EP4239247A1 - Gasmischverteiler - Google Patents

Gasmischverteiler Download PDF

Info

Publication number
EP4239247A1
EP4239247A1 EP22160009.1A EP22160009A EP4239247A1 EP 4239247 A1 EP4239247 A1 EP 4239247A1 EP 22160009 A EP22160009 A EP 22160009A EP 4239247 A1 EP4239247 A1 EP 4239247A1
Authority
EP
European Patent Office
Prior art keywords
manifold
mixer
gas
outlet
section
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
EP22160009.1A
Other languages
English (en)
French (fr)
Inventor
Andrea Pisoni
Nicolo ZANATTA
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.)
BDR Thermea Group BV
Original Assignee
BDR Thermea Group BV
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 BDR Thermea Group BV filed Critical BDR Thermea Group BV
Priority to EP22160009.1A priority Critical patent/EP4239247A1/de
Priority to PCT/EP2023/055185 priority patent/WO2023166059A1/en
Publication of EP4239247A1 publication Critical patent/EP4239247A1/de
Pending legal-status Critical Current

Links

Images

Classifications

    • 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
    • F23D14/46—Details, e.g. noise reduction means
    • F23D14/62—Mixing devices; Mixing tubes
    • 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, e.g. noise reduction means
    • F23D14/72—Safety devices, e.g. operative in case of failure of gas supply
    • F23D14/82—Preventing flashback or blowback
    • 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
    • F23D2209/00—Safety arrangements
    • F23D2209/10—Flame flashback

