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EP4320388A1 - A hydrogen premix burner - Google Patents

A hydrogen premix burner

Info

Publication number
EP4320388A1
EP4320388A1 EP22737518.5A EP22737518A EP4320388A1 EP 4320388 A1 EP4320388 A1 EP 4320388A1 EP 22737518 A EP22737518 A EP 22737518A EP 4320388 A1 EP4320388 A1 EP 4320388A1
Authority
EP
European Patent Office
Prior art keywords
combustion
supply device
gas
burner
hollow
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
EP22737518.5A
Other languages
German (de)
French (fr)
Inventor
Robert Parsons
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Ideal Boilers Ltd
Original Assignee
Ideal Boilers Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Ideal Boilers Ltd filed Critical Ideal Boilers Ltd
Publication of EP4320388A1 publication Critical patent/EP4320388A1/en
Pending legal-status Critical Current

Links

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23N—REGULATING OR CONTROLLING COMBUSTION
    • F23N1/00—Regulating fuel supply
    • F23N1/02—Regulating fuel supply conjointly with air supply
    • F23N1/022—Regulating fuel supply conjointly with air supply using electronic means
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23D—BURNERS
    • F23D14/00—Burners for combustion of a gas, e.g. of a gas stored under pressure as a liquid
    • F23D14/46—Details
    • F23D14/62—Mixing devices; Mixing tubes
    • F23D14/64—Mixing devices; Mixing tubes with injectors
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23D—BURNERS
    • F23D14/00—Burners for combustion of a gas, e.g. of a gas stored under pressure as a liquid
    • F23D14/02—Premix gas burners, i.e. in which gaseous fuel is mixed with combustion air upstream of the combustion zone
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23D—BURNERS
    • F23D14/00—Burners for combustion of a gas, e.g. of a gas stored under pressure as a liquid
    • F23D14/34—Burners specially adapted for use with means for pressurising the gaseous fuel or the combustion air
    • F23D14/36—Burners specially adapted for use with means for pressurising the gaseous fuel or the combustion air in which the compressor and burner form a single unit
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23L—SUPPLYING AIR OR NON-COMBUSTIBLE LIQUIDS OR GASES TO COMBUSTION APPARATUS IN GENERAL ; VALVES OR DAMPERS SPECIALLY ADAPTED FOR CONTROLLING AIR SUPPLY OR DRAUGHT IN COMBUSTION APPARATUS; INDUCING DRAUGHT IN COMBUSTION APPARATUS; TOPS FOR CHIMNEYS OR VENTILATING SHAFTS; TERMINALS FOR FLUES
    • F23L5/00—Blast-producing apparatus before the fire
    • F23L5/02—Arrangements of fans or blowers
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23N—REGULATING OR CONTROLLING COMBUSTION
    • F23N1/00—Regulating fuel supply
    • F23N1/02—Regulating fuel supply conjointly with air supply
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23C—METHODS OR APPARATUS FOR COMBUSTION USING FLUID FUEL OR SOLID FUEL SUSPENDED IN  A CARRIER GAS OR AIR 
    • F23C2900/00—Special features of, or arrangements for combustion apparatus using fluid fuels or solid fuels suspended in air; Combustion processes therefor
    • F23C2900/9901—Combustion process using hydrogen, hydrogen peroxide water or brown gas as fuel
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23D—BURNERS
    • F23D2203/00—Gaseous fuel burners
    • F23D2203/007—Mixing tubes, air supply regulation
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23D—BURNERS
    • F23D2203/00—Gaseous fuel burners
    • F23D2203/10—Flame diffusing means
    • F23D2203/103—Flame diffusing means using screens
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23D—BURNERS
    • F23D2212/00—Burner material specifications
    • F23D2212/20—Burner material specifications metallic
    • F23D2212/201—Fibres
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23N—REGULATING OR CONTROLLING COMBUSTION
    • F23N2225/00—Measuring
    • F23N2225/04—Measuring pressure
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23N—REGULATING OR CONTROLLING COMBUSTION
    • F23N2233/00—Ventilators
    • F23N2233/06—Ventilators at the air intake
    • F23N2233/08—Ventilators at the air intake with variable speed
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23N—REGULATING OR CONTROLLING COMBUSTION
    • F23N2900/00—Special features of, or arrangements for controlling combustion
    • F23N2900/05181—Controlling air to fuel ratio by using a single differential pressure detector

