Combustion chamber optical measurement test piece, test device and test method

Abstract

The present invention discloses a combustion chamber optical measurement test piece, a test device and a test method, which belong to the technical field of optical measurement inside combustion chambers. A measurement window is provided on the surface of a test piece body, a cavity is formed outside the test piece body through the measurement window, an inlet flow channel is opened on the measurement window, and the inlet flow channel is connected to a protective gas source through an air intake pipeline. The air pressure of the protective air flow is not less than the air pressure inside the test piece body, so that the inner cavity of the measurement window and the internal environment of the test piece body are isolated by the protective air flow in the measurement window, and finally the effect of preventing the internal combustion gas of the test piece body from entering the measurement window is achieved, and the transparent cover plate on the measurement window is prevented from being contaminated by fuel oil and unburned hydrocarbons, etc., so as to ensure the cleanliness and transmittance of the optical glass of the measurement window, and at the same time the measurement window is cooled to prevent the temperature of the measurement window from being too high, thereby improving the service life of the measurement window. At the same time, the measurement window will not damage the flow field and combustion field inside the combustion chamber.

Description

Technical Field

[0001] The present invention relates to the technical field of optical measurement inside a combustion chamber, and in particular to a combustion chamber optical measurement test piece, a test device and a test method. Background Art

[0002] The parameter information of the combustion component field, flow field, soot field and other parameters inside the combustion chamber is crucial to the design and optimization of the combustion chamber. It determines many performances such as the combustion organization of the combustion chamber head, the outlet temperature distribution, and the pollution emissions. Therefore, conducting multi-physics field measurement research inside the combustion chamber is an important part of the forward research and development process of the combustion chamber.

[0003] Early contact-based single-point flow field measurement techniques interfered with the flow field and had low accuracy, while the component field and soot field could not be measured. With the rapid development of computer technology, laser technology, and image processing technology, combustion optical measurement technology has emerged. It can achieve non-contact, transient, and full-field information measurement, and has gradually become the main means of combustion chamber measurement. Currently, domestic and foreign scholars have carried out a large number of studies on combustion chamber internal parameter measurement and related technologies, mainly using particle image velocimetry (PIV), laser-induced fluorescence (PLIF), and laser-induced incandescence (LII) to measure flow field, component field, and soot field information. However, the complex combustion chamber configuration poses great limitations and challenges to the measurement optical path layout. In order to achieve a better measurement optical path layout, existing studies have been based on simplified combustion chamber models for testing and measurement. For example, the combustion chamber head is unrestricted and open, the head is restricted but the flame tube and casing are simplified to a layer of glass wall, etc. This changes the original key structural features of the combustion chamber, destroys the original parameter characteristics of the combustion chamber, and cannot obtain true parameter information.

[0004] For example, Chinese invention patent application publication number CN113188804A discloses a recirculating combustion chamber test piece and a flow field measurement device for the recirculating combustion chamber. The combustion chamber of the recirculating combustion chamber test piece is designed to a 1:1 scale based on the actual structure of the recirculating combustion chamber, realistically simulating the flow characteristics within the recirculating combustion chamber. Furthermore, small holes are provided on both sides, the top, and the rear of the combustion chamber to facilitate the flexible arrangement of the internal flow field measurement optical path. This eliminates the need for large-scale windowing of the test piece, preserves the original detailed structure of the recirculating combustion chamber, and enables flow field measurement at multiple internal cross-sections. This significantly improves the measurement capability of the internal flow field of the recirculating combustion chamber and accurately captures the true flow characteristics within the recirculating combustion chamber.

[0005] The above invention patent application opens a small hole in the exhaust section for flexible arrangement of the internal flow field measurement optical path, thereby preserving the original detailed structure of the recirculation combustion chamber to accurately obtain the true flow characteristics inside the recirculation combustion chamber;

[0006] However, when conducting the test, combustion needs to be carried out in the combustion chamber of the combustion chamber test piece. The high-temperature combustion gas in the above-mentioned invention patent will directly enter the measuring light path formed by the circular tube channel and come into contact with the endoscope. The fuel oil and unburned hydrocarbons in the high-temperature combustion gas will contaminate the optical glass of the endoscope and place the endoscope in a high-temperature environment. The contaminated optical glass will block the measuring light path, resulting in inaccurate measurement results or inability to measure, affecting the accuracy of the test results or affecting the progress of the test. At the same time, the endoscope will accelerate aging if it works in a high-temperature environment for a long time, resulting in a reduced service life.

