JP2001124305A - Combustion device and combustion method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a combustion device and a combustion method in which the controllability of a combustion flow entering a combustion area is improved and a flame property can be controlled under the control of the combustion flow. SOLUTION: A combustion device comprises a combustion air feeder for introducing air for combustion to a combustion area, a combustion gas discharge device, a steam feeder, a mixer (mixing area) and a fuel gas introducing device. The combustion gas discharge device discharges the combustion gas generated in the combustion area outside a furnace therefrom. The mixer mixes the combustion gas and/ or steam with fuel. The fuel gas introducing device introduces the mixed fluid of the combustion gas, the steam and the fuel to the combustion area as fuel gas to mix the fuel gas with the air for combustion. The mixed fluid is introduced to the combustion area as a relatively large amount of fuel gas including lean fuel to be mixed with the air for combustion and thus generate a slow combustion reaction of the fuel gas in the combustion area. Thus, a flame property can be controlled by a fuel gas flow and the mixture of the fuel and the air for combustion can be more freely and assuredly controlled.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a combustion apparatus and a combustion method, and more particularly, to a combustion apparatus and a combustion method for improving controllability of a flame in a combustion zone of an industrial furnace or the like.

[0002]

2. Description of the Related Art Tube heating furnaces, metal heating furnaces, ceramic firing furnaces,
An industrial furnace such as a metal melting furnace, a gasification melting furnace or a boiler, or a combustion heating type radiator such as a radiant tube burner is a fuel supply device for supplying hydrocarbon-based fuel and an air supply device for supplying combustion air. And a combustion device such as a burner for mixing fuel and combustion air and burning the fuel. The fuel and combustion air mixed in the combustion device generate a flame due to diffusion combustion in the combustion zone. Premixing of fuel and combustion air before the burner is supplied is feared to cause an unexpected flashback phenomenon, and is not generally employed.

In order to achieve complete combustion of fuel in a general combustion apparatus, the actual air amount of combustion air must be set to an excess air ratio exceeding the theoretical air amount of fuel. The mixing ratio of air and fuel (air fuel efficiency) is generally set to 14 to 15 for liquid fuel such as an internal combustion engine.
For example, the fuel volume of methane fuel supplied to the combustion device is set to about 1/15 of the required air amount. Many combustion apparatuses are provided with a flame stabilizer such as a swirl flow type or a flame stabilizer plate type to mix a fuel injection flow having such a flow difference and an air flow as desired. The flame stabilizer is disposed in the mixing zone of fuel and air and forms a ignitable high-temperature circulating flow, thereby preventing the flame from blowing out and ensuring the stability of the flame.

On the other hand, as a combustion method developed by the present applicant, combustion air is preheated to an extremely high temperature of 800 ° C. or more,
2. Description of the Related Art An ultra-high-temperature air combustion method for introducing high-temperature preheated air into a mixing zone or a combustion zone is known. The combustion mode of the flame using the high-temperature preheated air heated to 800 ° C or higher is the normal flame combustion mode using the preheated air at 400 ° C or lower, or the combustion of the transition flame using the preheated air heated to the temperature range of 400 to 800 ° C. Compared with the mode, stable combustion is performed in a combustion atmosphere with an extremely wide air ratio. It is considered that the combustion stability in the ultra-high temperature air combustion method is due to the fact that the reaction rate increases due to the increase in the air preheating temperature, and the combustion characteristics are completely different from those of the conventional one. In particular, when the combustion air or the combustion mixture is heated to a temperature higher than the self-ignition temperature of the fuel, a combustion reaction that does not require external ignition in the ignition process can be realized. Moreover, 200 to 40
In the case of conventional preheated air which is only heated to a temperature of about 0 ° C., it is theoretically and practically possible to increase the supply flow rate of combustion air (preheated air) to a value higher than the limit of flame blowing. According to the ultra-high-temperature preheated air combustion method, the supply speed of the combustion air was considerably increased while avoiding the misfire phenomenon, and the combustion air was used as a high-speed flow in the mixing zone or combustion. Supply to the area. Further, in the flame formed in the combustion zone by such an ultra-high temperature air combustion method, while phenomena such as an increase in flame volume and a decrease in flame brightness are observed, a local heat generation phenomenon is suppressed. The temperature field in the region becomes uniform.

[0005]

Research on radiation and convection heat transfer effects on a heating device such as a tubular heating furnace has conventionally been conducted by preventing local overheating of a pipe to be heated and then setting a desired temperature in the furnace. It was intended mainly for the development of a combustion device that forms a field, and the arrangement and structure of heated tubes. However, in conventional combustion devices having an air-fuel ratio of more than 10, the mixing of air and fuel generally tends to be governed by control of the temperature, flow rate, flow velocity, directionality, etc. of the airflow, and is generated in the combustion zone. Flame characteristics are largely determined by the physical and fluid properties of the airflow. For example, since the fuel and air that have undergone combustion reaction in the mixing zone are burned off in the vicinity of the combustion device, the flame can only be formed in the vicinity of the combustion device, and hardly reaches the vicinity of the object to be heated. . On the other hand, even if the fuel supply pressure is increased or the fuel nozzle diameter is reduced in order to increase the reach distance of the fuel fluid, the fuel blowing speed can be increased,
Since the fuel fluid is much smaller than the air flow, the flow of the fuel fluid is canceled out by the flow of the large amount of air, and is lost immediately after discharge. It does not increase.

On the other hand, according to the ultrahigh-temperature air combustion method, as a result of reducing the air ratio and the air-fuel ratio and increasing the circulating flow rate of the combustion gas in the furnace, a slow combustion reaction is maintained in the furnace. It is possible to equalize the temperature field inside. However, in this type of combustion method, the supply flow rate of the air flow tends to be set relatively high. For this reason,
The tendency for fuel and air mixing control to depend on airflow control becomes even more pronounced.

Furthermore, it has been found that in the ultra-high temperature air combustion method, the mixed state of the fuel injection flow, the combustion air flow and the circulating flow in the furnace is an important factor in controlling the combustion reaction. It is necessary to adopt an apparatus configuration that emphasizes the control of mixing three types of fluids. However, it is extremely difficult in practice to reliably control the mixing of such various fluids by the conventional combustion method in which the circulating flow of the combustion gas in the furnace is mixed with the fuel or air flow in the furnace region. . Thus, the controllability of the fuel flow itself discharged into the furnace is improved, the position of the flame, the diffusion mode and the reaching distance are controlled by controlling the fuel flow, and the mixing position and the mixing ratio of the fuel, the combustion air and the combustion gas are controlled. It is desired to develop a new combustion method capable of improving the controllability of the fuel.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to improve controllability of a fuel flow flowing into a combustion zone and control flame characteristics by controlling the fuel flow. To provide a combustion apparatus and a combustion method.

Another object of the present invention is to provide a combustion apparatus and a combustion method capable of improving the degree of freedom in controlling the mixing of fuel, combustion air and combustion gas.

Another object of the present invention is to provide a heating apparatus and a heating method capable of controlling characteristics of a flame acting on an object to be heated.

[0011]

The present inventor has conducted intensive studies in order to achieve the above object, and as a result, led out high-temperature combustion gas in the combustion zone outside the furnace and mixed it with fuel, or
By adding steam to the combustion gas to adjust the amount of water vapor in the combustion gas and then mixing it with the fuel, or by mixing high-temperature steam with the fuel, the mixing of the fuel and the combustion gas can be reliably controlled. Instead, the present inventors have found that a large amount of fuel gas having novel combustion characteristics can be generated, and based on such findings, have achieved the present invention.

That is, according to the present invention, in a combustion apparatus having a fuel supply means for supplying combustion fuel and a combustion air supply means for supplying combustion air to a combustion zone, the combustion introduced outside the furnace is provided. A mixing device for mixing gas and / or water vapor of the water vapor supply means and fuel of the fuel supply means;
Combustion characterized by comprising a fuel gas introduction device for introducing a mixed fluid of the combustion gas and / or steam and the fuel as a fuel gas into the combustion zone, and mixing the fuel gas with the combustion air. Provide equipment.

[0013] The present invention also relates to a combustion method for introducing combustion air into a combustion zone and causing a combustion reaction by mixing the combustion air and fuel in the combustion zone. The steam of the supply means is supplied to the mixing zone, the fuel for combustion is supplied to the mixing zone, and a mixed fluid of the combustion gas and / or steam and the fuel is generated, and the mixed fluid is used as a fuel gas. A combustion method is provided wherein the combustion gas is introduced into a combustion zone, and the fuel gas is mixed with the combustion air to cause a combustion reaction of the fuel gas in the combustion zone.

According to the above configuration of the present invention, the fuel is mixed with the combustion gas led out of the furnace from the combustion zone and / or the steam of the steam supply means. In the mixed area of both,
A relatively large amount of mixed fluid containing lean fuel is produced. The mixed fluid is introduced into the combustion zone as a mass fuel gas stream having a momentum that can be controlled independently of the combustion air stream. Therefore, the characteristics of the flame generated in the combustion zone can be controlled not only by controlling the combustion air flow but also by controlling the fuel gas flow introduced into the combustion zone. Further, according to the above configuration, the fuel and the combustion gas and / or steam outside the furnace are preliminarily mixed and then mixed with the combustion air, so that the circulating flow in the furnace and the air or the fuel are mixed in the furnace. The degree of freedom and certainty in controlling the mixing of fuel and combustion air can be greatly improved as compared with the combustion method of the system.

According to another aspect of the present invention, there is provided a heating apparatus for heating an object to be heated by a combustion exothermic reaction of combustion air and fuel, wherein the combustion gas and / or steam of a steam supply means led out of the furnace are combined with the steam, A mixing device for mixing the fuel of the fuel supply means, a mixed fluid of the combustion gas and / or steam, and the fuel is introduced as a fuel gas into the combustion zone, and the fuel gas is mixed with the combustion air. A heating device comprising a fuel gas introduction device.

The present invention also provides a heating method for heating an object to be heated by a combustion exothermic reaction of combustion air and fuel, wherein a combustion gas led out of the furnace and / or steam from a steam supply means is supplied to a mixing zone, Supplying the fuel for combustion to the mixing zone to generate a mixed fluid of the combustion gas and / or steam and the fuel; introducing the mixed fluid as a fuel gas into the combustion zone; A heating method is provided wherein a combustion reaction of the fuel gas is caused to occur in the combustion zone by mixing with combustion air.

According to the above configuration of the present invention, by controlling a relatively large amount of fuel gas containing lean fuel,
The characteristics of the flame generated in the combustion zone can be controlled, whereby the combustion exothermic reaction in the combustion zone can be adjusted and the radiant and convective heat transfer of the flame to the object to be heated can be improved.

In the present specification, the term "fuel gas" is a mixed fluid obtained by mixing a fuel with a combustion gas and / or steam outside the furnace, and is a fuel capable of reacting with combustion air. Means a gaseous fluid containing the components.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGS. 1 to 4 are block flow diagrams of a combustion apparatus showing a preferred embodiment of the present invention. The combustion device shown in FIG. 1A has a mixed region of fuel and combustion gas, and a mixed gas combustion region. The high-temperature combustion gas generated in the combustion zone is led out of the combustion zone through a combustion gas outlet passage. The combustion gas at a predetermined flow rate is exhausted out of the system as combustion exhaust gas, and the remainder of the combustion gas is introduced into the mixing zone. If desired, steam from the steam generator is injected into the combustion gas to regulate the amount of steam in the combustion gas. The hydrocarbon-based fuel is introduced into the mixing zone via the fuel supply path and mixed with the combustion gas. As a result, a high-temperature mixed gas (fuel gas) obtained by diluting the fuel with the combustion gas is generated in the mixing zone. I do.

