Combustion System

Abstract

A combustion system (1) comprises: a combustor (12) including a first combustion region (12a) and a second combustion region (12b) continuous with the first combustion region (12a) on a downstream side; a first burner (13) including an injection portion (21) for ammonia, serving as a first fuel, facing the first combustion region (12a), and a first injection portion (22a) for a second fuel that does not contain nitrogen atoms, facing the first combustion region (12a); a second burner (14) including a second injection portion (22b) for the second fuel, facing the second combustion region (12b); and a control device (18) for adjusting a second fuel flow ratio, which is a ratio between a flow rate of the second fuel injected from the first injection portion (22a) and a flow rate of the second fuel injected from the second injection portion (22b).

Description

[Technical Field]

[0001] This application claims the benefit of priority from Japanese Patent Application No. 2022-049708, filed on March 25, 2022, the contents of which are incorporated herein by reference. [Background technology]

[0002] Combustion systems such as gas turbine systems that obtain power by burning fuel in a combustor are used. For example, some combustion systems such as gas turbine systems use ammonia as fuel, as disclosed in Patent Document 1. Using ammonia as fuel reduces carbon dioxide emissions. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-191507 Summary of the Invention [Problem to be solved by the invention]

[0004] In combustion systems that use ammonia as fuel, a second fuel that does not contain nitrogen atoms, such as natural gas, may be used in addition to ammonia as the first fuel. The flame temperature of the second fuel, such as natural gas, is higher than that of ammonia. Therefore, it is desirable to suppress damage to equipment such as burners caused by the flame, for example, when the co-firing ratio, which is the ratio of the calorific value of ammonia to the total calorific value of ammonia and the second fuel, is low.

[0005] An object of the present disclosure is to provide a combustion system that can suppress damage to equipment caused by flames. [Means for solving the problem]

[0006] In order to solve the above problems, the combustion system of the present disclosure includes a combustor including a first combustion zone and a second combustion zone continuous with the first combustion zone on the downstream side, a first burner including an injector for ammonia as a first fuel facing the first combustion zone and a first injector for a second fuel not containing nitrogen atoms facing the first combustion zone, a second burner including a second injector for the second fuel facing the second combustion zone, and a control device that adjusts a second fuel flow rate ratio, which is the ratio between the flow rate of the second fuel injected from the first injector and the flow rate of the second fuel injected from the second injector. The control device adjusts the second fuel flow ratio based on the mixed combustion ratio, which is the ratio of the calorific value of ammonia to the total calorific value of ammonia and the second fuel. .

[0007] The controller may adjust the second fuel flow ratio based on the temperature of the first combustion zone.

[0009] The engine may include a combustor, and the controller may adjust the second fuel flow ratio based on the load of the engine.

[0010] The controller may adjust the second fuel flow ratio based on the total heating value of the ammonia and the second fuel.

[0011] The first burner may include an air injection portion facing the first combustion region, and a swirling portion that swirls the air injected from the air injection portion. [Effects of the Invention]

[0012] According to the present disclosure, damage to the device caused by flames can be suppressed. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 is a schematic diagram showing the configuration of a combustion system according to an embodiment of the present disclosure. [Figure 2] FIG. 2 is a diagram illustrating an example of the relationship between the temperature of the first combustion zone, the natural gas flow rate of the first injection section, the natural gas flow rate of the second injection section, and the mixed combustion ratio in the combustion system according to the embodiment of the present disclosure. [Figure 3]FIG. 3 is a diagram illustrating an example of the relationship between the temperature of the first combustion zone, the natural gas flow rate of the first injection section, and the natural gas flow rate of the second injection section, and the engine load in the combustion system according to the embodiment of the present disclosure. [Figure 4] FIG. 4 is a diagram showing an example of the configuration of the air injection section of the first burner according to the embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. Dimensions, materials, and other specific numerical values ​​shown in the embodiments are merely examples for ease of understanding and, unless otherwise specified, do not limit the present disclosure. In this specification and drawings, elements having substantially the same functions and configurations are designated by the same reference numerals to avoid redundant explanation, and elements not directly related to the present disclosure are not shown.

[0015] FIG. 1 is a schematic diagram showing the configuration of a combustion system 1 according to this embodiment. The combustion system 1 is a gas turbine system that corresponds to an example of a combustion system that generates energy by combusting fuel. As shown in FIG. 1, the combustion system 1 includes a compressor 11a, a turbine 11b, a combustor 12, a first burner 13, a second burner 14, an ammonia supply source 15, a natural gas supply source 16, a temperature sensor 17, and a control device 18. The combustion system 1 also includes an engine E1 that includes the compressor 11a, the turbine 11b, and the combustor 12. The engine E1 is a gas turbine engine.

