the combined cycle plant; setting a load change rate for increasing a load of the combined cycle plant from the standby load to the target load within a preset constant required time based on the standby load; controlling the load of the combined cycle plant from the start of the steam supply to the completion of the startup based on the load change rate; Equipped with.

[0011] In order to solve the above problem, a startup control program according to at least one embodiment of the present disclosure includes: 1. A startup control program for starting up a combined cycle plant including a gas turbine and a steam turbine that can be driven by steam generated by exhaust heat of the gas turbine, comprising: A computer device includes: acquiring a standby load of the combined cycle plant at a time when steam supply to the steam turbine is started; acquiring a target load of the combined cycle plant at the time of completion of start-up of the combined cycle plant; setting a load change rate for increasing a load of the combined cycle plant from the standby load to the target load within a preset constant required time based on the standby load; controlling the load of the combined cycle plant from the start of the steam supply to the completion of the startup based on the load change rate; It is possible to execute the following. Effect of the Invention

[0012] According to at least one embodiment of the present disclosure, it is possible to provide a startup control device, a startup control method, and a startup control program that are capable of completing startup control on a fixed time schedule regardless of the operating state of a combined cycle plant. [Brief description of the drawings]

[0013] [Figure 1] 1 is a schematic configuration diagram of a combined cycle plant according to an embodiment. FIG. [Diagram 2] FIG. 2 is a block diagram of a start-up control device according to an embodiment. [Diagram 3] 3 is a time chart showing changes in control parameters in each component of the combined cycle plant when the startup control sequence executing unit in FIG. 2 executes the startup control sequence. [Figure 4] 3 is a control flow diagram of a standby load setting unit in FIG. 2. [Diagram 5] 5 is an explanatory diagram of a method of determining the startup mode by the startup mode determination unit in FIG. 4. [Figure 6] FIG. 5 is an example of the function. [Figure 7] FIG. 11 is a control flow diagram of a load change rate setting unit according to the reference technology. [Figure 8] FIG. 8 is a diagram showing a load transition of a combined cycle plant during execution of a startup control sequence in a case where a load change rate set by the load change rate setting unit in FIG. 7 is adopted. [Figure 9] 3 is a control flow diagram of a load change rate setting unit in FIG. 2. [Figure 10] FIG. 10 is a diagram showing load transition of a combined cycle plant during execution of a startup control sequence in the case where a load change rate set by the load change rate setting unit in FIG. 9 is adopted. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Hereinafter, some embodiments of the present invention will be described with reference to the accompanying drawings. However, the configurations described as the embodiments or shown in the drawings are merely illustrative examples and are not intended to limit the scope of the present invention.

[0015] First, a configuration of a combined cycle plant 1 that is a control target of a start-up control device according to at least one embodiment of the present disclosure will be described with reference to Fig. 1. Fig. 1 is a schematic configuration diagram of a combined cycle plant 1 according to one embodiment.

[0016] The combined cycle plant 1 includes a gas turbine 10, a heat recovery boiler 20 for generating steam using exhaust gas EG from the gas turbine 10, a steam turbine 30 that can be driven by steam from the heat recovery boiler 20, a condenser 40 for converting the steam from the steam turbine 30 back into water, a feedwater pump 76 for sending the water in the condenser 40 to the heat recovery boiler 20, a generator 45, and a starter motor 49.

[0017] The gas turbine 10 includes a compressor 11 for compressing combustion air A, a combustor 14 for generating combustion gas by combusting fuel F supplied from a fuel supply system (not shown) together with the combustion air A compressed by the compressor 11, and a turbine 15 that can be driven by the combustion gas generated in the combustor 14. The compressor 11 includes a compressor rotor 12 that rotates about an axis Ar, and a compressor casing 13 that covers the compressor rotor 12.

[0018] The turbine 15 has a turbine rotor 16 that is rotatable about an axis Ar, and a turbine casing 17 that covers the turbine rotor 16. The compressor rotor 12 and the turbine rotor 16 are connected to each other so as to be able to rotate integrally about the same axis Ar, thereby constituting a gas turbine rotor 19.

