JPH07293811A - Gas combustion device - Google Patents

Abstract

PURPOSE:To improve a life of a combustion device by a method wherein a burn loss at a flange part arranged at a partition wall among inner injection holes and outer injection holes arranged concentrically is prevented from being generated. CONSTITUTION:Inner injection holes 2 and outer injection holes 3 are arranged concentrically around an ignition fuel gas injection hole 1 through a partition wall. Then, the partition wall is provided with a flange 4 for preventing flames formed at each of the injection holes from being influenced from each other at their root parts. In such a gas combustion device as above, the partition wall is provided with an air feeding hole 5 along the walls of the inner injection holes at the flange 4 in a concentric manner.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas combustion device, and more particularly to a gas combustion device in which the concentration of nitrogen oxides (NO _x ) in combustion exhaust gas is reduced.

[0002]

2. Description of the Related Art In recent years, due to environmental considerations, the release of nitrogen oxides (NO _x ) generated by combustion into the atmosphere has become a serious problem. _x is so-called thermal NO _x in which nitrogen in air is oxidized in a high temperature region. Considering a gas turbine combustor as an example of a gas combustor, diffusion combustion, which provides stable combustion, is used in a conventional combustor. Combustion of a fuel / air mixture produces an adiabatic flame temperature of around 2000 ° C. This high-temperature combustion gas is mixed with the air to lower the temperature, NO _x in an unacceptable amount are generated by the diffusion flame surface is high temperature. Since the production of NO _x rises exponentially with increasing temperature,
The production of NO _x can be greatly reduced by slightly lowering the temperature of the combustion flame. As one of effective means for lowering the temperature of the combustion flame, a premixed combustion method in which a fuel and combustion air are mixed before combustion and burned as a lean premixed gas is known as a known technique.

The applicant has already developed and proposed a gas combustion apparatus as shown in FIGS. 6 and 7 as an improved gas combustion apparatus using the premixed combustion method (Japanese Patent Laid-Open No. 5-2.
96412). This gas combustion device is provided with an ignition fuel gas ejection hole in the center thereof, a primary combustion premixed gas ejection hole having a constant mixing ratio of air and fuel gas around the ejection hole, and a fuel injection hole further around the ejection hole. The injection holes for the secondary combustion premixed gas in which the mixing ratio of air and fuel gas is made variable by making the amount of gas variable are concentrically provided.

That is, in this gas combustion apparatus, a combustion gas injection block 10 is supported in a front portion (on the left side in the drawing) of the inside of the flanged tubular body 100 from substantially the center in the axial direction.
The rear part (right side in the figure) forms a combustion chamber 20.
As is well understood from FIG. 7, the combustion gas ejection block 10 has an ignition fuel gas ejection hole 1 formed at the center thereof, and an annular primary combustion premixed gas ejection hole 2 formed around the fuel gas ejection hole 1. An annular secondary combustion premixed gas ejection hole 3 is formed in the periphery, and the primary combustion premixed gas ejection hole 2 is formed.
The partition wall of the secondary combustion premixed gas ejection hole 3 is provided with a collar portion 4 for preventing the flames formed in the ejection holes 2 and 3 from affecting each other at their root portions. . The flange portion 4 allows the premixed gas injection hole 2 for primary combustion to be formed.
A small combustion space S is formed in front of the.

The ignition fuel gas injection hole 1 is supplied with the ignition fuel gas G via a conduit 11, and the primary combustion premixed gas injection hole 2 is supplied with the primary fuel gas G ₁ via a conduit 12. A pipe 1 is supplied to the premixed gas injection hole 3 for secondary combustion.
The secondary fuel gas G ₂ is supplied via 3 and is ejected from the tip side (ejection end). Swirlers (swirlers) 14 and 15 are attached to the opposite sides of the ejection ends of the primary and secondary combustion premixed gas ejection holes 2 and 3, respectively.

On the other hand, an air inlet 100a is formed in the rear portion (right side in the figure) of the cylindrical body 100, and the combustion air A is supplied from this. Further, the ends of the premixed gas injection holes 2 and 3 for primary and secondary combustion opposite to the injection ends communicate with the inside of the cylindrical body 100 via swirlers 14 and 15, and are used for premixing. Combustion air is introduced. Upon startup, the ignition fuel gas G is supplied from the conduit 11 to the ignition fuel gas ejection hole 1 to cause diffusion combustion. As will be described later, the flame from the ejection hole 1 plays a role of stable ignition of the premixed premixed gas for subsequent combustion and stable maintenance of the combustion flame. Then, the primary fuel gas G ₁ is supplied from the conduit 12 at a constant supply amount to the pre-combustion premixed gas ejection holes 2 at an air ratio of about 1.3, and after stable combustion, the conduit 1
3 to the secondary fuel gas G in the secondary combustion premixed gas injection hole 3
₂ supply is started and premixed combustion is performed. A certain amount of combustion air A is supplied from the air inlet 100a regardless of the load.

