Multi-stage partition separation multi-fuel combustion burner and operation method thereof

Abstract

The invention discloses a multi-stage partition separation multi-fuel combustion burner and an operation method. The multi-stage partition separation multi-fuel combustion burner comprises a main combustion chamber and a burnout chamber. The main combustion chamber is located at the axial head of the combustor, and the burnout chamber is located at the tail of the combustor. Wherein the main combustion chamber comprises a main combustion module, a first mixed gas inlet channel and a second mixed gas inlet channel; the first mixed gas inlet channel and the second mixed gas inlet channel are alternately arranged on the outer side of the main combustion module; wherein an air inlet is formed in the main combustion module; during operation, active fuel gas and / or air enters the main combustion chamber from the gas inlet of the main combustion module to form flames, and mixed gas of the active fuel gas and the air enters the main combustion chamber from the first mixed gas inlet channel to form flames; and ammonia / air mixed gas enters the main combustion chamber from the second mixed gas inlet channel to form flame. The problems that ammonia ignition is difficult, combustion is unstable and the like can be effectively solved, and the co-combustion uniformity is improved.

Description

Technical Field

[0001] The invention relates to the field of combustion technology, and in particular to a multi-stage partition separation mixed combustion burner and an operation method thereof. Background Art

[0002] In recent years, the country has vigorously promoted the policy of reducing pollution and carbon emissions, and proposed new environmental protection indicators for thermal power generation and high-temperature manufacturing industries. Implementing energy-saving and carbon-reduction transformation and energy-using equipment renewal in thermal power generation and high-temperature manufacturing industries is an effective means of energy conservation and emission reduction. In industrial boilers or kilns that use coal as fuel, there are still certain technical difficulties in developing burners suitable for ammonia hydrogen fuel to replace traditional coal combustion to achieve carbon reduction and emission reduction effects. This is mainly due to the difficulty in ignition of ammonia combustion, poor flame stability and narrow flammable limits. It is easy to extinguish and difficult to maintain stable combustion under low load, and high concentrations of ammonia combustion will lead to NO x High emissions. In contrast, hydrogen ignites easily and has a very fast flame propagation speed, but this also makes it prone to flashback, especially in strong swirl burners.

[0003] The mixed combustion of ammonia and hydrogen can significantly optimize the combustion characteristics of the two fuels. The invention patent "An ammonia-hydrogen mixed combustion chamber and ammonia-hydrogen mixed combustion method", patent number CN202211374834.X, shows an ammonia-hydrogen mixed combustion chamber and combustion method, which uses the heat energy of ammonia combustion itself to conduct to the wall of the pyrolysis chamber, and the high temperature of the wall completes the cracking of ammonia to produce hydrogen, and the prepared hydrogen enters the combustion chamber again to enhance combustion. This design does not require the additional installation of an ammonia cracking device, and makes good use of the heat energy after combustion, but does not consider the difficulty of ignition of the initial ammonia and the cracking efficiency of wall heat transfer. The utility model patent "An ammonia-hydrogen mixed burner", patent number CN217302790U, uses hydrogen combustion as a high-temperature heat source to ignite ammonia, solving the problem of difficult ammonia ignition, but the impact of the uniformity of the mixture of ammonia and hydrogen on the combustion effect, and how to stably burn ammonia at a subsequent low load, etc., have not been solved. The invention patent "A hydrogen-injected ammonia low-nitrogen swirl burner" is patented with the number CN112984508B. It uses the multi-stage swirl of the swirl burner to fully mix ammonia and air. By adding 2% to 5% hydrogen, the flame stabilization effect is enhanced to reduce fuel-type NO x , but cannot reduce thermal NO x generated, and the burner was not designed for ammonia ignition at high flow rates.

[0004] It can be seen that the existing ammonia-hydrogen mixed combustion burner has not completely solved the problem of ammonia ignition difficulty. The uneven mixing of ammonia and hydrogen leads to incomplete combustion and NO x Problems such as high emissions make it difficult to meet today's society's environmental protection requirements for the combustion field. Summary of the invention

[0005] In view of the above-mentioned problems of difficulty in igniting ammonia and incomplete combustion caused by uneven mixing of ammonia and hydrogen, the purpose of the present invention is to provide a multi-stage partitioned separation mixed combustion burner, which can effectively solve the problems of difficulty in ignition of ammonia, unstable combustion and easy flashback of hydrogen, and improve the uniformity of combustion of the ammonia-hydrogen mixture.

