JPH0835434A - Gasification combined power generating plant - Google Patents

Abstract

PURPOSE:To decrease the quick cooling water amount and to improve efficiency of a power generating plant by providing a secondary cooling water system for indirectly exchanging heat for primary cooling water to be brought in contact with high-temperature gasifying fuel in a quick gas cooling device for cooling the high-temperature gasifying fuel through a process of bringing the high-temperature gasifying fuel in direct contact with cooling water. CONSTITUTION:Fuel gasified in a coal gasifying furnace 5 is supplied into a combustion chamber 2 of a gas turbine, and a gas quick cooling device 6 into which high-temperature fuel gas from the gasifying furnace 5 is to be guided is provided, and fuel gas cooled in the quick gas cooling device is sequentially supplied into a gas washing device 7 or a gas purifying device 8 through a crude fuel gas piping 44, and purified fuel gas is supplied into a combustor 2 through a fuel heating device 23. In this case, a quick cooling water injection nozzle 33 is provided inside the quick gas cooling device 6, and a secondary cooling water heat exchanger 25 is provided, and secondary cooling water from the secondary cooling water heat exchanger 25 is circulated through a fuel heating device 23 and a discharge water cooling device 22, thereby the efficient cooling of the high-temperature fuel gas is realized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gasification combined cycle power plant, and more particularly to a gasification combined cycle power plant that gasifies raw fuel in a gasification furnace and supplies the gas fuel to a gas turbine.

[0002]

2. Description of the Related Art The structure of a combined coal gasification combined cycle power plant using a conventional oxygen oxidation type coal gasification furnace is described in, for example, JP-A-5-86897. In this example, an evaporator is installed in the gasification furnace, and a crude fuel gas heat recovery boiler for recovering sensible heat is installed at the gasification furnace outlet.
A feed water heater, an evaporator, and a superheater are installed in this crude fuel gas heat recovery boiler, and superheated steam is supplied to a steam turbine.

[0003]

In the prior art, since corrosion occurs at a high temperature, it may be necessary to use an expensive corrosion-resistant material in the crude fuel gas heat recovery boiler at the gasifier outlet depending on the raw fuel components to be handled. Becomes

An object of the present invention is to provide a system for effectively recovering sensible heat of gasified fuel in a gasification combined cycle power plant employing a quenching system in order to improve the efficiency of the power plant.

Another object of the present invention is to provide a system for reducing the amount of quench water that lowers the temperature of gasified fuel.

[0006]

According to the present invention, a fuel gas quenching device is installed at the exit of a gasification furnace, and cooling water is brought into direct contact with the fuel to quench the fuel, and at the same time, the primary cooling water is brought into direct contact with high-temperature fuel gas. A new secondary cooling water system will be installed to collect and transport the sensible heat of the high temperature combustion gas for use in the low temperature part inside the plant.

Further, the surplus nitrogen gas generated in the oxygen production plant is supplied to the fuel gas quenching device.

A specific configuration of the integrated gasification combined cycle power plant of the present invention comprises a gas quenching device for cooling the high temperature gasified fuel by directly contacting the gasified high temperature gasified fuel with cooling water. In addition, a secondary cooling water system that indirectly exchanges heat with the primary cooling water that comes into contact with the high-temperature gasified fuel in the gas quenching device is provided.

The secondary cooling water is preferably cooled by the refined fuel gas supplied to the gas turbine combustor, the raw fuel to be gasified is a liquid fuel, and the secondary cooling water is the raw fuel. It is preferably cooled.

Further, it is desirable to bring the secondary cooling water into direct contact with the purified fuel gas supplied to the gas turbine combustor, and it is desirable to use the secondary cooling water for heating the absorption liquid of the gas purification device.

Further, the integrated gasification combined cycle plant of the present invention comprises an oxygen production apparatus for separating oxygen from air, a gasification furnace for gasification using this oxygen as an oxidant, and a gasified high-temperature gasification fuel. And a quenching device for cooling the high-temperature gasified fuel by directly contacting the cooling water with each other. Nitrogen surplus in the oxygen production device is mixed with the high-temperature gasified fuel in the gas quenching device. It is characterized by

In the technical field employing the present invention, in the spouted bed gasification system, it is necessary to keep the temperature inside the gasification furnace at a high temperature in order to gasify the raw fuel inside the gasification furnace by the oxidizer. At the gasification furnace outlet, the gasified fuel is discharged at a high temperature.