Since the premixed flame of the primary fuel gas G ₁ can be used as a pilot flame and promotes the combustion of the secondary combustion premixed gas, the flow rate of the ignition fuel gas G is reduced or the supply thereof is stopped. . Also, the combustion with the secondary fuel gas G ₂ is performed at an air ratio of about 1.4 at the rated load,
The fuel supply amount is controlled according to the load. The combustion air A is supplied from the air inlet 100a in a constant amount regardless of the load. Therefore, at low load, the secondary fuel gas G ₂
The combustion of the premixed flame by means of super-lean combustion is performed, but stable combustion can be maintained by the heat and active groups supplied from the premixed flame by the primary fuel gas G ₁ .

Air cooling is performed as the inner cylinder 101.
When using the above, or gas turbine combustion
In case of having the same combustion load as the
Is estimated and calculated from the opening area distribution of the inner cylinder 101 1
The air ratio of the next premixed gas is NO _xConsidering emissions and stability
It was confirmed experimentally that an appropriate value around 1.8 would be obtained.
I was bitten

In the gas combustion apparatus according to the above proposal,
At startup, the fuel gas for ignition G is emitted from the fuel gas ejection hole 1 for ignition.
Is injected and burned, and a premixed gas of air and the primary fuel gas G ₁ is jetted from the precombustion premixed gas injection hole 2 for combustion, and after starting, the premixed gas for secondary combustion is started. Secondary fuel gas G with a gas amount corresponding to the load from the ejection hole 3
Eject a premixed gas of ₂ and air. After that, the fuel gas G for ignition is narrowed down. Since the premixed gas for primary combustion is constantly supplied to continue the combustion, the diffusion combustion with a large amount of NO _x components in the combustion exhaust gas is performed only at the time of startup, and thereafter, the air ratio is 1.3 to 3.5. It is possible to suppress the emission of NO _x while keeping the emission of the unburned component at a low value in a wide range of the degree, and to reduce the NO level significantly lower than that of the conventional gas combustion device.
_x can be realized.

That is, in the above-described gas combustion apparatus, since the supply amount of the combustion air A is unchanged regardless of the load fluctuation, the variable mechanism for controlling the flow rate of the combustion air is not necessary and the structure of the combustor is simple. As a result, there is an advantage that the size can be reduced. Further, since the collar portion 4 is provided between the primary combustion premixed gas ejection hole 2 and the secondary combustion premixed gas ejection hole 3, it is formed by the combustion of the primary combustion premixed gas. The flame is not strongly affected by the flame formed by the combustion of the premixed gas for secondary combustion, and the supply amount of the fuel gas in the premixed gas for secondary combustion is reduced at low load and the momentum of the flame is increased. It has an advantage that the flame formed by the combustion of the primary combustion premixed gas does not disappear even if the temperature becomes weak.

[0011]

In the gas combustion apparatus according to the above proposal, as described above, the diffusion combustion with a large amount of NO _x components in the combustion exhaust gas is performed only at the time of starting, and thereafter the air ratio is 1.
It is possible to suppress the NO _x emissions while suppressing the emission of unburnt to a low value over a wide area of about 3 to 3.5,
Compared with the conventional gas combustion device, it is possible to achieve a significantly lower NO _{x, and to} reduce the secondary fuel gas G ₂
Since it suffices to control only the supply amount of H.sub.2, there is no need for a mechanism for varying the amount of air as in the conventional gas combustion device, and there is an advantage that the structure of the device can be simplified and the size can be reduced.

The inventor of the present invention provided a partition wall between the primary combustion premixed gas ejection hole 2 and the secondary combustion premixed gas ejection hole 3 in the course of further continuing the combustion experiment for the above gas combustion apparatus. It has been found that the collar portion 4 may be overheated to a red heat state and burned during combustion, and there is a problem to be solved in terms of durability of the collar portion 4. Brim part 4
In addition to radiant heat and convection by the high temperature gas formed on the downstream side, it is heated by the primary premixed flame of about 1500 ° C, a part of which is formed in the small combustion space S inside it, and on the outside of it. Although it is cooled to some extent by the secondary combustion premixed gas of about 300 ° C. flowing through a certain secondary combustion premixed gas injection hole, the cooling is insufficient and causes an overheated state. In addition, the overheating of the collar portion not only lowers the durability due to burning, but also causes flashback of the flame, and therefore must be avoided.

