Evaporating pipe, flame tube, combustion chamber and engine

Abstract

The invention discloses an evaporation pipe, a flame tube, a combustion chamber and an engine, and relates to the technical field of aviation, the evaporation pipe comprises a pipe body, the center of the pipe body is provided with an airflow channel, a flow guide body is arranged in the pipe body, and a premixing and pre-evaporation cavity is formed between the flow guide body and the inner wall of the airflow channel; the outer wall of the pipe body is provided with an oil inlet leading to the premixing and pre-evaporating cavity, and the oil inlet faces the flow guide body; the preheating channel is located outside the pipe body, an inlet of the preheating channel is suitable for being communicated with a fuel oil main pipe, and an outlet of the preheating channel is communicated with an oil inlet of the pipe body; according to the evaporation pipe provided by the invention, fuel oil and air can be premixed more uniformly.

Description

Technical Field

[0001] The present invention relates to the field of aviation technology, and particularly relates to an evaporation tube, a combustion chamber liner, a combustor and an engine. Background Art

[0002] The combustor of an aeroengine is located between the compressor and the turbine, and is used to convert the chemical energy of fuel into heat energy through combustion, generate high-temperature and high-pressure gas to drive the turbine to do work, and provide power for the aircraft. The combustor includes: a diffuser, a combustor casing, a combustion chamber liner, etc. Among them, the diffuser is a ring-shaped expansion channel structure, which is used to decelerate the high-speed air flow for the first time before entering the combustor. The combustor casing is the outer shell of the combustor, which is used to install and support other components, and is usually made of high-strength and high-temperature-resistant materials. The combustion chamber liner is the main place where combustion occurs. There are various small holes and gaps on the wall of the combustion chamber liner, which are used to introduce air for combustion and cooling.

[0003] In order to pursue excellent performance, traditional combustors use high-precision multi-oil-way centrifugal nozzles and multi-stage swirlers to organize combustion. For example, a micro gas turbine combustor disclosed in Chinese Patent Document CN101818910A uses a combination of multiple swirlers and centrifugal nozzles, and installs the front end of the centrifugal nozzle into the nozzle installation hole of the corresponding swirler. However, the multi-oil-way centrifugal nozzle and multi-stage swirler have complex structures, cumbersome processes and high costs, and it is difficult to meet the requirements of the combustor for cost reduction.

[0004] At present, the main methods for cost reduction design of combustors include integrated design, evaporation tube design, etc. For example, a ring combustor model with integrated head structure and assembly method disclosed in Chinese Patent Document CN114822208A proposes a design and manufacturing scheme for the integrated head structure of the combustor. A kind of engine and its integrated design and manufacturing method of combustion components and combustion components disclosed in Chinese Patent Document CN108592086A proposes a design and manufacturing scheme for the integration of the combustion chamber liner and the nozzle. Both of these two schemes achieve the purpose of reducing the processing and assembly costs of the combustor by reducing the number of components.

[0005] Chinese Patent Document CN117663190A discloses a single-side single-air-intake vortex-stabilized cavity inter-stage combustor, which uses an evaporation tube to match hierarchical flow guiding and a cavity for flame stabilization. Chinese Patent Document CN115468187A discloses an evaporation tube type reverse flow combustor for a micro gas turbine engine, and gives an evaporation tube arrangement scheme that obliquely inserts into the combustion chamber liner from the outer ring cavity. Both of these two technical solutions reduce the manufacturing cost of the combustor by replacing expensive components. Thus, it can be seen that the design idea of using an evaporation tube to replace the centrifugal nozzle is a key path for the combustor to reduce costs. However, the evaporation tube currently mainly has the problem of unsatisfactory atomization performance.

[0006] For this reason, Chinese Patent Document CN116085828A provides a combustion chamber design scheme in which a spiral evaporation tube is matched with a tangential jet. Multiple discharge holes are opened on the spiral evaporation tube to promote the uniform distribution of fuel in the flame tube. Chinese Patent Document CN116792782A discloses an evaporation tube with a swirling device, in which swirling vanes are arranged inside the evaporation tube. The swirling vanes form a swirl to promote the mixing effect of oil and gas, so as to achieve the purpose of strengthening the atomization performance of the evaporation tube.

[0007] However, in the above two solutions, the means adopted to improve the atomization performance of the evaporation tube, such as the spiral evaporation tube and the swirling vanes, make the structure of the evaporation tube too complicated. In this way, even if such evaporation tubes are used to replace the centrifugal nozzles, the effect achieved in terms of cost reduction is not significant. Summary of the Invention

[0008] In view of this, the present invention provides an evaporation tube, a flame tube, a combustion chamber and an engine to solve the problem that the structure of the evaporation tube used to replace the centrifugal nozzle on the flame tube in the existing combustion chamber is relatively complicated.

[0009] In a first aspect, the present invention provides an evaporation tube, comprising:

[0010] A tube body having an air flow channel at the center. A deflector is arranged inside the tube body, and a premixing and pre-evaporation chamber is formed between the deflector and the inner wall of the air flow channel; an oil inlet leading to the premixing and pre-evaporation chamber is arranged on the outer wall of the tube body, and the oil inlet faces the deflector;

[0011] A preheating channel is located outside the tube body. The inlet of the preheating channel is adapted to be connected to a fuel manifold, and the outlet of the preheating channel is connected to the oil inlet of the tube body.

[0012] The technical solution of the present invention has the following advantages:

[0013] Before the fuel enters the tube body of the evaporation tube, it first flows in the preheating channel and is preheated by exchanging heat with an external heat source. After preheating, the viscosity of the fuel decreases and the surface tension decreases, making it easier to atomize into fine oil droplets. When the preheated fuel enters the premixing and pre-evaporation chamber from the oil inlet on the tube body, the fuel is directly sprayed onto the deflector, and under the action of the deflector, the fuel is broken into fine oil droplets. At the same time, the air flow flows in the air flow channel and generates disturbances when passing through the deflector, prompting the oil droplets to come into full contact with the air, so as to achieve a more uniform premixing of fuel and air in the premixing and pre-evaporation chamber.

