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

Abstract

The present 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: a casing front section, a casing rear section, a power turbine casing section and a gas turbine casing section; 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; some or all of the casing sections are provided with seat holes by stamping; at the same time, a mounting seat is formed by a bar machine; the machined parts are connected to form the hot-end casing; the originally complex structure becomes suitable for sheet metal processing, the processing efficiency is improved, and the processing difficulty and processing time are reduced.

Description

Technical Field

[0001] The present 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] Recirculation combustion chambers can effectively shorten engine shaft length and are often used in medium and small aircraft engines. A typical recirculation combustion chamber consists of a hot end casing, flame tube, exhaust elbow (also known as a large or small elbow), fuel nozzle, fuel manifold, and 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 mounting interfaces are usually required on the hot end casing surface to meet 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 needs to 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 mounting 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 places very high demands on the structural strength design of the hot end casing. In general, the hot end casing has many interfaces and a complex surface structure. The forging machining workload is large, and the processing tool wear is large. Since the components are composed of multiple casings and have high strength requirements, the assembly requirements are high and the assembly workload is large.

[0005] The flame tube consists of 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. 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 processing 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 includes the following steps:

[0007] The hot end casing is divided into four casing sections: 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 locally machined; the casing rear section is machined by forging;

[0008] The front section of the casing is then 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] Furthermore, part or all of the casing segments are formed with seat holes by stamping;

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

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

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

[0013] Process the flame tube separately according to the outer ring assembly and the inner ring assembly;

[0014] The outer ring assembly is then processed separately according to the outer wall mounting ring, the outer wall of the cylinder, 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. The outer wall of the cylinder, 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 machine 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 using 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. The casing rear section is respectively connected to 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 provided on the seat hole.

[0020] Furthermore, the lower end of the mounting seat is integrally formed with a mounting edge, which is adapted to the seat hole; the upper end of the mounting seat is connected to the mounting interface, and the mounting interface is provided with a mounting hole, which is adapted to the mounting seat.

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

[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 through 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 bend pipe; 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 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. While ensuring the important performance of the combustion chamber, it reduces the complexity and processing difficulty of the flame tube heads and achieves cost advantages.

[0028] This application strictly controls the requirements and quantities 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 for a single-stage vortex finder through a double-stage vortex finder to achieve consistency of the combined flow, thereby reducing the manufacturing difficulty and improving the qualified rate of the combined flow of the vortex finder.

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

[0031] Other features and advantages of the present invention will be described in the following description, and in part will become apparent from the description, or will be 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 is a brief introduction to 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 any creative work.

[0033] Figure 1 A schematic diagram showing the installation of the hot end casing and the flame tube in the combustion chamber of the present invention is shown;

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

[0035] Figure 3 The figure shows a schematic structural diagram of the mounting base of the present invention.

[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 finder;

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

[0044] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only 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 making creative efforts shall fall 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 in the figure indicates the weld position between the casing segments) The hot end casing 1 is divided into four casing segments, namely the casing front segment 1.1, the casing rear segment 1.2, the power turbine casing segment 1.3 and the gas turbine casing segment 1.4, and is processed separately. The casing front segment 1.1, the power turbine casing segment 1.3 and the gas turbine casing segment 1.4 are processed by sheet metal processing and then locally machined; the casing rear segment 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 the 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] Perform thickening treatment on the weld position of the hot end casing 1.

[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 blank has a large processing allowance, 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 process through 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. 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 surface structures, 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 eliminated, 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 very large number of process steps for the casing single piece and assembly, and a long processing cycle; in the present application, the seat hole 1.2.1 is formed on the casing segment, 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, and 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 through the mounting edge, which requires high processing accuracy of the structure, and thus high requirements for 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 for positioning, which increases the processing difficulty. In addition, there are some other mounting structures on the casing that may also contain precision structures. These precision dimension processing is basically carried out last and requires combined processing. The problem faced by combined processing is that the parts are too large, the operation on the machine tool is complicated, and it tests the performance of the machine tool and the operator's level. Therefore, the fewer the precision dimensions, the fewer the dimensions that need to be combined for processing, and the easier it is to process; this application welds each section after the casing section is processed, with reference 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 welded to the power turbine casing section 1.3 and the gas turbine casing section 1.4 respectively; 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 segmented processing and welding.

