JPH0633370B2 - Coal gasification power plant - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a combined coal gasification combined cycle power plant using a pressurized air-blown coal gasification furnace, and in the case of performing dry coal supply of pulverized coal to coal. A pulverized coal supply device, for example, a gas containing oxygen dioxide as a main component, which is separated from a rock hopper by a gas purification device, or a combustion gas after the tail gas of a sulfur recovery device is oxidized by a catalytic combustor, or a gasifier-generated steam The integrated coal gasification combined cycle power plant is characterized by providing a method by which the pulverized coal can be safely operated without burning or exploding in the coal supply process, and can be economically operated by improving the thermal efficiency by pressurizing by Coal supply device and its configuration.

[Background of the Invention]

Fig. 1 shows the overall equipment configuration of a combined coal gasification combined cycle power plant using a conventional pressurized air blowing coal gasification furnace.

The pulverized coal 1 is gasified in the gasification furnace 10 using the air 44 as a gasifying agent, typically under a pressure of ^{20 to} 70 kg / cm ² . The crude product gas 4 at the gasifier outlet is
It is cooled by the gasification furnace outlet steam generator 15. The sensible heat of the crude product gas 4 is recovered as steam. Gasification furnace outlet steam generator 15 outlet crude product gas 15 is gas /
The gas heat exchanger 20 exchanges heat with the purified gas 28 and is cooled. The cooled gas is washed and dedusted by the dedusting device 22. The desulfurization device 27 absorbs and removes the sulfur content in the gas, mainly hydrogen sulfide and carbonyl sulfide, by the desulfurization device 23, and becomes a purified gas 28. The purified gas 28 is gas /
After the heat is exchanged in the gas heat exchanger 20 and the temperature is raised, it is burned as the fuel gas 37 in the gas turbine combustor 38 and then worked as the high temperature gas in the gas turbine 90 and in the gas turbine generator 92. Generates electrical energy.

The air 44 as the gasifying agent is the gas turbine compressor 91.
A part of the air 40 whose pressure has been increased by is extracted, heat-exchanged with the feed water 62 of the exhaust heat recovery boiler 46, and once cooled, the pressure is further increased by the boost compressor 43 to a pressure required for the gasification furnace 10. Will be supplied.

As a heat recovery system, the gas turbine exhaust gas 45 is
The sensible heat is recovered in the exhaust heat recovery boiler 46 to generate steam, and at the same time, the gasification furnace outlet crude gas 11 recovers the sensible heat in the gasification furnace outlet steam generator 15 to generate steam. And they are combined to form a system.

The generated steam is superheated by the superheater 47, works in the steam turbine 58, and generates electric energy in the steam turbine generator 59.

The steam that has passed through the steam turbine 58 is cooled by the condenser 60 to become ascites 93, and is sent to the exhaust heat recovery boiler 46 by the water supply pump 61 as water supply 62.

As gasifiers for power generation, two types of gasifiers, namely, a spouted bed gasifier and a fluidized bed gasifier, have received attention and are currently under research and development.

A fluidized bed gasification furnace forms a fluidized bed with pulverized coal having a relatively large particle size and a gasifying agent and gasifies it, and the gasification temperature is generally low at about 950 ° C. or lower. This is because the ash content in the coal is extracted from the lower part as a solid due to the difference in specific gravity from the coal. When oxygen is used as a gasifying agent, the reaction between pulverized coal and oxygen proceeds too rapidly, and it becomes impossible to form a fluidized bed with pulverized coal and the gasifying agent.Therefore, the produced gas is recirculated to the gasifier and the oxygen concentration is low. Gasification is carried out in the state. For the above reasons, air is generally used as the gasifying agent in the fluidized bed gasification furnace.

