Boiler and boiler system

Abstract

To provide a boiler and a boiler system capable of performing stable operation in response to a temperature change and a pressure change of hydrogen gas fuel containing steam.SOLUTION: The boiler uses hydrogen gas fuel containing water vapor as fuel. The hydrogen gas fuel supply line includes a pressure regulator, a flow rate regulator, a first pressure detector disposed on an upstream side in the vicinity of the flow rate regulator and the pressure regulator, and a first temperature detector disposed in the vicinity thereof. The control unit includes a first storage unit that stores a first flow rate adjustment value of the flow rate adjustment unit at a predetermined temperature and pressure of the hydrogen gas fuel associated with a required combustion amount, a water vapor evaluation unit that evaluates a state of water vapor contained in the hydrogen gas fuel based on detection results of the first temperature detection unit and the first pressure detection unit, a flow rate correction unit that corrects the first flow rate adjustment value based on an evaluation result of the water vapor evaluation unit, and a flow rate control unit that controls the flow rate adjustment unit based on a correction result of the flow rate correction unit.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a boiler and a boiler system that uses hydrogen gas as fuel. [Background technology]

[0002] Boilers that use hydrogen gas fuel, which is primarily composed of hydrogen, as fuel have been known. Boilers that burn hydrogen gas fuel have attracted attention because they do not generate carbon dioxide during combustion (see, for example, Patent Document 1). Because hydrogen gas has a low minimum ignition energy and a wide flammable range, a water seal flashback prevention device is often installed in the fuel supply line from the hydrogen gas fuel supply source to the burner as a safety measure (see, for example, Patent Document 2). In such cases, the hydrogen gas supplied to the burner contains water vapor (saturated water vapor). Furthermore, when hydrogen gas produced by a water electrolysis device is used as fuel, the hydrogen gas also contains water vapor. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2018-179400 [Patent Document 2] Japanese Patent Publication No. 2020-020541 Summary of the Invention [Problem to be solved by the invention]

[0004] In hydrogen gas (gas whose main component is hydrogen) that contains water vapor, the proportion of hydrogen decreases and the density increases accordingly. Furthermore, the amount of water vapor contained in hydrogen gas varies depending on the temperature of the hydrogen gas. Therefore, when the combustion rate is adjusted so that hydrogen gas is supplied to the burner at a predetermined flow rate under predetermined temperature conditions in a boiler, fluctuations in the hydrogen gas temperature can cause changes in the density of the hydrogen gas and the calorific value per unit volume. This can cause the combustion rate to deviate from the set value, preventing the boiler from operating properly.

[0005] To solve this problem, a known method is to calculate the amount of saturated water vapor in hydrogen gas from the temperature of the hydrogen gas and then correct the combustion amount. The proportion of water vapor in hydrogen gas is determined by the hydrogen gas pressure and water vapor pressure, so the lower the hydrogen gas pressure, the higher the proportion of water vapor in the hydrogen gas. In boilers, the pressure of the hydrogen gas supplied as fuel is lower than in gas turbines, etc., and the proportion of water vapor tends to be higher. For this reason, conventional combustion amount correction based on the hydrogen gas temperature sometimes fails to properly correct the combustion amount.

[0006] An object of the present invention is to provide a boiler and a boiler system that can respond to temperature and pressure changes of hydrogen gas fuel containing steam and can operate stably. [Means for solving the problem]

[0007] The present invention solves the above problems by the following means.

[0008] The boiler of the present invention is a boiler that burns hydrogen gas fuel containing steam as fuel, and includes a burner that ejects the hydrogen gas fuel, a hydrogen gas fuel supply line that supplies the hydrogen gas fuel to the burner, and a control unit that controls operation of the boiler, wherein the hydrogen gas fuel supply line includes a pressure regulating unit that adjusts the pressure of the hydrogen gas fuel to a predetermined range, a flow rate adjusting unit that adjusts the flow rate of the hydrogen gas fuel, a first pressure detecting unit that is arranged upstream near the flow rate adjusting unit and the pressure regulating unit and that detects the pressure of the hydrogen gas fuel, and a second pressure detecting unit that is arranged upstream near the first pressure detecting unit and that detects the pressure of the hydrogen gas fuel. and a first temperature detection unit that detects the temperature of the hydrogen gas fuel, and the control unit includes a first memory unit that stores a first flow rate adjustment value of the flow rate adjustment unit at a predetermined temperature and pressure of the hydrogen gas fuel associated with a required combustion amount, a water vapor evaluation unit that evaluates the state of water vapor contained in the hydrogen gas fuel supplied to the burner based on the detection result of the first temperature detection unit and the detection result of the first pressure detection unit, a flow rate correction unit that corrects the first flow rate adjustment value based on the evaluation result of the water vapor evaluation unit, and a flow rate control unit that controls the flow rate adjustment unit based on the correction result of the flow rate correction unit.

[0009] The flow rate adjusting unit is preferably a flow rate adjusting valve in which an increase in the opening degree of a valve is proportional to an increase in the flow rate of the hydrogen gas fuel.

[0010] It is preferable that the flow rate correction unit calculates the density and the calorific value per unit volume of the hydrogen gas fuel based on the evaluation result of the water vapor evaluation unit, and corrects the first flow rate adjustment value based on the calculated density and the calorific value.

[0011] The boiler system of the present invention comprises the boiler described above, a moisture addition unit provided upstream of the hydrogen gas fuel supply line and configured to add moisture to the hydrogen gas fuel, a second temperature detection unit configured to detect the temperature of the hydrogen gas fuel to which moisture has been added by the moisture addition unit, and a second pressure detection unit disposed near the second temperature detection unit and configured to detect the pressure of the hydrogen gas fuel, wherein the water vapor evaluation unit compares the detection result of the first temperature detection unit with the detection result of the second temperature detection unit, and if the detection result of the second temperature detection unit is equal to or higher than the detection result of the first temperature detection unit, evaluates the state of the water vapor contained in the hydrogen gas fuel supplied to the burner based on the detection results of the first temperature detection unit and the first pressure detection unit, and if the detection result of the first temperature detection unit is higher than the detection result of the second temperature detection unit, evaluates the state of the water vapor contained in the hydrogen gas fuel supplied to the burner based on the detection results of the second temperature detection unit and the second pressure detection unit. [Effects of the Invention]

[0012] According to the present invention, it is possible to provide a boiler and a boiler system that can respond to temperature and pressure changes of hydrogen gas fuel containing steam and perform stable operation. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a diagram illustrating the configuration of a boiler and a boiler system according to an embodiment. FIG. [Figure 2] FIG. 2 is a diagram illustrating a control unit according to the embodiment. [Figure 3] This is a table showing the results of calculating the changes in hydrogen proportion in the water seal outlet region R1, the temperature / pressure detection region R2, and the pressure stabilization region R3, assuming a model of changes in the temperature and pressure of hydrogen gas fuel flowing through a hydrogen gas fuel supply line. DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, embodiments of the present invention will be described with reference to the drawings, etc. Note that the drawings shown below, including Fig. 1, are schematic diagrams, and the size and shape of each part are appropriately exaggerated to facilitate understanding. The boiler of the present invention is a boiler that burns hydrogen gas fuel F1. A boiler 10 of the embodiment described below is a boiler that uses hydrogen gas as the hydrogen gas fuel F1, and is, for example, a small once-through boiler or a small-scale once-through boiler. In this specification and claims, the hydrogen gas fuel F1 includes not only hydrogen gas consisting of only hydrogen, but also a mixed gas consisting of hydrogen and other gases containing at least 80% hydrogen. In this embodiment, as described above, an example in which hydrogen gas is used as the hydrogen gas fuel F1 is described, but this is not limiting, and a mixed gas containing at least 80% hydrogen may also be used as the hydrogen gas fuel F1.

