JP2004077004A - boiler - Google Patents

Abstract

An object of the present invention is to provide a boiler capable of preventing an increase in equipment costs and reducing maintenance costs even when fuels having different fuel types and different calorific values are supplied.
A tubular combustion chamber having one end opened into a furnace, an oxygen-containing gas injection nozzle and a fuel provided in such a manner that a blowing direction of the combustion chamber is substantially tangential to an inner wall surface of the combustion chamber. A tubular flame burner 2 having a blowing nozzle or a nozzle for premixing an oxygen-containing gas and a fuel, and a fuel for mixing and supplying two or more kinds of fuels having different calorific values to the tubular flame burner 2 And a supply device 7.
Further, a combustion control device 8 for controlling the mixing ratio of each fuel in the fuel supply device 7 may be provided.
[Selection diagram] Fig. 1

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a boiler provided with a tubular flame burner.
[0002]
[Prior art]
At steelworks, in order to make effective use of by-product gases generated from coke ovens, blast furnaces, converters, etc., these gases are burned in a boiler and the heat is used to generate steam. 2. Description of the Related Art In-house power generation is performed by sending power to a power generation turbine in a facility.
[0003]
FIG. 3 is a schematic configuration diagram when a combustion burner is attached to a boiler furnace 1 of a power generation boiler according to the related art. As shown in FIG. 3, the boiler furnace 1 has a burner for C gas (coke oven gas), a burner for LD gas (converter gas), and a burner for B gas (blast furnace gas) according to the kind of fuel to be supplied. , A high calorie gas burner, and the like.
[0004]
[Problems to be solved by the invention]
The reason for providing a burner according to the type of fuel supplied is that the conventional burner has a regulation on the kind of fuel that can be burned and the calorific value thereof, so that different types of fuel and fuels with different calorific values can be stably used by one burner. This is because it is difficult to burn.
[0005]
As a result, as shown in FIG. 3, a plurality of burners must be installed in accordance with the kind of fuel to be supplied and the like, so that the equipment cost is increased and the maintenance cost such as maintenance cost is also increased.
[0006]
The present invention has been made in order to solve the above-described problems. Even when a fuel having a different fuel type and a different calorific value is supplied, it is possible to prevent an increase in equipment cost and further reduce a maintenance cost. The aim is to provide a possible boiler.
[0007]
[Means for Solving the Problems]
The features of the present invention for solving such a problem are as follows.
[1] A tubular combustion chamber one end of which is opened into a furnace, an oxygen-containing gas injection nozzle and a fuel injection nozzle provided such that a blowing direction of the combustion chamber is substantially tangential to an inner wall surface of the combustion chamber. A tubular flame burner provided with a nozzle or a nozzle for injecting a pre-mixture of oxygen-containing gas and fuel, and a fuel supply device for mixing and supplying two or more kinds of fuels having different calorific values to the tubular flame burner A boiler comprising:
[2] The boiler according to [1], further including a combustion control device for controlling a mixing ratio of each fuel in the fuel supply device.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 is a cross-sectional view of a schematic configuration showing an embodiment of a boiler according to the present invention. The boiler furnace 1 of the power generation boiler has a tubular flame burner 2 and the tubular flame burner 2 has two or more different heating values. And a fuel supply device 7 capable of mixing and supplying the fuel. Here, the number and location of the tubular flame burners 2 are not particularly limited, and can be appropriately changed depending on the furnace structure, operating conditions, and the like.
[0009]
The details of the tubular flame burner 2 will be described with reference to FIG. The basic configuration of the tubular flame burner is the same as that shown in JP-A-11-281015.
[0010]
2A is a sectional side view of the tubular flame burner 2, and FIG. 2B is a sectional view taken along the line AA in FIG. 2A. Reference numeral 3 denotes a tubular combustion chamber, one end of which is opened to serve as a discharge port for combustion gas. Around the combustion chamber 3, a nozzle 4a for blowing the oxygen-containing gas and a nozzle 4b for blowing the fuel are separately provided. The nozzles 4a and 4b are provided such that the blowing direction of the oxygen-containing gas and the fuel into the combustion chamber 3 is substantially tangential to the inner wall surface of the combustion chamber. A swirling flow is formed in the chamber 3. Then, by forming the tip portions of the nozzles 4a and 4b to be flat and narrowing the opening area, a high-speed swirling flow can be formed in the combustion chamber. 5 indicates a spark plug, and 6 indicates a flame.
[0011]
In FIG. 2, the nozzle 4a for blowing the oxygen-containing gas and the nozzle 4b for blowing the fuel are separately provided, but the oxygen-containing gas and the fuel may be mixed before blowing. Further, the number and the installation position of each nozzle are not particularly limited, and can be appropriately selected depending on the device configuration and the like. Here, the oxygen-containing gas refers to a gas containing oxygen for combustion such as air, oxygen, oxygen-enriched air, and a mixed gas of oxygen and exhaust gas.
