JP2001065804A - Repowering apparatus and repowering method for boiler - Google Patents

Abstract

PROBLEM TO BE SOLVED: To establish a repowering system for an old coal fired boiler having high economy which is characteristic of a coal gasification system and having less formation of NOx in combustion gas. SOLUTION: A coal gasification device 9 is supplemented to an existing coal fired boiler 6 to collect dry distillation gas and char generated in the device 9 with a char collector 11, followed by separation thereof to use a portion of the dry distillation gas as a fuel for a gas turbine 12 and using the remaining dry distillation gas and char as a fuel for the boiler 6 for combustion. With such a system, despite the necessity of oil or gas fuel at the time of starting operation, only coal can be used in a normal operation. Since a portion of the dry distillation gas can be used as fuel for the existing coal fired boiler, a strong reduction region can be formed in a boiler furnace. Moreover, NOx formation in a boiler furnace which is a problem in a normal coal fired boiler, can be considerably reduced owing to the denitrification effect in the furnace by the dry distillation gas.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a boiler, and more particularly to a boiler combustion system having a partial gasifier suitable for repowering an aging boiler using coal as a fuel (measures for improving output), and a method for producing a combustion gas. Nitrogen oxides (NO
The present invention relates to a coal combustion method that produces a small amount of x).

[0002]

2. Description of the Related Art In commercial and industrial boilers, there are many systems in which a gas turbine is added as a countermeasure against repowering of an aging boiler. Since ordinary business and industrial boiler repowering systems use gas turbines, they are often applied to gas fired boilers. That is, the repowering system is a system in which gas fuel is supplied to a gas turbine to generate power, high-temperature combustion exhaust gas is used as combustion air for an existing boiler, and gas fuel is burned in the existing boiler.

A characteristic of this repowering system is that although the thermal efficiency is slightly inferior to a system using a combination of a gas turbine and an exhaust heat recovery boiler, the output of an aging boiler can be relatively easily increased by adding a gas turbine. What you can do. Furthermore, this repowering system has the features that the gas turbine is more compact than the boiler, so that the installation area is small and the construction period is short.

[0004] In a boiler for a thermal power plant using a normal fossil fuel as a main fuel, it is customary not to use a plurality of fuels. For example, a coal-fired boiler has an oil supply facility as a backup but no gas supply facility. Oil-fired boilers do not have gas supply facilities. Furthermore, in the case of gas-fired boilers, there are no coal or oil supply facilities.

[0005] In recent years, the construction of large-scale coal-fired power plants has been continued, and accordingly, measures for aging large-scale coal-fired boilers are urgently needed. Considering the exhaust reburning mechanism in which a gas turbine is added to a coal-fired boiler, the aforementioned fuel supply conditions, that is, in the case of a gas-fired boiler, there is no coal supply facility, so the combination of gas and coal is not feasible. It is scarce.

As shown in FIG. 8, a coal-fired boiler first stores coal in a lump coal of about 30 mm in a coal bunker 1, cuts out a necessary amount by a coal feeder 2, and supplies it to a mill 3. I do. In the mill 3, the specific surface area of the particles is increased by finely pulverizing the coal so that the average particle diameter becomes 50 microns or less, and the pulverized coal is easily ignited and burned.

[0007] Further, the obtained pulverized coal is conveyed by air in primary air, and burner 21 (only a part is shown) of coal-fired boiler 6 together with main combustion air 100 supplied from wind box 5.
And is burned in the boiler.

[0008] Since coal is a solid fuel, large-scale facilities are required for storage facilities and pulverizing facilities for handling the coal, and these facilities should be used effectively as much as possible when repowering a boiler. Is desirable.

[0009]

As described in the above prior art, repowering in a boiler is only applied to a gas-fired boiler, but there is no repowering of a coal-fired boiler 6; It is not suitable to use gas fuel. This is because the location conditions of the coal-fired boiler 6 and the gas-fired boiler are different, and gas fuel is supplied to the coal-fired boiler at least until now because a gas fuel supply base does not exist near the coal-fired boiler 6. Because he couldn't.

[0010] Even if gas fuel can be supplied to these coal-fired boilers 6 in the future due to improvements in location conditions and the like, it is inefficient to use gas fuel for repowering the coal-fired boilers 6. The reason is that the coal-fired boiler 6 is designed so as to be suitable for burning a flame-retardant solid fuel, and the furnace volume is too large for burning gas fuel. Therefore, repowering using coal is desirable for the coal-fired boiler 6.

