Hydrogen combustion system and method for purging hydrogen in the furnace of the combustor

Abstract

The present invention provides a hydrogen combustion system and a furnace hydrogen purging method that can inexpensively purge residual hydrogen in the furnace of a combustor in the event of an abnormal shutdown of the combustor. [Solution] The hydrogen combustion system comprises a first air supply pipe and a first exhaust pipe connected to a first combustor, a second air supply pipe and a second exhaust pipe connected to a second combustor, a first bypass pipe connecting the first air supply pipe and the second exhaust pipe, a second bypass pipe connecting the second air supply pipe and the first exhaust pipe, a first switch for switching to connect either a first air supply path between the air intake port of the first combustor and the first air supply source or a first bypass path between the air intake port of the first combustor and the second exhaust pipe, and a second switch for switching to connect either a second air supply path between the air intake port of the second combustor and the second air supply source or a second bypass path between the air intake port of the second combustor and the first exhaust pipe.

Description

Technical Field

[0001] The present disclosure relates to a hydrogen combustion system and a method for purging hydrogen in a furnace of a combustor thereof.

Background Art

[0002] In recent years, in order to reduce carbon dioxide emissions, attention has been paid to using hydrogen as a fuel for combustors such as boilers and industrial furnaces. Hydrogen is a fuel with low environmental impact that does not emit carbon dioxide upon combustion. On the other hand, hydrogen has a wide flammable range compared to other gas fuels, making it easy to ignite, and a small specific gravity, making it easy to diffuse. Therefore, when the combustor stops abnormally, it is not desirable for unburned hydrogen to remain in the furnace of the combustor.

[0003] Regarding purging hydrogen in the furnace of a combustor, Patent Document 1 below discloses a configuration in which a purge line for supplying an inert gas to a burner through a hydrogen supply line is connected downstream of a shut-off valve that opens and closes a flow path in a hydrogen supply line for supplying hydrogen gas to a burner of a boiler. According to this configuration, when the boiler stops, the supply of hydrogen gas is shut off by the shut-off valve, and then hydrogen purging in the furnace of the boiler can be performed by supplying an inert gas from the purge line to the burner.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the configuration of Patent Document 1 above, in preparation for an abnormal stop of the combustor, an inert gas for purging is constantly stored, resulting in high equipment costs. In addition, costs for equipment to generate the inert gas or costs for purchasing the inert gas also occur.

[0006] This disclosure has been made in view of the above-mentioned problems, and aims to provide a hydrogen combustion system that can purge residual hydrogen in the furnace of a combustor at low cost when the combustor malfunctions, and a method for purging hydrogen in the furnace of the combustor. [Means for solving the problem]

[0007] A hydrogen combustion system according to one aspect of the present disclosure is a hydrogen combustion system comprising two or more combustors for burning a hydrogen-containing fuel, wherein the two or more combustors include a first combustor and a second combustor, and the hydrogen combustion system comprises: a first air intake pipe connected to the air intake port of the first combustor and supplying air from a first air source to the first combustor; a first exhaust pipe connected to the exhaust port of the first combustor; a second air intake pipe connected to the air intake port of the second combustor and supplying air from a second air source to the second combustor; a second exhaust pipe connected to the exhaust port of the second combustor; and the first air intake pipe The system includes a first bypass pipe connecting the first combustion chamber to the second exhaust pipe, a second bypass pipe connecting the second supply pipe to the first exhaust pipe, a first switch for switching to connect either the first supply route between the intake port of the first combustion chamber and the first supply source, or the first bypass route between the intake port of the first combustion chamber and the second exhaust pipe, and a second switch for switching to connect either the second supply route between the intake port of the second combustion chamber and the second supply source, or the second bypass route between the intake port of the second combustion chamber and the first exhaust pipe.

[0008] A furnace hydrogen purging method according to another aspect of the present disclosure is a furnace hydrogen purging method in a combustor of a hydrogen combustion system comprising two or more combustors for burning a hydrogen-containing fuel, wherein the two or more combustors include a first combustor supplied with air from a first air supply source and a second combustor supplied with air from a second air supply source, and the furnace hydrogen purging method, in the event of an abnormal shutdown of the first combustor, purges the hydrogen in the furnace of the first combustor with the exhaust from the second combustor by supplying air from the second air supply source to the air intake port of the second combustor and supplying exhaust from the second combustor to the air intake port of the first combustor, and in the event of an abnormal shutdown of the second combustor, purges the hydrogen in the furnace of the second combustor with the exhaust from the first combustor by supplying air from the first air supply source to the air intake port of the first combustor and supplying exhaust from the first combustor to the air intake port of the second combustor. [Effects of the Invention]

[0009] According to this disclosure, residual hydrogen in the furnace of a combustor can be purged inexpensively when the combustor malfunctions. [Brief explanation of the drawing]

[0010] [Figure 1] Figure 1 is a diagram showing the schematic configuration of a hydrogen combustion system according to Embodiment 1 of this disclosure. [Figure 2] Figure 2 shows the state of the hydrogen combustion system shown in Figure 1 when the first combustor malfunctions and shuts down. [Figure 3] Figure 3 shows the state of the hydrogen combustion system shown in Figure 1 when the second combustor malfunctions and shuts down. [Figure 4] Figure 4 is a diagram showing the schematic configuration of a hydrogen combustion system according to Embodiment 2 of this disclosure. [Modes for carrying out the invention]

[0011] The embodiments of this disclosure will be described in detail below with reference to the drawings. In the following description, the same or corresponding elements are denoted by the same reference numerals in all the drawings, and redundant explanations are omitted.

[0012] [Embodiment 1] Figure 1 is a diagram showing a schematic configuration of a hydrogen combustion system according to Embodiment 1 of the present disclosure. The hydrogen combustion system 1A in this embodiment comprises a plurality of combustors. In the example of Figure 1, the plurality of combustors include two combustors, a first combustor 21 and a second combustor 22. These combustors 21 and 22 burn hydrogen as fuel gas. In the following description, the combustors 21 and 22 are exemplified as boilers that generate steam.

[0013] Furthermore, the hydrogen combustion system 1A includes a first air supply pipe 31 and a first exhaust pipe 41. The first air supply pipe 31 is connected to the air intake port 21a of the first combustor 21 and supplies air from the first air supply source 51 to the first combustor 21. The first exhaust pipe 41 is connected to the exhaust port 21b of the first combustor 21. The first air supply source 51 includes, for example, a forced-air fan.

