Graded high-pressure combustion chamber for re-injecting hydrogen at root of ammonia flame

Abstract

The invention discloses a graded high-pressure combustion chamber for re-injecting hydrogen at the root of ammonia flame, which belongs to the field of combustion chambers and comprises an oxygen conveying pipeline, an ammonia conveying pipeline, a hydrogen conveying pipeline, an air distributor, a swirler, an igniter, a flame arrester and a combustion chamber main body, hydrocyclones are respectively arranged at the rear parts of the junctions of hydrogen ammonia and oxygen ammonia, flame arresters are respectively arranged at the tail ends of ammonia, oxygen and hydrogen pipelines, and an igniter is arranged at the front part of the combustion chamber main body; most hydrogen is sent by the air distributor to be mixed with ammonia gas, and the rest hydrogen is directly guided into the flame root of the primary combustion area, so that the stability of the ammonia flame is obviously enhanced; a small amount of oxygen is sent by the air distributor to be mixed with the hydrogen and the ammonia gas, and the rest of oxygen is guided into the secondary combustion area, so that oxygen fuel staged combustion is realized, and low nitrogen oxide emission is kept.

Description

Technical Field

[0001] The invention belongs to the field of combustion chambers, and relates to a staged high-pressure combustion chamber for re-injecting hydrogen at the root of an ammonia flame. Background Art

[0002] The zero-carbon property of ammonia makes it a key fuel in future energy systems, but its extremely low flame stability and high nitrogen oxide emissions hinder its direct application; the current solution is generally to mix it with hydrogen, which is also a zero-carbon fuel and has a strong reaction activity. This can significantly improve the flame stability of ammonia fuel combustion while still maintaining low carbon emissions. By directly injecting a small amount of hydrogen into the flame root of the ammonia-hydrogen mixed fuel, the extended stability of the mixed fuel flame can be significantly improved. Through the "rich burn + lean burn" staged combustion mode, the nitrogen oxide emissions of the high-pressure combustion chamber fueled by ammonia can be significantly reduced, which is convenient for the subsequent selective / non-selective catalytic reduction work. Summary of the invention

[0003] In combination with the above background technology, the present invention provides a staged high-pressure combustion chamber for re-injecting hydrogen at the root of an ammonia flame, so that the stability of the ammonia flame is improved and relatively low nitrogen oxide emissions are maintained.

[0004] To achieve the above objectives, the present invention is implemented through the following technical solutions.

[0005] A staged high-pressure combustion chamber for re-injecting hydrogen at the root of an ammonia flame, comprising an oxygen delivery pipeline, an ammonia delivery pipeline, a hydrogen delivery pipeline, an oxygen air distributor, a hydrogen air distributor, a first cyclone, a second cyclone, an igniter, an ammonia delivery pipeline flame arrester, a hydrogen branch delivery pipeline flame arrester, an oxygen branch delivery pipeline flame arrester and a combustion chamber body;

[0006] The combustion chamber body is provided with a primary combustion zone, a secondary combustion zone and a dilution zone distributed from one end close to the pipeline to one end far from the pipeline;

[0007] The oxygen delivery pipeline and the hydrogen delivery pipeline are in an F shape, including a starting pipeline, a branch delivery pipeline and a second branch delivery pipeline, with a starting section inlet and two terminal outlets, and the oxygen delivery pipeline and the hydrogen delivery pipeline are respectively located on both sides of the combustion chamber body; one end point p of the hydrogen delivery pipeline is connected to the starting section of the ammonia delivery pipeline, and the other end point q is connected to the primary combustion zone of the combustion chamber body; one end point m of the oxygen delivery pipeline is connected to the end of the ammonia delivery pipeline, and the other end point n is connected to the secondary combustion zone of the combustion chamber body;

[0008] The oxygen air distributor is arranged at the starting section of the oxygen delivery pipeline, the hydrogen air distributor is arranged at the starting section of the hydrogen delivery pipeline, the first cyclone is arranged behind the intersection point p of the ammonia delivery pipeline and the hydrogen delivery pipeline, the second cyclone is arranged behind the intersection point m of the ammonia delivery pipeline and the oxygen delivery pipeline, and the igniter is placed in the front part of the primary combustion zone of the combustion chamber body;

[0009] The ammonia delivery pipeline flame arrester is arranged at the end of the ammonia delivery pipeline, the hydrogen branch delivery pipeline flame arrester is arranged at the end point q of the hydrogen branch delivery pipeline in the primary combustion zone of the combustion chamber body, and the oxygen branch delivery pipeline flame arrester is arranged at the end point n of the oxygen branch delivery pipeline in the secondary combustion zone of the combustion chamber body.

