WO2016031540A1 - Brûleur à combustion et chaudière - Google Patents

Brûleur à combustion et chaudière Download PDF

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Publication number
WO2016031540A1
WO2016031540A1 PCT/JP2015/072618 JP2015072618W WO2016031540A1 WO 2016031540 A1 WO2016031540 A1 WO 2016031540A1 JP 2015072618 W JP2015072618 W JP 2015072618W WO 2016031540 A1 WO2016031540 A1 WO 2016031540A1
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WIPO (PCT)
Prior art keywords
nozzle
fuel
air
exhaust gas
passage
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PCT/JP2015/072618
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English (en)
Japanese (ja)
Inventor
章泰 岡元
和明 橋口
大浦　康二
史裕 中島
宏 藤井
Original Assignee
三菱日立パワーシステムズ株式会社
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Publication of WO2016031540A1 publication Critical patent/WO2016031540A1/fr

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    • 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 
    • F23C99/00—Subject-matter not provided for in other groups of this subclass
    • 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
    • F23D14/20—Non-premix gas burners, i.e. in which gaseous fuel is mixed with combustion air on arrival at the combustion zone
    • F23D14/22—Non-premix gas burners, i.e. in which gaseous fuel is mixed with combustion air on arrival at the combustion zone with separate air and gas feed ducts, e.g. with ducts running parallel or crossing each other
    • 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
    • F23L7/00—Supplying non-combustible liquids or gases, other than air, to the fire, e.g. oxygen, steam

