JPH1180756A - Fluidized-layer pressurized gasification furnace - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fluidized-layer pressurized gasification furnace capable of controlling the temperature of the layer without varying the combustion rate in the gasification furnace which is the most important problem of a low-temperature gasification system and to provide a low-temperature gasification power-generation system having high efficiency by using a pressurized gasification furnace technology capable of properly and easily treating the char generated from the gasification furnace. SOLUTION: This fluidized-layer pressurized gasification furnace for gasifying a combustible material under pressure is provided with a gasification chamber 9 and a heat recovery chamber 10 in the gasification furnace. The gasification chamber 9 is connected to the heat recovery chamber 10 through two connection ports. One of the two connection ports is opened opposite to the bottom of the gasification chamber 9 and the other port is opened near the upper interface of the fluidized layer of the gasification chamber 9. The heat recovery chamber 10 is provided with a heat- conduction pipe 15 to recover heat from the fluidized medium. The furnace has a layer temperature controlling function capable of controlling the heat recovery by controlling the flow rate of the fluidizing gas blown into the heat recovery chamber 10 and varying the fluidized state. The gasification chamber 9 and the heat recovery chamber 10 are placed in a pressure vessel 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to coal, biomass,
The present invention relates to a pressurized fluidized-bed gasifier for gasifying solid combustibles such as combustible wastes under pressure using a fluidized bed, and a combined gasification power generation system using the pressurized fluidized-bed gasifier.

[0002]

2. Description of the Related Art In recent years, attempts have been made around the world to prevent global warming due to carbon dioxide gas, and there is an urgent need to improve the power generation efficiency of power plants. Power generation systems that use solid combustible fuels, such as coal, are more important than ever to cope with the depletion of petroleum resources, but it is difficult to supply high-quality coal in the near future for coal resources. Is expected to be. On the other hand, the demand for electric power is increasing year by year in Japan, but it is difficult to locate a new power plant, and so-called repowering technology is expected to improve efficiency and increase output by modifying existing equipment.

When a solid combustible is used as an energy source, it is ideally used for a system having a high theoretical efficiency of completely gasifying combustible components at a high temperature of about 1500 ° C., for example, a system such as coal gasification (IGCC). At the moment, systems such as the IGCC are expected to be used. However, at present, the equipment configuration is complicated to cope with various problems caused by high temperatures, and the energy required for generating oxygen used in the system is large due to the large amount of energy required. However, the problem is that the in-house rate has also increased and the net efficiency has not always increased.

[0004] For these reasons, in recent years, even in the same gasification system, a system in which the gasification reaction temperature is suppressed to about 900 ° C, that is, a so-called low-temperature gasification system, has been spotlighted. Because this system has a low gasification reaction temperature, complete gasification of solid combustibles cannot be expected, and the theoretical efficiency is IGCC
Although it is inferior to IGCC, it is expected that various problems associated with the high temperature can be avoided, so that the in-house rate can be reduced, and as a result, the net efficiency exceeds that of IGCC or the like.

In general, in a power generation system for solid fuel such as coal, the combustibility of the solid fuel varies depending on the fuel. Therefore, when designing a combustion furnace or the like, it is necessary to design the combustion furnace or the like specifically for the fuel. Then, the degree of freedom in fuel conversion is low. Therefore, in order to convert the fuel, it is necessary to remodel the equipment or crush the fuel. A system has been proposed to use this as a fuel pretreatment facility and to drive the gas turbine with gas generated from the gasifier to improve efficiency and increase output. Fluidized bed gasifiers that operate at relatively low temperatures are also suitable as gasifiers for various fuels such as coal and coal.

[0006] Fluidized bed gasifiers have very good heat transfer characteristics in the bed, but in order to exhibit these characteristics, it is essential to keep the fluidity of the fluidized medium in good condition at all times. However, in the case of pyrolysis or gasification at a temperature of 800 ° C. or less, it is necessary to exercise sufficient care so as not to generate tar which may hinder fluidization. Tar is a high molecular weight hydrocarbon compound and is generated when the thermal decomposition reaction is insufficient. Therefore, there is no problem if the temperature of the gasification furnace is maintained at about 900 ° C., but if the temperature drops,
If a situation occurs in which the thermal decomposition reaction stagnates, tar may be generated.

Therefore, in order to prevent tar from being generated, it is important to control the temperature of the fluidized bed. In a conventional fluidized-bed gasification furnace, a method of controlling the bed temperature generally involves changing the amount of oxygen blown into the gasification furnace to change the amount of combustible material in the bed. However, in the gasification furnace, the amount of oxygen blown is an important factor influencing the gasification efficiency, and when oxygen is blown to increase the bed temperature, there is a problem in that the gasification efficiency is reduced.

In a fluidized-bed gasification furnace, the gas blowing speed from the bottom of the furnace, that is, the fluidization speed, greatly affects the mixing state in the bed, and is an important factor that affects the reaction rate of thermal decomposition and gasification reaction. Is a factor. When the amount of oxygen to be blown is changed to control the bed temperature, the fluidized state also changes. Therefore, there is a problem that the response to the change of the oxygen blowing amount appears as a synergistic effect thereof, so that the control becomes very difficult.

In the fluidized bed gasifier, it is necessary to pay attention not only to tar generation but also to a so-called clinker trouble in which molten fluid medium and ash adhere to each other. Clinker trouble occurs when the bed temperature rises to near the melting temperature of ash in solid combustibles. Therefore, temperature control of the fluidized bed is very important to avoid clinker trouble.

[0010] Gasification by a fluidized bed requires a reaction temperature of 8%.
Since it is about 900-900 ° C, it is 130 like IGCC.
Gasification efficiency is low compared to gasification at a high temperature of 0 ° C or higher, and a large amount of char is generated in the gasifier depending on the properties of the fuel. Therefore, a char combustor must be provided separately from the gasification furnace. No. However, the provision of a char combustor not only complicates the equipment, but the technology for handling high-temperature char between the gasifier and the char combustor is not yet completed.

[0011]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described circumstances, and has been made in consideration of the above-mentioned circumstances. The most important problem of the low-temperature gasification system is that the bed temperature can be controlled without changing the combustion amount in the gasification furnace. The purpose of the present invention is to provide a pressurized fluidized-bed gasification furnace and a high-efficiency low-temperature gasification power generation system using pressurized gasification technology that can appropriately and easily process the char generated from the gasification furnace. I do.

