Gas-liquid ammonia two-phase combustor based on plasma on-line ammonia cracking hydrogen production and plasma ignition and combustion supporting and operation method of gas-liquid ammonia two-phase combustor

Abstract

The invention discloses a gas-liquid ammonia two-phase combustor based on plasma on-line ammonia cracking hydrogen production and plasma ignition and combustion supporting and an operation method of the gas-liquid ammonia two-phase combustor, and the gas-liquid ammonia two-phase combustor comprises an inner-layer combustor, an outer-layer combustor, a liquid ammonia supply system, a gas ammonia supply system, an ammonia-hydrogen mixed gas supply system and an air supply system. The gas ammonia combustor is made to burn sufficiently, ammonia and hydrogen mixed gas is provided for the gas ammonia combustor by adopting plasma to crack ammonia to produce hydrogen, accordingly, the flame propagation speed of ammonia combustion is increased, ignition and stable combustion of ammonia combustion are completed through a plasma ignition and combustion-supporting device, the liquid ammonia combustor is made to burn sufficiently, and the combustion efficiency of the gas ammonia combustor is improved. The gas ammonia combustor is used for ignition, meanwhile, the plasma ammonia cracker and the plasma ignition and combustion-supporting device are used for improving the combustion performance of liquid ammonia, the problem that an existing pure ammonia combustor is low in power can be solved, and the problems that the ammonia combustion speed is low, ignition is difficult and the like can be solved.

Description

Technical Field

[0001] The present invention relates to the technical field of burners, and more particularly to a gas-liquid ammonia two-phase burner based on plasma online cracking of ammonia to produce hydrogen and plasma ignition and combustion support, and an operating method thereof. Background Art

[0002] Hydrogen energy has the advantages of being green, efficient, carbon-free, and having a wide range of applications. However, hydrogen has a low volume density, and the conditions for converting it into liquid hydrogen are harsh. It is also prone to hydrogen embrittlement, which poses certain obstacles to its large-scale application. Ammonia is easy to liquefy and store, making it a more ideal hydrogen storage medium. However, compared with pulverized coal, gaseous ammonia also has problems such as low volume energy density. For example, the thermal power of pulverized coal burners in boiler power plants can reach 50MW, while the thermal power of pure gaseous ammonia burners is difficult to exceed 20MW. The use of liquid ammonia can significantly increase the thermal power of pure ammonia burners, but its ignition and stable combustion are more difficult than those of gaseous ammonia.

[0003] To address the above issues, relevant scholars at home and abroad have primarily focused on developing and researching gas ammonia burners, while there have been no public reports on liquid ammonia burners. The present invention proposes a gas-liquid two-phase pure ammonia burner. This utilizes plasma ignition, a combustion aid, and plasma ammonia cracking to produce hydrogen to achieve stable combustion in the gas ammonia burner. This in turn drives the combustion of the liquid ammonia burner. Furthermore, a plasma ammonia combustion module is installed within the liquid ammonia burner to heat the liquid ammonia, partially converting it into gas ammonia as it is ejected from the nozzle. This addresses the current drawback of pure ammonia burners, which generally have lower thermal power than pulverized coal burners, and also solves the current difficulty in burning gaseous and liquid ammonia, particularly liquid ammonia. Summary of the Invention

[0004] In order to overcome the above-mentioned defects of the prior art, the present invention provides a gas-liquid ammonia two-phase burner based on plasma online cracking of ammonia to produce hydrogen and plasma ignition and combustion support, and its operation method, to realize 10-50MW level pure ammonia burners in coal-fired power plants, replace existing pulverized coal burners, achieve energy conservation and emission reduction of pulverized coal boilers, and solve the problems raised in the above-mentioned background technology.