[0010] In the above technical solution, oxygen, ammonia and hydrogen are preheated to 600K and then introduced into the oxygen delivery pipeline, the ammonia delivery pipeline and the hydrogen delivery pipeline.

[0011] In the above technical solution, the volume ratio of oxygen, ammonia and hydrogen is 27:14:6.

[0012] In the above technical solution, the oxygen air distributor delivers 3 / 8 of the oxygen to the ammonia delivery pipeline through a branch oxygen delivery pipeline, and the remaining 5 / 8 of the oxygen is delivered to the secondary combustion zone of the combustion chamber body through another branch.

[0013] In the above technical solution, the hydrogen air distributor sends 2 / 3 of the hydrogen to the ammonia delivery pipeline through a hydrogen branch delivery pipeline, and the remaining 1 / 3 of the hydrogen is sent to the root position of the mixed fuel flame in the primary combustion zone of the combustion chamber body through another branch.

[0014] In the above technical solution, the swirl numbers of the first swirler and the second swirler are 0.75.

[0015] In the above technical solution, an annular gas injection channel is formed on the inner wall of the combustion chamber body located in the primary combustion zone and the secondary combustion zone, and a hole is formed on the inner side of the annular gas injection channel.

[0016] Beneficial effects:

[0017] The present invention proposes a hierarchical high-pressure combustion chamber for re-injecting hydrogen at the root of an ammonia flame, comprising an oxygen delivery pipeline, an ammonia delivery pipeline, a hydrogen delivery pipeline, an air distributor, a cyclone, an igniter, a flame arrester, and a combustion chamber body; when the present invention is working, all input oxygen, ammonia, and hydrogen are preheated, a small portion of oxygen is distributed to the ammonia delivery pipeline by the air distributor, and the remaining oxygen is distributed to the secondary combustion zone of the combustion chamber body, most of the hydrogen is delivered to the ammonia delivery pipeline by the air distributor, and the remaining hydrogen is delivered to the mixed gas flame root position of the primary combustion zone of the combustion chamber body. The present invention can be used to solve the problems of poor flame stability and high nitrogen oxide generation in ammonia combustion. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural schematic diagram of a staged high-pressure combustion chamber for re-injecting hydrogen at the root of an ammonia flame according to the present invention;

[0019] Figure 2 It is a structural schematic diagram of the secondary hydrogen injection position in the present invention;

[0020] Figure 3 It is a structural schematic diagram of the secondary oxygen injection position in the present invention.

[0021] In the figure: 1 is an oxygen delivery pipeline, 2 is an ammonia delivery pipeline, 3 is a hydrogen delivery pipeline, 4 is an oxygen air distributor, 5 is a hydrogen air distributor, 6 is a first cyclone, 7 is a second cyclone, 8 is an igniter, 9 is an ammonia delivery pipeline flame arrester, 10 is a hydrogen branch delivery pipeline flame arrester, 11 is an oxygen branch delivery pipeline flame arrester, and 12 is a combustion chamber body. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] Example

[0024] A staged high-pressure combustion chamber for re-injecting hydrogen at the root of an ammonia flame, comprising an oxygen delivery pipeline 1, an ammonia delivery pipeline 2, a hydrogen delivery pipeline 3, an oxygen air distributor 4, a hydrogen air distributor 5, a first cyclone 6, a second cyclone 7, an igniter 8, an ammonia delivery pipeline flame arrester 9, a hydrogen branch delivery pipeline flame arrester 10, an oxygen branch delivery pipeline flame arrester 11 and a combustion chamber body 12;

[0025] The oxygen, ammonia and hydrogen are preheated to 600K before being introduced into the oxygen delivery pipeline 1, the ammonia delivery pipeline 2 and the hydrogen delivery pipeline 3;

[0026] The combustion chamber body 12 is provided with a primary combustion zone, a secondary combustion zone and a dilution zone distributed from one end close to the pipeline to one end far away from the pipeline;

