JP2001141207A - Combustor and method for combustion - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a combustor and a method for combustion in which heavy load combustion can be carried out while red NOx and SPM and the facility can be made compact even when by-production gas from an iron mill or an waste treatment facility or a new fuel having a low heat generation rate (exhaust gas from refuse incinerator) is used as well as general good quality fuels having a high heat generation rate. SOLUTION: The combustor comprises a tubular combustion chamber having one end opening into a furnace, a burner section 8 provided, on the periphery of the combustion chamber, with nozzles for blowing oxygen containing gas and fuel individually or mixedly in the direction substantially tangential to the inner wall face of the combustion chamber, and high temperature air blowing sections 9a, 9b disposed in the vicinity of the open end of the burner section.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a combustion apparatus and a combustion method, and more particularly to a combustion apparatus capable of adjusting a combustion load in a wide range, reducing NOx and reducing suspended particulate matter (SPM). The present invention relates to an apparatus and a combustion method.

[0002]

BACKGROUND OF THE INVENTION Conventional combustion devices used in industrial furnaces,
For example, as a combustion device applied to heating equipment, boilers, power generation equipment, etc., primary combustion is performed by mixing fuel and a part of combustion air, and secondary combustion is performed by mixing the remaining combustion air. A two-stage combustion system is known.

[0003] As the burners used in the above-mentioned conventional furnace, gas burners, oil burners, pulverized coal burners and the like are known depending on the type of fuel.

[0004] Conventional gas burners are roughly classified into a diffusion combustion system (external mixing) and a premix combustion system (internal mixing) according to a method of mixing a fuel gas and an oxygen-containing gas. Each of these types of gas burners has a structure in which a flame is formed in a furnace in front of the tip of the burner. The diffusion combustion type is a type in which the two gases are mixed and burned at the tip of a burner, and a high-temperature flame can be obtained, and is widely used. Further, the premixed combustion type has an advantage that a relatively short flame can be formed.

[0005] Conventional oil burners are roughly classified into spray type and pre-evaporation type. Spray-type burners are based on a system that pressurizes liquid fuel, injects it at high speed from an injection port, atomizes and burns, and a system that sprays liquid fuel together with an airflow of pressurized air to atomize and burn. The fuel is injected downstream of the burner. The pre-evaporation type burner heats and gasifies liquid fuel in advance, mixes it with air, and burns it. The fuel is injected upstream of the burner. In these types of oil burners, a flame is formed in the furnace in front of the burner.

[0006]

However, there are some problems in the combustion device having the above-mentioned conventional burner. The main ones are as follows.

[0007] Since a flame is formed ahead of the tip of the burner, a wide combustion space must be secured in front of the burner, and the size of the combustion equipment increases. Further, when the adjustment range of the combustion amount is narrow and the combustion amount needs to be largely changed, a plurality of burners sharing the adjustment range of the combustion amount must be installed, which complicates the operation. In addition, the size of the combustion equipment is further increased.

Further, depending on combustion conditions, the amount of harmful substances such as NOx increases, and unburned components such as hydrocarbons are generated. Furthermore, there is a concern that the formation of soot and the like may become one of the sources of environmental pollution.

Furthermore, the effective use of by-product gas from steelworks, waste treatment facilities and the like and newly created low calorific value fuels (exhaust gas from garbage incinerators, etc.) and, for example, heating equipment, boilers, power generation There is the following problem when trying to respond to the diversification of fuel types (lower quality, more fuel types) in facilities and the like.

When a by-product gas or a newly created low calorific value fuel is used, (1) the composition and the flow rate of the fuel greatly fluctuate, and (2) the flame length becomes longer due to low reactivity. (3) Since the calorific value is low, it is difficult to start up the equipment in a cold state, and long-term auxiliary combustion is required.

In order to cope with diversification of the type of fuel used (lower quality, more types of fuel), (1) the number of installed burners increases because the combustibility differs for each type of fuel, and (2) switching from gas to oil. At the same time, as fuel quality deteriorates, NOx, SP
M (suspended particulate matter) and the like increase.

Further, when a burner is applied to a boiler, a power generation facility, or the like, high load combustion of the burner is required in order to make the facility compact and improve thermal efficiency.

Therefore, the present invention is not limited to the case of using not only high quality fuel having a high calorific value but also by-product gas or a newly created low calorific value fuel, or diversification of fuel types (lower quality). It is an object of the present invention to provide a combustion apparatus and a combustion method capable of performing high-load combustion, achieving low NOx and low SPM even in the case of using various types of fuels, and capable of downsizing equipment.

[0014]

Means for Solving the Problems The inventors of the present invention have studied to solve the above-mentioned problems, and as a result, have a tubular combustion chamber having one end opened in a furnace, and a periphery of the combustion chamber. A burner portion provided with a nozzle for blowing oxygen-containing gas and fuel separately or mixed so that the blowing direction is substantially tangential to the inner wall surface of the combustion chamber, and a burner portion open end. By having a high-temperature air blowing part in the vicinity, the range of adjustment of the combustion amount is wide, high load combustion is possible, and low N
It has been found that there is provided a combustion apparatus which can achieve a low Ox and a low SPM and which can make the system compact.

Further, since the nozzles for injecting the oxygen-containing gas and the fuel include a plurality of nozzles for the oxygen-containing gas, the liquid fuel, and the gaseous fuel, low-quality fuel can be used. Furthermore, by having a plurality of nozzles, the adjustment range of the combustion amount is wide and high load combustion is possible,
It has been found that there is provided a combustion device which can achieve a low NOx and a low SPM, and can make the system compact. Here, the low-quality fuel refers to by-product gas from a steelworks, a waste treatment facility, or the like, or a newly created low-calorific value fuel (such as exhaust gas from a garbage incinerator).

Further, by providing means for adjusting the passage cross-sectional area of the nozzle throttle section in one or both of the nozzles for injecting the oxygen-containing gas and the fuel, the swirling speed in the burner section can be changed without changing the flow rate. It has been found that this can change the flame diameter and flame length.

Further, by having a circulating gas outlet between the open end of the burner portion and the high-temperature air blowing portion, uniformization of secondary combustion in a combustion furnace or the like is promoted, and NOx reduction and NOx reduction. It has been found that low SPM is promoted.

Further, by providing an ejector in the middle of the pipe for introducing the circulating gas, the flow rate of the circulating gas can be adjusted without being affected by pressure fluctuations in the combustion chamber of the burner or in the boiler furnace. This enables more precise combustion control in the furnace, lowering NOx,
It has been found that low SPM is promoted.

Further, the fuel is blown into the combustion chamber of the burner.
CO and H before this fuel _TwoReforming to main gas
NOx reduction and SPM reduction
Was found to be promoted.

Further, by adding H ₂ or an H ₂ -containing fuel to the fuel before the fuel is blown into the combustion chamber of the burner, low NOx and low SPM can be achieved, and the system can be made compact. I found something like that.