The combustion gas generally has only a residual oxygen concentration in the range of 0% to 10%, so that the fuel in the fuel supply passage does not substantially react with the combustion gas without burning.
Mix with combustion gas. The temperature of the combustion gas is substantially equal to the temperature of the combustion zone, so that a mixed gas containing a small amount of low-temperature fuel has a temperature slightly lower than the temperature of the combustion gas, for example, in the range of 800C to 1200C. Retain temperature still. In such a high-temperature gas mixture, the fuel is activated, and the combustion reaction is easier than that of a normal-temperature fuel.
The low oxygen concentration combustion gas suppresses the combustion reaction of the fuel.

The flow rate of the combustion gas is much larger than the fuel supply amount. Therefore, the mixed gas is introduced into the combustion zone as a large amount of fuel gas containing a lean fuel. Combustion air is introduced into the combustion zone through a combustion air supply passage, and the mixed gas stream mixes with the combustion air stream in the combustion zone without being substantially affected by the combustion gas circulation flow in the combustion zone. , Combustion reaction.

As fuel, gaseous, liquid, solid or semi-solid fuels can be used. For example, when a hydrocarbon gas fuel such as methane is used as the fuel, the gas fuel is
The fuel gas flows into the combustion zone as a high-temperature fuel gas diluted by the combustion gas. A high-quality reformed gas containing a relatively large amount of hydrocarbon radicals, hydrogen, carbon or carbon monoxide, etc. due to a pyrolysis reaction and / or a steam reforming reaction of the fuel which may occur in a mixing process and an introduction process of the fuel and the combustion gas. Can be generated and supplied to the combustion zone as fuel gas. When a hydrocarbon-based liquid fuel is used as the above fuel, the reforming reaction of the fuel including the evaporation process and the pyrolysis process proceeds in the mixing zone and the introduction path, and a high-quality fuel gas (reformed gas) is produced. It can be supplied to the combustion zone. Further, when a solid fuel such as pulverized coal is used as a fuel, the fuel floats in the high-temperature combustion gas and is thermally decomposed in the mixing zone and the introduction path, thereby causing hydrocarbon radicals, hydrogen, carbon and monoxide. It becomes possible to supply high-grade fuel gas containing carbon to the combustion zone. Since the steam in the combustion gas is considered to substantially affect such a fuel hydrocarbon reforming action, the steam generator increases the steam amount in the combustion gas. To this end, if desired, steam is added to the combustion gas to promote the steam reforming reaction of the fuel.

FIG. 5A is a schematic sectional view of a combustion apparatus to which the configuration shown in FIG. 1A is applied. The combustion device includes a combustion chamber 1, a forced air supply fan 2, an exhaust gas circulation fan 3, a fuel mixing device 10, and a combustion air supply device 30. The air supply fan 2 pressure-feeds the outside air sucked through the outside air suction passage OA to the fuel air supply passage CA. The air supply device 30 includes a combustion air discharge port 35 opened to the combustion chamber 1, and combustion air in the supply path CA flows into the combustion chamber 1 from the discharge port 35. The exhaust gas circulation fan 3 attracts the combustion gas in the combustion chamber 1 via the combustion gas outlet 90 and the combustion gas outlets EX and ER, and converts the combustion gas into the combustion gas introduction passage RG.
To the fuel mixing device 10. A steam generator 8 such as a steam boiler is connected to the combustion gas introduction passage RG via a steam supply passage ST, injects superheated steam at 150 to 300 ° C. into the fuel gas, and adjusts the amount of steam in the combustion gas. A part of the combustion gas is exhausted out of the system through the exhaust passage EG.

The fuel mixing device 10 disposed inside the air supply device 30 includes a fuel nozzle 11 and a combustion gas introduction unit 1.
2, a mixing zone 15 and a fuel gas injection port 16 are provided. The fuel nozzle 11 injects the fuel supplied from the fuel supply path F into the mixing area 15, and the combustion gas introduction unit 12 introduces the combustion gas (and steam) from the combustion gas introduction path RG into the mixing area 15. The mixing zone 15 mixes fuel and combustion gas (and steam), and injects the mixed gas (fuel gas) into the combustion chamber 1. The flow rate, injection pressure and direction of the mixed gas injected into the combustion chamber 1 are as follows:
It is controlled by the flow rate, injection pressure and direction of the fuel and combustion gas injected by the fuel nozzle 11 and the combustion gas introduction unit 12, and is regulated by the structure of the mixing zone 15.

The mixed gas injected into the combustion chamber 1 mixes with the combustion air discharged from the air supply device 30 and burns. Since the mixed gas having a flow rate substantially equal to that of the combustion air has a momentum corresponding to the momentum of the combustion air flow (momentum), the buoyancy due to the temperature difference and the direction and flow of the combustion air flow are substantially changed. Without being affected, the fuel mixing device 10 flows in the set direction and mixes with the combustion air.
The mixed gas whose combustion reaction is suppressed by the low oxygen concentration combustion gas slowly reacts with the combustion air, so that the mixed gas diffused into the combustion zone secures the expected reach, and the combustion flame is It is not generated locally and intensively only in the vicinity of the fuel mixing device 10 and the air supply device 30, but is generated as desired in a predetermined region in the furnace.

According to such a combustion method, the composition and the flow rate of the mixed gas are determined by the flow rate of the combustion gas (and steam) introduced into the mixing zone 15, the fuel supply amount of the fuel supply path F, and furthermore,
It is variably controlled by the mixing ratio of combustion gas (and steam) and fuel. The mixing ratio of the combustion gas and the fuel is preferably
It is set in the range of 1: 1 to 20: 1. The high-temperature mixed gas generated in the mixing zone is supplied to the combustion zone as a fuel gas having a flow rate much larger than the supply flow rate of the fuel itself. Mix with air. The mixing position, mixing form and combustion characteristics of the fuel gas and combustion air are controlled by adjusting both the combustion air flow and the fuel gas flow. The mixing ratio of the fuel gas and the combustion air is preferably set in the range of 1:10 to 20:10. Further, the flow velocity of the fuel gas flowing into the combustion zone is preferably set in a range of 10 to 150 m / s. Thus, it is possible to control not only the region of the combustion reaction, the position and direction of the flame, and the like by the combustion air flow, but also by the flow rate, flow rate, direction, and the like of the mixed gas (fuel gas).

Another embodiment of the present invention is shown in FIG. In the combustion device shown in FIG. 1 (B), a circulation circuit including a combustion gas outlet passage, a mixing zone, and a fuel gas introduction passage includes a circulation device such as a forced circulation fan for forcibly circulating a gas fluid and heat of the circulation device. In order to reduce the load and the thermal stress, a heat exchange device for transiently cooling the combustion gas is provided. The heat exchange device includes a cooling unit that transiently cools the high-temperature combustion gas and a heating unit that reheats the cooled combustion gas. The cooling unit converts the combustion gas derived from the combustion zone into 200
After cooling to a temperature of about 300C to about 300C, the heating unit radiates the sensible heat received in the cooling unit to the cooled combustion gas.
The temperature of the combustion gas, which has been lowered in the cooling unit, is mixed with steam of the steam generator if desired, and then, in the heating unit, the temperature is increased to a temperature equivalent to the temperature immediately after the discharge. The combustion device furthermore
An air preheating device is provided for preheating combustion air to an ultra-high temperature range of 800 ° C or higher, preferably 1000 ° C or higher.

FIG. 5B is a schematic sectional view of a combustion apparatus to which the configuration shown in FIG. 1B is applied. The combustion device is shown in FIG.
A combustion chamber 1, a forced air supply fan 2, an exhaust gas circulation fan 3, a steam generator 8, a fuel mixing device 10, and an air supply device 30 which are substantially the same as the combustion device shown in FIG.
The combustion device further has heat exchange devices 13, 33 and a forced exhaust fan 4, and each of the heat exchange devices 13, 33 has a heat storage body 14, 34 divided into a plurality of sections. The heat exchange device 13 constitutes a cooling unit and a heating unit shown in FIG.
The heat exchange device 33 constitutes the air preheating device shown in FIG. As the heat exchangers 13 and 33, high-speed switching type heat storage type heat exchangers provided with disk rotating flow path switching devices 20 and 40 are preferably used. It is possible to suitably use a ceramic heat storage body having a honeycomb structure. The structure of this type of heat exchanger is disclosed in, for example, Japanese Patent Application No. 7-284825 by the present applicant.
No. (Japanese Unexamined Patent Application Publication No. 9-126675) and the like, and further detailed description will be omitted.

The supply fan 2 connected to the outside air intake passage OA and the air supply passage CA introduces combustion air into the heat exchange device 33, and the exhaust fan 4 includes the combustion gas outlet 91, the exhaust passage E1, The combustion gas in the combustion chamber 1 is attracted through the heat exchange device 33 and the exhaust passage E2. Each section of the heat storage unit 34 alternately comes into heat transfer contact with the high-temperature combustion exhaust gas and the low-temperature combustion air, transfers the sensible heat of the combustion exhaust gas to the combustion air, and heats the combustion air to 800 ° C. or more. Heat to ultra-high temperature range.
The high-temperature combustion air is supplied to the air supply device 30 via the high-temperature air supply path SA, and flows into the combustion chamber 1 from the discharge port 35. On the other hand, the combustion exhaust gas in the exhaust passage E2, whose temperature has dropped to about 200 ° C. to 300 ° C., is exhausted from the exhaust passage E3 to the outside of the system.

The exhaust gas circulation fan 3 connected to the exhaust gas circulation paths R3 and R4 draws the combustion gas in the combustion chamber 1 through the combustion gas outlet 90, the combustion gas outlet path EX and the heat exchanger 13. The low temperature section of the heat storage unit 14 is in heat transfer contact with the high temperature combustion gas to store heat and cool the combustion gas. The cooled combustion gas is pressurized by the circulation fan 3, mixed with steam of the steam generator 8 as required, and then brought into heat transfer contact with the high temperature section of the heat storage body 14 whose temperature has been increased by heat storage. The combustion gas (and steam) cools the heat storage body 14 and
Heat is received from the heat storage body 14 and is 800 ° C. or more, preferably 1
The fuel is heated to an ultra-high temperature range of 000 ° C. or higher and supplied to the fuel mixing device 10 from the combustion gas introduction passage RG as high-temperature combustion gas. If desired, part of the combustion gas is exhausted from the exhaust passage EG to the outside of the system as combustion exhaust gas.

According to the embodiment shown in FIGS. 1B and 5B, the fuel supply device includes a combustion gas circulation circuit EX, in which a heat exchange device 13 constituting a cooling unit and a heating unit is interposed.
RG is provided, and the thermal load and thermal stress of the circulation fan 3 are greatly reduced. The combustion device further includes a heat exchange device 33 for preheating the combustion air to the ultrahigh temperature range, and the combustion region of the combustion chamber 1 is supplied with the ultrahigh temperature preheated air.

