Gas turbine control device, gas turbine control method and gas turbine control program

Abstract

To prevent generation of nozzle coking by suitably supplying purge gas to a supply system of fuel oil regardless of an operating state of a gas turbine.SOLUTION: A gas turbine includes a purge gas supply system for supplying purge gas to a fuel oil injection nozzle for injecting fuel oil to a combustion chamber. A gas turbine control device sets a supply pressure target value of purge gas on the basis of an operating state obtained from the gas turbine, and controls a purge gas supply pressure regulation part so that supply pressure of the purge gas becomes the supply pressure target value. An increase rate of the supply pressure target value is restricted to become an increase rate upper limit value or lower. When the necessity of correction is determined on the basis of the operating state, the increase rate upper limit value is corrected so that the increase rate upper limit value becomes larger.SELECTED DRAWING: Figure 1

Description

[Technical field]

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

[0002] For example, in thermal power plants, gas turbines are used as a power source for driving generators. The gas turbine includes a combustor capable of generating combustion gas by burning fuel, and the generated combustion gas rotates the turbine to drive a generator connected to the turbine, thereby generating electric power. As one type of gas turbine of this kind, a so-called dual-fired gas turbine is known, which is capable of switching between fuel gas and fuel oil as the fuel supplied to the combustor (for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2002-250517 A Summary of the Invention [Problem to be solved by the invention]

[0004] In a dual-fired gas turbine such as that described in Patent Document 1, a fuel injection nozzle for injecting fuel gas into a combustion chamber and a fuel injection nozzle for injecting fuel oil into the combustion chamber are provided. When the gas turbine is operated using fuel gas as fuel, if fuel oil remains in the fuel injection nozzle on the fuel oil side that is in a stopped state, the remaining fuel oil may coke due to heating, causing clogging. For this reason, the remaining fuel oil is discharged by supplying purge gas from a purge gas supply system provided in parallel to the fuel oil supply system.

[0005] The pressure of the purge gas used to discharge the fuel oil needs to be set higher than that of the casing to which it is supplied. For example, compressed air is used as the purge gas, but if its temperature falls below 100 degrees, drainage may occur. The accumulation of such drainage increases the pressure loss in the supply path of the purge gas and inhibits the supply of the purge gas. As a result, the purge gas is not sufficiently supplied to the fuel injection nozzle, and the fuel oil remaining in the fuel injection nozzle may cause nozzle coking.

[0006] In addition, the casing pressure of a gas turbine is variable depending on the operating state (e.g., load) of the gas turbine. Therefore, even if the casing pressure fluctuates, the purge gas pressure setting value must also be variably set in response to the casing pressure so that an appropriate amount of purge gas can be supplied. However, if the casing pressure decreases, a large amount of purge gas is temporarily supplied, which may cause a misfire in the gas turbine. Therefore, a predetermined upper limit value for the increase rate is set for the purge gas pressure setting value.

[0007] However, in a transient state in which the casing pressure changes significantly due to a sudden change in the required output of the gas turbine, the balance between the casing pressure and the set pressure value of the purge gas may be lost due to the influence of the piping length in the purge gas supply system and the delay in the operation of the valve, which may make it difficult to supply the purge gas normally. For example, when the casing pressure increases suddenly, the set pressure value of the purge gas may temporarily become smaller than the casing pressure, which may cause a shortage of the purge gas supply.

[0008] At least one embodiment of the present disclosure has been made in consideration of the above-mentioned circumstances, and has an object to provide a gas turbine control device, a gas turbine control method, and a gas turbine control program that are capable of preventing the occurrence of nozzle coking by suitably supplying purge gas to a fuel oil supply system regardless of the operating state of the gas turbine. [Means for solving the problem]

[0009] In order to solve the above problems, a gas turbine control device according to at least one embodiment of the present disclosure includes: a combustor having a fuel oil injection nozzle for injecting fuel oil into a combustion chamber; A fuel oil supply system for supplying the fuel oil to the fuel oil injection nozzle; a purge gas supply system for supplying a purge gas to the fuel oil injection nozzle; a purge gas supply pressure adjusting unit for adjusting the supply pressure of the purge gas; A gas turbine control device for controlling a gas turbine comprising: an operating state acquisition unit for acquiring an operating state of the gas turbine; a supply pressure target value setting unit for setting a supply pressure target value of the purge gas based on the operating state; an increase rate limiting unit for limiting an increase rate of the supply pressure target value to be equal to or less than an increase rate upper limit value, thereby obtaining a limited supply pressure target value; a determination unit for determining whether or not the increase rate upper limit value needs to be corrected based on the operating state; an increase rate upper limit correction unit that corrects the increase rate upper limit value to be larger when the determination unit determines that the correction is necessary; a control unit for controlling the purge gas supply pressure adjusting unit so that the supply pressure of the purge gas becomes the post-limitation supply pressure target value; Equipped with.

