JP2016075448A - Combustor for gas turbine engine and operating method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the of back-fire into a burner in a combustor for a gas turbine engine, in which fuel having faster combustion speed than that of natural gas such as hydrogen-containing fuel is combusted.SOLUTION: A fuel injection device 36 of a combustor 12 has a pilot burner 40 and a main burner 4, and the main burner 4 has at least one first fuel injection port 41a for supplying first fuel to the upstream side of a combustion chamber 35 and at least one second fuel injection port 42a for supplying second fuel to the upstream side of the combustion chamber 35. The combustor 12 comprises a control device controlling the operation of the combustor 12 in such a manner that upon start-up, the main burner 4 is combusted with a flame of the pilot burner 40 to combust the first fuel as the main fuel and when a gas turbine engine 1 reaches a predetermined rated operation condition, the fuel is changed over to the second fuel having the maximum faster combustion speed than that of the first fuel as the main fuel.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a combustor provided in a gas turbine engine.

  In recent years, as a fuel for gas turbine engines, in addition to LNG (Liquefied Natural Gas), which is the main fuel of the past, hydrogen generated as a by-product in each production process in the chemical and steel industries including petroleum (by-product) Use of hydrogen) is under consideration. By recovering the energy with a gas turbine that uses hydrogen as a byproduct, fuel costs can be reduced and resources can be effectively used by reducing the amount of fossil fuel used, and global warming due to the absence of carbon dioxide during hydrogen combustion. It can contribute to prevention.

However, since the hydrogen flame is about 100 to 200 ° C. higher than the natural gas flame, when the hydrogen-containing fuel is burned in the gas turbine engine combustor in the same manner as natural gas (NG), the natural gas is burned. compared to NO _X in the exhaust gas of the combustor is increased. Therefore, in order to reduce of the NO _X emissions, measures dilution or the like of the cooling and fuel flame by injecting water or steam has been studied in the combustion chamber.

For example, in Patent Document 1, a hydrogen-containing fuel is supplied to a first fuel nozzle that supplies a hydrogen-containing fuel to a primary combustion region upstream of a combustion chamber by a diffusion combustion method, and a reduction region downstream of the primary combustion region. A combustor including a second fuel nozzle and an air outlet for supplying lean combustion air to a secondary combustion region downstream from the reduction region is shown. In this combustor, NO _X generated in the primary combustion region due to the oxidation reaction of hydrogen is reduced in the reduction region, and then the unburned fuel is burned in the secondary combustion region under the lean fuel condition. _X emissions are reduced.

JP 2011-75174 A

By the way, as a general fuel injection system to a combustor of a gas turbine engine, a premixed combustion system and a diffusion combustion system are known. In the premix combustion method, fuel and air mixed in advance are supplied to the combustion chamber and burned. In this manner, by performing combustion at a fuel lean state, it is possible to reduce the NO _X emissions from the combustor. However, since hydrogen-containing fuel has a wide flammable range and a combustion speed of about 10 times faster than natural gas, when hydrogen-containing fuel is burned by the preheating mixing method as with natural gas, the flame is injected into the fuel injection nozzle and the wall surface. There is a risk of damaging them or approaching a fire. On the other hand, in the diffusion combustion method, fuel and air are supplied to the combustion chamber from different flow paths and burned. In this manner, flashback is hard to occur, fuel and because the degree of mixing of the air tends to be uneven, NO _X emissions the higher local flame temperature by darker regions locally fuel is formed Will increase.

  In the said patent document 1, in order to prevent generation | occurrence | production of backfire, the diffusion combustion system is employ | adopted. On the other hand, the present invention proposes a technique for suppressing the occurrence of flashback in a premixed combustion system in a combustor of a gas turbine engine that burns a fuel having a combustion speed higher than that of natural gas, such as a hydrogen-containing fuel.

A combustor of a gas turbine engine according to the present invention,
A liner that forms a combustion chamber therein;
At least one first fuel injection port for injecting first fuel to the upstream portion of the combustion chamber, and pilot fuel for igniting the first fuel injected from the at least one first fuel injection port in the combustion chamber And at least one second fuel injection port for supplying a second fuel having a maximum combustion speed higher than that of the first fuel to the upstream portion of the combustion chamber It is characterized by having.

  According to the above configuration, the first fuel having a relatively slow combustion rate and the second fuel having a relatively fast combustion rate can be supplied to the combustion chamber 35 alternatively or simultaneously. Utilizing such characteristics, for example, when using a fuel with a high combustion speed compared to natural gas such as hydrogen-containing fuel, a comparison is made in the process of gradually increasing or decreasing the fuel injection amount at startup or stop A fuel with a relatively slow combustion rate can be burned, and a fuel with a relatively fast combustion rate can be burned in a state where the engine speed and engine operating load are increased. By switching the main fuel of the combustor in this way, it is possible to operate the combustor capable of suppressing the occurrence of backfire into the burner.