[0014] Optionally, the fuel inlet is a direct injection type. With this setting, the fuel entering the pre-mixing and pre-evaporation chamber from this fuel inlet impacts on the deflector to form an oil film, which breaks, atomizes, evaporates under the action of aerodynamic force, and mixes with the high-speed air flow to form a relatively uniform fuel-air mixture and enters the combustion chamber to complete combustion. By adjusting the area of the direct injection fuel hole, the pressure loss and velocity distribution of the internal fuel can be controlled. Generally, the diameter of the fuel hole can be 0.5 mm - 1.5 mm.

[0015] Optionally, the preheating channel is U-shaped. The U-shaped structure of the preheating channel makes the flow path of the fuel in the channel longer and the residence time increased. By reasonably controlling the width and spacing of the U-shaped structure, the temperature rise of the fuel can be controlled while reducing the gradient of the head temperature distribution of the combustion chamber.

[0016] There are at least two preheating channels arranged oppositely on both sides of the pipe body. The throttling areas of the two preheating channels may not be the same, and the throttling area can be adjusted according to the head temperature distribution of the combustion chamber to control the fuel flow distribution and balance the heat load distribution.

[0017] The pipe body has at least two fuel inlets arranged at intervals along the air flow channel direction, and each fuel inlet communicates with one preheating channel. The interval arrangement of multiple fuel inlets on the pipe body enables the fuel to be mixed with air at different positions, further enhancing the mixing uniformity.

[0018] Optionally, the preheating channel is of a flat structure. The preheating channel of the flat structure significantly increases the contact area with the surrounding heat medium. Compared with channels with conventional cross-sectional shapes such as circular ones, the flat shape enables the channel wall to be more widely exposed to the thermal environment.

[0019] Optionally, the pipe body is inclined relative to the preheating channel. With the above setting, the angle at which the fuel enters the combustion chamber from the pipe body is changed, so that when the fuel enters the combustion chamber, it can enter at a specific angle, which helps the fuel to be more evenly dispersed.

[0020] Optionally, the pipe body is integrally circumferentially deflected by 30° - 60° relative to the outer mounting surface of the head. That is to say, multiple pipe bodies are integrally deflected in the clockwise or counterclockwise direction on the outer mounting surface of the head; with this setting, the mixture can enter the combustion chamber in a swirling manner. The swirl makes the air flow in the combustion chamber in a strongly disturbed state. This disturbance promotes the energy transfer between different regions, enabling the heat to be more evenly distributed in the combustion chamber.

[0021] Optionally, the tube body is cylindrical, the fluid guide is cylindrical, and the premixing and pre-evaporation chamber is annular; the cylindrical tube body and the cylindrical fluid guide are geometrically adapted to the annular premixing and pre-evaporation chamber. This matching makes the process of air flow entering the premixing and pre-evaporation chamber from the tube body through the fluid guide smoother, reducing the air flow resistance and energy loss caused by sudden shape changes.

[0022] Optionally, the diameter of the inlet section of the premixing and pre-evaporation chamber is greater than the average diameter, the end of the inlet section contracts inward along the air flow direction, and the outlet end of the premixing and pre-evaporation chamber expands outward along the air flow direction. Specifically, the contraction angle of the end of the inlet section is 10° - 30°, the expansion angle of the outlet end is 30° - 60°, the front section of the fluid guide is straight and the rear section expands, and the expansion angle is 30° - 50°. Through the expansion of the outlet end and the rear end of the fluid guide, the oil-gas mixture can be sprayed into the combustion chamber in the form of a hollow cone with a certain cone angle, so that it can be more evenly distributed in the combustion chamber.

[0023] That is to say, the end of the inlet section contracts inward along the air flow direction, accelerating the air flow in the contraction section. The accelerated air flow will form a strong shearing action with the surrounding air, further enhancing the mixing effect of fuel and air. This shearing force can further break and refine the fuel droplets, making them contact the air more fully and improving the uniformity of premixing. The diameter of the inlet section of the premixing and pre-evaporation chamber is greater than the average diameter, forming an expanded area. When the air flow carrying fuel enters the premixing and pre-evaporation chamber from the tube body, the larger inlet space reduces the air flow speed and pressure. This helps the fuel to disperse better around the fluid guide, avoiding fuel concentration in local areas and creating conditions for more uniform mixing of fuel and air. The outlet end of the premixing and pre-evaporation chamber expands outward along the air flow direction, playing a role in rectifying and stabilizing the air flow. The premixed air flow gradually reduces in speed and recovers in pressure in the expansion section, enabling the air flow to be smoothly output to the subsequent combustion area. This helps to form a stable flame in the combustion area, avoiding flame instability or even extinction caused by sudden changes in air flow speed and ensuring the continuous and stable progress of the combustion process.

[0024] In a second aspect, the present invention also provides a combustion chamber, comprising: an inner ring, an outer ring, a head connecting the inner ring and the outer ring, and the evaporation tube according to any one of the above solutions, wherein the evaporation tube is connected to the outside of the head or the outer ring.

[0025] Due to the adoption of the above-mentioned evaporation tube in the technical solution of the present invention, all the advantages of this evaporation tube are thus possessed. Specifically, in the technical solution of the present invention, the characteristics of pre-film atomization and pneumatic atomization of the evaporation tube are utilized. When the fuel impacts the deflector through the oil inlet holes on both sides of the pre-mixing and pre-evaporation chamber, it will spread out to form a liquid film flowing closely along the wall surface. Subsequently, under the action of the gas flow in the pre-mixing and pre-evaporation chamber, the liquid film is pushed and broken to form liquid droplets, which also promotes the mixing of oil and gas, and finally realizes the full atomization, evaporation and pre-mixing of the fuel.

