Combustor for hydrogen diffusion re-circulation combustor and hydrogen diffusion re-circulation combustor

Abstract

This invention relates to the field of aero-engine technology, and provides a flame tube and a hydrogen diffusion recirculation combustion chamber for use in a hydrogen diffusion recirculation combustion chamber. The flame tube includes a cylinder, a hydrogen collection box, and air microtubes. The cylinder has a mounting hole at one end and a gas outlet at the other end. The hydrogen collection box is sealed to the mounting hole and contains a gas collection chamber. The hydrogen collection box has a hydrogen inlet communicating with the gas collection chamber. The first end of the air microtube communicates with the external space of the cylinder, and the second end communicates with the interior of the cylinder. Both ends of the air microtube are sealed to the two ends of the hydrogen collection box. A hydrogen injection hole is provided on the side wall of the second end of the air microtube to connect the internal space of the air microtube with the gas collection chamber. Multiple air microtubes are provided, spaced apart. This design solves the problem that existing recirculation combustion chambers are not suitable for micro-mixing diffusion combustion technology.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of aero-engines, in particular to a flame tube for a hydrogen diffusion backflow combustion chamber and a hydrogen diffusion backflow combustion chamber. BACKGROUND

[0002] Micro-mixing diffusion combustion is a combustion method, which realizes a soft and stable combustion process by short-distance and rapid mixing of fuel and air, and then further mixing and combustion in the combustion chamber. Since there is no strong flame and high temperature area during combustion, the safe operation of the combustor can be ensured, and the emission of harmful substances such as nitrogen oxides can be reduced, so micro-mixing diffusion combustion has become one of the key technologies for the development of aero-engines, aerospace propulsion systems and gas turbines.

[0003] As an aero-engine, the backflow combustion chamber is generally used as a combustion chamber in the turboshaft engine. In the turboshaft engine, the backflow combustion chamber is matched with the centrifugal compressor upstream thereof, which can effectively shorten the length of the engine shaft, which can effectively alleviate the rotor dynamics problem of the high-speed turboshaft engine.

[0004] However, the air flowing out of the centrifugal compressor needs to turn 180 degrees to enter the backflow combustion chamber, and the turned air is difficult to be uniformly distributed, which is prone to uneven mixing when mixed with hydrogen, thereby causing local hot spots during combustion in the backflow combustion chamber, resulting in uneven temperature distribution in the backflow combustion chamber, and prone to local hot spots with a temperature higher than 1850k. When the temperature is higher than 1850k, the emission of nitrogen oxides increases sharply, which loses the significance of micro-mixing diffusion combustion.

[0005] Therefore, how to solve the problem that the backflow combustion chamber in the prior art is not suitable for micro-mixing diffusion combustion technology has become an important technical problem to be solved by those skilled in the art. SUMMARY

[0006] The present application provides a flame tube for a hydrogen diffusion backflow combustion chamber, a hydrogen diffusion backflow combustion chamber and a turboshaft engine to solve the defect that the backflow combustion chamber in the prior art is not suitable for micro-mixing diffusion combustion technology.

[0007] The present application provides a flame tube for a hydrogen diffusion backflow combustion chamber, which is arranged in the interior of a combustion chamber case, and the flame tube for the hydrogen diffusion backflow combustion chamber comprises:

[0008] a cylinder body having a cavity in the interior, a mounting hole at a first end of the cylinder body, and a fuel gas outlet at a second end of the cylinder body in communication with the cavity of the cylinder body;

[0009] A hydrogen gas collecting box, a first end of the hydrogen gas collecting box is located outside the cylinder body, a second end of the hydrogen gas collecting box is in sealed connection with the mounting hole, an inside of the hydrogen gas collecting box has a gas collecting cavity, a hydrogen gas inlet is arranged at the first end of the hydrogen gas collecting box, and the hydrogen gas inlet is in communication with the gas collecting cavity;

[0010] An air micro-pipe, penetrating through two ends of the hydrogen gas collecting box, a first end of the air micro-pipe is in communication with an outside space of the cylinder body, a second end of the air micro-pipe is in communication with the cavity of the cylinder body, the two ends of the air micro-pipe are in sealed connection with the two ends of the hydrogen gas collecting box, a hydrogen gas injection hole for connecting an inside space of the air micro-pipe with the gas collecting cavity is arranged on a side wall of the second end of the air micro-pipe, and a plurality of air micro-pipes are arranged.

[0011] According to the flame tube for the hydrogen diffusion backflow combustion chamber provided by the application, the hydrogen gas collecting box is in a circular ring shape, a plurality of groups of air micro-pipes are arranged, each group of air micro-pipes is uniformly distributed along a circumferential direction of the hydrogen gas collecting box, and a plurality of groups of air micro-pipes are uniformly distributed along a radial direction of the hydrogen gas collecting box.