[0014] The first combustor 21 includes a burner 61 and a combustion furnace 71. The air inlet 21a of the first combustor 21 is located at the burner 61. The burner 61 is supplied with hydrogen from a first hydrogen supply source 81 and with air from a first air supply source 51 through a first air supply pipe 31. The burner 61 mixes the hydrogen and the air supply and burns the hydrogen in the combustion furnace 71. The exhaust port 21b of the first combustor 21 is located at the combustion furnace 71 and discharges the exhaust gas after combustion in the combustion furnace 71.

[0015] The hydrogen combustion system 1A includes a first economizer 91 and a first gas air heater 101. The first economizer 91 preheats the water supplied to the first combustor 21 using exhaust gas flowing through the first exhaust pipe 41. The first preheater 101 preheats the air supplied from the first air supply source 51 to the first combustor 21 using exhaust gas flowing through the first exhaust pipe 41. The first preheater 101 is located downstream of the first economizer 91 in the first exhaust pipe 41.

[0016] The hydrogen combustion system 1A also has a configuration similar to that of the first combustor 21 and its surroundings with respect to the second combustor 22. That is, the hydrogen combustion system 1A is equipped with a second air supply pipe 32 and a second exhaust pipe 42. The second air supply pipe 32 is connected to the air intake port 22a of the second combustor 22 and supplies air from the second air supply source 52 to the second combustor 22. The second exhaust pipe 42 is connected to the exhaust port 22b of the second combustor 22. The second air supply source 52 includes, for example, a forced-air blower.

[0017] The second combustor 22 includes a burner 62 and a combustion furnace 72. The air inlet 22a of the second combustor 22 is located on the burner 62. The burner 62 is supplied with hydrogen from a second hydrogen supply source 82 and with air from a second air supply source 52 through a second air supply pipe 32. The burner 62 mixes the hydrogen and the air supply and burns the hydrogen in the combustion furnace 72. The exhaust port 22b of the second combustor 22 is located on the combustion furnace 72 and discharges the exhaust gas after combustion in the combustion furnace 72.

[0018] The hydrogen combustion system 1A includes a second economizer 92 and a second gas air heater 102. The second economizer 92 preheats the water supplied to the second combustor 22 using exhaust gas flowing through the second exhaust pipe 42. The second preheater 102 preheats the air supplied from the second air supply source 52 to the second combustor 22 using exhaust gas flowing through the second exhaust pipe 42. The second preheater 102 is located downstream of the second economizer 92 in the second exhaust pipe 42.

[0019] In addition, in FIG. 1, the carbon-saving devices 91 and 92 are abbreviated as ECO, and the preheaters 101 and 102 are abbreviated as GAH. Also, the hydrogen supply sources 81 and 82 may be a common hydrogen supply source. Further, a plurality of burners 61 and 62 may be installed for one combustion furnace 71 and 72.

[0020] Furthermore, the hydrogen combustion system 1A includes a first bypass pipe 111 and a second bypass pipe 112. The first bypass pipe 111 connects the first air supply pipe 31 and the second exhaust pipe 42. The second bypass pipe 112 connects the second air supply pipe 32 and the first exhaust pipe 41. In the present embodiment, the first bypass pipe 111 is connected upstream of the second preheater 102 and downstream of the second carbon-saving device 92 in the second exhaust pipe 42. Similarly, the second bypass pipe 112 is connected upstream of the first preheater 101 and downstream of the first carbon-saving device 91 in the first exhaust pipe 41.

[0021] Also, the hydrogen combustion system 1A includes a first switch 121 and a second switch 122. The first switch 121 switches to connect either one of the first air supply path Ri1 between the air supply port 21a of the first combustor 21 and the first air supply source 51 or the first bypass path Rb1 between the air supply port 21a of the first combustor 21 and the second exhaust pipe 42. The second switch 122 switches to connect either one of the second air supply path Ri2 between the air supply port 22a of the second combustor 22 and the second air supply source 52 or the second bypass path Rb2 between the air supply port 22a of the second combustor 22 and the first exhaust pipe 41.

[0022] In the present embodiment, the first switch 121 includes a first air supply damper 131 and first bypass dampers 141 and 151. The first air supply damper 131 switches the flow or blockage between the first air supply source 51 and the first air supply pipe 31. The first bypass dampers 141 and 151 switch the flow or blockage in the first bypass pipe 111. The first bypass damper includes an inlet-side damper 141 disposed at a position close to the second exhaust pipe 42 of the first bypass pipe 111, and an outlet-side damper 151 disposed at a position close to the first air supply pipe 31 of the first bypass pipe 111. As will be described later, in the first bypass pipe 111, the exhaust gas of the second combustor 22 flows from the second exhaust pipe 42 toward the first air supply pipe 31. Therefore, the outlet-side damper 151 is disposed on the downstream side in the exhaust gas flow direction from the inlet-side damper 141.

[0023] Similarly, the second switch 122 includes a second air supply damper 132 and second bypass dampers 142 and 152. The second air supply damper 132 switches the flow or blockage between the second air supply source 52 and the second air supply pipe 32. The second bypass dampers 142 and 152 switch the flow or blockage in the second bypass pipe 112. The second bypass damper includes an inlet-side damper 142 disposed at a position close to the first exhaust pipe 41 of the second bypass pipe 112, and an outlet-side damper 152 disposed at a position close to the second air supply pipe 32 of the second bypass pipe 112. As will be described later, in the second bypass pipe 112, the exhaust gas of the first combustor 21 flows from the first exhaust pipe 41 toward the second air supply pipe 32. Therefore, the outlet-side damper 152 is disposed on the downstream side in the exhaust gas flow direction from the inlet-side damper 142.

[0024] A first induced draft fan 161 is installed in the first bypass piping 111. The first induced draft fan 161 facilitates the flow of exhaust air from the second exhaust piping 42 to the first supply air piping 31 in the first bypass piping 111. The first induced draft fan 161 is positioned between the inlet damper 141 and the outlet damper 151 of the first bypass damper in the first bypass piping 111. Similarly, a second induced draft fan 162 is installed in the second bypass piping 112. The second induced draft fan 162 facilitates the flow of exhaust air from the first exhaust piping 41 to the second supply air piping 32 in the second bypass piping 112. The second induced draft fan 162 is positioned between the inlet damper 142 and the outlet damper 152 of the second bypass damper in the second bypass piping 112.

[0025] The hydrogen combustion system 1A includes a first pressure detector 171 for detecting the outlet pressure P1 of the first bypass pipe 111 and a second pressure detector 172 for detecting the outlet pressure P2 of the second bypass pipe 112. The pressure detectors 171 and 172 are positioned downstream of the induced fans 161 and 162 and upstream of the outlet dampers 151 and 152 in the corresponding bypass pipes 111 and 112.