[0015] (Embodiment) FIG. 1 is a diagram illustrating the configuration of a boiler 10 and a boiler system 1 according to this embodiment. As shown in Fig. 1, the boiler 10 of this embodiment includes a boiler body 20, a burner 21, and a control unit 60. The boiler 10 also includes a hydrogen gas fuel supply line L100 and an air supply line L300. The boiler system 1 of this embodiment further includes the boiler 10 and a hydrogen supply facility 50 having a water electrolysis device 51, a water seal flashback prevention device 52, and the like. In this specification, the term "line" is a general term for a flow path, a passage, a pipeline, and the like.

[0016] The boiler body 20 is configured to include a lower header, multiple water pipes, an upper header (none of which are shown), and a combustion chamber B, and generates steam by heating water supplied to the boiler body 20. The generated steam is supplied to a load device (not shown) through a steam supply line (not shown). The combustion gas from which heat has been recovered is discharged as exhaust gas to the outside of the system through an exhaust pipe (not shown) connected to the boiler body 20.

[0017] The burner 21 is disposed on top of the boiler body 20 and sprays hydrogen gas fuel F1. The hydrogen gas fuel F1 sprayed by the burner 21 is ignited by a pilot burner (not shown) or the like. The hydrogen gas fuel F1 sprayed from the burner 21 is combusted in the combustion chamber B of the boiler body 20. In the boiler 10 of this embodiment, the burner 21 sprays the hydrogen gas fuel F1 supplied from the hydrogen gas fuel supply line L100 and combusts it as fuel. The window box 23 is connected to an air supply line L300, which will be described later, and supplies combustion air A1 to the burner 21.

[0018] The hydrogen gas fuel supply line L100 supplies hydrogen gas fuel F1 as fuel to the burner 21. The downstream side of the hydrogen gas fuel supply line L100 is connected to the burner 21, and the upstream side is connected to a water seal flashback prevention device 52 of the hydrogen supply equipment 50. The hydrogen supply equipment 50 will be described later. The hydrogen gas fuel supply line L100 is equipped with, in order from the upstream side, a second pressure sensor 102, a second temperature sensor 103, a first pressure sensor 104, a first temperature sensor 105, a shut-off valve 107, a pressure regulating unit 108, a pressure gauge 110, a flow rate control valve 111, a pressure abnormality detection sensor 112, a shut-off valve 113, and a flame arrester 114.

[0019] The second pressure sensor 102 is a pressure detection unit that detects the pressure of the hydrogen gas fuel F1 in the hydrogen gas fuel supply line L100. The second pressure sensor 102 is electrically connected to the control unit 60, and the control unit 60 can acquire the detection result of the second pressure sensor 102. In this embodiment, the second pressure sensor 102 is disposed near the water seal flashback prevention device 52 of the hydrogen supply facility 50, and detects the pressure of the hydrogen gas fuel F1 that has left the water seal flashback prevention device 52. The second temperature sensor 103 is a temperature detection unit that detects the temperature of the hydrogen gas fuel F1 flowing through the hydrogen gas fuel supply line L100. The second temperature sensor 103 is electrically connected to the control unit 60, and the control unit 60 can acquire the detection result of the second temperature sensor 103. In this embodiment, the second temperature sensor 103 is disposed near the water seal flashback prevention device 52 of the hydrogen supply facility 50, and detects the temperature of the hydrogen gas fuel F1 that has left the water seal flashback prevention device 52.

[0020] The first pressure sensor 104 is a pressure sensor that detects the pressure of the hydrogen gas fuel F1 flowing through the hydrogen gas fuel supply line L100, and detects the pressure of the hydrogen gas fuel F1 near the upstream side of the pressure regulating unit 108. The first pressure sensor 104 is electrically connected to the control unit 60, and the control unit 60 can acquire the detection result of the first pressure sensor 104. The detection result of the first pressure sensor 104 is used to correct the flow rate of the hydrogen gas fuel F1. Furthermore, if the pressure is below a predetermined pressure value (pressure lower limit), the first pressure sensor 104 transmits a signal to the control unit 60 to notify that the pressure has fallen below the lower limit. The control unit 60 receives this signal transmitted by the first pressure sensor 104, and based on this, issues an alarm or the like to notify that the pressure of the hydrogen gas fuel F1 is below the pressure lower limit. A drain L121 is provided in the hydrogen gas fuel supply line L100 near the upstream side of the first pressure sensor 104. The drain L121 discharges condensed water in the hydrogen gas fuel supply line L100 to the outside of the system.

[0021] The first temperature sensor 105 is provided near the upstream side of the pressure regulating unit 108 and near the first pressure sensor 104, and is a temperature detecting unit that detects the temperature of the hydrogen gas fuel F1 near the upstream side of the pressure regulating unit 108. In this embodiment, as shown in FIG. 1 , the first temperature sensor 105 is disposed downstream of the first pressure sensor 104. The first temperature sensor 105 is electrically connected to the control unit 60, and the control unit 60 can acquire the detection result of the first temperature sensor 105.

[0022] The shutoff valves 107 and 113 are disposed in the hydrogen gas fuel supply line L100 upstream of the flame arrestor 114. The shutoff valves 107 and 113 are configured by electromagnetic valves and open and close the flow path of the hydrogen gas fuel supply line L100. In this embodiment, the shutoff valve 107 is disposed upstream of the shutoff valve 113.

[0023] The pressure regulating unit 108 adjusts the pressure of the hydrogen gas fuel F1 flowing through the hydrogen gas fuel supply line L100. In this embodiment, the pressure regulating unit 108 is configured by, for example, a gas governor, and reduces the pressure of the hydrogen gas fuel F1 to adjust it within a predetermined range. The pressure adjusting unit 108 may be electrically connected to the control unit 60 and controlled based on a signal sent from the control unit 60, or may be a mechanical pressure adjusting unit.