[0012] According to the flame tube for the hydrogen diffusion backflow combustion chamber provided by the application, the hydrogen gas collecting box is in a circular ring shape, and the air micro-pipe comprises:

[0013] A straight pipe section, an axis of the straight pipe section is parallel to an axis of the hydrogen gas collecting box, and a first end of the straight pipe section is connected with a first end of the hydrogen gas collecting box.

[0014] An inclined pipe section, an axis of the inclined pipe section has an angle with the axis of the straight pipe section, a first end of the inclined pipe section is smoothly connected with a second end of the straight pipe section, a second end of the inclined pipe section is connected with a second end of the hydrogen gas collecting box, and the inclined pipe section extends along a circumferential direction of the hydrogen gas collecting box relative to the axis of the straight pipe section.

[0015] According to the flame tube for the hydrogen diffusion backflow combustion chamber provided by the application, the hydrogen gas injection hole is arranged at the second end of the inclined pipe section, and an axis of the hydrogen gas injection hole is perpendicular to the axis of the inclined pipe section.

[0016] And / or, the angle between the axis of the inclined pipe section and the axis of the straight pipe section is 30-45 degrees.

[0017] According to the flame tube for the hydrogen diffusion backflow combustion chamber provided by the application, the hydrogen gas collecting box is in a circular ring shape, and the cylinder body comprises:

[0018] The outer cylinder has openings at both ends. The cross-section of the outer cylinder is circular. The axis of the outer cylinder coincides with the axis of the hydrogen collection box. The first end of the outer cylinder is sealed to the outer circular surface of the hydrogen collection box.

[0019] The inner cylinder has openings at both ends and a circular cross-section. The axis of the inner cylinder coincides with the axis of the hydrogen collection box. The first end of the inner cylinder is sealed to the inner circular surface of the hydrogen collection box. The distance between the second end of the inner cylinder and the outer cylinder is less than the distance between the first end of the inner cylinder and the outer cylinder.

[0020] According to the present invention, a flame tube for a hydrogen diffusion reflux combustion chamber is provided on the outer cylinder, wherein a first through hole and a first guide ring are provided on the outer cylinder, and a plurality of the first through holes are provided at intervals along the circumference of the outer cylinder;

[0021] The first guide ring is disposed inside the outer cylinder, the axis of the first guide ring coincides with the axis of the outer cylinder, the first end of the first guide ring is located on the side of the first through hole away from the second end of the outer cylinder and the first end of the first guide ring is sealed to the outer cylinder, and the second end of the first guide ring extends in a direction close to the second end of the outer cylinder.

[0022] According to the present invention, a flame tube for a hydrogen diffusion reflux combustion chamber is provided, wherein at least two sets of first through holes are provided, and each set of first through holes is distributed at intervals along the axial direction of the outer cylinder, and each set of first through holes is provided with a first guide ring.

[0023] According to the present invention, a flame tube for a hydrogen diffusion reflux combustion chamber is provided at the first end of the inner cylinder, wherein a second through hole and a second guide ring are provided, and a plurality of second through holes are provided at intervals along the circumference of the inner cylinder;

[0024] The second guide ring is disposed inside the inner cylinder, the axis of the second guide ring coincides with the axis of the inner cylinder, the first end of the second guide ring is located on the side of the second through hole away from the second end of the inner cylinder and the first end of the second guide ring is sealed to the inner cylinder, and the second end of the second guide ring extends in a direction close to the second end of the inner cylinder.

[0025] The present invention also provides a hydrogen diffusion recirculation combustion chamber, including a combustion chamber casing, a flame tube and an intake pipe, wherein the flame tube is the flame tube for hydrogen diffusion recirculation combustion chamber described above.

[0026] The flame tube is disposed inside the combustion chamber casing. Gas flow channels are formed between the outer wall of the flame tube and the combustion chamber casing, and between the first end of the flame tube and the combustion chamber casing. An air inlet connected to the gas flow channels is formed between the second end of the flame tube and the second end of the combustion chamber casing. The air at the air inlet is turned 180 degrees at the first end of the flame tube through the gas flow channels, forming a backflow.

[0027] The first end of the intake pipe passes through the first end of the combustion chamber casing, and the second end of the intake pipe is connected to the hydrogen inlet of the flame tube.

[0028] The present invention also provides a turboshaft engine, including the flame tube for the hydrogen diffusion recirculation combustion chamber described above, or including the hydrogen diffusion recirculation combustion chamber described above.

