Hot end casing, flame tube, manufacturing method and engine combustion chamber

Abstract

The invention belongs to the technical field of aero-engines, and particularly relates to a hot end casing, a flame tube, a manufacturing method and an engine combustion chamber. The hot end casing is divided into four casing sections including a casing front section, a casing rear section, a power turbine casing section and a gas turbine casing section, wherein the casing front section, the power turbine casing section and the gas turbine casing section are subjected to local machining forming after being machined through a sheet metal process; the rear section of the casing is machined and formed through a forge piece; wherein part or all of the casing sections are provided with seat holes through punch forming; meanwhile, a mounting seat is formed through a bar machine; the machined and formed parts are connected to form a hot-end casing; the original complex structure becomes suitable for sheet metal machining, the machining efficiency is improved, and therefore the machining difficulty is reduced, and the machining time is shortened.

Description

Technical Field

[0001] The invention belongs to the technical field of aviation engines, and in particular relates to a hot end casing, a flame tube, a manufacturing method and an engine combustion chamber. Background Art

[0002] The recirculation combustion chamber can effectively shorten the length of the engine shaft system and is often used in the field of medium and small aircraft engines. A typical recirculation combustion chamber mainly includes a hot end casing, a flame tube, an exhaust elbow (also called a large / small elbow), a fuel nozzle, a fuel main pipe, and an ignition nozzle.

[0003] Turboshaft and turboprop engines are a type of aircraft engine. Many small turboprop engines use a recirculating combustion chamber structure. For small and medium-sized turboshaft and turboprop engine combustion chambers, some installation interfaces are usually required on the hot end casing surface to meet the testing and installation requirements:

[0004] As a connecting component, the combustion chamber needs to transfer the compressor center to the turbine, so the center transfer function should be considered when designing the hot end casing. The usual hot end casing includes multiple casings such as the outer casing, inner casing, and gas turbine casing. The casings are connected by mounting edges, locating pins, or stoppers to achieve the needs of casing connection and center transfer. The hot end casing is processed by forging machining, and many test installation structures are integrated at the same time, such as nozzle mounting seats, probe mounting seats, and even mounting nodes. All engine loads converge on the hot end casing, which puts very high demands on the structural strength design of the hot end casing. In general, the hot end casing has many interfaces, complex surface structures, large forging machining workload, and large wear and tear on processing tools. Since the components are composed of multiple casings and have high strength requirements, they have high assembly requirements and large assembly workload.

[0005] The flame tube includes an outer ring assembly and an inner ring assembly, which are connected to form a flame tube through a mounting edge. The flame tube is an annular thin-walled structure as a whole. Since the flame tube is responsible for organizing combustion and withstanding high temperatures, a large number of divergent cooling holes and large air intake holes for main combustion and mixing are distributed on its wall surface. A heat shield is installed on the head of the flame tube to protect the head. Similar to the hot end casing, the processing method of the flame tube is generally based on forging machining. Due to its relatively large size, the overall machining is very time-consuming and expensive, and the blank machining allowance is required to be large, which increases the workload and raw material consumption. Summary of the invention

[0006] In view of the above problems, the present invention proposes a method for manufacturing a hot end casing, which specifically comprises the following steps:

[0007] The hot end casing is divided into four casing sections, namely, the casing front section, the casing rear section, the power turbine casing section and the gas turbine casing section, and is processed separately. The casing front section, the power turbine casing section and the gas turbine casing section are processed by sheet metal technology and then partially machined; the casing rear section is machined by forging;

[0008] The front section of the casing is connected to one end of the rear section of the casing by welding; the other two ends of the rear section of the casing are respectively welded to the power turbine casing section and the gas turbine casing section to form a hot end casing.

[0009] Further, part or all of the casing segments are formed with seat holes by stamping;

[0010] At the same time, a forming mounting seat is formed by a bar machine; and the mounting seat and the seat hole are welded to the casing section.

[0011] Furthermore, thickening treatment is performed at the hot end casing weld position.