[0024] The pressure gauge 110 is provided downstream of the pressure regulator 108 and measures the pressure of the hydrogen gas fuel F1 flowing through the hydrogen gas fuel supply line L100.

[0025] The flow rate adjustment valve 111 is a flow rate adjustment unit that adjusts the flow rate of the hydrogen gas fuel F1 flowing through the hydrogen gas fuel supply line L100. The flow rate adjustment valve 111 is electrically connected to the control unit 60, and its opening degree is controlled based on a signal sent from the control unit 60. From the viewpoint of facilitating correction of the valve opening degree, it is preferable that the valve opening degree of this flow rate adjustment valve 111 is proportional to the flow rate of the hydrogen gas fuel F1 at that opening degree.

[0026] The pressure abnormality detection sensor 112 detects the pressure of the hydrogen gas fuel F1 flowing in the hydrogen gas fuel supply line L100 downstream of the flow rate adjustment valve 111. This pressure abnormality detection sensor 112 is electrically connected to the control unit 60, and when the pressure of the hydrogen gas fuel F1 flowing in the hydrogen gas fuel supply line L100 downstream of the flow rate adjustment valve 111 is outside a predetermined range, it transmits a pressure abnormality to the control unit 60. The flame arrester 114 is a dry flashback prevention device that prevents a flashback that occurs in the hydrogen gas fuel supply line L100 from progressing upstream from the burner 21.

[0027] The hydrogen supply facility 50 is located upstream of the hydrogen gas fuel supply line L100 and includes a water electrolysis device 51, a water seal type flashback prevention device 52, a water wash cooling tower 53, and a hydrogen gas fuel supply line L110 within the hydrogen supply facility 50 that connects these. The water electrolysis device 51 is a device that electrolyzes water to generate high-purity hydrogen gas. The hydrogen gas generated in the water electrolysis device 51 passes through the water wash cooling tower 53 and the hydrogen gas fuel supply line L110 in the hydrogen supply facility 50, and is supplied to the water seal flashback prevention device 52 as hydrogen gas fuel F1.

[0028] The water wash cooling tower 53 is disposed downstream of the water electrolysis device 51, and washes away caustic soda mist contained in the hydrogen gas generated in the water electrolysis device 51 and cools the hydrogen gas. The water wash cooling tower 53 also functions as a moisture addition section that adds moisture to the hydrogen gas, and the hydrogen gas fuel F1 that has passed through the water wash cooling tower 53 comes to contain saturated water vapor. The water seal backfire prevention device 52 is located downstream of the water wash cooling tower 53 and upstream of the hydrogen gas fuel supply line L100, and is a device that prevents the flame generated by the burner 21 from flowing back through the hydrogen gas fuel supply line L100, and is a moisture addition section that adds moisture to the hydrogen gas fuel F1. The water-sealed flashback prevention device 52 is a container that seals water W inside, and is connected to the downstream end of the hydrogen gas fuel supply line L110 in the hydrogen supply equipment 50 and the upstream end of the hydrogen gas fuel supply line L100.

[0029] In the water-sealed flashback prevention device 52, the downstream end of the hydrogen gas fuel supply line L110 in the hydrogen supply equipment 50 is positioned so as to be submerged in the water W, and the upstream end of the hydrogen gas fuel supply line L100 is positioned so as to be located above the water level of the water W. Therefore, the hydrogen gas fuel F1 generated in the water electrolysis device 51 is discharged through the hydrogen gas fuel supply line L110 into the water W sealed inside the water seal flashback prevention device 52. The discharged hydrogen gas fuel F1 turns into bubbles, rises in the water, emerges from the water surface, is introduced into the hydrogen gas fuel supply line L100, and heads toward the burner 21. The water seal flashback prevention device 52 functions as a moisture addition section, and as the hydrogen gas fuel F1 passes through the water W inside the water seal flashback prevention device 52, moisture is added to the hydrogen gas fuel F1 by the water W, and the hydrogen gas fuel F1 comes to contain saturated water vapor.

[0030] The water seal flashback prevention device 52 also includes a water level gauge 521, a water supply line L530, a drainage line L540, and a water seal flashback prevention device control unit (not shown). The water level gauge 521 measures the water level of the water W sealed inside the water seal type flashback prevention device 52. The water level gauge 521 is electrically connected to a water seal type flashback prevention device control unit (not shown), and the water seal type flashback prevention device control unit can acquire the detection result of the water level gauge 521.

[0031] The water replenishment line L530 is equipped with an on-off valve 531, and supplies water W1 from a water supply source (not shown) to the inside of the water seal type flashback prevention device 52. The on-off valve 531 opens and closes the water replenishment line L530. The on-off valve 531 is electrically connected to the water seal type flashback prevention device control unit, and is controlled based on a signal sent from the water seal type flashback prevention device control unit. The drain line L540 is equipped with an on-off valve 541 and a shutoff valve 542, and discharges water W2 from the water seal type flashback prevention device 52 to the outside of the system, etc. The on-off valve 541 and the shutoff valve 542 are electrically connected to a water seal type flashback prevention device control unit (not shown) provided in the water seal type flashback prevention device 52, and are controlled based on a signal transmitted from the water seal type flashback prevention device control unit. The water seal flashback prevention device control unit instructs the opening and closing of the on-off valves 531, 541 and the shutoff valve 542 based on the detection result of the water level meter 521, and maintains the water level of the water W in the water seal flashback prevention device 52 within a predetermined range.

[0032] The air supply line L300 supplies combustion air A1 to the burner 21. The air supply line L300 is connected to the blower 31 on the upstream side and to the window box 23 on the downstream side.

[0033] The blower 31 supplies combustion air A1 to the burner 21. The blower 31 includes a fan (not shown) and a motor (not shown) that rotates the fan. The blower 31 can adjust the rotation speed of the motor by controlling the frequency of the inverter 32, thereby controlling the supply amount of combustion air A1 flowing through the air supply line L300. The inverter 32 is electrically connected to the control unit 60 and is controlled based on a signal transmitted from the control unit 60 .

[0034] The air supply line L300 is provided with a fixed pressure loss 301, an air differential pressure sensor 302, and a damper 303. The fixed pressure drop 301 reduces the pressure of the combustion air A1 flowing through the air supply line L300, and may be, for example, an orifice, a punched metal, etc. In this embodiment, an orifice is used as the fixed pressure drop 301. The air differential pressure sensor 302 detects the differential pressure between the pressure of the combustion air A1 on the upstream side of the fixed pressure loss 301 and the pressure of the combustion air A1 on the downstream side. The air differential pressure sensor 302 is electrically connected to the control unit 60, which can acquire information on the differential pressure of the combustion air A1 detected by the air differential pressure sensor 302. Based on this information on the differential pressure of the combustion air A1, the control unit 60 calculates the flow rate (air amount) of the combustion air A1. The control unit 60 changes the flow rate of the combustion air A1 in accordance with a combustion request from a load device (not shown), and adjusts the flow rate of hydrogen gas fuel F1, which serves as fuel, in accordance with the flow rate of the combustion air A1.