[0029] The present invention provides a flame tube for a hydrogen diffusion recirculation combustion chamber, disposed inside the combustion chamber casing. The flame tube includes a tube body, a hydrogen collection box, and an air microtube. The tube body has an internal cavity, and a mounting hole at its first end for mounting the hydrogen collection box. A gas outlet at the second end of the tube body communicates with the cavity to allow gas to escape from the cavity. The hydrogen collection box is disposed within the mounting hole, with its second end sealed to the hole, and its first end located outside the tube body. The hydrogen collection box has an internal collection chamber, and a hydrogen inlet at its first end communicates with the collection chamber. The hydrogen inlet communicates with the external space of the combustion chamber casing for connection to a hydrogen source, allowing hydrogen to enter the collection chamber of the hydrogen collection box. An air microtube is disposed inside the hydrogen collection box, with both ends extending through both ends of the hydrogen collection box. The first end of the air microtube is connected to the external space of the cylinder, and the second end is connected to the cavity of the cylinder. Both ends of the air microtube are sealed to the ends of the hydrogen collection box. The first end of the air microtube is located inside the combustion chamber casing, allowing air from the combustion chamber casing to enter the cavity of the cylinder. A hydrogen injection hole is provided on the side wall of the second end of the air microtube. This hydrogen injection hole connects the internal space of the air microtube to the collection chamber, allowing hydrogen from the collection chamber to be injected at high speed laterally through the tiny hydrogen injection hole into the high-speed flowing mainstream air inside the air microtube for mixing, and then entering the cavity of the cylinder along with the air. Multiple air microtubes are provided, spaced apart from each other. This configuration allows the flame tube for hydrogen diffusion recirculation combustion chamber provided by this invention to be applied to a recirculation combustion chamber. Air discharged from the centrifugal compressor flows through the combustion chamber casing and then enters the cavity of the tube body through multiple air microtubes. This facilitates uniform air distribution within the cavity. Furthermore, each air microtube is equipped with a hydrogen injection hole, allowing air to be mixed with hydrogen individually. This reduces the size of the reaction zone, enabling rapid short-distance mixing within a small space. This promotes uniform mixing of air and hydrogen, avoiding localized hot spots during combustion. It ensures uniform temperature distribution within the recirculation combustion chamber, reduces nitrogen oxide emissions, and improves the applicability of micro-mixing diffusion combustion technology in recirculation combustion chambers. This solves the problem that existing recirculation combustion chambers are unsuitable for micro-mixing diffusion combustion technology.

[0030] Furthermore, the hydrogen diffusion recirculation combustion chamber provided by the present invention also possesses the various advantages described above, since it has a flame tube for the hydrogen diffusion recirculation combustion chamber as described above.

[0031] Furthermore, the turboshaft engine provided by the present invention also possesses the various advantages described above, as it has a flame tube or hydrogen diffusion recirculation combustion chamber for hydrogen diffusion recirculation combustion chamber as described above. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0033] Figure 1 This is a schematic diagram of the external structure of the hydrogen diffusion reflux combustion chamber provided by the present invention;

[0034] Figure 2 This is a cross-sectional view of the hydrogen diffusion recirculation combustion chamber provided by the present invention (the arrows in the figure indicate the flow paths of air and hydrogen).

[0035] Figure 3 This is a cross-sectional view of the combustion chamber casing provided by the present invention;

[0036] Figure 4 This is a schematic diagram of the external structure of the flame tube for a hydrogen diffusion reflux combustion chamber provided by the present invention;

[0037] Figure 5 This is a schematic diagram of the hydrogen collection box provided by the present invention;

[0038] Figure 6 This is a schematic diagram showing the extension direction of the air microtube provided by the present invention inside the hydrogen collection box;

[0039] Figure 7 This is a schematic diagram showing the distribution of air microtubes inside the hydrogen collection box provided by the present invention;

[0040] Figure 8 This is a schematic diagram of the structure of the air microtube provided by the present invention;

[0041] Figure 9 This is a cross-sectional view of the cylinder provided by the present invention.

[0042] Figure label:

[0043] 1. Combustion chamber casing; 2. Mounting hole; 3. Gas outlet; 4. Hydrogen collection box; 5. Hydrogen inlet; 6. Air microtube; 7. Hydrogen injection hole; 8. Straight pipe section; 9. Inclined pipe section; 10. Outer cylinder; 11. Inner cylinder; 12. First through hole; 13. First guide ring; 14. Second through hole; 15. Second guide ring; 16. Inlet pipe; 17. Air inlet; 18. Gas flow channel. Detailed Implementation

[0044] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0045] The following is combined with Figures 1 to 9 The present invention describes a flame tube for a hydrogen diffusion reflux combustion chamber.

