JPH0255835A - Gas turbine device additionally providing exhaust gas boiler with built-in exhaust gas denitrification device - Google Patents

Abstract

PURPOSE:To reduce the cost of equipment by mixing denitrificating ammonia gas in gas turbine cooling compressed air. CONSTITUTION:A feed pipe 20 of gasified ammonia gas by an ammonia liquid carburetor 12 is connected to cooling compressed air pipes 24, 27 of a gas turbine 5. Mixed gas of ammonia gas with compressed air is jetted mixing in combustion exhaust gas from a cooling hole in a gas turbine blade. Thus enabling the ammonia gas to be used for cooling the gas turbine, the cost of equipment can be reduced by decreasing the capacity of an air compressor.

Description

[Detailed description of the invention]

[Industrial Field of Application J] The present invention relates to a gas turbine device equipped with an exhaust gas boiler incorporating an exhaust gas denitrification device.

[Prior art] High calorie fuel gas such as liquefied natural gas or liquefied petroleum gas is usually used as fuel for gas turbines for power generation, and in this case, the combustion flame temperature is high and the Noxa degree in the exhaust gas is 150 ppm. To reduce NOx, we installed an exhaust gas reduction and denitrification device that uses ammonia gas.
The NOx concentration in exhaust gas is reduced to 50 ppm or less. On the other hand, gas turbine blades are exposed to flames of approximately 1,100°C, and if not cooled they will melt or wear out due to oxidation. Generally, these blades are cooled by an air compressor that rotates coaxially with the gas turbine. This is done by passing the oil and gas through a number of cooling holes provided in the turbine blades and jetting them into the combustion exhaust gas in the gas turbine from the tips of the cooling holes. FIG. 5 is a configuration diagram showing an example of a conventional liquefied natural gas-fired gas turbine combined cycle power generation system. In FIG. 5, 1a is a starting device, e.g. an electric motor, lb
is a speed reducer. Steam turbine 21 generator 3. The air compressor 4 and the gas turbine 5 are connected by coaxial rotary transmission shafts 17c and 17d, respectively, and the generator 3 and the air compressor 4 are rotated by the outputs of the gas turbine 5 and the steam turbine 2, respectively, and generate electricity and air. It is designed to perform compression. The compressed air discharged from the compressor 4 mixes and burns natural gas supplied from the supply pipe 18 in the combustor 6 . The combustion exhaust gas of natural gas mixed and burned with compressed air in the combustor 6 collides with the stator blades and rotor blades of the gas turbine, causing the rotor to rotate. Exhaust gas from the gas turbine 5 is guided to an exhaust gas boiler 7 incorporating a denitrification device 8. The exhaust gas boiler 7 has a built-in nozzle 15 for injecting ammonia gas for denitrification. The ammonia liquid sent out from the ammonia liquid storage tank 11 via the feed pipe 19 is vaporized by exchanging heat with steam, which is a heating medium, in the vaporizer 12 . The ammonia gas after vaporization passes through the ammonia gas supply pipe 20 to the ammonia gas injection nozzle 1.
Sent to 5. Steam generated in the exhaust gas boiler 7 is sent to the steam turbine 2 via a steam feed pipe 21. The condensate of the steam turbine returns to the boiler 7 through the condensate return pipe 22. Since the wandering gas of the gas turbine has a high NOx concentration, it is reduced and denitrated using ammonia gas in a denitrification device 8 filled with an appropriate reduction catalyst. This denitrification is done by the exhaust gas boiler 7.
This is done by injecting and mixing ammonia gas into the exhaust gas from an ammonia gas injection nozzle 15 built into the exhaust gas. The denitrified exhaust gas is discharged from the outlet side of the exhaust gas boiler 7 as low NOx boiler exhaust gas. FIG. 6(a) shows a partially omitted longitudinal section of an air compressor 4 and a gas turbine 5 as an example of a conventional gas turbine cooling means. FIG. 6(b) is an enlarged vertical sectional view of the vicinity of the stator blade 10a of the gas turbine, FIG. 6(C) is a plan view thereof, FIG. 6(d) is a sectional view of the moving blade 9a of the gas turbine, and FIG. Figure (e
) is a vertical cross-sectional view of the vicinity of the rotor blade 9a. Cooling air for the stationary blades 10a of the gas turbine is supplied to a low-pressure air bleed chamber 23a in the middle stage of the air compressor 4. Low pressure compressed air extraction pipes 24a, 2 from 23b, 23c
4b and 24c, and is sent to the compressed air distribution chamber 10C provided in the circumferential direction of the stator (casing) 28 of the gas turbine 5, and cooled by the cooling holes 10b provided in the stationary blades 10a all around the circumference. After cooling the stake 28 and stator vane 10a, it is ejected from the tip of the cooling hole lOb into the exhaust gas in the gas turbine. On the other hand, the compressed air for cooling the gas turbine rotor blades 9a is compressed to 12 to 13 kg/c by the air compressor 4, and is taken out of the machine from the high-pressure compressed air discharge chamber 25 via the high-pressure compressed air take-out pipe 26. After being cooled by the air cooler 13, it passes through the air filter 14 and is taken into the aircraft again via the high-pressure compressed air supply pipe 27, and is then cooled by the rotor blades provided on the outer peripheral surface of the rotor 29 of the gas turbine. The air is sent to the air distribution chamber 9c, from which the cooling holes 9 of the rotor blades 9a, which are erected all around the outer circumference of the rotor, are sent to the air distribution chamber 9c.