Definitions

  • the present invention relates to a combustion burner which forms a flame by injecting a fluid fuel and air and injecting the mixture, and a boiler using the combustion burner.
  • a typical boiler has a hollow furnace in the vertical direction, and a plurality of combustion burners are arranged along the circumferential direction on the furnace wall, and are arranged in multiple stages in the vertical direction. ing.
  • the combustion burner forms a flame by blowing gas fuel or oil fuel and air into the furnace, and can burn in the furnace.
  • a flue is connected to the upper part of the furnace, and a superheater, a reheater, a economizer, etc. for recovering the heat of the exhaust gas are provided in the flue, and it was generated by the combustion in the furnace Heat exchange takes place between the exhaust gas and the water and steam can be generated.
  • TM burner As a combustion burner used in this boiler, there is one called a TM burner.
  • This TM burner is a combination of premixed combustion and diffusion combustion. Then, the concentration of NOx generated when the fuel burns varies with the ratio of air to fuel (air ratio). In this case, the concentration of NOx generated changes depending on the air ratio (air / fuel) between the premixed combustion and the diffusion combustion. Therefore, the TM burner can reduce the generation amount of NOx by combining the premixed combustion and the diffusion combustion.
  • combustion burners examples include those described in Patent Documents 1 and 2 below.
  • a diffusion flame is formed by injecting air and fuel to the central portion and igniting, and the primary air is injected to the outside thereof and the fuel and the secondary air are injected and ignited.
  • Premixed combustion forms a premixed flame by injecting and igniting an air-fuel mixture in which fuel and secondary air are mixed. Therefore, when the ratio of fuel increases and the air ratio moves to 1.0 due to variations in the amount of supplied fuel or the amount of supplied air, the premixed flame that has been ignited by a predetermined distance from the nozzle tip is a nozzle As the tip approaches, the nozzle tip may be thermally damaged.
  • the present invention solves the above-mentioned problems, and provides a combustion burner and a boiler that reduce the amount of NOx generation by preventing the heat damage of the nozzle tip by making the mixing ratio of fluid fuel and air a proper ratio.
  • the purpose is to
  • the combustion burner of the present invention comprises an air nozzle for injecting air, a first fuel nozzle for injecting fluid fuel outside the air nozzle, and a primary fuel nozzle outside the first fuel nozzle.
  • the fluid fuel injected from the first fuel nozzle mixes with the air injected from the air nozzle, mixes with the primary air injected from the primary air nozzle, and forms a diffusion flame by igniting.
  • the fluid fuel injected from the second fuel nozzle is mixed with the recirculating exhaust gas in the recirculating exhaust gas nozzle and then injected, mixed with the secondary air injected from the secondary air nozzle, and pre-ignitioned by ignition. Form a mixed flame. Therefore, the NOx generation amount can be reduced by setting the mixing ratio of the fluid fuel and air to an appropriate ratio.
  • the fluid fuel injected from the second fuel nozzle is mixed with the recirculation exhaust gas, mixed with the secondary air, and ignited, so that the premixed flame is slowly burned in the area away from the nozzle tip. As a result, thermal damage to the nozzle tip can be prevented.
  • the second fuel nozzle is characterized in that the fluid fuel is injected into the passage of the recirculation exhaust gas nozzle and the passage of the secondary air nozzle.
  • the second fuel nozzle is characterized in that 30% to 40% of the fluid fuel of a fuel amount preset in the passage of the recirculation exhaust gas nozzle is injected.
  • the second fuel nozzle is characterized in that the entire amount of fluid fuel is injected into the passage of the recirculation exhaust gas nozzle.
  • thermal damage to the nozzle tip can be properly prevented by injecting all of the fluid fuel into the passage of the recirculation exhaust gas nozzle, and by keeping the flame away from the nozzle tip.
  • an air nozzle for injecting air a first fuel nozzle for injecting fluid fuel outside the air nozzle, and a primary for injecting primary air outside the first fuel nozzle
  • a recirculated exhaust gas nozzle for spouting the recirculated exhaust gas.
  • the fluid fuel injected from the first fuel nozzle mixes with the air injected from the air nozzle, mixes with the primary air injected from the primary air nozzle, and forms a diffusion flame by igniting. Further, the fluid fuel injected from the second fuel nozzle is mixed with the secondary air and the recirculated exhaust gas in the passage of the secondary air nozzle, and then injected and ignited to form a premixed flame. Therefore, the NOx generation amount can be reduced by setting the mixing ratio of the fluid fuel and air to an appropriate ratio.
  • the fuel injected from the second fuel nozzle is mixed with the secondary air and the recirculated exhaust gas and ignited, so that the premixed flame slowly burns in a region separated from the nozzle tip, Thermal damage to the nozzle tip can be prevented.
  • the recirculation exhaust gas nozzle is disposed outside the secondary air nozzle and ejects the recirculation exhaust gas to the outside of the secondary air, and the recirculation exhaust gas in the passage of the secondary air nozzle It is characterized by spouting.