This is not limited to the gas combustion apparatus of the above-mentioned type, but the inner ejection holes and the outer ejection holes are concentrically provided with the partition walls separated from each other, and the ejection holes are provided in the partition walls. This phenomenon occurs equally in a gas combustor of the type in which a flange is provided to prevent the flame formed by the gas ejected from the bases from affecting each other at their roots.

The present invention has been made in view of the above points, in which concentric circular inner and outer ejection holes are provided with a partition wall, and each partition wall has a respective ejection port. In a gas combustion device provided with a collar portion for preventing flames formed by the gas ejected from the holes from affecting each other at the root portion, by actively cooling the collar portion, The purpose is to prevent burnout due to overheating, thereby improving the durability of the collar portion and prolonging the life of the gas combustion device. A further object of the present invention is to provide a gas combustion device capable of continuously performing stable combustion without causing flashback of flame. Further, the present invention actively cools the collar portion, but does not lower the flame temperature inside the collar portion, and does not cause instability of the flame or increase in the emission amount of unburned CO and HC. An object is to provide a gas combustion device.

[0015]

In order to achieve the above object, in the present invention, basically, an inner ejection hole and an outer ejection hole are provided concentrically with a partition wall, and In the gas combustion device, wherein the partition wall is provided with a flange portion for preventing flames formed by the gas ejected from the respective ejection holes from affecting each other at the root portions thereof, further, in the partition wall, It is characterized in that the air introduction holes are provided concentrically along the wall portion on the ejection hole side on the inner side of the collar portion.

A so-called premixed gas may be supplied to the inner ejection hole and the outer ejection hole which are concentrically provided with a partition wall therebetween, and the fuel gas and the combustion air are separately supplied. So-called diffusion combustion may be caused. Further, the premixed gas may be supplied to one of the ejection holes, and the fuel gas and the combustion air may be separately supplied to the other ejection hole to cause so-called diffusion combustion.

Further, by providing an ignition fuel gas ejection hole in the center portion, ignition stability can be obtained especially when the premixed gas is ejected from the ejection hole. In a preferred embodiment of the gas combustion apparatus according to the present invention, an ignition fuel gas ejection hole is provided in the center portion, and a mixing ratio of air and fuel gas is constant around the ignition fuel gas ejection hole.
For secondary combustion in which the mixing ratio of air and fuel gas is made variable by making the amount of fuel gas variable around the injection holes for premixed gas for secondary combustion and the outer periphery of the holes for premixed gas for primary combustion The premixed gas ejection holes are concentrically provided with a partition wall, and the partition wall is provided with a collar portion for preventing the flames formed in the respective ejection holes from affecting each other at their root portions. In the gas combustion apparatus described above, further, the partition wall is concentrically provided with an air introduction hole along the wall portion of the flange portion on the side of the premixed gas injection hole for primary combustion.

In the present invention, the upstream side opening of the air introducing hole may be provided so as to face the combustion air introducing passage of the gas combustion apparatus, and only air may be introduced into the air introducing hole. The fuel gas supply conduit may be positioned facing the upstream opening to introduce a premixed gas of fuel gas and air having a lean concentration below the combustion limit into the air introduction hole. Also. A swirl vane may be attached to the air introduction hole.

[0019]

[Operation] In the gas combustion apparatus according to the present invention, in the process of combustion, the above-mentioned collar portion is formed on the primary premixed flame (or diffusion flame) formed in the small combustion space inside thereof and on the downstream side. The secondary premixed flame (or diffusion flame) is heated by the radiant heat and convection of the hot gas. However, in the present invention, in the partition wall that divides the inner ejection hole and the outer ejection hole provided concentrically, the air introduction holes are concentrically formed along the wall portion on the inner ejection hole side of the collar portion. It is provided in the shape of,
Into the air introducing hole, only air or a premixed gas of fuel gas and air having a lean concentration below the combustion limit is introduced.
The introduced air or premixed gas flows along the inner wall of the collar portion on the side of the ejection hole, and forms a thin-film air layer or mixture layer therein.