[0010] In order to solve the above problem, a gas turbine control method according to at least one embodiment of the present disclosure includes: a combustor having a fuel oil injection nozzle for injecting fuel oil into a combustion chamber; A fuel oil supply system for supplying the fuel oil to the fuel oil injection nozzle; a purge gas supply system for supplying a purge gas to the fuel oil injection nozzle; a purge gas supply pressure adjusting unit for adjusting the supply pressure of the purge gas; 1. A gas turbine control method for controlling a gas turbine comprising: acquiring an operating state of the gas turbine; setting a supply pressure target value of the purge gas based on the operating state; determining a post-limiting supply pressure target value by limiting an increase rate of the supply pressure target value to be equal to or less than an increase rate upper limit value; determining whether or not the increase rate upper limit value needs to be corrected based on the operating state; when it is determined that the correction is necessary, correcting the increase rate upper limit value so as to be larger; controlling the purge gas supply pressure adjusting unit so that the supply pressure of the purge gas becomes the post-limiting supply pressure target value; Equipped with.

[0011] In order to solve the above problem, a gas turbine control program according to at least one embodiment of the present disclosure includes: a combustor having a fuel oil injection nozzle for injecting fuel oil into a combustion chamber; A fuel oil supply system for supplying the fuel oil to the fuel oil injection nozzle; a purge gas supply system for supplying a purge gas to the fuel oil injection nozzle; a purge gas supply pressure adjusting unit for adjusting the supply pressure of the purge gas; A gas turbine control program for controlling a gas turbine comprising: A computer device includes: acquiring an operating state of the gas turbine; setting a supply pressure target value of the purge gas based on the operating state; determining a post-limiting supply pressure target value by limiting an increase rate of the supply pressure target value to be equal to or less than an increase rate upper limit value; determining whether or not the increase rate upper limit value needs to be corrected based on the operating state; when it is determined that the correction is necessary, correcting the increase rate upper limit value so as to be larger; controlling the purge gas supply pressure adjusting unit so that the supply pressure of the purge gas becomes the post-limiting supply pressure target value; 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 gas turbine control device, a gas turbine control method, and a gas turbine control program that are capable of preventing the occurrence of nozzle coking by suitably supplying purge gas to a fuel oil supply system regardless of the operating state of the gas turbine. [Brief description of the drawings]

[0013] [Figure 1] FIG. 1 is a schematic configuration diagram of a gas turbine according to an embodiment. [Diagram 2] FIG. 2 is a block diagram of a gas turbine control device for controlling the gas turbine of FIG. [Diagram 3] 3 is a diagram showing changes over time in each parameter of the gas turbine in the case where correction control is not performed by the increase rate upper limit correcting unit in FIG. 2. [Figure 4] 3 is a diagram showing changes over time in each parameter of the gas turbine when correction control is performed by the increase rate upper limit correcting unit in FIG. 2. [Figure 5A] FIG. 2 is a schematic configuration diagram of a gas turbine according to another embodiment. [Figure 5B] FIG. 2 is a schematic configuration diagram of a gas turbine according to another embodiment. 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] 1 is a schematic diagram of a gas turbine 1 according to one embodiment. The gas turbine 1 includes a compressor 3 for generating compressed air, a combustor 2 for generating combustion gas by mixing and burning the compressed air generated by the compressor 3 with fuel, and a turbine 6 driven by the combustion gas. The combustor 2 is supplied with the compressed air compressed by the compressor 3 and fuel supplied from a fuel supply system (described below), and these are mixed and burned to generate combustion gas. This combustion gas flows into the turbine 6 and functions as power for driving the turbine 6.

[0016] The gas turbine 1 is a dual-fuel gas turbine capable of switching between fuel gas Fg and fuel oil Fo as fuel. The gas turbine 1 includes a fuel gas supply system 10 and a fuel oil supply system 20 as fuel supply systems for supplying these fuels to the combustor 2, respectively.

[0017] The combustor 2 also has a plurality of fuel injection nozzles for injecting fuel into a combustion chamber for generating combustion gas. When a plurality of types of fuel are handled in the gas turbine, the plurality of fuel injection nozzles include fuel injection nozzles corresponding to each type of fuel. In this embodiment, the fuel gas supply system 10 is connected to a fuel gas injection nozzle that is a fuel injection nozzle corresponding to the fuel gas, and the fuel oil supply system 20 is connected to a fuel oil injection nozzle that is a fuel injection nozzle corresponding to the fuel oil.

[0018] The fuel gas supply system 10 is configured to supply fuel gas Fg as fuel to the fuel gas injection nozzle of the combustor 2. The fuel gas supply system 10 includes a fuel gas supply line 14 that connects a fuel gas supply source 12 to the fuel gas injection nozzle. The fuel gas supply line 14 is provided with a fuel gas flow rate control valve 16 for adjusting the flow rate of the fuel gas Fg supplied to the fuel gas injection nozzle. The opening degree of the fuel gas flow rate control valve 16 can be controlled based on a control signal from a gas turbine control device 100 (see FIG. 2) that serves as a controller.