[0012]

The first aspect of the present invention is characterized in that the pressurized internal circulating fluidized bed boiler shown in FIG. 1 is used as a gasifier. The amount of oxygen supplied to the pressurized internal circulation fluidized bed boiler is used as a gasifier with the amount of oxygen being less than the theoretical amount of oxygen, and the gas generated there is generated by a gas turbine via a high-temperature dust collector. On the other hand, the char (carbon content) collected by the high-temperature dust collector is supplied to a pulverized coal boiler or the like to collect steam and generate power by a steam turbine.

A pressurized internal circulating fluidized-bed boiler is disclosed in Japanese Patent Application No. 6-5 / 1993.
As described in 5208, the inside of the furnace is functionally divided into a main combustion chamber and a heat recovery chamber, and the amount of heat recovered from the fluidized bed can be easily controlled only by changing the fluidized state of the heat recovery chamber. it can. Therefore, if the pressurized internal circulating fluidized bed boiler is used as a pressurized gasifier, the temperature of the bed can be controlled without changing the oxygen ratio.

In the pressurized internal circulation fluidized-bed boiler, a high-temperature fluid medium circulates between the main combustion chamber and the heat recovery chamber, but the main combustion chamber and the heat recovery chamber are separated by a partition wall. Therefore, there is no need for circulating particles to pass through thin tubes as in a two-tower circulating gasifier or an external circulating fluidized-bed boiler. There is little, and the controllability of the layer temperature is excellent.

[0015] The char collected by the high-temperature dust collector is dry-distilled in the gasification furnace and contains almost no volatile matter, so that its ignitability is inferior to that of the original fuel. Therefore, when it is difficult to burn char in a pulverized coal boiler or the like, complete combustion can be achieved by burning in a high-temperature melting furnace, and slag of ash can be formed. High-temperature exhaust gas from the melting furnace is recovered in a waste heat boiler.

The higher the temperature, the more advantageous the gasification reaction is, while the higher the temperature of the high-temperature dust collector, which is an important component of the present system, the greater the technical difficulty. Therefore, in order to alleviate the technical difficulties of the high-temperature dust collector, a heat transfer surface for gas cooling may be provided on the free board portion in the gasification furnace. If the gas temperature is cooled to about 500 ° C., a low-cost high-temperature dust collector can be adopted. However, when the gas temperature is lowered, not only the efficiency is lowered, but also the char temperature is lowered, so that the combustibility of the char is further lowered.

The shape of the pressurized internal circulating fluidized-bed boiler was originally developed as a combustion furnace rather than a gasifier. Since the gasification furnace generates much less heat in the bed than in the combustion, the heat transfer area in the bed required for controlling the bed temperature may be much smaller than that in the combustion furnace. Therefore, when applied to a gasifier, the volume of the heat recovery chamber may be smaller than that of a pressurized internal circulating fluidized-bed boiler as a combustion furnace. A heat recovery furnace may be independently provided outside the gasification furnace, and two types of fluid medium communication ports may be provided at the top and bottom. However, in this case, it is preferable that the communication port is as short as possible and the diameter is large. Ideally, it is desirable to approach a structure in which one partition wall having upper and lower openings is used.

When gasifying a fuel such as bituminous coal, 8
Since the gasification rate is low in the fluidized-bed gasification temperature range of 00 to 900 ° C., the char accumulates in the gasification furnace unless the char particle size becomes small enough to be entrained by the gas. In that case, the char may be extracted and crushed to the extent that it is entrained by the gas and returned to the gasifier, or may be directly charged into a char combustor such as a pulverized coal boiler or a melting furnace.

However, if the high-temperature char is extracted from the gasification furnace and crushed, the sensible heat of the high-temperature char is lost or a heat-resistant crusher is required. It is desirable not to crush the high-temperature char as much as possible. Therefore, when the char accumulates, it is preferable that a part of the heat recovery chamber has a structure without a heat transfer tube and that part is a char combustion chamber. However, if the burning amount of the char increases, the concentration of carbon dioxide in the gas increases and the calorific value of the gas decreases, so it goes without saying that the burning amount of the char is limited.

Further, similarly to the above-described type in which a heat recovery furnace is provided outside the gasification furnace, an independent char combustion furnace can be provided outside the gasification furnace. In this case as well, the communication port between the gasification furnace and char combustion furnace should be as short as possible and the diameter should be large, ideally approaching a structure that is divided by a single partition wall with openings at the top and bottom. It is desirable.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a pressurized fluidized-bed gasification furnace according to the present invention will be described below with reference to the drawings. In the following description of the embodiments, components having the same or similar functions are denoted by the same reference numerals. (Embodiment 1) FIG. 1 shows a first embodiment of a pressurized fluidized bed gasification furnace according to the present invention.
It is a longitudinal section showing an example. The embodiment shown in FIG. 1 is an embodiment in which a cylindrical internal circulation type fluidized-bed gasification furnace is built in a cylindrical pressure vessel, and a schematic configuration of the present invention will be described using this.

The pressure vessel 1 has a cylindrical shape, and an upper surface is a head plate having a product gas outlet 4, and a lower surface is a head plate having a flow gas inlet 3, a heat recovery chamber control gas inlet 5, and the like. It is configured so that an internal pressure equal to or higher than the atmospheric pressure can be maintained. The pressure vessel 1 shown in FIG. 1 has a cylindrical shape, but may have a spherical shape.

Inside the pressure vessel 1, an internal circulation type cylindrical gasification furnace 2 is arranged. The cylindrical gasification furnace 2 has one closed cylindrical wall 11 having a cylindrical outer wall 11 formed by connecting water pipes. It is a container, in which a gasification chamber fluidized bed is formed. A product gas outlet 2 a is provided at the upper end of the cylindrical gasifier 2, and this gas outlet 2 a is joined to the product gas outlet 4 of the pressure vessel 1. Further, the periphery of the bottom of the cylindrical gasifier 2 is supported by a cylindrical support 7 mounted on a lower head plate of the pressure vessel 1.

