JPS61207493A - Coal gasifying apparatus - Google Patents

Abstract

PURPOSE:To provide the titled apparatus capable of economically gasifying coal with excellent adaptability to coal and starting characteristics and high gasification efficiency and heat exchange capacity, by gasifying a fuel such as coal using a gasifying oven comprising a specific water-cooled wall and a thin heat-resistant and refractory material lined on the inner wall surface of the gasifying oven. CONSTITUTION:A part of a finely divided coal, a circulating char and O2 or air which is a pressurized gasifying agent are fed to a combustor 18 of a gasifying oven comprising a combustor 18, diffuser 19 and reductor 20, surrounded with water-cooled wall 5 formed with a rifle tube and a fin and lined on the inside wall surface with a relatively thin heat- resistant and refractory material 6 in a thickness of 50mm or less and ignited at 1,400-1,800 deg.C under a pressure of about 40kg/cm<2>G. The high temperature gas and fuel are fed to the diffuser 19 while the remaining coal is also fed to conduct the carbonization. The carbonization products are homogeneously mixed, and the flow thereof is uniformalized. The endothermic gasifying reaction of the carbon particles is conducted in a reductor 20. The gas is fed to a heat exchanger 21. A drain is passed from a steam drum 1 through a downcomer 2, pressurized with a circulating pump 3, passed from a tube end 4 through the rifle tube forming the water cooled tube 5 and the heat resistant and refractory material 6 to absorb the heat, returned to the drum 1 through a tube end 7. The steam which has been separated in the drum 1 is taken out through a superheater 15.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a coal gasification device.

(Conventional technology) A conventional coal gasifier (single-stage spouted bed type) is shown in Figure 3.

A refractory heat-resistant material 22 having a thickness of 100 to 150 mm or more is provided inside the pressure vessel 21, and a gasifier 23 is formed in the upper part and a cooler part 24 is formed in the lower part. The upper part of the gasifier 23 contains coal,
Alternatively, an oil, air, or oxygen supply means 25 may be arranged, a radiant cooler 26 may be arranged within the cooler section 24, and a gas outlet 27 may be provided at the lower part.

Further, an ash hopper 28 is formed at the bottom of the cod 240.

When starting up the apparatus, oil and air are supplied from the supply means 25 into the gasification furnace 23 and burned to perform walking. The temperature inside the gasifier 25 is set to a predetermined temperature, for example, 1400 degrees Celsius.
As the temperature rises, oil is gradually switched to coal. When switching to coal, the amount of air supplied is lowered and the coal is incompletely combusted to produce combustible gases such as CO, α, and gas. The combustible gas enters the cooler section 24 from the gasifier 23, where it is passed through the radiant cooler 26 to a temperature of 1000 to 110 degrees Celsius.
It is cooled down to about 0 degrees.

The gas cooled to about 1000 to 1100 degrees Celsius exits from the gas outlet 27 and is sent to the heat exchanger. The slag produced in the gasifier 23 passes through the cooler section 24 and falls into the ash hopper 28, and is discharged from the outlet at the bottom of the ash hopper 28.

This conventional single-stage entrained bed gasifier has the following drawbacks.

(1) Because a thick fireproof and heat-insulating material is installed directly inside the pressure vessel without using a water-cooled wall, it takes a long time to walk during startup.

(2) In order to maintain the lifespan of the refractory material, the inside of the furnace cannot be heated to a high temperature, so coal, which has a high melting point, is not compatible with the ash. In other words, it depends on the compatibility with the coal type.

(3) In the case of the one-stage spouted bed system, it is necessary to lower the temperature of the log gas exiting the furnace using water or a radiant cooler, resulting in large heat loss and making it difficult to achieve high efficiency gasification.

(4) Partial breakage of the refractory material is likely to occur, which is very troublesome in terms of protecting the pressure vessel.

(Problems to be solved by the invention) The present invention solves the drawbacks of conventional coal gasifiers, and (1) Realizes a highly efficient gasifier (measures for thermal power generation): water quench or radiant cooler. This eliminates the ineffective content caused by the gas and increases the gasification efficiency.

(2) Expansion of compatibility with coal types: By adopting a water-cooled wall structure and two-inning construction of thin heat-resistant and refractory materials, the furnace temperature can be raised while minimizing heat loss, and coal types with high ash melting temperatures can be used. About 4 Make this available.

13) Realizing a highly reliable gasifier; shutting off high-temperature gas with a water-cooled wall (4) Realizing a gasifier with high operability; reducing warming time by using thin heat-resistant and refractory materials; (5) It is an object of the present invention to provide a coal gasification device that makes it possible to ensure the protection of water-cooled walls and prevent problems from occurring even if heat-resistant and fire-resistant materials are partially missing.

(Means for Solving the Problems) The present invention provides high performance and high This furnace aims to realize a reliable gasifier, and is located above the combustor section that burns fuel to form a high-temperature atmosphere. a diffuser section that mixes high-temperature gas and fuel;
and a gasification furnace consisting of a reductor section located above the diffuser section and communicating with the diffuser section to perform an endothermic gasification reaction to gasify the carbon particles from the diffuser section. The chemical furnace is formed of a water-cooled wall composed of pipes and a relatively thin heat-resistant/refractory material lined inside the water-cooled wall, and at least a portion of the pipes of the water-cooled wall are formed of rifled pipes. The coal gasification apparatus is characterized in that the top of the water-cooled wall is connected to a steam drum, and the bottom of the water-cooled wall is connected to the steam drum by a downcomer pipe equipped with a circulation pump in the middle.