[0012] The present invention provides a flame tube manufacturing method, which specifically comprises the following steps:

[0013] The flame tube is processed separately according to the outer ring component and the inner ring component;

[0014] The outer ring assembly is then processed separately according to the outer wall mounting ring, the outer wall of the tube, the outer wall of the large bend pipe, the inner wall of the large bend pipe, the inner mounting ring and the rear section of the inner wall of the bend pipe, wherein the outer wall of the tube, the outer wall of the large bend pipe and the inner wall of the large bend pipe are formed by sheet metal processing; the outer wall mounting ring, the rear section of the inner wall of the bend pipe and the inner mounting ring are formed by forging machining;

[0015] The inner ring assembly is processed separately according to the head ring, the inner ring of the cylinder and the U-shaped ring; the inner ring of the cylinder is formed by sheet metal stamping; the head ring and the U-shaped ring are formed by sheet metal processing and then machining; the head ring is formed with a circular ring hole by machining;

[0016] The outer ring assembly is connected to the head ring on the inner ring assembly through the outer wall mounting ring to form a flame tube.

[0017] Furthermore, the outer wall mounting ring is welded to the outer wall of the tube; the outer wall of the tube is welded to the outer wall and inner wall of the large bend, the other end of the outer wall of the large bend is welded to the inner mounting ring, and the other end of the inner wall of the large bend is welded to the rear section of the inner wall of the bend.

[0018] Furthermore, a screen body formed by stamping a plate and a heat-insulating mounting ring formed by a bar feeder are combined to form a heat-insulating screen; the heat-insulating screen and the vortex finder are connected to the inner ring assembly.

[0019] The present invention proposes a hot end casing, which is processed by the above-mentioned manufacturing method of a hot end casing, and includes a casing front section, a casing rear section, a power turbine casing section and a gas turbine casing section, wherein the casing rear section is respectively connected with the casing front section, the power turbine casing section and the gas turbine casing section to form a whole; a seat hole is opened on the surface of each casing section; and a mounting seat is arranged on the seat hole.

[0020] Furthermore, a mounting edge is integrally formed at the lower end of the mounting seat, and the mounting edge is matched with the seat hole; the upper end of the mounting seat is connected to the mounting interface, and a mounting hole is opened on the mounting interface, and the mounting hole is matched with the mounting seat.

[0021] The present invention provides a flame tube, which is processed by the above-mentioned flame tube manufacturing method, and comprises an outer ring assembly and an inner ring assembly; the outer ring assembly is formed by fixing an inner mounting ring, a tube outer wall, a large curved pipe outer wall, a large curved pipe inner wall, an inner mounting ring and a rear section of the curved pipe inner wall;

[0022] The inner ring assembly is formed by fixedly connecting a head ring, a barrel inner ring and a U-shaped ring.

[0023] Furthermore, the heat shield and the vortex finder are connected to the head ring via threads; and the vortex finder is a double-stage vortex finder.

[0024] The present invention proposes an engine combustion chamber, comprising the above-mentioned hot end casing and the above-mentioned flame tube, and also comprising a fuel nozzle, a fuel main pipe and a small elbow; the side of the casing front section away from the casing rear section is connected to the compressor, and the side of the power turbine casing section away from the casing rear section is connected to the turbine component.

[0025] The weld positions of the hot end casing and the flame tube of the present application are carried out in accordance with the principle of facilitating the use of sheet metal processing for a single piece, making the originally complex structure suitable for sheet metal processing, improving processing efficiency, thereby reducing processing difficulty and shortening processing time.

[0026] The mounting seat of the present application adopts a split design, which makes the surface structure of the receiver simple and facilitates the use of sheet metal processing. The mounting seat and the mounting interface are welded in combination, and the welds of the mounting seat are rounded, such as using a circular structure, chamfered corners, etc., to reduce stress concentration.

[0027] This application uses fuel atomization selection technology to determine the number of flame tube heads. Under the premise of ensuring the important performance of the combustion chamber, it reduces the complexity and processing difficulty of the flame tube head and achieves cost advantages.

[0028] This application strictly controls the requirements and quantity of precision dimensions through tolerance analysis, reduces the difficulty of manufacturing combustion chamber parts, and improves manufacturing efficiency and qualification rate.

[0029] The present application adopts group flow control on a single-stage vortex finder through a double-stage vortex finder to achieve consistency of combined flow, thereby reducing manufacturing difficulty and improving the qualified rate of the combined flow of the vortex finder.

[0030] This application adopts a performance design solution that is insensitive to structural dimensions, such as a full-size head reflow zone, to ensure that the combustion chamber performance meets the requirements at a low cost.