After cooling the rotor 29 and the rotor blades 9a through the cooling hole 9b, it is ejected into the combustion exhaust gas in the gas turbine from the tip of the cooling hole 9b. FIG. 7 shows a partially cut away longitudinal sectional view of a conventional exhaust gas boiler incorporating an exhaust gas denitrification device disclosed in, for example, Japanese Unexamined Patent Publication No. 54-96604. The gas boiler 7 consists of a high pressure steam boiler section 7a and a low pressure steam boiler 7b, and has a built-in denitrification device 8. The high-pressure steam boiler 7a is located upstream of the denitrification device 8, cools the high-temperature exhaust gas to a temperature suitable for denitrification, and recovers high-pressure steam. The low-pressure steam boiler 7b cools the wandering gas after denitrification and recovers the low-pressure steam. A denitrification ammonia gas injection nozzle 15 is provided in a part of the high-pressure steam boiler 7a. [Problems to be Solved by the Invention] The conventional devices as described above have the following problems. (1) High-pressure compressed air for cooling gas turbine rotor blades is cooled by an air cooler, and in this case, steam turbine condensate is used as the heat exchange refrigerant. This is to prevent a decrease in heat exchange efficiency or blockage of the flow path due to deposition of Ca ions or microorganisms in the refrigerant flow path of the heat exchanger. Since the condensate of the steam turbine has a high temperature, the high pressure compressed air after being cooled by the air cooler has a temperature of 220 to 370
℃, and the effect of cooling the rotor blades is low. (2) Compressed air for cooling gas turbine stator blades is not actively cooled, and combined with (1) above, a large amount of compressed air is required to cool the gas turbine rotor blades and stator blades. The capacity of the compressor has increased, which reduces the energy conversion efficiency or power generation efficiency of the gas turbine. (3) Space is required to install the ammonia gas injection nozzle inside the exhaust gas boiler, making the structure of the exhaust gas boiler complicated.
And it is large. (4) Ammonia gas used in denitrification equipment (approximately 70℃
) is not used effectively at all, and only lowers the temperature of the exhaust gas in the boiler and reduces the amount of steam recovered.Also, a large amount of compressed air for cooling the gas turbine enters the exhaust gas boiler together with the combustion exhaust gas, so the amount of exhaust gas decreases. This has led to an increase in the size of exhaust gas boilers. (5) To obtain the ammonia gas used in the denitrification equipment, the liquefied ammonia gas is passed through a vaporizer and heated and vaporized using steam, which not only does not effectively utilize the cold energy of the liquefied ammonia gas, but also wastes the steam generated by the boiler. This not only causes a decrease in energy conversion efficiency or power generation efficiency, but also requires a large vaporizer, making the device complex and expensive. The present invention aims to solve the problems of the conventional technology as described above. In other words, it increases the cooling effect of gas turbine rotor blades and stationary blades, reduces the amount of compressed air required for cooling,
The capacity of the air compressor can be reduced, improving the energy conversion efficiency or power generation efficiency of the gas turbine. Additionally, the installation of an ammonia gas injection nozzle for denitrification in the exhaust gas boiler is eliminated, making the structure of the exhaust gas boiler simpler and smaller. The present invention also effectively utilizes part or all of the cold energy of liquefied ammonia gas as an ammonia gas source for wandering gas denitrification equipment, thereby reducing or eliminating the need for heating steam for vaporizing liquefied ammonia gas. The purpose of the present invention is to provide a gas turbine device equipped with an exhaust gas boiler with a built-in exhaust gas denitrification device, which can reduce the size of the vaporizer or omit it, thereby improving energy conversion efficiency or power generation efficiency. do. [Means for Solving the Problems and Effects 1] The present invention relates to an improvement of a gas turbine device equipped with an exhaust gas boiler incorporating a reduction and denitrification device for wandering gas using ammonia gas. The technical means and their effects are as follows. (a) Connect the ammonia gas supply pipe for denitrification that has passed through the ammonia liquid vaporizer to the supply pipe for compressed air for cooling the stator, rotor, and blades of the gas turbine, and connect the stator, rotor, and blades of the gas turbine with the ammonia gas. This mixed