  The combustor of the gas turbine engine is formed by alternately arranging the at least one first fuel injection port and the at least one second fuel injection port around the at least one pilot fuel injection port. A single annular injection port array may be formed. Here, the at least one annular injection port array may be provided on the inner peripheral surface of the liner on the downstream side of the at least one pilot fuel injection port of the combustion chamber.

  Alternatively, in the combustor of the gas turbine engine, a first annular injection port array in which the at least one first fuel injection port is arranged in an annular shape is formed around the at least one pilot fuel injection port, and the first A second annular injection port array in which the at least one second fuel injection port is arranged in an annular shape may be formed around the annular injection port array.

  Alternatively, the at least one first fuel injection port that is annular around the at least one pilot fuel injection port is provided, and the at least one second fuel injection that is annular around the at least one first fuel injection port. A mouth may be provided.

In any of the above configurations, since the first fuel and the second fuel are distributed and supplied into the combustion chamber, it is possible to prevent the formation of a locally rich region of fuel. Thus, it is possible to suppress the increase of the NO _X emissions from the local flame temperature rises.

  The gas turbine engine combustor gradually increases the injection amount of the first fuel from zero at start-up, and gradually decreases the injection amount of the first fuel to a predetermined value when the gas turbine engine reaches a predetermined rated operating condition. And a control device for controlling the injection amount of the first fuel and the injection amount of the second fuel so that the injection amount of the second fuel is gradually increased so that the gas turbine engine maintains the rated operating condition. May be further provided.

  According to the above configuration, the first fuel having a relatively low combustion speed is combusted at the time of start-up including ignition, so that the occurrence of backfire into the burner at the time of start-up can be suppressed. In addition, since the second fuel is combusted after the engine speed and the engine operating load have increased to the rated operating conditions, stable operation can be performed even when the second fuel having a relatively high combustion speed is used. it can.

  In the combustor of the gas turbine engine, the supply amount of the second fuel to the fuel injection device is determined by the control device after the injection amount of the first fuel is reduced to the predetermined value at the start-up. Control may be made to increase the injection amount of the first fuel when the injection amount of the second fuel for maintaining the operating condition is insufficient. According to this configuration, when the supply amount of the second fuel fluctuates, the shortage of the injection amount of the second fuel can be compensated with the first fuel.

  In the combustor of the gas turbine engine, the control device gradually reduces the injection amount of the second fuel to zero and stops the injection amount of the first fuel while the gas turbine engine maintains the rated operating condition when stopped. The injection amount of the first fuel and the injection amount of the second fuel are controlled so that the injection amount of the first fuel is gradually reduced to zero when the injection amount of the second fuel becomes zero. May be.

  According to the above configuration, the main fuel of the combustor is switched from the second fuel to the first fuel before the stop, thereby preventing the second fuel from remaining in the combustor after the operation stop and its downstream pipe. Can do. Thereby, it is possible to prevent explosive combustion from occurring due to the unburned second fuel remaining at the next start-up.

  In the combustor of the gas turbine engine, the second fuel may be hydrogen or a hydrogen-containing fuel, and the first fuel may be natural gas or a hydrogen-containing fuel having a lower hydrogen content than the second fuel.

The operation method of the combustor of the gas turbine engine according to the present invention is as follows:
Igniting the pilot burner;
Igniting the main burner with a flame of the pilot burner and burning the first fuel as the main fuel in the main burner;
Switching the start-up fuel so that when the gas turbine engine reaches a predetermined rated operating condition, the main burner burns the second fuel having a maximum combustion speed faster than the first fuel as the main fuel. It is characterized by.

  According to the above operation method, the pilot fuel and the first fuel, which have a relatively low combustion speed, are combusted at the time of start-up, so that it is possible to suppress the occurrence of backfire in the burner at the time of start-up (particularly during ignition). Further, since the second fuel is burned after the engine speed and the engine operating load are increased, stable operation can be performed even when the second fuel having a relatively high combustion speed is used.

  In the operation method of the combustor of the gas turbine engine, performing the start-up fuel switching gradually reduces the injection amount of the first fuel to a predetermined value and reduces the injection amount of the second fuel to the gas turbine engine. May gradually increase to maintain the rated operating conditions.

  In the gas turbine engine combustor operating method, after the start-up fuel switching, the second fuel supply amount to the main burner is the second fuel for maintaining the rated operating condition. Increasing the injection amount of the first fuel may be performed when the injection amount is insufficient. According to this, when the supply amount of the second fuel fluctuates, the shortage of the injection amount of the second fuel can be compensated with the first fuel.

  In the operation method of the combustor of the gas turbine engine, when the gas turbine engine is stopped, switching the fuel at the time of stop so that the main fuel burns the first fuel as the main fuel; and It is desirable to further include extinguishing the fire.

  According to the above operation method, the main fuel of the combustor is switched from the second fuel to the first fuel before the stop, thereby preventing the second fuel from remaining in the combustor after the stop and its downstream piping. be able to. Thereby, it is possible to prevent explosive combustion from occurring due to the unburned second fuel remaining at the next start-up.