[0026] The first supply pipe 31, the second supply pipe 32, the first exhaust pipe 41, the second exhaust pipe 42, the first bypass pipe 111, and the second bypass pipe 112 may each be configured as a single pipe, or they may be configured by connecting multiple pipes. In addition, devices other than those exemplified in this disclosure, such as flow control valves, shut-off valves, and flow detectors, may be placed in the middle of these pipes.

[0027] Furthermore, exhaust dampers 181 and 182 are positioned in the exhaust pipes 41 and 42. The first exhaust damper 181 is positioned downstream of the connection point of the second bypass pipe 112 in the first exhaust pipe 41 and upstream of the first preheater 101. The first exhaust damper 181 adjusts the flow rate of exhaust from the first combustor 21. Similarly, the second exhaust damper 182 is positioned downstream of the connection point of the first bypass pipe 111 in the second exhaust pipe 42 and upstream of the second preheater 102. The second exhaust damper 182 adjusts the flow rate of exhaust from the second combustor 22. In addition, the exhaust dampers 181 and 182 also function as switches that switch the flow or blockage of exhaust downstream of the bypass pipe connection point of the corresponding exhaust pipes 41 and 42.

[0028] The hydrogen combustion system 1A includes a controller 19. The controller 19 includes a processing circuit 20 that performs various signal processing. The processing circuit 20 includes a computer such as a microcontroller, personal computer, or PLC (Programmable Logic Controller). More specifically, the processing circuit 20 includes a processor, memory, and peripheral circuits. The processor includes, for example, a CPU or MPU. The memory includes ROM, RAM, registers, non-volatile storage, etc. The peripheral circuits include input / output interfaces, etc. Furthermore, the controller 19 may include an input device for user operation input and an output device such as a monitor that outputs the control status.

[0029] The functions of the elements disclosed herein can be performed using circuits or processing circuits, including general-purpose processors, dedicated processors, integrated circuits, ASICs (Application Specific Integrated Circuits), conventional circuits, and / or combinations thereof, configured or programmed to perform the disclosed functions. A processor is considered a processing circuit or circuit because it includes transistors and other circuits. In this specification, a circuit, unit, means, or part is hardware that performs the enumerated functions, or hardware programmed to perform the enumerated functions. The hardware may be hardware disclosed herein, or other known hardware that is programmed or configured to perform the enumerated functions. If the hardware is a processor, which is considered a type of circuit, the circuit, unit, or control means is a combination of hardware and software, and the software is used to configure the hardware and / or the processor.

[0030] The memory stores the control program. The processing circuit 20 reads the control program from the memory and generates a control signal to control the controlled object based on the control program. In this embodiment, the controlled object of the controller 19 includes the first supply air damper 131 and the first bypass dampers 141, 151 constituting the first switch 121, the second supply air damper 132 and the second bypass dampers 142, 152 constituting the second switch 122, the first exhaust damper 181 and the second exhaust damper 182, and the first induced draft fan 161 and the second induced draft fan 162.

[0031] In Figure 1, the control signal for the first intake damper 131 is denoted as Ci1, the control signal for the first exhaust damper 181 is denoted as Ce1, the control signals for the first bypass dampers 141 and 151 are denoted as Cb1, the control signal for the second intake damper 132 is denoted as Ci2, the control signal for the second exhaust damper 182 is denoted as Ce2, and the control signals for the second bypass dampers 142 and 152 are denoted as Cb2.

[0032] The controller 19 acquires the outlet pressures P1 and P2 of the bypass pipes 111 and 112 detected by the pressure detectors 171 and 172 in order to control the exhaust dampers 181 and 182. It also receives abnormal stop signals E1 and E2 sent from the abnormally stopped combustors 21 and 22 if the combustors 21 and 22 have abnormally stopped.

[0033] For example, combustors 21 and 22 may abnormally shut down if a flame detector detects the flame in the corresponding combustion furnace 71 and 72 and determines that the flame has disappeared despite the unit being in operation. Additionally, combustors 21 and 22 may abnormally shut down if any of the following are determined to be outside the appropriate range: the furnace pressure detected by a pressure detector that detects the pressure inside the combustion furnace 71 and 72, the furnace temperature detected by a temperature detector that detects the temperature inside the combustion furnace 71 and 72, or the exhaust temperature detected by an exhaust temperature detector installed in the exhaust pipes 41 and 42. Furthermore, combustors 21 and 22 may abnormally shut down if either the supply temperature or supply pressure of the hydrogen fuel supplied to the combustors 21 and 22 is determined to be outside the appropriate range.

[0034] Furthermore, the combustors 21 and 22 may also malfunction due to a malfunction of the air supply sources 51 and 52. For example, the drive current to the air supply sources 51 and 52 is detected, and if the drive current exceeds a threshold, it is detected that the air supply sources 51 and 52 are in a malfunction state. Alternatively, the air supply sources 51 and 52 may be detected as malfunctioning if they output an error signal indicating that the inverter driving the air supply sources 51 and 52 has tripped. Alternatively, the outlet pressure of the air supply sources 51 and 52 is detected, and if the outlet pressure is outside the appropriate range, it is detected that the air supply sources 51 and 52 are in a malfunction state.

[0035] Based on the abnormal shutdown of the air supply sources 51 and 52, abnormal shutdown signals E1 and E2 are generated. For example, abnormal shutdown signals E1 and E2 are transmitted from the controllers that control the combustors 21 and 22. The controller 19 may also receive the detection signals themselves from each of the exemplified detectors as abnormal shutdown signals E1 and E2.

[0036] During normal operation, i.e., when the first combustor 21 and the second combustor 22 are operating, the controller 19 controls the first switch 121 to connect the first air supply path Ri1 and the second switch 122 to connect the second air supply path Ri2. As a result, as shown in Figure 1, the first air supply damper 131 and the second air supply damper 132 are in the open state, and the first bypass dampers 141, 151 and the second bypass dampers 142, 152 are in the closed state. In Figure 1, a damper with a flap inside facing in the direction along the piping in which the damper is located is an open damper, and a damper with a flap facing in a direction perpendicular to the piping is a closed damper.

[0037] As a result, the first air supply path Ri1 between the air intake port 21a of the first combustor 21 and the first air supply source 51, and the second air supply path Ri2 between the air intake port 22a of the second combustor 22 and the second air supply source 52 are connected. In addition, the controller 19 opens the first exhaust damper 181 and the second exhaust damper 182 during normal operation.

