System and method for flashback arrest and flame temperature reduction for hydrogen-based fuels

Abstract

The present disclosure relates to hydrogen-based fuel combustion systems, and more particularly to systems and methods for flashback arrest and flame temperature reduction using a liquid barrier. A system for combusting hydrogen-based fuel includes a liquid reservoir containing a liquid and having an inlet configured to receive hydrogen-based fuel from a fuel source, a bubbler disposed within the liquid reservoir configured to receive the hydrogen-based fuel and disperse it through the liquid such that the fuel forms bubbles that rise through the liquid and exit at a liquid-air interface, and an ignitor positioned proximate the liquid-air interface configured to ignite the bubbles when they exit the liquid, wherein the liquid provides a barrier between the fuel source and a flame formed by combustion of the bubbles to arrest flashback.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application Ser. No. 63 / 780,809, filed on 31 Mar. 2025, which is incorporated herein by reference in its entirety as if fully set forth below.FIELD OF INVENTION

[0002] The present disclosure relates to hydrogen-based fuel combustion systems, and more particularly to systems and methods for flashback arrest and flame temperature reduction in hydrogen-based fuel combustion using a liquid barrier.BACKGROUND

[0003] Hydrogen is a versatile fuel that can be used across various sectors as an energy source, meeting the needs of a wide range of end users. Hydrogen fuel can be stored and converted into useful energy as needed, either by using it as a feedstock for fuel cells or through direct combustion, utilizing the thermal energy to drive turbines or support other heating applications. Unlike carbon-based fuels, which vary in composition due to differences in their carbon chains, hydrogen consists of a single element. While carbon-based fuels are often sector-specific, hydrogen is versatile enough to meet the energy demands across various sectors. Hydrogen combustion is an appealing option for thermal treatment applications such as heating, cooking, metallurgy, turbines, and more. Current hydrogen combustion systems typically employ metal burners and conventional gas delivery mechanisms to facilitate the combustion process.

[0004] However, existing hydrogen combustion systems suffer from several limitations. One challenge in safely using hydrogen for combustion arises when the gas flow velocity is lower than the flame speed. In such cases, the flame can backflow into the source, creating a safety hazard. This issue is particularly problematic during the start-up and shutdown phases of the combustion process, where achieving consistently high gas flow velocities may not be feasible. Additionally, conventional metal burner materials can reach temperatures approaching the flame temperature during combustion, which can contribute to elevated overall flame temperatures and thermal stress on system components. These deficiencies present obstacles to the safe and efficient deployment of hydrogen as a combustion fuel across various applications.

[0005] What is needed, therefore, is an improved hydrogen combustion system that addresses the challenge of flame backflow by providing a barrier between the flame and the fuel source. Such a system would mitigate flashback during periods of low fuel flow velocity while also maintaining lower temperatures at the flame base compared to conventional metal burner configurations.SUMMARY

[0006] This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.

[0007] According to an aspect of the present disclosure, a system for combusting hydrogen-based fuel can be provided. The system can include a liquid reservoir containing a liquid and having an inlet configured to receive hydrogen-based fuel from a fuel source. The system can include a bubbler disposed within the liquid reservoir and configured to receive the hydrogen-based fuel at the inlet and disperse the hydrogen-based fuel through the liquid such that the hydrogen-based fuel forms a plurality of bubbles that rise through the liquid and exit at a liquid-air interface. The system can include an ignitor positioned proximate the liquid-air interface and configured to ignite the plurality of bubbles when the plurality of bubbles exit the liquid, wherein the liquid provides a barrier between the fuel source and a flame formed by combustion of the plurality of bubbles to arrest flashback.

[0008] According to another aspect of the present disclosure, a method of combusting hydrogen-based fuel can be provided. The method can include flowing hydrogen-based fuel from a fuel source through a liquid contained in a liquid reservoir, wherein the hydrogen-based fuel forms a plurality of bubbles that rise through the liquid. The method can include allowing the plurality of bubbles to exit the liquid at a liquid-air interface. The method can include igniting the plurality of bubbles after the plurality of bubbles exit the liquid, wherein the liquid acts as a barrier to arrest flashback toward the fuel source when flow of the hydrogen-based fuel is stopped.

[0009] According to another aspect of the present disclosure, a liquid-assisted burner system for hydrogen-based fuel combustion can be provided. The system can include a fuel source configured to supply hydrogen-based fuel. The system can include a bubbler containing a liquid, the bubbler configured to receive the hydrogen-based fuel and disperse the hydrogen-based fuel through the liquid to form a plurality of bubbles. The system can include a water reservoir disposed coaxially around the bubbler and configured to catch liquid spillover from the bubbler, wherein the plurality of bubbles rise through the liquid and combust upon exiting the liquid at a liquid-air interface, and wherein the liquid arrests flashback by providing a barrier between the fuel source and combustion occurring above the liquid-air interface.

[0010] The foregoing general description of the illustrative embodiments and the following detailed description thereof are merely exemplary aspects of the teachings of this disclosure and are not restrictive.BRIEF DESCRIPTION OF FIGURES

[0011] Non-limiting and non-exhaustive examples are described with reference to the following figures.

[0012] FIG. 1 illustrates a system for hydrogen-based fuel combustion, according to examples of the disclosed technology.