Further, by providing either or both of the recess and the projection in the combustion chamber of the burner section,
It has been found that the mixing of the fuel and the oxygen-containing gas is promoted downstream of these, so that the NOx and SPM can be reduced, and the system can be made compact.

Further, since the open end of the burner section has a nozzle shape, mixing of fuel and oxygen-containing gas in the nozzle section and in the boiler furnace is promoted, so that NOx is reduced.
It has been found that the SPM can be reduced and the system can be made compact.

The present invention has been made based on such findings, and is a combustion apparatus and a combustion method having the following features.

[1] An oxygen-containing gas and a tubular combustion chamber having one end opened into the furnace are provided around the combustion chamber so that the blowing direction is substantially tangential to the inner wall surface of the combustion chamber. A combustion device comprising: a burner section provided with nozzles for separately or mixedly injecting fuel, and a high-temperature air blowing section near an open end of the burner section.

[2] A combustion apparatus in which the nozzle for injecting the oxygen-containing gas and the fuel of the above [1] comprises a plurality of nozzles for the oxygen-containing gas, liquid fuel and gaseous fuel.

[3] The combustion apparatus according to the above [1] or [2], wherein one or both of the nozzles for injecting the oxygen-containing gas and the fuel has a means for adjusting a passage cross-sectional area of a nozzle throttle section. .

[4] The combustion apparatus according to any one of [1] to [3], further comprising a circulating gas outlet between the burner open end and the high-temperature air outlet.

[5] The combustion apparatus according to any one of the above [1] to [4], further comprising an ejector in a pipe for introducing the circulating gas.

[6] The combustion apparatus according to the above [1] to [5], further comprising means for reforming the fuel into a gas mainly composed of CO and H ₂ before blowing the fuel into the combustion chamber of the burner section.

[7] The combustion apparatus according to the above [1] to [6], further comprising means for adding H ₂ or an H ₂ -containing fuel to the fuel before the fuel is blown into the combustion chamber of the burner section.

[8] The combustion apparatus according to any one of the above [1] to [7], wherein the combustion chamber has one or both of a recess and a projection in the burner section combustion chamber.

[9] The combustion device according to any one of [1] to [8], wherein the open end of the burner has a nozzle shape.

[10] An oxygen-containing gas and a tubular combustion chamber having one end opened into the furnace are provided around the combustion chamber so that the blowing direction is substantially tangential to the inner wall surface of the combustion chamber. Primary combustion is performed in a burner portion provided with a nozzle for blowing fuel separately or mixed, and primary combustion gas discharged from the burner portion and high-temperature air provided near the open end of the burner portion A combustion method comprising performing secondary combustion with high-temperature air blown from a blowing section.

[11] The combustion method according to the above [10], wherein the fuel is reformed into a gas mainly composed of CO and H ₂ and then blown into the burner section combustion chamber.

The oxygen-containing gas refers to a gas containing oxygen for combustion, such as air, oxygen, oxygen-enriched air, and a mixed gas of oxygen and exhaust gas.

[0036]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1A is a diagram showing a side view of a schematic configuration when applied to a boiler as a first embodiment of the present invention. (B) is sectional drawing of the AA arrow.
(C) is an enlarged view of the combustion device 1.

The combustion apparatus 1 according to this embodiment comprises a burner section 8 and switchable high-temperature air blowing sections 9a and 9b provided above and below an open end of the burner section, and is installed in the boiler furnace 2. Here, primary combustion is performed in the burner section 8 and secondary combustion is performed in the boiler furnace 2 with primary combustion gas injected into the boiler furnace 2 together with high-temperature air blown from the high-temperature air blowing section. FIG. 1 (b)
As shown in (2), when the combustion device 8 is installed at a corner portion of the boiler furnace 2, each burner center axis is horizontally shifted from the furnace center in a horizontal cross section. The direction of the central axis is preferably the tangential direction when a circle having a width of approximately W / 10 at the furnace center in the horizontal cross section is assumed in the cross section. The generation of the swirling flow in the furnace promotes the agitation of the gas and makes the secondary combustion uniform.

In this embodiment, the case where eight boilers 1 are installed in the boiler furnace 2 is shown. It goes without saying that the number can be increased or decreased. Further, in the present embodiment, a case where the combustion device 1 is installed in a boiler will be described. However, it goes without saying that the present invention can be used not only for the boiler but also for general heating equipment.

FIG. 2A is a view showing a burner according to the first embodiment of the present invention, and FIG.
It is sectional drawing of the -B arrow view. 10 is a tubular combustion chamber,
One end is open to serve as a discharge port for the combustion exhaust gas. A long slit is formed at the other end along the pipe axis direction, and a nozzle 11 that is connected to the slit and blows an oxygen-containing gas is provided. The nozzle 11 is provided so that the injection direction is substantially tangential to the inner wall surface of the combustion chamber 10, and is blown by an oxygen-containing gas.
An exhaust gas flow is formed in the combustion chamber 10. The tip of the nozzle 11 has a flat shape and its opening area is reduced, so that the oxygen-containing gas is blown at a high speed at the nozzle throttle portion. At this time, the oxygen-containing gas may be supplied after being preheated.

A liquid fuel injection valve 12 is provided on the same peripheral surface as the position where the nozzle 11 is disposed, so that the liquid fuel is injected into the exhaust gas flow of the oxygen-containing gas. I have. Injection valve 1 in this embodiment
Reference numeral 2 denotes a device (two-fluid injection valve) for injecting liquid fuel together with an airflow of pressurized air to atomize the liquid fuel. The injection valve 12 is connected to a liquid fuel pipe and an air pipe. 13 is a spark plug.

A nozzle 11 for blowing an oxygen-containing gas
A gas fuel nozzle 14 for blowing a premixed gas mixture of gaseous fuel and air is provided upstream of the position where the liquid fuel injection valve 12 is arranged. The gaseous fuel nozzle 14 is provided such that the injection direction is substantially tangential to the inner wall surface of the combustion chamber 10, and a swirling flow is formed in the combustion chamber 10 by blowing the gas.

In the burner section having the above-described structure, when the oxygen-containing gas is blown from the nozzle 11 to form a swirling flow and the liquid fuel is injected from the injection valve 12, the liquid fuel starts to evaporate, and the droplets are vaporized. Or the droplets become finer. When ignited in such a state, the injected liquid fuel burns in the same manner as gaseous fuel.

Then, in the combustion chamber 10, the fluid is stratified by the density difference, and layers having different densities are formed on both sides of the flame. That is, high-temperature combustion gas is present on the axial center side having a small centrifugal force, and unburned gas or gas containing unevaporated droplets is present on the inner wall side of the combustion chamber having a large centrifugal force. Further, in the vicinity of the inner wall, no flame is formed because the turning speed is higher than the flame propagation speed. Therefore, the flame is generated in the combustion chamber 10 in a tubular shape. Reference numeral 50 denotes a tubular flame. And the gas in the combustion chamber 10 flows downstream while swirling,
During this time, the gas and liquid droplets on the inner wall side are sequentially burned, move to the axial center side, and are discharged from the open end. Since unburned gas exists near the inner wall of the combustion chamber, the wall surface of the combustion chamber 10 does not become hot due to direct heat transfer.