[0007] Based on this, the present invention designs a combustion chamber optical measurement test piece, a test device and a test method to solve the above problems. Summary of the Invention

[0008] The technical problem to be solved by the present invention is to provide a combustion chamber optical measurement test piece, a test device and a test method which prevent gas from entering the measurement window to contaminate the optical glass and do not destroy the internal flow field and combustion field of the test piece.

[0009] According to one aspect of the present invention, a combustion chamber optical measurement test piece is provided for connection to an airflow output end of a test device to simulate the parametric characteristics of a real combustion chamber, comprising a test piece body, at least two measurement holes being provided on the surface of the test piece body for arranging a measurement light path for optical measurement of the interior of the test piece body, the combustion chamber optical measurement test piece further comprising a measurement window provided on the surface of the test piece body, the measurement window comprising a cylinder formed by enclosing side walls and a transparent cover provided at one end of the cylinder away from the test piece body, the inner cavity of the cylinder being connected to the inner cavity of the test piece body through the measurement holes, and the transparent cover being provided at one end of the cylinder away from the test piece body. The exposed cover is used to separate the internal environment of the specimen body from the external environment without obstructing the measurement optical path; a plurality of measurement windows are provided on the specimen body, and the plurality of measurement windows are arranged in one-to-one correspondence with the plurality of measurement holes; an intake air flow duct is provided on the surface of the cylinder body that passes through the inner and outer cavities of the cylinder body, and the combustion chamber optical measurement test piece also includes an intake air line for connecting the intake air flow duct with the protective gas source, and the intake air line is used to introduce the protective gas flow output by the protective gas source into the cylinder body, and to ensure that the air pressure of the protective gas flow in the cylinder body is not less than the air pressure of the inner cavity of the specimen body, so as to prevent the air flow inside the specimen body from entering the cylinder body.

[0010] As a further solution of the present invention, the side wall includes an outer wall for forming the outer surface of the cylinder and an inner wall for forming the inner surface of the cylinder. The outer wall and the inner wall are spaced apart and are used to form an insulating air chamber between the outer wall and the inner wall. The inlet flow duct includes an air inlet hole opened in the outer wall and an exhaust hole opened in the inner wall. The air inlet hole and the exhaust hole are staggered and are both connected to the insulating air chamber, so that the protective air flow flows through the air inlet hole, the insulating air chamber and the exhaust hole in sequence and then enters the inner cavity of the cylinder.

[0011] As a further solution of the present invention, the air inlet is provided on a side of the outer wall close to the specimen body, and the air outlet is provided on a side of the inner wall close to the transparent cover.

[0012] As a further solution of the present invention, a plurality of intake air ducts are provided on the cylinder; the cylinder is a cylinder, and the plurality of intake air ducts are arranged at equal intervals along the circumference of the cylinder; or, the cylinder is a regular polygon, and the plurality of intake air ducts are evenly distributed on different side walls forming the regular polygon cylinder.

[0013] As a further solution of the present invention, the multiple intake flow ducts are connected to the protective gas source through different intake pipes, and the intake pipes are provided with regulating valves for adjusting the intake air pressure to respectively adjust the pressure of the protective air flow in different intake flow ducts.

[0014] As a further solution of the present invention, the specimen body includes an air intake section, a test section and an exhaust section connected in sequence, the air intake section is used to be connected to the airflow output end of the test device to introduce the test airflow output by the airflow output section of the test device into the test section, the test section is adapted to the actual structure of the combustion chamber to be tested, the exhaust section is used to discharge the burned test airflow in the test section, the measuring hole is opened in the test section and the exhaust section, the exhaust section includes a bending section, the internal airflow direction of the bending section has an angle with respect to the internal airflow direction of the test section, and the side wall of the bending section is provided with a measuring hole facing the area to be tested in the test section.