In general, it has been found that the combustion reaction using the ultra-high temperature preheated air proceeds smoothly in the presence of a high-speed combustion air flow, and the flow velocity of the combustion air flow is 10 m / m.
s or higher. The high-speed air flow not only activates the circulation flow in the furnace, but also forms a wide combustion reaction zone in the combustion chamber 1. In addition, the mixed gas containing a large amount of the combustion gas having a low oxygen concentration is mixed with the combustion air preheated to the ultra-high temperature range and self-ignites to form a high-temperature combustion atmosphere having a low oxygen concentration in the furnace. The fuel component in the mixed gas promotes the combustion reaction due to the high temperature combustion atmosphere, and the combustion gas (and water vapor)
Activated fuel by premixing with, suppression of combustion reaction due to low oxygen concentration, furthermore, the effect of widening the combustion reaction by high-speed flow, etc., the combustion reaction slowly in a wide range,
A relatively low temperature and wide area combustion flame is generated in the combustion area.

FIG. 6 is a schematic vertical sectional view showing a combustion apparatus having another configuration to which the configuration of the combustion apparatus shown in FIG. 1B is applied. FIG. 6A shows a first combustion process of the combustion device, and FIG. 6B shows a second combustion process of the combustion device. In FIG. 6, the same reference numerals are given to components substantially the same as or equivalent to the components of the above embodiments.

The combustion device shown in FIG. 6 has a pair of fuel mixing devices 10A and 10B and a pair of air supply devices 30A and 30A.
B is provided. The combustion device differs from the combustion device shown in FIG. 5 in the configuration of the heat exchange device.
A and 10B each have a built-in heat storage body 14, and the air supply devices 30A and 30B each have a built-in heat storage body 34. As the heat storage bodies 14 and 34, ceramic heat storage bodies having a honeycomb structure can be suitably used. The combustion device also includes a flow path switching device 20 that switches the flow path of the combustion gas, and a flow path switching device 40 that switches the flow path of the combustion air. Channel switching device 2
0 and 40 are alternately switched to the first position (FIG. 6A) or the second position (FIG. 6B) at predetermined time intervals set to 60 seconds or less.

In the first combustion step (FIG. 6A), the air supply fan 2 converts the outside air of the outside air intake passage OA into the fuel air supply passage C.
A is introduced into the flow switching device 40 through A, and the combustion air is
The air is supplied to the air supply device 30A via the supply / discharge flow path L1. The combustion air comes into heat transfer contact with the heat storage body 34 of the air supply device 30 </ b> A, is heated to the above-mentioned ultra-high temperature region by the heat radiation effect of the heat storage body 34, and then flows into the combustion chamber 1 from the air discharge port 35. The exhaust fan 4 exhausts the combustion gas in the combustion chamber 1 to the outside of the system via the air supply device 30B, the supply / discharge passage L2, the passage switching device 40, and the exhaust passages E2 and E3. The heat storage body 34 of the air supply device 30B is heated by being in heat transfer contact with the high-temperature combustion exhaust gas, and the temperature of the combustion gas drops.

The exhaust gas circulation fan 3 includes a fuel mixing device 10
B, the combustion gas in the combustion chamber 1 is attracted through the exhaust gas circulation paths R2 and R3 and the flow path switching device 20, and the combustion gas is introduced into the fuel mixing device 10A through the flow path switching device 20 and the exhaust gas circulation paths R4 and R1. Supply. The high-temperature combustion gas in the combustion chamber 1 flowing through the fuel mixing device 10B is brought into heat transfer contact with the heat storage body 14 of the fuel mixing device 10B to cool and heat the heat storage body 14. The cooled combustion gas is mixed with the steam of the steam generator 8 as required, and then supplied to the fuel mixing device 10A under the circulation pressure of the circulation fan 3 to be supplied to the fuel mixing device 10A.
A flows through the heat storage body 14 of A, and is heated to the above-mentioned ultra-high temperature region by heat exchange with the heat storage body 14 of high temperature. Fuel mixing device 10A
The fuel nozzle 11 of the combustion gas after heating (and steam)
And the mixed gas of the combustion gas and the fuel flows into the combustion chamber 1 from the fuel gas injection port 16 as the fuel gas.

In the second combustion step (FIG. 6B), the combustion air is supplied to the air supply device 30B via the outside air intake passage OA, the air supply passage CA, the passage switching device 40, and the supply / discharge passage L2. . The combustion air exchanges heat with the heat storage body 34 of the air supply device 30B, is heated to the ultrahigh temperature range, and flows into the combustion chamber 1 from the air discharge port 35 as high-temperature combustion air. The exhaust fan 4 includes an air supply device 30A, a supply / discharge flow path L
1. The combustion gas is exhausted to the outside of the system via the flow path switching device 40 and the exhaust flow paths E2 and E3. The heat storage body 34 of the air supply device 30A is heated by being in heat transfer contact with the high-temperature combustion gas, and the combustion exhaust gas is cooled.

The exhaust gas circulating fan 3 includes a fuel mixing device 10.
A, the combustion gas in the combustion chamber 1 is attracted through the exhaust gas circulation paths R1, R3 and the flow path switching device 20, and the combustion gas is introduced into the fuel mixing device 10B through the flow path switching device 20 and the exhaust gas circulation paths R4, R2. Supply. The high-temperature combustion gas in the combustion chamber 1 is brought into heat transfer contact with the heat storage body 14 of the fuel mixing device 10A and cooled,
The regenerator 14 is heated. The cooled combustion gas is mixed with the steam of the steam generator 8 if desired, and then supplied to the fuel mixing device 10B under the circulation pressure of the circulation fan 3 and exchanges heat with the heat storage body 14 of the fuel mixing device 10B to make the superheated gas. Heated to high temperature range. Fuel nozzle 11 of fuel mixing device 10B
Discharges fuel into the combustion gas (and steam) after heating,
The mixed gas of the combustion gas and the fuel flows into the combustion chamber 1 from the fuel gas injection port 16 as a fuel gas.

FIG. 7 shows the fuel mixing device 10A shown in FIG.
It is a block flow figure which shows the effect | action of 10B schematically.
FIG. 7A shows a first combustion step of the combustion device, and FIG.
(B) shows a second combustion step of the combustion device.

According to the configuration of the combustion device, the combustion gas in the combustion chamber 1 is led out of the combustion zone through the one fuel mixing device 10 and flows through the circulation passages R 1 and R 2 under the circulation pressure of the exhaust gas circulation fan 3. Circulating, optionally adding steam,
The fuel is supplied to the other fuel mixing device 10, mixed with fuel after reheating, and introduced into the combustion zone as fuel gas. The sensible heat of the high-temperature combustion gas is transiently stored in the heat storage unit 14 when it is taken out of the furnace, and is radiated to the low-temperature combustion gas immediately before mixing with the fuel.
The first and second combustion steps are alternately and repeatedly performed in a short time,
The combustion gases (and steam) are continuously cooled and reheated.

Similarly, by repeating the first and second combustion steps, the combustion air continuously receives the sensible heat of the combustion gas via the regenerator 34 (FIG. 6) and continuously receives the ultra-high temperature range. Preheated. The mixed gas and the combustion air are introduced into the combustion chamber 1 from the adjacent fuel mixing device 10 and the air supply device 30, respectively, and the combustion zone of the combustion chamber 1 has a slow combustion reaction and a fuel gas flow as described above. A wide-area and relatively low-temperature combustion flame is generated due to an increase in the volume and the flow velocity, and further, an increase in the flow velocity of the combustion air.

Another embodiment of the present invention is shown in FIG. The combustion device shown in FIG.
Similar to the embodiment shown in (B), the apparatus includes a combustion gas cooling unit and a heating unit, and an air preheating device. However, in the present embodiment, the mixing zone 15 is disposed between the heating unit and the circulation device. According to such an embodiment, the fuel is mixed with the combustion gas (and steam) whose temperature has been lowered in the cooling unit, and the mixed gas in the mixing region is heated in the heating unit to the ultrahigh temperature region. During the heating process of the mixed gas in the heating section, a thermal decomposition reaction and a steam reforming reaction of the mixed gas occur, and the mixed gas is a high-quality fuel containing a relatively large amount of hydrocarbon radicals, hydrogen, carbon, carbon monoxide, or the like. Reformed into gas.

FIG. 8 is a schematic vertical sectional view of a combustion apparatus to which the configuration of the combustion apparatus shown in FIG. 1C is applied, and FIG.
Shows a first combustion step of the combustion device, and FIG. 8B shows a second combustion step of the combustion device. Components that are substantially the same as or equivalent to the components of the above embodiments are given the same reference numerals.

The combustion device shown in FIG. 8 switches between the fuel mixing devices 10A and 10B containing the heat storage material 14, the air supply devices 30A and 30B containing the heat storage material 34, and the flow paths of the combustion gas and the combustion air. It is similar to the embodiment shown in FIG. 6 in that it has the flow path switching devices 20 and 40. However, in the combustion device of the present embodiment, the heat storage 14
Is interposed between the combustion chamber 1 and the mixing zone 15,
The narrow passage 4 interconnects the combustion chamber 1 and the mixing zone 15.

In the first combustion step (FIG. 8A), the low-temperature combustion gas (and steam) supplied to the combustion gas introduction section 12 of the fuel mixing device 10A is mixed with the fuel discharged from the fuel nozzle 11 of the fuel mixing device 10A. The mixed gas of the combustion gas (and water vapor) and the fuel flows through the heat storage unit 14 of the fuel mixing device 10A, and is heated to the ultrahigh temperature region by heat exchange with the high-temperature storage unit 14. The high-temperature fuel gas flows into the combustion chamber 1 from the fuel gas injection port 16.

In the second combustion step (FIG. 8B), the low-temperature combustion gas (and steam) supplied to the combustion gas introduction section 12 of the fuel mixing device 10B is combined with the fuel discharged from the fuel nozzle 11 of the fuel mixing device 10B. The mixed gas of the combustion gas (and water vapor) and the fuel flows through the heat storage unit 14 of the fuel mixing device 10B, and is heated to the ultra-high temperature range by heat exchange with the high-temperature storage unit 14 and then the fuel is heated. The gas flows into the combustion chamber 1 from the gas injection port 16.

The mixed gas is supplied to the fuel mixing devices 10A, 10B
While flowing through the heat accumulator 14, undergoes a thermal decomposition reaction and is reformed into a relatively high quality fuel gas. Fuel mixing device 10
The mixed gas injected into the combustion chamber 1 from A and 10B is mixed with the high-temperature combustion air flowing into the combustion zone from the adjacent combustion air discharge port 35, and is subjected to wide-range combustion with a low oxygen concentration and high-temperature combustion atmosphere. A flame is generated in the combustion chamber 1.

FIGS. 2A, 2B and 2C show another embodiment of the present invention. FIG. 2 (A), (B)
And (C) have a configuration generally corresponding to each of the embodiments of FIGS. 1 (A), (B) and (C), but in each of the embodiments shown in FIG. Mix with. In the combustion device shown in FIG. 2A, the combustion gas (and water vapor) led out of the furnace is introduced not only into the mixing zone with the fuel but also into the mixing zone with the combustion air. .
The fuel supply device shown in FIG. 2 (B) has a mixing zone for mixing the high-temperature preheated air and the high-temperature combustion gas, and a part of the combustion gas (and steam) reheated in the heating unit is heated at a high temperature. It is mixed with combustion air preheated to a very high temperature by the device. The combustion device shown in FIG. 2 (C) includes a mixing region for mixing combustion air and low-temperature combustion gas (and steam), and the temperature of the combustion gas dropped to a temperature range of about 200 ° C. to 300 ° C. in the cooling unit. Some (and water vapor) mix with the room temperature air before it is preheated to a high temperature.

