TDLAS (tunable diode laser absorption spectroscopy) optical test window for high-temperature and high-pressure environment

Abstract

The invention provides a TDLAS (tunable diode laser absorption spectroscopy) optical test window for a high-temperature and high-pressure environment, and belongs to the technical field of aero-engine tests. The mounting base is provided with a rectangular channel penetrating front and back and a mounting groove communicating with the rectangular channel, and the rectangular channel is provided with a cold water gas pipeline; the optical glass is installed in the installation groove, an elastic protection gasket is arranged on the side edge of the optical glass, the optical glass is limited through a gland fixed to the installation base, and elastic sealing gaskets are arranged between the gland and the optical glass and between the optical glass and the installation base; wherein a gap is formed between the optical glass and the mounting groove, a gas collecting cavity is formed in the mounting seat, a gas inlet hole communicated with the gas collecting cavity is formed in the outer side of the mounting seat, two rows of cooling holes are formed in one side, facing the optical glass, of the mounting seat, and cooling gas enters the gas collecting cavity through the gas inlet hole and then can flow out from the cooling holes; and the cooling gas cools the optical glass while blowing the optical glass and enters the gap to form gas seal.

Description

Technical Field

[0001] This application belongs to the field of aero-engine testing technology, and specifically relates to a TDLAS optical test window for high temperature and high pressure environments. Background Technology

[0002] TDLAS (Tunable Diode Laser Absorption Spectroscopy) technology plays an important role in testing the temperature field at the exhaust of aero-engine combustion chambers. The optical test window is a key component that affects the success of the test. Especially under high temperature and high pressure conditions, problems such as contamination, breakage, and sealing failure of the observation window glass often occur, affecting TDLAS testing.

[0003] Existing optical testing windows mainly come in two structural forms: one is a single-layer glass structure, where the glass is pressed together by a cap and sealed with a gasket; the other is a double-layer glass structure, where the inner glass withstands heat and the outer glass withstands pressure. However, current optical testing windows lack glass blowing or cleaning functions, making the glass susceptible to contamination and affecting testing results. Furthermore, they are generally used at gas pressures below 1 MPa; at higher pressures, the sealing effect is poor. The glass mounting base typically relies solely on water cooling, resulting in limited cooling area and a tendency for thermal deformation, which can compress the glass and cause it to shatter, compromising optical testing and equipment safety. Summary of the Invention

[0004] The purpose of this application is to provide a TDLAS optical test window for high temperature and high pressure environments to solve or mitigate at least one of the problems in the prior art.

[0005] The technical solution of this application is: a TDLAS optical testing window for high temperature and high pressure environments, comprising: Water-cooled gas pipelines are used to supply high-temperature gas. The mounting base has a rectangular channel running through the front and back and a mounting groove connecting the rectangular channel, wherein a water-cooled gas pipe is installed in the rectangular channel; Optical glass, wherein the optical glass is installed in the mounting groove and the side of the optical glass is provided with an elastic protective gasket, the optical glass is limited by a pressure cap fixed to the mounting base, and an elastic sealing gasket is provided between the pressure cap and the optical glass and between the optical glass and the mounting base; The optical glass has a gap with the mounting groove. The mounting base has an internal air collection chamber. The outer side of the mounting base has an air inlet that connects to the air collection chamber. The mounting base has two rows of cooling holes on the side facing the optical glass. Cooling gas is introduced through a cooling gas inlet pipe installed at the air inlet and flows out of the cooling holes after entering the air collection chamber. The cooling gas blows and cools the optical glass at the same time. The cooling gas enters the gap to form an air seal, protecting the elastic protective gasket and / or the elastic sealing gasket.

[0006] In at least one embodiment of this application, the water-cooled gas pipeline is a rectangular cross-section pipeline, the sidewall of the water-cooled gas pipeline is a sandwich structure, cooling water can flow inside the sandwich structure, and the upper and lower sides of the water-cooled gas pipeline are respectively provided with a cooling inlet and a cooling outlet communicating with the sandwich structure, and the cooling water flows into the sandwich structure from the cooling inlet and flows out from the cooling outlet.