[0031] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0033] Figure 1 The figure shows the installation schematic diagram of the hot end casing and the flame tube in the combustion chamber of the present invention;

[0034] Figure 2 A simplified structural diagram of the hot end casing of the present invention is shown.

[0035] Figure 3 The schematic diagram of the structure of the mounting base of the present invention is shown.

[0036] Figure 4 A schematic structural diagram of the outer ring assembly of the present invention is shown.

[0037] Figure 5 A schematic structural diagram of the inner ring assembly of the present invention is shown.

[0038] Figure 6 A schematic diagram of the structural installation of the heat shield and vortex finder of the present invention is shown.

[0039] Figure 7 A schematic diagram of the recirculation zone of the combustion chamber of the present invention is shown.

[0040] Figure 8 A schematic diagram of the processing of the U-shaped ring of the present invention is shown.

[0041] In the figure, 1, hot end casing; 1.1, casing front section; 1.2, casing rear section; 1.2.1, seat hole; 1.3, power turbine casing section; 1.4, gas turbine casing section; 1.5, mounting interface; 1.5.1, mounting hole; 1.6, mounting seat; 1.6.1, mounting edge;

[0042] 2. Flame tube; 2.1. Outer ring assembly; 2.1.1. Outer wall mounting ring; 2.1.2. Outer wall of tube; 2.1.3. Outer wall of large elbow; 2.1.4. Inner wall of large elbow; 2.1.5. Inner mounting ring; 2.1.6. Rear section of inner wall of elbow; 2.2. Inner ring assembly; 2.2.1. Head ring; 2.2.1.1. Ring hole; 2.2.2. Inner ring of tube; 2.2.3. U-shaped ring; 2.2.4. Heat shield; 2.2.4.1. Heat shield mounting ring; 2.2.4.2. Shield body; 2.2.5. Vortex flow device;

[0043] 3. Fuel nozzle; 4. Fuel main pipe; 5. Small elbow. DETAILED DESCRIPTION

[0044] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0045] The present application provides a method for manufacturing a hot end casing, which specifically includes the following steps: Figure 2 ( Figure 2 a represents the weld position between the casing sections) The hot end casing 1 is processed separately according to the four casing sections, namely, the casing front section 1.1, the casing rear section 1.2, the power turbine casing section 1.3 and the gas turbine casing section 1.4. The casing front section 1.1, the power turbine casing section 1.3 and the gas turbine casing section 1.4 are processed by sheet metal technology and then partially machined; the casing rear section 1.2 is machined by forging;

[0046] The casing front section 1.1 is connected to one end of the casing rear section 1.2 by welding; the other two ends of the casing rear section 1.2 are respectively welded to the power turbine casing section 1.3 and the gas turbine casing section 1.4 to form a hot end casing 1.

[0047] Part or all of the casing segments are formed with seat holes 1.2.1 by stamping;

[0048] At the same time, the mounting seat 1.6 is formed by a bar machine; the mounting seat 1.6 and the seat hole 1.2.1 are welded to the casing section.

[0049] The hot end casing 1 weld position is thickened.

[0050] In the prior art, the hot end casing 1 uses a forging blank required for forging machining, and the size is relatively large. Since the complex surface structure is processed by CNC milling, the processing allowance of the blank is large, resulting in large material waste and high cost. In addition, the material preparation cycle will also increase; therefore, in the manufacturing process of the hot end casing 1, the present application selects the position of the weld from the perspective of reducing costs, so that a single casing segment is easy to be processed by sheet metal processing, while reducing the number of welds as much as possible.

[0051] The hot end casing 1 is divided into four parts, three of which are mainly straight sections, namely the casing front section 1.1, the power turbine casing section 1.3 and the gas turbine casing section 1.4, which are convenient for adopting wall thickness sheet metal forming technology and small gradient sheet metal stretching forming technology, and the parts close to the straight sections are formed into blanks by stretching small gradient sheet metal; the casing front section 1.1, the power turbine casing section 1.3 and the gas turbine casing section 1.4 are stretched into blanks by thick sheet metal, and then the blanks are locally machined with a small amount of surface structure. The local machining is performed to form small structures on the surface, such as irregular small steps formed for local thickening and increasing strength, or some raised structures set to form special surfaces; because the mounting edge structure between the casing sections is cancelled, the casing assembly workload is reduced and the maintenance convenience of the engine is improved.

