CN118009353B - A gas turbine staged combustion device coupled with ammonia fuel pre-cracking - Google Patents

Abstract

The invention discloses a gas turbine staged combustion device for coupling ammonia fuel pre-cracking, which comprises a combustion tube, a fuel channel outer tube and an air channel outer tube which are coaxially and fixedly arranged from inside to outside; the front end of the combustion tube is provided with an air inlet orifice plate, the air inlet orifice plate is provided with an axial air inlet through hole, the rear end of the combustion tube is provided with a flue gas outlet, a first-stage porous medium and a second-stage porous medium are arranged in a multi-stage combustion cavity at intervals, and a fuel injection hole penetrating through the wall of the combustion tube is arranged at a position on the combustion tube corresponding to the second-stage porous medium; the front end of the fuel channel outer tube is provided with an air input through hole, and the rear end of the fuel channel outer tube is provided with an ammonia fuel inlet communicated with the annular fuel channel; the rear end of the air channel outer tube is provided with an air inlet communicated with the annular air channel. The invention can realize clean, stable and efficient combustion of the applicable ammonia fuel, and can solve the problems that the traditional gas turbine combustion chamber cannot realize pre-cracking of the ammonia fuel, the stable combustion in a wide range is difficult and the NO _x is more discharged in the prior art.

Description

A gas turbine staged combustion device coupled with ammonia fuel pre-cracking

Technical Field

The invention relates to a gas turbine combustion device, in particular to a gas turbine staged combustion device coupled with ammonia fuel pre-cracking, belonging to the technical field of gas turbines.

Background Art

A gas turbine is an internal combustion power machine that uses a continuously flowing gas as a working fluid to drive the impeller to rotate at high speed, converting the energy of the fuel into useful work. It is a rotating impeller heat engine that is widely used in the electric power industry, petrochemical industry, aerospace, shipbuilding, military and other fields. The gas turbine cycle, which consists of only three major components: the compressor, the combustion chamber and the gas turbine, is generally called a simple cycle, and most gas turbines use a simple cycle scheme. The working principle of a gas turbine: the compressor continuously inhales air from the atmosphere and compresses it; the compressed air enters the combustion chamber, is mixed with the injected fuel through the combustion device, and then burns to become high-temperature combustion gas, which then flows into the gas turbine to expand and do work, driving the turbine impeller to rotate with the compressor impeller; while the high-temperature combustion gas drives the gas turbine to do work and drives the compressor, there is still surplus work as the output mechanical work of the gas turbine.

Different application scenarios have different requirements and usage conditions for gas turbines. Most gas turbines with a power of more than 10 megawatts are used for power generation, while those with a power of more than 30 to 40 megawatts are almost all used for power generation. Faced with the urgent need for global decarbonization and increasingly stringent environmental regulations, the demand for low-carbon emission and low _NOx pollutant emission gas turbines is also increasing. Replacing traditional fossil fuels with new zero-carbon or low-carbon fuels can effectively reduce carbon dioxide emissions.

Ammonia is a zero-carbon fuel and an efficient hydrogen storage carrier. It has significant advantages such as high energy density, safe storage and transportation, and low cost. Green ammonia synthesized from clean low-carbon hydrogen is considered by the industry to be an ideal clean energy carrier. Therefore, the development of gas turbines using ammonia as fuel is one of the most promising paths to decarbonize existing gas turbines. However, there are still huge challenges in the combustion and utilization of ammonia fuel in gas turbines. Compared with conventional hydrocarbon fuels, ammonia combustion has problems such as low flame speed, narrow flammable range, and high pollutant emissions. In order to improve the combustion stability of ammonia, hydrogen-blended combustion is an effective way to increase the combustion speed. Since ammonia fuel is rich in hydrogen, ammonia can be decomposed into nitrogen and hydrogen under the action of a catalyst, thus providing a source of hydrogen. Therefore, the development of a gas turbine combustion device coupled with ammonia fuel pre-cracking to achieve efficient and stable combustion of ammonia fuel and lower pollutant emissions is the key to the large-scale promotion and application of ammonia fuel gas turbines and a problem that needs to be solved urgently in the industry.