[0015] A combustion chamber optical measurement test device includes the above-mentioned combustion chamber optical measurement test piece, as well as a test gas source, a first gas path and a second gas path. The first gas path and the second gas path are arranged in parallel. The test gas source is connected to the test piece body through the first gas path and the second gas path. A tracer particle generator is provided on the second gas path.

[0016] A combustion chamber optical measurement test method uses the above-mentioned combustion chamber optical measurement test piece to perform the test.

[0017] As a further solution of the present invention, during the test, the protective air flow pressure in the measuring window located in the exhaust section is greater than the air pressure in the exhaust section, and the pressure difference is in the range of 1000Pa to 2000Pa; the protective air flow pressure in the measuring window located in the test section is greater than the air pressure in the test section, and the pressure difference is not greater than 500Pa.

[0018] As a further solution of the present invention, during the test, the protective gas flow introduced into the measuring window provided in the test section is an inert gas.

[0019] The present invention has the following beneficial effects:

[0020] The present invention provides a measuring window for arranging a measuring optical path on the surface of the specimen body, forms a cavity outside the specimen body through the measuring window, provides an inlet flow channel on the measuring window, and is connected to a protective gas source through an inlet pipe. During the test, while the test gas is introduced into the specimen body, a protective gas flow is conveyed into the measuring window through the protective gas source, and the air pressure of the protective gas flow is not less than the air pressure in the specimen body, thereby isolating the inner cavity of the measuring window from the internal environment of the specimen body through the protective gas flow in the measuring window, and ultimately preventing the internal gas of the specimen body from entering the measuring window, and preventing the transparent cover on the measuring window from being contaminated by fuel oil, unburned hydrocarbons, etc., and at the same time cooling the measuring window to prevent the temperature of the measuring window from being too high, thereby improving the service life of the measuring window.

[0021] In addition to the above-described objects, features and advantages, the present invention has other objects, features and advantages. The present invention will be further described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The accompanying drawings, which constitute part of this application, are intended to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are intended to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0023] Figure 1 Provide a schematic diagram of the layout of the optical measuring instruments;

[0024] Figure 2 Schematic diagram of the structure of the specimen body in the present invention;

[0025] Figure 3 Schematic diagram of the cross-sectional structure of the measuring window in the present invention;

[0026] Figure 4 Schematic diagram of the air path for protecting the air flow;

[0027] Figure 5 Schematic diagram of the test air flow path.

[0028] Legend:

[0029] 1. Measuring window; 11. Cylinder; 12. Transparent cover; 13. Outer wall; 14. Inner wall; 15. Insulated air chamber; 16. Air inlet; 17. Exhaust hole; 21. Air inlet pipe; 22. Protective air source; 23. Regulating valve; 31. Air inlet section; 32. Test section; 33. Exhaust section; 34. Bend section; 41. Test air source; 42. First air path; 43. Second air path; 44. Tracer particle generator; 45. Dry filter. DETAILED DESCRIPTION

[0030] The embodiments of the present invention are described in detail below with reference to the accompanying drawings. However, the present invention can be implemented in many different ways as defined and covered below.

[0031] See also Figure 1-5 The present invention provides a combustion chamber optical measurement test piece, which is used to connect to the airflow output end of a test device to simulate the parameter characteristics of a real combustion chamber. The test piece includes a test piece body, and at least two measurement holes are opened on the surface of the test piece body for arranging a measurement light path to perform optical measurement on the interior of the test piece body.

[0032] like Figure 1 As shown, when optically measuring the interior of the specimen body, it is necessary to supply oil and gas to the specimen body for combustion, and to emit sheet laser to the measurement position through the laser, and to record the measurement position in real time through the camera from another direction. In order to allow the sheet laser emitted by the laser to enter the measurement position and to enable the camera to record the measurement position in real time, the measurement hole opened on the surface of the specimen body can be used for the sheet laser emitted by the laser to enter and for the camera to image the inner cavity of the specimen body. Therefore, at least two measurement holes need to be opened on the surface of the specimen body. The opening positions of the measurement holes are adjusted according to the different measurement methods and measurement equipment. There is no restriction here. For example, when optically measuring the specimen body using the three methods of particle image velocimetry PIV, laser induced fluorescence PLIF and laser induced incandescence LII, as shown in FIG. Figure 1 As shown in the figure, the sheet laser and the camera need to be arranged at 90 degrees. At this time, a measurement hole can be opened on the surface of the specimen body according to this requirement.

