A low NO X Hydrogen-ammonia fusion micro gas turbine emissions

Abstract

This invention discloses a low NO X A hydrogen-ammonia fusion micro gas turbine includes a combustion chamber with several secondary air inlets on its wall. These secondary air inlets are used to introduce a portion of compressed air and a first-pass liquid ammonia fuel into the combustion chamber. Within the combustion chamber, a pyrolysis chamber with a pyrolysis gas outlet is located near the turbine end. This pyrolysis chamber contains a catalyst and is supplied with a second-pass liquid ammonia fuel. The second-pass liquid ammonia fuel is pyrolyzed under the heat energy of the combustion chamber and the action of the catalyst. The resulting pyrolysis gas enters the combustion chamber through the pyrolysis gas outlet for combustion. This invention utilizes the high-temperature flue gas generated in the combustion chamber as a heat source to achieve catalytic pyrolysis of ammonia within the gas turbine combustion chamber, producing a hydrogen-rich mixture, which is then introduced into the combustion chamber as a combustion aid to stabilize the ammonia combustion flame and reduce NO. X While emitting pollutants, energy is utilized in a tiered manner.

Description

Technical Field

[0001] This invention belongs to the field of gas turbine technology, and specifically relates to a low NO content gas turbine. X The emitted hydrogen-ammonia fusion micro gas turbine. Background Technology

[0002] Traditional gas turbines rely on fossil fuels such as natural gas, generating significant amounts of carbon dioxide during operation. Hydrogen and ammonia, as the only two zero-carbon fuels, produce no carbon dioxide in their ideal combustion products. Applying them to gas turbines can significantly reduce industrial carbon emissions. Furthermore, hydrogen and ammonia, as stable and synthesizable energy storage media, contribute to the diversification of the energy structure and reduce dependence on fossil fuels.

[0003] Compared to hydrogen energy, ammonia energy has significant advantages in terms of storage safety and infrastructure compatibility: ammonia production technology is mature, synthesis costs are low, it is easily liquefied at room temperature, liquid ammonia transportation costs are low, and safety is high. However, ammonia fuel has characteristics such as low flame propagation speed and wide quenching distance, resulting in unstable combustion flames and NO content. X Emissions are high. Summary of the Invention

[0004] In order to overcome the shortcomings of the prior art, the present invention aims to provide a low NO content. X The hydrogen-ammonia fusion micro gas turbine uses liquid ammonia as fuel. Through fuel staging, ammonia catalytic cracking, hydrogen-assisted combustion, and multi-stage combustion, it achieves stable flame combustion while reducing NO emissions. X emission.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] A low NO X The emitted hydrogen-ammonia fusion micro gas turbine includes a combustion chamber, the wall of which is provided with several secondary air inlets, which are used to feed a portion of compressed air and a first-pass liquid ammonia fuel into the combustion chamber.

[0007] Within the combustion chamber, a cracking chamber with a cracked gas outlet is located at one end near the turbine. A catalyst is placed in the cracking chamber, and a second stream of liquid ammonia fuel is fed in. The second stream of liquid ammonia fuel is cracked under the thermal energy of the combustion chamber and the action of the catalyst. The resulting cracked gas enters the combustion chamber through the cracked gas outlet for combustion.

[0008] In one embodiment, the combustion chamber is an annular combustion chamber with a plurality of cooling holes and a plurality of secondary air inlets evenly distributed on its wall surface; the compressor passes through the hollow part of the annular combustion chamber, and air enters the compressor through the air inlet and is compressed. Part of the compressed air enters the pyrolysis chamber through the liquid ammonia inlet of the pyrolysis chamber and mixes with the pyrolysis gas, and then enters the combustion chamber through the pyrolysis gas outlet. The other part enters the combustion chamber through some of the secondary air inlets.

[0009] The cooling holes cover the inner and outer surfaces of the combustion chamber, causing the compressed air output from the compressor to accumulate at the cooling holes, forming a gas film cooling layer that wraps around the inner and outer walls of the combustion chamber, preventing the combustion chamber walls from being scorched by high-temperature flue gas.