Summary of the invention

In view of the problems existing in the above-mentioned prior art, the present invention provides a gas turbine staged combustion device coupled with ammonia fuel pre-cracking, which can achieve clean, stable and efficient combustion of applicable ammonia fuel, and can solve the problems in the prior art that traditional gas turbine combustion chambers cannot achieve ammonia fuel pre-cracking, have difficulty in stable combustion over a wide range, and have high _NOx emissions.

To achieve the above-mentioned purpose, the present gas turbine staged combustion device coupled with ammonia fuel pre-cracking comprises a combustion tube, a fuel channel outer tube and an air channel outer tube coaxially fixedly arranged from the inside to the outside;

The front end of the combustion tube is coaxially sealed and fixed with an air inlet plate, the air inlet plate is provided with an axial air inlet through hole, the rear end of the combustion tube is a smoke outlet, the inner cavity of the combustion tube between the air inlet plate and the smoke outlet forms a multi-stage combustion chamber, the multi-stage combustion chamber is sequentially provided with a primary porous medium and a secondary porous medium from front to back, and a fuel injection hole penetrating the combustion tube wall is provided at a position on the combustion tube corresponding to the secondary porous medium;

The outer tube of the fuel channel is in the form of a blind hole sleeve structure with a front end blocked. An air input through hole is provided at a position of the front end blocked position of the outer tube of the fuel channel corresponding to the position of the air inlet plate. An annular fuel channel is formed between the inner surface of the outer tube of the fuel channel and the outer surface of the combustion tube. An ammonia fuel inlet that is connected to the annular fuel channel is provided at the rear end of the outer tube of the fuel channel. A catalyst assembly in the form of an annular structure is fixedly filled in the annular fuel channel. The catalyst assembly includes an ammonia decomposition hydrogen production catalyst. The catalyst assembly includes a primary catalyst assembly, and the primary catalyst assembly is located behind the fuel injection hole.

The air channel outer tube is a blind hole sleeve structure with a blocked front end. An annular air channel is formed between the inner surface of the air channel outer tube and the outer surface of the fuel channel outer tube. An air inlet communicating with the annular air channel is provided at the rear end of the air channel outer tube.

As a further improvement of the present invention, the primary porous medium includes a primary porous medium I and a primary porous medium II which are arranged in sequence from front to back.

As a further improvement of the present invention, the primary porous medium I is tightly connected to the primary porous medium II, and the porosity of the primary porous medium I is smaller than the porosity of the primary porous medium II.

As a further improvement of the present invention, the porosity of the primary porous medium I is 20% to 60%, and the porosity of the primary porous medium II is 60% to 90%.

As a further improvement of the present invention, the catalyst assembly also includes a secondary catalyst assembly, the primary catalyst assembly includes a low-temperature ammonia decomposition hydrogen production catalyst, the secondary catalyst assembly is located in front of the fuel injection hole, and the secondary catalyst assembly includes a high-temperature ammonia decomposition hydrogen production catalyst.

As a further improvement of the present invention, the primary porous medium includes a primary porous medium I and a primary porous medium II arranged in sequence from front to back, and the secondary catalyst assembly is arranged at a position corresponding to the primary porous medium II.

As a further improvement of the present invention, the amount of ammonia fuel entering the interior of the secondary porous medium from the fuel injection hole is 5% to 30% of the total amount of ammonia fuel entering from the ammonia fuel inlet.

As a further improvement of the present invention, a plurality of axial air inlet holes are symmetrically arranged relative to the center of the air inlet plate, the plurality of axial air inlet holes are in a multi-layer annular array structure, and the apertures of the plurality of axial air inlet holes are gradually reduced in the direction from the center to the edge of the central symmetry.

As a further improvement of the present invention, a gap is provided between the primary porous medium and the air inlet plate.