[0016] The compressor 11a and the turbine 11b rotate as a unit and are connected to each other by a shaft.

[0017] The compressor 11a is provided in an intake air flow path 101 connected to the combustor 12. Air to be supplied to the combustor 12 flows through the intake air flow path 101. An intake port (not shown) through which air is taken in from the outside is provided at the upstream end of the intake air flow path 101. The air taken in through the intake port passes through the compressor 11a and is sent to the combustor 12. The compressor 11a compresses the air and discharges it downstream.

[0018] The turbine 11b is provided in an exhaust flow path 102 connected to the combustor 12. Exhaust gas discharged from the combustor 12 flows through the exhaust flow path 102. The exhaust gas discharged from the combustor 12 passes through the turbine 11b and is sent to a portion of the exhaust flow path 102 downstream of the turbine 11b. The turbine 11b is rotated by the exhaust gas to generate rotational power.

[0019] The compressor 11a is connected to a generator (not shown), and the rotational power transmitted from the turbine 11b to the compressor 11a is used for generating electricity by the generator.

[0020] As will be described later, air, ammonia, and natural gas can be supplied to the combustor 12. Air compressed by the compressor 11a is supplied to the combustor 12 through the intake passage 101. The combustor 12 performs combustion using at least one of ammonia and natural gas as fuel. That is, the combustor 12 may use both ammonia and natural gas as fuel, or may use only one of ammonia and natural gas as fuel. Ammonia corresponds to the first fuel. Natural gas corresponds to an example of a second fuel that does not contain nitrogen atoms. However, the second fuel is not limited to natural gas. The second fuel may be, for example, natural gas, hydrogen, kerosene, or a combination thereof. Exhaust gas generated in the combustor 12 is discharged to the exhaust passage 102.

[0021] The combustor 12 includes a first combustion zone 12a and a second combustion zone 12b as combustion zones where fuel is burned. The first combustion zone 12a is located upstream of the second combustion zone 12b in the gas flow direction within the combustor 12. The second combustion zone 12b is continuous downstream with the first combustion zone 12a. The combustion zone including the first combustion zone 12a and the second combustion zone 12b is, for example, a space defined by a cylindrical wall. The upstream side of this space corresponds to the first combustion zone 12a, and the downstream side of this space corresponds to the second combustion zone 12b. The exhaust passage 102 described above is connected to the downstream end of the second combustion zone 12b. The combustor 12 is provided with a first burner 13 and a second burner 14 as burners that inject fuel and air to form a flame into each combustion zone.

[0022] The first burner 13 faces the first combustion zone 12a and injects fuel and air into the first combustion zone 12a. The first burner 13 is provided at the upstream end of the first combustion zone 12a. FIG. 1 shows an example in which there is one first burner 13. However, there may be more than one first burner 13. The positional relationship of the multiple first burners 13 is not limited. For example, the multiple first burners 13 may be provided at intervals in the circumferential direction of the first combustion zone 12a. The first burner 13 includes an ammonia injection section 21, a natural gas injection section 22a, and an air injection section 23a. Each of these injection sections faces the first combustion zone 12a. That is, fuel or air is injected from each of these injection sections into the first combustion zone 12a.

[0023] The ammonia injection unit 21 specifically includes a flow path to which ammonia is supplied and which communicates with the first combustion zone 12a. The ammonia supplied to this flow path is injected into the first combustion zone 12a. The natural gas injection unit 22a specifically includes a flow path to which natural gas is supplied and which communicates with the first combustion zone 12a. The natural gas supplied to this flow path is injected into the first combustion zone 12a. The air injection unit 23a specifically includes a flow path to which air is supplied and which communicates with the first combustion zone 12a. The air supplied to this flow path is injected into the first combustion zone 12a.

[0024] The second burner 14 faces the second combustion zone 12b and injects fuel and air into the second combustion zone 12b. The second burner 14 is provided on the side of the second combustion zone 12b. FIG. 1 shows an example in which there is one second burner 14. However, there may be more than one second burner 14. The positional relationship of the multiple second burners 14 is not limited. For example, the multiple second burners 14 may be provided at intervals in the circumferential direction of the second combustion zone 12b. The second burner 14 includes a natural gas injection portion 22b and an air injection portion 23b. Each of these injection portions faces the second combustion zone 12b. That is, fuel or air is injected from each of these injection portions into the second combustion zone 12b.