  In the operation method of the combustor of the gas turbine engine, performing the fuel switching at the time of stopping gradually reduces the injection amount of the second fuel to zero, and the gas turbine engine reduces the injection amount of the first fuel. Increasing gradually may be included to maintain the rated operating conditions.

  In the operation method of the combustor of the gas turbine engine, the second fuel is hydrogen or a hydrogen-containing fuel, and the first fuel is natural gas or a hydrogen-containing fuel having a lower hydrogen content than the second fuel. Good.

  ADVANTAGE OF THE INVENTION According to this invention, generation | occurrence | production of the backfire in a burner can be suppressed in the combustor of the gas turbine engine which burns fuel whose combustion speeds, such as a hydrogen containing fuel, are quick compared with natural gas.

It is a figure showing the schematic structure of the gas turbine engine provided with the combustor concerning one embodiment of the present invention. It is sectional drawing which shows schematic structure of the combustor which concerns on 1st Embodiment of this invention. It is a layout diagram of a fuel injection port. It is a graph which shows the time-sequential change of the engine speed at the time of starting of a gas turbine engine. It is a graph which shows the relationship between the engine operation load of a gas turbine engine, and fuel consumption. It is a graph which shows the time-sequential change of fuel injection quantity. 6 is a layout diagram of a fuel injection port according to Modification Example 1. FIG. FIG. 10 is a layout diagram of a fuel injection port according to Modification Example 2. 10 is a layout diagram of a fuel injection port according to Modification 3. FIG. FIG. 10 is a layout diagram of a fuel injection port according to Modification Example 4. 10 is a layout diagram of a fuel injection port according to Modification Example 5. FIG. It is the schematic diagram which showed arrangement | positioning of each burner of the combustor which concerns on 2nd Embodiment of this invention. It is the schematic diagram which showed arrangement | positioning of each burner of the combustor which concerns on 3rd Embodiment of this invention. It is the schematic diagram which showed arrangement | positioning of each burner of the combustor which concerns on 4th Embodiment of this invention.

  Embodiments of the present invention will be described below with reference to the drawings. First, a schematic configuration of a gas turbine engine 1 including a combustor 12 according to an embodiment of the present invention will be described. As shown in FIG. 1, a gas turbine engine 1 includes a compressor 11, a combustor 12 connected to the compressor 11 and an air supply passage 21, and a turbine 13 connected to the combustor 12 and a combustion gas supply passage 22. And. The compressor 11 and the turbine 13 are connected by a rotating shaft 14, and a load such as a generator 15 and a starter (starting motor) 18 are connected to the rotating shaft 14. In the gas turbine engine 1 having the above-described configuration, the compressor 11 compresses the air sucked from the atmosphere and supplies it as combustion air to the combustor 12, and the combustor 12 has a high temperature generated by the mixed combustion of the combustion air and the fuel. High-pressure combustion gas is supplied to the turbine 13, and the turbine 13 rotates blades with the combustion gas to convert the thermal energy of the combustion gas into rotational kinetic energy. This rotational kinetic energy is used for compression power by the compressor 11, and is converted into electric energy by the generator 15. Further, the exhaust gas from the turbine 13 is sent to the boiler 16 connected to the turbine 13 through the exhaust passage 23 and used as a heat source for the boiler 16.

  Next, the combustor 12 according to the first embodiment of the present invention will be described. FIG. 2 is a sectional view showing a schematic configuration of the combustor 12 according to the first embodiment of the present invention, and FIG. 3 is a layout diagram of the fuel injection port. In FIG. 3 and the layout diagram of the fuel injection port shown below, the pilot fuel injection port 40a is hatched, the first fuel injection port 41a is light, and the second fuel injection port 42a so that the type of the fuel injection port can be easily understood. Are shaded and hatched respectively.

  As shown in FIGS. 2 and 3, the combustor 12 includes a cylindrical casing 31, a cylindrical liner 32 accommodated in the casing 31, and a fuel injection device 36. A combustion chamber 35 is formed inside the liner 32, and an air passage 33 for introducing combustion air is formed between the casing 31 and the liner 32. A fuel injection device 36 that injects fuel into the combustion chamber 35 is provided at one end of the liner 32. Hereinafter, one side where the fuel injection device 36 in the combustion chamber 35 is provided is referred to as an upstream side, and the other side is referred to as a downstream side.

