Combustion system

Abstract

A combustion system (100) is provided with: an ammonia supply source (1); a cracking device (3) which is connected to the ammonia supply source (1) and decomposes ammonia into hydrogen and nitrogen; a burner (42) that is connected to the ammonia supply source (1) and the cracking device (3) and combusts ammonia from the ammonia supply source (1) and a hydrogen-containing gas from the cracking device (3); a sensor (Se) that detects combustion abnormalities in the combustor (42); and a control device (90) which is communicably connected to the sensor (Se) and which adjusts the amount of gas from the cracking device (3) to the burner (42) on the basis of the detection result of the sensor (Se).

Description

Technical Field

[0001] The present disclosure relates to a combustion system. This application claims the benefit of priority based on Japanese Patent Application No. 2022-173338 filed on October 28, 2022, the content of which is incorporated herein by reference. Background Art

[0002] Ammonia is known as a fuel that does not emit CO 2 For example, Patent Document 1 discloses a gas turbine system that uses ammonia as a fuel. The system includes an ammonia tank and a first combustion chamber. Ammonia in the tank passes through a first mass flow separator, and a part of it is directly fed into the first combustion chamber, and the remaining part is sent to the first cracking chamber. In the first cracking chamber, ammonia is decomposed into a hydrogen-rich gas mixture containing nitrogen, hydrogen, and other components. Ammonia and the hydrogen-rich gas mixture are injected into the first combustion chamber and burned. The exhaust gas from the first combustion chamber contains a high level of NOx. In addition, the system includes a second combustion chamber. The exhaust gas from the first combustion chamber is guided to the second combustion chamber. Ammonia in the tank passes through a second mass flow separator, and a part of it is directly fed into the second combustion chamber, and the remaining part is fed into the second cracking chamber. In the second cracking chamber, ammonia is decomposed into a hydrogen-rich gas mixture containing nitrogen, hydrogen, and other components. Ammonia and the hydrogen-rich gas mixture are injected into the second combustion chamber and burned. In the second combustion chamber, the fuel burns at a high equivalence ratio of 1.0 to 1.2. Thus, NOx is removed from the exhaust gas from the first combustion chamber.

[0003] Prior Art Documents

[0004] Patent Documents

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2018-535355 Summary of the Invention

[0006] Problems to be Solved by the Invention

[0007] In a combustion system using ammonia, combustion abnormalities such as an increase in NOx in the exhaust gas, an increase in ammonia in the exhaust gas, flashback, or combustion vibration may occur. Such combustion abnormalities should be prevented.

[0008] An object of the present disclosure is to provide a combustion system that uses ammonia as a fuel and can prevent combustion abnormalities.

[0009] Means for Solving the Problems

[0010] One aspect of the present disclosure provides a combustion system comprising: an ammonia supply source; a cracking device connected to the ammonia supply source for decomposing ammonia into hydrogen and nitrogen; a burner connected to the ammonia supply source and the cracking device for burning ammonia from the ammonia supply source and a hydrogen-containing gas from the cracking device; a sensor for detecting combustion abnormalities in the burner; and a control device communicably connected to the sensor for adjusting the amount of gas from the cracking device to the burner based on the detection result of the sensor.

[0011] The sensor may also include a first sensor disposed in the burner for detecting combustion vibrations.

[0012] The sensor may include a second sensor disposed in the burner for detecting the movement of the flame.

[0013] The sensor may also include a third sensor for detecting NOx in the exhaust gas at a position downstream of the burner.

[0014] The sensor may also include a fourth sensor for detecting ammonia in the exhaust gas at a position downstream of the burner.

[0015] The burner may include a plurality of burners, and the control device may control the operation of the plurality of burners based on the detection result of the sensor.

[0016] Advantages of the Invention

[0017] According to the present disclosure, combustion abnormalities can be prevented. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a schematic diagram showing a gas turbine system according to the first embodiment.

[0019] Figure 2 is showing Figure 1 a schematic diagram of the burner in

[0020] Figure 3 is showing Figure 1 a flowchart of the operation of the gas turbine system of

[0021] Figure 4 is following Figure 3 a flowchart of

[0022] Figure 5 is following Figure 3 a flowchart of

[0023] Figure 6 is following Figure 3 a flowchart of

[0024] Figure 7 is following Figure 3 a flowchart of

[0025] Figure 8 is a flowchart showing the operation of the gas turbine system according to the second embodiment.

[0026] Figure 9 is a schematic curve showing the relationship between the ammonia decomposition rate and each parameter. Detailed Embodiment

[0027] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. The specific dimensions, materials, numerical values, etc. shown in this embodiment are merely illustrative for easy understanding, and do not limit the present disclosure except in the case of special instructions. In addition, in this specification and the accompanying drawings, elements having substantially the same functions and structures are denoted by the same reference numerals, and redundant descriptions are omitted. In addition, elements not directly related to the present disclosure are omitted from the illustration.