Therefore, in a gasification combined cycle power plant that uses the gasified fuel generated in the gasification furnace as a fuel for a combined cycle power generation plant equipped with a gas turbine and a steam turbine, in order to improve power generation efficiency, the gasification furnace outlet is used. It is necessary to recover as much as possible the sensible heat of the gasification fuel of.

Further, the raw fuel to be gasified is coal or heavy oil containing impurities such as sulfur. After gasification, the fuel gas is refined so that it can be supplied to the gas turbine as fuel. ing. For example, when vanadium is contained in the raw fuel to be gasified, such as heavy oil, molten salt corrosion is likely to occur in the high temperature part of the gasification process, and HCl (hydrochloric acid) is contained in the gasified fuel. In the presence of, the protective oxide film is hard to be formed on the surface of the material, and the material is exposed to the severe sulfide gas corrosive environment.However, by adopting the present invention, these problems can be solved. It

The present invention employs a rapid cooling system in which high temperature fuel at the gasifier outlet and cooling water are brought into contact with each other to rapidly reduce the fuel temperature from the viewpoint of improving reliability and reducing cost. With this method, the temperature of the fuel gas can be lowered. Furthermore,
The present invention can effectively recover the sensible heat of the fuel gas to the power plant. Further, in the present invention, since the temperature of the crude fuel gas is lowered, a large amount of quench water is not required.

[0016]

In the fuel gas quenching apparatus, the primary cooling water that is in direct contact with the high temperature fuel gas at the gasifier outlet is partially vaporized and mixed into the fuel gas, and at the same time, the heat transfer during contact causes It takes heat and the temperature rises. The sensible heat of the fuel gas collected in the primary cooling water is transferred to the secondary cooling water system provided so as to come into contact with the primary cooling water, and as a result, the sensible heat of the fuel gas is indirectly cooled by the secondary cooling water. Can be collected in the water system. Since the primary cooling water and the secondary cooling water system do not come into direct contact with each other, the primary cooling water mixed with impurities due to direct contact with the fuel does not contaminate the secondary cooling water and there is a risk of corrosion in the piping. Since there is no cooling pipe, the cooling pipe can be easily connected to the low temperature part inside the plant, and the sensible heat of fuel can be effectively used in the plant.

Further, since the primary cooling water is cooled by the secondary cooling water, it is possible to reduce the amount of the primary cooling water used which is mixed with impurities and requires a treatment for reuse.

In an oxygen oxidative gasification furnace using oxygen as an oxidant, an oxygen production plant for producing oxygen is installed in a power plant. In the air separation device, air is taken into the device from the outside to separate nitrogen and oxygen. Oxygen is supplied to the gasifier as an oxidant, but nitrogen becomes an excess. By mixing the surplus nitrogen with the high-temperature gasified fuel gas at the gasifier outlet, the temperature of the fuel gas is lowered and the amount of primary cooling water required for quenching the fuel gas can be reduced.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG. The gas turbine device includes a gas turbine compressor 1, a combustor 2, a gas turbine 3, and a gas turbine generator 4.

In the gasification furnace 5, a fuel supply pipe 42 and an oxygen producing device 10 including an air separation device are connected to the oxygen supply pipe 4.
1 is connected, and an oxygen compressor 11 is installed in this pipe.

Oxygen production device 10 comprising an air separation device and the like
Is connected to the air pipe from the air compressor 12, and a compressor inlet air pipe 40 is connected to the inlet of the air compressor 12. From the outlet of the gasification furnace 5, a high temperature fuel gas passage is connected to the gas quenching device 6. A crude fuel gas pipe 44 is connected to the gas cleaning device 7 from the gas quenching device 6, a fuel gas pipe from the gas cleaning device 7 is connected to a gas purification device 8, and a gas turbine fuel supply pipe is connected from the gas purification device 8. 9 is connected to the combustor 2, and a fuel heating device 23 is installed in the middle of the gas turbine fuel supply pipe 9.