On the upstream side of the liquid fuel injection valve 12, the gaseous fuel blown from the nozzle 14 burns to form a tubular flame. The gaseous fuel nozzle 14 functions as a pilot burner and also has a function of promoting the evaporation of the liquid fuel when it is being injected. Further, in the case of using a liquid fuel having poor ignitability, it is possible to reliably ignite by injecting the liquid fuel after igniting a premixed gaseous fuel / air mixture blown from the nozzle 14.

In FIG. 2, a two-fluid injection valve is used as the liquid fuel injection valve. However, the liquid fuel injection valve does not necessarily have to be a two-fluid injection valve. A pressure spray type may be used. However, if the droplets of the liquid fuel become finer, the combustibility is further improved, and from this viewpoint, a two-fluid injection valve is preferable as the injection valve.

In FIG. 2, a gaseous fuel nozzle 14 for blowing a premixed gas mixture of gaseous fuel and air to form a tubular flame upstream of the position where the liquid fuel injection valve 12 is disposed. However, the gaseous fuel that forms the tubular flame does not have to be a premixed gas, and the gaseous fuel and air may be blown from separate nozzles.

Also, since means for increasing or decreasing the passage cross-sectional area of the air or fuel nozzle is provided, it is possible to change the turning speed in the burner without changing the flow rate, thereby changing the flame diameter and the flame length. it can.

With the above configuration, in the burner section,
High-temperature flue gas exists on the shaft center side where the centrifugal force is small,
Unburned gas is present on the inner wall side of the combustion chamber having a large centrifugal force, and a tubular flame is present therebetween. Therefore, the unburned gas is not diluted with the flue gas,
Stable combustion becomes possible.

By obtaining stable combustion, it is possible to increase the utilization efficiency of oxygen, and it is not necessary to supply extra air in connection with this, so that high-temperature combustion gas can be generated. In addition, since combustion can be performed even under a condition in which the fuel gas component is extremely lean or rich, the stable combustion range of the burner section itself can be widened, and the selection range of the combustion exhaust gas temperature can be widened. .

Further, since a stable flame is formed in the burner portion, the flame does not blow out even if a flow field is formed at the introduction destination of the combustion gas, and it is necessary to provide a flame stabilizer or the like. Absent.

Further, since the flame length from the burner end can be adjusted at the burner portion, by shortening the flame length,
The volume of the boiler can be reduced, and the whole system can be made compact.

The switchable high-temperature air blowing section 9 shown in FIG.
Each of a and 9b has a structure in which air blown into the boiler furnace 2 passes through the heat storage body 35. When the air blown into the boiler furnace passes through the heat storage 35, the heat storage 3
The temperature is raised by the heat stored in 5 and introduced into the boiler furnace.

As shown in FIG. 1C, the switching high-temperature air blowing portions 9a and 9b installed above and below the open end of the burner portion are pushed through a four-way valve 6 as shown in FIG. 7 is connected. The switchable hot air blowing sections 9a and 9b installed above and below the burner open end are
The switching of the four-way valve 6 alternately blows out hot air and takes in gas in the boiler furnace. Switching is
The switching may be performed at a preset time or may be arbitrarily set. When the gas in the boiler furnace is taken in, the heat storage body 35 stores the sensible heat of the exhaust gas. On the contrary, when the air is blown out, the heat stored in the heat storage body 35 raises the temperature of the air from the blower and is introduced into the boiler furnace. Is done. The gas taken in from the boiler furnace is returned to the boiler furnace again, or is discharged to the atmosphere after exhaust gas treatment.

The high-temperature air increases the reactivity of combustion in the boiler furnace, so that secondary combustion is performed efficiently.
Contributes to lower NOx and lower SPM.

By switching between blowing and taking in the high-temperature air blowing sections 9a and 9b, an unsteady exhaust gas or air flow can be generated in the boiler furnace from top to bottom or from bottom to top. The supply of primary combustion exhaust gas with a stable composition and temperature distribution from the burner section, and unsteady high-temperature air blowing or exhaust gas flow average the temperature and gas composition distribution in the boiler furnace, and It is possible to prevent local high / low temperature areas and excess / deficiency of oxygen, and to burn with the minimum amount of air or fuel required for combustion, and to expand the upper or lower limit of the amount of air required for combustion. Can be. As a result, lower NOx and lower SPM can be achieved, the maintenance cycle of the entire system can be extended, and the service life can be extended.
Further, since high load combustion is possible, the size of the boiler can be reduced.

FIG. 3A is a view showing a burner section according to a second embodiment of the present invention. FIG. 3B is a cross-sectional view taken along the line CC in FIG. Here, the parts other than the burner part are the same as those of the first embodiment, so that the description and description are omitted.

The burner section according to the present embodiment is formed such that a part of a combustion chamber is formed in a double tubular shape, and a nozzle for blowing an oxygen-containing gas into an outer tube is substantially tangential to an inner wall surface. The pipe is provided with a plurality of slits formed along the pipe axis direction on the same peripheral surface, and an injection valve for spraying liquid fuel into the inner pipe is arranged.

In FIG. 3, the portions described in FIG. 2 are denoted by the same reference numerals and description thereof will be omitted. In this embodiment, a part of the combustion chamber 10 includes an outer pipe 15 and an inner pipe 16.
And has a double tubular shape. This double tubular portion serves as a fuel injection portion, and the outer tube 15
Is provided with a nozzle 11 for blowing an oxygen-containing gas so as to be substantially tangential to the inner wall surface.

The inner pipe 16 is provided with a plurality of slits 17 formed in the circumferential direction along the pipe axis direction. The slits 17 allow the gas blown from the nozzle 11 to enter the combustion chamber 10. It is a spout. Slit 17
Are arranged at equal intervals in the circumferential direction, or are arranged at symmetrical positions.

The slit 17 is provided so that the gas blowing direction is substantially tangential to the inner wall surface of the inner tube 16. The gas blown from the nozzle 11 and forming a swirling flow inside the outer tube 15 is formed by the slit 17. The air is blown again from the slit 17 in a direction substantially tangential to the inner wall surface, so that a swirling flow is also formed in the inner pipe 16. Further, the inner pipe 16 is provided with an injection valve 12 for spraying liquid fuel into the pipe so that the liquid fuel is injected into the oxygen-containing gas which is blown from the slit 17 and forms a swirling flow. Has become.