As a combined cycle using coal as a main fuel, a coal gasification system (IGCC) can be considered. FIG. 9 shows the basic configuration of a coal gasification system.
The pulverized coal as the main fuel is stored in the pulverized coal bottle 7 after being pulverized by a mill (not shown) to adjust the particle size. Then, a fixed amount is cut out by the feeder 8 and supplied to the coal gasifier 9.
Inside the coal gasifier 9, the coal burns,
The coal is carbonized by the reaction heat and gasified. The resulting combustible gas rich in CO and H _2, also CO ₂ generated by the combustion of the combustible gas is reduced to CO in an atmosphere of high temperature oxygen deficient.

These combustible dry distillation gases are discharged out of the coal gasifier 9 together with the char that has released volatile components.
Since the char is solid and is unsuitable as a gas turbine fuel, the char is collected and separated by the char collector 11 and then returned to the coal gasifier 9 again. On the other hand, the carbonized gas separated by the char collector 11 is supplied to the gas turbine 12.

The carbonized gas is burned inside the gas turbine 12 together with the pressurized air supplied from the air compressor 13, and is used for power generation by rotating the power generator 15. Since the combustion gas obtained by the gas turbine 12 has a high temperature of 500 to 600 ° C., it is sent to the exhaust heat recovery boiler 16 and used for steam generation. The steam obtained by the exhaust heat recovery boiler 16 is used for power generation by turning a steam turbine (not shown).

The coal gasification system as shown in FIG. 9 enables high-efficiency operation as compared with a conventional coal-fired boiler, is a facility used in a new thermal power generation facility, and is an existing coal-fired boiler. Departs from the concept of repowering.

Considering the repowering of an old coal-fired boiler, it is necessary to consider coal as the main fuel, and it is desired to add the high economic advantage of the coal gasification system. Furthermore, the combustion method is low NO
x combustion is essential.

An object of the present invention is to establish a repowering system for an aged coal-fired boiler that has the high economic efficiency of a coal gasification system and that generates a small amount of NOx in combustion gas.

[0017]

An object of the present invention relating to repowering of a coal-fired boiler is to add a coal gasifier to an existing coal-fired boiler, and to convert the carbonized gas generated from the coal gasifier and char into the existing coal-fired boiler. The problem can be solved by burning in a boiler and gas turbine.

That is, coal fuel is gasified to produce a carbonized gas and char, and all or a part of the carbonized gas is used as a fuel for a gas turbine, and the char or the char and a part of the carbonized gas are supplied to an existing coal-fired boiler. Systems that supply fuel are suitable.

With such a system, an auxiliary fuel such as oil is required at the time of startup, but an operation using only coal as a fuel at the time of normal operation becomes possible. In addition, since a portion of the carbonized gas can be used as fuel for existing coal-fired boilers, a strong reduction zone can be formed in the boiler furnace in such a case, which is a problem in boiler furnaces, which is a problem with ordinary coal-fired boilers. The problem of NOx generation in the furnace can be greatly reduced by the effect of denitration in the furnace by the carbonization gas.

[0020]

According to the present invention, since a gas turbine can be additionally installed in a coal-fired boiler, repowering in an existing aging coal-fired boiler becomes possible.
In addition, since a part of the carbonization gas from the coal gasifier can be used for burning the existing coal-fired boiler, in such a case, the N2 in the boiler furnace generated by the combustion of the char is used.
Ox can be brought into direct contact with the carbonization gas to be reduced to nitrogen gas, and the amount of NOx generated can be suppressed.

[0021]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a system diagram of a repowering system for a coal-fired boiler according to an embodiment of the present invention. The coal used as the fuel of the present system is adjusted to a particle size of about 30 mm, and then supplied to a mill (not shown) to a predetermined particle size (for example, a 200 mesh passing weight of 80 to 90 mm).
(wt%), and is temporarily stored in the pulverized coal storage bottle 7 after the particle size is adjusted.

The pulverized coal is cut out in a predetermined amount by a coal feeder 8, transported in a gas stream by a carrier gas such as oxygen, air, or nitrogen, and supplied into a coal gasifier 9. Then, the pulverized coal is burned in the coal gasifier 9 to generate heat, and is further gasified in a reducing atmosphere.