[0010] In one embodiment, the secondary air intake holes are distributed in the middle and lower reaches of the combustion chamber wall. Part of the compressed air enters the combustion zone through the secondary air holes to make the air excessive, thereby achieving staged combustion.

[0011] In one embodiment, a secondary air inlet for feeding the first liquid ammonia fuel into the combustion chamber is connected to a liquid ammonia feed line, and a pressure atomizing nozzle is provided at one end of the outlet of the liquid ammonia feed line.

[0012] In one embodiment, the pyrolysis chamber is located at the outlet of the combustion chamber, with its liquid ammonia inlet located downstream of the pyrolysis chamber and connected to the liquid ammonia feed pipeline. The pyrolysis gas outlet is located upstream of the pyrolysis chamber, guiding the pyrolysis gas to form a reflux zone along the inner wall of the combustion chamber. After being fully mixed with the compressed air introduced through the secondary air hole, the pyrolysis gas enters the combustion zone for combustion.

[0013] In one embodiment, the second liquid ammonia feed line adopts a straight pipe feed.

[0014] In one embodiment, the second liquid ammonia feed line adopts a coil structure. At the outlet of the combustion chamber, the high temperature of the combustion chamber and the high temperature and high pressure gas generated by the compressor are used to heat the second liquid ammonia feed line, so that it absorbs heat and pre-evaporates, and then enters the pyrolysis chamber for pyrolysis.

[0015] In one embodiment, the catalyst is a packed catalyst.

[0016] In one embodiment, the cracked gas is a hydrogen-rich mixture, which is used as a duty fuel for combustion and applied to the gas turbine when the output power is under no-load conditions or not higher than 20% of the rated power. The first-stage liquid ammonia fuel is used as the main combustion stage fuel and together with the duty fuel for the gas turbine when the output power is higher than 20% of the rated power but not exceeding the full-load power.

[0017] In one embodiment, when the gas turbine output power is under no-load conditions or not exceeding 20% ​​of the rated power, only the second stream of liquid ammonia fuel needs to be introduced to provide energy through combustion of the cracked gas from the liquid ammonia. When the gas turbine output power is higher than 20% of the rated power but not exceeding the full-load power, both the first and second streams of liquid ammonia fuel need to be introduced simultaneously. As the gas turbine output power increases, the amounts of the first and second streams of liquid ammonia fuel introduced increase, and the proportion of the first stream of liquid ammonia fuel introduced to the total amount of liquid ammonia fuel introduced increases. When the gas turbine output power is higher than 50% of the rated power but not exceeding the full-load power, the ratio of the first stream of liquid ammonia fuel to the second stream of liquid ammonia fuel introduced ranges between 1:1.2 and 1:1.8.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0019] 1. This invention utilizes the high-temperature flue gas generated in the combustion chamber as a heat source to achieve catalytic cracking of ammonia within the gas turbine combustion chamber, producing a hydrogen-rich mixture, which is then introduced into the combustion chamber as a combustion aid to stabilize the ammonia combustion flame and reduce NO. X While emitting pollutants, energy is utilized in a tiered manner.

[0020] 2. This invention divides liquid ammonia into two feed streams. A portion of the liquid ammonia is used as the main combustion stage fuel, directly injected into the main combustion zone of the combustion chamber through a pressure atomizing nozzle at the front end of the liquid ammonia pipeline at the secondary air vent. This utilizes the latent heat of vaporization of liquid ammonia to reduce the temperature of locally high-temperature flue gas and suppress thermal NO₂. X The generation of ammonia; another portion of liquid ammonia is introduced as standby fuel into the ammonia cracking chamber for cracking into a hydrogen-rich mixture, which is then introduced into the combustion chamber for combustion. The high-level flow combustion velocity of hydrogen improves the basic combustion characteristics of ammonia, significantly enhancing ammonia combustion stability and reducing NO in the exhaust gas. X content. Attached Figure Description

[0021] Figure 1 As a low NO X A schematic diagram of the main structure of the hydrogen-ammonia fusion micro gas turbine.

