阅读说明：本技术 一种金属铝粉悬浮燃烧的试验系统及方法 (Test system and method for suspension combustion of metal aluminum powder ) 是由 向小凤 白文刚 张波 高炜 杨玉 于 2021-09-09 设计创作，主要内容包括：本发明一种金属铝粉悬浮燃烧的试验系统及方法,系统的悬浮燃烧装置包括燃烧筒,顶端设有出气口,底端为缩径结构并设进气口,中上部筒体外包裹设加热装置,中上部筒体内设加热丝网；悬浮气体供给装置包括压缩空气罐,其出口和进气口连接；金属铝粉悬浮装置包括铝粉腔室、腔室拉杆和若干半球面喷口；铝粉腔室横向设在燃烧筒的缩径结构的顶部,一端与燃烧筒内壁固定,另一端伸出燃烧筒外；铝粉腔室包括固定壳体和与固定壳体下端滑动连接的多孔材料底板；腔室拉杆一端与多孔材料底板连接,另一端伸出固定壳体外；若干半球面喷口设在固定壳体上方,其伞柄端与固定壳体连通,球面端设有若干出气小孔；测量记录装置用于采集金属铝粉悬浮燃烧图像。(The invention relates to a test system and a test method for suspension combustion of metal aluminum powder.A suspension combustion device of the system comprises a combustion cylinder, wherein the top end of the combustion cylinder is provided with an air outlet, the bottom end of the combustion cylinder is of a reducing structure and is provided with an air inlet, a heating device is wrapped outside a cylinder body at the middle upper part, and a heating wire net is arranged in the cylinder body at the middle upper part; the suspension gas supply device comprises a compressed air tank, and an outlet of the compressed air tank is connected with an air inlet; the metal aluminum powder suspension device comprises an aluminum powder chamber, a chamber pull rod and a plurality of hemispherical nozzles; the aluminum powder chamber is transversely arranged at the top of the reducing structure of the combustion cylinder, one end of the aluminum powder chamber is fixed with the inner wall of the combustion cylinder, and the other end of the aluminum powder chamber extends out of the combustion cylinder; the aluminum powder chamber comprises a fixed shell and a porous material bottom plate which is in sliding connection with the lower end of the fixed shell; one end of the cavity pull rod is connected with the porous material bottom plate, and the other end of the cavity pull rod extends out of the fixed shell; the plurality of hemispherical nozzles are arranged above the fixed shell, the umbrella handle end of the hemispherical nozzles is communicated with the fixed shell, and the spherical end is provided with a plurality of small air outlet holes; the measuring and recording device is used for collecting the suspension combustion image of the metal aluminum powder.)

1. A test system for suspension combustion of metal aluminum powder is characterized by comprising a suspension combustion device, a suspension gas supply device, a metal aluminum powder suspension device and a measurement recording device, wherein the suspension gas supply device, the metal aluminum powder suspension device and the measurement recording device are connected with the suspension combustion device;

the suspension combustion device comprises a combustion cylinder (7); the combustion cylinder (7) is in a vertical cylindrical shape, the top end of the combustion cylinder is provided with an air outlet (14), the bottom end of the combustion cylinder is in a reducing structure and is provided with an air inlet (20), the middle upper cylinder is wrapped with a heating device (11), and a heating wire mesh (12) is arranged in the middle upper cylinder;

the suspension gas supply device comprises a compressed air tank (1); the outlet of the compressed air tank (1) is connected with the air inlet (20);

the metal aluminum powder suspension device comprises an aluminum powder chamber (8), a chamber pull rod (9) and a plurality of hemispherical nozzles (10); the aluminum powder chamber (8) is transversely arranged at the top of the reducing structure of the combustion cylinder (7); one end of the aluminum powder chamber (8) is fixed with the inner wall of the combustion cylinder (7), and the other end of the aluminum powder chamber extends out of the combustion cylinder (7); the aluminum powder chamber (8) comprises a hollow cylindrical fixed shell with an opening at the lower end and a porous material bottom plate in sliding connection with the lower end of the fixed shell; one end of the chamber pull rod (9) is connected with the porous material bottom plate, and the other end of the chamber pull rod extends out of the fixed shell; the hemispherical nozzles (10) are arranged above the fixed shell of the aluminum powder chamber (8) in the direction facing the gas outlet (14), the hemispherical nozzles (10) are hollow and umbrella-shaped, the umbrella handle end is communicated with the fixed shell, and the spherical end is provided with a plurality of gas outlet small holes (23);

the measurement recording device is used for collecting the suspension combustion image of the metal aluminum powder.