A partition wall 8 is provided inside the fluidized bed of the cylindrical gasifier 2, and separates the gasification chamber 9 and the heat recovery chamber 10 by the partition wall 8. The partition wall 8 is constituted by a water pipe taken out from the cylindrical outer wall 11, and this water pipe is further covered with a fire-resistant and heat-resistant material. The partition wall 8 includes a cylindrical partition wall 8a and a conical partition wall 8b formed on the cylindrical partition wall 8, and the conical partition wall 8b is formed.
Functions as a reflecting wall that intercepts the upward flow path of the fluidizing air and reflects and redirects the fluidizing air toward the center of the furnace. As a result, a swirling flow as indicated by an arrow is generated inside the gasification chamber 9. . The upper part of the gasification chamber 9 and the upper part of the heat recovery chamber 10 form a free board 31 integrally. Between the free board above the heat recovery chamber 10 and the free board above the gasification chamber 9, there is no partition wall or the like, and there is a free board 31 in an integrated space, and both generated gases are free to each other. It is configured to go around.

In the heat recovery chamber 10, an in-layer heat transfer tube 15 branched from an in-layer tube upper header 13 and an in-layer tube lower header 14 provided outside the cylindrical outer wall 11 is disposed. A water supply inlet 16 is provided at a lower portion of the pressure vessel 1, and boiler water introduced from the water supply inlet 16 passes through the cylindrical outer wall 11 and then flows into the lower header 14 for the in-layer pipe via the connecting pipe 16a. Then, it is distributed from the lower header tube 14 for the in-layer tube to the in-layer heat transfer tube 15. Then, the steam generated in the in-layer heat transfer tube 15 is collected in the in-layer tube upper header 13 and is led out from the steam outlet 17 to the outside.

On the other hand, the pressure vessel 1 is provided with a pressure equalizing nozzle 18. The pressure equalizing nozzle 18 branches from a high-pressure flowing gas system 19 connected to the flowing gas inlet 3. The inside of the pressure vessel 1 and the inside of the cylindrical gasifier 2 are made to have a substantially uniform pressure except for the pressure loss of the fluidized bed, so that the gasifier 2 has a non-pressure-resistant structure. However, in this case, the free board 31 of the cylindrical gasifier 2 receives an external pressure corresponding to the fluidized bed pressure loss. Further, a pressure reducing valve or the like is provided in front of the equalizing nozzle 18 so that the space 36 between the pressure vessel 1 and the cylindrical gasifier 2 and the free board 31 have a uniform pressure. The lower part of the furnace 2 below the fluidized bed receives the internal pressure corresponding to the fluidized bed pressure loss. The pressure vessel 1 is provided with a solid combustible material inlet 6, which is connected to a combustible material inlet 22.

The gasification chamber 9 is provided with a conical hearth 20 whose center is higher and becomes lower toward the outer periphery.
An air diffuser 21 is provided on the hearth 20. And
Fluidizing gas is ejected from the air diffuser 21 communicating with the fluidizing gas inlet 3 to fluidize the fluid medium in the gasification chamber 9. The combustible material inlet 22 is open near the hearth 20 of the gasification chamber 9 and near the partition wall 8. The mass velocity of the fluidizing gas ejected from the outer annular portion of the diffuser 21 is set to a velocity sufficient to form a fluidized bed of the fluidized medium in the furnace. The mass velocity of the forming gas is selected to be smaller than that of the outer peripheral portion. Thereby, the range of the concentric circle having a diameter of about 1/2 of the gasification chamber 9 is a moving bed in a gently fluidized state of about 1 to 2.5 times the minimum fluidization speed, and the outer annular portion of the concentric circle is formed. In the fluidized bed of the gasification chamber, the fluidized medium is directed in all directions from the center along the conical hearth surface. After gently dispersing and moving, when reaching the outer peripheral annular portion, the moving direction is turned upward due to a high fluidization speed, and blows up along the inside of the partition wall 8, but gradually toward the center. When the cohesive force increases and reaches the maximum on the surface of the fluidized bed, the fluid medium explosively scatters in the circumferential and upward directions due to the reaction force.

As a result, a large amount of the fluid medium enters the heat recovery chamber 10 across the partition wall 8. At this time, the fluidized bed of the heat recovery chamber is in a gently flowing state within twice the minimum fluidization rate, so that agglomeration is likely to occur,
It is necessary to avoid the incorporation of solid fuel such as coarse-grained coal. Therefore, the free board 31 is provided with a screen 12 composed of a water pipe and a protector having a comb-like shape so as to surround the heat recovery chamber 10, and this screen 12 prevents the inflow of coarse solid fuel and The gas generated from the heat recovery chamber 10 has a baffle effect, and is sufficiently mixed and stirred with the gas generated from the gasification chamber 9.

On the other hand, the fluid medium remaining on the surface of the fluidized bed forms a cylindrical flow near the center and sinks while entraining the surrounding fluid medium. A circulating flow is created which turns into a transfer to
Due to the effect of this circulating flow, solid combustibles such as combustible wastes injected from the combustibles inlet 22 provided near the hearth are uniformly dispersed in all directions in the gasification chamber, and this is a simple coal supply facility. However, uneven distribution of fuel is avoided, and there is no danger of clinker generation.

In the heat recovery chamber 10, an inverted conical hearth 23 that is higher from the inner circumference toward the outer circumference is installed, and an air diffuser 24 is installed on the hearth 23.
Fluidizing gas is ejected from the diffuser 24 communicating with the gas inlet 5 for controlling the heat recovery chamber, and flows slowly through the heat recovery chamber 10 so as to flow through the partition wall 8 and enter the heat recovery chamber 10. Gently settles in the fluidized bed of the heat recovery chamber while being cooled by the in-bed heat transfer tube 15, and then passes through the communication passage 27 below the partition wall 8 along the inclined hearth, and flows through the fluidized bed of the gasification chamber. Reflux. As a result, the amount of heat generated in the gasification chamber 9 is effectively recovered through the in-layer heat transfer tube 15 of the heat recovery chamber 10. The communication passage 27 forms a communication port between the gasification chamber 9 and the heat recovery chamber 10 and faces the hearth 20 of the gasification chamber 9. The vicinity of the upper end of the partition wall 8 forms a communication port between the gasification chamber 9 and the heat recovery chamber 10, and is near the upper interface of the fluidized bed. A gas introduction pipe 25 and a back diffusion nozzle 26 are also provided on the back of the conical partition wall 8b, and the heat recovery chamber 10
It is possible to fluidize the fluid medium that has entered and partially burn it, but it may not be provided if the angle of the conical partition wall 8b is increased.