[0033] The combustion chamber optical measurement test piece also includes a measurement window 1 provided on the surface of the test piece body. The measurement window 1 includes a cylinder 11 formed by enclosing side walls and a transparent cover 12 provided at one end of the cylinder 11 away from the test piece body. The inner cavity of the cylinder 11 is connected to the inner cavity of the test piece body through the measurement hole. The transparent cover 12 is used to separate the internal environment of the test piece body from the external environment and does not block the measurement light path. The cylinder 11 is formed by enclosing side walls, and a transparent cover 12 is provided at one end of the cylinder 11 away from the test piece body. The laser light of the laser or the camera imaging light path passes through the cover 12, and the laser and the camera are directed toward the inner cavity of the cylinder 11. The sheet laser emitted by the laser can pass through the transparent cover 12 and the inner cavity of the cylinder 11 and enter the inner cavity of the test piece body from the measurement hole. Similarly, the field of view of the camera will not be obstructed, and the setting of the measurement window 1 will not affect the optical measurement of the test piece body.

[0034] Specifically, a plurality of measurement windows 1 are provided on the specimen body, and the plurality of measurement windows 1 are provided in one-to-one correspondence with the plurality of measurement holes;

[0035] Specifically, the transparent cover plate 12 can be made of glass material, which has the ability to withstand high temperature and high pressure, and also has high optical transmittance;

[0036] An inlet flow passage is provided on the surface of the cylinder 11, which passes through the inner and outer cavities of the cylinder 11. The combustion chamber optical measurement test piece also includes an inlet pipe 21 for connecting the inlet flow passage with a shielding gas source 22. The inlet pipe 21 is used to introduce the shielding gas flow output by the shielding gas source 22 into the cylinder 11, and ensure that the pressure of the shielding gas flow in the cylinder 11 is not less than the pressure of the inner cavity of the test piece body, so as to prevent the air flow inside the test piece body from entering the cylinder 11.

[0037] During the test, the airflow output end of the test device will deliver the test airflow to the specimen body, and the test airflow will mix with the fuel in the specimen body and then burn, thereby simulating the working environment of the inner cavity of a real combustion chamber. At this time, the protective gas source 22 delivers the protective airflow to the cylinder 11 through the air intake pipe 21 connected to the cylinder 11. The protective airflow flows through the air intake pipe 21 and the air intake channel in turn and enters the cylinder 11. The air pressure of the protective airflow is greater than the air pressure inside the specimen body. Therefore, the protective airflow can prevent the gas in the specimen body from entering the cylinder 11, thereby achieving the purpose of separating the internal environment of the cylinder 11 from the internal environment of the specimen body. The effect is achieved, so that the cylinder 11 is always filled with clean and low-temperature protective airflow, preventing the fuel oil and unburned hydrocarbons in the fuel gas from contaminating the inner surface of the cylinder 11 and the transparent cover 12, ensuring the smooth measurement light path during the test, ensuring the accuracy of the test structure, and at the same time isolating the high temperature inside the specimen body, so that the cylinder 11 and the transparent cover 12 are in a relatively low-temperature working environment, thereby improving the service life of the cylinder 11 and the transparent cover 12, and the cylinder 11 is arranged on the surface of the specimen body, forming a chamber outside the specimen body for accommodating the protective airflow, and the cylinder 11 will not affect the flow of the test airflow inside the specimen body.

[0038] Furthermore, the side wall includes an outer wall 13 for forming the outer surface of the cylinder 11 and an inner wall 14 for forming the inner surface of the cylinder 11. The outer wall 13 and the inner wall 14 are spaced apart and used to form an insulating air chamber 15 between the outer wall 13 and the inner wall 14. The inlet air duct includes an air inlet hole 16 opened in the outer wall 13 and an exhaust hole 17 opened in the inner wall 14. The air inlet hole 16 and the exhaust hole 17 are staggered and connected to the insulating air chamber 15, so that the protective air flow flows through the air inlet hole 16, the insulating air chamber 15 and the exhaust hole 17 in sequence and then enters the inner cavity of the cylinder 11.