[0025] The natural gas injection section 22b specifically includes a flow path to which natural gas is supplied and which communicates with the second combustion region 12b. The natural gas supplied to this flow path is injected into the second combustion region 12b. The air injection section 23b specifically includes a flow path to which air is supplied and which communicates with the second combustion region 12b. The air supplied to this flow path is injected into the second combustion region 12b.

[0026] Hereinafter, among the natural gas injection parts, the natural gas injection part 22a of the first burner 13 will also be referred to as the first injection part 22a. Among the natural gas injection parts, the natural gas injection part 22b of the second burner 14 will also be referred to as the second injection part 22b.

[0027] As described above, the compressor 11a compresses and discharges air. Air is supplied from the compressor 11a to the first burner 13 and the second burner 14 via the intake air flow path 101. The intake air flow path 101 includes a flow path 101a, a flow path 101b, and a flow path 101c. The compressor 11a is provided in the flow path 101a. The flow path 101a branches into the flow path 101b and the flow path 101c downstream of the compressor 11a.

[0028] Flow path 101b is connected to the air injection portion 23a of the first burner 13. Therefore, air can be supplied from the compressor 11a to the air injection portion 23a of the first burner 13 via flow path 101a and flow path 101b. Flow path 101c is connected to the air injection portion 23b of the second burner 14. Therefore, air can be supplied from the compressor 11a to the air injection portion 23b of the second burner 14 via flow path 101a and flow path 101c.

[0029] The ammonia supply source 15 is, for example, an ammonia tank that stores ammonia. In the ammonia tank, ammonia is stored, for example, in a liquid state. However, the ammonia supply source 15 is not limited to an ammonia tank. For example, the ammonia supply source 15 may be a device that generates ammonia.

[0030] The ammonia supply source 15 is connected to the ammonia injector 21 of the first burner 13 via a flow path 103. Therefore, ammonia can be supplied from the ammonia supply source 15 to the ammonia injector 21 of the first burner 13 via the flow path 103. The supply of ammonia from the ammonia supply source 15 to the first burner 13 is achieved by, for example, a pump (not shown). A flow control valve 31 is provided in the flow path 103. The flow control valve 31 adjusts the flow rate of ammonia sent to the first burner 13 through the flow path 103. Specifically, the amount of ammonia supplied to the first burner 13 is adjusted by adjusting the opening of the flow control valve 31.

[0031] The natural gas supply source 16 is, for example, a natural gas tank that stores natural gas. In the natural gas tank, natural gas is stored, for example, in a liquid state. However, the natural gas supply source 16 is not limited to a natural gas tank. For example, the natural gas supply source 16 may be a device that generates natural gas.

[0032] The natural gas supply source 16 is connected to a flow path 104. The flow path 104 branches into a flow path 105 and a flow path 106. The flow path 105 is connected to the natural gas injection portion 22a of the first burner 13. Therefore, natural gas can be supplied from the natural gas supply source 16 to the natural gas injection portion 22a of the first burner 13 via the flow paths 104 and 105. The flow path 106 is connected to the natural gas injection portion 22b of the second burner 14. Therefore, natural gas can be supplied from the natural gas supply source 16 to the natural gas injection portion 22b of the second burner 14 via the flow paths 104 and 106. The supply of ammonia from the natural gas supply source 16 to the first burner 13 and the second burner 14 is achieved, for example, by a pump (not shown).

[0033] A flow control valve 32 is provided in the flow path 105. The flow control valve 32 adjusts the flow rate of natural gas sent to the first burner 13 through the flow path 105. Specifically, the amount of natural gas supplied to the first burner 13 is adjusted by adjusting the aperture of the flow control valve 32. A flow control valve 33 is provided in the flow path 106. The flow control valve 33 adjusts the flow rate of natural gas sent to the second burner 14 through the flow path 106. Specifically, the amount of natural gas supplied to the second burner 14 is adjusted by adjusting the aperture of the flow control valve 33.

[0034] The temperature sensor 17 detects the temperature of the first combustion area 12a of the combustor 12. The temperature sensor 17 is provided, for example, on the side of the first combustion area 12a.

[0035] The control device 18 includes a central processing unit (CPU), a ROM in which programs and the like are stored, a RAM as a work area, and the like. The functions of the control device 18 are realized by the central processing unit, the ROM, and the like. The control device 18 controls the operation of each device in the combustion system 1. For example, the control device 18 controls the operation of each of the flow control valves 31, 32, and 33. The control device 18 also acquires information from the temperature sensor 17.