[0046] like Figures 1 to 9 As shown, the flame tube for the hydrogen diffusion recirculation combustion chamber provided in this embodiment of the invention is disposed inside the combustion chamber casing 1 and cooperates with the combustion chamber casing 1 to form a recirculation combustion chamber.

[0047] The flame tube for the hydrogen diffusion reflux combustion chamber includes a tube body, a hydrogen collection box 4, and an air microtube 6.

[0048] Specifically, the cylinder has an internal cavity, and the first end of the cylinder has a mounting hole 2 for mounting a hydrogen gas collection box 4. The second end of the cylinder has a gas outlet 3, which is connected to the cavity of the cylinder to allow the gas inside the cavity to be discharged.

[0049] The hydrogen collection box 4 is installed inside the mounting hole 2. The second end of the hydrogen collection box 4 is sealed to the mounting hole 2, and the first end of the hydrogen collection box 4 is located outside the cylinder.

[0050] The hydrogen gas collection box 4 has a gas collection chamber inside, and a hydrogen inlet 5 is provided at the first end of the hydrogen gas collection box 4, which is connected to the gas collection chamber. The hydrogen inlet 5 is connected to the external space of the combustion chamber casing 1 and is used to connect to a hydrogen source so that hydrogen can enter the gas collection chamber of the hydrogen gas collection box 4.

[0051] An air microtube 6 is disposed inside the hydrogen collection box 4, with both ends of the air microtube 6 penetrating both ends of the hydrogen collection box 4. The first end of the air microtube 6 is connected to the external space of the cylinder, and the second end of the air microtube 6 is connected to the cavity of the cylinder. Both ends of the air microtube 6 are respectively sealed to both ends of the hydrogen collection box 4. The first end of the air microtube 6 is located inside the combustion chamber casing 1, and is used to allow air from the combustion chamber casing 1 to enter the cavity of the cylinder.

[0052] A hydrogen injection hole 7 is provided on the side wall of the second end of the air microtube 6. The hydrogen injection hole 7 is used to connect the internal space of the air microtube 6 with the gas collection chamber, so that the hydrogen in the gas collection chamber can be injected at high speed laterally into the high-speed flowing mainstream air in the air microtube 6 through the extremely small hydrogen injection hole 7 and mixed with it, and enter the cavity of the cylinder along with the air.

[0053] Multiple air microtubes 6 are provided, and the air microtubes 6 are distributed at intervals. Air in the combustion chamber casing 1 can enter the cavity of the cylinder through each air microtube 6. Each air microtube 6 has a hydrogen injection hole 7 at its second end. The air in each air microtube 6 can be mixed with hydrogen individually, and the hydrogen is mixed with the air flowing to the hydrogen injection hole 7 in real time.

[0054] This configuration allows the flame tube for the hydrogen diffusion recirculation combustion chamber provided in this embodiment of the invention to be applied to a recirculation combustion chamber. Air discharged from the centrifugal compressor flows through the combustion chamber casing 1 and then enters the cavity of the tube body through multiple air microtubes 6, which facilitates uniform air distribution within the cavity. Furthermore, each air microtube 6 is equipped with a hydrogen injection hole 7, allowing air in each microtube 6 to be mixed with hydrogen individually. This reduces the size of the reaction zone, enabling rapid mixing over short distances within a small space, which promotes uniform mixing of air and hydrogen. This avoids the problem of localized hot spots during combustion, ensures uniform temperature distribution within the recirculation combustion chamber, reduces nitrogen oxide emissions, and improves the applicability of micro-mixing diffusion combustion technology in recirculation combustion chambers. It also solves the problem that existing recirculation combustion chambers are not suitable for micro-mixing diffusion combustion technology.

[0055] In this embodiment of the invention, the hydrogen gas collection box 4 is set to an annular shape, and correspondingly, the cylinder body needs to be set to a hollow cylindrical shape, and the combustion chamber casing 1 also needs to be set to a hollow cylindrical shape.

[0056] Reference Figure 2 The outer diameter of the hydrogen collection box 4 and the outer diameter of the cylinder are both smaller than the inner diameter of the combustion chamber casing 1. Spacing exists between the side wall of the cylinder and the side wall of the combustion chamber casing 1, between the side wall of the hydrogen collection box 4 and the side wall of the combustion chamber casing 1, and between the end wall of the hydrogen collection box 4 and the end arm of the combustion chamber casing 1, forming a gas flow channel 18 for air circulation. An air inlet 17 is provided at one end of the gas flow channel 18 corresponding to the second end of the cylinder, allowing air discharged from the centrifugal compressor to enter the gas flow channel 18 and then enter the inner cavity of the cylinder through various air microtubes 6.