The fuel injection device 36 includes a pilot burner 40 and a main burner 4. The main burner 4 includes at least one first main burner 41 that ejects the first fuel to the upstream portion of the combustion chamber 35, and at least one second main burner 42 that ejects the second fuel to the upstream portion of the combustion chamber 35. have. The fuel injection port (pilot fuel injection port 40 a) of the pilot burner 40 is provided at a position that substantially passes through the axial center of the cylindrical liner 32. Around the pilot fuel injection port 40a, there are at least a fuel injection port (first fuel injection port 41a) of the first main burner 41 and a fuel injection port (second fuel injection port 42a) of the second main burner 42. A single annular jet row is provided. The annular injection port row is formed by alternately arranging at least one first fuel injection port 41a and at least one second fuel injection port 42a. With the arrangement of the fuel injection ports 41a and 42a, the first fuel and the second fuel are distributed and supplied into the combustion chamber 35, thereby preventing the formation of a locally rich region of fuel. can do. Hence, it is possible to suppress the increase of the NO _X emissions from the local flame temperature rises.

  The pilot burner 40 according to the present embodiment uses the first fuel as the pilot fuel, and the pilot burner 40 directly injects the pilot fuel into the combustion chamber 35 to cause diffusion combustion. However, the pilot fuel may be a fuel that is not the first fuel. For example, when the first fuel is natural gas, the pilot fuel may be a liquid fuel. The first main burner 41 injects the first premixed gas in which the first fuel supplied from the first fuel supply source 51 and the combustion air are mixed in advance into the combustion chamber 35 to cause premix combustion. The second main burner 42 injects the second premixed gas, in which the second fuel supplied from the second fuel supply source 52 and the combustion air are premixed, into the combustion chamber 35 and performs premix combustion.

  The first fuel (or first fuel and pilot fuel) is natural gas, vented methane (VAM), natural gas mixed with less than 5% hydrogen, vented methane mixed with less than 5% hydrogen, or Liquid fuel such as kerosene or light oil. The second fuel is hydrogen gas, by-product hydrogen, liquefied petroleum gas (LPG), natural gas mixed with 5% or more hydrogen, or vented methane mixed with 5% or more hydrogen. As described above, the composition of the first fuel (or the first fuel and the pilot fuel) and the second fuel is different, and the second fuel has a higher combustion rate than the maximum combustion rate of the first fuel (or the first fuel and the pilot fuel). Maximum burning speed is fast. The maximum burning rate is determined by the composition of the gas. In the hydrogen-containing gas, the higher the hydrogen content, the faster the maximum burning rate. Examples of such a combination of the first fuel and the second fuel include a hydrogen-containing gas as the second fuel and a natural gas as the first fuel, a hydrogen-containing gas as the second fuel and a second fuel as the first fuel. And hydrogen-containing gas having a lower hydrogen content.

  The pilot burner 40 includes a pilot fuel nozzle 43, and an outlet of the pilot fuel nozzle 43 serves as a fuel injection port 40a. The pilot fuel nozzle 43 is connected to a first fuel supply source 51 or a pilot fuel supply source (not shown) via a pilot fuel supply pipe 44. The pilot fuel supply pipe 44 is provided with a pilot fuel control valve 61 that adjusts the flow rate of pilot fuel (first fuel) ejected from the pilot burner 40. An air nozzle 62 is formed around the pilot fuel nozzle 43 to inject combustion air from the air passage 33 into the combustion chamber 35.

  The first main burner 41 includes a flow path member 46 that forms a premixing passage 45, a swirler 48 provided in an air intake 47 that opens upstream of the premixing passage 45, and a first main burner 41 that faces the air intake 47. And a first fuel nozzle 49 having an injection hole for injecting one fuel. The outlet of the premixing passage 45 is a fuel injection port 41a. The first fuel nozzle 49 is connected to the first fuel supply source 51 via the first fuel supply pipe 50. The first fuel supply pipe 50 is provided with a first fuel control valve 63 that adjusts the flow rate of the first fuel. In the first main burner 41 configured as described above, the first fuel injected from the injection hole of the first fuel nozzle 49 toward the air intake 47 and the combustion air in the air passage 33 are swirled by the swirler 48. The air is introduced into the premixing passage 45 through the air intake 47. The first fuel and combustion air premixed in the premixing passage 45 are jetted into the combustion chamber 35 as a first premixed gas.

  The second main burner 42 includes a flow path member 56 that forms a premixing passage 55, a swirler 58 provided in an air intake 57 that opens to the upstream side of the premixing passage 55, and a second main burner 42 that faces the air intake 57. And a second fuel nozzle 59 having an injection hole for injecting two fuels. The outlet of the premixing passage 55 is a fuel injection port 42a. The second fuel nozzle 59 and the second fuel supply source 52 are connected by a second fuel supply pipe 60. The second fuel supply pipe 60 is provided with a second fuel control valve 64 that adjusts the flow rate of the second fuel. In the second main burner 42 configured as described above, the second fuel injected from the injection hole of the second fuel nozzle 59 toward the air intake port 57 and the combustion air in the air passage 33 are swirled by the swirler 58. The air is introduced into the premixing passage 55 through the air intake 57. The second fuel and combustion air premixed in the premixing passage 55 are jetted into the combustion chamber 35 as a second premixed gas.

