Hydrogen burner generator and power generation system

Abstract

To provide a hydrogen burner power generator that uses hydrogen as fuel.SOLUTION: A hydrogen burner power generator 110 uses hydrogen gas and oxygen gas as fuel. The hydrogen burner power generator includes: a hydrogen burner 102 to which hydrogen gas and oxygen gas are supplied to generate a flame; a turbine part 103 that rotates by receiving kinetic energy of the flame of the hydrogen burner 102; a power generator 104 that rotates a rotor through the rotation of a central shaft of the turbine part 103 to generate electric power; an inverter 105 that converts output of the power generator 104; and a control section 106 that controls the inverter 105.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a hydrogen burner generator and a power generation system that use hydrogen as fuel.

Background Art

[0002] In recent years, concerns about global warming have increased, and there has been a growing demand to suppress the emission of carbon dioxide (CO2). Along with this trend, power generation using hydrogen-oxygen as fuel has been studied, but all of them are on a large scale and can be said to be unsuitable for small-scale power generation applications.

[0003] On the other hand, the daily power consumption of a general household is approximately 10 kW, and it is not necessary to use large-scale hydrogen turbine power generation equipment. In addition, a hydrogen burner generator burns hydrogen and oxygen, and the combustion products become harmless water.

[0004] As described above, although generators using hydrogen as fuel have the drawback of low combustion heat, they can provide various advantages. However, currently developed hydrogen turbine power generation is only for large-scale power generation devices, and it still takes a long time to put them into practical use. This is because problems such as turbine design and combustion stability when burning hydrogen are involved.

[0005] Power generation methods using the combustion of hydrogen and oxygen have been studied variously. For example, in Japanese Patent Application Laid-Open No. 2016-146679 (Patent Document 1), there is a power supply system that uses both a generator that converts renewable energy into electrical energy and power generation by an engine generator. A part of the electrical energy obtained by the generator is supplied to an electrolysis device to produce hydrogen and oxygen, and the produced hydrogen and oxygen are directly supplied to the engine generator, and power generation is performed by the engine generator using at least one of hydrogen or engine fuel as fuel.

[0006] Furthermore, Japanese Patent Publication No. 2001-197790 (Patent Document 2) describes a hybrid generator configured to pressurize hydrogen generated by the electrolysis of water, drive a turbine generator with the pressurized hydrogen, and supply the hydrogen released from the turbine generator as fuel to a fuel cell or hydrogen engine generator, thereby storing the power generated by the fuel cell or hydrogen engine generator and the power generated by the first turbine generator in a secondary battery. In addition, Japanese Patent Publication No. 2003-254012 (Patent Document 3) describes an exhaust turbine that generates electricity by burning hydrogen, but it operates solely on the pressure of the burnt water vapor, and has the problem that it cannot achieve sufficient efficiency from the viewpoint of utilizing the dynamic pressure of the combustion gas.

[0007] Conversely, it is known that small hydrogen burners can maintain a flame from a low temperature of 280°C by adjusting, for example, the mixing ratio of oxygen and hydrogen, and there are no material limitations compared to the large systems described in Patent Documents 1 and 2. Furthermore, hydrogen tanks installed in fuel cell vehicles, for example, can store about 6 kg of hydrogen gas at a pressure of about 20-80 MPa (about 800 atmospheres), and it can be said that the decrease in the heat of combustion of hydrogen can be compensated for by the pressurized energy stored in the hydrogen tank. [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] Japanese Patent Publication No. 2016-146679 [Patent Document 2] Japanese Patent Publication No. 2001-197790 [Overview of the project] [Problems that the invention aims to solve]

[0009] The present invention has been made in view of the problems of the prior art described above, and aims to provide a small hydrogen burner generator (SHBGE: Small Hydrogen Burner Generating Electricity) and power generation system that uses hydrogen and oxygen as fuel and oxidizer, respectively. [Effects of the Invention]

