CN118306948A - High-response combustion-inductance coupling ammonia modification system and control method - Google Patents

Abstract

The invention discloses a high-response combustion-inductance coupling ammonia modification system and a control method, comprising the following steps: the high-temperature combustion gas flow passage is positioned at the outer periphery of the combustion chamber, and the air inlet end of the high-temperature combustion gas flow passage is communicated with the combustion chamber; the ammonia preheating flow passage comprises a first preheating section and a second preheating section which are sequentially communicated, and the first preheating section extends along the combustion chamber and is clung to the combustion chamber; the second preheating section extends along the high-temperature combustion gas flow passage and is clung to the high-temperature combustion gas flow passage; the ammonia cracking tube is arranged in the high-temperature combustion gas flow passage, and the inlet end of the ammonia cracking tube is communicated with the outlet end of the second preheating section; the electric heating piece comprises a high-frequency induction heating coil wound on the periphery of the ammonia cracking tube. The invention meets the second-level rapid cold start requirement, long-term operation requirement, high ammonia cracking rate and high energy utilization efficiency requirement of a high-response combustion-inductance coupling ammonia modifying system.

Description

High-response combustion-inductance coupling ammonia modification system and control method

Technical Field

The invention relates to the technical field of hydrogen preparation, in particular to a high-response combustion-inductance coupling ammonia modification system and a control method.

Background

The hydrogen energy is a zero-carbon fuel with wide prospect, can be applied to a vehicle-mounted hydrogen fuel cell or an ammonia-hydrogen fusion engine, and can also be applied to a fixed hydrogen power generation system, so that the development of low-carbon, efficient, low-cost, safe and clean renewable energy hydrogen production technology is imperative. Ammonia is the second largest industrial chemical in world production, storage and use, which has established a complete industrial chain, industry standard and safety specification. Meanwhile, ammonia is used as a zero carbon compound, the hydrogen content of the zero carbon compound reaches 17.6%, and the zero carbon compound is the compound with the highest hydrogen content in nature. Moreover, ammonia can be liquefied only at 8.58 atmospheres at normal temperature or at-33 ℃ at normal pressure, so that large-scale storage and transportation of ammonia are excellent in economy. In addition, ammonia has a high ignition point, a low flame propagation speed, a narrow explosion limit range, and a pungent odor, so that ammonia also has good safety. In the last decades, technologies for producing hydrogen by catalytic thermal cracking of ammonia have been proposed and developed: at a certain reaction temperature and with the aid of an ammonia cracking catalyst, ammonia can be effectively cracked and hydrogen gas is produced. Therefore, subjecting ammonia to thermocatalytic cracking to obtain hydrogen is considered to be one of the most promising hydrogen production methods.

In previous studies, ammonia upgrading systems for the thermal catalytic cracking of ammonia to produce hydrogen were developed. Some of the ammonia reforming systems use flame combustion to provide heat energy for thermal cracking of ammonia, but the inherent slow heat transfer characteristics of flame combustion of current ammonia reforming systems make these ammonia reforming systems unable to meet the requirements of rapid cold start response in vehicular or fixed end application scenarios. Other ammonia reforming systems use an electric heating furnace to provide heat energy for thermal cracking of ammonia, but the electric heating furnace needs a large amount of external power supply, which not only makes the ammonia reforming system difficult to deploy in a vehicle-mounted application scene, but also causes serious reduction of the efficiency of a fixed-end hydrogen power generation system. In addition, the electric heating furnace still needs minute-level heating time, and the requirement of the quick cold start response of the ammonia modification system in the vehicle-mounted application scene is difficult to meet.

Disclosure of Invention

The present invention is directed to a high-response combustion-inductance coupling ammonia modifying system and control method, which solves one or more of the technical problems of the prior art, and at least provides a beneficial choice or creation condition.

The technical scheme adopted for solving the technical problems is as follows:

The invention provides a high-response combustion-inductance coupling ammonia modifying system, which comprises: the device comprises a combustion chamber, a high-temperature combustion gas flow passage, an ammonia preheating flow passage, an ammonia cracking tube and an electric heating element, wherein the combustion chamber is provided with a combustor; the high-temperature combustion gas flow passage is positioned on the outer peripheral side of the combustion chamber, and the air inlet end of the high-temperature combustion gas flow passage is communicated with the combustion chamber; the ammonia preheating flow passage is arranged between the high-temperature combustion gas flow passage and the combustion chamber, and comprises a first preheating section and a second preheating section which are sequentially communicated, wherein the first preheating section extends along the combustion chamber and is clung to the combustion chamber; the second preheating section extends along the high-temperature combustion gas flow passage and is clung to the high-temperature combustion gas flow passage; the ammonia cracking tube is provided with at least one ammonia cracking tube, the ammonia cracking tube is arranged in the high-temperature combustion gas flow channel, the inlet end of the ammonia cracking tube is communicated with the outlet end of the second preheating section, and an ammonia cracking catalyst is filled in the ammonia cracking tube; the electric heating piece is used for heating the ammonia cracking tube, the electric heating piece comprises a high-frequency induction heating coil wound on the periphery of the ammonia cracking tube, and the ammonia cracking tube is a metal component and serves as a magnetic core of the high-frequency induction heating coil.

The high-response combustion-inductance coupling ammonia modification system has the beneficial effects that:

the invention takes the combustion of fuel gas and the electric heating element as the coupling heat source of the ammonia cracking tube, and under the cold starting working condition, the electric heating element heats the ammonia cracking tube rapidly so as to meet the second-level high-response requirement of the ammonia modification system, meanwhile, the burner generates high-temperature combustion gas, and the ammonia cracking tube is gradually heated to gradually replace electric heating and be used as the heat source when the ammonia cracking tube works for a long time, thereby greatly saving electric energy.