The spouted bed gasification furnace gasifies pulverized coal with a relatively small particle size for a short time as it passes through the gasification furnace, typically in about 1 second. Since it is extracted in a more molten state, it is necessary to set the gasification temperature to the melting point of ash or higher, and the gasification temperature is as high as about 1300 ° C or higher. When air is used as the gasifying agent for the spouted bed gasification furnace, extra heat is consumed to raise the nitrogen content in the air to the gasification temperature. The cold gas efficiency, which is a ratio to the above, is lower than that when oxygen is used as the gasifying agent, and the generated gas contains a large amount of nitrogen, so the calorific value is reduced.

However, when oxygen is used as the gasifying agent, it is necessary to install an oxygen generator, which increases construction cost and auxiliary machine power.

The gasifying agent of the spouted bed gasification furnace has advantages and disadvantages of air and oxygen. Generally, oxygen is applied to a wide range of coal types and is put into practical use at a relatively early stage. Air is
Coal species are limited to some extent, but due to future development progress,
There is a possibility that the thermal efficiency can be increased as compared with the case of using oxygen. Therefore, in coal gasification power generation using a spouted bed gasification furnace, the method using oxygen as a gasifying agent and the method using air are considered to be complementary and compatible with each other.

Combining the coal gasifier 10 and the gas turbine 90,
In the integrated coal gasification combined cycle power plant, it is necessary to raise the pressure required for the gas turbine combustor 38 to 20 atg to 30 atg.

There are roughly two methods for boosting the fuel. One is a method in which the pressure of the gasification furnace is set to normal pressure, and then the generated gas is pressurized after gasification.One is to pressurize and supply coal and a gasifying agent, and gasify under pressure. And a method of supplying the gas to the gas turbine.

When the gasification furnace is at normal pressure and the generated gas is pressurized,
Since the produced gas contains sulfur compounds and dust, it is necessary to pressurize the purified gas after performing the gas purification, and the gasification furnace, the gasification furnace outlet steam generator, and the gas purification work at almost atmospheric pressure. Therefore, the capacity of the equipment must be larger than that of a pressurized gasification furnace. Further, in gas refining, particularly wet gas refining, since the absorption of gas generally increases in proportion to the operating pressure, it is necessary to absorb the gas with a large amount of absorbing liquid. And the amount of utility usage increases. Further, the purified gas has a larger capacity than air or oxygen which is a gasifying agent, and the power required for pressurizing is larger than that when pressurizing the gasifying agent. It has been discovered that a system for supplying fuel gas to a gas turbine combustor by using a furnace as a pressurizer is excellent in terms of thermal efficiency and reduction of the apparatus capacity.

Coal supply methods include pulverized coal dry coal supply and water / slurry supply. The water / slurry supply consumes combustible components in the produced gas in order to evaporate the water content in the slurry in the gasification furnace 10, so that the cold gas efficiency and the thermal efficiency are lower than those of the dry coal supply.

From the above, as a gasifier for combined coal gasification combined cycle power generation,
It is clear that the pressurization method and dry coal supply are excellent in terms of plant thermal efficiency.

The pulverized coal supply method to the pressurized gasification furnace is generally the following method called a rockhopper method.

In the small pilot plant currently in operation, a pressurized screw feeder is also used, but the gasification pressure is about several atmospheres and many troubles have not been put to practical use. In an actual plant, it is necessary to perform gasification at a high pressure of several tens of atmospheres, and as a method of supplying pulverized coal to such a pressurized gasification furnace, it is inevitable that the rockhopper method is used. is there.

The pulverized coal 1 is sent to the coal storage tank 2.
The pulverized coal is further sent to the lock hopper 3. The outlet of the lock hopper 3 is provided with a switching valve. The outlet directional control valve is closed, pressurized nitrogen is sent to the lock hopper 3, and pulverized coal is pressurized in the lock hopper 3. When the pressurization is completed, the pulverized coal which is pressurized by closing the switching valve at the inlet of the lock hopper 3 and opening the outlet switching valve is sent to the gasification furnace 10 through the feed tank 4. A plurality of rock hoppers are usually installed in one gasification furnace, and pulverized coal can be continuously supplied by performing a switching operation.

