Gas turbine system and control method thereof

Abstract

To reduce operation cost of a gas turbine engine by appropriately regulating pressure of fuel gas to be supplied by using a simple control method.SOLUTION: A gas turbine system (1) includes: a gas turbine engine (3) having a compressor (11), a combustor (13), and a turbine (15); and a fuel gas pressure regulating device (5) that regulates pressure of fuel gas (F) to be introduced to the combustor (13). The gas turbine system also includes a control device (7) that directly calculates a command pressure value (Pc) of the fuel gas (F) introduced from the fuel gas pressure regulating device (5) to the combustor (13) on the basis of an operating environment state of the gas turbine engine (3), and controls the fuel gas pressure regulating device (5) on the basis of the calculated command pressure value.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a gas turbine system and a control method thereof. [Background technology]

[0002] In the operation of a gas turbine engine, conventionally, fuel gas is generally supplied to a combustor while maintaining a constant fuel gas pressure (see, for example, Patent Document 1). The pressure value when maintaining such a constant fuel gas supply pressure is determined based on the maximum load at the lowest temperature at the site where the gas turbine engine is installed. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-252397 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in reality, it is not necessary to keep the fuel gas pressure constant all the time, and there are cases where the gas turbine engine can be operated even if the fuel gas is supplied at a lower pressure, for example, when the intake air temperature is high. In other words, operating the engine at a constantly high fuel gas pressure results in unnecessary operating costs for compressing the fuel gas.

[0005] Furthermore, Patent Document 1 also proposes changing the fuel gas supply pressure, but this control requires the acquisition and calculation of parameters that are not directly related to the fuel gas pressure, such as estimating the cabin pressure based on the inlet guide vane opening, which complicates the control algorithms and systems.

[0006] In order to solve the above-mentioned problems, an object of the present disclosure is to reduce the operating costs of a gas turbine engine by appropriately adjusting the pressure of the fuel gas supplied using a simple control method. [Means for solving the problem]

[0007] In order to achieve the above object, a gas turbine system according to the present disclosure includes: a gas turbine engine including a compressor, a combustor, and a turbine; a fuel gas pressure adjusting device for adjusting the pressure of the fuel gas introduced into the combustor; a control device that directly calculates a command pressure value of the fuel gas to be introduced from the fuel gas pressure regulator into the combustor based on an operating environmental state of the gas turbine engine, and controls the fuel gas pressure regulator based on the calculated command pressure value; Equipped with.

[0008] Further, a control method for a gas turbine system according to the present disclosure includes: a gas turbine engine including a compressor, a combustor, and a turbine; a fuel gas pressure adjusting device for adjusting the pressure of the fuel gas introduced into the combustor; 1. A method of controlling a gas turbine system comprising: directly calculating a command pressure value of the fuel gas introduced from the fuel gas pressure regulator to the combustor based on an operating environmental state of the gas turbine engine; controlling the fuel gas pressure regulating device based on the calculated command pressure value; Includes. [Effects of the Invention]

[0009] According to the gas turbine system and the control method thereof according to the present disclosure, the pressure of the fuel gas supplied can be appropriately adjusted using a simple control method, thereby reducing the operating costs of the gas turbine engine. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a block diagram illustrating a schematic configuration of a gas turbine system according to an embodiment of the present disclosure. FIG. [Figure 2] 2 is a graph schematically showing an example of a fuel gas pressure schedule for the gas turbine system of FIG. 1. [Figure 3] 2 is a graph schematically showing an example of a control method for the gas turbine system of FIG. 1. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, an embodiment according to the present disclosure will be described with reference to the drawings, but the present disclosure is not limited to this embodiment.

[0012] 1 shows a schematic configuration of a gas turbine system 1 according to a first embodiment of the present disclosure. The gas turbine system 1 includes a gas turbine engine (hereinafter simply referred to as a "gas turbine") 3, a fuel gas pressure regulator 5, and a control device 7.

[0013] The gas turbine 3 includes a compressor 11, a combustor 13, and a turbine 15 as its main components. Air A, which is a working medium taken into the gas turbine 3, is compressed by the compressor 11 and sent to the combustor 13, where it is mixed with fuel gas F supplied to the combustor 13 and burned as an air-fuel mixture. The high-temperature combustion gas generated in the combustor 13 is sent to the turbine 15 to rotate it. The rotational power of the turbine 15 is output via an output rotating shaft 17. The output rotating shaft 17 of the gas turbine 3 is connected to a load 19, such as a generator, via a reduction gear (not shown).

