Pressure test method for combustion chamber with inner and outer casing structure

Abstract

The invention discloses a pressure test method for a combustion chamber with an inner and outer casing structure, and the method comprises the steps: taking anti-wear hydraulic oil as a medium for transmitting pressure, carrying out the strength examination of an outer casing of the combustion chamber at 2.0 times of maximum working pressure through adjusting the oil pressure, and avoiding the impact on the flight safety caused by the gas leakage due to the breakage or burst of the casing; the combustion chamber casing is subjected to stability examination at the maximum working pressure of 1.5 times, so that the casing is prevented from being unstable and deformed; the test method can effectively perform pressure test research on the combustion chamber casing, and the casing assessed by the method is applied to the turboprop engine and has good use conditions.

Description

Technical Field

[0001] The present invention relates to the technical field of aircraft engine combustion chamber casing testing, and more specifically, to a pressure testing method for a combustion chamber with an inner and outer casing structure. Background Art

[0002] Currently, testers verify whether the engine casing has sufficient strength reserves by testing the casing pressure, and understand the strength and failure mode of the engine casing and main load-bearing parts by measuring the strain and deformation of specified parts.

[0003] The combustion chamber of a certain type of engine consists of a combustion chamber casing and a rear jacket. The rear jacket is the rear section of the combustion chamber casing. The combustion chamber casing is an integral welded part. The inner and outer casings are welded together by 10 support plates. It is the main load-bearing casing of the engine. Figure 1 As shown in the figure, the combustion chamber structure has its particularity, which is divided into two parts: the inner and outer casings. The outer casing mainly includes the front and rear casings of the combustion chamber casing, which are the main load-bearing parts of the casing. The inner casing mainly includes parts such as ball bearing seats, roller bearing seats and tapered beams. In order to reduce weight, a large number of 1.5mm thick plates are selected for the inner casing of the combustion chamber, which is much lower than the wall thickness of not less than 2.5mm of the outer casing of the combustion chamber. The force analysis of the engine combustion chamber shows that the combustion chamber mainly bears the flight maneuvering load, the pressure and temperature load it bears. The outer casing of the combustion chamber bears the circumferential internal aerodynamic force, thermal stress and the axial force and torque of the front and rear mounting edges, and the load is relatively large. Compared with the outer casing, the inner casing of the combustion chamber does not bear the force transmitted by the turbine casing and the compressor casing through the front and rear mounting edges of the combustion chamber, and the load is relatively small. Therefore, the test and assessment of the combustion chamber casing of this type of turboprop engine is carried out at twice the conventional maximum working pressure, which is too harsh for the inner casing.

[0004] Invention application CN110926921A discloses a pressure test system for an outer casing of a combustion chamber. The application performs a pressure load test on the outer casing of the combustion chamber, but does not test the pressure load on the inner casing of the combustion chamber. In addition, pressure tests have not been performed on casings with a special structure of inner and outer casings in China so far. Therefore, a pressure test method for a combustion chamber with an inner and outer casing structure is urgently needed. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a pressure test method for a combustion chamber with an inner and outer casing structure.

[0006] The purpose of the present invention is achieved through the following technical solutions:

[0007] A pressure test method for a combustion chamber having an inner and outer casing structure, comprising the following steps:

[0008] Inner casing pressure test:

[0009] S1. Install the test transition section 1 and the test transition section 2 on the combustion chamber;

[0010] S2, injecting hydraulic oil into the outer chamber of the combustion chamber through the oil injection hole to apply pressure load;

[0011] S3, Preload: According to 1.5 times the maximum working pressure, load step by step every 5-10% to 40-50% of the test load, and unload step by step after loading;

[0012] S4, Simulated load: Load step by step every 5-10% to 100% of the test load;

[0013] Outer casing pressure test:

[0014] S1. Install the test adapter section 2 on the combustion chamber and seal the oil return pipe;

[0015] S2, injecting hydraulic oil into the combustion chamber through the oil injection hole to apply pressure load;

[0016] S3, Preload: According to 2 times the maximum working pressure, load step by step every 5-10% to 40-50% of the test load, and unload step by step after loading;

[0017] S4. Simulated load: Load step by step every 5-10% to 100% of the test load.

