KR102030739B1 - Combusting system of hydrogen enriched fuel for a gas turbine - Google Patents

Abstract

The present invention relates to an H2 fuel injection system for a gas turbine, and more particularly, a fuel injection system supplied to a combustor of a gas turbine, the H2 generator for generating gasified hydrogen fuel, which is provided inside a combustion nozzle, H2 supply pipe for transferring the generated hydrogen fuel along the longitudinal direction of the combustion nozzle and H2 injection unit for injecting the hydrogen fuel transferred to the H2 supply pipe to the premixed gas including the fuel already injected from the combustion nozzle, A gas turbine capable of ensuring sufficient flame stability while maintaining ultra-least premixed combustion conditions with a very small mixing ratio to reduce NOx in the turbine exhaust. For a H2 fuel injection system.

Description

H2 fuel injection system for gas turbines {COMBUSTING SYSTEM OF HYDROGEN ENRICHED FUEL FOR A GAS TURBINE}

The present invention relates to a gas turbine, and more particularly to a combustion system for injecting hydrogen fuel in a combustor for a gas turbine.

A combustor for a gas turbine is provided between the compressor and the turbine, and mixes compressed air supplied from the compressor with the fuel to isostatically burn the fuel, thereby producing a high energy combustion gas and sending the combustion gas into mechanical energy. To perform.

As such, the combustor mixes the compressed air supplied from the outlet of the compressor with the fuel and isostatically burns to produce a high energy combustion gas (see FIG. 2). To this end, a combustor is arranged with a plurality of burners along the combustor casing. Each burner is equipped with several combustion nozzles, and the fuel injected from the combustion nozzles is mixed with air at an appropriate ratio to achieve a state suitable for combustion.

The fuel supplied to the combustor may be composed of a gaseous fuel, a liquid fuel, or a combined fuel thereof, and in recent years, emissions of nitrogen oxides (NOx), etc., which are subject to legal regulation by applying premixed combustion. Efforts have been made to create a combustion environment to reduce the amount of gas, in particular, there are several ways to reduce NOx, such as lowering the combustion temperature and creating a uniform combustion, or an example of very small mixing ratios. Maintaining the mixed gas operating conditions (Ultra Lean Premixed Combustion) to minimize the proportion of the fuel mixed.

However, while lowering the combustion temperature, a problem of increasing emissions such as CO or UHC occurred, and there was a problem of requiring a separate development apparatus because the flame stability was lowered while minimizing the fuel ratio.

The present invention is to solve the above problems, while continuously maintaining the ultra-lean premixed gas operating conditions (Ultra Lean Premixed Combustion) of the ultra-low mixing ratio to reduce the NOx in the exhaust gas of the gas turbine, It is an object of the present invention to provide an H2 fuel injection system for gas turbines capable of ensuring sufficient flame stability.

In addition, by establishing an H2 fuel injection system for realizing this, an object of the present invention is to provide a gas turbine H2 fuel injection system capable of stably supplying highly diffusible hydrogen fuel into a combustor and mixing it with a conventional fuel mixture for a gas turbine. There is this.

H2 fuel injection system for a gas turbine and a gas turbine combustor using the same according to the present invention for achieving the above object is a fuel injection system supplied to a combustor of a gas turbine, the H2 generator for generating gasified hydrogen fuel, combustion A premixing is provided inside the nozzle and includes a H2 supply pipe that transfers the hydrogen fuel generated from the H2 generator along the longitudinal direction of the combustion nozzle and a hydrogen fuel transferred to the H2 supply pipe including fuel already injected from the combustion nozzle. It characterized in that it comprises a H2 injection unit for injecting gas

In addition, the fuel supply unit is provided with a water removal unit, the H2 generator is characterized in that for generating hydrogen fuel using the water absorbed from the water removal unit.

In addition, the H2 supply pipe is provided in the combustion nozzle, characterized in that configured to be spatially separated from the fuel supply pipe to which the conventional composite fuel for gas turbine is transported.

In addition, the cross section of the H2 supply pipe is characterized in that it is formed to surround the outer peripheral surface of the fuel supply pipe.