[0039] like Figure 3As shown, the side wall enclosed to form the cylinder 11 includes an inner wall 14 and an outer wall 13. The inner wall 14 is used to form the inner surface of the cylinder 11, and the outer wall 13 is used to form the outer surface of the cylinder 11. The outer wall 13 and the inner wall 14 are arranged at intervals, thereby forming an insulating air chamber 15 between the outer wall 13 and the inner wall 14. An air inlet 16 is provided on the outer wall 13, and an exhaust hole 17 is provided on the inner wall 14. The air inlet 16 and the exhaust hole 17 are both connected to the insulating air chamber 15. The protective air flow enters the insulating air chamber 15 from the air inlet 16 and then enters the inner cavity of the cylinder 11 from the exhaust hole 17. By dividing the side wall forming the cylinder 11 into the inner wall 14 and the exhaust hole 17, the insulating air chamber 15 is formed. The outer wall 13 is formed, and a protective air flow is introduced into the heat-insulating air chamber 15 formed between the inner wall 14 and the outer wall 13. The protective air flow in the heat-insulating air chamber 15 contacts the inner wall 14 and the outer wall 13 for heat exchange, thereby taking away the heat on the inner wall 14 and the outer wall 13, greatly increasing the contact area between the protective air flow and the side wall, thereby achieving efficient heat dissipation of the side wall through the protective air flow, dissipating the heat conducted to the cylinder 11 from the contact position between the specimen body and the cylinder 11, preventing the heat from being further conducted to the transparent cover plate 12, preventing the cylinder 11 and the transparent cover plate 12 from being in a high-temperature working environment, and improving the service life of the cylinder 11 and the transparent cover plate 12;

[0040] Specifically, the air inlet 16 is provided on a side of the outer wall 13 close to the specimen body, and the air outlet 17 is provided on a side of the inner wall 14 close to the transparent cover 12;

[0041] The air inlet 16 and the exhaust 17 are offset in the height direction of the cylinder 11, so that the protective airflow entering the heat-insulating air chamber 15 from the air inlet 16 needs to move in the protective airflow along the height direction of the cylinder 11 before being discharged from the exhaust 17. The position arrangement of the air inlet 16 and the exhaust 17 guides the protective airflow to flow in the heat-insulating air chamber 15, and increases the flow path length of the protective airflow in the heat-insulating air chamber 15 to increase the heat exchange area, thereby achieving the purpose of improving the heat exchange effect and improving the heat dissipation effect of the protective airflow in the heat-insulating air chamber 15 on the inner wall 14 and the outer wall 13;

[0042] Specifically, the height direction of the cylinder 11 refers to the end of the cylinder 11 where the transparent cover 12 is installed to the end connected to the specimen body;

[0043] Furthermore, the cylinder 11 is provided with a plurality of air inlet channels, which are evenly distributed on the cylinder 11 to achieve uniform air intake of the protective airflow within the cylinder 11, thereby achieving uniform heat dissipation within the cylinder 11 and preventing the problem of heat accumulation caused by poor local heat dissipation. At the same time, the airflow pressure inside the cylinder can be evened out to avoid affecting the flow of the test airflow inside the test piece, thereby ensuring the accuracy of the final test results.

[0044] Specifically, when the cylinder 11 is a cylinder, the plurality of inlet flow passages are arranged at equal intervals along the circumference of the cylinder 11;

[0045] Alternatively, the cylinder 11 is a regular polygon, and the plurality of inlet flow channels are evenly distributed on different side walls of the cylinder 11 forming the regular polygon;

[0046] Furthermore, the plurality of inlet flow passages are connected to the protective gas source 22 through different inlet pipes 21, and the inlet pipes 21 are provided with regulating valves 23 for adjusting the inlet air pressure, so as to respectively adjust the pressure of the protective air flow in the different inlet flow passages, thereby facilitating precise fine-tuning of the air pressure in the cylinder 11.

[0047] Figure 3-4 An example of the cylinder 11 is shown. In this example, the cylinder 11 is a cube, which is formed by four side walls. The angles between the side walls are the same, and each side wall is provided with an inlet flow duct. Each inlet flow duct is connected to the protective gas source 22 through an inlet pipe 21. The inlet pipe 21 is also provided with a regulating valve 23 for adjusting the air pressure, thereby realizing separate adjustment of the air pressure in each inlet flow duct. By separate adjustment of the air pressure in each inlet flow duct, the protective gas flow in the cylinder 11 is made uniform and stable.