According to such an embodiment, the oxygen concentration of the combustion air is reduced by mixing the combustion air with the combustion gas (and steam), and the combustion reactivity of the combustion air is suppressed. The low oxygen concentration combustion air is mixed with the low oxygen concentration fuel gas similarly diluted with the combustion gas (and steam) to form a low oxygen concentration combustion atmosphere in the combustion zone. As a result, a slow combustion reaction proceeds in the combustion zone, and a wide and uniform flame is generated.

FIGS. 9A, 9B and 10 are schematic longitudinal sectional views of a combustion apparatus to which the configuration of the combustion apparatus shown in FIG. 2 is applied. In FIGS. 9 and 10, the same reference numerals are given to components that are substantially the same as or equivalent to the components of the above embodiments.

The combustion device shown in FIGS. 9A and 9B has a combustion gas introduction passage RG connected to an air supply device 30.
Is provided. The combustion gas (and steam) flowing through the combustion gas introduction passage RG is split at the branch of the branch channel R5, and part of the combustion gas (and steam) is supplied to the air supply device 3.
At 0, mix with combustion air.

FIG. 9 (B) relates to a combustion apparatus to which the configuration of FIG. 2 (B) is applied. In the configuration of FIG. 9 (B), the exhaust gas circulation path R4 and the air supply path CA are connected. As shown in FIG. 2C, low-temperature combustion gas (and steam) may be mixed with low-temperature combustion air.

In the combustion apparatus shown in FIG. 10, the branch R5 of the exhaust gas circulation path R1 is connected to the air supply device 30A,
The branch path R6 of the exhaust gas circulation path R2 is connected to the air supply device 30B.
Connected to. In the first combustion step (FIG. 10A), the combustion gas (and steam) in the exhaust gas circulation path R1
5 is partially introduced into the air supply device 30A and mixed with the combustion air. In the second combustion step (FIG. 10B),
The combustion gas (and steam) in the exhaust gas circulation path R2 is partially introduced into the air supply device 30B from the branch path R6, and mixes with the combustion air.

FIGS. 3A, 3B and 3C show still another embodiment of the present invention. The embodiment shown in FIG. 3 has a configuration in which the action of water vapor in the combustion gas is particularly emphasized, and is 700 ° C. or higher, preferably 1000 ° C. or higher, more preferably 1500 ° C. due to the heat of the combustion gas.
The above-described steam heated to an extremely high temperature mixes with the fuel.
That is, in each of the above-described embodiments, the reforming reaction of the hydrocarbons contained in the fuel is considered to have proceeded effectively mainly due to the presence of high-temperature steam in the combustion gas. In order to make the action of such high-temperature steam more apparent, the sensible heat of the combustion gas is transferred to the steam to heat the steam to an extremely high temperature of 700 ° C. or more, and mix the high-temperature steam with the fuel. . The high-temperature steam functions as a reforming material and a high-temperature heat medium, and the fuel is reformed into a high-quality fuel containing a relatively large amount of hydrocarbon radicals, hydrogen, carbon, carbon monoxide, and the like by the action of the high-temperature steam, Combustes with high-temperature combustion air. In the devices shown in FIGS. 3A and 3B, the combustion gas is exhausted out of the system after heating the steam.

FIGS. 11, 12 and 13 are schematic longitudinal sectional views of a combustion device provided with the fuel supply device shown in each of FIGS. The combustion apparatus shown in each of FIGS.
The overall configuration is similar to the combustion device shown in FIG. However, in the present embodiment, the steam of the steam generator 8 is
The water is supplied to the flow path switching device 20 and / or the outside air intake passage OA via the steam supply passage ST. The water vapor is stored in the heat storage 14,
34, and is mixed with fuel after being heated to a high temperature of 700 ° C. or higher. FIG. 11 shows a first combustion step (FIG. 11A) and a second combustion step (FIG. 11B) of the combustion device.
12 and 13 show only the first combustion step of the combustion device.

FIG. 4 shows still another embodiment of the present invention. The embodiment shown in FIG. 4 is different from the embodiment shown in FIG. 3 in that high-temperature steam is mixed with fuel to promote a fuel reforming reaction.
However, in the present embodiment, the fuel supply device further includes a steam heating device that heats steam to a high temperature. The fuel for steam heating and the combustion air are supplied to the combustion chamber of the steam heating device, and the steam of the steam generating device receives the heat of combustion in the combustion chamber and is heated to a high temperature of 700 ° C. or higher. The high-temperature steam is supplied to the mixing zone and mixes with the fuel to reform the fuel. The mixture of fuel and high-temperature steam is further mixed as high-quality fuel gas with high-temperature combustion air, and burns in the combustion zone of the combustion device.

FIG. 14 is a schematic vertical sectional view of a combustion device provided with the fuel supply device shown in FIG. 4, and FIG. 15 and FIG.
FIG. 2 is a cross-sectional view illustrating a configuration of a steam heating device. FIG.
As shown in the figure, the steam heating device 80 has a steam supply passage LS
Is connected to the steam generator 8 via a high-pressure steam supply path HS, and is connected to the flow path switching apparatus 20 via a high-temperature steam supply path HS. The high-temperature steam is introduced into the mixing zone 15 of the fuel mixing device 10A in the first combustion step (FIG. 14A),
In the combustion step (FIG. 14B), the fuel is introduced into the mixing zone 15 of the fuel mixing device 10B. In any of the combustion steps, the high-temperature steam flows into the combustion chamber 1 from the fuel gas injection port 16 after being mixed with the fuel discharged from the fuel nozzle 11. The high-temperature steam forms a high-temperature atmosphere in the mixing zone 15 and undergoes a steam reforming reaction with the hydrocarbon-based fuel to reform the fuel into a high-quality fuel gas.

As shown in FIGS. 15 and 16, the steam heating device 80 includes a heating furnace main body 88, a four-way valve 95, and switching control valves 85, 86, 87. The heating furnace main body 88 has a pair of left and right honeycomb heat storage bodies 81, a combustion chamber 82, a combustion air discharge section 83, and a fuel nozzle 84. The air and fuel in the combustion air supply passage SA and the fuel supply passage SF are supplied to the air discharge portion 83 and the fuel nozzle 8 under the control of the control valves 85 and 86.
4 to one of the combustion chambers 82 alternately, and the steam in the steam supply passage LS is alternately supplied to one of the heat storage bodies 81 under the control of the four-way valve 95. Combustion chamber 82
After the heat storage body 81 is heated, the high-temperature combustion gas generated in the above is exhausted from the exhaust passage EA and the exhaust passage EG. The relatively low-temperature steam is supplied from the distribution path L1 or L2 to the high-temperature heat storage body 81, and is brought into contact with the heat storage body 81 by heat transfer at 800 ° C.
After being heated to the above high temperature, it flows out to the supply path HS and is supplied to the flow path switching device 20 (FIG. 14). If desired, the control valve 87 may be opened to introduce a part or all of the combustion gas in the exhaust gas circulation path R3 from the combustion gas flow path EB to the steam supply path LS, and mix it with the steam flow in the steam supply path LS. .

[0059]

Preferred embodiments of the present invention will be described below in detail with reference to FIGS. In the following drawings, components that are substantially the same as or equivalent to the components shown in FIGS. 1 to 16 are denoted by the same reference numerals.

FIG. 17 is a sectional view showing a combustion apparatus according to the first embodiment of the present invention. FIG. 17A shows a first combustion process of the combustion device, and FIG. 17B shows a second combustion process of the combustion device.
3 shows a combustion process.

The combustion device shown in FIG. 17 is a further embodiment of the basic configuration of the combustion device shown in FIG. 6, and includes fuel mixing devices 10A and 10B, air supply devices 30A and 30B, and flow switching devices 20 and 40. , An air supply fan 2 and an exhaust gas circulation fan 3.
The position (FIG. 17A) or the second position (FIG. 17B) is alternately switched. The fuel mixing devices 10A and 10B and the air supply devices 30A and 30B are fixed to the furnace body W of the combustion chamber 1 at a predetermined inclination angle. The central axes of the devices 10A, 30A are oriented to intersect in the combustion zone within the combustion chamber 1 and the central axes of the devices 10B, 30B are oriented to intersect in the combustion zone within the combustion chamber 1.

Each of the fuel mixing devices 10A and 10B includes a cylindrical casing 17, a heat storage body 14 accommodated in the casing 17, and a fuel nozzle 11 penetrating through the center of the heat storage body 14.
It is generally composed of The distal end of the casing 17 has a frusto-conical reduced diameter portion 16a, and a fuel gas injection port 16a.
Opens at the tip of the reduced diameter portion 16a. The fuel injection port 11a of the fuel nozzle 11 is disposed at a position slightly retracted from the fuel gas injection port 16, and a mixing area 15 is formed between the fuel gas injection port 16 and the fuel injection port 11a. The bottom of the casing 17 is closed by a bottom plate 19, and the combustion gas introduction unit 12 is defined between the heat storage unit 14 and the bottom plate 19.
The introduction section 12 communicates with the combustion gas port 18 and the port 1
8 is connected to the exhaust gas circulation paths R1 and R2. The fuel nozzle 11 penetrates through the bottom plate 19 and is connected to fuel supply pipes F1 and F2. The fuel supply control valves V1 and V2 are connected to the fuel supply pipe F
1 and F2, respectively.

Each of the air supply devices 30A and 30B is generally composed of a cylindrical casing 37 and a heat storage unit 34 accommodated in the casing 37. The distal end of the casing 37 has a frusto-conical reduced diameter portion 36a, and the combustion air discharge port 35 opens at the distal end of the reduced diameter portion 36a. The bottom of the casing 37 is closed by a bottom plate 39, and the combustion air introduction unit 32 is defined between the heat storage unit 34 and the bottom plate 39.
The introduction section 32 communicates with a combustion air port 38, and the port 38 is connected to the supply / discharge flow paths L1 and L2.

The regenerators 14 and 34 are formed of a lattice-like ceramic honeycomb structure having a large number of square cross-section cell holes. The honeycomb structure has a cross-sectional dimension and a total length that can be incorporated into the casings 17 and 37.
It constitutes a narrow flow path through which combustion gas or combustion air can flow. The wall thickness of the cell walls and the pitch (interval) of each cell wall preferably corresponds to the maximum value of the volumetric efficiency of the regenerator and is equal to 0.1.
The wall thickness and pitch are set so as to achieve a temperature efficiency in the range of 7 to 1.0.

The flow path switching device 20 is a high-speed switching type four-way valve that can be selectively switched to the first position or the second position, and includes a plate-shaped valve body 26 fixed to the center rotation shaft 25. Have. The flow path switching device 20 includes supply / discharge ports 21 and 22 connected to the exhaust gas circulation paths R1 and R2, respectively, and an exhaust gas circulation path R
3, bypass ports 23 and 24 respectively connected to R4. The circulation path R3 is connected to a suction port of the exhaust gas circulation fan 3, and the circulation path R4 is connected to a discharge port of the circulation fan 3. An exhaust passage EG and a steam supply passage ST are connected to the circulation passage R4, and a part of the combustion gas is exhausted to the outside of the system as required, and the steam of the steam generation device (not shown) passes through the circulation passage R4. Injected into the combustion gas stream.