[0028] Figure 1 is a schematic diagram showing the gas turbine system 100 according to the first embodiment. In this embodiment, the gas turbine system 100 functions as a combustion system. In the present disclosure, the gas turbine system 100 may also be simply referred to as "system 100". For example, the system 100 includes a tank (ammonia supply source) 1, a pressurizer 2, a cracking device 3, a gas turbine 4, a generator 5, and a control device 90. The system 100 may also include other components. In addition, the system 100 may not include one or more of the above components.

[0029] The tank 1 stores ammonia. Specifically, the tank 1 stores liquid ammonia. The tank 1 is connected to the pressurizer 2 through a pipe P1. The liquid ammonia stored in the tank 1 is supplied to the pressurizer 2 through the pipe P1. In other embodiments, for example, an ammonia manufacturing device may be used as the ammonia supply source instead of the tank 1.

[0030] The pressurizer 2 pressurizes the ammonia from the tank 1. The pressurizer 2 is communicably connected to the control device 90 by wire or wirelessly and is controlled by the control device 90. The pressurizer 2 is connected to a pipe P2. The pressurized ammonia flows from the pressurizer 2 to the pipe P2.

[0031] In this embodiment, ammonia is supplied to the cracking device 3 and the gas turbine 4 in a liquid state. In this case, for example, the pressurizer 2 may also be a pump. In other embodiments, for example, the system 100 may include a vaporizer in the pipe P1 or the pipe P2, and ammonia may be supplied to the cracking device 3 and the gas turbine 4 in a gaseous state. When the pressurizer 2 pressurizes gaseous ammonia, for example, the pressurizer 2 may also be a compressor.

[0032] A valve V1 is provided in the pipe P2. The valve V1 is communicably connected to the control device 90 by wire or wirelessly and is controlled by the control device 90. For example, the control device 90 controls the opening degree of the valve V1 based on the power demand and the power generation amount in the generator 5, thereby adjusting the flow rate of ammonia flowing in the pipe P2. The pipe P2 branches into a pipe P21 and a pipe P22. The pipe P21 is connected to the cracking device 3, and the pipe P22 is connected to the gas turbine 4.

[0033] At least a part of the pressurized ammonia is supplied to the gas turbine 4 via the pipe P22. In addition, although not shown in Figure 1 , the pipe P22 may also be branched into a plurality of pipes P22 in the gas turbine 4 in a manner connected to a plurality of combustion chambers 45 (refer to Figure 2 ).

[0034] The remaining part of the pressurized ammonia is supplied to the cracking device 3 via the pipe P21. A valve V2 is provided in the pipe P21. The valve V2 is communicably connected to the control device 90 by wire or wirelessly and is controlled by the control device 90. For example, the control device 90 controls the opening degree of the valve V2 based on the detection result of at least one of the first sensor Se1, the second sensor Se2, the third sensor Se3, and the fourth sensor Se4 described later, thereby adjusting the flow rate of ammonia supplied to the cracking device 3.

[0035] The cracking device 3 decomposes ammonia into hydrogen and nitrogen. The cracking device 3 includes a catalyst for decomposing ammonia into hydrogen and nitrogen. Such a catalyst includes, for example, at least one of Ru, Rh, Pt, and Pd. The cracking device 3 is connected to the gas turbine 4 through the pipe P23. The gas containing hydrogen and nitrogen (in the present disclosure, it may also be referred to as "hydrogen-rich gas") is supplied from the cracking device 3 to the gas turbine 4 via the pipe P23. In addition, although not shown in Figure 1 , the pipe P23 may also be branched into a plurality of pipes P23 in the gas turbine 4 in a manner connected to a plurality of combustion chambers 45 (refer to Figure 2 ).

[0036] Refer to Figure 1 , the gas turbine 4 includes a compressor 41, a burner 42, and a turbine 43. The gas turbine 4 may also have other components. The compressor 41 pressurizes air and delivers the pressurized air to the burner 42.

[0037] The burner 42 is fluidly connected to the tank 1 via the above-mentioned pipes P1, P2, and P22. The burner 42 receives ammonia from the tank 1. In addition, the burner 42 is fluidly connected to the cracking device 3 via the above-mentioned pipe P23. The burner 42 receives the hydrogen-rich gas from the cracking device 3. In the present embodiment, the burner 42 burns ammonia and the hydrogen-rich gas. The burner 42 may also burn other fuels according to the situation.

[0038] Figure 2 is a schematic diagram of the burner 42 Figure 1 in. The burner 42 includes a housing 44 that defines a chamber C and a plurality of combustion chambers 45. The burner 42 may also include other components such as a lining.