A gas turbine exhaust duct 13 is installed between the gas turbine 3 and the exhaust heat recovery boiler 14. Inside the exhaust heat recovery boiler 14, a medium pressure drum 50 and a medium pressure evaporator 5 are provided.
1, medium pressure superheater 52, high pressure economizer 54, high pressure drum 5
5, a high pressure evaporator 56 and a high pressure superheater 57 are installed. The steam turbine system includes a high pressure steam turbine 15, an intermediate pressure steam turbine 16, a low pressure turbine 17, a steam turbine generator 18, a condenser 19, and a feed water pump 20. The water supply pipe from the condenser 19 is divided at the outlet of the water supply pump 20 and passes through the water supply temperature controller 49 and is connected to the intermediate pressure drum 50, and the gas installed through the booster pump 48 in the gas cleaning device 7. The pipe connected to the cleaning device heater 27 and returning to the feed water temperature controller 49, the booster pump 48, the drainage cooling device B29, the cleaning water heat exchanger 30 in the gas cleaning device 7, and the feed water temperature controller 49. To the high-pressure economizer 54. The pipe line at the outlet of the high-pressure booster pump 53 is branched and connected to the gasifier furnace heater 26 of the gasifier 5, and the pipe from the gasifier furnace heater 26 is connected to the high-pressure drum 55.

A quenching water injection nozzle 33 is installed inside the gas quenching device 6, and a cooling water pipe is connected to a solids separating device A21 from the lower part of the gas quenching device 6 to form a solids separating device A.
The cooling water pipe from 21 is connected to the primary cooling water treatment device 31 via the drainage cooling device A22. From the primary cooling water treatment device 31, a cooling water pipe is installed in the gas quenching device 6 via the primary cooling water pump 32, and the quenching water injection nozzle 3 is provided.
3 and the cleaning water jet nozzle 34 installed in the gas cleaning device 7. Gas cleaning device 7
A cooling water pipe is connected to the lower part of the solids separation device B28, and a cooling water pipe from the solids separation device B28 is connected to a primary cooling water treatment device 31 via a drainage cooling device B29.

A secondary cooling water heat exchanger 25 is installed inside the gas quenching device 6, the secondary cooling water pipe from the secondary cooling water heat exchanger 25 is connected to the fuel heating device 23, and the fuel heating device 23. A secondary cooling water pipe that returns to the secondary cooling water heat exchanger 25 via the drainage cooling device A22 is connected from the above. A secondary cooling water pump 24 is installed in the secondary cooling water pipe between the fuel heating device 23 and the drainage cooling device A22.

Oxygen production device 10 comprising an air separation device, etc.
Then, the air that has passed through the compressor inlet air pipe 40 and is pressurized by the air compressor 12 is separated into oxygen and nitrogen. The concentration of oxygen separated in the oxygen production device 10 including an air separation device is generally 90% or more, and the pressure is increased by the oxygen compressor 11 and is supplied to the gasification furnace 5 through the oxygen supply pipe 41 to generate the fuel. The raw fuel supplied from the supply pipe 42 to the gasification furnace 5 is gasified. As the raw fuel, the basic system of this embodiment can be applied regardless of whether it is coal or heavy oil. The high temperature fuel gas 43 gasified in the gasification furnace 5 is a gas quenching device 6
And is directly contacted with the primary cooling water supplied from the quenching water injection nozzle 33 to be cooled. A cooling water storage unit is provided below the gas quenching device 6, and the primary cooling water after direct contact is collected in this cooling water storage unit, and then the solid separation device A
21. The solids separation device A21 separates impurities A45 in the cooling water, discharges it to the outside, and then collects it in the primary cooling water treatment device 31 through the drainage cooling device A22.