[0019] The fuel oil supply system 20 is configured to supply fuel oil Fo as fuel to the fuel oil injection nozzle of the combustor 2. The fuel oil supply system 20 includes a fuel oil supply line 24 that connects a fuel oil supply source 22 to the fuel oil injection nozzle. A fuel oil flow rate control valve 26 is provided in the fuel oil supply line 24 to adjust the flow rate of the fuel oil Fo supplied to the fuel oil injection nozzle. The opening degree of the fuel oil flow rate control valve 26 can be controlled based on a control signal from a gas turbine control device 100 (see FIG. 2) which is a controller.

[0020] The purge gas supply system 30 is configured to supply purge gas A to the fuel oil injection nozzle of the combustor 2. When the gas turbine 1 is stopped or is operated with fuel gas Fg, the supply of fuel oil Fo by the fuel oil supply system 20 is stopped. In this case, if fuel oil Fo remains in the fuel oil injection nozzle of the combustor 2 to which the fuel oil supply system 20 is connected, the fuel oil Fo is heated by heat generated during operation of the gas turbine 1, and coking may occur in the fuel oil injection nozzle, causing clogging. Therefore, in the gas turbine 1, when the fuel oil supply system 20 is in a stopped state, the purge gas A is supplied from the purge gas supply system 30 to the fuel oil injection nozzle of the combustor 2 to discharge the fuel oil Fo remaining in the fuel oil injection nozzle and prevent the occurrence of coking.

[0021] The purge gas supply system 30 has a purge gas supply line 34 connected to the purge gas supply source 32. The purge gas supply line 34 joins with the fuel oil supply line 24 at a joining portion 40 and is connected to a fuel oil injection nozzle. The purge gas supply line 34 is provided with a purge gas pressure control valve 36 as an example of a purge gas supply pressure adjustment unit for adjusting the pressure of the purge gas A. A pressure sensor 38 for detecting the pressure Pa of the purge gas A is installed downstream of the purge gas pressure control valve 36 in the purge gas supply line 34. The pressure Pa of the purge gas A detected by the pressure sensor 38 is sent as an electrical signal to a gas turbine control device 100 (see FIG. 2 ) which is a controller, and the opening degree of the purge gas pressure control valve 36 can be controlled based on a control signal obtained by calculation processing of the gas turbine control device 100.

[0022] Next, a gas turbine control device 100 for controlling the gas turbine 1 having the above configuration will be described. The gas turbine control device 100 is composed of, for example, a central processing unit (CPU), a random access memory (RAM), a read only memory (ROM), 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 the 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.

[0023] Fig. 2 is a block configuration diagram of a gas turbine control device 100 for controlling the gas turbine 1 in Fig. 1. The gas turbine control device 100 includes an operating state acquisition unit 102, a supply pressure target value setting unit 104, an increase rate limiting unit 106, a trigger index determination unit 107, an increase rate upper limit value correction unit 108, and a control unit 110.

[0024] The operating state acquisition unit 102 is configured to acquire the operating state of the gas turbine 1. The operating state acquired by the operating state acquisition unit 102 includes parameters necessary for various calculations performed by the gas turbine control device 100, and in this embodiment includes at least the casing pressure Ps, rotational frequency R, load L, and opening degree D of an inlet guide vane (IGV) of the gas turbine 1. Each parameter acquired as these operating states may be a detection value by a sensor installed at an appropriate position of the gas turbine 1, or may be an estimated value calculated by calculation.

[0025] The supply pressure target value setting unit 104 is configured to set a supply pressure target value Pt of the purge gas A based on the operating state of the gas turbine 1. The supply pressure target value Pt is a control target value related to the supply pressure Pa of the purge gas A, and in this embodiment, the supply pressure target value Pt is set based on the casing pressure Ps acquired as the operating state of the gas turbine 1. More specifically, the supply pressure target value setting unit 104 sets the supply pressure target value Pt by adding a predetermined differential pressure ΔP set in advance to the casing pressure Ps, as shown in the following equation. Pt = Ps + ΔP (1)

[0026] The increase rate limiting unit 106 is configured to limit the increase rate C of the supply pressure target value Pt to be equal to or less than the increase rate upper limit value Climit. As described above, the supply pressure target value Pt is set based on the operating state of the gas turbine 1, and therefore, when the operating state of the gas turbine 1 changes, the supply pressure target value Pt also changes. When the increase rate C of the supply pressure target value Pt exceeds the increase rate upper limit value Climit, the increase rate limiting unit 106 limits it to be equal to the increase rate upper limit value Climit (hereinafter, the supply pressure target value output from the increase rate limiting unit 106 will be appropriately referred to as the "limited supply pressure target value Pt'"). Furthermore, when the increase rate C of the supply pressure target value Pt is equal to or less than the increase rate upper limit value Climit, the increase rate C is not limited, and the limited supply pressure target value Pt′ becomes equal to the supply pressure target value Pt input to the increase rate limiting unit 106.

[0027] The upper limit value Climit of the increase rate is set in advance, for example, as a value suitable for suppressing the occurrence of misfires caused by a large amount of purge gas A being supplied to the combustor 2 when the cylinder pressure Ps suddenly changes.