2. The test system for suspension combustion of metal aluminum powder as claimed in claim 1, wherein the diameter range of the small gas outlet holes (23) is 1.0-1.5mm, and the small gas outlet holes are uniformly arranged along the spherical surface of the hemispherical nozzle (10).

3. The system for testing the suspension combustion of the aluminum powder in the metal, the aluminum powder and the heat insulation material according to claim 1, wherein the cross section of the heating wire mesh (12) is the same as that of the combustion cylinder (7), the heating wire mesh is perpendicular to the central axis of the combustion cylinder (7) and is arranged inside the combustion cylinder (7) above the aluminum powder chamber (8), and the wire mesh pull rod (13) extending out of the combustion cylinder (7) is arranged in the middle of the heating wire mesh.

4. The test system for suspension combustion of metal aluminum powder as claimed in claim 1, wherein the measurement recording device comprises a thermocouple (15), a temperature control display (16), a data acquisition instrument (17), a computer (18) and a high-speed camera (19); the detection end of the thermocouple (15) is connected with the heating device (11), and the output end of the thermocouple is connected with the input end of the temperature control display (16); the output end of the temperature control display (16) is connected with a computer (18) through a data acquisition instrument (17); the high-speed camera is used for collecting flame images of suspension combustion of the metal aluminum powder, and the output end of the high-speed camera is connected with the computer (18).

5. A test system for suspension combustion of metal aluminum powder according to claim 1, wherein the suspension gas supply device further comprises a pressure reducing valve (2), a pressure gauge and a compressed air buffer chamber (3) which are sequentially arranged between the outlet and the air inlet (20) of the compressed air tank (1).

6. The system for testing the suspension combustion of the metal aluminum powder as claimed in claim 5, wherein the outlet of the compressed air buffer chamber (3) is connected with the air inlet (20) through the electromagnetic valve (4), the one-way valve (5) and the gas flowmeter (6) in sequence.

7. The system for testing the suspension combustion of the aluminum metal powder as claimed in claim 1, wherein the chamber pull rod (9) is provided with a sealing baffle plate which is in sealing fit with the end face of the fixed shell.

8. The system for testing the suspension combustion of the aluminum powder in the metal, the aluminum powder and the compressed air buffer chamber as claimed in claim 1, wherein the combustion cylinder (7), the aluminum powder chamber (8), the hemispherical nozzle (10) and the compressed air buffer chamber (3) are all made of stainless steel.

9. A method for testing suspension combustion of aluminum metal powder, which is based on the system of any one of claims 1 to 8, comprising,

weighing an aluminum powder mixture, placing the aluminum powder mixture on a porous material bottom plate, and feeding the aluminum powder mixture into a fixed shell of an aluminum powder chamber (8) through a chamber pull rod (9);

starting the heating device (11) and the compressed air tank (1), and sending high-pressure airflow in the compressed air buffer (3) chamber to the bottom of the combustion cylinder (7) through the air inlet (20);

high-pressure airflow enters an aluminum powder chamber (8) through a reducing structure at the bottom of a combustion cylinder (7), rising airflow passes through a porous material bottom plate to carry aluminum powder mixture to pass through a hemispherical nozzle (10) and enter the combustion cylinder (7) from small air outlet holes (23) in all directions, and the air speed is controlled to ensure that the aluminum powder mixture is uniformly distributed in all directions in the combustion cylinder (7) and is ready for combustion after being in a uniform suspension state;

when the aluminum powder mixture is stable along with the gas velocity, the uniform suspended aluminum powder mixture moves to the heating wire mesh (12) along with the gas flow, and the heat of the uniform suspended aluminum powder mixture reaches the ignition temperature of the aluminum powder mixture, so that the aluminum powder mixture is combusted; the test was ended when the aluminum powder mixture was burnt out.