[0010] According to the present invention, it is possible to provide a small hydrogen burner generator and power generation system that does not emit CO2 or nitrogen oxides, has a low environmental impact, provides a cogeneration system for home use, and enables the effective use of waste heat and combustion product water. [Means for solving the problem]

[0011] According to this embodiment, A hydrogen burner generator that uses hydrogen gas and oxygen as fuel, A hydrogen burner to which the hydrogen gas and oxygen are supplied to generate a high-temperature combustion gas, A turbine that rotates using the kinetic energy of the combustion gas of the hydrogen burner, wherein the combustion gas flowing into the turbine is directed around a central shaft. Across the disk from the generator, from the center A turbine, which discharges through radially arranged turbine blades, deflecting the discharge to the opposite side of the generator located across the disk, On the downstream side in the flow direction, where the combustion gas discharged from the hydrogen burner is received, A generator that generates electricity by rotating the rotor of the generator located on the opposite side of the disk due to the rotation of the central shaft of the turbine blade that receives the exhausted combustion gas, An inverter for converting the output of the aforementioned generator, A control unit that controls the inverter and A hydrogen burner generator is provided, including one that includes this feature.

[0012] Furthermore, the system is equipped with a waste heat recovery device for recovering heat from the combustion gases of the turbine, and the waste heat recovery device recovers water generated by the combustion of the hydrogen gas and the oxygen gas.

[0013] Furthermore, the waste heat recovery device includes a heat exchanger that provides the recovered water for cogeneration.

[0014] The hydrogen burner includes a housing, a core disposed inside the housing for forming an oxygen flow path, and a hydrogen pipe extending into the housing through the center of the housing and the core. The tip of the core is formed with a taper toward the tip of the hydrogen burner. The hydrogen pipe is provided with a leak hole for leaking the hydrogen gas to form a high oxygen concentration region.

Brief Description of the Drawings

[0015] [Figure 1] FIG. 1 is a block diagram of an exemplary embodiment. [Figure 2] FIG. 2 is a schematic diagram showing the positional relationship between the turbine section 103 and the burner 102 of the present embodiment. [Figure 3] FIG. 3 is a view showing an exemplary embodiment of the turbine blade 130a and the central shaft 130b as viewed from above in FIG. 2. [Figure 4] FIG. 4 is a view showing the detailed cross-sectional structure of the burner 102 of the present embodiment.

Description of the Reference Numerals

[0016] 30a: Turbine blade 100: Hydrogen supply source 100a: Oxygen supply source 101: Check valve 102: Hydrogen burner 102a: Flame 102b: Housing 102c: Hydrogen pipe 102d: Core 102e: Hole 102f: Spark gap 102g: Piezoelectric element 102h: Thermocouple 103: Turbine section 130a: Turbine blade 130b: Central shaft 130c: Disc 104: Generator 105: Inverter 106: Control Unit 107:Heat exchanger 108: Condenser 109: Recovered water tank 110: Hydrogen burner generator 111: Pump 113: Fan 120: Waste heat recovery device 130: Impulse Turbine 130a: Turbine blade 130a-1: Outer edge 130a-1: End 130a-2: End 130b: Central shaft 130c: Disc [Modes for carrying out the invention]

[0017] The present invention will be described below with reference to embodiments, but the present invention is not limited to these embodiments. Modifications, alterations, alternatives, and other design considerations and equivalents that can be commonly made by those skilled in the art are intended to be included within the scope of the present invention.

[0018] Figure 1 is a block diagram of an exemplary embodiment. The hydrogen burner generator of this embodiment (and the power generation system as a whole, as shown in Figure 1) includes a hydrogen supply source 100, a hydrogen burner generator 110, and optionally a waste heat recovery device 120. The hydrogen supply source 100 can be, for example, a hydrogen tank from a fuel cell vehicle, which can safely hold about 6 kg of hydrogen gas at about 80 MPa. In the most readily available embodiment, a commercially available hydrogen tank from a fuel cell vehicle can be used. Alternatively, a dedicated hydrogen tank with similar functionality to that of a fuel cell vehicle can be installed in a home, for example, similar to a kerosene tank, to serve as a hydrogen supply source. Furthermore, hydrogen from an unused fuel cell vehicle can be used as a hydrogen source.