According to the invention, a high-frequency alternating magnetic field is formed through the high-frequency induction heating coil, so that an induced electric vortex is generated by the ammonia cracking tube and the ammonia cracking catalyst in the ammonia cracking tube, and the ammonia cracking catalyst can be quickly heated to a set temperature value within a few seconds, thereby meeting the second-level high-response requirement of an ammonia modification system.

As a further improvement of the above technical solution, the high-response combustion-inductance coupling ammonia modification system is provided with a combustion wall pipe, an ammonia preheating wall pipe and a combustion gas wall pipe which are sequentially sleeved at intervals from inside to outside, the combustion chamber is formed in the combustion wall pipe, the burner is arranged in one end of the combustion wall pipe, the other end of the combustion wall pipe is provided with an exhaust port, one end of the combustion gas wall pipe, which is close to the exhaust port, is provided with a first sealing plate, and a second sealing plate is arranged between the ammonia preheating wall pipe and one end of the combustion wall pipe, which is close to the exhaust port;

the combustion gas preheating device comprises a combustion gas wall pipe, an ammonia preheating wall pipe, an ammonia returning guide wall pipe and a combustion gas returning flow port.

According to the scheme, the annular ammonia preheating flow passage is internally provided with the ammonia foldback guide wall pipe, the ammonia preheating flow passage is divided into the annular first preheating section and the annular second preheating section, so that a preheating flow path of ammonia to be cracked is U-shaped, the ammonia to be cracked flows along the first preheating section, the ammonia foldback flow port and the second preheating section in sequence, high-temperature combustion gas is generated through combustion of a combustor in the combustion wall pipe, during combustion, firstly, combustion heat in the combustion chamber heats the ammonia in the first preheating section through the wall body of the combustion wall pipe, then the high-temperature combustion gas is generated through combustion and flows to the high-temperature combustion gas flow passage along the exhaust port and the combustion gas foldback backflow port in sequence, the ammonia in the second preheating section is heated through the ammonia preheating wall pipe by the high-temperature combustion gas in the high-temperature combustion gas flow passage at this moment, the preheated ammonia enters the ammonia cracking pipe by the high-temperature combustion gas in the high-temperature combustion gas flow passage at this moment, the high-temperature combustion gas also heats the ammonia cracking pipe, and thus the combustion energy realizes a three-stage heating effect on the ammonia;

And the flow direction of the gas in the ammonia cracking tube is opposite to that of the high-temperature combustion gas in the high-temperature combustion gas flow passage, so that the efficient and uniform heat exchange in the ammonia cracking tube is realized.

The ammonia preheating flow passage and the high-temperature combustion gas flow passage in the scheme are annular and can improve the heat exchange area and the gas flow area.

As a further improvement of the technical scheme, a plurality of ammonia cracking tubes are arranged in the high-temperature combustion gas flow passage at annular intervals; multiple ammonia cracking tubes can increase the amount of ammonia gas reacted.

The outer peripheral wall of the ammonia preheating wall pipe is provided with a plurality of annular first combustion gas guide plates at intervals along the axial direction, the inner peripheral wall of the combustion gas wall pipe is provided with a plurality of annular second combustion gas guide plates at intervals along the axial direction, and the plurality of first combustion gas guide plates and the plurality of second combustion gas guide plates are arranged at intervals along the axial direction in a staggered manner so as to form a snake-shaped high-temperature combustion gas flow passage;

The heat exchange time of high-temperature combustion gas and the ammonia cracking tube can be remarkably prolonged by arranging the plurality of first combustion gas guide plates and the plurality of second combustion gas guide plates, and meanwhile, the high-temperature combustion gas can fully contact the surface of the ammonia cracking tube, so that the utilization efficiency of combustion energy is further increased.

The first combustion gas guide plate and the second combustion gas guide plate are respectively provided with a plurality of holes, and the ammonia cracking tube is sequentially inserted into the holes along the axial direction.

As a further improvement of the technical scheme, the ammonia preheating wall pipe is provided with an annular ammonia distribution cavity, the outlet end of the second preheating section is communicated with the inlet ends of the ammonia cracking pipes through the ammonia distribution cavity, and an expansion joint is connected between the ammonia cracking pipes and the ammonia distribution cavity.

The preheated ammonia gas enters an ammonia gas distribution cavity, and the ammonia gas is uniformly distributed into a plurality of ammonia cracking tubes through the ammonia gas distribution cavity. The expansion joint can effectively slow down the thermal stress generated in the second-level heating process of the electric heating element for the ammonia cracking tube.

As a further improvement of the technical scheme, one end of the combustion gas wall pipe, which is close to the exhaust port, is connected with a gas collecting device, the gas collecting device comprises a conical gas collecting sleeve, one end of the gas collecting sleeve is connected with the combustion gas wall pipe, and the gas collecting sleeve and the first sealing plate form a gas collecting cavity communicated with the outlet end of the ammonia cracking pipe.

The pyrolysis gas from the outlet ends of the ammonia pyrolysis tubes is collected in the gas collecting cavity, and then is collected through the gas collecting sleeve, so that the hydrogen-nitrogen mixed gas outlet pipelines of the parallel ammonia pyrolysis units can be integrated, and the integration of the system is improved.

As a further improvement of the technical scheme, an annular ammonia gas inlet cavity is arranged between one end, far away from the exhaust port, of the ammonia gas preheating wall pipe and one end, far away from the exhaust port, of the combustion wall pipe, the ammonia gas inlet cavity is communicated with the inlet end of the first preheating section, an ammonia gas inlet is arranged on the periphery of the ammonia gas inlet cavity, and the ammonia gas inlet cavity is connected with the ammonia gas inlet cavity in a circumferential tangential direction.

The ammonia air inlet that this scheme adopted is connected with annular ammonia gas inlet chamber with circumference tangential direction, makes treat schizolysis ammonia rotatory back in ammonia gas inlet chamber, evenly gets into first preheating section, promotes ammonia preheating degree of consistency and combustion energy utilization efficiency.