10. The method for testing suspension combustion of aluminum metal powder as claimed in claim 9,

in the test process, the temperature of internal combustion is obtained by a thermocouple (15) and a temperature control display (16), and is sent to a computer (18) for data processing through a data acquisition instrument (17);

during the test, the process image of the internal combustion is recorded by a high-speed camera (19) and transmitted to a computer (18) for data processing.

Technical Field

The invention relates to the technical field of metal aluminum fuel energy storage utilization, in particular to a system and a method for testing suspension combustion of metal aluminum powder.

Background

The metal fuel is used as a high-energy fuel, the combustion heat of the metal fuel is 5-20 times that of a common fuel, and the metal fuel has the characteristics of high energy density and the like. Among them, aluminum powder is a novel high-energy fuel, and because of the advantages of large energy density, non-toxic combustion oxide, abundant aluminum resource storage and the like, it is one of the research hotspots of metal energy storage in recent years to convert and utilize aluminum powder as a metal fuel.

In order to research the combustion characteristics of the nano metal aluminum powder in different atmospheres, the conventional research method is to investigate the combustion characteristics of the aluminum powder in a static environment. The surface of the aluminum powder is covered with oxide, and when the combustion characteristic is researched, the aluminum powder can be ignited and combusted only when the oxide layer covered on the surface of the aluminum powder is dissolved. Meanwhile, under a static condition, aluminum powder particles are in a close packing state and do not move obviously, so that the combustion is more difficult.

At present, the common metal dust particles are combusted, compressed air is generally used for impacting the dust particles, clean and dry compressed air passes through a pressure reducing valve and then blows away the particles, and the air flow rate is controlled by adjusting the pressure reducing valve so that the particles are in a natural suspension state. Thereby enhancing the influence among the metal particles, transferring heat more quickly during combustion and achieving the purpose of enhancing combustion.

However, the density of the metal aluminum is higher than that of the general dust, and slag products are easily formed in the combustion process of the bulk state, so that the combustion efficiency of the aluminum powder is reduced. In a combustion test, the requirement on the uniformity of particle distribution is high, the conventional compressed gas impact dust cannot reach the uniformity of particle distribution, dead angles exist, and the like, and uniform aluminum powder suspension cannot be kept in the device for a long time, so that the continuous propagation effect of flame in a combustion cylinder is reduced, the combustion position and the volume of a combustion space are not adjustable, and combustion components cannot be added at any time.

Disclosure of Invention

Aiming at the problems in the prior art, the invention provides a test system and a test method for suspension combustion of metal aluminum powder, which have the advantages of convenient operation, simple structure, obvious effect, more uniform suspension of aluminum powder and higher combustion efficiency.

The invention is realized by the following technical scheme:

a test system for suspension combustion of metal aluminum powder comprises a suspension combustion device, a suspension gas supply device, a metal aluminum powder suspension device and a measurement recording device, wherein the suspension gas supply device, the metal aluminum powder suspension device and the measurement recording device are connected with the suspension combustion device;

the suspension combustion device comprises a combustion cylinder; the combustion cylinder is in a vertical cylindrical shape, the top end of the combustion cylinder is provided with an air outlet, the bottom end of the combustion cylinder is in a reducing structure and is provided with an air inlet, the middle upper part of the cylinder body is wrapped with a heating device, and a heating wire mesh is arranged in the middle upper part of the cylinder body;

the suspension gas supply device comprises a compressed air tank; the outlet of the compressed air tank is connected with the air inlet;

the metal aluminum powder suspension device comprises an aluminum powder chamber, a chamber pull rod and a plurality of hemispherical nozzles; the aluminum powder chamber is transversely arranged at the top of the reducing structure of the combustion cylinder; one end of the aluminum powder chamber is fixed with the inner wall of the combustion cylinder, and the other end of the aluminum powder chamber extends out of the combustion cylinder; the aluminum powder chamber comprises a hollow cylindrical fixed shell with an opening at the lower end and a porous material bottom plate in sliding connection with the lower end of the fixed shell; one end of the cavity pull rod is connected with the porous material bottom plate, and the other end of the cavity pull rod extends out of the fixed shell; the hemispherical nozzles are arranged above the fixed shell of the aluminum powder chamber in the direction facing the air outlet, are hollow and umbrella-shaped, the umbrella handle end is communicated with the fixed shell, and the spherical end is provided with a plurality of air outlet small holes;

the measurement recording device is used for collecting the suspension combustion image of the metal aluminum powder.