As a further improvement of the present invention, the fuel injection hole is located at the middle front position of the secondary porous medium. The fuel injection hole can be provided in plurality and the plurality of fuel injection holes are evenly distributed along the circumferential direction of the combustion tube.

Compared with the prior art, the gas turbine staged combustion device coupled with ammonia fuel pre-cracking has the following beneficial effects:

1. In terms of heat recovery and utilization, the heat required for the cracking catalytic process of the catalyst assembly is directly provided by the heat released by the combustion of the fuel in the burner. When the combustion device is started, the ammonia fuel pre-cracking process can continue under the condition of combustion heat release without additional heat input. Furthermore, according to the gradient characteristic of the temperature distribution in the combustion chamber, a two-stage ammonia fuel pre-cracking process is designed, which can make full use of the low-temperature and medium-high-temperature catalytic conditions, thereby increasing the hydrogen content in the first-stage combustion inlet mixed gas, thereby improving the combustion flame stability of the ammonia fuel. In addition, the flow direction of the fuel is opposite to the flow direction of the high-temperature flue gas, and the temperature of the combustion tube wall increases due to the heating of the high-temperature flue gas. The higher combustion tube wall temperature can preheat the incoming fuel;

2. The porous combustion technology is combined with the fuel staged combustion technology. The porous medium can improve the uniformity of the mixed gas distribution, the uniformity of the flame temperature and the combustion intensity. The fuel staged combustion technology can effectively reduce _NOx emissions. The hydrogen content in the inlet mixed gas of the primary combustion area in the combustion device is relatively high, and the flame has a strong combustion stability under lean combustion conditions. The high-temperature flue gas generated in the primary combustion area is mixed and burned with the secondary fuel inside the porous medium, which helps to reduce the _NOx generated in the primary combustion area to _N2 in a reducing atmosphere, thereby reducing _NOx emissions in the high-temperature combustion process;

3. The secondary combustion area also uses porous media combustion. The secondary fuel is mixed and burned inside the secondary porous media, which can ensure a good mixing effect between the secondary fuel and the primary high-temperature flue gas, and avoid the problem of NO _x generation caused by local high temperature due to improper mixing of the primary high-temperature flue gas and the secondary fuel;

4. The two-stage ammonia fuel pre-cracking device coupled with self-heating operation integrates porous combustion technology and fuel staged combustion technology, which can significantly improve combustion efficiency and flame stability, while extremely low pollutant emissions; the overall structure of this combustion device is simple, the integration is high, and it is easy to assemble. It can integrate multiple burners in a ring array to achieve high power output, with good economy and good application prospects.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is a schematic diagram of the planar structure of the present invention;

FIG2 is a schematic diagram of the three-dimensional structure of the combustion tube of the present invention;

FIG3 is a schematic diagram of the planar structure of the air inlet plate of the present invention;

FIG4 is a schematic diagram of a three-dimensional structure of the present invention;

FIG. 5 is a schematic diagram of the appearance structure of the present invention.

In the figure: 1-ammonia fuel inlet, 11-fuel channel outer tube, 12-annular fuel channel, 2-air inlet, 21-air channel outer tube, 22-annular air channel, 3-inlet orifice plate, 31-axial air inlet hole, 41-first-stage porous medium I, 42-first-stage porous medium II, 43-secondary porous medium, 51-first-stage catalyst assembly, 52-secondary catalyst assembly, 6-fuel injection hole, 7-smoke outlet, 71-combustion tube, 72-multi-stage combustion chamber.

DETAILED DESCRIPTION

The present invention will be further described below in conjunction with the accompanying drawings (hereinafter described with the left side of FIG. 1 as the front).

As shown in FIG. 1 to FIG. 5 , the gas turbine staged combustion device coupled with ammonia fuel pre-cracking includes a combustion tube 71 , a fuel channel outer tube 11 and an air channel outer tube 21 , which are coaxially fixedly arranged from the inside to the outside.