A gas box 28 for fluidized gasification is formed below the hearth 20 of the gasification chamber. The gas box 28 for fluidized gasification is surrounded by a water pipe 29 supporting the partition wall 8 and a gas inlet for fluidized gas. 3
Is connected to Also, below the hearth 23 of the heat recovery chamber,
A heat recovery control wind box 30 is formed, and the heat recovery control wind box 30 is connected to the outside through the heat recovery control gas inlet 5.

The upper part of the heat recovery chamber 10 is integrated with the upper part of the gasification chamber 9 to form a wide free board 31 in which the gas generated from the heat recovery chamber 10 and the gasification chamber 9 are formed. And the gas generated from the mixture. Therefore, the gas residence time in the free board 31 can be lengthened, and the combustibles can be sufficiently gasified in the free board 31. Further, a plurality of secondary air nozzles 33 are provided on the free board 31, so that a two-stage gasification method can be adopted. Reference numeral 34 denotes a secondary air inlet.

Next, the gasification step will be described. In the gasification furnace 2 shown in FIG. 1, the fluidizing gas supplied through the diffuser 21 disposed at the furnace bottom in the gasification chamber 9 is supplied from the vicinity of the center of the furnace bottom of the gasification chamber 9 to the inside of the furnace. And a peripheral fluidizing gas supplied as an upward flow from the periphery of the furnace bottom of the gasification chamber 9 into the furnace.

[0034] The central fluidizing gas is one of three gases: steam, a mixture of steam and air, and air;
The peripheral fluidizing gas is one of three gases: oxygen, a mixture of oxygen and air, and air. The air amount of the entire fluidizing gas is set to be equal to or less than the theoretical combustion air amount required for combustible matter combustion, and the inside of the furnace is set to a reducing atmosphere.

The mass velocity of the central fluidizing gas is less than the mass velocity of the peripheral fluidizing gas, and the upward flow of the fluidizing gas above the perimeter in the furnace is diverted such that it is directed toward the center of the furnace. As a result, a moving bed in which the fluidized medium (usually silica sand) is settled and diffused is formed in the center of the furnace, and a fluidized bed in which the fluidized medium is actively fluidized is formed in the periphery of the furnace. .

The combustible material supplied to the upper part of the moving bed from the combustible material supply port 22 is heated by the heat of the flowing medium while descending in the moving bed together with the fluidized medium, and the volatile components are mainly gasified. . Since there is no or little oxygen in the moving bed, the product gas consisting of gasified volatiles passes through the moving bed without being burned. Therefore, the moving bed forms a gasification zone. The product gas moved to the free board 31 rises and is discharged from the gas outlet 4 as a product gas 50.

Not gasified in the moving bed of the gasification chamber 9;
Mainly, char (fixed carbon content) and tar move from the lower part of the moving bed to the lower part of the fluidized bed around the furnace inside the gasification chamber 9 together with the fluidized medium, and are burned by the peripheral fluidized gas having a relatively high oxygen content. And is partially oxidized. The fluidized bed forms an oxidation zone for combustibles. In the fluidized bed, the fluidized medium is heated by combustion heat in the fluidized bed to a high temperature. The high temperature fluid medium is inverted by the partition wall 8, moves to the moving bed, and again becomes a heat source for gasification. The temperature of the fluidized bed is 4
The temperature is maintained at 50 to 800 ° C., and the suppressed combustion reaction is continued.

According to the gasification furnace shown in FIG.
A gasification zone at the center and an oxidation zone at the periphery are formed in the central zone, and the fluidized medium serves as a heat transfer medium in both zones, so that a high-quality combustible gas having a high calorific value is generated in the gasification zone. In the above, char and tar, which are difficult to gasify, can be partially burned and gasified efficiently. Therefore, the gasification efficiency of combustibles can be improved, and high-quality combustible gas can be generated.

Since the char is uniformly dispersed around the furnace by the swirling flow, the char can be efficiently oxidized. As a result, it does not occur that unreacted oxygen rises and oxidizes the upper product gas. Therefore, gas oxidation is prevented, gasification efficiency is high, and since char is oxidized efficiently, the energy recovery rate is high. Also, due to the swirling flow, there is a lateral flow at the bottom of the furnace, so even if there is large non-crushable incombustible material, it does not accumulate on the bottom of the furnace and can be discharged, allowing raw material to be crushed and charged. . In addition, the swirling promotes the diffusion of heat in the furnace, prevents agglomeration of sand (agglomeration), increases the load on the hearth, and makes the furnace compact.

In the embodiment shown in FIG. 1, the generated gas and the char are sent from the gas outlet 4 to the melting furnace through a duct.
The temperature is kept between 0 and 750 ° C. For that purpose, the amount of the fluidizing gas is adjusted by the diffuser 24 in the heat recovery chamber 10 and the amounts of the peripheral fluidizing gas and the central fluidizing gas for forming the fluidized bed and the moving bed are adjusted in the gasification chamber 9. The temperature of the fluid medium is not excessively increased, and the gas sent from the free boat to the duct is adjusted to 900 ° C. or less.

In the heat recovery chamber 10, a heat transfer tube 15 through which a heat receiving fluid passes is disposed inside the waste heat boiler connected to the waste heat boiler, and performs heat exchange with a fluid medium moving downward in the heat recovery chamber 10. Heat is recovered from the flowing medium. The heat transfer coefficient in the heat recovery section greatly changes when the amount of diffused air in the heat recovery chamber is changed from 0 to 3 Gmf.

In order to control the heat recovery amount, as described above, the heat transfer coefficient is controlled at the same time as the flow medium circulation amount is controlled. That is, if the amount of fluidized gas in the gasification chamber 9 is constant, if the amount of diffused air in the heat recovery chamber 10 is increased, the amount of fluidized medium circulated is increased, and at the same time, the heat transfer coefficient is increased. The amount increases significantly. This has the effect of preventing the temperature of the fluidized medium from rising to a predetermined temperature or higher from the viewpoint of the temperature of the fluidized medium in the fluidized bed.
Therefore, even if the combustible material is plastic or the like that emits high temperature during combustion, the fluidized bed can be controlled at 450 to 800 ° C.
As a result, the free board portion is 900 ° C. or less (for example, 700 ° C.).
~ 750 ° C).