Furthermore, the diameter range of the small air outlet holes is 1.0-1.5mm, and the small air outlet holes are uniformly distributed along the spherical surface of the hemispherical nozzle.

Furthermore, the cross section of the heating screen is the same as that of the combustion cylinder, the heating screen is perpendicular to the central axis of the combustion cylinder and is arranged in the combustion cylinder above the aluminum powder chamber, and the middle of the heating screen is provided with a screen pull rod extending out of the combustion cylinder.

Furthermore, the measurement recording device comprises a thermocouple, a temperature control display, a data acquisition instrument, a computer and a high-speed camera; the thermocouple detection end is connected with the heating device, and the output end is connected with the input end of the temperature control display; the output end of the temperature control display is connected with a computer through a data acquisition instrument; the high-speed camera is used for collecting flame images of suspension combustion of the metal aluminum powder, and the output end of the high-speed camera is connected with the computer.

Furthermore, the suspension gas supply device also comprises a pressure reducing valve, a pressure gauge and a compressed air buffer chamber which are sequentially arranged between the outlet of the compressed air tank and the air inlet.

Furthermore, the outlet of the compressed air buffer chamber is connected with the air inlet through an electromagnetic valve, a one-way valve and a gas flowmeter in sequence.

Furthermore, a sealing baffle plate which is in sealing fit with the end face of the fixed shell is arranged on the cavity pull rod.

Furthermore, the combustion cylinder, the aluminum powder chamber, the hemispherical nozzle and the compressed air buffer chamber are all made of stainless steel materials.

A test method for suspension combustion of metal aluminum powder comprises,

weighing an aluminum powder mixture, placing the aluminum powder mixture on a porous material bottom plate, and conveying the aluminum powder mixture into a fixed shell of an aluminum powder chamber through a chamber pull rod;

starting the heating device and the compressed air tank, and sending the high-pressure airflow in the compressed air buffer chamber into the bottom of the combustion cylinder through the air inlet;

high-pressure airflow enters the aluminum powder chamber through a reducing structure at the bottom of the combustion cylinder, rising airflow passes through the porous material bottom plate to carry aluminum powder mixture to enter the combustion cylinder from small air outlet holes in all directions through the hemispherical nozzle, and the air speed is controlled to ensure that the aluminum powder mixture is uniformly distributed in all directions in the combustion cylinder and is ready for combustion after the aluminum powder mixture is in a uniform suspension state;

when the aluminum powder mixture is stable along with the gas velocity, the uniform suspended aluminum powder mixture moves to the heating wire mesh along with the gas flow, and the heat of the uniform suspended aluminum powder mixture reaches the ignition temperature of the aluminum powder mixture, so that the aluminum powder mixture is combusted; the test was ended when the aluminum powder mixture was burnt out.

Further, in the above-mentioned case,

in the test process, the temperature of internal combustion is obtained by a thermocouple and a temperature control display and is sent to a computer for data processing through a data acquisition instrument;

in the test process, the process image of the internal combustion is recorded by a high-speed camera and transmitted to a computer for data processing.