[0019] Furthermore, if, for example, an infrastructure is established in the future that allows for the supply of hydrogen fuel in the same way as city gas, then the same supply system as for city gas can be used.

[0020] The hydrogen burner generator 110 comprises a hydrogen burner 102 (hereinafter referred to as burner 102 for simplification), a flow rate adjustment / check valve 101, a turbine section 103, and a generator 104. The flow rate adjustment / check valve 101 provides the function of controlling fluid communication and flow rate between the hydrogen supply source 100 and the burner 102. The burner 102 uses hydrogen gas supplied from the hydrogen supply source 100 and oxygen supplied from the oxygen supply source 100a as a fuel composition to generate a high-temperature, high-pressure flame 102a. The flame 102a is directed toward the turbine section 103, and its kinetic and thermal energy rotates the turbine blades (also called impellers: not shown) in the turbine section 103 at 70,000 to 200,000 rpm. The shaft of the turbine section 103 is connected to the generator 104 located on the front side of the paper, and rotates the rotor of the generator 104, generating electricity through induced electromotive force between it and the stator (magnet or coil).

[0021] Furthermore, the hydrogen burner generator 110 is equipped with an inverter (INV) 105, which converts the alternating current generated by the generator 104 into alternating current and direct current of the desired voltage and frequency, enabling the operation of household electrical appliances and the like. The inverter 105 is controlled by a control unit 106 installed within the hydrogen burner generator 110, which controls the voltage and frequency of the generated alternating current power using power supplied from a secondary battery, such as a lithium-ion battery 106a. After the hydrogen burner generator 110 reaches steady-state operation, it can be autonomously controlled without receiving power from the lithium-ion battery by using the DC power separately output from the inverter 105. The generated DC power can also be used to charge the secondary battery 106a.

[0022] Furthermore, the control unit 106 receives a signal from a temperature sensor (not shown) located inside the burner 102 to check the combustion of hydrogen gas, detects whether the ignition and combustion of hydrogen gas are normal or abnormal, and simultaneously determines whether hydrogen is being generated when an abnormality occurs. In response to the detection of an abnormality, it stops the flow rate adjustment / check valve 101 to stop the supply of hydrogen and continues to supply oxygen in order to lower the hydrogen concentration inside the burner 102.

[0023] The combustion gas from the turbine section 103 contains excess oxygen and combustion product water, and does not contain any environmentally harmful CO2 or NOx. In the illustrated embodiment, the combustion gas is sent to an optional waste heat recovery device 120. The waste heat recovery device 120 may include a heat exchanger 107 and a condenser 108. An exhaust duct 103a extends from the back of the turbine section 103 to the heat exchanger 107, enabling efficient heat exchange of the combustion gas. The heat exchanger 107 performs heat exchange between the combustion gas and chilled water (recovered water) supplied from the recovery water tank 109 via a pump 111 that operates on electricity generated by the turbine. The regenerated water generated during heat exchange is also sent to the recovery water tank 109 via piping. The recovered water after heat exchange can be used for heating, cooling, or hot water supply in a home via piping.

[0024] The combustion gas after heat exchange from the heat exchanger 107 is sent to the condenser 108, where it further condenses the water contained in the exhaust gas discharged from the heat exchanger 107 and is sent to the recovery water tank 109. In this invention, the heat exchanger 107 also has the function of improving power generation efficiency by condensing water, which is the main component of the combustion products, and lowering the static pressure on the exhaust side (in short, by drawing the combustion gas from the upstream side), similar to the function of the high-pressure turbine of a turbofan engine. The condenser 108 can receive airflow from the fan 113. When using the fan 113, the power output from the inverter 105 can be used. The fan 113 also functions as an exhaust system to rapidly reduce the hydrogen concentration in the hydrogen burner generator 110 when hydrogen combustion stops.