[0005] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a gas-liquid ammonia two-phase burner based on plasma online cracking ammonia to produce hydrogen and plasma ignition and combustion-supporting, and an operation method thereof, comprising an inner burner, an outer burner, a liquid ammonia supply system, a gas ammonia supply system, an ammonia-hydrogen mixed gas supply system and an air supply system; the inner burner is a gas-liquid burner, the outer burner is a gas ammonia or liquid ammonia burner, the inner burner and the outer burner are coaxially arranged, and the outer burner comprises three parts: a head, a middle and a tail; wherein the outer burner head comprises a laminar air nozzle, a first ammonia-hydrogen mixed gas nozzle, a first plasma ignition and combustion-supporting nozzle, a gas-liquid ammonia nozzle, a first rotary nozzle, and a second rotary nozzle in the direction of the normal vector of the inner burner axis. The inner burner comprises a front-stage plasma ammonia combustion module and an evaporator in the middle, and a first air inlet, a liquid ammonia inlet and a first ammonia-hydrogen mixture gas inlet in the tail; the inner burner comprises a head and a tail; wherein the head of the inner burner comprises a second swirl air nozzle, a second ammonia-hydrogen mixture gas nozzle, a gas ammonia nozzle and a second plasma ignition and combustion-supporting nozzle, and the tail comprises a second air inlet, a second ammonia-hydrogen mixture gas inlet and a first gas ammonia inlet; the ammonia-hydrogen mixture gas supply system comprises an ammonia-hydrogen mixture gas outlet, a catalyst module, a rear-stage plasma ammonia combustion module, a second gas ammonia inlet and a third air inlet; the rear-stage plasma ammonia combustion module and the catalyst module constitute a plasma ammonia cracker, and convert ammonia into an ammonia-hydrogen mixture gas.

[0006] In a preferred embodiment, the inner burner and the outer burner are the first-stage burner and the second-stage burner respectively, the outer burner is evenly arranged circumferentially outside the inner burner, the nozzle openings of the inner burner and the outer burner are not in the same plane, and the fuel nozzle opening of the inner burner is located inside the outer burner.

[0007] In a preferred embodiment, the number of the inner layer burner is one, the number of the outer layer burners is multiple, and the gas ammonia burners and liquid ammonia burners in the multiple outer layer burners are evenly cross-distributed.

[0008] In a preferred embodiment, the types of the front-stage plasma ammonia combustion module and the rear-stage plasma ammonia combustion module are at least one of dielectric barrier discharge plasma, radio frequency plasma or microwave plasma.

[0009] In a preferred embodiment, the catalyst module is at least one of iron-based, ruthenium-based, nickel-based, transition metal nitride or carbide.

[0010] In a preferred embodiment, the fuel used by the inner burner is gaseous ammonia and ammonia-hydrogen mixture, and the fuel used by the outer burner is ammonia-hydrogen mixture or gas-liquid ammonia mixture.

[0011] A method for operating a gas-liquid ammonia two-phase burner based on plasma online cracking of ammonia to produce hydrogen and plasma ignition and combustion support, comprising the following steps:

[0012] S1: Open the air supply system of the inner burner and the outer burner;

[0013] S2: Turn on the front-stage plasma ammonia combustion module to generate a plasma jet;

[0014] S3: Start the ammonia supply in the ammonia-hydrogen mixed gas supply system, and then start the post-stage plasma ammonia combustion module to convert the gaseous ammonia into an ammonia-hydrogen mixed gas;

[0015] S4: Opening the gas ammonia supply system in the inner burner, including a first gas ammonia inlet and a second ammonia-hydrogen mixed gas inlet;

[0016] S5: Open the first ammonia-hydrogen mixture inlet in the outer burner;

[0017] S6: Turn on the front-stage plasma ammonia combustion module, and then turn on the liquid ammonia inlet to gasify part of the liquid ammonia.