[0028] The trigger index determination unit 107 is configured to determine, based on a trigger index, whether or not the increase rate upper limit value Climit needs to be corrected by the increase rate upper limit value correction unit 108. In this embodiment, at least one of the vehicle interior pressure Ps, the rotation frequency R, the load L, and the IGV opening degree D is adopted as the trigger index.

[0029] More specifically, when the cabin pressure Ps is used as the trigger index, the trigger index determination unit 107 determines that the increase rate upper limit value Climit needs to be corrected when the cabin pressure Ps increases suddenly (when the increase rate of the cabin pressure Ps is equal to or greater than a reference value). When the rotation frequency R is used as the trigger index, the trigger index determination unit 107 determines that the increase rate upper limit value Climit needs to be corrected when the rotation frequency R decreases suddenly (when the decrease rate of the rotation frequency R is equal to or greater than a reference value). When the load L is used as the trigger index, the trigger index determination unit 107 determines that the increase rate upper limit value Climit needs to be corrected when the load L increases suddenly (when the increase rate of the load L is equal to or greater than a reference value). When the IGV opening D is used as the trigger index, the trigger index determination unit 107 determines that the increase rate upper limit value Climit needs to be corrected when the IGV opening D increases suddenly (when the increase rate is equal to or greater than a reference value).

[0030] The increase rate upper limit value correcting unit 108 is configured to correct the increase rate upper limit value Climit in the increase rate limiting unit 106 based on the determination result of the trigger index determining unit 107. When the trigger index determining unit 107 determines that the increase rate upper limit value Climit needs to be corrected based on any one of the trigger indexes as described above, the increase rate upper limit value correcting unit 108 corrects the increase rate upper limit value Climit. This correction is performed so as to increase the increase rate upper limit value Climit when the casing pressure Ps of the gas turbine 1 becomes higher than the post-limitation supply pressure target value Pt'.

[0031] The control unit 110 is configured to adjust the supply pressure of the purge gas A to the post-restriction supply pressure target value Pt' by controlling the opening degree of the purge gas pressure regulating valve 36, which is a purge gas supply pressure adjusting unit. This control may be performed as a feedback control, for example, so that the difference between the supply pressure of the purge gas A and the post-restriction supply pressure target value Pt' becomes small.

[0032] Here, the correction control of the increase rate upper limit value Climit by the increase rate upper limit value correction unit 108 will be specifically described. FIG. 3 is a diagram showing the temporal changes of each parameter of the gas turbine 1 when the correction control by the increase rate upper limit value correction unit 108 in FIG. 2 is not performed. In this example, at time t1, the operating state of the gas turbine 1 is shown to change such that the rotational speed R of the gas turbine 1 rapidly decreases and the cabin pressure Ps rapidly increases. At this time, since the supply pressure target value Pt is obtained by adding a predetermined differential pressure ΔP to the cabin pressure Ps as shown in the above equation (1), the supply pressure target value Pt also changes so as to increase.

[0033] From time t1 to time t3, since the increase rate C of the supply pressure target value Pt exceeds the increase rate upper limit value Climit, the supply pressure target value Pt' after restriction shows a linear behavior with a constant slope corresponding to the increase rate upper limit value Climit. Here, in the period from time t1 to time t2 (<t3), the cabin pressure Ps is greater than the supply pressure target value Pt' after restriction. This means that in the purge gas supply system 30, since the downstream pressure is higher than the upstream pressure, the purge gas A cannot be properly supplied. In this case, due to the insufficient supply of the purge gas A to the fuel oil injection nozzle, the fuel oil Fo remaining in the fuel oil injection nozzle cannot be discharged, and coking may occur.

[0034] On the other hand, FIG. 4 is a diagram showing the temporal changes of each parameter of the gas turbine 1 when the correction control by the increase rate upper limit value correction unit 108 in FIG. 2 is performed. In the gas turbine control device 100 according to the present embodiment, as described above, in the vicinity of time t1, since the rotational frequency R rapidly decreases and the cabin pressure Ps rapidly increases, the trigger index determination unit 107 determines that it is necessary to correct the increase rate upper limit value Climit. As a result, in the increase rate upper limit value correction unit 108, during the period when the cabin pressure Ps of the gas turbine 1 becomes greater than the supply pressure target value Pt' after restriction in FIG. 3 (between time t1 and time t3), the increase rate upper limit value Climit is corrected to increase.

[0035] In Fig. 4, the increase rate upper limit value Climit is corrected to infinity (i.e., eliminated) in the period from time t1 to time t3, so that the casing pressure Ps of the gas turbine 1 becomes substantially equal to the supply pressure target value Pt (or the post-restriction supply pressure target value Pt'), and the period during which the casing pressure Ps of the gas turbine 1 is greater than the supply pressure target value Pt (or the post-restriction supply pressure target value Pt') is eliminated (or is significantly reduced) compared to Fig. 3. This indicates that the state in which the purge gas A cannot be appropriately supplied to the fuel oil injection nozzle due to the casing pressure Ps being greater than the post-restriction supply pressure target value Pt' is improved.