  • the fluid fuel injected from the second fuel nozzle is injected after being mixed with the secondary air and a part of the recirculated exhaust gas in the passage of the secondary air nozzle, whereby a part of the recirculated exhaust gas is a fluid fuel After mixing with this, it will be injected from the tip of the nozzle and ignited, and heat damage to the tip of the nozzle can be properly prevented by keeping the flame away from the tip of the nozzle while securing sufficient ignitability. .
  • fluid fuel and air are burned in a hollow furnace and heat exchange is performed in the furnace to recover heat, and the combustion burner is disposed on the furnace wall It is characterized by
  • NOx can be obtained by making the mixing ratio of the fluid fuel and the air appropriate.
  • the amount of generation can be reduced, and thermal damage to the nozzle tip can be prevented.
  • FIG. 1 is a cross-sectional view showing the combustion burner of the first embodiment.
  • FIG. 2 is a front view of the combustion burner.
  • FIG. 3 is a schematic configuration diagram showing a boiler of the first embodiment.
  • FIG. 4 is a graph showing the relationship between the air ratio of the combustion burner in which diffusion combustion and premixed combustion are combined and the NOx generation amount.
  • FIG. 5 is a cross-sectional view showing a combustion burner of a second embodiment.
  • FIG. 6 is a cross-sectional view showing a combustion burner of a third embodiment.
  • FIG. 3 is a schematic configuration diagram showing a boiler of the first embodiment.
  • the boiler of the first embodiment can use gas fuel (natural gas) as fluid fuel, inject this gas fuel and air by a combustion burner, burn it in a furnace, and recover the heat generated by this combustion It is a boiler.
  • gas fuel natural gas
  • the boiler of the first embodiment can use not only fluid fuel but also heavy oil (or light oil, slurry of coal, etc.) as fuel, and this heavy oil can be injected by a combustion burner and burned in a furnace.
  • the boiler 10 is a conventional boiler, and includes a furnace 11 and a combustion device 12.
  • the furnace 11 has a hollow shape of a square cylinder and is installed along the vertical direction, and the combustion apparatus 12 is provided at the lower part of the furnace wall constituting the furnace 11.
  • the combustion device 12 has a plurality of combustion burners 21 mounted on the furnace wall.
  • the combustion burners 21 are, for example, four arranged at equal intervals along the circumferential direction, for example, three sets, that is, three stages along the vertical direction. It is arranged.
  • the arrangement location and the number of the combustion burners 21 are not limited to this.
  • Each combustion burner 21 is connected to a fuel supply source 23 via a fuel supply pipe 22, and the fuel supply pipe 22 is provided with a flow control valve 24 capable of adjusting a fuel supply amount.
  • a flow control valve 24 capable of adjusting a fuel supply amount.
  • an air box 25 is provided at the mounting position of each combustion burner 21.
  • One end of an air duct 26 is connected to the air box 25.
  • the air duct 26 is connected to the other end.
  • a blower 27 is mounted.
  • each combustion burner 21 is supplied with gaseous fuel from the fuel supply source 23 through the fuel supply pipe 22.
  • the combustion air heated from the air duct 26 in heat exchange with the exhaust gas is supplied to the air box 25. Therefore, the combustion burner 21 can form a flame in the furnace 11 by injecting gas fuel into the furnace 11 and injecting combustion air into the furnace 11 to ignite the same.
  • the flue 31 is connected to the upper part of the furnace 11 and superheaters (super heaters) 32, 33 for recovering the heat of the exhaust gas as a convection heat transfer part (heat recovery part) are connected to the flue 31.
  • Heaters (reheaters) 34, 35 and economizers (economizers) 36, 37, 38 are provided, and heat exchange is performed between the exhaust gas generated by the combustion in the furnace 11 and water.
  • the flue 31 is connected downstream with an exhaust gas pipe 39 through which the exhaust gas subjected to heat exchange is discharged.
  • the exhaust gas pipe 39 is provided with a NOx removal device, an electrostatic precipitator, an induction fan, and a desulfurization device, and a chimney is provided at the downstream end.
  • water supplied from a water supply pump (not shown) is preheated by economizers 36, 37, 38 and then supplied to a steam drum (not shown) and supplied to water pipes (not shown) of the furnace wall. It is heated to become saturated steam and is fed to a steam drum (not shown). Furthermore, saturated steam of a steam drum (not shown) is introduced into the superheaters 32, 33 and is overheated by the combustion gas. The superheated steam generated by the superheaters 32 and 33 is supplied to a power plant (for example, a turbine etc.) not shown. Further, the steam taken out in the middle of the expansion process in the turbine is introduced into the reheaters 34, 35, and is again overheated and returned to the turbine.
  • the furnace 11 was demonstrated as a drum type (steam drum), it is not limited to this structure.