Definitions

  • the present invention relates generally to the field of gas boilers.
  • the invention concerns a gas burner assembly for a gas boiler, with the combustion gas delivery device situated downstream of the fan or air inlet device.
  • Premixing the gas and air is generally but not exclusively done prior to the boilers fan, this has both advantages and disadvantages.
  • the turbulence created by the impeller blades of the fan will ensure a good mix of the gas and air before it enters the burner and to the point of combustion however the overall volume of gas and air mix prior to the point of combustion will be larger.
  • specific gases most notably Hydrogen
  • a larger volume of combustible mix could create a bigger problem if a fault condition occurs.
  • the description refers to a gas and air mixing system that in this instance is applied to a heating boiler.
  • the application is relevant to any widely used combustible gas mixed with air, but it is very relevant to a Hydrogen and air mixing system, as Hydrogen has different combustion characteristics and in certain circumstances can be more volatile than for example Methane or Propane.
  • a significant risk of Hydrogen boilers is the consequence of an accidental ignition of the combustible mixture upstream of the burner.
  • the pressure developed during a Hydrogen explosion can cause significant damage to the appliance. It is the intention of this invention to mitigate the severity of such an event to a safe level and to prevent the possible assembly of components that would cause an unsafe gas mixture.
  • Conventional combustion systems for domestic and commercial boilers commonly but not exclusively use pneumatic gas air ratio control systems, electronic gas air ratio control systems could also be used but this is currently less widely used within the boiler industry.
  • the (pneumatic) system is pressurised by a fan which delivers the mixture of gas and air via a pneumatic device at its inlet. Consequently, the fan, burner and connections contain together a relatively large volume of combustible mixture that will create a significant explosion if ignited.
  • Embodiments of the invention seek to at least partially overcome or ameliorate any one or more of the abovementioned disadvantages or provide the consumer with a useful or commercial choice.
  • a gas burner assembly with post-fan mixing comprising: a) A hollow burner body; b) A burner associated with the hollow burner body; c) A venturi cone located within the hollow burner body, the venturi cone having a smaller, entry end and a larger, exit end; d) A combustion air supply device associated with the hollow burner body; and e) A combustion gas supply device positioned at least partially within the smaller entry end of the venturi cone;
  • combustion air supply device is provided upstream of the combustion gas supply device relative to the burner.
  • Providing a gas burner assembly with the combustion air supply upstream of the combustion gas supply means that the gas burner assembly has a minimal volume of combustible mixture so that it can manage an accidental ignition of the combustible mixture without damage to the structure of the gas burner.
  • the combustion gas is delivered down-stream of the combustion air supply (closer to the burner), which decreases the likelihood that static build-up of the combustible mixture can reach the combustion air supply device (against the positive pressure of the combustion air supply), thus reducing the likelihood and intensity of any explosion.
  • a gas burner assembly comprising: a) A hollow burner body; b) A burner associated with the hollow burner body; c) A venturi cone located within the hollow burner body, the venturi cone having a smaller, entry end and a larger, exit end; d) A combustion air supply device associated with the hollow burner body; and e) A combustion gas supply device positioned at least partially with the smaller entry end of the venturi cone;
  • combustion gas supply device is sized relative the smaller entry end of the venturi cone to control air delivery into the venturi cone and the combustion gas supply device has an inner diameter to dictate combustion gas supply.
  • Providing the combination of sizes of the combustion gas supply device relative to the smaller entry end of the venturi cone and the inner diameter of the combustion gas supply device ensures a safe gas and air mixture is delivered to the point of combustion.
  • the geometric relationship between the fixed size of the annular combustion air orifice and the fixed size of the combustion gas supply orifice means that the respective flow rates are much more easily controlled.
  • the gas burner assembly of an embodiment is typically provided for or as a part of a water boiler.
  • the gas burner assembly is referred to as a gas burner assembly with ‘post-fan mixing as the mixing of the combustion air with the combustion gas takes place downstream of the combustion air supply device, most commonly referred to as a ‘fan’.
  • the combustion gas is typically added to a mass, preferably a moving mass of combustion air, to form the combustion mixture with the amount of combustion air.
  • the combustion air will typically be moving under pressure at the entry end of the venturi cone of the gas burner assembly.
  • the gas burner assembly typically includes a hollow burner body.
  • the hollow burner body may be any shape.
  • the size (volume) of the hollow burner body will be minimised to allow for the venturi cone to be mounted within the hollow burner body but otherwise as small as possible. This is typically achieved by mounting the venturi cone laterally within the hollow burner body.
  • the hollow burner body will typically be substantially boxdike in shape, or a 3D hollow rectangular shape. In this configuration, the hollow burner body will normally have 5 side walls with one open side.
  • the hollow burner body may be provided in a single piece or multiple pieces attached together.
  • the hollow burner body will preferably have a major side wall which is larger in area and at least one, typically more than one minor side walls extending at an angle (normally perpendicularly) from the edge(s) of the major side wall to define a hollow burner body with one open side, but otherwise closed.
  • An outwardly extending lip or flange may be provided about the open side of the hollow burner body.
  • the outwardly extending lip or flange may extend substantially perpendicularly to the side wall(s).
  • the burner will be mounted relative to the open side of the hollow burner body to close the hollow burner body.
  • An opening will normally be provided in at least one of the side walls to allow the mounting of the combustion air supply device to the hollow burner body.
  • the opening to mount the combustion air supply device may be through the major side wall.
  • An opening will normally be provided in at least one of the side walls to allow the mounting of the combustion gas supply device to the hollow burner body.
  • the opening to mount the combustion gas supply device may be through a minor side wall.
  • An opening will normally be provided in at least one of the side walls to allow the mounting of a reference pressure probe/measurement device or conduit to the hollow burner body.
  • the opening for the reference pressure probe/measurement device or conduit will normally be provided in the same wall as the opening to mount the combustion gas supply device to the hollow burner body.
  • the respective openings will be adjacent to one another to allow the reference pressure probe/measurement device or conduit to measure the pressure close to the gas supply device.
  • the opening for the reference pressure probe/measurement device or conduit will normally be provided in a location which is separated from the burner.
  • the openings in the hollow burner body are typically provided in predefined positions and with different predefined sizes so that the components cannot be assembled differently.
  • the gas burner assembly also typically includes a burner associated with the hollow burner body.
  • the burner will typically close the open side of the hollow burner body.
  • a metal fibre burner is preferred.
  • the burner will normally be provided with a surface which provides one or more points of combustion. Typically, these points of combustion are in the downstream surface, that is, after the venturi cone.
  • the burner may preferably be a planar burner.
  • the burner may be provided with one or more side flanges to mount the burner relative to the open side of the hollow burner body.
  • the gas burner assembly also typically includes a Venturi cone located within the hollow burner body, the venturi cone having a smaller, entry end and a larger, exit end.
  • the venturi cone is typically mounted within the hollow burner body.
  • the venturi cone is normally mounted so that the entry end and exit end face the minor side wall(s) to minimise the profile of the hollow burner body.
  • An angled side wall of the venturi cone is typically oriented toward the combustion air supply device.
  • An opposite angled side wall of the venturi cone is typically oriented toward the burner. The opposite angled side is typically separated from the burner by a mount of the venturi cone.
  • the Venturi cone may include an outward or flared entry lip.
  • the outward or flared entry lip may be arcuate.
  • the entry lip may promote mixing of the combustion air with the combustion gas within the Venturi cone by disrupting the pattern of airflow from the combustion air supply device to the entry end of the Venturi cone.
  • venturi cone is preferably mounted laterally within the hollow burner body between the combustion air supply device and the burner, as opposed to longitudinally (with the exit end of the venturi cone facing the burner).
  • the exit end of the Venturi cone is preferably sealed to one or more sidewalls of the burner body to define a flow path for the combustion air, combustion gas and combustion mixture within the burner body.
  • one or more mounting members or structures will typically extend from the periphery of the exit end of the Venturi cone to one or more sidewalls of the burner body. This may confine or direct the flow of the combustion air to the entry end of the Venturi cone.