[0039] Each combustion chamber 45 is arranged to face the chamber C. The plurality of combustion chambers 45 can be arranged in any pattern such as a circular pattern, a matrix pattern, or a polygonal pattern.

[0040] Each combustion chamber 45 is connected to the above-mentioned pipe P22. Ammonia from the tank 1 is supplied to each combustion chamber 45 via the pipe P22. A valve V3 is provided in each pipe P22. The valve V3 is communicably connected to the control device 90 by wire or wirelessly and is controlled by the control device 90. For example, the control device 90 controls the opening degree of the valve V3 based on the detection result of at least one of the first sensor Se1, the second sensor Se2, the third sensor Se3, and the fourth sensor Se4, thereby adjusting the flow rate of ammonia supplied to the corresponding combustion chamber 45.

[0041] Each combustion chamber 45 is connected to the above-mentioned pipe P23. Hydrogen-rich gas from the cracking device 3 is supplied to each combustion chamber 45 via the pipe P23. A valve V4 is provided in each pipe P23. The valve V4 is communicably connected to the control device 90 by wire or wirelessly and is controlled by the control device 90. For example, the control device 90 controls the opening degree of the valve V4 based on the detection result of at least one of the first sensor Se1, the second sensor Se2, the third sensor Se3, and the fourth sensor Se4, thereby adjusting the flow rate of hydrogen-rich gas supplied to the corresponding combustion chamber 45.

[0042] Each combustion chamber 45 is connected to the pipe P24. Compressed air from the compressor 41 is supplied to each combustion chamber 45 via the pipe P24.

[0043] In the chamber C, a mixed gas of ammonia and hydrogen-rich gas burns. Refer to Figure 1 , the exhaust gas generated by combustion is supplied from the burner 42 to the turbine 43. The turbine 43 rotates by the exhaust gas. In the present embodiment, the rotational force of the turbine 43 is used for the operation of the generator 5. In other embodiments, the rotational force of the turbine 43 can also be used in other devices.

[0044] The turbine 43 is connected to the pipe P3. The exhaust gas passes from the turbine 43 through the pipe P3 and is supplied to other devices (not shown) located downstream of the turbine 43, such as a waste heat recovery boiler and a denitration device.

[0045] Generally, the combustion rate of ammonia is slow. Therefore, when only ammonia burns in the chamber C, the combustion in the chamber C tends to become unstable. However, in the present embodiment, a part of the ammonia from the tank 1 is decomposed into hydrogen and nitrogen in the cracking device 3 and then supplied to the burner 42. Since the combustion rate of hydrogen is fast, the combustion in the chamber C is stable, and the amount of ammonia that can be burned also increases. As a result, the ammonia remaining in the exhaust gas from the burner 42 due to various factors (for example, unreacted ammonia in the cracking device 3 and unburned ammonia in the burner 42) is reduced. As a result, for example, the operating cost of the denitration device is reduced.

[0046] In addition, as described above, in the present embodiment, a part of the ammonia from the tank 1 is decomposed into hydrogen and nitrogen in the cracking device 3 and then supplied to the chamber C. In this case, the nitrogen atom N combines with the nitrogen molecule N in an environment where there is no oxygen atom O or little oxygen atom O in the section from the cracking device 3 to the burner 42. 2 The nitrogen molecule N 2 is stable and is less likely to combine with the oxygen atom O compared to the nitrogen atom N. Therefore, the generation of NOx, particularly fuel NOx, is suppressed.

[0047] However, as described above, the combustion rate of hydrogen is fast. Therefore, when the amount of hydrogen-rich gas from the cracking device 3 to the burner 42 increases, the combustion rate in the chamber C increases, and the flame tends to move to a position upstream of the desired position. Therefore, an excessive increase in the hydrogen-rich gas from the cracking device 3 to the burner 42 may cause flashback.

[0048] In addition, when the amount of hydrogen-rich gas from the cracking device 3 to the burner 42 increases, the combustion rate of hydrogen is fast, so the combustion in the chamber C expands. As a result, the internal pressure of the chamber C increases. In this case, the fuel from the spray combustion chamber 45 must push back a higher internal pressure and is difficult to inject. As a result, the amount of fuel injected into the chamber C decreases and the combustion becomes smaller. Therefore, the internal pressure of the chamber C decreases. As a result, in the chamber C, the increase and decrease of the internal pressure are repeated alternately. In this way, an excessive increase in the hydrogen-rich gas from the cracking device 3 to the burner 42 may cause combustion vibration.

[0049] In the present embodiment, as described in detail later, by adjusting the amount of hydrogen-rich gas from the cracking device 3 to the burner 42 and the operation of the plurality of spray combustion chambers 45, combustion abnormalities such as flashback, combustion vibration, an increase in NOx in the exhaust gas, and an increase in ammonia in the exhaust gas are suppressed.

