WO2021161875A1 - ラジアントチューブバーナ、ラジアントチューブ、及びラジアントチューブバーナの設計方法 - Google Patents
ラジアントチューブバーナ、ラジアントチューブ、及びラジアントチューブバーナの設計方法 Download PDFInfo
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- WO2021161875A1 WO2021161875A1 PCT/JP2021/003975 JP2021003975W WO2021161875A1 WO 2021161875 A1 WO2021161875 A1 WO 2021161875A1 JP 2021003975 W JP2021003975 W JP 2021003975W WO 2021161875 A1 WO2021161875 A1 WO 2021161875A1
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- WIPO (PCT)
- Prior art keywords
- combustion air
- primary combustion
- radiant tube
- flow rate
- minor axis
- Prior art date
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- 238000000034 method Methods 0.000 title claims description 8
- 238000002485 combustion reaction Methods 0.000 claims abstract description 135
- 239000007789 gas Substances 0.000 claims abstract description 30
- 238000002347 injection Methods 0.000 claims abstract description 26
- 239000007924 injection Substances 0.000 claims abstract description 26
- 239000002737 fuel gas Substances 0.000 claims abstract description 22
- 101100467422 Arabidopsis thaliana RABA5E gene Proteins 0.000 description 12
- 101100467420 Arabidopsis thaliana RABA5C gene Proteins 0.000 description 10
- 239000000567 combustion gas Substances 0.000 description 9
- 238000011144 upstream manufacturing Methods 0.000 description 9
- 101100411566 Arabidopsis thaliana RABA1A gene Proteins 0.000 description 5
- 101100411656 Arabidopsis thaliana RABE1C gene Proteins 0.000 description 3
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- 239000003054 catalyst Substances 0.000 description 3
- 230000003247 decreasing effect Effects 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- MWUXSHHQAYIFBG-UHFFFAOYSA-N nitrogen oxide Inorganic materials O=[N] MWUXSHHQAYIFBG-UHFFFAOYSA-N 0.000 description 3
- 231100000572 poisoning Toxicity 0.000 description 3
- 230000000607 poisoning effect Effects 0.000 description 3
- 238000011084 recovery Methods 0.000 description 3
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- 238000005338 heat storage Methods 0.000 description 2
- 229910000831 Steel Inorganic materials 0.000 description 1
- 239000006227 byproduct Substances 0.000 description 1
- 238000009841 combustion method Methods 0.000 description 1
- 238000013329 compounding Methods 0.000 description 1
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- 230000001747 exhibiting effect Effects 0.000 description 1
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- 230000005855 radiation Effects 0.000 description 1
- 238000004088 simulation Methods 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
- 230000001629 suppression Effects 0.000 description 1
Images
Classifications
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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
- F23C3/00—Combustion apparatus characterised by the shape of the combustion chamber
- F23C3/002—Combustion apparatus characterised by the shape of the combustion chamber the chamber having an elongated tubular form, e.g. for a radiant tube
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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
- F23C9/00—Combustion apparatus characterised by arrangements for returning combustion products or flue gases to the combustion chamber
- F23C9/08—Combustion apparatus characterised by arrangements for returning combustion products or flue gases to the combustion chamber for reducing temperature in combustion chamber, e.g. for protecting walls of combustion chamber
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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
- F23D14/12—Radiant burners
-
- 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
- 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
- F23D14/48—Nozzles
- F23D14/58—Nozzles characterised by the shape or arrangement of the outlet or outlets from the nozzle, e.g. of annular configuration
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- 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
- F23L1/00—Passages or apertures for delivering primary air for combustion
-
- 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
- F23L1/00—Passages or apertures for delivering primary air for combustion
- F23L1/02—Passages or apertures for delivering primary air for combustion by discharging the air below the fire
-
- 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
- F23L15/00—Heating of air supplied for combustion
- F23L15/04—Arrangements of recuperators
-
- 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
- F23L3/00—Arrangements of valves or dampers before the fire
-
- 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
- F23L9/00—Passages or apertures for delivering secondary air for completing combustion of fuel
- F23L9/06—Passages or apertures for delivering secondary air for completing combustion of fuel by discharging the air into the fire bed
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23D—BURNERS
- F23D2900/00—Special features of, or arrangements for burners using fluid fuels or solid fuels suspended in a carrier gas
- F23D2900/14—Special features of gas burners
- F23D2900/14003—Special features of gas burners with more than one nozzle
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23D—BURNERS
- F23D2900/00—Special features of, or arrangements for burners using fluid fuels or solid fuels suspended in a carrier gas
- F23D2900/14—Special features of gas burners
- F23D2900/14064—Burner heads of non circular shape
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E20/00—Combustion technologies with mitigation potential
- Y02E20/34—Indirect CO2mitigation, i.e. by acting on non CO2directly related matters of the process, e.g. pre-heating or heat recovery
Definitions
- the present invention is a technique relating to a radiant tube.