  The control device 5 is configured to control the fuel supply to the fuel injection device 36, that is, the injection amounts of the pilot fuel, the first fuel, and the second fuel. The control device 5 includes a rotation speed sensor 71 that detects the engine rotation speed (for example, the rotation speed of the rotary shaft 14), a wattmeter 73 that detects power generated by the generator 15 that serves as an index of the engine operating load, An operation input device 72 for inputting an operation command to the control device 5 and the fuel control valves 61, 63, 64 are connected. Based on the command from the operation input device 72, the engine rotational speed detected by the rotational speed sensor 71, and the generated power (engine operating load) detected by the wattmeter 73, the control device 5 controls the pilot fuel control valve 61, Control signals are output to the first fuel control valve 63 and the second fuel control valve 64. Note that the pilot fuel control valve 61, the first fuel control valve 63, and the second fuel control valve 64 during standby are all closed.

  Here, especially start control and stop control among the operation control (operation method) of the combustor 12 by the said control apparatus 5 are demonstrated using FIGS. 4 is a graph showing a time-series change in the engine speed when the gas turbine engine 1 is started, and FIG. 5 is a graph showing the relationship between the engine operation load of the gas turbine engine 1 and the fuel consumption. Is a graph showing a time-series change of the fuel injection amount. In the graph of FIG. 6, the vertical axis represents the fuel injection amount, the horizontal axis represents time, the solid line represents the first fuel injection amount from the first main burner 41, and the broken line represents the second fuel injection amount from the second main burner 42. The amount of fuel injection is shown.

  In start-up control, control from starter start-up, ignition, and idling is performed. When the starter 18 is started when the gas turbine engine 1 is started, the engine speed starts to increase. When the control device 5 receives the start signal from the operation input device 72, the control device 5 starts discharge or heat generation of a spark plug (not shown) and opens the pilot fuel control valve 61. Thereby, in the pilot burner 40, the 1st fuel and the combustion air which were injected to the combustion chamber 35 are ignited, and it carries out diffusion combustion.

  Subsequently, the control device 5 opens the first fuel control valve 63. As a result, in the first main burner 41, the first premixed gas ejected to the combustion chamber 35 is ignited by the flame of the pilot burner 40 and premixed and combusted. Here, the control device 5 controls the opening degree of the first fuel control valve 63 so that the injection amount of the first fuel becomes zero from the injection amount (hereinafter referred to as “rated operation”). Gradually increase to “hour injection amount”). Even when the injection amount of the first fuel is zero, that is, when the first fuel control valve 63 is closed, the combustion air is jetted from the first main burner 41 to the combustion chamber 35, and the combustion chamber No back flow of gas from 35 to the premixing passage 45 occurs. Similarly, when the injection amount of the second fuel is zero, that is, when the second fuel control valve 64 is closed, the combustion air is jetted from the second main burner 42 to the combustion chamber 35, and the combustion is performed. No back flow of gas from the chamber 35 to the premixing passage 55 occurs.

  The control device 5 monitors the engine speed and the engine operating load through start-up control, and starts fuel switching (start-up fuel switching) when these satisfy the rated operation conditions. The rated operating condition is, for example, that the detected engine speed is equal to or higher than the speed at which the turbine 13 rotates autonomously, and the engine operating load is equal to or higher than a predetermined value.

  The control device 5 that has started the fuel switching first stops the discharge or heat generation of the spark plug, closes the pilot fuel control valve 61, extinguishes the pilot burner 40, or fuel that can ensure a minimum flame holding performance. Reduce fuel flow to flow. Subsequently, the control device 5 gradually decreases the opening degree of the first fuel control valve 63 over a predetermined switching time, and changes the injection amount of the first fuel from the rated operation injection amount to the predetermined maintenance injection amount. Reduce gradually. Here, the maintenance injection amount is an injection amount of the first fuel that does not cause a backflow of gas in the first main burner 41. At the same time, the control device 5 gradually increases the degree of opening of the second fuel control valve 64 over a predetermined switching time, and injects the second fuel so that the gas turbine engine 1 maintains the rated operating condition. The amount is gradually increased from zero. Thus, the combustor 12 at the end of the fuel switching has the second fuel injection amount larger than the first fuel injection amount, and the main fuel of the main burner 4 is changed from the first fuel to the second fuel. It has been switched.