  • the exit end of the venturi cone is preferably adjacent to the burner. The exit end of the venturi cone typically does not face the burner.
  • the combustion air will typically be provided under positive pressure and the positive pressure of the combustion air and/or combustion gas will typically drive the combustion mixture toward the burner.
  • the Venturi cone may be formed of any material, but typically, robust material such as a metal will be used.
  • the Venturi cone may comprise a throat at the entry end in which one or more sidewalls of the Venturi cone are parallel with one another. This may form parallel throat which is linear between the entry end of the Venturi cone and the conical part of the Venturi cone.
  • the gas burner assembly may include a combustion air supply device associated with the hollow burner body.
  • the combustion air supply device may be of any type suitable for providing or injecting combustion air into the hollow burner body.
  • the combustion air supply device may be referred to as a "fan" even if the combustion air supply device is not actually a fan.
  • the combustion air supply device will normally be mounted relative to the major side wall of the burner body. Typically, an opening is provided in the major side wall of the burner body to mount the combustion air supply device relative thereto.
  • the combustion air supply device will normally face the burner.
  • the Venturi cone will typically be interposed between the combustion air supply device and the burner such that the combustion air is driven to, and into the Venturi cone where the combustion air can mix with the combustion gas.
  • the combustion air supply device will typically deliver combustion air required for combustion into the burner body volume in a controlled manner.
  • the combustion air supply device will normally provide combustion air in a volume or amount which is coordinated with the volume or amount of the combustion gas provided by the combustion gas supply device.
  • a controller is provided to control and coordinate the volume of combustion air and/or the volume of the combustion gas.
  • the combustion air supply device will preferably drive combustion air, in a required amount, to the Venturi cone where the combustion gas is injected into the, preferably moving mass of combustion air being driven into the Venturi cone under positive pressure allowing the combustion gas to mix within the Venturi cone with the combustion air.
  • the gas burner may include a combustion gas supply device positioned at least partially within the smaller entry end of the Venturi cone.
  • the combustion gas supply device may be positioned in the parallel throat of the Venturi cone.
  • the combustion gas supply device may be an injector.
  • the combustion gas supply device may be associated with a gas valve.
  • a conduit may be supplied between the combustion gas injector and the gas valve.
  • the combustion gas supply device is typically provided in line with the length of the Venturi cone. Typically, the combustion gas supply device is coaxial with the long axis of the Venturi cone. The combustion gas supply device will typically be provided centrally within the entry end of the Venturi cone. As explained above, the Venturi cone will normally be mounted relative to the side wall through which the combustion gas supply is mounted to position the combustion gas supply device at least partially within the entry end of the Venturi cone.
  • the gas valve may be controlled by the controller to provide of volume of gas into the entry end of the Venturi cone via the combustion gas supply device.
  • a reference pressure probe or similar apparatus may be provided, associated with the burner body and in connection or communication with the gas valve.
  • the reference pressure probe or apparatus will typically measure the pressure of the combustion gas and/or the combustion mixture to provide information to the controller and/or gas valve about the volume of combustion gas to be provided.
  • the reference pressure probe or apparatus will typically be provided adjacent to the entry end of the Venturi cone.
  • the combustion air supply device and the optional gas valve or gas delivery device will normally both be connected to the controller in order that the controller can control the operation of both components. This allows the controller to coordinate control of the respective amounts of combustion air and combustion gas provided.
  • the combustion air supply device is provided upstream of the combustion gas supply device relative to the burner assembly.
  • the combustion gas supply device is preferably provided closer to the burner assembly than the combustion air supply device. In this way, the combustion air is being driven towards the combustion gas supply device rather than the combustion air being drawn into the Venturi cone by the Venturi effect caused by the injection of the combustion gas.
  • the fan delivers the combustion air required for combustion into the burner body.
  • the gas valve via the combustion gas injector, delivers the combustion gas required for combustion into the burner body.
  • Both the volume of air delivered by the fan and the volume of gas delivered by the gas valve through the injector are typically coordinated and regulated by control electronics.
  • the burner assembly is provided as a part of a water boiler
  • the volume of air delivered by the fan and the volume of gas delivered by the gas valve through the injector may be coordinated and regulated by control electronics of the water boiler.
  • the reference pressure feedback assembly is provided to monitor pressure and feedback to the controller.
  • the reference pressure feedback assembly typically includes a feedback tube from the burner body to the gas valve or measurement probe or similar.
  • the regulated incoming combustion gas and combustion air volumes are typically induced and mixed within the venturi cone incorporated into the burner body.
  • the combustion gas supply device may be sized relative to the size of the smaller, entry end of the Venturi cone.
  • the Venturi cone will normally be mounted relative to the side wall through which the combustion gas supply is mounted to position the combustion gas supply device at least partially within the entry end of the Venturi cone.
  • the provision of the combustion gas supply device at least partially within the entry end of the Venturi cone will typically form an annular first opening about the combustion gas supply device defined between an outer surface of the combustion gas supply device and an inner surface of the Venturi cone. This annular first opening will preferably have a first area.
  • the combustion gas supply device will normally have an opening therein.
  • the combustion gas supply device opening will typically have a second area.
  • the provision of the annular first area and the second area of the opening of the combustion gas supply device and the relative sizes of the first and second area defines a geometric relationship between the first area and the second area.
  • the relationship between the first area and the second area can be used to control or limit the volume of combustion gas and combustion air delivered to the Venturi cone and then, to the point of combustion.
  • Manipulation of the relationship between the first area and the second area may allow definition of a specific heat output for the gas burner.
  • the specific heat output of a gas burner made be dependent on the type of gas but will preferably also be dependent on the geometric relationship between the first area and second area.
  • the respective areas may allow a designer to provide working limits on the volumes of combustion gas and/or combustion air that can be injected into the gas burner assembly by adjusting the respective areas and/or the size of one of the areas, with respect to the other area.
  • Figure 1 A is a schematic view of a gas burner according to an embodiment.
  • Figure IB is an enlarged view of the portion identified on Figure 1 A.
  • Figure 1C is an end view of the configuration shown in Figure IB.
  • a gas burner assembly 10 with post-fan mixing is provided.
  • the gas burner assembly 10 illustrated in Figure 1 A comprises a hollow burner body 11, a burner 12 associated with the hollow burner body 11, a venturi cone 13 located within the hollow burner body 11, the venturi cone 13 having a smaller, entry end ( Figure IB) and a larger, exit end 14, a combustion air supply fan 15 associated with the hollow burner body 11 and a combustion gas supply injector 16 positioned at least partially within the smaller entry end of the venturi cone 13. As illustrated, the combustion air supply fan 15 is provided upstream of the combustion gas supply injector 16 relative to the burner 12.
  • the combustion gas is typically added to a mass, preferably a moving mass of combustion air, to form the combustion mixture with the amount of combustion air.
  • the combustion air will typically be moving under pressure at the entry end of the venturi cone 13 towards the exit end 14 of the venturi cone 13 with the combustion gas injected into this moving mass of combustion air.
  • the hollow burner body 11 may be any shape. Typically, the size (volume) of the hollow burner body 11 will be minimised to allow for the venturi cone 13 to be mounted within the hollow burner body 11 but otherwise as small as possible. This is typically achieved by mounting the venturi cone 13 laterally within the hollow burner body 11 as shown in Figure 1 A.
  • the hollow burner body 11 of the illustrated embodiment is substantially box like in shape, or a 3D hollow rectangular shape. In this configuration, the hollow burner body 11 has 5 side walls with one open side.
  • the hollow burner body 11 may be provided in a single piece or multiple pieces attached together.
  • the hollow burner body 11 has a major side wall 17 which is larger in area, and four minor side walls extending perpendicularly from the edges of the major side wall 17 to define a hollow burner body 11 with one open side, but otherwise closed (except for mounting openings to mount the components thereto).
  • An outwardly extending lip or flange 18 is provided about the open side of the hollow burner body 11.