As a means for introducing gas into the heat recovery chamber 10, various devices can be considered, but generally, a method in which a diffuser or a diffuser nozzle is installed horizontally is adopted. In this case, if the openings for introducing gas are provided uniformly on the entire hearth surface, the supply gas amount per unit area becomes uniform over the entire hearth surface regardless of the gas supply amount to the diffuser.
When the gas supply amount to the air diffuser is gradually increased, the fluidized medium in the heat recovery chamber changes from a fixed bed to a moving bed and a fluidized bed at a certain supply gas amount.

The heat transfer in the heat recovery chamber 10 is not only a heat transfer by the direct contact between the fluid medium and the heat transfer tube 15, but also a gas that rises while vibrating irregularly and violently due to the flow of the fluid medium. There is heat transfer. In the latter case, there is almost no boundary layer on the solid surface that hinders the heat transfer with respect to the normal gas-solid contact heat transfer, and the flowing media are well stirred by the flow. Unlike heat transfer in powder, it shows extremely large heat transfer characteristics. Therefore,
In the heat recovery chamber of the present invention, a heat transfer coefficient nearly ten times higher than that of a normal combustion gas boiler can be obtained.

As described above, the heat transfer phenomenon between the flowing medium and the heat transfer surface largely depends on the strength of the flow, and the amount of the flowing medium can be adjusted by adjusting the amount of gas introduced from the diffuser 24, and By making the heat recovery chamber 10 using a moving bed independent of the gasification chamber 9 in the furnace, a fluidized bed heat recovery chamber that is compact, has a large turndown ratio, and is easy to control can be obtained.

The temperature of the gasification chamber 9 is controlled by adjusting the ejection amount of the central fluidizing gas and the peripheral fluidizing gas in the gasification chamber 9. Therefore, it is possible to control the temperature by combining temperature control in the heat recovery chamber 10 and temperature control in the gasification chamber 9 by the central fluidizing gas and the peripheral fluidizing gas in the gasification chamber 9. Temperature control with the former being the main and the latter being the slave, or vice versa, is also conceivable. In both cases where the temperature control in the heat recovery chamber is main and when it is subordinate, the temperature is largely changed in the room where the main temperature control is performed, and the temperature is almost constant in the room where the temperature control is performed. Control to keep in.

(Embodiment 2) FIG. 2 is a partial sectional view showing a second embodiment of the pressurized fluidized-bed gasification furnace according to the present invention. FIG.
Indicates a horizontal section of the fluidized bed portion. Further, in FIG. 2, the vertical cross section of the fluidized bed portion corresponds to the view along arrow aa in FIG. Here, description will be made with reference to FIGS.

The interior of the pressure vessel 1 is divided into a gasification chamber 9 and an annular heat recovery chamber 10 by a first partition wall 8 concentric with the outer wall. The inside of the pressure vessel 1 is maintained at a predetermined pressure higher than the atmospheric pressure. The first partition 8 is provided with a plurality of rectangular upper communication ports 37 and a plurality of rectangular lower communication ports 38, and the gasification chamber 9 and the heat recovery chamber 10 are connected to each other. Although not shown in the figure, the first partition wall 8 that forms the boundary between the gasification chamber 9 and the heat recovery chamber 10 has an inclined surface that falls on the gasification chamber side on the gasification chamber side. The heat recovery chamber side is vertical. The gasification chamber 9 is provided with a gas outlet 49, from which the product gas 50 is led out.

On the other hand, the heat recovery chamber 10 is further provided with a plurality of heat recovery sections 1 having a plurality of combustion sections 10A without heat transfer tubes and a plurality of heat transfer pipes 15 by a plurality of second partition walls 32 extending in the radial direction.
0B. However, the upper part is not divided, and the free board part is composed of the combustion part 10A and the heat recovery part 10B.
After the respective flue gases are mixed at the freeboard portion, the flue gas is discharged from the gas discharge port 51 to the outside as a flue gas 52. Each heat recovery unit 10B
Has a heat transfer tube 15 embedded therein so that heat can be recovered from the fluid medium. In the heat recovery chamber 10, the combustion unit 10
The second partition wall 32, which forms a boundary between A and the heat recovery unit 10B,
Although not shown in the figure, the combustion section has an inclined surface falling down to the combustion section, while the heat recovery section has a vertical surface. Further, a lower communication port 40 is provided in each second partition wall 32 so that the flow medium can be moved between the combustion unit 10A and the heat recovery unit 10B together with the upper opening 39.

At the lower part of the gasification chamber 9, a conical hearth 127 is formed in which the center is higher and becomes lower toward the outer periphery, and an annular hearth 128 is formed so as to surround the hearth 127. Have been. Wind boxes 78 and 79 are provided below the hearths 127 and 128, and fluidizing gases 118 and 119 are introduced into the wind boxes 78 and 79 through connection ports 113 and 114, respectively. A gas containing oxygen is not introduced into the wind box 78, and a gas containing oxygen is introduced into the wind box 79.

On the other hand, the hearths 127 and 128 are provided with air diffusers 132 and 133, respectively. Air diffuser 13
From 2, the fluidizing gas is ejected so as to give a substantially small fluidizing speed, and as a result, a weak fluidizing zone 41 is formed above the hearth 127. A fluidizing gas is ejected from the air diffuser 133 so as to give a substantially high fluidizing speed, and the strong fluidizing region 42 is formed above the hearth 128. As a result of the presence of two different fluidization zones in the fluidized bed of the gasification chamber 9, it rises in the strong fluidization zone 42 in the surrounding annular area, flows toward the center, and weakly flows in the central cylindrical area. A swirling flow is generated in the gasification zone 41.

On the other hand, also in the heat recovery chamber 10, the combustion section 1
Hearths 129 and 130 are formed at the lower part of 0A.
Wind boxes 110 and 111 are provided below the hearths 129 and 130. Fluidizing gases 120 and 121 are introduced into the wind boxes 110 and 111 through connection ports 115 and 116, respectively. On the other hand, the hearths 129 and 130 are provided with air diffusers 134 and 135, respectively. Air diffuser 134
From above, the fluidizing gas is ejected so as to give a substantially small fluidizing speed, and as a result, a weak fluidized area 43 is formed above the hearth 129. A fluidizing gas is ejected from the air diffuser 135 so as to give a substantially large fluidizing speed,
The strong fluidization zone 44 is formed above the hearth 130. As a result of the presence of the two different fluidization zones in the fluidized bed of the combustion unit 10A, a swirling flow that sinks in the weak fluidization zone 43 and rises in the strong fluidization zone 44 occurs.

