JP2003193068A - Burner for gasification furnace - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a burner for a gasification furnace, capable of finely spraying a fuel slurry without causing plugging of a passage even in a small- scale gasification furnace such as a test facility, enabling a stable operation by promoting the mixing with an oxidant, and improving gasification efficiency. <P>SOLUTION: An oxidant-jetting orifice 22 for jetting the oxidant at a high speed to the fuel slurry jetted from the tip of a slurry tip nozzle part 17a is arranged at the outer periphery part of the tip of the slurry tip nozzle part 17a of a slurry burner tip 17. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gasifier burner.

[0002]

2. Description of the Related Art Generally, as shown in FIG. 3, a coal gasification facility comprises a gasification furnace 1 for partially oxidizing coal as a fuel with an oxidant such as oxygen, and a gasification in the gasification furnace 1. The gas cooling device 2 for cooling the generated gas that has been turned into a gas and the gas refining device 3 for refining the generated gas cooled by the gas cooling device 2 are provided.

In the case of coal gasification equipment, as a method of supplying fuel to the gasification furnace 1, there are a wet method (supply of fuel slurry in which coal and water are mixed) and a dry method (air flow transfer of pulverized coal by carrier gas). However, FIG. 3 shows a wet type.

On the other hand, the gasification reaction of coal in the gasification furnace 1 is as follows: -water evaporation (only in the case of wet type, hardly occurs in the case of dry type) -vaporization of volatile matter

[Chemical 1] Coal → C _(S) + C _n H _m + O ₂・ Oxidation of volatile matter

Embedded image C _n H _m + (n + m / 4) O ₂ → nCO ₂ + m / 2H
₂ O ・ Char oxidation

[Chemical Formula 3] C _(S) + 1 / 2O ₂ → CO CO + 1 / 2O ₂ → CO ₂ · Gasification reaction

[Chemical formula 4] C _(S) + CO ₂ → 2CO C _(S) + H ₂ O → CO + H ₂ C _(S) + 2H ₂ → CH ₄・ Gas phase equilibrium

[Chemical Formula 5] CO + H ₂ O = CO ₂ + H ₂ , and the coal is reacted with oxygen in the oxidizer at high temperature and high pressure to generate a fuel gas containing CO, H _{2 and the} like as main components (however, , C _(S) in the above reaction formula is solid carbon in char produced by removing volatile components from coal.).

During operation of the coal gasification equipment, the fuel slurry in which coal and water are mixed is supplied to the gasification furnace 1 and an oxidizing agent such as oxygen is supplied, and the fuel slurry is partially converted by the oxidizing agent in the gasification furnace 1. The generated gas that has been oxidized and gasified in the gasification furnace 1 is cooled in the gas cooling device 2, and the generated gas cooled in the gas cooling device 2 is purified in the gas purification device 3. The generated gas purified by the gas purification device 3 is guided to the gas turbine 4 and burned, and a generator (not shown) is driven by the drive of the gas turbine 4 to generate electricity and drive the gas turbine 4. The discharged exhaust gas is introduced into the exhaust heat recovery boiler 5, the heat of the exhaust gas is recovered in the exhaust heat recovery boiler 5, steam is generated from the feed water, and the steam turbine 6 is driven by the steam. To generate electricity by driving a generator (not shown), the exhaust gas after passing through the exhaust heat recovery boiler 5 is adapted to release from the stack 7 to the atmosphere.

In the gas cooling device 2, the generated gas gasified in the gasification furnace 1 is cooled by water supply, and the steam generated by heat recovery from the generated gas is recovered by the exhaust heat recovery. The steam generated in the boiler 5 is introduced into the steam turbine 6 together with the steam.

On the other hand, a burner for gasification furnace is inserted and arranged in the gasification furnace 1. The burner for gasification furnace is
For example, as shown in FIG. 4, a slurry burner tip 9 is concentrically disposed in the outer burner tip 8 via a spacer 10, and an oxygen burner tip 11 is disposed in the slurry burner tip 9 via a spacer 12. Primary oxygen as an oxidant supplied to the primary oxygen flow path 13 between the outer burner tip 8 and the slurry burner tip 9 and the slurry burner tip 9
The fuel slurry supplied to the slurry flow path 14 between the oxygen burner chip 11 and the oxygen burner chip 11, and the secondary oxygen as an oxidant supplied to the secondary oxygen flow path 15 in the oxygen burner chip 11 is gasified. It is designed to be injected and mixed into the furnace 1 (see FIG. 3).