  • the outwardly extending lip or flange 18 extends substantially perpendicularly to the side walls.
  • the burner 12 is provided as a planar burner plate and is mounted relative to the open side of the hollow burner body 11 to close the hollow burner body 11.
  • An opening is provided in the major side wall 17 to allow the mounting of the combustion air supply fan 15 to the hollow burner body 11.
  • An opening is provided in one of the minor side walls to allow the mounting of the combustion gas supply injector 16 to the hollow burner body 11.
  • An opening is provided in a minor side wall to allow the mounting of a reference pressure probe conduit 26 to the hollow burner body 11.
  • the reference pressure probe conduit 26 is provided in the same minor side wall as the opening to mount the combustion gas supply injector 16 to the hollow burner body 11. As shown, the respective openings are adjacent to one another to allow the reference pressure probe conduit 26 to measure the level of combustion gas close to the combustion gas supply injector.
  • the opening for the reference pressure probe conduit 26 is provided in a location which is separated from the burner assembly 12.
  • the openings in the hollow burner body 11 are typically provided in predefined positions and with different predefined sizes, so that the components cannot be assembled differently relative to the hollow burner body 11.
  • the burner 12 will typically close the open side of the hollow burner body 11.
  • a metal fibre burner is provided in the illustrated embodiment.
  • the burner 12 is a metal fibre burner plate, with a surface oriented toward the interior of the hollow burner body 11 which provides multiple points of combustion.
  • the illustrated burner 12 is planar, provided with one or more side flanges to mount the burner 12 relative to the open side of the hollow burner body 11.
  • venturi cone 13 is typically mounted within the hollow burner body 11.
  • the venturi cone 13 is normally mounted so that the entry end and exit 14 face minor side walls to minimise the profile (and the volume) of the hollow burner body 11.
  • An angled side wall of the venturi cone 13 is typically oriented toward the combustion air supply fan.
  • An opposite angled side wall of the venturi cone 13 is typically oriented toward the burner 12. The opposite angled side is typically separated from the burner 12 by a mount 20 of the venturi cone 13.
  • the Venturi cone 13 may include an outward or flared entry lip as shown best in Figure IB.
  • the outward or flared entry lip shown, is arcuate.
  • the entry lip may promote mixing of the combustion air with the combustion gas within the Venturi cone 13 by disrupting the pattern of airflow from the combustion air supply fan to the entry end 22 of the Venturi cone 13.
  • the exit end 14 of the Venturi cone 13 is preferably sealed to one or more sidewalls of the burner body 11 to define a flow path for the combustion air, combustion gas and combustion mixture within the burner body 11.
  • one or more mounting members or structures 20 will typically extend from the periphery of the exit end 14 of the Venturi cone 13 to one or more sidewalls of the burner body 11. This may confine or direct the flow of the combustion air to the entry end of the Venturi cone 13.
  • the combustion air will typically be provided under positive pressure and the positive pressure of the combustion air and/or combustion gas will typically drive the combustion mixture toward the burner assembly 12.
  • the Venturi cone 13 may be formed of any material, but typically, robust material such as a metal will be used.
  • the Venturi cone 13 may comprise a throat at the entry end in which one or more sidewalls of the Venturi cone 13 are parallel with one another. This may form parallel throat section 21 which is linear between the annular entry 22 of the Venturi cone 13 and the conical part 23 of the Venturi cone 13.
  • the combustion air supply fanl5 may be of any type suitable for providing or injecting combustion air into the burner body.
  • the combustion air supply device may typically be referred to as a "fan" even if the combustion air supply device is not actually a fan.
  • the combustion air supply fan 15 of the illustrated embodiment is mounted relative to the major side wall of the burner body 11. Typically, an opening is provided in the major side wall of the burner body 11 to mount the combustion air supply fan 15 relative thereto.
  • the combustion air supply fan 15 (the outlet from the fan 15) faces the burner assembly 12.
  • the Venturi cone 13 is interposed between the combustion air supply fan 15 and the burner 12 such that the combustion air is driven to, and into the Venturi cone 13 where the combustion air can mix with the combustion gas to form the combustion mixture.
  • the combustion mixture is only formed within the venturi cone 13 and has a very small distance to travel to the burner 12 once the combustion mixture has been formed.
  • the combustion air supply fan 15 will typically deliver combustion air required for combustion into the burner body volume in a controlled manner.
  • the combustion air supply fan 15 will normally provide combustion air in a volume or amount which is coordinated with the volume or amount of the combustion gas provided by the combustion gas supply injector 16.
  • a controller is provided to control and coordinate the volume of combustion air and/or the volume of the combustion gas.
  • the combustion air supply fan 15 will normally drive combustion air, in a required amount, to the Venturi cone 13 where the combustion gas is injected into the preferably moving mass of combustion air being driven into the Venturi cone 13 under positive pressure allowing the combustion gas to mix within the Venturi cone 13 with the combustion air.
  • the combustion gas supply injector is positioned at least partially within the smaller entry end of the Venturi cone 13. As shown in Figure IB, the combustion gas supply device may be positioned in the parallel throat 21 of the Venturi cone 13.
  • the combustion gas supply injector 16 is normally associated with a gas valve 24.
  • a conduit 25 may be provided between the combustion gas injector 16 and the gas valve 24.
  • the combustion gas supply injector 16 is typically provided in line with the length of the Venturi cone 13. Typically, the combustion gas supply injector 15 is coaxial with the long axis of the Venturi cone 13. The combustion gas supply injector 16 will typically be provided centrally within the entry end of the Venturi cone 13.
  • the Venturi cone 13 will normally be mounted such that the longitudinal axis of the venturi cone 13 is perpendicular to the minor side wall through which the combustion gas supply injector 16 is mounted to position the combustion gas supply injector 16 at least partially within the entry end of the Venturi cone 13.
  • the gas valve 24 may be controlled by the controller to provide of volume of gas into the entry end of the Venturi cone 13 via the combustion gas supply injector 16.
  • a reference pressure probe or similar apparatus is provided to measure the pressure of the combustion gas and/or the combustion mixture to provide information to the controller and/or gas valve 24 about the volume of combustion gas to be provided.
  • the reference pressure probe or similar apparatus is associated with the burner body 11 and in communication with the gas valve 24 via conduit 26.
  • the combustion air supply fan 15 and the gas valve 24 will normally both be connected to the controller in order that the controller can control the operation of both components. This allows the controller to coordinate control of the respective amounts of combustion air and combustion gas provided.
  • the combustion air supply fan 15 is provided upstream of the combustion gas supply injector 16 relative to the burner 12.
  • the combustion gas supply injector 16 is provided closer to the burner 12 than the combustion air supply fan 15. In this way, the combustion air is being driven towards the combustion gas supply injector 16 rather than the combustion air being drawn into the Venturi cone 13 by the Venturi effect caused by the injection of the combustion gas or by placing the fan downstream of the venturi cone 13 which increases the volume of the hollow burner body.
  • the fan 15 delivers the combustion air required for combustion into the burner body 11.
  • the gas valve 24, via the combustion gas injector 16, delivers the combustion gas required for combustion into the burner body 11.
  • the gas burner illustrated in the Figures also shows that the combustion gas supply injector 16 is sized relative the smaller entry end of the venturi cone 13 to control combustion air delivery into the venturi cone 13 and the combustion gas supply injector 16 has an inner diameter to dictate combustion gas supply.
  • the combustion gas supply injector 16 is typically sized relative to the size of the smaller, entry end of the Venturi cone 13 to define an annular orifice of a particular area.
  • the Venturi cone 13 will normally be mounted relative to the side wall through which the combustion gas supply injector 16 is mounted to position the combustion gas supply injector 16 at least partially within the entry end 22 of the Venturi cone 13.
  • the provision of the combustion gas supply injector 16 at least partially within the entry end 22 of the Venturi cone 13 will typically form an annular orifice 27 about the combustion gas supply injector 16 defined between an outer surface of the combustion gas supply injector 16 and an inner surface of the Venturi cone 13. This annular orifice 27 has a first, fixed area.
  • the combustion gas supply injector 16 will normally have an opening therein.
  • the combustion gas supply injector 16 opening will typically have a second, fixed area.
  • the provision of the annular first area and the second area of the opening of the combustion gas supply injector 16 and the relative sizes of the first and second areas defines a geometric relationship between the first area and the second area.
  • the relationship between the first area and the second area can be used to control or limit the volume of combustion gas and combustion air delivered to the Venturi cone 13 and then to the point of combustion.