The flow path switching device 40 is a high-speed switching type four-way valve that can be switched to the first position and the second position at the same time as the flow path switching device 20. It has a valve body 46. The passage switching device 40 includes an air supply port 41 connected to the fuel air supply passage CA, an exhaust passage E2.
, And supply / discharge ports 43, 44 connected to the supply / discharge flow paths L1, L2, respectively.

In the first combustion step (FIG. 17A), the flow path switching devices 20, 40 are held at the first position. The combustion gas in the combustion chamber 1 is drawn into the exhaust gas circulation fan 3 via the heat storage unit 14 of the fuel mixing device 10B. The combustion gas is pressurized by the circulation fan 3 and, if desired, added with steam in the supply path ST.
And is discharged to the same mixing area 15 via the. Fuel supply control valve V1
Supplies fuel to the fuel nozzle 11 of the fuel mixing device 10A, and discharges the fuel to the mixing zone 15 of the fuel mixing device 10A. The fuel and the combustion gas (and steam) are mixed in the mixing zone 15, and the mixed gas flows out of the fuel gas injection port 16 into the combustion chamber 1 as a fuel gas. The combustion gas in the combustion chamber 1 is also led out to the supply / exhaust flow path L2 via the heat storage unit 14 of the air supply device 30B, and the flow switching device 40 and the exhaust flow are controlled under the exhaust pressure of an exhaust fan (not shown). The air is exhausted out of the system via the path E2. The air supply fan 2 introduces combustion air into the heat storage unit 34 of the air supply device 30A through the fuel air supply path CA, the flow path switching device 40, and the supply / discharge flow path L1, and the combustion flowing through the heat storage body 34 The air for combustion is the combustion air outlet 3
5 flows into the combustion chamber 1. The fuel gas flow and the combustion air flow discharged from the devices 10A and 30A are mixed in the combustion chamber 1, and the fuel gas burns.

In the second combustion step (FIG. 17B), the flow switching devices 20, 40 are held at the second position. The combustion gas in the combustion chamber 1 is drawn into the exhaust gas circulation fan 3 via the heat storage unit 14 of the fuel mixing device 10A. After the combustion gas is pressurized by the circulation fan 3 and, if desired, added with steam in the supply path ST, the combustion gas is discharged to the mixing zone 15 via the heat storage body 14 of the fuel mixing device 10B. The fuel supply control valve V2 is
Supplying fuel to the fuel nozzle 11 of the fuel mixing device 10B,
The fuel is discharged to the mixing area 15 of the fuel mixing device 10B.
The fuel and the combustion gas (and steam) are mixed in the mixing zone 15, and the mixed gas flows out of the fuel gas injection port 16 into the combustion chamber 1 as a fuel gas. The combustion gas in the combustion chamber 1 is also led out to the supply / exhaust passage L1 via the heat storage unit 14 of the air supply device 30A, and the passage switching device 40 and the exhaust flow are controlled by the exhaust air (not shown). The air is exhausted out of the system via the path E2. The air supply fan 2 is connected to the fuel air supply passage C.
A, the combustion air is introduced into the heat storage unit 34 of the air supply device 30B via the flow path switching device 40 and the supply / discharge flow path L2, and the combustion air flowing through the heat storage unit 34 is supplied to the combustion air discharge port 35.
From the combustion chamber 1. The fuel gas flow and the combustion air flow discharged from the devices 10B and 30B are mixed in the combustion chamber 1, and the fuel gas burns.

The flow path switching devices 20 and 40 are alternately switched to the first position or the second position at predetermined time intervals set to 60 seconds or less, and the first combustion step (FIG. 17A) and the second combustion step (FIG. 17B) are executed alternately. Each of the heat storage bodies 14 of the fuel mixing devices 10A and 10B is in contact with the high-temperature combustion gas for heat transfer to cool the combustion gas, and for heat transfer contact with the cooled combustion gas to heat the combustion gas to an ultra-high temperature range. And the heat radiation action is repeated. Therefore, the exhaust gas circulation paths R3, R
4, the heat load and the thermal stress of the exhaust circulation fan 3 are reduced, while the combustion gas (and water vapor) to be discharged to the mixing zone 15 is slightly lower than the temperature immediately after the discharge. To be reheated. Air supply device 30A, 3
Each of the heat storage elements 34B has a heat storage function of cooling the combustion gas by heat transfer contact with the high-temperature combustion gas, and a heat dissipation function of heat transfer contact with the low-temperature combustion air to heat the combustion air to an ultra-high temperature range. Is repeated. Accordingly, the sensible heat of the combustion exhaust gas transfers heat to the combustion air via the heat storage unit 14, and the combustion air discharged from the combustion air discharge port 35 is continuously preheated to an extremely high temperature range.

As described above, the injection flow of the high-temperature combustion air and the high-temperature mixed gas is jetted from the fuel gas injection port 16 and the combustion air discharge port 35 into the combustion zone, and the fuel mixture device 10 and the air supply device 30 are discharged. A high-temperature combustion atmosphere mixed with a low oxygen concentration in the intersection region of the central axis is formed in the intersection region. The flow rates of the fuel gas and the combustion air at the fuel gas injection port 16 and the combustion air discharge port 35 whose flow path cross-sectional areas are restricted are set to, for example, high speeds exceeding 10 m / s, and the high-speed fuel gas flow and the combustion An air flow flows into the combustion chamber 1. The fuel gas stream having a flow rate substantially equal to the flow rate of the combustion air has the same momentum as the flow rate of the combustion air, and therefore, it is possible to perform control of the fuel gas flow independent of the flow of the combustion air. Become. The combustion method using such a large flow of fuel gas is completely different from the conventional combustion method in which only a small amount of fuel fluid is mixed with a large amount of combustion air flow as follows.

That is, the combustion gas (and steam) having a high temperature and a low oxygen concentration functions as a high-temperature fuel carrier or a fuel increasing means for suppressing the combustion reaction of the fuel and greatly increasing the momentum of the fuel. The working air acts as an oxidizing agent that causes a slow combustion reaction of the fuel gas by self-ignition of the fuel gas in a low oxygen concentration combustion atmosphere. The fuel fluid having increased momentum is less susceptible to buoyancy due to the furnace temperature difference, and can prevent incomplete combustion or local heat generation due to uneven and local mixing with combustion air. Furthermore, since the fuel fluid has a momentum that can be controlled independently of the combustion air flow and is hardly affected by the circulation flow in the furnace, the mixing position, mixing state, mixing speed, and the like of the fuel fluid and the combustion air are determined. It is regulated by controlling the fuel gas, which makes it possible to control the position and characteristics of the flame as desired.

Further, in the conventional high-speed switching regenerative combustion device, the exhaust gas outlet of the combustion exhaust gas and the discharge port of the air and the fuel are arranged adjacent to each other on the furnace wall, so that the fuel jet at the discharge port is short-passed to the exhaust port. Tend to do it, and
As a result of the repetition of the supply / exhaust switching operation in a short period of time, vibrations in the circulating flow in the furnace and the like occur, and due to this effect, the vibration of the fuel jet or the vibration of the mixture of fuel and air tends to occur. Such fluid vibration may cause shading of the fuel in the combustion atmosphere, oscillating combustion, and furthermore, an unstable combustion reaction, and measures for reliably avoiding this have been desired. On the other hand, according to the combustion device having the above configuration,
Due to the increase in the momentum of the fuel fluid, the fuel and the combustion air are mixed properly and reliably in the combustion zone and are stably burned. Therefore, the occurrence of the fuel short path, the vibration of the air-fuel mixture, and the like can be prevented.

FIG. 18 is a sectional view showing a second embodiment of the combustion apparatus according to the present invention. FIG. 18A shows a first combustion process of the combustion device, and FIG. 18B shows a second combustion process of the combustion device.
3 shows a combustion process.

The embodiment shown in FIG. 18 includes flow switching devices 20, 40, an air supply fan 2, and an exhaust gas circulation fan 3 having substantially the same structure as the first embodiment, and the flow switching device 20, 40 is alternately switched to a first position (FIG. 10A) or a second position (FIG. 10B) at predetermined time intervals. In the combustion device of the present embodiment, the fuel mixing device 10 has a structure in which the fuel mixing devices 10A and 10B of the first embodiment are substantially integrated, and the air supply device 30 includes
It has a structure in which the air supply devices 30A and 30B of the embodiment are substantially integrated.

The fuel mixing device 10 includes a pair of heat storage bodies 14
A, 14B. In the first combustion step (FIG. 18A), the combustion gas in the combustion chamber 1 is led out of the furnace via the second heat storage body 14B and pressurized by the exhaust gas circulating fan 3, and then, if desired, the steam supply path ST Of steam is added. The combustion gas (and steam) is discharged from the first heat storage body 14A to the mixing area 15, mixed with the fuel injected by the fuel nozzle 11, and flows into the combustion chamber 1 as a fuel gas. In the second combustion step (FIG. 18B), the combustion gas in the combustion chamber 1
After being led out of the furnace through the first heat storage body 14A and pressurized by the exhaust gas circulation fan 3, steam in the steam supply path ST is added as required. Combustion gas (and steam)
Is discharged from the second heat storage body 14B to the mixing area 15, mixed with the fuel injected by the fuel nozzle 11, and flows into the combustion chamber 1 as fuel gas. The flow path switching device 20 includes first and second
The positions are alternately controlled, and the heat storage bodies 14A and 14B are
The heat storage function and the heat release function are repeated. The fuel supply control valve V1 of the fuel supply pipe F1 always supplies fuel to the fuel nozzle 11. The fuel is constantly discharged to the mixing area 15 and mixed with the high-temperature combustion gas (and steam) discharged from one of the heat storage bodies 14A and 14B to continuously generate a mixed gas (fuel gas).

Similarly, the air supply device 30 also includes a pair of regenerators 34A and 34B, and a fuel nozzle 31 disposed between the regenerators 34A and 34B. In the first combustion step (FIG. 10A), the combustion gas in the combustion chamber 1 is led out of the furnace through the second heat storage body 34B and is exhausted out of the system from the exhaust passage E2. The air is introduced into the combustion chamber 1 from the first heat storage body 34A under the air supply pressure of the air supply fan 2. In the second combustion step (FIG. 10B), the combustion chamber 1
Is discharged out of the furnace through the first heat storage body 34A and exhausted out of the system from the exhaust passage E2. On the other hand, the combustion air Thermal storage 3
4B is introduced into the combustion chamber 1. Channel switching device 40
Is switched to the first position or the second position at the same time as the flow path switching device 20, and the heat storage bodies 34A and 34B repeat the heat storage function and the heat radiation function. The fuel nozzle 31 is connected to a fuel supply pipe F3 provided with a fuel supply control valve V3. The fuel nozzle 31 supplies fuel to the fuel nozzle 31 only when the furnace temperature is relatively low (cold), such as when the combustion device is started. The fuel injection port located at the tip of the fuel nozzle 31 injects fuel and causes a combustion reaction of fuel by combustion air containing a relatively large amount of oxygen in a combustion zone. Fuel nozzle 31
Stops fuel injection at a time when the furnace temperature rises to a predetermined temperature (at a hot time).

