A swirl micro-mixing nozzle and micro-mixing burner with built-in plasma combustion support

Abstract

The present invention discloses a swirl micro-mixing nozzle and a micro-mixing burner with built-in plasma combustion-supporting. The swirl micro-mixing nozzle includes a coaxially arranged tangential swirl component, a fuel pipe and a mixing pipe, and a plasma combustion-supporting exciter arranged on the fuel pipe and the mixing pipe. The present invention integrates the plasma combustion-supporting exciter inside the nozzle, which can simplify the structural design of the micro-mixing burner and reduce the volume and complexity of the micro-mixing burner; the present invention installs the plasma combustion-supporting exciter on the top of the mixed gas channel of the swirl micro-mixing nozzle, and can control the opening and closing and discharge intensity of the plasma combustion-supporting exciter when the load changes, so as to achieve stable regulation of the combustion process under variable working conditions and improve the response speed under different working conditions; the present invention uses the swirl airflow generated by the tangential swirl component to make the air or oxidant fully mixed with the fuel at a specific swirl degree, which can widen the combustion range and enhance the stable combustion effect under extreme working conditions.

Description

Technical Field

[0001] The invention relates to a micro-mixing nozzle and a micro-mixing burner, in particular to a swirl micro-mixing nozzle and a micro-mixing burner with built-in plasma combustion assistance, belonging to the technical field of micro-mixing combustion. Background Art

[0002] Micro-mixing combustion technology achieves low NOx combustion by reducing the mixing scale of fuel and air flow to enhance outlet uniformity. It fully mixes fuel and oxidant in a millimeter-level pipe to form a premixed gas, and then sprays it out of the nozzle to form a small-scale flame. Multiple small-scale flames are used to replace traditional large-scale combustion, reducing the width and length of the flame, and shortening the residence time of flue gas in the high-temperature zone to achieve ultra-low emissions. Micro-mixing combustion technology is particularly suitable for aerospace, energy generation and other fields due to its high efficiency and low pollution, such as hydrogen-fueled aviation power units and gas turbine combustion chambers.

[0003] Taking the application of micro-mixed combustion technology in gas turbine combustion chambers as an example, the combustion chambers of aircraft engines need to maintain stable combustion at variable flight speeds and altitudes during flight, which makes the design and control of the combustion chamber extremely complex and requires consideration of wide operating conditions and fast dynamic response capabilities; in addition, when micro-mixed combustion technology is applied to gas turbine combustion chambers, it is also necessary to consider multi-fuel adaptability and stable combustion under a wide range of operating conditions. Therefore, in order to further improve the combustion efficiency of micro-mixed combustion and broaden the stable combustion range of micro-mixed combustion, industry researchers began to explore plasma combustion-assisted technology. Plasma, as the fourth state of matter, is an electrically neutral gas composed of electrons, ions and neutral particles (including atoms, molecules and free radicals, etc.). It contains a wealth of active particles, such as electrons, ions and free radicals. The active particles are highly chemically active and can effectively promote the oxidation and combustion reactions of the fuel, thereby improving the combustion efficiency and stability. However, the current micro-mixed combustion technology based on plasma-assisted combustion still faces many challenges in the application of actual aircraft engines or gas turbines: on the one hand, in miniaturized and sophisticated micro-mixed combustion systems, due to the limitation of space size, the generation, control and maintenance of plasma are relatively difficult; on the other hand, in a micro-mixed combustion environment, due to the large changes in parameters such as air flow velocity, temperature, and pressure in the combustion chamber, the stability and reliability of the plasma may be affected, which may lead to problems such as unstable combustion, flameout or flashback; on the other hand, plasma-assisted combustion technology not only has limited adaptability to fuels, but also because the changes in air flow and flow rate in the micro-mixed combustion system have an important influence on the combustion process, so plasma-assisted combustion needs to adapt to the combustion requirements under different air flow and flow rate conditions, especially stable combustion under extreme conditions and rapid dynamic response capabilities under variable conditions, which increases the complexity of the system and the difficulty of control. Summary of the invention

[0004] In view of the problems existing in the above-mentioned prior art, the present invention provides a swirl micro-mixing nozzle and a micro-mixing burner with built-in plasma combustion-assisted, which can not only realize the high integration of the plasma combustion-assisted exciter in the micro-mixing burner, but also improve the adaptability of the combustion system to multiple fuels, enhance the rapid dynamic response capability under a wide range of operating conditions and widen the stable combustion range of the combustion chamber.