In FIG. 4, reference numeral 16 denotes a cooling water passage formed in the outer burner chip 8.
The outer burner chip 8 is protected from heat by circulating cooling water therethrough.

[0009]

In the burner for a gasification furnace as described above, it is necessary to finely spray the fuel slurry because the quality of the fuel spray greatly affects the gasification efficiency. The slurry flow passage 14 is narrowed down at the tip of the slurry burner tip 9 to increase the flow rate of the fuel slurry to 100 [m / s] or more, and the fuel slurry is sprayed into the gasification furnace 1 at a stroke to finely atomize the fuel slurry. In addition, primary oxygen and secondary oxygen as oxidants are similarly blown into the gasification furnace 1 by increasing the gas flow rate so as to be along the fuel slurry to assist atomization of the fuel slurry.

By the way, for example, in the case of downsizing the gasifier 1 such as in a test facility, the burner for the gasifier needs to be downsized, but the pulverized coal contained in the fuel slurry using coal is used. Since the particle size of is limited by the performance and economy of the mill, it does not decrease with the downsizing of the gasifier burner. In addition, usually 200 [mesh]
The fuel slurry having a passage rate of about 70% (average particle size of about 50 μm) is supplied to the gasifier burner.

Therefore, in the gasifier burner used in the small-scale gasifier 1, the diameter of the passage through which the fuel slurry flows is larger than that of the solid content of the fuel slurry, as compared with the large-scale burner. Becomes relatively small, and the possibility that the flow path will be blocked increases.

In order to avoid the blockage of the flow path, the flow path diameter may be increased (by the way, in order to supply the fuel slurry as described above to the gasifier burner, the flow path diameter of the fuel slurry is approximately φ3. However, if the flow path diameter is simply increased, the mixed state of the fuel slurry and the oxidizer at the gasifier furnace burner outlet is maintained and the gasification efficiency is optimized. It becomes impossible to maintain the ejection velocity condition of the fuel slurry at the gasifier burner outlet, which is required for the fuel cell, while the gasifier burner becomes relatively large with respect to the capacity of the gasifier 1. The jetting conditions at the gasifier burner outlet change, a dripping phenomenon occurs at the gasifier burner outlet, and the fuel slurry flows into the gasifier 1 in the form of drops without being sprayed, which is efficient. Gasification Geni problem that has occurred.

In view of the above situation, the present invention is capable of finely spraying the fuel slurry without blocking the flow path even in a small gasification furnace such as a test facility, and is capable of forming the same with the oxidizer. An object of the present invention is to provide a burner for a gasification furnace, which can promote mixing to perform stable operation and can improve gasification efficiency.

[0014]

According to the present invention, a fuel slurry is injected into a gasification furnace from a slurry burner tip and an oxidizer burner tip is provided concentrically on the outer peripheral side of the slurry burner tip. A burner for a gasification furnace for injecting and mixing the oxidizer, and an oxidant injection port for injecting an oxidant at high speed toward the fuel slurry injected from the tip of the slurry burner tip is provided in the outer peripheral portion of the tip of the slurry burner tip. The present invention relates to a gasifier burner characterized by the above.

According to the above means, the following effects can be obtained.

When the oxidizer is sprayed at a high speed from the oxidizer injection port toward the fuel slurry injected from the tip of the slurry burner tip, the flow path diameter of the fuel slurry becomes the minimum required size for avoiding blockage. Even if the jetting speed of the fuel slurry at the gasifier burner outlet is slowed to some extent by doing so, the fuel slurry is finely sprayed while being blown off by the oxidizer and the mixing with the oxidizer is also promoted, It becomes difficult for the dripping phenomenon to occur at the outlet of the burner for the gasification furnace, and it is possible to prevent the fuel slurry from dropping into the gasification furnace in the form of droplets, which leads to efficient gasification.

In the gasifier burner, the plurality of oxidant injection ports are directed to the axial center portion at equal intervals in the circumferential direction of the slurry burner tip and at an inclination angle of less than 45 ° with respect to the axis of the slurry burner tip. In this way, the oxidizer can be tilted at an angle of less than 45 ° with respect to the axis of the slurry burner chip from the plurality of oxidizer injection ports arranged at equal intervals in the circumferential direction of the slurry burner chip. The fuel slurries that are injected toward the axial center at an angle are less likely to interfere with each other, and the fuel slurries that are injected oppositely are less likely to interfere with each other, and the fuel slurries are easily affected by the oxidizer injection flow velocity, and the fuel slurries that pass directly below The droplets are unlikely to grow,
Finer spraying of the fuel slurry will be performed more reliably.