[0025] The recovered water tank stores the water produced by the combustion of the burner 102, providing water for cogeneration and also functioning as a water storage tank to provide water for daily use in emergencies. Furthermore, by installing the recovered water tank 109 underground on the property of the home rather than above ground, the entire system, including the hydrogen burner generator 110, can be contained to a size comparable to, for example, EcoCute (registered trademark) or EneFarm (registered trademark).

[0026] Figure 2 is a schematic diagram showing the positional relationship between the turbine section 103 and the burner 102 in this embodiment. In this exemplary embodiment, the turbine section 103 is configured as an impulse turbine 130, and a configuration is adopted in which the turbine blades 130a are rotated by the kinetic energy of the flame from the burner 102. The reason for this is that if a reaction turbine is adopted, the amount of hydrogen supplied to the burner 102 becomes significantly large, making it unsuitable for small-scale power generation. However, depending on the amount of hydrogen used and the size of the system, the adoption of a reaction turbine using stator vanes and rotators is not ruled out, and the root of the turbine blades can be made into reaction blades. Furthermore, the hydrogen gas in this embodiment does not need to be as high-purity as that used in fuel cells, and general-purpose grade hydrogen gas or hydrogen gas produced by photosynthesis can be used.

[0027] On the far side of the turbine 130, a disc 130c is formed integrally with the central shaft 130b. This disc 130c functions as a flywheel, stabilizing the rotational motion of the turbine 130. A shaft to the generator 104 is inserted through the disc 130c via a suitable bearing mechanism, transmitting the rotational force of the turbine 130 to the generator 103.

[0028] Furthermore, the burner 102 is supplied with hydrogen from the hydrogen supply source 100, which has been reduced to a pressure of approximately 1 to 1 MPa. To prevent flame backpropagation, the mixed gas is supplied so that the flow velocity at the opening of the burner 102 is at least approximately 2 m / s. In this combustion state, the opening diameter of the burner 102 is approximately 1 cm. 2 Assuming a diameter of approximately 12 mm, the flow rate at room temperature and pressure is approximately 0.72 m³. 3 This is calculated as / hr. Assuming that approximately 50% of this is hydrogen fuel, the hydrogen consumption per hour is 0.36m³. 3 (Approximately 16g) is needed, and with a hydrogen tank capacity of 6kg in a fuel cell vehicle, continuous operation is possible for 375 hours (approximately 16 days), so power can be supplied for a sufficient period of time.

[0029] On the other hand, combustion gases with a flow velocity of 2 m / s are mainly composed of water (molecular weight 18), and this is present in 1 cm³. 2 If ejected from the opening at a flow velocity of 2 m / s, approximately 3 kg / m³ 3 It was calculated that this pressure would be generated. This calculation assumes that the oxygen-hydrogen mixed gas collides directly with the turbine blade 130a without combustion. Furthermore, considering the high temperature due to combustion, the combustion gas is expected to expand in volume by several times (1073K / 300K = 3.57, assuming the flame temperature of the burner 102 in this embodiment is approximately 800°C and the temperature of the fuel gas mixture is 27°C), so in this embodiment, it is expected to expand in volume by approximately 10 kg / m³. 3 It was shown that dynamic pressure up to a certain level could be generated, which was sufficient to drive the impulse turbine 130. Furthermore, in the arrangement shown in Figure 2, the combustion gas is exhausted toward the upper side of the paper and discharged into the exhaust duct 103a connected via a shroud formed in the casing that forms the turbine section 103. In addition, by extending the heat exchanger piping to an appropriate portion of the exhaust duct 103a and condensing water, the main component of the combustion gas, to reduce the dynamic pressure, more efficient exhaust efficiency can be achieved.

[0030] The impulse turbine 130 shown in Figure 2 comprises a central shaft 130b and a plurality of turbine blades 130a that extend radially outward from the central shaft 130b and along the axial direction of the central shaft 103b. The outer ends of the turbine blades 103a are subjected to dynamic pressure from the flame from the burner 102, which allows the central shaft 130b, which is rotatably held by bearing means such as ball bearings and thrust bearings, to rotate.