An oxidizing agent such as oxygen or air is introduced into the coal gasifier 9. The amount of the oxidizing agent is set to an amount less than the stoichiometric air flow rate required for the pulverized coal to undergo a gasification reaction. Become. Further, the furnace pressure and temperature are, for example, 3 MPa,
The temperature is about 1800 ° C., but under the condition of 1000 ° C. or more, the gasification of pulverized coal proceeds. It is essential that the pressure be 3 MPa or more in order to start the gas turbine 12 described later.

After the carbonized gas and the char are generated in the coal gasifier 9, they are collected by the char collector 11 and then separated into the char and the carbonized gas. The char is supplied to the burner 21 of the coal-fired boiler 6 together with a char carrier gas such as compressed air, oxygen or nitrogen.

On the other hand, most of the carbonized gas is supplied to a combustor (combustor) of the gas turbine 12 for combustion during steady operation, that is, when a sufficient calorific value can be secured for the carbonized gas. Here, the dry distillation gas is gas turbine 12
Is burned together with the pressurized air supplied from the air compressor 13 and used for power generation for rotating the generator 15.
Since the exhaust gas of the gas turbine 12 has a sufficiently high oxygen concentration of about 15% and a high temperature of about 500 to 600 ° C., the exhaust gas can be used as combustion air in the burner 21 of the coal-fired boiler 6 and can be used during normal operation. The water is supplied from the road 41 to the wind box 5 of the boiler 6. As shown in FIG. 1, a part of the carbonization gas is branched from a flow path 22 and supplied from a flow path 43 to the burner 21 as an auxiliary fuel for the coal-fired boiler 6.
It can also burn inside. At a branch point of the flow path 22 to the flow path 43, a flow control device 42 such as a damper is provided. Also,
FIG. 1 (similar to FIGS. 4 and 5 described later) shows combustion air 100.
Is supplied, but the flow rate, the temperature, and the oxygen concentration are adjusted appropriately with the exhaust gas from the gas burner 21.

The ordinary coal gasifier 9 has a low ambient temperature or partial gasification depending on the type of coal, resulting in a decrease in gasification efficiency, specifically, a decrease in the calorific value of the generated gas ( Cold gas efficiency is low), and the effective utilization rate of carbon is reduced (carbon conversion rate is low). As a countermeasure, in the case of the system shown in FIG. 1, a switching device 24 is provided in the flow path 22 for supplying the carbonized gas to the gas turbine 12, and the carbonized gas flow path for supplying the gas turbine 12 is instantaneously switched to the boiler side. It is possible to avoid misfire of the gas turbine 12 in advance, and the safety and reliability of power generation are improved.

In FIG. 1, the dry distillation gas flow path to the burner 21 of the boiler 6 is provided separately for the normal use and the emergency use. One of them may be shared.

FIG. 10 (FIG. 10 (a) is a sectional view of the burner, and FIG. 10 (b) is a front view of the burner as viewed from the furnace side) shows a structure of a pulverized coal burner 211 of a conventional coal-fired boiler. Normally, it is impossible for the pulverized coal boiler 6 to burn using only the coal with the burner 211, and the furnace 23
Until the inside can be preheated sufficiently, the load is increased by the oil burner 25 provided on the central axis of the burner. After the coal is pulverized by the mill, the coal is supplied to the primary flow path 26 of the pulverized coal burner 211 with the primary air which is a mixed fluid of the conveying air and the pulverized coal, and flows into the furnace 23 at a flow rate of about 20 m / s. Gushing.

The flow rate of the primary air is about 20% of the total flow rate of the combustion air, and the pulverized coal cannot be completely burned with this air alone. The air is swirled from the secondary air flow path 27 and the tertiary air flow path 28 around the space 26 and is charged into the furnace 23. Normally, the secondary air flow rate is distributed so as to be about 10 to 15% of the whole air, and the tertiary air flow rate is about 60%. Burner 21
The total amount of air introduced from 1 is about 90% of the theoretical air amount.
%, And the remaining 25% (determined in consideration of the excess air ratio) is supplied from an after-air port (not shown) provided on the downstream side of the pulverized coal burner 211. The amount of combustion air supplied to the entire furnace 23 is determined in consideration of the excess air ratio in accordance with the type of coal and the like, but is based on 115% of the theoretical air amount.