Definitions

  • the invention relates to a manifold for a combustion appliance. Additionally, the invention relates to a combustion appliance comprising said manifold and the use of the manifold in a combustion appliance for the combustion of fuel gas, in particular comprising at least 20 mol% hydrogen, in particular pure hydrogen, natural gas or mixtures thereof.
  • gas boilers combust gas fuel to heat water for domestic use and/or central heating systems in buildings.
  • the market is looking into cleaner alternatives for combusting natural gas.
  • One of these alternatives is combusting fuel gas comprising 20 mol% hydrogen, in particular pure hydrogen, or natural gas or mixtures thereof.
  • gas boilers combusting pure hydrogen i.e. hydrogen boiler
  • gas boilers combusting pure hydrogen are boilers to which fuel gas is supplied that comprises at least 90 mol% hydrogen.
  • natural gas (or propane) boilers on the market which are only suitable to combust up to 20% hydrogen into the gas blend (according to the specifications).
  • current boilers on the market are not directly suitable for combustion of hydrogen and important modifications are needed to possibly convert a standard natural gas boiler into a hydrogen boiler. These modifications are in most cases expensive and time consuming.
  • connection system suitable to be used in hydrogen gas boilers for transporting an air/gas mixture to the burner by reducing to the minimum the size and the number of structural components to be used in the connecting system.
  • the object of the invention is therefore to provide a manifold that is cost-effective, safe, and that is effective in coping with risks in connection with distributing an air/gas mixture to the burner of a boiler configured to combust hydrogen.
  • a manifold for a combustion appliance for a gas boiler, for distributing an air/gas mixture to a burner of said combustion appliance
  • the manifold having a one-piece hollow frame structure comprising a first inlet section for receiving fuel gas through a first inlet opening, a second inlet section for receiving air through a second inlet opening, the second inlet section being located upstream the first inlet section, and an outlet section for releasing the air/gas mixture to the burner through an outlet opening, the outlet section being located downstream the first inlet section and the second inlet section
  • the manifold comprises a mixer for allowing the mixing of the fuel gas and air at a mixer outlet.
  • the mixer is located downstream the connection for receiving air, i.e. after the blower, thereby reducing the air/gas mixture and consequently reducing an unexpected ignition in case of flashback.
  • the mixer is merged directly in the manifold frame structure since it is inserted in the frame structure of the manifold passing through the second inlet opening. Therefore, the connection system transporting air/gas mixture to the burner is more compact and less structural components as possible are used that is a safety feature for hydrogen gas boiler. This means less mechanical connections and possible gas leakages as well as easy maintenance and accessibility for the service people.
  • the mixer can be inserted into the frame structure through the second inlet opening.
  • the mixer can be inserted into the frame structure through a different opening, for example through the outlet opening or the first inlet opening.
  • the mixer can comprise a main body having a first region for receiving fuel gas from the first inlet section and extending transversally in the main body, and a second region for receiving air from the second inlet section and extending longitudinally in the main body.
  • the mixer is structurally compact and the main body comprises two regions dedicated to receive the fuel gas and the air arranged in such a way to efficiently provide an air/gas mixture at the mixer outlet.
  • the mixer can comprise an elongated hollow structure located in the first region, said elongated structure comprising a gas inlet coupled to the first inlet section and an outlet slot for releasing the fuel gas at the mixer outlet.
  • the gas flows outside from the slot and it is pulled by the air (pushed by the fan from the bottom). Since the gas, in particular hydrogen, is lighter than the air, it tends to rise. It is noted that the effect of pulling the gas by the air helps the mixing.
  • the elongated structure can have a suitable shape.
  • the elongated structure can have a funnel shape. This can advantageously provide a homogeneous distribution of the gas at the mixer outlet.
  • the outlet slot of the elongated structure at the gas inlet can have an increased aperture, in particular in comparison to the remaining part of the outlet slot.
  • the mixer outlet can have a polygonal cross section, in particular a rectangular cross-section.
  • the main body of the mixer can have a polygonal cross section, in particular a rectangular cross-section.
  • the second inlet opening can have a polygonal shape, in particular a rectangular shape. It is noted that the particular shape of the mixer outlet improves the mixing of the gas with the air. Also, this shape as well as the shape of the main body of the mixer can be adapted to the shape of the manifold, i.e. of the shape of the second inlet opening, in order to facilitate the insertion of the mixer in the frame structure of the manifold and increasing the overall compactness of the system. As mentioned above, alternatively, the mixer can be inserted into the frame structure through a different opening, for example through the outlet opening or the first inlet opening.
  • the mixer comprises one or more engaging means, in particular pins or fins
  • the second inlet section comprises one or more guiding means, in particular seats or slots, for allowing the positioning and guiding of the mixer inside the manifold. In this way, the mixer can be easily inserted and fixed inside the manifold.