[0048] Specifically, the test piece body includes an air intake section 31, a test section 32, and an exhaust section 33 connected in sequence. The air intake section 31 is used to connect to the airflow output end of the test device to introduce the test airflow output by the airflow output section of the test device into the test section 32. The test section 32 is adapted to the actual structure of the combustion chamber to be tested. The exhaust section 33 is used to discharge the burned test airflow in the test section 32. Measurement holes are opened in the test section 32 and the exhaust section 33. The exhaust section 33 includes a bent section 34. The internal airflow direction of the bent section 34 is at an angle to the internal airflow direction of the test section 32. The side wall of the bent section 34 is provided with a measurement hole facing the area to be tested in the test section 32.

[0049] like Figure 2 As shown, the test piece body includes an intake section 31, a test section 32, and an exhaust section 33, which are connected in sequence. The test airflow enters the test section 32 from the intake section 31, mixes with the fuel in the test section 32, and is then discharged from the exhaust section 33. At the same time, the test section 32 is designed in a 1:1 scale according to the actual structure of the combustion chamber to be measured, thereby simulating the parameter characteristics of a real combustion chamber and ensuring that the final measurement results are consistent with the actual results.

[0050] As for the exhaust section 33, the exhaust sections 33 of different combustion chambers have different structural shapes. When using the three methods of particle image velocimetry (PIV), laser induced fluorescence (PLIF) and laser induced incandescence (LII) to perform optical measurement on the test section 32, the sheet laser needs to be arranged at 90 degrees to the camera. However, the exhaust section 33 of the straight-line combustion chamber is coaxially arranged with the combustion chamber, which makes it impossible to set the measurement window 1. Therefore, the exhaust section 33 needs to be bent to form a bent section 34 on the exhaust section 33 to change the exhaust direction, so that the final exhaust direction of the exhaust section 33 is at an angle to the flow direction of the test airflow in the test section 32, or the final exhaust position of the exhaust section 33 is misaligned with the measurement position in the test section 32, so as to facilitate the arrangement of the measurement window 1 in the exhaust section 33. The protective airflow in the measurement window 1 arranged in the exhaust section 33 will be discharged together with the test airflow in the exhaust section 33, and will not affect the test airflow in the test section 32.

[0051] Figure 2 An example of a bent section 34 is shown. In this example, the exhaust direction in the bent section 34 forms a 90° angle with the direction of the test airflow in the test section 32. The tail of the bent section 34 then bends 90° again, leaving the final exhaust direction of the exhaust section 33 unchanged. However, the exhaust position is vertically offset from the test section 32. This allows a measurement hole to be opened in the exhaust section 33 and a measurement window 1 to be set, while allowing the high-temperature test airflow in the exhaust section 33 to avoid the measurement window 1.

[0052] A combustion chamber optical measurement test device includes the above-mentioned combustion chamber optical measurement test piece, as well as a test gas source 41, a first gas path 42, and a second gas path 43. The first gas path 42 and the second gas path 43 are arranged in parallel. The test gas source 41 is connected to the test piece body through the first gas path 42 and the second gas path 43. A tracer particle generator 44 is provided on the second gas path 43.

[0053] When measuring different parameters of the combustion chamber, there are cases where tracer particles are not needed. For example, when measuring the component field and the soot field, tracer particles are not needed. Instead, a first gas path 42 and a second gas path 43 are provided, and a tracer particle generator 44 is provided on the second gas path 43, thereby flexibly controlling the use of tracer particles.

[0054] When tracer particles are needed, the first gas path 42 and the second gas path 43 are opened simultaneously. The test airflow output from the test gas source 41 enters the first gas path 42 and the second gas path 43 respectively, and finally enters the air inlet section 31 simultaneously. The test airflow flowing through the second gas path 43 passes through the tracer particle generator 44, so that the test airflow in the second gas path 43 carries the tracer particles, and the test airflow that finally enters the test section 32 carries the tracer particles.