[0013] FIG. 2 illustrates a system for hydrogen-based fuel combustion, according to examples of the disclosed technology.

[0014] FIG. 3 illustrates a high-speed camera image of a hydrogen flame over a liquid, according to examples of the disclosed technology.DETAILED DESCRIPTION

[0015] The following description sets forth exemplary aspects of the present disclosure. It should be recognized, however, that such description is not intended as a limitation on the scope of the present disclosure. Rather, the description also encompasses combinations and modifications to those exemplary aspects described herein.

[0016] The present disclosure relates to systems and methods for combusting hydrogen-based fuel using a liquid-assisted burner configuration. Hydrogen-based fuels present a versatile energy source that can be utilized across various sectors for thermal treatment applications including heating, cooking, metallurgy, and turbines. Hydrogen can be produced directly from water via electrolysis using renewable energy sources such as wind, solar, or nuclear power. Given the intermittent nature of wind and solar energy, surplus energy generated during windy days or sunny periods can be used to produce hydrogen, which can then be stored for later use when direct energy supply falls short of demand.

[0017] One challenge in safely using hydrogen for combustion arises when gas flow velocity is lower than flame speed. In such cases, a flame can backflow into a fuel source, creating a safety hazard. This challenge of flame backflow is particularly present during start-up and shutdown phases of a combustion process, where achieving consistently high gas flow velocities is not always feasible. The disclosed technology addresses this challenge by utilizing a liquid barrier between a fuel source and a combustion zone. The liquid barrier provides a dynamic mechanism that arrests flashback by filling a flow path when fuel flow stops, thereby preventing flame propagation back toward the fuel source. The liquid barrier also maintains a lower temperature at a flame base compared to conventional metal burner materials, as liquid temperature does not exceed a boiling point of the liquid during combustion.

[0018] Referring to FIG. 1, a system 100 for combusting hydrogen-based fuel includes a hydrogen source 105, a valve 140, a flow meter 135, a bubbler 110, a water reservoir 125, and an ignitor 120. The hydrogen source 105 can be referred to herein as a fuel source. The hydrogen source 105 stores hydrogen gas and supplies hydrogen-based fuel to the system 100.

[0019] The water reservoir 125 contains a liquid and includes an inlet configured to receive hydrogen-based fuel from the hydrogen source 105. In some cases, the liquid comprises water. The bubbler 110 is disposed within the water reservoir 125 and is configured to receive the hydrogen-based fuel at the inlet and disperse the hydrogen-based fuel through the liquid. The liquid allows the fuel to ascend through the liquid, distributing via a nozzle size and density of a supply system associated with the bubbler 110. As the hydrogen-based fuel passes through the liquid, the hydrogen-based fuel forms a plurality of hydrogen bubbles 115 that rise through the liquid and exit at a liquid-air interface formed at a surface of the liquid.

[0020] With continued reference to FIG. 1, the valve 140 is disposed between the hydrogen source 105 and the inlet of the water reservoir 125. The valve 140 is configured to control flow of the hydrogen-based fuel to the bubbler 110. The flow meter 135 is disposed between the valve 140 and the inlet. The flow meter 135 is configured to measure a rate of hydrogen-based fuel flowing to the bubbler 110. In some cases, a LabView-based control system can be used for on / off bang-bang control of hydrogen flow through the valve 140.

[0021] The ignitor 120 is positioned proximate the liquid-air interface and is configured to ignite the plurality of hydrogen bubbles 115 when the hydrogen bubbles 115 exit the liquid. Upon ignition, hydrogen gas 130 combusts above the liquid surface. The liquid provides a barrier between the hydrogen source 105 and a flame formed by combustion of the plurality of hydrogen bubbles 115 to arrest flashback. When flow of the hydrogen-based fuel stops, the liquid fills a flow path of the hydrogen-based fuel, thereby arresting flashback toward the hydrogen source 105.

[0022] As further shown in FIG. 1, a temperature of the liquid does not exceed a boiling point of the liquid during combustion of the plurality of hydrogen bubbles 115. This characteristic allows the liquid to maintain a lower temperature at a flame base compared to conventional metal burner materials, where a metal burner base temperature can approach a flame temperature.

[0023] Referring to FIG. 2, a liquid-assisted burner system 200 for hydrogen-based fuel combustion includes a hydrogen source 205, a bubbler 210, a water reservoir 225, a water source 245, a water pump 250, a water pump 255, a differential pressure flow device (e.g., venturi vacuum, orifice plates, etc.) 260, and a hydrogen / water inlet 265. The hydrogen source 205 can be referred to herein as a fuel source and is configured to supply hydrogen-based fuel to the liquid-assisted burner system 200.

[0024] Referring to FIG. 2, a liquid-assisted burner system 200 for hydrogen-based fuel combustion includes a hydrogen source 205, a bubbler 210, a water reservoir 225, a water source 245, a float valve 250, a water pump 255, a differential pressure flow device 260, and a hydrogen / water inlet 265. The hydrogen source 205 can be referred to herein as a fuel source and is configured to supply hydrogen-based fuel to the liquid-assisted burner system 200.