[0006] The invention also provides an operating method of a multi-stage partition separation mixed combustion burner.

[0007] To achieve the above purpose, the technical solution adopted by the present invention is:

[0008] A multi-stage partitioned separation mixed combustion burner, comprising a main combustion chamber and a burnout chamber; the main combustion chamber is located at the axial head of the burner, and the burnout chamber is located at the tail of the burner;

[0009] The main combustion chamber comprises a main combustion module, a first mixed gas intake passage and a second mixed gas intake passage; the first mixed gas intake passage and the second mixed gas intake passage are alternately arranged on the outside of the main combustion module;

[0010] The main combustion module is provided with an air inlet;

[0011] During operation, active fuel gas and / or air enters the main combustion chamber from the air inlet of the main combustion module to form a flame, and the mixed gas of active fuel gas and air enters the main combustion chamber from the first mixture gas inlet duct to form a flame; the ammonia / air mixture enters the main combustion chamber from the second mixture gas inlet duct and is ignited by the high-temperature flame of the active fuel gas to form a flame.

[0012] The burner further comprises a third mixed gas inlet passage for introducing a mixed gas of active fuel gas and air, and the third mixed gas inlet passage is communicated with the burnout chamber.

[0013] Wherein, the burner further comprises an air supply chamber and an air inlet duct, the air supply chamber is located downstream of the main combustion chamber, the burnout chamber is located downstream of the air supply chamber, and the air inlet duct is connected with the air supply chamber through an air supply duct;

[0014] Preferably, the air outlet of the air supply duct is inclined toward the burnout chamber.

[0015] Wherein, a contraction cavity structure is arranged at the front end of the burnout chamber to reduce the residence time of the airflow in the burnout chamber.

[0016] Wherein, a main bluff body is arranged on the inner side wall of the main combustion chamber.

[0017] Wherein, the air supply duct is located behind the main bluff body.

[0018] The main combustion module has a plurality of air inlets, and a mixed gas of active fuel gas and air is introduced into the air inlets of the main combustion module.

[0019] Among them, there are multiple air inlets, which are divided into a main combustion module fuel inlet and a main combustion module air inlet; the main combustion module air inlet passes through the main combustion module to form a microchannel tube; the main combustion module air inlet and the microchannel tube are connected through a through hole.

[0020] Preferably, the microchannel tubes are evenly distributed in multiple rows in the circumferential direction;

[0021] Preferably, the diameter of the microchannel tube does not exceed 10 cm.

[0022] Among them, the main combustion module is located at the center position of the axial head of the main combustion chamber. The main combustion module also includes a first nozzle arranged at the air outlet of the main combustion module and an ignition device arranged on the inner wall of the main combustion module. When in use, the active fuel gas and air are sprayed out through the first nozzle and form a flame through the ignition device.

[0023] Wherein, a second nozzle and an ignition device are arranged at the outlet end of the first mixed gas intake passage, and the mixed gas of the active fuel gas and air is sprayed out through the second nozzle and forms a flame through the ignition device.

[0024] Preferably, there are at least two first mixture gas inlet passages, and the outermost first mixture gas inlet passage is not provided with a nozzle and an ignition device.

[0025] Wherein, a swirler is provided at the outlet end of the second mixed gas inlet passage, and the ammonia / air mixed gas is ejected through the swirler;

[0026] Preferably, an ammonia channel blunt body is further provided at the outlet of the second mixed gas inlet channel; the cyclone rotates and ejects the ammonia / air mixed gas, and generates a small recirculation zone through the ammonia channel blunt body;

[0027] Preferably, a flow control valve is provided on the second mixture gas inlet passage, and after the flame generated by the active fuel is stabilized, the second mixture gas inlet passage is opened to gradually increase the flow rate of the ammonia / air mixture until the target flow rate is reached.

[0028] The number of the first mixture air intake passages and the second mixture air intake passages is n, and n>2, and the n first mixture air intake passages and the n second mixture air intake passages are alternately stacked.

[0029] Wherein, a microchannel hole-type nozzle is arranged on the inner wall of the burnout chamber, and the microchannel hole-type nozzle is arranged at the connection between the third mixed gas inlet passage and the burnout chamber; the mixed gas of the active fuel gas and the air enters the third mixed gas inlet passage, and then is ejected through the microchannel hole-type nozzle;

[0030] Preferably, the microchannel holes of the microchannel hole-type nozzle are evenly distributed in multiple rows in the circumferential direction, and the aperture of the microchannel holes does not exceed 2 cm;

[0031] Preferably, an ignition device is provided at the outlet of the microchannel hole-type nozzle of the burnout chamber.

