JP2001050010A - Power plant - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the number of facilities additionally provided for suppressing emission of hazardous substances by mixing organic fuel to be combusted in a supercritical pressure boiler with supercritical pressure water to reform fuel not containing hazardous material, and separating the reformed fuel from the mixture to be supplied in the supercritical pressure boiler. SOLUTION: In a reformer 7, critical pressure water extracted from a supercritical pressure boiler 1 and fuel containing hazardous substances are mixed to separate the hazardous substances therefrom and reform the fuel not to contain hazardous substances. In a separator 7, the mixture of the supercritical pressure water is separated into the reformed fuel, hazardous substances, clean supercritical pressure water having a temperature higher than that when extracted from the supercritical pressure boiler 1. The separated reform fuel is supplied in the supercritical pressure boiler 1 by a reformed-fuel supply device 12. The high-temperature supercritical pressure water is returned to a high-temperature section at an outlet point in a supercritical pressure system 8. Since the reformed fuel is combusted in the supercritical pressure boiler 1, devices such as smoke desulphurizer and dust collector become unnecessary.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power generation facility in which an organic fuel is reformed using supercritical water and power is generated using the reformed fuel.

[0002]

2. Description of the Related Art Generally, a thermal power plant uses an organic substance such as coal, oil, or natural gas as a fuel. For example,
In a coal-fired power plant, coal (pulverized coal) is blown into a boiler as fuel and burned. The water supply to the boiler is supplied by a boiler water supply pump, heated by a high pressure feed water heater, preheated by a coal saver, and turned into steam in a heat exchange pipe in the boiler. This steam is superheated by a primary superheater and a secondary superheater to be superheated steam, and then guided to a high-pressure turbine to be driven. Further, after reheating through the reheater, the medium pressure / low pressure turbine is driven, and the high pressure turbine and the generator directly connected to the medium pressure / low pressure turbine are driven to generate power.

[0003] The steam that drives the turbine is returned to water by a condenser and then sent to a condensate treatment device by a condensate pump to remove impurities (inorganic, organic, ions, etc.) in the water. After that, the water is supplied to the boiler again through the low pressure feed water heater and the deaerator and again through the boiler feed pump.

In such a coal-fired power plant,
Exhaust gas is generated with coal combustion. Therefore, for environmental measures, ancillary equipment for removing substances (sulfur oxide, nitrogen oxide, dust, etc.) contained in the exhaust gas is provided. Generally, a flue gas denitration and dust collection device (such as an electric dust collector) and a flue gas desulfurization device are provided, and the exhaust gas is discharged from the chimney after passing through these auxiliary facilities.

[0005] On the other hand, in a heavy oil-fired power plant, fuel is replaced with heavy oil as compared with a coal-fired power plant. If the fuel oil used is a fuel oil having a lower sulfur content than coal or a fuel oil subjected to a desulfurization treatment, the desulfurization treatment from the exhaust gas can be omitted, and it can be replaced with a denitration dust collector. Further, when the amount of dust in the exhaust gas is small, there is a difference in that a dust collector, which is an auxiliary facility for exhaust gas treatment, may be omitted. Other configurations of the plant are substantially the same as those of the coal-fired power plant.

A gas turbine combined cycle power plant using liquefied natural gas (LNG) as a fuel
A gas turbine device, an exhaust heat recovery boiler device that generates steam using the combustion exhaust gas as a heat source, a steam turbine device driven by the steam generated by the exhaust heat recovery boiler device, and directly connected to the gas turbine device and the steam turbine device And a generator provided.

The gas turbine apparatus of this gas turbine combined cycle power plant comprises an air compressor for generating compressed air, a combustor for mixing fuel (LNG) from a fuel system with compressed air for combustion, and a combustor. A gas turbine driven by the generated combustion gas. The exhaust heat recovery boiler device includes a deheater, a first evaporator, a denitration device having a denitration catalyst, and a second evaporator, which are arranged in order from upstream to downstream of the gas flow of the combustion gas discharged from the gas turbine. And an economizer is installed, and the exhaust gas is discharged from the chimney.

[0008] Feed water from a condensate pump is supplied to the economizer of the waste heat recovery boiler to be preheated, and a part of the feed water is vaporized by a second evaporator and then sent to a steam turbine device. Can be The remaining feedwater is vaporized by a first evaporator through a feedwater pump, and then superheated by a superheater to become superheated steam and introduced into a steam turbine. The steam that has completed its work in the steam turbine is condensed in the condenser and returned to water.