[0025] With continued reference to FIG. 2, the water reservoir 225 is disposed coaxially around the bubbler 210 and is configured to catch liquid spillover from the bubbler 210. The coaxial arrangement of the water reservoir 225 around the bubbler 210 allows the water reservoir 225 to catch water spillover droplets 270 that spill from the bubbler 210 during operation. The water reservoir 225 can be referred to herein as a liquid reservoir.

[0026] The differential pressure flow device 260 is configured to receive hydrogen-based fuel from the hydrogen source 205 and water from the water reservoir 225. The water pump 255 is configured to supply water from the water reservoir 225 to the differential pressure flow device 260. The differential pressure flow device 260 is configured to generate a mixture of the hydrogen-based fuel and the water and deliver the mixture to the bubbler 210 through the hydrogen / water inlet 265. The hydrogen / water inlet 265 can be referred to herein as an inlet. In some cases, mixing the hydrogen-based fuel with water using the differential pressure flow device 260 prior to flowing the hydrogen-based fuel through the liquid provides a consistent hydrogen and water mixture to the bubbler 210.

[0027] As further shown in FIG. 2, the water source 245 is configured to supply water to the water reservoir 225 to maintain a water level in the water reservoir 225. The float valve 250 is configured to maintain a constant water level in the water reservoir 225 by controlling water flow from the water source 245.

[0028] The liquid-assisted burner system 200 can be configured to integrate into an oven for thermal treatment applications. In some cases, the liquid-assisted burner system 200 provides a configuration suitable for heating applications, cooking applications, metallurgy applications, and turbine applications where hydrogen-based fuel combustion with flashback arrest capabilities is desired.

[0029] Referring to FIG. 3, a high-speed camera captured image of a hydrogen flame over the liquid is shown. The image depicts a luminous flame structure rising from a liquid surface against a dark background. The flame exhibits a characteristic mushroom-like shape with a broader upper region that tapers toward a base where the flame contacts the liquid surface. The flame appears diffuse and exhibits varying intensities of brightness, with brightest regions concentrated in an upper portion of the flame structure. A thin wisp of flame or combustion gases extends laterally from the base of a main flame body near the liquid surface. The liquid surface is visible as a horizontal boundary at a bottom portion of the image where the flame originates.

[0030] In some cases, the system can include a high-speed camera for capturing images of the hydrogen flame over the liquid for evaluation purposes. The high-speed camera captured image shown in FIG. 3 can be used to observe combustion characteristics of the system. Such visualization allows for evaluation of flame behavior, flame shape, and flame stability during operation of the liquid-assisted burner system. The high-speed camera can capture flame dynamics that occur during combustion of the plurality of hydrogen bubbles as the hydrogen bubbles exit the liquid at the liquid-air interface.

[0031] The disclosed technology can be further understood according to the following clauses:

[0032] Clause 1: A system for combusting hydrogen-based fuel, comprising: a liquid reservoir containing a liquid and having an inlet configured to receive hydrogen-based fuel from a fuel source; a bubbler disposed within the liquid reservoir and configured to receive the hydrogen-based fuel at the inlet and disperse the hydrogen-based fuel through the liquid such that the hydrogen-based fuel forms a plurality of bubbles that rise through the liquid and exit at a liquid-air interface; and an ignitor positioned proximate the liquid-air interface and configured to ignite the plurality of bubbles when the plurality of bubbles exit the liquid, wherein the liquid provides a barrier between the fuel source and a flame formed by combustion of the plurality of bubbles to arrest flashback.

[0033] Clause 2: The system of clause 1, further comprising a valve disposed between the fuel source and the inlet, the valve configured to control flow of the hydrogen-based fuel to the bubbler.

[0034] Clause 3: The system of clause 2, further comprising a flow meter disposed between the valve and the inlet, the flow meter configured to measure a rate of hydrogen-based fuel flowing to the bubbler.

[0035] Clause 4: The system of clause 1, wherein the liquid comprises water.

[0036] Clause 5: The system of clause 1, wherein a temperature of the liquid does not exceed a boiling point of the liquid during combustion of the plurality of bubbles.

[0037] Clause 6: The system of clause 1, further comprising a differential pressure flow device configured to receive hydrogen-based fuel from the fuel source and water from the liquid reservoir, the differential pressure flow device configured to generate a mixture of the hydrogen-based fuel and the water and deliver the mixture to the bubbler through the inlet.

[0038] Clause 7: The system of clause 6, further comprising a water pump configured to supply water from the liquid reservoir.

[0039] Clause 8: The system of clause 1, further comprising a water source and a water pump configured to supply water from the water source to the liquid reservoir to maintain a water level in the liquid reservoir.

[0040] Clause 9: The system of clause 1, wherein the liquid reservoir extends coaxially around the bubbler and is configured to catch water spillover droplets from the bubbler.

[0041] Clause 10: The system of clause 9, further comprising a float valve configured to maintain a constant water level in the liquid reservoir.

[0042] Clause 11: The system of clause 1, wherein the liquid fills a flow path of the hydrogen-based fuel when flow of the hydrogen-based fuel stops, thereby arresting flashback.

[0043] Clause 12: A method of combusting hydrogen-based fuel, comprising: flowing hydrogen-based fuel from a fuel source through a liquid contained in a liquid reservoir, wherein the hydrogen-based fuel forms a plurality of bubbles that rise through the liquid; allowing the plurality of bubbles to exit the liquid at a liquid-air interface; and igniting the plurality of bubbles after the plurality of bubbles exit the liquid, wherein the liquid acts as a barrier to arrest flashback toward the fuel source when flow of the hydrogen-based fuel is stopped.