- the radiant tube supplies fuel gas and combustion air into the tube from the gas injection part of the radiant tube burner and burns them, and the heat generated by the tube heated by the generated combustion gas indirectly indirectly heats the object to be heated outside the tube. It is a heating device. Therefore, the combustion space of the radiant tube is limited, and the heat cannot be used effectively by the radiant tube alone. Heat recovery is performed in the form of preheating the combustion air by using various exhaust heat recovery devices such as a recuperator and a heat storage burner. In many cases.
- the combustion gas generated in the tube passes through the tube and is discharged, but when the temperature of the combustion gas rises, the amount of harmful nitrogen oxides (hereinafter referred to as NOx) produced increases. There is a problem of increasing. Therefore, the amount of exhaust heat recovered may be limited in order to suppress the amount of NOx emissions.
- Patent Document 1 discloses a technique for reducing the generation of NOx by mixing exhaust gas into fuel gas or secondary combustion air by using a fan to reduce the combustion rate.
- Patent Document 2 discloses that the generated NOx is purified by a catalyst.
- Patent Document 1 a fan for guiding the exhaust gas to the fuel gas or the air for secondary combustion is required. For example, installing a fan for each radiant tube adversely affects maintainability. Further, in the configuration of Patent Document 1, there is also a problem that the radiant tube becomes large due to the provision of the fan. Further, in Patent Document 2, deterioration due to poisoning of the catalyst, which is remarkable in the steel industry using by-product gas, becomes a problem. Further, in the configuration of Patent Document 2, there is also a problem that the radiant tube becomes large due to the provision of the catalyst.
- the present invention has been made by paying attention to the above points, does not adversely affect maintainability, does not reduce the low NOx effect due to poisoning, etc., and can reduce the generation of NOx by a simple configuration. It is an object of the present invention to provide a radiant tube burner and a radiant tube.
- the present inventors conducted various combustion analyzes including the generation of NOx around the burner without being bound by the existing radiant tube shape. From the results, the present inventors made the opening cross-sectional shape of the radiant tube an elliptical shape having a major axis and a minor axis different, arranged a secondary combustion air nozzle in the center of the radiant tube, and arranged the secondary combustion air nozzle. A plurality of fuel gas nozzles and a plurality of primary combustion air nozzles are arranged around the burner, and the primary combustion is performed at an air ratio of 1.0 or less to circulate the flow in the primary combustion region around the burner. It was found that the NOx concentration on the front side of the burner decreased.
- the inventors appropriately distribute the flow rate of the primary combustion air injected from the plurality of primary combustion air nozzles between the major axis side and the minor axis side of the tube-shaped ellipse, thereby further NOx. It was found that the concentration decreased.
- the present invention has been made based on such findings.
- one aspect of the present invention is a radiant tube burner that is inserted and installed in a tube having an elliptical open cross section, and a gas injection unit injects air for secondary combustion.
- a plurality of primary combustion air nozzles for injecting primary combustion air and a plurality of fuels for injecting fuel gas are arranged in the center of the secondary combustion air nozzle so as to surround the secondary combustion air nozzle.
- a radiant tube burner in which a gas nozzle is arranged, the opening cross section of the tube is defined by two straight lines in which the minor axis of the ellipse, which is the shape of the opening cross section, is tilted ⁇ 45 degrees about the center of the ellipse.
- FIG. 1 It is a schematic diagram for demonstrating the structure of the radiant tube provided with the radiant tube burner which concerns on embodiment based on this invention. It is a figure explaining the opening cross-sectional shape of the tube shown by the cross section AA'in FIG. It is a schematic perspective view which shows the relationship between the gas injection part of a radiant tube burner, and a tube. It is a conceptual diagram which shows each nozzle of a gas injection part. It is a front view which shows the arrangement relation of 4 regions and each nozzle. It is a figure which shows the relationship between the flow rate ratio and NOx ratio. It is a figure which shows the relationship between the flow rate ratio and the combustion gas temperature on the minor axis side.
- the ellipse does not include a perfect circle
- the minor axis of the ellipse refers to the shortest diameter
- the major axis refers to the diameter in the direction orthogonal to the minor axis.
- the minor axis is an axis extending in the minor axis direction
- the major axis is an axis extending in the major axis direction.
- the radiant tube 100 of the present embodiment includes a tube 1 through which combustion gas flows and a radiant tube burner 2 that generates combustion gas in the tube 1.
- the radiant tube 100 may or may not include a heat transfer promoter 4, various exhaust heat recovery devices 5 such as a recuperator and a heat storage burner, and other known parts.