[0022] Figure 2 As a low NO X Cross-sectional view of the emitted hydrogen-ammonia fusion micro gas turbine.

[0023] Figure 3 As a low NO X A three-dimensional structural diagram of a hydrogen-ammonia fusion micro gas turbine.

[0024] Figure 4 As a low NO X A schematic diagram of the fluid flow in the emitted hydrogen-ammonia fusion micro gas turbine.

[0025] Attached reference numerals: 1. Combustion chamber; 11. Cooling hole; 12. Secondary air hole; 2. Liquid ammonia inlet pipe two; 3. Liquid ammonia inlet pipe one; 31. Pressure atomizing nozzle; 4. Spark plug; 5. Cracking chamber; 51. Cracking gas outlet; 51. Liquid ammonia inlet; 6. Catalyst; 7. Compressor; 8. Inlet duct; 9. Exhaust duct; 10. Turbine. Detailed Implementation

[0026] The specific embodiments of the present invention will now be described with reference to the accompanying drawings, but this does not limit the scope of protection of the present invention.

[0027] To improve the basic combustion characteristics of ammonia, combustion can be achieved through methods such as ammonia-hydrogen blending or combustion of ammonia cracked gas, thereby increasing flame stability and reducing NO. X The emissions are reduced. In this invention, ammonia cracking is integrated into the combustion chamber, providing a low NO emission level. X The emitted hydrogen-ammonia fusion micro gas turbine.

[0028] refer to Figure 1 , Figure 2 , Figure 3 , Figure 4 As shown, this invention mainly includes a combustion chamber 1, a pyrolysis chamber 5, and a turbine 10. The combustion chamber 1 has several secondary air inlets 12 on its wall, preferably evenly distributed in a selected area, for introducing a portion of compressed air and a first-pass liquid ammonia fuel into the combustion chamber 1. In this invention, the compressed air can be obtained through a compressor 7, which can be an external independent device or integrated into the gas turbine of this invention. The first-pass liquid ammonia fuel is used to supplement the ammonia fuel in the combustion chamber 1 and also serves to cool the local high-temperature flue gas and protect the combustion chamber wall. The combustion chamber 1 is equipped with a spark plug 4 for ignition.

[0029] The turbine 10 is located downstream of the combustion chamber 1. The high-temperature and high-pressure gas obtained after combustion in the combustion chamber 1 does work at the turbine 10, and the gas after doing work is discharged through the exhaust port 9.

[0030] The cracking chamber 5 is located inside the combustion chamber 1, specifically at one end near the turbine 10, i.e., near the high-temperature, high-pressure gas outlet of the combustion chamber 1. The cracking chamber 5 has a liquid ammonia inlet 52 and a cracked gas outlet 51, and contains a catalyst 6. The catalyst 6 is used to achieve ammonia catalytic cracking at high temperatures; it can be a packed HTCZ-7 type catalyst or a La / Ca modified NiO / MgO catalyst, etc. The liquid ammonia inlet 52 is used to feed a second stream of liquid ammonia fuel. This second stream of liquid ammonia fuel utilizes the heat of the combustion chamber and is cracked under the catalytic action of the catalyst 6. The resulting cracked gas enters the combustion chamber 1 through the cracked gas outlet 51 for combustion.

[0031] According to this structure, the present invention provides a pyrolysis chamber 5 inside the combustion chamber 1, which can utilize the heat generated by the combustion chamber 1 as a heat source to achieve catalytic pyrolysis of ammonia within the pyrolysis chamber 5 (actually, within the combustion chamber 1). The resulting pyrolysis gas is a hydrogen-rich mixture mainly composed of hydrogen and nitrogen, which can be introduced into the combustion chamber 1 as a combustion aid to stabilize the ammonia combustion flame and reduce NO. X This process allows for the emission of pollutants and the tiered utilization of energy. Consequently, the hydrogen-rich mixture can supplement combustion chamber 1 with hydrogen fuel and reduce the combustion chamber temperature, achieving hydrogen-ammonia fusion combustion and reducing thermal NOx emissions. x The combustion chamber 1 of this invention is actually a combustion structure involving the fusion of ammonia and hydrogen.