[0044] Clause 13: The method of clause 12, further comprising controlling flow of the hydrogen-based fuel from the fuel source using a valve disposed between the fuel source and the liquid reservoir.

[0045] Clause 14: The method of clause 13, further comprising measuring a rate of the hydrogen-based fuel flowing to the liquid reservoir using a flow meter disposed between the valve and the liquid reservoir.

[0046] Clause 15: The method of clause 12, further comprising mixing the hydrogen-based fuel with water using a differential pressure flow device prior to flowing the hydrogen-based fuel through the liquid, wherein the differential pressure flow device receives the hydrogen-based fuel from the fuel source and water from the liquid reservoir.

[0047] Clause 16: The method of clause 12, wherein a temperature of the liquid does not exceed a boiling point of the liquid during igniting of the plurality of bubbles.

[0048] Clause 17: A liquid-assisted burner system for hydrogen-based fuel combustion, comprising: a fuel source configured to supply hydrogen-based fuel; a bubbler containing a liquid, the bubbler configured to receive the hydrogen-based fuel and disperse the hydrogen-based fuel through the liquid to form a plurality of bubbles; and a water reservoir disposed coaxially around the bubbler and configured to catch liquid spillover from the bubbler, wherein the plurality of bubbles rise through the liquid and combust upon exiting the liquid at a liquid-air interface, and wherein the liquid arrests flashback by providing a barrier between the fuel source and combustion occurring above the liquid-air interface.

[0049] Clause 18: The liquid-assisted burner system of clause 17, further comprising a differential pressure flow device configured to receive the hydrogen-based fuel from the fuel source and water from the water reservoir, the differential pressure flow device configured to mix the hydrogen-based fuel and the water and deliver the mixture to the bubbler.

[0050] Clause 19: The liquid-assisted burner system of clause 18, further comprising a water pump configured to supply water from the water reservoir.

[0051] Clause 20: The liquid-assisted burner system of clause 17, further comprising a float valve configured to maintain a constant water level in the water reservoir.

[0052] The dimensions and values disclosed herein are not to be understood as being strictly limited to the exact numerical values recited. Instead, unless otherwise specified, each such dimension is intended to mean both the recited value and a functionally equivalent range surrounding that value. For example, a dimension disclosed as “40 wt. %” is intended to mean “about 40 wt. %”.

[0053] A number of implementations have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the disclosure. Accordingly, other implementations are within the scope of the following claims.

Examples

Embodiment Construction

[0015]The following description sets forth exemplary aspects of the present disclosure. It should be recognized, however, that such description is not intended as a limitation on the scope of the present disclosure. Rather, the description also encompasses combinations and modifications to those exemplary aspects described herein.

[0016]The present disclosure relates to systems and methods for combusting hydrogen-based fuel using a liquid-assisted burner configuration. Hydrogen-based fuels present a versatile energy source that can be utilized across various sectors for thermal treatment applications including heating, cooking, metallurgy, and turbines. Hydrogen can be produced directly from water via electrolysis using renewable energy sources such as wind, solar, or nuclear power. Given the intermittent nature of wind and solar energy, surplus energy generated during windy days or sunny periods can be used to produce hydrogen, which can then be stored for later use when direct ener...

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application Ser. No. 63 / 780,809, filed on 31 Mar. 2025, which is incorporated herein by reference in its entirety as if fully set forth below.FIELD OF INVENTION

[0002] The present disclosure relates to hydrogen-based fuel combustion systems, and more particularly to systems and methods for flashback arrest and flame temperature reduction in hydrogen-based fuel combustion using a liquid barrier.BACKGROUND

[0003] Hydrogen is a versatile fuel that can be used across various sectors as an energy source, meeting the needs of a wide range of end users. Hydrogen fuel can be stored and converted into useful energy as needed, either by using it as a feedstock for fuel cells or through direct combustion, utilizing the thermal energy to drive turbines or support other heating applications. Unlike carbon-based fuels, which vary in composition due to differences in their carbon chains, hydrogen consists of a single element. While carbon-based fuels are often sector-specific, hydrogen is versatile enough to meet the energy demands across various sectors. Hydrogen combustion is an appealing option for thermal treatment applications such as heating, cooking, metallurgy, turbines, and more. Current hydrogen combustion systems typically employ metal burners and conventional gas delivery mechanisms to facilitate the combustion process.

[0004] However, existing hydrogen combustion systems suffer from several limitations. One challenge in safely using hydrogen for combustion arises when the gas flow velocity is lower than the flame speed. In such cases, the flame can backflow into the source, creating a safety hazard. This issue is particularly problematic during the start-up and shutdown phases of the combustion process, where achieving consistently high gas flow velocities may not be feasible. Additionally, conventional metal burner materials can reach temperatures approaching the flame temperature during combustion, which can contribute to elevated overall flame temperatures and thermal stress on system components. These deficiencies present obstacles to the safe and efficient deployment of hydrogen as a combustion fuel across various applications.