[0027] The oxygen delivery pipeline 1 and the hydrogen delivery pipeline 3 are in an F shape, including a starting pipeline, a branch delivery pipeline and a second branch delivery pipeline, and have a starting section inlet and two terminal outlets. The oxygen delivery pipeline 1 and the hydrogen delivery pipeline 3 are respectively located on both sides of the combustion chamber body; one end point p of the hydrogen delivery pipeline 3 is connected to the starting section of the ammonia delivery pipeline 2, and the other end point q is connected to the primary combustion zone of the combustion chamber body 12; one end point m of the oxygen delivery pipeline 1 is connected to the end of the ammonia delivery pipeline 2, and the other end point n is connected to the secondary combustion zone of the combustion chamber body 12;

[0028] The oxygen air distributor 4 is arranged at the starting section of the oxygen delivery pipeline 1, the hydrogen air distributor 5 is arranged at the starting section of the hydrogen delivery pipeline 3, the first cyclone 6 is arranged behind the intersection point p of the ammonia delivery pipeline 2 and the hydrogen delivery pipeline 3, the second cyclone 7 is arranged behind the intersection point m of the ammonia delivery pipeline 2 and the oxygen delivery pipeline 1, and the igniter 8 is placed in the front part of the primary combustion zone of the combustion chamber body 12;

[0029] The flame arrester includes an ammonia delivery pipeline flame arrester 9, a hydrogen branch delivery pipeline flame arrester 10 and an oxygen branch delivery pipeline flame arrester 11. The ammonia delivery pipeline flame arrester 9 is arranged at the end of the ammonia delivery pipeline, the hydrogen branch delivery pipeline flame arrester 10 is arranged at the end point q of the hydrogen branch delivery pipeline in the primary combustion zone of the combustion chamber body 12, and the oxygen branch delivery pipeline flame arrester 11 is arranged at the end point n of the oxygen branch delivery pipeline in the secondary combustion zone of the combustion chamber body 12.

[0030] like Figure 1 As shown, this embodiment provides a staged high-pressure combustion chamber for re-injecting hydrogen at the root of the ammonia flame, and the volume ratio of the supplied oxygen, ammonia and hydrogen is 27:14:6. The oxygen air distributor 4 delivers 3 / 8 of the oxygen to the ammonia delivery pipeline 2 via an oxygen branch delivery pipeline, and the remaining 5 / 8 of the oxygen is delivered to the secondary combustion zone of the combustion chamber body 12 via another branch. The hydrogen air distributor 5 delivers 2 / 3 of the hydrogen to the ammonia delivery pipeline 2 via a hydrogen branch delivery pipeline, and the remaining 1 / 3 of the hydrogen is delivered to the primary combustion zone of the combustion chamber body via another branch to the root position of the mixed fuel flame, so that the primary combustion zone in the combustion chamber body is in a slightly rich combustion state with an equivalence ratio of 1.2, and the overall equivalence ratio is a lean combustion state of 0.5, maintaining a two-stage combustion mode of "rich combustion + lean combustion".

[0031] like Figure 1 As shown, the swirl numbers of the first swirler 6 and the second swirler 7 are both 0.75, which can generate high swirl. The strong swirl can promote the full mixing of multi-component gases and form a flame stabilizing reflow zone within a certain range.

[0032] like Figure 2 , 3 As shown, an annular gas injection channel is formed on the inner wall of the combustion chamber body located in the primary combustion zone and the secondary combustion zone, and a hole is formed on the inner side of the annular gas injection channel. The airflows at the secondary hydrogen injection and secondary oxygen injection positions first enter the annular gas injection channel to decelerate, and then are slowly injected through the annular holes in the primary combustion zone and the secondary combustion zone of the combustion chamber body.

[0033] The working principle of a staged high-pressure combustion chamber with hydrogen injection at the root of the ammonia flame is as follows:

[0034] When the present invention is working, all the input oxygen, ammonia and hydrogen are preheated, a small part of the oxygen is distributed to the ammonia delivery pipeline by the air distributor, the remaining oxygen is distributed to the secondary combustion zone of the combustion chamber body, most of the hydrogen is sent to the ammonia delivery pipeline by the air distributor, and the remaining hydrogen is sent to the root of the mixed gas flame in the primary combustion zone of the combustion chamber body. The present invention can be used to solve the problems of poor flame stability and high nitrogen oxide generation in ammonia combustion.