The tertiary air is supplied to an air swirler 3 having a normal door structure.
At 0, a strong swivel is applied and thrown into the furnace. This is the most important air for the stable combustion of the flame obtained by the combustion of pulverized coal. Since the tertiary air contributes to the formation of an internal hot gas recirculation zone near the burner 211 in the furnace 23, its swirling strength and mass flow rate determine the shape of the hot gas reduction zone near the burner. It is an important factor related to NOx generation and its reduction.

It is said that NOx is obtained by heating a substance in which pyridine or pyrrole is bonded to a benzene ring contained in coal, and in the process of thermal decomposition, cyan is obtained, and the cyan is generated via ammonia. . However, in a high temperature region where oxygen does not exist, NOx once generated is N
To be reduced to _2, thereby forming a large small reduction zone oxygen at high temperature (the fuel combustion zone immediately after fuel injection from the burner 211) area after the pulverized coal burner 211 is important.

A high temperature field is required for the pyrolysis of the combustion components in the coal. If the high temperature field is not formed, not only the reduction region is not formed but also the nitrogen inside the char is hardly released. And this char is the furnace 23
Oxidation occurs in the oxidation region of the combustion gas on the downstream side of the inside, and the nitrogen component tends to become NOx.

In order to prevent such a phenomenon, it is necessary to rapidly ignite the fuel immediately after the fuel is injected from the pulverized coal burner 211, and to stably maintain the flame of the ignited fuel.

The pulverized coal jet is a two-phase flow of a high-concentration solid and a gas. However, the heating of the pulverized coal particles at the burner outlet is mainly governed by the radiation from the flame. It is important for the ignition of pulverized coal how thin and strong turbulence is generated.

In the conventional pulverized coal burner 211 shown in FIG. 10, a flame stabilizer 33 and a turbulence promoter 34 are attached to an outlet of a primary flow path 26 which is a mixed fluid flow path of pulverized coal and air. The flame stabilizer 33 forms a circulation area of the combustion gas in the subsequent flow,
Ignition is achieved by increasing the residence time of the particles. Also,
The turbulence enhancer 34 cuts the outer surface of the pulverized coal jet to promote turbulence, and the jet is radiated from a flame (Radiation).
The structure is easy to receive.

Since a bent guide sleeve 35 extending in the radial direction is provided at the outlet portion of the outer peripheral portion of the secondary air flow path 27, the guide sleeve 35 further serves to circulate the ignited combustion gas flow. It can be enlarged.

In the present invention, the purpose of repowering the coal-fired boiler 6 is to use the existing pulverized coal burner 211 as shown in FIG. 10 as much as possible rather than replacing it with a completely new burner. connection,
It was completed with the belief that it would also contribute to improving the feasibility of the system.

The burner 21 shown in FIG. 2A is a sectional view of the burner 21 according to the embodiment of the present invention capable of burning the char and the carbonization gas separately or simultaneously, and FIG. 2B is viewed from the furnace side. FIG. 11 is a front view of the burner 21 (view from the furnace), and the basic configuration of the burner 21 is the same as the pulverized coal-fired burner 211 shown in FIG. This is because the char is solid and has a low burning rate like pulverized coal, so that its ignitability is poor. Further, the burner 21 can be used not only for char combustion but also for pulverized coal combustion as before.

The burner 21 shown in FIGS. 2 (a) and 2 (b)
The members having the same functions as the members shown in FIG. 10 among the members constituting are denoted by the same reference numerals, and description thereof will be omitted.

The burner 21 shown in FIGS. 2A and 2B
The feature of this is that the carbonization gas nozzle 37 (FIG. 2) for the carbonization gas supplied from the coal gasifier 9 (FIG. 1) to the secondary air flow path 27.
(See (c)).

The dry distillation gas nozzle 37 extends through the flame holder 33 to the outlet of the burner 21 on the furnace 23 side.
An injection port 37a for injecting the carbonization gas is provided at the tip of the nozzle 37. By injecting the combustible gas from the carbonization gas nozzle 37 toward the high-temperature gas circulation region, the temperature of the combustion gas can be further increased, and an effective result in lowering the NOx concentration of the combustion gas can be obtained.

FIG. 2C is a detailed perspective view of the tip of the carbonization gas nozzle 37. The carbonized gas is supplied to the burner shaft (90
Injection is performed from the injection port 37a at an angle of -θ).
The reason why the fuel is not injected along the burner main axis is that mixing with combustion air is required.