[0038] In this embodiment, if the first combustor 21 malfunctions during the operation of multiple combustors 21 and 22, the supply air from the second air supply source 52 is supplied to the air inlet 22a of the second combustor 22, and the exhaust gas from the second combustor 22 is supplied to the air inlet 21a of the first combustor 21, thereby purging the hydrogen in the furnace of the first combustor 21 with the exhaust gas from the second combustor 22. Similarly, if the second combustor 22 malfunctions during the operation of multiple combustors 21 and 22, the supply air from the first air supply source 51 is supplied to the air inlet 21a of the first combustor 21, and the exhaust gas from the first combustor 21 is supplied to the air inlet 22a of the second combustor 22, thereby purging the hydrogen in the furnace of the second combustor 22 with the exhaust gas from the first combustor 21.

[0039] The following is an example of what happens when the first combustor 21 malfunctions. Figure 2 shows the state of the hydrogen combustion system shown in Figure 1 when the first combustor malfunctions. In Figure 2, the only difference from Figure 1 is the open / closed state of each damper. The configuration of the hydrogen combustion system shown in Figure 2 is the same as the hydrogen combustion system 1A shown in Figure 1, except for the open / closed state of each damper, but in Figure 2, it is denoted as 1B.

[0040] If the first combustor 21 malfunctions, the supply of hydrogen from the first hydrogen source 81 to the burner 61 is stopped based on the control command for the first combustor 21. However, there is a time lag between the extinguishing of the flame due to a malfunction in the combustion furnace 71 and the actual cessation of the hydrogen supply, so there is a risk that unburned hydrogen will remain in the combustion furnace 71. For this reason, residual hydrogen is purged in the combustion furnace 71 in order to restart the operation of the malfunctioning first combustor 21.

[0041] In this embodiment, when the controller 19 receives a first abnormal stop signal E1 based on an abnormal stop of the first combustor 21, it controls the first switch 121 to connect the first bypass path Rb1 and the second switch 122 to connect the second supply air path Ri2. More specifically, as a control signal for the first switch 121, the controller 19 transmits a control signal Ci1 to the first supply air damper 131 to close it and a control signal Cb1 to open the first bypass dampers 141 and 151. The controller 19 also transmits a control signal to the first induced draft fan 161 to start operation.

[0042] The controller 19 transmits control signals Ci2 and Cb2 to the corresponding dampers 132, 142, and 152 as control signals for the second switch 122, which maintain the operating state of the second combustor 22. That is, the controller 19 maintains the control of the second air supply damper 132 as is, and transmits a control signal Cb2 to close the second bypass dampers 142 and 152. For example, if the control signal for switching the connection mode of the second switch 122 is a predetermined pulse signal, and the input of the pulse signal causes the connection mode of the second switch 122 to switch from one state to the other, the controller 19 does not need to transmit a control signal to the second switch 122.

[0043] With this control, the operation of the second combustor 22, which has not abnormally stopped, continues, and the air from the second air supply source 52 is supplied to the second combustor 22, and hydrogen is burned in the combustion furnace 72. The exhaust gas discharged from the combustion furnace 72 flows through the first bypass path Rb1, which passes through the first bypass pipe 111, and is introduced into the combustion furnace 71 from the air supply port 21a of the first combustor 21. At this time, the first induced draft fan 161 located in the first bypass pipe 111 facilitates the introduction of the exhaust gas from the second exhaust pipe 42 into the first air supply pipe 31 via the first bypass pipe 111. The exhaust gas discharged from the second combustor 22 has a reduced residual oxygen concentration due to combustion. For example, the residual oxygen concentration in the exhaust gas is about 2%, making it usable as an inert gas for hydrogen purging.

[0044] This exhaust is introduced into the combustion furnace 71 of the abnormally shut-down first combustor 21. As a result, unburned hydrogen in the combustion furnace 71 is purged and discharged through the first exhaust pipe 41.

[0045] The controller 19 controls the opening of the second exhaust damper 182 so that the pressure detected by the first pressure detector 171 becomes a predetermined first target pressure when the first bypass path Rb1 is connected. Depending on the capacity of the first combustor 21, such as the capacity of the combustion furnace 71 in the first combustor 21 or the supply pressure from the first hydrogen supply source 81, the appropriate exhaust supply pressure or flow rate for performing in-furnace hydrogen purging may vary. Therefore, by controlling the second exhaust damper 182 so that the outlet pressure P1 of the first bypass piping 111 becomes a predetermined first target pressure, exhaust gas at an appropriate supply pressure or flow rate can be supplied to the first combustor 21 as purge gas. Of the exhaust discharged from the second combustor 22, the remaining exhaust that was not introduced into the first bypass piping 111 passes through the second exhaust damper 182 and is discharged through the second exhaust piping 42 as in normal operation.

[0046] The same applies if the second combustor 22 malfunctions. Figure 3 shows the state when the second combustor malfunctions in the hydrogen combustion system shown in Figure 1. The configuration of the hydrogen combustion system shown in Figure 3 is the same as the hydrogen combustion system 1A shown in Figure 1 except for the open / closed state of each damper, but in Figure 3 it is denoted as 1C. When the second combustor 22 malfunctions, the supply of hydrogen from the second hydrogen supply source 82 to the burner 62 is stopped based on the control command of the second combustor 22.

[0047] When controller 19 receives a second abnormal stop signal E2 based on an abnormal stop of the second combustor 22, it controls the first switch 121 to connect the first supply air path Ri1 and the second switch 122 to connect the second bypass path Rb2. More specifically, as a control signal for the second switch 122, controller 19 transmits a control signal Ci2 to the second supply air damper 132 to close it and a control signal Cb2 to open the second bypass dampers 142 and 152. Controller 19 also transmits a control signal to the second induced draft fan 162 to start its operation.

[0048] The controller 19 transmits control signals Ci1 and Cb1 to the corresponding dampers 131, 141, and 151 as control signals for the first switch 121, in order to maintain the operating state of the first combustor 21. Specifically, the controller 19 transmits a control signal Ci1 to the first air intake damper 131 to open it, and also transmits a control signal Cb1 to close the first bypass dampers 141 and 151.

[0049] With this control, the operation of the first combustor 21, which has not malfunctioned, continues, and the air from the first air supply source 51 is supplied to the first combustor 21, and hydrogen is burned in the combustion furnace 71. The exhaust gas discharged from the combustion furnace 71 flows through the second bypass path Rb2, which passes through the second bypass pipe 112, and is introduced into the combustion furnace 72 from the air supply port 22a of the second combustor 22. At this time, the second induced draft fan 162 located in the second bypass pipe 112 facilitates the introduction of the exhaust gas from the first exhaust pipe 41 into the second air supply pipe 32 via the second bypass pipe 112. When this exhaust gas is introduced into the combustion furnace 72 of the malfunctioning second combustor 22, the unburned hydrogen in the combustion furnace 72 is purged and discharged through the second exhaust pipe 42.