In addition, the combustion nozzle is provided with a fuel injection port for injecting the composite fuel for the gas turbine, the H2 injection portion is characterized in that formed behind the fuel injection port.

In addition, the H2 injection portion is characterized in that formed on the rear end of the combustion nozzle.

In addition, the H2 injection portion is formed on the end surface of the combustion nozzle, characterized in that the injection hole is formed in a plurality of spaced apart annularly.

By applying the H2 fuel injection system of the present invention to the combustor of the gas turbine, a means of mixing H2 fuel with the existing fuel mixture for the gas turbine is realized, and the ultra-lean premixed combustion condition of the ultra-low mixing ratio Nevertheless, it is possible to secure sufficient flame stability and to continuously maintain a combustion environment for reducing NOx.

In addition, by stably supplying a highly diffusible gaseous hydrogen fuel through the H2 fuel injection system of the present invention, there is an advantage to overcome the instability of hydrogen fuel such as ignition to build a substantially semi-permanent composite fuel injection system.

However, the effects of the present invention are not limited to the above-mentioned effects, and other effects not mentioned will be clearly understood by those skilled in the art from the following description.

1 is a view showing the overall structure of a gas turbine.
2 is a view showing a combustor and a fuel injection system of a conventional gas turbine.
3 is a view showing a conceptual diagram according to an embodiment of the present invention H2 fuel injection system for a gas turbine.
4 is a view showing a conceptual diagram according to another embodiment of the present invention H2 fuel injection system for a gas turbine.
5 is a view showing a conceptual diagram according to another embodiment of the present invention H2 fuel injection system for a gas turbine.
6 is a cross-sectional view according to an embodiment of a combustion nozzle to which an H2 fuel injection system for a gas turbine according to the present invention is applied.
FIG. 7 is a view illustrating a rear surface of the combustion nozzle to which the H2 fuel injection system for the gas turbine of FIG. 6 is applied.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

In describing the embodiments of the present invention, descriptions of well-known configurations that will be obvious to those skilled in the art will be omitted so as not to obscure the subject matter of the present invention. In addition, in adding reference numerals to the components of each drawing, the same components will be given the same reference numerals as much as possible even if they are shown in different drawings. It should be considered that the size of the elements may be exaggerated for clarity and convenience of description.

In describing the components of the embodiments of the present invention, terms such as first, second, A, B, (a), and (b) may be used. These terms are only for distinguishing the components from other components, and the nature, order or order of the components are not limited by the terms. If a component is described as being "connected", "coupled" or "connected" to another component, that component may be directly connected or connected to that other component, but there is another component between each component. It is also to be understood that intervening may be "connected", "coupled" or "connected" indirectly.

The thermodynamic cycle of the gas turbine ideally follows the Brayton cycle. The Brayton cycle consists of four processes: isotropic compression (thermal insulation compression), static pressure quenching, isotropic expansion (thermal insulation expansion), and constant pressure heat dissipation. That is, the air is inhaled and compressed to high pressure, and the fuel is combusted in a constant pressure environment to release thermal energy. The high-temperature combustion gas is expanded and converted into kinetic energy, and the exhaust gas containing residual energy is released into the atmosphere. . That is, the cycle consists of four processes: compression, heating, expansion, and heat dissipation.

Gas turbines that realize these Brayton cycles include compressors, combustors, and turbines. 1 is a view schematically showing the overall configuration of the gas turbine 1000. Although the following description will refer to FIG. 1, the description of the present invention can also be widely applied to a turbine engine having a configuration equivalent to that of the gas turbine 1000 illustrated by way of example in FIG. 1.

The compressor 1100 of the gas turbine 1000 is a portion that sucks and compresses air, and supplies air for combustion to the combustor 1200 while cooling air in a high temperature region in which the gas turbine 1000 requires cooling. The main role is to supply. Since the sucked air is subjected to adiabatic compression in the compressor 1100, the pressure and temperature of the air passing through the compressor 1100 are increased.

The compressor 1100 included in the gas turbine 1000 is usually designed as centrifugal compressors or axial compressors. In a small gas turbine, a centrifugal compressor is applied, whereas a large one such as shown in FIG. Since the gas turbine 1000 needs to compress a large amount of air, the multistage axial compressor 1100 is generally applied.