The fuel gas cooled by the gas quenching device 6 is supplied to the gas cleaning device 7 through the crude fuel gas pipe 44 and is cleaned by the cooling water supplied from the cleaning water injection nozzle 34. After the cleaning, the cooling water is collected in the lower part of the gas cleaning device 7 and is then collected by the solids separating device B28 to remove impurities B in the cooling water.
After separating 46, it is discharged to the outside and is collected by the primary cooling water treatment device 31 through the drainage cooling device B29. In the primary cooling water treatment device 31, the impurities dissolved in the cooling water are treated, supplementary water 47 is supplemented, the pressure is increased by the primary cooling water pump 32, and then the quenching water injection nozzle 33 and the wash water injection nozzle 34 are supplied as primary cooling water. Supply.

The fuel gas cleaned by the gas cleaning device 7 is supplied to the gas purification device 8. In this embodiment, the gas purifier 8 is a wet desulfurization system, and the fuel gas at the outlet of the gas purifier 8 comes out at a low temperature. This fuel gas flows through the gas turbine fuel supply pipe 9 and passes through the fuel heating device 23 and the combustor 2
Is supplied to.

In the gas turbine, the air passing through the gas turbine inlet air pipe 58 is compressed by the gas turbine compressor 1 and supplied to the combustor 2, and the fuel supplied through the fuel heating device 23 is combusted to burn the high temperature combustion gas. Is generated and supplied to the gas turbine 3 to be expanded to generate power. The power generated in the gas turbine 3 drives the gas turbine compressor 1 and the gas turbine generator 4, and the gas turbine generator 4 generates electric power.

Since the combustion exhaust gas that has expanded from the gas turbine 3 has a high temperature (about 600 ° C. in the current gas turbine), it is supplied to the exhaust heat recovery boiler 14 through the gas turbine exhaust duct 13. In the exhaust heat recovery boiler 14, steam is generated using the sensible heat of the combustion exhaust gas. The water condensed in the condenser 19 is pressurized by the water supply pump 20 and the high-pressure booster pump 53 and supplied to the high-pressure economizer 54 as high-pressure water, and the water supplied to the high-pressure economizer 54 is heated to high pressure. Drum 5
5, is converted into steam by the high-pressure evaporator 56, is superheated by the high-pressure superheater 57, and is then supplied to the high-pressure steam turbine 15. Part of the water supply at the outlet of the high-pressure booster pump 53 is the gasifier 5
Is supplied to the gasification furnace heater 26 installed in the gasification furnace, cools the gasification furnace 5, and is then collected in the high-pressure drum 55.

A part of the water supply at the outlet of the water supply pump 20 is boosted by the pressure boosting pump 48 and a part of the water is supplied to the gas cleaning device heater 27 provided in the gas cleaning device 7 to be supplied to the gas cleaning device 7.
The temperature of the fuel gas in the inside is lowered, heat is exchanged, and the water is recovered by the feed water temperature controller 49. The remaining water supply from the booster pump 48 is supplied to the drainage cooling device B29, preheated by the primary cooling water separated by the solids separation device B28, and then supplied to the cleaning water heat exchanger 30 in the gas cleaning device 7. . The cleaning water heat exchanger 30 is installed at the bottom of the gas cleaning device 7, and the cooling water ejected from the cleaning water injection nozzle 34 is accumulated after cleaning the fuel gas. The supply water is heated and the supply water temperature controller 4
9.

In the feed water temperature controller 49, the temperature of the high temperature feed water at the outlet of the gas cleaning device heater 27 and the wash water heat exchanger 30 is adjusted by mixing the low temperature feed water at the outlet of the feed water pump 20, and then to the intermediate pressure drum 50. Supply. In the medium-pressure evaporator 51, the sensible heat of the combustion exhaust gas evaporates, and the steam is supplied to the medium-pressure superheater 52 and superheated.
6.

The steam at the outlet of the high-pressure steam turbine 15 is mixed with the steam from the medium-pressure superheater 52, and the medium-pressure steam turbine 16 is mixed.
The steam leaving the medium-pressure steam turbine 16 is supplied to the low-pressure steam turbine 17, and is discharged to the condenser 19. The steam turbine generator 18 is driven by the power generated in the high-pressure steam turbine 15, the medium-pressure steam turbine 16, and the low-pressure steam turbine 17 to generate electric power.