[0055] When tracer particles are not needed, the first air path 42 is opened and the second air path 43 is closed, so that the test air flow output by the test gas source 41 enters the air inlet section 31 from the first air path 42. At this time, the test air flow entering the test section 32 will not carry tracer particles to meet the optical measurement of different parameter information.

[0056] Furthermore, a drying filter 45 is provided between the test gas source 41 and the first gas path 42 and the second gas path 43 for drying the test gas flow output by the test gas source 41 to prevent moisture in the test gas flow from affecting combustion.

[0057] A combustion chamber optical measurement test method, using the above-mentioned combustion chamber optical measurement test piece for testing;

[0058] Preferably, during the test, the air pressure of the protective airflow in the measuring window 1 provided in the exhaust section 33 is greater than the air pressure in the exhaust section 33, and the pressure difference is in the range of 1000Pa to 2000Pa. Since the measuring instrument needs to face the measuring position of the test section 32, the opening position of the measuring hole on the exhaust section 33 and the setting position of the measuring window 1 must be subjected to the positive impact of the test airflow in the exhaust section 33. In order to prevent the test airflow in the exhaust section 33 from entering the measuring window 1 provided in the exhaust section 33, it is necessary to make the air pressure of the protective airflow in the measuring window 1 greater than the air pressure in the exhaust section 33, and the pressure difference is in the range of 1000Pa to 2000Pa, so that the protective airflow can effectively resist the test airflow, and at this time, the protective airflow entering the exhaust section 33 will not affect the airflow in the test section 32, and will not affect the parameter characteristics of the measurement position.

[0059] Preferably, during the test, the air pressure of the protective airflow in the measuring window 1 provided in the test section 32 is greater than the air pressure in the test section 32, and the pressure difference is not greater than 500Pa. The protective airflow introduced by the measuring window 1 provided in the test section 32 during the test will eventually enter the test section 32. Therefore, the air pressure of the protective airflow and the air pressure in the test section 32 need to be controlled within a reasonable range. While ensuring that the protective airflow can ensure that the test airflow does not enter the measuring window 1, it is also necessary to ensure that the influence of the protective airflow on the test airflow in the test section 32 is reduced to a minimum level. Therefore, the air pressure of the protective airflow in the measuring window 1 provided in the test section 32 and the air pressure difference in the test section 32 is not greater than 500Pa. When the protective airflow in the measuring window 1 enters the test section 32, it will immediately flow along the inner cavity wall of the test section 32 under the drive of the test airflow, and will not rush into the test section 32 to affect the flow of the test airflow, thereby ensuring that the parameter characteristics in the test section 32 conform to the actual situation and ensuring the accuracy of the measurement results.

[0060] Preferably, the protective gas flow introduced into the measuring window 1 of the test section 32 is an inert gas to avoid changing the original combustion oil-gas ratio (i.e., the ratio of fuel to air) inside the test section 32, so as to obtain true combustion characteristics. Nitrogen can be used as the inert gas.

[0061] For the measurement window 1 set in the exhaust section 33, since the exhaust section is no longer burning, the protective air flow entering the measurement window 1 set in the exhaust section 33 is not restricted and air can be used without affecting the combustion oil-gas ratio inside the test section 32.

