A staged high pressure combustion chamber with hydrogen re-injection at the ammonia flame root

Abstract

The application discloses a staged high-pressure combustion chamber with hydrogen re-injection at the ammonia flame root, and belongs to the combustion chamber field.The combustion chamber 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 body; the air distributors are respectively arranged at the starting sections of the oxygen pipeline and the hydrogen pipeline; the swirlers are respectively arranged at the rear portions of hydrogen-ammonia intersection and oxygen-ammonia intersection; the flame arresters are respectively arranged at the terminal ends of the ammonia pipeline, the oxygen pipeline and the hydrogen pipeline; and the igniter is arranged at the front portion of the combustion chamber body; most of the hydrogen is sent to mix with the ammonia by the air distributor, and the rest is directly introduced into the flame root of the primary combustion zone, so that the stability of the ammonia flame is remarkably enhanced; a small amount of oxygen is sent to mix with the hydrogen and the ammonia by the air distributor, and the rest is introduced into the secondary combustion zone, so that the staged combustion of the oxygen fuel is realized, and the nitrogen oxide emission is kept low.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of combustion chambers, and relates to a staged high-pressure combustion chamber with hydrogen re-injection at the root of an ammonia flame. BACKGROUND

[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 emission hinder its direct application; the current solution is to mix it with hydrogen, which is also a zero-carbon fuel and has relatively high reactivity, so that the flame stability of ammonia fuel combustion can be significantly improved while keeping the carbon emission low. By directly injecting a small amount of hydrogen at the root of the ammonia-hydrogen mixed fuel flame, the expansion stability of the mixed fuel flame can be significantly improved. Through the staged combustion mode of “rich + lean”, the nitrogen oxide emission of the high-pressure combustion chamber using ammonia as fuel can be significantly reduced, facilitating the subsequent selective / non-selective catalytic reduction work. SUMMARY

[0003] In combination with the above background, the application provides a staged high-pressure combustion chamber with hydrogen re-injection at the root of an ammonia flame, which improves the ammonia flame stability and keeps the nitrogen oxide emission relatively low.

[0004] To achieve the above object, the application is implemented through the following technical scheme.

[0005] A staged high-pressure combustion chamber with hydrogen re-injection 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 swirler, a second swirler, an igniter, an ammonia delivery pipeline flame arrester, a hydrogen one-branch delivery pipeline flame arrester, an oxygen one-branch delivery pipeline flame arrester, and a combustion chamber main body.

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

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

[0008] The oxygen air distributor is arranged at the initial section of the oxygen delivery pipeline, the hydrogen air distributor is arranged at the initial section of the hydrogen delivery pipeline, the first cyclone is arranged behind the intersection p point of the ammonia delivery pipeline and the hydrogen delivery pipeline, the second cyclone is arranged behind the intersection m point of the ammonia delivery pipeline and the oxygen delivery pipeline, and the igniter is arranged at the front 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 q point of the hydrogen branch delivery pipeline of the primary combustion zone of the combustion chamber body, and the oxygen branch delivery pipeline flame arrester is arranged at the end n point of the oxygen branch delivery pipeline of the secondary combustion zone of the combustion chamber body.

[0010] In the above technical solution, the 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 the oxygen, ammonia and hydrogen is 27:14:6.

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

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

[0014] In the above technical solution, the swirl number of the first cyclone and the second cyclone is 0.75.

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

[0016] Advantages:

[0017] The application provides a staged high-pressure combustion chamber with hydrogen re-injection at the root of an ammonia flame, comprising an oxygen delivery pipeline, an ammonia delivery pipeline, a hydrogen delivery pipeline, an air distributor, a swirler, an igniter, a flame arrestor, and a combustion chamber body; during operation, all of the input oxygen, ammonia, and hydrogen are preheated, a small amount of 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. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 is a structural schematic diagram of the staged high-pressure combustion chamber with hydrogen re-injection at the root of an ammonia flame according to the application;

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

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

[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 swirler, 7 is a second swirler, 8 is an igniter, 9 is an ammonia delivery pipeline flame arrestor, 10 is a hydrogen one-branch delivery pipeline flame arrestor, 11 is an oxygen one-branch delivery pipeline flame arrestor, and 12 is a combustion chamber body. DETAILED DESCRIPTION

[0022] To make the purpose, technical solutions, and advantages of the embodiments of the application clearer, the technical solutions in the embodiments of the application will be described below in connection with the drawings of the embodiments of the application. Obviously, the described embodiments are only a part of the embodiments of the application, rather than all the embodiments of the application. Based on the embodiments in the application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the application.

[0023] EMBODIMENT

[0024] A staged high-pressure combustion chamber with hydrogen re-injection 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 swirler 6, a second swirler 7, an igniter 8, an ammonia delivery pipeline flame arrestor 9, a hydrogen one-branch delivery pipeline flame arrestor 10, an oxygen one-branch delivery pipeline flame arrestor 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 the end closer to the pipeline to the end farther away from the pipeline;