gas is then jetted and mixed into the combustion exhaust gas in the gas turbine through the cooling holes of the gas turbine blades. Therefore, the cold energy of ammonia gas can be used to cool the stator, rotor, and blades of the gas turbine, reducing the amount of compressed air required for cooling, reducing the capacity of the air compressor, and reducing equipment costs. It is possible to reduce energy consumption and improve energy conversion efficiency. In addition, it is not necessary to install ammonia and agas injection nozzles in the exhaust gas boiler, which not only makes the boiler more compact and reduces equipment costs, but also allows for sufficient mixing of ammonia gas and combustion exhaust gas, which reduces stray gas denitrification. The efficiency is also as good as the conventional one. (b) Another technical means of the present invention is to provide a heat exchanger using the ammonia liquid for denitration of the ammonia liquid vaporizer as a refrigerant to cool the compressed air for cooling the gas turbine blades and/or the compressor intake air. After that, the ammonia liquid is gasified through a vaporizer, and this ammonia gas supply pipe is connected to a gas turbine blade cooling air supply pipe, and the gas turbine blade is supplied with a mixed gas of ammonia gas and compressed air. After cooling, the mixed gas of 4: was injected and mixed into the combustion exhaust gas in the gas turbine through the cooling hole of the gas turbine blade. Therefore, part of the cold energy of the ammonia liquid and all of the cold energy of the ammonia gas can be used in the gas turbine blade cooler, and the required amount of compressed air for cooling is smaller than in the case of the configuration (a) above. Not only can the capacity of the air compressor be further reduced, but also the capacity of the ammonia evaporator and the amount of steam required for the heat transfer medium can be reduced, resulting in lower equipment costs and energy conversion efficiency. It is possible to improve the Furthermore, the same effects as in (a) above can be expected for the exhaust gas boiler. (c) As another technical means of the present invention, a liquid supply pipe for ammonia for denitration is directly connected to a supply pipe for compressed air for cooling of a gas turbine through a gas-liquid mixing means, and the stator of the gas turbine is directly connected to a supply pipe for compressed air for cooling the gas turbine. After cooling the rotor and blades with a mixed fluid of ammonia liquid mist and compressed air for cooling, this mixed fluid is jetted and mixed into the combustion exhaust gas in the gas turbine through the cooling holes of the gas turbine blades. . Therefore, all of the cold energy of the ammonia liquid can be used to cool the gas turbine blades, and the need for compressed air for cooling can be further reduced, making it possible to further downsize the air compressor and reduce equipment costs. Not only this, but also the ammonia vaporizer can be omitted, and the use of the steam generated by the exhaust heat recovery boiler as a heat medium for the ammonia vaporizer becomes unnecessary. From this, it is possible to reduce the equipment cost of the - layer and improve the energy conversion efficiency of the - layer.4 Note that the same effects as in (a) above can be expected for the exhaust gas boiler. . (d) According to a further aspect of the present invention, compressed air for cooling the stator, rotor, and blades of a gas turbine and/or compressed air intake air is supplied through a heat exchanger using denitrification ammonia liquid as a refrigerant. After cooling, the ammonia liquid and/or vaporized ammonia gas supply pipe is connected to the gas turbine cooling air supply pipe through a mixing means, and the stator, rotor, and blades of the gas turbine are supplied with the ammonia liquid and/or vaporized ammonia gas. After cooling with mist and/or a mixed fluid of ammonia gas and compressed air,
This mixed fluid is jetted and mixed into the combustion exhaust gas in the gas turbine through the cooling holes of the gas turbine blades. Therefore, the same effect as described in the above section (C) can be expected. [Example] A specific configuration of the present invention will be explained using an example shown in FIG. FIG. 1 shows a liquefied natural gas-fired gas turbine combined cycle power generation system according to a first embodiment of the present invention.
FIG. 2 is a system diagram showing an example. 43 in Figure 1 and numbers 2 to 8. 11 to 12 are already numbered 5.
This is the same as explained in the figure. In this embodiment, the ammonia gas injection nozzle 15 is not included in the denitrification device 8 built in the conventional exhaust gas boiler 7 shown in FIG. The ammonia gas supply pipe 20 is connected to a low-pressure compressed air take-off and supply pipe 24 and a high-pressure air supply pipe 27, and the ammonia gas is mixed with these compressed air to cool the stator, rotor, and blades of the gas turbine, and then The cooling hole 9b of the rotor blade i9a and the stationary blade i9a explained in FIG.