[0031] Page of central shaft 130b lower side In this direction, generator 104 is connected, and the central shaft The rotation of the shaft 130b causes the rotor of the generator 104 to rotate, generating electricity. The central shaft 130b side of the turbine blade 130a is formed to be narrow, and as the combustion gas moves along the turbine blade 130a toward the center, the dynamic pressure increases, making discharge more efficient. In addition, a rotary encoder (not shown) can be installed to detect the rotation of the turbine section 103 and monitor the operation of the turbine section 103.

[0032] Figure 2 also shows another embodiment of heat, in which burners 202 are placed above and below the turbine blades 130a to rotate the turbine section 103 more efficiently. When burners 102 and 202 are used, the rotational speed of the turbine section 103 can be improved while using the same amount of fuel gas mixture, enabling more efficient power generation. The burners 202 can be positioned at the same height as burner 102, offset in the plane of the paper, to apply dynamic pressure to the turbine 130 in tandem.

[0033] Figure 3 shows an exemplary embodiment of the turbine blades 130a and central shaft 130b as seen from above in Figure 2. The outer edge end 130a-1 of the turbine blade 130a is positioned along the central shaft 130b to efficiently receive the flame and convert the kinetic energy of the flame into rotational energy. The end 130a-2 of the turbine blade 130a on the central shaft 130b side may be inclined toward the right side of the paper to more efficiently discharge the combustion gases axially (to the left side of the paper). Furthermore, the impulse-reaction ratio of the turbine blades 130a can be configured differently from that shown in Figure 3 to optimize efficiency. Additionally, the outer edge end 130a-1 can be formed to be wider and the end 130a-2 to be narrower, allowing for efficient discharge of the combustion gases, whose static pressure increases as they move toward the center of the turbine blades 130a.

[0034] The turbine blades 130a and central shaft 130b shown in Figures 2 and 3 can be formed by forging, casting, powder metallurgy, or 3D printing. The central shaft 130b and turbine blades 130a can also be formed separately and connected by welding or dovetail joints. However, since the turbine blades 130a of this embodiment are small, do not bear a large load, and are intended for household use, it is preferable to form them by a 3D printer, which is inexpensive and easy to replace. Furthermore, the lifespan of the turbine blades 130a formed by 3D printing can be improved by coating the outer surface with, for example, metal oxide powder. In another embodiment, multiple burners 102 can be arranged on the upper or lower side along the circumferential direction of the turbine section 103 in order to ensure operational stability by reigniting in the event of a burner 102 going out.

[0035] Figure 4 shows a detailed cross-sectional structure of the burner 102 of this embodiment. The burner 102 used in this embodiment comprises a housing 102b, a core 102d disposed inside the housing 102b to form an oxide flow path, and a hydrogen pipe 102c extending through the center of the housing 102b and the core 102d to an appropriate position in the housing 102b.

[0036] Hydrogen gas is supplied to the hydrogen pipe 102c, and a leak hole 102e is formed circumferentially near its tip. The leak hole 102e can be a mechanically formed opening or, for example, formed from porous ceramics. A spark gap 102f is located directly downstream of the leak hole 102e. The leak hole 102e is formed to allow a small amount of supplied hydrogen gas to leak to the outside, thereby creating a high-oxygen concentration region in the fuel composition nearby. This is because, in an oxygen-rich environment, the combustion temperature can be kept low, approximately 800°C or below. The spark gap 102f is located in this low-temperature combustion region, and the high voltage generated by the piezoelectric element 102g enables ignition using the principle of a disposable lighter. For this purpose, the housing 102b and hydrogen pipe 102c are grounded, and the piezoelectric element 102g is connected to an insulated wire from the housing 102b and core 102d, enabling safe, on-demand ignition through actuation of the piezoelectric element 102g.