[0026] Optionally, the preheating channel of the evaporation tube is attached to the outer mounting surface of the head; or, the preheating channel is formed on the head, and the evaporation tube and the flame tube are integrally processed. The preheating channel can be used to cool the head of the flame tube. That is to say, the preheating channel of the evaporation tube is used to achieve two functions simultaneously: one is to solve the problem of difficult thermal protection of the middle area of the head of the flame tube due to insufficient gas flow penetration in the starting section, and to cool the head of the flame tube. By cooling the head of the flame tube through the preheating channel, the demand for cooling air volume and the cost of machining cooling holes can be reduced; the other is to heat the fuel through the preheating channel to increase the temperature of the fuel entering the pre-mixing and pre-evaporation chamber, reduce the fuel viscosity and promote fuel atomization. In addition, by integrally processing the evaporation tube and the flame tube, the number of components of the flame tube can be reduced.

[0027] Optionally, there are multiple evaporation tubes on the outer mounting surface of the head, and the multiple evaporation tubes are inclined clockwise or counterclockwise. The preheating channels of the multiple evaporation tubes are connected to the same fuel main pipe through fuel branches. Through the above setting, the multiple evaporation tubes can ensure the uniform distribution of fuel in the circumferential direction of the head of the flame tube. This uniform distribution enables the fuel and air to mix more fully when entering the flame tube, avoiding the situation of local fuel being too rich or too lean. The multiple evaporation tubes are inclined and connected to the head clockwise or counterclockwise, and a certain direction of swirl will be formed when the fuel is ejected. The swirl can extend the residence time of the fuel in the flame tube and further promote the progress of the combustion reaction. The preheating channels of the multiple evaporation tubes are connected to the same fuel main pipe through fuel branches, ensuring the unity and stability of fuel supply. The fuel main pipe can precisely control the total fuel flow rate, and then evenly distribute it to each evaporation tube through the fuel branches, avoiding the problem of uneven fuel supply to each evaporation tube.

[0028] At the head of the flame tube, a compact fuel supply and preheating system is formed by arranging several evaporation tubes circumferentially and connecting them to the main pipe through fuel branches. This compact layout effectively reduces the temperature of the head of the flame tube, reduces the demand for cooling air volume and the machining cost of cooling holes.

[0029] Optionally, one end of the head close to the outer ring has a first air inlet, and a first deflector is provided on the inner wall of the head, and the first deflector opens in the direction of the evaporation tube; one end of the head close to the inner ring has a second air inlet, and a second deflector is provided on the inner wall of the head, and the second deflector opens in the direction away from the evaporation tube.

[0030] With the above arrangement, after part of the air enters the combustion chamber through the first air inlet, under the guiding action of the first deflector, it flows from the outer ring to the inner ring along the inner side of the head of the combustion chamber. After part of the air enters the combustion chamber through the second air inlet, under the guiding action of the second deflector, it flows toward the outlet end along the inner ring; thus, a radial large vortex is formed in the combustion chamber, which helps to more reasonably distribute the heat in the combustion chamber.

[0031] Specifically, the air in the outer ring flows toward the head direction, which can take away part of the heat near the head and prevent the head from being damaged due to excessive temperature. The air in the inner ring flows away from the head direction, which helps to cool the inner ring wall surface and evenly distribute the heat inside the combustion chamber, improving the overall thermal stability of the combustion chamber. Through the arrangement of the first deflector and the second deflector, the air forms a specific flow pattern in the combustion chamber, and this pattern helps to stabilize the flame. It solves the problem that the ignition and extinction performance of the combustion chamber is poor when using a preheated premixed evaporation tube. By adopting a ring vortex flow design with excellent flame propagation characteristics to organize the combustion of oil and gas, on the basis of replacing expensive multi-oil-way centrifugal nozzles and multi-stage swirlers, the stable operation of the combustion chamber is ensured.

[0032] The evaporation tube is connected to the middle section of the mounting surface of the head. On the one hand, because the distance (i.e., the cavity height) between the outer ring and the inner ring of the combustion chamber is relatively large, if it is arranged on the outer ring, it is difficult for the oil-gas mixture to reach the vicinity of the inner ring of the combustion chamber, and the space utilization rate of the combustion chamber is low and the temperature distribution is poor; on the other hand, because of the design method of the radial ring vortex in the head, the coverage range of the air flow entering through the outer ring air inlet is difficult to reach the middle and lower sections of the head, resulting in insufficient thermal protection of the head. Therefore, arranging the evaporator on the head can not only achieve a more uniform distribution of the oil-gas mixture in the entire combustion chamber, but also achieve the cooling of the head of the combustion chamber. The head of the combustion chamber does not require other cooling designs and only relies on the preheating channel to achieve active cooling of the head, saving production costs.

[0033] Optionally, main combustion holes are respectively provided on the opposite surfaces of the inner ring and the outer ring, and the circumferential angle of the main combustion holes is between 10° and 30°. With such an arrangement, the air ejected from the main combustion holes will enter the interior of the combustion chamber at a specific inclination angle, so as to make full use of the space inside the combustion chamber, further increase the residence time of the oil-gas mixture in the combustion chamber, strengthen the circumferential propagation of the flame, and improve the ignition and extinction performance and the outlet temperature distribution of the combustion chamber.

[0034] Optionally, one end of the inner ring away from the head is close to the outer ring, and the inner ring is provided with first mixing holes on the section close to the outer ring, and the outer ring is provided with second mixing holes on the surface opposite to the first mixing holes of the inner ring. By raising the outlet section of the inner ring towards the outer ring in the form of a "convex surface", the distance between the mixing holes on the inner ring and the outer ring is reduced, and the mixing effect is improved.

[0035] Optionally, the circumferential angles of the first mixing holes and the second mixing holes are between 10° and 30°. With the above settings, the air ejected from the mixing holes will enter the inside of the combustion chamber at a specific inclination angle, so as to make full use of the space inside the combustion chamber, thereby increasing the residence time of the fuel-air mixture in the combustion chamber, strengthening the circumferential propagation of the flame, and improving the ignition and extinction performance and the outlet temperature distribution of the combustion chamber.

[0036] Optionally, mixing hoppers are respectively arranged at the main combustion holes and the second mixing holes on the outside of the outer ring, and the mixing hoppers are used to increase the jet penetration depth of the main combustion holes and the mixing holes, and promote the interaction between the jets of the outer ring and the inner ring.