As a further improvement of the technical scheme, a plurality of heat transfer fins extending along the axial direction are arranged in each of the first preheating section and the second preheating section, and the plurality of heat transfer fins are radially and annularly arranged at intervals.

The heat transfer fin that this scheme set up can increase the heat transfer area of ammonia in first preheating section and second preheating section to show improvement heat exchange efficiency, increase the preheating effect of waiting schizolysis ammonia.

As a further improvement of the technical scheme, the burner comprises a fuel nozzle, a plurality of air spray holes which are annularly and uniformly distributed at the periphery side of the fuel nozzle, a high-energy ignition electrode which is arranged at the side of the fuel nozzle, a fuel gas conveying pipeline which is connected with the fuel nozzle, and an air conveying pipeline which is communicated with the plurality of air spray holes, wherein the fuel gas conveying pipeline is coaxially sleeved in the air conveying pipeline, and an annular air homogenizing grating plate is arranged in the air conveying pipeline.

During combustion, fuel gas is injected into the combustion chamber through a fuel gas conveying pipeline and a fuel nozzle, wherein the fuel nozzle is provided with a spiral fuel gas spray hole, so that the fuel gas generates rotational flow to enter the combustion chamber, meanwhile, air is injected into the combustion chamber through an air conveying pipeline through an air grid plate after being uniformly distributed through the air grid plate and is mixed with the fuel gas through the air spray hole, and a high-energy ignition electrode ignites the fuel gas and combusts to generate high-temperature combustion gas;

Further, the combustion chamber on the opposite side of the burner is provided with the backflow baffle, the exhaust port is arranged at the center of the backflow baffle, the caliber of the exhaust port is smaller than the inner diameter of the combustion chamber, high-temperature combustion gas is caused to flow back, and the combustion efficiency in the combustion chamber is further improved.

In addition, the invention also provides a control method suitable for the high-response combustion-inductance coupling ammonia modification system, which comprises the following steps:

When the cold starting working condition is adopted, the burner is started and generates high-temperature combustion gas, the electric heating element is started, the ammonia cracking catalyst is quickly heated to a first set temperature value, then ammonia gas is introduced into the ammonia preheating flow passage, the combustion chamber heats the ammonia gas flowing through the first preheating section, the high-temperature combustion gas flow passage simultaneously heats the ammonia cracking tube and the ammonia gas flowing through the second preheating section, after the ammonia gas is preheated to the set temperature value, the ammonia gas flows into the ammonia cracking tube and contacts the heated ammonia cracking catalyst, an ammonia cracking reaction occurs, and the operation power of the electric heating element is gradually reduced until the ammonia cracking tube is completely closed along with gradual appearance of the heating effect of the high-temperature combustion gas generated by the burner on the ammonia cracking tube;

In normal operation, according to the different hydrogen demand, the specific method is as follows:

under the working condition of higher hydrogen demand:

Increasing the combustion working condition of a combustor to generate high-flow and high-temperature combustion gas, increasing the reaction temperature in the ammonia cracking tube to a second set temperature value, and simultaneously increasing the flow of ammonia to be cracked entering an ammonia preheating flow passage, so that the ammonia cracking reaction in the ammonia cracking tube is carried out at a higher airspeed;

under the working condition of lower hydrogen demand:

the combustion working condition of the burner is reduced to generate combustion gas with lower flow and lower temperature, the reaction temperature in the ammonia cracking tube is reduced to a third set temperature value, and simultaneously the flow of ammonia to be cracked entering the ammonia preheating flow passage is reduced, so that the ammonia cracking reaction in the ammonia cracking tube is carried out at a lower airspeed.

The control method of the invention meets the second-level rapid cold start requirement, long-term operation requirement, high ammonia cracking rate and high energy utilization efficiency requirement of the high-response combustion-inductance coupling ammonia modification system.

Drawings

The invention is further described below with reference to the drawings and examples;

FIG. 1 is a schematic illustration of an internal high temperature combustion gas flow path of an embodiment of a high response combustion-inductively coupled ammonia upgrading system provided by the present invention;

FIG. 2 is a schematic diagram of a preheating, cracking flow path and a cracking gas flow path of ammonia gas for cracking in an embodiment of a high-response combustion-inductively coupled ammonia upgrading system according to the present invention;

FIG. 3 is an axial cross-sectional view of one embodiment of a high response combustion-inductively coupled ammonia upgrading system provided by the present invention;

Fig. 4 is a schematic structural diagram of an embodiment of the present invention.

Detailed Description

Reference will now be made in detail to the present embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein the accompanying drawings are used to supplement the description of the written description so that one can intuitively and intuitively understand each technical feature and overall technical scheme of the present invention, but not to limit the scope of the present invention.

In the description of the present invention, it should be understood that references to orientation descriptions such as upper, lower, front, rear, left, right, etc. are based on the orientation or positional relationship shown in the drawings, are merely for convenience of description of the present invention and to simplify the description, and do not indicate or imply that the apparatus or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus should not be construed as limiting the present invention.

In the description of the present invention, if there is a word description such as "a plurality" or the like, the meaning of a plurality is one or more, and the meaning of a plurality is two or more, and greater than, less than, exceeding, etc. are understood to not include the present number, and above, below, within, etc. are understood to include the present number.

In the description of the present invention, unless explicitly defined otherwise, terms such as arrangement, installation, connection, etc. should be construed broadly and the specific meaning of the terms in the present invention can be reasonably determined by a person skilled in the art in combination with the specific contents of the technical scheme.