[0057] The aforementioned air microtubes 6 are provided in multiple sets, with each set of air microtubes 6 evenly distributed circumferentially along the hydrogen gas collecting box 4, and multiple sets of air microtubes 6 evenly distributed radially along the hydrogen gas collecting box 4, as shown in the reference. Figures 5 to 7 It is equipped with three sets of air microtubes 6.

[0058] In this embodiment of the invention, the air microtube 6 is non-linear. The air microtube 6 includes a straight tube section 8 and an inclined tube section 9. Both the straight tube section 8 and the inclined tube section 9 are disposed inside the hydrogen collection box 4. The first end of the straight tube section 8 is connected to the first end of the hydrogen collection box 4. The first end of the inclined tube section 9 is smoothly connected to the second end of the straight tube section 8. The second end of the inclined tube section 9 is connected to the second end of the hydrogen collection box 4.

[0059] The axis of the straight pipe section 8 is parallel to the axis of the hydrogen collection box 4, while the axis of the inclined pipe section 9 forms an angle with the axis of the straight pipe section 8. The inclined pipe section 9 extends circumferentially along the hydrogen collection box 4 relative to the axis of the straight pipe section 8. Understandably, the axis of the inclined pipe section 9 is not perpendicular to the end face of the second end of the hydrogen collection box 4. The axis of the inclined pipe section 9 is inclined relative to both the end face of the second end of the hydrogen collection box 4 and the axis of the hydrogen collection box 4. When air and hydrogen enter the inner cavity of the cylinder from the second end of the air microtube 6, they possess both axial and circumferential velocity components. Both air and hydrogen have a certain circumferential velocity, forming circumferential rotation, which promotes further mixing of hydrogen and air. During combustion, this circumferential rotation prevents the flame from drifting and stabilizes the flame. Furthermore, the circumferential rotation of air and hydrogen promotes the transfer of circumferential heat, resulting in a uniform circumferential temperature distribution in the cylinder, further reducing the possibility of local hot spots, and enabling a uniform temperature distribution at the gas outlet 3, reducing the radial temperature distribution coefficient at the gas outlet 3, lowering the requirements for turbine blade strength, and improving the applicability of the combustion chamber.

[0060] In this embodiment, the angle between the axis of the inclined pipe section 9 and the axis of the straight pipe section 8 is 30 to 45 degrees. The larger this angle is, the greater the number of air swirls along the circumference of the cylinder, and the more uniform the temperature distribution at the gas outlet 3. Specifically, this angle also needs to be matched with the inlet of the turbine guide vane located at the gas outlet 3.

[0061] In this embodiment, the hydrogen injection hole 7 is located at the second end of the inclined tube section 9, adjacent to the end of the inclined tube section 9, which facilitates processing and manufacturing. Moreover, the hydrogen is injected at the outlet end of the air microtube 6, which can avoid the problems of spontaneous combustion and backfire caused by premixing.

[0062] The axis of the hydrogen injection hole 7 is perpendicular to the axis of the inclined tube section 9. When the hydrogen in the gas collecting chamber flows into the connecting tube, the direction of hydrogen flow is perpendicular to the direction of air flow, which is conducive to hydrogen penetrating the air jet, strengthening the mixing of hydrogen and air, and improving the mixing uniformity.

[0063] In a specific embodiment, the diameter of the air microtube 6 can be set to 4-8 mm, the diameter of the hydrogen injection hole 7 can be set to 0.6-0.8 mm, and the hydrogen injection speed can be controlled at 500-800 m / s, specifically determined according to the requirements of the hydrogen and air flow ratio of the micro-mixing diffusion combustion technology.

[0064] In this embodiment of the invention, the cylinder includes an outer cylinder 10 and an inner cylinder 11. Both the inner cylinder 11 and the outer cylinder 10 are cylindrical structures with openings at both ends. The cross-sections of the inner cylinder 11 and the outer cylinder 10 are circular. The axes of the outer cylinder 10 and the inner cylinder 11 coincide with the axis of the hydrogen gas collecting box 4.

[0065] The first end of the outer cylinder 10 is fitted over the second end of the hydrogen collection box 4, and the first end of the outer cylinder 10 is sealed to the outer circular surface of the hydrogen collection box 4. The first end of the inner cylinder 11 extends into the inner circle of the second end of the hydrogen collection box 4, and the first end of the inner cylinder 11 is sealed to the inner circular surface of the hydrogen collection box 4. The outer cylinder 10 is fitted over the inner cylinder 11, and the space between the outer cylinder 10 and the inner cylinder 11 forms the cavity of the aforementioned cylinder.