Further, in terms of operation, the burner 21 can be supplied with only the char or only the carbonized gas and burned.

FIG. 3 (a) (where FIG. 3 (a) is a sectional view of the burner and FIG. 3 (b) is a front view of the burner as viewed from the furnace side) shows a burner 21 according to another embodiment of the present invention. Indicated. This burner 21 is basically the same as the pulverized coal burner 211 shown in FIG. However, the structure was such that the dry distillation gas nozzle 37 was inserted into the normal primary flow path 26. In this example, four dry distillation gas nozzles 37 are provided, but up to eight can be used. Injection port 37a of dry distillation gas nozzle 37
The injection direction of the gas from the burner was made to have an angle with respect to the main axis of the burner as in the case shown in FIG.

That is, the carbonization gas is injected inside the primary flow path 26 to be premixed with the char, and then injected into the furnace 23 of the boiler 6. The target gases for premixing are air, oxygen,
It is a diluent gas with nitrogen gas, and the premixed gas is selectively used depending on the calorific value of the carbonization gas. With such a configuration, the carbonization gas can suppress the initial velocity at the outlet portion of the burner 21, thereby enabling stable ignition.

The burner 21 can be operated with pulverized coal instead of char, and can also be operated with char or carbonized gas alone.

With the combination of the burners shown in FIGS. 2 and 3, NOx generated in the furnace 23 of the coal-fired boiler 6
The reason why the amount can be reduced will be described.

FIG. 6 shows a case where a denitration system in the furnace 23 of the boiler 6 is constructed by combining a char combustion burner for supplying only char and a carbonized gas combustion burner for supplying only carbonized gas. The outline of the burner layout and the reaction inside the furnace 23 is shown.

The char combustion burner 21a is disposed below the boiler furnace 23 from the carbonization gas combustion burner 21b, and the char ejected from the combustion burner 21a is burned in the furnace 23. Normally, solid fuel is converted to gas fuel. Since the combustion rate is slower, the unburned char that rises in the furnace 23 is burned together with a highly combustible dry distillation gas, after-air, etc. to increase the complete combustion area in the furnace 23, thereby increasing the combustion efficiency. It is suitable as a means for increasing. Therefore, in the system shown in FIG. 6, the burner 21 is provided in two stages, and the after-air port 40 is provided in one stage. In a normal coal-fired boiler 6, the burner 21
Has a two-stage to four-stage configuration, but a simple configuration will be described here.

The lowermost burner is a char combustion burner 21a,
A carbonization gas burner 21b is provided thereon, and an after-air port 40 is provided above it. The air ratio of the char combustion burner 21a is 0.7 to 1.0, that of the carbonization gas burner 21b is 0.5 to 0.8, and that of the after air port 40 is only air and 0.25 to 0.55. The total is 1.15.

Here, the combustion state in the furnace 23 is as follows.
Since the dry distillation gas is introduced into the downstream side of the char combustion region in a state of insufficient air, there is a strong denitration effect of the combustion gas.

Generally, in the case of the ordinary coal-fired boiler 6,
Although the air ratio is biased with pulverized coal having low activity, that is, the burner for denitration is operated with a reduced air ratio, the present situation is that a sufficient denitration effect cannot be expected.

In comparison with this, in the system shown in FIG. 6, NO generated by char combustion by the carbonization gas was used.
capable of reducing x to _{N 2.} As the medium, HCN, NH ₃
Or its radicals.

FIG. 7 shows an example in which a burner 21 for simultaneously supplying the carbonization gas and the char is applied to a boiler system. The example shown in FIG. 7 is a case of a two-stage burner, in which burners 21 having the same specifications are applied. Since it is the coaxial burner 21, the carbonization gas and the char are mixed and charged into the furnace 23. However, the burner 21 shown in FIG. 7 can form a strong reduction region in the vicinity of the burner 21 by entraining gaseous fuel excellent in fuel ignitability as compared with the burner 21 shown in FIG.
NOx can be reduced by the burner 21 alone. FIG. 7 shows an example in which no after-air port is provided,
As in the case of the stage combustion, as shown in FIG. 6, even if the after-air port is turned on, the NOx concentration of the combustion gas can be further reduced. In the burner 21 shown in FIG. 7, the local air ratio of the coaxial combustion burner 21 for burning the char and the carbonized gas without biasing the air ratio between the two-stage burners 21 is 0.95 from the result of pulverized coal combustion. Do the following.