[0014] The fuel gas pressure regulator 5 regulates the pressure of the fuel gas F introduced into the combustor 13. In this embodiment, a plurality of devices for regulating the pressure of the fuel gas F are provided on a fuel gas inlet path 21 that introduces the fuel gas F from a fuel gas source into the combustor 13, and these multiple devices constitute the "fuel gas pressure regulator 5." In the illustrated example, the fuel gas pressure regulator 5 includes a fuel gas compressor 23 that compresses the fuel gas F from the fuel gas source, a fuel gas pressure regulator valve 25 that regulates the pressure of the fuel gas F compressed by the fuel gas compressor 23 and discharged from the fuel gas compressor 23, a fuel gas control valve 27 that regulates the flow rate of the fuel gas F introduced into the combustor 13, a pressure detector 29 provided downstream of each valve, and the like.

[0015] More specifically, in the illustrated example, the fuel gas pressure regulating valve 25 includes a first gas pressure regulating valve 25A configured as a slide valve and a second gas pressure regulating valve 25B that is a bypass valve disposed downstream of the first gas pressure regulating valve 25A. The second gas pressure regulating valve 25B that is a bypass valve has the following features: fuel Gas compressor 23 a fuel gas bypass passage communicating with the upstream side of the 32 is connected.

[0016] Furthermore, in the illustrated example, a first fuel gas control valve 27A, a second fuel gas control valve 27B, and a third fuel gas control valve 27C are provided as the fuel gas control valves 27. These fuel gas control valves 27 correspond to the multiple fuel gas injection nozzles 31 provided in the combustor 13, respectively. For example, the first fuel gas control valve 27A adjusts the flow rate of the fuel gas supplied to the pilot fuel injection nozzle 31A, the second fuel gas control valve 27B adjusts the flow rate of the fuel gas supplied to the main fuel injection nozzle 31B, and the third fuel gas control valve 27C adjusts the flow rate of the fuel gas supplied to the booster fuel injection nozzle 31C. However, the number and arrangement of the fuel gas control valves 27 are not limited to this example and may be selected appropriately depending on the specifications of the combustor 13.

[0017] The control device 7 may be a device that controls the operation of the entire gas turbine system 1, but in this specification, only the functions and configuration of the control device 7 related to pressure control of the fuel gas F will be described.

[0018] The control operation by the control device 7 in the gas turbine system 1, that is, the control method for the gas turbine system 1, will be described below.

[0019] In this embodiment, the control device 7 directly calculates a command pressure value of the fuel gas F introduced from the fuel gas pressure regulator 5 to the combustor 13 based on the operating environmental state of the gas turbine 3, and controls the fuel gas pressure regulator 5 based on the calculated command pressure value. In this way, the control device 7 adjusts the pressure of the fuel gas F introduced from the fuel gas pressure regulator 5 to the combustor 13 in accordance with the operating environmental state of the gas turbine 3.

[0020] In the illustrated example, the control device 7 includes a command pressure value calculation unit 33 and a gas pressure control unit 35, and the command pressure value calculation unit 33 directly calculates the command pressure value based on the operating environment state, and the gas pressure control unit 35 controls the fuel gas pressure regulating device 5. Note that, for convenience of explanation, the command pressure value calculation unit 33 and the gas pressure control unit 35 are provided separately in FIG. 1, but the command pressure value calculation unit 33 and the gas pressure control unit 35 do not necessarily have to be provided separately as hardware.

[0021] In this specification, the term "operating environment conditions" refers to external environmental conditions that may affect the operation of the gas turbine 3. Parameters indicating the operating environment conditions include, for example, intake air temperature, fuel density, fuel temperature, and atmospheric pressure at the installation site of the gas turbine 3. In other words, the operating environment conditions do not include the operating conditions of the components of the gas turbine 3 during operation, such as the inlet guide vane opening degree and compressor discharge pressure.