[0037] Optionally, a number of cooling holes are provided on the inner ring and the outer ring, and the circumferential angles of the cooling holes are between 10° and 30°. That is to say, all the openings on the combustion chamber have a circumferential angle of 10° - 30°, so that the air flow inside the combustion chamber has a certain tangential velocity component, making full use of the space inside the combustion chamber, thereby increasing the residence time of the fuel-air mixture in the combustion chamber and strengthening the circumferential propagation of the flame.

[0038] In a third aspect, the present invention also provides a combustion chamber, including: a casing and the combustion chamber according to any one of the above solutions arranged inside the casing, and the casing has a diffuser opening opposite to the head of the combustion chamber.

[0039] Due to the adoption of the above combustion chamber in the technical solution of the present invention, it has all the advantages of the combustion chamber.

[0040] In a fourth aspect, the present invention also provides an engine, including: a compressor, the combustion chamber according to the above solution arranged at the outlet of the compressor, and a turbine arranged at the outlet of the combustion chamber.

[0041] Due to the adoption of the above combustion chamber in the technical solution of the present invention, it has all the advantages of the combustion chamber. Description of the Drawings

[0042] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0043] Figure 1 The front view of an engine provided by an embodiment of the present invention;

[0044] Figure 2 is Figure 1 the partial perspective cross-sectional view of the combustion chamber shown in

[0045] Figure 3 is Figure 2 the partial perspective cross-sectional view of the flame tube shown in

[0046] Figure 4 is Figure 3 the perspective view of the evaporation tube shown in

[0047] Figure 5 is Figure 4 the perspective view of the tube body shown in

[0048] Figure 6 is Figure 5 the front cross-sectional view of the tube body shown in

[0049] Figure 7 is Figure 3 the side view of the flame tube shown in

[0050] Figure 8 is Figure 2 the enlarged view of the flame tube shown in

[0051] Explanation of reference numerals:

[0052] 1. Compressor; 2. Combustion chamber; 3. Turbine; 4. Casing; 5. Diffuser port; 6. Flame tube; 7. Inner ring; 8. Outer ring; 9. Head; 10. Evaporation tube; 11. Tube body; 12. Air flow channel; 13. Flow guide; 14. Oil inlet; 15. Preheating channel; 16. First air inlet; 17. First deflector; 18. Second air inlet; 19. Second deflector; 20. Main combustion hole; 21. First mixing hole; 22. Second mixing hole; 23. Mixing hopper; 24. Cooling hole. Detailed embodiments

[0053] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0054] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0055] In the description of the present invention, it should be noted that unless otherwise clearly specified and limited, the terms "mounted", "connected", and "coupled" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected, or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0056] In addition, the technical features involved in different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0057] As Figure 1 shown, a specific embodiment of the engine provided in this embodiment includes: a compressor 1, a combustion chamber 2 provided at the outlet of the compressor 1, and a turbine 3 provided at the outlet of the combustion chamber 2. Among them, the combustion chamber 2 is installed between the compressor 1 and the turbine 3 and is used to generate high-temperature gas to drive the turbine 3 to do work.

[0058] Traditional combustion chambers usually match with multi-stage swirlers to organize combustion. The design method of multi-stage swirlers divides the head parts of the combustion chamber into relatively independent recirculation zones, and the flame propagation ability between the heads also decreases. Therefore, the pre-evaporation combustion chamber faces problems of poor ignition and extinction performance.

[0059] As Figure 2As shown in the figure, in this embodiment, the combustion chamber 2 includes: a casing 4 and a flame tube 6 disposed within the casing 4. The casing 4 has a diffuser port 5, and the diffuser port 5 is opposite to the head 9 of the flame tube 6. The fuel manifold is arranged between the diffuser port 5 inside the combustion chamber 2 and the head 9 of the flame tube 6. One end of the fuel manifold is connected to the preheating channel 15 through a fuel branch pipe, and the other end extends out of the casing 4 and is connected to the fuel supply pipeline. The number of fuel branch pipes is the same as the number of preheating channels 15.

[0060] In this embodiment, the multi-stage swirler is omitted. During use, the airflow generated by the compressor 1 enters the combustion chamber 2 through the diffuser port 5 and then blows towards the flame tube 6.

[0061] As Figure 3 shown in the figure, in this embodiment, the flame tube 6 includes: an inner ring 7, an outer ring 8, a head 9 connecting the inner ring 7 and the outer ring 8, and an evaporation tube 10. The evaporation tube 10 is connected to the middle position of the outer part of the head 9.

[0062] In addition, in some alternative embodiments, the evaporation tube 10 can also be optionally connected to the outside of the outer ring 8.

[0063] The traditional evaporation tube design mainly absorbs heat by inserting into the interior of the flame tube and realizes pre-evaporation with the assistance of aerodynamic force. However, to ensure the atomization performance of the evaporation tube, it usually needs to be inserted into the flame tube to a relatively deep length and be in close contact with the high-temperature gas, thus causing the risk of ablation.

[0064] In this embodiment, the evaporation tube 10 does not need to be inserted too deeply into the interior of the flame tube 6, avoiding the risk of ablation.

[0065] As Figure 3 、 Figure 4 shown in the figure, in this embodiment, the evaporation tube 10 includes: a tube body 11 and a preheating channel 15. The preheating channel 15 is attached to the outer mounting surface of the head 9. Through the preheating channel 15, it can be used to cool the head 9 of the flame tube 6, solve the problem of difficult thermal protection of the middle area of the head 9 of the flame tube 6 due to insufficient penetration of the airflow in the starting section, and realize the cooling of the head 9 of the flame tube 6. By cooling the head 9 of the flame tube 6 through the preheating channel 15, the demand for cooling air volume and the cost of processing the cooling holes 24 can be reduced.

[0066] The center of the tube body 11 has an air flow channel 12. The tube body 11 is inserted into the head 9 of the flame tube 6, so that the air flow channel 12 is communicated with the inside of the flame tube 6. A fluid guide 13 is arranged in the tube body 11, and a premixing and pre-evaporation chamber is formed between the fluid guide 13 and the inner wall of the air flow channel 12. An oil inlet 14 leading to the premixing and pre-evaporation chamber is arranged on the outer wall of the tube body 11, and the oil inlet 14 faces the fluid guide 13.