[0035] The damper 303 adjusts the amount of combustion air A1 supplied from the air supply line L300 to the window box 23 by adjusting the opening degree of the damper. Specifically, the damper 303 is rotatable between a closed state in which the flow path of the air supply line L300 is blocked and an open state in which the damper 303 rotates a predetermined angle (e.g., 90 degrees) from the closed state and opens the flow path of the air supply line L300. The damper 303 is electrically connected to the control unit 60 and is controlled based on a signal transmitted from the control unit 60.

[0036] FIG. 2 is a diagram illustrating the control unit 60 of this embodiment. The control unit 60 controls the operation of the boiler 10. The control unit 60 includes a memory unit 61, a steam evaluation unit 62, a flow rate correction unit 63, and a flow rate control unit 64. The control unit 60 also includes a combustion control unit (not shown) that controls combustion in the boiler 10. The control unit 60 is configured with an arithmetic processor such as a PLC (Programmable Logic Controller), a DSP (Digital Signal Processor), or an FPGA (Field Programmable Gate Array). The various functions of the control unit 60 are realized, for example, by executing predetermined software (programs) stored in the storage unit 61. The various functions of the control unit 60 may be realized by a combination of hardware and software, or may be realized only by hardware (electronic circuits).

[0037] The storage unit 61 stores various types of setting information. The storage unit 61 also includes a first storage unit 611 and a second storage unit 612. The first storage unit 611 stores a first flow rate adjustment value V1 that sets the opening degree, etc., of the flow rate adjustment valve 111, which is a flow rate adjustment unit. This first flow rate adjustment value V1 is a numerical value (so-called initial setting value) that sets the opening degree of the flow rate adjustment valve 111 at a predetermined temperature and pressure of the hydrogen gas fuel F1, which is associated with the combustion amount required for the boiler 10. The second storage unit 612 stores the first flow rate adjustment value V1 corrected by the flow rate correction unit 63 as a second flow rate adjustment value V2. The control unit 60 is not limited to the above example, and may have at least one of the first storage unit 611 and the second storage unit 612 outside the storage unit 61, or the storage unit 61 may have only the first storage unit 611 and not the second storage unit 612. If the storage unit 61 does not have the second storage unit 612, the second flow rate adjustment value V2 may be acquired by the flow rate control unit 64, for example.

[0038] The water vapor evaluation unit 62 evaluates the state of water vapor contained in the hydrogen gas fuel F1 supplied to the burner 21 based on either the detection results of the second temperature sensor 103 and the second pressure sensor 102 or the detection results of the first temperature sensor 105 and the first pressure sensor 104. The water vapor evaluation unit 62 compares the detection result of the second temperature sensor 103 with the detection result of the first temperature sensor 105, and if the detection result of the first temperature sensor 105 is higher than the detection result of the second temperature sensor 103, evaluates the state of water vapor contained in the hydrogen gas fuel F1 based on the detection results of the second temperature sensor 103 and the second pressure sensor 102. On the other hand, if the detection result of the second temperature sensor 103 is equal to or higher than the detection result of the first temperature sensor 105, the water vapor evaluation unit 62 evaluates the state of water vapor contained in the hydrogen gas fuel F1 based on the detection results of the first temperature sensor 105 and the first pressure sensor 104.

[0039] The state of water vapor contained in the hydrogen gas fuel F1 refers to the pressure and proportion of water vapor contained in the hydrogen gas fuel F1. Based on this state of water vapor (particularly the proportion of hydrogen gas contained in the hydrogen gas fuel F1), the flow rate correction unit 63, which will be described later, can calculate the density (gas density) of the hydrogen gas fuel F1 containing water vapor, the calorific value per unit volume, etc. at the temperature of the hydrogen gas fuel F1 at which the state of water vapor was evaluated.

[0040] The flow rate correction unit 63 corrects the first flow rate adjustment value V1 stored in the first storage unit 611 based on the evaluation result of the water vapor evaluation unit 62. As an example, the flow rate correction unit 63 calculates the hydrogen proportion contained in the hydrogen gas fuel F1 based on the evaluation result of the water vapor evaluation unit 62, calculates the density (gas density) and heat value per unit volume of the hydrogen gas fuel F1 based on the calculated hydrogen proportion, and calculates a second flow rate adjustment value V2 (corrected first flow rate adjustment value V1) obtained by correcting the first flow rate adjustment value V1 or a correction coefficient X1 for correcting the first flow rate adjustment value V1 based on the calculated density and heat value. The second flow rate adjustment value V2 obtained by correcting the first flow rate adjustment value V1 is stored in the second storage unit 612. The flow rate control unit 64 controls the flow rate adjustment valve 111, which is a flow rate adjustment unit, based on the second flow rate adjustment value V2 (corrected first flow rate adjustment value V1) stored in the second memory unit 612. Alternatively, when the flow rate correction unit 63 calculates the correction coefficient X1, the flow rate control unit 64 controls the flow rate adjustment valve 111, which is a flow rate adjustment unit, based on the first flow rate adjustment value V1 acquired from the first memory unit 611 and the correction coefficient X1 acquired from the flow rate correction unit 63.

[0041] The regions R1 to R3 indicated by dashed lines in FIG. 1 will be described. R1 denotes the region near the outlet of the hydrogen gas fuel F1 of the water seal flashback prevention device 52, R2 denotes the region where the temperature and pressure of the hydrogen gas fuel F1 near the upstream side of the pressure regulating unit 108 are detected, and R3 denotes the region where the pressure of the hydrogen gas fuel F1 is adjusted to a predetermined range. Hereinafter, these regions will be referred to as the water seal outlet region R1, the temperature / pressure detection region R2, and the pressure regulating region R3, respectively. The water seal outlet region R1 is provided with a second pressure sensor 102 and a second temperature sensor 103. The temperature / pressure detection region R2 is provided with a first pressure sensor 104 and a first temperature sensor 105. The pressure regulating region R3 is provided with a pressure gauge 110.

