Gas turbine system, gas turbine combustion chamber control device and gas turbine combustion chamber control method

Abstract

A gas turbine combustion chamber control device (11;41;51;61;71), comprising: a load interruption detector (16) that detects a load interruption of a gas turbine (10), a delay circuit (D) for setting a delay time based on the detection of the load interruption, a pilot nozzle flow rate control unit (17) which increases the amount of premixed fuel supplied to a pilot nozzle (13) based on a detection of load interruption, a first main jet flow rate control unit (18) which reduces the amount of premixed fuel supplied to a first main jet (14) based on the detection of the load interruption to a first quantity, and a second main jet flow rate control unit (19) which reduces the amount of premixed fuel supplied to a second main jet (15) based on the detection of the load interruption to a second quantity that is different from the first quantity, and then further reduces the amount of premixed fuel supplied to the second main jet (15) after the delay time has elapsed from the second quantity to a third quantity that is smaller than the first and the second quantity.

Description

[0001] The present invention relates to a gas turbine system, a gas turbine combustion chamber control device and a gas turbine combustion chamber control method.

[0002] A gas turbine combustion chamber is integrated into a gas turbine power plant or a combined cycle power plant, and a gas turbine is driven by introducing a combustion gas from the gas turbine combustion chamber into the gas turbine.

[0003] Various technologies are known to be related to such a background (see, for example, JP H05 - 149 544 A).

[0004] In a gas turbine system disclosed in JP H05 - 149 544 A, a first main nozzle function generator outputs a first main nozzle control signal based on a predetermined function value according to a load.

[0005] A second main nozzle function generator outputs a second main nozzle control signal based on a predetermined function value according to the operating conditions of a gas turbine. A follow-up circuit outputs a third main nozzle control signal by following the second main nozzle control signal after the first.

[0006] A pilot nozzle function generator outputs a control signal based on a predetermined function value to open and close a pilot nozzle distribution valve according to the third main nozzle control signal, and this signal is used as a pilot nozzle control signal. A control device uses the third main nozzle control signal as a main nozzle control signal. In this way, according to this gas turbine system, it is possible to perform stable two-stage combustion, thereby preventing a pilot nozzle misfire by setting the pilot nozzle distribution valve to a predetermined opening degree at the time of a load interruption.

[0007] Furthermore, in the past, energy generation was carried out in a gas turbine used in a power plant or the like by supplying compressed air and fuel to a combustion chamber and rotating a turbine using a high-temperature combustion gas due to combustion in the combustion chamber.

[0008] Several technologies related to such a background are known (see, for example, JP 2011 – 85 105 A).

[0009] In a gas turbine system disclosed in JP 2011-85105A, a first information acquisition unit acquires a pilot fuel ratio supplied to a combustion chamber. A second information acquisition unit acquires the air flow rate supplied to the combustion chamber. A target fuel-air ratio acquisition unit possesses combustion maintenance boundary information, which specifies the relationship between the pilot ratio and the fuel-air ratio, determined by the stability of a combustion state in the combustion chamber.

[0010] Furthermore, the target fuel-air ratio acquisition unit acquires a fuel-air ratio based on the pilot ratio acquired by the first information acquisition unit from the combustion maintenance limit information and outputs this fuel-air ratio as a target fuel-air ratio. A command generation unit determines a minimum fuel command by using the target fuel-air ratio and the airflow rate acquired by the second information acquisition unit. In this way, according to this gas turbine system, it is possible to reliably maintain combustion in the combustion chamber even in the event of a rapid load reduction, such as a load interruption or an auxiliary / additional load.

[0011] The technology disclosed in JP H05 - 149 544 A causes the main fuel to follow a set value, and it is not possible to control interruption timing at the time of staging, so it is not possible to reliably prevent combustion chamber misfires.

[0012] The technology disclosed in JP 2011 – 85 105 A not only does not target a premix pilot unit, although stable combustion can be carried out at the time of a load interruption, but also does not take into account a staging of a main jet, so that it is not possible to reliably prevent a misfire of the combustion chamber.