[0019] The heat recovery boiler 20 includes an economizer 21 for heating water supplied from the condenser 40 by the feed water pump 76 with heat contained in the exhaust gas EG from the gas turbine 10, an evaporator 22 capable of generating steam by heating the water heated by the economizer 21 with the heat of the exhaust gas EG, and a superheater 23 capable of further superheating the steam with the heat of the exhaust gas EG. The economizer 21, the evaporator 22, and the superheater 23 all have heat transfer tubes through which water or steam passes and for exchanging heat between the water or steam and the exhaust gas EG. The evaporator 22 includes a drum 22a in addition to the heat transfer tubes. A portion of the water or steam stored in the drum 22a can be supplied to the condenser 40 via a boiler water discharge line 88. A boiler water discharge valve 89 is provided on the boiler water discharge line 88.

[0020] The steam superheated by the superheater 23 is supplied to the steam turbine 30 via a main steam line 81. A shutoff valve 78 and a control valve 79 are provided on the main steam line 81.

[0021] The steam turbine 30 has a steam turbine rotor 31 rotatable about an axis Ar, and a steam turbine casing 34 covering the steam turbine rotor 31. The steam turbine rotor 31 has a rotor shaft 32 rotatable about the axis Ar, and a plurality of moving blade rows 33 fixed to the rotor shaft 32. The plurality of moving blade rows 33 are arranged along the axial direction in which the axis Ar extends. A plurality of stator blade rows 36 are fixed to an inner circumferential surface of the steam turbine casing 34. The plurality of stator blade rows 36 are arranged along the direction in which the axial direction extends. Each of the plurality of stator blade rows 36 is disposed upstream of the steam flow with respect to any one of the plurality of moving blade rows 33.

[0022] Incidentally, the steam turbine 30 shown in FIG. 1 is a two-flow exhaust type steam turbine that divides the inflowing steam into two directions, but it may be a steam turbine that does not divide the inflowing steam.

[0023] The generator 45 has a generator rotor 46 that is rotatable about an axis Ar, and a generator casing 47 that covers the generator rotor 46. The generator 45 is electrically connected to an external system 63 by a connection line 60.

[0024] The gas turbine rotor 19, the steam turbine rotor 31, and the generator rotor 46 are located on the same axis Ar and are mechanically connected to one another. That is, the combined cycle plant 1 is a single-shaft combined cycle plant. The starter motor 49 can rotate these rotors about the axis Ar.

[0025] Next, a description will be given of a startup control device 100 for carrying out startup control of the combined cycle plant 1 having the above configuration. Fig. 2 is a block configuration diagram of the startup control device 100 according to an embodiment.

[0026] The start control device 100 is composed of, for example, a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), and a computer-readable storage medium. A series of processes for realizing various functions is stored in a storage medium or the like in the form of a program, for example, and the CPU reads this program into the RAM or the like and executes information processing and arithmetic processing to realize various functions. The program may be installed in a ROM or other storage medium in advance, may be provided in a state stored in a computer-readable storage medium, or may be distributed via a wired or wireless communication means. The computer-readable storage medium may be a magnetic disk, a magneto-optical disk, a CD-ROM, a DVD-ROM, a semiconductor memory, or the like.

[0027] As shown in FIG. 2, the activation control device 100 includes an activation control sequence execution unit 102, a standby load acquisition unit 104, a target load acquisition unit 106, a required time acquisition unit 108, a load change rate setting unit 110, and a load control unit 112.

[0028] The startup control sequence executing unit 102 is configured to execute a startup control sequence for starting up the combined cycle plant 1. Each operation in the startup control of the combined cycle plant 1 is stored in a storage medium as a sequence program, and a preset startup control sequence is executed by executing the sequence program.

[0029] The startup control sequence executed by the startup control sequence executing unit 102 will now be described in detail with reference to Fig. 3. Fig. 3 is a time chart showing transitions of control parameters in each component of the combined cycle plant 1 when the startup control sequence executing unit 102 in Fig. 2 executes the startup control sequence.