[0022] In this embodiment, the control device 7 directly calculates a command pressure value (hereinafter, may be simply referred to as "command pressure value") Pc of the fuel gas F to be supplied to the combustor 13 from the parameters indicating the above-mentioned operating environment conditions. The control device 7 further controls the fuel gas pressure regulator 5 based on the command pressure value Pc. Here, "directly calculating the command pressure value Pc" means that the command pressure value Pc is calculated based on the parameters indicating the operating environment conditions, without using parameters related to the operating conditions in the gas turbine 3, such as the compressor discharge pressure and the casing pressure.

[0023] For example, the control device 7 calculates the command pressure value Pc to be supplied to the combustor 13 using the following equation (1) as a function f of the intake air temperature, the fuel gas density, and the fuel gas temperature. P = f (intake air temperature, fuel gas density, fuel gas temperature) + fuel control valve pressure loss +Pipe pressure loss ... Equation (1)

[0024] The function f used by the control device 7 to determine the command pressure value Pc does not need to be a function of all of the factors such as intake air temperature, fuel gas density, and fuel gas temperature exemplified above as parameters indicating the operating environment state, but may be a function of only some of these, for example, the intake air temperature. FIG. 1 shows an example in which the control device 7 adjusts the fuel gas pressure based on the intake air temperature. That is, FIG. 1 shows an example in which a temperature detector 39 that detects the intake air temperature is provided in an intake passage 37 that introduces air into the compressor. However, a necessary detector may be provided in an appropriate location depending on the type of operating environment state parameter used for control.

[0025] An example of a schedule for the command pressure value Pc when the function f is a function of intake air temperature is shown in Figure 2, in comparison with the conventional case where the gas pressure is constant. In Figure 2, the conventional gas pressure schedule is shown by a dashed line, and the gas pressure schedule when f is a function of intake air temperature is shown by a solid line.

[0026] In addition, in the operation of the gas turbine 3, the value of the required command pressure value Pc also changes depending on the load factor of the gas turbine 3. That is, the gas pressure required during partial load operation of the gas turbine 3 is lower than the gas pressure required during full load operation. Therefore, the control device 7 may determine the command pressure value Pc taking into account the load factor of the gas turbine 3, as indicated by the dashed dotted line in Fig. 2, in addition to the operating environment state.

[0027] In this example, the control of the fuel gas pressure regulator 5 based on the command pressure value Pc is as follows: fuel Gas compressor 23 the rotation speed of the first gas pressure regulating valve 25A, the second gas pressure regulating valve 25B, the fuel gas control Valve 27 A~ 27 This is done by changing the opening of each of C.

[0028] When adjusting the pressure of the fuel gas by controlling the fuel gas pressure regulating device 5, the speed of the pressure change may be adjusted, for example, by adjusting the opening degree of the first gas pressure regulating valve 25A and the second gas pressure regulating valve 25B, to prevent a sudden pressure change.

[0029] 3, in this embodiment, the control device 7 maintains the fuel gas pressure at a predetermined constant value in a state S1 from when the gas turbine 3 is started until steady operation is reached, and adjusts the fuel gas pressure in accordance with the operating environment state after the gas turbine 3 reaches a steady operation state S2. Note that the figure shows an example in which full load operation is performed at the beginning of the steady operation state S2, and then the operation transitions to partial load operation.

[0030] In this way, by maintaining the pressure of the fuel gas F at a predetermined constant value from the time the gas turbine 3 starts up until it reaches steady operation, stable operation can be achieved by maintaining the fuel gas pressure at a constant value during start-up, when the operation of the gas turbine 3 is likely to become unstable. Furthermore, operating costs can be reduced by adjusting the fuel gas pressure during subsequent steady operation. Note that it is not essential to maintain the pressure of the fuel gas F at a predetermined constant value from the time the gas turbine 3 starts up until it reaches steady operation, and the pressure of the fuel gas F may be adjusted according to the operating environment conditions from the time the gas turbine 3 starts up.