[0005] What is needed, therefore, is an improved hydrogen combustion system that addresses the challenge of flame backflow by providing a barrier between the flame and the fuel source. Such a system would mitigate flashback during periods of low fuel flow velocity while also maintaining lower temperatures at the flame base compared to conventional metal burner configurations.SUMMARY

[0006] This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.

[0007] According to an aspect of the present disclosure, a system for combusting hydrogen-based fuel can be provided. The system can include a liquid reservoir containing a liquid and having an inlet configured to receive hydrogen-based fuel from a fuel source. The system can include a bubbler disposed within the liquid reservoir and configured to receive the hydrogen-based fuel at the inlet and disperse the hydrogen-based fuel through the liquid such that the hydrogen-based fuel forms a plurality of bubbles that rise through the liquid and exit at a liquid-air interface. The system can include an ignitor positioned proximate the liquid-air interface and configured to ignite the plurality of bubbles when the plurality of bubbles exit the liquid, wherein the liquid provides a barrier between the fuel source and a flame formed by combustion of the plurality of bubbles to arrest flashback.

[0008] According to another aspect of the present disclosure, a method of combusting hydrogen-based fuel can be provided. The method can include flowing hydrogen-based fuel from a fuel source through a liquid contained in a liquid reservoir, wherein the hydrogen-based fuel forms a plurality of bubbles that rise through the liquid. The method can include allowing the plurality of bubbles to exit the liquid at a liquid-air interface. The method can include igniting the plurality of bubbles after the plurality of bubbles exit the liquid, wherein the liquid acts as a barrier to arrest flashback toward the fuel source when flow of the hydrogen-based fuel is stopped.

[0009] According to another aspect of the present disclosure, a liquid-assisted burner system for hydrogen-based fuel combustion can be provided. The system can include a fuel source configured to supply hydrogen-based fuel. The system can include a bubbler containing a liquid, the bubbler configured to receive the hydrogen-based fuel and disperse the hydrogen-based fuel through the liquid to form a plurality of bubbles. The system can include a water reservoir disposed coaxially around the bubbler and configured to catch liquid spillover from the bubbler, wherein the plurality of bubbles rise through the liquid and combust upon exiting the liquid at a liquid-air interface, and wherein the liquid arrests flashback by providing a barrier between the fuel source and combustion occurring above the liquid-air interface.

[0010] The foregoing general description of the illustrative embodiments and the following detailed description thereof are merely exemplary aspects of the teachings of this disclosure and are not restrictive.BRIEF DESCRIPTION OF FIGURES

[0011] Non-limiting and non-exhaustive examples are described with reference to the following figures.

[0012] FIG. 1 illustrates a system for hydrogen-based fuel combustion, according to examples of the disclosed technology.

[0013] FIG. 2 illustrates a system for hydrogen-based fuel combustion, according to examples of the disclosed technology.

[0014] FIG. 3 illustrates a high-speed camera image of a hydrogen flame over a liquid, according to examples of the disclosed technology.DETAILED DESCRIPTION

[0015] The following description sets forth exemplary aspects of the present disclosure. It should be recognized, however, that such description is not intended as a limitation on the scope of the present disclosure. Rather, the description also encompasses combinations and modifications to those exemplary aspects described herein.

[0016] The present disclosure relates to systems and methods for combusting hydrogen-based fuel using a liquid-assisted burner configuration. Hydrogen-based fuels present a versatile energy source that can be utilized across various sectors for thermal treatment applications including heating, cooking, metallurgy, and turbines. Hydrogen can be produced directly from water via electrolysis using renewable energy sources such as wind, solar, or nuclear power. Given the intermittent nature of wind and solar energy, surplus energy generated during windy days or sunny periods can be used to produce hydrogen, which can then be stored for later use when direct energy supply falls short of demand.

[0017] One challenge in safely using hydrogen for combustion arises when gas flow velocity is lower than flame speed. In such cases, a flame can backflow into a fuel source, creating a safety hazard. This challenge of flame backflow is particularly present during start-up and shutdown phases of a combustion process, where achieving consistently high gas flow velocities is not always feasible. The disclosed technology addresses this challenge by utilizing a liquid barrier between a fuel source and a combustion zone. The liquid barrier provides a dynamic mechanism that arrests flashback by filling a flow path when fuel flow stops, thereby preventing flame propagation back toward the fuel source. The liquid barrier also maintains a lower temperature at a flame base compared to conventional metal burner materials, as liquid temperature does not exceed a boiling point of the liquid during combustion.

[0018] Referring to FIG. 1, a system 100 for combusting hydrogen-based fuel includes a hydrogen source 105, a valve 140, a flow meter 135, a bubbler 110, a water reservoir 125, and an ignitor 120. The hydrogen source 105 can be referred to herein as a fuel source. The hydrogen source 105 stores hydrogen gas and supplies hydrogen-based fuel to the system 100.

[0019] The water reservoir 125 contains a liquid and includes an inlet configured to receive hydrogen-based fuel from the hydrogen source 105. In some cases, the liquid comprises water. The bubbler 110 is disposed within the water reservoir 125 and is configured to receive the hydrogen-based fuel at the inlet and disperse the hydrogen-based fuel through the liquid. The liquid allows the fuel to ascend through the liquid, distributing via a nozzle size and density of a supply system associated with the bubbler 110. As the hydrogen-based fuel passes through the liquid, the hydrogen-based fuel forms a plurality of hydrogen bubbles 115 that rise through the liquid and exit at a liquid-air interface formed at a surface of the liquid.