  Until the stop signal is received after the end of fuel switching, the control device 5 performs steady operation control. In the steady operation control, the control device 5 acquires the engine speed and the engine operation load, and controls the fuel injection amount so that these operation conditions maintain the required values. The required value may be a desired value that satisfies at least the rated operating condition. For example, a preset value for the engine speed and the engine operating load, or a safety value is added to the rated operating condition (or the rated operating condition). The predetermined threshold value) can be used as the required value. Further, a plurality of required values may be set, and a different fuel injection amount control method may be performed according to each required value. In the combustor 12 according to the present embodiment, it is assumed that the supply amount of the second fuel to the fuel injection device 36 varies. For example, when the second fuel is a hydrogen-containing gas containing byproduct hydrogen, a situation is assumed in which the amount of byproduct hydrogen produced decreases. In such a situation, there is a fear that the required value cannot be maintained because the injection amount of the second fuel is insufficient. In the present embodiment, the engine speed decreases and the power generation amount of the generator 15 decreases. Therefore, the control device 5 increases or decreases the opening of the second fuel control valve 64 to increase or decrease the second fuel injection amount so as to keep the power generation amount constant. The opening amount of the valve 63 can be increased to increase or decrease the injection amount of the first fuel. For example, the control device 5 can increase the engine operating load while maintaining the engine speed by increasing the opening amount of the first fuel control valve 63 and increasing the injection amount of the first fuel. it can. As described above, during steady operation control, in addition to the increase / decrease adjustment of the injection amount of the second fuel, the supply amount of the second fuel to the fuel injection device 36 (main burner 4) holds the required value of the operating condition. In the case where the amount of fuel injected is less than the amount required for the second fuel, replenishment by the first fuel may be performed.

  When receiving the stop signal from the operation input device 72, the control device 5 starts the stop control. In the stop control, first, fuel switching (fuel switching at stop) is started. The control device 5 that has started the fuel switching gradually decreases the opening of the second fuel control valve 64 over a predetermined switching time, and gradually decreases the injection amount of the second fuel to zero, so that the second main burner Extinguish 42. At the same time, the control device 5 gradually increases the opening degree of the first fuel control valve 63 over a predetermined switching time so that the gas turbine engine 1 maintains the rated operating condition so that the first fuel injection is performed. The amount is gradually increased from the maintenance injection amount. Here, when the flame holding property is insufficient, the pilot fuel may be gradually increased. Thus, the combustor 12 at the end of the fuel switching has the first fuel injection amount larger than the second fuel injection amount, and the main fuel of the main burner 4 is changed from the second fuel to the first fuel. It has been switched.

  After the fuel switching is completed, the control device 5 gradually decreases the opening degree of the first fuel control valve 63 so that the injection amount of the first fuel decreases from the rated operation injection amount to zero. When the first fuel injection amount becomes zero and the first main burner 41 extinguishes, the stop control is terminated.

  As described above, in the stop control, after switching the fuel of the combustor 12 from the second fuel to the first fuel (or the first fuel and the pilot fuel), after the second main burner 42 is extinguished, The first main burner 41 (or the first main burner 41 and the pilot burner 40) is extinguished. In this manner, in the gas turbine engine 1 after the operation is stopped, the second fuel is prevented from staying in the combustor 12 and its downstream piping. Thereby, it is possible to prevent explosive combustion from occurring due to the unburned second fuel remaining at the next start-up.

  As described above, the main burner 4 of the combustor 12 according to the present embodiment is configured to be able to burn two fuels (first fuel and second fuel) having different combustion speeds alternatively or simultaneously. Therefore, the main fuel of the combustor 12 can be switched between the first fuel and the second fuel. Utilizing this feature, operation control is performed in the combustor 12 such that backfire into the burner hardly occurs. Specifically, in a situation where the flow rate of fuel at the time of starting and stopping of the gas turbine engine 1 (combustor 12) is relatively slow, the first fuel having a combustion speed slower than that of the second fuel is burned. Further, the second fuel is burned by the combustor 12 in a state where the engine speed and the engine operation load are sufficiently increased (that is, the rated operation condition is satisfied). More specifically, at startup, the first main burner 41 burns the first fuel, and when the gas turbine engine 1 reaches a predetermined rated operating condition, the second main burner 42 burns the second fuel and the first main burner. The combustion amount of the burner 41 is reduced. Moreover, at the time of a stop, the 2nd main burner 42 is extinguished, the combustion amount of the 1st main burner 41 is increased, and after the 2nd main burner 42 extinguishes, the 1st main burner 41 is extinguished. Thus, in the combustor 12 according to the present embodiment, the first fuel or the pilot fuel is burned at the time of start-up and at the time of stop including the ignition time that is particularly likely to cause backfire. Can be suppressed. By suppressing the occurrence of backfire, burnout of the combustor 12 can be prevented. Since the second fuel is burned after the gas turbine engine 1 reaches the rated operating condition, the combustor 12 and the gas turbine are used even when a fuel having a higher combustion speed than natural gas such as hydrogen-containing fuel is used. The operation of the engine 1 can be stabilized.

  In the combustor 12 of the gas turbine engine 1 according to the first embodiment described above, the first fuel injection ports 41a and the second fuel injection ports 42a are alternately arranged. However, the layout of the fuel injection port is not limited to the above. Therefore, in the following, modifications 1 to 5 of the layout of the fuel injection port of the first embodiment will be described. 7 to 11 are layout diagrams of the fuel injection ports according to the first to fifth modifications, respectively.