As a method for pressurizing the lock hopper, when oxygen is used as the gasifying agent, the gas generated in the gas generator 10 is pressurized by increasing the pressure of nitrogen by-produced by the oxygen generator.
Supplies coal to.

On the other hand, since there is no oxygen generator in the air oxidation gasifier,
The supply of gas for pressurizing the lock hopper becomes a problem.

In the conventional embodiment shown in FIG. 1, a nitrogen separator 9 is installed, and the separated nitrogen 8 is pressurized by a nitrogen booster 7 and supplied to the lock hopper 3. In the prior art shown in FIG. 1, by using nitrogen, there is no possibility of coal dust explosion in the lock hopper 3, the feed tank 4, and the supply system 5 and the possibility of backfire from the gasification furnace, and safe operation is possible. It is possible to do this, but the operating power of the nitrogen separator 9 is 1000
It is not economical because it reaches 5 to 20 MW in MW-class coal gasification combined cycle power plant.

Further, in the prior art shown in FIG. 2, the air 85 is pressurized by the air compressor 83 and the lock hopper 3 is pressurized. According to this conventional technique, the construction cost and the operating power can be saved because the nitrogen separator 9 shown in FIG. 1 is not provided.

However, in the present technology, since the pulverized coal supply gas contains oxygen, it cannot be said that there is no possibility of backfire or coal dust explosion from the coal gasification furnace 10, and a safety-oriented gasification furnace for power generation. As for, there are many issues to be developed.

In a pulverized coal fired boiler, the fine powder is supplied by blowing air, but the pulverized coal fired boiler sucks the combustion gas with a blower blower, and the inside of the boiler is slightly higher than the atmospheric pressure. Since the pressure is low, there is no possibility of backfire from the boiler. Regarding coal dust explosion, basic experiment data under atmospheric pressure is accumulated, and it is known that the explosion range of pulverized coal is 30 to 40 g / m ³ , and the supply of pulverized coal is 30 -40g / m ³ or more,
It supplies coal by increasing the pulverized coal concentration. Load change,
As for the operation at the time of starting and stopping, it is possible to operate without entering the explosion range including the transient state, based on the experience of operating many pulverized coal burning boilers.

On the other hand, in the pressurized gasification furnace, since the gasification reaction is carried out under a high pressure of several tens of atmospheres, there is a possibility that the supply system is backfired from the gasification furnace and an explosion due to the backfire occurs. In particular, the lock hopper needs to perform a switching operation in order to continuously supply pulverized coal, the lock hopper is pressurized, and at the beginning of opening the outlet switching valve, the lock hopper is at a pressure sufficiently higher than that of the chemical reactor, The pressure gradually decreases, and just before switching to another lock hopper, the pressures of the gasification furnace 10 and the lock hopper 3 are almost balanced, and there is a risk of back fire.

Regarding coal dust explosion, in the case of a pulverized coal boiler, it is possible to continuously supply pulverized coal by an air supply fan, and it is possible to maintain the pulverized coal concentration outside the range of coal dust explosion. When supplying pulverized coal to the pressurized gasification furnace, it is necessary to perform a switching operation of the rock hopper, and the pulverized coal concentration will pass the explosion range during the pulverized coal supply process, and always
It is difficult to supply pulverized coal beyond the explosion range.

For the above reasons, it is very problematic in terms of safety to use air for boosting the pressure of the lock hopper 3. In particular, coal for the gasification furnace of the gasification power plant for power generation, where importance is placed on reliability, is used. Regarding supply by air, the possibility is currently under consideration, and in practical application,
It is common to use a gas that does not contain oxygen.