[0018] The technical effects and advantages of the present invention are as follows:

[0019] 1. The present invention adopts a two-stage ammonia burner, namely a gas ammonia burner and a liquid ammonia burner. The high-temperature flue gas generated by the gas ammonia burner is used to ignite the liquid ammonia burner. In order to ensure sufficient combustion of the gas ammonia burner, plasma cracking of ammonia to produce hydrogen is used to provide an ammonia-hydrogen mixture for the gas ammonia burner, thereby increasing the flame propagation speed of ammonia combustion.

[0020] 2. Plasma ignition and combustion support are used to complete the ignition and stable combustion of ammonia. In order to make the liquid ammonia burner burn fully, in addition to using the gas ammonia burner for ignition, plasma ammonia cracker and plasma ignition and combustion support are also used to improve the combustion performance of liquid ammonia.

[0021] 3. Using gas-liquid two-phase ammonia burners to achieve 10-50MW level ammonia combustion technology. This technology can not only solve the current low power of pure ammonia burners (<10MW), but also solve the problems of low ammonia combustion speed and ignition difficulty. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the principle of the present invention.

[0023] Figure 2 It is a schematic diagram of the transverse cross-section principle of the burner of the present invention.

[0024] Figure 3 It is a schematic diagram of the principle of the outer burner of the present invention.

[0025] Figure 4 It is a schematic diagram of the principle of the inner burner of the present invention.

[0026] Figure 5 Schematic diagram of the principle of the ammonia-hydrogen mixed gas supply system of the present invention. DETAILED DESCRIPTION

[0027] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only 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 making creative efforts are within the scope of protection of the present invention.

[0028] like Figure 1-5 As shown, a gas-liquid ammonia two-phase burner based on plasma online cracking of ammonia to produce hydrogen and plasma ignition and combustion-supporting, and an operation method thereof, comprises an inner burner, an outer burner, a liquid ammonia supply system, a gas ammonia supply system, an ammonia-hydrogen mixed gas supply system and an air supply system; the inner burner is a gas-liquid burner, the outer burner is a gas ammonia or liquid ammonia burner, the inner burner and the outer burner are coaxially arranged, and the outer burner comprises three parts: a head, a middle part and a tail part; wherein, the head part of the outer burner comprises, in sequence along the direction of the normal vector of the axis of the inner burner, a laminar air nozzle, a first ammonia-hydrogen mixed gas nozzle, a first plasma ignition and combustion-supporting nozzle, a gas-liquid ammonia nozzle and a first swirl air nozzle, and the middle part comprises a front-stage plasma ammonia combustion module and an evaporator, The tail part includes a first air inlet, a liquid ammonia inlet and a first ammonia-hydrogen mixture inlet, and utilizes the front-stage plasma ammonia combustion module and the evaporator to convert part or all of the liquid ammonia into gaseous ammonia; the inner burner includes a head part and a tail part; wherein, the head part of the inner burner includes a second swirl air nozzle, a second ammonia-hydrogen mixture nozzle, a gas ammonia nozzle and a second plasma ignition and combustion-supporting nozzle, and the tail part includes a second air inlet, a second ammonia-hydrogen mixture inlet and a first gas ammonia inlet; the ammonia-hydrogen mixture supply system includes an ammonia-hydrogen mixture outlet, a catalyst module, a rear-stage plasma ammonia combustion module, a second gas ammonia inlet and a third air inlet, and the rear-stage plasma ammonia combustion module and the catalyst module constitute a plasma ammonia cracker, and convert ammonia into an ammonia-hydrogen mixture.

[0029] By setting the outer burner to a gas ammonia or liquid ammonia burner, the ammonia burner can have two working modes. The first working mode is that the outer burner is a pure gas ammonia mode, and the second working mode is that the outer burner is a gas-liquid mixed mode, thereby improving the combustion performance of the device.