Referring to fig. 1-4, the high response combustion-inductance coupling ammonia upgrading system of the present invention makes the following examples:

The high-response combustion-inductance coupling ammonia modifying system of the embodiment comprises: the combustion chamber 100, the high temperature combustion gas flow passage 300, the ammonia preheating flow passage 400, the ammonia cracking tube 500 and the electric heating member, wherein the high temperature combustion gas flow passage 300 is arranged at the outer circumference side of the combustion chamber 100, the inlet end of the high temperature combustion gas flow passage 300 is communicated with the combustion chamber 100, the ammonia preheating flow passage 400 is arranged between the high temperature combustion gas flow passage 300 and the combustion chamber 100, and the burner 200 is arranged in the combustion chamber 100.

The ammonia preheating flow path 400 in this embodiment includes a first preheating section 410 and a second preheating section 420 that are sequentially connected, where the first preheating section 410 extends along the combustion chamber 100 and is tightly attached to an outer wall of the combustion chamber 100, the first preheating section 410 can implement heat exchange with the combustion chamber 100, the second preheating section 420 extends along the high-temperature combustion gas flow path 300 and is tightly attached to a side wall of the high-temperature combustion gas flow path 300, the second preheating section 420 and the high-temperature combustion gas flow path 300 can implement heat exchange, an ammonia cracking tube 500 is disposed in the high-temperature combustion gas flow path 300, an inlet end of the ammonia cracking tube 500 is connected to an outlet end of the second preheating section 420, and an ammonia cracking catalyst is disposed inside the ammonia cracking tube 500.

The electric heating element is used for heating the ammonia cracking tube 500, under the cold starting working condition, the electric heating element is used for rapidly heating the ammonia cracking tube 500 to meet the second-level high-response requirement of an ammonia modification system, meanwhile, the combustor 200 is used for generating high-temperature combustion gas, the ammonia cracking tube 500 is gradually heated to gradually replace electric heating and is used as a heat source when the ammonia cracking tube 500 works for a long time, so that electric energy is greatly saved.

As shown in fig. 1 to 3, the high-response combustion-inductance coupling ammonia modifying system of the present embodiment is provided with a combustion wall pipe 110, an ammonia preheating wall pipe 430 and a combustion gas wall pipe 310, wherein the combustion wall pipe 110, the ammonia preheating wall pipe 430 and the combustion gas wall pipe 310 are coaxially sleeved at intervals from inside to outside, the combustion wall pipe 110, the ammonia preheating wall pipe 430 and the combustion gas wall pipe 310 are all arranged to extend left and right, the combustion chamber 100 is formed inside the combustion wall pipe 110, and the combustion chamber 100 is arranged to extend left and right.

The burner 200 is disposed in the right end of the combustion chamber 100, the burner 200 performs injection combustion towards the left, the left end of the combustion wall tube 110 is provided with an exhaust port 111 communicated with the combustion chamber 100, the left end of the combustion wall tube 310 extends to the left, the left end of the combustion wall tube 310 is plugged with a first sealing plate 311, and an annular second sealing plate 112 is plugged between the ammonia preheating wall tube 430 and the left end of the combustion wall tube 110, so that an annular high-temperature combustion gas flow channel 300 is formed between the outer peripheral wall of the ammonia preheating wall tube 430 and the inner peripheral wall of the combustion wall tube 310, and the outer peripheral wall of the combustion wall tube 110 and the inner peripheral wall of the ammonia preheating wall tube 430 form an annular ammonia preheating flow channel 400.

In this embodiment, an ammonia gas turning-back flow guiding wall pipe 440 is sleeved in the ammonia gas preheating flow channel 400, an annular first preheating section 410 is formed between the inner peripheral wall of the ammonia gas turning-back flow guiding wall pipe 440 and the outer peripheral wall of the combustion wall pipe 110, an annular second preheating section 420 is formed between the outer peripheral wall of the ammonia gas turning-back flow guiding wall pipe 440 and the inner peripheral wall of the ammonia gas preheating wall pipe 430, an annular ammonia gas turning-back flow port 450 is formed between the left end of the ammonia gas turning-back flow guiding wall pipe 440 and the second sealing plate 112, and the first preheating section 410 is communicated with the second preheating section 420 through the ammonia gas turning-back flow port 450 to form the ammonia gas preheating flow channel 400.

And a combustion gas return port 320 is formed between the first sealing plate 311 and the second sealing plate 112, and the exhaust port 111 communicates with the high-temperature combustion gas flow path 300 through the combustion gas return port 320.

It is understood that the first preheating section 410 surrounds the outer circumference of the combustion chamber 100, the second preheating section 420 surrounds the outer circumference of the first preheating section 410, and the high temperature combustion gas flow path 300 surrounds the outer circumference of the second preheating section 420.

The gas flow direction of the first preheating stage 410 is from right to left, the gas flow direction of the second preheating stage 420 is from left to right, the gas flow direction of the high temperature combustion gas flow path 300 is from left to right, and the gas flow direction of the combustion chamber 100 is from right to left.

The ammonia cracking tubes 500 of this embodiment are provided with a plurality of ammonia cracking tubes 500, the plurality of ammonia cracking tubes 500 are arranged in the high-temperature combustion gas flow channel 300 at annular intervals, the ammonia cracking tubes 500 are arranged in a left-right extending manner, the gas flow direction of the ammonia cracking tubes 500 is from right to left, the ammonia cracking tubes 500 and the high-temperature combustion gas flow channel 300 have a heat exchange relationship, and the flow direction of ammonia in the ammonia cracking tubes 500 is opposite to the flow direction of high-temperature combustion gas in the high-temperature combustion gas flow channel 300.

