阅读说明：本技术 一种用于微热光电的旋流式进气多孔介质燃烧器 (Spiral-flow type air inlet porous medium burner for micro-thermal photoelectricity ) 是由 卢青波 苟杰 潘剑锋 张倚 于 2020-06-29 设计创作，主要内容包括：本发明提供了一种用于微热光电的旋流式进气多孔介质燃烧器,包括进气区、燃烧区和预混区,所述预混区位于进气区和燃烧区之间,所述进气区内均布若干进气通道,任一所述进气通道的进口与出口在周向上偏移,所述预混区内设有与所述进气通道一一对应的催化挡板,且所述催化挡板靠近进气通道的出口,用于使燃料迅速混合达到均匀状态。所述燃烧区内根据流向依次填充燃烧区多孔介质和蓄热区多孔介质。本发明在预混合区域采用气体预混合方式,可以大幅增强点火处气流的稳定性,提高了燃烧强度,且增大了预混气流与多孔介质的接触面积,更加充分的利用了多孔介质的回热作用,提高了燃烧效率,令燃烧更加完全。(The invention provides a spiral-flow type air inlet porous medium burner for micro-thermal photoelectricity, which comprises an air inlet area, a combustion area and a premixing area, wherein the premixing area is positioned between the air inlet area and the combustion area, a plurality of air inlet channels are uniformly distributed in the air inlet area, the inlet and the outlet of any air inlet channel are deviated in the circumferential direction, catalytic baffles which are in one-to-one correspondence with the air inlet channels are arranged in the premixing area, and the catalytic baffles are close to the outlet of the air inlet channel and used for enabling fuel to be rapidly mixed to achieve a uniform state. And the combustion zone is filled with porous media of the combustion zone and porous media of the heat storage zone in sequence according to the flow direction. The invention adopts a gas premixing mode in the premixing area, can greatly enhance the stability of gas flow at the ignition position, improves the combustion intensity, increases the contact area of the premixed gas flow and the porous medium, more fully utilizes the heat regeneration effect of the porous medium, improves the combustion efficiency and leads the combustion to be more complete.)

1. The utility model provides a porous medium combustor of spiral-flow type air inlet for it is little hot photoelectricity, includes intake zone (6) and combustion area (9), its characterized in that still includes mixes district (7) in advance, it is located between intake zone (6) and combustion area (9) to mix district (7) in advance, a plurality of inlet channel (5) of equipartition in intake zone (6), arbitrary inlet channel (5) and export skew in circumference, be equipped with in mixing district (7) in advance with inlet channel (5) one-to-one's catalysis baffle (4), just catalysis baffle (4) are close to the export of inlet channel (5) for make the rapid mixing of fuel reach the homogeneous state.

2. A swirling-type intake porous medium burner for micro-thermal photoelectricity according to claim 1, characterized in that the axis of the intake duct (5) is inclined at an angle of 20 ° to 60 °.

3. A swirling-type air-intake porous medium burner for micro thermal photoelectricity according to claim 1, characterized in that the angle between the catalytic baffle (4) and the radial plane of the premixing zone (7) is 20 ° to 60 °.

4. The cyclone type air inlet porous medium burner for micro-thermal photoelectricity according to claim 1, characterized in that the material of the catalytic baffle (4) is high temperature resistant ceramic, and the catalytic baffle (4) corresponding to the outlet of the air inlet channel (5) is coated with catalyst (8).

5. A swirling-type intake porous medium burner for micro thermal electro-optic according to claim 4, characterized in that the catalyst (8) is a noble metal or metal oxide.

6. A swirling-type intake porous medium burner for micro thermal electro-optic according to claim 1, characterized in that the number of the intake passages (5) is not less than 6.

7. The cyclone type air inlet porous medium burner for micro-thermophotovoltaic according to claim 1, wherein the combustion zone (9) is filled with a combustion zone porous medium (2) and a heat storage zone porous medium (1) in sequence according to the flow direction, and the materials of the combustion zone porous medium (2) and the heat storage zone porous medium (1) are silicon carbide or corundum or zirconia.

8. The swirling flow type intake porous medium burner for micro thermal photoelectricity according to claim 1, wherein the porosity of the combustion zone porous medium (2) is 0.7 to 0.9, and the pore density is 10 to 30 ppi; the porosity of the heat storage area porous medium (1) is 0.5-0.65, and the pore density is 50 ppi.

Technical Field

The invention relates to the technical field of micro-scale thermal photoelectric energy conversion, in particular to a spiral-flow type air inlet porous medium burner for micro-thermal photoelectricity.