[0013] From US Patent 2008 / 0071427A1, a method for transient fuel control for fuel supply circuits for a plurality of connected gas turbines is known, wherein the method comprises: detecting a transient grid event based on an indication of at least one rapid change in a fuel command to the gas turbine or an acceleration of the turbine shaft, upon detection of the transient grid event, instructing a gas turbine control to transfer the gas turbine to at least one intermediate load, setting a fuel split to maintain burner stability during the transient grid event, and using a predetermined island load demand signal to split an island load demand among the connected gas turbine generators.

[0014] According to the present invention, a gas turbine combustion chamber control device according to claim 1 is proposed.

[0015] The combustion chamber control device can temporarily reduce the flow rate of the first main nozzle based on a detection of load interruption.

[0016] The combustion chamber control device can reduce the amount of premixed fuel supplied to the second main nozzle, using a parameter required for a flame as an indicator.

[0017] The combustion chamber control device can set a delay time when the amount of premixed fuel supplied to the second main nozzle is reduced to a predetermined amount, based on a detection of the load interruption, and it can then further reduce the amount of premixed fuel supplied after a predetermined time has elapsed.

[0018] The combustion chamber control device may include an adjustment of the opening degree of an inlet guide vane provided in the gas turbine.

[0019] According to the present invention, a gas turbine system with the gas turbine combustion chamber control device according to claim 6 is also proposed.

[0020] According to the present invention, a gas turbine combustion chamber control method according to claim 7 is also proposed.

[0021] The above-mentioned aspects of the invention are not intended to represent all the necessary features of the present invention.

[0022] According to the gas turbine system, the gas turbine combustion chamber control device and the gas turbine combustion chamber control method as described above, misfires in the combustion chamber can be reliably prevented. In Fig. Figure 1 is a concept block diagram of a gas turbine system of a first embodiment. Fig. Figure 2 is a schematic representation of a gas turbine system of the first embodiment. Fig. Figure 3 is a schematic sectional view of a combustion chamber in a gas turbine of the first embodiment. Fig. Figure 4 is a schematic circuit diagram of a gas turbine combustion chamber control device of the first embodiment. Fig. Figure 5 is a time sequence diagram describing a gas turbine combustion chamber control method of the first embodiment. Fig. Figure 6 is a time sequence diagram describing a gas turbine combustion chamber control method of a second embodiment. Fig. Figure 7 is a schematic circuit diagram of a gas turbine combustion chamber control device of a third embodiment. Fig. Figure 8 is a schematic circuit diagram of a gas turbine combustion chamber control device of a fourth embodiment. Fig. Figure 9 is a time sequence diagram describing a gas turbine combustion chamber control method of the fourth embodiment. Fig. Figure 10 is a time sequence diagram describing a gas turbine combustion chamber control method of a fifth embodiment.

[0023] The invention will be described below using embodiments of the invention.

[0024] The Fig. Figure 1 is a conceptual block diagram of a gas turbine system of a first embodiment. According to the Fig. The system comprises a gas turbine 1, a gas turbine 10, and a combustion chamber control device 11. The gas turbine 10 is provided with a combustion chamber 12. The combustion chamber 12 is provided with a pilot nozzle 13, a first main nozzle 14, and a second main nozzle 15. The combustion chamber control device 11 is provided with a load interruption detector 16, a pilot nozzle flow rate control unit 17, a first main nozzle flow rate control unit 18, and a second main nozzle flow rate control unit 19.

[0025] The pilot nozzle 13 injects a premixed fuel gas. The first main nozzle 14 injects a premixed fuel gas around the pilot nozzle 13. The second main nozzle 15 injects a premixed fuel gas around the pilot nozzle 13 in a manner similar to the first main nozzle 14. The load interruption detector 16 detects a load interruption of the gas turbine 10. The pilot nozzle flow rate control unit 17 increases the amount of premixed fuel supplied to the pilot nozzle 13 based on the detected load interruption. The first main nozzle flow rate control unit 18 decreases the amount of premixed fuel supplied to the first main nozzles 14 based on the detected load interruption.The second main jet flow rate control unit 19 reduces the amount of premixed fuel supplied to the second main jets 15 to a predetermined quantity, based on the detection of the load interruption, and then further reduces the amount of premixed fuel supplied after a predetermined time. Furthermore, there is no limitation to the first main jet 14 and the second main jet 15, and a plurality of main jets, including a third or fourth main jet, may be provided. In this case, various systems from the plurality of main jet groups are reserved for rotational speed control, and the remaining systems perform a control such that a reduction in the amount of premixed fuel supplied is carried out at a time interval.