  • a cross-sectional gas flow area and a cross-sectional air flow area are present, wherein the cross-sectional gas flow area at the mixer outlet is smaller than the cross-sectional air flow area.
  • the ratio between the cross-sectional gas flow area and the cross-sectional air flow area at the mixer outlet is comprised between 0.13 and 0.17.
  • the mixer is designed with a specific shape in order to have the optimal mixing between gas and the air from the blower.
  • the aim is to have the mixing just before the burner and not inside the burner. In fact, if the mixing occurs in the burner, the flame distribution could be not uniform. This could create different temperature area on the burner deck with consequent not expected combustion values.
  • the position in the manifold is in according with pressure loss and the minimum opening area is defined by the crossing section of the manifold.
  • the cross sectional gas area can depend on the power of the burner has to provide. In particular, the cross sectional gas area can be advantageously less than 1/3 of the crossing section of the manifold.
  • the ratio between the cross-sectional gas flow area and the cross-sectional air flow area at the mixer outlet can be between 1:6 to 1:7. With these values, a correct compromise between free air area and gas area is obtained. In this way, less pressure loss as possible is ensured in order to have a reasonable fan speed at maximum heat input and enough gas to reach the maximum heat input. It is noted that these values can vary based on the manifold dimension. However, they are particularly advantageous for combustion appliance, such as gas boilers of up to 28kW.
  • the manifold further comprises a suppressor located in the frame structure downstream the mixer for avoiding a flame back in the manifold.
  • the no return valve in standard boilers e.g. natural gas boilers
  • this valve blocks the flame back in the manifold/blower in case of flashback also reducing the noise of the explosion.
  • the suppressor has a specific shape and weight to have a compromise in terms of pressure lost in the system, response of the flashback, and anti-rebound phenomena.
  • the manifold further comprises a mixing chamber positioned downstream the mixer, in particular between the mixer outlet and the outlet opening of the outlet portion, for mixing the fuel gas and the air received from the mixer.
  • the manifold further comprises a first seat for positioning the suppressor, the first seat being located in the mixing chamber.
  • the suppressor is merged in the frame structure of the manifold and the manifold is specifically designed to contain a flashback suppressor by providing a dedicated seat.
  • a single integrated part that is a multipurpose element constituted by a manifold to drive the air/gas mixture to the burner, with a mixer to adequately mix fuel gas and air after the fan element and a suppressor to suppress any possible flashback.
  • the second inlet section of the manifold is connectable to a fan element.
  • the present manifold can simply be connected between the fan element and the burner so that the mixing of the air and fuel gas can occur after the blower/fan element, thereby reducing the risk on an expected ignition when using hydrogen as fuel gas.
  • the manifold can further comprise a second seat for a, in particular mass, flow sensor, the second seat being located at the first inlet section downstream the first inlet opening. Additionally or alternatively, the manifold can further comprise a third seat for a, in particular mass, flow sensor, the third seat can be located at the second inlet section.
  • the manifold can further comprise a gas regulation valve to limit the maximum gas flow in the manifold.
  • This valve acts as a sort of restrictor to limit the maximum gas flow in case of malfunction of the gas valve. This part can prevent unexpected no safety situation.
  • a combustion appliance in particular a gas boiler, the combustion appliance comprising an inventive manifold.
  • combustion appliances can include furnaces, water heaters, boilers, direct/in-direct make-up air heaters, power/jet burners and any other residential, commercial or industrial combustion appliance.
  • the appliance including the present manifold can be a gas boiler for the combustion of pure hydrogen gas.
  • a fuel gas that comprises at least 90 mol% hydrogen.
  • the use of the inventive manifold in a combustion appliance for the combustion of fuel gas in particular comprising at least 20 mol% hydrogen, in particular pure hydrogen, natural gas or mixtures thereof.
  • a manifold 1 is shown.
  • the manifold 1 is connected to a burner 3 of a gas appliance 2 (e.g. a gas boiler, in particular a hydrogen boiler).
  • the manifold 1 receives air A and fuel gas G and provides the burner 3 with an air/gas mixture M.
  • the manifold 1 has a frame structure 4, in particular a hollow one-piece frame structure made of metal, for example aluminum, realized with tooling machines.
  • the frame 4 comprises a first inlet section 6, a second inlet section 7 and an outlet section 8.
  • the manifold 1 comprises a mixer 11.
  • the mixer 11 is located inside the frame structure 4 of the manifold 1 and allows the mixing at the mixer outlet 12. In other words, as described in more detail in figures 4A and 5A , the mixer 11 receives the fuel gas G from the first inlet section 6 and the air A from the second inlet section 7 and mix them at the mixer outlet 12.
  • the mixer 11 is not an integral part of the frame structure 4 but can be inserted into or removed from the frame structure 4 through an opening, in particular the outlet opening 9 or the first inlet opening 5 or the second inlet opening 10 or another opening.
  • the mixer 11 is shaped in accordance with the second inlet opening 10.
  • Figures 2A and 2B illustrate the frame structure 4 from a rear view ( Fig. 2A ) and from a front view ( Fig. 2B ). From the figures emerges that the frame structure 4 is a one-piece structure with a first inlet section 6, a second inlet section 7 and an outlet section 8.