  • the exhaust gas that has passed through the economizers 36, 37, 38 of the flue 31 is subjected to exhaust gas pipe 39 with a NOx removal device (not shown) to remove harmful substances such as NOx by the catalyst and particulate matter with an electrostatic precipitator Is removed and the sulfur content is removed by the desulfurization device, and then discharged to the atmosphere from the chimney.
  • NOx removal device not shown
  • FIG. 1 is a cross-sectional view showing the combustion burner of the first embodiment
  • FIG. 2 is a front view of the combustion burner.
  • the combustion burner 21 includes an air nozzle 41 disposed from the center (axial center O) side to the outside, a first fuel nozzle 42, and a primary air nozzle 43, 2.
  • a secondary air nozzle 44, a recirculating exhaust gas nozzle 45, and a second fuel nozzle 46 are provided.
  • the central axis 51 has a cylindrical shape, and the cylindrical tube 52 is provided at a predetermined distance outside the outer peripheral surface of the central axis 51 to configure the air nozzle 41 between the central axis 51 and the cylindrical tube 52.
  • the passage 41a is formed along the axial direction.
  • the central shaft 51 is provided with an ignition unit 61 at its tip end, and a ring-shaped flame stabilizer 62 is provided on the outer peripheral surface so as to protrude toward the passage 41 a.
  • the cylindrical tubes 52 are provided with a cylindrical tube 53 spaced apart from the outer peripheral surface by a predetermined distance outside, and a plurality (six in this embodiment) of the cylindrical tubes 52 and 53 at predetermined intervals in the circumferential direction.
  • the first fuel nozzle 42 is disposed, and a passage 42a is formed in the inside along the axial direction.
  • the cylindrical tube 53 is provided with the cylindrical tube 54 at a predetermined distance away from the outer peripheral surface so that the passage 43a constituting the primary air nozzle 43 between the respective cylindrical tubes 53 and 54 extends in the axial direction. It is formed.
  • the cylindrical pipe 54 is provided with a cylindrical pipe 55 spaced apart from the outer peripheral surface by a predetermined distance, so that a passage 44 a constituting the secondary air nozzle 44 is formed along the axial direction between the cylindrical pipes 54 and 55. It is done.
  • the cylindrical pipe 55 is provided with a cylindrical pipe 56 spaced apart from the outer peripheral surface by a predetermined distance so that a passage 45a constituting the recirculation exhaust gas nozzle 45 is formed along the axial direction between the respective cylindrical pipes 55, 56. It is done.
  • a plurality of (four in the present embodiment) second fuel nozzles 46 are provided at equal intervals in the circumferential direction of the cylindrical tubes 55 and 56. Each second fuel nozzle 46 penetrates from the outside of the cylindrical tube 56 to the cylindrical tube 55, and is disposed in the passage 45a.
  • the air nozzle 41 can supply air to the passage 41a and can jet the air forward.
  • the first fuel nozzle 42 can supply gas fuel to the passage 42 a and inject the gas fuel (weak fuel) forward on the outside of the air nozzle 41.
  • the primary air nozzle 43 can supply the primary air to the passage 43 a and inject the primary air forward on the outside of the first fuel nozzle 42.
  • the secondary air nozzle 44 can supply the secondary air to the passage 44 a and can jet the secondary air forward on the outside of the primary air nozzle 43.
  • the recirculation exhaust gas nozzle 45 can supply the recirculation exhaust gas to the passage 45 a and can jet the recirculation exhaust gas forward on the outside of the secondary air nozzle 44.
  • the second fuel nozzle 46 can inject gas fuel (conch fuel) into the passage 45 a of the recirculation exhaust gas nozzle 45 to which the recirculation exhaust gas is supplied.
  • the second fuel nozzle 46 injects the entire amount of gas fuel into the passage 45 a of the recirculation exhaust gas nozzle 45.
  • air is represented by a white-blown arrow
  • fuel is represented by a hatched arrow
  • recirculated exhaust gas is represented by a dotted arrow.
  • the air nozzle 41 jets air forward, and the first fuel nozzle 42 jets gas fuel forward. Then, since the air becomes a swirling flow toward the center (axial center O) by the flame holder 62, the gas fuel is also attracted to the central (axial center O) side by the swirling flow. Therefore, the gas fuel and the air are mixed and ignited by the igniter 61 to form a diffusion flame (fuel rich flame) A. Then, the primary air nozzle 43 jets the primary air toward the front, and the secondary air nozzle 44 jets the secondary air toward the front. Further, the recirculation exhaust gas nozzle 45 injects the recirculation exhaust gas forward, and the second fuel nozzle 46 injects the gas fuel into the passage 45 a of the recirculation exhaust gas nozzle 45.
  • the recirculation exhaust gas in which the secondary air injected to the front and the gas fuel are mixed is mixed in front of the nozzles 44 and 45, and the diffusion flame A is ignited as a spark and a premixed flame (fuel lean flame) B is It is formed.
  • gas fuel is injected into the passage 45 a of the recirculation exhaust gas nozzle 45.