According to the invention, the annular ammonia preheating flow passage 400 is internally provided with the ammonia foldback flow guide wall pipe 440, the ammonia foldback flow guide wall pipe 440 divides the ammonia preheating flow passage 400 into the annular first preheating section 410 and the annular second preheating section 420, so that the ammonia to be cracked flows along the first preheating section 410, the ammonia foldback flow port 450 and the second preheating section 420 in sequence, high-temperature combustion gas is generated by combustion in the combustor 200 in the combustion wall pipe 110, during combustion, firstly, combustion heat in the combustion chamber 100 heats the ammonia in the first preheating section 410 through the wall body of the combustion wall pipe 110, then the high-temperature combustion gas flows to the high-temperature combustion gas flow passage 300 along the exhaust port 111 and the combustion gas foldback flow port 320 in sequence, at this moment, the high-temperature combustion gas in the high-temperature combustion gas flow passage 300 heats the ammonia in the second preheating section 420 through the ammonia preheating wall pipe 430, the preheated ammonia enters the ammonia cracking pipe 500, and the high-temperature combustion gas in the high-temperature combustion gas flow passage 300 also heats the ammonia cracking pipe 500, so that the high-temperature combustion gas realizes the high-temperature heat exchange effect of the ammonia gas.

The gas in the ammonia cracking tube 500 flows in the opposite direction to the high temperature combustion gas in the high temperature combustion gas flow path 300, which helps to achieve efficient and uniform heat exchange in the ammonia cracking tube 500.

The ammonia preheating flow passage 400 and the high-temperature combustion gas flow passage 300 are both annular in shape, and can increase the heat exchange area and the gas flow area.

The electric heating member of the present embodiment includes a high-frequency induction heating coil 700 wound around the periphery of an ammonia cracking tube 500, and the ammonia cracking tube 500 is a metal member as a magnetic core of the high-frequency induction heating coil 700.

According to the invention, a high-frequency alternating magnetic field is formed through the high-frequency induction heating coil 700, so that an induced electric vortex is generated by the ammonia cracking tube 500 and the ammonia cracking catalyst in the ammonia cracking tube, and the ammonia cracking catalyst can be quickly heated to a set temperature value within a few seconds, thereby achieving the second-level response requirement of the high-response combustion-inductance coupling ammonia modifying system.

The ammonia cracking catalyst of the embodiment is loaded with metal foam nickel, and the lead wire of the high-frequency induction heating coil 700 is made of copper, and is covered with a ceramic insulating material, so that the metal foam nickel can be used as a carrier of the ammonia cracking catalyst to effectively generate induced eddy current under a high-frequency alternating magnetic field, thereby rapidly heating the ammonia cracking catalyst; the ceramic insulating material coated outside the wire of the high-frequency induction heating coil 700 can effectively protect the copper coil from corrosion of residual ammonia in the combustion gas.

Further, an annular ammonia distribution chamber 432 is disposed at the outer side of the ammonia preheating wall tube 430 in this embodiment, the outlet end of the second preheating section 420 is connected to the inlet ends of the ammonia cracking tubes 500 through the ammonia distribution chamber 432, the preheated ammonia enters the ammonia distribution chamber 432, and the ammonia is uniformly distributed into the ammonia cracking tubes 500 through the ammonia distribution chamber 432.

An expansion joint 510 is connected between the inlet end of the ammonia cracking tube 500 and the ammonia gas distribution chamber 432, and the expansion joint 510 can effectively slow down the thermal stress generated in the heating process of the high-frequency induction heating coil 700 for 500 seconds.

In this embodiment, an annular ammonia gas inlet chamber 433 is disposed between the ammonia preheating wall tube 430 and the end of the combustion wall tube 110 far away from the exhaust port 111, the ammonia gas inlet chamber 433 is communicated with the inlet end of the first preheating section 410, an ammonia gas inlet 434 is disposed at the periphery of the ammonia gas inlet chamber 433, and the ammonia gas inlet 434 is connected with the ammonia gas inlet chamber 433 in a circumferential tangential direction.

The ammonia gas inlet 434 is connected with the annular ammonia gas inlet cavity 433 in a circumferential tangential direction, so that the ammonia gas to be cracked uniformly enters the first preheating section 410 after rotating in the ammonia gas inlet cavity 433, and the ammonia gas preheating uniformity and the combustion energy utilization efficiency are improved.

The left end of the combustion gas wall pipe 310 of the present embodiment is connected with a gas collecting device 600, the gas collecting device 600 includes a conical gas collecting sleeve 610, the right end of the gas collecting sleeve 610 is connected with the left end of the combustion gas wall pipe 310, a gas collecting cavity 620 communicated with the outlet end of the ammonia cracking pipe 500 is formed between the gas collecting sleeve 610 and the first sealing plate 311, and the outlet end of the ammonia cracking pipe 500 passes through the hole on the first sealing plate 311 and then is communicated with the gas collecting cavity 620.

The cracked gas from the outlet ends of the ammonia cracking tubes 500 is collected in the gas collecting chamber 620, and then collected by the gas collecting sleeve 610, so that the hydrogen-nitrogen mixed gas outlet pipelines of the parallel ammonia cracking units can be integrated, and the integration of the system is improved.

The ammonia gas to be cracked enters from the ammonia gas inlet 434, flows into the first preheating section 410 through the ammonia gas inlet 433, is preheated by the first preheating section 410 and the second preheating section 420 in sequence, enters into the ammonia gas distribution chamber 432, and then uniformly distributes the ammonia gas into the plurality of ammonia cracking tubes 500 through the ammonia gas distribution chamber 432 for cracking catalysis, and then the cracked gas is collected in the gas collection chamber 620 and then is collected through the gas collection sleeve 610, as shown in fig. 2.

Further, in this embodiment, a plurality of heat transfer fins 460 extending along the axial direction are disposed in the first preheating section 410 and the second preheating section 420, the plurality of heat transfer fins 460 are disposed in radial annular space, the heat transfer fins 460 extend left and right, and the heat transfer fins 460 disposed in this embodiment can increase the heat exchange area of the ammonia gas in the first preheating section 410 and the second preheating section 420, thereby remarkably improving the heat exchange efficiency and increasing the preheating effect of the ammonia gas to be cracked.