  • Figure 2A shows that functional components, such as the mixer 11 and the suppressor 13 can be advantageously inserted into the frame structure 4.
  • the mixer 11 is located in a lower region of the frame 4 at the first inlet section 6 and at the second inlet section 7 (downstream these two sections) and can be inserted through an opening, in particular through one of the aforementioned openings.
  • the suppressor 13 is located in an upper region of the frame 4 at the outlet section 8 (downstream the mixer 11) and can be inserted through the outlet opening 9.
  • the suppressor 13 is located in a dedicated seat 27 (first seat) inside a mixing chamber 26 arranged downstream the mixer 11.
  • figure 3A shows the frame structure 4 according to a top view
  • figure 3B shows the frame structure 4 according to a side view.
  • the suppressor 13 can have a polygonal cross section in order to perfectly fit the first seat 27 in the mixing chamber 26, the first seat 27 also having a polygonal cross section.
  • the suppressor 13 can be made of metal, for example aluminum, manufactured by tooling machines.
  • FIGS 4A and 4B illustrate the structure of a mixer 11 according to one example.
  • the mixer has a main body 17 having a polygonal cross section with a first region 14 for receiving fuel gas G from the first inlet section 6 of the manifold 1 and a second region 15 for receiving air from the second inlet section 7 of the manifold 1.
  • the first region 14 is located in an upper portion of the main body 17 and extends transversally in the main body 17.
  • the second region 15 basically extends overall the main body 17 of the mixer 11 and in particular it extends longitudinally in the main body 17.
  • the mixer 11 can be a one single piece structure made of plastic material and realized using for example a stereolithographic 3D printer.
  • the mixer 11 can be made of metal, for example aluminium or brass.
  • the main body 17 comprises, at the bottom, two engaging means 21 in the form of fins. These engaging means 21 can be coupled to corresponding (two) guiding means 22 present in the second inlet section 7 of the manifold 1 (see Fig. 2B ).
  • the guiding means 22 are in the form of elongated slots extending along an internal surface of the frame structure 4 at the profile of the second inlet opening 10. In this way, the mixer 11 can be easily inserted and guided in the frame structure 4 of the manifold 1. Also, the coupling of the engaging means 21 and the guiding means 22 allows the mixer 11 to be in the correct position during the operation of the combustion appliance.
  • the coupling ensures that, one the mixer 11 is inserted into the manifold 1, the first region 14 of the mixer 11 is aligned with the first inlet section 6 and then with the first inlet opening 5 to correctly receive the fuel gas G and the second region 15 is aligned with the second inlet section 7 and then with the second inlet opening 10 to correctly receive air A.
  • the mixer 11 comprises an elongated hollow structure 16 located in the first region 14.
  • the elongated structure 16 receives the fuel gas G from the gas inlet 18 and releases the received fuel gas from an outlet slot 19 at the mixer outlet 12.
  • the elongated structure 16 has a funnel shape. This shape serves to homogenously distribute the fuel gas G at the mixer outlet 12.
  • the elongated structure 16 extends transversally the main body 17 of the mixer 11 and the outlet slot 19 basically extends from one end to another end of the mixer outlet 12.
  • the elongated structure 16 and therefore the outlet slot 19 covers the mixer outlet 12 only in part. Accordingly, at the mixer outlet 12, the fuel gas G exiting from the outlet slot 19 meets the air A coming from the second inlet section 7 and passing through the second region 15 of the main body 17 and exiting at a region of the mixer outlet 12 not covered by the elongated structure 16 (i.e. laterally from the elongated structure 16). This produces an air/gas mixture M that is provided further in the manifold 1 and then in the burner 3. It is noted that the fuel gas enters the gas inlet 18 according to a first direction and exits through the outlet slot 19 according to a second direction, orthogonal to the first direction and parallel to the direction of the air flowing in the main body 17 of the mixer 11. In particular, at the mixer outlet 12 both fuel gas G and air A exit according the same direction and are mixed to form an air/gas mixture M.
  • Figure 4B shows the mixer 11 according to a top view.
  • a cross-sectional gas flow area 23 is formed and extends in the center of the opening 12 (region with a squared pattern).
  • a cross sectional air flow area 24 is formed and extends laterally in the opening 12 (two regions with vertical lines pattern).
  • the mixer 11 is designed to find a correct compromise between free air area and gas area and particularly to achieve the target in terms of heating power and modulation ratio. This to ensure less pressure loss as possible.
  • the ratio between the cross-sectional gas flow area 23 and the cross-sectional air flow area 24 at the mixer outlet 12 is comprised between 0.14 and 0.17, that is about between 1:6 and 1:7.
  • FIGS 5A and 5B show a mixer 11 according a different configuration. Indeed, the components of the mixer 11 and the mixing functioning is exactly the same as those in figure 4A and 4B . Therefore, the components description is not repeated here. The only difference lies in the different form of the outlet slot 19. In fact, whereas the outlet slot 19 of figures 4A and 4B comprises an increased outlet 20 at the gas inlet 18, the outlet portion 19 of figures 5A and 5B comprises an outlet portion 19 with constant dimensions (i.e. a rectangular slot). This serves to make the mixing at the mixer outlet 12 more homogeneous.