On the other hand, also in the heat recovery section 10B, a hearth 131 is formed at a lower part, and a wind box 112 is provided at a lower part of the hearth 131. Connection box 1 in wind box 112
Fluidizing gas 122 is introduced through 17. A diffuser 136 is provided on the hearth 131. A fluidizing gas is ejected from the air diffuser 136 so as to give a substantially small fluidizing speed, and as a result, a weak fluidizing region 45 is formed above the hearth 131.

As described above, by combining fluidization zones having different fluidization rates inside the gasification chamber 9 and the heat recovery chamber 10, the following flows occur. That is, in the fluidized bed of the gasification chamber 9, the fluidized medium descends along the settling flow 55 in the weak fluidized area 41. Then, near the hearth 127, the flow changes to a horizontal flow 56 toward the strong fluidization region 42, and further becomes an upward flow 57 in the strong fluidization region 42. On the other hand, the ascending flow 57 branches near the surface of the fluidized bed into a flow 58 toward the central weak fluidization region 41 and a reverse flow 59 toward the heat recovery chamber 10 through the communication port 37 of the first partition wall 8. Therefore, a swirling flow is formed in the fluidized bed of the gasification chamber 9 in the weak fluidized region and rises in the strong fluidized region, while a part of the fluid medium is supplied to the communication port 37 above the first partition wall. Through the heat recovery chamber 10
To the combustion section 10A.

On the other hand, also in the combustion section 10A, the communication port 3
7, a weak fluidization zone 43 is formed.
The fluidized medium 44 descends along the settling flow 60 in the weak fluidized area 43 even in the fluidized bed of the combustion section 10A because the strong fluidized area 44 is formed above the fluidized bed. Therefore, the fluid medium containing the unburned char that has flowed from the gasification chamber 9 by the reverse flow 59 is also swallowed by the settling flow 60 into the inside of the combustion section 10A, and is completely burned.

Then, near the hearth, some of the flowing medium
In addition to returning to the gasification chamber 9 as a reflux 67 through the lower communication port 38 of the partition wall 8, a horizontal flow 61 toward the strong fluidization area 44
In the strong fluidization zone 44, the flow further rises.
On the other hand, the upward flow 62 is in the vicinity of the fluidized bed surface,
The flow 63 branches toward a flow 63 toward the heat recovery unit 10B through the upper space of the second partition wall 32.
Therefore, in the fluidized bed of the heat recovery chamber 10, the weak fluidized area 43
And a rising flow is formed in the strong fluidization zone 44, while a part of the flowing medium is introduced into the heat recovery unit 10B over the upper part of the second partition wall 32, and another flowing medium is 1
The gas is returned to the gasification chamber 9 from the communication port 38 below the partition wall 8.

On the other hand, in the heat recovery section 10 B, since the weak fluidized area 45 is formed, a settling flow 65 is generated, and the fluid medium is combusted by the reflux 66 passing through the lower communication port 40 of the second partition wall 32. Return to unit 10A. As described above, in the fluidized bed of the gasification chamber 9, the combustion section 10A of the heat recovery chamber 10, and the fluidized bed of the heat recovery section 10B of the heat recovery chamber 10, an internal swirling flow and a mutual circulating flow are respectively formed. Therefore, when the combustible material inlet 47 is provided above the weak fluidization region 41 of the gasification chamber 9 and the combustible material 48 is charged, the combustible material 48 is swallowed by the settling flow 55 into the fluidized bed of the gasification chamber 9, and is swirled by the swirl flow. , And partial combustion and gasification are performed. The oxygen content of the fluidizing gas supplied to the hearth portion of the gasification chamber 9 is set to be equal to or less than the oxygen amount necessary for theoretical combustion of the combustibles 48 to be charged.

On the other hand, the fluid medium containing the unburned char is introduced into the main combustion chamber 6 by the reversal flow 59, where the sedimentation flow 60
The liquid is swallowed into the fluidized bed, uniformly dispersed and mixed by the swirling flow, and completely burned in an oxidizing atmosphere. As shown in FIG. 2, it is also possible to provide a fuel inlet 68 above the weak fluidization zone 43 and supply an auxiliary fuel 69 as needed. In addition, a plurality of nozzles 53 may be provided on the free board, and secondary air 54 may be introduced to perform complete combustion as needed.

A part of the heat generated by the combustion in the combustion section 10 A of the heat recovery chamber 10 is introduced into the gasification chamber 9 by the reflux 67 passing through the lower communication port 38 of the first partition wall 8, and the heat generated by the gasification heat source. In addition, the fluid enters the heat recovery unit 10B over the upper part of the second partition wall, and is taken out to the outside through the heat transfer tube 15 of the heat recovery unit 10B by the flowing medium circulating flow returning to the combustion unit 10A from the lower communication port 40. A part of the energy of the combustibles thus input is converted into chemical energy as gas, and components that are difficult to gasify are converted into heat energy in the heat recovery chamber 10 to be effectively and efficiently recovered. Is possible.

In addition, non-combustible components are often mixed in the combustibles to be charged. Therefore, in the present embodiment, the hearth 128 of the gasification chamber 9 and the hearth 12 of the heat recovery chamber 10
9 is provided with a noncombustible substance discharge port 123, and the noncombustible substance 125 is discharged from this discharge port 123. Further, when incombustibles are mixed in the auxiliary fuel 69, an incombustibles outlet is provided near the lower part of the second partition wall, between the gasification chamber hearth and the heat recovery chamber hearth, though not particularly shown, as shown in FIG.
Incombustibles may be discharged. Further, in order to facilitate discharge of incombustibles, it is preferable that each hearth has a downward slope toward the incombustibles outlet.

(Embodiment 3) FIG. 4 is a sectional view showing a third embodiment of a pressurized fluidized bed gasifier according to the present invention. In this embodiment, the gasification chamber 9, the heat recovery chamber 10, and the char combustion chamber 19
0 are disposed in independent pressure vessels 1A, 1B, and 1C, respectively. The interior of the pressure vessels 1A, 1B, 1C
Each is maintained at a predetermined pressure higher than the atmospheric pressure.

