JP2014035182A - Combustion apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a combustion apparatus for reducing generation of NOx by securing more time for mixing fuel and air and uniformly mixing fuel and air by forming a flame at a position spaced apart from an outlet.SOLUTION: A combustion apparatus according to an embodiment of the present invention, includes: a reforming part configured in the center to reform supplied hydrocarbon based fuel and air and discharge high temperature reformed gas including hydrogen to an outlet; and a supply part configured at least at an outer side of the outlet to inject fuel and air to one side of the reformed gas discharged from the reforming part and to form a flame at a position spaced apart by a pre-set distance from the outlet.

Description

  The present invention relates to a combustion apparatus that reduces the amount of NOx generated by injecting a gas containing high-temperature hydrogen produced by reforming a hydrocarbon-based fuel and forming a flame at a position away from an outlet. It is.

A typical combustion device is configured to form a diffusion flame by meeting supplied fuel and air inside or outside. At this time, the amount of NOx generated may vary depending on the degree of mixing of fuel and air and the mixing speed.
In order to reduce the amount of NOx generated, a combustion apparatus has been developed that injects air or fuel in multiple stages, or performs multiple stages of rich combustion and lean combustion. However, multistage combustion increases the length of the flame and complicates the structure of the combustion apparatus.
In order to solve this problem, combustion apparatuses that reduce the amount of NOx generated by rapidly mixing fuel and air have been developed. In this case, the combustion apparatus requires an igniter for ignition of the flame, and a pilot flame must be formed at the outlet of the combustion apparatus for fixing and stabilizing the flame in the combustion apparatus. In other words, if there is no pilot flame, the flame will disappear away from the outlet of the combustion device (blow off).

An object of the present invention is to form a flame at a position away from the outlet, thereby further ensuring the mixing time of fuel and air, and making the mixing of fuel and air uniform, thereby reducing the amount of NOx generated. Is to provide a device.
Another object of the present invention is to provide a combustion apparatus that reforms fuel and supplies reformed gas containing hydrogen from the center of the outlet, and forms a flame at a position away from the outlet without being blown off. It is.

  A combustion apparatus according to an embodiment of the present invention is a reformer formed on the center side so as to reform supplied hydrocarbon-based fuel and air and discharge a high-temperature reformed gas containing hydrogen to an outlet. And at least the outside of the outlet so as to form a flame at a position spaced apart from the outlet by injecting fuel and air into one side of the reforming portion and the reformed gas discharged from the reforming portion. Including a supply unit.

  In the mixture of fuel and air supplied to the reforming section, in the case of hydrocarbon fuel, the equivalent ratio may be equal to or higher than the theoretical equivalent ratio of partial oxidation and lower than the theoretical equivalent ratio of combustion.

  The reformer may include a first housing that is electrically grounded, and an electrode that is spaced apart from the inner center of the first housing and to which a voltage is applied.

  The first housing forms a discharge gap between the electrode and the discharge part that reacts fuel and air under partial oxidation conditions, and the discharge that reacts in the discharge part and stabilizes the discharged gas. And an extension part formed to be extended at the part.

  The supply unit is formed so that fuel and air can be injected outside the reformed gas discharged from the reforming unit.

  The supply unit includes a second housing spaced apart on the outer periphery of the first housing and a third housing spaced apart on the outer periphery of the second housing, and the first housing and the second housing It may further include a fuel passage formed therebetween and an air passage formed between the second housing and the third housing.

  The air passage can be connected to the discharge portion across the fuel passage by a passage connecting member that connects the second housing and the first housing.

  The second housing may have a side wall on one side of the fuel passage, and the first housing may be connected to the side wall by a method such as screw connection or welding.

  The first housing further forms a coupling portion that protrudes toward a side wall of the second housing, and the fuel passage includes an inflow side formed at one side center of the first housing; And a supply side connected to the outer peripheral side, and the coupling portion may form a through-hole connecting the inflow side and the supply side.