The front end of the combustion tube 71 is coaxially sealed and fixedly provided with an air inlet plate 3, on which an axial air inlet through hole 31 is provided. The rear end of the combustion tube 71 is a smoke outlet 7. The inner cavity of the combustion tube 71 between the air inlet plate 3 and the smoke outlet 7 forms a multi-stage combustion chamber 72. The multi-stage combustion chamber 72 is sequentially provided with a primary porous medium and a secondary porous medium 43 from front to back. A fuel injection hole 6 that penetrates the wall of the combustion tube 71 is provided at a position on the combustion tube 71 corresponding to the secondary porous medium 43.

The outer tube 11 of the fuel channel is generally in the form of a blind hole sleeve structure with a front end blocked. An air input through hole is provided at the front end blocked position of the outer tube 11 of the fuel channel corresponding to the position of the air inlet plate 3. An annular fuel channel 12 is formed between the inner surface of the outer tube 11 of the fuel channel and the outer surface of the combustion tube 71. An ammonia fuel inlet 1 which penetrates the annular fuel channel 12 is provided at the rear end of the outer tube 11 of the fuel channel. A catalyst assembly which is generally in an annular structure is fixedly filled in the annular fuel channel 12, and the catalyst assembly is located at least behind the fuel injection hole 6. The catalyst assembly includes an ammonia decomposition hydrogen production catalyst. Ammonia fuel can enter the annular fuel channel 12 through the ammonia fuel inlet 1 and flow from back to front.

The air channel outer tube 21 as a whole is a blind hole sleeve structure with a sealed front end. An annular air channel 22 is formed between the inner surface of the air channel outer tube 21 and the outer surface of the fuel channel outer tube 11. The rear end of the air channel outer tube 21 is provided with an air inlet 2 that penetrates the annular air channel 22. Pressurized air can enter the annular air channel 22 through the air inlet 2 and flow from back to front.

When the gas turbine staged combustion device coupled with ammonia fuel pre-cracking is installed on a gas turbine for use, ammonia fuel is injected into the annular fuel channel 12 through the ammonia fuel inlet 1, and pressurized air is injected into the annular air channel 22 through the air inlet 2. The ammonia fuel flows from back to front along the annular fuel channel 12 and is cracked through the catalyst assembly. When reaching the fuel injection hole 6, a part of the ammonia cracking fuel continues to flow forward, and another part of the ammonia cracking fuel enters the secondary porous medium 43 from the fuel injection hole 6. The pressurized air flows from back to front along the annular air channel 22. The compressed air flows through the air input hole at the front end of the fuel channel outer tube 11 and enters the annular fuel channel 12. The compressed air entering the annular fuel channel 12 is mixed with the ammonia cracking fuel flowing to the front end of the annular fuel channel 12, and then flows backward through the air inlet plate 3 into the multi-stage combustion chamber 72. When flowing through the primary porous medium, primary combustion occurs to form primary combustion flue gas. The primary combustion flue gas continues to flow backward, and when flowing through the secondary porous medium 43, it is mixed with the ammonia cracking fuel in the secondary porous medium 43 to cause secondary combustion. The completely burned flue gas is discharged through the flue gas outlet 7. Ammonia fuel is cracked into nitrogen and hydrogen under the catalytic action of the catalyst assembly, thereby making the hydrogen content in the mixed gas at the entrance of the primary combustion area higher, and the combustion stability of the flame operating under the lean-burn condition of the primary porous medium is stronger; the high-temperature flue gas generated in the primary combustion area and the secondary fuel entering the secondary porous medium 43 through the fuel injection hole 6 are mixed and burned inside the secondary porous medium 43, which helps to reduce the _NOx generated in the primary combustion area into _N2 under the reducing atmosphere, thereby reducing the _NOx emissions in the high-temperature combustion process.

In order to achieve a better primary combustion effect, as a further improvement scheme of the present invention, the primary porous medium includes a primary porous medium I41 and a primary porous medium II42 arranged from front to back, the primary porous medium I41 serves as a preheating zone, and the primary porous medium II42 serves as a primary combustion zone.