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Abstract

A gas burner assembly with post-fan mixing, the gas burner comprising a hollow burner body, a burner associated with the hollow burner body, a venturi cone located within the hollow burner body, the venturi cone having a smaller, entry end and a larger, exit end, a combustion air supply device associated with the hollow burner body, and a combustion gas supply device positioned at least partially within the smaller entry end of the venturi cone, wherein the combustion air supply device is provided upstream of the combustion gas supply device relative to the burner.

Description

A HYDROGEN PREMIX BURNER
Technical Field of the Invention
The present invention relates generally to the field of gas boilers. In particular, but not exclusively, the invention concerns a gas burner assembly for a gas boiler, with the combustion gas delivery device situated downstream of the fan or air inlet device.
Background to the Invention
The gas boiler market in the UK and mainland Europe is regulated by a series of standards and legislation which govern safe practice and promote higher efficiency appliances being developed, sold and installed. For approximately 20 years it has been common practice to premix the gas and air which forms the combustible mix prior to it arriving at the point of combustion at the surface of the burner, this practice is necessary to achieve efficiency levels dictated by the legislation in place.
Premixing the gas and air is generally but not exclusively done prior to the boilers fan, this has both advantages and disadvantages. The turbulence created by the impeller blades of the fan will ensure a good mix of the gas and air before it enters the burner and to the point of combustion however the overall volume of gas and air mix prior to the point of combustion will be larger. With specific gases (most notably Hydrogen) a larger volume of combustible mix could create a bigger problem if a fault condition occurs.
The description refers to a gas and air mixing system that in this instance is applied to a heating boiler. The application is relevant to any widely used combustible gas mixed with air, but it is very relevant to a Hydrogen and air mixing system, as Hydrogen has different combustion characteristics and in certain circumstances can be more volatile than for example Methane or Propane.
A significant risk of Hydrogen boilers is the consequence of an accidental ignition of the combustible mixture upstream of the burner. The pressure developed during a Hydrogen explosion can cause significant damage to the appliance. It is the intention of this invention to mitigate the severity of such an event to a safe level and to prevent the possible assembly of components that would cause an unsafe gas mixture. Conventional combustion systems for domestic and commercial boilers commonly but not exclusively use pneumatic gas air ratio control systems, electronic gas air ratio control systems could also be used but this is currently less widely used within the boiler industry. Typically, the (pneumatic) system is pressurised by a fan which delivers the mixture of gas and air via a pneumatic device at its inlet. Consequently, the fan, burner and connections contain together a relatively large volume of combustible mixture that will create a significant explosion if ignited.
Embodiments of the invention seek to at least partially overcome or ameliorate any one or more of the abovementioned disadvantages or provide the consumer with a useful or commercial choice.
Summary of the Invention
According to a first aspect of the invention there is provided a gas burner assembly with post-fan mixing, the gas burner comprising: a) A hollow burner body; b) A burner associated with the hollow burner body; c) A venturi cone located within the hollow burner body, the venturi cone having a smaller, entry end and a larger, exit end; d) A combustion air supply device associated with the hollow burner body; and e) A combustion gas supply device positioned at least partially within the smaller entry end of the venturi cone;
Wherein the combustion air supply device is provided upstream of the combustion gas supply device relative to the burner.
Providing a gas burner assembly with the combustion air supply upstream of the combustion gas supply means that the gas burner assembly has a minimal volume of combustible mixture so that it can manage an accidental ignition of the combustible mixture without damage to the structure of the gas burner. The combustion gas is delivered down-stream of the combustion air supply (closer to the burner), which decreases the likelihood that static build-up of the combustible mixture can reach the combustion air supply device (against the positive pressure of the combustion air supply), thus reducing the likelihood and intensity of any explosion.
According to a second aspect of the invention there is provided a gas burner assembly comprising: a) A hollow burner body; b) A burner associated with the hollow burner body; c) A venturi cone located within the hollow burner body, the venturi cone having a smaller, entry end and a larger, exit end; d) A combustion air supply device associated with the hollow burner body; and e) A combustion gas supply device positioned at least partially with the smaller entry end of the venturi cone;
Wherein the combustion gas supply device is sized relative the smaller entry end of the venturi cone to control air delivery into the venturi cone and the combustion gas supply device has an inner diameter to dictate combustion gas supply.
Providing the combination of sizes of the combustion gas supply device relative to the smaller entry end of the venturi cone and the inner diameter of the combustion gas supply device (the outer diameter of the combustion gas supply device relative to the diameter of the smaller entry end of the venturi cone and the inner diameter of the combustion gas supply device) ensures a safe gas and air mixture is delivered to the point of combustion. The geometric relationship between the fixed size of the annular combustion air orifice and the fixed size of the combustion gas supply orifice means that the respective flow rates are much more easily controlled.
The gas burner assembly of an embodiment is typically provided for or as a part of a water boiler.
The gas burner assembly is referred to as a gas burner assembly with ‘post-fan mixing as the mixing of the combustion air with the combustion gas takes place downstream of the combustion air supply device, most commonly referred to as a ‘fan’. In this configuration, the combustion gas is typically added to a mass, preferably a moving mass of combustion air, to form the combustion mixture with the amount of combustion air. The combustion air will typically be moving under pressure at the entry end of the venturi cone of the gas burner assembly.
This will typically minimise the back flow of the combustion mixture to the combustion air supply device.
The gas burner assembly typically includes a hollow burner body. The hollow burner body may be any shape. Typically, the size (volume) of the hollow burner body will be minimised to allow for the venturi cone to be mounted within the hollow burner body but otherwise as small as possible. This is typically achieved by mounting the venturi cone laterally within the hollow burner body.
Although any material of construction could be used, a metal material is typically used.
The hollow burner body will typically be substantially boxdike in shape, or a 3D hollow rectangular shape. In this configuration, the hollow burner body will normally have 5 side walls with one open side. The hollow burner body may be provided in a single piece or multiple pieces attached together.
The hollow burner body will preferably have a major side wall which is larger in area and at least one, typically more than one minor side walls extending at an angle (normally perpendicularly) from the edge(s) of the major side wall to define a hollow burner body with one open side, but otherwise closed.
An outwardly extending lip or flange may be provided about the open side of the hollow burner body. The outwardly extending lip or flange may extend substantially perpendicularly to the side wall(s).
In an embodiment, the burner will be mounted relative to the open side of the hollow burner body to close the hollow burner body.
An opening will normally be provided in at least one of the side walls to allow the mounting of the combustion air supply device to the hollow burner body. The opening to mount the combustion air supply device may be through the major side wall. An opening will normally be provided in at least one of the side walls to allow the mounting of the combustion gas supply device to the hollow burner body. The opening to mount the combustion gas supply device may be through a minor side wall.
An opening will normally be provided in at least one of the side walls to allow the mounting of a reference pressure probe/measurement device or conduit to the hollow burner body. The opening for the reference pressure probe/measurement device or conduit will normally be provided in the same wall as the opening to mount the combustion gas supply device to the hollow burner body. Typically, the respective openings will be adjacent to one another to allow the reference pressure probe/measurement device or conduit to measure the pressure close to the gas supply device. The opening for the reference pressure probe/measurement device or conduit will normally be provided in a location which is separated from the burner.
The openings in the hollow burner body are typically provided in predefined positions and with different predefined sizes so that the components cannot be assembled differently.
The gas burner assembly also typically includes a burner associated with the hollow burner body. The burner will typically close the open side of the hollow burner body. Although any suitable type of burner could be used, a metal fibre burner is preferred.
The burner will normally be provided with a surface which provides one or more points of combustion. Typically, these points of combustion are in the downstream surface, that is, after the venturi cone.
The burner may preferably be a planar burner. The burner may be provided with one or more side flanges to mount the burner relative to the open side of the hollow burner body.
The gas burner assembly also typically includes a Venturi cone located within the hollow burner body, the venturi cone having a smaller, entry end and a larger, exit end. The venturi cone is typically mounted within the hollow burner body. The venturi cone is normally mounted so that the entry end and exit end face the minor side wall(s) to minimise the profile of the hollow burner body. An angled side wall of the venturi cone is typically oriented toward the combustion air supply device. An opposite angled side wall of the venturi cone is typically oriented toward the burner. The opposite angled side is typically separated from the burner by a mount of the venturi cone.
The Venturi cone may include an outward or flared entry lip. The outward or flared entry lip may be arcuate. The entry lip may promote mixing of the combustion air with the combustion gas within the Venturi cone by disrupting the pattern of airflow from the combustion air supply device to the entry end of the Venturi cone.