The temperature of the air introduced in this type of gas combustion apparatus is usually about 300 ° C., and in the gas combustion apparatus according to the present invention, the collar portion is a fluid flowing outside thereof (combustion air or premixed gas). In addition to the cooling by the above, the cooling is also performed by the air or the premixed gas from the air introduction hole that flows in a thin film inside thereof. As a result, overheating of the collar portion can be reliably prevented, the occurrence of burnout can be reduced, and the durability of the collar portion can be improved.

In the apparatus of the present invention, when the air or premixed gas introduced into the air introduction hole flows in a thin film shape along the inner surface of the collar portion, at the same time, it also comes into contact with the ejected gas flame from the inner ejection hole. Mix. Therefore, when only air is introduced from the air introduction hole, the cooling effect of the collar becomes insufficient when the amount of introduced air is too small, while when the air is excessively introduced, for example, the inner ejection port 1 in the case of a combustion device that supplies premixed gas from
There is a possibility that the flame temperature of the pre-mixed gas for secondary combustion is excessively cooled and the stability of the flame is impaired, resulting in an increase in the emission amount of unburned CO and HC. If the air ratio is set low, that is, the fuel concentration is set high, for the purpose of ensuring the stability of the primary premixed flame, the NO _x emission tends to increase.
Therefore, in the case of supplying the premixed gas from the inner ejection holes, when only the air is introduced from the air introduction hole to cool the collar portion, the strict setting of the supply air amount is required.

When introducing a premixed gas of fuel gas and air set to a lean concentration below the combustion limit from the air introduction hole, the introduced premixed gas is a thin film along the inner surface of the collar portion. When flowing like a stream, the collar portion is cooled, and at the same time, it comes into contact with and mixes with the gas flame ejected from the inner ejection hole, and finally burns. For that reason, the gas flames ejected from the inner ejection holes are not extremely cooled.Therefore, when supplying the fuel gas in the form of premixed gas from the inner ejection holes, it is often necessary to obtain a sufficient cooling effect. Even if the amount of the premixed gas is introduced, the stability of the premixed flame is not impaired, and it is possible to avoid increasing the emission amount of unburned CO and HC. Further, at this time, it is not necessary to set the air ratio of the combustion premixed gas to be low, that is, to set the fuel concentration to be high, so that there is an advantage that the emission of NO _x does not increase.

In the present invention, when a swirl vane is attached to the air introduction hole, the introduced air or the premixed gas becomes a swirl flow, so that the cooling effect of the collar portion can be further improved. Since the collar portion at the same time constitutes the inner wall of the gas passage from the outer outlet, overheating of the collar portion is one of the factors that cause flashback of the flame of the gas jet. On the other hand, when the brim is overheated, its radiation acts to increase the temperature of the combustion field in the space inside the brim and the temperature in the vicinity of the inner ejection holes, and therefore causes the flashback of the flame of the ejected gas. It can be one. However, since the overheating of the collar portion is suppressed as described above, the collar portion is not directly connected to the gas passages discharged from the inner discharge holes, so that the flashback of the flames of the respective discharge gas is also suppressed. , Driving stability is improved.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the following, one embodiment of the gas combustion apparatus according to the present invention will be described in more detail with reference to the case where it is applied to the gas combustion apparatus of the type shown in FIGS. In the description, members having the same functions as those of the gas combustion device shown in FIGS. 6 and 7 are designated by the same reference numerals in the drawings, and detailed description thereof will be omitted.

FIGS. 1 and 2 are an enlarged cross-sectional view and an end view showing the vicinity of the combustion gas ejection block 10 of the gas combustion apparatus of the type shown in FIGS. 6 and 7, and the fuel provided in the central portion. Around the gas ejection hole 1, a pre-combustion gas ejection hole 2 for primary combustion having a constant mixing ratio of air and fuel gas, and 1
A secondary combustion premixed gas injection hole 3 in which the mixing ratio of air and fuel gas is variable by varying the amount of fuel gas around the outer periphery of the secondary combustion premixed gas injection hole 2 is provided with a partition wall. Are provided concentrically, and the partition wall is provided with a collar portion 4 for preventing the flames formed in the ejection holes 2 and 3 from affecting each other at their root portions.