[0018] Furthermore, the combustion chamber includes an inner casing and an outer casing; the inner casing surrounds the inner wall of the combustion chamber, the inner wall of the combustion chamber is a tubular structure with openings at both ends, and is sealed and connected through a test transition section 1 to form a combustion chamber inner cavity; the combustion chamber inner cavity is provided with an oil return pipe connected to the external environment; the outer casing surrounds the outer wall of the combustion chamber, the outer wall of the combustion chamber is a tubular structure with openings at both ends, and is sealed and connected with a test transition section 2 at both ends to form a combustion chamber outer cavity; the test transition section 2 is provided with an oil filling hole.

[0019] Furthermore, the test transition section 1 is fixedly connected to the combustion chamber by bolts.

[0020] Furthermore, the second test transition section is fixedly connected to the combustion chamber by bolts.

[0021] Furthermore, the test transition section 2 is provided with a pressure sensor.

[0022] Furthermore, strain data collectors are provided on the inner casing and the outer casing.

[0023] Furthermore, in the inner casing pressure test S4 step, each level of load is maintained for ≥3S, and the maintenance time under the maximum load state is ≥5min.

[0024] Furthermore, in the step S4 of the outer casing pressure test, each level of load is maintained for ≥3S, and the maintenance time under the maximum load state is ≥5min.

[0025] Furthermore, the inner casing and outer casing pressure test also includes unloading the pressure value to zero after the S4 simulated load is completed.

[0026] Furthermore, the inner and outer casings also include an inspection step after the S4 simulated load, and the inspection step includes inspecting the casing appearance and measuring the casing size.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] Aiming at the structural and stress analysis of the inner and outer casings of the combustion chamber, the present invention proposes a new pressure test method, in which the strength of the outer casing of the combustion chamber is tested at 2.0 times of the maximum working pressure to prevent the casing from rupture or explosion, resulting in gas leakage and affecting flight safety; the stability of the casing of the combustion chamber is tested at 1.5 times of the maximum working pressure to prevent the casing from becoming unstable and deforming; this test method can effectively carry out pressure test research on the combustion chamber casing, and the casing tested by this method has been applied on this type of turboprop engine and is in good condition. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a structural schematic diagram of a combustion chamber with an inner and outer casing structure;

[0030] Figure 2 This is a schematic diagram of the structure of the test transition section 1 and the test transition section 2 installed on the combustion chamber;

[0031] Figure 3 This is a flow chart of the inner casing pressure test method of the present invention;

[0032] Figure 4 This is a flow chart of the outer casing pressure test method of the present invention;

[0033] Among them: 1. Outer casing; 2. Inner casing; 3. Oil return pipe; 4. Test transition section 1; 5. Test transition section 2; 6. Pressure sensor; 7. Oil filling hole. DETAILED DESCRIPTION

[0034] In order to clearly illustrate the technical features of this solution, the present invention is described in detail below through specific implementation methods and in combination with the accompanying drawings. In the following description, many specific details are described to facilitate a full understanding of the present application, but the present application can also be implemented in other ways different from those described herein, so the protection scope of the present application is not limited by the specific embodiments disclosed below. In addition, in the description of the present application, it should be understood that the orientation or position relationship indicated by the terms "center", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "axial", "radial", "circumferential", etc. is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing the present application 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 cannot be understood as a limitation on the present application. In addition, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, the features defined as "first" and "second" can explicitly or implicitly include one or more of the features. In the description of this application, "multiple" means two or more, unless otherwise clearly specified and specifically defined. In this application, unless otherwise clearly specified and defined, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral body; it can be a mechanical connection, an electrical connection, or a communication; it can be directly connected, or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific circumstances. In this application, unless otherwise clearly specified and defined, the first feature "on" or "under" the second feature can be the first and second features directly contacting, or the first and second features indirectly contacting through an intermediate medium. In the description of this specification, the description of the reference terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of this application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0035] Example 1

[0036] An embodiment provided by the present invention is a method for pressure testing a combustion chamber having an inner and outer casing structure.