  On the opposite side of the side wall of the second housing, the end of the first housing is in the longitudinal direction of the second housing, and the diametrical direction of the second housing is spaced from the end of the second housing. And the gap set between the flange and the end of the second housing is arranged so that the supply side of the fuel passage is in the diametrical outline of the second housing. It can be opened.

  The end of the second housing and the end of the third housing can be arranged on the same line in the diametrical direction.

  The first housing includes an inner member that forms an air injection port that injects air toward the electrode, and a chamber that is coupled to the outer periphery of the inner member and receives and stores the air injected to the air injection port. And an outer member to be formed.

  A plurality of the air injection ports may be spaced apart in the circumferential direction by the inner member and may have an angle inclined with respect to the diameter direction of the inner member.

  The supply unit may be formed so as to inject fuel and air in a direction aligned with a discharge direction of the reformed gas outside the reformed gas discharged from the reforming unit.

  The supply unit includes a second housing spaced apart on the outer periphery of the first housing and a third housing spaced apart on the outer periphery of the second housing, and the first housing and the second housing And an air passage formed between the second housing and the third housing, wherein the end of the first housing is inside the end of the second housing. And a flange that protrudes inwardly in the diameter direction of the first housing.

  The end of the first housing and the end of the second housing are formed side by side, and a first swirler is provided between the end of the first housing and the end of the second housing. A second swirler may be provided between the end of the second housing and the end of the third housing.

  Thus, in one embodiment of the present invention, the reforming unit reforms the fuel, discharges the reformed gas containing hydrogen, and supplies the fuel and air to the outside of the outlet to the supply unit. A flame can be stably formed at a position separated by a set distance.

  Therefore, in the combustion apparatus, it is possible to further ensure the mixing time of the fuel and air supplied from the supply unit as much as the distance between the outlet and the flame. By extending the mixing time, the mixing of fuel and air becomes more uniform, thereby reducing the amount of NOx generated.

1 is a partial cross-sectional perspective view of a combustion apparatus according to a first embodiment of the present invention. It is sectional drawing of the combustion apparatus shown by FIG. It is sectional drawing along the III-III line of FIG. It is a photograph which shows the state of the flame at the time of burning a fuel with the combustion apparatus of FIG. It is a photograph which shows the state of the flame when burning a fuel with the combustion apparatus concerning a prior art. It is sectional drawing of the combustion apparatus concerning 2nd Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art to which the present invention pertains can easily implement the embodiments. However, the present invention can be implemented in various different forms and is not limited to the embodiments described herein. In the drawings, parts not necessary for the description are omitted in order to clearly describe the present invention, and the same reference numerals are given to the same or similar components throughout the specification.

  FIG. 1 is a partial cross-sectional perspective view of a combustion apparatus according to a first embodiment of the present invention, FIG. 2 is a cross-sectional view of the combustion apparatus shown in FIG. 1, and FIG. It is sectional drawing along a III line.

  1 to 3, a combustion apparatus 1 according to the first embodiment includes a reforming unit 100 that reforms a hydrocarbon-based fuel into a high-temperature reformed gas containing hydrogen, and an outlet of the combustion apparatus 1. 101 includes a supply unit 200 for injecting fuel and air.

  Hydrogen contained in the reformed gas has a high property in terms of combustion rate and diffusion rate. Therefore, the high-temperature reformed gas and hydrogen supplied from the reforming unit 100 cause a flame F to be formed at a position separated from the outlet 101 of the combustion apparatus 1, and the flame F is blown off. To prevent. That is, the reformed gas and hydrogen can stabilize the flame F at a position separated from the outlet 101 of the combustion apparatus 1.

  For this purpose, the reforming unit 100 is provided on the center side of the combustion apparatus 1, reacts the supplied fuel under partial oxidation conditions, reforms it into a gas containing high-temperature hydrogen, and this hydrogen and reforming It is configured to discharge gas to the outlet 101.

  The reformed gas discharged from the reforming unit 100 is injected forward (flame F side) from the outlet 101, thereby pushing the flame F generated by the combustion of fuel and air supplied from the supply unit 200, and the combustion apparatus 1. It is stably maintained at a position separated from the outlet 101 by a distance L set.