[0052] In the prior art, the surface structure of the casing is relatively complex, including the mounting structure and the test structure, etc., which are processed by CNC milling, resulting in a large number of processing steps for the casing single piece and assembly, and a long processing cycle. In the present application, the casing segment is then processed to form a seat hole 1.2.1, and the mounting seat 1.6 is formed by bar machining. While the casing segment is being processed, the mounting seat 1.6 can be processed in parallel. The two are processed at the same time, which not only reduces the difficulty of machining large parts such as the hot end casing 1, but also shortens the processing cycle, further reducing the processing cost.

[0053] In the prior art, the casing is installed by means of mounting edges, which requires high machining accuracy of the structure, and thus high requirements on the performance of the machine tool and the technical level of the operator; too many mounting edges will increase the assembly workload, and at the same time, there are many precision structures used for positioning, which increases the difficulty of machining. In addition, there are some other mounting structures on the casing that may also include precision structures. These precision dimension machining is basically carried out last and requires combined machining. The problem faced by combined machining is that the parts are too large, and the operation on the machine tool is complicated, which tests the performance of the machine tool and the level of the operator. Therefore, the fewer the precision dimensions, the fewer the dimensions that need to be combined for machining, and the easier it is to machine; this application welds each section after the casing section machining is completed, referring to Figure 2, the rear end of the casing front section 1.1 is welded to the casing rear section 1.2; the casing rear section 1.2 is respectively welded to the power turbine casing section 1.3 and the gas turbine casing section 1.4; then the bottom of the mounting seat 1.6 is welded to the seat hole 1.2.1 to form a whole; the difficulty of the processing operation is reduced after the segmented processing and welding.

[0054] At the same time, the walls of three butt welds in the hot end casing 1 are thickened to ensure that the hot end casing 1 as a whole has sufficient strength after welding.

[0055] The present application provides a method for manufacturing a flame tube, which specifically comprises the following steps: Figure 4 ( Figure 4 a represents the weld position on the outer ring assembly 2.1), and the flame tube is processed separately according to the outer ring assembly 2.1 and the inner ring assembly 2.2;

[0056] The outer ring assembly 2.1 is processed separately according to the outer wall mounting ring 2.1.1, the outer wall of the tube 2.1.2, the outer wall of the large bend 2.1.3, the inner wall of the large bend 2.1.4, the inner mounting ring 2.1.5 and the rear section of the inner wall of the bend 2.1.6. Among them, the outer wall of the tube 2.1.2, the outer wall of the large bend 2.1.3 and the inner wall of the large bend 2.1.4 are formed by sheet metal processing; the outer wall mounting ring 2.1.1, the rear section of the inner wall of the bend 2.1.6 and the inner mounting ring 2.1.5 are formed by forging machining.

[0057] refer to Figure 5 ( Figure 5 a represents the weld position on the inner ring assembly 2.2), wherein the inner ring assembly 2.2 is processed separately according to the head ring 2.2.1, the barrel inner ring 2.2.2 and the U-shaped ring 2.2.3; wherein the barrel inner ring 2.2.2 is formed by sheet metal stamping; the head ring 2.2.1 and the U-shaped ring 2.2.3 are formed by sheet metal processing and then machining;

[0058] The head ring 2.2.1 is formed with a ring hole 2.2.1.1 by machining;

[0059] The outer ring assembly 2.1 is connected to the head ring 2.2.1 on the inner ring assembly 2.2 by the outer wall mounting ring 2.1.1 and the head ring 2.2.1 on the inner ring assembly 2.2 to form the flame tube 2. The inner ring 2.2.2, the head ring 2.2.1 and the U-shaped ring 2.2.3 are combined to form the inner ring assembly 2.2; the outer wall mounting ring 2.1.1 on the outer ring assembly 2.1 and the head ring 2.2.1 on the inner ring assembly 2.2 ( Figure 5 The raised position in the upper middle part (not marked) is connected.

[0060] The outer wall mounting ring 2.1.1 is welded to the outer wall 2.1.2 of the tube; the outer wall 2.1.2 of the tube is welded to the outer wall 2.1.3 of the large bend and the inner wall 2.1.4 of the large bend; the other end of the outer wall 2.1.3 of the large bend is welded to the inner mounting ring 2.1.5; the other end of the inner wall 2.1.4 of the large bend is welded to the rear section 2.1.6 of the inner wall of the bend.