[0026] Fig. Figure 2 is a schematic view of a gas turbine system of the first embodiment. According to the illustration in Fig. In section 2, the gas turbine 10 has a compressor 21 on the air inlet side of a turbine body 20. The gas turbine 10 is equipped with an inlet guide vane 22 for adjusting the amount of intake air on the inlet side. A premix pilot fuel gas flow path 23, a diffusion pilot fuel gas flow path 24, a first main nozzle fuel gas flow path 25, and a second main nozzle fuel gas flow path 26 are connected to the combustion chamber 12 in such a way that they communicate with it. In addition, a number of top-hat fuel gas flow paths, such as a first top-hat fuel gas flow path 27 and a second top-hat fuel gas flow path 28, are connected to the combustion chamber 12 in such a way that they communicate with it.

[0027] A premix combustion pilot pressure control valve 29 and a premix combustion pilot flow control valve 30 are connected to the premix pilot fuel gas flow path 23 in the sequence from the upstream side of a fuel gas to the downstream side, enabling them to communicate with it. A diffusion combustion pilot pressure control valve 31 and a diffusion combustion pilot flow control valve 32 are connected to the diffusion pilot fuel gas flow path 24 in the sequence from the upstream side of a fuel gas to the downstream side, enabling them to communicate with it.

[0028] A first main jet pressure control valve 33 and a first main jet flow control valve 34 are connected, in sequence from the upstream side of a fuel gas to the downstream side, to the first main jet fuel gas flow path 25 so that they communicate with it. A second main jet pressure control valve 35 and a second main jet flow control valve 36 are connected, in sequence from the upstream side of a fuel gas to the downstream side, to the second main jet fuel gas flow path 26 so that they communicate with it.

[0029] Fig. Figure 3 is a schematic sectional view of the combustion chamber in the gas turbine of the first embodiment. As shown in Fig. In the combustion chamber 12, the pilot nozzle 13 is provided in the center, and three first main nozzles 14 are provided side by side in a circumferential direction on the outer circumferential side of the pilot nozzle 13. Furthermore, in the combustion chamber 12, five second main nozzles 15 are provided side by side in a circumferential direction on the outer circumferential side of the pilot nozzle 13. The arrangement or number of the respective nozzles can also be adjusted appropriately.

[0030] The Fig. Figure 4 is a schematic circuit diagram of a gas turbine combustion chamber control device of the first embodiment. According to the diagram in Fig. 4. In the combustion chamber control device 11, a load interruption signal is input into a first switch SW1 during premix pilot operation. Additionally, the load interruption signal is input into a second switch SW2 with a remaining time set by a delay circuit D. A fuel flow rate command calculation signal for the second main jet 15, generated by a normal controller, is input to an OFF input of the first switch SW1. A residual quantity setting signal is input to an OFF input of the second switch SW2. A zero signal is input to an ON input of the second switch SW2. The second switch SW2 executes an input to an ON input of the first switch SW1. The combustion chamber control device 11 determines a fuel flow rate command to the second main jet 15 via a normal controller in the first switch SW1.In contrast, at the time of a load interruption, after a delay time has been set in the delay circuit D, a fuel flow rate command to the second main jet 15 is determined by the second switch SW2 and the first switch SW1.