- the tube 1 of the present embodiment has a zigzag shape having a substantially W-shaped side view, has four straight pipe portions 1A to 1D arranged one above the other, and has four straight pipe portions 1A to adjacent to each other. The ends of 1D are connected to each other by curved pipe portions 1E to 1G extending in an arc shape.
- Reference numeral 6 is a separator member that prevents the space between adjacent straight pipe portions from becoming narrow.
- Reference numeral 7 is a support member supported by the overhanging portion 3A and suppressing the downward displacement of the tube. Further, the tube 1 is supported by the furnace wall 3 by fixing the inlet side of the straight pipe portion 1A at the most upstream position and the outlet side of the straight pipe portion 1D at the most downstream position to the furnace wall 3.
- the opening cross section of at least the straight pipe portion 1A at the most upstream position of the tube 1 has an elliptical shape in which the minor axis La and the major axis Lb are different. That is, the straight pipe portion 1A at the most upstream position where the gas injection portion 2A of the radiant tube burner 2 is arranged has an elliptical shape in which the minor axis La and the major axis Lb are different from each other in the opening cross section.
- the tube 1 has an elliptical shape with the major axis Y oriented vertically over the entire length of the tube 1.
- the tube 1 is set so that the major axis Y, which is an axis having a major axis orthogonal to the minor axis of the ellipse, faces in the vertical direction.
- the rigidity of the tube 1 is improved as compared with the case where the opening cross-sectional shape of the tube 1 is a perfect circle, and the tube 1 is affected by its own weight and heat load. The downward displacement of the straight pipe portions 1A to 1D constituting the above can be suppressed.
- the ellipse that defines the cross section of the tube is not particularly limited because the rigidity is improved as compared with the perfect circular shape if the lengths of the minor axis La and the major axis Lb are different.
- (major diameter Lb / minor diameter La) is 1.1 or more and 1.4 or less.
- the heated body (not shown) moves up and down in front of and behind the tube 1, so that the heated body is heated by the radiant heat from the radiant tube 100. ..
- reference numeral 50 indicates an example of the moving direction of the object to be heated.
- the gas injection portion 2A is coaxial with the straight pipe portion 1A from the upstream end portion of the straight pipe portion 1A in the straight pipe portion 1A at the most upstream position. Is inserted.
- the gas injection unit 2A is a header unit in which a nozzle for injecting combustion air and fuel gas is formed.
- the gas injection unit 2A of the present embodiment has a cylindrical outer shape, and is arranged so that the central P-axis of the cylindrical shape and the central P-axis of the tube 1 are coaxial. Has been done.
- a secondary combustion air nozzle 21, a plurality of primary combustion air nozzles 22, and a plurality of fuel gas nozzles 23 are provided at the tip of the gas injection unit 2A.
- the surface of the tip portion of the gas injection portion 2A will also be referred to as a gas injection surface.
- the gas injection axis of each nozzle is set parallel to the central P axis of the gas injection unit 2A, and the gas can be injected in the same direction as the extending direction of the tube 1.
- the secondary combustion air nozzle 21 is a nozzle that injects secondary combustion air.
- the primary combustion air nozzle 22 is a nozzle that injects primary combustion air.
- the fuel gas nozzle 23 is a nozzle for injecting fuel gas.
- the secondary combustion air nozzle 21 is arranged at the center of a circular gas injection surface, and is composed of a tubular portion extending forward (gas injection direction) from the gas injection surface. ing.
- the secondary combustion air nozzle 21 of the present embodiment is set to be coaxial with the gas injection unit 2A.
- a plurality of primary combustion air nozzles 22 and a plurality of primary combustion air nozzles 22 are formed so as to surround the outer periphery of the secondary combustion air nozzle 21 at an outer radial position of the secondary combustion air nozzle 21.
- a fuel gas nozzle 23 is arranged. Then, a hole forming a tip opening between the plurality of primary combustion air nozzles 22 and the plurality of fuel gas nozzles 23 is opened on the gas injection surface.
- a total of two air nozzles 22 for primary combustion two on the left and right and two on the top and bottom, so as to be point-symmetrical with respect to the center of the gas injection surface (center P of the ellipse).
- center P of the ellipse The case where four pieces are provided is illustrated.
- fuel gas nozzles 23 are arranged between adjacent primary combustion air nozzles 22 along the circumferential direction.
- Reference numeral 24 is a back plate, and the shape of the back plate 24 is an elliptical shape similar to the elliptical shape of the tube 1.
- the flow rate of the total amount of air mx of the primary combustion air injected from all the primary combustion air nozzles 22 is set so that the primary combustion is performed at an air ratio of 1.0 or less.