[0042] Figure 3 is a table showing the results of calculating the changes in hydrogen proportion in the water seal outlet region R1, the temperature / pressure detection region R2, and the pressure stabilization region R3, assuming a model of changes in the temperature and pressure of the hydrogen gas fuel F1 flowing through the hydrogen gas fuel supply line L100. The gauge pressure, absolute pressure, and gas temperature shown in Figure 3 are the gauge pressure, absolute pressure, and temperature of the hydrogen gas fuel F1, the water vapor partial pressure is the partial pressure of the water vapor contained in the hydrogen gas fuel F1, the hydrogen partial pressure is the partial pressure of the hydrogen contained in the hydrogen gas fuel F1, and the hydrogen proportion indicates the proportion of hydrogen contained in the hydrogen gas fuel F1. 3, when the first flow rate adjustment value V1 is stored in the first memory unit 611, that is, at the "setting time" shown in Fig. 3, the temperature of the hydrogen gas fuel F1 in the water seal outlet region R1 is set to 40°C, and the pressure of the hydrogen gas fuel F1 is set to 50 kPa (absolute pressure: 151 kPa). Also, it is assumed that the flow path pressure loss from the water seal outlet region R1 to the temperature / pressure detection region R2 is negligible, that the temperature of the hydrogen gas fuel F1 in the temperature / pressure detection region R2 drops to 20°C due to a temperature drop caused by heat radiation, and that the temperature / pressure detection region R2 and the pressure stabilization region R3 are close to each other, so that the temperature drop caused by heat radiation can be ignored.

[0043] With this setting, in the section from the water seal outlet region R1 to the temperature / pressure detection region R2 (hereinafter referred to as the first section K1), condensed water is generated due to a drop in the temperature of the hydrogen gas fuel F1, and the hydrogen proportion in the hydrogen gas fuel F1 increases as the water is removed from the hydrogen gas fuel F1. The condensed water is discharged from the hydrogen gas fuel supply line L100, for example, via drain L121. As a result, the hydrogen partial pressure becomes a pressure excluding the saturated water vapor pressure at 20°C from 151 kPa, and the hydrogen proportion in the hydrogen gas fuel F1 in the temperature / pressure detection region R2 is calculated to be 98.5%. Meanwhile, in the section from the temperature / pressure detection region R2 to the pressure regulation region R3, the volume of the hydrogen gas fuel F1 expands due to the drop in pressure, but the hydrogen proportion in the hydrogen gas fuel F1 does not change.

[0044] The "pressure drop increase" shown in Figure 3 refers to a situation where pressure drop in the piping increases in the first section K1 due to factors such as adjusting the opening of a valve (not shown) in the hydrogen gas fuel supply line L100, clogging of a strainer (not shown), or changes to the piping. When pressure drop increases as shown in Figure 3, the pressure (absolute pressure, gauge pressure) of the hydrogen gas fuel F1 in the temperature / pressure detection region R2 decreases compared to the preset value, and the gauge pressure is assumed to be 20 kPa. Furthermore, at this time, the hydrogen partial pressure decreases due to the decrease in pressure of the hydrogen gas fuel F1, and the hydrogen fraction of the hydrogen gas fuel F1 in the pressure regulation region R3 decreases from the preset value of 98.5% to 98.1%.

[0045] The "temperature rise" state shown in FIG. 3 assumes a case in which the temperature of the hydrogen gas fuel F1 in the temperature / pressure detection region R2 rises above the "set time" state due to factors such as an increase in the temperature of the hydrogen gas fuel F1 supplied from the water electrolysis device 51. During the temperature rise state shown in FIG. 3, the temperature of the hydrogen gas fuel F1 is assumed to be 60°C in the water seal outlet region R1 and 30°C in the temperature / pressure detection region R2, higher than the temperature of the hydrogen gas fuel F1 in the water seal outlet region R1 and the temperature / pressure detection region R2 at the set time. Because the temperature of the hydrogen gas fuel F1 in the water seal outlet region R1 and the temperature / pressure detection region R2 rises compared to the set time, the saturated water vapor pressure increases and the hydrogen partial pressure decreases. As a result, the hydrogen content of the hydrogen gas fuel F1 in the pressure regulation region R3 decreases from 98.5% at the set time to 97.2% at the temperature rise state.

[0046] The "temperature reversal" shown in Figure 3 refers to a situation where the temperature of the hydrogen gas fuel F1 is higher in the temperature / pressure detection region R2 than in the water seal outlet region R1, such as when the water temperature of the water seal flashback prevention device 52 is low and the temperature of the hydrogen gas fuel F1 in the water seal outlet region R1 is lower than the ambient temperature. During the temperature reversal shown in Figure 3, the temperature of the hydrogen gas fuel F1 is assumed to be 10°C in the water seal outlet region R1 and 20°C in the temperature / pressure detection region R2, and the gauge pressure of the hydrogen gas fuel F1 is assumed to be 50 kPa in the water seal outlet region R1 and 45 kPa in the temperature / pressure detection region R2.

[0047] At this time, the temperature of the hydrogen gas fuel F1 in the water seal outlet region R1 is at its lowest, so no water is lost as condensed water from the hydrogen gas fuel F1 in the hydrogen gas fuel supply line L100. In this case, the hydrogen proportion of the hydrogen gas fuel F1 does not change due to a temperature increase and pressure decrease (pressure decrease by the pressure regulating unit 108) of the hydrogen gas fuel F1 in the hydrogen gas fuel supply line L100, and the hydrogen proportion calculated from the saturated water vapor pressure and hydrogen partial pressure in the water seal outlet region R1 is maintained also in the pressure regulating region R3. It should be noted that the temperature and pressure changes shown in FIG. 3 are an example based on a simplified model, and do not take into consideration small temperature and pressure changes that actually occur in the boiler system 1 and the boiler 10.

[0048] When the hydrogen gas fuel F1 contains saturated water vapor, if the temperature of the hydrogen gas fuel F1 is constant, the hydrogen proportion in the hydrogen gas fuel F1 decreases as the pressure of the hydrogen gas fuel F1 decreases. On the other hand, if the pressure of the hydrogen gas fuel F1 is constant, the water vapor contained in the hydrogen gas fuel F1 is lost as condensed water due to the decrease in the temperature of the hydrogen gas fuel F1, and the hydrogen proportion in the hydrogen gas fuel F1 increases.

[0049] The hydrogen gas fuel F1, which has passed through the water seal flashback prevention device 52 and contains saturated water vapor, generally has a lower pressure and temperature the further downstream it is along the hydrogen gas fuel supply line L100. By measuring the pressure and temperature of the hydrogen gas fuel F1 at the most downstream point where the hydrogen gas fuel F1 contains saturated water vapor (i.e., the point downstream where there is no condensation of water and the gas composition does not change, and the point downstream where the gas density depends on the pressure of the hydrogen gas fuel F1), the saturated water vapor pressure can be estimated from the temperature of the hydrogen gas fuel F1, and the hydrogen percentage of the hydrogen gas fuel F1, etc. can be calculated from this saturated water vapor pressure and the pressure of the hydrogen gas fuel F1. Therefore, the proportion of hydrogen in the hydrogen gas fuel F1 that passes through the water seal flashback prevention device 52 and contains saturated water vapor is evaluated by the water vapor evaluation unit 62 based on the detection results of the first temperature sensor 105 and the first pressure sensor 104 provided in the temperature / pressure detection area R2, and the flow rate correction unit 63 can correct the first flow rate adjustment value based on that.