In the burner section having the above-described configuration, liquid fuel is injected into the swirling flow of the oxygen-containing gas blown from a plurality of locations of the inner pipe 16, so that mixing of the liquid fuel and the oxygen-containing gas is promoted, Combustibility is improved. Further, since the outer tube 15 is provided with the nozzle 11 for blowing the oxygen-containing gas, and the inner tube 16 is always covered with the blown oxygen-containing gas, the inner tube 16 is self-cooled.
For this reason, even if it is heated by the radiant heat of the flame existing inside and the hot gas on the axial center side, the temperature rise of the inner tube 16 can be suppressed.

In the first embodiment or the second embodiment, a gas fuel and an oxygen-containing gas are provided upstream of a position where a nozzle for injecting the oxygen-containing gas and a liquid fuel injection valve are arranged. A nozzle for blowing a premixed gas or a nozzle for blowing a gaseous fuel and a nozzle for blowing an oxygen-containing gas may be provided.

FIG. 4 is a view showing a burner according to a third embodiment of the present invention. Here, the parts other than the burner part are the same as those of the first embodiment, so that the description and description are omitted.

The burner according to this embodiment is different from the first or second embodiment in that a spacer movable in the tube axis direction is provided at the other end of the combustion chamber. .

In FIG. 4, the parts described in FIG. 2 are denoted by the same reference numerals and description thereof is omitted. In this embodiment, a spacer 18 is inserted at the upstream end of the combustion chamber 10. This spacer 18 is used for the combustion chamber 1.
0 and can be moved in the tube axis direction. 1
9 is a driving device for the spacer. Therefore, if the spacer 18 is moved to the downstream side, the combustion section in the combustion chamber 10 is shortened. The spacer 18
Is moved to a part of the position where the liquid fuel injection valve 12 is installed, if only the injection valve at that position is fully closed, there is no hindrance to the injection of the liquid fuel.

According to the burner section having such a configuration, even if the flame length is shortened when the amount of combustion is reduced, the position where the flame is formed is adjusted by appropriately moving the spacer 18 to the downstream side. Thus, the end of the flame can always be formed at the downstream end of the burner. For this reason, the problem that the downstream end of the combustion chamber 10 is damaged by being exposed to high temperature is prevented.

FIG. 5 is a view showing a burner according to a fourth embodiment of the present invention. Here, the parts other than the burner part are the same as those of the first embodiment, so that the description and description are omitted.

The burner according to this embodiment is the same as the burner according to any one of the first to third embodiments, except that a heater is provided in an oxygen-containing gas supply line connected to a nozzle for blowing oxygen-containing gas. A device for adjusting the temperature of the oxygen-containing gas at the outlet of the heater is provided.

In FIG. 5, the portions described in FIG. 2 are denoted by the same reference numerals, and description thereof will be omitted. In this embodiment, a heater 20 for preheating the oxygen-containing gas is provided in the oxygen-containing gas supply line connected to the nozzle 11 for blowing the oxygen-containing gas. Heater 20
, A combustion exhaust gas is circulated as a heating fluid, and heat recovery is performed. In addition, a temperature controller 21 is provided for adjusting the temperature of the heated oxygen-containing gas. The temperature control device 21 has a thermometer 22 for detecting the outlet temperature of the heater 20 and a flow control valve 23 for the combustion exhaust gas, and is configured to be able to preheat the oxygen-containing gas to a predetermined temperature.

The heating fluid introduced into the heater 20 is not limited to the combustion exhaust gas, but may be a high-temperature gas or the like obtained by separately burning. It is desirable to improve the ignitability.
Also, when adjusting the temperature of the oxygen-containing gas heated by the heater 20, instead of adjusting the flow rate of the heating fluid as described above, a method of mixing cold air with the heated oxygen-containing gas is adopted. You may.

However, the preheating temperature of the oxygen-containing gas is about 600
It is necessary to set the upper limit to ° C. When an oxygen-containing gas of 600 ° C. or more is blown into the combustion chamber 10, the liquid fuel is thermally decomposed and carbonized in or near the injection valve 12, and soot is easily generated.

FIG. 6 is a view showing a burner according to a fifth embodiment of the present invention. Here, the parts other than the burner part are the same as those of the first embodiment, so that the description and description are omitted.

The burner according to this embodiment is provided with a thermometer for measuring the inner wall temperature at the downstream end of the combustion chamber in any one of the first to fourth embodiments. A control mechanism configured to adjust the flow rate of the liquid fuel and / or the oxygen-containing gas based on the detection value of the thermometer is provided.

In FIG. 6, the portions described in FIG. 2 are denoted by the same reference numerals, and description thereof is omitted. In this embodiment, a thermometer 24 for measuring the inner wall temperature at the downstream end of the combustion chamber 10 is provided.
The signal of the value detected at 4 is sent to the arithmetic and control unit 25. In addition, flow controllers 26 and 27 are provided in the liquid fuel pipe connected to the injection valve 12 and the oxygen-containing gas pipe connected to the nozzle 11, respectively. The signal of the flow rate value is sent to the arithmetic and control unit 25 and the arithmetic and control unit 2
Control signals are sent from 5 to the flow controller 26 and the flow controller 27.

Incidentally, depending on the combustion conditions, the tubular flame tends to attenuate the swirling flow toward the downstream, and the shape of the flame tends to collapse, so that the inner wall temperature at the downstream end becomes high, or unburned gas remains. Occurs in the burner unit configured as described above, so that the inner wall temperature at the downstream end becomes a predetermined temperature based on a control signal from the arithmetic and control unit 25. In addition, the flow rate of the liquid fuel and the flow rate of the oxygen-containing gas are adjusted,
Alternatively, control is performed in which the flow rates of the liquid fuel and the oxygen-containing gas are individually adjusted. Therefore, a tubular flame is always formed at the downstream end of the combustion chamber 10 and the length of the flame is maintained so as not to go out of the combustion chamber 10, so that the downstream end is exposed to high temperature and is damaged. And the problem of unburned gas being discharged is prevented.

FIG. 7 is a view showing a burner section according to a sixth embodiment of the present invention. Here, the parts other than the burner part are the same as those of the first embodiment, so that the description and description are omitted.

The burner according to the present embodiment has a shape in which the downstream part of the combustion chamber is reduced in diameter toward the open end in any one of the first to fifth embodiments. Things.

In FIG. 7, the portions described in FIG. 2 are denoted by the same reference numerals, and description thereof will be omitted.

In this embodiment, the downstream portion of the combustion chamber 10 is reduced in diameter toward the open end and has a tapered shape. In this way, if the downstream portion of the combustion chamber 10 is made thinner, the swirling speed at the downstream end portion can be increased even if the blowing amount is reduced. For this reason, a normal tubular flame is also formed at the downstream end, and the problem that the inner wall of the downstream end becomes abnormally high temperature and is damaged, and the composition of the combustion exhaust gas is deteriorated does not occur.

FIG. 8 is a view showing a burner according to a seventh embodiment of the present invention. Here, the parts other than the burner part are the same as those of the first embodiment, so that the description and description are omitted.

The burner according to this embodiment is the same as any one of the first to sixth embodiments, except that at least a part of the inner wall of the combustion chamber is made of a refractory.