[0030] In the startup control sequence, first, at time t1, the gas turbine 10 is started. The startup of the gas turbine 10 is performed by rotating the gas turbine rotor 19 together with the steam turbine rotor 31 and the generator rotor 46 by the startup motor 49.

[0031] Next, the rotation speed Rg of the gas turbine 10 is gradually increased so as to reach a preset reference rotation speed Rref (e.g., a rated rotation speed). In Fig. 3, the rotation speed Rg of the gas turbine 10 starts to gradually increase from time t1, and reaches the preset reference rotation speed Rref (e.g., a rated rotation speed) at time t2.

[0032] When the rotation speed Rg of the gas turbine 10 reaches the reference rotation speed Rref at time t2, the load L of the combined cycle plant 1 is controlled to become a predetermined standby load Lw. The load change rate when the load L is increased to the standby load Lw at time t2 is controlled to be equal to or lower than a preset allowable upper limit value. The load L of the combined cycle plant is maintained constant at the standby load Lw until time t3 when a condition for starting the steam supply to the steam turbine 30 (steam supply start condition) is satisfied. The value of this standby load Lw is variable depending on the operating state of the combined cycle plant 1, as described later.

[0033] When the steam supply start condition is satisfied at time t3, steam supply to the steam turbine 30 is started, and the rotation speed Rs of the steam turbine 30 gradually increases, and the load L of the combined cycle plant 1 also increases. The load L of the combined cycle plant 1 after time t3 changes at a predetermined load change rate R by being controlled by the load control unit 112. Then, at time t4, when the load L of the combined cycle plant 1 reaches a preset target load Lm (for example, 50% of the rated load), a series of startup controls are completed, and the plant transitions to normal operation.

[0034] Returning to FIG. 2, the standby load setting unit 103 is configured to set the standby load Lw based on the operating state of the combined cycle plant 1. The standby load Lw is set based on at least one of first information related to the rotor temperature of the steam turbine 30 and second information related to the exhaust gas temperature of the gas turbine 10. The first information may be the metal temperature of the steam turbine rotor 31 itself, or may be a parameter that affects the temperature of the steam turbine rotor 31, such as the elapsed time since the steam turbine 30 was last stopped. The second information may include at least one of the atmospheric temperature and the intake temperature of the gas turbine 10. In the embodiment described below, a case in which the atmospheric temperature Ta detected by an atmospheric temperature sensor (not shown) is used as the operating state of the combined cycle plant 1 is exemplified, but other parameters related to the operating state of the combined cycle plant 1 may be used.

[0035] 4 is a control flow diagram of the standby load setting unit 103 in FIG. 2, FIG. 5 is an explanatory diagram of a method of determining the start-up mode by the start-up mode determining unit 103a in FIG. 4, and FIG. 6 is an example of the function FX in FIG.

[0036] As shown in Fig. 4, the standby load setting unit 103 has a start-up mode determination unit 103a. The start-up mode determination unit 103a is configured to determine the start-up mode of the combined cycle plant 1. In this embodiment, as shown in Fig. 5, one of three start-up modes, namely, a cold start-up mode, a warm start-up mode, and a hot start-up mode, is selected based on the inlet metal temperature Ts of the steam turbine 30. Specifically, the cold start-up mode corresponds to the lowest temperature range of the metal temperature Ts, the warm start-up mode corresponds to a temperature range in which the metal temperature Ts is higher than that of the cold start-up mode, and the hot start-up mode corresponds to a temperature range in which the metal temperature Ts is higher than that of the warm start-up mode. In this embodiment, the inlet metal temperature Ts of the steam turbine 30 is used as an index for determining the start-up mode, but this is merely an example and is not limiting.

[0037] Based on the determination result of the start-up mode determination unit 103a, the standby load setting unit 103 employs one of the first function FX1 to the third function FX3 shown in FIG. 6 as the function FX. The first function FX1 is a function corresponding to the case where the cold start-up mode is selected by the start-up mode determination unit 103a. The second function FX2 is a function corresponding to the case where the warm start-up mode is selected by the start-up mode determination unit 103a. The third function FX3 is a function corresponding to the case where the hot start-up mode is selected by the start-up mode determination unit 103a. The first function FX1 and the third function FX3 are defined so that the standby load Lw monotonically decreases as the atmospheric temperature Ta increases.