[0009] Here, the denitration device is for reducing the concentration of nitrogen oxides NOx contained in the combustion gas.
The reactor includes a reactor having a catalyst layer for removing NOx by catalytic reductive decomposition, and a reducing agent injection nozzle for injecting a reducing agent (usually ammonia gas) upstream of the reactor.

[0010]

However, existing thermal power plants require large-scale exhaust gas treatment facilities. In other words, in addition to the main equipment that converts thermal energy into steam energy to generate power, exhaust gas for removing sulfur oxides, nitrogen oxides, dust, harmful organic substances, etc. contained in the exhaust gas (exhaust gas) Ancillary equipment for processing is required. In addition, since the amount of exhaust gas is generally large, facilities for exhaust gas treatment for this purpose are large-scale. Further, when fuel containing harmful substances (such as sulfur) is burned, there is a problem that members of the combustion system cause corrosion damage and shorten the life of the members of the combustion system.

In a gas turbine combined cycle power plant, combustion gas is generally sent to a gas turbine using liquefied natural gas (LNG gas) as a fuel, but the reserves of LNG gas are limited. In addition, in order to use LNG gas, it is necessary to construct a huge LNG base around the base, and the cost of the base construction is enormous, and it is not easy to construct the base.

On the other hand, there is an urgent need to effectively use coal fuel which is almost inexhaustible on the earth as a response to these problems, and a gasification system of low quality coal has been studied and put to practical use. . However, these are still inadequate in terms of equipment cost-effectiveness.

[0013] An object of the present invention is to provide a power generation facility capable of reducing incidental facilities for suppressing emission of harmful substances contained in fuel.

[0014]

According to a first aspect of the present invention, there is provided a power generation facility, wherein steam from a supercritical pressure boiler drives a steam turbine to which a generator is connected, and supplies water condensed after completing work in the steam turbine. In a power generation facility that is heated by a superheater and returned to the supercritical pressure boiler, a supercritical water system that takes out supercritical water from the supercritical pressure boiler, and a fuel of an organic substance to be burned in the supercritical pressure boiler A fuel supply system to be supplied, a reformer that mixes fuel from the fuel supply system and supercritical water from the supercritical water system to reform the fuel into a fuel containing no harmful substances, A separator that separates and extracts the reformed fuel from the mixture and supplies the reformed fuel to the supercritical boiler.

In the power generation equipment according to claim 1, the reformer mixes the fuel from the fuel supply system and the supercritical water from the supercritical water system to reform the fuel into a fuel containing no harmful substances. Separates and extracts reformed fuel from the mixture from the reformer and supplies it to the supercritical boiler.

According to a second aspect of the present invention, in the power generation equipment according to the first aspect, the separator separately takes out the reformed fuel, the harmful substance, and the supercritical water from the mixture from the reformer. The fuel and the supercritical water are supplied to the supercritical boiler, and the harmful substances are discharged out of the system.

In the power generation equipment according to claim 2, claim 1 is
In addition to the operation of the invention, the separator separately removes reformed fuel, harmful substances, and supercritical water from the mixture from the reformer.
Then, the reformed fuel and the supercritical water are supplied to the supercritical pressure boiler, and the harmful substances are discharged out of the system.

According to a third aspect of the present invention, in the power generation equipment according to the first or second aspect, high-pressure water supplied to the supercritical pressure boiler is electrolyzed to generate high-pressure hydrogen, and the high-pressure hydrogen is generated. A high-pressure hydrogen generator for injecting into the reformer is provided.

In the power generation equipment according to claim 3, claim 1 is
Alternatively, in addition to the function of the invention of claim 2, the high-pressure hydrogen generator introduces high-pressure water supplied to the supercritical pressure boiler and electrolyzes to generate high-pressure hydrogen. The high pressure hydrogen is injected into the reformer.

According to a fourth aspect of the present invention, in the power generation equipment according to the first aspect of the present invention, the reformed fuel separated by the separator is guided to a gasification furnace of a gas turbine power generation system.

In the power generation equipment according to claim 4, claim 1 is provided.
In addition to the operation of the invention of the above, the reformed fuel separated by the separator is
It is led not only to supercritical boilers but also to gasifiers in gas turbine power generation systems.