  In the layout of the fuel injection port according to the first modification shown in FIG. 7, the annular fuel injection nozzle array is formed around the pilot fuel injection nozzle 40a, and the first fuel injection is alternately arranged. The port 41a group and a plurality of second fuel injection ports 42a group are formed.

  In the fuel injection port layout according to the modified example 2 shown in FIG. 8, a double annular injection port array is formed around the pilot fuel injection port 40a, and the annular injection port arrays are alternately arranged. The first fuel injection port 41a and the second fuel injection port 42a are formed.

  In the fuel injection port layout according to the third modification shown in FIG. 9, a first annular injection port array in which a plurality of first fuel injection ports 41a are arranged in an annular shape is formed around the pilot fuel injection port 40a. A second annular injection port array in which a plurality of second fuel injection ports 42a are arranged in an annular shape is formed around the annular injection port array.

  In the fuel injection port layout according to the fourth modification shown in FIG. 10, an annular first fuel injection port 41a is provided around the annular pilot fuel injection port 40a, and an annular first fuel injection port 41a is provided around the first fuel injection port 41a. Two fuel injection ports 42a are provided. Here, as shown in FIG. 11, even if a vane 66 is provided in each fuel injection port 40a, 41a, 42a so that a swirl flow is formed by the fuel gas blown out from each fuel injection port 40a, 41a, 42a. Good.

  Next, the combustor 12 of the gas turbine engine 1 according to second to fourth embodiments of the present invention will be described. The combustor 12 according to the second to fourth embodiments is different in that the arrangement of the combustor 12 according to the first embodiment, the first main burner 41, and the second main burner 42 is different. Therefore, hereinafter, only the arrangement of the first main burner 41 and the second main burner 42 will be described in detail, and the further description will be omitted.

[Second Embodiment]
FIG. 12 is a schematic view showing the arrangement of the pilot burner 40, the first main burner 41, and the second main burner 42 of the combustor 12A according to the second embodiment, and FIG. FIG.12 (b) is the figure seen from the axial direction. As shown in FIGS. 12A and 12B, the fuel injection port 41a of the first main burner 41 and the fuel injection port 42a of the second main burner 42 of the combustor 12A according to the second embodiment are pilot burners. 40 are arranged alternately on the inner peripheral surface of the liner 32 on the downstream side of the fuel injection port 40a to form an annular shape. Then, fuel is ejected from the fuel injection port 41 a of the first main burner 41 and the fuel injection port 42 a of the second main burner 42 toward the inner side in the radial direction of the liner 32.

[Third Embodiment]
FIG. 13 is a schematic diagram showing the arrangement of the pilot burner 40, the first main burner 41, and the second main burner 42 of the combustor 12B according to the third embodiment. As shown in FIG. 13, the fuel injection port 41 a of the first main burner 41 of the combustor 12 </ b> B according to the third embodiment is provided on the inner periphery of the fuel injection port 40 a of the pilot burner 40. The fuel injection port 42 a of the second main burner 42 is annularly provided on the inner peripheral surface of the liner 32 on the downstream side of the fuel injection port 40 a of the pilot burner 40 and the fuel injection port 41 a of the first main burner 41. Yes. From the second main burner 42, fuel is ejected toward the inner side in the radial direction of the liner 32.

[Fourth Embodiment]
FIG. 14 is a schematic diagram showing the arrangement of the pilot burner 40, the first main burner 41, and the second main burner 42 of the combustor 12C according to the fourth embodiment. As shown in FIG. 14, the fuel injection port 41a of the first main burner 41 of the combustor 12C according to the fourth embodiment is provided on the inner peripheral surface of the liner 32 on the downstream side of the fuel injection port 40a of the pilot burner 40. It has been. From the first main burner 41, fuel is ejected toward the inner side in the radial direction of the liner 32. The fuel injection port 42 a of the second main burner 42 is provided on the inner peripheral surface of the liner 32 on the downstream side of the fuel injection port of the first main burner 41. From the second main burner 42, fuel is ejected toward the inner side in the radial direction of the liner 32.

  Although the preferred embodiment of the present invention and its modification have been described above, the above-described configuration can be changed as follows, for example.

  For example, in the above-described embodiment and its modifications, the fuel injection methods of the first main burner 41 and the second main burner 42 are both premixed combustion methods, but of the first main burner 41 and the second main burner 42 At least one may be a diffusion combustion system. In the combustor 12 according to the present invention, it is possible to suppress the occurrence of flashback regardless of the diffusion combustion method and the premixed combustion method.

  Further, for example, in the above-described embodiment and its modifications, the first main burner 41 and the second main burner 42 are both configured to eject a mixed gas in which air and fuel are mixed in advance. At least one of the first main burner 41 and the second main burner 42 may be configured to eject water, water vapor, or a mixed gas in which an inert gas and fuel are mixed in advance. In this case, the combustion air flow path may be formed so that the combustion air is ejected into the combustion chamber 35 from a flow path different from the mixed gas.