[0007] In at least one embodiment of this application, the mounting base is a rectangular cross structure, the mounting groove is four and distributed on the four sides of the mounting base, the mounting groove is a rectangular stepped groove, and the shape of the optical glass is adapted to the mounting groove.

[0008] In at least one embodiment of this application, the middle part of the cover is provided with an observation port, the shape of which is adapted to the shape of the smaller end of the optical glass.

[0009] In at least one embodiment of this application, the diameter of the cooling hole closer to the rectangular channel in the two rows of cooling holes is larger than the diameter of the cooling hole farther from the rectangular channel.

[0010] In at least one embodiment of this application, both the elastic sealing gasket and the elastic protective gasket are made of graphite material.

[0011] In at least one embodiment of this application, the cooling gas is nitrogen.

[0012] In at least one embodiment of this application, a cooling water jacket is further included, which is fixed to the outside of the mounting base, and a cooling channel is formed between the cooling water jacket and the side of the mounting base for cooling the mounting base.

[0013] The TDLAS optical test window provided in this application for high temperature and high pressure environments can meet the TDLAS test requirements of the outlet temperature field of the aero-engine combustion chamber under high temperature and high pressure conditions. By setting a cooling purging function, contamination on the inner side of the optical glass can be prevented. At the same time, the mounting base can be cooled to reduce thermal deformation of the mounting base, provide a sealing effect, and make the optical glass stable and reliable. Attached Figure Description

[0014] To more clearly illustrate the technical solutions provided in this application, the accompanying drawings will be briefly described below. Obviously, the drawings described below are merely some embodiments of this application.

[0015] Figure 1 This is the main view of the TDLAS optical test window for high temperature and high pressure environments according to this application.

[0016] Figure 2 Based on Figure 1 A schematic diagram of direction AA.

[0017] Figure 3 This is a schematic diagram of the mounting base for this application.

[0018] Figure 4 Based on Figure 3 A schematic diagram of the BB direction.

[0019] Figure 5 This is a schematic diagram of the cooling holes in this application.

[0020] Figure 6 Based on Figure 3 A schematic diagram of the CC direction.

[0021] Figure label: 1-Water-cooled gas pipeline, 11-Cooling inlet, 12-Cooling outlet 2-Mounting base, 21-Rectangular channel, 22-Mounting slot, 23-Air collection chamber, 24-Air inlet, 25-Cooling hole 3-Optical Glass 4-Elastic sealing gasket 5-Elastic protective gasket 6-Cooling water jacket 7-Cooling air inlet pipe 8-Capping, 81-Observation port Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of this application will be described in more detail below with reference to the accompanying drawings.

[0023] To address the problems of existing optical test window glass being easily contaminated on the inside, having poor sealing performance under high pressure and high temperature conditions, being prone to thermal deformation of the mounting base, and being easily broken by glass extrusion, this application provides a TDLAS optical test window for high temperature and high pressure environments.

[0024] like Figures 1 to 6As shown, the TDLAS optical test window for high temperature and high pressure environments provided in this application includes: a water-cooled gas pipe 1, a mounting base 2, optical glass 3, an elastic sealing gasket 4, an elastic protective gasket 5, a cooling water jacket 6, a cooling gas inlet pipe 7, and a pressure cap 8.

[0025] The water-cooled gas pipeline 1 is a rectangular cross-section pipeline. High-pressure and high-temperature gas is introduced into the interior of the water-cooled gas pipeline 1. The side wall of the water-cooled gas pipeline 1 is a sandwich structure, and cooling water can flow through the sandwich structure. The upper and lower sides of the water-cooled gas pipeline 1 are respectively provided with a cooling inlet 11 and a cooling outlet 12 that connects to the sandwich structure. Cooling water flows in from the cooling inlet 11, flows along the sandwich structure, and flows out from the cooling outlet 12, thereby cooling the inner wall surface of the water-cooled gas pipeline 1.