[0061] The screen body 2.2.4.2 formed by stamping the sheet metal is combined with the heat insulation mounting ring 2.2.4.1 formed by a bar feeder to form a heat insulation screen 2.2.4; the heat insulation screen 2.2.4 and the vortex finder 2.2.5 are connected to the inner ring assembly 2.2.

[0062] The flame tube in the prior art has many parts and is machined using forgings. The cycle from material preparation to processing is long, and the time and money costs are high. The present application first splits the complex structure of the flame tube 2 into a simple structure; specifically, the outer ring assembly 2.1 is split into an outer wall mounting ring 2.1.1, a tube outer wall 2.1.2, a large bend outer wall 2.1.3, a large bend inner wall 2.1.4, an inner mounting ring 2.1.5 and a bend inner wall rear section 2.1.6.

[0063] The inner wall 2.1.4 and the outer wall 2.1.3 of the large curved pipe are separated from the outer wall 2.1.2 of the tube, so as to separate the large curved surface into a small curved surface structure; the upper end of the outer wall 2.1.3 and the inner wall 2.1.4 of the large curved pipe (with Figure 4 The upper end of the large elbow (taking the upper end as an example) are respectively welded to the outer wall 2.1.2 of the barrel, and the welding method adopts butt welding, which is more conducive to the cooling of the welded wall; the other end of the outer wall 2.1.2 of the barrel is welded to the outer wall mounting ring 2.1.1; the other end of the outer wall 2.1.3 of the large elbow is welded to the inner mounting ring 2.1.5, and the inner wall 2.1.4 of the large elbow is welded to the rear section 2.1.6 of the inner wall of the elbow; the other end of the inner mounting ring 2.1.5 is connected to the partition between the combustion chamber and the compressor.

[0064] The inner ring 2.2.2 of the cylinder is formed by one-time stamping of sheet metal, wherein the U-shaped ring 2.2.3 and the head ring 2.2.1 are separated and stamped into blanks of similar size through thick sheet metal. One thick sheet metal can be processed into multiple pieces (such as Figure 8 The two ends of the inner ring 2.2.2 of the tube are respectively welded to the U-shaped ring 2.2.3 and the head circular ring 2.2.1, and the three are combined to form the inner ring assembly 2.2; the vortexer 2.2.5 is assembled with the heat shield 2.2.4 and the inner ring assembly 2.2 to form the inner ring of the flame tube; the other end of the U-shaped ring 2.2.3 is overlapped with the small bend pipe 5.

[0065] The heat shield 2.2.4 is welded by a heat insulation mounting ring 2.2.4.1 and a screen body 2.2.4.2. The screen body 2.2.4.2 is formed by one-time stamping of sheet metal, and the heat insulation mounting ring 2.2.4.1 is formed by a bar machine. The vortex generator 2.2.5 is connected with the heat shield 2.2.4 and the inner ring assembly 2.2 by threads to form the inner ring of the flame tube.

[0066] In the prior art, the vortex finder and the heat shield are installed by welding, which is easy to deform and inconvenient to disassemble and assemble. In the present application, the heat shield 2.2.4 is welded to the screen body 2.2.4.2 through the heat insulation mounting ring 2.2.4.1. The inner ring of the heat insulation mounting ring 2.2.4.1 has threads, and the screen body 2.2.4.2 is welded to the outer ring of the heat insulation mounting ring 2.2.4.1. The outer ring of the vortex finder 2.2.5 is also provided with threads, and the threads on the vortex finder 2.2.5 are connected to the heat insulation The threads of the inner ring of the mounting ring 2.2.4.1 are adapted; a circular hole 2.2.1.1 is opened in the middle of the head circular ring 2.2.1, and the threaded section of the vortex finder 2.2.5 and the heat insulation mounting ring 2.2.4.1 pass through the circular hole 2.2.1.1 of the head circular ring 2.2.1 and are threadedly connected and tightened. After installation, the heat insulation screen 2.2.4 and the vortex finder 2.2.5 are clamped on the head circular ring 2.2.1, which is not easy to deform during work and is convenient for disassembly, replacement or maintenance.

[0067] The manufacturing method of the present application has the advantages of high structural strength, integration of various installation and testing interfaces, ease of processing, which can significantly shorten the processing cycle and improve processing efficiency, and excellent maintainability.