[0036] Control device 18 controls the flow rate of ammonia injected from ammonia injector 21 of first burner 13. Specifically, control device 18 controls the operation of flow control valve 31 to control the flow rate of ammonia injected from injector 21 of first burner 13.

[0037] The control device 18 controls the flow rate of natural gas injected from the first injection part 22a, which is the injection part of the natural gas of the first burner 13. Specifically, the control device 18 controls the operation of the flow control valve 32 to control the flow rate of natural gas injected from the first injection part 22a of the first burner 13.

[0038] The control device 18 controls the flow rate of natural gas injected from the second injection part 22b, which is the injection part of the natural gas of the second burner 14. Specifically, the control device 18 controls the operation of the flow control valve 33 to control the flow rate of natural gas injected from the second injection part 22b of the second burner 14.

[0039] As described above, the control device 18 can individually control the flow rate of ammonia injected from the injection unit 21 of the first burner 13, the flow rate of natural gas injected from the first injection unit 22a of the first burner 13, and the flow rate of natural gas injected from the second injection unit 22b of the second burner 14. Therefore, the control device 18 can control the ratio between the amount of ammonia supplied to the combustor 12 and the amount of natural gas supplied to the combustor 12. In other words, the control device 18 can control the co-firing ratio, which is the ratio of the calorific value of ammonia to the total calorific value of ammonia and natural gas in the combustor 12.

[0040] Furthermore, the control device 18 can adjust the natural gas flow rate ratio, which is the ratio between the flow rate of the natural gas injected from the first natural gas injection portion 22a of the first burner 13 and the flow rate of the natural gas injected from the second natural gas injection portion 22b of the second burner 14. As described above, the second fuel is not limited to natural gas. Therefore, the natural gas flow rate ratio corresponds to an example of the second fuel flow rate ratio, which is the ratio between the flow rate of the second fuel injected from the first injection portion 22a and the flow rate of the second fuel injected from the second injection portion 22b.

[0041] In the combustion system 1, if the temperature of the flame formed in the first combustion zone 12a becomes excessively high, there is a risk of damaging devices such as the liner of the combustor 12 or the first burner 13. For example, because the flame temperature of a second fuel such as natural gas is higher than that of ammonia, if the mixed-fuel ratio is low and natural gas is injected only from the first injection section 22a of the first burner 13, there is a risk of the temperature of the flame formed in the first combustion zone 12a becoming excessively high. For example, if the load of the engine E1 is high, the total amount of fuel supplied to the combustor 12 increases, and therefore if natural gas is injected only from the first injection section 22a of the first burner 13, there is a risk of the temperature of the flame formed in the first combustion zone 12a becoming excessively high.

[0042] As described above, in the combustion system 1, the control device 18 adjusts the natural gas flow rate ratio, which is the ratio between the flow rate of natural gas injected from the first natural gas injection section 22a of the first burner 13 and the flow rate of natural gas injected from the second natural gas injection section 22b of the second burner 14. Therefore, it is possible to inject a portion of the natural gas supplied to the combustor 12 from the second injection section 22b of the second burner 14, without injecting all of the natural gas from the first injection section 22a of the first burner 13. This makes it possible to prevent the temperature of the flame formed in the first combustion region 12a from becoming excessively high, thereby suppressing damage to the device due to the flame.

[0043] 2 and 3, a process for adjusting the natural gas flow ratio by the control device 18 will be described in detail below. The control device 18 adjusts the natural gas flow ratio based on, for example, the temperature of the first combustion zone 12a. An example in which the natural gas flow ratio is adjusted based on the temperature of the first combustion zone 12a will be described below. However, as will be described later, the control device 18 may adjust the natural gas flow ratio based on a parameter other than the temperature of the first combustion zone 12a.

[0044] For example, when the temperature of the first combustion zone 12a is lower than the upper limit temperature, the control device 18 adjusts the natural gas flow ratio so that all of the natural gas supplied to the combustor 12 is injected from the first injection portion 22a of the first burner 13 and no natural gas is injected from the second injection portion 22b of the second burner 14. Furthermore, when the temperature of the first combustion zone 12a has reached the upper limit temperature, the control device 18 adjusts the natural gas flow ratio so that part of the natural gas supplied to the combustor 12 is injected from the second injection portion 22b of the second burner 14. The upper limit temperature can be set appropriately taking into account the heat resistance and other factors of the devices near the first combustion zone 12a.