[0026] Water-cooled gas pipe 1 is installed at the front and rear of mounting base 2. For example, water-cooled gas pipe 1 can be fixed to mounting base 2 as a whole by welding, so that the cooling water at the rear end of the sandwich structure of water-cooled gas pipe 1 can also cool the front and rear of mounting base 2.

[0027] The mounting base 2 has a rectangular cross structure, with a rectangular channel 21 running through it from front to back and at least one mounting groove 22 connecting the rectangular channel 21. In this embodiment, there are four mounting grooves 22, located on the top, bottom, left, and right sides of the mounting base 2, and each mounting groove 22 is a rectangular stepped groove. It is understood that there could also be one or two mounting grooves 22, located on the TDLAS incident side. The rectangular channel 21 on the front and back of the mounting base 2 is fixedly connected to the water-cooled gas pipe 1. Optical glass 3 is installed in the mounting grooves 22 on all four sides of the mounting base 2. The TDLAS can test the temperature field of the rectangular channel 21 area through the optical glass 3. The shape of the optical glass 3 is adapted to the shape of the mounting groove 22; that is, the optical glass 3 has a rectangular stepped structure, and there is a small gap between the optical glass 3 and the mounting groove 22 of the mounting base 2. For example, this gap can be 1mm to 3mm.

[0028] The mounting base 2 has an internal gas collection chamber 23. For example, the gas collection chamber 23 in this application has a circular cross section and is opened along the length direction of the optical glass 3 (i.e., the axial direction of the water-cooled gas pipeline 1). The mounting base 2 has two rows of cooling holes 25 on the side facing the mounting optical glass 3 (i.e., the inner side), and an air inlet 24 is provided on the mounting base 2. Cooling gas inlet pipes 7 are installed at the air inlet 24. Cooling gas enters the gas collection chamber 23 through the four cooling gas inlet pipes 7 and is ejected from the cooling holes 25. The cooling holes 25 closer to the rectangular channel 21 have a slightly larger diameter and their main function is to blow away the inner side of the optical glass 3, preventing unburned oil or carbon soot from contaminating the optical glass 3, and also cooling the optical glass 3. The cooling holes 25 further away from the rectangular channel 21 (i.e., the outer side) have a slightly smaller diameter and their main function is to introduce cooling gas into the gap between the mounting base 2 and the optical glass 3 to form an air seal, thereby preventing high-temperature combustion gas from flowing along the gap and contacting the outer gasket, thus improving the sealing performance. Simultaneously, this portion of cooling gas can cool the mounting base 2 body, reducing its thermal deformation. In a preferred embodiment of this application, the cooling gas is nitrogen.

[0029] Furthermore, in this application, the axis of the cooling hole 25 has a certain angle with the center line of the air collection chamber 23, so that the cold air can have a certain angle when it is blown out from the cooling hole 25.

[0030] The optical glass 3 is surrounded by elastic protective gaskets 5 to prevent direct contact between the optical glass 3 and the mounting base 2, thus protecting the optical glass 3 and reducing the risk of breakage. Elastic sealing gaskets 4 are provided on the outer and inner sides of the optical glass 3. These gaskets 4 are located between the pressure cap 8 and the optical glass 3, and between the optical glass 3 and the mounting base 2. The elastic sealing gaskets 4 are installed between the optical glass 3 and the pressure cap 8 by bolts. The pressure cap 8 has an observation port 81 in its center, the shape and area of ​​which are identical to the structure of the smaller end of the optical glass 3.

[0031] In some embodiments of this application, the elastic sealing gasket 4 has a certain thickness, enabling it to absorb some of the unevenness between the optical glass 3 and the mounting base 2 and the pressure cap 8. For example, the thickness of the elastic sealing gasket 4 is 1cm to 2cm.

[0032] In a preferred embodiment of this application, both the elastic protective gasket 5 and the elastic sealing gasket 4 are made of high-temperature resistant materials, such as graphite.

[0033] In this application, a cooling water jacket 6 is welded to the outside of the mounting base 2, and a cooling channel is formed between the cooling water jacket 6 and the side of the mounting base 2. By introducing cooling water into the cooling channel to cool the mounting base 2, the thermal deformation of the mounting base 2 can be reduced, thereby reducing the risk of air leakage caused by the optical glass 3 breaking or the sealing surface deforming due to the compression of the optical glass 3.