[0068] The present application provides a hot end casing, which is processed by the above-mentioned manufacturing method of a hot end casing 1, and includes a casing front section 1.1, a casing rear section 1.2, a power turbine casing section 1.3 and a gas turbine casing section 1.4, and the casing rear section 1.2 is respectively connected to the casing front section 1.1, the power turbine casing section 1.3 and the gas turbine casing section 1.4 to form a whole; a seat hole 1.2.1 is opened on the surface of each casing section; a mounting seat 1.6 is arranged on the seat hole 1.2.1.

[0069] refer to Figure 3 The lower end of the mounting seat 1.6 is integrally formed with a mounting edge 1.6.1, which is matched with the seat hole 1.2.1; the upper end of the mounting seat 1.6 is connected to the mounting interface 1.5, and the mounting interface 1.5 is provided with a mounting hole 1.5.1, which is matched with the mounting seat 1.6; if the structure of the mounting interface 1.5 is simple, the mounting seat 1.6 or the mounting interface 1.5 can be designed as an integrated type and machined as a whole; the mounting seat 1.6 and the mounting interface 1.5 can also be split, the mounting interface 1.5 is formed by stamping, and the mounting seat 1.6 is machined.

[0070] The present application provides a flame tube, which is processed by the above-mentioned flame tube 2 manufacturing method, and includes an outer ring assembly 2.1 and an inner ring assembly 2.2; the outer ring assembly 2.1 is fixedly connected by an inner mounting ring 2.1.5, a tube outer wall 2.1.2, a large bend pipe outer wall 2.1.3, a large bend pipe inner wall 2.1.4, an inner mounting ring 2.1.5 and a rear section 2.1.6 of the bend pipe inner wall.

[0071] The inner ring assembly 2.2 is formed by fixedly connecting a head ring 2.2.1, a barrel inner ring 2.2.2 and a U-shaped ring 2.2.3.

[0072] refer to Figure 6 ( Figure 6 b in the figure indicates the position of the outer thread of the vortex finder 2.2.5 and the position of the inner thread of the heat insulation mounting ring 2.2.4.1), the heat insulation screen 2.2.4 and the vortex finder 2.2.5 are connected to the head ring 2.2.1 through threads; the vortex finder 2.2.5 is a double-stage vortex finder.

[0073] The present application provides an engine combustion chamber, referring to Figure 1 , including the above-mentioned hot end casing 1 and the above-mentioned flame tube 2, and also including a fuel nozzle 3, a fuel main pipe 4 and a small curved pipe 5; the side of the casing front section 1.1 away from the casing rear section 1.2 is connected to the compressor, and the side of the power turbine casing section 1.3 away from the casing rear section 1.2 is connected to the turbine component; the nozzle oil circuit of the fuel nozzle 3 and the fuel main pipe 4 are connected through a branch pipe; there is a pin seat on the hot end casing 1, and there is a pin hole on the flame tube 2, and the hot end casing 1 and the flame tube 2 are connected by pins.

[0074] Among them, the number of heads of the flame tube 2 is determined by the fuel atomization selection technology, that is, to ensure that the SMD (Sauter Mean Diameter) of the fuel sprayed from the fuel nozzle 3 under the ignition state is less than 40μm, and the SMD of the fuel under the high-altitude and low-temperature ignition state on the ground is below 55μm, and the temperature field at the combustion chamber outlet still has good quality. Selecting a smaller number of heads reduces the complexity and processing difficulty of the flame tube 2 head while ensuring the important performance of the combustion chamber (such as the ignition and flameout envelope, temperature field), and obtains cost advantages. The number of combustion chamber heads determines the number of parts such as the fuel nozzle 3, the vortex generator 2.2.5, the guide plate, and the complexity of parts such as the flame tube 2, the hot end casing 1, and the main pipe. The fewer the number of heads, the more favorable it is to control the cost of the combustion chamber.

[0075] The dimensional accuracy of the flame tube 2 and the hot end casing 1 is precisely controlled through tolerance analysis, which reduces the difficulty of manufacturing combustion chamber parts and improves manufacturing efficiency and qualification rate. For example, the influence of dimensional tolerance grade on combustion chamber performance is first determined through CFD simulation, and the tolerance grade is controlled under the guidance of the simulation results. Most of the structural dimensions and surface tolerances of the flame tube 2 and the hot end casing 1 adopt tolerance grades of IT8 to IT12. A small number of precise dimensions are mainly concentrated in the precise positioning structure and installation matching structure, which must adopt a higher precision tolerance grade. This greatly reduces the processing difficulty and saves processing costs.