[0054] At the same time, the walls of the 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 includes the following steps: Figure 4 ( Figure 4 (a) indicates 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) indicates the weld position on the inner ring assembly 2.2. 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. 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 machined to form a circular hole 2.2.1.1;

[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 cylinder; the outer wall 2.1.2 of the cylinder 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 the bar machine to form the 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 existing technology has many parts and is machined by 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 bend are separated from the outer wall 2.1.2 of the tube to separate the large curvature profile into small curved surface structures; the upper end of the outer wall 2.1.3 and the inner wall 2.1.4 of the large bend (with Figure 4 For example, the upper end of the large bend is welded to the outer wall 2.1.2 of the cylinder by butt welding, which is more conducive to cooling the welded wall surface; the other end of the outer wall 2.1.2 of the cylinder is welded to the outer wall mounting ring 2.1.1; the other end of the outer wall 2.1.3 of the large bend is welded to the inner mounting ring 2.1.5, and 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; 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 stamping the sheet metal at one time, 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 inner ring 2.2.2 is then machined; the two ends of the inner ring 2.2.2 are respectively welded to the U-shaped ring 2.2.3 and the head ring 2.2.1 to form the inner ring assembly 2.2; the vortex finder 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 together 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 stamped from sheet metal in one step, and the heat insulation mounting ring 2.2.4.1 is formed by a bar machine. The vortex finder 2.2.5 is threadedly connected to the heat shield 2.2.4 and the inner ring assembly 2.2 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 this 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 a thread, 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 a thread, and the thread on the vortex finder 2.2.5 is connected to the heat insulation The threads on the inner ring of the mounting ring 2.2.4.1 match the threads. A circular hole 2.2.1.1 is provided in the middle of the head ring 2.2.1. 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 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 to the head ring 2.2.1, which is not easily deformed during operation 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 using 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. 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 provided 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 compatible 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 compatible 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 using 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, an outer wall of the tube 2.1.2, an outer wall of a large bend 2.1.3, an inner wall of a large bend 2.1.4, an inner mounting ring 2.1.5 and a rear section 2.1.6 of the inner wall of the bend.

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

[0072] refer to Figure 6 ( Figure 6 Reference numeral b indicates the position of the outer thread of the vortex finder 2.2.5 and 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] This 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 bend 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 a pin hole on the flame tube 2, and the hot end casing 1 and the flame tube 2 are connected by a pin.

[0074] The number of heads in the flame tube 2 is determined using fuel atomization selection technology. This ensures that the SMD (Sauter Mean Diameter) of the fuel ejected from the fuel nozzle 3 during ignition is less than 40μm, and that the SMD is below 55μm during both high-altitude and low-temperature ignition conditions on the ground, while maintaining a high-quality temperature field at the combustion chamber outlet. Selecting a smaller number of heads reduces the complexity and machining difficulty of the flame tube 2 head while ensuring key combustion chamber performance (such as the ignition and extinguishing envelope and temperature field), achieving cost advantages. The number of combustion chamber heads determines the number of components such as the fuel nozzle 3, swirl finders 2, 2, 5, and guide plates, as well as the complexity of components such as the flame tube 2, hot end casing 1, and manifold. Fewer heads improves combustion chamber cost control.

[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. Under the guidance of the simulation results, the tolerance grade is controlled. 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 and matching structure. Such parts must adopt higher precision tolerance grades. This greatly reduces the difficulty of processing and saves processing costs.