The fuel mixing device 10 and the air supply device 30
Are fixed to the furnace body W of the combustion chamber 1 at a predetermined inclination angle, and the central axes of the apparatuses 10 and 30 are oriented so as to intersect in the combustion zone of the combustion chamber 1. The combustion air flowing into the combustion chamber 1 from the air supply device 30 is supplied to the fuel mixing device 1.
The fuel gas mixes with the mixed gas (fuel gas) flowing into the combustion chamber 1 from 0 to cause a combustion reaction.

According to such a combustion device, as in the first embodiment, not only the momentum of the fuel fluid can be increased and its controllability can be improved, but also the switching of the fuel injection timing of the fuel nozzle 11 can be controlled. Without this, the fuel can be continuously injected from the fuel nozzle 11. Note that the fuel injection of the fuel nozzle 31 may be continued during a hot period. In this case,
The fuel injection amount of the fuel nozzle 31 is limited during a hot period.

FIG. 19 is a sectional view showing a third embodiment of the combustion apparatus according to the present invention. FIG. 19A shows a first combustion step of the combustion device, and FIG. 19B shows a second combustion step of the combustion device.
3 shows a combustion process.

The embodiment shown in FIG. 19 is similar to the first and second embodiments.
A flow path switching device 20 having substantially the same structure as the embodiment,
40, an air supply fan 2 and an exhaust gas circulation fan 3, and the flow path switching devices 20, 40 are alternately switched to a first position (FIG. 9A) or a second position (FIG. 9B) at predetermined time intervals. Each fuel nozzle 11 is synchronously controlled with the flow path switching devices 20 and 40 and injects fuel alternately.

In the combustion device of this embodiment, the fuel mixing device 10A
A combined combustion device 50A integrally assembled with the air supply device 30A and a combined combustion device 50B integrally assembled with the fuel mixing device 10B and the air supply device 30B are used. The configuration of such a combustion apparatus is a further embodiment of the embodiment shown in FIG.

Fuel Mixing Apparatus 1 Constituting Composite Apparatus 50A
0A is a fuel nozzle 11, a heat storage body 14, a casing 17
And an air supply device 30A
Is a heat storage element 3 arranged outside the fuel mixing device 10A.
4, a casing 37 and a combustion air introduction unit 32 are provided. The combustion gas port 18 is connected to the exhaust gas circulation path R1, and the combustion air port 38 is connected to the supply / discharge flow path L1. Further, the fuel nozzle 11 is connected to a fuel supply pipe F1 provided with a fuel supply control valve V1.

The composite device 50B has a fuel mixing device 10B and an air supply device 3 having substantially the same configuration as the fuel mixing device 10A and the air supply device 30A of the composite device 50A.
0B, and the components of the multifunction device 50B are configured symmetrically with the multifunction device 50A. The combustion gas port 18 of the composite device 50B is connected to the exhaust gas circulation path R2, and the combustion air port 38 is connected to the supply / discharge flow path L2. The fuel nozzle 11 of the fuel mixing device 10B is connected to a fuel supply pipe F2 provided with a fuel supply control valve V2.

In the first combustion step (FIG. 19A), the combustion gas in the combustion chamber 1 is supplied to the heat storage bodies 14 and 34 of the combined device 50B.
Through the exhaust gas circulation path R2 and the supply / discharge flow path L2. The combustion gas in the circulation path R2 is drawn into the exhaust gas circulation fan 3 via the flow path switching device 20. After the combustion gas is pressurized by the circulation fan 3 and steam is injected as desired, the combustion gas is discharged from the heat storage unit 14 of the multifunction device 50B to the mixing area 15, mixed with the fuel injected by the fuel nozzle 11, and Flows into. On the other hand, the combustion gas in the supply / discharge flow path L2 is
The air is exhausted out of the system via the flow path switching device 40 and the exhaust flow path E2. Further, the combustion air flows through the heat storage body 34 of the multifunction device 50A and flows into the combustion chamber 1 from the discharge port 35 of the multifunction device 50A.

In the second combustion step (FIG. 19B), the combustion gas in the combustion chamber 1 is supplied to the heat storage bodies 14 and 34 of the combined device 50A.
Through the exhaust gas circulation path R1 and the supply / discharge flow path L1. The combustion gas in the circulation path R1 is led to the exhaust gas circulation fan 3 via the flow path switching device 20. After the combustion gas is pressurized by the circulation fan 3 and steam is injected as desired, the combustion gas is discharged from the heat storage unit 14 of the multifunction device 50B to the mixing area 15, mixed with the fuel injected by the fuel nozzle 11, and Flows into. On the other hand, the combustion gas in the supply / discharge passage L1 is
The air is exhausted out of the system via the flow path switching device 40 and the exhaust flow path E2. Further, the combustion air flows through the heat storage body 34 of the multifunction device 50B and flows into the combustion chamber 1 from the discharge port 35 of the multifunction device 50B.

The flow switching devices 20 and 40 are synchronously switched to the first position or the second position at a predetermined time interval set to 60 seconds or less, and the heat storage members 14 and 34 perform the heat storage function and the heat radiation function. Repeat. The fuel gas flow and the combustion air flow discharged from the composite devices 50A and 50B are mixed in the combustion zone in the combustion chamber 1 and undergo a combustion reaction.

According to such an embodiment, the fuel nozzle 1
The first fuel fluid is injected into a central portion of the high-temperature combustion gas flow flowing out of the regenerator 14, and mixes with the combustion gas from the central portion of the combustion gas flow. The combustion air flow flows out of the regenerator 34 so as to surround the combustion gas flow, and reacts with a mixed gas (fuel gas) of the combustion gas and the fuel from an outer peripheral region of the combustion gas flow. Thus, the combustion gas (and water vapor) flow forms an annular interference band that reliably separates the fuel injection flow from the combustion air flow, so that the fuel fluid does not directly react with the combustion air and (And water vapor) and reacts with combustion air.

FIG. 20 is a sectional view showing a fourth embodiment of the combustion apparatus according to the present invention. FIG. 20A shows a first combustion step of the combustion apparatus, and FIG. 20B shows a second combustion step of the combustion apparatus.
3 shows a combustion process.

The embodiment shown in FIG. 20 has a configuration in which the embodiment shown in FIGS. 1C and 8 is further embodied.
The fuel nozzle 11 of the combustion device is disposed in the combustion gas introduction section 12, and the combustion gas introduction section 12 functions as a mixing zone 15. That is, in the first combustion step (FIG. 20A), the fuel injected by the fuel nozzle 11 of the fuel mixing device 10A is mixed with the low-temperature combustion gas (and steam) in the mixing zone 15 in the combustion gas introduction unit 12 and mixed. The gas flows through the heat storage body 14 of the fuel mixing device 10A, and is heated by the high-temperature heat storage body 14. On the other hand, in the second combustion step (FIG. 20B), the fuel injected by the fuel nozzle 11 of the fuel mixing device 10B is mixed with the low-temperature combustion gas (and steam) in the mixing zone 15 in the combustion gas introduction section 12 and mixed. The gas flows through the regenerator 14 of the fuel mixing device 10B, and the high-temperature regenerator 1
4 heated. In this example, the fuel mixing device 10
The fuel gas injection port 16 and the combustion air discharge port 35 of A and 10B do not have a reduced diameter portion.
Has a relatively large channel area. The high-temperature mixed gas and the combustion air injected from the injection port 16 and the discharge port 35 are mixed in the combustion zone in the combustion chamber 1 and undergo a combustion reaction. Other configurations and operation modes are substantially the same as those of the first embodiment shown in FIG.
Omitted.

According to this embodiment, the mixed gas receives heat while flowing through the regenerator 14 of the fuel mixing devices 10A and 10B, and is heated to a high temperature. Mixing with the working air, a wide combustion flame having a low oxygen concentration and high temperature combustion atmosphere is generated in the combustion chamber 1.

FIG. 21 is a sectional view showing a fifth embodiment of the combustion apparatus according to the present invention. FIG. 13A shows a first combustion process of the combustion device, and FIG. 13B shows a second combustion process of the combustion device.
3 shows a combustion process.

FIG. 21 shows a more specific configuration of the embodiment shown in FIGS.
A, 30B of the combustion air introduction section 32, via the combustion gas introduction port 60, the branch path R of the exhaust gas circulation path R1, R2
5. Communicate with R6. The combustion gas (and steam) introduced into the introduction section 32 through the port 60 is mixed with the combustion air, and the mixed fluid of the combustion air and the combustion gas is mixed with the heat storage material 3.
After being preheated to the ultrahigh temperature range by 4, it flows into the furnace from the discharge port 35. According to such a configuration, the combustion air, like the fuel, is also mixed with the combustion gas (and steam) before being introduced into the furnace, and the combustion reactivity of the combustion air is reduced.
A mixture of combustion gas and combustion air is introduced into the furnace,
Similarly, the fuel gas stream diluted with the combustion gas and the steam impinges and mixes in the in-furnace combustion zone to cause a slow combustion reaction with a low oxygen concentration in the combustion zone. Note that the basic configuration and operation of the combustion device shown in FIG. 21 are substantially the same as those of the embodiment shown in FIG. 17, and therefore, further detailed description will be omitted.

FIG. 22 is a sectional view of a combustion apparatus according to the sixth embodiment of the present invention. FIG. 22 (A) and FIG. 22 (B)
Indicates a first combustion step and a second combustion step of the combustion device, respectively.

FIG. 22 shows a further embodiment of the embodiment shown in FIGS. 3 and 11, wherein the exhaust passage EG is connected to the discharge port of the circulation fan 3 and the steam supply passage of the steam generator 8 is provided. ST1 is connected to the bypass port 24 of the flow path switching device 20. The steam generator 8 is also supplied to the outside air suction passage OA via the steam supply passage ST2. The steam of the steam generator 8 is supplied to a steam supply passage ST1: ST2.
Is supplied to the flow path switching device 20 and the outside air suction passage OA through the heat storage members 14 and 34, and is heated to a high temperature of 800 ° C. or more. The high-temperature steam discharged to the mixing zone 15 is
The fuel is mixed with the hydrocarbon-based fuel of the fuel nozzle 11, and the fuel is reformed into a high-quality fuel containing a relatively large amount of hydrocarbon radicals, hydrogen, carbon, carbon monoxide, or the like by a hydrocarbon steam reforming reaction. . According to such a configuration, a relatively heavy, low-quality, or low-grade hydrocarbon-based fuel such as heavy oil can be reformed into a light, high-quality, or high-grade fuel. The fuel gas containing the reformed fuel is further mixed with the high-temperature air and high-temperature steam flowing out of the combustion air discharge port 35 into the furnace, and a wide range of combustion flames having a low oxygen concentration and a high-temperature combustion atmosphere is formed in the combustion chamber 1. Generate within.

FIG. 23 is a schematic plan view showing an embodiment of a heating device provided with a combustion device according to the present invention. FIG.
FIG. 23A shows a first combustion step of the combustion apparatus, and FIG.
(B) shows a second combustion step of the combustion device.

The heating device is configured as a tubular heating furnace such as a steam reforming furnace, and a number of heated tubes 5 through which a fluid to be heated can flow are arranged relatively densely in the combustion chamber 1 of the heating device. You. The heated pipe 5 constitutes a heat receiving segment of the heating device. The combustion device includes fuel mixing devices 10A and 10B, air supply devices 30A and 30B, flow path switching devices 20 and 40, an air supply fan 2, and an exhaust gas circulation fan 3 having substantially the same configuration as the combustion device shown in FIG. And a flow path switching device 2
0 and 40 are the first position (FIG. 23A) and the second position (FIG. 2A).
3B).