In FIG. 8, the portions described in FIG. 2 are denoted by the same reference numerals and description thereof will be omitted.

In this embodiment, the combustion chamber 10 has two parts, the upstream part 10a is made of metal, and the downstream part 10b is made of refractory. The two parts are connected by a flange joint. The combustion chamber 10 is flange-joined to an opening provided in a device to which the combustion chamber 10 is attached. Numeral 40 denotes a steel shell of a device for attaching the burner portion, and 41 denotes a refractory lining the steel shell.

As described above, if at least the downstream portion of the combustion chamber 10 is formed of a refractory, the flame length is shortened or the swirling flow is attenuated due to a change in the mixing ratio of the liquid fuel and the oxygen-containing gas. And the shape of the tubular flame collapsed,
Even if the downstream side of the combustion chamber 10 becomes hot, or is heated by radiant heat from a flame or hot gas on the axial side,
Damage to the combustion chamber 10 is avoided.

As means for preventing damage to the combustion chamber 10 due to fluctuations in the combustion state, in addition to the embodiment shown in FIG. 8, at least a downstream portion of the combustion chamber 10 is provided with a cooling structure (cooling jacket). Is also good. When selecting a cooling method, an air cooling method is preferable to a water cooling method. In the case of water cooling, the inner wall is excessively cooled,
This is because moisture in the combustion exhaust gas may condense on the inner wall surface.

FIG. 9A is a view showing a burner according to an eighth embodiment of the present invention, wherein FIG. 9B is a sectional view taken along the line DD in FIG. 9A, and FIG. EE in (a)
It is sectional drawing of an arrow. Here, the parts other than the burner part are
The description and the description are omitted because they are the same as the first embodiment.

In this embodiment, in any of the first to sixth embodiments, the position of the combustion chamber where the liquid fuel injection valve is disposed is closer to the exhaust gas discharge side of the combustion exhaust gas. Is provided with a cooling jacket, and this portion is formed in a double tubular shape, and a nozzle for supplying an oxygen-containing gas serving as a cooling fluid to the outer tube of the portion formed in the double tubular shape is provided. Is provided with a slit-shaped opening along the pipe axis direction, and the oxygen-containing gas is blown into the combustion chamber from this opening.

In FIG. 9, the portions described in FIG. 2 are denoted by the same reference numerals, and description thereof will be omitted. In the present embodiment, a cooling jacket 28 is provided on the combustion exhaust gas outlet side of the combustion chamber 10 from the position where the liquid fuel injection valve 12 is disposed, and this portion is formed in a double tubular shape. ing. A nozzle 30 for supplying an oxygen-containing gas serving as a cooling fluid is provided on the outer tube 29 of the double-tubular portion so as to be substantially tangential to the inner wall surface. Further, a slit-shaped opening 31 is provided along the pipe axis direction in the combustion chamber 10 which is an inner pipe of a portion formed in a double tubular shape, and oxygen-containing gas is blown into the combustion chamber 10 from this opening 31. It is supposed to be. The slit-shaped opening 31 provided in the combustion chamber 10 is provided so as to be substantially tangential to the inner wall surface.

When the nozzle 30 for supplying the oxygen-containing gas is provided so as to be substantially tangential to the inner wall surface, the flow rate of the oxygen-containing gas flowing on the outer periphery of the combustion chamber 10 increases, and the transmission from the combustion chamber 10 increases. The heat is promoted, and the temperature difference in the jacket 28 is reduced. If the opening 31 is provided so as to be substantially tangential to the inner wall surface of the combustion chamber 10, the oxygen-containing gas blown into the combustion chamber 10 is mixed while swirling, and is formed by a swirling flow. The phenomenon of disturbing a tubular flame does not occur.

As described above, when the oxygen-containing gas is supplied as a cooling fluid to the cooling jacket 28, the combustion chamber 10
Is cooled, the abnormal temperature rise caused by the fluctuation of the combustion conditions as described above is prevented, and the heat radiated from the combustion chamber 10 is recovered by the oxygen-containing gas. And
Since the oxygen-containing gas is blown into the combustion chamber 10 as secondary air, the temperature of the combustion exhaust gas becomes high, and the generation of harmful gases such as CO is suppressed. For this reason, according to the above configuration, it is possible to obtain a burner portion having functions of energy saving and low pollution.

In the above embodiment, after the oxygen-containing gas supplied to the jacket 28 is heated,
Although the heated oxygen-containing gas is blown into the combustion chamber 10, the heated oxygen-containing gas may be supplied to the blowing nozzle 11 as primary air for burning liquid fuel.

FIG. 10A is a view showing a side surface of a combustion apparatus according to a ninth embodiment of the present invention, and FIG.
It is sectional drawing of an arrow.

The nozzles for injecting the oxygen-containing gas and the fuel are composed of a plurality of nozzles for the oxygen-containing gas nozzles 60 and 65, the liquid fuel nozzle 61, and the gas fuel nozzle 64. With this configuration, even in the case of low-quality fuel, a wide adjustment range of the combustion amount is possible, and high-load combustion can be performed.
Provided is a combustion device that can achieve a low SPM and can make the system compact.

In the case of low-quality fuel, the fuel is preferably supplied to the burner section 8 by an external mixing method (mixing in the burner section).
As shown in FIG. 10B, the oxygen-containing gas and the fuel vapor are blown from separate nozzles in a substantially tangential direction on the inner wall surface of the combustion chamber.

It is preferable that the oxygen-containing gas be preheated by the heat exchanger 62 or the like. For example, when the oxygen-containing gas is introduced into the heat exchanger 62 while being heated to a temperature equal to or higher than the ignition temperature of the fuel gas, the reactivity in the combustion chamber increases, and the combustion speed increases. As a result, the overall length of the burner can be reduced, and the apparatus can be made more compact. In addition, by raising the temperature of the oxygen-containing gas, the reactivity as an oxidant increases, so that combustion can be performed even when a lower-quality fuel is used. As the heating temperature, an optimum temperature is selected depending on the fuel used.

The oxygen-containing gas may be oxygen-enriched air. The oxygen-enriched air preferably has an oxygen concentration of about 25 to 30%. By using oxygen-enriched air as the oxygen-containing gas, the amount of exhaust gas can be reduced, and sensible heat released into the atmosphere together with the exhaust gas can be reduced. As a result, heat efficiency can be increased, and energy saving can be achieved.

The oxygen-containing gas blown from the nozzle 60 and the fuel blown from the liquid fuel nozzle 61 are
Although it is blown substantially tangentially to the inner wall surface of the combustion chamber, it is preferable that both or one of the nozzles is a variable slit nozzle. The slit width of the variable slit nozzle can be arbitrarily adjusted by the slit width adjusting jig 63, and the blowing speed can be arbitrarily adjusted without changing the flow rate of the oxygen-containing gas or fuel. Thus, even when the oxygen-containing gas is at a high temperature, it is possible to stabilize the extinction region near the inner wall by setting the blowing speed higher than the flame transmission speed, and it is possible to adjust the flame diameter in the burner portion over a wide range. Become. Further, by adjusting the blowing speed and the blowing amount of the oxygen-containing gas, and also the blowing speed and the blowing amount of the fuel, the flame length can be controlled, and the heat utilization efficiency can be improved.