[0037] According to the load and strength analysis of the casing bearing parts, the casing in the combustion chamber meets the "medium-length" shell condition, which can be expressed as:

[0038]

[0039] From this, the critical pressure q when the inner casing is unstable and deformed can be calculated KP , the expression is:

[0040]

[0041] Then, the critical pressure of the combustion chamber casing instability and the maximum working pressure q 工作max The instability assessment pressure coefficient K is calculated to be 1.5 times, and the expression is:

[0042]

[0043] Among them, E is the elastic modulus, h is the thickness of the shell, R is the radius of the shell, L is the length of the shell, and υ is Poisson's ratio.

[0044] Therefore, the inner casing of the combustion chamber is tested for stability at 1.5 times the maximum working pressure, and the outer casing is tested for stability at twice the maximum working pressure. A pressure test method for a combustion chamber with an inner and outer casing structure includes the following steps:

[0045] Inner casing pressure test:

[0046] S1. Install the test transition section 1 4 and the test transition section 2 5 on the combustion chamber;

[0047] S2, injecting hydraulic oil into the outer chamber of the combustion chamber through the oil injection hole 7 to apply pressure load;

[0048] S3, preload: according to 1.5 times the maximum working pressure, load step by step every 5% to 40% of the test load, unload step by step after loading, each load holding time is 3S, and the holding time under the maximum load state is 5min;

[0049] S4, Simulated load: Load step by step every 5% to 100% of the test load;

[0050] External casing pressure test:

[0051] S1. Install the test adapter section 2 5 on the combustion chamber and seal the oil return pipe 3;

[0052] S2, injecting hydraulic oil into the combustion chamber through the oil injection hole to apply pressure load;

[0053] S3, preloading: according to 2 times the maximum working pressure, load to 40% of the test load every 5 steps, unload step by step after loading, each load holding time is 3S, and the holding time under the maximum load state is 5min;

[0054] S4. Simulated load: Load step by step every 5% to 100% of the test load.

[0055] The combustion chamber includes an inner casing 2 and an outer casing 1; the inner casing 2 forms the inner wall of the combustion chamber, and the inner wall of the combustion chamber is a tubular structure with openings at both ends, and is sealed and connected through a test transition section 4 to form a combustion chamber inner cavity; the combustion chamber inner cavity is provided with an oil return pipe 3 to communicate with the external environment; the outer casing 1 forms the outer wall of the combustion chamber, and the outer wall of the combustion chamber is a tubular structure with openings at both ends, and is sealed and connected with a test transition section 2 5 at both ends to form a combustion chamber outer cavity; the test transition section 2 is provided with an oil injection hole 7.

[0056] The test transition section 1-4 is fixedly connected to the combustion chamber by bolts.

[0057] The test transition section 2 5 is fixedly connected to the combustion chamber by bolts.

[0058] After the S4 simulated load is completed, the pressure value is unloaded to zero, and the inner and outer casings are inspected. The inspection items include inspecting the casing appearance and measuring the casing dimensions.