[0034] The TDLAS optical test window provided in this application for high temperature and high pressure environments can meet the TDLAS test of the outlet temperature field of the aero-engine combustion chamber under high temperature and high pressure conditions. By setting a cooling purging function, contamination on the inner side of the optical glass can be prevented. At the same time, the mounting base can be cooled to reduce thermal deformation of the mounting base, provide a sealing effect, and make the optical glass stable and reliable.

[0035] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A TDLAS optical testing window for high-temperature and high-pressure environments, characterized in that, include: Water-cooled gas pipeline (1) is used to introduce high-temperature gas; Mounting base (2), the mounting base (2) has a rectangular channel (21) that runs through the front and back and a mounting groove (22) that connects the rectangular channel (21), the rectangular channel (21) is used to install water-cooled gas pipe (1); Optical glass (3), the optical glass (3) is installed in the mounting groove (22) and the side of the optical glass (3) is provided with an elastic protective gasket (5). The optical glass (3) is limited by a pressure cap (8) fixed to the mounting base (2). An elastic sealing gasket (4) is provided between the pressure cap (8) and the optical glass (3) and between the optical glass (3) and the mounting base (2). There is a gap between the optical glass (3) and the mounting groove (22). The mounting base (2) is provided with a gas collection chamber (23) inside. The mounting base (2) is provided with an air inlet (24) that connects to the gas collection chamber (23) on the outside. The mounting base (2) is provided with two rows of cooling holes (25) on the side facing the optical glass (3). Cooling gas is introduced through the cooling gas inlet pipe (7) installed at the air inlet (24) and enters the gas collection chamber (23) and can flow out from the cooling holes (25). The cooling gas blows the optical glass (3) and cools the optical glass (3) at the same time. The cooling gas enters the gap to form an air seal to protect the elastic protective gasket (5) and / or the elastic sealing gasket (4).

2. The TDLAS optical test window for high temperature and high pressure environments as described in claim 1, characterized in that, The water-cooled gas pipeline (1) is a rectangular cross-section pipeline. The side wall of the water-cooled gas pipeline (1) is a sandwich structure. Cooling water can flow through the sandwich structure. The upper and lower sides of the water-cooled gas pipeline (1) are respectively provided with a cooling inlet (11) and a cooling outlet (12) that connects to the sandwich structure. Cooling water flows into the sandwich structure from the cooling inlet (11) and flows out from the cooling outlet (12).

3. The TDLAS optical test window for high temperature and high pressure environments as described in claim 2, characterized in that, The mounting base (2) has a rectangular cross structure, and there are four mounting grooves (22) distributed on the four sides of the mounting base (2). The mounting grooves (22) are rectangular stepped grooves, and the shape of the optical glass (3) is adapted to the mounting grooves (22).

4. The TDLAS optical test window for high temperature and high pressure environments as described in claim 3, characterized in that, The cover (8) has an observation port (81) in the middle, and the shape of the observation port (81) is adapted to the shape of the smaller end of the optical glass (3).

5. The TDLAS optical test window for high temperature and high pressure environments as described in claim 1, characterized in that, The diameter of the cooling hole (25) closer to the rectangular channel (21) in the two rows of cooling holes (25) is larger than the diameter of the cooling hole (25) farther away from the rectangular channel (21).

6. The TDLAS optical test window for high temperature and high pressure environments as described in claim 1, characterized in that, Both the elastic sealing gasket (4) and the elastic protective gasket (5) are made of graphite material.

7. The TDLAS optical test window for high temperature and high pressure environments as described in claim 1, characterized in that, The cooling gas is nitrogen.

8. The TDLAS optical test window for high temperature and high pressure environments as described in claim 1, characterized in that, It also includes a cooling water jacket (6), which is fixed to the outside of the mounting base (2). A cooling channel is formed between the cooling water jacket (6) and the side of the mounting base (2) for cooling the mounting base (2).

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