[0036] Next, a configuration of the gas turbine 1 according to another embodiment will be described. Fig. 5A is a schematic configuration diagram of the gas turbine 1 according to another embodiment. In the following description, components corresponding to those in the above-described embodiment are denoted by the same reference numerals, and duplicate descriptions will be omitted as appropriate.

[0037] In the gas turbine 1 of this embodiment, the mixing tube 50 connecting the junction 40 and the combustor 2 has a height difference H. The mixing tube 50 illustrated in FIG. 5A includes a first section 50a, a second section 50b, and a third section 50c. The first section 50a extends in a substantially horizontal direction, and one end on the upstream side is connected to the junction 40, and the other end on the downstream side is connected to the second section 50b. The second section 50b extends in a substantially vertical direction and has a length corresponding to the height difference H, and one end on the upstream side is connected to the first section 50a, and the other end on the downstream side is connected to the third section 50c. The third section 50c extends in a substantially horizontal direction, and one end on the upstream side is connected to the second section 50b, and the other end on the downstream side is connected to the combustor 2. The shape of the mixing tube 50 is not limited to this.

[0038] As described above, compressed air is used as the purge gas A, but drain may occur when the temperature falls below 100 degrees. If drain accumulates in the mixing tube 50 having the height difference H, the supply of the purge gas A is hindered, and nozzle coking may occur in the fuel injection nozzle of the combustor 2. In order to prevent such nozzle coking, the supply pressure of the purge gas A is set to be higher than a reference pressure that takes into account the volume of drain accumulated in the mixing tube 50 having the height difference H. Specifically, the opening of the purge gas pressure control valve 36 is controlled so that the pressure of the purge gas A detected by the pressure sensor 38 is higher than the reference pressure. That is, a reference pressure is set based on the height difference H to allow the purge gas A to flow appropriately against the accumulated drain. As a result, even if drain accumulates in the mixing tube 50 having the height difference H, the purge gas A is suitably supplied to the fuel injection nozzle of the combustor 2 against the drain, and nozzle coking can be prevented.

[0039] FIG. 5B is a schematic configuration diagram of the gas turbine 1 according to another embodiment. In the following description, components corresponding to those in the above-described embodiment are denoted by the same reference numerals, and duplicate descriptions will be omitted as appropriate.

[0040] In the gas turbine 1 of this embodiment, a flow rate sensor 52 for detecting the flow rate of the purge gas A is provided on the purge gas supply line 34. The gas turbine control device 100 determines whether or not the purge gas A is flowing appropriately by monitoring the flow rate of the purge gas A detected by the flow rate sensor 52. This determination is made by comparing the detection value of the flow rate sensor 52 with a threshold value for determining whether the purge gas A is flowing normally.

[0041] The gas turbine control device 100 may stop (trip) the operation of the gas turbine 1 when it is determined that the purge gas A is not flowing appropriately. If the operation of the gas turbine 1 is continued without the purge gas A being supplied to the fuel injection nozzle, the possibility of the occurrence of nozzle coking increases. Therefore, by stopping the operation of the gas turbine 1 in this manner, the occurrence of nozzle coking can be prevented in advance. Also, when it is impossible to supply the purge gas A due to a large amount of accumulated drainage, the occurrence of nozzle coking can be prevented by stopping the operation of the gas turbine 1.

[0042] Furthermore, when the gas turbine control device 100 determines that the purge gas A is not flowing appropriately, the gas turbine control device 100 may control so as to increase the supply pressure of the purge gas A. For example, when the control of the supply pressure of the purge gas A is performed by adjusting the aperture of the purge gas pressure control valve 36 so that the detection value of the pressure sensor 38 becomes the reference pressure, the supply pressure of the purge gas A can be increased by changing so as to increase the reference pressure. By increasing the supply pressure of the purge gas A in this manner, the purge gas A overcomes the accumulated drainage, and the purge gas A is supplied to the fuel injection nozzle of the combustor 2, thereby making it possible to prevent nozzle coking.

[0043] As described above, according to each of the above embodiments, when the casing pressure Ps of the gas turbine 1 becomes higher than the target value of the supply pressure of the purge gas, the upper limit of the increase rate is corrected to be larger. In this way, by increasing the target value of the supply pressure limited by the upper limit of the increase rate, it is possible to shorten the period during which there is concern about a shortage of the supply of the purge gas due to the casing pressure of the gas turbine becoming higher than the target value of the supply pressure of the purge gas. As a result, the supply of the purge gas to the fuel oil injection nozzle is promoted, and the occurrence of coking can be effectively suppressed.

[0044] 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.

[0045] The contents described in each of the above embodiments can be understood, for example, as follows.