In the secondary cooling water heat exchanger 25 provided in the gas quenching device 6, the secondary cooling water heated by heat exchange with the primary cooling water is sent to the fuel heating device 23 to supply gas turbine fuel. The fuel flowing through the pipe 9 is heated. The primary cooling water that has left the fuel heating device 23 is the secondary cooling water pump 24.
The pressure is increased to be supplied to the drainage cooling device A22, is preheated by the primary cooling water from which the impurities A45 are separated by the solid matter separating device A21, and is then supplied to the secondary cooling water heat exchanger 25.

Since the fuel gas is heated by the fuel heating device 23, the sensible heat is increased, so that the efficiency of the power generation plant is improved.

In this embodiment, the temperature of the primary cooling water can be lowered by the secondary cooling water to reduce the flow rate of the primary cooling water, and the sensible heat of the high temperature fuel gas can be recovered.

Further, in this embodiment, the wash water heat exchanger 30 is used.
Since the feed water can be heated in the above, there is an effect that the feed water can be supplied to the intermediate pressure drum 50 without installing a feed water heater in the exhaust heat recovery boiler 14.

In the present embodiment, the fuel gas temperature is lowered by directly injecting the primary cooling water from the quench water injection nozzle 33 into the high temperature fuel gas inside the gas quenching device 6, but the gas quenching device 6 Even if it is a quenching method in which the high temperature fuel gas is passed through the inside of the primary cooling water stored in the bottom of the gas quenching device 6 as the structure of 1, the secondary cooling water heat exchanger 25 is installed in the stored primary cooling water. The same effect as that of the embodiment can be obtained.

Another embodiment of the present invention is shown in FIG. The embodiment of FIG. 2 is different from the embodiment of FIG. 1 in that the raw fuel is limited to liquid in the embodiment of FIG.
2, the combustion oil supply pipe 203 is connected to the gasification furnace 5,
A fuel oil booster pump 204 is installed in the combustion oil supply pipe 203. The secondary cooling water from the secondary cooling water heat exchanger 25 installed in the gas quenching device 6 is supplied to the fuel oil heating device 20.
The secondary cooling water pipe that is supplied to the fuel oil heating device 202 and returns from the fuel oil heating device 202 passes through the secondary cooling water circulation pump 201 and the drainage cooling device A22 and returns to the secondary cooling water heat exchanger 25.

The secondary cooling water whose pressure has been raised by the secondary cooling water circulation pump 201 and which has been heated through the drainage cooling device A22 and the secondary cooling water heat exchanger 25 is supplied to the fuel oil heating device 202, and the fuel oil heating device 202 is supplied. The liquid fuel in 202 is heated and heated. The liquid fuel whose temperature has been raised is boosted by the fuel oil boosting pump 204 and supplied to the gasification furnace 5 through the combustion oil supply pipe 203.

According to this embodiment, the raw fuel can be heated by safe water supply and the sensible heat of the raw fuel can be increased, so that the thermal efficiency can be improved. In particular, since liquid fuel has a larger specific heat than gas fuel, the amount of heat that can be recovered by the secondary cooling water is large and there is an effect of improving thermal efficiency.

Another embodiment of the present invention is shown in FIG. The embodiment of FIG. 3 is different from the embodiment of FIG. 1 in that, in FIG.
2 is connected to the gas quenching device 6, and the nitrogen compressor 301 is installed in the nitrogen supply pipe 302.

Oxygen production device 10 comprising an air separation device, etc.
Then, through the compressor inlet air pipe 40, the air compressor 12
The air that was inhaled and pressurized was separated into oxygen and nitrogen. Oxygen flows through the oxygen supply pipe 41, is pressurized by the oxygen compressor 11, and is supplied to the gasification furnace 5 as an oxidant. The remaining nitrogen obtained by separating oxygen from air in the oxygen production device 10 including an air separation device is pressurized by the nitrogen compressor 301 and supplied to the gas quenching device 6 through the nitrogen supply pipe 302. In the gas quenching device 6, the nitrogen and the high temperature fuel gas 43 are mixed,
The temperature of the high temperature fuel gas 43 is lowered together with the primary cooling water from the quench water injection nozzle 33. In this embodiment, the flow rate of the primary cooling water required for cooling can be further reduced by mixing the high temperature fuel gas 43, as compared with the embodiment shown in FIG. Further, since nitrogen, which is an inert gas, can be mixed with the fuel gas, the calorific value of the fuel gas processed in the gas purification device 8 and supplied to the combustor 2 can be reduced, and the amount of NOx generated in the combustor 2 can be reduced. There is an effect that can be reduced.