[0038] In the standby load setting unit 103 configured as above, the atmospheric temperature Ta is input to the function FX, whereby the standby load Lw is variably set in accordance with the operating state of the combined cycle plant 1.

[0039] Returning to FIG. 2, the standby load acquisition unit 104 is configured to acquire the standby load Lw set by the standby load setting unit 103 .

[0040] The target load acquisition unit 106 is configured to acquire a target load Lm in the startup control sequence executed by the startup control sequence execution unit 102 .

[0041] The required time acquisition unit 108 is configured to acquire the time (required time tr) required from the start of steam supply (time t3) to the completion of startup (time t4) in the startup control sequence executed by the startup control sequence execution unit 102. This required time tr is a parameter that can be specified by the user, and is input by various input devices such as a keyboard, a mouse, or a touch panel.

[0042] The load change rate setting unit 110 is configured to set the change rate (load change rate R) of the load L of the combined cycle plant 1 from the start of steam supply (time t3) to the completion of startup (time t4) in the startup control sequence executed by the startup control sequence execution unit 102.

[0043] The load control unit 112 is configured to control the load L of the combined cycle plant 1 in accordance with the load change rate R set by the load change rate setting unit 110 from time t3 to time t4 in the startup control sequence.

[0044] Here, a load change rate setting unit 110' according to the reference technology will be described with reference to Fig. 7 and Fig. 8. Fig. 7 is a control flow diagram of the load change rate setting unit 110' according to the reference technology, and Fig. 8 is a diagram showing load transition of the combined cycle plant 1 during execution of a startup control sequence in the case where a load change rate R' set by the load change rate setting unit 110' in Fig. 7 is adopted.

[0045] As shown in FIG. 7, a load change rate setting unit 110' according to the reference technique includes a start-up mode determination unit 111' and a load change rate selection unit 112'.

[0046] The start-up mode determination unit 111' is configured to determine the start-up mode of the combined cycle plant 1, similar to the start-up mode determination unit 103a shown in FIG.

[0047] The load change rate selection unit 112' is configured to select a load change rate R' corresponding to the startup mode. Specifically, when the startup mode determination unit 111' determines that the startup mode is the cold startup mode, the load change rate selection unit 112' selects a first load change rate R1 corresponding to the cold startup mode as the load change rate R'. When the startup mode determination unit 111' determines that the startup mode is the warm startup mode, the load change rate selection unit 112' selects a second load change rate R2 corresponding to the warm startup mode as the load change rate R'. When the startup mode determination unit 111' determines that the startup mode is the hot startup mode, the load change rate selection unit 112' selects a third load change rate R3 corresponding to the hot startup mode as the load change rate R'.

[0048] As described above, the standby load setting unit 103 variably sets the standby load Lw based on the atmospheric temperature Ta, which is the operating state of the combined cycle plant 1. Here, as shown in Fig. 8, it is assumed that the standby load Lw set by the standby load setting unit 103 is Case 1 (see the solid line) which takes a first value Lw1 corresponding to the case where the atmospheric temperature Ta is relatively high, and Case 2 (see the dashed line) which takes a second value Lw2 (<first value Lw1) corresponding to the case where the atmospheric temperature Ta is relatively low.

[0049] In Case 1, the load L of the combined cycle plant 1 is controlled to be kept constant at a first value Lw1 (standby load Lw) from time t2 to time t3, and then increased to the target load Lm at a load change rate R' from time t3 to time t4a. In this case, the required time tr1 (=t4a-t3) for the load L of the combined cycle plant 1, which is at the first value Lw1, which is the standby load Lw at time t3, to reach the target load Lm at time t4a, is calculated by the following equation. tr1=(Lm-Lw1) / R´ (1)