[0067] Since the atomization process of the evaporation tube mainly relies on aerodynamic force, once in a low-temperature and low-pressure environment or when the air flow rate is small, the atomization performance of the evaporation tube will deteriorate significantly. Specifically, the contact area between oil and gas decreases, and the probability of fire kernel generation also decreases accordingly.

[0068] In this embodiment, the preheating channel 15 is located outside the tube body 11. The inlet of the preheating channel 15 is adapted to be communicated with the fuel manifold, and the outlet of the preheating channel 15 is communicated with the oil inlet 14 of the tube body 11. Before the fuel enters the tube body 11 of the evaporation tube 10, it first flows in the preheating channel 15 and realizes preheating of the fuel through heat exchange with the external heat source. The viscosity of the preheated fuel decreases, the surface tension decreases, and it is easier to be atomized into fine oil droplets. That is to say, by heating the fuel through the preheating channel 15 and increasing the temperature of the fuel entering the premixing and pre-evaporation chamber, the fuel viscosity can be reduced and fuel atomization can be promoted.

[0069] When the preheated fuel enters the premixing and pre-evaporation chamber from the oil inlet 14 on the tube body 11, the fuel is directly sprayed onto the fluid guide 13. Under the action of the fluid guide 13, the fuel is broken up into fine oil droplets. At the same time, the air flow flows in the air flow channel 12 and will generate disturbances when passing through the fluid guide 13, prompting the oil droplets to come into full contact with the air, so as to realize more uniform premixing of fuel and air in the premixing and pre-evaporation chamber.

[0070] The flame tube 6 of this embodiment utilizes the characteristics of pre-film atomization and pneumatic atomization of the evaporation tube 10. When the fuel impacts the fluid guide 13 through the oil inlet holes on both sides of the premixing and pre-evaporation chamber, it will spread out to form a liquid film flowing closely along the wall surface. Subsequently, under the action of the air flow in the premixing and pre-evaporation chamber, the liquid film is pushed and broken, and then forms droplets, while promoting the mixing of oil and gas, and finally realizing full atomization, evaporation and premixing of the fuel.

[0071] In addition, in some alternative embodiments, the preheating channel 15 can be integrally formed on the head 9. By integrally processing the evaporation tube 10 and the flame tube 6, the number of components of the flame tube 6 can be reduced.

[0072] Such as Figure 5As shown, in this embodiment, the fuel inlet 14 is a direct injection type, and the diameter of the fuel inlet hole is 0.5 mm - 1.5 mm. Through this setting, the fuel entering the premixing and pre-evaporation chamber from the fuel inlet 14 impacts on the deflector 13 to form an oil film, which breaks, atomizes, evaporates under the action of aerodynamic force, and mixes with the high-speed air flow to form a relatively uniform fuel-air mixture and enters the combustion chamber 6 to complete combustion. By adjusting the area of the direct injection fuel inlet hole, the pressure loss and velocity distribution of the internal fuel can be controlled. Of course, the above description is not restrictive. In some alternative embodiments, the fuel inlet 14 can also be in other forms, such as having a certain bend.

[0073] As Figure 3 , Figure 4 shown, in this embodiment, the preheating channel 15 is U-shaped. The U-shaped structure of the preheating channel 15 makes the flow path of the fuel in the channel longer and the residence time increase. By reasonably controlling the width and spacing of the U-shaped structure, the temperature rise of the fuel can be controlled while reducing the temperature distribution gradient of the head 9 of the combustion chamber 6.

[0074] In addition, in some alternative embodiments, the preheating channel 15 can also be selected in other layout forms such as "I-shaped", "Z-shaped", "T-shaped", etc.

[0075] There are at least two relatively arranged preheating channels 15 on both sides of the pipe body 11. The throttling areas of the two preheating channels 15 can be different, and the throttling area can be adjusted according to the temperature distribution of the head 9 of the combustion chamber 6 to control the fuel flow distribution and balance the heat load distribution.

[0076] The pipe body 11 has at least two fuel inlets 14 arranged at intervals along the direction of the air flow channel 12, and each fuel inlet 14 is communicated with one preheating channel 15. The interval arrangement of multiple fuel inlets 14 on the pipe body 11 enables the fuel to be mixed with air at different positions, further enhancing the mixing uniformity.

[0077] As Figure 4 shown, in this embodiment, the preheating channel 15 is a flat structure. The flat preheating channel 15 significantly increases the contact area with the surrounding heat medium. Compared with channels with conventional cross-sectional shapes such as circular, the flat shape enables the channel wall to be more widely exposed to the thermal environment. Of course, the above description is not restrictive. In some alternative embodiments, the cross-sectional shape of the preheating channel 15 can also be circular, triangular, elliptical, etc.

[0078] As Figure 3 , Figure 4 and Figure 7As shown in the figure, in this embodiment, the tube body 11 is inclined with respect to the preheating passage 15. Through the above arrangement, the angle at which the fuel enters the flame tube 6 from the tube body 11 is changed, so that when the fuel enters the flame tube 6, it can enter at a specific angle, which helps the fuel to be more evenly dispersed.

[0079] Specifically, in this embodiment, the tube body 11 is circumferentially deflected by 30°-60° as a whole relative to the outer mounting surface of the head 9. That is to say, a plurality of tube bodies 11 are deflected as a whole in the clockwise or counterclockwise direction on the outer mounting surface of the head 9; with such an arrangement, the mixture gas can enter the flame tube 6 in a swirling manner. The swirling makes the air flow in the flame tube 6 in a strongly disturbed state. This disturbance promotes the energy transfer between different regions, so that the heat can be more evenly distributed in the flame tube 6.

[0080] As Figure 5 , Figure 6 As shown in the figure, in this embodiment, the tube body 11 is cylindrical, the deflector 13 is cylindrical, and the premixing and pre-evaporation chamber is annular; the tube body 11 being cylindrical and the deflector 13 being cylindrical are geometrically adapted to the annular premixing and pre-evaporation chamber. This matching makes the process of the air flow entering the premixing and pre-evaporation chamber from the tube body 11 through the deflector 13 smoother, reducing the air flow resistance and energy loss caused by sudden shape changes.