DESCRIPTION OF SYMBOLS 1 Gas turbine engine 4 Main burner 5 Control apparatus 11 Compressor 12 Combustor 13 Turbine 14 Rotating shaft 15 Generator 16 Boiler 18 Starter 31 Casing 32 Liner 33 Air passage 35 Combustion chamber 36 Fuel injection device 40 Pilot burner 40a Pilot fuel injection port 41 1st main burner 41a 1st fuel injection port 42 2nd main burner 42a 2nd fuel injection port

Claims (15)

A liner that forms a combustion chamber therein;
At least one first fuel injection port for injecting first fuel to the upstream portion of the combustion chamber, and pilot fuel for igniting the first fuel injected from the at least one first fuel injection port in the combustion chamber A fuel injection device having at least one pilot fuel injection port that jets to the upstream side of the combustion chamber and at least one second fuel injection port that jets the second fuel having a higher maximum combustion speed than the first fuel to the upstream portion of the combustion chamber And
Gas turbine engine combustor.   Around the at least one pilot fuel injection port, an at least one annular injection port row is formed in which the at least one first fuel injection port and the at least one second fuel injection port are alternately arranged. The combustor of a gas turbine engine according to claim 1.   The combustion of a gas turbine engine according to claim 2, wherein the at least one annular injection port array is provided on an inner peripheral surface of the liner at a downstream side of the at least one pilot fuel injection port of the combustion chamber. vessel.   A first annular injection port array in which the at least one first fuel injection port is arranged in an annular shape is formed around the at least one pilot fuel injection port, and the at least one pilot fuel injection port is arranged around the first annular injection port array. The combustor of the gas turbine engine according to claim 1, wherein a second annular injection nozzle row in which the second fuel injection nozzles are arranged in an annular shape is formed.   The at least one first fuel injection port having an annular shape is provided around the at least one pilot fuel injection port, and the at least one second fuel injection port having an annular shape is provided around the at least one first fuel injection port. The combustor of the gas turbine engine according to claim 1, wherein the combustor is provided.   At startup, the first fuel injection amount is gradually increased from zero, and when the gas turbine engine reaches a predetermined rated operating condition, the first fuel injection amount is gradually decreased to a predetermined value and the second fuel injection amount. The apparatus further comprises a control device for controlling the injection amount of the first fuel and the injection amount of the second fuel so that the gas turbine engine gradually increases so as to maintain the rated operating condition. The combustor of the gas turbine engine as described in any one of -5.   After the control device reduces the first fuel injection amount to the predetermined value at the start-up, the second fuel supply amount to the fuel injection device maintains the rated operating condition. The combustor of the gas turbine engine according to claim 6, wherein control is performed to increase the injection amount of the first fuel when the fuel injection amount is insufficient with respect to the two fuel injection amounts.   The control device gradually decreases the injection amount of the second fuel at the time of stop and gradually increases the injection amount of the first fuel so that the gas turbine engine maintains the rated operating condition. The gas according to claim 6 or 7, wherein the injection amount of the first fuel and the injection amount of the second fuel are controlled so that the injection amount of the first fuel is gradually reduced to zero when the injection amount of the fuel becomes zero. Turbine engine combustor.   The second fuel is hydrogen or a hydrogen-containing fuel, and the first fuel is natural gas or a hydrogen-containing fuel having a hydrogen content lower than that of the second fuel. Gas turbine engine combustor. Igniting the pilot burner;
Igniting the main burner with a flame of the pilot burner and burning the first fuel as the main fuel in the main burner;
When the gas turbine engine reaches a predetermined rated operating condition, the start burner is switched so that the main fuel burns the second fuel having a maximum combustion speed faster than the first fuel as the main fuel.
A method of operating a combustor of a gas turbine engine. Performing the start-up fuel switching,
Gradually reducing the injection amount of the first fuel to a predetermined value, and gradually increasing the injection amount of the second fuel so that the gas turbine engine maintains the rated operating condition.
The operation method of the combustor of the gas turbine engine according to claim 10. When the fuel supply amount to the main burner is insufficient with respect to the injection amount of the second fuel for maintaining the rated operating condition after the start-up fuel switching, Including increasing the fuel injection amount,
The operation method of the combustor of the gas turbine engine according to claim 11. When the gas turbine engine is stopped, performing fuel switching at the time of stopping so that the main fuel is burned as the main fuel by the main burner;
Extinguishing the main burner,
The operation method of the combustor of the gas turbine engine as described in any one of Claims 10-12. Performing the fuel switching at the time of stopping,
Gradually reducing the injection amount of the second fuel to zero, and gradually increasing the injection amount of the first fuel so that the gas turbine engine maintains the rated operating condition.
A method for operating a combustor of a gas turbine engine according to claim 13.   The second fuel is hydrogen or a hydrogen-containing fuel, and the first fuel is natural gas or a hydrogen-containing fuel having a lower hydrogen content than the second fuel. Of operating a combustor of a gas turbine engine in Japan.

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