[0046] (1) A gas turbine control device according to one aspect includes: a combustor having a fuel oil injection nozzle for injecting fuel oil into a combustion chamber; A fuel oil supply system for supplying the fuel oil to the fuel oil injection nozzle; a purge gas supply system for supplying a purge gas to the fuel oil injection nozzle; a purge gas supply pressure adjusting unit for adjusting the supply pressure of the purge gas; A gas turbine control device for controlling a gas turbine comprising: an operating state acquisition unit for acquiring an operating state of the gas turbine; a supply pressure target value setting unit for setting a supply pressure target value of the purge gas based on the operating state; an increase rate limiting unit for limiting an increase rate of the supply pressure target value to be equal to or less than an increase rate upper limit value, thereby obtaining a limited supply pressure target value; a determination unit for determining whether or not the increase rate upper limit value needs to be corrected based on the operating state; an increase rate upper limit correction unit that corrects the increase rate upper limit value to be larger when the determination unit determines that the correction is necessary; a control unit for controlling the purge gas supply pressure adjusting unit so that the supply pressure of the purge gas becomes the post-limitation supply pressure target value; Equipped with.

[0047] According to the above aspect (1), when it is determined based on the operating state of the gas turbine that there is a concern about a shortage of purge gas supply, for example, because the casing pressure of the gas turbine becomes higher than the target value for the supply pressure of the purge gas, the increase rate upper limit for limiting the increase rate of the target value for the supply pressure is corrected to be larger. This makes it possible to shorten the period during which the casing pressure of the gas turbine becomes higher than the target value for the supply pressure of the purge gas by limiting the target value for the supply pressure of the purge gas using the upper limit of the increase rate. As a result, the supply of purge gas to the fuel oil injection nozzle is promoted, and the occurrence of coking can be effectively suppressed.

[0048] (2) In another embodiment, in the above embodiment (1), The determination unit determines that the correction is necessary when the increase rate of the vehicle compartment pressure is equal to or greater than a reference value.

[0049] When the increase rate of the casing pressure of the gas turbine is equal to or higher than a reference value, a sudden increase in the casing pressure causes the casing pressure of the gas turbine to exceed the target value of the purge gas supply pressure, which may cause a concern of a shortage of the purge gas supply. According to the above aspect (2), in such a case, the upper limit value of the increase rate is corrected as described above, thereby effectively shortening the period during which a shortage of the purge gas supply may occur due to the casing pressure of the gas turbine exceeding the target value of the purge gas supply pressure.

[0050] (3) In another embodiment, in the above embodiment (1) or (2), The determination unit determines that the correction is necessary when a rate of decrease in the rotation speed of the gas turbine is equal to or greater than a reference value.

[0051] When the rate of decrease in the rotational frequency of the gas turbine is equal to or greater than a reference value, a sudden decrease in the rotational frequency causes the casing pressure of the gas turbine to exceed the target value of the purge gas supply pressure, which may cause a concern of a shortage of the purge gas supply. According to the above aspect (3), in such a case, the upper limit value of the increase rate is corrected as described above, thereby effectively shortening the period during which a shortage of the purge gas supply may occur due to the casing pressure of the gas turbine exceeding the target value of the purge gas supply pressure.

[0052] (4) In another embodiment, in any one of the above (1) to (3), The determination unit determines that the correction is necessary when an increase rate of the load on the gas turbine is equal to or greater than a reference value.

[0053] When the increase rate of the load on the gas turbine is equal to or greater than a reference value, a sudden increase in the load causes the casing pressure of the gas turbine to exceed the target value of the supply pressure of the purge gas, which may cause a concern of a shortage of the supply of the purge gas. According to the above aspect (4), in such a case, the upper limit value of the increase rate is corrected as described above, thereby effectively shortening the period during which a shortage of the supply of the purge gas may occur due to the casing pressure of the gas turbine exceeding the target value of the supply pressure of the purge gas.

[0054] (5) In another embodiment, in any one of the above (1) to (4), The determination unit determines that the correction is necessary when an increase rate of an opening degree of an inlet guide vane provided in the gas turbine is equal to or greater than a reference value.

[0055] When the rate of increase in the opening of an inlet guide vane (IGV) equipped in a gas turbine is equal to or greater than a reference value, a sudden increase in the opening causes the casing pressure of the gas turbine to exceed the target value of the purge gas supply pressure, which may cause a concern of a shortage of purge gas supply. According to the above aspect (5), in such a case, the upper limit value of the increase rate is corrected as described above, thereby effectively shortening the period during which the casing pressure of the gas turbine exceeds the target value of the purge gas supply pressure, causing a concern of a shortage of purge gas supply.

[0056] (6) In another embodiment, in any one of the above (1) to (5), The supply pressure target value setting unit sets the supply pressure target value by adding a preset reference differential pressure to a casing pressure of the gas turbine.

[0057] According to the above aspect (6), the supply pressure target value is set by adding the reference pressure difference to the cylinder pressure. As a result, unless the supply pressure target value is limited by the increase rate upper limit, the supply pressure target value becomes higher than the cylinder pressure, so that the purge gas can be supplied appropriately.