- the minor axis X which is the axis of the minor axis of the ellipse, which is the open cross-sectional shape of the straight pipe portion at the most upstream position, is ⁇ 45 degrees with the center P of the ellipse as the center. With the two straight lines X1 and X2 tilted in the circumferential direction as boundaries, the opening cross section of the straight pipe portion at the most upstream position is virtually divided into four regions ARA-1 to ARA-4.
- the flow rate mt of the primary combustion air injected from the primary combustion air nozzles 22A and 22B located in the regions ARA-1 and ARA-2 including the elliptical minor axis X includes the elliptical minor axis X.
- the flow rate of the primary combustion air injected from the primary combustion air nozzles 22C and 22D located in the non-existing region (hereinafter, also referred to as the region including the long axis Y) ARA-3 and ARA-4 is reduced.
- the flow rate ratio (mt / mx) which is the ratio of the flow rate mt of the primary combustion air injected from 22A and 22B, is set to less than 0.5.
- the flow rate ratio (mt / mx) is set to 0.45 or less.
- the flow rate ratio (mt / mx) is La 2 / (La 2 + Lb 2 ) or more.
- the flow rate ratio (mt / mx) is La / (La + Lb) or more. That is, in the present embodiment, the flow rate distribution of the primary combustion air is designed so as to satisfy the following equation (1). La 2 / (La 2 + Lb 2 ) ⁇ (mt / mx) ⁇ 0.5 ... (1)
- the flow rate mt of the primary combustion air from the primary combustion air nozzles 22A and 22B on the short axis X side is set from the primary combustion air nozzles 22C and 22D on the long axis Y side.
- the total opening cross-sectional area of the primary combustion air nozzle 22 located in the regions ARA-1 and ARA-2 including the elliptical minor axis X is set to the elliptical major axis. It is set smaller than the total opening cross-sectional area of the next combustion air nozzles located in the regions ARA-3 and ARA-4 including Y, and the ratio of the two total opening areas is the flow rate ratio satisfying the equation (1). Adjust so that
- the flow rate mt of the primary combustion air from the primary combustion air nozzles 22A and 22B on the short axis X side is set to the primary combustion air from the primary combustion air nozzles 22C and 22D on the long axis Y side.
- each combustion air supply path is provided independently on the short axis X side and the long axis Y side to supply combustion air individually, or a flow rate control valve is provided in the middle of the flow path.
- the flow rates of the primary combustion air from the regions ARA-1 to ARA-4 are the same. That is, the flow rate of the primary combustion air supplied from the upper region ARA-4 and the flow rate of the primary combustion air supplied from the lower region ARA-3 are set to be the same amount. Further, the flow rate of the primary combustion air supplied from the left region ARA-1 and the flow rate of the primary combustion air supplied from the right region ARA-2 are set to be the same amount.
- FIG. 5 illustrates a case where one primary combustion air nozzle 22 is arranged in each of the four regions ARA-1 to ARA-4, but the present invention is not limited to this.
- two or more primary combustion air nozzles 22 may be arranged in each of the regions ARA-1 to ARA-4.
- FIG. 5 illustrates a case where the primary combustion air nozzles 22 are arranged on the elliptical long axis Y or the short axis X, but the present invention is not limited to this.
- the primary combustion air nozzles 22 do not have to be arranged so as to overlap each other on the long axis Y or the short axis X.
- the opening shape of the holes constituting each of the primary combustion air nozzles 22 a fan-shaped shape in which the distance in the circumferential direction increases as the distance from the center P of the ellipse increases in the outer diameter direction is illustrated.
- the opening shape of the hole forming the primary combustion air nozzle 22 is not particularly limited, and may be a shape other than the fan shape.
- the distances from the center P of the ellipse to each of the primary combustion air nozzles 22 are the primary combustion air nozzles 22A and 22B on the short axis X side and the primary combustion air nozzles 22C and 22D on the long axis Y side. May be set to different distances.
- combustion air or fuel gas is injected (discharged) from the radiant tube burner 2 in a direction parallel to the axis of the straight pipe portion 1A at the most upstream position constituting the tube 1 from each nozzle. Is supplied.
- the fuel gas injected from the fuel gas nozzle 23 is mixed with the primary combustion air injected from the primary combustion air nozzle 22 and incompletely burned, and then the incompletely burned combustion gas is secondarily burned. It is a two-stage combustion method that reduces NOx by completely burning with the secondary combustion air discharged from the combustion air nozzle 21. The generated combustion gas flows along the tube 1.
- the total amount of the supplied primary combustion air is relatively the amount of the primary combustion air from the primary combustion air nozzles 22A and 22B on the minor axis X side, which is the minor axis.