  • the recirculated exhaust gas is generated by combustion of gas fuel and air, contains almost no air, and is difficult to ignite even when mixed with gas fuel. Therefore, when the recirculation exhaust gas containing the gas fuel is injected from the recirculation exhaust gas nozzle 45 and the secondary air is injected from the second fuel nozzle 46, the recirculation exhaust gas containing the gas fuel and the secondary air The air-fuel mixture is difficult to ignite, and the premixed flame B is formed in a front region spaced apart from the tip of the nozzles 44 and 45 by a predetermined distance. Therefore, the premixed flame B does not approach the tips of the nozzles 44 and 45, and the tips of the nozzles 44 and 45 are not thermally damaged.
  • the combustion burner 21 of the first embodiment is a combination of premixed combustion and diffusion combustion.
  • FIG. 4 is a graph showing the relationship between the air ratio of the combustion burner in which diffusion combustion and premixed combustion are combined and the NOx generation amount.
  • the concentration of NOx generated when the gas fuel burns varies with the ratio of air to fuel (air ratio).
  • the concentration of NOx generated changes depending on the air ratio (air / fuel) between the premixed combustion and the diffusion combustion.
  • premixed combustion premixed flame B
  • the concentration of NOx is low in the high air ratio (more air) region or the low air ratio (less air) region, the air ratio is 1.0 (theoretical air) Ratio) is high.
  • the concentration of NOx is low in the region where the air ratio is low (less air) and is low in the region where the air ratio is high (more air).
  • the position b where the air ratio is high and the concentration of NOx is low in premixed combustion and the position a where the air ratio is low and concentration of NOx is low in diffusion combustion
  • the dotted line connected as a whole and based on the position c where the air ratio is higher than 1.0 (theoretical air ratio)
  • the air nozzle 41 for injecting air, the first fuel nozzle 42 for injecting gas fuel outside the air nozzle 41, and the outside of the first fuel nozzle 42 A primary air nozzle 43 that jets primary air, a secondary air nozzle 44 that jets secondary air outside the primary air nozzle 43, and a recirculation that jets recirculated exhaust gas outside the secondary air nozzle 44
  • An exhaust gas nozzle 45 and a second fuel nozzle 46 for injecting gas fuel into the passage 45 a of the recirculation exhaust gas nozzle 45 are provided.
  • the gaseous fuel injected from the first fuel nozzle 42 mixes with the air injected from the air nozzle 41 and mixes with the primary air injected from the primary air nozzle 43, and is ignited by igniting it.
  • the gas fuel injected from the second fuel nozzle 46 is injected after being mixed with the recirculated exhaust gas in the recirculated exhaust gas nozzle 45, mixed with the secondary air injected from the secondary air nozzle 44, and ignited Form a premixed flame B. Therefore, the NOx generation amount can be reduced by setting the mixing ratio of the gas fuel to the air to an appropriate ratio.
  • the gaseous fuel injected from the second fuel nozzle 46 is mixed with the recirculated exhaust gas, mixed with the secondary air, and ignited, in a region where the premixed flame B is separated from the nozzle tip. It will burn slowly and can prevent the heat damage of the nozzle tip.
  • the second fuel nozzle 46 injects the entire amount of gas fuel into the passage 45 a of the recirculation exhaust gas nozzle 45. Therefore, by injecting all of the gas fuel into the passage 45a of the recirculation exhaust gas nozzle 45, heat damage to the nozzle tip can be properly prevented by keeping the flame away from the nozzle tip.
  • the gas fuel and the air are burned in the hollow furnace 11 and heat exchange is performed in the furnace 11 to recover the heat.
  • a burner 21 is disposed. Therefore, by setting the mixing ratio of gas fuel to air to an appropriate ratio in the combustion burner 21, it is possible to reduce the amount of NOx generation and to prevent the thermal damage of the nozzle tip, and as a result, the boiler The efficiency can be improved and the life of the boiler can be extended.
  • FIG. 5 is a cross-sectional view showing a combustion burner of a second embodiment.
  • the members having the same functions as those in the above-described embodiment are denoted by the same reference numerals, and detailed descriptions thereof will be omitted.
  • the combustion burner 71 is an air nozzle 41 disposed outward from the center (axial center O) side, a first fuel nozzle 42, and a primary air nozzle 43. , A secondary air nozzle 44, a recirculation exhaust gas nozzle 45, and a second fuel nozzle 72.
  • a plurality of second fuel nozzles 72 are provided at equal intervals in the circumferential direction of the cylindrical tubes 54, 55, 56. Each second fuel nozzle 72 penetrates from the outside of the cylindrical tube 56 to the cylindrical tube 54, and is disposed in the passages 44a and 45a.
  • the air nozzle 41 can supply air to the passage 41a and can jet the air forward.
  • the first fuel nozzle 42 can supply gas fuel to the passage 42 a and inject the gas fuel (weak fuel) forward on the outside of the air nozzle 41.
  • the primary air nozzle 43 can supply the primary air to the passage 43 a and inject the primary air forward on the outside of the first fuel nozzle 42.
  • the secondary air nozzle 44 can supply the secondary air to the passage 44 a and can jet the secondary air forward on the outside of the primary air nozzle 43.
  • the recirculation exhaust gas nozzle 45 can supply the recirculation exhaust gas to the passage 45 a and can jet the recirculation exhaust gas forward on the outside of the secondary air nozzle 44.