[0045] 2 is a diagram showing an example of the relationship between the temperature of the first combustion zone 12a, the natural gas flow rate of the first injection section 22a, the natural gas flow rate of the second injection section 22b, and the mixed-fuel ratio in the combustion system 1. The natural gas flow rate of the first injection section 22a refers to the flow rate of natural gas injected from the first injection section 22a of the first burner 13. The natural gas flow rate of the second injection section 22b refers to the flow rate of natural gas injected from the second injection section 22b of the second burner 14. In FIG. 2, the temperature of the first combustion zone 12a, the natural gas flow rate of the first injection section 22a, and the natural gas flow rate of the second injection section 22b are shown by a solid line, a dashed-dotted line, and a broken line, respectively.

[0046] The higher the mixed-fuel ratio, the higher the ratio of the total supply amount of ammonia to the total supply amount of fuel supplied to the combustor 12. On the other hand, the lower the mixed-fuel ratio, the higher the ratio of the total supply amount of natural gas to the total supply amount of fuel supplied to the combustor 12. In the example of Figure 2, the load on the engine E1 is constant. In this case, the total heat value of the fuel supplied to the combustor 12 is also approximately constant.

[0047] Referring to Figure 2, consider the process of decreasing the fuel-mixture ratio from a high level. In the example of Figure 2, the process of the fuel-mixture ratio changing from the right end to the left corresponds to the process of decreasing the fuel-mixture ratio from a high level. In the example of Figure 2, in the region where the fuel-mixture ratio is higher than R1, the temperature of the first combustion zone 12a is lower than the upper limit temperature. Therefore, all of the natural gas supplied to the combustor 12 is injected from the first injection section 22a of the first burner 13, and no natural gas is injected from the second injection section 22b of the second burner 14. In the region where the fuel-mixture ratio is higher than R1, the natural gas flow rate of the first injection section 22a increases as the fuel-mixture ratio decreases. Therefore, in the region where the fuel-mixture ratio is higher than R1, the temperature of the first combustion zone 12a also increases as the fuel-mixture ratio decreases.

[0048] When the fuel-mixture ratio reaches value R1, the temperature of the first combustion zone 12a reaches the upper limit temperature. Therefore, in a region where the fuel-mixture ratio is lower than value R1, part of the natural gas supplied to the combustor 12 is injected from the second injection portion 22b of the second burner 14. Specifically, in a region where the fuel-mixture ratio is lower than value R1, the control device 18 adjusts the natural gas flow ratio so that the temperature of the first combustion zone 12a is maintained at the upper limit temperature.

[0049] For example, when the temperature of the first combustion zone 12a exceeds the upper limit temperature due to a decrease in the mixed-fuel ratio, the control device 18 adjusts the natural gas flow rate ratio so that the ratio of the natural gas flow rate of the second injection unit 22b to the total flow rate of natural gas increases. As a result, as shown in FIG. 2, in a region where the mixed-fuel ratio is lower than value R1, the ratio of the natural gas flow rate of the second injection unit 22b to the total flow rate of natural gas increases as the mixed-fuel ratio decreases. This maintains the temperature of the first combustion zone 12a at the upper limit temperature. As shown in FIG. 2, in a region where the mixed-fuel ratio is lower than value R1, the natural gas flow rate of the first injection unit 22a increases as the mixed-fuel ratio decreases. This suppresses a decrease in the temperature of the first combustion zone 12a caused by a decrease in the flow rate of ammonia supplied to the first combustion zone 12a from the ammonia injection unit 21 of the first burner 13 as the mixed-fuel ratio decreases.

[0050] As described above, in the region where the temperature of the first combustion region 12a is lower than the upper limit temperature (i.e., the region where the mixed-fuel ratio is higher than the value R1), natural gas is not injected from the second injection portion 22b of the second burner 14, and all of the natural gas supplied to the combustor 12 is injected from the first injection portion 22a of the first burner 13. This prevents the temperature of the first combustion region 12a from decreasing excessively, thereby ensuring flame stability in the first combustion region 12a.

[0051] Fig. 3 is a diagram showing an example of the relationship between the temperature of the first combustion region 12a, the natural gas flow rate of the first injection section 22a, the natural gas flow rate of the second injection section 22b, and the load of the engine E1 in the combustion system 1. In Fig. 3, similar to Fig. 2, the temperature of the first combustion region 12a, the natural gas flow rate of the first injection section 22a, and the natural gas flow rate of the second injection section 22b are shown by a solid line, a dashed line, and a broken line, respectively.