The heating device can also be used when the furnace temperature is relatively low,
For example, an auxiliary combustion device (not shown) that performs a combustion operation when starting the heating device or the like is provided, and the operation of the auxiliary combustion device stops at a hot time when the furnace temperature increases. Fuel mixing device 10A, 1
0B is activated when the furnace temperature rises due to the combustion operation of the auxiliary combustion device. In the first combustion step (FIG. 14A), the combustion gas in the combustion chamber 1 is led out of the furnace via the heat storage units 14 and 34 of the fuel mixing device 10B and the air supply device 30B. A predetermined flow rate of the combustion gas is sent to the exhaust passage E2, and the predetermined flow rate of the combustion gas is added with water vapor.
The fuel mixture 14 of the fuel mixing device 10A flows through
After flowing into the combustion chamber 1 and mixing with the fuel, the fuel gas is introduced into the combustion chamber 1 as a fuel gas. The air supply device 30A includes a heat storage body 34.
The combustion air in the ultrahigh temperature range preheated by the above is introduced into the combustion chamber 1. In the second combustion step (FIG. 14B), the combustion gas in the combustion chamber 1 is led out of the furnace via the heat storage units 14 and 34 of the fuel mixing device 10A and the air supply device 30A. The combustion gas having a predetermined flow rate is sent to the exhaust passage E2,
After the steam is added to the combustion gas at a predetermined flow rate, the combustion gas flows through the regenerator 14 of the fuel mixing device 10B, flows into the mixing area 15, and is mixed with the fuel, and is introduced into the combustion chamber 1 as a fuel gas. You. The air supply device 30 </ b> B introduces the combustion air in the ultrahigh temperature range preheated by the heat storage body 34 into the combustion chamber 1.

The fuel mixing device 10A and the air supply device 30
A is oriented toward the central region in the furnace where the tubes 5 to be heated are arranged, and the high-speed fuel gas flow having a low oxygen concentration and a high temperature causes a high-temperature and high-speed flow in the central region in the furnace where the tubes 5 are densely packed. Cross-mixing collision with the combustion air flow causes a combustion reaction. Such a heating method is intended to uniformly heat the entire circumference of the tube by a radiant heat transfer effect and a convection heat transfer effect of the flame itself, which is a conventional heating method in a tubular heating furnace, In other words, in order to heat the entire circumference of the pipe evenly, the conventional heating method is required to heat both sides of the pipe depending on the heat transfer of gas radiation from the flame and the heat transfer of solid radiation from the furnace wall. Essentially different.

In this example, the large and lean fuel gas stream injected by the fuel mixing device 10 cross-collides with the high-temperature combustion air in the central region of the furnace, and the slow combustion flame of the low-oxygen concentration and high-temperature combustion atmosphere. Is generated in the central region in the furnace.
Fuel gas containing a large amount of combustion gas forms a combustion atmosphere with a low oxygen concentration and suppresses the combustion reaction of the fuel component.On the other hand, high-temperature combustion air promotes self-ignition of the fuel component and a low oxygen concentration. A combustion reaction of a fuel component in a combustion atmosphere is enabled. As a result, the fuel gas does not burn out immediately after being mixed with the combustion air, and the fuel component in the fuel gas slowly diffuses and burns in a combustion atmosphere having a high temperature and a low oxygen concentration. Under such a combustion reaction, the flame is stable, and local heat generation of the flame is unlikely to occur.

According to such a heating method, unlike the conventional heating method in which the flame is separated from the heated pipe 5 in order to prevent local heating of the heated pipe 5, local heating of the heated pipe 5 is caused. Without generating a flame near or near the heated pipe, the entire circumference of the heated pipe 5 can be substantially uniformly heated.

In addition, according to the configuration of the heating device, the high-speed fuel gas flow and the combustion air flow cross-collide in the central region of the furnace where the pipes 5 to be heated are densely packed, attracting the furnace gas, and causing the furnace gas to flow. The convection of the internal gas is activated, and a continuous and irregular flame behavior is always generated near the heated pipe 5. As a result, the heated pipes 5 arranged relatively densely
Is affected by the effects of flame flow and activation of gas convection in the furnace, along with the increase in flame volume and the uniformization of flame temperature in a low oxygen concentration and high temperature combustion atmosphere. To receive heat. Further, as a result of switching between the first combustion step and the second combustion step being repeatedly performed in a short time, the position and characteristics of the flame fluctuate in a short time even by the switching control of the combustion step. That is, the temperature field and the heating action of the entire combustion zone are equalized by the switching operation of the combustion process.

By equalizing the radiant heat transfer effect and the convection heat transfer effect by controlling the flame itself, it is possible to increase the pipe density of the pipe 5 to be heated. In addition to making it possible to design a heating furnace having a novel structure, it is extremely advantageous in practice.

FIGS. 24 and 25 are schematic plan views of a heating device showing a modification of the heating device shown in FIG. The operation mode of the heating device when it is cold is shown in FIG. 24, and the operation mode of the heating device when it is hot is shown in FIG. Also, in each of the figures, (A) shows a first combustion step of the combustion device, and (B) shows a second combustion step of the combustion device.

The heating device is configured as a tubular heating furnace such as a steam reforming furnace, and a number of heated tubes 5 through which a fluid to be heated can flow are arranged relatively densely in the combustion chamber 1 of the heating device. You. The combustion device shown in FIGS. 24 and 25 has a configuration similar to that of the combustion device shown in FIG. However, the air heating devices 30A and 30B include the fuel nozzles 31 that inject fuel when cold, and perform combustion operation when cold. In the cold operation mode shown in FIG. 24, the air supply device 30A,
30B includes a first combustion step (FIG. 24A) of injecting fuel and combustion air from the air heating device 10A and discharging combustion exhaust gas from the air heating device 30B, and an air heating device 30B.
Fuel and combustion air from the air and air heating device 30
Second combustion step of exhausting combustion exhaust gas from A (FIG. 24B)
Are alternately executed at predetermined time intervals. Fuel mixing device 1
0A and 10B repeat the derivation and introduction of the combustion gas in conjunction with the air heating devices 30A and 30B.
1 does not discharge fuel, and therefore the fuel mixing device 10A,
10B only functions as a general exhaust gas recirculation device.

On the other hand, in the hot operating mode shown in FIG. 25, the fuel nozzle 31 stops fuel injection,
The air heating devices 10A and 10B function only as combustion air introduction / extraction means for introducing high-temperature air into the furnace and exhausting part of the combustion gas in the furnace to the outside of the furnace.
0A and 10B are a first combustion step (FIG. 25A) for injecting a mixture (fuel gas) of fuel, combustion gas, and water vapor from the fuel mixing device 10A and deriving the combustion gas from the fuel mixing device 10B. A second combustion step of injecting a mixture (fuel gas) of fuel, combustion gas, and water vapor from the fuel mixing device 10B and deriving the combustion gas from the fuel mixing device 10A (FIG. 25)
And B) are alternately executed at predetermined time intervals. That is, the high-temperature combustion gas generated in the furnace with the rise in the furnace temperature is led out of the furnace, mixed with steam and fuel, re-introduced into the furnace as a high-temperature fuel gas, and It mixes with the working air and burns in the combustion chamber 1.

In each combustion step, the air heating device 10 and the fuel mixing device 10 introduce combustion air and fuel gas into the furnace in orthogonal directions, and the combustion air and fuel gas are mainly introduced into the furnace by mutual attraction. The mixture is mixed in the inner central region, and a flame of a combustion atmosphere having a high temperature and a low oxygen concentration is generated near the heated pipe 5 as described above.

FIG. 26 is a schematic vertical sectional view of a heating apparatus showing an embodiment in which the configuration of the combustion apparatus according to the present invention is disposed in a continuous firing type heating furnace. FIG. 26A shows a first combustion step of the combustion device, and FIG. 26B shows a second combustion step of the combustion device.

The heating apparatus shown in FIG. 26 constitutes a reducing combustion zone such as a steel heating furnace or a ceramic firing furnace for continuously firing a work such as a steel material or a ceramic material in a reducing combustion atmosphere. Fuel mixing devices 10A and 10B and air supply device 3
Reference numerals 0A and 30B are disposed in the furnace body W of the heating furnace, and form a flame acting on the workpiece 6 continuously conveyed on the conveying device 7 in the furnace. As in the above-described embodiment, the first and second combustion processes are alternately performed at predetermined time intervals, and the
The fuel gas and the high-temperature combustion air flowing out of A, 10B and the air supply devices 30A, 30B form a flame near the work 6.

The fuel gas discharged from the fuel mixing devices 10A and 10B into the furnace forms a lower layer flow flowing along the surface of the work 6, and the high-temperature combustion air discharged from the air supply devices 30A and 30B is An upper stream is formed that flows above the stream. The low oxygen concentration fuel gas flow forms a reducing combustion atmosphere near the upper surface of the work 6, and the flame generated by the fuel gas and the high temperature combustion air acts on the surface of the work 6 as a reducing flame.

According to such a configuration, not only can a flat flame be formed on the work 6 located in the central region in the furnace, but also the fuel Is formed around the object to be heated, whereby the object to be heated can be heated while suppressing the oxidizing action. For example, according to the combustion apparatus of this example, in a metal heating furnace or a ceramic firing furnace that performs annealing or reduction flame firing of a material in a reducing flame combustion atmosphere, a low oxygen concentration planar fuel gas flowing in the vicinity of the material. A flow, thereby forming a reducing flame firing atmosphere near the material.

Although the preferred embodiments of the present invention have been described in detail, the present invention is not limited to the above-described embodiments, and various modifications may be made within the scope of the present invention described in the appended claims. It is needless to say that the modification or the modification is also included in the scope of the present invention.

For example, in each of the above embodiments, a switching valve having a four-way valve structure is used as a flow path switching device, but a flow switching device having a configuration in which a plurality of on-off valves are combined may be used. .

In the configuration of the heating device, the fuel mixing device and the air heating device may be arranged at positions facing each other, and the fuel gas flow and the combustion air flow may be introduced into the furnace as counterflows.

Further, the structure of the fuel mixing device and the air heating device is not limited to the structure of the above-described embodiment. For example, a heat storage type heat exchanger of a type incorporating a large number of heat storage bodies may be used as a fuel mixing device and an air heater. It may be used as an air heating device.
Further, a process steam supply system in a factory or a manufacturing plant may be used as the steam supply means.

[0115]

As described above, according to the above configuration of the present invention, the controllability of the fuel flow flowing into the combustion zone is improved, and the combustion apparatus and the combustion system capable of controlling the flame characteristics by controlling the fuel flow are provided. A method can be provided.

According to the combustion apparatus and the combustion method of the present invention, the degree of freedom in controlling the mixing of fuel, combustion air and combustion gas can be improved.

Further, according to the heating apparatus and the heating method of the present invention, it is possible to control the characteristics of the flame acting on the object to be heated.

[Brief description of the drawings]

FIG. 1 is a block flow diagram of a combustion device showing a preferred embodiment of the present invention.

FIG. 2 is a block flow diagram of a combustion apparatus showing another preferred embodiment of the present invention.

FIG. 3 is a block flow diagram of a combustion apparatus showing another preferred embodiment of the present invention.