[0059] Example 2

[0060] This embodiment provides a pressure test method for a combustion chamber with an inner and outer casing structure, and the test is performed by changing the test loading pressure parameters, including the following steps:

[0061] Inner casing pressure test:

[0062] S1. Install the test transition section 1 4 and the test transition section 2 5 on the combustion chamber;

[0063] S2, injecting hydraulic oil into the outer chamber of the combustion chamber through the oil injection hole 7 to apply pressure load;

[0064] S3, preload: according to 1.5 times the maximum working pressure, load step by step every 10% to 50% of the test load, and unload step by step after loading. Each load level is maintained for 10 seconds, and the maximum load state is maintained for 10 minutes;

[0065] S4, Simulated load: Load step by step every 10% to 100% of the test load;

[0066] Outer casing pressure test:

[0067] S1. Install the test adapter section 2 5 on the combustion chamber and seal the oil return pipe 3;

[0068] S2, injecting hydraulic oil into the combustion chamber through the oil injection hole 7 to apply pressure load;

[0069] S3, preloading: according to 2 times the maximum working pressure, load step by step every 10% to 50% of the test load, and unload step by step after loading. Each load level is maintained for 10 seconds, and the maximum load state is maintained for 10 minutes;

[0070] S4. Simulated load: Load step by step every 10% to 100% of the test load.

[0071] The combustion chamber includes an inner casing 2 and an outer casing 1; the inner casing 2 forms the inner wall of the combustion chamber, and the inner wall of the combustion chamber is a tubular structure with openings at both ends, and is sealed and connected through a test transition section 4 to form a combustion chamber inner cavity; the combustion chamber inner cavity is provided with an oil return pipe 3 to communicate with the external environment; the outer casing 1 forms the outer wall of the combustion chamber, and the outer wall of the combustion chamber is a tubular structure with openings at both ends, and is sealed and connected with a test transition section 2 5 at both ends to form a combustion chamber outer cavity; the test transition section 2 5 is provided with an oil injection hole 7.

[0072] The test transition section 1-4 is fixedly connected to the combustion chamber by bolts.

[0073] The test transition section 2 5 is fixedly connected to the combustion chamber by bolts.

[0074] After the S4 simulated load is completed, the pressure value is unloaded to zero, and the inner and outer casings are inspected. The inspection items include inspecting the casing appearance and measuring the casing dimensions.

[0075] Example 3

[0076] This embodiment provides a pressure test method for a combustion chamber with an inner and outer casing structure. Different from the second embodiment, this embodiment adds a strain data collector and a pressure sensor to monitor the test process, including the following steps:

[0077] Inner casing pressure test:

[0078] S1. Install the test transition section 1 4 and the test transition section 2 5 on the combustion chamber;

[0079] S2, injecting hydraulic oil into the outer chamber of the combustion chamber through the oil injection hole 7 to apply pressure load;

[0080] S3, preload: according to 1.5 times the maximum working pressure, load step by step every 10% to 50% of the test load, and unload step by step after loading. Each load level is maintained for 10 seconds, and the maximum load state is maintained for 10 minutes;

[0081] S4, Simulated load: Load step by step every 10% to 100% of the test load;

[0082] Outer casing pressure test:

[0083] S1. Install the test adapter section 2 5 on the combustion chamber and seal the oil return pipe 3;

[0084] S2, injecting hydraulic oil into the combustion chamber through the oil injection hole 7 to apply pressure load;

[0085] S3, preloading: according to 2 times the maximum working pressure, load step by step every 10% to 50% of the test load, and unload step by step after loading. Each load level is maintained for 10 seconds, and the maximum load state is maintained for 10 minutes;

[0086] S4. Simulated load: Load step by step every 10% to 100% of the test load.

[0087] The combustion chamber includes an inner casing 2 and an outer casing 1; the inner casing 2 forms the inner wall of the combustion chamber, and the inner wall of the combustion chamber is a tubular structure with openings at both ends, and is sealed and connected through a test transition section 4 to form a combustion chamber inner cavity; the combustion chamber inner cavity is provided with an oil return pipe 3 to communicate with the external environment; the outer casing 1 forms the outer wall of the combustion chamber, and the outer wall of the combustion chamber is a tubular structure with openings at both ends, and is sealed and connected with a test transition section 2 5 at both ends to form a combustion chamber outer cavity; the test transition section 2 5 is provided with an oil injection hole 7.