FIG. 3 shows that the supply of coal bypasses a part of the exhaust gas 67 of the exhaust heat recovery boiler 46, and the exhaust gas compressor 86
Although the pressure is increased by and is supplied to the rock hopper, the exhaust gas contains about 10 to 15% oxygen, so the oxygen concentration is less than that when air (oxygen concentration 21%) in FIG. 2 is used. Although there is less possibility of backfire and coal dust explosion, there is a problem in safety as in the prior art shown in FIG.

[Object of the Invention]

An object of the present invention is to provide a combined coal gasification combined cycle power plant using a pressurized coal gasification furnace, CO ₂ which separates the pressurization of a coal supply device, typically a rock hopper from gas purification,
Alternatively, a combustion gas obtained by burning off-gas of a sulfur recovery device by a catalytic combustor, or a refined gas that is further refined, for example, a refined gas in which sulfides such as hydrogen sulfide are almost removed by a reactor filled with zinc oxide. Or, if a spouted bed gasifier is used, the gasifier generated steam is heated by the superheated steam that is heated in the gasifier outlet steam generator, which may cause a backfire from the gasifier or a coal dust explosion. It is to provide a method and an apparatus capable of supplying coal that is completely safe and economical.

[Summary of the Invention] In a combined coal gasification combined cycle power plant that uses a pressurized gasification furnace, the gas required for pressurizing a coal supply device, typically a rock hopper, is an oxygen injection furnace, and if By using nitrogen separated from the generator, a safe and economical coal feeder can be constructed. On the other hand, when an air blowing furnace is used, it is not economical to construct a safe coal supply device using nitrogen because there is no oxygen generator. Therefore,
As the pressurized gas, it is possible to construct an economical coal supply device by using air or the exhaust gas from the exhaust heat recovery boiler, but since the pressurized gasification furnace is used, the gas from the gasification furnace is used. There is a possibility of coal dust explosion in Buckeye and coal supply system, and there is a problem in terms of safety.

The present invention is an economically superior and safe coal supply to a coal gasification combined cycle power plant using a pressurized gasification furnace for the coal produced and separated in the system. A method and apparatus.

The first method for supplying inert gas to coal is
In the case of using an air-blown gasification furnace, a carbon dioxide absorption device is installed on the downstream side of the desulfurization device, and carbon dioxide separated and recovered is used.

Secondly, similarly, when an air oxidation gasification furnace is used, carbon dioxide obtained by burning the tail gas of the sulfur recovery device by a catalytic combustor is subjected to cooling heat recovery and used.

Third, when using an air-blown spouted bed gasifier,
The steam generated in the gasification furnace is superheated and used in the gasification furnace outlet steam generator.

Fourthly, it can be applied to the case of using either the gas blowing furnace of air blowing or the gas blowing furnace of oxygen, but the refined gas after desulfurization is further subjected to precision desulfurization and used.

As a result, by using an inert gas for coal separated from the system of the integrated coal gasification combined cycle power plant,
A method for supplying coal to a coal gasification furnace that is safe from backfire from the gasification furnace, does not cause coal dust explosion in the supply system, and saves the power required to generate and pressurize the inert gas, and is economical. Regarding the device.

Example of Invention

 FIG. 4 shows an example of the first embodiment of the present invention.

The basic plant configuration is the same as the conventional technique shown in FIGS. 1 to 3.

As the gasification furnace, an air-blown, pressurized gasification furnace is used.

In the present embodiment, oxygen dioxide contained in the purified gas 28 at the outlet of the desulfurization device 23 is further absorbed by installing the decarbonation device 75, and carbon dioxide separated from the regeneration tower 77 for regenerating the absorption liquid is removed. The inert gas 80, which is the main component, is pressurized by the boost compressor 81 and supplied to the lock hopper.

The gas purification equipment in this embodiment is a water washing tower 22 and a desulfurization tower 23 by physical absorption, and is installed for the purpose of removing dust and sulfur compounds in crude gas. As the gas refining equipment, there is a method using iron oxide as an absorbent, which is called a dry method, in addition to the wet method used in the present embodiment.