[0032] A method for operating a multi-stage partition separation mixed combustion burner is implemented using the multi-stage partition separation mixed combustion burner as described above, and the operating method comprises:

[0033] The active fuel gas is divided into two parts and introduced into the burner. The part of the active fuel gas enters through the air inlet of the main combustion module, then enters the microchannel tube through the through hole, mixes with the air in the microchannel tube, and enters the main combustion chamber; the mixed gas of part of the active fuel gas and air enters the main combustion chamber from the first mixed gas inlet duct; the ammonia / air mixed gas enters all from the second mixed gas inlet duct;

[0034] The volume ratio of the active fuel gas entering through the main combustion module intake passage and the active fuel gas entering through the first mixed gas passage is 0.1-10:1;

[0035] Preferably, the volume ratio of the active fuel gas entering through the main combustion module intake passage and the active fuel gas entering through the first mixed gas intake passage is 1-2:1.

[0036] The air is introduced into the burner in two stages, and the equivalence ratio of ammonia to air in the main combustion chamber is controlled in a rich combustion state, and the equivalence ratio of ammonia to air in the burnout chamber is controlled in a lean combustion state.

[0037] Compared with the prior art, the present invention has achieved the following technical effects:

[0038] (1) The multi-stage partitioned separation and mixed combustion burner of the present invention separates the air intake pipes of ammonia and active fuel gas and stacks them on each other to achieve separation and mixed combustion, and uses the active fuel gas as the duty flame to ignite ammonia by using its easy ignition and fast combustion characteristics; the air intake pipes of the two fuels are arranged alternately, and the two flames diffuse with each other, thus solving the problems of ammonia being difficult to ignite and uneven mixed combustion, and improving the uniformity and stability of the main combustion stage flame.

[0039] (2) The multi-stage partition separation mixed combustion burner of the present invention grades the active fuel gas to prevent the flame temperature in the main combustion chamber from being too high. An air supply chamber is arranged downstream of the main combustion chamber to provide air and reduce the flame temperature entering the burnout chamber. A contraction cavity structure is arranged at the entrance of the burnout chamber to reduce the residence time of the airflow in the burnout chamber, thereby suppressing the thermal NO x Generation of.

[0040] (3) The multi-stage partition separation mixed combustion burner of the present invention grades the air, forms a rich flame in the main combustion chamber, and suppresses the fuel-type NO x The generation of NOx is controlled by introducing an appropriate amount of air into the air supply chamber and introducing an appropriate amount of active fuel gas and excess air into the burnout chamber. A lean flame is formed in the burnout chamber, avoiding the high temperature reaction zone, burning out the remaining fuel, and inhibiting the generation of thermal NOx. x Generation of.

[0041] (4) For active fuel gas combustion, its nozzle is set to a microchannel tube / hole structure, and for ammonia combustion, a swirler and a blunt body are set at the outlet of the air inlet. The blunt body structure is set to further improve the stability of the main combustion stage flame.

[0042] (5) The multi-stage partition separation mixed combustion burner of the present invention uses mixed combustion and achieves low NO through novel and reasonable structural layout. x Emissions, and solve problems such as difficult ammonia ignition and unstable combustion. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 It is a structural schematic diagram of an embodiment of a multi-stage partition separation mixed combustion burner of the present invention;

[0044] Figure 2 It is a side view schematic diagram of the main combustion module of the multi-stage partition separation mixed combustion burner of the present invention;

[0045] Figure 3 It is a structural schematic diagram of another embodiment of a multi-stage partition separation mixed combustion burner of the present invention;

[0046] Figure 4 It is a side schematic view of a main combustion module of another embodiment of the multi-stage zoned separation mixed combustion burner of the present invention.