[0081] Of course, the above description is not restrictive. In some alternative embodiments, the tube body 11 can also be other cylindrical shapes, and the deflector 13 can be other shapes, such as a square column, etc.

[0082] As Figure 6 As shown in the figure, in this embodiment, the diameter of the inlet section of the premixing and pre-evaporation chamber is larger than the average diameter, the end of the inlet section contracts inward along the air flow direction, and the outlet end of the premixing and pre-evaporation chamber expands outward along the air flow direction. Specifically, the contraction angle of the end of the inlet section is 10°-30°, the expansion angle of the outlet end is 30°-60°, the front section of the deflector 13 is straight and the rear section expands, and the expansion angle is 30°-50°. Through the expansion of the outlet end and the expansion of the rear end of the deflector 13, the oil-gas mixture can be sprayed into the flame tube 6 in the form of a hollow cone with a certain cone angle, so that it can be more evenly distributed in the flame tube 6.

[0083] That is to say, the end of the inlet section contracts inward along the air flow direction, causing the air flow to accelerate in the contraction section. The accelerated air flow will form a strong shearing effect with the surrounding air, further enhancing the mixing effect of fuel and air. This shearing force can further break and refine the fuel droplets, making their contact with air more sufficient and improving the uniformity of premixing. The diameter of the inlet section of the premixing and pre-evaporation chamber is larger than the average diameter, forming an expanding area. When the air flow carrying fuel enters the premixing and pre-evaporation chamber from the pipe body 11, the larger inlet space reduces the air flow velocity and pressure. This helps the fuel to disperse better around the fluid guide body 13, avoiding fuel concentration in local areas and creating conditions for more uniform mixing of fuel and air. The outlet end of the premixing and pre-evaporation chamber expands outward along the air flow direction, playing a role in rectifying and stabilizing the air flow. The premixed air flow gradually reduces in velocity and recovers in pressure in the expanding section, enabling the air flow to be smoothly output to the subsequent combustion area. This helps to form a stable flame in the combustion area, avoiding flame instability or even flameout caused by sudden changes in air flow velocity and ensuring the continuous and stable progress of the combustion process.

[0084] Of course, the above description is not restrictive. In some alternative embodiments, the entire section of the premixing and pre-evaporation chamber can have the same diameter, and the contraction and expansion at its inlet end and outlet end can be omitted.

[0085] In addition, in this embodiment, there are multiple evaporation tubes 10 on the outer mounting surface of the head 9. The multiple evaporation tubes 10 are inclined clockwise or counterclockwise. The preheating channels 15 of the multiple evaporation tubes 10 are connected to the same fuel main pipe through fuel branch pipes. Through the above arrangement, the multiple evaporation tubes 10 can ensure the uniform distribution of fuel in the circumferential direction of the head 9 of the flame tube 6. This uniform distribution enables the fuel and air to be more fully mixed when entering the flame tube 6, avoiding the situation of local fuel being too rich or too lean. The multiple evaporation tubes 10 are inclined and connected to the head 9 clockwise or counterclockwise. When the fuel is ejected, a swirling flow in a certain direction will be formed. The swirling flow can extend the residence time of the fuel in the flame tube 6, further promoting the combustion reaction. The preheating channels 15 of the multiple evaporation tubes 10 are connected to the same fuel main pipe through fuel branch pipes, ensuring the unity and stability of fuel supply. The fuel main pipe can precisely control the total fuel flow rate and then evenly distribute it to each evaporation tube 10 through the fuel branch pipes, avoiding the problem of uneven fuel supply to each evaporation tube 10.

[0086] At the head 9 of the flame tube 6, a compact fuel supply and preheating system is formed by the structure of circumferentially arranging several evaporation tubes 10 and connecting them to the main pipe through fuel branch pipes. This compact layout effectively reduces the temperature of the head 9 of the flame tube 6, reducing the demand for cooling air volume and the processing cost of the cooling holes 24.

[0087] Such as Figure 8As shown, in this embodiment, one end of the head 9 close to the outer ring 8 has a first air inlet 16, and a first flow guide plate 17 is provided on the inner wall of the head 9. The first flow guide plate 17 opens in the direction of the evaporation tube 10. One end of the head 9 close to the inner ring 7 has a second air inlet 18, and a second flow guide plate 19 is provided on the inner wall of the head 9. The second flow guide plate 19 opens in the direction away from the evaporation tube 10.

[0088] Through the above settings, after part of the air enters the combustion chamber 6 through the first air inlet 16, under the guiding action of the first flow guide plate 17, it flows from the outer ring 8 to the inner ring 7 along the inner side of the head 9 of the combustion chamber 6. After part of the air enters the combustion chamber 6 through the second air inlet 18, under the guiding action of the second flow guide plate 19, it flows towards the outlet end along the inner ring 7. Thus, a radial large vortex is formed in the combustion chamber 6, which helps to more reasonably distribute the heat in the combustion chamber 6.

[0089] Specifically, the air flowing from the outer ring 8 towards the head 9 can take away part of the heat near the head 9, avoiding damage to the head 9 due to excessive temperature. The air flowing from the inner ring 7 away from the head 9 helps to cool the inner wall of the inner ring 7 and evenly distribute the heat inside the combustion chamber 6, improving the overall thermal stability of the combustion chamber 6. Through the settings of the first flow guide plate 17 and the second flow guide plate 19, the air forms a specific flow pattern in the combustion chamber 6, and this pattern helps to stabilize the flame. It solves the problem that the ignition and extinction performance of the combustion chamber 6 is poor due to the use of the preheated premixed evaporation tube 10. By adopting the ring vortex flow design with excellent flame propagation characteristics to organize the combustion of oil and gas, on the basis of replacing the expensive multi-oil-way centrifugal nozzle and multi-stage swirler, the stable operation of the combustion chamber 6 is ensured.