The gasification chamber 9 and the heat recovery chamber 10 are connected via upper and lower communication pipes 150 and 151. The communication port of one communication pipe 150 of the two communication pipes faces the furnace bottom of the gasification chamber 9, and the communication port of the other communication pipe 151 is provided near the upper interface of the fluidized bed of the gasification chamber 9. Have been.
The gasification chamber 9 and the char combustion chamber 190 are connected via upper and lower communication pipes 250 and 251. The communication port of one communication pipe 250 of the two communication pipes faces the furnace bottom of the gasification chamber 9, and the communication port of the other communication pipe 251 is provided near the upper interface of the fluidized bed of the gasification chamber 9. Have been. The combustible material 48 is supplied from the combustible material supply port 47 into the gasification chamber 9. The gas generated in the gasification chamber 9 is discharged from a gas discharge port 49.

At the lower part of the gasification chamber 9, a conical hearth 127 is formed in which the central part is higher and becomes lower toward the outer peripheral side, and an annular hearth 128 is formed so as to surround the hearth 127. Have been. Wind boxes 78 and 79 are provided below the hearths 127 and 128, and fluidizing gases 118 and 119 are introduced into the wind boxes 78 and 79 through connection ports 113 and 114, respectively.

On the other hand, the hearths 127 and 128 are provided with air diffusers 132 and 133, respectively. Air diffuser 13
From 2, the fluidizing gas is ejected so as to give a substantially small fluidizing speed, and as a result, a weak fluidizing zone 41 is formed above the hearth 127. A fluidizing gas is ejected from the air diffuser 133 so as to give a substantially high fluidizing speed, and the strong fluidizing region 42 is formed above the hearth 128. As a result of the presence of two different fluidization zones in the fluidized bed of the gasification chamber 9, it rises in the strong fluidization zone 42 in the surrounding annular area, flows toward the center, and weakly flows in the central cylindrical area. A swirling flow is generated in the gasification zone 41.

In the fluidized bed of the gasification chamber 9, the weak fluidized zone 4
1, and a swirling flow that rises in the strong fluidization zone 42 is formed, while a part of the fluid medium is introduced into the heat recovery chamber 10 through the communication pipe 151. In the heat recovery chamber 10, a settling flow of the fluid medium is formed by the fluidizing gas 122, and the fluid medium returns to the gasification chamber 9 through the communication pipe 150 after applying heat to the heat transfer pipe 15. A part of the fluidized medium containing the char in the gasification chamber 9 is introduced into the char combustion chamber 190 through the communication pipe 251 and the char is burned by the fluidized gas 120 containing combustion oxygen. And
The flow medium in the lower part of the char and the combustion chamber 190 is connected to the connecting pipe 250.
Through the gasification chamber 9. Since the functions and effects of the gasification chamber 9 and the heat recovery chamber 10 are the same as those of the first embodiment, detailed description thereof will be omitted.

FIG. 5 is a view showing a fourth embodiment of the present invention, in which a pressurized fluidized bed gasification combined cycle system using the pressurized fluidized bed gasifier of the present invention for repowering of an existing pulverized coal boiler is shown. It is a block diagram of a main part. The internal circulating fluidized bed gasifier 2 is housed inside the pressure vessel 1, and the generated gas is guided to a gas combustor 206 via a high-temperature dust collector 205 and then driven by a gas turbine 209 to generate electric power. Generator 211 generates power. The configurations of the internal circulating fluidized bed gasifier 2 and the pressure vessel 1 are the same as those in the embodiment shown in FIG. However, the difference from the embodiment of FIG. 1 is that a heat transfer tube 170 constituting a heat transfer surface for gas cooling is arranged on the free board 31 of the gasification furnace 2 of the present embodiment.

The gas turbine 209 has an air compressor 210
Is connected to supply compressed air for a gasifier or a combustor. The unburned char collected by the high-temperature dust collector 205 is supplied to the pulverized coal boiler 214 and burned by the exhaust gas of the gas turbine 209. If there is not enough oxygen left in the gas turbine exhaust, supply air or oxygen for char combustion. If steam, nitrogen gas or the like is used for fluidization adjustment of the gasification furnace 2, the fluidization of the gasification furnace can be adjusted without affecting the gasification rate.

The char accumulated in the gasifier is extracted from the furnace, crushed by a crusher 218, and supplied to the gasifier or the pulverized coal boiler. A pneumatic transport system using the pressure of a gasifier can be used to transport the char when supplying it to an existing pulverized coal boiler.

FIG. 6 is a diagram showing the overall configuration of the combined pressurized fluidized bed gasification combined cycle system shown in FIG. Pulverized coal boiler 2
The steam generated at 14 is guided to a steam turbine 213, which drives the steam turbine 213 to generate power with a generator 211. The exhaust gas from the steam turbine 213 is guided to a condenser 216. The flue gas from the pulverized coal boiler 214 is
Is discharged through.

(Embodiment 5) FIG. 7 is a view showing a fifth embodiment of the present invention, and is a configuration diagram of a system using a high-temperature melting furnace as a main combustion furnace of a char. In this embodiment, a high-temperature melting furnace 21 is used instead of the pulverized coal boiler 214 of the embodiment shown in FIG.
5 is provided. That is, the unburned portion including the char collected by the high-temperature dust collector 205 is completely burned in the high-temperature melting furnace 215, and the ash becomes molten slag. Other configurations are shown in FIG.
This is the same as the embodiment shown in FIG.

FIG. 8 is a diagram showing the overall configuration of the combined pressurized fluidized bed gasification combined cycle system shown in FIG. High-temperature melting furnace 2
In 15, unburned components such as chars collected by the high-temperature dust collector 205 are introduced. The exhaust of the gas turbine 209 is
After being pressurized through the pressurizing blower 220, it is supplied to the high-temperature melting furnace 215. The unburned matter introduced into the high-temperature melting furnace 215 is completely burned here, and the ash becomes molten slag.
The combustion exhaust gas from the high-temperature melting furnace 215 is supplied to a heat recovery unit 212.
After flowing into the dust collector 203, heat is recovered. And the exhaust gas that has exited the dust collector 203 is the waste heat boiler 1
09 and is discharged from the chimney 217. The steam generated in the waste heat boiler 109 is guided to a steam turbine 213,
The steam turbine 213 is driven to generate power by the generator 211. Exhaust gas from the steam turbine 213 is guided to a condenser 216.