Another embodiment of the present invention is shown in FIG. The embodiment of FIG. 4 differs from the embodiment of FIG. 1 in the system of the secondary cooling water heat exchanger 25 provided in the gas quenching device 6. The high temperature water supply pipe 402 provided at the outlet of the secondary cooling water heat exchanger 25 is connected to the combustion direct heater 401, and from the combustion direct heater 401, the high temperature water return pipe 403 is connected to the quench water injection nozzle 33, Step-up pump 404 in the water return pipe 403
Is installed. A water supply pipe at the outlet of the booster pump 48 is connected to the drainage cooling device A22. The combustion direct heater 401 is connected to the high temperature water supply pipe 402 and the high temperature water return pipe 403, and at the same time, connected to the gas turbine fuel supply pipe 9.

The water supplied by the booster pump 48 is
It becomes the secondary cooling water, is preheated by the primary cooling water that has separated the impurities A45 in the solid waste separation device A21 in the drainage cooling device A22, and then is supplied to the secondary cooling water heat exchanger 25, and indirectly passes through the primary cooling water to obtain the high-temperature fuel. The sensible heat of the gas 43 is recovered. The feed water exiting the secondary cooling water heat exchanger 25 is supplied to the combustion direct heater 401 through the high temperature water supply pipe 402,
Combustion direct heater 4 through gas turbine fuel supply pipe 9
Directly contact with the fuel gas flowing into 01, and partly evaporates to raise the fuel gas temperature. The remaining secondary cooling water collected in the lower portion of the combustion direct heater 401 is the high temperature water return pipe 403.
It is injected by the quench water injection nozzle 33 into the gas quenching device 6 whose pressure has been boosted by the boosting pump 404.

As described above, in this embodiment, the sensible heat of the high-temperature fuel gas 43 can be recovered to the fuel gas via the primary cooling water and the secondary cooling water, and at the same time, the secondary cooling water and the fuel gas are directly contacted with each other. As a result, the fuel gas contains saturated vapor, so that NOx generated during combustion in the combustor 2 can be reduced.

Another embodiment of the present invention is shown in FIG. The embodiment of FIG. 5 is different from the embodiment of FIG. 1 in the secondary cooling water system, in which the pipe at the outlet of the secondary cooling water heat exchanger 25 is connected to the regenerator reboiler 503 of the gas purifier 8 The return pipe from the reboiler 503 is connected to the inlet of the secondary cooling water heat exchanger 25 through the secondary cooling water pump 506 and the drainage cooling device A22.

In the gas purifier 8, the pipe from the cleaning water injection nozzle 34 is connected to the gas purifier washing tower 501, and the gas turbine fuel supply pipe 9 is connected to the combustor 2 from the gas purifier washing tower 501. It A pipe is connected to the outlet of the gas purification device cleaning tower 501 and the regeneration tower 502, a pipe of the outlet of the regeneration tower 502 is connected to the gas purification device cleaning tower 501, and the circulating liquid pump 505 and the circulating liquid cooling device 50 are connected.
4 are installed. A hydrogen sulfide discharge pipe 507 is further connected to the regeneration tower 502, and a circulating liquid cooling device 504 is installed on a pipe connected from the outlet of the circulating liquid pump 505 to the gas purification device cleaning tower 501.

The fuel gas discharged from the gas cleaning device 7 and entering the gas purification device cleaning tower 501 is converted into the gas purification device cleaning tower 50.
By spraying an absorbing liquid that absorbs hydrogen sulfide from above, hydrogen sulfide in the fuel gas is removed. In this case, in order to effectively perform the absorption, since the gas is absorbed by the liquid, it is necessary that the temperature is low. Therefore, the absorbing liquid is cooled in advance by the circulating liquid cooling device 504. The fuel gas from which hydrogen sulfide has been removed is supplied to the combustor 2 through the gas turbine fuel supply pipe 9. The absorption liquid that has absorbed hydrogen sulfide in the gas purification device cleaning tower 501 is supplied to the regeneration tower 502, which receives heat from another heat source in the plant and is absorbed by warming the absorption liquid. The existing hydrogen sulfide is separated and discharged from the hydrogen sulfide discharge pipe 507 to the hydrogen sulfide treatment process.