  • the second fuel nozzle 72 injects the gas fuel (conch fuel) into both the passage 44a of the secondary air nozzle 44 to which the secondary air is supplied and the passage 45a of the recirculation exhaust gas nozzle 45 to which the recirculated exhaust gas is supplied. can do.
  • the second fuel nozzle 72 injects 30% to 40% of gaseous fuel into the passage 45a of the recirculation exhaust gas nozzle 45 in advance. That is, 30% to 40% of the gas fuel injected by the second fuel nozzle 72 is injected into the passage 45a of the recirculation exhaust gas nozzle 45, and the remaining 60% to 70% of the gas fuel is injected into the secondary air nozzle 44. To the passage 44a of the
  • the air nozzle 41 jets air forward, and the first fuel nozzle 42 jets gas fuel forward. Then, since the air becomes a swirling flow toward the center (axial center O) by the flame holder 62, the gas fuel is also attracted to the central (axial center O) side by the swirling flow. Therefore, the gas fuel and the air are mixed and ignited by the igniter 61 to form a diffusion flame (fuel rich flame) A. Then, the primary air nozzle 43 jets the primary air forward, the secondary air nozzle 44 jets the secondary air forward, and the recirculation exhaust gas nozzle 45 directs the recirculation exhaust gas Inject.
  • the second fuel nozzle 72 injects the gas fuel into the passage 44 a of the secondary air nozzle 44 and the passage 45 a of the recirculation exhaust gas nozzle 45. Therefore, the gas fuel and the secondary air are mixed in the passage 44a of the secondary air nozzle 44, and further, the gas fuel in the recirculated exhaust gas is mixed in the front, and the diffusion flame A is ignited as a spark to mix the premixed flame (fuel Lean flame) B is formed.
  • gaseous fuel is injected into the passage 44 a of the secondary air nozzle 44 and the passage 45 a of the recirculation exhaust gas nozzle 45.
  • the recirculated exhaust gas is generated by combustion of gas fuel and air, contains almost no air, and is difficult to ignite even when mixed with gas fuel. Therefore, when the recirculation exhaust gas containing the gas fuel is injected from the recirculation exhaust gas nozzle 45 and the mixture of the secondary air and the gas fuel is injected from the second fuel nozzle 72, the recirculation containing the gas fuel is performed.
  • the exhaust gas and the air-fuel mixture are not easily ignited, and the premixed flame B is formed in a front region separated from the tip of the nozzles 44 and 45 by a predetermined distance. Therefore, the premixed flame B does not approach the tips of the nozzles 44 and 45, and the tips of the nozzles 44 and 45 are not thermally damaged.
  • the second fuel nozzle 72 for injecting the gas fuel is provided in the passage 44 a of the secondary air nozzle 44 and the passage 45 a of the recirculation exhaust gas nozzle 45.
  • the gas fuel into the passage 44a of the secondary air nozzle 44 and the passage 45a of the recirculation exhaust gas nozzle 45, a part of the gas fuel is mixed with the recirculation exhaust gas, and the remaining gas fuel is mixed with the secondary air.
  • the nozzle tip is injected and ignited, and heat damage to the nozzle tip can be properly prevented by keeping the flame away from the nozzle tip while securing sufficient ignition performance.
  • the second fuel nozzle 72 injects 30% to 40% of gaseous fuel to the passage 45 a of the recirculating exhaust gas nozzle 45 in advance. Therefore, by setting the ratio of the gas fuel injected into the passage 45a of the recirculating exhaust gas nozzle 45 to the gas fuel injected into the passage 44a of the secondary air nozzle 44 to an appropriate value, sufficient ignitability and thermal damage to the nozzle tip Can be achieved at the same time.
  • FIG. 6 is a cross-sectional view showing a combustion burner of a third embodiment.
  • the members having the same functions as those in the above-described embodiment are denoted by the same reference numerals, and detailed descriptions thereof will be omitted.
  • the combustion burner 81 has an air nozzle 41, a first fuel nozzle 42, and a primary air nozzle 43 disposed outward from the center (axial center O) side. , A secondary air nozzle 44, a recirculation exhaust gas nozzle 45, and a second fuel nozzle 82.
  • the cylindrical pipe 54 is provided with a cylindrical pipe 55 spaced apart from the outer peripheral surface by a predetermined distance, so that a passage 44 a constituting the secondary air nozzle 44 is formed along the axial direction between the cylindrical pipes 54 and 55. It is done.
  • the cylindrical pipe 55 is provided with a cylindrical pipe 56 spaced apart from the outer peripheral surface by a predetermined distance so that a passage 45a constituting the recirculation exhaust gas nozzle 45 is formed along the axial direction between the respective cylindrical pipes 55, 56. It is done.
  • the cylindrical tube 44 is formed with an opening 83 communicating the passages 44a and 45a.
  • the openings 83 may be continuous in the circumferential direction, or a plurality of the openings 83 may be provided at predetermined intervals in the circumferential direction.
  • a passage may be provided to connect the passages 44a and 45a.
  • a plurality of second fuel nozzles 82 are provided at equal intervals in the circumferential direction of the cylindrical tubes 54 and 55. Each second fuel nozzle 82 penetrates from the outside of the cylindrical tube 55 to the cylindrical tube 54 and is disposed in the passage 44 a.