Background

With the continuous development of micro-electro-mechanical systems (MEMS) and the continuous improvement of micro-combustion theory, people have an increasing interest in the field of micro energy, wherein the micro-thermo-electro-optical system has a simple structure, no moving parts and good practicability, and thus, the micro-thermo-electro-optical system also becomes the focus of current research. The basic principle of the micro-thermal photoelectric system is that fuel is combusted in a combustor to generate chemical energy, radiation is generated on the wall surface of the combustor, and then electric energy is generated through a photoelectric cell. The scale of the whole combustion reaction is very small, so that the problems different from the traditional combustor can be caused, firstly, the heat loss of the wall surface is greatly increased due to the overlarge face-to-face ratio of the micro combustion chamber, and when the heat generated by the mixed gas is less than the heat lost by the pipe wall, the quenching phenomenon can be caused; secondly, the residence time of the fuel in the combustion chamber is short, the combustion is insufficient, and the problems of low flame temperature, uneven temperature distribution and low energy conversion rate can occur.

In a micro-thermophotovoltaic system, a micro-combustion chamber is a key component, and the conventional micro-scale combustion chamber mainly has the problems of uneven temperature distribution, low combustion efficiency, poor combustion stability, incomplete combustion and the like, and the problems can directly influence the photoelectric energy conversion efficiency.

Disclosure of Invention

Aiming at the defects in the prior art, the invention provides the spiral-flow type air inlet porous medium burner for micro-thermal photoelectricity, a novel gas premixing mode is adopted in a premixing area, the stability of air flow at an ignition part can be greatly enhanced, the burning intensity is improved, the contact area of the premixed air flow and the porous medium is increased, the heat regeneration effect of the porous medium is more fully utilized, the burning efficiency is improved, and the burning is more complete. The invention can also effectively solve the problems of low combustion efficiency, uneven temperature distribution, low energy conversion rate and the like in the traditional micro-combustor. The invention has simple structure, easy realization and low cost, can meet the stable combustion under the conditions of various fuels and flow rates, and has wider combustion limit.

The present invention achieves the above-described object by the following technical means.

The utility model provides a porous medium combustor of spiral-flow type air inlet for it is little hot photoelectricity, includes air intake zone, combustion area and mixes the district in advance, mix the district in advance and be located between air intake zone and the combustion area, a plurality of inlet channel of equipartition in the air intake zone, arbitrary inlet channel's import and export skew in week, mix in advance the district be equipped with the catalysis baffle of inlet channel one-to-one, just catalysis baffle is close to inlet channel's export for make fuel mix rapidly and reach the homogeneous state.

Further, the inclination angle of the axis of the air inlet pipeline is 20-60 degrees.

Furthermore, the included angle between the catalytic baffle and the radial plane of the premixing area is 20-60 degrees.

Furthermore, the material of the catalytic baffle is high-temperature-resistant ceramic, and the plane of the catalytic baffle corresponding to the outlet of the air inlet channel is coated with a catalyst.

Further, the catalyst is a noble metal or a metal oxide.

Further, the number of the intake passages is not less than 6.

Further, the combustion zone is filled with a porous medium of the combustion zone and a porous medium of the heat storage zone in sequence according to the flow direction, and the porous medium of the combustion zone and the porous medium of the heat storage zone are made of silicon carbide or corundum or zirconia.

Further, the porosity of the porous medium in the combustion zone is 0.7-0.9, and the pore density is 10-30 ppi; the porosity of the porous medium in the heat storage area is 0.5-0.65, and the pore density is 50 ppi.

The invention has the beneficial effects that:

1. according to the swirling type air inlet porous medium burner for micro-thermophotovoltaic, an air inlet area adopts an annular porous air inlet mode that fuel-oxygen-fuel-oxygen are crossed, and the air is inclined at a certain angle when entering a premixing area, so that circulating type air inlet of the premixing area can be realized.

2. According to the spiral-flow type air inlet porous medium burner for micro-thermophotovoltaic, the baffle is arranged in the premixing area, so that fuel gas and oxygen can be rapidly mixed, the uniform state can be achieved within a very short time, an annular spiral flow is formed and is introduced into porous medium in the burning area, the burning stability is greatly improved, the collision probability of active free radicals and the radiation wall surface is increased, the local temperature difference is reduced, and the burning in the porous medium is more sufficient.

3. According to the spiral-flow type air inlet porous medium burner for micro-thermophotovoltaic, the catalyst is arranged on the baffle of the premixing area, and in the premixing area, when the gas continuously flushes the baffle, partial catalytic oxidation is generated, so that the activation energy of the fuel is effectively reduced, the fuel meets the ignition requirement in a micro scale, the combustion is more complete, and the generation of pollutants is reduced.

Drawings

FIG. 1 is a schematic structural view of a swirling-type air-intake porous medium burner for micro-thermophotovoltaic according to the present invention.

FIG. 2 is a schematic view of the installation of the catalytic baffle of the swirling-type intake porous media burner for micro-thermophotovoltaic according to the present invention.

FIG. 3a shows the outlet H of the premixing chamber₂A component cloud picture.

FIG. 3b shows the center O of the catalytic baffle₂A component cloud picture.

In the figure:

1-porous medium in heat accumulating area; 2-a combustion zone porous medium; 3-an electronic igniter; 4-a catalytic baffle; 5-an air intake passage; 6-a gas inlet zone; 7-a premixing area; 8-a catalyst; 9-combustion zone.