[0050] When the second bypass path Rb2 is connected, the controller 19 controls the opening of the first exhaust damper 181 so that the pressure detected by the second pressure detector 172 becomes a predetermined second target pressure. By controlling the first exhaust damper 181 so that the outlet pressure P2 of the second bypass piping 112 becomes a predetermined second target pressure, exhaust gas at an appropriate supply pressure or flow rate can be supplied to the second combustor 22 as purge gas. Of the exhaust gas discharged from the first combustor 21, the remaining exhaust gas that was not introduced into the second bypass piping 112 passes through the first exhaust damper 181 and is discharged through the second exhaust piping 42 as in normal operation.

[0051] As described above, with the above configuration, the first bypass pipe 111 connecting the first supply pipe 31 and the second exhaust pipe 42 allows the second supply path Ri2 between the supply port 22a of the second combustor 22 (which is not experiencing any abnormalities) and the second supply source 52 to be connected when the first combustor 21 is stopped abnormally, and the first bypass path Rb1 between the supply port 21a of the first combustor 21 and the second exhaust pipe 42 to be connected. This allows the supply air from the second supply source 52 to be supplied to the supply port 22a of the second combustor 22, and the exhaust from the second combustor 22 to be supplied to the supply port 21a of the first combustor 21, thereby purging the hydrogen in the furnace of the first combustor 21 with the exhaust from the second combustor 22.

[0052] Similarly, the second bypass pipe 112 connecting the second air supply pipe 32 and the first exhaust pipe 41 allows for the supply of air from the first air source 51 to the air inlet 21a of the first combustor 21 and the exhaust from the first combustor 21 to the air inlet 22a of the second combustor 22 during an abnormal shutdown of the second combustor 22. This allows for the purging of hydrogen in the furnace of the second combustor 22 with the exhaust from the first combustor 21. Therefore, in the event of an abnormal shutdown of some of the combustors of multiple combustors, residual hydrogen in the furnace of the abnormally shut-down combustor can be purged using the exhaust from combustion in the other combustors that are not abnormally shut down. As a result, it is not necessary to prepare an inert gas separately for hydrogen purging, thus preventing an increase in equipment costs due to the installation of an inert gas storage facility and an increase in running costs due to storing inert gas in a storage facility. Thus, hydrogen purging in the furnaces of combustors 21 and 22 can be performed inexpensively during abnormal shutdowns of the combustors 21 and 22.

[0053] Furthermore, according to this embodiment, the switching of the supply and exhaust air flow paths can be appropriately performed by the controller 19 during operation of the first combustor 21 and the second combustor 22, during abnormal shutdown of the first combustor 21, and during abnormal shutdown of the second combustor 22.

[0054] Furthermore, according to this embodiment, when the first bypass path Rb1 is connected, the opening degree of the second exhaust damper 182 is controlled so that the outlet pressure P1 of the first bypass pipe 111 becomes a predetermined first target pressure. Therefore, in the event of an abnormal shutdown of the first combustor 21, an appropriate amount of exhaust gas can be supplied to the first combustor 21 in order to perform hydrogen purging in the furnace of the first combustor 21. Similarly, when the second bypass path Rb2 is connected, the opening degree of the first exhaust damper 181 is controlled so that the outlet pressure P2 of the second bypass pipe 112 becomes a predetermined second target pressure. Therefore, in the event of an abnormal shutdown of the second combustor 22, an appropriate amount of exhaust gas can be supplied to the second combustor 22 in order to perform hydrogen purging in the furnace of the second combustor 22.

[0055] Note that the first target pressure and the second target pressure may be the same value or different values. For example, if the first combustor 21 and the second combustor 22 have the same capacity, the first target pressure and the second target pressure may be the same value.

[0056] Furthermore, according to this embodiment, the first bypass pipe 111 is connected upstream of the second preheater 102 in the second exhaust pipe 42, and the second bypass pipe 112 is connected upstream of the first preheater 101 in the first exhaust pipe 41. When preheating the supply air in the preheaters 101 and 102, if the supply air leaks into the preheaters 101 and 102, there is a risk that the oxygen concentration in the exhaust will increase in the exhaust pipes 41 and 42 thereafter. Therefore, by connecting the first bypass pipe 111 upstream of the second preheater 102 in the second exhaust pipe 42, and connecting the second bypass pipe 112 upstream of the first preheater 101 in the first exhaust pipe 41, it is possible to prevent exhaust with increased oxygen concentration from being introduced into the combustors 21 and 22 that should be used as a purge gas for hydrogen purging. This allows exhaust with a low oxygen concentration to be appropriately introduced into the combustors 21 and 22 that should be used as a purge gas for hydrogen purging.

[0057] Furthermore, according to this embodiment, the first bypass pipe 111 is connected downstream of the second emulator 92 of the second exhaust pipe 42, and the second bypass pipe 112 is connected downstream of the first emulator 91 of the first exhaust pipe 41. Hydrogen purging can be carried out more safely when the temperature of the purge gas used is lower. As described above, the emulators 91 and 92 preheat the water supplied to the combustors 21 and 22. That is, heat exchange occurs between the exhaust gas from the exhaust pipes 41 and 42 and the water in the emulators 91 and 92, so that the exhaust gas flowing downstream of the emulators 91 and 92 of the exhaust pipes 41 and 42 is at a lower temperature. Therefore, by connecting the first bypass pipe 111 downstream of the second emulator 92 of the second exhaust pipe 42, and connecting the second bypass pipe 112 downstream of the first emulator 91 of the first exhaust pipe 41, hydrogen purging can be carried out more safely in the combustors 21 and 22 where hydrogen purging is to be performed.

[0058] [Embodiment 2] Figure 4 is a diagram showing the schematic configuration of a hydrogen combustion system according to Embodiment 2 of this disclosure. In the hydrogen combustion system 2 shown in Figure 4, components similar to those in the hydrogen combustion system 1A shown in Figure 1 are denoted by the same reference numerals, and their descriptions are omitted.

[0059] The difference between the hydrogen combustion system 2 in this embodiment and the hydrogen combustion systems 1A to 1C shown in Figures 1 to 3 is that some of the piping in the first bypass piping 211 and the second bypass piping 212 includes common piping. More specifically, the first bypass piping 211 and the second bypass piping 212 include a common intermediate piping 110, the first bypass upstream piping 111a, the first bypass downstream piping 111b, the second bypass upstream piping 112a, and the second bypass downstream piping 112b.