[0088] The test transition section 1 5 is fixedly connected to the combustion chamber by bolts.

[0089] The test transition section 2 5 is fixedly connected to the combustion chamber by bolts.

[0090] After the S4 simulated load is completed, the pressure value is unloaded to zero, and the inner and outer casings are inspected. The inspection items include inspecting the casing appearance and measuring the casing dimensions.

[0091] Furthermore, the test adapter section 2 6 is provided with a pressure sensor, and the inner casing 2 and the outer casing 1 are provided with strain data collectors, which can collect and record the pressure data and strain data during the test, facilitate the monitoring of the pressure and casing load during the test, and facilitate subsequent test analysis.

[0092] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A pressure test method for a combustion chamber with an inner and outer casing structure, characterized in that: The following steps are involved: Inner casing pressure test: S1. Install the test transition section 1 and the test transition section 2 on the combustion chamber; S2, injecting hydraulic oil into the outer chamber of the combustion chamber through the oil injection hole to apply pressure load; S3, Preload: According to 1.5 times the maximum working pressure, load step by step every 5-10% to 40-50% of the test load, and unload step by step after loading; S4, Simulated load: Load step by step every 5-10% to 100% of the test load; Outer casing pressure test: S1. Install the test adapter section 2 on the combustion chamber and seal the oil return pipe; S2, injecting hydraulic oil into the combustion chamber through the oil injection hole to apply pressure load; S3, Preload: According to 2 times the maximum working pressure, load step by step every 5-10% to 40-50% of the test load, and unload step by step after loading; S4. Simulated load: Load step by step every 5-10% to 100% of the test load.

2. A pressure test method for a combustion chamber with an inner and outer casing structure according to claim 1, characterized in that: The combustion chamber includes an inner casing and an outer casing; the inner casing surrounds the inner wall of the combustion chamber, the inner wall of the combustion chamber is a tubular structure with openings at both ends, and is sealed and connected through a test transition section 1 to form a combustion chamber inner cavity; the combustion chamber inner cavity is provided with an oil return pipe connected to the external environment; the outer casing surrounds the outer wall of the combustion chamber, the outer wall of the combustion chamber is a tubular structure with openings at both ends, and is sealed and connected with a test transition section 2 at both ends to form a combustion chamber outer cavity; the test transition section 2 is provided with an oil filling hole.

3. A pressure test method for a combustion chamber with an inner and outer casing structure according to claim 1, characterized in that: The test transition section 1 is fixedly connected to the combustion chamber by bolts.

4. A pressure test method for a combustion chamber with an inner and outer casing structure according to claim 1, characterized in that: The test transition section 2 is fixedly connected to the combustion chamber by bolts.

5. A pressure test method for a combustion chamber with an inner and outer casing structure according to claim 3, characterized in that: The test transition section 2 is provided with a pressure sensor.

6. A pressure test method for a combustion chamber with an inner and outer casing structure according to claim 1, characterized in that: The inner casing and the outer casing are provided with strain data collectors.

7. A pressure test method for a combustion chamber with an inner and outer casing structure according to claim 1, characterized in that: In the inner casing pressure test S4 step, each load level is maintained for ≥3S, and the maintenance time under the maximum load state is ≥5min.

8. A pressure test method for a combustion chamber with an inner and outer casing structure according to claim 1, characterized in that: In the outer casing pressure test S4 step, each load level is maintained for ≥3S, and the maintenance time under the maximum load state is ≥5min.

9. A pressure test method for a combustion chamber with an inner and outer casing structure according to claim 1, characterized in that: The inner casing and outer casing pressure test also includes unloading the pressure value to zero after the S4 simulated load is completed.

10. A pressure test method for a combustion chamber with inner and outer casing structures according to claim 1, characterized in that: The inner and outer casings further include an inspection step after the S4 simulated load, and the inspection step includes inspecting the casing appearance and measuring the casing dimensions.

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