- the opening cross-sectional shape of the tube 1 is an ellipse (minor axis La: 188 mm, major axis Lb: 236 mm)
- the relationship between the flow rate ratio (mt / mx) and NOx is measured by NOx generation prediction simulation using the finite volume method. Analyzed. The result is shown in FIG.
- the minor axis X side primary combustion air nozzle 22A As can be seen from FIG. 6, relative to the flow rate of the primary combustion air from the major axis Y side primary combustion air nozzles 22C and 22D, the minor axis X side primary combustion air nozzle 22A, It was found that NOx decreased as the flow rate mt of the primary combustion air from 22B was reduced.
- the surface on the minor axis La side which has a relatively large area, may face the object to be heated in consideration of the radiation area with the object to be heated. preferable. Reducing the amount of air injected to the minor axis La side as in the present embodiment is due to the increase in non-combustibility in the regions ARA-1 and ARA-2 on the minor axis La side, so that the minor axis La side of the radiant tube 100 is reduced. There is a risk that the surface temperature will drop and the heat transfer efficiency will drop.
- FIG. 7 shows the average temperature on the minor axis X in an ellipse having a cross section perpendicular to the flow direction at a point 2000 mm away from the injection surface from the primary combustion air nozzle 22 and the fuel gas nozzle 23, that is, from the injection surface. It is a thing. As can be seen from FIG. 7, as the flow rate ratio (mx / mt) is made smaller than 0.5, the average gas temperature on the short axis X side decreases.
- the flow rate ratio (mx / mt) is La 2 / (La 2 + Lb 2 ) or more in order to prevent a decrease in heat transfer efficiency while exhibiting a low NOx effect. Furthermore, the flow rate ratio (mx / mt) is La / (La + Lb) or more.
- the radiant tube burner 2 and the radiant tube burner 2 which can reduce the generation of NOx by a simple configuration without adversely affecting maintainability and without reducing the low NOx effect due to poisoning or the like. It becomes possible to provide the radiant tube 100.
- Tube 1A Straight pipe part at the most upstream position 2 Radiant tube burner 2A Gas injection part 3 Furnace wall 21 Secondary combustion air nozzle 22 Primary combustion air nozzle 22A, 22B Short axis side primary combustion air nozzle 22C, 22D Air nozzle for primary combustion on the long axis side 23 Fuel gas nozzle ARA-1 to ARA-4 Area La Minor axis Lb Major axis X Minor axis Y Major axis