In the gasifier furnace burner, the tip of the slurry burner tip can be projected.
By doing so, it is possible to prevent the fuel slurry from flowing down through the end face of the gasifier burner outlet through the oxidizer injection port, and in this case, further, the tip of the slurry burner tip becomes a truncated cone shape. And the inclination angle of the conical surface with respect to the axis of the slurry burner tip is 60 ° or less, even if the droplet of the fuel slurry adheres to and grows on the conical surface of the tip of the slurry burner tip, the droplet Flows down along the conical surface toward the axial center and is blown off by the oxidizer together with the injected fuel slurry to be atomized, thereby avoiding the dripping phenomenon.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1 and 2 show an example of an embodiment of the present invention, showing a gasifier burner applied to a small gasifier 1 (see FIG. 3). In the burner, an oxidant burner tip 18 is concentrically arranged on the outer peripheral side of the slurry burner tip 17, and the oxidant burner tip 1
8, an outer burner chip 19 is concentrically arranged on the outer peripheral side of the slurry burner chip 17, and a slurry flow path 2 in the slurry burner chip 17 is provided.
0, and the oxidant flow passage 21 between the slurry burner tip 17 and the oxidant burner tip 18.
The oxidant supplied to the gasification furnace 1 is injected and mixed into the gasification furnace 1.

In the illustrated example, the tip of the slurry burner tip 17 is integrally formed with the slurry tip nozzle portion 17a, and the tip of the oxidizer burner tip 18 is integrally formed with the oxidizer tip nozzle portion 18a. Three oxidant injection ports that are formed and spray an oxidant at high speed on the outer peripheral portion of the tip of the slurry tip nozzle portion 17a of the slurry burner tip 17 toward the fuel slurry injected from the tip of the slurry tip nozzle portion 17a. 22 are provided.

The oxidizer injection port 22 is used to squeeze the mating surface 17b of the slurry tip nozzle 17a of the slurry burner tip 17 against the mortar-shaped portion 18b of the oxidizer tip nozzle 18a of the oxidizer burner tip 18. The oxidizer injection ports 22 are formed by closely contacting each other and engraving a groove in the abutting surface 17b. The oxidant injection ports 22 are arranged at equal intervals in the circumferential direction of the slurry burner tip 17 and the axis line of the slurry burner tip 17 is formed. The inclination angle α is less than 45 ° with respect to L (α = 30 ° in the example of the figure), and is arranged so as to face the axial center portion.

Further, the tip of the slurry tip nozzle portion 17a of the slurry burner tip 17 is projected so as to have a truncated cone shape, and the conical surface 17c has an inclination angle β with respect to the axis L of the slurry burner tip 17 of 60 °. Below (β = 60 ° in the example of the drawing), the conical surface 17c of the slurry tip nozzle portion 17a is continuous with the tip surface 18c of the oxidant tip nozzle portion 18a of the oxidizer burner tip 18 without forming a step. I am doing it.

A cooling water passage 23 is formed between the oxidizer burner tip 18 and the outer burner tip 19, and cooling water is passed through the cooling water passage 23. The outer burner tip 19 is protected from heat.

Next, the operation of the illustrated example will be described.

When the oxidizer is sprayed at a high speed from the oxidizer injection port 22 toward the fuel slurry injected from the tip of the slurry chip nozzle portion 17a of the slurry burner tip 17, the passage diameter of the fuel slurry is prevented from being blocked. Even if the jet speed of the fuel slurry at the burner outlet for the gasification furnace is slowed to some extent by making the size to the minimum required, the fuel slurry is finely sprayed while being blown away by the oxidizer and is Since the mixing is also promoted, the dripping phenomenon hardly occurs at the burner outlet for the gasification furnace, the fuel slurry is prevented from flowing into the gasification furnace 1 in the form of droplets, and efficient gasification is achieved. It will be done.

In the illustrated example, a plurality (three) of oxidant injection ports 22 are equally spaced in the circumferential direction of the slurry burner tip 17 and 45 with respect to the axis of the slurry burner tip 17.
Since the oxidizer is arranged so as to be directed toward the axial center portion at an inclination angle α of less than ° (α = 30 ° in the example in the figure), a plurality of oxidizers are arranged at equal intervals in the circumferential direction of the slurry burner tip 17. From the oxidant injection port 22 of the above, the jets of the oxidizer that are jetted toward the axial center portion at an inclination angle α of less than 45 ° with respect to the axis of the slurry burner tip 17 and jetted opposite to each other are less likely to interfere with each other. At the same time, the fuel slurry is easily affected by the injection flow velocity of the oxidant, the droplets of the fuel slurry that pass through directly below do not easily grow, and the fine spray of the fuel slurry is more reliably performed.