In order to ensure the stability of combustion and prevent backfire, as a further improvement scheme of the present invention, the first-level porous medium I41 is tightly connected to the first-level porous medium II42, and the porosity of the first-level porous medium I41 is less than the porosity of the first-level porous medium II42. The porosity of the first-level porous medium I41 can be 20% to 60%, and the porosity of the first-level porous medium II42 can be 60% to 90%.

In order to achieve better combustion effect and lower combustion pollutant emissions, as a further improvement scheme of the present invention, the catalyst assembly includes a primary catalyst assembly 51 and a secondary catalyst assembly 52. The primary catalyst assembly 51 is located behind the fuel injection hole 6, and the primary catalyst assembly 51 includes a low-temperature ammonia decomposition hydrogen production catalyst. The secondary catalyst assembly 52 is located in front of the fuel injection hole 6, and the secondary catalyst assembly 52 includes a high-temperature ammonia decomposition hydrogen production catalyst. The secondary catalyst assembly 52 can be set at a position corresponding to the primary porous medium II42. The ammonia fuel is cracked after passing through the primary catalyst assembly 51. When it reaches the fuel injection hole 6, a part of the ammonia cracking fuel continues to flow forward and is further cracked through the secondary catalyst assembly 52, so that the hydrogen content in the mixed gas at the entrance of the primary combustion area is further increased, and another part of the ammonia cracking fuel directly enters the secondary porous medium 43 from the fuel injection hole 6.

In order to achieve lower combustion pollutant emissions, as a further improvement of the present invention, the amount of ammonia fuel entering the secondary porous medium 43 from the fuel injection hole 6 is 5% to 30% of the total amount of ammonia fuel entering from the ammonia fuel inlet 1.

In order to achieve a more uniform mixing and flow distribution effect of the gaseous fuel and pressurized air, as a further improvement scheme of the present invention, a plurality of axial air intake holes 31 are symmetrically arranged relative to the center of the air intake orifice plate 3, and the plurality of axial air intake holes 31 are in a multi-layer annular array structure, and the apertures of the plurality of axial air intake holes 31 are gradually reduced in the direction from the center of the center to the edge.

In order to achieve a more uniform mixing effect of the gaseous fuel and the pressurized air, as a further improvement of the present invention, a gap is provided between the primary porous medium and the air inlet plate 3 to ensure that the mixed gas passing through the air inlet plate 3 can flow into the primary porous medium more evenly.

In order to achieve a better secondary combustion effect, as a further improvement scheme of the present invention, the fuel injection hole 6 is located at the middle front position of the secondary porous medium 43, and the fuel injection hole 6 can be set to be multiple, and the multiple fuel injection holes 6 are evenly distributed along the circumferential direction of the combustion tube 71.

The gas turbine staged combustion device coupled with ammonia fuel pre-cracking can achieve clean, stable and efficient combustion of applicable ammonia fuel, and can solve the problems in the prior art that the traditional gas turbine combustion chamber cannot achieve ammonia fuel pre-cracking, has difficulty in stable combustion over a wide range, and has high _NOx emissions.

Claims (10)

1. A gas turbine staged combustion device coupled with ammonia fuel pre-cracking, which is characterized by comprising a combustion tube (71), a fuel passage outer tube (11) and an air passage outer tube (21) which are coaxially and fixedly arranged from inside to outside;

The front end of the combustion tube (71) is coaxially plugged and fixedly provided with an air inlet orifice (3), an axial air inlet through hole (31) is formed in the air inlet orifice (3), the rear end of the combustion tube (71) is provided with a flue gas outlet (7), a multi-stage combustion cavity (72) is formed in the inner cavity of the combustion tube (71) between the air inlet orifice (3) and the flue gas outlet (7), a primary porous medium and a secondary porous medium (43) are sequentially arranged in the multi-stage combustion cavity (72) at intervals from front to back, and a fuel injection hole (6) penetrating through the wall of the combustion tube (71) is formed in the position, corresponding to the secondary porous medium (43), on the combustion tube (71);