According to a fifth aspect of the present invention, the steam from the subcritical boiler drives a steam turbine to which a generator is connected, and heats condensed water after completing work in the steam turbine and heating the condensed water with a feedwater superheater. In a power generation facility adapted to return to the subcritical boiler, a fuel supply system for supplying a fuel of an organic substance to be burned in the subcritical boiler, and a supercritical water extracting and extracting high pressure water to be supplied to the subcritical boiler A reformer for mixing fuel from the fuel supply system and supercritical water from the supercritical water generator to reform the fuel into a fuel containing no harmful substances; and And a separator for separating and extracting the reformed fuel from the mixture from the reformer and supplying the reformed fuel to the subcritical boiler.

[0023] In the power generation equipment according to claim 5, the reformer mixes the fuel from the fuel supply system and the supercritical water from the supercritical water generator to reform the fuel into a fuel containing no harmful substances. The separator separates and extracts the reformed fuel from the mixture from the reformer and supplies it to the subcritical boiler.

According to a sixth aspect of the present invention, in the power generation equipment according to the fifth aspect of the present invention, high-pressure water supplied to the subcritical boiler is electrolyzed to generate high-pressure hydrogen, and the high-pressure hydrogen is converted into the reformer. A high-pressure hydrogen generator for injecting hydrogen into the fuel cell.

In the power generation equipment according to claim 6,
In addition to the operation of the invention, the high-pressure hydrogen generator generates high-pressure hydrogen by electrolyzing high-pressure water supplied to the subcritical boiler. Then, the high-pressure hydrogen is injected into the reformer.

According to a seventh aspect of the present invention, in the power generation equipment according to the fifth aspect, the reformed fuel separated by the separator is guided to a gasification furnace of a gas turbine power generation system.

In the power generation equipment according to claim 7,
In addition to the operation of the invention of the above, the reformed fuel separated by the separator is
It is led not only to subcritical boilers but also to gasifiers in gas turbine power generation systems.

[0028]

Embodiments of the present invention will be described below. FIG. 1 is a configuration diagram of a power generation facility according to a first embodiment of the present invention. In FIG. 1, steam generated by a supercritical boiler 1 is guided to a steam turbine 2 to drive a generator 3 to generate power. The steam that has finished work in the steam turbine 2
The water condensed in the condenser 4 and the condensed water is
Is led to the feed water heater 6. And feed water heater 6
And returned to the supercritical boiler 1.

In the supercritical pressure boiler 1, the state of water is supercritical water exceeding the critical pressure and critical temperature. In other words, the supercritical region has a critical temperature of 374 ° C. or higher and a critical pressure of 22.1 MPa or higher, and does not exhibit a transition between a gas phase and a liquid phase.

The reformer 7 includes supercritical water discharged from the supercritical boiler 1 via a supercritical water system 8 and a fuel supply system 9.
Is mixed with a fuel containing a harmful substance supplied through the fuel cell, a harmful substance of the fuel is extracted, and the fuel is reformed into a fuel containing no harmful substance. That is, the supercritical water injected from the vicinity of the furnace portion downstream of the economizer of the supercritical pressure boiler 1 is supplied to the reformer 7 via the supercritical water system 8. On the other hand, low quality fuel for boilers is supplied to the reformer 7 from the fuel supply system 9 and mixed with supercritical water in the reformer 7. After a certain period of time in the mixing state, harmful substances are extracted from the supplied low-quality fuel into supercritical water.

The mixture of supercritical water passing through this state is led to a separator 10 where it has a higher temperature than when it was extracted from the reformed fuel, noxious substances and supercritical pressure boiler 1. It is separated into clean supercritical water.

The separated reformed fuel is supplied to the reformed fuel supply system 1
After that, the fuel is guided to the reforming fuel supply device 12 and supplied to the supercritical boiler 1. On the other hand, harmful substances are discharged from the harmful substance discharge system 13. Further, the higher-temperature supercritical water is returned to the high-temperature portion from the extraction point of the supercritical water system 8 of the supercritical pressure boiler 1 via the supercritical water return system 14.

In order to further enhance the reforming of the fuel, high-pressure water heated by the feed water heater 6 is extracted and led to the high-pressure hydrogen generator 16 via the high-pressure water system 15, and this high-pressure hydrogen generation is performed. The apparatus 16 generates hydrogen by electrolysis.
The high-pressure hydrogen generated by the high-pressure hydrogen generator 16 is sent to the reformer 7 via the hydrogen supply system 17. Thereby, the calorific value of the fuel can be increased and the thermal efficiency of the supercritical power plant can be increased.