[0037] In an exemplary embodiment, the piezoelectric element 102g can be remotely activated via an indoor switch, allowing for ignition control from inside the room. Furthermore, the tip of the core 102d is tapered toward the tip of the burner 102, improving the mixing of oxygen gas flowing through the outer passage with the leak hole 102e and enabling rectification of the flame 102a. Additionally, multiple spiral grooves along the axial direction may be formed on the leak hole 102e side of the core 102d to generate a swirl, improving the mixing between the fuel and oxides and reducing the possibility of blow-off (extinguishing the flame).

[0038] Furthermore, a temperature sensor such as a thermocouple 102h is positioned in the low-temperature combustion region of the burner 102's casing. The thermocouple 102h monitors the combustion state, including ignition and combustion of hydrogen gas, and in the event of an abnormality such as blowout, the control unit 106 immediately stops the supply of hydrogen gas. If cost is not a consideration, a radiation thermometer can also be used as a temperature sensor, placed immediately behind the opening of the burner 102 to detect the flame temperature.

[0039] The generated flame 102a progresses from the low-temperature combustion region towards the burner opening, increasing its flame temperature. In this embodiment, the flame temperature near the burner opening is approximately 800°C. This temperature is comparable to the exhaust gas temperature of a reciprocating engine, allowing the use of conventional turbocharger impeller materials. Furthermore, even metal blades formed by 3D printing technology can be used, thus broadening material selectivity and providing a low-cost, compact hydrogen burner generator (SHBGE) and system. The hydrogen burner generator of this application can be incorporated into a module of a hydrogen-fueled reciprocating engine automobile, and the power generation system disclosed herein can be used as a power source for EVs other than fuel cell vehicles. Moreover, the power generation system of this embodiment is promising as a core system for generating lifelines such as heating, water, and electricity, as it can be used as fuel and oxidizer for rocket engines if humanity were to live on the moon or elsewhere in the near future.

[0040] Although the present invention has been described above with reference to embodiments, the present invention is not limited to the embodiments shown in the drawings. It can be modified to the extent that a person skilled in the art can conceive of other embodiments, additions, changes, deletions, etc., and any embodiment that achieves the function and effects of the present invention is included within the scope of the present invention.

Claims

1. A hydrogen burner generator that uses hydrogen gas and oxygen as fuel, A hydrogen burner to which the hydrogen gas and oxygen are supplied to generate a high-temperature combustion gas, A turbine that rotates using the kinetic energy of the combustion gas of the hydrogen burner, wherein the combustion gas flowing into the turbine is deflected and discharged on the opposite side of the generator, separated from the generator by a disk, via turbine blades arranged radially from the center of a central shaft, separated from the generator by a disk. A generator is provided that generates electricity by rotating the rotor of a generator located on the opposite side of the disk, on the downstream side in the flow direction from which the combustion gas discharged from the hydrogen burner is received, and by the rotation of the central shaft of the turbine blade that receives the discharged combustion gas. An inverter for converting the output of the aforementioned generator, A control unit that controls the inverter and including, Hydrogen burner generator.

2. Furthermore, it is equipped with a waste heat recovery device for recovering heat from the combustion gases from the turbine, The waste heat recovery device uses the combustion gas generated by the combustion of hydrogen gas and oxygen. A hydrogen burner generator according to claim 1, which recovers water.

3. Furthermore, the waste heat recovery device provides the recovered water for cogeneration. A hydrogen burner generator according to claim 2, comprising a heat exchanger.

4. The hydrogen burner comprises a housing and is positioned inside the housing to form an oxide channel. The core and the housing and the hydrogen pipe extending into the interior of the housing through the center of the core Prepare, The tip of the core is tapered toward the tip of the hydrogen burner. The hydrogen pipe is equipped with a rib for leaking the hydrogen gas to form a high oxygen concentration region. A hydrogen burner generator according to any one of claims 1 to 3, comprising a hole.

5. A power generation system comprising a hydrogen burner generator as described in claim 1.

Images