[0050] System 100 is equipped with a sensor Se configured to detect combustion abnormalities in the burner 42. Specifically, the sensor Se includes a first sensor Se1, a second sensor Se2, a third sensor Se3, and a fourth sensor Se4. In other embodiments, the sensor Se may also not include a part of the first sensor Se1, the second sensor Se2, the third sensor Se3, and the fourth sensor Se4.

[0051] Refer to Figure 2 , the first sensor Se1 is disposed in the burner 42. The first sensor Se1 is configured to detect combustion vibrations in the chamber C. For example, the first sensor Se1 can be mounted on the wall surface of the housing 44 or the lining. For example, the first sensor Se1 can also be a pressure sensor. The first sensor Se1 is communicably connected to the control device 90 by wire or wirelessly, and sends the detection data to the control device 90. The control device 90 can detect combustion vibrations by detecting pressure fluctuations in the chamber C.

[0052] The second sensor Se2 is disposed in the burner 42. The second sensor Se2 is configured to detect the movement of the flame in the chamber C. Specifically, the second sensor Se2 is configured to detect that the flame moves to a position upstream of the desired position in the chamber C. For example, the second sensor Se2 may also include temperature sensors disposed around the outlets of the respective combustion chambers 45. The second sensor Se2 is communicably connected to the control device 90 by wire or wirelessly, and sends the detection data to the control device 90. The control device 90 can detect the approach of the flame to the corresponding combustion chamber 45 by detecting a temperature rise around the outlet of the combustion chamber 45. Instead, the second sensor Se2 can also be a light sensor capable of detecting the flame.

[0053] Refer to Figure 1 , the third sensor Se3 is disposed in the pipe P3. In other embodiments, the third sensor Se3 may also be disposed at other positions downstream of the burner 42. For example, the third sensor Se3 can be a NOx sensor that detects the concentration of NOx in the exhaust gas. The third sensor Se3 is communicably connected to the control device 90 by wire or wirelessly, and sends the detection data to the control device 90.

[0054] The fourth sensor Se4 is disposed in the pipe P3. In other embodiments, the fourth sensor Se4 may also be disposed at other positions downstream of the burner 42. The fourth sensor Se4 can be an ammonia sensor that detects the concentration of ammonia in the exhaust gas. The fourth sensor Se4 is communicably connected to the control device 90 by wire or wirelessly, and sends the detection data to the control device 90.

[0055] The control device 90 controls the whole or a part of the system 100. For example, the control device 90 may also be composed of one or more PCs. The control device 90 includes, for example, components such as a processor 90a, a storage device 90b, and a connector 90c, and these components are interconnected via a bus. For example, the processor 90a includes a CPU (Central Processing Unit). For example, the storage device 90b includes a hard disk, a ROM that stores programs, and a RAM that serves as a work area, etc. The control device 90 is communicably connected to each component of the system 100 via the connector 90c, either wired or wirelessly. For example, the control device 90 may also include other components such as a display device like a liquid crystal display or a touch panel, and an input device such as a keyboard, buttons, or a touch panel. For example, the following operations of the control device 90 can also be achieved by causing the processor 90a to execute a program stored in the storage device 90b.

[0056] Next, the operation of the system 100 will be described.

[0057] Figure 3 It represents Figure 1 a flowchart of the operation of the gas turbine system 100. Figures 4 to 7 It is next Figure 3 a flowchart. For example, Figures 3 to 7 the operations shown can also be repeated at a predetermined interval during the operation of the gas turbine system 100.

[0058] Referring to Figure 3 , the processor 90a of the control device 90 determines whether the temperature detected by each second sensor Se2 is less than a predetermined limit value (step S100). For example, the limit value of the temperature can be determined through experiments or analysis as the maximum value that allows the flame to approach each combustion chamber 45 in the chamber C, or it can be stored in the storage device 90b. Instead, when an optical sensor is used as the second sensor Se2, in step S100, it can also be determined whether the position of the flame detected by the second sensor Se2 is within a predetermined range. The predetermined range can be determined through experiments or analysis as the range that allows the presence of a flame in the chamber C, or it can be stored in the storage device 90b.

[0059] In step S100, when the temperature detected by each second sensor Se2 is less than the limit value (Yes), the processor 90a proceeds to step S102.

[0060] In step S100, when the temperature detected by any second sensor Se2 is equal to or greater than the limit value (No), the processor 90a proceeds to Figure 4 the operation (A) shown.

[0061] Referring toFigure 4 The processor 90a adjusts at least one of the flow rate of the hydrogen-rich gas from the cracking device 3 to the burner 42 and the operation of the combustion chamber 45 (step S200).