[0052] The load on the engine E1 varies depending on, for example, the required amount of power generation by the generator connected to the compressor 11a. The higher the load on the engine E1, the greater the total heat value of the fuel supplied to the combustor 12. In the example of Figure 3, the mixed-fuel ratio is constant.

[0053] Referring to FIG. 3, consider the process in which the load of engine E1 increases from a low state. In the example of FIG. 3, the process in which the load of engine E1 changes from the left end to the right corresponds to the process in which the load of engine E1 increases from a low state. In the example of FIG. 3, when the load of engine E1 is less than value L1, the temperature of the first combustion zone 12a is lower than the upper limit temperature. Therefore, all of the natural gas supplied to the combustor 12 is injected from the first injection section 22a of the first burner 13, and no natural gas is injected from the second injection section 22b of the second burner 14. In the region in which the load of engine E1 is less than value L1, as the load of engine E1 increases, the natural gas flow rate of the first injection section 22a increases. Therefore, in the region in which the load of engine E1 is less than value L1, as the load of engine E1 increases, the temperature of the first combustion zone 12a also increases.

[0054] Then, when the load of engine E1 reaches value L1, the temperature of the first combustion zone 12a reaches the upper limit temperature. Therefore, in the region where the load of engine E1 is greater than value L1, part of the natural gas supplied to the combustor 12 is injected from the second injection portion 22b of the second burner 14. Specifically, in the region where the load of engine E1 is greater than value L1, the control device 18 adjusts the natural gas flow ratio so that the temperature of the first combustion zone 12a is maintained at the upper limit temperature.

[0055] For example, when the temperature of the first combustion region 12a exceeds the upper limit temperature due to an increase in the load of the engine E1, the control device 18 adjusts the natural gas flow rate ratio so that the ratio of the natural gas flow rate of the second injection section 22b to the total flow rate of natural gas increases. As a result, as shown in Fig. 3, in a region where the load of the engine E1 is greater than value L1, the ratio of the natural gas flow rate of the second injection section 22b to the total flow rate of natural gas increases as the load of the engine E1 increases. This maintains the temperature of the first combustion region 12a at the upper limit temperature.

[0056] As described above, in the region where the temperature of the first combustion zone 12a is lower than the upper limit temperature (i.e., the region where the load of the engine E1 is lower than the value L1), natural gas is not injected from the second injection portion 22b of the second burner 14, and all of the natural gas supplied to the combustor 12 is injected from the first injection portion 22a of the first burner 13. This prevents the temperature of the first combustion zone 12a from decreasing excessively. This ensures flame stability in the first combustion zone 12a. Even during ignition when the fuel input amount is small or immediately after ignition, natural gas is not injected from the second injection portion 22b of the second burner 14, and all of the natural gas supplied to the combustor 12 is injected from the first injection portion 22a of the first burner 13. This prevents the temperature of the first combustion zone 12a from decreasing excessively, and stable ignition in the first combustion zone 12a is achieved.

[0057] As described above, the control device 18 adjusts the natural gas flow ratio based on the temperature of the first combustion zone 12a. This prevents the temperature of the flame formed in the first combustion zone 12a from becoming excessively high. Specifically, when the fuel-fuel ratio is low or the load on the engine E1 is high, the temperature of the first combustion zone 12a can be prevented from exceeding the upper limit temperature. This prevents damage to the device caused by the flame. Furthermore, the temperature of the first combustion zone 12a can be prevented from decreasing excessively. Specifically, when the fuel-fuel ratio is high or the load on the engine E1 is low, the temperature of the first combustion zone 12a can be prevented from decreasing excessively. This ensures the stability of the flame in the first combustion zone 12a.

[0058] In the above, an example has been described in which the natural gas flow ratio is adjusted based on the temperature of the first combustion area 12a. However, the control device 18 may adjust the natural gas flow ratio based on a parameter other than the temperature of the first combustion area 12a.

[0059] The control device 18 may adjust the natural gas flow rate ratio based on the fuel-fuel mixture ratio. For example, information on the fuel-fuel mixture ratio, which changes according to a preset schedule, is input to the control device 18. The control device 18 can obtain the fuel-fuel mixture ratio using this information. For example, when the fuel-fuel mixture ratio is higher than the value R1 in FIG. 2, the control device 18 adjusts the natural gas flow rate ratio so that all of the natural gas supplied to the combustor 12 is injected from the first injection portion 22a of the first burner 13 and no natural gas is injected from the second injection portion 22b of the second burner 14.