[0076] The vortex finder 2.2.5 adopts a two-stage vortex finder to assist the fuel atomization in the flame tube 2, including a primary vortex finder and a secondary vortex finder. A relatively loose flow qualified range is set for the primary and secondary vortex finders, and the flow range is divided into class I, II, and III intervals (as the flow range increases, the number of divided intervals can be appropriately increased). By matching the primary vortex finder (or secondary vortex finder) in the class I flow interval with the secondary vortex finder (or primary vortex finder) in the class III flow interval, the corresponding flow interval vortex finders 2.2.5 are matched to achieve consistency of the combined flow rate; the narrower the flow range, the higher the processing precision requirements and the higher the cost. The present application relaxes the flow range of the single-stage vortex finder through flow grouping, while ensuring that the combined flow meets the requirements, thereby improving the qualified rate of the combined flow of the vortex finder 2.2.5.

[0077] refer to Figure 7 ( Figure 7 c represents the position of the recirculation zone), the present application adopts a full-size head recirculation zone and other performance design solutions that are insensitive to structural dimensions. The machining accuracy of parts has a great influence on the performance of the combustion chamber, but a suitable design solution can be used to appropriately reduce the requirements for machining accuracy. The full-size head recirculation zone solution is that the head airflow of the flame tube 2 has two large recirculation zones, which can fill the entire head, so that the oil and gas can be fully mixed in the head, easy to ignite, and burn evenly. Compared with the head design solution with a smaller recirculation zone, such a design solution is easier to implement and is not sensitive to dimensional changes caused by machining, which is conducive to reducing machining difficulty and reducing costs; such as Figure 7 As shown, the airflow is controlled by the swirler 2.2.5. After passing through the swirler 2.2.5, a recirculation zone can be generated. The swirler 2.2.5 has different structures and different sizes of recirculation zones. The swirler 2.2.5 structure is appropriately adjusted to control the swirl speed, so that the recirculation zone can fill the entire head. The recirculation zone can always fill the entire head, ensuring that the fuel and air are fully mixed in the combustion chamber at the head of the flame tube 2, reducing the dependence of the combustion chamber performance on the precise structural dimensions, and in terms of performance design, the important dimensional tolerances of the combustion chamber (such as the air inlet, the flame tube profile, the spray cone angle, etc.) are fully evaluated for performance inclusiveness (calculated using CFD simulation software) to ensure that the low-cost manufacturing of the combustion chamber performance meets the requirements.

[0078] Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent substitutions for some of the technical features therein; and these modifications or substitutions do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for manufacturing a hot end casing, characterized in that: The specific steps include: The hot end casing (1) is processed separately into four casing sections, namely, a casing front section (1.1), a casing rear section (1.2), a power turbine casing section (1.3) and a gas turbine casing section (1.4); The casing front section (1.1), the power turbine casing section (1.3) and the gas turbine casing section (1.4) are processed by sheet metal technology and then locally machined; the casing rear section (1.2) is machined by forging; The casing front section (1.1) is then connected to one end of the casing rear section (1.2) by welding; the other two ends of the casing rear section (1.2) are respectively welded to the power turbine casing section (1.3) and the gas turbine casing section (1.4) to form a hot end casing (1).

2. A method for manufacturing a hot end casing according to claim 1, characterized in that: Part or all of the casing sections are formed with seat holes (1.2.1) by stamping; At the same time, a mounting seat (1.6) is formed by a bar machine; the mounting seat (1.6) and the seat hole (1.2.1) are welded to the casing section.

3. A method for manufacturing a hot end casing according to claim 2, characterized in that: A thickening treatment is performed at the weld position of the hot end casing (1).