[0066] The distance between the second end of the inner cylinder 11 and the outer cylinder 10 is less than the distance between the first end of the inner cylinder 11 and the outer cylinder 10, as shown in the reference. Figure 9 The cavity of the cylinder is narrowed at the second end of the cylinder, which can effectively prevent the gas from forming a vortex at the gas outlet 3, ensuring that the gas can be discharged smoothly from the gas outlet 3, avoiding the problem of damage to the flame tube due to the inability of the gas to be discharged effectively, and at the same time, it can improve the heat capacity of the flame tube to a certain extent.

[0067] In this embodiment of the invention, a first through hole 12 and a first guide ring 13 are provided on the outer cylinder 10.

[0068] The first through hole 12 connects the gas flow channel 18 to the cavity of the cylinder, and some of the air in the gas flow channel 18 can enter the cylinder through the first through hole 12.

[0069] like Figure 9 As shown, the first guide ring 13 is disposed inside the outer cylinder 10. The axis of the first guide ring 13 coincides with the axis of the outer cylinder 10. The first end of the first guide ring 13 is located on the side of the first through hole 12 away from the second end of the outer cylinder 10. The first end of the first guide ring 13 is sealed to the outer cylinder 10. The second end of the first guide ring 13 extends in the direction close to the second end of the outer cylinder 10.

[0070] There is a gap between the first guide ring 13 and the outer cylinder 10. After passing through the first through hole 12, some of the air in the gas flow channel 18 flows along the inner wall of the outer cylinder 10 towards the second end of the cylinder under the action of the first guide ring 13. The temperature of the air in the gas flow channel 18 is relatively low. When it flows along the inside of the outer cylinder 10, it can cool the wall surface of the outer cylinder 10 and reduce wall wear.

[0071] Multiple first through holes 12 are provided, and the multiple first through holes 12 are evenly distributed along the circumference of the outer cylinder 10, so that the air flowing along the inner wall surface of the outer cylinder 10 is evenly distributed, which is conducive to the uniform cooling of the outer cylinder 10 and ensures uniform temperature distribution.

[0072] In this embodiment, at least two sets of first through holes 12 are provided, and each set of first through holes 12 is distributed at intervals along the axial direction of the outer cylinder 10. Each set of first through holes 12 is provided with a first guide ring 13.

[0073] Reference Figure 2 , Figure 4 and Figure 9 There are two sets of first through holes 12 and two sets of first guide rings 13. One set of first through holes 12 is located at the first end of the outer cylinder 10, and the other set of first through holes 12 is located adjacent to the second end of the outer cylinder 10. There are two sets of first guide rings 13, with one first guide ring 13 corresponding to each set of first through holes 12.

[0074] By placing one set of first through holes 12 adjacent to the second end of the outer cylinder 10, the temperature at the gas outlet 3 can be reduced.

[0075] In this embodiment of the invention, a second through hole 14 and a second guide ring 15 are provided at the first end of the inner cylinder 11.

[0076] The second through hole 14 connects the gas flow channel 18 to the cavity of the cylinder, and some of the air in the gas flow channel 18 can enter the cylinder through the second through hole 14.

[0077] like Figure 9 As shown, the second guide ring 15 is disposed inside the inner cylinder 11. The axis of the second guide ring 15 coincides with the axis of the inner cylinder 11. The first end of the second guide ring 15 is located on the side of the second through hole 14 away from the second end of the inner cylinder 11. The first end of the second guide ring 15 is sealed to the inner cylinder 11. The second end of the second guide ring 15 extends in the direction close to the second end of the inner cylinder 11.

[0078] There is a gap between the second guide ring 15 and the inner cylinder 11. After passing through the second through hole 14, some of the air in the gas flow channel 18 flows along the inner wall of the inner cylinder 11 towards the second end of the cylinder under the action of the second guide ring 15. The temperature of the air in the gas flow channel 18 is relatively low. When it flows along the inside of the inner cylinder 11, it can cool the wall surface of the inner cylinder 11 and reduce wall wear.

[0079] Multiple second through holes 14 are provided, and the multiple second through holes 14 are evenly distributed and spaced apart along the circumference of the inner cylinder 11, so that the air flowing along the inner wall surface of the inner cylinder is evenly distributed, which is conducive to the uniform cooling of the inner cylinder 11 and ensures uniform temperature distribution.

[0080] The aforementioned first through hole 12 and second through hole 14 can be provided in 60 to 90 numbers.