[0032] In practical applications, this hydrogen-rich mixture can be used as standby fuel, utilizing the high temperature of the combustion chamber to achieve ammonia cracking, and then burning the cracked gas, thus suitable for gas turbines with lower output power. Meanwhile, the first-stage liquid ammonia fuel, as the main combustion stage fuel, directly enters the combustion chamber for combustion, and can be used together with the standby fuel for gas turbines with higher output power, ultimately achieving stable hydrogen-ammonia combustion and reducing NO. x emission.

[0033] Furthermore, when the gas turbine output power is under no-load conditions or not exceeding 20% ​​of its rated power, only the second stream of liquid ammonia fuel needs to be introduced, utilizing the cracked gas from the liquid ammonia for combustion to provide energy. When the gas turbine output power exceeds 20% of its rated power but does not exceed its full-load power, both the first and second streams of liquid ammonia fuel need to be introduced simultaneously. As the gas turbine output power increases, the amounts of the first and second streams of liquid ammonia fuel introduced increase, and the proportion of the first stream of liquid ammonia fuel in the total amount of liquid ammonia fuel introduced also increases. When the gas turbine output power exceeds 50% of its rated power but does not exceed its full-load power, the ratio of the first to second streams of liquid ammonia fuel introduced ranges between 1:1.2 and 1:1.8.

[0034] Furthermore, the combustion chamber 1 of the present invention is an annular combustion chamber, with a plurality of cooling holes 11 and a plurality of secondary air inlets 12 evenly distributed on its wall surface; the compressor 7 is integrated into the gas turbine of the present invention, specifically, it passes through the hollow position of the annular combustion chamber, and is connected to the intake duct 8 upstream. Air enters the compressor 7 through the intake duct 8 and is compressed to obtain compressed air. Part of the compressed air enters the cracking chamber 5 through the liquid ammonia inlet 52 and mixes with the cracked gas, and then enters the combustion chamber 1 through the cracked gas outlet 51. The other part enters the combustion chamber 1 through some of the secondary air inlets 12.

[0035] Furthermore, the cooling holes 11 of the present invention cover the inner and outer surfaces of the combustion chamber 1, so that the compressed air output by the compressor 7 accumulates at the cooling holes 11, forming a gas film cooling layer that wraps around the inner and outer walls of the combustion chamber 1, preventing the walls of the combustion chamber 1 from being scorched by high-temperature flue gas.

[0036] Furthermore, the secondary air intake 12 of the present invention is distributed in the middle and lower reaches of the combustion chamber 1 wall. Part of the compressed air enters the combustion zone through the secondary air intake 12 to make the air excessive, thereby realizing staged combustion.

[0037] Furthermore, the secondary air inlet 12 for feeding the first stream of liquid ammonia fuel into the combustion chamber 1 is connected to the liquid ammonia feed pipe 3. One end of the liquid ammonia feed pipe 3 is equipped with a pressure atomizing nozzle 31. The first stream of liquid ammonia fuel utilizes the high-pressure gas flow in the secondary air inlet 12 to directly inject liquid ammonia into the high-temperature flue gas region of the combustion chamber 1 through the pressure atomizing nozzle 31 for combustion. Simultaneously, the latent heat of vaporization of the liquid ammonia is used to reduce the temperature of the localized high-temperature flue gas region within the combustion chamber, thereby reducing thermal NO₂. X While facilitating emissions, it also protects the combustion wall surface.