[0020] With continued reference to FIG. 1, the valve 140 is disposed between the hydrogen source 105 and the inlet of the water reservoir 125. The valve 140 is configured to control flow of the hydrogen-based fuel to the bubbler 110. The flow meter 135 is disposed between the valve 140 and the inlet. The flow meter 135 is configured to measure a rate of hydrogen-based fuel flowing to the bubbler 110. In some cases, a LabView-based control system can be used for on / off bang-bang control of hydrogen flow through the valve 140.

[0021] The ignitor 120 is positioned proximate the liquid-air interface and is configured to ignite the plurality of hydrogen bubbles 115 when the hydrogen bubbles 115 exit the liquid. Upon ignition, hydrogen gas 130 combusts above the liquid surface. The liquid provides a barrier between the hydrogen source 105 and a flame formed by combustion of the plurality of hydrogen bubbles 115 to arrest flashback. When flow of the hydrogen-based fuel stops, the liquid fills a flow path of the hydrogen-based fuel, thereby arresting flashback toward the hydrogen source 105.

[0022] As further shown in FIG. 1, a temperature of the liquid does not exceed a boiling point of the liquid during combustion of the plurality of hydrogen bubbles 115. This characteristic allows the liquid to maintain a lower temperature at a flame base compared to conventional metal burner materials, where a metal burner base temperature can approach a flame temperature.

[0023] Referring to FIG. 2, a liquid-assisted burner system 200 for hydrogen-based fuel combustion includes a hydrogen source 205, a bubbler 210, a water reservoir 225, a water source 245, a water pump 250, a water pump 255, a differential pressure flow device (e.g., venturi vacuum, orifice plates, etc.) 260, and a hydrogen / water inlet 265. The hydrogen source 205 can be referred to herein as a fuel source and is configured to supply hydrogen-based fuel to the liquid-assisted burner system 200.

[0024] Referring to FIG. 2, a liquid-assisted burner system 200 for hydrogen-based fuel combustion includes a hydrogen source 205, a bubbler 210, a water reservoir 225, a water source 245, a float valve 250, a water pump 255, a differential pressure flow device 260, and a hydrogen / water inlet 265. The hydrogen source 205 can be referred to herein as a fuel source and is configured to supply hydrogen-based fuel to the liquid-assisted burner system 200.

[0025] With continued reference to FIG. 2, the water reservoir 225 is disposed coaxially around the bubbler 210 and is configured to catch liquid spillover from the bubbler 210. The coaxial arrangement of the water reservoir 225 around the bubbler 210 allows the water reservoir 225 to catch water spillover droplets 270 that spill from the bubbler 210 during operation. The water reservoir 225 can be referred to herein as a liquid reservoir.

[0026] The differential pressure flow device 260 is configured to receive hydrogen-based fuel from the hydrogen source 205 and water from the water reservoir 225. The water pump 255 is configured to supply water from the water reservoir 225 to the differential pressure flow device 260. The differential pressure flow device 260 is configured to generate a mixture of the hydrogen-based fuel and the water and deliver the mixture to the bubbler 210 through the hydrogen / water inlet 265. The hydrogen / water inlet 265 can be referred to herein as an inlet. In some cases, mixing the hydrogen-based fuel with water using the differential pressure flow device 260 prior to flowing the hydrogen-based fuel through the liquid provides a consistent hydrogen and water mixture to the bubbler 210.

[0027] As further shown in FIG. 2, the water source 245 is configured to supply water to the water reservoir 225 to maintain a water level in the water reservoir 225. The float valve 250 is configured to maintain a constant water level in the water reservoir 225 by controlling water flow from the water source 245.

[0028] The liquid-assisted burner system 200 can be configured to integrate into an oven for thermal treatment applications. In some cases, the liquid-assisted burner system 200 provides a configuration suitable for heating applications, cooking applications, metallurgy applications, and turbine applications where hydrogen-based fuel combustion with flashback arrest capabilities is desired.

[0029] Referring to FIG. 3, a high-speed camera captured image of a hydrogen flame over the liquid is shown. The image depicts a luminous flame structure rising from a liquid surface against a dark background. The flame exhibits a characteristic mushroom-like shape with a broader upper region that tapers toward a base where the flame contacts the liquid surface. The flame appears diffuse and exhibits varying intensities of brightness, with brightest regions concentrated in an upper portion of the flame structure. A thin wisp of flame or combustion gases extends laterally from the base of a main flame body near the liquid surface. The liquid surface is visible as a horizontal boundary at a bottom portion of the image where the flame originates.

[0030] In some cases, the system can include a high-speed camera for capturing images of the hydrogen flame over the liquid for evaluation purposes. The high-speed camera captured image shown in FIG. 3 can be used to observe combustion characteristics of the system. Such visualization allows for evaluation of flame behavior, flame shape, and flame stability during operation of the liquid-assisted burner system. The high-speed camera can capture flame dynamics that occur during combustion of the plurality of hydrogen bubbles as the hydrogen bubbles exit the liquid at the liquid-air interface.