[0012]
In the burner configured as described above, when the air-fuel mixture blown from the nozzles 4a and 4b and forming a swirling flow is ignited, the gas in the combustion chamber 3 is stratified by the density difference, and the density of the gas is increased on both sides of the flame. Different gas layers are formed. That is, high-temperature combustion gas exists on the axis side where the swirling speed is low, and unburned gas exists on the inner wall side where the swirling speed is high.
[0013]
In the vicinity of the inner wall, the swirling speed is higher than the flame propagation speed, and the flame does not propagate to the vicinity of the inner wall. Therefore, the flame is generated in the combustion chamber 3 in a tubular shape. Since unburned gas exists near the inner wall of the combustion chamber, the wall surface of the combustion chamber 3 is not directly heated and is not exposed to a high temperature. The gas in the combustion chamber 3 flows to the downstream side while swirling, and during that time, the gas on the inner wall side sequentially burns, moves to the axial center side, and is discharged from the open end.
[0014]
With the above configuration, in the combustion chamber 3, high-temperature combustion exhaust gas exists on the axis side with a low swirling speed, and unburned gas exists on the inner wall side of the combustion chamber with a high swirling speed. In between, a tubular flame will be present. Therefore, the unburned gas is not diluted with the combustion exhaust gas, and stable combustion can be performed.
[0015]
By obtaining such stable combustion, the utilization efficiency of oxygen can be increased, and in connection with this, there is no need to supply extra air, so that high-temperature combustion gas can be generated. In addition, since a gas having an extremely low calorific value with a very low fuel gas component can be stably burned, a stable combustion range can be widened and a selection range of the combustion exhaust gas temperature can be widened.
[0016]
Further, in the present embodiment, a fuel supply device 7 capable of mixing and supplying two or more kinds of fuels having different calorific values at a predetermined ratio to the nozzle 4b for blowing the fuel is connected.
[0017]
Here, as the fuel having two or more different calorific values, for example, C gas (coke oven gas), B gas (blast furnace gas), by-product in LNG, propane gas, kerosene, heavy oil and steel manufacturing process, LD gas (converter gas) or the like can be used. By connecting these fuels to the fuel supply device 7 and mixing these fuels in the fuel supply device 7 at a predetermined ratio, it is possible to supply a fuel having a predetermined calorific value to the tubular flame burner.
[0018]
Further, as shown in FIG. 2, a combustion control device 8 may be provided, and the mixing ratio of each fuel supplied to the fuel supply device 7 may be adjusted by a control signal from the combustion control device 8. By adjusting the mixing ratio of each fuel and adjusting the amount of heat generated, it is possible to arbitrarily adjust the amount of steam generated by the boiler. For example, it is possible to generate power in accordance with the demand for electric power.
[0019]
As described above, the tubular flame burner can perform stable combustion with respect to various fuels. Therefore, it is not necessary to provide a plurality of burners according to the type of fuel to be supplied as in the prior art, and one tubular flame burner can cope with various types of fuels having different calorific values. . As a result, the number of burners installed in the boiler furnace can be significantly reduced, an increase in equipment costs can be prevented, and maintenance costs such as maintenance costs can be reduced.
[0020]
Further, the tubular flame burner can stably burn a wide variety of fuels, and thus contributes to lowering NOx and lowering SPM of the exhaust gas.
[0021]
【The invention's effect】
As described above, according to the present invention, there is provided a boiler capable of preventing an increase in equipment costs and reducing maintenance costs even when fuels having different fuel types and different calorific values are supplied. Is done.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a schematic configuration showing an embodiment of a continuous heating furnace according to the present invention.
FIG. 2 (a) is a side sectional view of a tubular flame burner.
(B) It is sectional drawing in the AA arrow in (a).
FIG. 3 is a schematic configuration diagram when a combustion burner is attached to a boiler furnace of a power generation boiler according to the related art.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Heating furnace 2 Tubular flame burner 3 Combustion chamber 4 Nozzle 5 Spark plug 6 Flame 7 Fuel supply device 8 Combustion control device

Claims (2)

A tubular combustion chamber having one end opened into the furnace, and an oxygen-containing gas injection nozzle and a fuel injection nozzle provided such that the injection direction is substantially tangential to the inner wall surface of the combustion chamber with respect to the combustion chamber, or A tubular flame burner with a nozzle for injecting a premix of oxygen-containing gas and fuel,
A boiler comprising: a fuel supply device for mixing and supplying two or more types of fuels having different calorific values to the tubular flame burner. The boiler according to claim 1, further comprising a combustion control device that controls a mixing ratio of each fuel in the fuel supply device.

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