Detailed Description

The invention will be further described with reference to the following figures and specific examples, but the scope of the invention is not limited thereto.

As shown in fig. 1 and 2, the swirling flow type air intake porous medium burner for micro thermophotovoltaic disclosed by the invention comprises an air intake zone 6, a combustion zone 9 and a premixing zone 7, wherein the premixing zone 7 is located between the air intake zone 6 and the combustion zone 9, the air intake zone 6 is in the shape of an inverted circular truncated cone, at least 6 air intake channels 5 are uniformly distributed in the air intake zone 6, an inlet and an outlet of any air intake channel 5 are offset in the circumferential direction, the axial angle of the air intake channel 5 is 20-60 degrees, that is, if the inlet of the air intake channel 5 is located at 0 degree in the circumferential direction of the small end surface of the circular truncated cone, the outlet of the air intake channel 5 is shifted by a certain angle in the circumferential direction of the large end surface of the circular truncated cone clockwise or counterclockwise, so that the included angle between the axial line of the air intake channel 5 and the small end surface or the large end. The inlet channel 5 can be machined by a laser puncher and has a channel diameter of 2 mm.

And the premixing area 7 is internally provided with catalytic baffles 4 which are in one-to-one correspondence with the air inlet channels 5, and the catalytic baffles 4 are close to the outlets of the air inlet channels 5 and used for rapidly mixing the fuel to achieve a uniform state. The wall surface material of the premixing area 7 is high temperature resistant ceramic, and the lower part of the premixing area is bonded to one end of the air inlet area by high temperature resistant glue. The material of the catalytic baffle 4 is high-temperature resistant ceramic, and the plane of the catalytic baffle 4 corresponding to the outlet of the air inlet channel 5 is coated with a catalyst 8. The catalyst 8 is selected from noble metals or noble metal oxides, such as Pt, and the catalyst coating is performed by vapor deposition. The thickness of the catalytic baffle 4 is 0.5mm, the upper and lower width is 4mm, and the length of the radial central line is 3 mm. The included angle between the catalytic baffle 4 and the radial plane of the premixing area 7 is 20-60 degrees. When fuel and oxygen alternately enter the premixing chamber 7 through the intake passage 5 at the same time, the catalytic baffle 4 changes the traveling direction of the air flow, and forms an annular circumferential flow while traveling upward, and enters the combustion zone 9. The channel of the combustion area 9 is made of high-light-transmittance quartz glass and is bonded to the upper part of the premixing channel by high-temperature-resistant glue, the porous medium 2 of the combustion area is arranged at the lower part of the combustion area 9, and the porous medium 1 of the heat storage area is filled above the porous medium 2 of the combustion area. The ignition mode is arc ignition, and the selected equipment is an electronic igniter 3.

The actual effect of the invention is numerically simulated by FLUENT, H is selected₂And O₂The ratio of the two gases used was 1 equivalent and the gas inlet flow rate was 4 m/s. FIG. 3a is H₂Component cloud at the outlet of the premixing chamber, FIG. 3b is O₂The cloud picture is formed in the center of the baffle of the premixing chamber, and it can be seen that gas at the baffle is strongly disturbed, and rotational flow is generated in the center of the premixing chamber. At the inlet H₂The mass fraction of the components is low, the rest components are all oxygen, and the rotational flow is generated, and the gas distribution is uniform.

The operation mode is that fuel and oxidant enter the premixing area 7 through the air inlet channel 5 in a staggered mode, the direction of the fuel and oxidant is directed to the surface of the catalyst 8 coated on the catalytic baffle 4, the airflow instantly reacts when contacting the catalytic baffle 4, the air inlet direction is changed by the baffle, the inclined angles of the catalytic baffles 4 are consistent, and therefore the fuel and the oxidant can be mixed quickly. The premixed gas enters the combustion zone 9 and is ignited via the electronic igniter 3 and combusted in the combustion zone porous medium 2.

And the combustion zone 9 is filled with a combustion zone porous medium 2 and a heat storage zone porous medium 1 in sequence according to the flow direction, and the combustion zone porous medium 2 and the heat storage zone porous medium 1 are made of silicon carbide or corundum or zirconia. In order to ensure that the fuel is combusted more fully and stably, the porosity of the porous medium 2 in the combustion area is 0.7-0.9, and the pore density is 10-30 ppi; the porosity of the porous medium 1 in the heat storage area is 0.5-0.65, the pore density is 50ppi, the heat loss can be effectively reduced, the tail gas pollution is reduced, the energy exchange avoided by radiation is enhanced, the heat can be transferred to the premixing area 7 after entering the porous medium, the premixed gas is preheated, the ignition can be accelerated on the one hand, and the flame stability is improved.

The present invention is not limited to the above-described embodiments, and any obvious improvements, substitutions or modifications can be made by those skilled in the art without departing from the spirit of the present invention.