4. A method for manufacturing a flame tube, characterized in that: The specific steps include: The flame tube is processed separately according to the outer ring component (2.1) and the inner ring component (2.2); The outer ring assembly (2.1) is processed separately according to the outer wall mounting ring (2.1.1), the outer wall of the tube (2.1.2), the outer wall of the large bend pipe (2.1.3), the inner wall of the large bend pipe (2.1.4), the inner mounting ring (2.1.5) and the rear section of the inner wall of the bend pipe (2.1.6), wherein the outer wall of the tube (2.1.2), the outer wall of the large bend pipe (2.1.3) and the inner wall of the large bend pipe (2.1.4) are formed by sheet metal processing; the outer wall mounting ring (2.1.1), the rear section of the inner wall of the bend pipe (2.1.6) and the inner mounting ring (2.1.5) are formed by forging machining; The inner ring assembly (2.2) is processed separately according to the head ring (2.2.1), the inner ring (2.2.2) and the U-shaped ring (2.2.3); the inner ring (2.2.2) is formed by sheet metal stamping; the head ring (2.2.1) and the U-shaped ring (2.2.3) are formed by sheet metal processing and then machining; the head ring (2.2.1) is formed with a ring hole (2.2.1.1) by machining; The outer ring assembly (2.1) is connected to the head ring (2.2.1) on the inner ring assembly (2.2) through the outer wall mounting ring (2.1.1) to form a flame tube (2).

5. A flame tube manufacturing method according to claim 4, characterized in that: The outer wall mounting ring (2.1.1) is welded to the outer wall (2.1.2) of the tube; the outer wall (2.1.2) of the tube is welded to the outer wall (2.1.3) and the inner wall (2.1.4) of the large curved tube; the other end of the outer wall (2.1.3) of the large curved tube is welded to the inner mounting ring (2.1.5); the other end of the inner wall (2.1.4) of the large curved tube is welded to the rear section (2.1.6) of the inner wall of the curved tube.

6. A flame tube manufacturing method according to claim 5, characterized in that: The screen body (2.2.4.2) formed by stamping a plate and the heat-insulating mounting ring (2.2.4.1) formed by a bar machine are combined to form a heat-insulating screen (2.2.4); the heat-insulating screen (2.2.4) and the vortex generator (2.2.5) are connected to the inner ring assembly (2.2).

7. A hot end casing, manufactured by the manufacturing method of a hot end casing according to any one of claims 1 to 3, characterized in that: The invention comprises a casing front section (1.1), a casing rear section (1.2), a power turbine casing section (1.3) and a gas turbine casing section (1.4); the casing rear section (1.2) is respectively connected to the casing front section (1.1), the power turbine casing section (1.3) and the gas turbine casing section (1.4) to form a whole; a seat hole (1.2.1) is provided on the surface of each casing section; and a mounting seat (1.6) is provided on the seat hole (1.2.1).

8. A hot end casing according to claim 7, characterized in that: The lower end of the mounting seat (1.6) is integrally formed with a mounting edge (1.6.1), and the mounting edge (1.6.1) is adapted to the seat hole (1.2.1); the upper end of the mounting seat (1.6) is connected to the mounting interface (1.5), and the mounting interface (1.5) is provided with a mounting hole (1.5.1), and the mounting hole (1.5.1) is adapted to the mounting seat (1.6).

9. A flame tube, manufactured by the flame tube manufacturing method (2) according to any one of claims 4 to 6, characterized in that: It comprises an outer ring assembly (2.1) and an inner ring assembly (2.2); the outer ring assembly (2.1) is fixedly connected by an inner mounting ring (2.1.5), a tube outer wall (2.1.2), a large curved pipe outer wall (2.1.3), a large curved pipe inner wall (2.1.4), an inner mounting ring (2.1.5) and a curved pipe inner wall rear section (2.1.6); The inner ring assembly (2.2) is formed by fixedly connecting a head circular ring (2.2.1), a barrel inner ring (2.2.2) and a U-shaped ring (2.2.3).

10. A flame tube according to claim 6, characterized in that: The heat shield (2.2.4) and the vortex finder (2.2.5) are connected to the head ring (2.2.1) via threads; the vortex finder (2.2.5) is a double-stage vortex finder.

11. An engine combustion chamber, characterized in that: It comprises the hot end casing (1) according to any one of claims 7 to 8 and the flame tube (2) according to any one of claims 9 to 10, and also comprises a fuel nozzle (3), a fuel main pipe (4) and a small elbow (5); the side of the casing front section (1.1) away from the casing rear section (1.2) is connected to the compressor, and the side of the power turbine casing section (1.3) away from the casing rear section (1.2) is connected to the turbine component.

Images