The venturi cone is preferably mounted laterally within the hollow burner body between the combustion air supply device and the burner, as opposed to longitudinally (with the exit end of the venturi cone facing the burner).
The exit end of the Venturi cone is preferably sealed to one or more sidewalls of the burner body to define a flow path for the combustion air, combustion gas and combustion mixture within the burner body. Typically, one or more mounting members or structures will typically extend from the periphery of the exit end of the Venturi cone to one or more sidewalls of the burner body. This may confine or direct the flow of the combustion air to the entry end of the Venturi cone. The exit end of the venturi cone is preferably adjacent to the burner. The exit end of the venturi cone typically does not face the burner.
The combustion air will typically be provided under positive pressure and the positive pressure of the combustion air and/or combustion gas will typically drive the combustion mixture toward the burner.
The Venturi cone may be formed of any material, but typically, robust material such as a metal will be used.
The Venturi cone may comprise a throat at the entry end in which one or more sidewalls of the Venturi cone are parallel with one another. This may form parallel throat which is linear between the entry end of the Venturi cone and the conical part of the Venturi cone.
The gas burner assembly may include a combustion air supply device associated with the hollow burner body. The combustion air supply device may be of any type suitable for providing or injecting combustion air into the hollow burner body. The combustion air supply device may be referred to as a "fan" even if the combustion air supply device is not actually a fan.
The combustion air supply device will normally be mounted relative to the major side wall of the burner body. Typically, an opening is provided in the major side wall of the burner body to mount the combustion air supply device relative thereto.
The combustion air supply device will normally face the burner. The Venturi cone will typically be interposed between the combustion air supply device and the burner such that the combustion air is driven to, and into the Venturi cone where the combustion air can mix with the combustion gas.
The combustion air supply device will typically deliver combustion air required for combustion into the burner body volume in a controlled manner. The combustion air supply device will normally provide combustion air in a volume or amount which is coordinated with the volume or amount of the combustion gas provided by the combustion gas supply device. Typically, a controller is provided to control and coordinate the volume of combustion air and/or the volume of the combustion gas.
As mentioned above, the combustion air supply device will preferably drive combustion air, in a required amount, to the Venturi cone where the combustion gas is injected into the, preferably moving mass of combustion air being driven into the Venturi cone under positive pressure allowing the combustion gas to mix within the Venturi cone with the combustion air.
The gas burner may include a combustion gas supply device positioned at least partially within the smaller entry end of the Venturi cone. The combustion gas supply device may be positioned in the parallel throat of the Venturi cone.
The combustion gas supply device may be an injector. The combustion gas supply device may be associated with a gas valve. A conduit may be supplied between the combustion gas injector and the gas valve.
The combustion gas supply device is typically provided in line with the length of the Venturi cone. Typically, the combustion gas supply device is coaxial with the long axis of the Venturi cone. The combustion gas supply device will typically be provided centrally within the entry end of the Venturi cone. As explained above, the Venturi cone will normally be mounted relative to the side wall through which the combustion gas supply is mounted to position the combustion gas supply device at least partially within the entry end of the Venturi cone.
The gas valve may be controlled by the controller to provide of volume of gas into the entry end of the Venturi cone via the combustion gas supply device.
A reference pressure probe or similar apparatus may be provided, associated with the burner body and in connection or communication with the gas valve. The reference pressure probe or apparatus will typically measure the pressure of the combustion gas and/or the combustion mixture to provide information to the controller and/or gas valve about the volume of combustion gas to be provided. The reference pressure probe or apparatus will typically be provided adjacent to the entry end of the Venturi cone.
The combustion air supply device and the optional gas valve or gas delivery device will normally both be connected to the controller in order that the controller can control the operation of both components. This allows the controller to coordinate control of the respective amounts of combustion air and combustion gas provided.
The combustion air supply device is provided upstream of the combustion gas supply device relative to the burner assembly. The combustion gas supply device is preferably provided closer to the burner assembly than the combustion air supply device. In this way, the combustion air is being driven towards the combustion gas supply device rather than the combustion air being drawn into the Venturi cone by the Venturi effect caused by the injection of the combustion gas.
In use, the fan delivers the combustion air required for combustion into the burner body. The gas valve, via the combustion gas injector, delivers the combustion gas required for combustion into the burner body.
Both the volume of air delivered by the fan and the volume of gas delivered by the gas valve through the injector are typically coordinated and regulated by control electronics. Where the burner assembly is provided as a part of a water boiler, the volume of air delivered by the fan and the volume of gas delivered by the gas valve through the injector may be coordinated and regulated by control electronics of the water boiler.
The reference pressure feedback assembly is provided to monitor pressure and feedback to the controller. The reference pressure feedback assembly typically includes a feedback tube from the burner body to the gas valve or measurement probe or similar.
The regulated incoming combustion gas and combustion air volumes are typically induced and mixed within the venturi cone incorporated into the burner body.
The combustion gas supply device may be sized relative to the size of the smaller, entry end of the Venturi cone. As explained above, the Venturi cone will normally be mounted relative to the side wall through which the combustion gas supply is mounted to position the combustion gas supply device at least partially within the entry end of the Venturi cone. The provision of the combustion gas supply device at least partially within the entry end of the Venturi cone will typically form an annular first opening about the combustion gas supply device defined between an outer surface of the combustion gas supply device and an inner surface of the Venturi cone. This annular first opening will preferably have a first area.
The combustion gas supply device will normally have an opening therein. The combustion gas supply device opening will typically have a second area.
In use, the provision of the annular first area and the second area of the opening of the combustion gas supply device and the relative sizes of the first and second area defines a geometric relationship between the first area and the second area. The relationship between the first area and the second area can be used to control or limit the volume of combustion gas and combustion air delivered to the Venturi cone and then, to the point of combustion.
Manipulation of the relationship between the first area and the second area may allow definition of a specific heat output for the gas burner. The specific heat output of a gas burner made be dependent on the type of gas but will preferably also be dependent on the geometric relationship between the first area and second area. The respective areas may allow a designer to provide working limits on the volumes of combustion gas and/or combustion air that can be injected into the gas burner assembly by adjusting the respective areas and/or the size of one of the areas, with respect to the other area.
Detailed Description of the Invention
In order that the invention may be more clearly understood one or more embodiments thereof will now be described, by way of example only, with reference to the accompanying drawings, of which:
Figure 1 A is a schematic view of a gas burner according to an embodiment.
Figure IB is an enlarged view of the portion identified on Figure 1 A.
Figure 1C is an end view of the configuration shown in Figure IB.
With reference to the accompanying figures, a gas burner assembly 10 with post-fan mixing is provided.
The gas burner assembly 10 illustrated in Figure 1 A comprises a hollow burner body 11, a burner 12 associated with the hollow burner body 11, a venturi cone 13 located within the hollow burner body 11, the venturi cone 13 having a smaller, entry end (Figure IB) and a larger, exit end 14, a combustion air supply fan 15 associated with the hollow burner body 11 and a combustion gas supply injector 16 positioned at least partially within the smaller entry end of the venturi cone 13. As illustrated, the combustion air supply fan 15 is provided upstream of the combustion gas supply injector 16 relative to the burner 12.
In this configuration, the combustion gas is typically added to a mass, preferably a moving mass of combustion air, to form the combustion mixture with the amount of combustion air. The combustion air will typically be moving under pressure at the entry end of the venturi cone 13 towards the exit end 14 of the venturi cone 13 with the combustion gas injected into this moving mass of combustion air.
The hollow burner body 11 may be any shape. Typically, the size (volume) of the hollow burner body 11 will be minimised to allow for the venturi cone 13 to be mounted within the hollow burner body 11 but otherwise as small as possible. This is typically achieved by mounting the venturi cone 13 laterally within the hollow burner body 11 as shown in Figure 1 A.
Although any material of construction could be used for the hollow burner body 11, a metal material is typically used.
The hollow burner body 11 of the illustrated embodiment is substantially box like in shape, or a 3D hollow rectangular shape. In this configuration, the hollow burner body 11 has 5 side walls with one open side. The hollow burner body 11 may be provided in a single piece or multiple pieces attached together.
As shown in Figure 1A, the hollow burner body 11 has a major side wall 17 which is larger in area, and four minor side walls extending perpendicularly from the edges of the major side wall 17 to define a hollow burner body 11 with one open side, but otherwise closed (except for mounting openings to mount the components thereto).