Compared with the prior art, the invention has the following beneficial technical effects:

according to the system, the aluminum powder chamber with the hemispherical nozzle is arranged in the combustion cylinder, and the aluminum powder mixture is fed into the combustion cylinder from various directions through the plurality of small air outlet holes on the hemispherical nozzle in cooperation with the compressed gas in the compressed air tank, so that the statically accumulated aluminum powder mixture is loosened and suspended along with the compressed gas, and the metal aluminum powder is combusted in a suspended state in cooperation with the heating device and the heating wire mesh, and the problem that slag bonding products are easily formed in the accumulation combustion process and the combustion efficiency of the aluminum powder is reduced is solved; meanwhile, the combustion characteristics of the metal aluminum powder under different atmospheres can be researched by matching with a measurement and recording device, and the gas and the metal powder are fully contacted in a suspension state, so that a chemical reaction can be better generated; the arrangement of the small air outlet holes can ensure that the unburned dust suspension flow keeps a good suspension state before the arrival of the flame front, so that the flame can be continuously propagated in the combustion cylinder, and the combustion effect of the metal aluminum powder is optimized; and the porous material bottom plate arranged in a sliding manner is connected with the cavity pull rod to form a push-pull type design that the cavity pull rod sends the aluminum powder mixture into the fixed shell of the aluminum powder cavity, so that the composition of the metal aluminum powder mixed raw materials and the addition of different additives can be freely blended, the combustion position and the combustion space can be adjusted according to the situation, the design is reasonable, and the operation is simple and easy.

Furthermore, the arrangement mode of the small air outlet holes adopted in the system can effectively convey the aluminum powder mixture into the combustion cylinder from all directions, thereby ensuring that the concentration of the metal aluminum powder mixture in the combustion cylinder is uniformly distributed along the axial direction and the radial direction, ensuring more complete combustion and improving the combustion efficiency.

Furthermore, the system freely adjusts the specific position of the heating wire mesh by arranging the wire mesh pull rod on the heating wire mesh, can be conveniently adjusted according to the specific position of combustion in the combustion cylinder, and has flexible operation and more sufficient reaction.

Furthermore, the system adopts the thermocouple to input the temperature data in the combustion cylinder into the computer in real time through the temperature control display and the data acquisition instrument, and records the specific combustion flame condition through the high-speed camera and then inputs the recorded flame condition into the computer, so that the recording is accurate, and the analysis result is more reliable.

Furthermore, the system is more convenient and controllable by arranging the compressed air buffer chamber to store the air volume required by each test, and is provided with the pressure reducing valve to improve the safety and reliability, and the pressure in the compressed air buffer chamber is monitored in real time by configuring the pressure gauge; the check valve that sets up simultaneously plays the effect of non return, can effectively avoid gaseous backrush to through gas flowmeter record gas flow, accurate reliable.

Furthermore, the system adopts the sealing baffle arranged on the cavity pull rod, and the sealing baffle is in sealing fit with the end surface of the fixed shell, so that the tightness of the aluminum powder cavity is ensured when the aluminum powder mixture is combusted, the suspended aluminum powder mixture is prevented from scattering outwards, and the air tightness of the system is effectively ensured.

Furthermore, the combustion cylinder, the aluminum powder chamber, the hemispherical nozzle and the compressed air buffer chamber are made of stainless steel, so that the safety and reliability can be effectively ensured, and the service life is prolonged.

Drawings

FIG. 1 is a schematic diagram of the system in an embodiment of the invention.

FIG. 2 is a schematic cross-sectional view of a hemispherical nozzle according to an embodiment of the present invention.

FIG. 3 is a schematic diagram illustrating the distribution of the small air outlet holes on the hemispherical nozzle according to the embodiment of the present invention.

In the figure: 1-compressed air tank, 2-pressure reducing valve, 3-compressed air buffer chamber, 4-electromagnetic valve, 5-one-way valve, 6-gas flowmeter, 7-combustion cylinder, 8-aluminum powder chamber, 9-chamber pull rod, 10-hemispherical nozzle, 11-heating device, 12-heating wire mesh, 13-wire mesh pull rod, 14-gas outlet, 15-thermocouple, 16-temperature control display, 17-data acquisition instrument, 18-computer, 19-high speed camera, 20-gas inlet, 21-gas inlet route, 22-spherical gas path and 23-gas outlet small hole.

Detailed Description

The present invention will now be described in further detail with reference to specific examples, which are intended to be illustrative, but not limiting, of the invention.