When a liquid low-quality fuel is used as the fuel, it is preferable to provide a pre-evaporation chamber 69. Pre-evaporation chamber 6
At 9, the combustion efficiency is improved by mixing the low-quality liquid fuel and the atomizing air to promote evaporation. The vaporized fuel is blown from a nozzle 61 opened substantially in a tangential direction on the inner wall surface of the combustion chamber, mixed with an oxygen-containing gas, and burned.

The number of nozzles into which fuel is blown may be one, but a plurality of nozzles are preferably provided. By allowing a plurality of installed fuel nozzles to be opened and closed arbitrarily, it is possible to control the fuel flow rate according to the operating condition without changing the atomization state of the fuel. Here, the plurality of fuel nozzles are more preferably arranged linearly in the longitudinal direction of the combustion chamber in order to avoid interference between fuel sprays.

Further, when a low-quality gaseous fuel is used, it is preferable to have a dedicated fuel injection nozzle 64 and an oxygen-containing gas injection nozzle 65. In this case, it is preferable that the fuel injection nozzle 64 and / or the oxygen-containing gas injection nozzle 65 be a variable slit nozzle as described above.

It is preferable that the position of the pilot burner 66 for igniting the inside of the combustion chamber is such that the tip end thereof is approximately at the center near the upstream end of the tubular combustion chamber. This is because the central portion of the combustion chamber has the lowest swirling flow velocity of the gas and has a high temperature, so that it is the most easily ignited position. Further, it is preferable to attach a misfire detector 67 to the pilot burner. This is to detect a misfire and to enable a safe stop or re-ignition operation.

The burner section can respond to various fuels by arranging independent fuel supply nozzles for liquid fuel and gas fuel and nozzles for blowing oxygen-containing gas. This makes it possible to reduce the number of burners to be installed, contributing to downsizing of the entire system.
Further, since the flame structure of the burner is simple, even if the fuel composition or the flow rate fluctuates, the flame diameter follows itself by changing, contributing to the stabilization of combustion.

FIG. 11 is a view showing a side surface of a combustion apparatus according to a tenth embodiment of the present invention. The parts described in FIG. 10 are denoted by the same reference numerals and description thereof will be omitted.

In this embodiment, a structure having a circulating gas outlet 68 is provided between the open end of the burner and the hot air outlet. This can be achieved, for example, by forming the vicinity of the discharge port of the burner section 8 into a double pipe structure and introducing exhaust gas in the boiler furnace to this portion via the four-way valve 6. In this case, since a high-speed combustion gas is blown out from the burner section, the pressure near the open end of the burner section becomes negative pressure, and the exhaust gas in the boiler furnace 2 is sucked through the four-way valve 6 to be circulated gas. It is blown out from the circulating gas blowout port 68.

Here, the high-temperature exhaust gas from the boiler furnace is absorbed by the regenerator 35 of the switchable high-temperature air blowing section 9b to lower the temperature. The low temperature exhaust gas is
The four-way valve 6 is introduced into the double pipe by a pipe 70. The exhaust gas introduced into the double pipe has a cooling effect around the discharge port of the burner section 8 and, between the primary combustion exhaust gas of the burner section 8 and the high-temperature air blown from the switchable high-temperature air blowing section. The rapid combustion of the primary combustion exhaust gas that is blown out and near the boiler wall and the high-temperature air that is blown out from the switchable high-temperature air blowing unit is prevented.
As a result, the formation of a local high-temperature region or a local low-temperature region in the boiler furnace is suppressed, which has the effect of reducing NOx and reducing SPM.

FIG. 12 (a) is a diagram showing a side surface of a combustion device according to an eleventh embodiment of the present invention, and FIG. 12 (b) is a diagram showing an arrangement of an ejector. The parts described in FIG. 11 are denoted by the same reference numerals and description thereof will be omitted.

In this embodiment, an ejector 73 is provided in a pipe 70 between the four-way valve 6 and the double pipe structure around the discharge port of the burner 8. It is preferable that the ejector is one that can switch between air and exhaust gas as a driving gas, which is shown in FIG.
This is achieved by adopting a configuration as described below. That is, a switching valve is used to switch the exhaust gas pipe 75 branched from the outlet of the boiler exhaust gas induction fan 4 shown in FIG. 1A and the air pipe 76 branched from the outlet of the pushing blower 7 shown in FIG. It is supplied to the ejector 73 via 77 as a driving gas.

By providing the ejector, the flow rate of the circulating gas can be adjusted without being affected by the pressure fluctuation in the furnace 2. As a result, combustion control in the furnace becomes possible more precisely, which is effective in reducing NOx and SPM. Further, by providing the ejector, the amount of circulating gas passing through the heat storage body 35 is increased, and the temperature of the heat storage body is further increased, so that higher-temperature heat storage air can be obtained.

Switching of air or exhaust gas as the driving gas is performed, for example, because a local high-temperature region is formed around the primary combustion gas from the burner section injected into the boiler furnace 2 for some reason, and the NOx emission concentration at the exit of the boiler furnace. Indicates a high value, the driving gas for the ejector 73 is switched to the exhaust gas side. In this way, a circulating gas having a low oxygen concentration is supplied into the boiler furnace 2 to reduce a local high temperature and an oxygen excess region around the primary combustion gas from the burner, thereby reducing NOx. If the flame in the secondary combustion area in the boiler furnace 2 becomes unstable or unburned components such as carbon monoxide or hydrocarbons increase at the boiler furnace outlet, the driving gas for the ejector 73 is increased. To the air side. As a result, a circulating gas containing sufficient oxygen is supplied into the combustion chamber, and the local low-temperature or oxygen-deficient region in the secondary combustion region in the boiler furnace 2 can be reduced. The unburned components such as hydrogen are reduced and the SPM is reduced.

FIG. 13 is a view showing a side surface of a combustion apparatus according to a twelfth embodiment of the present invention. The parts described in FIG. 10 are denoted by the same reference numerals and description thereof will be omitted.

In this embodiment, there is provided means for reforming the fuel into a gas mainly composed of CO and H ₂ just before blowing the fuel into the combustion chamber of the burner section. For example,
When the main component of the fuel is hydrocarbon, NOx is reduced from Fuel N during combustion regardless of premixed flame or diffusion flame.
Conversion rate is high and there is a problem in reducing NOx.
On the other hand, when the main component of the fuel is CO or H ₂ and is a diffusion flame, the conversion rate from Fuel N to NOx during combustion is extremely low, which is advantageous for reducing NOx. Therefore, in this embodiment, before the fuel is blown into the combustion chamber of the burner section, the gas is reformed into a gas mainly composed of CO and H ₂ to reduce NOx. Further, by reforming the fuel into a gas mainly composed of CO and H ₂ , the concentration of hydrocarbons that easily generate soot is reduced, so that the SPM can be reduced.