[0062] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A combustion chamber optical measurement test specimen, used to connect to the airflow output port of a test device to simulate the parametric characteristics of a real combustion chamber, comprising a specimen body with at least two measurement holes formed on the surface of the specimen body for arranging a measurement optical path to perform optical measurements on the interior of the specimen body, characterized in that: The combustion chamber optical measurement test piece further comprises a measurement window (1) provided on the surface of the test piece body, the measurement window (1) comprising a cylinder (11) formed by enclosing side walls and a transparent cover (12) provided at one end of the cylinder (11) away from the test piece body, the inner cavity of the cylinder (11) being connected to the inner cavity of the test piece body through the measurement hole, and the transparent cover (12) being used to separate the internal environment of the test piece body from the external environment and not obstructing the measurement light path; The specimen body is provided with a plurality of measurement windows (1), and the plurality of measurement windows (1) are arranged in a one-to-one correspondence with the plurality of measurement holes; An inlet flow passage penetrating the inner and outer cavities of the cylinder (11) is provided on the surface of the cylinder (11), and the combustion chamber optical measurement test piece further comprises an inlet pipe (21) for connecting the inlet flow passage with a protective gas source (22), the inlet pipe (21) being used to introduce the protective gas flow outputted by the protective gas source (22) into the cylinder (11), and ensuring that the air pressure of the protective gas flow in the cylinder (11) is not less than the air pressure in the inner cavity of the test piece body, so as to prevent the air flow in the test piece body from entering the cylinder (11); The side wall comprises an outer wall (13) for forming the outer surface of the cylinder (11) and an inner wall (14) for forming the inner surface of the cylinder (11); the outer wall (13) and the inner wall (14) are arranged at intervals and are used to form a heat-insulating air chamber (15) between the outer wall (13) and the inner wall (14); the inlet flow channel comprises an air inlet hole (16) opened in the outer wall (13) and an exhaust hole (17) opened in the inner wall (14); the air inlet hole (16) and the exhaust hole (17) are staggered and are both connected to the heat-insulating air chamber (15), so that the protective air flow flows through the air inlet hole (16), the heat-insulating air chamber (15) and the exhaust hole (17) in sequence and then enters the inner cavity of the cylinder (11).

2. The combustion chamber optical measurement test piece according to claim 1, characterized in that: The air inlet (16) is provided on a side of the outer wall (13) close to the specimen body, and the air outlet (17) is provided on a side of the inner wall (14) close to the transparent cover plate (12).

3. The combustion chamber optical measurement test piece according to claim 1, characterized in that: The cylinder (11) is provided with a plurality of air inlet passages; The cylinder (11) is a cylinder, and the plurality of inlet airflow passages are arranged at equal intervals along the circumference of the cylinder (11); Alternatively, the cylinder (11) is a regular polygon, and the plurality of intake air channels are evenly distributed on different side walls forming the regular polygon cylinder (11).

4. The combustion chamber optical measurement test piece according to claim 3, characterized in that: The plurality of intake flow passages are connected to a protective gas source (22) through different intake pipes (21), and a regulating valve (23) for regulating intake air pressure is provided on the intake pipe (21), so as to respectively regulate the air pressure of the protective airflow in the different intake flow passages.

5. The combustion chamber optical measurement test piece according to claim 1, characterized in that: The test piece body comprises an air intake section (31), a test section (32) and an exhaust section (33) connected in sequence, wherein the air intake section (31) is used to be connected to the airflow output end of the test device so as to introduce the test airflow outputted by the airflow output section of the test device into the test section (32), the test section (32) is adapted to the actual structure of the combustion chamber to be tested, the exhaust section (33) is used to discharge the test airflow that has been burned in the test section (32), the measuring hole is provided in the test section (32) and the exhaust section (33), the exhaust section (33) comprises a bending section (34), the internal airflow direction of the bending section (34) has an angle with respect to the internal airflow direction of the test section (32), and a measuring hole facing the area to be tested in the test section (32) is provided on the side wall of the bending section (34).

6. A combustion chamber optical measurement test device, characterized in that: The invention comprises a combustion chamber optical measurement test piece according to any one of claims 1 to 5, and a test gas source (41), a first gas path (42) and a second gas path (43), wherein the first gas path (42) and the second gas path (43) are arranged in parallel, the test gas source (41) is connected to the test piece body through the first gas path (42) and the second gas path (43), and a tracer particle generator (44) is provided on the second gas path (43).

7. A combustion chamber optical measurement test method, characterized in that: The test is carried out using the combustion chamber optical measurement test piece described in claim 5.

8. The combustion chamber optical measurement test method according to claim 7, characterized in that: During the test, the air pressure of the protective air flow in the measuring window (1) located in the exhaust section (33) is greater than the air pressure in the exhaust section (33), and the pressure difference is within the range of 1000Pa to 2000Pa. The air pressure of the protective air flow in the measuring window (1) located in the test section (32) is greater than the air pressure in the test section (32), and the pressure difference is not greater than 500Pa.

9. The combustion chamber optical measurement test method according to claim 7, characterized in that: During the test, the protective gas flow introduced into the measuring window (1) of the test section (32) is an inert gas.

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