Here, the oxidizer injection port 22 is inclined at an angle α of 45 ° or more with respect to the axis of the slurry burner tip 17.
The oxidizer is disposed so as to face the axial center portion of the slurry burner chip 17 from the plurality of oxidizer injection ports 22 arranged at equal intervals in the circumferential direction of the slurry burner chip 17 with respect to the axis of the slurry burner chip 17 by at least 45 ° When the fuel is injected toward the axial center portion at an inclination angle α of, the jet streams of the oxidant injected opposite to each other are likely to interfere with each other, and the fuel slurry is less likely to be affected by the jet flow rate of the oxidant. It has been confirmed by an actual experiment conducted by the present inventors that the droplets of the fuel slurry that easily slip through are likely to be large, making it difficult to finely atomize the fuel slurry.

Further, in the illustrated example, the tip of the slurry tip nozzle portion 17a of the slurry burner tip 17 is projected so as to have a truncated cone shape, and the conical surface 17c thereof is provided.
Since the inclination angle β of the slurry burner tip 17 with respect to the axis L is 60 ° or less (β = 60 ° in the example of the figure), the fuel slurry is applied between the oxidizer injection port 22 and the burner outlet end face of the gasifier. Even if droplets of the fuel slurry adhere to and grow on the conical surface 17c at the tip of the slurry tip nozzle portion 17a of the slurry burner tip 17, the droplets will pass along the conical surface 17c. Flows down toward the axial center and is blown off by the oxidizer together with the injected fuel slurry to be atomized, so that the dripping phenomenon is avoided.

Thus, even in a small gasification furnace 1 such as a test facility, the fuel slurry can be finely sprayed without blocking the flow path, and the mixing with the oxidizer is promoted and stabilized. The operation can be performed, and the gasification efficiency can be improved.

The burner for a gasification furnace of the present invention is not limited to the above-mentioned illustrated example, and it goes without saying that various changes can be made without departing from the gist of the present invention.

[0032]

As described above, according to the gasifier burner of the present invention, even in a small gasifier such as a test facility, the fuel slurry can be supplied without blocking the flow passage. It can be finely sprayed, promotes mixing with an oxidizer, can perform stable operation, and can exert an excellent effect that gasification efficiency can be improved.

[Brief description of drawings]

FIG. 1 is a sectional view of an example of an embodiment of the present invention.

FIG. 2 is a plan view showing a tip surface of a slurry burner tip according to an example of an embodiment of the present invention.

FIG. 3 is an overall schematic configuration diagram showing an example of a coal gasification facility adopting a conventional wet coal feeding system.

FIG. 4 is a cross-sectional view showing an example of a conventional gasifier burner.

[Explanation of symbols]

1 gasification furnace 17 Slurry burner tip 17a Slurry tip nozzle part 17c conical surface 18 oxidizer burner chips 18a Oxidizing agent tip nozzle 19 Outer burner tip 20 Slurry channel 21 Oxidant channel 22 Oxidant injection port 23 Cooling water flow path L axis α inclination angle β inclination angle

Claims (4)

[Claims] 1. Gasification in which fuel slurry is injected from a slurry burner chip into a gasification furnace and an oxidizer is injected from an oxidizer burner chip coaxially arranged on the outer peripheral side of the slurry burner chip to mix. A furnace burner, characterized in that an oxidizer injection port for spraying an oxidizer at a high speed toward the fuel slurry injected from the slurry burner chip tip is provided on the outer peripheral portion of the slurry burner chip tip. Burner for furnace. 2. A plurality of oxidant injection ports are arranged at equal intervals in the circumferential direction of the slurry burner tip and toward the axial center portion at an inclination angle of less than 45 ° with respect to the axis of the slurry burner tip. Burner for gasification furnace. 3. The gasifier burner according to claim 1, wherein the tip of the slurry burner tip is projected. 4. The gasifier burner according to claim 3, wherein the tip of the slurry burner tip is projected so as to have a truncated cone shape, and the inclination angle of the conical surface with respect to the axis of the slurry burner tip is 60 ° or less. .