[0081] In this embodiment of the invention, the flame tube used for the hydrogen diffusion reflux combustion chamber allows the air in the gas flow channel 18 to flow relatively smoothly from the outside to the inside along the radial direction of the tube body. The air changes from a direction parallel to the axis of the tube body to an oblique direction, and mixes with the high-speed hydrogen ejected from the hydrogen injection hole 7 at the second end of the air microtube 6. This facilitates the penetration of hydrogen in the air jet, strengthens the mixing of hydrogen and air, and improves the uniformity of mixing.

[0082] Furthermore, the flame tube used for hydrogen diffusion recirculation combustion chamber allows most of the air in the gas flow channel 18 to enter the tube body through the air microtube 6 on the hydrogen collection box 4, increasing the air flow rate and helping to increase the air ratio in the main combustion zone of the tube body. The air ratio can reach 45% to 60%, and the hydrogen-air ratio range in the main combustion zone is 0.012 to 0.016, realizing lean combustion in the main combustion zone, making combustion more stable and ignition more controllable, which is conducive to improving the output of engine power. It also reduces the adiabatic flame temperature of hydrogen combustion, making the combustion temperature in the main combustion zone less than 1862K, reducing nitrogen oxide emissions, and making it more environmentally friendly.

[0083] The flame tube for hydrogen diffusion recirculation combustion chamber provided in this embodiment of the invention realizes the application of micro-mixing diffusion combustion technology in the recirculation combustion chamber of a small engine, providing a new approach to the design of hydrogen fuel recirculation combustion chambers for small engines.

[0084] On the other hand, embodiments of the present invention also provide a hydrogen diffusion recirculation combustion chamber, including a combustion chamber casing 1, an intake pipe 16, and a flame tube for the hydrogen diffusion recirculation combustion chamber provided in any of the above embodiments. The flame tube for the hydrogen diffusion recirculation combustion chamber provided in the above embodiments can improve the applicability of micro-mixing diffusion combustion technology in recirculation combustion chambers. Therefore, the hydrogen diffusion recirculation combustion chamber in this embodiment achieves micro-mixing diffusion combustion, resulting in uniform temperature distribution during combustion and low nitrogen oxide emissions. The derivation process of the beneficial effects of the hydrogen diffusion recirculation combustion chamber in the embodiments of the present invention is largely similar to the derivation process of the beneficial effects of the flame tube for the hydrogen diffusion recirculation combustion chamber described above, and therefore will not be repeated here.

[0085] In this embodiment, the flame tube is disposed inside the combustion chamber casing 1. Gas flow channels 18 are formed between the outer wall of the flame tube and the combustion chamber casing 1, and between the first end of the flame tube and the combustion chamber casing 1. An air inlet 17 is formed between the second end of the flame tube and the second end of the combustion chamber casing 1. The air inlet 17 is connected to the gas flow channel 18, allowing the air discharged from the centrifugal compressor to enter the hydrogen diffusion reflux combustion chamber. The air at the air inlet 17 undergoes a 180-degree turn at the first end of the flame tube through the gas flow channel 18, forming a reflux.

[0086] The first end of the intake pipe 16 is located at the first end of the flame tube. The intake pipe 16 passes through the first end of the combustion chamber casing 1. The first end of the intake pipe 16 is used to connect to the hydrogen source. The second end of the intake pipe 16 is connected to the hydrogen inlet 5 of the flame tube.

[0087] In another aspect, embodiments of the present invention also provide a turboshaft engine, including the flame tube or hydrogen diffusion recirculation combustion chamber provided in any of the above embodiments. It possesses all the advantages of the flame tube for hydrogen diffusion recirculation combustion chamber described above, which will not be repeated here. The derivation process of the beneficial effects of the turboshaft engine in the embodiments of the present invention is largely similar to the derivation process of the beneficial effects of the flame tube or hydrogen diffusion recirculation combustion chamber described above, and therefore will not be repeated here.

[0088] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A flame tube for a hydrogen diffusion reflux combustion chamber, characterized in that, Located inside the combustion chamber casing, the flame tube for hydrogen diffusion recirculation combustion chamber includes: The cylinder has an internal cavity, a first end of the cylinder has a mounting hole, and a second end of the cylinder has a gas outlet that communicates with the cavity of the cylinder. The hydrogen gas collecting box has a first end located outside the cylinder, a second end sealed to the mounting hole, an internal gas collecting chamber, a hydrogen inlet at the first end of the hydrogen gas collecting box, and the hydrogen inlet connected to the gas collecting chamber. The hydrogen gas collecting box is annular in shape. An air microtube extends through both ends of the hydrogen collection box. The first end of the air microtube communicates with the external space of the cylinder, and the second end communicates with the cavity of the cylinder. Both ends of the air microtube are sealed to both ends of the hydrogen collection box. A hydrogen injection hole is provided on the sidewall of the second end of the air microtube to connect the internal space of the air microtube to the collection chamber. Multiple air microtubes are provided, spaced apart. Each air microtube includes a straight section and an inclined section. The axis of the straight section is parallel to the axis of the hydrogen collection box, and its first end is connected to the first end of the hydrogen collection box. The axis of the inclined section forms an angle with the axis of the straight section, and its first end is smoothly connected to the second end of the straight section. The second end of the inclined section is connected to the second end of the hydrogen collection box, and the inclined section extends circumferentially along the hydrogen collection box relative to the axis of the straight section.