And the heat transfer fins 460 also have the effect of fixing the combustion wall pipe 110, the ammonia gas turn-around guide wall pipe 440, and the ammonia gas preheating wall pipe 430.

The radial distance between the ammonia gas turning-back guide wall pipe 440 and the combustion wall pipe 110 in this embodiment is smaller than the radial distance between the ammonia gas preheating wall pipe 430 and the ammonia gas turning-back guide wall pipe 440, it can be understood that the flow cross-sectional area of the first preheating section 410 is smaller than the flow cross-sectional area of the second preheating section 420, when the ammonia gas enters the first preheating section 410, the ammonia gas is preheated in the initial stage, the volume expansion of the gas is also smaller due to the smaller temperature rise, the smaller flow cross-sectional area can ensure that the gas smoothly flows, and the ammonia gas in the second preheating section 420 is sufficiently heated to a higher temperature, the volume is several times that before preheating, so that increasing the flow cross-sectional area of the second preheating section 420 can effectively reduce the flow backpressure of the ammonia gas.

Further, the outer peripheral wall of the ammonia preheating wall tube 430 is provided with a plurality of annular first combustion gas guide plates 431 along the axial direction at intervals, the inner peripheral wall of the combustion gas wall tube 310 is provided with a plurality of annular second combustion gas guide plates 312 along the axial direction at intervals, the plurality of first combustion gas guide plates 431 and the plurality of second combustion gas guide plates 312 are arranged along the axial direction at intervals in a staggered manner so as to form a "snake" type high-temperature combustion gas flow channel 300, the plurality of first combustion gas guide plates 431 and the plurality of second combustion gas guide plates 312 can obviously prolong the heat exchange time of the high-temperature combustion gas and the ammonia cracking tube 500, and meanwhile, the high-temperature combustion gas fully contacts the surface of the ammonia cracking tube 500, so that the combustion energy utilization efficiency is further increased.

And the first combustion gas guide plate 431 and the second combustion gas guide plate 312 are respectively provided with a plurality of holes, and the ammonia cracking tubes 500 are sequentially inserted into the holes along the axial direction, so that the ammonia cracking tubes 500 are fixedly installed.

The burner 200 of the present embodiment includes a fuel nozzle 210, a plurality of air injection holes 220 annularly and uniformly distributed at the periphery side of the fuel nozzle 210, a high-energy ignition electrode 230 disposed at the side of the fuel nozzle 210, a fuel gas delivery pipeline 240 connected with the fuel nozzle 210, and an air delivery pipeline 250 communicated with the plurality of air injection holes 220, wherein the fuel gas delivery pipeline 240 is coaxially sleeved in the air delivery pipeline 250, the fuel gas delivery pipeline 240 and the air delivery pipeline 250 are all extended left and right, and an annular air-homogenizing grid plate 260 is disposed in the air delivery pipeline 250.

During combustion, fuel gas is injected into the combustion chamber 100 through the fuel gas delivery pipeline 240 and the fuel nozzle 210, wherein the fuel nozzle 210 is provided with spiral fuel gas injection holes, so that the fuel gas generates rotational flow to enter the combustion chamber 100, meanwhile, air is evenly distributed through the air delivery pipeline 250 and the air grid plate 260, then is injected into the combustion chamber 100 through the air injection holes 220 and mixed with the fuel gas, and the high-energy ignition electrode 230 ignites the fuel gas and combusts to generate high-temperature combustion gas.

Further, a backflow baffle is disposed in the combustion chamber 100 opposite to the burner 200, the exhaust port 111 is disposed at the center of the backflow baffle, and the caliber of the exhaust port 111 is smaller than the inner diameter of the combustion chamber 100, so that the high-temperature combustion gas is backflow, and the combustion efficiency in the combustion chamber 100 is further improved.

As shown in fig. 1, the fuel gas in the present embodiment is swirled through the fuel gas delivery line 240 via the fuel nozzle 210 and enters the combustion chamber 100, and meanwhile, the air delivery line 250 is uniformly air-distributed via the air grid plate 260, then is injected into the combustion chamber 100 via the air injection holes 220 and mixed with the fuel gas, the high-energy ignition electrode 230 ignites the fuel gas and combusts to generate high-temperature combustion gas, and the high-temperature combustion gas sequentially flows to the high-temperature combustion gas flow channel 300 along the exhaust port 111 and the combustion gas return flow port 320, and is discharged after heat exchange.

The invention also provides a control method suitable for the high-response combustion-inductance coupling ammonia modification system, which comprises the following steps:

in the cold start working condition, the specific electric control method is as follows:

Starting the burner 200 and generating high-temperature combustion gas to gradually heat the ammonia cracking tube 500, and starting the high-frequency induction heating coil 700 to enable the induction coil to generate high-frequency alternating current, wherein a high-frequency alternating magnetic field is formed inside the induction coil, so that the ammonia cracking tube 500 and the internal metal foam nickel catalyst load generate induced electric vortex, and the ammonia cracking catalyst is rapidly heated to a first set temperature value, such as 500 ℃ in a few seconds;

Subsequently, ammonia gas is introduced into the ammonia gas preheating flow passage 400, the combustion chamber 100 heats the ammonia gas flowing through the first preheating section 410, and the high-temperature combustion gas flow passage 300 simultaneously heats the ammonia gas flowing through the second preheating section 420, so that the ammonia gas flows into the ammonia cracking tube 500 and contacts the heated ammonia cracking catalyst after being preheated to a set temperature value such as 550 ℃ in the ammonia gas preheating flow passage 400, ammonia cracking reaction occurs, ammonia cracking gas composed of hydrogen gas and nitrogen gas is generated, and finally the ammonia cracking gas of each ammonia cracking tube 500 is collected in the gas collecting device 600 and discharged from the gas collecting sleeve 610;