In the gasification furnace crude product gas 21, the sulfur compound containing a sulfur compound of 500 to 3000 ppm is typically contained in an environment-friendly concentration, typically up to about 50 to 200 ppm, though it greatly varies depending on the properties of coal to be used. At this time, in the wet method, since the absorbing liquid that selectively absorbs the sulfur compound is used, the purified gas 28 contains 50 to 9% of the crude product gas 21.
0% will be left.

The carbon dioxide remaining in the purified gas 28 is removed by the decarbonation tower 7
By contact with the absorbing liquid at 5, it is absorbed by the amount required for coal supply. The absorption liquid that has absorbed carbon dioxide is the regeneration tower 7
The carbon dioxide that has been sent to No. 7 is decompressed and heated to separate the absorbed carbon dioxide, which is regenerated and reused. In this process, the regeneration tower 7
Carbon dioxide is separated from 7.

In this embodiment, the sulfur compound concentration in the crude product gas 21 is 1200
Absorb and remove ppm by the desulfurization device 23 by physical absorption 2
15% of carbon dioxide was absorbed in the process of setting it to 00 ppm. The purified gas 28 contains 7.3% carbon dioxide, and this amount is about 100,000 Nm ³ / H in the present embodiment having a plant output of 1000 MW. On the other hand, the gas required to supply coal is about 2
It is 10,000 Nm ³ / H. Therefore, the carbon dioxide in the purified gas is further purified in the decarbonation tower 75 installed on the downstream side by using the same absorbent as that used in the desulfurization device 23 in the present embodiment. Absorb 20% of the inside, regeneration tower 7
Regenerated and separated at 7. In the decarbonation tower 75, the same absorbent is used because the sulfur concentration in the refined gas is low and the ratio of the sulfur compound that is difficult to be absorbed in the absorbing liquid is relatively increased compared to the crude product gas 21. Even when used, the sulfur compound was absorbed only about half, and it was possible to obtain a regenerated gas having about 95% carbon dioxide and about 4% nitrogen. In this embodiment, since the regenerated gas contains a sulfur compound, a precision desulfurization device 95 is installed to prevent the corrosion of the booster compressor 81, the lock hopper 3, and the feed tank 4, and the sulfur compound is supplied at about 1 ppm. The precision desulfurization apparatus 95 is composed of a converter of carbonyl sulfide to hydrogen sulfide and a reactor filled with zinc oxide in this embodiment. This precision desulfurization equipment 95
Is an oil refining plant with a proven track record.

According to the present embodiment, since the pressurized gas of the lock hopper 3 contains oxygen, the danger of coal dust explosion in the back fire from the gasification furnace 10 and the coal supply system such as the lock hopper 3 and the feed tank 4 can be expected. Not safe, can configure a coal feeder.

In addition, compared with the case where nitrogen is separated by the nitrogen separator and the pressure is increased to pressurize the lock hopper, when carbon dioxide is separated, the operating power can be saved by about 6000 kW at the coal gasification combined cycle power plant of 1000 MW, which is economical. is there.

Example 2 FIG. 5 shows an example of Example 2 of the present invention.

In the present embodiment, the tail gas 33 of the sulfur recovery device 32 is oxidized by the catalytic combustor 68 to generate a gas containing nitrogen and carbon dioxide as main components, and the heat exchanger 70 recovers the heat,
The pressure is boosted by the boost compressor 72 and is supplied to the lock hopper 3.

In the conventional techniques shown in FIGS. 1 to 3, the tail gas 33 of the sulfur recovery device 32 is burned by the combustor 35 and then mixed with the exhaust heat recovery boiler 46 exhaust gas and discharged from the stack. This is because the tail gas contains harmful substances such as carbon monoxide, hydrogen, hydrogen sulfide, etc., and therefore, it is necessary to burn and oxidize the harmful substances when discharging them out of the system.