[0030] The outer burner has two working states, the first is liquid ammonia state, and the second is gas-liquid mixed state. The two working states are switched according to the closing and opening of the front-stage plasma ammonia combustion module. When the front-stage plasma ammonia combustion module is turned on, the outer burner works in gas-liquid ammonia mixed mode. When the front-stage plasma ammonia combustion module is turned off, the outer burner works in liquid ammonia mode. The opening and closing of the front-stage plasma ammonia combustion module is related to the state of the burner. When the entire burner is in the process of starting and stabilizing, all outer burners are in gas ammonia burner state. When the entire burner is running stably, the gas ammonia burner is gradually converted into a liquid ammonia burner.

[0031] Among them, the inner burner and the outer burner are the first-stage burner and the second-stage burner respectively, the outer burner is evenly arranged circumferentially outside the inner burner, the nozzle openings of the inner burner and the outer burner are not in the same plane, and the fuel nozzle opening of the inner burner is located inside the outer burner.

[0032] There are two types of plasma ammonia combustion modules within the burner. The first is the front-stage plasma ammonia combustion module, where ammonia combustion is in a lean-burn state. The high-temperature flue gas from the plasma-assisted ammonia combustion enters the heat exchanger, heating the liquid ammonia flowing through the heat exchanger, causing it to partially or completely vaporize and then be fed into the gas-liquid ammonia nozzle. The second is the rear-stage plasma ammonia combustion module, where ammonia combustion is in a high-rich state, meaning that most of the ammonia does not participate in combustion. The high-temperature flue gas from the plasma-assisted ammonia combustion enters the catalyst module, where it is decomposed into an ammonia-hydrogen mixture under the action of the catalyst.

[0033] There is one inner burner, and there are multiple outer burners. The gas ammonia burners and liquid ammonia burners in the multiple outer burners are evenly cross-distributed.

[0034] Wherein, the types of the front-stage plasma ammonia combustion module and the rear-stage plasma ammonia combustion module are at least one of dielectric barrier discharge plasma, radio frequency plasma or microwave plasma.

[0035] Wherein, the catalyst module is at least one of iron-based, ruthenium-based, nickel-based, transition metal nitride or carbide.

[0036] The fuel used by the inner burner is gaseous ammonia and ammonia-hydrogen mixture, and the fuel used by the outer burner is ammonia-hydrogen mixture or gas-liquid ammonia mixture.

[0037] A method for operating a gas-liquid ammonia two-phase burner based on plasma online cracking of ammonia to produce hydrogen and plasma ignition and combustion support, comprising the following steps:

[0038] S1: Open the air supply system of the inner burner and the outer burner;

[0039] S2: Turn on the front-stage plasma ammonia combustion module to generate a plasma jet;

[0040] S3: Start the ammonia supply in the ammonia-hydrogen mixed gas supply system, and then start the post-stage plasma ammonia combustion module to convert the gaseous ammonia into an ammonia-hydrogen mixed gas;

[0041] S4: Opening the gas ammonia supply system in the inner burner, including a first gas ammonia inlet and a second ammonia-hydrogen mixed gas inlet;

[0042] S5: Open the first ammonia-hydrogen mixture inlet in the outer burner;

[0043] S6: Turn on the front-stage plasma ammonia combustion module, and then turn on the liquid ammonia inlet to gasify part of the liquid ammonia.

[0044] Finally, a few points should be noted: the drawings of the embodiments disclosed in the present invention only involve structures related to the embodiments disclosed in the present invention. Other structures can refer to conventional designs. In the absence of conflicts, the same embodiment and different embodiments of the present invention can be combined with each other.