[0031] The disclosed technology can be further understood according to the following clauses:

[0032] Clause 1: A system for combusting hydrogen-based fuel, comprising: a liquid reservoir containing a liquid and having an inlet configured to receive hydrogen-based fuel from a fuel source; a bubbler disposed within the liquid reservoir and configured to receive the hydrogen-based fuel at the inlet and disperse the hydrogen-based fuel through the liquid such that the hydrogen-based fuel forms a plurality of bubbles that rise through the liquid and exit at a liquid-air interface; and an ignitor positioned proximate the liquid-air interface and configured to ignite the plurality of bubbles when the plurality of bubbles exit the liquid, wherein the liquid provides a barrier between the fuel source and a flame formed by combustion of the plurality of bubbles to arrest flashback.

[0033] Clause 2: The system of clause 1, further comprising a valve disposed between the fuel source and the inlet, the valve configured to control flow of the hydrogen-based fuel to the bubbler.

[0034] Clause 3: The system of clause 2, further comprising a flow meter disposed between the valve and the inlet, the flow meter configured to measure a rate of hydrogen-based fuel flowing to the bubbler.

[0035] Clause 4: The system of clause 1, wherein the liquid comprises water.

[0036] Clause 5: The system of clause 1, wherein a temperature of the liquid does not exceed a boiling point of the liquid during combustion of the plurality of bubbles.

[0037] Clause 6: The system of clause 1, further comprising a differential pressure flow device configured to receive hydrogen-based fuel from the fuel source and water from the liquid reservoir, the differential pressure flow device configured to generate a mixture of the hydrogen-based fuel and the water and deliver the mixture to the bubbler through the inlet.

[0038] Clause 7: The system of clause 6, further comprising a water pump configured to supply water from the liquid reservoir.

[0039] Clause 8: The system of clause 1, further comprising a water source and a water pump configured to supply water from the water source to the liquid reservoir to maintain a water level in the liquid reservoir.

[0040] Clause 9: The system of clause 1, wherein the liquid reservoir extends coaxially around the bubbler and is configured to catch water spillover droplets from the bubbler.

[0041] Clause 10: The system of clause 9, further comprising a float valve configured to maintain a constant water level in the liquid reservoir.

[0042] Clause 11: The system of clause 1, wherein the liquid fills a flow path of the hydrogen-based fuel when flow of the hydrogen-based fuel stops, thereby arresting flashback.

[0043] Clause 12: A method of combusting hydrogen-based fuel, comprising: flowing hydrogen-based fuel from a fuel source through a liquid contained in a liquid reservoir, wherein the hydrogen-based fuel forms a plurality of bubbles that rise through the liquid; allowing the plurality of bubbles to exit the liquid at a liquid-air interface; and igniting the plurality of bubbles after the plurality of bubbles exit the liquid, wherein the liquid acts as a barrier to arrest flashback toward the fuel source when flow of the hydrogen-based fuel is stopped.

[0044] Clause 13: The method of clause 12, further comprising controlling flow of the hydrogen-based fuel from the fuel source using a valve disposed between the fuel source and the liquid reservoir.

[0045] Clause 14: The method of clause 13, further comprising measuring a rate of the hydrogen-based fuel flowing to the liquid reservoir using a flow meter disposed between the valve and the liquid reservoir.

[0046] Clause 15: The method of clause 12, further comprising mixing the hydrogen-based fuel with water using a differential pressure flow device prior to flowing the hydrogen-based fuel through the liquid, wherein the differential pressure flow device receives the hydrogen-based fuel from the fuel source and water from the liquid reservoir.

[0047] Clause 16: The method of clause 12, wherein a temperature of the liquid does not exceed a boiling point of the liquid during igniting of the plurality of bubbles.

[0048] Clause 17: A liquid-assisted burner system for hydrogen-based fuel combustion, comprising: a fuel source configured to supply hydrogen-based fuel; a bubbler containing a liquid, the bubbler configured to receive the hydrogen-based fuel and disperse the hydrogen-based fuel through the liquid to form a plurality of bubbles; and a water reservoir disposed coaxially around the bubbler and configured to catch liquid spillover from the bubbler, wherein the plurality of bubbles rise through the liquid and combust upon exiting the liquid at a liquid-air interface, and wherein the liquid arrests flashback by providing a barrier between the fuel source and combustion occurring above the liquid-air interface.

[0049] Clause 18: The liquid-assisted burner system of clause 17, further comprising a differential pressure flow device configured to receive the hydrogen-based fuel from the fuel source and water from the water reservoir, the differential pressure flow device configured to mix the hydrogen-based fuel and the water and deliver the mixture to the bubbler.

[0050] Clause 19: The liquid-assisted burner system of clause 18, further comprising a water pump configured to supply water from the water reservoir.

[0051] Clause 20: The liquid-assisted burner system of clause 17, further comprising a float valve configured to maintain a constant water level in the water reservoir.

[0052] The dimensions and values disclosed herein are not to be understood as being strictly limited to the exact numerical values recited. Instead, unless otherwise specified, each such dimension is intended to mean both the recited value and a functionally equivalent range surrounding that value. For example, a dimension disclosed as “40 wt. %” is intended to mean “about 40 wt. %”.

[0053] A number of implementations have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the disclosure. Accordingly, other implementations are within the scope of the following claims.