[0005] To achieve the above-mentioned purpose, the swirl micro-mixing nozzle with built-in plasma combustion support comprises a coaxially arranged tangential swirl component, a fuel pipe and a mixing pipe, and a plasma combustion support exciter arranged on the fuel pipe and the mixing pipe;

[0006] The tangential swirl component is a blind hole sleeve structure with a blind hole coaxially arranged inside, and the opening position of the blind hole is located at the top of the tangential swirl component, the blind hole of the tangential swirl component forms a primary mixing chamber, and an air tangential swirl structure is arranged on the outer wall of the primary mixing chamber, and the air tangential swirl structure includes a tangential swirl channel with a swirl angle, and the tangential swirl channel runs through the outer wall of the primary mixing chamber, and the outer end of the tangential swirl channel is an air swirl inlet, and the inner end is an air swirl outlet;

[0007] The fuel pipe is a cylindrical structure with a blind hole coaxially arranged at the bottom end. The blind hole of the fuel pipe is opened at the fuel pipe air inlet. The blind hole of the fuel pipe forms a fuel channel. The bottom end of the fuel pipe passes through the bottom end of the tangential swirl component and is sealed and fixedly connected to the tangential swirl component. The depth dimension of the fuel channel matches the depth dimension of the primary mixing chamber of the tangential swirl component. The top end of the fuel pipe extends out and extends to the outside of the top end of the tangential swirl component. A radial fuel outlet is arranged at a position on the fuel channel corresponding to the primary mixing chamber of the tangential swirl component.

[0008] The bottom end of the mixing tube is sealed and fixedly connected to the top end of the primary mixing chamber of the tangential swirl component, and is sleeved on the fuel pipe. The top end of the mixing tube is flush with the top end of the fuel pipe, and a mixed gas channel is formed between the inner surface of the mixing tube and the outer surface of the fuel pipe.

[0009] The plasma combustion-supporting exciter is arranged at the top of the fuel pipe and the mixing pipe, and includes a cathode electrode, an anode electrode assembly and a high-voltage cable connector; the cathode electrode of the ring-shaped structure is fixedly sleeved on the outer surface of the top of the fuel pipe; the anode electrode assembly of the ring-shaped structure is fixedly arranged on the inner surface of the top of the mixing pipe opposite to the cathode electrode, and the anode electrode assembly includes an anode electrode and an insulating medium layer, and the insulating medium layer is located between the anode electrode and the inner surface of the mixing pipe; the high-voltage cable connector is fixedly arranged on the mixing pipe, and the high-voltage cable connector is electrically connected to the anode electrode; a plasma combustion-supporting excitation field is formed between the cathode electrode and the anode electrode assembly.

[0010] As an embodiment of the plasma combustion-supporting exciter of the present invention, the plasma combustion-supporting exciter is a dielectric barrier plasma combustion-supporting exciter structure, the mixing tube is a straight tube structure, the mixed gas channel as a whole is an equal-diameter annular cavity structure, and the insulating medium layer is wrapped and arranged on the outside of the anode electrode.

[0011] As another embodiment of the plasma combustion-supporting exciter of the present invention, the plasma combustion-supporting exciter is a sliding arc plasma combustion-supporting exciter structure, the mixing tube includes a straight pipe section located at the bottom and a conical expansion pipe section connected to and located at the top of the straight pipe section, the conical expansion pipe section with a small diameter at the bottom and a large diameter at the top corresponds to the plasma combustion-supporting excitation field, the position of the mixed gas channel corresponding to the plasma combustion-supporting excitation field is a conical channel structure with a gradually increasing cross-sectional area, and the anode electrode corresponds to the cathode electrode and is exposed on the insulating medium layer.

[0012] As a further improvement of the present invention, the swirl angle range of the tangential swirl channel is 0° to 65°.

[0013] As a further improvement of the present invention, a plurality of tangential swirl channels are evenly distributed around the primary mixing chamber, and the swirl degrees of the plurality of tangential swirl channels are the same.

[0014] As a further improvement of the present invention, the inner surface of the primary mixing chamber is a regular polygonal structure.

[0015] As a further improvement of the present invention, the diameter of the radial fuel outlet is smaller than the diameter of the air swirl outlet.

[0016] As a further improvement of the present invention, the inner surface of the primary mixing chamber is a regular polygonal structure.

[0017] As a further improvement of the present invention, multiple radial fuel outlets are arranged, and the multiple radial fuel outlets are evenly distributed along the circumferential direction of the fuel channel to form a radial fuel outlet assembly, and the radial fuel outlet assemblies are evenly distributed along the axial direction of the fuel channel to form multiple groups.