In this embodiment, the tail gas 33 is self-combusted in the catalytic combustor 68 at a low excess air ratio, so that the exhaust gas contains almost no oxygen, and in this embodiment, about 0.1% of carbon monoxide is generated. It was possible to generate a gas, which is the main component and is inert to coal. The amount of production is 1000 MW class plant, 3
It was 10,000 Nm ³ / H, and the flow rate necessary for coal supply was secured.

To burn carbon monoxide, hydrogen, and hydrogen sulfide using a normal combustor, supply auxiliary fuel, and in the condition of excess air,
Since it is necessary to raise the temperature to 500 to 800 ° C. or higher, the combustion exhaust gas 36 contains oxygen in an amount of 2 to 10%. Therefore, it is safe to use the combustion gas 36 for coal supply, as in the prior art. Because there is a problem with.

On the other hand, when the catalytic combustor 68 filled with the combustion catalyst used in this example is used, carbon monoxide, hydrogen, and hydrogen sulfide naturally occur at a temperature of 300 to 400 ° C., so that oxygen in the combustion exhaust gas is generated. The concentration can be reduced, and coal can be safely supplied using this combustion gas 71.

Further, according to the present embodiment, the power consumption of the nitrogen separation device can be saved by 8,000 kW in the plant of 1000 MW class as compared with the prior art of FIG. 1 which performs nitrogen separation.

In this example, instead of the catalytic combustor 68, the example 1
In the precision desulfurization device used in, a similar system can be constructed using the desulfurized tail gas.

Further, in the present Example, in the precision desulfurization apparatus used in Example 1, the sulfur compound concentration was lowered to about 5 ppm in advance, and then catalytic combustion was performed to release it to the atmosphere as it was. However, it has an advantage that an inert gas that is environmentally safe can be generated, and that this inert gas can be used for sealing equipment or for systems in which atmospheric release is essential.

Example 3 FIG. 6 shows an example of Example 3 of the present invention.

In particular, in a coal gasification combined cycle power plant using a spouted bed pressure gasification furnace, the heat of reaction in the gasification furnace 10 is recovered as steam using the gasification furnace 10 as a water cooling wall.

When using a pressurized gasification furnace, in order to reduce the heat load on the furnace wall, heat is recovered as saturated saturated steam that is slightly higher than the gasification pressure to lower the metal temperature on the furnace wall and reduce the gas vapor It is common to have a highly reliable system configuration that does not mix.

In this embodiment, saturated vapor having a relatively low pressure is further
The gasification furnace outlet steam generator 15 does not overheat to prevent condensation of steam due to heat release in the lock hopper 3, the feed tank 4 and the coal supply system. In the present embodiment, 40 kg / g at a particularly high heat load portion of the gasification furnace 10.
The steam recovered as a saturated steam of cm ² is heated to 350 ° C. and supplied by the gasification furnace outlet steam generator 15.

The steam supplied to the gasification furnace 10 is
When almost no reaction occurs and wet gas purification is used,
It is removed in the process of gas purification,
It becomes a loss, but if this loss is converted to auxiliary machine power, it will be 10
At a plant of 00 MW, it is about 3500 kW, which is about 8000 kW compared with the method of Fig. 1 in which nitrogen is separated and used, and operating power can be saved.

Further, since the steam at 350 ° C. is inactive to coal, it is possible to construct a coal supply method without the possibility of backfire and coal dust explosion.

Embodiment 4 FIG. 7 shows an example of Embodiment 4 of the present invention.

In the present embodiment, the purified gas 28 is supplied to the precision desulfurization device 95,
It absorbs sulfur compounds, purifies them, and pressurizes them with a booster compressor.

The purified gas contains 50 to 500 ppm of a sulfur compound. In order to prevent the booster compressor from being corroded by this sulfur compound, the sulfur compound is added in an amount of 1 to 1 by a precision desulfurization device.
It was decided to remove it to about 0 ppm.