The compressor 1100 is driven using a portion of the power output from the turbine 1300. To this end, as shown in FIG. 1, the rotating shaft of the compressor 1100 and the rotating shaft of the turbine 1300 are directly connected to each other. In the case of the large gas turbine 1000, almost half of the output produced by the turbine 1300 is consumed to drive the compressor 1100. Thus, improving the efficiency of the compressor 1100 has a direct and profound effect on improving the overall efficiency of the gas turbine 1000.

In addition, the combustor 1200 mixes compressed air supplied from the outlet of the compressor 1100 with fuel to produce isostatic combustion gas by isostatic combustion. 2 shows an example of the combustor 1200 provided in the gas turbine 1000. The combustor 1200 is disposed downstream of the compressor 1100, and a plurality of burners 1220 are disposed along the annular combustor casing 1210. Each burner 1220 is provided with several combustion nozzles 1230, and the fuel injected from the combustion nozzles 1230 is mixed with air at an appropriate ratio to achieve a state suitable for combustion.

In the gas turbine 1000, a gas fuel and a liquid fuel, or a combination fuel thereof may be used. It is important to create a combustion environment to reduce the amount of emissions such as carbon monoxide and nitrogen oxide, which are subject to legal regulation. Although the control of combustion is relatively difficult, it has the advantage of reducing the emission by lowering combustion temperature and making uniform combustion. In recent years, a lot of premixed combustion is applied. In the case of premixed combustion, compressed air is mixed with fuel injected from the combustion nozzle 1230 and then enters the combustion chamber 1240. The initial ignition of the premixed gas is performed using an igniter, and then combustion is maintained by supplying fuel and air once the combustion is stable.

Since the combustor 1200 achieves the highest temperature environment in the gas turbine 1000, appropriate cooling is required. Referring to FIG. 2, a duct assembly connected between the burner 1220 and the turbine 1300 to flow hot combustion gas, that is, a duct assembly including a liner 1250, a transition piece 1260, and a flow sleeve 1270. Compressed air flows along the outer surface of the gas and is supplied toward the combustion nozzle 1230, in which the heated duct assembly is appropriately cooled by the hot combustion gas.

The duct assembly has a double structure in which the flow sleeve 1270 surrounds the liner 1250 connected to the elastic support means 1280 and the transition piece 1260, and the compressed air is annular inside the flow sleeve 1270. Penetrate into the space to cool the liner 1250 and the transition piece 1260.

Here, since each end of the liner 1250 and the transition piece 1260 are fixed to the combustor 1200 and the turbine 1300, respectively, the elastic support means 1280 can accommodate the length and diameter extension due to thermal expansion. It should be possible to support the liner 1250 and the transition piece 1260 in a structure that is present.

The hot and high pressure combustion gas produced by the combustor 1200 is supplied to the turbine 1300 through a duct assembly. In the turbine 1300, while the combustion gas is adiabaticly expanded, a collision and reaction force are applied to a plurality of blades disposed radially on the rotation axis of the turbine 1300, thereby converting thermal energy of the combustion gas into mechanical energy in which the rotation axis rotates. Part of the mechanical energy obtained from the turbine 1300 is supplied to the energy required to compress the air in the compressor, the remainder is used as the effective energy, such as driving the generator to produce power.

As such, since the gas turbine 1000 does not reciprocate its main components, there is no mutual frictional portion such as a piston-cylinder, so the consumption of lubricating oil is extremely low, and the amplitude characteristic of the reciprocating machine is drastically reduced. There is an advantage to exercise.

In addition, since the thermal efficiency in the Brayton cycle increases as the compression ratio for compressing air increases and the temperature (turbine inlet temperature) of the combustion gas flowing into the isentropic expansion process increases, the gas turbine 1000 also has a compression ratio and a turbine. It is developing in the direction of raising the temperature at the entrance.

Hereinafter, the gas turbine H2 fuel injection system 10 of the present invention applied to the combustor 1200 of the gas turbine 1000 will be described in detail with reference to FIGS. 2 to 7.

3 is a view showing a conceptual diagram according to an embodiment of the present invention H2 fuel injection system 10 for the gas turbine.