The fuel passage outer tube (11) is integrally in a blind hole shaft sleeve structure with a blocked front end, an air input through hole is formed in the position, corresponding to the air inlet hole plate (3), of the front end blocking position of the fuel passage outer tube (11), an annular fuel passage (12) is formed between the inner surface of the fuel passage outer tube (11) and the outer surface of the combustion tube (71), an ammonia fuel inlet (1) communicated with the annular fuel passage (12) is formed in the rear end of the fuel passage outer tube (11), a catalyst component which is integrally in an annular structure is fixedly filled in the annular fuel passage (12), the catalyst component comprises an ammonia decomposition hydrogen production catalyst, the catalyst component comprises a primary catalyst component (51), and the primary catalyst component (51) is positioned behind the fuel injection hole (6);

the whole blind hole axle sleeve structure that is the front end shutoff of air channel outer tube (21), form annular air channel (22) between the internal surface of air channel outer tube (21) and the surface of fuel channel outer tube (11), the rear end of air channel outer tube (21) is equipped with air inlet (2) with annular air channel (22) link up.

2. The coupled ammonia fuel pre-cracking gas turbine staged combustion device of claim 1, wherein the primary porous media comprises a primary porous media I (41) and a primary porous media II (42) arranged in sequence from front to back.

3. The gas turbine staged combustion device coupled with pre-splitting of ammonia fuel as claimed in claim 2, wherein the primary porous medium I (41) is in close fitting connection with the primary porous medium II (42), and the porosity of the primary porous medium I (41) is smaller than the porosity of the primary porous medium II (42).

4. A gas turbine staged combustion device coupled with pre-cracking of ammonia fuel as claimed in claim 3, wherein the primary porous medium I (41) has a porosity of 20% to 60% and the primary porous medium II (42) has a porosity of 60% to 90%.

5. The coupled ammonia fuel pre-cracking gas turbine staged combustion device of claim 1, wherein the catalyst assembly further comprises a secondary catalyst assembly (52), the primary catalyst assembly (51) comprises a low temperature ammonia decomposition hydrogen production catalyst, the secondary catalyst assembly (52) is positioned in front of the fuel injection holes (6), and the secondary catalyst assembly (52) comprises a high temperature ammonia decomposition hydrogen production catalyst.

6. The ammonia fuel pre-cracking coupled gas turbine staged combustion device of claim 5, wherein the primary porous media comprises a primary porous media I (41) and a primary porous media II (42) arranged in sequence from front to back, and the secondary catalyst assembly (52) is arranged at a position corresponding to the primary porous media II (42).

7. The coupled ammonia-fueled pre-split gas turbine staged combustion device according to any of claims 1 to 6, wherein the amount of ammonia fuel entering the interior of the secondary porous medium (43) from the fuel injection holes (6) is 5% to 30% of the total amount of ammonia fuel entering from the ammonia fuel inlet (1).

8. The ammonia fuel pre-cracking coupled gas turbine staged combustion device as claimed in any of claims 1 to 6, wherein the axial air inlet holes (31) are arranged in a plurality symmetrically with respect to the center of the air inlet orifice (3), the plurality of axial air inlet holes (31) are arranged in a multi-layer annular array structure, and the apertures of the plurality of axial air inlet holes (31) are gradually reduced in sequence from the center of the symmetry to the edge.

9. The gas turbine staged combustion device coupled with pre-splitting of ammonia fuel as claimed in any of claims 1 to 6, wherein a gap is provided between the primary porous medium and the inlet orifice (3).

10. The ammonia fuel coupled pre-cracking gas turbine staged combustion device according to any of claims 1 to 6, wherein the fuel injection holes (6) are located at the middle front position of the secondary porous medium (43), the fuel injection holes (6) are provided in plurality, and the plurality of fuel injection holes (6) are uniformly distributed along the circumferential direction of the combustion tube (71).