[0050] In Case 2, the load L of the combined cycle plant 1 is controlled to be kept constant at a second value Lw2 (standby load Lw) from time t2 to time t3, and then increased to the target load Lm at a load change rate R' from time t3 to time t4b. In this case, the required time tr2 (=t4b-t3) for the load L of the combined cycle plant 1, which is at the second value Lw2, which is the standby load Lw at time t3, to reach the target load Lm at time t4b, is calculated by the following equation. tr2=(Lm-Lw2) / R´ (2)

[0051] Comparing the above formulas (1) and (2), the required time tr changes depending on the value of the standby load Lw. Specifically, in Case 2, the standby load Lw is a second value Lw2 smaller than the first value Lw1, so the required time tr is longer than in Case 1. Therefore, in a start-up control device including a load change rate setting unit 110' according to the reference technology, the required time tr changes depending on the operating state of the combined cycle plant 1, so that the start-up completion time (the period from time t1 when the gas turbine is started to time t4 when the load L of the combined cycle plant 1 reaches the target load Lm) becomes variable, and start-up control cannot be performed according to a fixed time schedule. Such a problem can be solved by the start-up control device 100 including the load change rate setting unit 110 according to the present embodiment described below.

[0052] FIG. 9 is a control flow diagram of the load change rate setting unit 110 of FIG. 2, and FIG. 10 is a diagram showing load transition of the combined cycle plant 1 during execution of the startup control sequence in a case where the load change rate R set by the load change rate setting unit 110 of FIG. 9 is adopted.

[0053] The load change rate setting unit 110 according to this embodiment sets a load change rate R for increasing the load L of the combined cycle plant 1 from the standby load Lw to the target load Lm in a preset constant required time tr, based on the standby load Lw. Specifically, as shown in Fig. 9, the standby load Lw acquired by the standby load acquisition unit 104, the target load Lm acquired by the target load acquisition unit 106, and the required time tr acquired by the required time acquisition unit 108 are input to the load change rate setting unit 110. The load change rate setting unit 110 calculates the load change rate R by dividing the difference Δ between the target load Lm and the standby load Lw by the required time tr using the following equation. R = (Lm-Lw) / tr (3)

[0054] The load change rate R calculated based on the above formula (3) is variable based on the standby load Lw. As shown in Fig. 10, in Case 1 where the standby load Lw is relatively large, the load change rate R is calculated to be a relatively small value, whereas in Case 2 where the standby load Lw is relatively small, the load change rate R is calculated to be a relatively large value. As a result, in the load change rate setting unit 110, the load change rate R is variably set according to the operating state of the combined cycle plant 1, so that the start-up completion time (the period from time t1, when the gas turbine is started, to time t4, when the load L of the combined cycle plant 1 reaches the target load Lm) becomes invariable, and start-up control can be operated on a fixed time schedule.

[0055] The load change rate setting unit 110 also includes a start-up mode determination unit 111 , an allowable upper limit value setting unit 113 , and a low value selection unit 114 .

[0056] The start-up mode determination unit 111 is configured to determine the start-up mode of the combined cycle plant 1, similar to the start-up mode determination unit 103a shown in FIG.

[0057] The allowable upper limit setting unit 113 is configured to set the allowable upper limit value RL of the load change rate R in accordance with the startup mode. Specifically, when the startup mode determination unit 111 determines that the startup mode is cold startup mode, the allowable upper limit setting unit 113 sets the allowable upper limit value RL to a first allowable upper limit value RL1 corresponding to the cold startup mode. When the startup mode determination unit 111 determines that the startup mode is warm startup mode, the allowable upper limit setting unit 113 sets the allowable upper limit value RL to a second allowable upper limit value RL2 corresponding to the warm startup mode. When the startup mode determination unit 111 determines that the startup mode is hot startup mode, the allowable upper limit setting unit 113 sets the allowable upper limit value RL to a third allowable upper limit value RL3 corresponding to the hot startup mode.

[0058] The lower value selection unit 114 is configured to compare the load change rate R calculated by the above formula (3) with the allowable upper limit value RL set by the allowable upper limit value setting unit 113, and output the lower value as the final load change rate R. As a result, when the load change rate R calculated by the above formula (3) exceeds the allowable upper limit value RL, the allowable upper limit value RL is set as the load change rate R. As a result, by minimizing fluctuations in the required time tr within a range that does not exceed the allowable upper limit value RL, it is possible to suppress changes in the time schedule.