[0060] The first bypass upstream piping 111a connects the second exhaust piping 42 and the intermediate piping 110. The first bypass downstream piping 111b connects the intermediate piping 110 and the first supply air piping 31. The second bypass upstream piping 112a connects the first exhaust piping 41 and the intermediate piping 110. The second bypass downstream piping 112b connects the intermediate piping 110 and the second supply air piping 32. In other words, the first bypass piping 211 includes, in order from upstream, the first bypass upstream piping 111a, the intermediate piping 110, and the first bypass downstream piping 111b. The second bypass piping 212 includes, in order from upstream, the second bypass upstream piping 112a, the intermediate piping 110, and the second bypass downstream piping 112b.

[0061] The inlet damper 141 of the first bypass damper is located in the upstream piping 111a of the first bypass, and the outlet damper 151 is located in the downstream piping 111b of the first bypass. The inlet damper 142 of the second bypass damper is located in the upstream piping 112a of the second bypass, and the outlet damper 152 is located in the downstream piping 112b of the second bypass. In this embodiment, the induced draft fan 160 is located in the intermediate piping 110.

[0062] Figure 4, similar to Figure 2, shows the state in which the first combustor 21 has abnormally stopped. When the controller 19 receives the first abnormal stop signal E1 based on the abnormal stop of the first combustor 21, it controls the first switch 121 to connect the first bypass path Rb1 and the second switch 122 to connect the second supply air path Ri2, similar to Embodiment 1. More specifically, the controller 19 transmits a control signal Ci1 to the first supply air damper 131 to close it, and a control signal Cb1 to open the first bypass dampers 141 and 151, as a control signal for the first switch 121. The controller 19 transmits a control signal to the induced draft fan 160 to start operation of the induced draft fan 160.

[0063] The controller 19 transmits control signals Ci2 and Cb2 to the corresponding dampers 132, 142, and 152 as control signals for the second switch 122, to maintain the operating state of the second combustor 22. Specifically, the controller 19 transmits a control signal Ci2 to the second air intake damper 132 to open it, and a control signal Cb2 to close the second bypass dampers 142 and 152.

[0064] Similar to Embodiment 1, the controller 19 controls the opening degree of the second exhaust damper 182 so that the pressure detected by the first pressure detector 171 becomes a predetermined first target pressure when the first bypass path Rb1 is connected.

[0065] The control modes during normal operation and in the event of an abnormal shutdown of the second combustor 22 are the same as those shown in Figures 1 and 3, respectively.

[0066] In this embodiment, as in Embodiment 1, when some of the combustors of a plurality of combustors malfunction and stop, residual hydrogen in the furnace of the malfunctioning combustor can be purged using exhaust gas from combustion in the other combustors that are not malfunctioning. Therefore, hydrogen purging can be performed inexpensively without using a separate inert gas for hydrogen purging. In addition, a portion of the bypass piping 211 and 212 is common, and the induced draft fan 160 can be placed in the common intermediate piping 110. This reduces the number of induced draft fans 160, thereby reducing equipment costs.

[0067] While embodiments of this disclosure have been described above, this disclosure is not limited to the embodiments described above, and various improvements, changes, and modifications are possible without departing from the spirit of this disclosure.

[0068] [Other embodiments] For example, in the above embodiment, a boiler that generates steam by evaporating water supplied as a combustor was given as an example, but the combustor is not limited to this as long as it is supplied with hydrogen. For example, the combustor may include industrial furnaces that process or heat-treat materials by heating predetermined materials. Multiple combustors included in one hydrogen combustion system 1A, 1B, 1C, 2 may include combustors of different types from each other.

[0069] Furthermore, although the above embodiment illustrates a configuration in which the combustors 21 and 22 burn only hydrogen gas, the combustor is not limited to this configuration as long as it burns a fuel containing hydrogen. For example, the combustor may be one that co-burns hydrogen gas with other fuels such as heavy oil.

[0070] Furthermore, although the above embodiments illustrate configurations in which hydrogen combustion systems 1A, 1B, 1C, and 2 are equipped with economizers 91 and 92 and preheaters 101 and 102, the system is not limited to this configuration, and at least one of the economizers 91 and 92 and the preheaters 101 and 102 may not be provided. The economizers 91 and 92 or the preheaters 101 and 102 may be provided in only one of the first exhaust pipe 41 and the second exhaust pipe 42.

[0071] Furthermore, in the first embodiment described above, the bypass pipes 111 and 112 are connected downstream of the economizers 91 and 92 in the exhaust pipes 41 and 42, but the bypass pipes 111 and 112 may be connected upstream of the economizers 91 and 92 in the exhaust pipes 41 and 42. Similarly, in the configuration of the second embodiment, the bypass pipes 211 and 212 may be connected upstream of the economizers 91 and 92 in the exhaust pipes 41 and 42.

[0072] Furthermore, in the above embodiments, the hydrogen combustion systems 1A, 1B, 1C, and 2 are exemplified as having two combustors 21 and 22, but the hydrogen combustion systems 1A, 1B, 1C, and 2 may have three or more combustors. If one of the three or more combustors malfunctions and stops, exhaust gas from any one of the remaining combustors may be introduced into the malfunctioning combustor, or exhaust gas from two or more of the remaining combustors may be introduced into the malfunctioning combustor.

[0073] Furthermore, in the above embodiment, an example was given in which the controller 19 controls the switches 121 and 122 based on abnormal stop signals E1 and E2. However, the switching of the paths by the switches 121 and 122 may be performed manually. In other words, the controller 19 may not be necessary in the hydrogen combustion systems 1A, 1B, 1C, and 2.

[0074] [Summary of this disclosure] [Item 1] A hydrogen combustion system according to one aspect of the present disclosure is a hydrogen combustion system comprising two or more combustors for burning a hydrogen-containing fuel, wherein the two or more combustors include a first combustor and a second combustor, and the hydrogen combustion system comprises: a first air intake pipe connected to the air intake port of the first combustor and supplying air from a first air source to the first combustor; a first exhaust pipe connected to the exhaust port of the first combustor; a second air intake pipe connected to the air intake port of the second combustor and supplying air from a second air source to the second combustor; a second exhaust pipe connected to the exhaust port of the second combustor; and the first air intake pipe The system includes a first bypass pipe connecting the first combustion chamber to the second exhaust pipe, a second bypass pipe connecting the second supply pipe to the first exhaust pipe, a first switch for switching to connect either the first supply route between the intake port of the first combustion chamber and the first supply source, or the first bypass route between the intake port of the first combustion chamber and the second exhaust pipe, and a second switch for switching to connect either the second supply route between the intake port of the second combustion chamber and the second supply source, or the second bypass route between the intake port of the second combustion chamber and the first exhaust pipe.