[0062] Refer to Figure 1 , for example, the processor 90a can also reduce the amount of ammonia supplied to the cracking device 3 by adjusting the opening degree of the control valve V2. In this case, the amount of hydrogen-rich gas generated in the cracking device 3 decreases. Therefore, the amount of hydrogen supplied from the cracking device 3 to the burner 42 decreases, and the combustion speed in the chamber C decreases. As a result, the flame moves downstream and away from the combustion chamber 45. As a result, flashback is prevented.

[0063] Refer to Figure 2 , alternatively or additionally, for example, the processor 90a can also adjust the operation of at least one of the plurality of combustion chambers 45. For example, the processor 90a can open the valves V3 and V4 of the unused combustion chamber 45 among the plurality of combustion chambers 45 and start using this combustion chamber 45. That is, a part of the fuel supplied to the used combustion chamber 45 is allocated to the unused combustion chamber 45. In this case, the amount of hydrogen supplied to the combustion chamber 45 corresponding to the second sensor Se2 that detects a temperature above the limit value decreases, and the combustion speed around this combustion chamber 45 decreases. As a result, the flame moves downstream and away from the corresponding combustion chamber 45. As a result, flashback is prevented.

[0064] Refer to Figure 4 , the processor 90a determines again whether the temperature detected by each second sensor Se2 is less than the limit value (step S202).

[0065] In step S202, when the temperature detected by each second sensor Se2 is less than the limit value (Yes), the processor 90a proceeds to Figure 3 step S102(E).

[0066] In step S202, when the temperature detected by any second sensor Se2 is above the limit value (No), the processor 90a repeats the Figure 4 actions shown.

[0067] Refer to Figure 3 , the processor 90a determines whether the pressure change detected by the first sensor Se1 is less than a predetermined limit value (step S102). The pressure change can also be calculated by various methods. For example, the pressure change can also be calculated as the difference between the maximum value and the minimum value of the pressure within a predetermined period. The pressure change is not limited to this and can be calculated by various other methods. For example, the limit value of the pressure change can be determined through experiments or analysis as the maximum value of the allowable combustion vibration, or can be stored in the storage device 90b.

[0068] In step S102, when the pressure change is less than the limit value (Yes), the processor 90a proceeds to step S104.

[0069] In step S102, when the pressure change is equal to or greater than the limit value (No), the processor 90a proceeds to Figure 5 the operation (B) shown.

[0070] Referring to Figure 5 , the processor 90a adjusts at least one of the flow rate of the hydrogen-rich gas from the cracking device 3 to the burner 42 and the operation of the combustion chamber 45 (step S300).

[0071] Referring to Figure 1 , for example, the processor 90a can also adjust the amount of ammonia supplied to the cracking device 3 by the opening degree of the control valve V2. In this case, the amount of hydrogen-rich gas generated in the cracking device 3 changes. Therefore, the amount of hydrogen supplied from the cracking device 3 to the burner 42 changes, and the combustion rate in the chamber C also changes. As a result, the combustion state in the chamber C changes, and the pressure state also changes. Thereby, the injection of fuel from the combustion chamber 45 into the chamber C becomes stable. Therefore, combustion vibration can be prevented.

[0072] Referring to Figure 2 , alternatively or additionally, for example, the processor 90a can also adjust the operation of at least one of the plurality of combustion chambers 45. For example, the processor 90a can open the valves V3 and V4 of the unused combustion chamber 45 among the plurality of combustion chambers 45 and start using this combustion chamber 45. That is, a part of the fuel supplied to the used combustion chamber 45 is distributed to the unused combustion chamber 45. In this case, the amount of hydrogen supplied to one combustion chamber 45 decreases, and the combustion around the used combustion chamber 45 becomes smaller. As a result, the pressure around the used combustion chamber 45 becomes stable, and the injection of fuel from the combustion chamber 45 into the chamber C also becomes stable. Therefore, combustion vibration can be prevented.

[0073] Referring to Figure 5 , the processor 90a determines again whether the pressure change is less than the limit value (step S302).

[0074] In step S302, when the pressure change is less than the limit value (Yes), the processor 90a proceeds to Figure 3 step S104 (F) of

[0075] In step S302, when the pressure change is equal to or greater than the limit value (No), the processor 90a repeats Figure 5 the operation shown.

[0076] Referring to Figure 3, the processor 90a determines whether the concentration of ammonia detected by the fourth sensor Se4 is less than a predetermined limit value (step S104). For example, the limit value of ammonia can be determined based on regulations or stored in the storage device 90b.

[0077] In step S104, when the concentration of ammonia is less than the limit value (Yes), the processor 90a proceeds to step S106.

[0078] In step S104, when the concentration of ammonia is equal to or greater than the limit value (No), the processor 90a proceeds to Figure 6 the operation (C) shown.