[0050] Furthermore, when the temperature of the hydrogen gas fuel F1 in the temperature / pressure detection region R2 is higher than the temperature of the hydrogen gas fuel F1 in the water seal outlet region R1, the hydrogen gas fuel F1 contains saturated water vapor only in the water seal outlet region R1, and therefore the water vapor evaluation unit 62 evaluates the state of the water vapor in the hydrogen gas fuel F1 based on the detection results of the second temperature sensor 103 and the second pressure sensor 102 provided in the water seal outlet region R1, and the flow rate correction unit 63 can correct the first flow rate adjustment value based on that.

[0051] In addition, when the temperature of the hydrogen gas fuel F1 in the temperature / pressure detection region R2 (i.e., the detection result of the first temperature sensor 105) is used to evaluate the state of water vapor in the hydrogen gas fuel F1, and there is no substantial difference between the temperature of the hydrogen gas fuel F1 in the temperature / pressure detection region R2 (i.e., the detection result of the first temperature sensor 105) and the temperature of the hydrogen gas fuel F1 in the pressure stabilization region R3 (i.e., the detection result of a temperature sensor not shown in the figure provided in the pressure stabilization region R3), the temperature of the hydrogen gas fuel F1 in the pressure stabilization region R3 (the detection result of a temperature sensor not shown in the figure provided in the pressure stabilization region R3) may be used to calculate the hydrogen ratio, etc., rather than the temperature of the hydrogen gas fuel F1 in the temperature / pressure detection region R2.

[0052] When hydrogen gas fuel F1 is supplied to the burner 21 at a predetermined flow rate, the boiler 10 and boiler system 1 of this embodiment adjust the supply amount of hydrogen gas fuel F1 in consideration of changes in the composition or calorific value of the hydrogen gas fuel F1 due to changes in the temperature and pressure of the hydrogen gas fuel F1, thereby suppressing fluctuations in the amount of heat input and achieving stable operation. Specifically, the boiler 10 and boiler system 1 of this embodiment achieve stable operation as follows.

[0053] The boiler 10 sets the flow rate of the combustion air A1 in accordance with the required load required by a load device (not shown). The control unit 60 calculates the frequency of the blower 31 and the opening degree of the damper 303 based on the flow rate of the combustion air A1 set in accordance with the required load. The control unit 60 then controls the inverter 32 based on the calculated frequency, and the blower 31 drives the fan at a rotation speed corresponding to the frequency. The control unit 60 also adjusts the opening degree of the damper 303. As a result, the control unit 60 adjusts the flow rate of the combustion air A1 supplied to the burner 21.

[0054] The flow rate control unit 64 controls the aperture of the flow rate adjustment valve 111 based on an aperture value set to ensure a flow rate of the hydrogen gas fuel F1 that corresponds to the required load. This aperture value is set to ensure a flow rate of the hydrogen gas fuel F1 that can obtain a combustion amount that corresponds to the load requirement based on the flow rate of the combustion air A1 supplied from the air supply line L300. This allows the flow rate control unit 64 to control the flow rate of the hydrogen gas fuel F1 based on the flow rate of the combustion air A1. The first storage unit 611 stores a function formula or a data table or the like that sets an opening value corresponding to the flow rate of the combustion air A1 under predetermined conditions, and is used to calculate the opening value. The predetermined conditions here refer to various conditions that are set in advance, such as a reference calorific value based on the composition of the hydrogen gas fuel F1, a temperature (combustion air, etc.), and an air ratio.

[0055] The hydrogen gas fuel F1 ejected from the burner 21 is ignited by a pilot burner (not shown) or the like, and is burned in the combustion chamber B. The heat generated by the combustion of the hydrogen gas fuel F1 heats the water in a water pipe (not shown) in the can body 20, generating steam, which is supplied to a load device (not shown). The combustion gas is exhausted to the outside of the system through an exhaust pipe (not shown).

[0056] During boiler operation, the water vapor evaluation unit 62 compares the detection result of the second temperature sensor 103 with the detection result of the first temperature sensor 105, and if the detection result of the first temperature sensor 105 is higher than the detection result of the second temperature sensor 103, acquires the detection results of the second temperature sensor 103 and the second pressure sensor 102 and evaluates the state of the water vapor contained in the hydrogen gas fuel F1 based on the acquired detection results. Also, if the detection result of the second temperature sensor 103 is equal to or higher than the detection result of the first temperature sensor 105, the water vapor evaluation unit 62 acquires the detection results of the first temperature sensor 105 and the first pressure sensor 104 and evaluates the state of the water vapor contained in the hydrogen gas fuel F1 based on the acquired detection results.

[0057] As described above, the state of water vapor contained in the hydrogen gas fuel F1 refers to the pressure and proportion of water vapor contained in the hydrogen gas fuel F1, and is information that can be used to correct the flow rate of the hydrogen gas fuel F1. From the pressure and proportion of water vapor contained in the hydrogen gas fuel F1, the flow rate corrector 63 can calculate the gas density of the hydrogen gas fuel F1, the hydrogen proportion of the hydrogen gas fuel F1, the composition of the hydrogen gas fuel F1, the heat quantity per unit volume of the hydrogen gas fuel F1, etc., at the gas temperature at which the pressure and proportion of water vapor have been calculated.

[0058] Next, the flow rate correction unit 63 calculates a second flow rate adjustment value V2 by correcting the first flow rate adjustment value V1 read from the first storage unit 611, or calculates a correction coefficient X1 for correcting the first flow rate adjustment value V1, based on the evaluation result of the water vapor evaluation unit 62. Note that the first flow rate adjustment value V1 may be provided in the flow rate correction unit 63. The flow rate correction unit 63 calculates the hydrogen proportion of the hydrogen gas fuel F1 at the gas temperature at which the water vapor state is evaluated, based on the state of water vapor (water vapor pressure and proportion) in the hydrogen gas fuel F1 evaluated by the water vapor evaluation unit 62, and based on this, calculates the density (gas density) and calorific value per unit volume in the hydrogen gas fuel F1. Then, the flow rate correction unit 63 calculates a second flow rate adjustment value V2 or a correction coefficient X1 based on the density (gas density) and calorific value per unit volume in the hydrogen gas fuel F1.

[0059] The first flow rate adjustment value V1 is a value that sets the aperture of the flow rate adjustment valve 111, which is a flow rate adjustment unit, and is a value associated with the combustion amount required for the boiler 10. This first flow rate adjustment value V1 is a value set corresponding to a predetermined temperature and pressure of the hydrogen gas fuel F1. The temperature and pressure of the hydrogen gas fuel F1 are, for example, the temperature and pressure at the aperture setting of the fuel lower valve corresponding to the flow rate of the combustion air A1 during test operation of the boiler system 1 and the boiler 10, and do not need to be stored in the first storage unit 611 but may be stored in a location separate from the control unit 60. Also, for example, the flow rate correction unit 63 may hold a standard value of the calorific value corresponding to the flow rate of the combustion air A1, and correct the first flow rate adjustment value V1 based on this standard value and the evaluation result of the water vapor evaluation unit 62.