[0047] Wherein, the accompanying drawings are marked as follows:

[0048] 100-main combustion chamber; 110-main combustion module; 111-air inlet; 112-fuel inlet of main combustion module, 113-air inlet of main combustion module; 114-through hole; 120-first mixture inlet duct, 121-inner first mixture inlet duct; 122-outer first mixture inlet duct; 123-second nozzle; 130-second mixture inlet duct; 131-inner second mixture inlet duct; 132-outer second mixture inlet duct; 133-swirler; 134-ammonia duct blunt body; 140-third mixture inlet duct; 150-main blunt body; 200-air supply chamber; 210-air inlet duct; 220-air supply duct; 300-burnout chamber; 310-shrinkage cavity structure; 320-microchannel hole nozzle. DETAILED DESCRIPTION

[0049] The technical solutions 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 only part of the embodiments of the present invention, rather than all 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 protection scope of the present invention.

[0050] In order to make the features and advantages of the present invention more clear and obvious, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0051] According to one embodiment of the present invention, Figure 1 As shown, a multi-stage partitioned separation mixed combustion burner includes a main combustion chamber 100 and a burnout chamber 300; the main combustion chamber 100 is located at the axial head of the burner, and the burnout chamber 300 is located at the tail of the burner, that is, the burnout chamber is located downstream of the main combustion chamber.

[0052] The main combustion chamber 1 includes a main combustion module 110, a first mixed gas intake passage 120 and a second mixed gas intake passage 130. Figure 1 As shown, the first mixture air intake passage and the second mixture air intake passage are alternately arranged outside the main combustion module (that is, the first mixture air intake passage and the second mixture air intake passage are alternately located outside the main combustion module, and the first mixture air intake passage and the second mixture air intake passage are alternately arranged);

[0053] An air inlet 111 is provided on the main combustion module 110; when in use, active fuel gas and / or air enters the main combustion chamber from the air inlet of the main combustion module to form a flame; the mixed gas of active fuel gas and air enters the main combustion chamber from the first mixture gas inlet duct to form a flame, and the ammonia / air mixture enters the main combustion chamber from the second mixture gas inlet duct to form a flame.

[0054] When in use, the nozzle at the air outlet of the main combustion module sprays out a hydrogen / air mixture, which is ignited and burned to form a duty-class main flame. The outlet of the first mixture air inlet duct sprays out a hydrogen / air mixture, which is ignited and burned to form a duty-class flame. The duty-class main flame and the duty-class flame continuously ignite the ammonia / air mixture, and the active fuel gas and the ammonia flame diffuse with each other to form a uniform and stable main combustion level flame.

[0055] See also Figure 1 In this embodiment, there are two first mixture air intake passages, namely the inner first mixture air intake passage 121 and the outer first mixture air intake passage 122; there are two second mixture air intake passages, namely the inner second mixture air intake passage 131 and the outer second mixture air intake passage 132. When set, the second mixture air intake passage is closer to the main combustion module. In this embodiment, multiple intake passages are set for the two fuels, and they are arranged alternately to increase the uniformity of flame mixing. Active fuel gases such as hydrogen and air are ejected from the air inlet of the main combustion module through the nozzle, and ignited to form a stable duty class main flame. The first mixture gas inlet duct 120 and the second mixture gas inlet duct 130 are arranged alternately, and the active fuel gas and air are premixed in the first mixture gas inlet duct (or the mixture of active fuel gas and air is directly introduced), sprayed out and ignited at the outlet end to form a stable duty class flame; ammonia and air are premixed in the second mixture gas inlet duct, and after being ejected, they are ignited by the adjacent duty flame to form a stable main combustion stage flame, thereby improving the uniformity and stability of the main combustion stage flame.

[0056] Among them, the concentration of active fuel gas in the mixed gas of active fuel gas and air entering the main combustion module is different from that in the mixed gas of active fuel gas and air entering the first mixture gas intake duct; preferably, the volume ratio of the active fuel gas entering through the main combustion module intake duct and the active fuel gas entering through the first mixture gas intake duct is set to 0.1~10:1.

[0057] Preferably, the concentration of the active fuel gas in the mixed gas of the active fuel gas and air entering the main combustion module is greater than the concentration of the active fuel gas in the mixed gas of the active fuel gas and air entering the first mixed gas inlet passage. More preferably, the volume ratio of the active fuel gas entering through the main combustion module inlet passage to the active fuel gas entering through the first mixed gas inlet passage is set to 1-2:1.

[0058] In one embodiment, see Figure 1 and Figure 2 The main combustion module 110 has a plurality of air inlets 111 , and a mixed gas of active fuel gas and air is introduced into the air inlet of the main combustion module. Figure 2 There are five air inlets in the main combustion module, and the air inlets penetrate the main combustion module to form a channel. Multiple air inlets can be provided, such as Figure 2The annular arrangement shown may also be arranged in other ways. The more air inlets are arranged, the more uniform the distribution of the intake air can be achieved.