[0079] Referring to Figure 6 , the processor 90a adjusts at least one of the flow rate of the hydrogen-rich gas from the cracking device 3 to the burner 42 and the operation of the combustion chamber 45 (step S400).

[0080] Referring to Figure 1 , for example, the processor 90a can also increase the amount of ammonia supplied to the cracking device 3 by adjusting the opening degree of the control valve V2. In this case, the amount of hydrogen-rich gas generated in the cracking device 3 increases. Therefore, the amount of hydrogen supplied from the cracking device 3 to the burner 42 increases, and the combustion in the chamber C becomes stable. As a result, the amount of ammonia that can be burned also increases. Therefore, the ammonia in the exhaust gas decreases.

[0081] Referring to Figure 2 , alternatively or additionally, for example, the processor 90a can also adjust the operation of at least one of the plurality of combustion chambers 45. For example, the processor 90a can close the valves V3 and V4 of a part of the combustion chambers 45 in use to stop using that combustion chamber 45. That is, the fuel supplied to a part of the combustion chambers 45 in use is distributed to other combustion chambers 45 in use. In this case, the amount of hydrogen supplied to one combustion chamber 45 increases, and the combustion around the combustion chambers 45 in use becomes stable. As a result, the amount of ammonia that can be burned also increases. Therefore, the ammonia in the exhaust gas decreases.

[0082] Referring to Figure 6 , the processor 90a determines again whether the concentration of ammonia is less than the limit value (step S402).

[0083] In step S402, when the concentration of ammonia is less than the limit value (Yes), the processor 90a proceeds to Figure 3 step S106 (G) of

[0084] In step S402, when the concentration of ammonia is equal to or greater than the limit value (No), the processor 90a repeats Figure 6 the operation shown.

[0085] Referring to Figure 3, the processor 90a determines whether the concentration of NOx detected by the third sensor Se3 is less than a predetermined limit value (step S106). For example, the limit value of NOx can be determined based on regulations or stored in the storage device 90b.

[0086] In step S106, when the concentration of NOx is less than the limit value (Yes), the processor 90a ends a series of operations.

[0087] In step S106, when the concentration of NOx is equal to or greater than the limit value (No), the processor 90a proceeds to Figure 7 the operation (D) shown.

[0088] Referring to Figure 7 , the processor 90a adjusts at least one of the flow rate of the hydrogen-rich gas from the cracking device 3 to the burner 42 and the operation of the combustion chamber 45 (step S500).

[0089] Referring to Figure 1 , for example, the processor 90a can also increase the amount of ammonia supplied to the cracking device 3 by adjusting the opening degree of the control valve V2. In this case, the ratio of the ammonia decomposed in the cracking device 3 to the total ammonia from the tank 1 increases. In this case, more nitrogen atoms N of ammonia combine with nitrogen molecules N 2 in the section from the cracking device 3 to the burner 42 in an environment without oxygen atoms O or with few oxygen atoms O. The nitrogen molecules N 2 are stable and are less likely to combine with oxygen atoms O compared to the nitrogen atoms N in the ammonia molecules directly supplied to the burner 42. Therefore, the generation of NOx, especially fuel NOx, is suppressed.

[0090] Referring to Figure 2 , alternatively or additionally, for example, the processor 90a can also adjust the operation of at least one of the plurality of combustion chambers 45. For example, the processor 90a can open the valves V3 and V4 of the unused combustion chamber 45 among the plurality of combustion chambers 45 and start using this combustion chamber 45. That is, a part of the fuel supplied to the in-use combustion chamber 45 is distributed to the unused combustion chamber 45. In this case, the amount of fuel supplied to one combustion chamber 45 decreases, and the combustion temperature around the in-use combustion chamber 45 becomes lower. As a result, the generation of NOx, especially thermal NOx, around the in-use combustion chamber 45 is suppressed.

[0091] Referring to Figure 7 , the processor 90a determines again whether the concentration of NOx is less than the limit value (step S502).

[0092] In step S502, when the concentration of NOx is less than the limit value (Yes), the processor 90a ends a series of operations (H).

[0093] In step S502, when the concentration of NOx is above the limit value (No), the processor 90a repeats Figure 7 the actions shown.