Along with the gradual appearance of the heating effect of the high-temperature combustion gas generated by the burner 200 on the ammonia cracking tube 500, the high-frequency induction heating coil 700 gradually reduces the operation power until the high-frequency induction heating coil is completely closed, and at the moment, the heat required by the ammonia cracking tube 500 is completely derived from the high-temperature combustion gas;

under normal operation conditions, the specific electric control method is as follows according to the difference of the hydrogen demand:

under the working condition of higher hydrogen demand:

Increasing the flow rate of ammonia gas and air entering the combustion chamber 100, adjusting the flow rate to be stoichiometric ratio, generating high-flow rate and high-temperature combustion gas, increasing the reaction temperature in the ammonia cracking tube 500 to a second set temperature value, such as 600 ℃, and simultaneously increasing the flow rate of ammonia gas to be cracked entering the ammonia preheating flow passage 400, so that the ammonia cracking reaction in the ammonia cracking tube 500 is performed at a higher airspeed, and generating ammonia cracking gas composed of hydrogen gas and nitrogen gas at a higher flow rate;

under the working condition of lower hydrogen demand:

The flow rate of ammonia gas and air entering the combustion chamber 100 is reduced, the equivalence ratio is adjusted to generate combustion gas with lower flow rate and lower temperature, the reaction temperature in the ammonia cracking tube 500 is reduced to a third set temperature value, such as 400 ℃, and simultaneously the flow rate of ammonia gas to be cracked entering the ammonia preheating flow passage 400 is reduced, so that the ammonia cracking reaction in the ammonia cracking tube 500 is performed at a lower airspeed to generate ammonia cracking gas composed of hydrogen gas and nitrogen gas with lower flow rate.

The fuel gas of this embodiment is ammonia, and other fuel gases may be used in other embodiments.

In summary, the combustion of ammonia and the high-frequency induction heating coil 700 are the coupling heat sources of the ammonia cracking tube 500, and under the cold start working condition, the high-frequency induction heating coil 700 can rapidly heat the ammonia cracking tube, so as to meet the second-level high response requirement of the high-response combustion-inductance coupling ammonia modifying system; meanwhile, the high-temperature combustion gas generated by the burner 200 gradually replaces high-frequency induction heating and is used as a heat source when the ammonia cracking tube 500 works for a long time, so that electric energy is greatly saved;

The combustion energy is also used for heating the ammonia preheating runner 400, so that not only is the ammonia fuel utilization efficiency improved, but also the reaction temperature of the ammonia cracking catalyst bed is uniform; the ammonia gas turn-back guide wall pipe 440 can enable the preheated ammonia gas flow path to be U-shaped, and the ammonia gas preheating flow channel 400 adopts the heat transfer fins 460, so that the heat exchange efficiency is remarkably improved, the flow cross section of the U-shaped ammonia gas preheating flow channel 400 is increased along with the increase of the ammonia gas temperature, and the gas flow back pressure can be remarkably reduced;

The flow direction of the ammonia gas in the ammonia cracking tube 500 is opposite to the flow direction of the high-temperature combustion gas in the high-temperature combustion gas flow channel 300, so that the uniformity of the reaction temperature is further improved;

the fuel of the burner 200 is ammonia, and a small part of ammonia is combusted to crack a large amount of ammonia, so that the complexity of fuel storage can be remarkably reduced;

The plurality of ammonia cracking tubes 500 obviously increases the heat exchange area with the high-temperature combustion gas flow channel 300, the first combustion gas flow guide plate 431 and the second combustion gas flow guide plate 312 enable the high-temperature combustion gas flow channel 300 to be in a snake shape, the heat exchange time between the high-temperature combustion gas and the ammonia cracking tubes 500 is obviously prolonged, and the periphery of the combustion gas wall tube 310 is wrapped with heat insulation materials, so that combustion energy dissipation is effectively reduced.

The expansion joint 510 at the joint of the ammonia cracking tube 500 and the ammonia gas distributing chamber 432 can effectively relieve the thermal stress generated in the 500 second-level heating process of the high-frequency induction heating coil 700 for the ammonia cracking tube.

The ammonia air inlet 434 is connected with the annular ammonia air inlet cavity 433 in the circumferential tangential direction, so that the ammonia preheating uniformity and the ammonia combustion energy utilization efficiency are improved; the gas collecting device 600 can integrate the hydrogen-nitrogen mixed gas outlet pipelines of the parallel ammonia cracking tubes 500, thereby improving the integration of the system.

While the preferred embodiment of the present application has been described in detail, the application is not limited to the embodiments, and various equivalent modifications and substitutions can be made by those skilled in the art without departing from the spirit of the application, and these modifications and substitutions are intended to be included in the scope of the present application as defined in the appended claims.

Claims (9)

1. A high response combustion-inductance coupling ammonia upgrading system, comprising:

The combustion chamber is provided with a burner;

the high-temperature combustion gas flow passage is positioned on the outer peripheral side of the combustion chamber, and the air inlet end of the high-temperature combustion gas flow passage is communicated with the combustion chamber;

The ammonia preheating flow passage is arranged between the high-temperature combustion gas flow passage and the combustion chamber and comprises a first preheating section and a second preheating section which are sequentially communicated, and the first preheating section extends along the combustion chamber and is clung to the combustion chamber; the second preheating section extends along the high-temperature combustion gas flow passage and is clung to the high-temperature combustion gas flow passage;

the ammonia cracking tube is provided with at least one ammonia cracking tube, the ammonia cracking tube is arranged in the high-temperature combustion gas flow channel, the inlet end of the ammonia cracking tube is communicated with the outlet end of the second preheating section, and an ammonia cracking catalyst is filled in the ammonia cracking tube;

The electric heating piece is used for heating the ammonia cracking tube and comprises a high-frequency induction heating coil wound on the periphery of the ammonia cracking tube, and the ammonia cracking tube is a metal component and serves as a magnetic core of the high-frequency induction heating coil.