Further, in the gas combustion apparatus according to this embodiment, the air introducing hole 5 is further provided in the partition wall so as to extend along the wall portion 4a of the collar portion 4 on the side of the premixed gas injection hole 2 for primary combustion.
Are provided concentrically. In this embodiment, the ejection end 5a of the air introduction hole 5 is formed by the flange 4 at the position along the wall 4a of the flange 4 on the side of the primary combustion premixed gas injection hole 2 and by the flange 4. It is open to the side of a small combustion space S formed in the front surface of the gas ejection hole 2, and the ejection end 5a
The upstream end 5b on the opposite side to is open to the air inlet 100a (FIG. 6) formed in the cylindrical body 100. Further, a swirler 16 similar to that provided on the side opposite to the ejection ends of the primary and secondary combustion premixed gas ejection holes 2 and 3 is attached to the upstream end 5b.

In this embodiment, in the process of combustion, the flange portion 4 is heated by radiant heat and convection by the primary premixed flame formed in the small combustion space S inside the flange portion 4 and the high temperature gas formed in the downstream side. However, since the air introduction holes 5 are provided concentrically along the wall portion 4a of the collar portion 4 on the side of the premixed gas injection holes 2 for primary combustion,
During combustion, air is introduced into the air introduction hole 5 from the air introduction port 100a formed in the cylindrical body 100. Then, the introduced air flows in a form swirled by the swirler 16 along the wall portion of the flange portion 4 on the side of the primary combustion premixed gas ejection hole 2 and forms a thin film air layer therein.

As a result, the collar portion 4 is the outer side 2
In addition to the cooling by the secondary combustion premixed gas flowing through the secondary combustion premixed gas ejection holes 3, it is also cooled by the air flowing in a thin film inside, so that the overheating of the collar portion 4 is reliably prevented, and the occurrence of burnout is prevented. The durability of the collar portion is improved by reducing the amount. Figure 3,
FIG. 4 shows another embodiment of the gas combustion device according to the present invention. In this example, the extension portion 12a of the primary fuel gas injection conduit 12 to the primary combustion premixed gas injection hole 2 faces the opening of the upstream end 5b of the air introduction hole 5. A nozzle hole 12b for ejecting the primary fuel gas is formed in the extended portion 12a. And the nozzle hole 1
The diameter of 2b is set so that the premixed gas of fuel gas and air, which is set to a lean concentration below the combustion limit, is introduced into the air introduction hole 5.

In this embodiment, during combustion, the primary fuel gas from the extended portion 12a of the primary fuel gas jetting conduit 12 and the air from the air inlet 100a set to a lean concentration below the combustion limit. A premixed gas with is introduced into the air introduction hole 5. The introduced premixed gas is ejected from the ejection end 5a of the air introduction hole 5 and flows in a thin film shape along the inner surface of the collar portion 4. As a result, the flange portion 4 is cooled, and at the same time, the flame of the primary combustion premixed gas ejected from the primary combustion premixed gas ejection hole 2 is contact-mixed and finally burned.

In the embodiment shown in FIGS. 1 and 2, it is possible to control the air supply amount within a narrow range in order to avoid excessive cooling of the primary premixed flame by the air ejected from the air introduction hole 5. Although desired, in this embodiment, combustion of the premixed gas does not significantly cool the primary premixed flame. Thereby, even if a large amount of premixed gas is introduced from the air introduction hole 5 in order to obtain a sufficient cooling effect,
It does not impair the stability of the secondary premixed flame,
It is possible to avoid an increase in the amount of unburned carbon emissions. Furthermore, since there is no need to set thicken low i.e. fuel concentration of air ratio of the primary combustion premixed gas from the viewpoint of stability of the flame, NO _x emissions also has the advantage of not increasing.

FIG. 5 shows a gas combustor of the type described above with reference to FIGS. 6 and 7, which has no special means for cooling the collar, and the invention of the type shown in FIGS. 3 and 4 above. The cooling effect of the collar part 4 by the combustion test with a gas combustion device is shown. As is clear from the figure, the air ratio is 1.5 to 4
In any of the combustion tests described above, the gas combustion apparatus according to the present invention exhibits a cooling effect of about 300 ° C. to 400 ° C., and it can be understood that burnout due to overheating of the collar portion can be avoided.

As described above, since the collar portion 4 simultaneously constitutes the inner wall of the gas jet passage from the jet hole 3 on the outer side, the overheating of the collar portion 4 means that the flame of the jet gas is reversed. It is one of the causes of fire. On the other hand, the brim 4
Is not directly connected to the gas passage from the inner ejection port 2, but when the collar 4 overheats, the radiation causes the temperature of the combustion field in the space S inside the collar and the temperature near the inner ejection port 2 to change. Since it works in the ascending direction, it can be one of the causes of the flashback of the flame of each ejected gas. However, in the present invention, since the overheating of the collar portion 4 is suppressed, the flashback of the flame of each of the jetted gases is also suppressed, and the stability of operation is improved.