The invention relates to a test system for suspension combustion of metal aluminum powder, which comprises a suspension gas supply device, a metal aluminum powder suspension device, a suspension combustion device and a measurement and recording device, wherein the suspension gas supply device comprises a compressed air tank 1, a compressed air buffer chamber 3, an electromagnetic valve 4, a one-way valve 5, a gas flowmeter 6 and the like, the metal aluminum powder suspension device comprises an aluminum powder chamber 8, a chamber pull rod 9, a hemispherical nozzle 10, a gas outlet small hole 23 and the like, the suspension combustion device comprises a combustion cylinder 7, a heating device 11, a heating wire mesh 12, a wire mesh pull rod 13 and the like, and the measurement and recording device comprises a thermocouple 15, a temperature control display 16, a data acquisition instrument 17, a computer 18 and a high-speed camera 19;

the suspension gas supply device is used for supplying compressed gas and comprises a compressed air tank 1, a compressed air buffer chamber 3, an electromagnetic valve 4, a one-way valve 5 and a gas flowmeter 6;

the compressed air tank 1 stores dry clean air and is provided with a pressure reducing valve 2;

the compressed air buffer chamber 3 is composed of a stainless steel gas cylinder, stores the air volume required by each test, and the air is supplied by a compressed air tank 1;

the outlet of the compressed air buffer chamber 3 is sequentially connected with the air inlet 20 through the electromagnetic valve 4, the one-way valve 5 and the gas flowmeter 6, the compressed air is sent to the combustion cylinder 7 through the electromagnetic valve 4 through the one-way valve 5, the flow is calculated through the gas flowmeter 6, and the one-way valve 5 plays a role in non-return and prevents the gas from returning.

The metal aluminum powder suspension device is used for feeding an aluminum powder mixture into a suspension combustion system by matching with compressed gas and comprises an aluminum powder chamber 8, a chamber pull rod 9, a hemispherical nozzle 10 and a small gas outlet hole 23;

the aluminum powder chamber 8 is in a hollow cylinder shape and comprises a fixed shell and a porous material bottom plate; the lower end of the fixed shell is provided with an opening and extends out of the combustion cylinder 7, and the other end of the fixed shell is fixedly arranged on the inner wall of the combustion cylinder 7; the porous material bottom plate is made of porous stainless steel materials, is connected with one end of the cavity pull rod 9, is pulled out by the cavity pull rod 9 and extends into the fixed shell, and metal powder and additives can be added or adjusted at any time according to specific conditions when the porous material bottom plate is used; the chamber pull rod 9 is also provided with a sealing baffle plate which is in sealing fit with the end face of the fixed shell, and after the chamber pull rod 9 drives the porous material bottom plate to be fed into the fixed shell, the sealing baffle plate is in sealing fit with the end face of the fixed shell; a plurality of hemispherical nozzles 10 are arranged upwards (facing the direction of the air outlet 14) at the top of the fixed shell of the aluminum powder chamber 8, the aluminum powder chamber 8 is arranged in the combustion cylinder 7 and cannot be pulled out along with the chamber pull rod 9, and a channel is arranged for a gas path entering the aluminum powder chamber 8;

the hemispherical nozzle 10 is made of stainless steel and is in a hollow umbrella shape, as shown in fig. 2, the umbrella handle end is communicated with the fixed shell, and a plurality of small air outlet holes 23 are uniformly arranged at the spherical surface end; the diameter of the small air outlet holes 23 is about 1.0-1.5mm, and the small air outlet holes 23 are staggered or uniformly distributed for 6-10 circles along the spherical surface or are distributed on the spherical surface according to the condition, so that the concentration of the metal aluminum powder in the combustion cylinder 7 is uniformly distributed along the axial direction and the radial direction.

The measurement recording device is used for collecting suspension combustion images of the metal aluminum powder and comprises a thermocouple 15, a temperature control display 16, a data collector 17, a computer 18 and a high-speed camera 19; the high-speed camera is used for collecting flame images of suspension combustion of the metal aluminum powder, the output end of the high-speed camera is connected with the computer 18, the computer 18 is connected with the output end of the temperature control display 16 through the data acquisition instrument 17, the input end of the temperature control display 16 is connected with the output end of the thermocouple 15, and the detection end of the thermocouple 15 is connected with the heating device 11.