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- Gas Burners (AREA)
Abstract
Description
ここで、ラジアントチューブは、チューブ内で発生した燃焼ガスがチューブ内を通過して排出されるが、燃焼ガスの温度が上昇すると、有害な窒素酸化物(以下、NOxという。)の生成量が増加するという課題がある。このため、NOx排出量を抑えるために排熱回収量が制限される場合がある。
特許文献1には、ファンを用いて、排ガスを燃料ガスもしくは2次燃焼用空気に混入することで燃焼速度を低下させて、NOxの発生を低減させる技術が開示されている。また、特許文献2には、発生したNOxを触媒により浄化することが開示されている。
また、特許文献2では、副生ガスを使用している鉄鋼業で顕著である、触媒の被毒による劣化が課題となる。また、特許文献2の構成では、触媒を設ける分、ラジアントチューブが大型化するという課題もある。
ここで、図面は模式的なものであり、各部品の大きさや長さの比率等は現実のものとは異なる。また、以下に示す実施形態は、本発明の技術的思想を具体化するための構成を例示するものであって、本発明の技術的思想は、構成部品の材質、形状及び構造等を下記のものに特定するものでない。本発明の技術的思想は、特許請求の範囲に記載された請求項が規定する技術的範囲内において、種々の変更を加えることが出来る。
ここで、本明細書では、楕円には、真円が含まれず、楕円の短径とは最も短い直径を、長径とは短径に直交する方向の直径を指すものとする。また、短軸とは、短径方向に延在する軸であり、長軸とは、長径方向に延在する軸である。
本実施形態のラジアントチューブ100は、図1に示すように、燃焼ガスが流れるチューブ1と、チューブ1内で燃焼ガスを発生するラジアントチューブバーナ2と、を備える。ラジアントチューブ100は、伝熱促進体4や、レキュペレータや蓄熱バーナなどの各種排熱回収装置5、その他の公知の部品を備えていても良いし、備えていなくても構わない。
本実施形態のチューブ1は、図1に示すように、側面視略W状のつづら折り形状となっており、上下に並ぶ4つの直管部1A~1Dを有し、隣り合う直管部1A~1Dの端部同士が円弧形状に延びる曲管部1E~1Gによって連結されて構成される。符号6は隣り合う直管部間が狭くなることを防止するセパレータ部材である。符号7は、張出部3Aに支持されて、チューブの下方への変位を抑えるサポート部材である。
また、最上流位置の直管部1Aの入口側と最下流位置の直管部1Dの出口側とが炉壁3に固定されることで、チューブ1は炉壁3に支持されている。
すなわちチューブ1は、上記の楕円の短径と直交する長径の軸である長軸Yが上下方向を向くように設定されている。楕円の長軸Yが上下方向を向けてチューブ1を配置することで、チューブ1の開口断面形状が真円形状の場合に比べてチューブ1の剛性が向上し、自重や熱負荷によって、チューブ1を構成する直管部1A~1Dの下方への変位が抑制可能となっている。
ここで、本実施形態では、チューブ1の前方及び後方を被加熱体(不図示)が上下に移動することで、ラジアントチューブ100からの輻射熱で当該被加熱体が加熱される構成となっている。図2中、符号50は被加熱体の移動方向の例を示す。
ラジアントチューブバーナ2は、図1に示すように、ガス噴射部2Aが、最上流位置の直管部1A内において、直管部1Aの上流側端部からに直管部1Aと同軸になるようにして挿入されている。ガス噴射部2Aは、燃焼用空気及び燃料ガスを噴射するノズルが形成されたヘッダ部である。
本実施形態のガス噴射部2Aは、図3に示すように、躯体の外形が円柱形状となっており、円柱形状の中心P軸と、チューブ1の中心P軸とが同軸となるように配置されている。
ここで、2次燃焼用空気ノズル21は、2次燃焼用空気を噴射するノズルである。1次燃焼用空気ノズル22は、1次燃焼用空気を噴射するノズルである。燃料ガスノズル23は、燃料ガスを噴射するノズルである。
また、ガス噴射面には、2次燃焼用空気ノズル21の外径方向外方位置で、当該2次燃焼用空気ノズル21の外周を囲むようにして、複数の1次燃焼用空気ノズル22と複数の燃料ガスノズル23とが配置されている。そして、ガス噴射面に、複数の1次燃焼用空気ノズル22と複数の燃料ガスノズル23との先端部開口を形成する穴が開口している。
なお、符号24はバックプレートであって、該バックプレート24の形状は、チューブ1の楕円形状と相似の楕円形状となっている。
空気比1.0以下で1次燃焼するように、全ての1次燃焼用空気ノズル22から噴射される、1次燃焼用空気の空気総量mxの流量を設定する。
また、本実施形態では、図5に示すように、最上流位置の直管部の開口断面形状である楕円の短径の軸である短軸Xを楕円の中心Pを中心として±45度それぞれ周方向に傾けた2本の直線X1、X2を境界として、最上流位置の直管部の開口断面を、仮想的に4つの領域ARA-1~ARA-4に区画する。
すなわち、本実施形態では、下記(1)式を満足するように、1次燃焼用空気の流量配分について設計する。
La2/(La2 +Lb2) ≦ (mt/mx) < 0.5 ・・・(1)
ここで、本実施形態では、短軸X側の1次燃焼用空気ノズル22A、22Bからの1次燃焼用空気の流量mtを、長軸Y側の1次燃焼用空気ノズル22C、22Dからの1次燃焼用空気の流量よりも小さくする構成として、楕円の短軸Xを含む領域ARA-1、ARA-2に位置する1次燃焼用空気ノズル22の全開口断面積を、楕円の長軸Yを含む領域ARA-3、ARA-4に位置する次燃焼用空気ノズルの全開口断面積よりも小さく設定し、その2つの全開口面積の比が、(1)式を満足する流量比となるように調節する。