[0060] 2, the control device 18 adjusts the natural gas flow rate ratio so that a portion of the natural gas supplied to the combustor 12 is injected from the second injection section 22b of the second burner 14. Specifically, when the mixed combustion ratio is lower than the value R1 in FIG. 2, the control device 18 adjusts the natural gas flow rate ratio so that the proportion of the natural gas flow rate from the second injection section 22b to the total flow rate of natural gas increases as the mixed combustion ratio decreases.

[0061] Even when the natural gas flow rate ratio is adjusted based on the fuel-fuel mixture ratio, the temperature of the first combustion zone 12a can be prevented from exceeding the upper limit temperature, as in the case where the natural gas flow rate ratio is adjusted based on the temperature of the first combustion zone 12a, thereby preventing damage to the device due to flames. Furthermore, the temperature of the first combustion zone 12a can be prevented from decreasing excessively, ensuring the stability of the flame in the first combustion zone 12a.

[0062] The control device 18 may adjust the natural gas flow ratio based on the load of the engine E1. For example, information about the load of the engine E1, which changes according to a preset schedule, is input to the control device 18. The control device 18 can obtain the load of the engine E1 using this information. For example, when the load of the engine E1 is smaller than the value L1 in FIG. 3, the control device 18 adjusts the natural gas flow ratio so that all of the natural gas supplied to the combustor 12 is injected from the first injection portion 22a of the first burner 13 and no natural gas is injected from the second injection portion 22b of the second burner 14.

[0063] Furthermore, for example, when the load of engine E1 is greater than value L1 in Fig. 3, control device 18 adjusts the natural gas flow rate ratio so that a portion of the natural gas supplied to the combustor 12 is injected from the second injection portion 22b of the second burner 14. Specifically, when the load of engine E1 is greater than value L1 in Fig. 3, control device 18 adjusts the natural gas flow rate ratio so that the proportion of the natural gas flow rate of the second injection portion 22b to the total flow rate of natural gas increases as the load of engine E1 increases.

[0064] Even when the natural gas flow ratio is adjusted based on the load of the engine E1, the temperature of the first combustion zone 12a can be prevented from exceeding the upper limit temperature, as in the case where the natural gas flow ratio is adjusted based on the temperature of the first combustion zone 12a, and therefore damage to the device due to a flame can be suppressed. Furthermore, the temperature of the first combustion zone 12a can be prevented from decreasing excessively, ensuring the stability of the flame in the first combustion zone 12a.

[0065] The control device 18 may adjust the natural gas flow ratio based on the total calorific value of the ammonia and natural gas. For example, information on the load of the engine E1, which changes according to a preset schedule, is input to the control device 18. The control device 18 can obtain the total calorific value of the ammonia and natural gas using this information. The total calorific value is correlated with the load of the engine E1. Therefore, for example, when the total calorific value is smaller than a threshold, the control device 18 adjusts the natural gas flow ratio so that all of the natural gas supplied to the combustor 12 is injected from the first injection portion 22a of the first burner 13 and no natural gas is injected from the second injection portion 22b of the second burner 14.

[0066] Furthermore, for example, when the total calorific value is greater than a threshold value, the control device 18 adjusts the natural gas flow rate ratio so that a portion of the natural gas supplied to the combustor 12 is injected from the second injection section 22b of the second burner 14. Specifically, when the total calorific value is greater than a threshold value, the control device 18 adjusts the natural gas flow rate ratio so that the ratio of the natural gas flow rate of the second injection section 22b to the total flow rate of natural gas increases as the load of the total calorific value increases.

[0067] Even when the natural gas flow rate ratio is adjusted based on the total calorific value of ammonia and natural gas, the temperature of the first combustion zone 12a can be prevented from exceeding the upper limit temperature, as in the case where the natural gas flow rate ratio is adjusted based on the temperature of the first combustion zone 12a, thereby preventing damage to the device due to a flame. Furthermore, the temperature of the first combustion zone 12a can be prevented from decreasing excessively, ensuring the stability of the flame in the first combustion zone 12a.

[0068] In the above, the temperature of the first combustion region 12a, the fuel-fuel mixture ratio, the load of the engine E1, and the total heat value have been described as parameters used to adjust the natural gas flow rate ratio. However, a combination of these parameters may be used as parameters to adjust the natural gas flow rate ratio. Furthermore, parameters other than the parameters described above may be used as parameters to adjust the natural gas flow rate ratio.