[0090] Before the improvement, in order to meet the long-term use conditions of the combustion chamber 2, usually more cold air is required to achieve the thermal protection of the wall surface of the combustion chamber 6. Especially for the combustion chamber 2 with a higher temperature rise, as the average temperature at the outlet of the combustion chamber 2 increases, it often requires more cold sources or improves the cooling design to improve the cooling efficiency.

[0091] Such as Figure 3As shown in the figure, in this embodiment, the evaporation tube 10 is connected to the middle section of the mounting surface of the head 9. On the one hand, it is because the distance (i.e., the cavity height) between the outer ring 8 and the inner ring 7 of the flame tube 6 is relatively large. If it is arranged on the outer ring 8, it is difficult for the oil-gas mixture to reach the vicinity of the inner ring 7 of the flame tube 6, resulting in a low space utilization rate of the flame tube 6 and a poor temperature distribution. On the other hand, due to the design method of the radial ring vortex of the head 9, the coverage range of the air flow entering through the air inlet holes of the outer ring 8 is difficult to reach the middle and lower sections of the head 9, thus leading to insufficient thermal protection of the head 9. Therefore, arranging the evaporator on the head 9 can not only achieve a relatively uniform distribution of the oil-gas mixture throughout the flame tube 6, but also achieve the cooling of the head 9 of the flame tube 6. This enables the head 9 of the flame tube 6 to rely solely on the preheating channel 15 for active cooling without other cooling designs, saving production costs.

[0092] In addition, in some alternative embodiments, the settings of the above-mentioned first deflector 17 and second deflector 19 can be omitted, and vortex vanes can be arranged inside the head 9 of the flame tube 6 to form a circumferential ring vortex, and the circumferential ring vortex can be used to replace the above-mentioned radial ring vortex.

[0093] As Figure 8 shown in the figure, in this embodiment, main combustion holes 20 are respectively provided on the opposite surfaces of the inner ring 7 and the outer ring 8, and the circumferential angle of the main combustion holes 20 is between 10° and 30°. With such a setting, the air ejected from the main combustion holes 20 will enter the interior of the flame tube 6 at a specific inclination angle, thereby making full use of the space inside the flame tube 6, further increasing the residence time of the oil-gas mixture in the flame tube 6, strengthening the circumferential propagation of the flame, and improving the ignition and extinction performance and the outlet temperature distribution of the flame tube 6.

[0094] As Figure 8 shown in the figure, in this embodiment, one end of the inner ring 7 far from the head 9 approaches the direction of the outer ring 8, and a first mixing hole 21 is provided on the section of the inner ring 7 approaching the outer ring 8, and a second mixing hole 22 is provided on the surface of the outer ring 8 opposite to the first mixing hole 21 of the inner ring 7. By making the outlet section of the inner ring 7 raise in the form of a "convex surface" towards the outer ring 8, the distance between the mixing holes on the inner ring 7 and the outer ring 8 is reduced, improving the mixing effect.

[0095] As Figure 8 shown in the figure, in this embodiment, the circumferential angles of the first mixing hole 21 and the second mixing hole 22 are between 10° and 30°. With the above setting, the air ejected from the mixing holes will enter the interior of the flame tube 6 at a specific inclination angle, thereby making full use of the space inside the flame tube 6, further increasing the residence time of the oil-gas mixture in the flame tube 6, strengthening the circumferential propagation of the flame, and improving the ignition and extinction performance and the outlet temperature distribution of the flame tube 6.

[0096] As Figure 8As shown in the figure, in this embodiment, mixing hoppers 23 are respectively arranged at the main combustion holes 20 and the second mixing holes 22 on the outside of the outer ring 8. The mixing hoppers 23 are used to increase the jet penetration depth of the main combustion holes 20 and the mixing holes, and promote the interaction between the jets of the outer ring 8 and the inner ring 7.

[0097] As Figure 8 As shown in the figure, in this embodiment, a number of cooling holes 24 are provided on the inner ring 7 and the outer ring 8. The circumferential angle of the cooling holes 24 is between 10° and 30°. That is to say, all the openings on the flame tube 6 have a circumferential angle of 10° - 30°, so that the air flow in the flame tube 6 has a certain tangential velocity component, making full use of the space in the flame tube 6, thereby increasing the residence time of the oil-gas mixture in the flame tube 6 and strengthening the circumferential propagation of the flame.

[0098] Working principle: For the flame tube 6 provided in this embodiment, during use, the fuel first enters the preheating channel 15 arranged at the head 9 of the flame tube 6, is heated in the preheating channel 15 and then enters the premixing and pre-evaporation chamber. In the premixing and pre-evaporation chamber, the fuel impacts the deflector 13 to form a liquid film and is atomized and evaporated under the action of aerodynamic force, and then enters the flame tube 6 and is fully combusted under the action of the radial ring vortex.

[0099] The flame tube 6 provided in this embodiment has the following innovations:

[0100] 1. The evaporation tube 10 is used to replace the multi-oil-way centrifugal nozzle to achieve fuel atomization and premixing. The matching ring vortex flow field replaces the multi-stage swirler and uses its superior flame propagation characteristics to improve the stable working boundary of the combustion chamber 2.

[0101] 2. A radial ring vortex is arranged inside the head 9 of the flame tube 6, matching the "U-shaped" preheating channel 15 design: Radial ring vortices are formed by arranging air inlet holes at both ends of the head 9, and at the same time, the preheating channel 15 is arranged in the middle section of the head 9. On the one hand, it makes up for the problem of insufficient air flow penetration in the starting section and the difficulty of thermal protection in the middle area of the head 9. On the other hand, the fuel is heated through the preheating channel 15 to increase the temperature of the fuel entering the premixing and pre-evaporation chamber and improve the atomization performance of the fuel.

[0102] 3. The design of the premixing and pre-evaporation chamber combining pre-film atomization and pneumatic atomization: The fuel impacts on the deflector 13 to form a liquid film, and under the action of aerodynamic force, the breakage and atomization of the liquid film are promoted to improve the uniformity of fuel-air mixing.

[0103] 4. The integrated design of the evaporation tube 10 and the head 9 of the flame tube 6: By integrating the fuel manifold inside and directly connecting it to the evaporation tube 10 and the flame tube 6, the integrated design is realized, reducing the number of components in the combustion chamber 2.