[0045] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A gas-liquid ammonia two-phase burner based on plasma online cracking of ammonia to produce hydrogen and plasma ignition and combustion support, characterized by: It includes inner burner, outer burner, liquid ammonia supply system, gaseous ammonia supply system, ammonia-hydrogen mixed gas supply system and air supply system; The inner burner is a gas-liquid burner, and the outer burner is a gas ammonia or liquid ammonia burner. The inner burner and the outer burner are coaxially arranged, and the outer burner includes three parts: a head part, a middle part, and a tail part; The outer burner head includes a laminar air nozzle, a first ammonia-hydrogen mixture nozzle, a first plasma ignition and combustion-supporting nozzle, a gas-liquid ammonia nozzle, and a first swirl air nozzle in the direction of the normal vector of the inner burner axis. The middle part includes a front-stage plasma ammonia combustion module and an evaporator. The tail part includes a first air inlet, a liquid ammonia inlet, and a first ammonia-hydrogen mixture inlet. The inner burner comprises two parts: a head and a tail; The head of the inner burner includes a second swirl air nozzle, a second ammonia-hydrogen mixture nozzle, a gas ammonia nozzle and a second plasma ignition and combustion-supporting nozzle, and the tail includes a second air inlet, a second ammonia-hydrogen mixture inlet and a first gas ammonia inlet; The ammonia-hydrogen mixed gas supply system includes an ammonia-hydrogen mixed gas outlet, a catalyst module, a post-stage plasma ammonia combustion module, a second gas ammonia inlet and a third air inlet. The post-stage plasma ammonia combustion module and the catalyst module constitute a plasma ammonia cracker and convert ammonia into an ammonia-hydrogen mixed gas.

2. The gas-liquid ammonia two-phase burner based on plasma online cracking of ammonia to produce hydrogen and plasma ignition and combustion support according to claim 1 is characterized in that: The inner burner and the outer burner are the first-stage burner and the second-stage burner respectively. The outer burner is evenly arranged circumferentially outside the inner burner. The nozzle openings of the inner burner and the outer burner are not in the same plane. The fuel nozzle opening of the inner burner is located inside the outer burner.

3. The gas-liquid ammonia two-phase burner based on plasma online cracking of ammonia to produce hydrogen and plasma ignition and combustion support according to claim 1 is characterized in that: The number of the inner layer burner is one, the number of the outer layer burners is multiple, and the gas ammonia burners and liquid ammonia burners in the multiple outer layer burners are evenly cross-distributed.

4. The gas-liquid ammonia two-phase burner based on plasma online cracking of ammonia to produce hydrogen and plasma ignition and combustion support according to claim 1 is characterized in that: The types of the front-stage plasma ammonia combustion module and the rear-stage plasma ammonia combustion module are at least one of dielectric barrier discharge plasma, radio frequency plasma or microwave plasma.

5. The gas-liquid ammonia two-phase burner based on plasma online cracking of ammonia to produce hydrogen and plasma ignition and combustion support and its operating method according to claim 1, characterized in that: The catalyst module is at least one of iron-based, ruthenium-based, nickel-based, transition metal nitride or carbide.

6. The gas-liquid ammonia two-phase burner based on plasma online cracking of ammonia to produce hydrogen and plasma ignition and combustion support according to claim 1, characterized in that: The fuel used by the inner burner is gaseous ammonia and ammonia-hydrogen mixture, and the fuel used by the outer burner is ammonia-hydrogen mixture or gas-liquid ammonia mixture.

7. A method for operating a gas-liquid ammonia two-phase burner based on plasma online ammonia cracking to produce hydrogen and plasma ignition and combustion support, characterized by: The following steps are involved: S1: Open the air supply system of the inner burner and the outer burner; S2: Turn on the front-stage plasma ammonia combustion module to generate a plasma jet; S3: Start the ammonia supply in the ammonia-hydrogen mixed gas supply system, and then start the post-stage plasma ammonia combustion module to convert the gaseous ammonia into an ammonia-hydrogen mixed gas; S4: Opening the gas ammonia supply system in the inner burner, including a first gas ammonia inlet and a second ammonia-hydrogen mixed gas inlet; S5: Open the first ammonia-hydrogen mixture inlet in the outer burner; S6: Turn on the front-stage plasma ammonia combustion module, and then turn on the liquid ammonia inlet to gasify part of the liquid ammonia.

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