  • the air nozzle 41 can supply air to the passage 41a and can jet the air forward.
  • the first fuel nozzle 42 can supply gas fuel to the passage 42 a and inject the gas fuel (weak fuel) forward on the outside of the air nozzle 41.
  • the primary air nozzle 43 can supply the primary air to the passage 43 a and inject the primary air forward on the outside of the first fuel nozzle 42.
  • the secondary air nozzle 44 can supply the secondary air to the passage 44 a and can jet the secondary air forward on the outside of the primary air nozzle 43.
  • the recirculation exhaust gas nozzle 45 supplies recirculation exhaust gas to the passage 45 a and injects the recirculation exhaust gas forward toward the outside of the secondary air nozzle 44, and part of the recirculation exhaust gas nozzle 45 in the passage 44 a of the secondary air nozzle 44. It can be injected.
  • the second fuel nozzle 82 can inject gas fuel (conch fuel) into the passage 44 a of the secondary air nozzle 44 to which the secondary air and the recirculated exhaust gas are supplied.
  • the air nozzle 41 jets air forward, and the first fuel nozzle 42 jets gas fuel forward. Then, since the air becomes a swirling flow toward the center (axial center O) by the flame holder 62, the gas fuel is also attracted to the central (axial center O) side by the swirling flow. Therefore, the gas fuel and the air are mixed and ignited by the igniter 61 to form a diffusion flame (fuel rich flame) A. Then, the primary air nozzle 43 jets the primary air toward the front, and the secondary air nozzle 44 jets the secondary air toward the front. Further, the recirculation exhaust gas nozzle 45 jets the recirculation exhaust gas forward, and injects part of the recirculation exhaust gas into the passage 44 a of the secondary air nozzle 44.
  • the second fuel nozzle 82 injects the gas fuel into the passage 44 a of the secondary air nozzle 44. Therefore, the secondary air and the gas fuel injected forward are mixed in front of the nozzles 44 and 45, and the diffusion flame A is ignited as a flame to form a premixed flame (fuel lean flame) B.
  • the recirculated exhaust gas is injected in advance into the passage 44 a of the secondary air nozzle 44.
  • the recirculated exhaust gas is generated by combustion of gas fuel and air, contains almost no air, and is difficult to ignite even when mixed with gas fuel. Therefore, when the gas fuel is injected to the secondary air containing the recirculation exhaust gas and the secondary air and the recirculation exhaust gas and the gas fuel are injected from the second fuel nozzle 82, the gas fuel and the secondary air are injected by the recirculation exhaust gas.
  • the premixed flame B is formed in a front region separated from the tip of the nozzles 44 and 45 by a predetermined distance. Therefore, the premixed flame B does not approach the tips of the nozzles 44 and 45, and the tips of the nozzles 44 and 45 are not thermally damaged.
  • the air nozzle 41 for injecting air As described above, in the combustion burner of the third embodiment, the air nozzle 41 for injecting air, the first fuel nozzle 42 for injecting gas fuel outside the air nozzle 41, and the outside of the first fuel nozzle 42
  • the primary air nozzle 43 injecting primary air
  • the secondary air nozzle 44 injecting secondary air outside the primary air nozzle 43
  • the recirculation exhaust gas nozzle 45 injects the fuel gas into the passage 44 a of the secondary air nozzle 44
  • the second fuel nozzle 82 injects the gas fuel into the passage 44 a of the secondary air nozzle 44.
  • the gaseous fuel injected from the first fuel nozzle 42 mixes with the air injected from the air nozzle 41 and mixes with the primary air injected from the primary air nozzle 43, and is ignited by igniting it.
  • the gas fuel injected from the second fuel nozzle 82 is injected to the mixture of the secondary air and the recirculated exhaust gas in the passage 44a of the secondary air nozzle 44, mixed with the secondary air, and ignited.
  • the gaseous fuel injected from the second fuel nozzle 82 is ignited after being mixed with the secondary air and the recirculated exhaust gas, so that the premixed flame B burns slowly in a region separated from the nozzle tip. As a result, thermal damage to the nozzle tip can be prevented.
  • the air nozzle 41, the first fuel nozzle 42, the primary air nozzle 43, and the secondary air nozzle 44 are obtained by combining a plurality of cylindrical tubes 52, 53, 54, 55, and 56 having different diameters.
  • the recirculation exhaust gas nozzle 45 and the second fuel nozzles 46, 72, 82 are configured, the present invention is not limited to this configuration. It may replace with a cylindrical pipe and may provide a square cylindrical pipe (polygonal cylindrical pipe). Further, as in Patent Document 2, an air nozzle and a first fuel nozzle are provided at the center, and a secondary air nozzle and a second fuel nozzle are provided at the upper and lower portions, and the primary air nozzle and the recirculation exhaust gas nozzle are interposed therebetween. You may provide.
  • the recirculation exhaust gas is effectively used to prevent the premixed flame ignited in front of the nozzle tip from approaching the nozzle tip and causing thermal damage.
  • the order of mixing the next air and the recirculated exhaust gas is not limited to the embodiment described above, and may be set as appropriate.
  • the recirculation exhaust gas may be injected into the mixture of the second fuel and the secondary air.