  In the present embodiment, the reforming unit 100 is provided integrally with the combustion apparatus 1, so that hydrogen can be stably supplied toward the air and fuel supplied from the supply unit 200 to the outlet 101. Therefore, the reforming unit 100 can supply hydrogen with a simple configuration, that is, does not require a separate device for supplying hydrogen.

  The supply unit 200 is provided at least outside the outlet 101, and is configured to inject a fuel and air into the outline of the reformed gas to be discharged to form a flame F. The supply unit 200 of the present embodiment is formed in a structure that accommodates the reforming unit 100. The fuel and air supplied from the supply unit 200 are pushed by the distance L set from the outlet 101 by the reformed gas supplied from the reforming unit 100.

  However, fuel and air supplied from the supply unit 200 are blown off at a position separated from the outlet 101 by a distance L due to the fast combustion and diffusion rate of the high-temperature reformed gas and hydrogen supplied from the reforming unit 100. The flame F is stably maintained while burning without any problems.

  The separation distance L set between the outlet 101 and the flame F ensures a longer mixing time of the fuel and air supplied from the supply unit 200. Therefore, the fuel and the air can be mixed more uniformly while traveling the separation distance L in the state where the outlet 101 is separated.

  As described above, the combustion apparatus 1 of the present embodiment uses the high-temperature reformed gas generated in the reforming unit 100 and the rapid combustion and diffusion performance of hydrogen during the combustion of fuel to reduce the amount of NOx generated. It can be greatly reduced.

  If the mixing ratio of the fuel and air is excessively excessive in the reforming unit 100, the partial oxidation reaction does not occur and hydrogen is not generated. On the contrary, if the mixing ratio of the fuel and air is excessively close to the combustion ratio in the reforming unit 100, the flame is maintained only in the reforming unit 100, and hydrogen is not generated.

  Thus, if hydrogen is not generated in the reforming unit 100, the flame formed by the combustion of the fuel and air supplied to the supply unit 200 disappears at the outlet 101 of the combustion apparatus 1. Therefore, the fuel and air mixture must have an appropriate equivalence ratio.

For example, in a hydrocarbon-based fuel, the theoretical equivalent ratio of partial oxidation is 0.5 and the theoretical equivalent ratio of combustion is 2.0. Therefore, in the reforming unit 100, the main component is methane in a mixture of fuel and air. For liquefied natural gas (LNG), the O ₂ / C ratio ranges between 0.7 and 1.9.

  More specifically, the reforming unit 100 is provided with a first housing 10 that is supplied with air and is electrically grounded, and is spaced apart from the inner center of the first housing 10 to supply fuel. And an electrode E to which the voltage HV is applied.

  When the voltage HV is applied to the electrode E, plasma discharge is generated in the fuel and air mixed between the electrode E and the first housing 10. At this time, the fuel is partially oxidized to form a high-temperature reformed gas containing hydrogen.

  The first housing 10 includes a discharge part 111 and an extension part 112 set along the discharge direction of the reformed gas reformed by the inflow of fuel and air. The discharge unit 111 forms a discharge gap G between the first housing 10 and the electrode E, causes plasma discharge in the discharge gap G, and reforms the supplied fuel and air by reacting under partial oxidation conditions.

  The extended portion 112 is formed to be larger than the diameter of the discharge portion 111 on one side of the discharge portion 111, and stably discharges the gas discharged by reacting under the partial oxidation condition in the discharge portion 111. That is, the reformed gas reacted under the partial oxidation condition in the discharge unit 111 is stabilized while being recirculated in the wide space of the expansion unit 112.

  The supply unit 200 includes a second housing 20 spaced apart on the outer periphery of the first housing 10 and a third housing 30 spaced apart on the outer periphery of the second housing 20. At this time, the first housing 10 is accommodated in the second housing 20, and the second housing 20 is accommodated in the third housing 30 in stages. For example, the first, second, and third housings 10, 20, and 30 can form a concentric structure.

  The first housing 10 and the second housing 20 form a fuel passage P1 between the separated ones, and the second housing 20 and the third housing 30 form an air passage P2 between the separated ones. The fuel passage P1 and the air passage P2 supply fuel and air supplied to one side to the reforming unit 100 and the supply unit 200.