Referring to FIG. 3, the present invention is a system applied to a power generation gas turbine 1000. The gas turbine 1000 forms compressed air by sucking external air (AA) as described above. Compressor (1100) and the combustor 1200 and the combustion gas supplied from the combustor 1200 to form a high-energy combustion gas by mixing isostatic combustion of the compressed air (A) supplied from the compressor (1100) with the fuel The turbine 1300 converts thermal energy of the combustion gas into mechanical energy in which the rotating shaft rotates while adiabatic expansion. In addition, the mechanical energy obtained from the turbine 1300 is used as an effective energy, such as driving the generator (G) to produce power.

The present invention relates to a fuel injection system supplied to the combustor (1200), wherein the combustor (1200) has an annular combustor casing (1210) and a plurality of burners (1220) disposed along the casing. And a combustion nozzle 1230 provided in each of the burners 1220 and injecting the fuel F to be mixed at an appropriate ratio with the air drawn from the compressor 1100 (see FIG. 2).

The H2 fuel injection system for the gas turbine of the present invention is composed of an H2 generator 100 and an H2 supply system for transporting and injecting hydrogen fuel (HEF: Hydrogen Enriched Fuel) generated therefrom.

The H2 generator 100 converts liquefied hydrogen into gasified hydrogen fuel (HEF). Prior to this, the method may include converting moisture or water vapor into hydrogen gas. Therefore, gaseous hydrogen fuel (HEF) may be produced by supplying liquefied moisture to the H2 generator 100, which may be stably transported and injected to the combustion nozzle 1230 in the combustor 1200 by the H2 supply system which will be described later. Will be.

The H2 generator 100 may be implemented in various physical forms and locations, as long as the H2 generator 100 can perform the function of producing or converting the gasified hydrogen fuel (HEF) to be transferred to the H2 supply system.

For example, the H2 generator 100 may be provided to be attached to the outside of the combustion chamber 1240 of the combustor 1200. Accordingly, the transport length of the H2 supply system can be shortened, and at the same time, the gas can be provided to absorb the heat in the physically opposed combustion chamber 1240 while gasifying liquefied hydrogen or the like to exert a cooling effect.

Alternatively, if necessary, it may be disposed outside the gas turbine 1000 as a separate device to achieve portability.

Or, it may be formed to be arranged in parallel in the composite fuel supply pipe 210 and one pipe portion which is continued from the existing composite fuel supply unit 200 to be described later.

4 and 5 are conceptual views showing another embodiment of the H2 fuel injection system for a gas turbine according to the present invention.

Referring to FIG. 4, moisture, etc., required to produce hydrogenated gaseous fuel (HEF) in the H2 generator 100 may be supplied from the water removal unit 220. The water removing unit 220 absorbs the water of the liquefied fuel combined in the composite fuel supply unit 200 to be described later, the absorbed water may be provided to be delivered to the H2 generator 100 through the supply pipe 221. have. Accordingly, new cycles of water supply for water removal of liquefied fuel and generation of hydrogen fuel are formed, so that the waste water is recycled, thereby increasing the overall efficiency of the gas turbine.

In addition, referring to FIG. 5, moisture, etc. required to produce hydrogenated gaseous fuel (HEF) in the H2 generator 100 may be supplied from the HRSG system 300. This is to consider the overall efficiency increase of the combined cycle power plant (CCPP), the steam so that the exhaust gas 310 discharged at very high temperature is utilized to operate the steam turbine (not shown) in the HRSG system 300 When the circulated steam is converted into water 320 by a condenser (not shown), a separate cycle may be formed in the H2 generator 100 to enable continuous hydrogen fuel generation.

On the other hand, the H2 supply system is specifically composed of the H2 supply pipe 110 and H2 injection unit 120, which will be described in detail in Figures 6 to 7 below.

FIG. 6 is a cross-sectional view according to an embodiment of the combustion nozzle 1230 to which the present inventors H2 fuel injection system 10 is applied, and FIG. 7 is a view illustrating a rear surface of the combustion nozzle 1230.

Referring to this, the H2 supply pipe 110 is provided inside the combustion nozzle 1230 to transfer the hydrogen fuel (HEF) generated from the H2 generator 100 along the longitudinal direction of the combustion nozzle 1230. It becomes possible.