Examples

Embodiment Construction

[0015]The following description sets forth exemplary aspects of the present disclosure. It should be recognized, however, that such description is not intended as a limitation on the scope of the present disclosure. Rather, the description also encompasses combinations and modifications to those exemplary aspects described herein.

[0016]The present disclosure relates to systems and methods for combusting hydrogen-based fuel using a liquid-assisted burner configuration. Hydrogen-based fuels present a versatile energy source that can be utilized across various sectors for thermal treatment applications including heating, cooking, metallurgy, and turbines. Hydrogen can be produced directly from water via electrolysis using renewable energy sources such as wind, solar, or nuclear power. Given the intermittent nature of wind and solar energy, surplus energy generated during windy days or sunny periods can be used to produce hydrogen, which can then be stored for later use when direct ener...

Claims

1. A system for combusting hydrogen-based fuel, comprising:a liquid reservoir containing a liquid and having an inlet configured to receive hydrogen-based fuel from a fuel source;a bubbler disposed within the liquid reservoir and configured to receive the hydrogen-based fuel at the inlet and disperse the hydrogen-based fuel through the liquid such that the hydrogen-based fuel forms a plurality of bubbles that rise through the liquid and exit at a liquid-air interface; andan ignitor positioned proximate the liquid-air interface and configured to ignite the plurality of bubbles when the plurality of bubbles exit the liquid, wherein the liquid provides a barrier between the fuel source and a flame formed by combustion of the plurality of bubbles to arrest flashback.

2. The system of claim 1, further comprising a valve disposed between the fuel source and the inlet, the valve configured to control flow of the hydrogen-based fuel to the bubbler.

3. The system of claim 2, further comprising a flow meter disposed between the valve and the inlet, the flow meter configured to measure a rate of hydrogen-based fuel flowing to the bubbler.

4. The system of claim 1, wherein the liquid comprises water.

5. The system of claim 1, wherein a temperature of the liquid does not exceed a boiling point of the liquid during combustion of the plurality of bubbles.

6. The system of claim 1, further comprising a differential pressure flow device configured to receive hydrogen-based fuel from the fuel source and water from the liquid reservoir, the differential pressure flow device configured to generate a mixture of the hydrogen-based fuel and the water and deliver the mixture to the bubbler through the inlet.

7. The system of claim 6, further comprising a water pump configured to supply water from the liquid reservoir.

8. The system of claim 1, further comprising a water source and a water pump configured to supply water from the water source to the liquid reservoir to maintain a water level in the liquid reservoir.

9. The system of claim 1, wherein the liquid reservoir extends coaxially around the bubbler and is configured to catch water spillover droplets from the bubbler.

10. The system of claim 9, further comprising a float valve configured to maintain a constant water level in the liquid reservoir.

11. The system of claim 1, wherein the liquid fills a flow path of the hydrogen-based fuel when flow of the hydrogen-based fuel stops, thereby arresting flashback.

12. A method of combusting hydrogen-based fuel, comprising:flowing hydrogen-based fuel from a fuel source through a liquid contained in a liquid reservoir, wherein the hydrogen-based fuel forms a plurality of bubbles that rise through the liquid;allowing the plurality of bubbles to exit the liquid at a liquid-air interface; andigniting the plurality of bubbles after the plurality of bubbles exit the liquid, wherein the liquid acts as a barrier to arrest flashback toward the fuel source when flow of the hydrogen-based fuel is stopped.

13. The method of claim 12, further comprising controlling flow of the hydrogen-based fuel from the fuel source using a valve disposed between the fuel source and the liquid reservoir.

14. The method of claim 13, further comprising measuring a rate of the hydrogen-based fuel flowing to the liquid reservoir using a flow meter disposed between the valve and the liquid reservoir.

15. The method of claim 12, further comprising mixing the hydrogen-based fuel with water using a differential pressure flow device prior to flowing the hydrogen-based fuel through the liquid, wherein the differential pressure flow device receives the hydrogen-based fuel from the fuel source and water from the liquid reservoir.

16. The method of claim 12, wherein a temperature of the liquid does not exceed a boiling point of the liquid during igniting of the plurality of bubbles.

17. A liquid-assisted burner system for hydrogen-based fuel combustion, comprising:a fuel source configured to supply hydrogen-based fuel;a bubbler containing a liquid, the bubbler configured to receive the hydrogen-based fuel and disperse the hydrogen-based fuel through the liquid to form a plurality of bubbles; anda water reservoir disposed coaxially around the bubbler and configured to catch liquid spillover from the bubbler, wherein the plurality of bubbles rise through the liquid and combust upon exiting the liquid at a liquid-air interface, and wherein the liquid arrests flashback by providing a barrier between the fuel source and combustion occurring above the liquid-air interface.

18. The liquid-assisted burner system of claim 17, further comprising a differential pressure flow device configured to receive the hydrogen-based fuel from the fuel source and water from the water reservoir, the differential pressure flow device configured to mix the hydrogen-based fuel and the water and deliver the mixture to the bubbler.

19. The liquid-assisted burner system of claim 18, further comprising a water pump configured to supply water from the water reservoir.

20. The liquid-assisted burner system of claim 17, further comprising a float valve configured to maintain a constant water level in the water reservoir.

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