2. The high response combustion-inductive coupling ammonia upgrading system of claim 1, wherein:

The high-response combustion-inductance coupling ammonia modification system is provided with a combustion wall pipe, an ammonia preheating wall pipe and a combustion gas wall pipe which are sequentially sleeved at intervals from inside to outside, the combustion chamber is formed in the combustion wall pipe, the combustor is arranged in one end of the combustion wall pipe, the other end of the combustion wall pipe is provided with an exhaust port, one end of the combustion gas wall pipe, which is close to the exhaust port, is provided with a first sealing plate, and a second sealing plate is arranged between the ammonia preheating wall pipe and one end of the combustion wall pipe, which is close to the exhaust port;

the combustion gas preheating device comprises a combustion gas wall pipe, an ammonia preheating wall pipe, an ammonia returning guide wall pipe and a combustion gas returning flow port.

3. The high response combustion-inductive coupling ammonia upgrading system of claim 2, wherein:

The ammonia cracking tubes are annularly arranged on the high-temperature combustion gas flow passage at intervals;

The outer peripheral wall of the ammonia preheating wall pipe is provided with a plurality of annular first combustion gas guide plates at intervals along the axial direction, the inner peripheral wall of the combustion gas wall pipe is provided with a plurality of annular second combustion gas guide plates at intervals along the axial direction, and the plurality of first combustion gas guide plates and the plurality of second combustion gas guide plates are arranged at intervals along the axial direction in a staggered manner so as to form a snake-shaped high-temperature combustion gas flow passage;

The first combustion gas guide plate and the second combustion gas guide plate are respectively provided with a plurality of holes, and the ammonia cracking tube is sequentially inserted into the holes along the axial direction.

4. The high-response combustion-inductively coupled ammonia upgrading system of claim 3, wherein:

The ammonia preheating wall pipe is provided with an annular ammonia distribution cavity, the outlet end of the second preheating section is communicated with the inlet ends of the ammonia cracking pipes through the ammonia distribution cavity, and an expansion joint is connected between the ammonia cracking pipes and the ammonia distribution cavity.

5. The high response combustion-inductive coupling ammonia upgrading system of claim 2, wherein:

the gas collecting device comprises a conical gas collecting sleeve, one end of the gas collecting sleeve is connected with the gas wall pipe, and the gas collecting sleeve and the first sealing plate form a gas collecting cavity communicated with the outlet end of the ammonia cracking pipe.

6. The high response combustion-inductive coupling ammonia upgrading system of claim 2, wherein:

an annular ammonia gas inlet cavity is arranged between one end, far away from the exhaust port, of the ammonia gas preheating wall pipe and one end, far away from the exhaust port, of the combustion wall pipe, the ammonia gas inlet cavity is communicated with the inlet end of the first preheating section, an ammonia gas inlet is arranged on the periphery of the ammonia gas inlet cavity, and the ammonia gas inlet cavity is connected with the ammonia gas inlet cavity in a circumferential tangential direction.

7. The high response combustion-inductive coupling ammonia upgrading system of claim 2, wherein:

the first preheating section and the second preheating section are internally provided with a plurality of heat transfer fins extending along the axial direction, and the plurality of heat transfer fins are radially and annularly arranged at intervals.

8. The high response combustion-inductive coupling ammonia upgrading system of claim 2, wherein:

The burner comprises a fuel nozzle, a plurality of air spray holes which are uniformly distributed on the periphery side of the fuel nozzle in an annular mode, a high-energy ignition electrode which is arranged on the side of the fuel nozzle, a fuel gas conveying pipeline which is connected with the fuel nozzle, and an air conveying pipeline which is communicated with the plurality of air spray holes, wherein the fuel gas conveying pipeline is coaxially sleeved in the air conveying pipeline, and an annular air homogenizing grating plate is arranged in the air conveying pipeline.

9. A control method suitable for use in the high-response combustion-inductance coupling ammonia reforming system according to any one of claims 1 to 8, comprising:

When the cold starting working condition is adopted, the burner is started and generates high-temperature combustion gas, the electric heating element is started, the ammonia cracking catalyst is quickly heated to a first set temperature value, then ammonia gas is introduced into the ammonia preheating flow passage, the combustion chamber heats the ammonia gas flowing through the first preheating section, the high-temperature combustion gas flow passage simultaneously heats the ammonia cracking tube and the ammonia gas flowing through the second preheating section, after the ammonia gas is preheated to the set temperature value, the ammonia gas flows into the ammonia cracking tube and contacts the heated ammonia cracking catalyst, an ammonia cracking reaction occurs, and the operation power of the electric heating element is gradually reduced until the ammonia cracking tube is completely closed along with gradual appearance of the heating effect of the high-temperature combustion gas generated by the burner on the ammonia cracking tube;

In normal operation, according to the different hydrogen demand, the specific method is as follows:

under the working condition of higher hydrogen demand:

Increasing the combustion working condition of a combustor to generate high-flow and high-temperature combustion gas, increasing the reaction temperature in the ammonia cracking tube to a second set temperature value, and simultaneously increasing the flow of ammonia to be cracked entering an ammonia preheating flow passage, so that the ammonia cracking reaction in the ammonia cracking tube is carried out at a higher airspeed;

under the working condition of lower hydrogen demand:

the combustion working condition of the burner is reduced to generate combustion gas with lower flow and lower temperature, the reaction temperature in the ammonia cracking tube is reduced to a third set temperature value, and simultaneously the flow of ammonia to be cracked entering the ammonia preheating flow passage is reduced, so that the ammonia cracking reaction in the ammonia cracking tube is carried out at a lower airspeed.