Specifically, the H2 supply pipe 110 may be configured to be spatially separated from the fuel supply pipe 210 to which the conventional composite fuel (F) for the gas turbine is transported, and the fuel supply pipe 210 is also the combustion nozzle 1230. It may be provided in the interior.

According to this dual structure, the hydrogen fuel (HEF) is the basis for controlling mixing with the existing composite fuel (F) at a specific point in time.

As an embodiment for implementing the dual structure inside the combustion nozzle 1230, a cross section of the H2 supply pipe 110 may be formed to surround an outer circumferential surface of the fuel supply pipe 210. Specifically, referring to FIG. 7, the H2 supply pipe 110 is provided in an outer annular space of the combustion nozzle 1230, and the fuel supply pipe 210 is provided in a circular space surrounded by the H2 supply pipe 110. Can be.

On the other hand, the H2 injection unit 120 injects hydrogen fuel (HEF) transferred to the H2 supply pipe 110 to the pre-mixed gas (PG) including the fuel (F) already injected from the combustion nozzle 1230. It may be provided to perform a function.

To this end, the combustion nozzle 1230 is provided with a fuel injection hole 1232 for injection of the gas fuel composite fuel (F), the H2 injection portion 120 is formed behind the fuel injection hole (1232) It may be provided to be.

Here, the term "rear" means a point located relatively downstream based on the flow of compressed air or premixed gas. Referring to FIG. 6, the H2 injection unit 120 may be formed at a right point of the fuel injection hole 1232 to which the composite fuel F for gas turbine is injected, and may be formed in the combustion nozzle 1230.

The fuel injection hole 1232 may be provided in the swizzle 1231 formed to protrude outward from the stop point of the combustion nozzle 1230. Accordingly, the existing composite fuel F injected into the combustion nozzle 1230 through the fuel supply pipe 210 passes through the main passage 230 and the auxiliary passage 231 inside the swizzle 1231. By injection from the fuel injection port 1232, it may be provided to be premixed with the compressed air facing.

The premixed gas PG moving backwards through the fuel injection hole 1232 is mixed with the H2 injection part 120 to generate the premixed gas PG including the fuel F that has already been injected. Before entering the combustion chamber 1240 where the ignition occurs, that is, mixing occurs at a specific moment and at a specific point, the highly diffusive hydrogen fuel is stably supplied into the combustor, and the hydrogenated premixed gas (HPG), which is the final composite fuel, is supplied. Means for igniting in a timely manner can be realized.

More preferably, the H2 injection unit 120 may be formed at the rear end of the combustion nozzle 1230, and the H2 injection unit 120 may be formed at an end surface of the combustion nozzle. Is formed in 121, the injection hole 125 may be provided so that a plurality of spaced apart in an annular shape (see Fig. 7).

As such, by applying the H2 fuel injection system of the present invention to the gas turbine and the combustor included therein, a means for mixing H2 fuel into a conventional fuel mixture for a gas turbine is realized, and thus, premixed gas operation conditions of ultra-low mixing ratio (Ultra Despite Lean Premixed Combustion, it is possible to secure sufficient flame stability and to maintain a combustion environment for reducing NOx.

In addition, by stably supplying a highly diffusible gaseous hydrogen fuel through the H2 fuel injection system of the present invention, it is possible to overcome the instability of hydrogen fuel such as ignition to build a substantially semi-permanent composite fuel injection system.

The gas turbine H2 fuel injection system according to the present invention has been described above. Such a technical configuration of the present invention will be understood by those skilled in the art that the present invention can be implemented in other specific forms without changing the technical spirit or essential features of the present invention.

Therefore, the above-described embodiments are to be understood in all respects as illustrative and not restrictive.