[0058] (7) In another embodiment, in any one of the above (1) to (6), The increase rate upper limit correction unit corrects the increase rate upper limit so as to eliminate it when it is determined that the correction is necessary.

[0059] According to the above aspect (7), the increase rate upper limit value is corrected so as to eliminate the increase rate upper limit value, whereby the supply pressure target value restricted by the increase rate upper limit value is increased, so that the casing pressure of the gas turbine becomes higher than the supply pressure target value of the purge gas, thereby shortening the period during which there is concern about a shortage of the purge gas supply.

[0060] (8) In another embodiment, in any one of the above (1) to (7), The gas turbine The gas turbine includes a fuel gas injection nozzle for injecting fuel gas into the combustion chamber. a fuel gas supply system for supplying the fuel gas to the fuel gas injection nozzle; It further comprises:

[0061] According to the above aspect (8), in a so-called dual-fired gas turbine in which fuel gas can be used as fuel in addition to the above-mentioned fuel oil, a shortage in the supply of purge gas can be effectively eliminated.

[0062] (9) In another embodiment, in any one of the above (1) to (8), The purge gas is compressed air.

[0063] According to the above aspect (9), in a gas turbine that uses compressed air as purge gas, which is prone to generating drainage when the temperature falls below 100 degrees, it is possible to effectively solve the shortage of purge gas supply.

[0064] (10) A gas turbine control method according to one aspect includes the steps of: a combustor having a fuel oil injection nozzle for injecting fuel oil into a combustion chamber; A fuel oil supply system for supplying the fuel oil to the fuel oil injection nozzle; a purge gas supply system for supplying a purge gas to the fuel oil injection nozzle; a purge gas supply pressure adjusting unit for adjusting the supply pressure of the purge gas; 1. A gas turbine control method for controlling a gas turbine comprising: acquiring an operating state of the gas turbine; setting a supply pressure target value of the purge gas based on the operating state; determining a post-limiting supply pressure target value by limiting an increase rate of the supply pressure target value to be equal to or less than an increase rate upper limit value; determining whether or not the increase rate upper limit value needs to be corrected based on the operating state; when it is determined that the correction is necessary, correcting the increase rate upper limit value so as to be larger; controlling the purge gas supply pressure adjusting unit so that the supply pressure of the purge gas becomes the post-limiting supply pressure target value; Equipped with.

[0065] According to the above aspect (10), when it is determined based on the operating state of the gas turbine that there is a concern about a shortage of purge gas supply, for example, because the casing pressure of the gas turbine becomes higher than the target value for the supply pressure of the purge gas, the upper limit of the increase rate for limiting the increase rate of the target value for the supply pressure is corrected to be larger. This makes it possible to shorten the period during which the casing pressure of the gas turbine becomes higher than the target value for the supply pressure of the purge gas by limiting the target value for the supply pressure of the purge gas using the upper limit of the increase rate. As a result, the supply of purge gas to the fuel oil injection nozzle is promoted, and the occurrence of coking can be effectively suppressed.

[0066] (11) A gas turbine control program according to one embodiment of the present invention comprises: a combustor having a fuel oil injection nozzle for injecting fuel oil into a combustion chamber; A fuel oil supply system for supplying the fuel oil to the fuel oil injection nozzle; a purge gas supply system for supplying a purge gas to the fuel oil injection nozzle; a purge gas supply pressure adjusting unit for adjusting the supply pressure of the purge gas; A gas turbine control program for controlling a gas turbine comprising: A computer device includes: acquiring an operating state of the gas turbine; setting a supply pressure target value of the purge gas based on the operating state; determining a post-limiting supply pressure target value by limiting an increase rate of the supply pressure target value to be equal to or less than an increase rate upper limit value; determining whether or not the increase rate upper limit value needs to be corrected based on the operating state; when it is determined that the correction is necessary, correcting the increase rate upper limit value so as to be larger; controlling the purge gas supply pressure adjusting unit so that the supply pressure of the purge gas becomes the post-limiting supply pressure target value; It is possible to execute the following.

[0067] According to the above aspect (11), when it is determined based on the operating state of the gas turbine that, for example, the casing pressure of the gas turbine becomes higher than the target value of the supply pressure of the purge gas, and thus there is a concern about a shortage of the supply of the purge gas, the increase rate upper limit for limiting the increase rate of the target value of the supply pressure is corrected to be larger. This makes it possible to shorten the period during which the casing pressure of the gas turbine becomes higher than the target value of the supply pressure of the purge gas by limiting the target value of the supply pressure of the purge gas by the increase rate upper limit. As a result, the supply of the purge gas to the fuel oil injection nozzle is promoted, and the occurrence of coking can be effectively suppressed. [Explanation of symbols]