[0059] As another embodiment, see Figure 3 and Figure 4 In this embodiment, there are multiple air inlets 111, which are divided into a main combustion module fuel inlet 112 and a main combustion module air inlet 113, wherein the main combustion module fuel inlet 112 is not through-going, the main combustion module air inlet 113 passes through the main combustion module to form a microchannel tube, and the main combustion module fuel inlet 112 is only connected to the microchannel tube through the through hole 114. This arrangement improves the fuel gas premixing effect. Figure 4 The main combustion module fuel inlet 112 is a groove located on the main combustion module. Figure 4 The middle is an annular groove, the microchannel tube is located in the middle of the annular groove, and the groove and the microchannel tube are connected through a through hole. When in use, the active fuel gas enters from the fuel inlet 112 of the main combustion module, diffuses to the microchannel tube through the through hole, and the air enters the microchannel tube from the air inlet 113 of the main combustion module. The active fuel gas and air are mixed in the microchannel tube and then ejected and ignited to form the main flame of the duty class. The microchannel tubes are evenly distributed in multiple rows in the circumferential direction, and the diameter of any microchannel tube does not exceed 10 cm to prevent backfire.

[0060] The active fuel gas in the present invention is hydrogen, natural gas, carbon monoxide, etc.

[0061] Preferably, the main combustion module is located at the center position of the axial head of the main combustion chamber, and the main combustion module also includes a first nozzle arranged at the outlet end of the microchannel tube and an ignition device arranged on the inner wall of the main combustion module (used to ignite the active fuel gas / air mixture to form a stable duty flame). When in use, the active fuel gas and air are sprayed out through the nozzle and form a flame through the ignition device.

[0062] Better, see Figure 1 A second nozzle 123 is provided at the outlet end of the first mixed gas intake passage 120 , and the mixed gas of the active fuel gas and air is ejected through the second nozzle 123 .

[0063] In this embodiment, the first nozzle and the second nozzle are both microchannel tube nozzles, which are cylindrical.

[0064] More preferably, it is not necessary to set a nozzle and an ignition device in each first mixed gas intake passage, and preferably the outermost active fuel gas / air mixed gas intake passage close to the inner wall of the main combustion chamber is not provided with the nozzle and the ignition device. In this embodiment, the outer first mixed gas intake passage 122 is at the outermost side, and is not provided with a nozzle and an ignition device, and only supplies active fuel gas and air. This arrangement prevents the flame from directly baking the inner wall of the main combustion chamber, thereby extending the service life.

[0065] Better, see Figure 1 The burner further includes a third mixed gas inlet 140 for introducing a mixed gas of active fuel gas and air, and the third mixed gas inlet is connected to the burnout chamber 300. Introducing active fuel gas, such as hydrogen, into the burnout chamber has a certain reduction effect on the combustion of ammonia. The unburned fuel and air mixed gas enters the burnout chamber, and the mixed gas of active fuel gas and air forms a lean high-temperature flame in the burnout chamber to fully burn the remaining fuel.

[0066] In one embodiment, the burner also includes an air supply chamber 200 and an air intake duct 210, the air supply chamber 200 is located downstream of the main combustion chamber 100, the burnout chamber 300 is located downstream of the air supply chamber 200, and the air intake duct 210 is connected to the air supply chamber 200 through an air supply duct 220; the air supply chamber is arranged behind the main combustion chamber, and air enters through the air intake duct through the air supply duct and mixes with the main combustion stage flame, thereby reducing the flame temperature entering the burnout chamber and avoiding premature combustion of unburned fuel.

[0067] Preferably, the air outlet of the air supply duct 220 is inclined toward the burnout chamber. The air outlet of the air supply duct is inclined toward the burnout chamber, which is beneficial for air to enter the burnout chamber, thereby forming a lean combustion zone in the burnout chamber.

[0068] In this embodiment, the front end (inlet end) of the burnout chamber 300 is provided with a contraction chamber structure 310 to reduce the residence time of the airflow in the burnout chamber, increase the gas flow rate, reduce the residence time, and reduce the thermal NO x generate.