As described above, supercritical water is extracted from the supercritical pressure boiler 1 of the supercritical power plant, and the supercritical water is injected into low-quality fuel to reform the fuel. Since the reformed fuel is burned in the supercritical boiler 1, a flue gas desulfurization device and a dust collector of the supercritical boiler 1 become unnecessary. Therefore, it is possible to reduce the construction cost of the entire supercritical power plant, to increase the thermal efficiency of the entire plant, and to reduce the corrosion trouble of the supercritical boiler 1.

Next, a second embodiment of the present invention will be described. FIG. 2 is a configuration diagram of a power generation facility according to the second embodiment of the present invention. The second embodiment differs from the first embodiment shown in FIG. 1 in that the reformed fuel separated by the separator 10 is supplied to the gasification furnace 1 of the gas turbine power generation system 18.
9. FIG. 2 shows a combined power generation system including a gas turbine 20 and a steam turbine 2A as the gas turbine power generation system 18.

In FIG. 2, the reformed fuel reformed by the separator 10 is supplied to the supercritical boiler 1 via the reformed fuel supply device 12, and the gas turbine power generation system 1
8 is also supplied to the gasification furnace 19. The gasifier 19 supplies the reformed fuel to the combustor 21 of the gas turbine 20 as a gaseous fuel.

The reformed fuel burned in the combustor 21 is supplied to the gas turbine 20 as a driving fuel gas for the gas turbine 20, and drives the gas turbine 20. Gas turbine 20
The exhaust gas that has finished the work is led to the exhaust heat recovery boiler 22,
The exhaust heat generates steam. The steam generated by the exhaust heat recovery boiler 22 is supplied to a steam turbine 2A connected to a gas turbine, and drives a generator 3A to generate power. The steam that has finished its work in the steam turbine 2A is condensed in the condenser 4A, and the condensed water is guided to the feed water heater 6A by the feed water pump 5A. Then, it is heated by the feed water heater 6A and returned to the exhaust heat recovery boiler 22. Further, the exhaust gas having undergone the heat exchange in the exhaust heat recovery boiler 22 is discharged out of the system via an exhaust gas device 23.

As described above, the separator 1 reformed in the reformer 7
The reformed fuel separated at 0 is guided to the gasifier 19 of the gas turbine power generation system and used as fuel. Therefore, the fuel is supplied to the gas turbine 20 as a fuel free of harmful substances equivalent to or more than a commonly used LNG fuel.

Thus, a gas turbine power plant using coal as a fuel which does not require a system for purifying generated gas such as a desulfurization device and an exhaust treatment device required for a coal gasification plant and which does not rely on LNG can be provided. .

Next, a third embodiment of the present invention will be described. FIG. 3 is a configuration diagram of a power generation facility according to the third embodiment of the present invention. According to the third embodiment, a supercritical water generator 24 is provided in a thermal power plant (subcritical pressure power plant) having no supercritical pressure power plant, and supercritical water generated from the supercritical water generator 24 is provided. Water is mixed with the fuel from the fuel supply system 9 and the subcritical boiler 1A is
This is to obtain the fuel.

FIG. 3 shows an example in which a gas turbine power plant 16 is provided in addition to a subcritical pressure power plant, and reforming fuel is also supplied to a gasifier 19 of the gas turbine power plant 16.

The reformer 7 mixes the fuel from the fuel supply system 9 and the supercritical water from the supercritical water generator 24 to reform the fuel into a fuel containing no harmful substances. The separator 10 includes the reformer 7
The reformed fuel is separated and extracted from the mixture from the mixture, and supplied to the subcritical boiler 1A, and the reformed fuel is also supplied to the gasifier 19 of the gas turbine power plant 16.

As described above, in the power plant without the supercritical pressure boiler 1, the supercritical water generator 24 is introduced to generate supercritical water, and the supercritical water is used to reform low-quality fuel. I do. Similarly, in order to further enhance the reforming of the fuel, high-pressure water heated by the feed water heater 6 is extracted and led to the high-pressure hydrogen generator 16 via the high-pressure water system 15. The hydrogen generator 16 generates hydrogen by electrolysis. The high-pressure hydrogen generated by the high-pressure hydrogen generator 16 is sent to the reformer 7 via the hydrogen supply system 17. Thereby, the calorific value of the fuel can be increased and the thermal efficiency of the supercritical power plant can be increased.