In this embodiment, a part of the absorption liquid is circulated to the regeneration tower reboiler 503 by the circulating liquid pump 505 and heated by the secondary cooling water heat exchanger 25 as a heat source for warming the absorption liquid in the regeneration tower reboiler 503. The secondary cooling water is used. The secondary cooling water leaving the regeneration tower reboiler 503 is pressurized by the secondary cooling water pump 506, and the drainage cooling device A22.
And is circulated to the secondary cooling water heat exchanger 25.

According to this embodiment, since the sensible heat of the high temperature fuel gas can be used as the gas treatment heat source for gas purification, a new heat supply source for gas purification, for example, steam piping from the exhaust heat recovery boiler, etc. There is an effect that it is not necessary to provide.

[0051]

According to the present invention, the sensible heat of the gasified fuel can be effectively recovered, so that the efficiency of the power generation plant can be improved.

Further, according to the present invention, there is an effect that the amount of cooling water used for lowering the gasification temperature can be reduced.

[Brief description of drawings]

FIG. 1 is a system configuration diagram showing a first embodiment of the present invention.

FIG. 2 is a system configuration diagram showing a second embodiment of the present invention.

FIG. 3 is a system configuration diagram showing a third embodiment of the present invention.

FIG. 4 is a system configuration diagram showing a fourth embodiment of the present invention.

FIG. 5 is a system configuration diagram showing a fifth embodiment of the present invention.

[Explanation of symbols]

1 ... Compressor, 2 ... Combustor, 5 ... Coal gasification furnace, 6 ... Gas quenching device, 7 ... Gas cleaning device, 10 ... Air separation device, 1
DESCRIPTION OF SYMBOLS 1 ... Oxygen compressor, 12 ... Air compressor, 22 ... Waste water cooling device A, 23 ... Fuel heating device, 25 ... Secondary cooling water heat exchanger, 202 ... Fuel oil heating device, 301 ... Nitrogen compressor, 4
01 ... Combustion direct heater, 503 ... Regeneration tower reboiler.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Internal reference number FI Technical indication location F02C 6/00 Z (72) Inventor Zensuke Tamura 4-6 Kanda Surugadai, Chiyoda-ku, Tokyo Hitachi, Ltd. Inside the factory

Claims (6)

[Claims] 1. A high temperature gasification in a gas quenching apparatus in a gasification combined cycle power plant equipped with a gas quenching device for directly cooling gasified high temperature gasified fuel and cooling water to cool the high temperature gasified fuel. A combined gasification combined cycle power plant comprising a secondary cooling water system that indirectly exchanges heat with primary cooling water that comes into contact with fuel. 2. The integrated gasification combined cycle power plant according to claim 1, wherein the secondary cooling water is cooled by the refined fuel gas supplied to the gas turbine combustor. 3. The integrated gasification combined cycle plant according to claim 1, wherein the raw fuel to be gasified is a liquid fuel, and the secondary cooling water is cooled by the raw fuel. 4. An oxygen production apparatus for separating oxygen from air,
Combined gasification combined power generation equipped with a gasification furnace that gasifies using this oxygen as an oxidant, and a gas quenching device that cools the high-temperature gasification fuel by directly contacting the gasified high-temperature gasification fuel and cooling water An integrated gasification combined cycle power plant characterized by mixing surplus nitrogen in an oxygen production device with a high-temperature gasification fuel in a gas quenching device in the plant. 5. The integrated gasification combined cycle power plant according to claim 1, wherein the secondary cooling water and the refined fuel gas supplied to the gas turbine combustor are brought into direct contact with each other. 6. The integrated gasification combined cycle power plant according to claim 1, wherein the secondary cooling water is used for heating the absorption liquid of the gas purifying device.