[0031] 1 includes, for example, various circuits that perform the processes necessary for the above-mentioned control, a memory for storing information necessary for these processes, a power supply element such as a battery or a power supply circuit for receiving power from an external source, a receiving circuit for receiving input signals from the outside via a wired or wireless connection, a transmitting circuit for transmitting output signals to the outside via a wired or wireless connection, etc. Furthermore, the control device 7 includes a sensor element that detects the physical quantity of the detection target (pressure, temperature, flow rate, etc.), various circuits that perform necessary processes such as signal conversion processing and arithmetic processing on the acquired detected quantities, a memory for storing information necessary for these processes, a power supply element such as a battery or a power supply circuit for receiving power from an external source, a transmitting circuit for transmitting output signals to the outside via a wired or wireless connection, etc.

[0032] The type of fuel gas F used to operate the gas turbine 3 is not particularly limited, and may be any commonly available fuel gas, such as natural gas, city gas, biogas, liquefied petroleum gas, coke oven gas, VR gasification gas, hydrogen gas, etc.

[0033] Furthermore, in the present embodiment, an example has been shown in which the fuel gas compressor 23, the fuel gas pressure regulating valve 25, and the fuel gas control valve 27 are provided as an example of a specific aspect of the fuel gas pressure regulating device 5, but the specific aspect of the fuel gas pressure regulating device 5 is not limited to this. For example, if the supply source of the fuel gas F itself has a pressure regulating function, such supply source can also be a component of the fuel gas pressure regulating device 5. Furthermore, the gas turbine system 1 may be provided with various devices and valves other than those shown in FIG. 1 that are necessary for the operation of the system.

[0034] A gas turbine system 1 according to a first aspect of this embodiment includes a gas turbine engine 3 having a compressor 11, a combustor 13, and a turbine 15, a fuel gas pressure regulator 5 that regulates the pressure of the fuel gas F introduced into the combustor 13, and a control device 7 that directly calculates a command pressure value of the fuel gas F introduced from the fuel gas pressure regulator 5 to the combustor 13 based on the operating environment state of the gas turbine engine 3, and controls the fuel gas pressure regulator 5 based on the calculated command pressure value. According to this configuration, the pressure of the supplied fuel gas F can be appropriately adjusted by a simple control method in which the required gas pressure is directly calculated from the operating environment state. This reduces unnecessary operating costs of the fuel gas pressure regulator 5, thereby reducing the operating costs of the entire gas turbine 3.

[0035] In the gas turbine system 1 according to a second aspect of the present embodiment, in the gas turbine system 1 according to the first aspect, the control device 7 directly calculates the command pressure value based on at least one parameter indicating the operating environment state, which is an intake air temperature, a fuel density, and a fuel temperature. According to this configuration, the pressure of the fuel gas F can be efficiently adjusted by using an operating environment state parameter that has a particularly large effect on the required fuel gas pressure.

[0036] The gas turbine system 1 according to a third aspect of the present embodiment is the gas turbine system 1 according to the first or second aspect, wherein the control device 7 further directly calculates the command pressure value based on the load factor of the gas turbine engine 3. With this configuration, when the gas turbine 3 is operating at partial load, it is possible to more appropriately adjust the fuel gas pressure according to the load factor.

[0037] The gas turbine system 1 according to a fourth aspect of this embodiment is the gas turbine system 1 according to any one of the first to third aspects, wherein the control device 7 maintains the pressure of the fuel gas F at a predetermined constant value from the time of startup of the gas turbine engine 3 until steady operation is reached, and controls the fuel gas pressure regulator 5 based on the command pressure value after the gas turbine engine 3 reaches steady operation. With this configuration, stable operation is achieved by keeping the fuel gas pressure at a constant value during startup, when operation of the gas turbine 3 engine is likely to become unstable, and the fuel gas pressure is then adjusted during steady operation, thereby reducing operating costs.

[0038] A control method for a gas turbine system 1 according to a first aspect of this embodiment is a method for controlling a gas turbine system 1 including a gas turbine engine 3 having a compressor 11, a combustor 13, and a turbine 15, and a fuel gas pressure regulator 5 that regulates the pressure of the fuel gas F introduced into the combustor 13, and includes directly calculating a command pressure value of the fuel gas F introduced from the fuel gas pressure regulator 5 to the combustor 13 based on the operating environment state of the gas turbine engine 3, and controlling the fuel gas pressure regulator 5 based on the calculated command pressure value. According to this configuration, the pressure of the supplied fuel gas F can be appropriately adjusted by a simple control method in which the required gas pressure is directly calculated from the operating environment state. This reduces unnecessary operating costs of the fuel gas pressure regulator 5, thereby reducing the operating costs of the entire gas turbine 3.