  For example, the air passage P2 is connected to the discharge unit 111 of the reforming unit 100 over the fuel passage P1 by the passage connecting member 22 that passes through the second housing 20 and is connected to the first housing 10. The air passage P <b> 2 supplies air to the discharge unit 111. The air passage P <b> 2 supplies air between the end portions E <b> 2 and E <b> 3 of the second and third housings 20 and 30 of the supply unit 200.

  For example, the second housing 20 forms a side wall 21 on one side of the fuel passage P1, and the first housing 10 can be connected to the side wall 21 of the second housing 20 by various methods such as screw connection or welding. For the screw connection, the first housing 10 further forms a connection part 11 protruding toward the side wall 21 of the second housing 20. That is, the male screw of the coupling part 11 is screw-coupled to the female screw of the side wall 21.

  At this time, the fuel passage P <b> 1 set between the first and second housings 10 and 20 is connected to an inflow side P <b> 11 formed at one side center of the first housing 10 and an outer peripheral side of the first housing 10. And supply side P12.

  The coupling portion 11 of the first housing 10 forms a through-hole 12 that connects the inflow side P11 and the supply side P12 of the fuel passage P1. The air flowing into the inflow side P11 is supplied to the discharge part 111 and simultaneously supplied to the supply side P12 through the through-hole 12 of the coupling part 11.

  On the opposite side of the side wall 21 of the second housing 20, the first housing 10 forms a flange 13 at an end E <b> 1 set on one side of the longitudinal direction of the second housing 20 (left and right direction in FIG. 2).

  The flange 13 protrudes outward in the diameter direction of the second housing 20, and forms a gap C with the end E <b> 2 of the second housing 20. The interval C opens the supply side P12 of the fuel passage P1 toward the outer surface of the second housing 20 in the diametrical direction, so that the supplied fuel can be supplied in the outer direction of the second housing 20.

  At this time, the end E2 of the second housing 20 and the end E3 of the third housing 30 are arranged on the same line in the diameter direction, and the air supplied to the air passage P2 is supplied between the both ends E2 and E3. So that it can be mixed with fuel.

  That is, the fuel supplied to the fuel passage P1 is supplied to the end of the air passage P2 via the interval C, mixed with the air supplied to the air passage P2, and discharged from the combustion device 1 to the front of the outlet 101. A flame F is formed.

  The size of the interval C can be adjusted according to the fastening range of the coupling portion 11 of the first housing 10 with respect to the side wall 21 of the second housing 20. Depending on the size of the interval C, the amount of fuel supplied to the fuel passage P1 with respect to the amount of air supplied to the air passage P2 can be controlled to set the mixing ratio of air and fuel.

  The first housing 10 includes an inner member 14 and an outer member 15 that are coupled to each other and partially overlap in the longitudinal direction. The inner member 14 forms an air injection port 16 that injects air toward the electrode E of the discharge unit 111.

  A plurality of air injection ports 16 are arranged in the circumferential direction on the inner member 14 and have an angle θ inclined with respect to the diameter direction of the inner member 14 (see FIG. 3). Therefore, the air supplied to the air injection port 16 is supplied while rotating in the circumferential direction between the electrode E and the first housing 10 and in the gap G.

  The outer member 15 is coupled to the outer periphery of the inner member 14, and forms a chamber 17 that receives and stores the air injected to the air injection port 16. Therefore, the chamber 17 keeps the pressure of the supplied air constant, and makes the amount of air injected to the plurality of air injection ports 16 uniform.

  On the other hand, the electrode E which forms the discharge part 111 with the inner member 14 forms a fuel injection port 26 for injecting fuel. The fuel injection port 26 is connected to the inflow side P11 of the fuel passage P1, and injects the supplied fuel from the periphery of the gap G to the inner wall of the inner member 14.