[0069] The multi-stage partition separation mixed combustion burner of the present invention divides the active fuel gas into two stages (i.e., the main combustion module and the third mixed gas inlet duct) in the axial direction and introduces it into the combustion chamber, thereby avoiding the flame temperature of the main combustion chamber from being too high and suppressing the thermal NO x Generation of.

[0070] Preferably, a microchannel hole-type nozzle 320 is provided on the burnout chamber 300, and an ignition device is provided at the outlet of the microchannel hole-type nozzle. In this embodiment, two microchannel hole-type nozzles 320 are symmetrically distributed on the upper and lower sides of the burnout chamber. The active fuel gas and air are premixed in the third mixed gas inlet duct, sprayed out and ignited through the microchannel hole-type nozzle 320 with anti-backfire design, and the remaining fuel is burned. The microchannel holes of the microchannel hole-type nozzle are evenly distributed in multiple rows in the circumferential direction, and the aperture of the microchannel holes does not exceed 2 cm to avoid backfire. An ignition device is provided at the nozzle, and the active fuel gas / air mixture is sprayed out through the nozzle and ignited, burning out the excess ammonia, active fuel gas and air mixture in the main combustion flame, strengthening the main combustion stage flame, and finally spraying out from the burner.

[0071] In this embodiment, further optimization can be performed by setting an ignition device at the outlet of the microchannel hole nozzle 320 of the burnout chamber. At the initial stage of combustion in the burnout chamber, the ignition device is activated to form a duty flame to assist in igniting the remaining ammonia until the flame is stable.

[0072] In this embodiment, the two types of fuel intake passages, the first mixed gas intake passage and the second mixed gas intake passage, can be optionally expanded to n (n>2) according to actual needs and arranged in alternate layers. The larger the n value, the better the separation and mixing uniformity. Figure 1 As shown, this embodiment is provided with two first mixed gas intake passages, namely the inner first mixed gas intake passage 121 and the outer first mixed gas intake passage 122; this embodiment is provided with two second mixed gas intake passages, namely the inner second mixed gas intake passage 131 and the outer second mixed gas intake passage 132. The main combustion chamber is in a concentric circle structure as a whole, and the first mixed gas intake passage and the second mixed gas intake passage are alternately stacked. The first mixed gas intake passage, the second mixed gas intake passage and the third mixed gas intake passage are all annular air passages.

[0073] In this embodiment, see Figure 1 A swirler 133 is provided at the outlet end of the second mixed gas inlet duct, and the swirler 133 rotates and ejects the ammonia / air mixed gas; more preferably, an ammonia duct blunt body 134 is also provided at the outlet of the second mixed gas inlet duct; the swirler rotates and ejects the ammonia / air mixed gas, and generates a small reflux zone through the ammonia duct blunt body.

[0074] Preferably, the inner wall of the main combustion chamber 100 is provided with a main bluff body 150 , and the main bluff body 150 forms a large recirculation zone in the main combustion chamber 100 to enhance the stability of the main combustion stage flame.

[0075] In this embodiment, the air supply chamber 200 is located behind the main combustion chamber 100, and includes two symmetrically distributed air supply ducts 220. The air supply ducts 220 are located behind the main bluff body 150 (that is, the outlet of the air supply duct is located between the main bluff body and the burnout chamber), and the air outlet of the air supply duct 220 is slightly inclined toward the downstream burnout chamber.

[0076] In this embodiment, based on the above-mentioned multi-stage partition separation mixed combustion burner, an operation method is provided:

[0077] The active fuel gas is divided into two parts and introduced into the main combustion chamber (i.e., one part of the active fuel gas enters the main combustion chamber through the main combustion module; and one part of the active fuel gas enters the main combustion chamber from the first mixture gas intake duct), and the ammonia / air mixture gas all enters from the second mixture gas intake duct; by simultaneously introducing the active fuel gas into the main combustion module and the first mixture gas intake duct to form multiple beams of high-temperature duty flames, the problem of difficult ignition of ammonia is solved; the first mixture gas intake duct and the second mixture gas intake duct are alternately arranged on the outside of the main combustion module so that the main combustion module and the second mixture gas intake duct are arranged alternately, which solves the problem of uneven mixed combustion.

[0078] In addition, 30% of the active fuel gas by volume enters the burnout chamber from the third mixture inlet duct to form fuel grading, thereby preventing the flame temperature in the main combustion chamber from being too high and suppressing the thermal NO x generate.