Here, as a method of reforming the fuel into a gas mainly composed of CO and H ₂ , a method of performing thermal decomposition at a high temperature, a method of adding active chemical species such as O, H, and OH by plasma, or a method of reforming the fuel. Can be used.

The thermal decomposition at a high temperature is carried out, for example, by heating the fuel in the presence of a trace amount of oxygen at least at about 500 ° C.
It is performed by heating to 0 ° C. or more. As a result, the fuel is reformed into a gas mainly composed of CO and H ₂ . The upper limit temperature of the thermal decomposition is determined by the balance with the heat loss due to the thermal dissociation.

As a method of generating plasma, a method using electric discharge, a method using high-temperature exhaust gas by pure oxygen combustion, a method using continuous detonation (detonation), a method combining these methods, and the like can be used.

Here, as a heating method, for example, FIG.
As shown in (1), this can be achieved by a structure having a heater 80 around the pre-evaporation chamber 69. In addition, instead of heating by a heater, a heating method by a heat exchanger using sensible heat of exhaust gas in a burner or a furnace may be used. However, in these cases, in order to suppress the generation of soot, it is desirable to use it together with the addition of an active chemical species. Further, a method of generating plasma can be achieved by adopting a structure having a plasma generator 81 in the pre-evaporation chamber 69.

FIG. 14 is a view showing a side surface of a combustion apparatus according to a thirteenth embodiment of the present invention. The parts described in FIG. 10 are denoted by the same reference numerals and description thereof will be omitted.

In this embodiment, before the fuel is blown into the combustion chamber of the burner, H ₂ or H ₂ is added to the fuel.
₂ Includes fuel.

For example, by adding a highly reactive fuel such as H ₂ or H ₂ -containing fuel to low quality liquid fuel or low quality gaseous fuel or both, it is possible to increase the burning rate of the whole fuel. As a result, the overall length of the burner can be shortened, and the apparatus can be made compact. Further, by adding H ₂ or H ₂ -containing fuel, combustion becomes possible even when a lower quality fuel is used. Here, the containing H ₂ fuel, can be used C gas, by-product gas from e.g. steelworks.

The addition of H ₂ or the H ₂ -containing fuel is preferably performed in the mixers 71 and 72. As a mixer, for example, a swirl-mixing type mixer is used, and H ₂ or H ₂ -containing fuel is blown at a low speed from the center axis direction of the mixer, and high-speed swirl-blowing of fuel gas from the side wall of the mixer enables uniform mixing. Is more preferable.

FIG. 15 is a view showing a side surface of a combustion apparatus according to a fourteenth embodiment of the present invention. The parts described in FIG. 11 are denoted by the same reference numerals and description thereof will be omitted.

In this embodiment, the burner section 8 has a recess 78 in the combustion chamber. Recess 78
The structure is such that a groove is provided on the entire circumference or a part of the inner wall circumferential direction of the burner section combustion chamber. The generation of the gas vortex in the recess portion promotes the mixing of the fuel and the oxygen-containing gas, and accelerates the combustion. As a result, the burner length can be shortened, which contributes to downsizing of the apparatus. In this case, the amount of the oxygen-containing gas to be blown must be smaller than the theoretical air amount. This is because if the air amount is greater than the theoretical air amount, the concentration of NOx may increase.

The recess should be located at least more than the radius of the burner section combustion chamber from the open end of the burner section because it is necessary to secure a mixed region of fuel and oxygen-containing gas in the burner section combustion chamber. desirable. Further, the depth of the recess is preferably about 1/40 to 1/10, preferably about 1/20 of the inner diameter of the burner part combustion chamber, and the width of the recess is preferably about twice the depth of the recess.

Incidentally, the recesses may be provided at two or more locations for the purpose of adjusting the mixed state of the fuel and the oxygen-containing gas.

Further, the same effect can be obtained by providing a convex portion in a part or an annular shape of the inner wall of the burner part combustion chamber instead of or together with the recess.

FIG. 16 is a view showing a side surface of a combustion apparatus according to a fifteenth embodiment of the present invention. The parts described in FIG. 11 are denoted by the same reference numerals and description thereof will be omitted.

In this embodiment, the open end of the burner has a nozzle shape. By making the open end of the burner nozzle a nozzle shape, turbulence is formed near the open end, which promotes mixing of fuel and oxygen-containing gas and increases the blowing speed into the furnace. The internal temperature is made uniform. As a result, the burner length can be shortened, which contributes to downsizing of the apparatus. Furthermore, lower NOx and lower SP at the furnace outlet
M conversion is promoted. The diameter of the nozzle-shaped portion is preferably about half the diameter of the burner portion, and the elevation angle of the inclined portion of the throttle portion is preferably about 90 °. Further, the shape of the nozzle tip is not limited to a circle, but may be an oval shape or a rectangle.

[0127]

According to the present invention, the supply of the primary combustion exhaust gas having a stable composition and temperature distribution from the burner section, and the unsteady high-temperature air blowing or the exhaust gas flow,
The temperature and gas composition distribution in the boiler furnace are averaged,
It is possible to prevent local high / low temperature areas and excess / deficiency of oxygen in the boiler furnace, and to perform combustion with the minimum amount of air or fuel required for combustion. The lower limit can be extended. As a result of this,
Low NOx and low SPM can be achieved, the maintenance cycle of the entire system can be extended, and the service life can be extended. Further, since high load combustion is possible, the size of the boiler can be reduced.

Further, the burner section can be adapted to various fuels by arranging independent fuel supply nozzles for liquid fuel and gas fuel nozzles for blowing oxygen-containing gas, thereby reducing the number of burner sections. It is possible to make the whole system compact. Further, since the flame structure of the burner is simple, even if the fuel composition or the flow rate fluctuates, the flame diameter follows itself by changing, contributing to the stabilization of combustion.

Further, by providing one or both of the nozzles for injecting the oxygen-containing gas and the fuel with a means for adjusting the cross-sectional area of the passage of the nozzle throttle, the swirling speed in the burner can be changed without changing the flow rate. This allows the flame diameter and flame length to be changed.

Further, the exhaust gas in the boiler furnace is circulated and blown from the outer peripheral portion around the discharge port of the burner section to the high-temperature air blowing section, so that the cooling effect around the discharge port of the burner section is obtained. And prevents rapid combustion of the primary combustion exhaust gas from the burner near the boiler wall and the high-temperature air blown out from the high-temperature air blow-out section. This suppresses the formation of a local high-temperature region or a local low-temperature region in the boiler furnace, and has further effects on lowering NOx and lowering SPM.