[0059] When the load change rate R calculated by the above formula (3) is equal to or lower than the allowable upper limit value RL, the low value selection unit 114 outputs the load change rate R calculated by the above formula (3) as is.

[0060] In another embodiment, the load change rate setting unit 110 may predefine the relationship between the difference Δ between the target load Lm and the standby load Lw and the load change rate R as a function, and input the actual difference Δ to the function to set the load change rate R. In this embodiment, by predefining the function so as to correspond to an expected required time tr, it is also possible to omit the input of the required time tr by the operator.

[0061] As described above, according to each of the above embodiments, in the startup control of the combined cycle plant 1, the load change rate R when increasing the load L of the combined cycle plant 1 from the standby load Lw to the target load Lm is variably set based on the standby load Lw. As a result, even when the standby load Lw changes depending on the operating state of the combined cycle plant 1, the load change rate R is variably set, so that the time tr required for the load L to increase from the standby load Lw to the target load Lm can be made constant. As a result, regardless of the operating state of the combined cycle plant 1, the startup completion time of the combined cycle plant 1 (the time required for the load L of the combined cycle plant to reach the target load Lm from the start of the gas turbine) can be made constant, and the combined cycle plant 1 can always be operated according to the same time schedule.

[0062] In addition, within the scope of the present disclosure, the components in the above-described embodiments may be replaced with well-known components as appropriate, and the above-described embodiments may be combined as appropriate.

[0063] The contents described in each of the above embodiments can be understood, for example, as follows.

[0064] (1) A start-up control device according to one aspect includes: 1. A startup control device for starting up a combined cycle plant including a gas turbine and a steam turbine that can be driven by steam generated by exhaust heat of the gas turbine, comprising: a standby load acquisition unit for acquiring a standby load of the combined cycle plant at a time when steam supply to the steam turbine starts; a target load acquisition unit for acquiring a target load of the combined cycle plant at the time of completion of startup of the combined cycle plant; a load change rate setting unit for setting a load change rate for increasing a load of the combined cycle plant from the standby load to the target load within a predetermined constant required time based on the standby load; a load control unit for controlling the load of the combined cycle plant from the start of the steam supply to the completion of the startup based on the load change rate; Equipped with.

[0065] According to the above aspect (1), in the startup control of the combined cycle plant, the load change rate when increasing the load of the combined cycle plant from the standby load at the start of steam supply to the steam turbine to the target load is variably set based on the standby load. Thus, even when the standby load changes according to the operating state of the combined cycle plant, the time required for the load to increase from the standby load to the target load can be made constant by variably setting the load change rate. As a result, regardless of the operating state of the combined cycle plant, the startup completion time of the combined cycle plant (the time required for the load of the combined cycle plant to reach the target load from the start of the gas turbine) can be made constant, and the combined cycle plant can always be operated according to the same time schedule.

[0066] (2) In another embodiment, in the above embodiment (1), The load change rate setting unit calculates the load change rate by dividing a difference between the target load and the standby load by the required time.

[0067] According to the above aspect (2), the load change rate during load increase of the combined cycle plant is set by dividing the difference between the target load and the standby load by the required time. As a result, even if the standby load changes depending on the operating state of the combined cycle plant, the required time can be kept constant by performing the load increase control based on the load change rate set in this way.

[0068] (3) In another embodiment, in the above embodiment (1) or (2), The standby load is set based on at least one of first information on a rotor temperature of the steam turbine or second information on an exhaust gas temperature of the gas turbine.

[0069] According to the above aspect (3), the standby load of the combined cycle plant at the start of steam supply is variable based on at least one of the first information on the rotor temperature of the steam turbine and the second information on the exhaust gas temperature of the gas turbine. In this way, even if the standby load at the start of steam supply is variable, by variably setting the load change rate according to the standby load as described above, it is possible to perform startup control of the combined cycle plant so that the required time is constant.