[0068] 1. Gas turbine 2. Combustor 3. Compressor 10 Fuel gas supply system 12 Fuel gas supply source 14 Fuel gas supply line 16 Fuel gas flow control valve 20 Fuel oil supply system 22 Fuel oil sources 24 Fuel Oil Supply Line 26 Fuel oil flow control valve 30 Purge gas supply system 32 Purge gas supply source 34 Purge gas supply line 36 Purge gas pressure control valve 38 Pressure Sensor 40 Junction 100 Gas turbine control device 102 Operation status acquisition unit 104 Supply pressure target value setting unit 106 Increase Rate Limiter 107 Trigger index determination unit 108 Increase rate upper limit correction unit 110 Control section Fg Fuel gas Fo fuel oil A Purge gas Pt Supply pressure target value Pt´ Supply pressure target after restriction ΔP Predetermined differential pressure

Claims

1. a combustor having a fuel oil injection nozzle for injecting fuel oil into a combustion chamber; A fuel oil supply system for supplying the fuel oil to the fuel oil injection nozzle; a purge gas supply system for supplying a purge gas to the fuel oil injection nozzle; a purge gas supply pressure adjusting unit for adjusting the supply pressure of the purge gas; A gas turbine control device for controlling a gas turbine comprising: an operating state acquisition unit for acquiring an operating state of the gas turbine; a supply pressure target value setting unit for setting a supply pressure target value of the purge gas based on the operating state; an increase rate limiting unit for limiting an increase rate of the supply pressure target value to be equal to or less than an increase rate upper limit value, thereby obtaining a limited supply pressure target value; a determination unit for determining whether or not the increase rate upper limit value needs to be corrected based on the operating state; an increase rate upper limit correction unit that corrects the increase rate upper limit value to be larger when the determination unit determines that the correction is necessary; a control unit for controlling the purge gas supply pressure adjusting unit so that the supply pressure of the purge gas becomes the post-limitation supply pressure target value; A gas turbine control device comprising:

2. The gas turbine control device according to claim 1 , wherein the determination unit determines that the correction is necessary when the increase rate of the casing pressure is equal to or greater than a reference value.

3. 3. The gas turbine control device according to claim 1, wherein the determination unit determines that the correction is necessary when a rate of decrease in the rotation speed of the gas turbine is equal to or greater than a reference value.

4. 3. The gas turbine control device according to claim 1, wherein the determination unit determines that the correction is necessary when an increase rate of the load of the gas turbine is equal to or greater than a reference value.

5. 3. The gas turbine control device according to claim 1, wherein the determination unit determines that the correction is necessary when an increase rate of an opening degree of an inlet guide vane included in the gas turbine is equal to or greater than a reference value.

6. 3. The gas turbine control device according to claim 1, wherein the supply pressure target value setting unit sets the supply pressure target value by adding a preset reference differential pressure to a casing pressure of the gas turbine.

7. 3 . The gas turbine control device according to claim 1 , wherein the increase rate upper limit value correction unit corrects the increase rate upper limit value so as to eliminate it when it is determined that the correction is necessary.

8. The gas turbine The gas turbine includes a fuel gas injection nozzle for injecting fuel gas into the combustion chamber. a fuel gas supply system for supplying the fuel gas to the fuel gas injection nozzle; The gas turbine control device according to claim 1 or 2, further comprising:

9. The gas turbine control device according to claim 1 or 2, wherein the purge gas is compressed air.

10. a combustor having a fuel oil injection nozzle for injecting fuel oil into a combustion chamber; A fuel oil supply system for supplying the fuel oil to the fuel oil injection nozzle; a purge gas supply system for supplying a purge gas to the fuel oil injection nozzle; a purge gas supply pressure adjusting unit for adjusting the supply pressure of the purge gas; 1. A gas turbine control method for controlling a gas turbine comprising: acquiring an operating state of the gas turbine; setting a supply pressure target value of the purge gas based on the operating state; determining a post-limiting supply pressure target value by limiting an increase rate of the supply pressure target value to be equal to or less than an increase rate upper limit value; determining whether or not the increase rate upper limit value needs to be corrected based on the operating state; when it is determined that the correction is necessary, correcting the increase rate upper limit value so as to be larger; controlling the purge gas supply pressure adjusting unit so that the supply pressure of the purge gas becomes the post-limiting supply pressure target value; A gas turbine control method comprising:

11. a combustor having a fuel oil injection nozzle for injecting fuel oil into a combustion chamber; A fuel oil supply system for supplying the fuel oil to the fuel oil injection nozzle; a purge gas supply system for supplying a purge gas to the fuel oil injection nozzle; a purge gas supply pressure adjusting unit for adjusting the supply pressure of the purge gas; A gas turbine control program for controlling a gas turbine comprising: A computer device includes: acquiring an operating state of the gas turbine; setting a supply pressure target value of the purge gas based on the operating state; determining a post-limiting supply pressure target value by limiting an increase rate of the supply pressure target value to be equal to or less than an increase rate upper limit value; determining whether or not the increase rate upper limit value needs to be corrected based on the operating state; when it is determined that the correction is necessary, correcting the increase rate upper limit value so as to be larger; controlling the purge gas supply pressure adjusting unit so that the supply pressure of the purge gas becomes the post-limiting supply pressure target value; A gas turbine control program capable of executing the above.

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