[0069] From the viewpoint of ensuring flame stability in the first combustion region 12a, it is preferable to implement the following measures in the air injection portion 23a of the first burner 13. Such measures will be described below with reference to FIG.

[0070] FIG. 4 is a diagram showing an example of the configuration of the air injection section 23a of the first burner 13. As shown in FIG. 4, the first burner 13 is equipped with a swirl section 24. The swirl section 24 swirls the air injected from the air injection section 23a of the first burner 13. In the example of FIG. 4, the swirl section 24 includes a shaft 24a and swirler blades 24b. The shaft 24a extends, for example, on the central axis of the air flow path in the injection section 23a. The swirl blades 24b extend from the outer peripheral surface of the shaft 24a radially outward from the shaft 24a. For example, a plurality of swirl blades 24b are provided at intervals in the circumferential direction of the shaft 24a. As a result, a swirling force is imparted to the air flowing through the injection section 23a, as indicated by the arrows in FIG. 4. However, the swirling section 24 is not limited to the example of FIG. 4 as long as it can swirl the air injected from the air injection section 23a of the first burner 13.

[0071] As described above, the first burner 13 is provided with the swirl section 24 that swirls the air injected from the air injection section 23a of the first burner 13. This ensures the stability of the flame in the first combustion region 12a. However, the swirl section 24 may be omitted from the first burner 13.

[0072] Although the embodiments of the present disclosure have been described above with reference to the accompanying drawings, it goes without saying that the present disclosure is not limited to such embodiments. It is clear that a person skilled in the art can conceive of various modifications and alterations within the scope of the claims, and it is understood that such modifications and alterations also fall within the technical scope of the present disclosure.

[0073] The above describes an example in which the rotational power transmitted from the turbine 11b to the compressor 11a is used as energy to drive the generator in the combustion system 1. However, in the combustion system 1, the rotational power transmitted from the turbine 11b to the compressor 11a may also be used for other purposes, such as to drive a moving body such as a ship.

[0074] In the above, an example has been described in which the ammonia injection section 21 and the natural gas injection section 22a in the first burner 13 are separate injection sections. However, in the first burner 13, ammonia and natural gas may be mixed in advance and injected into the first combustion zone 12a from a single injection section. In this case, the single injection section functions both as an ammonia injection section and as an injection section for natural gas. Similarly, in the first burner 13, ammonia and air may be mixed in advance and injected into the first combustion zone 12a from a single injection section. Similarly, in the first burner 13, ammonia, natural gas, and air may be mixed in advance and injected into the first combustion zone 12a from a single injection section. Similarly, in the second burner 14, natural gas and air may be mixed in advance and injected into the second combustion zone 12b from a single injection section.

[0075] The present disclosure helps to suppress damage to equipment caused by flames in combustion systems such as gas turbine systems, and can therefore contribute to, for example, Goal 7 of the Sustainable Development Goals (SDGs), which is to "Ensure access to affordable, reliable, sustainable and modern energy." [Explanation of symbols]

[0076] 1: Combustion system 12: Combustor 12a: First combustion zone 12b: Second combustion zone 13: First burner 14: Second burner 18: Control device 21: Ammonia injection section 22a: Natural gas injection section (first injection section) 22b: Natural gas injection section (second injection section) 23a: Air injection section 24: Swirl section E1: Engine

Claims

1. a combustor including a first combustion zone and a second combustion zone downstream and continuous with the first combustion zone; a first burner including an injection portion for ammonia as a first fuel facing the first combustion zone, and a first injection portion for a second fuel not containing nitrogen atoms facing the first combustion zone; a second burner including a second injection portion for the second fuel facing the second combustion region; a control device that adjusts a second fuel flow rate ratio, which is a ratio between a flow rate of the second fuel injected from the first injection unit and a flow rate of the second fuel injected from the second injection unit; Equipped with the control device adjusts the second fuel flow ratio based on a mixed-combustion ratio that is a ratio of a calorific value of the ammonia to a total calorific value of the ammonia and the second fuel. Combustion system.

2. the control device adjusts the second fuel flow ratio based on the temperature of the first combustion zone. The combustion system of claim 1 .

3. an engine including the combustor; The control device adjusts the second fuel flow ratio based on a load of the engine.

3. A combustion system according to claim 1 or 2.

4. the control device adjusts the second fuel flow ratio based on a total calorific value of the ammonia and the second fuel.

3. A combustion system according to claim 1 or 2.

5. The first burner is an air injection section facing the first combustion region; a swirling unit that swirls the air injected from the air injection unit; Equipped with 3. A combustion system according to claim 1 or 2.

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