[0038] Furthermore, the pyrolysis chamber 5 of the present invention is located at the outlet of the combustion chamber 1, and preferably is close to the wall of the combustion chamber 1, so as to better utilize the latent heat of vaporization of liquid ammonia to cool the walls of the combustion chamber 1 and the pyrolysis chamber 5, and protect the walls. It can be an annular structure, coaxially designed with the combustion chamber 1, or it can be multiple independent chambers distributed circumferentially. The liquid ammonia inlet 52 of the pyrolysis chamber 5 is located downstream of the pyrolysis chamber 5 and is connected to the liquid ammonia feed pipe 2. The pyrolysis gas outlet 51 is located upstream of the pyrolysis chamber 5, and there can be multiple outlets, preferably directly facing the combustion zone of the combustion chamber 1, guiding the pyrolysis gas to diffuse along the inner wall of the combustion chamber 1 to form a reflux zone. After being fully mixed with the compressed air introduced by the secondary air hole 12, it enters the combustion zone for combustion, improving combustion efficiency and reducing NO in the exhaust gas. x And unburned NH3 emissions.

[0039] Furthermore, the liquid ammonia feed line 2 of the present invention adopts a straight pipe feed, with its front end extending into the cracking chamber 5, so that the liquid ammonia comes into contact with the catalyst 6 for catalytic cracking. The liquid ammonia feed line 2 is preferably designed between the combustion chamber 1 and the turbine 10, which can use the heat generated by the combustion chamber 1 and the high-temperature and high-pressure gas generated by the compressor 7 to achieve primary heating of the liquid ammonia feed, and send the preheated liquid ammonia into the ammonia cracking zone to achieve ammonia cracking.

[0040] Furthermore, the second liquid ammonia feed line 2 of the present invention adopts a coil structure and is at least located at the outlet of the combustion chamber 1. At the outlet, the high temperature of the combustion chamber 1 and the high-temperature, high-pressure gas generated by the compressor 7 can be used to heat the second liquid ammonia feed, causing it to absorb heat and pre-evaporate before entering the pyrolysis chamber 5 for pyrolysis. This design improves the pyrolysis efficiency.

[0041] Furthermore, the catalyst 6 of the present invention is a packed catalyst, and the packed design can ensure the full progress of the ammonia cracking reaction by extending the residence time of ammonia in the cracking chamber 5.

[0042] According to the above structure, the liquid ammonia feed is divided into two parts. One part enters the combustion chamber 1 directly through the liquid ammonia feed pipeline 1 3 using the pressure atomizing nozzle 31 and is burned as the main combustion stage fuel. The other part enters the cracking chamber 5 through the liquid ammonia feed pipeline 2 using the direct feeding method. Utilizing the high temperature generated by combustion in the combustion chamber 1, under the action of the catalyst 6, it is cracked into hydrogen and nitrogen, which are premixed with some air before entering the combustion chamber 1 as the shift fuel for combustion.

[0043] The combustion chamber 1, pyrolysis chamber 5, liquid ammonia feed line 1 3, liquid ammonia feed line 2 2, and pressure atomizing nozzle 31 of the present invention can be made of refractory bricks made of high-temperature resistant materials.

[0044] In summary, the hydrogen-ammonia fusion micro gas turbine of the present invention uses liquid ammonia as fuel and achieves stable combustion while reducing NO through fuel staging, ammonia catalytic cracking, hydrogen-assisted combustion, and multi-stage combustion. X emission.

[0045] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope disclosed in the present invention, based on the technical solution and inventive concept of the present invention, shall fall within the scope of protection of the present invention.