  The fuel injected into the gap G of the discharge part 111 is mixed with the rotating air injected into the air injection port 16 and causes a rotating arc by the voltage HV set between the electrode E and the inner member 14, Reacts under partial oxidation conditions. That is, the fuel is reformed into a high-temperature gas containing hydrogen.

  The hydrogen and reformed gas reformed in the discharge unit 111 are stabilized while being recirculated in the expansion unit 112 and discharged to the outlet 101. The discharged hydrogen and reformed gas act as a pushing force within a range L set in front of the outlet 101, and the fuel and air supplied to the supply unit 200 are pushed out of the range of the distance L.

  Accordingly, the fuel and air supplied to the supply unit 200 reach outside the range of the distance L through the outside of the hydrogen and reformed gas regions. At the same time, the reformed gas remains hot and hydrogen has a fast combustion and diffusion rate. Therefore, the fuel and air supplied to the supply unit 200 stably maintain the flame F while realizing lean combustion outside the range of the distance L.

  The fuel and air supplied to the supply unit 200 travel for a distance L, have an additional mixing time, and are mixed in a more uniform state to realize lean combustion. Therefore, the amount of NOx generated during fuel combustion can be reduced.

  FIG. 4 is a photograph showing the state of the flame when the fuel is burned by the combustion apparatus 1 of FIG. 1, and FIG. 5 is a photograph showing the state of the flame when the fuel is burned by the combustion apparatus 2 according to the prior art. It is.

  Referring to FIGS. 4 and 5, the conventional combustion apparatus 2 forms a flame F2 close to the outlet. On the other hand, the combustion apparatus 1 of the present invention stably forms the flame F at a position separated from the outlet 101 by a distance L. It can be confirmed that the flame F is not formed at the center of the outlet 101.

  Hereinafter, a second embodiment of the present invention will be described. Compared to the first embodiment, description of the same configuration is omitted, and different configurations are described.

  FIG. 6 is a cross-sectional view of a combustion apparatus according to the second embodiment of the present invention. Referring to FIG. 6, in the combustion apparatus 3 according to the second embodiment, the supply unit 300 is arranged in the direction aligned with the discharge direction of the reformed gas outside the reformed gas containing hydrogen discharged from the reforming unit 100. It is formed to inject fuel and air.

  For example, the end E <b> 21 of the first housing 10 includes a flange 23 that is disposed inside the end E <b> 22 of the second housing 20 and protrudes inward in the diameter direction of the first housing 10.

  The flange 23 can reduce or adjust the speed of the reformed gas containing hydrogen ejected through the outlet 102 by narrowing the outlet 102 at the discharge portion 111.

  The end E23 of the third housing 30 is arranged alongside the outlet 102 together with the end E22 of the second housing 20. A first swirler S1 is provided between the end portions E21 and E22 of the first and second housings 10 and 20 forming the fuel passage P1, and swirls the discharged fuel. A second swirler S2 is provided between the end portions E22 and E23 of the second and third housings 20 and 30 that form the air passage P2, and swirls the discharged air.

  Therefore, the fuel discharged between the ends E21 and E22 of the first and second housings 10 and 20 and the air discharged between the ends E22 and E23 of the second and third housings 20 and 30 are It is mixed while swirling by the first and second swirlers S1 and S2, and can be discharged while swirling in a direction aligned with the discharge direction of the reformed gas.

  The fuel and air mixed by the first and second swirlers S1 and S2 are separated from the outlet 102 by a separation distance L according to the discharge speed of the reformed gas, and can form the flame F without disappearing.

  The preferred embodiments of the present invention have been described above. However, the present invention is not limited to these embodiments, and various modifications may be made within the scope of the claims, the detailed description of the invention, and the attached drawings. Of course, this is also within the scope of the present invention.