[0031] Fig. Figure 5 is a timing diagram describing a gas turbine combustion chamber control method of the first embodiment. According to the illustration in Fig. 5. The combustion chamber control device 11 detects the load interruption command if a load interruption command is present at time t1. After time t1, the pilot nozzle flow rate control unit 17 increases the amount of premixed fuel supplied to the pilot nozzle 13 as a result of the detected load interruption command. Therefore, at time t2 after time t1, the first main nozzle flow rate control unit 18 decreases the amount of premixed fuel supplied to the first main nozzle 14. Then, the second main nozzle flow rate control unit 19 further reduces the amount of premixed fuel supplied after time t2, once the amount of premixed fuel supplied to the second main nozzle 15 has been reduced to a predetermined quantity. Thus, the second main jet 15 continues to supply a predetermined amount of fuel gas for a predetermined period of time.Then, during this time, flame maintenance is performed by starting the supply of the premixed pilot fuel gas.

[0032] According to the gas turbine system 1 of the first embodiment, during a load interruption, a premixed pilot fuel gas is increased, and the supply of a predetermined quantity of fuel gas continues for a predetermined period without immediately interrupting the second main nozzle 15. Then, during this period, the supply of the premixed pilot fuel gas is initiated. Therefore, according to the gas turbine system 1, it is possible to reliably prevent a misfire in the combustion chamber 12 by promoting flame diffusion from a main system.

[0033] According to the combustion chamber control device 11 of the first embodiment, the supply of a predetermined quantity of fuel gas through the second main nozzle 15 continues for a predetermined period of time, and during this time the supply of the premixed pilot fuel gas is initiated. Therefore, according to the combustion chamber control device 11, misfires in the combustion chamber 12 can be prevented by flame holding.

[0034] According to the gas turbine combustion chamber control method of the first embodiment, the supply of a predetermined quantity of fuel gas through the second main nozzle 15 continues for a predetermined period of time, and during this time the supply of the premixed pilot fuel gas is initiated. Therefore, according to the gas turbine combustion chamber control method, misfire of the combustion chamber 12 can be prevented by flame holding.

[0035] Next, a second embodiment will be described with reference to Fig. 6 described. The same elements as those in the first embodiment are designated by the same reference numerals, and their descriptions are omitted, so that only different points are described. Fig. Figure 6 is a timing diagram describing a gas turbine combustion chamber control method of the second embodiment. According to the illustration in Fig. Figure 6 is a gas turbine system 2 of the second embodiment equipped with a combustion chamber control device 41. In the gas turbine combustion chamber control method of this embodiment, at the time of a load interruption at time t1, a premixed pilot fuel gas is increased and the supply of a predetermined quantity of fuel gas is continued for a predetermined period without immediately interrupting the second main nozzle 15. Then, during the period up to time t2 after time t1, the quantity of fuel gas supplied to the first main nozzle 14 is temporarily reduced.

[0036] According to the second embodiment of the gas turbine system 2, at the time of the load interruption, a premixed pilot fuel gas is increased, and the supply of a predetermined quantity of fuel gas continues for a predetermined period without immediately interrupting the second main nozzle 15. Then, during this period, the supply of the premixed pilot fuel gas is started, and the quantity of fuel gas supplied to the first main nozzle 14 is temporarily reduced. Therefore, according to the gas turbine system 2, it can be equipped with the combustion chamber control device 41, which can suppress a significant increase in the rotational speed of the gas turbine 10.

[0037] According to the combustion chamber control device 41 of the second embodiment, the supply of a predetermined quantity of fuel gas through the second main nozzle 15 continues for a predetermined period of time, and during this time the supply of the premixed pilot fuel gas is started and the quantity of fuel gas supplied to the first main nozzle 14 is temporarily reduced. Therefore, according to the combustion chamber control device 41, it is possible to suppress a significant increase in the rotational speed of the gas turbine 10.

[0038] According to the gas turbine combustion chamber control method of the second embodiment, the supply of a predetermined quantity of fuel gas through the second main nozzle 15 continues for a predetermined period of time, and during this time the supply of the premixed pilot fuel gas is initiated and the quantity of fuel gas supplied to the first main nozzle 14 is temporarily reduced. Therefore, according to the gas turbine combustion chamber control method of this embodiment, a significant increase in the rotational speed of the gas turbine 10 can be suppressed.