[0018] A micro-mixing burner is provided with a fuel chamber, an air chamber and a combustion chamber in a coaxial and sealed manner from bottom to top, the fuel chamber and the air chamber are separated by a fuel chamber top plate, the air chamber and the combustion chamber are separated by a top partition plate, a middle partition plate is also provided in the air chamber, a fuel intake channel is provided on the fuel chamber, and an air intake channel is provided on the air chamber; it also includes a swirl micro-mixing nozzle with built-in plasma combustion assistance, a plurality of swirl micro-mixing nozzles with built-in plasma combustion assistance are fixedly arranged in the air chamber, the bottom end and the top end of the tangential swirl component of the swirl micro-mixing nozzle with built-in plasma combustion assistance are respectively sealed and fixedly connected to the fuel chamber top plate and the middle partition plate of the air chamber, and the top end of the mixing tube is arranged through the top partition plate, and the plurality of swirl micro-mixing nozzles with built-in plasma combustion assistance are symmetrical with respect to the center of the air chamber and form a ring-shaped multi-layer array structure.

[0019] As a further improvement of the present invention, a plurality of swirl micro-mixing nozzles with built-in plasma combustion support in an annular multi-layer array structure are staggered to set different swirl degrees according to different numbers of layers;

[0020] Alternatively, a plurality of built-in plasma-assisted combustion swirl micro-mixing nozzles are in an annular multi-layer array structure, and a plurality of built-in plasma-assisted combustion swirl micro-mixing nozzles located in the same layer are staggeredly arranged with different swirl degrees.

[0021] Compared with the prior art, the swirl micro-mixing nozzle and micro-mixing burner with built-in plasma combustion support have the following beneficial effects:

[0022] 1. In terms of improving the mixing characteristics, the present invention installs a plasma combustion-supporting exciter on the top of the mixed gas channel. When an alternating or pulse voltage of appropriate intensity is applied to the discharge electrode, a large amount of highly active plasma is generated in the mixed gas channel, which can significantly improve the mixing uniformity of the fuel and the oxidant.

[0023] 2. In terms of enhancing combustion stability, firstly, the present invention utilizes the swirl airflow generated by the tangential swirl component to fully mix the air or oxidant with the jet fuel in the primary mixing chamber with a specific swirl degree, and then ejects the mixed gas through the gas outlet for combustion. Pure hydrogen or hydrogen-rich flames can adopt a structural design with a lower swirl degree to avoid backfire. Fuels with relatively slow combustion speeds, such as natural gas and hydrogen-blended ammonia, can adopt a larger swirl degree, thereby further shortening the flame length and improving the combustion intensity. Secondly, whether to turn on the plasma combustion-aiding exciter can be determined according to the combustion state. After turning it on, the combustion stability can be enhanced, thereby widening the combustion range and enhancing the stable combustion effect under extreme working conditions.

[0024] 3. In terms of compact structural design, integrating the plasma combustion-supporting actuator into the nozzle can simplify the structural design of the micro-mixing burner and reduce the volume and complexity of the micro-mixing burner.

[0025] 4. In terms of multi-fuel adaptability, the design of the nozzle and burner takes into account the use requirements of multiple fuels. By flexibly adjusting the swirl degree of the tangential swirl component and assisting with the use of a plasma combustion-aiding actuator, it can adapt to the combustion characteristics of different fuels.

[0026] 5. In terms of rapid dynamic response capability under a wide range of operating conditions, through the rapid discharge characteristics of the plasma combustion-supporting exciter, the present invention can control the opening and closing of the plasma power supply and its discharge intensity when the load changes, thereby achieving stable regulation of the combustion process under variable conditions and improving the response speed of the micro-mixing burner under different conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1It is a schematic diagram of the three-dimensional structure of the swirl micro-mixing nozzle of the present invention when the medium-barrier plasma combustion-supporting exciter structure is adopted;

[0028] Figure 2 It is a schematic structural diagram of the swirl micro-mixing nozzle of the present invention when the medium-barrier plasma combustion-supporting exciter structure is adopted;

[0029] Figure 3 2 is a schematic structural diagram of a dielectric barrier plasma combustion-supporting exciter according to an embodiment of the present invention;

[0030] Figure 4 yes Figure 3 A right-side rotated diagram of ;

[0031] Figure 5 It is a schematic diagram of the three-dimensional structure of the swirl micro-mixing nozzle of the present invention when the sliding arc plasma combustion-supporting exciter structure is adopted;

[0032] Figure 6 It is a schematic structural diagram of the swirl micro-mixing nozzle of the present invention when the sliding arc plasma combustion-supporting exciter structure is adopted;

[0033] Figure 7 2 is a schematic diagram of the structure of a sliding arc plasma combustion-supporting exciter according to an embodiment of the present invention;

[0034] Figure 8 yes Figure 7 A right-side rotated diagram of ;

[0035] Fig. 9 It is a schematic diagram of the overall three-dimensional structure of the micro-mixing burner of the present invention;

[0036] Fig.10 is an overall top view of the micro-mixing burner of the present invention;

[0037] Fig.11 It is a cross-sectional view of the tangential swirl component of the present invention.