[0039] A control method according to a second aspect of the present embodiment is the control method according to the first aspect, The direct calculation includes directly calculating the command pressure value based on at least one parameter indicating the operating environment state, which is an intake air temperature, a fuel density, and a fuel temperature. With this configuration, the pressure of the fuel gas F can be efficiently adjusted by using the operating environment state parameter that has a particularly large effect on the required fuel gas pressure.

[0040] A control method according to a third aspect of the present embodiment is the control method according to the first or second aspect, wherein the direct calculation further includes calculating the command pressure value based on a load factor of the gas turbine engine 3. With this configuration, when the gas turbine 3 is operating at a partial load, it is possible to more appropriately adjust the fuel gas pressure according to the load factor.

[0041] A control method according to a fourth aspect of this embodiment is the control method according to any one of the first to third aspects, and includes maintaining the pressure of the fuel gas F at a predetermined constant value from the time of startup of the gas turbine engine 3 until steady operation is reached, and controlling the fuel gas pressure regulator 5 based on the command pressure value after the gas turbine engine 3 has reached steady operation. According to this configuration, during startup, when operation of the gas turbine 3 is likely to become unstable, stable operation is achieved by keeping the fuel gas pressure at a constant value, and then during steady operation thereafter, the fuel gas pressure can be adjusted to reduce operating costs.

[0042] As described above, the preferred embodiments of the present disclosure have been described with reference to the drawings, but various additions, modifications, and deletions can be made without departing from the spirit of the present disclosure. Therefore, such additions, modifications, and deletions are also included in the scope of the present disclosure. [Explanation of symbols]

[0043] 1 Gas turbine system 3. Gas turbine engine 5. Fuel gas pressure regulator 7 Control Device 11 Compressor 13 Combustor 15 Turbine F Fuel gas Pc command pressure value

Claims

1. a gas turbine engine including a compressor, a combustor, and a turbine; a fuel gas pressure adjusting device for adjusting the pressure of the fuel gas introduced into the combustor; a control device that directly calculates a command pressure value of the fuel gas to be introduced from the fuel gas pressure regulator into the combustor based on an operating environmental state of the gas turbine engine, and controls the fuel gas pressure regulator based on the calculated command pressure value; A gas turbine system comprising:

2. 2. The gas turbine system according to claim 1, the control device directly calculates the command pressure value based on at least one parameter of an intake air temperature, a fuel density, and a fuel temperature, which are parameters indicating the operating environment state; Gas turbine systems.

3. 3. The gas turbine system according to claim 1, the control device further directly calculates the command pressure value based on a load factor of the gas turbine engine. Gas turbine systems.

4. 3. The gas turbine system according to claim 1, The control device maintaining the pressure of the fuel gas at a predetermined constant value from the time of startup of the gas turbine engine until a steady operating state is reached; controlling the fuel gas pressure regulator based on the command pressure value after the gas turbine engine has reached a steady operating state; Gas turbine systems.

5. a gas turbine engine including a compressor, a combustor, and a turbine; a fuel gas pressure adjusting device for adjusting the pressure of the fuel gas introduced into the combustor; 1. A method of controlling a gas turbine system comprising: directly calculating a command pressure value of the fuel gas introduced from the fuel gas pressure regulator to the combustor based on an operating environmental state of the gas turbine engine; controlling the fuel gas pressure regulating device based on the calculated command pressure value; A method for controlling a gas turbine system, comprising:

6. 6. The control method according to claim 5, The direct calculation directly calculating the command pressure value based on at least one parameter of an intake air temperature, a fuel density, and a fuel temperature, which are parameters indicative of the operating environment state; A method for controlling a gas turbine system.

7. 7. The control method according to claim 5 or 6, The direct calculation further comprises: calculating the command pressure value based on a load factor of the gas turbine engine; A method for controlling a gas turbine system.

8. 7. The control method according to claim 5 or 6, maintaining the pressure of the fuel gas at a predetermined constant value from the time of startup of the gas turbine engine until a steady operating state is reached; controlling the fuel gas pressure regulator based on the command pressure value after the gas turbine engine reaches a steady operating state; Including, A method for controlling a gas turbine system.

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