[0039] Next, a third embodiment will be described with reference to Fig. 7 described. The same elements as those in the first embodiment are designated with the same reference numerals, and their descriptions are omitted, so that only different points are described. Fig. Figure 7 is a schematic circuit diagram of a gas turbine combustion chamber control device of the third embodiment. According to the illustration in Fig. 7 is a combustion chamber control device 51, provided in a gas turbine system 3, equipped with a high-value monitor HM for setting a threshold. The combustion chamber control device 51 performs an automatic cut using a parameter important for flame maintenance, such as a premix pilot flame temperature, a premix pilot fuel flow rate, or a premix pilot fuel-air ratio as an indicator. Since it is difficult to measure a flame temperature directly, an estimated value is calculated from various state variables such as a turbine casing temperature, a fuel temperature, and a fuel-air ratio.

[0040] According to the gas turbine system 3 of the third embodiment, the gas turbine system 3 can be equipped with the combustion chamber control device 51, which makes it possible to reliably prevent misfires and, because a fuel cut or fuel interruption can be carried out with suitable timing, an increase in the rotational speed of the gas turbine 10 can be suppressed.

[0041] According to the combustion chamber control device 51 of the third embodiment, a misfire can be reliably prevented, and, because a fuel cut or fuel interruption can be carried out with suitable timing, an increase in the rotational speed of the gas turbine 10 can be suppressed.

[0042] According to a gas turbine combustion chamber control method of the third embodiment, a misfire can be reliably prevented and, because a fuel cut or fuel interruption can be carried out with suitable timing, an increase in the rotational speed of the gas turbine 10 can be suppressed.

[0043] Next, a fourth embodiment will be described with reference to Fig. 8 described. The same elements as those in the first embodiment are designated with the same reference numerals, and their descriptions are omitted, so that only different points are described. Fig. Figure 8 is a schematic circuit diagram of a gas turbine combustion chamber control device of the fourth embodiment. According to the illustration in Fig. 8 is a combustion chamber control device 61 provided in a gas turbine system 4, equipped with a rate limiter RL for setting a rate. The rate limiter RL sets the rate based on the output of a switch SW3 for setting a residual setting parameter and the output of switch SW2.

[0044] Fig. Figure 9 is a timing diagram describing a gas turbine combustion chamber control method of the fourth embodiment. According to the illustration in Fig. In the gas turbine combustion chamber control procedure, the residual setting parameter is adjusted so that it is gradually reduced at time t6 and at time t7 after time t5.

[0045] According to the gas turbine system 4 of the fourth embodiment, the gas turbine system 4 can be provided with the combustion chamber control device 61, in which fuel waste can be prevented by adjusting in detail the amount of fuel gas supplied to the second main nozzle 15.

[0046] According to the combustion chamber control device 61 of the fourth embodiment, fuel waste can be prevented by adjusting in detail the amount of fuel gas supplied to the second main jet 15.

[0047] According to the gas turbine combustion chamber control method of the fourth embodiment, fuel waste can be prevented by adjusting in detail the amount of fuel gas supplied to the second main nozzle 15.

[0048] Next, a fifth embodiment will be described with reference to Fig. 10. The same elements as those in the first embodiment are designated with the same reference numerals, and their descriptions are omitted, so that only different points are described. Fig. Figure 10 is a timing diagram describing a gas turbine combustion chamber control method of the fifth embodiment. According to the illustration in Fig. 10 is a gas turbine system 5 of the fifth embodiment equipped with a combustion chamber control device 71. In the gas turbine combustion chamber control method of this embodiment, an airflow rate is set by adjusting the opening degree of the inlet guide vane 22 together with a control of the combustion side. Here, a dead time and a rate can be set as parameters when adjusting the opening degree of the inlet guide vane 22. For example, as shown in the illustration, an imaginary line in Fig.10. An airflow rate can be increased by adjusting the dead time or decreasing a rate after a load interruption occurs at time t1, compared to a case where the inlet guide vane is closed at a mechanically maximum speed.

[0049] According to the gas turbine system 5 of the fifth embodiment, the gas turbine system 5 can be provided with the combustion chamber control device 71, which increases the airflow rate and thus increases the power of the compressor 21, thereby reducing or preventing the maximum rotational speed of the gas turbine 10.