[0075] According to the above configuration, the first bypass piping connecting the first supply air piping and the second exhaust piping allows for a second supply air path to be connected between the supply port of the second combustor (which is not experiencing any abnormalities) and the second supply air source, and also connects the first bypass path between the supply port of the first combustor and the second exhaust piping, in the event of an abnormal shutdown of the first combustor. This allows for supplying air from the second supply air source to the supply port of the second combustor and supplying exhaust from the second combustor to the supply port of the first combustor, thereby purging the hydrogen in the furnace of the first combustor with exhaust from the second combustor.

[0076] Similarly, a second bypass pipe connecting the second air supply pipe and the first exhaust pipe allows for the supply of air from the first air source to the air intake of the first combustor and the exhaust from the first combustor to the air intake of the second combustor during an abnormal shutdown of the second combustor. This allows for the purging of hydrogen in the furnace of the second combustor with the exhaust from the first combustor. Therefore, in the event of an abnormal shutdown of some of the combustors in a group of combustors, residual hydrogen in the furnace of the abnormally shut-down combustor can be purged using the exhaust from combustion in the other combustors that are not malfunctioning. As a result, hydrogen purging can be performed inexpensively without the need for a separate inert gas for hydrogen purging.

[0077] [Item 2] The hydrogen combustion system of item 1 includes a controller that controls the first switch and the second switch, and the controller may control the first switch to connect the first supply air path and the second switch to connect the second supply air path when the first and second combustors are in operation, when a first abnormal stop signal is obtained based on an abnormal stop of the first combustor, the controller may control the first switch to connect the first bypass path and the second switch to connect the second supply air path, and when a second abnormal stop signal is obtained based on an abnormal stop of the second combustor, the controller may control the first switch to connect the first supply air path and the second switch to connect the second bypass path. According to this, the switching of the supply air and exhaust flow paths can be appropriately performed by the controller when the first and second combustors are in operation, when the first combustor is abnormally stopped, and when the second combustor is abnormally stopped.

[0078] [Item 3] The hydrogen combustion system of item 2 includes a first exhaust damper located downstream of the connection point of the second bypass piping in the first exhaust piping and adjusting the flow rate of exhaust from the first combustor, a second exhaust damper located downstream of the connection point of the first bypass piping in the second exhaust piping and adjusting the flow rate of exhaust from the second combustor, a first pressure detector for detecting the outlet pressure of the first bypass piping, and a second pressure detector for detecting the outlet pressure of the second bypass piping. The controller may control the opening of the second exhaust damper so that the pressure detected by the first pressure detector becomes a predetermined first target pressure when the first bypass path is connected, and control the opening of the first exhaust damper so that the pressure detected by the second pressure detector becomes a predetermined second target pressure when the second bypass path is connected. This allows an appropriate amount of exhaust to be supplied to the first combustor in order to perform hydrogen purging in the furnace of the first combustor in the event of an abnormal shutdown of the first combustor, and allows an appropriate amount of exhaust to be supplied to the second combustor in order to perform hydrogen purging in the furnace of the second combustor in the event of an abnormal shutdown of the second combustor.

[0079] [Item 4] In any of the hydrogen combustion systems described in items 1 to 3, the first bypass piping and the second bypass piping may include a common intermediate piping, a first bypass upstream piping connecting the second exhaust piping and the intermediate piping, a first bypass downstream piping connecting the intermediate piping and the first supply piping, a second bypass upstream piping connecting the first exhaust piping and the intermediate piping, and a second bypass downstream piping connecting the intermediate piping and the second supply piping.

[0080] [Item 5] The hydrogen combustion system of item 4 may include an induced draft fan located in the intermediate piping. By placing the induced draft fan in the intermediate piping of the common bypass piping, the number of induced draft fans can be reduced, thereby lowering equipment costs.

[0081] [Item 6] A hydrogen combustion system according to any of items 1 to 3 may include a first induced fan interposed in the first bypass piping and a second induced fan interposed in the second bypass piping.

[0082] [Item 7] In any of the hydrogen combustion systems described in items 1 to 6, the first switch includes a first air supply damper for switching the flow or shutoff of air from the first air supply source to the first air supply piping, and a first bypass damper for switching the flow or shutoff of air in the first bypass piping, and the second switch may include a second air supply damper for switching the flow or shutoff of air from the second air supply source to the second air supply piping, and a second bypass damper for switching the flow or shutoff of air in the second bypass piping.

[0083] [Item 8] A hydrogen combustion system according to any of items 1 to 7 includes a first preheater interposed in the first exhaust piping and preheating the supply air supplied from the first supply source to the first combustor by the exhaust flowing through the first exhaust piping, and a second preheater interposed in the second exhaust piping and preheating the supply air supplied from the second supply source to the second combustor by the exhaust flowing through the second exhaust piping, wherein the first bypass piping may be connected upstream of the second preheater in the second exhaust piping, and the second bypass piping may be connected upstream of the first preheater in the first exhaust piping. This configuration prevents exhaust gas with increased oxygen concentration from being introduced into the combustor where hydrogen purging is to be performed as a purge gas. This allows exhaust gas with a low oxygen concentration to be appropriately introduced into the combustor where hydrogen purging is to be performed as a purge gas.

[0084] [Item 9] A furnace hydrogen purging method according to another aspect of the present disclosure is a furnace hydrogen purging method in a combustor of a hydrogen combustion system comprising two or more combustors for burning a hydrogen-containing fuel, wherein the two or more combustors include a first combustor supplied with air from a first air supply source and a second combustor supplied with air from a second air supply source, and the furnace hydrogen purging method, in the event of an abnormal shutdown of the first combustor, purges the hydrogen in the furnace of the first combustor with the exhaust from the second combustor by supplying air from the second air supply source to the air intake port of the second combustor and supplying exhaust from the second combustor to the air intake port of the first combustor, and in the event of an abnormal shutdown of the second combustor, purges the hydrogen in the furnace of the second combustor with the exhaust from the first combustor by supplying air from the first air supply source to the air intake port of the first combustor and supplying exhaust from the first combustor to the air intake port of the second combustor.