[0070] (4) In another embodiment, in the above embodiment (3), The first information includes at least one of a measured metal temperature of a rotor of the steam turbine, or an elapsed time since the steam turbine was last shut down.

[0071] According to the above aspect (4), the standby load of the combined cycle plant at the start of steam supply is variable based on first information including at least one of the measured metal temperature of the rotor of the steam turbine or the elapsed time since the steam turbine was last stopped.

[0072] (5) In another embodiment, in the above embodiment (3) or (4), The second information includes at least one of an atmospheric temperature or an intake temperature of the gas turbine.

[0073] According to the above aspect (5), the standby load of the combined cycle plant at the start of steam supply is variable based on the second information including at least one of the atmospheric temperature and the intake temperature of the gas turbine.

[0074] (6) In another embodiment, in any one of the above (1) to (5), When the load change rate exceeds an allowable upper limit, the load change rate calculation unit sets the load change rate to the allowable upper limit.

[0075] According to the above aspect (6), when the load change rate exceeds a preset allowable upper limit, the allowable upper limit is set as the load change rate. This makes it possible to suppress fluctuations in the required time as much as possible without exceeding the allowable upper limit, thereby suppressing changes in the time schedule.

[0076] (7) In another embodiment, in any one of the above (1) to (6), At the time of starting the supply of steam, after the rotational speed of the gas turbine reaches the rated rotational speed, the load of the combined cycle plant is maintained constant at the standby load.

[0077] According to the above aspect (7), in the startup control of a combined cycle plant, after the gas turbine speed reaches the rated speed (under no load), steam supply to the steam turbine is started while the load of the combined cycle plant is maintained constant at the standby load.

[0078] (8) A startup control method according to one aspect includes the steps of: 1. A startup control method for starting up a combined cycle plant including a gas turbine and a steam turbine that can be driven by steam generated by exhaust heat of the gas turbine, comprising: acquiring a standby load of the combined cycle plant at a time when steam supply to the steam turbine is started; acquiring a target load of the combined cycle plant at the time of completion of start-up of the combined cycle plant; setting a load change rate for increasing a load of the combined cycle plant from the standby load to the target load within a preset constant required time based on the standby load; controlling the load of the combined cycle plant from the start of the steam supply to the completion of the startup based on the load change rate; Equipped with.

[0079] According to the above aspect (8), in the startup control of the combined cycle plant, the load change rate when increasing the load of the combined cycle plant from the standby load at the start of steam supply to the steam turbine to the target load is variably set based on the standby load. Thus, even when the standby load changes according to the operating state of the combined cycle plant, the time required for the load to increase from the standby load to the target load can be made constant by variably setting the load change rate. As a result, regardless of the operating state of the combined cycle plant, the startup completion time of the combined cycle plant (the time required for the load of the combined cycle plant to reach the target load from the start of the gas turbine) can be made constant, and the combined cycle plant can always be operated according to the same time schedule.

[0080] (9) A startup control program according to one aspect of the present invention includes: 1. A startup control program for starting up a combined cycle plant including a gas turbine and a steam turbine that can be driven by steam generated by exhaust heat of the gas turbine, comprising: A computer device includes: acquiring a standby load of the combined cycle plant at a time when steam supply to the steam turbine is started; acquiring a target load of the combined cycle plant at the time of completion of start-up of the combined cycle plant; setting a load change rate for increasing a load of the combined cycle plant from the standby load to the target load within a preset constant required time based on the standby load; controlling the load of the combined cycle plant from the start of the steam supply to the completion of the startup based on the load change rate; It is possible to execute the following.