また、楕円の中心Pに対し点対称の領域ARA-1~ARA-4(上下の領域、左右の領域)からの1次燃焼用空気の流量は、それぞれ同量であることが好ましい。すなわち、上方の領域ARA-4から供給される1次燃焼用空気の流量と下方の領域ARA-3から供給される1次燃焼用空気の流量とを同量とする。また、左側の領域ARA-1から供給される1次燃焼用空気の流量と右側の領域ARA-2から供給される1次燃焼用空気の流量とを同量とする。
ここで、図5では、各4つの領域ARA-1~ARA-4にそれぞれ、1個の1次燃焼用空気ノズル22が配置される場合を例示しているが、これに限定されない。例えば、各領域ARA-1~ARA-4にそれぞれ2個以上の1次燃焼用空気ノズル22を配置しても良い。
また、図5では、楕円形の長軸Y上又は短軸X上に各1次燃焼用空気ノズル22を配置する場合が例示されているが、これに限定されない。例えば、各1次燃焼用空気ノズル22が長軸Y上又は短軸X上に重なるように配置されていなくて良い。
また、楕円の中心Pから各1次燃焼用空気ノズル22までの距離は、短軸X側の1次燃焼用空気ノズル22A、22Bと長軸Y側の1次燃焼用空気ノズル22C、22Dとで異なる距離に設定しても良い。
本実施形態のラジアントチューブ100では、ラジアントチューブバーナ2から、チューブ1を構成する最上流位置の直管部1Aの軸と平行な方向に、各ノズルから燃焼用空気や燃料ガスが噴射(吐出)されて供給される。
本実施形態は、燃料ガスノズル23から噴射した燃料ガスは、1次燃焼用空気ノズル22から噴射した1次燃焼用空気と混合して不完全燃焼し、続いて不完全燃焼した燃焼ガスを2次燃焼用空気ノズル21から吐出される2次燃焼用空気によって完全燃焼させることで、NOxを低下させる2段燃焼方式となっている。なお、発生した燃焼ガスは、チューブ1に沿って流れる。
ここで、チューブ1の開口断面形状を楕円(短径La:188mm、長径Lb:236mm)として、流量比(mt/mx)とNOxとの関係について、有限体積法を用いたNOx生成予測シミュレーションによって解析した。その結果を図6に示す。
図6から分かるように、相対的に、長軸Y側の1次燃焼用空気ノズル22C、22Dからの1次燃焼用空気の流量に対し、短軸X側の1次燃焼用空気ノズル22A、22Bからの1次燃焼用空気の流量mtを少なくするほど、NOxが減少することが分かった。
この理由は、隣り合う領域ARA-1~ARA-4からの1次燃焼用空気の吐出量が異なることで、各々の領域ARA-1~ARA-4毎に、吹き込まれる空気比が調整され適切なN2濃度分布となることで、NOxの生成を抑制するに繋がると推定される。
図7は、1次燃焼用空気ノズル22及び燃料ガスノズル23から、すなわち噴出面から、噴射方向へ2000mm離れた地点での流れ方向に垂直な断面の楕円における、短軸X上の平均温度を求めたものである。
図7から分かるように、流量比(mx/mt)を、0.5よりも小さくするほど、短軸X側での平均ガス温度が低下している。
このような結果から、低NOx効果を発現しつつ伝熱効率の低下を防止するためには、流量比(mx/mt)をLa2/(La2 +Lb2)以上とすることが好ましく、更に好ましは、流量比(mx/mt)はLa/(La +Lb)以上である。
1A 最上流位置の直管部
2 ラジアントチューブバーナ
2A ガス噴射部
3 炉壁
21 2次燃焼用空気ノズル
22 1次燃焼用空気ノズル
22A、22B 短軸側の1次燃焼用空気ノズル
22C、22D 長軸側の1次燃焼用空気ノズル
23 燃料ガスノズル
ARA-1~ARA-4 領域
La 短径
Lb 長径
X 短軸
Y 長軸
Claims (5)
- 楕円形状の開口断面からなるチューブに挿入されて設置されるラジアントチューブバーナであり、且つガス噴射部が、2次燃焼用空気を噴射する2次燃焼用空気ノズルが中央部に配置され、上記2次燃焼用空気ノズルを囲むように、1次燃焼用空気を噴射する複数の1次燃焼用空気ノズルと燃料ガスを噴射する複数の燃料ガスノズルとが配置されたラジアントチューブバーナであって、
上記チューブの開口断面を、その開口断面形状である楕円の短軸を上記楕円の中心を中心として±45度傾けた2本の直線を境界として、仮想的に4つの領域に区画し、
仮想的に区画した上記4つの領域のうちの上記楕円の短軸を含む領域に位置する上記1次燃焼用空気ノズルから噴射される1次燃焼用空気の流量を、上記4つの領域のうちの上記楕円の短軸を含まない領域に位置する上記1次燃焼用空気ノズルから噴射される1次燃焼用空気の流量よりも少ないことを特徴とするラジアントチューブバーナ。 - 上記楕円の短径をLa、該短径と直交する長径をLbとする場合、
全ての1次燃焼用空気ノズルから噴射される1次燃焼用空気の空気総量mxに対する、上記短軸を含む領域に位置する上記1次燃焼用空気ノズルから噴射される1次燃焼用空気の流量mtの比である流量比(mt/mx)を、La2/(La2 +Lb2)以上とすることを特徴とする請求項1に記載したラジアントチューブバーナ。 - 1次燃焼用空気ノズルから噴射される1次燃焼用空気の流量の調整は、上記短軸を含む領域に位置する上記1次燃焼用空気ノズルの全開口断面積を、上記楕円の短軸を含まない領域に位置する上記1次燃焼用空気ノズルの全開口断面積よりも小さくすることで構成されることを特徴とする請求項1又は請求項2に記載したラジアントチューブバーナ。
- チューブの開口断面を楕円形状とすると共に、請求項1~請求項3のいずれか1項に記載のラジアントチューブバーナを有するラジアントチューブ。
- 楕円形状の開口断面からなるチューブに挿入されて設置されるラジアントチューブバーナであって、ガス噴射部が、2次燃焼用空気を噴射する2次燃焼用空気ノズルが中央部に配置され、上記2次燃焼用空気ノズルを囲むように、1次燃焼用空気を噴射する複数の1次燃焼用空気ノズルと燃料ガスを噴射する複数の燃料ガスノズルとが配置されたラジアントチューブバーナの設計方法であって、