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Pre-Mixing And Non-Premixing Gas Burner (AREA)
  • Air Supply (AREA)

Abstract

　L'invention concerne un brûleur à combustion et une chaudière, munis d'une buse d'air (41) destiné à pulvériser de l'air, une première buse de combustible (42) destiné à pulvériser un combustible gazeux à l'extérieur de la buse d'air (41), une buse d'air primaire (43) destiné à pulvériser de l'air primaire à l'extérieur de la première buse de combustible (42), une buse d'air secondaire (44) destiné à pulvériser de l'air secondaire à l'extérieur de la buse d'air primaire (43), une buse de gaz d'échappement recyclé (45) destiné à pulvériser du gaz d'échappement recyclé à l'extérieur de la buse d'air secondaire (44), et une seconde buse de combustible (46) destiné à pulvériser un combustible gazeux sur le passage (45a) de la buse de gaz d'échappement recyclé (45), ce qui permet d'amener le rapport de mélange de combustible liquide et d'air à un rapport optimal, de réduire la quantité de NOx produite et d'empêcher les dommages par échauffement de la section de pointe de buse.
PCT/JP2015/072618 2014-08-29 2015-08-10 Brûleur à combustion et chaudière WO2016031540A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2014-176067 2014-08-29
JP2014176067A JP6258160B2 (ja) 2014-08-29 2014-08-29 燃焼バーナ及びボイラ

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WO2016031540A1 true WO2016031540A1 (fr) 2016-03-03

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2024112660A1 (fr) * 2022-11-22 2024-05-30 Honeywell International Inc. Brûleur à faible émission de nox avec injection de gaz ciblée

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109611872B (zh) * 2018-12-05 2021-08-27 新奥数能科技有限公司 一种降低锅炉燃烧产生的氮氧化物的方法及装置

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5056228U (fr) * 1973-09-21 1975-05-27
JPS5178953U (fr) * 1974-12-19 1976-06-22
JPS598009U (ja) * 1982-07-08 1984-01-19 バブコツク日立株式会社 燃焼装置
JPH06123411A (ja) * 1992-10-12 1994-05-06 Mitsubishi Heavy Ind Ltd ガス焚きバーナ

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5056228U (fr) * 1973-09-21 1975-05-27
JPS5178953U (fr) * 1974-12-19 1976-06-22
JPS598009U (ja) * 1982-07-08 1984-01-19 バブコツク日立株式会社 燃焼装置
JPH06123411A (ja) * 1992-10-12 1994-05-06 Mitsubishi Heavy Ind Ltd ガス焚きバーナ

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2024112660A1 (fr) * 2022-11-22 2024-05-30 Honeywell International Inc. Brûleur à faible émission de nox avec injection de gaz ciblée

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JP2016050711A (ja) 2016-04-11

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