[0085] According to the above method, in the event of an abnormal shutdown of the first combustor, the hydrogen in the furnace of the first combustor can be purged with the exhaust from the second combustor by supplying air from the second air source to the air inlet of the second combustor and supplying exhaust from the second combustor to the air inlet of the first combustor. Similarly, in the event of an abnormal shutdown of the second combustor, the hydrogen in the furnace of the second combustor can be purged with the exhaust from the first combustor by supplying air from the first air source to the air inlet of the first combustor and supplying exhaust from the first combustor to the air inlet of the second combustor. Therefore, in the event of an abnormal shutdown of some of the combustors of multiple combustors, residual hydrogen in the furnace of the abnormally shut-down combustor can be purged using the exhaust from combustion in the other combustors that are not abnormally shut down. For this reason, hydrogen purging can be performed inexpensively without the need to use a separate inert gas for hydrogen purging. [Explanation of Symbols]

[0086] 1A, 1B, 1C, 2 Hydrogen combustion system 19. Controller 21. First Combustor 21a Air supply port 21b Exhaust port 22 Second Combustor 22a Air supply port 22b Exhaust port 31. First air supply piping 32. Second air supply piping 41. First exhaust piping 42. Second exhaust piping 101 First preheater 102 Second preheater 110 Intermediate piping 111,211 First Bypass Piping 111a First Bypass Upstream Piping 111b Downstream piping of the first bypass 112,212 Second Bypass Piping 112a Second Bypass Upstream Piping 112b Second Bypass Downstream Piping 121 Switcher No. 1 122 Second Switch 131 First intake damper 132 Second intake damper 141,151 First Bypass Damper 142,152 Second Bypass Damper 160 Inducing Fan 161 First Inducing Fan 162 Second Inducing Fan 171 First pressure detector 172 Second pressure detector 181 First exhaust damper 182 Second exhaust damper Rb1 First Bypass Route Rb2 Second Bypass Route Ri1 First air supply path Ri2 Second Air Supply Route

Claims

1. A hydrogen combustion system comprising two or more combustors for burning a hydrogen-containing fuel, The two or more combustors include a first combustor and a second combustor, The aforementioned hydrogen combustion system is A first air supply pipe connected to the air intake port of the first combustor supplies air from a first air supply source to the first combustor, A first exhaust pipe connected to the exhaust port of the first combustor, A second air supply pipe connected to the air intake port of the second combustion chamber supplies air from a second air supply source to the second combustion chamber, A second exhaust pipe connected to the exhaust port of the second combustion chamber, A first bypass pipe connecting the first air supply pipe and the second exhaust pipe, A second bypass pipe connecting the second air supply pipe and the first exhaust pipe, A first switch that switches to connect either a first air supply path between the air intake port of the first combustor and the first air supply source, or a first bypass path between the air intake port of the first combustor and the second exhaust pipe, A hydrogen combustion system comprising: a second switch for switching to connect either a second air supply path between the air intake port of the second combustor and the second air supply source, or a second bypass path between the air intake port of the second combustor and the first exhaust pipe.

2. The system includes a controller that controls the first switch and the second switch, The controller is, During operation of the first and second combustors, the first switch is controlled to connect the first air supply path, and the second switch is controlled to connect the second air supply path. When a first abnormal stop signal is obtained based on the abnormal stop of the first combustor, the first switch is controlled to connect the first bypass path and the second switch is controlled to connect the second air supply path. The hydrogen combustion system according to claim 1, wherein when a second abnormal stop signal is obtained based on the abnormal stop of the second combustor, the first switch is controlled to connect the first air supply path and the second switch is controlled to connect the second bypass path.

3. A first exhaust damper is located downstream of the connection point of the second bypass piping in the first exhaust piping and adjusts the flow rate of exhaust from the first combustor, A second exhaust damper is located downstream of the connection point of the first bypass piping in the second exhaust piping and adjusts the flow rate of exhaust from the second combustor, A first pressure detector for detecting the outlet pressure of the first bypass piping, The system includes a second pressure detector for detecting the outlet pressure of the second bypass piping, The controller is, When the first bypass path is connected, the opening degree of the second exhaust damper is controlled so that the pressure detected by the first pressure detector becomes a predetermined first target pressure. The hydrogen combustion system according to claim 2, wherein, when the second bypass path is connected, the opening degree of the first exhaust damper is controlled so that the pressure detected by the second pressure detector becomes a predetermined second target pressure.

4. The hydrogen combustion system according to any one of claims 1 to 3, wherein the first bypass piping and the second bypass piping include a common intermediate piping, a first bypass upstream piping connecting the second exhaust piping and the intermediate piping, a first bypass downstream piping connecting the intermediate piping and the first supply piping, a second bypass upstream piping connecting the first exhaust piping and the intermediate piping, and a second bypass downstream piping connecting the intermediate piping and the second supply piping.

5. The hydrogen combustion system according to claim 4, further comprising an induced fan positioned in the intermediate piping.

6. A first induced fan is interposed in the first bypass piping, A hydrogen combustion system according to any one of claims 1 to 3, comprising a second induced fan interposed in the second bypass piping.

7. The first switch includes a first air supply damper that switches the flow or blockage of air from the first air supply source to the first air supply piping, and a first bypass damper that switches the flow or blockage of air in the first bypass piping. The hydrogen combustion system according to any one of claims 1 to 3, wherein the second switch includes a second air supply damper for switching the flow or blockage of air from the second air supply source to the second air supply piping, and a second bypass damper for switching the flow or blockage of air in the second bypass piping.

8. A first preheater is interposed in the first exhaust piping and preheats the supply air supplied from the first supply air source to the first combustor by the exhaust flowing through the first exhaust piping, The system includes a second preheater interposed in the second exhaust piping, which preheats the supply air supplied from the second supply air source to the second combustor by the exhaust flowing through the second exhaust piping, The first bypass piping is connected upstream of the second preheater in the second exhaust piping. The hydrogen combustion system according to any one of claims 1 to 3, wherein the second bypass piping is connected upstream of the first preheater in the first exhaust piping.

9. A method for purging hydrogen in a combustion chamber of a hydrogen combustion system, which includes two or more combustion chambers for burning hydrogen-containing fuel, The two or more combustors include a first combustor supplied with air from a first air supply source and a second combustor supplied with air from a second air supply source. The above-mentioned in-furnace hydrogen purging method is, In the event of an abnormal shutdown of the first combustor, the air supplied from the second air source is supplied to the air inlet of the second combustor, and the exhaust from the second combustor is supplied to the air inlet of the first combustor, thereby purging the hydrogen in the furnace of the first combustor with the exhaust from the second combustor. A furnace hydrogen purging method, wherein, in the event of an abnormal shutdown of the second combustor, air from the first air supply source is supplied to the air intake port of the first combustor, and exhaust gas from the first combustor is supplied to the air intake port of the second combustor, thereby purging the hydrogen in the furnace of the second combustor with exhaust gas from the first combustor.

Images