[0038] In the figure: 1-fuel cavity, 11-fuel inlet channel, 2-air cavity, 21-air inlet channel, 3-swirl micro-mixing nozzle, 31-tangential swirl component, 311-air swirl inlet, 312-tangential swirl channel, 313-air swirl outlet, 314-upper thread, 315-lower thread, 32-fuel pipe, 321-fuel pipe inlet, 322-fuel channel, 323-radial fuel outlet, 324-cathode electrode, 33-mixing tube, 331-mixed gas inlet, 332-mixed gas channel, 333-anode electrode, 334-insulating medium layer, 335-mixed gas outlet, 34-high voltage cable connector, 4-top partition. DETAILED DESCRIPTION

[0039] The present invention will be further described below in conjunction with the accompanying drawings.

[0040] like Figure 1 , Figure 2 , Figure 5 , Figure 6 As shown, the swirl micro-mixing nozzle 3 with built-in plasma combustion support includes a coaxially arranged tangential swirl component 31, a fuel pipe 32 and a mixing pipe 33, and a plasma combustion support exciter arranged on the fuel pipe 32 and the mixing pipe 33.

[0041] The tangential swirl component 31 is a blind hole sleeve structure with a blind hole coaxially arranged inside, and the opening position of the blind hole is located at the top of the tangential swirl component 31. The blind hole of the tangential swirl component 31 forms a primary mixing chamber, and an air tangential swirl structure is arranged on the outer wall of the primary mixing chamber, such as Fig.11 As shown, the air tangential swirl structure includes a tangential swirl channel 312 with a swirl angle. The swirl angle of the tangential swirl channel 312 refers to the tangential angle between the central axis of the tangential swirl channel 312 and the inner surface of the primary mixing chamber. The swirl direction of the tangential swirl channel 312 can be positive rotation (clockwise rotation) or reverse rotation (counterclockwise rotation). The tangential swirl channel 312 runs through the outer wall of the primary mixing chamber. The outer end of the tangential swirl channel 312 is an air swirl inlet 311, and the inner end is an air swirl outlet 313. The swirl angle range of the tangential swirl channel 312 is 0° to 65°. When the swirl angle is 0°, the central axis of the tangential swirl channel 312 is perpendicular to the inner surface of the primary mixing chamber (that is, the central axis of the tangential swirl channel 312 passes through the central axis of the primary mixing chamber).

[0042] The fuel pipe 32 is a cylindrical structure with a blind hole coaxially provided at the bottom end. The blind hole of the fuel pipe 32 is opened at the fuel pipe air inlet 321. The blind hole of the fuel pipe 32 forms a fuel channel 322. The bottom end of the fuel pipe 32 passes through the bottom end of the tangential swirl component 31 and is sealed and fixedly connected to the tangential swirl component 31 through a threaded connection. The depth dimension of the fuel channel 322 matches the depth dimension of the primary mixing chamber of the tangential swirl component 31. The top end of the fuel pipe 32 protrudes and extends to the outside of the top end of the tangential swirl component 31. A radial fuel air outlet 323 is provided on the fuel channel 322 at a position corresponding to the primary mixing chamber of the tangential swirl component 31.

[0043] The bottom end of the mixing tube 33 is sealed and fixedly connected to the top end of the primary mixing chamber of the tangential swirl component 31 through a threaded connection and is in a sleeved state on the fuel pipe 32. The top end of the mixing tube 33 is flush with the top end of the fuel pipe 32. A mixture gas channel 332 is formed between the inner surface of the mixing tube 33 and the outer surface of the fuel pipe 32. The bottom end of the mixture gas channel 332 is a mixture gas inlet 331, and the top end is a mixture gas outlet 335.