In the above embodiment, the air introduction hole 5
The swirler 16 provided at the upstream end 5b of the swirler is provided for the purpose of improving the cooling effect of the collar portion and the combustion effect when introducing the premixed gas, but the swirler can be omitted. The initial purpose can be achieved by arranging a mere spacer instead of the swirler. In the present invention,
The overall configuration of the gas combustion device except the configuration related to the air introduction hole is not limited to the one having the illustrated structure,
In a conventionally known gas combustion device, an inner ejection hole and an outer ejection hole are provided concentrically with a partition wall therebetween, and the partition wall is formed by ejection gas from each ejection hole. It will be appreciated that all are applicable to gas combustion devices that are provided with a collar to prevent the flames from interacting at their roots.

[0034]

As described above, according to the present invention, the inner ejection holes and the outer ejection holes are concentrically provided with the partition walls separated from each other, and the partition walls are provided with the ejection holes from the respective ejection holes. In a gas combustor equipped with a brim to prevent the flame formed by the blown gas from affecting each other at its roots, the brim is positively cooled by the introduced air and burned by overheating. As a result, it is possible to prolong the service life of the collar portion and improve the durability of the gas combustion device. In particular, when cooling with an ultra-lean premixed air and fuel gas, it is possible to cool the collar portion while maintaining the stability of the gas flame ejected from the inner ejection hole, It is particularly effective in a gas combustion apparatus in which the premixed gas is supplied through the holes. Further, by suppressing overheating of the collar portion, flame backfire is also suppressed as a result, and the operation stability of the gas combustion apparatus is improved.

[Brief description of drawings]

FIG. 1 is an enlarged axial sectional view showing an embodiment of a gas combustion apparatus according to the present invention.

FIG. 2 is an end view of the gas combustion device shown in FIG.

FIG. 3 is an enlarged axial sectional view showing another embodiment of the gas combustion apparatus according to the present invention.

4 is an end view of the gas combustion device shown in FIG.

FIG. 5 is a graph showing the cooling effect of the collar portion of the gas combustion apparatus according to the present invention.

FIG. 6 is an axial cross-sectional view showing a gas combustion device which is the basis of the gas combustion device according to the present invention.

FIG. 7 is an end view of the gas combustion device shown in FIG.

[Explanation of symbols]

 1 ... Ignition fuel gas ejection hole 2 ... Primary combustion premixed gas ejection hole 3 ... Secondary combustion premixed gas ejection hole 4 ... Collar 5 ... Cooling air or premixed gas introduction hole 100 ... Outer cylinder 100a ... Air inlet 101 ... Inner cylinder

Claims (6)

[Claims] 1. An inner ejection hole and an outer ejection hole are provided concentrically across a partition wall, and the flame formed by the ejection gas from each ejection hole is at the base portion of the partition wall. In a gas combustion apparatus provided with a collar portion for preventing mutual influence, further, in the partition wall, air inlet holes along the wall portion on the inner ejection hole side of the collar portion are concentrically formed. A gas combustion device characterized by being provided. 2. The gas combustion device according to claim 1, further comprising an ignition fuel gas ejection hole in the center. 3. A fuel gas injection hole for ignition is provided in the center,
Around the ignition fuel gas ejection hole, a primary combustion premixed gas ejection hole having a constant mixing ratio of air and fuel gas,
A secondary combustion premixed gas ejection hole, in which the mixing ratio of air and fuel gas is made variable by varying the amount of fuel gas around the outer periphery of the primary combustion premixed gas ejection hole, is provided through a partition wall. In the gas combustion device, which is provided concentrically with each other, the partition wall is provided with a collar portion for preventing the flames formed in the respective ejection holes from affecting each other at their root portions, A gas combustion apparatus, wherein the partition wall is provided with air introduction holes concentrically along the wall portion of the flange portion on the premixed gas injection hole side for primary combustion. 4. The gas combustion device according to claim 1, wherein the upstream opening of the air introduction hole is provided so as to face the combustion air introduction passage of the gas combustion device. 5. A fuel gas supply conduit is located facing the upstream side opening of the air introduction hole, and a premixed gas of fuel gas and air having a lean concentration below a combustion limit is located in the air introduction hole. The gas combustion apparatus according to claim 2, wherein the gas can be supplied. 6. The gas combustion device according to claim 1, wherein a swirl vane is attached to the air introduction hole.