An outwardly extending lip or flange 18 is provided about the open side of the hollow burner body 11. The outwardly extending lip or flange 18 extends substantially perpendicularly to the side walls.
In the illustrated embodiment, the burner 12 is provided as a planar burner plate and is mounted relative to the open side of the hollow burner body 11 to close the hollow burner body 11.
An opening is provided in the major side wall 17 to allow the mounting of the combustion air supply fan 15 to the hollow burner body 11.
An opening is provided in one of the minor side walls to allow the mounting of the combustion gas supply injector 16 to the hollow burner body 11.
An opening is provided in a minor side wall to allow the mounting of a reference pressure probe conduit 26 to the hollow burner body 11. In the embodiment illustrated in Figure 1A, the reference pressure probe conduit 26 is provided in the same minor side wall as the opening to mount the combustion gas supply injector 16 to the hollow burner body 11. As shown, the respective openings are adjacent to one another to allow the reference pressure probe conduit 26 to measure the level of combustion gas close to the combustion gas supply injector. The opening for the reference pressure probe conduit 26 is provided in a location which is separated from the burner assembly 12.
The openings in the hollow burner body 11 are typically provided in predefined positions and with different predefined sizes, so that the components cannot be assembled differently relative to the hollow burner body 11.
As shown, the burner 12 will typically close the open side of the hollow burner body 11. Although any suitable type of burner could be used, a metal fibre burner is provided in the illustrated embodiment.
In the embodiment shown, the burner 12 is a metal fibre burner plate, with a surface oriented toward the interior of the hollow burner body 11 which provides multiple points of combustion.
The illustrated burner 12 is planar, provided with one or more side flanges to mount the burner 12 relative to the open side of the hollow burner body 11.
As shown, the venturi cone 13 is typically mounted within the hollow burner body 11. The venturi cone 13 is normally mounted so that the entry end and exit 14 face minor side walls to minimise the profile (and the volume) of the hollow burner body 11. An angled side wall of the venturi cone 13 is typically oriented toward the combustion air supply fan. An opposite angled side wall of the venturi cone 13 is typically oriented toward the burner 12. The opposite angled side is typically separated from the burner 12 by a mount 20 of the venturi cone 13.
The Venturi cone 13 may include an outward or flared entry lip as shown best in Figure IB. The outward or flared entry lip shown, is arcuate. The entry lip may promote mixing of the combustion air with the combustion gas within the Venturi cone 13 by disrupting the pattern of airflow from the combustion air supply fan to the entry end 22 of the Venturi cone 13.
The exit end 14 of the Venturi cone 13 is preferably sealed to one or more sidewalls of the burner body 11 to define a flow path for the combustion air, combustion gas and combustion mixture within the burner body 11. Typically, one or more mounting members or structures 20 will typically extend from the periphery of the exit end 14 of the Venturi cone 13 to one or more sidewalls of the burner body 11. This may confine or direct the flow of the combustion air to the entry end of the Venturi cone 13.
The combustion air will typically be provided under positive pressure and the positive pressure of the combustion air and/or combustion gas will typically drive the combustion mixture toward the burner assembly 12.
The Venturi cone 13 may be formed of any material, but typically, robust material such as a metal will be used.
The Venturi cone 13 may comprise a throat at the entry end in which one or more sidewalls of the Venturi cone 13 are parallel with one another. This may form parallel throat section 21 which is linear between the annular entry 22 of the Venturi cone 13 and the conical part 23 of the Venturi cone 13.
The combustion air supply fanl5 may be of any type suitable for providing or injecting combustion air into the burner body. The combustion air supply device may typically be referred to as a "fan" even if the combustion air supply device is not actually a fan.
The combustion air supply fan 15 of the illustrated embodiment is mounted relative to the major side wall of the burner body 11. Typically, an opening is provided in the major side wall of the burner body 11 to mount the combustion air supply fan 15 relative thereto.
The combustion air supply fan 15 (the outlet from the fan 15) faces the burner assembly 12. The Venturi cone 13 is interposed between the combustion air supply fan 15 and the burner 12 such that the combustion air is driven to, and into the Venturi cone 13 where the combustion air can mix with the combustion gas to form the combustion mixture. Given the orientation and positioning of the venturi cone 13 within the hollow burner body 11 of the illustrated embodiment, the combustion mixture is only formed within the venturi cone 13 and has a very small distance to travel to the burner 12 once the combustion mixture has been formed.
The combustion air supply fan 15 will typically deliver combustion air required for combustion into the burner body volume in a controlled manner. The combustion air supply fan 15 will normally provide combustion air in a volume or amount which is coordinated with the volume or amount of the combustion gas provided by the combustion gas supply injector 16. Typically, a controller is provided to control and coordinate the volume of combustion air and/or the volume of the combustion gas.
As mentioned above, the combustion air supply fan 15 will normally drive combustion air, in a required amount, to the Venturi cone 13 where the combustion gas is injected into the preferably moving mass of combustion air being driven into the Venturi cone 13 under positive pressure allowing the combustion gas to mix within the Venturi cone 13 with the combustion air.
The combustion gas supply injector is positioned at least partially within the smaller entry end of the Venturi cone 13. As shown in Figure IB, the combustion gas supply device may be positioned in the parallel throat 21 of the Venturi cone 13.
The combustion gas supply injector 16 is normally associated with a gas valve 24. A conduit 25 may be provided between the combustion gas injector 16 and the gas valve 24.
The combustion gas supply injector 16 is typically provided in line with the length of the Venturi cone 13. Typically, the combustion gas supply injector 15 is coaxial with the long axis of the Venturi cone 13. The combustion gas supply injector 16 will typically be provided centrally within the entry end of the Venturi cone 13.
The Venturi cone 13 will normally be mounted such that the longitudinal axis of the venturi cone 13 is perpendicular to the minor side wall through which the combustion gas supply injector 16 is mounted to position the combustion gas supply injector 16 at least partially within the entry end of the Venturi cone 13.
The gas valve 24 may be controlled by the controller to provide of volume of gas into the entry end of the Venturi cone 13 via the combustion gas supply injector 16.
A reference pressure probe or similar apparatus is provided to measure the pressure of the combustion gas and/or the combustion mixture to provide information to the controller and/or gas valve 24 about the volume of combustion gas to be provided. The reference pressure probe or similar apparatus is associated with the burner body 11 and in communication with the gas valve 24 via conduit 26. The combustion air supply fan 15 and the gas valve 24 will normally both be connected to the controller in order that the controller can control the operation of both components. This allows the controller to coordinate control of the respective amounts of combustion air and combustion gas provided.
The combustion air supply fan 15 is provided upstream of the combustion gas supply injector 16 relative to the burner 12. The combustion gas supply injector 16 is provided closer to the burner 12 than the combustion air supply fan 15. In this way, the combustion air is being driven towards the combustion gas supply injector 16 rather than the combustion air being drawn into the Venturi cone 13 by the Venturi effect caused by the injection of the combustion gas or by placing the fan downstream of the venturi cone 13 which increases the volume of the hollow burner body.
In use, the fan 15 delivers the combustion air required for combustion into the burner body 11. The gas valve 24, via the combustion gas injector 16, delivers the combustion gas required for combustion into the burner body 11.
The gas burner illustrated in the Figures also shows that the combustion gas supply injector 16 is sized relative the smaller entry end of the venturi cone 13 to control combustion air delivery into the venturi cone 13 and the combustion gas supply injector 16 has an inner diameter to dictate combustion gas supply.
A geometric relationship is provided between an annular combustion air orifice
27 defined by an outer diameter of the combustion gas supply injector 16 and the diameter of the smaller entry end 22 of the venturi cone 13, and the inner diameter 28 of the combustion gas supply injector 16, ensures a safe gas and air mixture is delivered to the point of combustion. The geometric relationship between the fixed size of the annular combustion air orifice 27 and the fixed size of the combustion gas supply orifice
28 means that the respective flow rates are much more easily controlled relative to one another.
The combustion gas supply injector 16 is typically sized relative to the size of the smaller, entry end of the Venturi cone 13 to define an annular orifice of a particular area. As explained above, the Venturi cone 13 will normally be mounted relative to the side wall through which the combustion gas supply injector 16 is mounted to position the combustion gas supply injector 16 at least partially within the entry end 22 of the Venturi cone 13. The provision of the combustion gas supply injector 16 at least partially within the entry end 22 of the Venturi cone 13 will typically form an annular orifice 27 about the combustion gas supply injector 16 defined between an outer surface of the combustion gas supply injector 16 and an inner surface of the Venturi cone 13. This annular orifice 27 has a first, fixed area.
The combustion gas supply injector 16 will normally have an opening therein. The combustion gas supply injector 16 opening will typically have a second, fixed area.
In use, the provision of the annular first area and the second area of the opening of the combustion gas supply injector 16 and the relative sizes of the first and second areas, defines a geometric relationship between the first area and the second area. The relationship between the first area and the second area can be used to control or limit the volume of combustion gas and combustion air delivered to the Venturi cone 13 and then to the point of combustion. The one or more embodiments are described above by way of example only.
Many variations are possible without departing from the scope of protection afforded by the appended claims.