[0079] Preferably, air is introduced into the air supply chamber through an air inlet duct; the air supply chamber is introduced with a proper amount of air, which reduces the temperature of the rich gas in the main combustion chamber entering the burnout chamber, thereby avoiding premature combustion of the rich gas.

[0080] Preferably, the shrinkage structure of the burnout chamber entrance accelerates the gas flow rate, reduces the residence time, and reduces the thermal NO x generate;

[0081] Preferably, the active fuel gas is hydrogen, which has a certain reducing effect on ammonia combustion, which is beneficial to reducing fuel-type NO x generate.

[0082] Furthermore, the present invention also adopts axial air staged combustion technology: the equivalent ratio of ammonia and air introduced into the main combustion chamber is controlled to be a rich combustion state, and the equivalent ratio of ammonia and air introduced into the burnout chamber is controlled to be a lean combustion state. In the main combustion chamber, ammonia ignites, burns, and diffuses mutually under the action of the high-temperature duty flame generated by the active fuel gas to form a rich combustion stage main combustion flame, which effectively suppresses fuel-type NO in a reducing atmosphere. xThe air inlet of the downstream air supply chamber is fed with an appropriate amount of air, and the third mixed gas inlet of the burnout chamber is fed with part of the active fuel gas and excess air, which are ejected through the microchannel hole nozzle and ignited by the main combustion stage flame. In the lean combustion atmosphere, the remaining ammonia is burned out, avoiding the high temperature reaction zone, reducing the thermal NO x emission;

[0083] As a further preferred embodiment, the equivalence ratio of ammonia combustion in a rich state is controlled at 1.2-1.3, and the equivalence ratio in a lean state is controlled at 0.7-0.8.

[0084] In this embodiment, a flow control valve is provided in the second mixed gas inlet passage. After the hydrogen flame is stably burning, the ammonia / air mixed gas inlet passage is opened to gradually increase the flow until the target flow is reached.

[0085] In one embodiment, the two gas fuels are arranged alternately, and hydrogen, an active gas fuel, is used as the duty flame to ignite ammonia, a stable gas fuel; optionally, a fuel with a similar combustion activity to hydrogen, such as natural gas, carbon monoxide, etc., can replace hydrogen as the duty flame, and the above-mentioned multi-stage partition separation mixed combustion burner and combustion method can also achieve a similar effect.

[0086] It will be easily understood by those skilled in the art that 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 and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

[0087] The parts not elaborated in detail in the description of the present invention belong to the known technology in the art. The above embodiments are provided only for the purpose of describing the present invention, and are not intended to limit the scope of the present invention. The scope of the present invention is defined by the appended claims. Various equivalent substitutions and modifications made without departing from the spirit and principle of the present invention should be included in the scope of the present invention.

Claims

1. A multi-stage partition separation mixed combustion burner, characterized in that: It includes a main combustion chamber and a burnout chamber; the main combustion chamber is located at the axial head of the burner, and the burnout chamber is located at the tail of the burner; The main combustion chamber comprises a main combustion module, a first mixed gas intake passage and a second mixed gas intake passage; the first mixed gas intake passage and the second mixed gas intake passage are alternately arranged on the outside of the main combustion module; The main combustion module is provided with an air inlet; During operation, active fuel gas and / or air enters the main combustion chamber from the air inlet of the main combustion module to form a flame, and the mixed gas of active fuel gas and air enters the main combustion chamber from the first mixture gas intake duct to form a flame; the ammonia / air mixture enters the main combustion chamber from the second mixture gas intake duct to form a flame.

2. The multi-stage partition separation mixed combustion burner according to claim 1 is characterized in that: The burner further comprises a third mixed gas inlet passage for introducing a mixed gas of active fuel gas and air, wherein the third mixed gas inlet passage is communicated with the burnout chamber.

3. The multi-stage partition separation mixed combustion burner according to claim 1 is characterized in that: The burner further comprises an air supply chamber and an air inlet passage, wherein the air supply chamber is located downstream of the main combustion chamber, the burnout chamber is located downstream of the air supply chamber, and the air inlet passage is connected to the air supply chamber through an air supply duct; And / or, the air outlet of the air supply duct is inclined toward the burnout chamber.

4. The multi-stage partition separation mixed combustion burner according to claim 3 is characterized in that: A contraction chamber structure is provided at the front end of the burnout chamber to reduce the residence time of the airflow in the burnout chamber; and / or, a main bluff body is provided on the inner side wall of the main combustion chamber; And / or, the air supply duct is located behind the main bluff body.