[0044] like Figure 3 , Figure 4, Figure 7 , Figure 8 As shown, the plasma combustion-supporting exciter is arranged at the top of the fuel pipe 32 and the mixing tube 33, including a cathode electrode 324, an anode electrode assembly and a high-voltage cable connector 34; the cathode electrode 324 of the ring-shaped structure is fixedly sleeved on the outer surface of the top of the fuel pipe 32, and the cathode electrode 324 is grounded; the anode electrode assembly of the ring-shaped structure is fixedly arranged on the inner surface of the top of the mixing tube 33 at a position opposite to the cathode electrode 324, and the anode electrode assembly includes an anode electrode 333 and an insulating medium layer 334, and the insulating medium layer 334 is located between the anode electrode 333 and the inner surface of the mixing tube 33; the high-voltage cable connector 34 is fixedly arranged on the mixing tube 33, and the high-voltage cable connector 34 is electrically connected to the anode electrode 333; a plasma combustion-supporting excitation field is formed between the cathode electrode 324 and the anode electrode assembly.

[0045] When the swirl micro-mixing nozzle 3 with built-in plasma combustion support is installed on a micro-mixing burner for use, Fig. 9 As shown, the micro-mixing burner is coaxially and sealedly provided with a fuel chamber 1, an air chamber 2 and a combustion chamber (not shown in the figure) from bottom to top, the fuel chamber 1 and the air chamber 2 are separated by a fuel chamber top plate, the air chamber 2 and the combustion chamber are separated by a top partition plate 4, and a middle partition plate is also provided in the air chamber 2. A plurality of swirl micro-mixing nozzles 3 with built-in plasma combustion support are fixedly arranged in the air chamber 2, and as shown in FIG. Fig.10 As shown, multiple swirl micro-mixing nozzles 3 for built-in plasma combustion assistance are symmetrically arranged in an annular multi-layer array structure relative to the center of the air cavity 2; multiple fuel inlet channels 11 are evenly distributed on the fuel cavity 1 along its circumferential direction, and the fuel can enter the fuel cavity 1 through the fuel inlet channels 11; multiple air inlet channels 21 are evenly distributed on the air cavity 2 along its circumferential direction, and air or oxidant can enter the air cavity 2 through the air inlet channels 21; the swirl micro-mixing nozzle 3 for built-in plasma combustion assistance can be sealed and fixedly connected to the fuel cavity top plate and the middle partition of the air cavity 2 respectively through the lower thread 315 arranged at the bottom end of the tangential swirl component 31 and the upper thread 314 arranged at the top end of the tangential swirl component 31, and the top end of the mixing tube 33 is arranged through the top partition 4, and the swirl angles of the tangential swirl channels 322 of the multiple swirl micro-mixing nozzles 3 for built-in plasma combustion assistance can be set to the same swirl angle or different swirl angles according to the working conditions.

[0046] When the micro-mixing burner equipped with the swirl micro-mixing nozzle 3 with built-in plasma combustion assistance is working, the cathode electrode 324 is first grounded; fuel is supplied to the fuel chamber 1 through the fuel inlet channel 11, and the fuel enters the fuel channel 332 through the fuel pipe inlet 321 of the fuel pipe 32, and enters the primary mixing chamber of the tangential swirl component 31 through the radial fuel outlet 323; air or oxidant is supplied to the air chamber 2 through the air inlet channel 21, and the air or oxidant enters the tangential swirl component 31 through the air swirl inlet 311, the tangential swirl channel 312, and the air swirl outlet 313 of the tangential swirl component 31 in turn. In the primary mixing chamber; under the swirl action of the tangential swirl channel 312, the air or oxidant with a certain swirl degree entering the primary mixing chamber is preliminarily mixed with the fuel entering the primary mixing chamber at the same time, and the swirl airflow can increase the circumferential and radial flow of the air or oxidant, and improve the mixing effect of the air or oxidant and the fuel. The mixed gas after the preliminary mixing enters the mixed gas channel 332 of the mixing tube 33 through the mixed gas inlet 331 for re-mixing to achieve better mixing uniformity. After the secondary mixed mixed gas passes through the plasma combustion-supporting excitation field, it is ejected through the mixed gas outlet 335 into the combustion chamber for combustion. During the ignition start-up phase and low-load operation, a sufficiently strong AC or pulse voltage can be applied to the anode electrode 333 of the plasma combustion-supporting actuator through the high-voltage cable connector 34, forming a plasma discharge in the plasma combustion-supporting excitation field, so that the secondary mixed gas is broken down to form a discharge and generate a large number of active particles. The mixed gas rich in a large number of active particles is ejected through the mixed gas outlet 335 into the combustion chamber for combustion. The generation of a large number of active particles can significantly increase the chemical reaction rate of the mixed gas, thereby effectively widening the stable combustion range of the micro-mixed burner, so that the micro-mixed burner can maintain stable combustion under wide operating conditions, and improve the adaptability and reliability of the combustion process. When the load changes, the flow ratio of fuel and air or oxidant can be adjusted according to the load, and a sufficiently strong AC or pulse voltage can be applied to the anode electrode 333 of the plasma combustion-supporting actuator through the high-voltage cable connector 34, which can improve the response capability of the micro-mixed burner under dynamic conditions.

[0047] A plurality of built-in plasma-assisted combustion swirl micro-mixing nozzles 3 are symmetrically arranged in an annular multi-layer array structure relative to the center of the air cavity 2. The built-in plasma-assisted combustion swirl micro-mixing nozzle 3 arranged in the center of the air cavity 2 is the first layer of nozzles, and a plurality of built-in plasma-assisted combustion swirl micro-mixing nozzles 3 uniformly arranged around the first layer of nozzles at a set interval are the second layer of nozzles. By analogy, an array nozzle of an annular multi-layer array structure is formed. Different air swirl degrees can be staggered for different layers of nozzles according to different working conditions (that is, different swirl degrees are set according to the number of layers: the swirl degrees of the tangential swirl channels 312 of the built-in plasma-assisted combustion swirl micro-mixing nozzles 3 located on the same layer are the same, and the tangential swirls of the built-in plasma-assisted combustion swirl micro-mixing nozzles 3 located on different layers are different). The swirl degrees of the tangential swirl channels 312 are different), or different air swirl degrees are staggered for the same layer of nozzles (that is, the swirl degrees of the tangential swirl channels 312 of the multiple built-in plasma-assisted swirl micro-mixing nozzles 3 located on the same layer are different and staggered), so as to achieve the staged coupled combustion of multiple nozzles in a large space, and achieve the purpose of enhancing combustion stability and improving temperature uniformity. Taking the staggered setting of different air swirl degrees for nozzles in different layers as an example, it can be achieved that the first layer nozzles and the third layer nozzles generate relatively long flames, while the second layer nozzles generate relatively short flames. The low flame can provide high-temperature flue gas for the high flame, thereby achieving the staged coupled combustion of multiple nozzles in a large space, and achieving the purpose of enhancing combustion stability and improving temperature uniformity.

[0048] As an embodiment of the plasma combustion-supporting actuator of the present invention, the plasma combustion-supporting actuator is a dielectric barrier plasma combustion-supporting actuator structure, such as Figures 1 to 4 As shown, the mixing tube 33 is a straight tube structure, the mixed gas channel 332 is an isodiameter annular cavity structure as a whole, and the insulating medium layer 334 is wrapped and arranged on the outside of the anode electrode 333, that is, the cathode electrode 324 is in a bare state, and the anode electrode 333 is in a non-exposed state wrapped by the insulating medium layer 334. The cathode electrode 324, the anode electrode 333, the insulating medium layer 334 and the mixed gas channel 332 can jointly form a dielectric barrier plasma combustion-supporting excitation field. When a sufficiently strong AC or pulse voltage is applied to the anode electrode 333 of the plasma combustion-supporting exciter through the high-voltage cable connector 34, the insulating medium layer 334 and the mixed gas are broken down to form a dielectric barrier discharge.

[0049] As another embodiment of the plasma combustion-supporting actuator of the present invention, the plasma combustion-supporting actuator is a sliding arc plasma combustion-supporting actuator structure, such as Figures 5 to 8As shown, the mixing tube 33 includes a straight tube section at the bottom and a tapered expansion tube section connected to and located at the top of the straight tube section. The tapered expansion tube section with a small bottom diameter and a large top diameter corresponds to the plasma combustion-supporting excitation field. The position of the mixed gas channel 332 corresponding to the plasma combustion-supporting excitation field is a tapered channel structure with a gradually increasing cross-sectional area. The anode electrode 333 corresponds to the cathode electrode 324 and is exposed on the insulating medium layer 334, that is, the cathode electrode 324 and the anode electrode 333 are both in a bare state, and the cathode electrode 324, the anode electrode 333, and the insulating medium layer 334 are exposed. The dielectric layer 334 and the mixture gas channel 332 can jointly form a sliding arc plasma combustion-supporting excitation field. When a sufficiently strong AC or pulse voltage is applied to the anode electrode 333 of the plasma combustion-supporting exciter through the high-voltage cable connector 34, the mixture gas in a swirling state entering the mixture gas channel 332 is punctured by high voltage at the minimum distance between the anode electrode 333 and the cathode electrode 324 to form a sliding arc discharge. Under the blowing of the airflow of the swirling mixture gas, the arc moves in a swirling state toward the mixture gas outlet 335, thereby forming a discharge area in a three-dimensional space.