[0072]

According to the present invention, a gasification furnace capable of controlling the gasification temperature without affecting the gas properties is realized, so that stable operation of the gasification furnace without generating tar or clinker trouble can be achieved. Will be possible. Further, since gasification of fuel in which char is accumulated in the gasification furnace is facilitated, the range of usable fuel is widened, and the versatility of the apparatus is enhanced. Further, when the present invention is used for repowering existing power generation equipment, the output can be increased at a much lower cost than when a new power generation equipment is constructed, and the power generation efficiency is improved.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a first embodiment of a pressurized fluidized-bed gasifier according to the present invention.

FIG. 2 is a front view having a partial cross section showing a second embodiment of the pressurized fluidized-bed gasifier according to the present invention.

FIG. 3 is a view showing a horizontal cross section of FIG. 2;

FIG. 4 is a longitudinal sectional view showing a third embodiment of the pressurized fluidized-bed gasifier according to the present invention.

FIG. 5 is a configuration diagram of a main part of an embodiment of a combined pressurized fluidized-bed gasification power generation system according to the present invention.

FIG. 6 is an overall configuration diagram of one embodiment of a pressurized fluidized-bed gasification combined cycle system of the present invention.

FIG. 7 is a main part configuration diagram of another embodiment of the combined pressurized fluidized-bed gasification combined cycle system of the present invention.

FIG. 8 is an overall configuration diagram of another embodiment of the combined pressurized fluidized bed gasification combined cycle system of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Pressure vessel 2 Cylindrical combustor 3 Fluid gas inlet 4 Product gas outlet 5 Heat recovery control gas inlet 6 Coal supply inlet 7 Cylindrical support 8 Partition wall 9 Gasification room 10 Heat recovery room 10A Combustion unit 10B Heat recovery unit DESCRIPTION OF SYMBOLS 11 Cylindrical outer wall 12 Screen 13 Upper header for inner layer pipe 14 Lower header for inner layer pipe 15 Heat transfer pipe in layer 16 Water supply inlet 18 Equalizing nozzle 19 Flow gas system 20, 21, 23, 24, 127, 128, 129, 1
30, 131, 132, 133, 134, 135, 1
36 Air diffuser 22, 47 Combustible material inlet 27 Communication passage 30, 78, 79, 110, 111, 112 Wind box 31 Free board 32 Second partition wall 33 Secondary air nozzle 123 Noncombustible material outlet 203, 205 Dust collection Apparatus 206 Combustor 209 Gas turbine 210 Compressor 211 Generator 212 Heat recovery unit 213 Steam turbine 214 Pulverized coal boiler 215 High-temperature melting furnace 216 Condenser 217 Chimney 218 Crusher

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI F02C 3/28 F02C 6/18 A 6/18 F23C 11/02 310 F23C 11/02 310 F23G 5/027 ZABB F23G 5/027 ZAB 5/30 ZABQ 5/30 ZAB 5/46 ZABB 5/46 ZAB F23J 1/00 B F23J 1/00 B09B 3/00 302F (72) Inventor Shinichiro Chiba 11-1 Haneda Asahimachi, Ota-ku, Tokyo Inside Ebara Corporation (72) Inventor Toshiya Orihara 11-1 Haneda Asahimachi, Ota-ku, Tokyo Inside Ebara Corporation

Claims (9)

[Claims] 1. A pressurized fluidized bed gasifier for gasifying combustibles under pressure, wherein a gasification chamber and a heat recovery chamber are provided inside the gasification furnace, and the gasification chamber and the heat recovery chamber are provided in two. One of the two communication ports faces the bottom of the gasification chamber, and the other is provided near the upper interface of the fluidized bed of the gasification chamber. A heat transfer tube that collects heat from the fluid medium is provided, and has a bed temperature control function that can control the heat recovery amount by changing the fluidization state by adjusting the flow rate of the fluidizing gas blown into the heat recovery chamber, A pressurized fluidized bed gasification furnace, wherein the gasification chamber and the heat recovery chamber are arranged in the same pressure vessel. 2. The pressurized fluidized bed according to claim 1, wherein the gasification chamber has a cylindrical shape, and the heat recovery chamber is disposed so as to substantially surround the periphery of the gasification chamber. Gasifier. 3. The pressurized flow according to claim 1, wherein a part without the heat transfer tube is provided in a part of the heat recovery chamber, and the char is actively burned in the part without the heat transfer tube. Bed gasifier. 4. A pressurized fluidized-bed gasification furnace for gasifying combustibles under pressure is provided with a gasification chamber and a heat recovery chamber, wherein the gasification chamber and the heat recovery chamber are communicated by two communication ports. One of the two ports faces the furnace bottom of the gasification chamber, and the other is located near the upper interface of the fluidized bed of the gasification chamber. The heat recovery chamber recovers heat from the fluidized medium. A heat transfer tube is provided, which has a bed temperature control function that controls the amount of heat recovery by adjusting the flow rate of the fluidizing gas blown into the heat recovery chamber and changing the fluidization state. A pressurized fluidized-bed gasification furnace, wherein the chambers are arranged in independent pressure vessels. 5. The pressurized fluidized bed gasification furnace according to claim 4, wherein both the gasification chamber and the heat recovery chamber are cylindrical. 6. A char combustion chamber disposed in an independent pressure vessel, wherein the char combustion chamber and the gasification chamber communicate with each other through two communication ports, and one of the two communication ports is a furnace of the gasification chamber. The pressurized fluidized-bed gasification furnace according to claim 4 or 5, characterized in that it faces the bottom and the other is provided near the upper interface of the fluidized bed in the gasification chamber. 7. A fluidizing gas wind box provided at a lower part of the gasification chamber is divided into at least two or more, and a flow velocity of the fluidizing gas blown into the gasification chamber from each wind box is changed. As a result, an ascending flow and a descending flow of the flowing medium are generated in the gasification chamber, and the gas containing oxygen is not introduced into the wind box of the portion forming the descending flow area, and the wind box of the portion forming the ascending flow is not introduced. The pressurized fluidized bed gasification furnace according to any one of claims 1 to 6, wherein a gas containing oxygen is introduced. 8. The gasification furnace according to claim 1, wherein the char discharged together with the gas from the gasification furnace is collected under high temperature and high pressure and used as fuel for the pulverized coal boiler.
An integrated gasification combined cycle system using the pressurized fluidized bed gasification furnace described in the paragraph. 9. Chars discharged from the gasification furnace together with the gas are collected under high temperature and high pressure and burned in a high temperature melting furnace.
A combined gasification combined cycle system using the pressurized fluidized bed gasification furnace according to any one of claims 1 to 7 as the gasification furnace.