[0094] The system 100 as described above includes: a tank 1 that stores ammonia; a cracking device 3 that is connected to the tank 1 and decomposes ammonia into hydrogen and nitrogen; a burner 42 that is fluidly connected to the tank 1 and the cracking device 3 and burns ammonia from the tank 1 and hydrogen-rich gas from the cracking device 3; a sensor Se that detects combustion abnormalities (flashback, combustion vibration, increase in NOx in the exhaust gas, and increase in ammonia in the exhaust gas) in the burner; and a control device 90 that is communicably connected to the sensor Se and adjusts the amount of hydrogen-rich gas from the cracking device 3 to the burner 42 based on the detection result of the sensor Se. With such a configuration, when a combustion abnormality is detected, based on the detection result of the sensor Se, the amount of hydrogen from the cracking device 3 to the burner 42 is adjusted to control the speed and size of combustion in the chamber C. Therefore, combustion abnormalities can be prevented. In addition, for example, as described above, in Patent Document 1, in order to remove NOx from the exhaust gas from the first combustion chamber, a second combustion chamber is provided. However, in the system 100, there is no need to provide an additional burner specifically for removing NOx. Therefore, with the configuration as described above, the system can be miniaturized.

[0095] In addition, in the system 100, the sensor Se includes a first sensor Se1 that is provided in the burner 42 and detects combustion vibration. With such a configuration, combustion vibration in the burner 42 can be prevented.

[0096] In addition, in the system 100, the sensor Se includes a second sensor Se2 that is provided in the burner 42 and detects the movement of the flame. With such a configuration, flashback in the burner 42 can be prevented.

[0097] In addition, in the system 100, the sensor Se includes a third sensor Se3 that detects NOx in the exhaust gas at a position downstream of the burner 42. With such a configuration, an increase in NOx in the exhaust gas can be prevented.

[0098] In addition, in the system 100, the sensor Se includes a fourth sensor Se4 that detects ammonia in the exhaust gas at a position downstream of the burner 42. With such a configuration, an increase in ammonia in the exhaust gas can be prevented.

[0099] In addition, in the system 100, the burner 42 includes a plurality of combustion chambers 45, and the control device 90 controls the actions of the plurality of combustion chambers 45 based on the detection result of the sensor Se. With such a configuration, the speed and size of combustion in the chamber C can be controlled in more detail. Therefore, combustion abnormalities can be further prevented.

[0100] Next, the systems of other embodiments will be described.

[0101] Figure 8 It is a flowchart showing the operation of the gas turbine system 100 of the second embodiment. The difference between the system 100 of the second embodiment and the system 100 of the first embodiment is that the processor 90a also executes steps S108, S110, and S112. Regarding other structures, the system 100 of the second embodiment may be the same as the system 100 of the first embodiment.

[0102] Figure 9 It is a schematic curve graph showing the relationship between the ammonia decomposition rate and various parameters. In Figure 9 , the horizontal axis represents the ratio of the ammonia decomposed in the cracking device 3 to the total ammonia from the tank 1. In addition, the amount of hydrogen supplied from the cracking device 3 to the burner 42 is proportional to the ammonia decomposition rate, so the horizontal axis also corresponds to the amount of hydrogen supplied from the cracking device 3 to the burner 42. The solid line represents the possibility of flashback. In addition, the possibility of flashback is low at low temperatures during normal operation, but when flashback occurs or when a flame moving upstream approaches, it is proportional to the temperature of the part that becomes high temperature, so the solid line also corresponds to the temperature of such a part. The dotted line represents the concentration of NOx and the concentration of ammonia in the exhaust gas. In addition, the operating cost of the denitration device is proportional to the concentration of ammonia in the exhaust gas, so the dotted line also corresponds to the operating cost of the denitration device. The dash-dotted line represents the energy required for the decomposition of ammonia in the cracking device 3. The decomposition of ammonia is an endothermic reaction, so energy is required. In addition, when obtaining energy from outside the system 100, the operating cost of the cracking device 3 is proportional to the amount of energy. Therefore, the dash-dotted line also corresponds to the operating cost of the cracking device 3.

[0103] As Figure 9 shown, in the region where the ammonia decomposition rate is low, the possibility of flashback is low and the operating cost of the cracking device 3 is also low. In contrast, in this region, the concentrations of NOx and ammonia are high, so the operating cost of the denitration device is also high. In the region where the ammonia decomposition rate is high, the possibility of flashback is high and the operating cost of the cracking device 3 is also high. In contrast, in this region, the concentrations of NOx and ammonia are low, so the operating cost of the denitration device is also low. For example, the control device 90 may also control the ammonia decomposition rate in such a way as to keep at least one cost parameter in the system 100 lower within the range where flashback does not occur. In addition, the parameters considered in the control device 90 are not limited to Figure 9 the parameters shown, and the control device 90 may also be configured to consider other parameters.

[0104] For example, in Figure 8 , the processor 90a is in Figures 3 to 7After the actions shown, the operating costs of the cracking device 3 and a denitration device (not shown) are calculated (step S108). As described above, for example, these operating costs can be calculated based on the decomposition rate of ammonia (or the amount of decomposed ammonia).

[0105] The processor 90a determines whether the total operating cost this time is less than or equal to the total operating cost last time (step S110). For example, the operating cost last time can also be stored in the storage device 90b.