[0081] According to the above aspect (9), in the startup control of the combined cycle plant, the load change rate when increasing the load of the combined cycle plant from the standby load at the start of steam supply to the steam turbine to the target load is variably set based on the standby load. Thus, even when the standby load changes according to the operating state of the combined cycle plant, the time required for the load to increase from the standby load to the target load can be made constant by variably setting the load change rate. As a result, regardless of the operating state of the combined cycle plant, the startup completion time of the combined cycle plant (the time required for the load of the combined cycle plant to reach the target load from the start of the gas turbine) can be made constant, and the combined cycle plant can be always operated according to the same time schedule. [Explanation of symbols]

[0082] 1. Combined cycle plant 10. Gas Turbine 11 Compressor 12 Compressor rotor 13 Compressor casing 14 Combustor 15 Turbine 16 Turbine rotor 19 Gas turbine rotor 20. Waste heat recovery boiler 21 Economizer 22 Evaporator 22a Drum 23 Superheater 30 Steam Turbine 31 Steam turbine rotor 32 Rotor shaft 33 Moving blade row 34 Turbine casing 36 Stator blade row 40 Condenser 45 Generator 46 Generator rotor 47 Generator casing 49 Starting motor 60 Connection Line 63 External system 78 Shut-off valve 79 Regulating valve 81 Main Steam Line 88 Boiler water discharge line 89 Exhaust valve 100 Start control device 102 Startup control sequence execution unit 103 Standby load setting unit 103a Start mode determination unit 104 Standby load acquisition unit 106 Target load acquisition section 108 Required time acquisition part 110 Load change rate setting unit 111 Startup mode determination unit 112 Load control section 113 Upper limit setting unit 114 Low Value Selection Section

Claims

1. 1. A startup control device for starting up a combined cycle plant including a gas turbine and a steam turbine that can be driven by steam generated by exhaust heat of the gas turbine, comprising: a standby load acquisition unit for acquiring a standby load of the combined cycle plant at a time when steam supply to the steam turbine starts; a target load acquisition unit for acquiring a target load of the combined cycle plant at the time of completion of startup of the combined cycle plant; a load change rate setting unit for setting a load change rate for increasing a load of the combined cycle plant from the standby load to the target load within a predetermined constant required time based on the standby load; a load control unit for controlling the load of the combined cycle plant from the start of the steam supply to the completion of the startup based on the load change rate; A start-up control device comprising:

2. The start-up control device according to claim 1 , wherein the load change rate setting unit calculates the load change rate by dividing a difference between the target load and the standby load by the required time.

3. 3. The start-up control device according to claim 1, wherein the standby load is set based on at least one of first information on a rotor temperature of the steam turbine and second information on an exhaust gas temperature of the gas turbine.

4. The start-up control device according to claim 3 , wherein the first information includes at least one of a measured metal temperature of a rotor of the steam turbine or an elapsed time since the steam turbine was last stopped.

5. The start-up control device according to claim 3 , wherein the second information includes at least one of an atmospheric temperature or an intake temperature of the gas turbine.

6. The start-up control device according to claim 1 , wherein the load change rate calculation unit is configured to set the load change rate to an allowable upper limit value when the load change rate exceeds an allowable upper limit value.

7. 3. The startup control device according to claim 1, wherein, at the start of the steam supply, after the rotational speed of the gas turbine has reached a rated rotational speed, the load of the combined cycle plant is maintained constant at the standby load.

8. 1. A startup control method for starting up a combined cycle plant including a gas turbine and a steam turbine that can be driven by steam generated by exhaust heat of the gas turbine, comprising: acquiring a standby load of the combined cycle plant at a time when steam supply to the steam turbine is started; acquiring a target load of the combined cycle plant at the time of completion of start-up of the combined cycle plant; setting a load change rate for increasing a load of the combined cycle plant from the standby load to the target load within a preset constant required time based on the standby load; controlling the load of the combined cycle plant from the start of the steam supply to the completion of the startup based on the load change rate; A startup control method comprising:

9. 1. A startup control program for starting up a combined cycle plant including a gas turbine and a steam turbine that can be driven by steam generated by exhaust heat of the gas turbine, comprising: A computer device includes: acquiring a standby load of the combined cycle plant at a time when steam supply to the steam turbine is started; acquiring a target load of the combined cycle plant at the time of completion of start-up of the combined cycle plant; setting a load change rate for increasing a load of the combined cycle plant from the standby load to the target load within a preset constant required time based on the standby load; controlling the load of the combined cycle plant from the start of the steam supply to the completion of the startup based on the load change rate; A startup control program that can execute the following:

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