[0050] According to the combustion chamber control device 71 of the fifth embodiment, an air flow rate is increased and thus the power of the compressor 21 is increased, so that the maximum rotational speed of the gas turbine 10 can be reduced or prevented.

[0051] According to the gas turbine combustion chamber control method of the fifth embodiment, the air flow rate is increased and thus the power of the compressor 21 is increased, so that the maximum rotational speed of the gas turbine 10 can be reduced or prevented.

[0052] According to the gas turbine system, the gas turbine combustion chamber control device and the gas turbine combustion chamber control method as described above, misfire of the combustion chamber can be reliably prevented. Reference symbol list: 1 Gas turbine system 2 Gas turbine systems 3 Gas turbine system 4 Gas turbine system 5 Gas turbine system 10 Gas turbine 11 Combustion chamber control device 13 Pilot nozzle 14 First main jet 15 Second main jet 16 Load interruption detector 17 Pilot nozzle flow rate control unit 18 First Main Nozzle Flow Rate Control Unit 19 Second Main Nozzle Flow Rate Control Unit 41 Combustion chamber control device 51 Combustion chamber control device 61 Combustion chamber control device 71 Combustion chamber control device

Claims

[1] A gas turbine combustion chamber control device (11;41;51;61;71), comprising: a load interruption detector (16) that detects a load interruption of a gas turbine (10), a delay circuit (D) for setting a delay time based on the detection of the load interruption, a pilot nozzle flow rate control unit (17) which increases the amount of premixed fuel supplied to a pilot nozzle (13) based on a detection of load interruption, a first main jet flow rate control unit (18) which reduces the amount of premixed fuel supplied to a first main jet (14) based on the detection of the load interruption to a first quantity, and a second main jet flow rate control unit (19) which reduces the amount of premixed fuel supplied to a second main jet (15) based on the detection of the load interruption to a second quantity that is different from the first quantity, and then further reduces the amount of premixed fuel supplied to the second main jet (15) after the delay time has elapsed from the second quantity to a third quantity that is smaller than the first and the second quantity. [2] The gas turbine combustion chamber control device (11;41;51;61;71) according to claim 1, wherein the combustion chamber control device (11;41;51;61;71) temporarily reduces the flow rate of the first main nozzle based on a detection of the load interruption. [3] The gas turbine combustion chamber control device (51) according to claim 1, wherein the combustion chamber control device (51) reduces the amount of premix fuel supplied to the second main nozzle (15) using a parameter required for a flame as an indicator. [4] The gas turbine combustion chamber control device (61) according to claim 1, wherein the combustion chamber control device (61) sets a delay time when the amount of premix fuel supplied to the second main nozzle (15) is reduced to a predetermined amount based on a detection of the load interruption, and then further reduces the amount of premix fuel supplied after a predetermined time has elapsed. [5] The gas turbine combustion chamber control device (71) according to any one of claims 1 to 4, wherein the combustion chamber control device (71) comprises an adjustment of the degree of opening of an inlet guide vane (22) provided in the gas turbine (10). [6] A gas turbine system (1;2;3;4;5), with: a gas turbine (10) with a combustion chamber (12) which a pilot nozzle (13) which injects premixed fuel, and a first main jet (14) and a second main jet (15) which are provided around the pilot jet (13) and inject premixed fuel, and a combustion chamber control device (11;41;51;61;71) according to any one of claims 1 to 5. [7] A gas turbine combustion chamber control method, with: a load interruption detection step of detecting a load interruption of a gas turbine (10), a delay step of setting a delay time based on the detection of the load interruption, a pilot nozzle flow rate control step of increasing the amount of premixed fuel supplied to a pilot nozzle (13) based on a detection of the load interruption, a first main jet flow rate control step of reducing the amount of premixed fuel supplied to a first main jet (14) to an initial amount based on the detection of the load interruption, and a second main jet flow rate control step of reducing the amount of premix fuel supplied to a second main jet (15) to a second quantity that is different from the first quantity, based on the detection of the load interruption, and then further reducing the amount of premix fuel supplied to the second main jet (15) after the delay time has elapsed from the second quantity to a third quantity that is smaller than the first and the second quantity.

Images