Further, by providing an ejector in the middle of the pipe for introducing the circulating gas, the flow rate of the circulating gas can be adjusted without being affected by pressure fluctuations in the combustion chamber of the burner or in the boiler furnace. This enables more precise combustion control in the furnace, lowering NOx,
Low SPM is promoted.

Further, by providing a means for thermally decomposing the fuel before the fuel is blown into the combustion chamber of the burner section, lowering of NOx and lowering of SPM are promoted.

Further, by adding H ₂ or an H ₂ -containing fuel to the fuel before the fuel is blown into the combustion chamber of the burner, low NOx and low SPM can be achieved, and the system can be made compact. Becomes

Further, by providing either or both of the recess and the projection in the combustion chamber of the burner section,
Mixing of the fuel and the oxygen-containing gas is promoted, so that NOx and SPM can be reduced, and the system can be made compact.

Further, since the burner open end has a nozzle shape, mixing of fuel and oxygen-containing gas is promoted, NOx and SPM can be reduced, and the system can be made compact.

[Brief description of the drawings]

FIG. 1A is a view showing a side surface of a combustion apparatus according to the present invention, which is preferable when applied to a boiler as an example of the present embodiment. (B) It is sectional drawing of the AA arrow. (C) It is an enlarged view of a combustion device.

FIG. 2A is a view showing a burner unit according to the first embodiment of the present invention. (B) It is sectional drawing of the BB arrow.

FIG. 3A is a view showing a burner unit according to a second embodiment of the present invention. (B) It is sectional drawing of CC arrow view.

FIG. 4 is a view showing a burner unit according to a third embodiment of the present invention.

FIG. 5 is a view showing a burner unit according to a fourth embodiment of the present invention.

FIG. 6 is a view showing a burner unit according to a fifth embodiment of the present invention.

FIG. 7 is a view showing a burner unit according to a sixth embodiment of the present invention.

FIG. 8 is a view showing a burner unit according to a seventh embodiment of the present invention.

FIG. 9A is a view showing a burner unit according to an eighth embodiment of the present invention. (B) It is sectional drawing of DD arrow. (C) It is sectional drawing of the EE arrow.

FIG. 10 (a) is a view showing a side surface of a combustion device according to a ninth embodiment of the present invention. (B) It is sectional drawing of FF arrow.

FIG. 11 is a view showing a side surface of a combustion device according to a tenth embodiment of the present invention.

FIG. 12 (a) is a view showing a side surface of a combustion device according to an eleventh embodiment of the present invention. (B) It is a figure showing the arrangement composition of an ejector.

FIG. 13 is a view showing a side surface of a combustion device according to a twelfth embodiment of the present invention.

FIG. 14 is a view showing a side surface of a combustion device according to a thirteenth embodiment of the present invention.

FIG. 15 is a view showing a side surface of a combustion device according to a fourteenth embodiment of the present invention.

FIG. 16 is a view showing a side surface of a combustion device according to a fifteenth embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Combustion apparatus 2 Boiler furnace 3 Dust collector 4 Boiler exhaust gas induction fan 5 Chimney 6 4-way valve 7 Push-in blower 8 Burner part 9a, 9b Switchable high-temperature air blowing part 10 Combustion chamber 10a Upstream part of combustion chamber 10b Combustion chamber Downstream part of the nozzle 11 nozzle for injecting oxygen-containing gas 12 injection valve for liquid fuel 13 spark plug 14 gas fuel nozzle 15 outer tube of fuel injection part formed in double tube 16 fuel injection formed in double tube Inner tube of the inset part 17 Slit provided in the inner tube 18 Spacer 19 Spacer driving device 20 Heater 21 Temperature controller 22 Thermometer 23 Flow control valve 24 Thermometer 25 Arithmetic / controller 26 Flow controller 27 Flow controller 28 cooling jacket 29 outer tube of cooling jacket 30 nozzle for supplying oxygen-containing gas to cooling jacket 31 Opening provided in the combustion chamber inside the cooling jacket 35 Heat storage unit 40 Steel shell of the device for attaching the burner 41 Refractory lined in steel shell 50 Tubular flame 60 Nozzle for oxygen-containing gas 61 Nozzle for liquid fuel 62 Heat Exchanger 63 Slit width adjusting jig 64 Gas gas nozzle 65 Oxygen-containing gas nozzle 66 Pilot burner 67 Misfire detector 68 Circulating gas outlet 69 Pre-evaporation chamber 70 Pipe 71, 72 Mixer 73 Ejector 75 Exhaust gas pipe 76 Air Piping 77 Switching valve 78 Recess 80 Heater 81 Plasma generator

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Shunichi Akiyama 1-2-2 Marunouchi, Chiyoda-ku, Tokyo F-term within Nihon Kokan Co., Ltd. 3K065 TA01 TA06 TC03 TC10 TD04 TD05 TE02 TE04 TF02 TJ07

Claims (11)

[Claims] An oxygen-containing gas and a fuel are provided around a periphery of the combustion chamber so that a blowing direction is substantially tangential to an inner wall surface of the combustion chamber. A burner section provided with a nozzle for blowing separately or mixed therein, and a high-temperature air blowing section near an open end of the burner section. 2. The combustion apparatus according to claim 1, wherein the nozzle for injecting the oxygen-containing gas and the fuel comprises a plurality of nozzles for an oxygen-containing gas, a liquid fuel, and a gas fuel. 3. The combustion apparatus according to claim 1, wherein one or both of the nozzles for injecting the oxygen-containing gas and the fuel have a means for adjusting a passage cross-sectional area of a nozzle throttle portion. 4. A circulating gas outlet is provided between the open end of the burner and the hot air outlet.
4. The combustion device according to any one of items 1 to 3. 5. The combustion apparatus according to claim 1, further comprising an ejector in a pipe for introducing the circulating gas. 6. The combustion apparatus according to claim 1, further comprising means for reforming the fuel into a gas mainly composed of CO and H ₂ before blowing the fuel into a combustion chamber of a burner section. 7. The combustion apparatus according to claim 1, further comprising means for adding H ₂ or an H ₂ -containing fuel to the fuel before the fuel is blown into the combustion chamber of the burner section. 8. The combustion apparatus according to claim 1, further comprising one or both of a recess and a projection in the burner section combustion chamber. 9. The combustion apparatus according to claim 1, wherein the open end of the burner has a nozzle shape. 10. An oxygen-containing gas and a fuel having a tubular combustion chamber open at one end into a furnace so that a blowing direction is substantially tangential to an inner wall surface of the combustion chamber. Primary combustion is performed in a burner portion provided with a nozzle for separately or mixedly blowing, and primary combustion gas discharged from the burner portion and high-temperature air blowing provided near the open end of the burner portion Combustion method characterized by performing secondary combustion with high-temperature air blown from a part. 11. The combustion method according to claim 10, wherein the fuel is reformed into a gas mainly composed of CO and H ₂ and then blown into a burner section combustion chamber.