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Gas Burners (AREA)
  • Feeding And Controlling Fuel (AREA)
EP22160009.1A 2022-03-03 2022-03-03 Gasmischverteiler Pending EP4239247A1 (de)

Priority Applications (2)

Application Number Priority Date Filing Date Title
EP22160009.1A EP4239247A1 (de) 2022-03-03 2022-03-03 Gasmischverteiler
PCT/EP2023/055185 WO2023166059A1 (en) 2022-03-03 2023-03-01 Gas mixing manifold

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
EP22160009.1A EP4239247A1 (de) 2022-03-03 2022-03-03 Gasmischverteiler

Publications (1)

Publication Number Publication Date
EP4239247A1 true EP4239247A1 (de) 2023-09-06

Family

ID=80628571

Family Applications (1)

Application Number Title Priority Date Filing Date
EP22160009.1A Pending EP4239247A1 (de) 2022-03-03 2022-03-03 Gasmischverteiler

Country Status (2)

Country Link
EP (1) EP4239247A1 (de)
WO (1) WO2023166059A1 (de)

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20110044868A1 (en) * 2008-01-25 2011-02-24 Sk Energy Co., Ltd. Steam Methane Reformer and Hydrogen Station Having it Using High Performing Metal Fiber Burner
US20200284473A1 (en) * 2019-03-08 2020-09-10 Bdr Thermea Group B.V. Gas heater, method for operating the gas heater and a gas boiler
US10808927B2 (en) * 2013-10-07 2020-10-20 Clearsign Technologies Corporation Pre-mixed fuel burner with perforated flame holder

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20110044868A1 (en) * 2008-01-25 2011-02-24 Sk Energy Co., Ltd. Steam Methane Reformer and Hydrogen Station Having it Using High Performing Metal Fiber Burner
US10808927B2 (en) * 2013-10-07 2020-10-20 Clearsign Technologies Corporation Pre-mixed fuel burner with perforated flame holder
US20200284473A1 (en) * 2019-03-08 2020-09-10 Bdr Thermea Group B.V. Gas heater, method for operating the gas heater and a gas boiler

Also Published As

Publication number Publication date
WO2023166059A1 (en) 2023-09-07

Similar Documents

Publication Publication Date Title
US9303868B2 (en) Burner system having premixed burners and flame transfer means
US10281143B2 (en) Pre-mix fuel-fired appliance with improved heat exchanger interface
EP0596555B1 (de) Gasbeheiztes Gerät mit atmosphärischem Brenner
US9033696B2 (en) Induced-draft low swirl burner for low NOx emissions
IE841868L (en) Apparatus for burning a combustible gas
KR20110036883A (ko) 오븐 또는 그릴용 가스 버너
CN101611263A (zh) 燃气锅炉的燃烧器
CN106152480A (zh) 燃气热水器
US8668489B2 (en) Racetrack carryover design for multi-burner ignition in induced draft heating system
US10006628B2 (en) Low NOx gas burners with carryover ignition
US20170009982A1 (en) Ultra low nox insulating burner without collar
CN109404905A (zh) 燃烧器及燃气热水器
CA3009668C (en) Low nox burner apparatus and method
MXPA04002016A (es) Calentador de agua que tiene sistema de quemador/alimentacion de combustible-aire de baja emision de nox autoenergizado.
EP4239247A1 (de) Gasmischverteiler
EP3152490B1 (de) Nicht symmetrischer brenner mit niedrigem nox-gehalt und verfahren
US20130252185A1 (en) Igniter air shield
EP0844436A1 (de) Gasbrenner
CN210241564U (zh) 安全引火系统和燃气设备
CN115560325A (zh) 燃烧器及燃气热水设备
KR20130100302A (ko) 사전혼합 가연성 가스 버너용 공기-가스 혼합 장치
EP3825607B1 (de) Modularer brenner
EP1217294A2 (de) Strahlrohrbrenner
JP2022164234A (ja) 給湯装置
CN109404906A (zh) 燃烧器及燃气热水器

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION HAS BEEN PUBLISHED

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR