Combustion for thermoacoustic engines and thermoacoustic power generation systems

Abstract

This invention relates to the field of burner technology, providing a burner for a thermoacoustic engine and a thermoacoustic power generation system. The burner for the thermoacoustic engine includes a fuel mixing device, a combustion chamber, and an ignition device. The fuel mixing device includes a first outer shell, an air inlet and a fuel inlet located within the first outer shell, and multiple branch tube bundles located within the first outer shell. A fuel chamber is formed between the multiple branch tube bundles and the inner wall of the first outer shell, and the fuel chamber is isolated from the inner cavities of the multiple branch tube bundles. The first ends of each of the multiple branch tube bundles are connected to the air inlet, and the fuel inlet is connected to the fuel chamber. Injection holes are provided on the side walls of the branch tube bundles. The fuel mixing device is located at the first end of the combustion chamber, and the second ends of the multiple branch tube bundles are connected to the inner cavity of the combustion chamber. The second end of the combustion chamber is used for the hot head of the thermoacoustic engine to extend into. An exhaust gas outlet is provided on the side wall of the combustion chamber. The ignition device is located inside the combustion chamber. This allows for thorough mixing of fuel and air, achieving uniform heating of the hot head of the thermoacoustic engine.

Description

Technical Field

[0001] This invention relates to the field of burner technology, and more particularly to a burner for a thermoacoustic engine and a thermoacoustic power generation system. Background Technology

[0002] As an external combustion power unit, the thermoacoustic engine relies on a continuous external heat source to supply heat to the heat head. The uniformity of the surface temperature distribution of the heat head directly determines the coordination of the expansion and compression processes of the working fluid inside the engine, thus affecting the overall power output and thermal efficiency. Unlike internal combustion engines, the burner of a thermoacoustic engine does not directly convert chemical energy into volume expansion energy to drive the piston. Instead, it acts as a heat supply device, similar to the combustion chamber in a boiler, converting the chemical energy of the fuel into high-temperature thermal energy and transferring it to the alternating flow working fluid inside through the heat head tube wall. Therefore, the burner design not only affects combustion efficiency and emission performance but also directly relates to heating uniformity, operational stability, and engine lifespan. For combustion-type thermoacoustic power generation systems, the burner is the starting point of the entire energy conversion process, and its performance determines whether the system can achieve efficient, reliable, and clean energy utilization. Developing burners specifically for thermoacoustic engines is of great significance.

[0003] In existing combustion technologies, burners are primarily designed for high-pressure, high-power conditions. The pressure inside the combustion chamber is typically above 1 MPa, with large airflow and long flame length. Design objectives focus on load regulation and outlet temperature distribution coefficient. In contrast, burners used in thermoacoustic engines operate at atmospheric pressure with relatively low heat loads, but require high uniformity of the hot-head surface temperature. However, existing burners operating at atmospheric pressure often employ single-stage fuel injection structures, lacking effective control over airflow distribution. Fuel and air mixing relies mainly on molecular diffusion, resulting in low mixing efficiency and uneven fuel-air distribution within the combustion chamber. This leads to localized lean combustion and flameout at lower stoichiometric levels, and localized rich combustion and high-temperature zones at higher stoichiometric levels, resulting in uneven combustion chamber temperatures and failing to guarantee the uniformity of the hot-head surface temperature in thermoacoustic engines.

[0004] Therefore, how to ensure that the burner provides uniform heat to the hot head of the thermoacoustic engine is an important issue that the industry urgently needs to address. Summary of the Invention

[0005] This invention aims to solve the technical problems existing in related technologies. To this end, this invention proposes a burner for a thermoacoustic engine, used to uniformly heat the hot head of the thermoacoustic engine.

[0006] The present invention also proposes a thermoacoustic power generation system.

[0007] A burner for a thermoacoustic engine according to an embodiment of the present invention includes: A fuel mixing device includes a first housing, an air inlet, a fuel inlet, and a plurality of split tube bundles. The air inlet and the fuel inlet are disposed in the first housing, and the plurality of split tube bundles are disposed inside the first housing. A fuel chamber is formed between the plurality of split tube bundles and the inner wall of the first housing, and the fuel chamber is isolated from the inner cavity of the plurality of split tube bundles. The first end of each of the plurality of split tube bundles is connected to the air inlet, and the fuel inlet is connected to the fuel chamber. An injection hole is provided on the side wall of each split tube bundle, and the injection hole connects the fuel chamber and the inner cavity of the split tube bundle. The combustion chamber has a fuel mixing device located at the first end, and the second ends of the plurality of split tube bundles are connected to the inner cavity of the combustion chamber. The second end of the combustion chamber is used for the hot head of the thermoacoustic engine to extend into, and the side wall of the combustion chamber is provided with an exhaust gas outlet. An ignition device is disposed inside the combustion chamber and is used to ignite the second end of the split tube bundle.

[0008] According to one embodiment of the present invention, each of the shunt tube bundles has a plurality of sets of injection holes on its sidewall, the plurality of sets of injection holes being spaced apart along the axial direction of the shunt tube bundles, and each set of injection holes including at least one injection hole.

[0009] According to one embodiment of the present invention, in each of the multiple sets of injection holes in the split tube bundle, the injection direction of at least one injection hole in one set of injection holes is set at an angle to the injection direction of at least one injection hole in another set of injection holes.

[0010] According to one embodiment of the present invention, a partition plate is provided in the fuel chamber, the partition plate divides the fuel chamber into a plurality of sub-fuel chambers, the plurality of sub-fuel chambers are distributed along the axial direction of the split tube bundle and are independent of each other, and each sub-fuel chamber is provided with the fuel inlet and at least one set of the injection holes.

[0011] According to one embodiment of the present invention, the cross-sectional shape of the first housing is circular, and the plurality of the shunt tube bundles are divided into multiple groups along the radial direction of the first housing, with each group of the shunt tube bundles distributed at intervals along the circumference of the first housing.

[0012] According to one embodiment of the present invention, a distribution cavity is provided inside the first housing, the distribution cavity being located between the first end of the plurality of shunt tube bundles and the air inlet; The fuel mixing device further includes: A flow guide plate is disposed in the distribution cavity. The outer edge of the flow guide plate is sealed to the inner wall of the first housing. At least one set of distribution holes is provided at the edge of the flow guide plate. The distribution holes penetrate the flow guide plate. Each set of distribution holes is staggered from the air inlet and the first end opening of the split tube bundle.

[0013] According to one embodiment of the present invention, a plurality of exhaust gas outlets are provided, and the plurality of exhaust gas outlets are distributed at intervals along the circumference of the combustion chamber; The burner for the thermoacoustic engine also includes: The gas collection chamber is arranged around the outside of the combustion chamber, and multiple exhaust gas outlets are connected to the gas collection chamber. The gas collection chamber is provided with a total exhaust gas outlet.

[0014] According to one embodiment of the present invention, it further includes: A water-cooling device is located on the side of the gas collection chamber away from the combustion chamber, and the water-cooling device is used to cool the gas collection chamber.

[0015] According to an embodiment of the present invention, a thermoacoustic power generation system includes a thermoacoustic engine and a burner for the thermoacoustic engine as described above, wherein the hot head of the thermoacoustic engine extends into the interior of the burner for the thermoacoustic engine.

[0016] According to one embodiment of the present invention, the thermoacoustic engine is an opposed thermoacoustic engine.

[0017] The above-described one or more technical solutions in the embodiments of the present invention have at least one of the following technical effects: In the burner for a thermoacoustic engine according to this invention embodiment, when fuel and air are mixed, the fuel is not simply mixed with air in a co-current flow. Instead, it forms a fine airflow through a split tube bundle, and the fuel is injected at high speed into the fine airflow in a transverse jet manner through injection holes on the sidewall of the split tube bundle. The strong turbulence generated by the cross-jet method promotes rapid and intense mixing of fuel and air at the microscale, thereby forming a highly uniform premixed gas over a short distance. Moreover, each split tube bundle outputs a premixed gas with highly consistent composition. The combustion does not form a single, unstable central flame, but rather a uniformly distributed micro-flame cluster composed of multiple flames of essentially the same size, temperature, and combustion state. This uniformly distributed micro-flame cluster can uniformly cover and heat the hothead of the thermoacoustic engine, avoiding the problem of localized high or low temperature zones that are common in traditional combustion methods. This ensures the uniformity of the surface temperature distribution of the hothead, improving the efficiency and operational stability of the thermoacoustic engine. In other words, the burner for a thermoacoustic engine provided by this invention embodiment achieves uniform heating of the hothead of the thermoacoustic engine.

[0018] Furthermore, the thermoacoustic power generation system provided in this embodiment of the invention has the advantages of stable operation and high energy conversion efficiency.

[0019] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or related technologies, the drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention and are not considered as limitations on this application. Moreover, those skilled in the art can obtain other drawings based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the burner for a thermoacoustic engine provided by the present invention when it is installed in a thermoacoustic engine.

[0022] Figure 2 This is a schematic diagram of the distribution of the shunt tube bundle provided by the present invention.

[0023] Figure 3 This is a schematic diagram of the structure of the burner for a thermoacoustic engine provided by the present invention when only one set of injection holes is provided on each split tube bundle.

[0024] Figure 4 This is a schematic diagram of the structure provided by the present invention for setting two sets of injection holes on each split tube bundle of a thermoacoustic engine.

[0025] Figure 5 This is a schematic diagram of the structure of a thermoacoustic engine with two sub-fuel chambers provided by the present invention.

[0026] Figure 6 This is a schematic diagram of the structure of the thermoacoustic power generation system provided by the present invention when the opposed thermoacoustic engine shares the expansion chamber.

[0027] Figure 7 This is a schematic diagram of the structure of the thermoacoustic power generation system provided by the present invention when the opposed thermoacoustic engine shares a power piston.

[0028] Figure label: 1. First outer casing; 2. Air inlet; 3. Fuel inlet; 4. Diverter tube bundle; 5. Injection orifice; 6. Fuel chamber; 7. Combustion chamber; 8. Heat head; 9. Exhaust outlet; 10. Divider plate; 11. Sub-fuel chamber; 12. Distribution chamber; 13. Guide plate; 14. Distribution hole; 15. Gas collection chamber; 16. Total exhaust outlet; 17. Water cooling device; 18. Expansion chamber; 19. Power piston; 20. Regenerator; 21. Cooler. Detailed Implementation

[0029] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0030] The terms “center,” “longitudinal,” “lateral,” “length,” “width,” “thickness,” “upper,” “lower,” “front,” “rear,” “left,” “right,” “vertical,” “horizontal,” “top,” “bottom,” “inner,” “outer,” “clockwise,” “counterclockwise,” “axial,” “radial,” and “circumferential” indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the present invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the present invention.

[0031] Furthermore, features specified as "first" or "second" may explicitly or implicitly include one or more of those features. In the description of this invention, unless otherwise stated, "multiple" means two or more. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0032] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0033] The following is combined Figures 1 to 7 The present invention describes a burner for a thermoacoustic engine.

[0034] As an external combustion power unit, the thermoacoustic engine relies on a continuous external heat source to supply heat to the heat head 8. The uniformity of the surface temperature distribution of the heat head 8 directly determines the coordination of the expansion and compression processes of the working fluid inside the thermoacoustic engine, thus affecting the overall power output and thermal efficiency. Unlike internal combustion engines, the burner of a thermoacoustic engine does not directly convert chemical energy into volume expansion energy to drive the piston. Instead, it acts as a heat supply device, similar to the combustion chamber 7 in a boiler, converting the chemical energy of the fuel into high-temperature thermal energy and transferring it to the internal alternating flow working fluid through the tube wall of the heat head 8. Therefore, the design of the burner not only affects combustion efficiency and emission performance but also directly relates to heating uniformity, operational stability, and engine lifespan. For combustion-type thermoacoustic power generation systems, the burner is the starting point of the entire energy conversion process, and its performance determines whether the system can achieve efficient, reliable, and clean energy utilization. Developing burners specifically for thermoacoustic engines is of great significance.

[0035] like Figures 1 to 7 As shown, the burner for a thermoacoustic engine provided in this embodiment of the invention includes a fuel mixing device, a combustion chamber 7, and an ignition device.

[0036] Specifically, the fuel mixing device includes a first housing 1, an air inlet 2, a fuel inlet 3, and multiple branch pipe bundles 4. The first housing 1 has an internal cavity. The air inlet 2 and fuel inlet 3 are located on the side walls of the first housing 1 and communicate with the cavity. The air inlet 2 is connected to a fan to supply air to the air inlet 2. The fuel inlet 3 is connected to a fuel supply source to supply fuel to the fuel inlet 3.

[0037] Multiple shunt tube bundles 4 are disposed inside the first housing 1. Both ends of the multiple shunt tube bundles 4 are sealed to the inner wall of the first housing 1. A fuel chamber 6 is formed between the multiple shunt tube bundles 4 and the inner wall of the first housing 1, so that the fuel chamber 6 is isolated from the inner cavity of the multiple shunt tube bundles 4.

[0038] In a specific embodiment, end plates can be configured at both ends of multiple shunt tube bundles 4, each end plate having a connecting hole corresponding one-to-one with a shunt tube bundle 4. The first ends of the multiple shunt tube bundles 4 are sealed and connected to the connecting holes of one end plate, and the second ends of the multiple shunt tube bundles 4 are sealed and connected to the connecting holes of the other end plate. The outer edges of the two end plates are then sealed and connected to the inner wall of the first outer casing 1. The space located between the outer wall of the shunt tube bundle 4 and the inner wall of the first outer casing 1, and between the two end plates, is called the fuel chamber 6.

[0039] The first ends of multiple split tube bundles 4 are all connected to air inlets 2. After the air from the air inlets 2 enters the interior of the first outer casing 1, it is split into multiple fine airflows within each split tube bundle 4. The fuel inlet 3 is connected to the fuel chamber 6, allowing fuel from the fuel inlet 3 to enter the fuel chamber 6. The sidewalls of the split tube bundles 4 are provided with injection holes 5, which connect the fuel chamber 6 and the inner cavity of the split tube bundles 4. Fuel in the fuel chamber 6 can be injected into the inner cavity of the split tube bundles 4 through the injection holes 5 to mix with the fine airflows within the split tube bundles 4.

[0040] A fuel mixing device is located at the first end of the combustion chamber 7, and the second ends of multiple split tube bundles 4 are connected to the inner cavity of the combustion chamber 7. After the fuel and the fine airflow are mixed in the split tube bundles 4, they enter the combustion chamber 7.

[0041] An ignition device is located inside the combustion chamber 7. The ignition device is used to ignite the fuel at the second end of the split tube bundle 4, so that the fuel can burn in the combustion chamber 7. The combustion of fuel generates a large amount of heat.

[0042] The second end of the combustion chamber 7 is used for the thermoacoustic engine's hot head 8 to extend into. The heat generated by fuel combustion is transferred to the thermoacoustic engine's hot head 8 to heat the hot head 8, which in turn heats the working fluid inside the thermoacoustic engine, thereby driving the thermoacoustic engine to work.

[0043] The side wall of the combustion chamber 7 is provided with an exhaust gas outlet 9, through which the exhaust gas generated by fuel combustion is discharged.

[0044] With this configuration, when fuel and air are mixed, the fuel does not simply mix with the air in a co-current manner. Instead, it forms a fine airflow through the split tube bundle 4, and the fuel is injected at high speed into the fine airflow in a transverse jet manner through the injection holes 5 on the side wall of the split tube bundle 4. The strong turbulence generated by the cross-jet method promotes rapid and intense mixing of fuel and air at the microscale, thereby forming a highly uniform premixed gas over a short distance. Moreover, each split tube bundle 4 outputs a premixed gas with highly consistent composition. The combustion does not form a single, unstable central flame, but a uniformly distributed micro-flame group composed of multiple flames with basically the same size, temperature, and combustion state. The uniformly distributed micro-flame group can uniformly cover and heat the hot head 8 of the thermoacoustic engine, avoiding the problem of local high or low temperature zones that are prone to occur in traditional combustion methods. This ensures the uniformity of the surface temperature distribution of the hot head 8, improving the efficiency and operational stability of the thermoacoustic engine. In other words, the burner for the thermoacoustic engine provided in this embodiment of the invention achieves uniform heating of the hot head 8 of the thermoacoustic engine.

[0045] The ignition device includes an ignition needle, which is inserted into the combustion chamber 7 and positioned around the second end of the shunt tube bundle 4. The ignition needle is disposed adjacent to the second end of the shunt tube bundle 4.

[0046] The hot head 8 of the thermoacoustic engine includes multiple curved tubular structures. One end of each tubular structure is connected to the expansion chamber 18 of the thermoacoustic engine, and the other end of each tubular structure is connected to the regenerator 20 of the thermoacoustic engine to allow the working fluid to circulate within the thermoacoustic engine. When the burner of the thermoacoustic engine heats the hot head 8, the working fluid within the thermoacoustic engine can be heated.

[0047] The inner diameter of the split tube bundle 4 is 3-5 mm. The smaller inner diameter of the split tube bundle 4 results in a higher gas velocity inside, effectively preventing backfire even when using fuels with characteristics such as fast diffusion and combustion speed, such as hydrogen. Specifically, the inner diameter of the split tube bundle 4 is 4 mm.

[0048] The diameter of the injection hole 5 is 0.5 to 2 mm. Specifically, the diameter of the injection hole 5 is 1 mm.

[0049] The distribution direction of the fuel mixing device and the combustion chamber 7 is a reference direction. In some embodiments, the axis of the split tube bundle 4 can be parallel to the reference direction, and the premixed gas enters the combustion chamber 7 along the reference direction. In other embodiments, the axis of the split tube bundle 4 can be set at an angle to the reference direction, and the velocity direction of the premixed gas entering the combustion chamber 7 can be set at an angle to the reference direction, which is beneficial to forming a vortex flame and making the temperature in the combustion chamber 7 more uniform.

[0050] In this embodiment of the invention, each shunt tube bundle 4 has multiple sets of injection holes 5 on its sidewall, such as... Figure 4 As shown, multiple sets of injection holes 5 are distributed at intervals along the axial direction of the split tube bundle 4, and each set of injection holes 5 includes at least one injection hole 5.

[0051] This configuration creates multiple fuel jets along the axial direction of each split tube bundle 4, forming a multi-stage fuel injection structure. Specifically, after fuel is injected from the upstream set of injection holes 5, a preliminary premixed gas is formed. As the preliminary premixed gas flows downstream, the fuel injected from the downstream set of injection holes 5 cross-jet mixing with the still incompletely mixed preliminary premixed gas. This allows the fuel to be injected into the fine airflow within each split tube bundle 4 in stages and regions, extending the mixing time and contact area between the fuel and air. Moreover, since the fuel is injected into the split tube bundle 4 at different axial positions, the problem of local over-rich or over-lean conditions caused by single-point injection can be avoided, further improving the uniformity of the premixed gas while maintaining the total mixing length (the distance between the injection hole 5 and the second end of the split tube bundle 4).

[0052] In a further embodiment, in each set of multiple injection holes 5 of the split tube bundle 4, the injection direction of at least one injection hole 5 of one set of injection holes 5 is set at an angle to the injection direction of at least one injection hole 5 of another set of injection holes 5.

[0053] This configuration allows fuel jets injected at different axial positions within the splitter bundle 4 to form a more complex and intense cross-jet field. Compared to parallel injection directions, angled injection directions introduce rotating or enhanced vortices into the fine airflow of the splitter bundle 4, thereby increasing the intensity and efficiency of turbulent mixing. Within a limited mixing distance, this promotes faster and more intense mixing of fuel and air at the microscale, resulting in a highly homogeneous premixed gas. This provides a crucial guarantee for the subsequent formation of a uniformly distributed microflame cluster within the combustion chamber 7 and for achieving uniform heating of the thermoacoustic engine's heat head 8.

[0054] Specifically, when each group of injection holes 5 includes only one injection hole 5, the injection directions of the two groups of injection holes 5 need to be different. If each group of injection holes 5 includes multiple injection holes 5, and the multiple injection holes 5 are distributed circumferentially along the split tube bundle 4, then the injection directions of each injection hole 5 in each group of injection holes 5 are different, and there must be injection holes 5 in the two groups of injection holes 5 with different injection directions. In this case, the premixed gas formed is more uniform.

[0055] When setting multiple sets of injection holes 5, the diameters of the injection holes 5 in different sets can be the same or different.

[0056] Regarding the direction of injection orifice 5, its axis can be perpendicular to the axis of the splitter tube bundle 4, i.e., the angle between the axis of injection orifice 5 and the axis of splitter tube bundle 4 is 90 degrees. Alternatively, the angle between the axis of injection orifice 5 and the axis of splitter tube bundle 4 can be set to other angle values. Different angles between the axis of injection orifice 5 and the axis of splitter tube bundle 4 result in different fuel-air mixing speeds, which can be determined according to specific design requirements.

[0057] In a further embodiment, a partition plate 10 is provided inside the fuel chamber 6, which divides the fuel chamber 6 into multiple sub-fuel chambers 11, as shown in the figure. Figure 5 Multiple sub-fuel chambers 11 are distributed along the axial direction of the split tube bundle 4 and are independent of each other. Each sub-fuel chamber 11 is provided with a fuel inlet 3 and at least one set of injection holes 5.

[0058] The partition plate 10 allows for the partitioning and independent control of fuel entering the fuel chamber 6 at different axial positions. Furthermore, the fuel inlets 3 of different sub-fuel chambers 11 can be connected to the same fuel supply source or to different fuel supply sources, providing a structural basis for the simultaneous combustion of multiple fuels.

[0059] When different fuel supply sources are connected to the fuel inlet 3 of different sub-fuel chambers 11, each sub-fuel chamber 11 can be supplied with different types of fuel through its respective fuel inlet 3. For example, one sub-fuel chamber 11 can be supplied with methane gas and another sub-fuel chamber 11 can be supplied with hydrogen gas. The flow ratio of different fuels can be adjusted according to the actual operating conditions such as fuel supply and load demand, thereby realizing the combustion of mixed fuels or the smooth switching between different fuels. This enhances the adaptability of the burner for the thermoacoustic engine provided in this embodiment to changes in fuel composition across the entire range, from methane gas to pure hydrogen gas.

[0060] It should be noted that when using dual-fuel simultaneous combustion, due to the differences in flame propagation speed and adiabatic flame temperature between different fuels, the injection positions and angles of each fuel stage can be designed separately to achieve zoned mixing of different fuels within the splitter bundle 4, forming a gradient fuel concentration field, thereby optimizing the flame structure and temperature distribution. The burner for the thermoacoustic engine in this embodiment can flexibly adapt to a full range of fuel composition changes from pure natural gas to pure hydrogen, providing an ideal solution for the fuel transition period of the thermoacoustic engine and future hydrogen energy applications.

[0061] In this embodiment of the invention, the first outer shell 1 has a circular cross-sectional shape, and multiple shunt tube bundles 4 are divided into multiple groups along the radial direction of the first outer shell 1. Each group of shunt tube bundles 4 is distributed at intervals along the circumference of the first outer shell 1, such as... Figure 2 As shown.

[0062] This concentric array arrangement is conducive to forming a uniformly distributed micro flame group composed of multiple flames of basically the same size and state. The flame group can uniformly cover and heat the hot head 8 of the thermoacoustic engine, thereby avoiding the decrease in heat exchange efficiency and thermal stress problems caused by local overheating or overcooling, and ensuring the uniformity of the surface temperature distribution of the hot head 8.

[0063] In a further embodiment, a distribution cavity 12 is provided inside the first outer shell 1. The distribution cavity 12 is located between the first end of the plurality of diversion tube bundles 4 and the air inlet 2, and is used to provide a buffer and rectification space for the air during the process of air flowing from the air inlet 2 to the plurality of diversion tube bundles 4.

[0064] The fuel mixing device also includes a guide plate 13, which is disposed in the distribution chamber 12. The outer edge of the guide plate 13 is sealed to the inner wall of the first housing 1. At least one set of distribution holes 14 are provided at the edge of the guide plate 13. The distribution holes 14 penetrate the guide plate 13. Each set of distribution holes 14 is staggered with the first end opening of the air inlet 2 and the split tube bundle 4 to avoid the distribution holes 14 being directly opposite to the split tube bundle 4. This avoids the problem that the other split tube bundle 4 cannot fully enter the air because the air passing through the distribution hole 14 directly enters the corresponding split tube bundle 4.

[0065] With this configuration, the air at air inlet 2 no longer flows directly to the first end of the multiple split tube bundles 4, but must instead enter the multiple split tube bundles 4 through the distribution holes 14 on the guide plate 13. The guide plate 13 blocks and redistributes the air entering the distribution chamber 12. Through the evenly distributed distribution holes 14 on the guide plate 13, the relative uniformity of the air flow entering each split tube bundle 4 can be improved, laying the foundation for the subsequent formation of a uniform premixed gas in each split tube bundle 4.

[0066] In this embodiment, the fuel mixing device for the burner of the thermoacoustic engine has a simple structure and the advantages of low flow resistance and low flow resistance loss. When supplying air and fuel to the fuel mixing device, there is no need to specially pressurize the air and fuel.

[0067] The fuel mixing device provided in this embodiment of the invention has a flexible design freedom. Parameters such as the inner diameter of the split tube bundle 4, the number of split tube bundles 4, the arrangement of the split tube bundles 4, and the angle between the axis of the split tube bundle 4 and the reference direction can all be specifically designed according to the geometric characteristics of the hot head 8 and the fuel characteristics. For example, when using hydrogen, which has a relatively fast flame propagation speed, the injection speed of the premixed gas into the combustion chamber 7 can be increased by reducing the inner diameter of the split tube bundle 4, thereby effectively suppressing the risk of backfire. Conversely, when using fuels with a slower flame propagation speed, such as methane, the inner diameter of the split tube bundle 4 or the number of split tube bundles 4 can be appropriately increased to reduce the injection speed of the premixed gas into the combustion chamber 7, ensuring stable combustion of the premixed gas at the second end opening of the split tube bundle 4. Furthermore, the arrangement range of the split tube bundles 4 and the angle between the axis of the split tube bundle 4 and the reference direction can also be designed according to the shape of the hot head 8, so that the flame group can better envelop the surface of the hot head 8.

[0068] The aforementioned key structural parameters can all be quantified and optimized through cold flow simulation, thereby achieving optimal mixing uniformity and combustion adaptability while ensuring low flow resistance, fully demonstrating the flexible adaptability of the combustor for thermoacoustic engines provided by the embodiments of the present invention under multiple fuel and multiple operating conditions.

[0069] In addition, the fuel mixing device and the combustion chamber 7 can be configured as a detachable connection structure, so that different fuel compositions can be adapted by replacing the fuel mixing device with different parameters.

[0070] In this embodiment of the invention, multiple exhaust gas outlets 9 are provided, and these outlets 9 are distributed circumferentially around the combustion chamber 7. The combustion exhaust gases produced after fuel combustion can be discharged from various locations around the circumference of the combustion chamber 7. This avoids the problem of uneven distribution of premixed gas caused by temperature and pressure gradients within the combustion chamber 7 due to unilateral exhaust.

[0071] The burner for the thermoacoustic engine also includes a gas collection chamber 15, which can be configured as an annular cavity, so that the gas collection chamber 15 is arranged around the outside of the combustion chamber 7. Multiple exhaust gas outlets 9 are connected to the gas collection chamber 15, and the gas collection chamber 15 is provided with a total exhaust gas outlet 16.

[0072] The gas collection chamber 15 collects combustion exhaust gases from multiple exhaust outlets 9, simplifying the structure of subsequent exhaust pipes and making the burner structure of the thermoacoustic engine provided in this embodiment more compact and regular. Furthermore, it stabilizes and balances the pressure at each exhaust outlet 9, ensuring uniformity of combustion exhaust gas discharge.

[0073] In this embodiment of the invention, the burner for the thermoacoustic engine further includes a water cooling device 17, which is disposed on the side of the gas collecting chamber 15 away from the combustion chamber 7, and is used to cool the gas collecting chamber 15.

[0074] The gas collection chamber 15 is directly connected to multiple exhaust gas outlets 9 of the combustion chamber 7 to collect high-temperature combustion exhaust gas. The temperature of the gas collection chamber 15 will continue to rise. By setting up a water cooling device 17 to actively cool the gas collection chamber 15, the problem of thermal damage or structural deformation caused by the gas collection chamber 15 being in a high-temperature condition for a long time can be avoided, thus ensuring the stability and reliability of the overall structure of the burner used in the thermoacoustic engine.

[0075] Moreover, and more importantly, the water-cooling device 17 creates a thermal isolation barrier. The water-cooling device 17 effectively isolates key components of the thermoacoustic engine, such as the gas collecting chamber 15 operating at high temperatures, from the combustion chamber 7, and from the temperature-sensitive regenerator 20 and cooler 21. This prevents excess heat from the gas collecting chamber 15 and combustion chamber 7 from being unintendedly transferred to the regenerator 20 and cooler 21, ensuring that the regenerator 20 and cooler 21 operate within their designed optimal temperature range. This provides a guarantee for the safe and reliable operation of the thermoacoustic engine under long-term, high-load conditions.

[0076] Specifically, the water-cooling device 17 includes a second outer shell, which is annular in shape, with its annular inner cavity serving as a flow channel for cooling water. An inlet and an outlet are provided on the second outer shell for the flow of cooling water. The second outer shell is located on the side of the gas collecting chamber 15 away from the combustion chamber 7, and its upper end face contacts the lower end face of the gas collecting chamber 15 to achieve heat exchange.

[0077] In summary, the burner for a thermoacoustic engine provided by this invention employs a micro-mixing structure based on a small-diameter split tube bundle 4, enabling lateral jet cross-mixing of fuel and air within the thin tubular split tube bundle 4, forming a highly uniform premixed gas under normal pressure. Simultaneously, cold-state flow simulation and computational optimization methods are introduced to quantitatively optimize key parameters of the micro-mixing structure, such as the diameter of the split tube bundle 4, the total mixing length (distance between the injection hole 5 and the second end of the split tube bundle 4), and the distance between the guide plate 13 and the first end of the split tube bundle 4. This enhances turbulent mixing while extending the mixing time and improving flow distribution, achieving excellent mixing uniformity and low flow resistance characteristics. Furthermore, the concentric array of split tube bundles 4 creates a uniformly distributed micro-flame cluster that envelops the heat head 8, ensuring uniform heating of the heating surface. The modular design of this burner for a thermoacoustic engine allows for adaptability to different fuels and has the potential to expand to clean fuels such as hydrogen.

[0078] On the other hand, embodiments of the present invention also provide a thermoacoustic power generation system, including a thermoacoustic engine and a burner for the thermoacoustic engine provided in any of the above embodiments, wherein the hot head 8 of the thermoacoustic engine extends into the interior of the burner. The burner for the thermoacoustic engine provided in any of the above embodiments can achieve highly uniform premixing of fuel and air, and can uniformly heat the hot head 8 of the thermoacoustic engine. Therefore, the thermoacoustic power generation system of this embodiment has the advantages of stable operation and high energy conversion efficiency.

[0079] In this embodiment, the fuel used for the burner of the thermoacoustic engine in the thermoacoustic power generation system can be, but is not limited to, natural gas, liquefied petroleum gas, methane, and hydrogen.

[0080] The derivation process of the beneficial effects of the thermoacoustic power generation system in the embodiments of the present invention is largely similar to the derivation process of the beneficial effects of the burner used in the thermoacoustic engine described above, so it will not be repeated here.

[0081] In this embodiment, the thermoacoustic engine is a opposed-type thermoacoustic engine. The opposed-type thermoacoustic engine helps to counteract the vibrations generated during the operation of the thermoacoustic engine, thereby improving the stability and reliability of the thermoacoustic power generation system. Moreover, the opposed-type thermoacoustic engine has a compact structural layout, which correspondingly gives the thermoacoustic power generation system the advantage of a compact structural layout.

[0082] The two opposing thermoacoustic engines can share the expansion chamber 18, such as Figure 6 As shown; the two opposing thermoacoustic engines can also share the power piston 19, such as Figure 7 As shown. In any case, the opposed thermoacoustic engine corresponds to two burners. The intake and exhaust processes of the two burners can be controlled independently or synchronously, thereby achieving independent adjustment and precise balance control of the heating power on both sides.

[0083] Specifically, the opposed thermoacoustic engine corresponds to two combustion chambers 7 and two fuel mixing devices. Each fuel mixing device has an air inlet 2 connected to a fan. These two fans can be controlled separately or synchronously.

[0084] It should be noted that in actual engineering applications, the specific shape and size of the shared expansion chamber 18 and the type of the hot head 8 are not fixed. They need to be specifically optimized according to the load characteristics and operating conditions of the thermoacoustic engine in order to give full play to the performance advantages of the burner used for the thermoacoustic engine in the embodiment of the present invention and meet the requirements of different power levels.

[0085] The aforementioned opposed-type thermoacoustic engine with a shared power piston 19 combines two independent generators into a centrally integrated generator, reducing the amount of material used in permanent magnets and stator coils, simplifying moving parts, reducing the number of friction pairs, and lowering mechanical friction losses. The centrally integrated generator makes full use of the central space, making the overall layout more compact and reducing the axial length of the thermoacoustic power generation system.

[0086] It should be noted that in actual engineering applications, the specific stroke of the shared power piston 19, the diameter of the power piston 19, the arrangement of the permanent magnets, the winding form of the outer stator, and the structural dimensions of the hot head 8 all need to be specifically optimized according to the power level, operating frequency, and load characteristics of the thermoacoustic engine, so as to give full play to the comprehensive performance advantages of the burner and thermoacoustic power generation system used for the thermoacoustic engine in this embodiment and meet the needs of different application scenarios.