It is jetted out and mixed into the combustion exhaust gas in the gas turbine from the cooling hole lOb of Jl l Oa, and is led to the exhaust gas boiler 7 . FIG. 2 is a system diagram showing a second embodiment of the present invention. In FIG. 2, the numbers 2-8, 11-12 are the same as those already explained in FIG. In this embodiment, the high-pressure compressed air sent from the high-pressure compressed air take-out pipe 26 is connected to the ammonia liquid supply pipe 19 on the inlet side of the ammonia vaporizer 12 of the first embodiment. It is cooled by a heat exchanger using a refrigerant, that is, an air cooler 13a, and is further cooled by a low-pressure air supply pipe 24.
The low-pressure air is cooled by an air cooler 13b provided midway through the air cooler 13b, which also uses ammonia liquid as a cooling medium. The ammonia solution for denitrification is sent to the ammonia vaporizer 12 through these air coolers, and after being completely vaporized, it is mixed with the cooling air by connecting the feed pipes 20 to the feed pipes 27 and 24, respectively, and Similar to the first embodiment, the snator, rotor, and blades of the gas turbine are cooled. After cooling, it is ejected and mixed into the combustion exhaust gas in the gas turbine through the cooling hole of the volume. In the example shown in Fig. 2, the intake air of the air compressor is not cooled, but it is of course possible to cool the intake air by using ammonia liquid as a refrigerant. It can be further reduced. FIG. 3 is a system diagram showing a third embodiment of the present invention. Numbers 2 to 8 are the same as in FIG. In this embodiment, unlike the first and second embodiments, the ammonia solution supply pipe 19 is directly connected from the ammonia solution storage tank 11 to the gas-liquid mixing means 30 without passing through an ammonia vaporizer.
．． 30 to the low-pressure compressed air supply pipe 24 and high-pressure compressed air supply pipe 27 to mix cooling compressed air and ammonia liquid, and use the gas-liquid mixed fluid to cool the stator, rotor, and blades of the gas turbine. After this, the gas is injected and mixed into the combustion exhaust gas in the gas turbine through the cooling holes of the blades. A portion of the ammonia liquid is vaporized while passing through the stator, rotor, and volume flow paths, but the rest is mixed with the high-temperature combustion exhaust gas, where it is completely vaporized and sent to the exhaust gas boiler, so it is not removed by the denitrification device 8. There is no problem with the exhaust gas denitrification reaction; on the contrary, it mixes better with the exhaust gas than the conventional device equipped with the ammonia gas injection nozzle 15 shown in Fig. 5, and the denitrification efficiency is superior, but inferior. Never. Further, a known device may be used as the gas-liquid mixing means 30, for example, ammonia liquid may be supplied into the cooling compressed air through an orifice. Depending on the relationship between the pressure of the compressed air for cooling and the pressure of the ammonia liquid, the ammonia liquid may be supplied using gravity and sucked into the compressed air flow. If necessary, the ammonia liquid may be pumped by a pressure pump. Press and inject into compressed air. FIG. 4 is a system diagram showing a fourth embodiment of the present invention. In the case of this embodiment, a compressor suction air cooler 13c using ammonia solution as a refrigerant, a low-pressure compressed air cooler 13b, and a high-pressure compressed air cooler 13c are installed in the middle of the ammonia liquid supply pipe 19 of the third embodiment. coolers 13a are sequentially provided,
In addition to cooling the cooling air, part or all of the ammonia liquid is heated and vaporized using the latent heat of the cooling air.
Thereafter, the mixture is connected to the low-pressure compressed air supply pipe 24 and the high-pressure compressed air supply pipe 27 via the mixing means 30, 30, respectively, and the mixed fluid of cooling compressed air and ammonia liquid and/or ammonia gas is supplied to the stator of the gas turbine,
It feeds the rotor and air passages within the blades. In this case, even if all of the ammonia is vaporized before entering the mixing means 30.30 during steady operation, during unsteady operation during startup and shutdown, the temperature of the compressed air is low and the ammonia is completely vaporized. Therefore, it is desirable to provide a gas-liquid mixing device as described in the third embodiment. [Effects of the Invention] Since the present invention has the above configuration, it has the following excellent effects. In other words, in a gas turbine system equipped with an exhaust gas boiler with a built-in denitrification device that reduces exhaust gas using ammonia gas, (a) a part or all of the cold energy of the ammonia gas or ammonia liquid for denitrification is used to cool the stator, rotor, and blades of the gas turbine; Since the air compressor is used for
Operating costs can be reduced by improving overall energy conversion efficiency. (b) The ammonia vaporizer for denitrification can be downsized or omitted, reducing equipment costs and the amount of recovered steam needed as a heating medium, further improving the overall energy conversion efficiency. (c) The ammonia gas injector in the exhaust gas boiler can be omitted without any effect on the exhaust gas denitrification efficiency, making it possible to downsize the exhaust gas boiler and reduce equipment costs.