FIGS. 4 and 5 show a system diagram of a system according to another embodiment of the present invention. In the systems of FIGS. 4 and 5, the same devices as those shown in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted.

The system shown in FIGS. 4 and 5 has a configuration in which the carbonized gas obtained in the coal gasifier 9 is separated from the char by the char collector 11 and the whole amount is sent to the gas turbine 12. The system shown in FIG. 5 is a case where the total amount of the char separated by the char collector 11 is returned to the coal gasifier 9.

Each of the systems shown in FIGS. 4 and 5 is characterized in that the system does not feed flammable gas into the coal-fired boiler 6. FIG. 5 shows that the coal-fired boiler 6 has a burner capable of burning pulverized coal in the first place because the complete coal gasifier 9 is added. Although charcoal fuel is used, oil fuel can also be used.

In the system shown in FIG. 4, the coal-fired boiler 6 uses only char as fuel.
Char cannot be burned due to poor ignitability of char. Therefore, a small amount of oil fuel is always required. However, each has the merit that the system can be simplified.

Although not shown, when the repowering is partially performed in combination with coal gasification when the burners 21 are multistage, the operation can be performed with a part of the conventional pulverized coal burner 211 remaining.

[0060]

According to the present invention, by adding a highly economical coal gasification system, NO in the combustion gas can be reduced.
An x-ray coal-fired boiler repowering system with a small amount of x can be achieved.

[Brief description of the drawings]

FIG. 1 is a system diagram of a boiler coal combustion system to which a gasifier according to an embodiment of the present invention is added.

FIG. 2 is an example of a burner structure of a boiler used in the coal combustion system of the boiler according to the present invention, and is a side sectional view of a coaxial combustion burner suitable for coaxially burning a char and a carbonization gas (FIG. 2 (a)). And front view from the furnace side (Fig. 2 (b))
FIG. 2 is a perspective view (FIG. 2C) of a tip portion of a dry distillation gas burner nozzle inserted into the burner.

3 is a side cross-sectional view (FIG. 3A) of a gas burner suitable for burning the carbonization gas of a boiler used in the boiler coal combustion system according to the present invention, and a front view as viewed from the furnace side (FIG. 3).
(B)).

FIG. 4 is a system diagram of a coal combustion system of a boiler to which a gasifier that does not supply the carbonized gas generated by the gasifier according to the embodiment of the present invention to a boiler furnace is added.

FIG. 5 is a system diagram of a coal combustion system of a boiler to which a gasifier for recycling char generated by the gasifier according to the embodiment of the present invention to the gasifier is added.

FIG. 6 is an explanatory diagram showing a denitration process in a boiler furnace when char and carbonization gas are burned by separate burners in a coal combustion system of a boiler according to the present invention.

FIG. 7 is an explanatory view showing an in-furnace denitration process when char and carbonized gas are burned by the same coaxial burner in the boiler coal combustion system according to the present invention.

FIG. 8 is a schematic sectional view of a conventional pulverized coal-fired boiler.

FIG. 9 is an existing gasification system that supplies waste heat of a gas turbine to a waste heat recovery boiler.

10 is an example of a conventional pulverized coal combustion burner, and FIG.
0 (a) is a side sectional view, and FIG. 10 (b) is a burner front view.

[Explanation of symbols]

Reference Signs List 1 coal bunker 2 coal feeder 3 mill 6 coal-fired boiler 5 wind box 7 pulverized coal storage bin 8 feeder 9 coal gasifier 11 char collector 12 gas turbine 13 air compressor 15 generator 16 exhaust heat recovery boiler 21 burner 21a Char combustion burner 21b Dry distillation gas burner 22 Flow path 23 Boiler furnace 24 Switching device 25 Oil-activated burner 26 Primary flow path 27 Secondary air flow path 28 Tertiary air flow path 30 Air swirler 33 Flame stabilizer 34 Turbulence promoter 35 Guide sleeve 37 Dry distillation gas nozzle 37a Dry distillation gas injection port 40 After air port 41, 43 Flow path 42 Flow control device 100 Main combustion air 211 Pulverized coal burner

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3K046 AA02 AB01 BA01 BA04 BA05 CA02 FA06 3K065 TA01 TA16 TB09 TB13 TB15 TC01 TD07 TE10 TF02 TG04 TH02 TH10 TL04 3K091 AA01 AA20 BB02 BB25 CC13 CC22 DD01 DD08 FB05 FB22 FB22 FB22 FB22 FB22