[0106] In step S110, when the total operating cost this time is less than or equal to the total operating cost last time (yes), the processor 90a ends a series of actions.

[0107] In step S110, when the total operating cost this time is higher than the total operating cost last time (no), the processor 90a adjusts at least one of the flow rate of the hydrogen-rich gas from the cracking device 3 to the burner 42 and the operation of the combustion chamber 45 in such a way as to reduce the total operating cost (step S112), and ends a series of actions.

[0108] The system 100 of the second embodiment as described above has the same effects as the system 100 of the first embodiment. In particular, in the second embodiment, the operating cost of the system 100 can be considered.

[0109] As described above, the embodiments have been described with reference to the drawings, but the present disclosure is not limited to the above embodiments. It is obvious that those skilled in the art can conceive of various modification examples or correction examples within the scope described in the claims, and it is understood that they also belong to the technical scope of the present disclosure.

[0110] For example, in the above embodiment, the gas turbine system 100 functions as a combustion system. In other embodiments, the combustion system can also be applied to other systems that use ammonia as a fuel. For example, the combustion system can also be applied to a steam turbine system. In this case, the steam turbine system can include a boiler that burns ammonia and a steam turbine that operates by steam generated by the boiler. In this case, the combustion system includes a burner of the boiler instead of the burner 42 of the gas turbine 4 described above.

[0111] Since the present disclosure can promote the use of ammonia to reduce CO 2 emissions, the present disclosure can contribute to, for example, Goal 7 of the Sustainable Development Goals (SDGs), "Ensure access to affordable, reliable, sustainable and modern energy".

[0112] Explanation of reference numerals

[0113] 1 tank (ammonia supply source)

[0114] 3 cracking device

[0115] 42 Burner

[0116] 45 Combustion Chamber

[0117] 90 Control Device

[0118] 100 Gas Turbine System (Combustion System)

[0119] Se Sensor

[0120] Se1 First Sensor

[0121] Se2 Second Sensor

[0122] Se3 Third Sensor

[0123] Se4 Fourth Sensor.

Claims

1. A combustion system, characterized in that, the combustion system comprises: an ammonia supply source; a cracking device connected to the ammonia supply source for decomposing ammonia into hydrogen and nitrogen; a burner connected to the ammonia supply source and the cracking device for burning ammonia from the ammonia supply source and a hydrogen-containing gas from the cracking device; a sensor for detecting combustion abnormalities in the burner; and a control device communicably connected to the sensor for adjusting the amount of the gas supplied from the cracking device to the burner based on the detection result of the sensor.

2. The combustion system according to claim 1, characterized in that, the sensor includes a first sensor disposed in the burner for detecting combustion vibration.

3. The combustion system according to claim 1 or 2, characterized in that, the sensor includes a second sensor disposed in the burner for detecting the movement of the flame.

4. The combustion system according to claim 1 or 2, characterized in that, the sensor includes a third sensor for detecting NOx in the exhaust gas at a position downstream of the burner.

5. The combustion system according to claim 3, characterized in that, the sensor includes a third sensor for detecting NOx in the exhaust gas at a position downstream of the burner.

6. The combustion system according to claim 1 or 2, characterized in that, the sensor includes a fourth sensor for detecting ammonia in the exhaust gas at a position downstream of the burner.

7. The combustion system according to claim 3, characterized in that, the sensor includes a fourth sensor for detecting ammonia in the exhaust gas at a position downstream of the burner.

8. The combustion system according to claim 4, characterized in that, the sensor includes a fourth sensor for detecting ammonia in the exhaust gas at a position downstream of the burner.

9. The combustion system according to claim 5, characterized in that, the sensor includes a fourth sensor for detecting ammonia in the exhaust gas at a position downstream of the burner.

10. The combustion system according to claim 1 or 2, characterized in that, the burner includes a plurality of combustion chambers, and the control device controls the operation of the plurality of combustion chambers based on the detection result of the sensor.

11. The combustion system according to claim 3, characterized in that, the burner includes a plurality of combustion chambers, and the control device controls the operation of the plurality of combustion chambers based on the detection result of the sensor.

12. The combustion system according to claim 4, characterized in that, the burner includes a plurality of combustion chambers, and the control device controls the operation of the plurality of combustion chambers based on the detection result of the sensor.

13. The combustion system according to claim 5, characterized in that, the burner includes a plurality of combustion chambers, and the control device controls the operation of the plurality of combustion chambers based on the detection result of the sensor.

14. The combustion system according to claim 6, characterized in that, the burner includes a plurality of combustion chambers, The control device controls the operations of the plurality of burner chambers based on the detection results of the sensor.

15. The combustion system according to claim 7, wherein, the burner includes a plurality of burner chambers, and the control device controls the operations of the plurality of burner chambers based on the detection results of the sensor.

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