FIG. 4 is a block flow diagram of a combustion apparatus showing still another preferred embodiment of the present invention.

FIG. 5 is a schematic sectional view of a combustion apparatus to which the basic configuration shown in FIGS. 1A and 1B is applied.

FIG. 6 is a schematic longitudinal sectional view showing a combustion device having another structure to which the basic configuration shown in FIG. 1B is applied.

FIG. 7 is a block flow diagram schematically showing the operation of the fuel mixing device shown in FIG. 6;

FIG. 8 is a schematic vertical sectional view of a combustion apparatus to which the basic configuration shown in FIG. 1 (C) is applied.

FIG. 9 is a schematic vertical sectional view of a combustion apparatus to which the basic configuration shown in FIGS. 2A and 2B is applied.

FIG. 10 is a schematic longitudinal sectional view of a combustion apparatus to which the basic configuration shown in FIG. 2 (B) is applied.

FIG. 11 is a schematic longitudinal sectional view of a combustion apparatus to which the basic configuration shown in FIG. 3A is applied.

FIG. 12 is a schematic vertical sectional view of a combustion apparatus to which the basic configuration shown in FIG. 3B is applied.

FIG. 13 is a schematic longitudinal sectional view of a combustion apparatus to which the basic configuration shown in FIG. 3 (C) is applied.

FIG. 14 is a schematic vertical sectional view of a combustion apparatus to which the basic configuration shown in FIG. 4 is applied.

FIG. 15 is a cross-sectional view showing a configuration of the steam heating device shown in FIG.

FIG. 16 is a cross-sectional view showing a configuration of the steam heating device shown in FIG.

FIG. 17 is a sectional view showing a first embodiment of the combustion apparatus according to the present invention.

FIG. 18 is a sectional view showing a second embodiment of the combustion apparatus according to the present invention.

FIG. 19 is a sectional view showing a third embodiment of the combustion apparatus according to the present invention.

FIG. 20 is a sectional view showing a fourth embodiment of the combustion apparatus according to the present invention.

FIG. 21 is a sectional view showing a fifth embodiment of the combustion apparatus according to the present invention.

FIG. 22 is a sectional view showing a sixth embodiment of the combustion apparatus according to the present invention.

FIG. 23 is a schematic plan view showing an embodiment of a heating device provided with a combustion device according to the present invention.

24 is a schematic plan view showing a modification of the heating device shown in FIG. 23, and shows an operation mode of the heating device in a cold state.

25 is a schematic plan view showing an operation mode of the heating device shown in FIG. 24 in a hot state.

FIG. 26 is a schematic longitudinal sectional view of a continuous firing type heating furnace to which the configuration of the combustion apparatus according to the present invention is applied.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Combustion chamber 2 Forced air supply fan 3 Exhaust gas circulation fan 8 Steam generator 10, 10A, 10B Fuel mixing device 11 Fuel nozzle 12 Combustion gas introduction part 14 Heat storage unit 15 Mixing area 16 Fuel gas injection port 20, 40 Flow path switching device 30, 30A, 30B Combustion air supply device 35 Combustion air discharge port 80 Steam heating device

Claims (38)

[Claims] 1. A fuel supply means for supplying combustion fuel,
A combustion apparatus comprising: combustion air supply means for supplying combustion air to a combustion zone; a mixing apparatus for mixing combustion gas and / or steam from a steam supply means led out of the furnace with fuel from the fuel supply means. A fuel gas introduction device for introducing a mixed fluid of the combustion gas and / or steam and the fuel as a fuel gas into the combustion zone, and mixing the fuel gas with the combustion air. And combustion equipment. 2. The mixing device has a mixing zone for mixing the combustion gas and / or steam with the fuel, and the combustion gas and / or steam and the fuel are introduced into the mixing zone. 2. The combustion apparatus according to claim 1, wherein a fuel gas is generated that can be introduced into the combustion zone. 3. A combustion gas cooling device for cooling the combustion gas, and a heating device for heating the combustion gas and / or the steam, wherein the mixing zone is provided between the heating device and the combustion zone. The combustion device according to claim 2, wherein the combustion device is disposed in a combustion chamber. 4. A combustion gas cooling device for cooling the combustion gas, and a heating device for heating the combustion gas and / or the steam, wherein the mixing zone is provided between the cooling device and the heating device. The combustion device according to claim 2, wherein the combustion device is disposed in a combustion chamber. 5. A combustion gas derived from the combustion zone through a combustion gas deriving device for guiding the combustion gas generated in the combustion zone out of the furnace from the combustion zone, and mixing the combustion gas with the steam added thereto. The combustion device according to any one of claims 1 to 4, further comprising a forced circulation device that feeds the pressure to the device. 6. The cooling device and the heating device each include a heat storage body that is in heat transfer contact with the high-temperature combustion gas to store heat, and is in heat transfer contact with the cooled combustion gas and / or the steam to release heat. The combustion device according to claim 3 or 4, wherein: 7. A fuel cell system comprising: a plurality of the mixing devices; and a flow switching device for switching a flow path of the combustion gas and / or steam to the mixing device. The fuel supply device according to any one of claims 1 to 6, further comprising fuel control means for switching a fuel supply path in synchronization. 8. The steam of said steam supply means is heated to 700 ° C.
The combustion device according to claim 1 or 2, further comprising a steam heating unit that heats the mixture to the above temperature and supplies the mixture to the mixing device. 9. The combustion gas and / or steam is partially supplied to the combustion air supply means, and the combustion gas and / or steam is supplied to the combustion air supply means.
The combustion apparatus according to any one of claims 1 to 8, further comprising mixing means for mixing steam with the combustion air. 10. The combustion air supply means includes a combustion gas exhaust means for exhausting combustion gas in the combustion zone, and heat transfer contact with the combustion gas to store heat and heat transfer contact with the combustion air. The combustion device according to any one of claims 1 to 9, further comprising a heat storage unit that dissipates heat, wherein the combustion air is preheated to a high temperature of 700 ° C or higher by the heat storage unit. 11. A combustion method for introducing combustion air into a combustion zone and causing a combustion reaction by mixing the combustion air and fuel in the combustion zone, wherein the combustion gas and / or steam supply means led out of the furnace is provided. Supplying steam to the mixing zone, supplying the combustion fuel to the mixing zone to generate a mixed fluid of the combustion gas and / or steam and the fuel, and using the mixed fluid as a fuel gas to the combustion zone; Introducing the fuel gas with the combustion air to cause a combustion reaction of the fuel gas in the combustion zone. 12. A high-temperature combustion gas discharged outside the furnace and / or
The combustion method according to claim 11, wherein high-temperature steam heated to 700 ° C or more by steam heating means is introduced into the mixing zone and mixed with the fuel. 13. The combustion apparatus according to claim 11, wherein the fuel is mixed with the combustion gas and / or steam after heating the combustion gas and / or the steam to a high temperature of 700 ° C. or higher. . 14. The fuel supply method according to claim 11, wherein, after mixing the fuel with the combustion gas and / or steam, the mixed fluid is heated to a high temperature of 700 ° C. or higher. 15. The method according to claim 11, wherein a part of the combustion gas and / or steam is mixed with the combustion air to reduce the oxygen concentration of the combustion air. The combustion method as described. 16. The combustion method according to claim 11, wherein the steam is added to the combustion gas to adjust the steam content of the combustion gas. 17. The combustion gas, the steam or the mixed fluid receives sensible heat radiated by the combustion gas when cooling the combustion gas, and is reheated or heated. The combustion method according to any one of the above items. 18. The fuel gas introduced into the combustion zone,
2. The method according to claim 1, wherein the temperature is not less than 700.degree.
18. The combustion method according to any one of 1 to 17. 19. The fuel gas introduced into the combustion zone,
19. Mixing with the combustion air preheated to a temperature of 700 [deg.] C. or more.
The combustion method according to the paragraph. 20. The combustion method according to claim 11, wherein the combustion gas has an oxygen concentration of 10% or less. 21. The fuel cell according to claim 11, wherein a mixing ratio of the combustion gas and / or steam to the fuel is set in a range of 1: 1 to 20: 1.
The combustion method according to the paragraph. 22. The fuel cell according to claim 11, wherein a mixing ratio of the fuel gas and / or steam to the combustion air is set in a range of 1:10 to 20:10. Item 2. The combustion method according to Item 1. 23. The combustion according to claim 11, wherein a flow velocity of the fuel gas flowing into the combustion zone is set in a range of 10 m / s to 150 m / s. Method. 24. A heating device comprising the combustion device according to claim 1. Description: 25. A heating device for heating an object to be heated by a combustion exothermic reaction of combustion air and fuel, wherein a combustion gas and / or steam of a steam supply means led out of the furnace and fuel of the fuel supply means are used. A mixing device for mixing, and a fuel gas introducing device for introducing a mixed fluid of the combustion gas and / or steam and the fuel as a fuel gas into the combustion zone, and mixing the fuel gas with the combustion air. A heating device, characterized in that: 26. The heating device according to claim 25, further comprising an auxiliary combustion device that introduces the combustion air and the fuel into the combustion zone when it is cold. 27. The heating device according to claim 25, wherein the fuel gas introduction device introduces a fuel gas flow into the combustion zone in parallel with the combustion air flow. 28. The heating device according to claim 25, wherein the fuel gas introduction device introduces a fuel gas flow into the combustion zone in a direction crossing the combustion air flow. 29. The heating device according to claim 25, wherein the fuel gas introduction device introduces a fuel gas flow into the combustion area in a direction opposite to the combustion air flow. 30. A tube heating furnace, a metal heating furnace, a ceramic sintering furnace, a metal melting furnace, a gasification melting furnace, a boiler or a radiant tube, comprising: Item 2. The heating device according to item 1. 31. A heating method characterized by heating an object to be heated by a flame generated by the combustion method according to claim 11. Description: 32. A heating method for heating an object to be heated by a combustion exothermic reaction of combustion air and fuel, wherein a combustion gas and / or steam from a steam supply means led out of the furnace is supplied to a mixing zone. Supplying a fuel to the mixing zone to generate a mixed fluid of the combustion gas and / or steam and the fuel; introducing the mixed fluid as a fuel gas into the combustion zone; And heating the fuel gas to cause a combustion reaction of the fuel gas in the combustion zone. 33. The heating method according to claim 32, wherein the object to be heated includes a plurality of heat receiving segments, and a flame is generated between the segments. 34. The fuel cell system according to claim 32, wherein the fuel gas is introduced into the combustion zone from a substantially constant position, and the combustion air is introduced into the combustion zone from a substantially constant position. Or the heating method according to 33. 35. The apparatus according to claim 32, wherein a position at which the fuel gas is introduced into the combustion area and a position at which the combustion air is introduced into the combustion area are changed at predetermined time intervals.
Or the heating method according to 33. 36. The method according to claim 32, wherein the fuel is mixed with the combustion air during a cold period, and the temperature of a combustion zone is raised by a combustion exothermic reaction between the fuel and the combustion air. Or the heating method according to claim 1. 37. The flame due to the fuel gas and the combustion air is in direct contact with the object to be heated.
37. The heating method according to any one of items 36 to 36. 38. The method according to claim 38, wherein a gas flow of the fuel gas flowing along the surface of the object to be heated is formed, and a reducing combustion atmosphere having a low oxygen concentration is formed near the object to be heated. The heating method according to any one of Items 32 to 37.