The device of the present invention includes (1) various gasification furnaces, (2) MEID
It can be advantageously applied to power generation combustors and (3) slag tap boilers.

FIG. 1 shows the structure of an embodiment of a coal gasification apparatus according to the present invention, and FIG. 2 shows a gasification principle diagram of the apparatus of the present invention to help understand the operation and effect of the apparatus of the present invention.

(Configuration) In Figure 1, the gasifier is normally operated at 40 kg/aFG, with a combustor 18 and a diffuser 19.
The three parts of the reductor 20 are surrounded by a water-cooled wall 5 formed by a rifle tube and fins, and a relatively thin (approximately 50 mm or less) heat-resistant/refractory material 6 is lined inside the furnace. has been done. The heat-resistant/refractory material 6 is preferably attached to the water-cooled wall 5 by lining it as thinly as possible via studs. The entire gasifier is housed in a pressure vessel 17.

A portion of coal, circulating char, is placed in the combustor 18.

and air or O, are injected into the high temperature state IJi (14
00 to 1800° C.), and when the ash is melted and discharged, it supplies the heat necessary for gasification in the upper part of the tank 41.

(See FIG. 2) The gasifying agent (air or Os) is pumped by a compressor (not shown), pressurized, and supplied into the furnace.

The remaining coal is put into the de7izer 19 and carbonized, and at the same time, it is uniformly mixed with gas and the flow is averaged (see Figure 2).The combustor 18 and the diffuser 19
The coal is fed into the furnace by pressurizing the finely pulverized coal using a lock hopper system (not shown) and transporting it into the furnace.

In the reductor 20, the carbon particles are gasified and the gas is cooled (see FIG. 2), and the generated char is collected by a collector (not shown) and is reinjected into the combustor 18 as circulating char. (See FIG. 2) An ash hopper 24 is provided at the bottom of the combustor 18, and the molten slag flowing down is water-cooled here and discharged to the outside as water-cooled slag 22. (See Figure 2) Canned water is passed through the steam drum 1, downcomer pipe 2, and circulation pump 3.
The pressure is increased at the gasifier and reaches the lower header 4 of the gasifier. Therefore, after absorbing some heat through the rifle tube forming the water-cooled wall 5 constituting the peripheral wall of the gasifier and passing through the heat-resistant/refractory material 6,
It reaches the upper header 7 and from there returns to the steam drum 1.

The heat exchanger 21 includes a peripheral wall 25, a flue evaporator 13, and a superheater 1.
5. Consists of a energy saver 11, a flue evaporator 13, and a superheater 1
5. The economizer 11 is installed inside the peripheral wall 25 and supported by these hanger tubes 26.

A portion of the canned water passes through the connecting pipe 9, a portion passes through the peripheral wall 25 and the hanger tube 26, and is returned to the steam drum 1, and a further portion enters the flue evaporator 13, from which it is steamed. The steam separated in the steam drum 1 that is not returned to the drum 1 is
It is sent to the superheater 15 via the communication pipe 8, and further sent to the gas turbine exhaust gas boiler 16 (not shown).

Rifle tubes are used for part or all of the water-cooled wall tubes constituting the water-cooled wall 5.

(Function/Effect) (1) During the fuel gasification reaction, the furnace outlet gas temperature can be controlled to an appropriate value (below the softening point of ash) by mainly utilizing the endothermic reaction characteristics of , resulting in high gasification efficiency. can get. That is, there is an advantage that heat loss due to water quench or radiant cooler method is eliminated.

[2] The effect of (1) above and the effect of the thin refractory insulation material lined with the water-cooled wall (even if the temperature of the refractory/insulation material reaches the temperature inside the furnace, the refractory/insulation material is relatively thin, so the water-cooled wall on the back side The temperature inside the combustor can be raised sufficiently ((1400 to 1800°C). Therefore, the temperature inside the furnace can be raised to a high temperature without damaging the refractory/insulating material.) It also has excellent compatibility with coal types.

(3) By providing a diffuser, it is possible to uniformly mix high-temperature gas and fuel and stabilize the gas flow.
High gasification efficiency can be obtained.

(4) By eliminating thick heat-resistant and fire-resistant materials, the starting characteristics can be improved.

(5) Since rifled tubes are used as water-cooled wall tubes in the water-cooled wall, the heat exchange surface area is large and the protection of heat-resistant and fire-resistant materials is improved.

(6) Since canned water from the steam drum is forcibly circulated through the water-cooled wall pipes using a circulation pump, the canned water flows smoothly and heat exchange performance is increased.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the structure of an embodiment of the coal gasification apparatus of the present invention, FIG. FIG. 3 is a diagram for explaining a conventional coal gasifier. Child 1 Figure 2 Slab

Claims (1)

[Claims] A combustor section that burns fuel to form a high-temperature atmosphere; a combustor section that is located above the combustor section and communicates with the combustor section, carbonizes and thermally decomposes the fuel, and mixes the high-temperature gas from the combustor section with the fuel. and a reductor section located above the diffuser section and communicating with the diffuser section to perform an endothermic gasification reaction to gasify the carbon particles from the diffuser section. , the gasifier is formed of a water-cooled wall composed of tubes and a relatively thin heat-resistant/refractory material lined inside the water-cooled wall, and at least a part of the tubes of the water-cooled wall are formed of rifled tubes. A coal gasification apparatus characterized in that the top of the water-cooled wall is connected to a steam drum, and the lower part of the water-cooled wall is connected to the steam drum by a downcomer having a circulation pump in the middle.