5. The multi-stage partition separation mixed combustion burner according to claim 1, characterized in that: The main combustion module has a plurality of air inlets, and a mixed gas of active fuel gas and air is introduced into the air inlets of the main combustion module.

6. The multi-stage partition separation mixed combustion burner according to claim 1, characterized in that: There are multiple air inlets, which are divided into a fuel inlet of the main combustion module and an air inlet of the main combustion module; the air inlet of the main combustion module penetrates the main combustion module to form a microchannel tube; the air inlet of the main combustion module and the microchannel tube are connected through a through hole; Preferably, the microchannel tubes are evenly distributed in multiple rows in the circumferential direction; Preferably, the diameter of the microchannel tube does not exceed 10 cm.

7. The multi-stage zone separation mixed combustion burner according to claim 1, characterized in that: The main combustion module is located at the center of the axial head of the main combustion chamber, and the main combustion module also includes a first nozzle arranged at the air outlet of the main combustion module and an ignition device arranged on the inner wall of the main combustion module. When in use, the active fuel gas and air are sprayed out through the first nozzle and form a flame through the ignition device; And / or, a second nozzle and an ignition device are provided at the outlet end of the first mixture gas intake passage, and the mixture gas of the active fuel gas and air is ejected through the second nozzle and forms a flame through the ignition device.

8. The multi-stage partition separation mixed combustion burner according to claim 7 is characterized in that: There are at least two first mixture air inlet passages, and the outermost first mixture air inlet passage is not provided with a nozzle and an ignition device.

9. The multi-stage partition separation mixed combustion burner according to claim 1, characterized in that: A swirler is provided at the outlet end of the second mixed gas inlet passage, and the ammonia / air mixed gas is ejected through the swirler; And / or, an ammonia channel blunt body is further provided at the outlet of the second mixed gas inlet channel; the cyclone rotates and ejects the ammonia / air mixed gas, and generates a small recirculation zone through the ammonia channel blunt body; And / or, a flow control valve is provided on the second mixture gas inlet passage, and after the flame generated by the active fuel is stabilized, the second mixture gas inlet passage is opened to gradually increase the flow rate of the ammonia / air mixture until the target flow rate is reached.

10. The multi-stage zone separation mixed combustion burner according to claim 1, characterized in that: The number of the first mixture air intake passages and the second mixture air intake passages is n, and n>2, and the n first mixture air intake passages and the n second mixture air intake passages are arranged alternately in layers.

11. The multi-stage partition separation mixed combustion burner according to claim 2, characterized in that: A microchannel hole-type nozzle is arranged on the inner wall of the burnout chamber, and the microchannel hole-type nozzle is arranged at the connection between the third mixed gas inlet passage and the burnout chamber; the mixed gas of active fuel gas and air enters the third mixed gas inlet passage, and then is ejected through the microchannel hole-type nozzle; And / or, the microchannel holes of the microchannel hole type nozzle are evenly distributed in multiple rows in the circumferential direction, and the aperture of the microchannel holes does not exceed 2 cm; And / or, an ignition device is arranged at the outlet of the microchannel hole type nozzle of the burnout chamber.

12. A method for operating a multi-stage partition separation mixed combustion burner, characterized in that: The multi-stage partition separation mixed combustion burner according to any one of claims 1 to 11 is used for implementation, and the operation method includes: The active fuel gas is introduced into the burner in two stages. Part of the active fuel gas enters through the air inlet of the main combustion module, then enters the microchannel tube through the through hole, mixes with the air in the microchannel tube, and enters the main combustion chamber; part of the mixed gas of the active fuel gas and air enters the main combustion chamber from the first mixed gas inlet duct; all the ammonia / air mixed gas enters from the second mixed gas inlet duct; The volume ratio of the active fuel gas entering through the main combustion module intake passage and the active fuel gas entering through the first mixed gas passage is 0.1-10:1; Preferably, the volume ratio of the active fuel gas entering through the main combustion module intake passage and the active fuel gas entering through the first mixed gas intake passage is 1-2:

1.

13. The operating method of the multi-stage zone separation mixed combustion burner according to claim 12, characterized in that: Air is introduced into the burner in two stages, and the equivalence ratio of ammonia to air in the main combustion chamber is controlled in a rich combustion state, and the equivalence ratio of ammonia to air in the burnout chamber is controlled in a lean combustion state.

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