[0050] In order to achieve a wider range of air swirl adjustment effects, as a further improvement of the present invention, Fig.11 As shown, multiple tangential swirl channels 312 are evenly distributed around the primary mixing chamber, and the swirl degrees of the multiple tangential swirl channels 312 are the same, that is, the multiple tangential swirl channels 312 are symmetrically arranged relative to the center of the primary mixing chamber.

[0051] In order to achieve a better mixing effect, as a further improvement scheme of the present invention, the aperture of the radial fuel outlet 323 is smaller than the aperture of the air swirl outlet 313. When the air or oxidant enters the primary mixing chamber of the tangential swirl component 31 in different directions along each tangential swirl channel 312, the gaseous fuel ejected through the radial fuel outlet 323 can impact the air or oxidant in the swirl state at a larger jet speed, thereby improving the mixing effect of the fuel and air or oxidant.

[0052] To facilitate the full mixing of the fuel and the air or the oxidant, as a further improvement of the present invention, the inner surface of the primary mixing chamber is a regular polygonal structure such as a regular hexagon or a regular octagon. When the air or the oxidant enters the primary mixing chamber of the tangential swirl component 31 in different directions along each tangential swirl channel 312, the inner surface of the primary mixing chamber with the regular polygonal structure can generate turbulence to the airflow, thereby facilitating the full mixing of the fuel and the air or the oxidant.

[0053] In order to allow the fuel to evenly enter the tangential swirl component 31, as a further improvement of the present invention, a plurality of radial fuel outlets 323 are provided, and the plurality of radial fuel outlets 323 are evenly distributed along the circumferential direction of the fuel channel 322 to form a radial fuel outlet assembly, and the radial fuel outlet assemblies are evenly distributed along the axial direction of the fuel channel 322 to form a plurality of groups.

[0054] The swirl micro-mixing nozzle and micro-mixing burner with built-in plasma combustion-assisted combustion can not only realize the high integration of the plasma combustion-assisted combustion exciter in the micro-mixing burner, but also improve the adaptability of the combustion system to multiple fuels, enhance the rapid dynamic response capability under wide operating conditions, and widen the stable combustion range of the combustion chamber.

Claims

1. A swirl micro-mixing nozzle with built-in plasma combustion support, characterized in that: The swirl micro-mixing nozzle (3) comprises a coaxially arranged tangential swirl component (31), a fuel pipe (32) and a mixing pipe (33), and a plasma combustion-supporting exciter arranged on the fuel pipe (32) and the mixing pipe (33); The tangential swirl component (31) is a blind hole sleeve structure with a blind hole coaxially arranged inside, and the opening position of the blind hole is located at the top of the tangential swirl component (31), the blind hole of the tangential swirl component (31) forms a primary mixing chamber, and an air tangential swirl structure is arranged on the outer wall of the primary mixing chamber, and the air tangential swirl structure includes a tangential swirl channel (312) with a swirl angle, and the tangential swirl channel (312) runs through the outer wall of the primary mixing chamber, and the outer end of the tangential swirl channel (312) is an air swirl inlet (311), and the inner end is an air swirl outlet (313); The fuel pipe (32) is a columnar structure with a blind hole coaxially arranged at the bottom end. The blind hole of the fuel pipe (32) is located at the fuel pipe air inlet (321). The blind hole of the fuel pipe (32) forms a fuel channel (322). The bottom end of the fuel pipe (32) penetrates the bottom end of the tangential swirl component (31) and is sealed and fixedly connected to the tangential swirl component (31). The depth dimension of the fuel channel (322) matches the depth dimension of the primary mixing chamber of the tangential swirl component (31). The top end of the fuel pipe (32) extends out and extends to the outside of the top end of the tangential swirl component (31). A radial fuel air outlet (323) is arranged on the fuel channel (322) at a position corresponding to the primary mixing chamber of the tangential swirl component (31). The bottom end of the mixing tube (33) is sealed and fixedly connected to the top end of the primary mixing chamber of the tangential swirl component (31) and is sleeved on the fuel pipe (32). The top end of the mixing tube (33) is flush with the top end of the fuel pipe (32). A mixed gas channel (332) is formed between the inner surface of the mixing tube (33) and the outer surface of the fuel pipe (32). The plasma combustion-supporting exciter is arranged at the top of the fuel pipe (32) and the mixing pipe (33), and comprises a cathode electrode (324), an anode electrode assembly and a high-voltage cable connector (34); the cathode electrode (324) of the ring-shaped structure is fixedly sleeved on the outer surface of the top of the fuel pipe (32); the anode electrode assembly of the ring-shaped structure is fixedly arranged on the inner surface of the top of the mixing pipe (33) at a position directly opposite to the cathode electrode (324); the anode electrode assembly comprises an anode electrode (333) and an insulating medium layer (334), and the insulating medium layer (334) is located between the anode electrode (333) and the inner surface of the mixing pipe (33); the high-voltage cable connector (34) is fixedly arranged on the mixing pipe (33), and the high-voltage cable connector (34) is electrically connected to the anode electrode (333); and a plasma combustion-supporting excitation field is formed between the cathode electrode (324) and the anode electrode assembly.