上記チューブの開口断面を、その開口断面形状である楕円の短軸を上記楕円の中心を中心として±45度傾けた2本の直線を境界として、仮想的に4つの領域に区画し、
上記楕円の短径をLa、該短径に直交する長径をLbとする場合、
全ての1次燃焼用空気ノズルから噴射される1次燃焼用空気の空気総量mxに対する、上記短軸を含む領域に位置する上記1次燃焼用空気ノズルから噴射される1次燃焼用空気の流量mtの比である流量比(mt/mx)が、下記(1)式を満足するように、各1次燃焼用空気ノズルからの1次空気の吹き出し量を設定することを特徴とするラジアントチューブバーナの設計方法。
La2/(La2 +Lb2) ≦ (mt/mx) <0.5 ・・・(1)
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Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS6446516A (en) * | 1987-08-13 | 1989-02-21 | Kawasaki Steel Co | Burner for radiant tube |
JPH04126905A (ja) * | 1990-07-31 | 1992-04-27 | Olympia Kogyo Kk | 低NOxバーナ |
WO2012098848A1 (ja) * | 2011-01-21 | 2012-07-26 | バブコック日立株式会社 | 固体燃料バーナおよび前記バーナを用いる燃焼装置 |
CN202660558U (zh) * | 2012-04-09 | 2013-01-09 | 空气化工产品有限公司 | 用于有色金属反射炉的烧嘴、烧嘴组件以及燃烧系统 |
WO2014027610A1 (ja) * | 2012-08-14 | 2014-02-20 | バブコック日立株式会社 | 固体燃料バーナを備えた燃焼装置 |
WO2018034286A1 (ja) * | 2016-08-19 | 2018-02-22 | 三菱日立パワーシステムズ株式会社 | 固体燃料バーナ |
JP2020020549A (ja) | 2018-08-02 | 2020-02-06 | 株式会社デンソー | 熱磁気サイクル装置 |
Family Cites Families (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS63113206A (ja) | 1986-10-30 | 1988-05-18 | Nippon Nenshiyou Syst Kk | ラジアントチユ−ブバ−ナ |
JPH0285207U (ja) * | 1988-12-06 | 1990-07-04 | ||
CN202132950U (zh) * | 2011-07-12 | 2012-02-01 | 重庆赛迪工业炉有限公司 | 扁平燃烧装置 |
JP6323366B2 (ja) * | 2015-03-03 | 2018-05-16 | Jfeスチール株式会社 | ラジアントチューブ |
JP6521905B2 (ja) | 2016-06-07 | 2019-05-29 | 中外炉工業株式会社 | ラジアントチューブバーナーユニット及び工業炉 |
-
2021
- 2021-02-03 JP JP2021521079A patent/JP7131701B2/ja active Active
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- 2021-02-03 MX MX2022009073A patent/MX2022009073A/es unknown
- 2021-02-03 EP EP21753499.9A patent/EP4105554A4/en active Pending
Patent Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS6446516A (en) * | 1987-08-13 | 1989-02-21 | Kawasaki Steel Co | Burner for radiant tube |
JPH04126905A (ja) * | 1990-07-31 | 1992-04-27 | Olympia Kogyo Kk | 低NOxバーナ |
WO2012098848A1 (ja) * | 2011-01-21 | 2012-07-26 | バブコック日立株式会社 | 固体燃料バーナおよび前記バーナを用いる燃焼装置 |
CN202660558U (zh) * | 2012-04-09 | 2013-01-09 | 空气化工产品有限公司 | 用于有色金属反射炉的烧嘴、烧嘴组件以及燃烧系统 |
WO2014027610A1 (ja) * | 2012-08-14 | 2014-02-20 | バブコック日立株式会社 | 固体燃料バーナを備えた燃焼装置 |
WO2018034286A1 (ja) * | 2016-08-19 | 2018-02-22 | 三菱日立パワーシステムズ株式会社 | 固体燃料バーナ |
JP2020020549A (ja) | 2018-08-02 | 2020-02-06 | 株式会社デンソー | 熱磁気サイクル装置 |
Non-Patent Citations (1)
Title |
---|
See also references of EP4105554A4 |
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