Claims (13)

[Claims] 1. A boiler having a burner for burning a solid fossil fuel such as coal as a main fuel, a coal gasifier for gasifying coal with a gas containing oxygen at a stoichiometric ratio or less,
A separator for separating the carbonized gas generated by the coal gasifier and the char generated after part or all of the volatiles in the coal are pyrolyzed and released, and the carbonized gas and the char; Characterized in that a flow path for supplying the burner to each of the burners is provided. 2. The repowering apparatus for a boiler according to claim 1, wherein a burner that supplies the carbonized gas and char simultaneously or individually is used as the burner. 3. A primary air flow path for supplying a mixed fluid of char and carrier air to the burner, a secondary air flow path provided on an outer peripheral portion of the flow path, and the secondary air flow path 3. A repowering apparatus for a boiler according to claim 2, further comprising a dry distillation gas supply nozzle provided in the inside. 4. A primary air flow path for supplying a mixed fluid of char and carrier air to the burner, a dry distillation gas supply nozzle provided in the primary air flow path, and a primary flow path. The repowering device for a boiler according to claim 2, further comprising a secondary air flow path provided on an outer peripheral portion of the boiler. 5. The repowering device for a boiler according to claim 1, further comprising an exhaust gas passage for supplying exhaust gas from the gas turbine to a burner of the boiler. 6. A gas turbine fueled by a carbonized gas connected to a supply path of the carbonized gas separated by the separator for separating the carbonized gas and the char, and a supply of the carbonized gas upstream of the gas turbine. The boiler according to claim 1, further comprising: a branch flow path provided with an on-off valve provided in the flow path; and a dry distillation gas flow path for supplying a dry distillation gas from the branch flow path to a burner portion of the boiler. Repowering equipment. 7. A boiler having a burner for burning a solid fossil fuel such as coal as a main fuel, a coal gasifier for gasifying coal with a gas containing oxygen having a stoichiometric ratio or less,
A separation device that separates the carbonization gas generated by the coal gasifier and char generated after part or all of the volatile components in the coal are pyrolyzed and released, and separated by the separation device. A fuel supply channel for supplying char to the burner, a gas turbine using the carbonized gas separated by the separation device as fuel, and an exhaust gas channel for supplying exhaust gas from the gas turbine to the burner. Characteristic boiler repowering device. 8. A boiler having a burner for burning a solid fossil fuel such as coal as a main fuel, a coal gasifier for gasifying coal with a gas containing oxygen at a stoichiometric ratio or less,
A separation device that separates the carbonization gas generated by the coal gasifier and char generated after part or all of the volatile components in the coal are pyrolyzed and released, and separated by the separation device. A flow path for returning the char to the coal gasifier, a gas turbine using the carbonization gas separated by the separation device as a fuel, and an exhaust gas flow path for supplying exhaust gas from the gas turbine to the burner are provided. Boiler repowering equipment. 9. A boiler having a plurality of burners burning pulverized coal as a main fuel, a coal gasifier for gasifying coal with a gas containing oxygen at a stoichiometric ratio or less, and a coal gasifier produced by the coal gasifier. A separation device for separating the carbonized gas and the char generated after part or all of the volatiles in the coal are pyrolyzed and released, and a carbonized gas and a char provided by replacing a part of the burner. A reburning apparatus for boilers, provided with a burner for supplying the carbonized gas and the char to the burner simultaneously or individually. 10. A dry distillation gas generated by a coal gasifier for gasifying coal with a gas containing oxygen at a stoichiometric ratio or less and part or all of volatile matter in the coal is thermally decomposed and released. A repowering combustion method for a boiler, wherein char produced later is supplied to a burner that burns solid fossil fuel such as coal in a boiler as a main fuel and burned. 11. A char is supplied from a lower burner in a multi-stage burner provided in a boiler and burned, and a carbonization gas is supplied from an upper burner in a multi-stage burner provided in the boiler and burned. 11. The method according to claim 10, wherein
A method for repowering and burning a boiler according to the above description. 12. The method for repowering and burning a boiler according to claim 10, wherein the local air ratio of the burner for burning the char of the boiler is 1.0 or less. 13. The method for repowering and burning a boiler according to claim 10, wherein part or all of the char and the carbonization gas are supplied from a coaxial burner of the boiler.