As the precision desulfurization device, the same device as that used in Example 1 can be applied.

In the present embodiment, the boost pressure of the boost compressor 94 is the same as in the first embodiment.
2 and the conventional example of FIGS. 1 to 3, purified gas 2
Since 8 pressures are in a pressurized state, the pressure is reduced, and the required power can be extremely small, about 1000kW, in a 1000MW class plant, which is very economically excellent.

Further, the purified gas 28 is a gas containing carbon monoxide, hydrogen, and nitrogen as main components, and at a purification temperature of 0 ° C to 200 ° C,
It is inert to coal, and can constitute a safe device without backfire from the gasifier or coal dust explosion.

〔The invention's effect〕

According to the present invention, by using the inert gas produced and separated from the system of the integrated coal gasification combined cycle power plant, the pulverized coal is supplied to the gasification furnace. It is possible to construct a safe coal feeder without the possibility of dust explosion.

Further, FIG. 10 shows the effect of reducing the operating power of the coal feeder of the present invention. The operating power of an integrated coal gasification combined cycle power plant with a transmission end output of 1000 MW is shown.

In the method shown in FIG. 1 in which nitrogen is used for separation using a nitrogen separation device, the nitrogen separation device operating power 100 and the nitrogen compressor power 101 are the operating power.

On the other hand, in Examples 1 to 3, the boosting power of the inert gas is
Although not different from the prior art, in the first embodiment, the operating power can be saved by about 6000 kW by using the carbon dioxide separator, and in the second and third embodiments, the power consumption of the nitrogen separator can be saved by about 8,000 kW. . In the second embodiment, about 2 is obtained by recovering the heat of combustion gas.
00kW can be saved further.

Further, in the fourth embodiment, the power required for boosting can be restricted, and it is possible to save about 1100 kW of operating power as compared with the conventional technique shown in FIG. 1 and about 2500 kW of operation power as compared with the first to third embodiments.

[Brief description of drawings]