2. The flame tube for a hydrogen diffusion recirculation combustion chamber according to claim 1, characterized in that, The hydrogen collection box is circular in shape, and multiple sets of air microtubes are provided. Each set of air microtubes is evenly distributed along the circumference of the hydrogen collection box, and the multiple sets of air microtubes are evenly distributed along the radial direction of the hydrogen collection box.

3. The flame tube for a hydrogen diffusion recirculation combustion chamber according to claim 1, characterized in that, The hydrogen injection hole is located at the second end of the inclined tube section, and the axis of the hydrogen injection hole is perpendicular to the axis of the inclined tube section. And / or, the angle between the axis of the inclined pipe section and the axis of the straight pipe section is 30 to 45 degrees.

4. The flame tube for a hydrogen diffusion recirculation combustion chamber according to claim 1, characterized in that, The cylindrical body includes: The outer cylinder has openings at both ends. The cross-section of the outer cylinder is circular. The axis of the outer cylinder coincides with the axis of the hydrogen collection box. The first end of the outer cylinder is sealed to the outer circular surface of the hydrogen collection box. The inner cylinder has openings at both ends and a circular cross-section. The axis of the inner cylinder coincides with the axis of the hydrogen collection box. The first end of the inner cylinder is sealed to the inner circular surface of the hydrogen collection box. The distance between the second end of the inner cylinder and the outer cylinder is less than the distance between the first end of the inner cylinder and the outer cylinder.

5. The flame tube for a hydrogen diffusion recirculation combustion chamber according to claim 4, characterized in that, The outer cylinder is provided with a first through hole and a first guide ring, and multiple first through holes are provided at intervals along the circumference of the outer cylinder; The first guide ring is disposed inside the outer cylinder, the axis of the first guide ring coincides with the axis of the outer cylinder, the first end of the first guide ring is located on the side of the first through hole away from the second end of the outer cylinder and the first end of the first guide ring is sealed to the outer cylinder, and the second end of the first guide ring extends in a direction close to the second end of the outer cylinder.

6. The flame tube for a hydrogen diffusion recirculation combustion chamber according to claim 5, characterized in that, The first through hole is provided in at least two sets, and the first through holes in each set are distributed at intervals along the axial direction of the outer cylinder. Each set of the first through holes is provided with a first guide ring.

7. The flame tube for a hydrogen diffusion recirculation combustion chamber according to claim 4, characterized in that, The first end of the inner cylinder is provided with a second through hole and a second guide ring, and multiple second through holes are provided at intervals along the circumference of the inner cylinder; The second guide ring is disposed inside the inner cylinder, the axis of the second guide ring coincides with the axis of the inner cylinder, the first end of the second guide ring is located on the side of the second through hole away from the second end of the inner cylinder and the first end of the second guide ring is sealed to the inner cylinder, and the second end of the second guide ring extends in a direction close to the second end of the inner cylinder.

8. A hydrogen diffusion reflux combustion chamber, characterized in that, It includes a combustion chamber casing, a flame tube, and an intake pipe, wherein the flame tube is the flame tube for hydrogen diffusion recirculation combustion chamber as described in any one of claims 1 to 7; The flame tube is disposed inside the combustion chamber casing. Gas flow channels are formed between the outer wall of the flame tube and the combustion chamber casing, and between the first end of the flame tube and the combustion chamber casing. An air inlet connected to the gas flow channels is formed between the second end of the flame tube and the second end of the combustion chamber casing. The air at the air inlet is turned 180 degrees at the first end of the flame tube through the gas flow channels, forming a backflow. The first end of the intake pipe passes through the first end of the combustion chamber casing, and the second end of the intake pipe is connected to the hydrogen inlet of the flame tube.

9. A turboshaft engine, characterized in that, It includes the flame tube for a hydrogen diffusion recirculation combustion chamber as described in any one of claims 1 to 7, or the hydrogen diffusion recirculation combustion chamber as described in claim 8.

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