[0035] The foregoing is merely a specific embodiment of the present invention, which enables those skilled in the art to understand or implement the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A staged high-pressure combustion chamber with hydrogen re-injection at the root of an ammonia flame, characterized in that: It includes an oxygen delivery pipeline, an ammonia delivery pipeline, a hydrogen delivery pipeline, an oxygen air distributor, a hydrogen air distributor, a first cyclone, a second cyclone, an igniter, an ammonia delivery pipeline flame arrester, a hydrogen branch delivery pipeline flame arrester, an oxygen branch delivery pipeline flame arrester and a combustion chamber body; The combustion chamber body is provided with a primary combustion zone, a secondary combustion zone and a dilution zone distributed from one end close to the pipeline to one end far away from the pipeline; The oxygen delivery pipeline and the hydrogen delivery pipeline are in an F shape, including a starting pipeline, a branch delivery pipeline and a second branch delivery pipeline, with a starting section inlet and two terminal outlets, and the oxygen delivery pipeline and the hydrogen delivery pipeline are respectively located on both sides of the combustion chamber body; one end point p of the hydrogen delivery pipeline is connected to the starting section of the ammonia delivery pipeline, and the other end point q is connected to the primary combustion zone of the combustion chamber body; one end point m of the oxygen delivery pipeline is connected to the end of the ammonia delivery pipeline, and the other end point n is connected to the secondary combustion zone of the combustion chamber body; The oxygen air distributor is arranged at the starting section of the oxygen delivery pipeline, the hydrogen air distributor is arranged at the starting section of the hydrogen delivery pipeline, the first cyclone is arranged behind the intersection point p of the ammonia delivery pipeline and the hydrogen delivery pipeline, the second cyclone is arranged behind the intersection point m of the ammonia delivery pipeline and the oxygen delivery pipeline, and the igniter is placed in the front part of the primary combustion zone of the combustion chamber body; The ammonia delivery pipeline flame arrester is arranged at the end of the ammonia delivery pipeline, the hydrogen branch delivery pipeline flame arrester is arranged at the end point q of the hydrogen branch delivery pipeline in the primary combustion zone of the combustion chamber body, and the oxygen branch delivery pipeline flame arrester is arranged at the end point n of the oxygen branch delivery pipeline in the secondary combustion zone of the combustion chamber body.

2. A staged high-pressure combustion chamber for re-injecting hydrogen at the root of an ammonia flame according to claim 1, characterized in that: Oxygen, ammonia and hydrogen are preheated to 600K and then introduced into the oxygen delivery pipeline, the ammonia delivery pipeline and the hydrogen delivery pipeline.

3. A staged high-pressure combustion chamber for re-injecting hydrogen at the root of an ammonia flame according to claim 2, characterized in that: The volume ratio of oxygen, ammonia and hydrogen is 27:14:

6.

4. A staged high-pressure combustion chamber for re-injecting hydrogen at the root of an ammonia flame according to claim 1, characterized in that: The oxygen air distributor delivers 3 / 8 of the oxygen to the ammonia delivery pipeline through a branch oxygen delivery pipeline, and the remaining 5 / 8 of the oxygen is delivered to the secondary combustion zone of the combustion chamber body through another branch.

5. The staged high-pressure combustion chamber for re-injecting hydrogen at the root of the ammonia flame according to claim 1, characterized in that: The hydrogen air distributor delivers 2 / 3 of the hydrogen to the ammonia delivery pipeline via a hydrogen branch delivery pipeline, and the remaining 1 / 3 of the hydrogen is delivered to the root position of the mixed fuel flame in the primary combustion zone of the combustion chamber body via another branch.

6. The staged high-pressure combustion chamber for re-injecting hydrogen at the root of the ammonia flame according to claim 1, characterized in that: The swirl numbers of the first swirler and the second swirler are 0.

75.

7. The staged high-pressure combustion chamber for re-injecting hydrogen at the root of the ammonia flame according to claim 1, characterized in that: The inner wall of the combustion chamber body located in the primary combustion zone and the secondary combustion zone is formed with an annular gas injection channel, and a hole is formed on the inner side of the annular gas injection channel.

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