[0060] The first flow rate adjustment value V1 is corrected by the flow rate correction unit 63 and stored as the second flow rate adjustment value V2 in the second storage unit 612. Note that the correction result by the flow rate correction unit 63 may be acquired by the flow rate control unit 64 without being stored in the second storage unit 612. The flow rate control unit 64 controls the flow rate adjustment valve 111, which is a flow rate adjustment unit, based on the second flow rate adjustment value V2 stored in the second storage unit 612, and adjusts the flow rate of the hydrogen gas fuel F1. In this way, by correcting the opening of the flow rate adjusting valve 111 in accordance with the state of water vapor in the hydrogen gas fuel F1, it is possible to ensure a standard calorific value set in accordance with the combustion amount.

[0061] Even if at least one of the temperature and pressure of the hydrogen gas fuel F1 changes during operation of the boiler 10 and the boiler system 1, the water vapor evaluation unit 62 evaluates the state of the water vapor contained in the hydrogen gas fuel F1 based on the detection result of the temperature detection unit (the detection result of the first temperature sensor 105 or the detection result of the second temperature sensor 103) and the detection result of the pressure detection unit (the detection result of the first pressure sensor 104 or the detection result of the second pressure sensor 102), and based on the evaluation result, the flow rate correction unit 63 corrects the first flow rate adjustment value V1 to calculate a second flow rate adjustment value V2, or calculates a correction coefficient X1 for correcting the first flow rate adjustment value V1. The second flow rate adjustment value V2 (the corrected first flow rate adjustment value V1) is stored in the second storage unit 612. The flow rate control unit 64 adjusts the opening degree of the flow rate adjustment valve 111 and the like based on the second flow rate adjustment value V2 stored in the second storage unit 612 or the correction coefficient X1, thereby adjusting the flow rate of the hydrogen gas fuel F1. Therefore, even if the temperature or pressure of the hydrogen gas fuel F1 changes during operation of the boiler 10 and the boiler system 1, the flow rate of the hydrogen gas fuel F1 can be adjusted in response to the change, and stable operation can be continued.

[0062] As described above, according to this embodiment, even when the temperature or pressure of the hydrogen gas fuel F1 changes, the flow rate of the hydrogen gas fuel F1 can be adjusted to achieve the required combustion amount. Therefore, the boiler 10 and the boiler system 1 can maintain a constant combustion amount and operate stably. This allows the boiler 10 and the boiler system 1 to stably supply steam to the load equipment.

[0063] As described above, the present embodiment provides the following advantages. (1) The boiler 10 is a boiler that burns hydrogen gas fuel F1 containing water vapor as fuel, and includes a burner 21 that sprays the hydrogen gas fuel F1, a hydrogen gas fuel supply line L100 that supplies the hydrogen gas fuel F1 to the burner 21, and a control unit 60 that controls the operation of the boiler 10. The hydrogen gas fuel supply line L100 includes a pressure regulating unit 108 that adjusts the pressure of the hydrogen gas fuel F1 within a predetermined range, a flow rate regulating valve 111 that is a flow rate regulating unit that adjusts the flow rate of the hydrogen gas fuel F1, a first pressure sensor 104 that is a first pressure detecting unit that is arranged upstream of the flow rate regulating valve 111 and the pressure regulating unit 108 and that detects the pressure of the hydrogen gas fuel F1, and a first temperature sensor 105 that is arranged upstream of the first pressure sensor 104 and that detects the temperature of the hydrogen gas fuel F1. The control unit 60 includes a first memory unit 611 that stores a first flow rate adjustment value V1 of the flow rate adjustment valve 111 at a predetermined temperature and pressure of the hydrogen gas fuel F1 associated with the required combustion amount, a water vapor evaluation unit 62 that evaluates the state of the water vapor contained in the hydrogen gas fuel F1 supplied to the burner 21 based on the detection results of the first temperature sensor 105 and the first pressure sensor 104, a flow rate correction unit 63 that corrects the first flow rate adjustment value V1 based on the evaluation result of the water vapor evaluation unit 62, and a flow rate control unit 64 that controls the flow rate adjustment valve 111 based on the correction result of the flow rate correction unit 63.

[0064] This allows the boiler 10 to grasp the state of water vapor in the hydrogen gas fuel F1 and calculate the gas density, calorific value, hydrogen proportion, etc. of the hydrogen gas fuel F1. Even when the temperature or pressure of the hydrogen gas fuel F1 changes, the boiler 10 can adjust the flow rate of the hydrogen gas fuel F1 in response to changes in the hydrogen proportion in the hydrogen gas fuel F1, thereby suppressing fluctuations in the heat input of the boiler 10. Therefore, the boiler 10 can operate stably.

[0065] (2) The boiler 10 has a flow rate adjusting unit which is a flow rate adjusting valve 111 in which an increase in the opening degree of the valve is proportional to an increase in the flow rate of the hydrogen gas fuel F1. Therefore, since an increase in the valve opening of the flow rate adjustment valve 111 and an increase in the flow rate of the hydrogen gas fuel F1 are proportional, the opening of the flow rate adjustment valve 111 can be easily corrected.

[0066] (3) In the boiler 10, the flow rate correction unit 63 calculates the density and calorific value per unit volume of the hydrogen gas fuel F1 based on the evaluation results of the water vapor evaluation unit 62, and corrects the first flow rate adjustment value V1 based on the calculated density and calorific value. This makes it possible to correct the influence of a change in flow rate due to a change in density of the hydrogen gas fuel F1, and to more accurately correct the first flow rate adjustment value V1.

[0067] (4) The boiler system 1 comprises a boiler 10 described in any one of (1) to (3) above, a water seal flashback prevention device 52 which is an addition unit provided upstream of the hydrogen gas fuel supply line L100 and which adds moisture to the hydrogen gas fuel F1, a second temperature sensor 103 which is a second temperature detection unit which detects the temperature of the hydrogen gas fuel F1 to which moisture has been added by the water seal flashback prevention device 52, and a second pressure sensor 102 which is a second pressure detection unit provided near the second temperature sensor 103 and which detects the pressure of the hydrogen gas fuel F1. The water vapor evaluation unit 62 compares the detection result of the first temperature sensor 105 with the detection result of the second temperature sensor 103, and if the detection result of the second temperature sensor 103 is higher than the detection result of the first temperature sensor 105, evaluates the state of the water vapor contained in the hydrogen gas fuel F1 supplied to the burner 21 based on the detection results of the first temperature sensor 105 and the first pressure sensor 104, and if the detection result of the first temperature sensor 105 is higher than the detection result of the second temperature sensor 103, evaluates the state of the water vapor contained in the hydrogen gas fuel F1 supplied to the burner 21 based on the detection results of the second temperature sensor 103 and the second pressure sensor 102.