The suspension combustion device provides a combustion reaction site for the aluminum powder mixture and comprises a combustion cylinder 7, a heating device 11, a heating wire mesh 12 and a wire mesh pull rod 13;

the combustion cylinder 7 is in a vertical cylindrical shape and made of stainless steel, an air outlet 14 is formed in the top, an air inlet 20 is formed in the bottom, and the bottom is in a reducing structure so as to ensure an entering gas channel; a pull-out aluminum powder chamber 8 is arranged at the top end of the reducing structure to provide a storage space for the metal powder; the upper part of the combustion cylinder 7 of the air inlet 20 is externally wrapped with a heating device 11 of a heat insulating material, so as to provide enough heat for the metal aluminum powder combustion section in the combustion cylinder 7;

the heating wire mesh 12 is arranged in the combustion cylinder 7, the cross section of the heating wire mesh 12 is consistent with that of the combustion cylinder 7, the longer wire mesh pull rod 13 is arranged in the middle of the heating wire mesh 12, the adjustment can be carried out according to the specific position of combustion in the combustion cylinder 7, and the operation is flexible;

the combustion temperature in the combustion cylinder 7 is input into a computer 18 in real time through a thermocouple 15, a temperature control display 16 and a data acquisition instrument 17, and the specific combustion flame condition is recorded by a high-speed camera 19.

In the experiments conducted using the present invention, the procedure was as follows,

opening a pressure reducing valve 2 of a compressed air tank 1 to enable dry clean air stored in the compressed air tank to fill a compressed air buffer chamber 3, monitoring the pressure in the compressed air buffer chamber 3 in real time by a pressure gauge arranged in the compressed air tank, opening an electromagnetic valve 4 and a check valve 5, and enabling the gas to enter a combustion cylinder 7 through an air inlet 20 after being regulated by a gas flowmeter 6;

the porous material bottom plate which is in sliding connection with the fixed shell of the aluminum powder chamber 8 is pulled out of the fixed shell of the aluminum powder chamber 8 by a chamber pull rod 9, the fixed shell is fixed in the process, then the pre-metered metal aluminum powder, additives and other fuels are uniformly spread on the porous material bottom plate, and then the porous material bottom plate is pushed into the fixed shell of the aluminum powder chamber 8 to be restored and combined with the fixed shell of the aluminum powder chamber 8;

the gas carrying aluminum powder fuel is dispersed into the combustion cylinder 7 through the hemispherical nozzle 10, and after the suspension state is stable, the heating device 11 is started to supplement heat to the middle upper part of the combustion cylinder 7 and provide heat for the heating wire mesh 12; the specific position of the heating wire mesh 12 can be freely adjusted by the wire mesh pull rod 13 at the top end of the combustion cylinder 7 according to the suspension position of the aluminum powder fuel, so that combustion is carried out at a set position, and the reaction is more sufficient;

the temperature of the internal combustion is obtained by a thermocouple 15 and a temperature control display 16 and is sent to a computer for processing through a data acquisition instrument 17; the combustion process may be recorded by a high speed camera 19.

After the compressed air enters the combustion cylinder 7, a vertical path passes through the porous material bottom plate of the aluminum powder chamber 8, as shown in fig. 2, the nano-scale aluminum powder particles carried on the porous material bottom plate at the bottom of the aluminum powder chamber 8 enter the umbrella handle end of the hemispherical nozzle 10 and rise along the gas inlet path 21 at the umbrella handle end of the hemispherical nozzle 10 to reach the upper part of the hemispherical nozzle 10, and the small gas outlet holes 23 distributed on the spherical end surface of the hemispherical nozzle 10 along the spherical gas path 22 carry metal aluminum powder to be uniformly dispersed on the middle upper part of the combustion cylinder 7 from different directions and are in a suspension state.

The hemispherical nozzle 10 is arranged at the top of the aluminum powder chamber 8 and inside the combustion cylinder 7 and is uniformly distributed, as shown in fig. 3, when viewed from the top view of the hemispherical nozzle 10, a plurality of small air outlet holes 23 are uniformly or alternatively arranged along the spherical surface, the diameter of each small air outlet hole 23 is about 1.0-1.5mm, or the small air outlet holes are distributed over the spherical surface as the case may be, so that the uniform distribution of the metal aluminum powder concentration in the combustion cylinder 7 along the axial direction and the radial direction is ensured.