2. The swirl micro-mixing nozzle with built-in plasma combustion support according to claim 1, characterized in that: The plasma combustion-supporting actuator is a dielectric barrier plasma combustion-supporting actuator structure, the mixing tube (33) is a straight tube structure, the mixed gas channel (332) is an annular cavity structure with equal diameter as a whole, and the insulating medium layer (334) is wrapped and arranged outside the anode electrode (333).

3. The swirl micro-mixing nozzle with built-in plasma combustion support according to claim 1, characterized in that: The plasma combustion-supporting exciter is a sliding arc plasma combustion-supporting exciter structure. The mixing tube (33) includes a straight tube section located at the bottom and a tapered expansion tube section connected to and located at the top of the straight tube section. The tapered expansion tube section with a small diameter at the bottom and a large diameter at the top is set corresponding to the plasma combustion-supporting excitation field. The position of the mixed gas channel (332) corresponding to the plasma combustion-supporting excitation field is a tapered channel structure with a gradually increasing cross-sectional area. The anode electrode (333) corresponds to the cathode electrode (324) and is exposed on the insulating medium layer (334).

4. The swirl micro-mixing nozzle with built-in plasma combustion support according to claim 1, 2 or 3, characterized in that: The swirl angle of the tangential swirl channel (312) ranges from 0° to 65°.

5. The swirl micro-mixing nozzle with built-in plasma combustion support according to claim 1, 2 or 3, characterized in that: A plurality of tangential swirl channels (312) are evenly distributed around the primary mixing chamber, and the swirl degrees of the plurality of tangential swirl channels (312) are the same.

6. The swirl micro-mixing nozzle with built-in plasma combustion support according to claim 1, 2 or 3, characterized in that: The aperture of the radial fuel outlet (323) is smaller than the aperture of the air swirl outlet (313).

7. The swirl micro-mixing nozzle with built-in plasma combustion support according to claim 1, 2 or 3, characterized in that: The inner surface of the primary mixing chamber is a regular polygonal structure.

8. The swirl micro-mixing nozzle with built-in plasma combustion support according to claim 1, 2 or 3, characterized in that: A plurality of radial fuel outlet ports (323) are provided, and the plurality of radial fuel outlet ports (323) are evenly distributed along the circumferential direction of the fuel channel (322) to form a radial fuel outlet assembly, and the radial fuel outlet assembly is evenly distributed along the axial direction of the fuel channel (322) to form a plurality of groups.

9. A micro-mixing burner, comprising a fuel chamber (1), an air chamber (2) and a combustion chamber coaxially and hermetically spaced from bottom to top, the fuel chamber (1) and the air chamber (2) being spaced apart by a fuel chamber top plate, the air chamber (2) and the combustion chamber being spaced apart by a top partition plate (4), a middle partition plate being further provided in the air chamber (2), a fuel intake passage (11) being provided on the fuel chamber (1), and an air intake passage (21) being provided on the air chamber (2); It is characterized in that It also includes a built-in plasma-assisted combustion swirl micro-mixing nozzle (3) as described in claim 1, a plurality of built-in plasma-assisted combustion swirl micro-mixing nozzles (3) are fixedly arranged in the air cavity (2), the bottom end and the top end of the tangential swirl component (31) of the built-in plasma-assisted combustion swirl micro-mixing nozzle (3) are respectively sealed and fixedly connected to the fuel cavity top plate and the middle partition of the air cavity (2), and the top end of the mixing tube (33) is arranged through the top partition (4), and the plurality of built-in plasma-assisted combustion swirl micro-mixing nozzles (3) are symmetrical with respect to the center of the air cavity (2) and form a ring-shaped multi-layer array structure.

10. The micro-mixing burner according to claim 9, characterized in that: A plurality of plasma combustion-supporting swirl micro-mixing nozzles (3) are provided in an annular multi-layer array structure, and different swirl degrees are staggeredly arranged according to different numbers of layers; Alternatively, the plurality of built-in plasma combustion-assisted swirl micro-mixing nozzles (3) are in an annular multi-layer array structure, and the plurality of built-in plasma combustion-assisted swirl micro-mixing nozzles (3) located in the same layer are staggeredly arranged with different swirl degrees.

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