[0104] 5. Design of the front elevation of the inner ring 7 at the end of the inner liner 6 of the combustion chamber: By elevating the inner ring 7, the problem of difficult mixing in the high large cavity of the inner liner 6 of the combustion chamber is solved, thereby improving the outlet temperature distribution of the inner liner 6 of the combustion chamber.

[0105] The inner liner 6 of the combustion chamber provided in this embodiment has the following advantages:

[0106] 1. Through the design of the preheating channel 15 based on the principle of regenerative cooling and the design of the pre-mixing and pre-evaporation chamber with pre-film and aerodynamic coupling, the atomization performance of fuel can be significantly improved, and the uniform mixing of oil and gas can be promoted.

[0107] 2. Through the design scheme of preheating, pre-mixing and pre-evaporation of fuel to match the radial annular vortex field, the problem of poor blowout performance at point 2 of the pre-evaporation combustion chamber can be improved.

[0108] 3. Through the preheating and pre-evaporation design and the radial annular vortex design to replace the expensive nozzle and swirler components, the manufacturing cost of the combustion chamber 2 can be reduced.

[0109] 4. Through the design of the preheating channel 15 based on the principle of regenerative cooling, the gas consumption of the combustion chamber 2 can be reduced by nearly 10%, and the processing of the cooling holes 24 at the head 9 of the inner liner 6 of the combustion chamber can be cancelled, further reducing the manufacturing cost of the combustion chamber 2.

[0110] 5. Through the integrated design of the fuel manifold, the evaporation tube 10 and the inner liner 6 of the combustion chamber, the number of components of the combustion chamber 2 can be reduced.

[0111] Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations all fall within the scope defined by the present invention.

Claims

1. An evaporation tube, characterized in that, Comprising: A tube body (11) with an air flow channel (12) at the center. A flow guide (13) is arranged inside the tube body (11), and a premixing and pre-evaporation chamber is formed between the flow guide (13) and the inner wall of the air flow channel (12). An oil inlet (14) leading to the premixing and pre-evaporation chamber is provided on the outer wall of the tube body (11), and the oil inlet (14) faces the flow guide (13). A preheating channel (15) is located outside the tube body (11). The inlet of the preheating channel (15) is adapted to be connected to a fuel manifold, and the outlet of the preheating channel (15) is connected to the oil inlet (14) of the tube body (11).

2. The evaporation tube according to claim 1, characterized in that, The preheating channel (15) is U-shaped, and at least two relatively arranged preheating channels (15) are provided on both sides of the tube body (11). The tube body (11) has at least two spaced oil inlets (14) along the direction of the air flow channel (12), and each oil inlet (14) is connected to one preheating channel (15).

3. The evaporation tube according to claim 1, wherein, The preheating channel (15) is of a flat structure.

4. The evaporation tube according to claim 1, characterized in that The tube body (11) is inclined relative to the preheating channel (15).

5. The evaporation tube according to any one of claims 1-4, characterized in that, The tube body (11) is cylindrical, the flow guide (13) is cylindrical, the premixing and pre-evaporation chamber is annular, the diameter of the inlet section of the premixing and pre-evaporation chamber is larger than the average diameter, the end of the inlet section contracts inward along the air flow direction, and the outlet end of the premixing and pre-evaporation chamber expands outward along the air flow direction.

6. A flame tube, characterized in that, Comprising: An inner ring (7), an outer ring (8), a head (9) connecting the inner ring (7) and the outer ring (8), and an evaporation tube (10) according to any one of claims 1-5, wherein the evaporation tube (10) is connected to the outside of the head (9) or the outer ring (8).

7. The flame tube according to claim 6, characterized in that, The preheating channel (15) of the evaporation tube (10) is attached to the outer mounting surface of the head (9); or, the preheating channel (15) is formed on the head (9), and the evaporation tube (10) is integrally processed with the flame tube (6).

8. The burner can according to claim 6, characterized in that A plurality of evaporation tubes (10) are provided on the outer mounting surface of the head (9), and the plurality of evaporation tubes (10) are inclined in a clockwise or counterclockwise direction. The preheating channels (15) of the plurality of evaporation tubes (10) are connected to the same fuel manifold through fuel branches.

9. The combustion chamber according to any one of claims 6-8, characterized in that, One end of the head (9) close to the outer ring (8) has a first air inlet (16), and a first flow guide plate (17) is provided on the inner wall of the head (9), and the first flow guide plate (17) opens in the direction of the evaporation tube (10); one end of the head (9) close to the inner ring (7) has a second air inlet (18), and a second flow guide plate (19) is provided on the inner wall of the head (9), and the second flow guide plate (19) opens in the direction away from the evaporation tube (10). The evaporation tube (10) is connected to the middle section position of the mounting surface of the head (9). Main combustion holes (20) are respectively provided on the opposite surfaces of the inner ring (7) and the outer ring (8), and the circumferential angle of the main combustion holes (20) is between 10° and 30°. One end of the inner ring (7) away from the head (9) approaches the outer ring (8). A first mixing hole (21) is provided on a section of the inner ring (7) approaching the outer ring (8). A second mixing hole (22) is provided on a surface of the outer ring (8) opposite to the first mixing hole (21) of the inner ring (7). The circumferential angles of the first mixing hole (21) and the second mixing hole (22) are between 10° and 30°. Mixing hoppers (23) are respectively provided at the main combustion holes (20) and the second mixing holes (22) on the outside of the outer ring (8). A number of cooling holes (24) are provided on the inner ring (7) and the outer ring (8). The circumferential angles of the cooling holes (24) are between 10° and 30°.

10. A combustion chamber, characterized in that, Comprising: A casing (4) and a flame tube (6) according to any one of claims 6-9 provided in the casing (4). The casing (4) has a diffuser port (5) opposite to the head (9) of the flame tube (6).

11. An engine, characterized in that, Comprising: A compressor (1), a combustion chamber (2) according to claim 10 provided at the outlet of the compressor (1), and a turbine (3) provided at the outlet of the combustion chamber (2).

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