[Brief explanation of the drawing]

Figs. 1 to 4 are system diagrams of a liquefied natural gas-fired gas turbine combined cycle power generation device showing embodiments of the present invention, and Fig. 5 shows an example of a conventional liquefied natural gas-fired gas turbine combined cycle power generation device. System diagram, Figure 6 (al is a sectional view of the main parts of the air compressor and gas turbine showing the conventional gas turbine cooling method, Figure 6 (1)), (C) is an enlarged cross section of the gas turbine stator blade. Figures 6(d) and 6(e) are enlarged sectional views and sectional views of gas turbine rotor blades, and Figure 7 is a partially cutaway sectional view of an exhaust gas boiler with a built-in conventional exhaust gas denitrification device. . 2...Steam turbine 3...-generator 4...Air pressure [! 5-... Gas turbine 6... Combustor 7... Exhaust gas boiler 8... Denitrification device 9a... Gas turbine rotor blade 9b... Rotor blade cooling hole 9c --- Rotor blade cooling air distribution chamber 10a... Gas turbine stator blade fob... Stator blade cooling hole 10c... Stator blade cooling air distribution chamber 11... - Liquefied ammonia storage FM 12... - Ammonia vaporizer 13 (13a, 13b, 13c) - --Air cooler 1
4...Air filter 15...-Ammonia injection nozzle 18...-Natural gas feed piping 19...Ammonia liquid feed piping 20...Ammonia gas feed piping 21...Steam feed piping 22・-Steam turbine condensate return piping 23a, 23b, 23cm low pressure compressed air compressed air chamber 24 (
24a, 24b, 24c)...Low pressure compressed air supply piping 5...-High pressure compressed air discharge chamber 6...High pressure compressed air take-out piping 7...High pressure compressed air supply piping 8...-Stator C casing ) 9・-rotor 0・-air 1fi mixing means

Claims (1)

[Claims] 1. An exhaust gas denitrification device characterized in that an ammonia gas supply pipe for denitration that has passed through an ammonia liquid vaporizer is connected to a supply pipe for compressed air for cooling the stator, rotor, and blades of a gas turbine. Gas turbine equipment equipped with a built-in exhaust gas boiler. 2. The gas turbine according to claim 1, wherein a heat exchanger is installed upstream of the ammonia liquid vaporizer, using the ammonia liquid for denitration as a refrigerant, and cooling compressed air for cooling gas turbine blades and/or compressor suction air. Device. 3. The gas turbine apparatus according to claim 1, wherein instead of the ammonia liquid vaporizer, a denitrification ammonia liquid supply pipe is connected to a compressed air supply pipe via a gas-liquid mixing means. 4 Instead of an ammonia liquid vaporizer, an ammonia liquid and/or
3. The gas turbine apparatus according to claim 2, wherein means for mixing vaporized ammonia gas and air is interposed, and the ammonia feed pipe downstream thereof is connected to the gas turbine cooling air feed pipe.