10, 20, 30: first, second, third housing 11: coupling portion 12: through-hole 13, 23: flange 14: inner member 15: outer member 16: air injection port 17: chamber 21: side wall 100: modified Mass part 101, 102: Exit 111: Discharge part 112: Expansion part 200: Supply part 300: Supply part C: Spaces E1, E2, E3, E21, E22, E23: End part F: Flame L: Distance P1: Fuel passage P11: Inflow side P12: Supply side P2: Air passages 1, 2, 3: Combustion device S1: First swirler S2: Second swirler

Claims (16)

A reforming section formed on the center side so as to reform the supplied hydrocarbon-based fuel and air and discharge a high-temperature reformed gas containing hydrogen to the outlet;
A supply unit provided at least outside the outlet so as to inject fuel and air into one side of the reformed gas discharged from the reforming unit and form a flame at a position spaced apart from the outlet by a distance; Combustion apparatus characterized by including.   The mixture of fuel and air supplied to the reforming section is characterized in that, in the case of hydrocarbon fuel, the equivalent ratio is equal to or higher than the theoretical equivalent ratio of partial oxidation and lower than the theoretical equivalent ratio of combustion. The combustion apparatus according to 1. The reformer is
A first housing that is electrically grounded;
2. The combustion apparatus according to claim 1, further comprising an electrode that is separately mounted at an inner center of the first housing and to which a voltage is applied. The first housing is
A discharge gap that forms a discharge gap between the electrode and reacts fuel and air under partial oxidation conditions;
The combustion apparatus according to claim 3, further comprising: an extension part that is extended and formed at the discharge part so as to stabilize the gas discharged by reacting at the discharge part. The supply unit
5. The combustion apparatus according to claim 3, wherein the combustion apparatus is configured to inject fuel and air to the outside of the reformed gas discharged from the reforming unit. The supply unit
A second housing spaced apart from the outer periphery of the first housing;
A third housing spaced apart on the outer periphery of the second housing,
A fuel passage formed between the first housing and the second housing;
The combustion apparatus according to claim 5, further comprising an air passage formed between the second housing and the third housing. The air passage is
The combustion apparatus according to claim 6, wherein the combustion device is connected to the discharge portion across the fuel passage by a passage connecting member that connects the second housing and the first housing. The second housing is
Forming a side wall on one side of the fuel passage;
The first housing is
The combustion apparatus according to claim 6, wherein the combustion apparatus is connected to the side wall by screw connection or welding. The first housing is
A coupling portion protruding toward the side wall of the second housing is further formed;
The fuel passage is
An inflow side formed at one side center of the first housing;
A supply side connected to the outer peripheral side of the first housing,
The coupling portion is
The combustion apparatus according to claim 8, wherein a through-hole that connects the inflow side and the supply side is formed. On the opposite side of the side wall of the second housing, the end of the first housing is
A flange projecting outwardly in a diametrical direction of the second housing to form an interval with an end of the second housing in a longitudinal direction of the second housing;
The interval set between the flange and the end of the second housing is:
The combustion apparatus according to claim 9, wherein a supply side of the fuel passage is opened to a diametrical outline of the second housing.   11. The combustion apparatus according to claim 10, wherein an end portion of the second housing and an end portion of the third housing are arranged on the same line in the diameter direction. The first housing is
An inner member that forms an air injection port for injecting air toward the electrode;
The combustion apparatus according to claim 3, further comprising: an outer member that is coupled to an outer periphery of the inner member and that forms a chamber that receives and accommodates the air injected to the air injection port. The air injection port is
A plurality of inner members spaced apart in the circumferential direction;
The combustion apparatus according to claim 12, wherein the combustion apparatus has an angle inclined with respect to a diameter direction of the inner member. The supply unit
The fuel and air are formed so as to be ejected in a direction aligned with a discharge direction of the reformed gas outside the reformed gas discharged from the reforming unit. Combustion device. The supply unit
A second housing spaced apart from the outer periphery of the first housing;
A third housing spaced apart on the outer periphery of the second housing,
A fuel passage formed between the first housing and the second housing;
An air passage formed between the second housing and the third housing;
The end of the first housing is
The combustion apparatus according to claim 12, wherein a flange is formed inside the end portion of the second housing and protrudes inward in the diameter direction of the first housing. The end of the first housing and the end of the second housing are formed side by side,
A first swirler is provided between an end of the first housing and an end of the second housing;
The combustion apparatus according to claim 15, wherein a second swirler is provided between an end of the second housing and an end of the third housing.