1 to 3 are system diagrams showing a cycle configuration of a conventional integrated coal gasification combined cycle power plant, FIG. 4 is Embodiment 1 of the present invention, FIG. 5 is Embodiment 2 and FIG. The figure shows Example 3.
FIG. 7 is a cycle configuration diagram of the integrated coal gasification combined cycle power plant showing Example 4 and FIG. 8 is a diagram showing the effect of the present invention. 1 ... Pulverized coal, 2 ... Coal storage tank, 3 ... Lock tank, 4 ... Feed tank, 5 ... Pressurized pulverized coal, 6 ... Pressurized nitrogen, 7 ... Nitrogen booster compressor, 8
... Nitrogen, 9 ... Nitrogen separator, 10 ... Gasifier, 1
1 ... Gasification furnace outlet crude gas, 12 ... Gasification furnace steam generator, 13 ... Gasification furnace steam generator water supply, 14 ...
… Gasifier steam generator generated steam, 15 …… Gasifier outlet steam generator, 16 …… Gasifier outlet steam generator water supply, 17 …… Gasifier outlet steam generator steam drum, 1
8 ... Gasification furnace outlet steam generator generated steam, 19 ... Gasification furnace outlet steam generator outlet crude gas, 20 ... Gas / gas heat exchanger, 21 ... Gas / gas heat exchanger outlet crude generation Gas, 22 ... Dust removal device, 23 ... Desulfurization device, 24 ...
… Desulfurizing agent regeneration device, 25 …… Desulfurizing agent circulation pump, 26…
… Heat exchanger, 27 …… Dust removal device outlet gas, 28 …… Desulfurization device outlet purified gas, 29 …… Absorption desulfurizing agent, 30 …… Regeneration desulfurizing agent, 31 …… Regeneration gas, 32 …… Sulfur recovery device, Three
3 ... tail gas, 34 ... sulfur, 35 ... combustor, 3
6 ... Combustion exhaust gas, 37 ... Fuel gas, 38 ... Gas turbine combustor, 39 ... Air, 40 ... Pressurized air, 41
...... Air cooler, 42 ...... Pressurized air, 43 ...... Air booster compressor, 44 ...... Pressurized air, 45 ...... Gas turbine exhaust gas, 46 ...... Exhaust heat recovery boiler, 47 ...... Superheater, 48 ...
… Reheater, 49 …… High pressure evaporator, 50 …… High pressure drum,
51 ... High-pressure economizer, 52 ... Low-pressure evaporator, 53 ... Low-pressure drum, 54 ... Low-pressure economizer, 55 ... Main steam, 56
...... Reheated steam, 57 …… Low temperature reheated steam, 58 …… Steam turbine, 59 …… Steam turbine generator, 60 …… Condenser, 61 …… Water pump, 62 …… Exhaust heat recovery boiler feed water, 63 ... Exhaust heat recovery boiler feed water, 64 ... Gasification furnace outlet steam generator feed water, 65 ... Feed water booster pump, 66 ...
... Gasifier steam generator water supply, 67 ... Exhaust heat recovery boiler exhaust gas, 68 ... Catalytic combustor, 69 ... Catalytic combustor exhaust gas, 70 ... Feed water heater, 71 ... Catalytic combustor exhaust gas,
72 ... Catalytic combustor exhaust gas compressor, 73 ... Pressurized catalytic combustor exhaust gas, 74 ... Pulverized coal pressurized steam, 75 ... Decarbonation device, 76 ... Decarbonation device outlet purified gas, 77 ... Absorbent Regeneration device, 78 ... Heat exchanger, 79 ... Absorption liquid circulation pump, 80 ... Carbon dioxide gas, 81 ... Carbon dioxide gas booster compressor, 82 ... Boosted carbon dioxide gas, 83 ... Air booster compressor,
84 ... boosted air, 85 ... air, 86 ... exhaust heat recovery boiler booster compressor, 87 ... boosted heat recovery boiler exhaust gas,
90 ... Gas turbine, 91 ... Gas turbine compressor,
92 ... Gas turbine generator, 93 ... Condensate, 94 ...
Purified gas booster compressor, 95 ... Precision desulfurization equipment, 100 ...
… Nitrogen separation device required power, 101 …… Nitrogen booster required power, 102 …… Carbon dioxide separation device required power, 103 ……
Carbon dioxide booster compressor required power, 104 ...... catalyst combustor booster required power, 105 ...... thermal efficiency improvement due to feed water heating, internal power conversion, 106 ... output reduction due to steam extraction,
In-house power conversion, 107 …… Power required for purified gas booster.

Continuation of front page (56) Reference JP-A-52-69405 (JP, A) JP-A-51-101002 (JP, A) JP-A-57-38316 (JP, A) JP-A-57-76089 (JP , A) JP 54-99103 (JP, A) JP 51-83602 (JP, A) JP 54-87704 (JP, A) JP 56-7831 (JP, A) JP 51-33102 (JP, A) JP-B Sho-33-175 (JP, B1)

Claims (1)

[Claims] 1. A coal gasification furnace supplied with pulverized coal and pressurized air, a steam generator for recovering the heat quantity of gasified coal to generate steam, and a gas from the steam generator for purification. A gas purifying apparatus for controlling the gas, a gas turbine driven by the gas from the gas purifying apparatus as a fuel, and an exhaust heat recovery boiler that generates steam by using the exhaust gas from the gas turbine as a heat source,
In a coal gasification power plant comprising the exhaust heat recovery boiler and a steam turbine using the steam obtained in the steam generator, an inert gas obtained from the gas purification device is used as a carrier gas for the pulverized coal. A coal gasification power generation plant characterized by supplying coal to a coal gasification furnace as dry coal of pulverized coal.