Claims

1. A low NOx hydrogen-ammonia hybrid microturbine comprising a combustion chamber (1), characterized by, X The combustion chamber (1) has several secondary air inlets (12) on its wall surface. The secondary air inlets (12) are used to feed a portion of compressed air and first-pass liquid ammonia fuel into the combustion chamber (1). ​ Inside the combustion chamber (1), a cracking chamber (5) with a cracked gas outlet (51) is provided at one end near the turbine (10). A catalyst (6) is provided inside the cracking chamber (5), and a second stream of liquid ammonia fuel is fed into it. The second stream of liquid ammonia fuel is cracked under the action of the thermal energy of the combustion chamber and the catalyst (6), and the resulting cracked gas enters the combustion chamber (1) through the cracked gas outlet (51) for combustion. The combustion chamber (1) is an annular combustion chamber with several cooling holes (11) and several secondary air inlets (12) evenly distributed on its wall surface; the compressor (7) passes through the hollow part of the annular combustion chamber, and the air enters the compressor (7) through the air inlet (8) and is compressed. Part of the compressed air enters the cracking chamber (5) through the liquid ammonia inlet (52) on the cracking chamber (5) and mixes with the cracked gas. Then, it enters the combustion chamber (1) through the cracked gas outlet (51), and the other part enters the combustion chamber (1) through some of the secondary air inlets (12). The cooling holes (11) cover the inner and outer surfaces of the combustion chamber (1), so that the compressed air output by the compressor (7) gathers at the cooling holes (11) to form a gas film cooling layer that wraps the inner and outer walls of the combustion chamber (1) and prevents the walls of the combustion chamber (1) from being burned by high-temperature flue gas. The secondary air inlet (12) for feeding the first liquid ammonia fuel into the combustion chamber (1) is connected to the liquid ammonia feed line (3), and the outlet end of the liquid ammonia feed line (3) is provided with a pressure atomizing nozzle (31). The cracked gas is a hydrogen-rich mixture, which is used as the shift fuel for combustion and is applied to the gas turbine output power under no-load conditions or at a level not exceeding 20% ​​of the rated power. The first-stage liquid ammonia fuel is used as the main combustion stage fuel and together with the shift fuel, it is used for the gas turbine output power when it is higher than 20% of the rated power but not exceeding the full-load power. When the gas turbine output power is under no-load conditions or not exceeding 20% ​​of the rated power, only the second stream of liquid ammonia fuel needs to be introduced to provide energy through combustion of the cracked gas from the liquid ammonia. When the gas turbine output power is higher than 20% of the rated power but does not exceed the full-load power, both the first and second streams of liquid ammonia fuel need to be introduced simultaneously. As the gas turbine output power increases, the amounts of the first and second streams of liquid ammonia fuel introduced increase, and the proportion of the first stream of liquid ammonia fuel introduced to the total amount of liquid ammonia fuel introduced also increases. When the gas turbine output power is higher than 50% of the rated power but does not exceed the full-load power, the ratio of the first to the second streams of liquid ammonia fuel introduced ranges between 1:1.2 and 1:1.

8.

2. The low NOx engine of claim 1 wherein: X A hydrogen-ammonia hybrid microturbine with low emissions, characterized by: The secondary air intake (12) is located in the middle and lower reaches of the combustion chamber (1) wall. Part of the compressed air enters the combustion zone through the secondary air intake (12) to make the air excessive, thereby achieving staged combustion.

3. The low NO content according to claim 1 X The emitted hydrogen-ammonia fusion micro gas turbine is characterized by, The pyrolysis chamber (5) is located at the outlet of the combustion chamber (1). Its liquid ammonia inlet (52) is located downstream of the pyrolysis chamber (5) and connected to the liquid ammonia feed pipeline (2). The pyrolysis gas outlet (51) is located upstream of the pyrolysis chamber (5), guiding the pyrolysis gas to form a reflux zone along the inner wall of the combustion chamber (1). After being fully mixed with the compressed air introduced through the secondary air inlet (12), it enters the combustion zone for combustion.

4. The low NOx combustor of claim 3 wherein the first and second fuel injectors are disposed in the first and second fuel injection zones, respectively. X A hydrogen-ammonia hybrid microturbine with reduced emissions, comprising: The liquid ammonia feed pipeline 2 (2) adopts a straight pipe feed.

5. The low NO content according to claim 3 or 4 X The emitted hydrogen-ammonia fusion micro gas turbine is characterized by, The second liquid ammonia feed line (2) adopts a coil structure. At the outlet of the combustion chamber (1), the high temperature of the combustion chamber (1) and the high temperature and high pressure gas generated by the compressor (7) are used to heat the second liquid ammonia feed, so that it absorbs heat and pre-evaporates, and then enters the pyrolysis chamber (5) for pyrolysis.

6. The low NO content according to claim 1 X The emitted hydrogen-ammonia fusion micro gas turbine is characterized by, The catalyst (6) is a packed catalyst.

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