Claims

1. A gas burner assembly with post-fan mixing, the gas burner comprising: a. A hollow burner body; b. A burner associated with the hollow burner body; c. A venturi cone located within the hollow burner body, the venturi cone having a smaller, entry end and a larger, exit end; d. A combustion air supply device associated with the hollow burner body; and e. A combustion gas supply device positioned at least partially within the smaller entry end of the venturi cone;
Wherein the combustion air supply device is provided upstream of the combustion gas supply device relative to the burner.
2. A gas burner assembly comprising: a) A hollow burner body; b) A burner associated with the hollow burner body; c) A venturi cone located within the hollow burner body, the venturi cone having a smaller, entry end and a larger, exit end; d) A combustion air supply device associated with the hollow burner body; and e) A combustion gas supply device positioned at least partially with the smaller entry end of the venturi cone;
Wherein the combustion gas supply device is sized relative the smaller entry end of the venturi cone to control air delivery into the venturi cone and the combustion gas supply device has an inner diameter to dictate combustion gas supply.
3. The gas burner assembly as claimed in claim 1 or claim 2 wherein the hollow burner body is substantially box-like in shape, or a 3D hollow rectangular shape.
4. The gas burner assembly as claimed in claims in claim 3 wherein the hollow burner body has a plurality of side walls with one open side.
5. The gas burner assembly as claimed in claim 4 wherein one of the plurality of side walls is a major side wall which is larger in area and a number of minor side walls extending substantially perpendicularly from respective edges of the major side wall to define a hollow burner body with one open side. 6. The gas burner assembly as claimed in claim 4 or claim 5 wherein the burner is mounted relative to the open side of the hollow burner body to close the hollow burner body.
7. The gas burner assembly as claimed in any one of claims 4 to 6 further comprising an opening provided in at least one of the side walls to mount the combustion air supply device to the hollow burner body.
8 The gas burner assembly as claimed in claim 7 wherein the opening to mount the combustion air supply device is through the major side wall.
9. The gas burner assembly as claimed in any one of claims 4 to 8 further comprising an opening provided in at least one of the side walls to allow the mounting of the combustion gas supply device to the hollow burner body.
10 The gas burner assembly as claimed in claim 9 wherein the opening to mount the combustion gas supply device is through one of the minor side walls.
11 The gas burner assembly as claimed in any one of the preceding claims wherein the burner is provided with a surface which provides one or more points of combustion.
12 The gas burner assembly as claimed in any one of the preceding claims wherein the venturi cone is mounted laterally within the hollow burner body with an angled side wall of the venturi cone oriented toward the combustion air supply device. 13. The gas burner assembly as claimed in any one of the preceding claims wherein an exit end of the Venturi cone is sealed to one or more sidewalls of the hollow burner body to define a flow path for the combustion air, combustion gas and combustion mixture within the hollow burner body.
14. The gas burner assembly as claimed in any one of the preceding claims wherein the combustion air supply device faces the burner.
15. The gas burner assembly as claimed in any one of the preceding claims wherein the combustion air supply device delivers combustion air required for combustion into the hollow burner body volume in a volume or amount which is coordinated with a volume or amount of the combustion gas provided by the combustion gas supply device.
16. The gas burner assembly as claimed in any one of the preceding claims wherein the Venturi cone comprises a throat at the entry end in which one or more sidewalls of the Venturi cone are parallel with one another to form a parallel throat which is linear between the entry end of the Venturi cone and a conical part of the Venturi cone.
17. The gas burner assembly as claimed in any one of the preceding claims wherein the combustion gas supply device has an outlet located coaxially with a long axis of the venturi cone and within the parallel throat.
18. The gas burner assembly as claimed in any one of the preceding claims wherein the combustion gas supply device is associated with a gas valve to provide of volume of combustion gas into the entry end of the Venturi cone via the combustion gas supply device. 19. The gas burner assembly as claimed in claim 18 further comprising a reference pressure probe or similar apparatus, associated with the hollow burner body and in connection or communication with the gas valve. 0 The gas burner assembly as claimed in any one of the preceding claims wherein the combustion air supply device provides combustion air under positive pressure and the positive pressure of the combustion air and/or combustion gas drives a combustion mixture formed by the combustion gas supply device, toward the burner. 1 The gas burner assembly as claimed in any one of claim 2, or claims 3 to 20 when dependent from claim 2 wherein the combustion gas supply device is sized relative to the size of the smaller, entry end of the Venturi cone to form an annular first opening about the combustion gas supply device defined between an outer surface of the combustion gas supply device and an inner surface of the Venturi cone, the annular first opening having a first area.
22. The gas burner assembly as claimed in claim 21 wherein the combustion gas supply device has an opening therein having a second area, the first area and the second area of the opening of the combustion gas supply device sized to define a geometric relationship between the first area and the second area to control or limit a volume of combustion gas and combustion air delivered to the Venturi cone and then, to a point of combustion. 23. The gas burner assembly as claimed in claim 22 wherein manipulation of the relationship between the first area and the second area allows definition of a specific heat output for the gas burner.
24. The gas burner assembly as claimed in claim 22 or claim 23 wherein the respective first and second areas provides working limits on the volumes of combustion gas and/or combustion air that can be injected into the gas burner assembly.
25. The gas burner assembly as claimed in any one of claim 2, or claims 3 to 20 when dependent from claim 2 wherein the combustion air supply device is provided upstream of the combustion gas supply device relative to the burner. 26. A water boiler comprising the gas burner assembly of any one of the preceding claims.
EP22737518.5A 2021-07-02 2022-07-01 A hydrogen premix burner Pending EP4320388A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB2109629.2A GB2608455B (en) 2021-07-02 2021-07-02 A burner
PCT/GB2022/051706 WO2023275564A1 (en) 2021-07-02 2022-07-01 A hydrogen premix burner

Publications (1)

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EP4320388A1 true EP4320388A1 (en) 2024-02-14

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EP22737518.5A Pending EP4320388A1 (en) 2021-07-02 2022-07-01 A hydrogen premix burner

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EP (1) EP4320388A1 (en)
GB (1) GB2608455B (en)
WO (1) WO2023275564A1 (en)

Families Citing this family (1)

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Publication number Priority date Publication date Assignee Title
DE102023204058A1 (en) 2023-05-03 2024-11-07 Robert Bosch Gesellschaft mit beschränkter Haftung Air-gas mixture combustion plant with one combustion unit

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2006019279A1 (en) * 2004-08-19 2006-02-23 Kyungdong Boiler Co., Ltd. Gas burner

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE6607199U (en) * 1968-06-06 1971-01-21 Fargas Spa BURNERS FOR GAS FUELS
US5423675A (en) * 1993-11-08 1995-06-13 Kratsch; Kenneth Burner mixing chamber
WO2016142770A2 (en) * 2015-03-11 2016-09-15 Tre P Engineering S.R.L. Gas domestic premixed ventilated hob

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2006019279A1 (en) * 2004-08-19 2006-02-23 Kyungdong Boiler Co., Ltd. Gas burner

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GB202109629D0 (en) 2021-08-18
GB2608455A (en) 2023-01-04
GB2608455B (en) 2024-08-28
WO2023275564A1 (en) 2023-01-05

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