[0044]

As described above, according to the present invention, supercritical water is extracted from the supercritical boiler of the supercritical power plant, and the supercritical water is extracted by the reformer using the supercritical water. Reforming the low-quality fuel to the boiler into fuel free of harmful substances,
The harmful substances contained in the flue gas can be reduced, and auxiliary equipment such as desulfurization equipment and ash treatment equipment can be reduced.

Further, since the reformed fuel is used, sulfur corrosion and the like of the supercritical boiler are reduced, and the life can be improved.
Furthermore, for gas turbine power generation systems, LNG
A reformed fuel can be used as a fuel similar to the fuel.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a power generation facility according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram of a power generation facility according to a second embodiment of the present invention.

FIG. 3 is a configuration diagram of a power generation facility according to a third embodiment of the present invention.

[Explanation of symbols]

Reference Signs List 1 supercritical pressure boiler 1A subcritical pressure boiler 2 steam turbine 3 generator 4 condenser 5 feedwater pump 6 feedwater heater 7 reformer 8 supercritical water system 9 fuel supply system 10 separator 11 reformed fuel supply system 12 Reformed fuel supply device 13 Hazardous substance discharge system 14 Supercritical water return system 15 High pressure water system 16 High pressure hydrogen generator 17
Hydrogen supply system 18 Gas turbine power generation system 19
Gasifier 20 Gas turbine 21 Combustor 22
Exhaust heat recovery boiler 23 Exhaust gas device 24 Supercritical water generator

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F22D 11/00 F22D 11/00 B (72) Inventor Kazuya Yamada 2nd Ukishimacho, Kawasaki-ku, Kawasaki-shi, Kawasaki-shi, Kanagawa No. 1 In the Toshiba Hamakawasaki Plant (72) Inventor Tetsuya Furuya 4-36-5, Tsurumichuo, Tsurumi-ku, Yokohama-shi, Kanagawa Prefecture F-term in Toshiba Documents Co., Ltd. 3G081 BA02 BA13 BA16 BB00 BC07 BC19 DA12

Claims (7)

[Claims] 1. A steam turbine connected to a generator is driven by steam from a supercritical boiler, and water condensed after finishing work in the steam turbine is heated by a feed water superheater and returned to the supercritical boiler. In such a power generation facility, a supercritical water system that takes out supercritical water from the supercritical pressure boiler, a fuel supply system that supplies a fuel of an organic substance burned in the supercritical pressure boiler, and a fuel supply system A reformer for mixing fuel and supercritical water from the supercritical water system and reforming the fuel into a fuel containing no harmful substances; separating and extracting a reformed fuel from the mixture from the reformer; A power generation facility comprising a separator for supplying to a critical pressure boiler. 2. The separator separates a reformed fuel, a harmful substance, and supercritical water from a mixture from the reformer, and separates the reformed fuel and the supercritical water into the supercritical pressure boiler. The power generation equipment according to claim 1, wherein the harmful substances are supplied and discharged outside the system. 3. A high-pressure hydrogen generator for electrolyzing high-pressure water supplied to the supercritical-pressure boiler to generate high-pressure hydrogen, and injecting the high-pressure hydrogen into the reformer. The power generation facility according to claim 1 or 2, wherein 4. The power generation equipment according to claim 1, wherein the reformed fuel separated by the separator is guided to a gasification furnace of a gas turbine power generation system. 5. The steam from a subcritical boiler drives a steam turbine to which a generator is connected, heats condensed water after finishing work in the steam turbine, and returns the condensed water to the subcritical boiler by using a feedwater superheater. A fuel supply system for supplying fuel of an organic substance to be burned in the subcritical pressure boiler, and supercritical water generation for extracting high pressure water to be supplied to the subcritical pressure boiler to generate supercritical water. A reformer for mixing the fuel from the fuel supply system with the supercritical water from the supercritical water generator to reform the fuel into a fuel containing no harmful substances; And a separator for separating and extracting high-quality fuel and supplying the separated fuel to the subcritical boiler. 6. A high-pressure hydrogen generator for electrolyzing high-pressure water supplied to the subcritical boiler to generate high-pressure hydrogen and injecting the high-pressure hydrogen into the reformer. The power generation facility according to claim 5, wherein 7. The power generation equipment according to claim 5, wherein the reformed fuel separated by the separator is guided to a gasification furnace of a gas turbine power generation system.