100: H2 generator 110: H2 supply pipe
120: injection hole H2: 125 injection hole
200: fuel supply unit 300: HRSG system
1000: gas turbine 1100: compressor
1200: combustor 1230: combustion nozzle
1231: Swazzle 1232: fuel injection
1233: nozzle shroud 1240: combustion chamber
PG: Premixed Gas HPG: Hydrogenated Premixed Gas

Claims (15)

As a fuel injection system supplied to the combustor of a gas turbine:
An H2 generator for generating gasified hydrogen fuel;
An H2 supply pipe provided inside the combustion nozzle and transferring hydrogen fuel generated from the H2 generator along a longitudinal direction of the combustion nozzle; And
H2 injection unit for injecting the hydrogen fuel transferred to the H2 supply pipe to the pre-mixed gas including the fuel already injected from the combustion nozzle,
The fuel supply unit includes a water removal unit, and the H2 generator generates hydrogen fuel using water absorbed from the water removal unit,
The H2 supply pipe is provided inside the combustion nozzle, the gas turbine H2 fuel injection system, characterized in that configured to be spatially separated from the fuel supply pipe to which the existing complex fuel for gas turbine is transported.
delete delete The method of claim 1,
The cross section of the H2 supply pipe is formed to surround the outer peripheral surface of the fuel supply pipe H2 fuel injection system for a gas turbine.
The method of claim 1,
The combustion nozzle is provided with a fuel injection hole for injecting the composite fuel for the gas turbine, the H2 injection portion is formed behind the fuel injection hole H2 fuel injection system for a gas turbine.
The method of claim 5,
The H2 injection unit H2 fuel injection system for a gas turbine, characterized in that formed on the rear end of the combustion nozzle.
The method of claim 6,
The H2 injection unit is formed on the end surface of the combustion nozzle, the injection hole is a H2 fuel injection system for a gas turbine, characterized in that a plurality formed in the annular spaced apart.
As the combustor of the gas turbine:
Annular combustor casings;
A plurality of burners disposed along the casing;
Each burner is provided with a combustion nozzle for injecting fuel to be mixed at an appropriate ratio with the air drawn from the compressor,
A fuel injection system supplied to the combustor:
An H2 generator for generating gasified hydrogen fuel;
An H2 supply pipe provided inside the combustion nozzle and configured to transfer hydrogen fuel generated from the H2 generator along a longitudinal direction of the combustion nozzle; And
H2 injection unit for injecting the hydrogen fuel transferred to the H2 supply pipe to the pre-mixed gas including the fuel already injected from the combustion nozzle,
The fuel supply unit includes a water removal unit, and the H2 generator generates hydrogen fuel using water absorbed from the water removal unit,
The H2 supply pipe is provided in the combustion nozzle, the combustor, characterized in that it is configured to be spatially separated from the fuel supply pipe to which the conventional composite fuel for gas turbine is transported.
delete delete The method of claim 8,
Combustor, characterized in that the cross section of the H2 supply pipe is formed to surround the outer peripheral surface of the fuel supply pipe.
The method of claim 8,
The combustion nozzle is provided with a fuel injection port for injecting the composite fuel for the gas turbine, and the H2 injection unit is formed behind the fuel injection port.
The method of claim 12,
And the H2 injection portion is formed at the rear end of the combustion nozzle.
The method of claim 13,
The H2 injection unit is formed on the end surface of the combustion nozzle, the combustor, characterized in that a plurality of injection holes are formed in the annular spaced apart.
With gas turbine for power generation:
A compressor for sucking outside air to form compressed air;
A combustor for mixing the compressed air supplied from the compressor with fuel to form isothermal combustion by isostatic combustion; And
Including a turbine in which the heat energy of the combustion gas is converted into mechanical energy of the rotating shaft while the combustion gas supplied from the combustor is adiabatic expansion,
A fuel injection system supplied to the combustor:
An H2 generator for generating gasified hydrogen fuel;
An H2 supply pipe provided inside the combustion nozzle and transferring hydrogen fuel generated from the H2 generator along a longitudinal direction of the combustion nozzle; And
H2 injection unit for injecting the hydrogen fuel transferred to the H2 supply pipe to the pre-mixed gas including the fuel already injected from the combustion nozzle,
The fuel supply unit includes a water removal unit, and the H2 generator generates hydrogen fuel using water absorbed from the water removal unit.
The H2 supply pipe is provided in the combustion nozzle, the gas turbine for power generation, characterized in that configured to be spatially separated from the fuel supply pipe to which the conventional complex fuel for gas turbine is transported.

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