The following is added with 1% KNO₃The aluminum powder mixture of (1) is exemplified by suspension combustion, and the specific test procedure is as follows,

step 1: selecting different proportions according to test requirements, preparing aluminum powder or additive with different experimental particle sizes, such as adding 1% KNO₃Respectively metering and recording, grinding and uniformly mixing, and placing in a dryer for later use;

step 2: weighing about 0.02g of mixed aluminum powder, placing the mixed aluminum powder on a porous metal tray, controlling the position of the aluminum powder away from an air inlet by a cavity pull rod 9 on the porous metal tray, recording, and placing the aluminum powder mixture in an aluminum powder cavity 8.

And step 3: starting the heating device 11 to stabilize the current flowing through the heating wire mesh 12;

and 4, step 4: opening a switch of a gas flowmeter 6 of the compressed air tank 1 to enable the gas pressure of the compressed air buffer chamber 3 to reach a certain value; opening the electromagnetic valve 4, buffering the high-pressure airflow in the chamber 3 by the compressed air, passing through the one-way valve 5, and sending the airflow into the bottom end of the combustion cylinder 7; the high-pressure airflow enters the aluminum powder chamber 8 through the diameter-reduced part at the bottom of the combustion cylinder 7, so that the aluminum powder mixture correspondingly loosens, suspends and the like along with the airflow; the ascending air flow carries the aluminum powder to pass through the hemispherical nozzle 10, enters the combustion cylinder 7 from the small air outlet holes 23 in all directions, controls the air speed, and enables the aluminum powder mixture to be uniformly distributed in all directions in the combustion cylinder 7 to present a uniform suspension state for combustion;

and 5: when the aluminum powder mixture is stable along with the gas velocity, the uniformly suspended aluminum powder mixture moves to the heating screen 12 along with the gas flow, and the heat of the uniformly suspended aluminum powder mixture reaches the ignition temperature of the aluminum powder mixture, so that the aluminum powder mixture is combusted; the above process, i.e. the process in which the aluminum powder mixture is burned, is recorded by the high-speed camera 19 and transmitted to the computer 18 for further data processing.

Step 6: the aluminum powder mixture was completely burned out and the experiment was ended.

Based on any one of the systems, the invention also provides a test method for suspension combustion of the metal aluminum powder, which comprises the following steps,

weighing an aluminum powder mixture, placing the aluminum powder mixture on a porous material bottom plate, and feeding the aluminum powder mixture into a fixed shell of an aluminum powder chamber 8 through a chamber pull rod 9;

starting the heating device 11 and the compressed air tank 1, and sending the high-pressure airflow in the compressed air buffer 3 chamber to the bottom of the combustion cylinder 7 through the air inlet 20;

high-pressure airflow enters the aluminum powder chamber 8 through a reducing structure at the bottom of the combustion cylinder 7, rising airflow passes through the porous material bottom plate to carry aluminum powder mixture to pass through the hemispherical nozzle 10 and enter the combustion cylinder 7 from the small air outlet holes 23 in all directions, and the air speed is controlled to ensure that the aluminum powder mixture is uniformly distributed in all directions in the combustion cylinder 7 and is ready for combustion after being in a uniform suspension state;

when the aluminum powder mixture is stable along with the gas velocity, the uniform suspension state aluminum powder mixture moves to the heating wire mesh 12 along with the air flow, and the heat of the uniform suspension state aluminum powder mixture reaches the ignition temperature of the aluminum powder mixture, so that the aluminum powder mixture is combusted; the test was ended when the aluminum powder mixture was burnt out.

Wherein the content of the first and second substances,

in the test process, the temperature of internal combustion is obtained by a thermocouple 15 and a temperature control display 16, and is sent to a computer 18 for data processing through a data acquisition instrument 17;

during the test, the process image of the internal combustion is recorded by the high speed camera 19 and transmitted to the computer 18 for data processing.