[0087] Finally, it should be noted that the above embodiments are only for illustrating the present invention and not for limiting the present invention. Although the present invention has been described in detail with reference to the embodiments, those skilled in the art should understand that various combinations, modifications, or equivalent substitutions of the technical solutions of the present invention do not depart from the spirit and scope of the technical solutions of the present invention and should be covered within the scope of the claims of the present invention.

Claims

1. A burner for a thermoacoustic engine, characterized in that, include: A fuel mixing device includes a first housing (1), an air inlet (2), a fuel inlet (3), and a plurality of split tube bundles (4). The air inlet (2) and the fuel inlet (3) are disposed in the first housing (1). The plurality of split tube bundles (4) are disposed inside the first housing (1). A fuel chamber (6) is formed between the plurality of split tube bundles (4) and the inner wall of the first housing (1). The fuel chamber (6) is isolated from the inner cavity of the plurality of split tube bundles (4). The first end of each of the plurality of split tube bundles (4) is connected to the air inlet (2). The fuel inlet (3) is connected to the fuel chamber (6). An injection hole (5) is provided on the side wall of the split tube bundle (4). The injection hole (5) is connected to the fuel chamber (6) and the inner cavity of the split tube bundle (4). Combustion chamber (7), the fuel mixing device is disposed at the first end of the combustion chamber (7), the second ends of the plurality of the split tube bundles (4) are connected to the inner cavity of the combustion chamber (7), the second end of the combustion chamber (7) is used for the hot head (8) of the thermoacoustic engine to extend into, and the side wall of the combustion chamber (7) is provided with an exhaust gas outlet (9). An ignition device is disposed inside the combustion chamber (7) and is used to ignite at the second end of the shunt tube bundle (4).

2. The burner for a thermoacoustic engine according to claim 1, characterized in that, Each of the shunt tube bundles (4) has a plurality of sets of injection holes (5) on its sidewall. The plurality of sets of injection holes (5) are distributed at intervals along the axial direction of the shunt tube bundles (4). Each set of injection holes (5) includes at least one injection hole (5).

3. The burner for a thermoacoustic engine according to claim 2, characterized in that, In each of the multiple sets of injection holes (5) of the shunt tube bundle (4), the injection direction of at least one injection hole (5) of one set of injection holes (5) is set at an angle to the injection direction of at least one injection hole (5) of another set of injection holes (5).

4. The burner for a thermoacoustic engine according to claim 2 or 3, characterized in that, A partition plate (10) is provided inside the fuel chamber (6). The partition plate (10) divides the fuel chamber (6) into multiple sub-fuel chambers (11). The multiple sub-fuel chambers (11) are distributed along the axial direction of the split tube bundle (4) and are independent of each other. Each sub-fuel chamber (11) is provided with the fuel inlet (3) and at least one set of injection holes (5).

5. The burner for a thermoacoustic engine according to claim 1, characterized in that, The first outer shell (1) has a circular cross-sectional shape. The multiple shunt tube bundles (4) are divided into multiple groups along the radial direction of the first outer shell (1), and each group of shunt tube bundles (4) is distributed circumferentially along the first outer shell (1).

6. The burner for a thermoacoustic engine according to claim 5, characterized in that, The first outer shell (1) is provided with a distribution cavity (12), which is located between the first end of the plurality of the split tube bundles (4) and the air inlet (2); The fuel mixing device further includes: A flow guide plate (13) is disposed in the distribution cavity (12). The outer edge of the flow guide plate (13) is sealed to the inner wall of the first outer shell (1). At least one set of distribution holes (14) is provided at the edge of the flow guide plate (13). The distribution holes (14) penetrate the flow guide plate (13). Each set of distribution holes (14) is staggered from the first end opening of the air inlet (2) and the diversion tube bundle (4).

7. The burner for a thermoacoustic engine according to claim 1, characterized in that, The exhaust gas outlet (9) is provided in multiple ways, and the multiple exhaust gas outlets (9) are distributed at intervals along the circumference of the combustion chamber (7); The burner for the thermoacoustic engine also includes: The gas collection chamber (15) is arranged around the outside of the combustion chamber (7), and multiple exhaust gas outlets (9) are connected to the gas collection chamber (15). The gas collection chamber (15) is provided with a total exhaust gas outlet (16).

8. The burner for a thermoacoustic engine according to claim 7, characterized in that, Also includes: A water cooling device (17) is provided on the side of the gas collection chamber (15) away from the combustion chamber (7), and the water cooling device (17) is used to cool the gas collection chamber (15).

9. A thermoacoustic power generation system, characterized in that, It includes a thermoacoustic engine and a burner for the thermoacoustic engine as described in any one of claims 1-8, wherein the hot head (8) of the thermoacoustic engine extends into the interior of the burner for the thermoacoustic engine.

10. The thermoacoustic power generation system according to claim 9, characterized in that, The thermoacoustic engine is a opposed thermoacoustic engine.

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