[0027] The oxygen delivery pipeline 1 and the hydrogen delivery pipeline 3 are F-shaped, including an initial pipeline, a first branch delivery pipeline, and a second branch delivery pipeline. They have one initial inlet and two end outlets. The oxygen delivery pipeline 1 and the hydrogen delivery pipeline 3 are located on opposite sides of the combustion chamber body. One end point p of the hydrogen delivery pipeline 3 is connected to the initial 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 distributor 4 is located at the beginning of the oxygen supply pipeline 1, the hydrogen distributor 5 is located at the beginning of the hydrogen supply pipeline 3, the first cyclone separator 6 is located behind the intersection point p of the ammonia supply pipeline 2 and the hydrogen supply pipeline 3, the second cyclone separator 7 is located behind the intersection point m of the ammonia supply pipeline 2 and the oxygen supply pipeline 1, and the igniter 8 is located in front 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 located at the end of the ammonia delivery pipeline. The hydrogen branch delivery pipeline flame arrester 10 is located at point q, the end of the hydrogen branch delivery pipeline in the primary combustion zone of the combustion chamber body 12. The oxygen branch delivery pipeline flame arrester 11 is located at point n, the end 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 with hydrogen re-injection at the root of the ammonia flame. The volume ratio of supplied oxygen, ammonia, and hydrogen is 27:14:6. The oxygen distributor 4 sends 3 / 8 of the oxygen to the ammonia supply pipeline 2 via an oxygen branch pipeline, and the remaining 5 / 8 of the oxygen is sent to the secondary combustion zone of the combustion chamber body 12 via another branch pipeline. The hydrogen distributor 5 sends 2 / 3 of the hydrogen to the ammonia supply pipeline 2 via a hydrogen branch pipeline, and the remaining 1 / 3 of the hydrogen is sent to the mixed fuel flame root position in the primary combustion zone of the combustion chamber body via another branch pipeline. This results in the primary combustion zone in the combustion chamber body being in a slightly rich combustion state with an equivalence ratio of 1.2, and an overall lean combustion state with an equivalence ratio of 0.5, maintaining a two-stage combustion mode of "rich combustion + lean combustion".

[0031] As Figure 1 shown, the swirl number of the first cyclone 6 and the second cyclone 7 is 0.75, which can generate high swirl, and the strong swirl can promote the full mixing of the multi-component gas and form a certain range of stable flame backflow area.

[0032] As Figure 2 , 3 shown, the annular gas injection channel is formed on the inner wall of the primary combustion zone and the secondary combustion zone of the combustion chamber body, the annular gas injection channel is formed with a hole on the inner side, and the gas flow at the positions of the secondary hydrogen injection and the secondary oxygen injection is first introduced into the annular gas injection channel for flow around and speed reduction, and then slowly injected through the annular hole of the primary combustion zone and the secondary combustion zone of the combustion chamber body.

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

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

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

Claims

1. A staged high-pressure combustion chamber with hydrogen reinjection at the root of an ammonia flame, characterized in that: It includes oxygen delivery pipeline, ammonia delivery pipeline, hydrogen delivery pipeline, oxygen air distributor, hydrogen air distributor, first cyclone separator, second cyclone separator, igniter, flame arrester for ammonia delivery pipeline, flame arrester for one branch of hydrogen delivery pipeline, flame arrester for one branch of oxygen delivery pipeline, and the main body of the combustion chamber. The combustion chamber body is provided with a primary combustion zone, a secondary combustion zone, and a dilution zone distributed from the end closer to the pipeline to the end farther away from the pipeline; The oxygen and hydrogen delivery pipelines are F-shaped, including an initial pipeline, a first branch pipeline, and a second branch pipeline. They have one initial inlet and two final outlets. The oxygen and hydrogen delivery pipelines are located on opposite sides of the combustion chamber body. One end (p) of the hydrogen delivery pipeline is connected to the initial section of the ammonia delivery pipeline, and the other end (q) is connected to the primary combustion zone of the combustion chamber body. One end (m) of the oxygen delivery pipeline is connected to the end of the ammonia delivery pipeline, and the other end (n) is connected to the secondary combustion zone of the combustion chamber body. The oxygen distributor is located at the beginning of the oxygen delivery pipeline, the hydrogen distributor is located at the beginning of the hydrogen delivery pipeline, the first cyclone separator is located behind point p, where the ammonia delivery pipeline and the hydrogen delivery pipeline intersect, the second cyclone separator is located behind point m, where the ammonia delivery pipeline and the oxygen delivery pipeline intersect, and the igniter is located in front of the primary combustion zone of the combustion chamber body. The flame arrester for the ammonia delivery pipeline is located at the end of the ammonia delivery pipeline; the flame arrester for the hydrogen branch delivery pipeline is located at point q, the end of the hydrogen branch delivery pipeline in the primary combustion zone of the main combustion chamber; and the flame arrester for the oxygen branch delivery pipeline is located at point n, the end of the oxygen branch delivery pipeline in the secondary combustion zone of the main combustion chamber. The oxygen distributor sends 3 / 8 of the oxygen into the ammonia supply pipeline via one oxygen supply line, and the remaining 5 / 8 of the oxygen is sent to the secondary combustion zone of the main combustion chamber via another branch. The hydrogen distributor sends 2 / 3 of the hydrogen to the ammonia delivery pipeline via a hydrogen branch pipeline, and the remaining 1 / 3 of the hydrogen is sent to the root of the mixed fuel flame in the primary combustion zone of the combustion chamber via another branch pipeline. The swirl number of the first and second cyclones is 0.

75.

2. The staged high-pressure combustion chamber with hydrogen reinjection 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, ammonia delivery pipeline, and hydrogen delivery pipeline, respectively.

3. A staged high-pressure combustion chamber with hydrogen reinjection 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. The staged high-pressure combustion chamber with hydrogen reinjection at the root of an ammonia flame according to claim 1, characterized in that: The combustion chamber body has an annular gas injection channel formed on the inner wall of the primary combustion zone and the secondary combustion zone, and the annular gas injection channel has a hole formed on one side.

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