[0076] The swirler 2.2.5 adopts a two-stage swirler to assist the atomization of the fuel in the flame tube 2, including a first-stage swirler and a second-stage swirler. A relatively loose flow qualified range is set for the first-stage and second-stage swirlers, 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 first-stage swirler (or second-stage swirler) in the Class I flow interval with the second-stage swirler (or first-stage swirler) in the Class III flow interval, the corresponding flow interval swirler 2.2.5 is 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 swirler through flow grouping, while ensuring that the combined flow meets the requirements, thereby improving the qualified rate of the combined flow of the swirler 2.2.5.

[0077] refer to Figure 7 ( Figure 7 (c represents the position of the recirculation zone), this 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 airflow at the head 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. A recirculation zone is generated after the airflow passes through the swirler 2.2.5. The size of the recirculation zone varies depending on the structure of the swirler 2.2.5. Appropriate adjustment of the structure of the swirler 2.2.5 to control the swirl speed can make the recirculation zone 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 precise structural dimensions, and in terms of performance design, a full performance tolerance evaluation (calculated using CFD simulation software) is carried out on the important dimensional tolerances of the combustion chamber (such as the air inlet, flame tube surface, spray cone angle, etc.) to ensure that the low-cost manufacturing of the combustion chamber meets the performance 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 replacements for some of the technical features therein; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An engine combustion chamber, characterized in that: It includes a hot end casing (1) and a flame tube (2), and also includes a fuel nozzle (3), a fuel main pipe (4) and a small elbow (5); 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; The hot end casing adopts the following manufacturing method, which specifically includes the following steps: The hot end casing (1) is processed into four casing sections, namely, a casing front section, a casing rear section, a power turbine casing section, and a gas turbine casing section; The front section of the casing, the power turbine casing section and the gas turbine casing section are processed by sheet metal technology and then locally machined; the rear section of the casing is machined by forging; The front section of the casing is then 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 (1); Part or all of the casing segments are formed with seat holes by stamping; a mounting seat is formed by a bar machine; and the mounting seat and the seat hole are welded to the casing segment; The flame tube is manufactured by the following method, which specifically includes the following steps: Process the flame tube separately according to the outer ring assembly and the inner ring assembly; The outer ring assembly is processed separately according to the outer wall mounting ring, the outer wall of the cylinder, 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. The outer wall of the cylinder, 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; 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; 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 (2); The heat insulation screen is formed by combining a screen body formed by stamping a plate with a heat insulation mounting ring added by a bar machine; the heat insulation screen and the eddy current collector are connected to the inner ring assembly.

2. An engine combustion chamber according to claim 1, characterized in that: The hot end casing (1) is thickened at the weld position.

3. An engine combustion chamber according to claim 1, characterized in that: The outer wall mounting ring is welded to the outer wall of the cylinder; the outer wall of the cylinder is welded to the outer wall and inner wall of the large bend pipe, the other end of the outer wall of the large bend pipe is welded to the inner mounting ring, and the other end of the inner wall of the large bend pipe is welded to the rear section of the inner wall of the bend pipe.

4. An engine combustion chamber according to claim 1 or 2, characterized in that: It includes a casing front section, a casing rear section, a power turbine casing section and a gas turbine casing section. The casing rear section is connected to 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. A mounting seat is provided on the seat hole.

5. An engine combustion chamber according to claim 4, characterized in that: The lower end of the mounting seat is integrally formed with a mounting edge, which is adapted to the seat hole; the upper end of the mounting seat is connected to the mounting interface, and the mounting interface is provided with a mounting hole, which is adapted to the mounting seat.

6. An engine combustion chamber according to claim 1 or 3, characterized in that: It includes an outer ring assembly and an inner ring assembly; the outer ring assembly is formed by fixing the inner mounting ring, the outer wall of the cylinder, the outer wall of the large bend, the inner wall of the large bend, the inner mounting ring and the rear section of the inner wall of the bend; The inner ring assembly is formed by fixedly connecting a head ring, a barrel inner ring and a U-shaped ring.

7. The engine combustion chamber according to claim 1, characterized in that: The heat shield and the vortex finder are connected to the head ring through threads; the vortex finder is a double-stage vortex finder.

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