[0068] Depending on the distance and installation location of the hydrogen gas fuel supply line L100, there may be cases where the temperature of the hydrogen gas fuel F1 near the flow rate control valve 111, which is the flow rate control unit, is higher than the temperature of the hydrogen gas fuel F1 at the time when moisture is added by the water seal flashback prevention device 52. However, even in such cases, the water vapor evaluation unit 62 compares the detection results of each temperature sensor as described above and selects the temperature of the hydrogen gas fuel F1 to be used for evaluating the state of the water vapor, so that the state of the water vapor in the hydrogen gas fuel F1 (water vapor amount, etc.) can be evaluated with high accuracy and the hydrogen proportion of the hydrogen gas fuel F1 supplied to the burner 21 can be appropriately evaluated. Therefore, the boiler system 1 including the boiler 10 can respond to temperature and pressure changes of the hydrogen gas fuel F1 containing water vapor and perform stable operation.

[0069] (Variations) The present invention is not limited to the above-described embodiment, and various modifications and variations are possible, and these are also within the scope of the present invention. The first temperature sensor 105 may be disposed upstream of the first pressure sensor 104 as long as the temperature of the hydrogen gas fuel F1 in the vicinity of the first pressure sensor 104 can be detected.

[0070] The boiler 10 has been shown to have a configuration in which the flow rate adjusting valve 111 is provided as a flow rate adjusting section, but is not limited to this, and a mass flow controller or the like may also be provided.

[0071] The first storage unit 611 may store the temperature and pressure of the hydrogen gas fuel F1 corresponding to the first flow rate adjustment value V1 together with the first flow rate adjustment value V1. Furthermore, the first flow rate adjustment value V1 may be the valve opening degree of the flow rate adjustment valve 111, or, if a mass flow controller is provided as the flow rate adjustment unit as described above, it may be a value (including voltage, etc.) for adjusting the flow rate.

[0072] The flow control valve 111 has been described as having a linear characteristic in which the opening degree is proportional to the flow rate of the hydrogen gas fuel F1, but this is not limited thereto, and the flow control valve may have an equal percentage characteristic, or may have a characteristic in which the opening degree is not proportional to the flow rate.

[0073] The boiler system 1 has been shown as an example equipped with a water seal flashback prevention device 52 and a water wash cooling tower 53 as moisture addition sections that add moisture to the hydrogen gas fuel F1, but is not limited to this, and the boiler system 1 may have at least one of the water seal flashback prevention device 52 or the water wash cooling tower 53 as the moisture addition section.

[0074] The present invention is not limited to the above-described embodiments, but may be combined with other embodiments as desired.

[0075] Furthermore, the present invention promotes the use of hydrogen as a fuel, which does not emit carbon dioxide, and can therefore contribute to, for example, Goal 7 of the United Nations-led Sustainable Development Goals (SDGs), which is to "ensure access to affordable, reliable, sustainable and modern energy." [Explanation of symbols]

[0076] 1. Boiler system 10. Boiler 20 can body 21 Burner 23 Window Box 50 Hydrogen supply equipment 51 Water electrolysis equipment 52 Water ring type flashback prevention device (moisture addition part) 53 Water washing cooling tower (moisture addition section) 60 Control Unit 61 Storage section 611 1st memory section 612 2nd memory section 62 Water Vapor Evaluation Section 63 Flow rate correction section 64 Flow control section 102 second temperature sensor (second temperature detection unit) 103 second pressure sensor (second pressure detection unit) 104 first pressure sensor (first pressure detection unit) 105 first temperature sensor (first temperature detection unit) 108 Pressure Regulating Unit 110 Pressure Gauge 111 Flow control valve (flow control part) L100 Hydrogen gas fuel supply line L300 Air Supply Line

Claims

1. A boiler that burns hydrogen gas fuel containing steam as fuel, a burner that ejects the hydrogen gas fuel; a hydrogen gas fuel supply line for supplying the hydrogen gas fuel to the burner; a control unit for controlling the operation of the boiler; Equipped with The hydrogen gas fuel supply line a pressure adjusting unit that adjusts the pressure of the hydrogen gas fuel within a predetermined range; a flow rate adjusting unit that adjusts the flow rate of the hydrogen gas fuel; a first pressure detection unit that is disposed upstream of the flow rate adjustment unit and the pressure regulation unit and detects the pressure of the hydrogen gas fuel; a first temperature detection unit disposed near the first pressure detection unit and configured to detect a temperature of the hydrogen gas fuel; Equipped with The control unit a first storage unit configured to store a first flow rate adjustment value of the flow rate adjustment unit at a predetermined temperature and pressure of the hydrogen gas fuel associated with a required combustion amount; a water vapor evaluation unit that evaluates a state of water vapor contained in the hydrogen gas fuel supplied to the burner based on a detection result of the first temperature detection unit and a detection result of the first pressure detection unit; a flow rate correcting unit that corrects the first flow rate adjustment value based on the evaluation result of the water vapor evaluating unit; a flow rate control unit that controls the flow rate adjustment unit based on a correction result of the flow rate correction unit; A boiler equipped with:

2. the flow rate adjusting unit is a flow rate adjusting valve in which an increase in the opening degree of the valve is proportional to an increase in the flow rate of the hydrogen gas fuel; The boiler of claim 1.

3. the flow rate correction unit calculates a density and a calorific value per unit volume of the hydrogen gas fuel based on the evaluation result of the water vapor evaluation unit, and corrects the first flow rate adjustment value based on the calculated density and the calculated calorific value. The boiler of claim 1.

4. The boiler according to claim 1; a moisture addition unit provided upstream of the hydrogen gas fuel supply line and configured to add moisture to the hydrogen gas fuel; a second temperature detection unit that detects the temperature of the hydrogen gas fuel to which moisture has been added by the moisture addition unit; a second pressure detection unit disposed near the second temperature detection unit and configured to detect the pressure of the hydrogen gas fuel; Equipped with the water vapor evaluation unit compares the detection result of the first temperature detection unit with the detection result of the second temperature detection unit; When the detection result of the second temperature detection unit is equal to or higher than the detection result of the first temperature detection unit, a state of water vapor contained in the hydrogen gas fuel supplied to the burner is evaluated based on the detection results of the first temperature detection unit and the first pressure detection unit; When the detection result of the first temperature detection unit is higher than the detection result of the second temperature detection unit, the boiler system evaluates the state of the water vapor contained in the hydrogen gas fuel supplied to the burner based on the detection results of the second temperature detection unit and the second pressure detection unit.

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