Multi-stage high-low temperature gas mixer based on Y-shaped separation structure

Abstract

The invention provides a multi-stage high-low temperature gas mixer based on a Y-shaped separation structure, and belongs to the technical field of aero-engine test equipment. The mixer comprises at least two stages of mixing units which are sequentially connected in the airflow direction, wherein each stage of unit comprises a secondary flow cavity conical barrel, a main flow diffusion section conical barrel and a secondary flow pipe orifice, and the main flow diffusion section conical barrel and the secondary flow pipe orifice are coaxially arranged in the secondary flow cavity conical barrel. The adjacent units are connected through a Y-shaped partition structure, and the Y-shaped partition structure comprises a first conical cylinder part, a second conical cylinder part, a root partition plate connecting the first conical cylinder part and the second conical cylinder part and an inner side conical ring. And an axial thermal expansion gap is reserved between the main flow diffusion section conical cylinder and the inner side conical ring. The multistage mixing units are matched with the Y-shaped separation structure, wide-temperature-range and high-uniformity mixing of gas is achieved, meanwhile, the problem of structural thermal stress under the large-temperature-difference working condition is effectively solved, and the gas mixing device has the advantages of being compact in structure, high in reliability, high in expandability and the like.

Description

Technical Field

[0001] This invention relates to the field of aero-engine testing equipment technology, and in particular to a multi-stage high and low temperature gas mixer based on a Y-shaped partition structure. Background Technology

[0002] Aircraft engine test benches are key ground simulation facilities for studying various aerodynamic and thermodynamic characteristics of engines. To simulate intake conditions at different flight altitudes and speeds, test benches need to use mixers to mix airflows of different temperatures in order to precisely adjust and homogenize the intake air temperature field entering the engine.

[0003] Currently, there are two main types of mixing structures: one is the direct pipeline mixing structure, which can achieve multi-flow mixing and wide temperature regulation, but the temperature uniformity after mixing is poor, and improving uniformity often requires a long straight pipe section, which occupies a lot of space; the other is the double-layer cavity mixing structure, which has better mixing uniformity, but is limited by the temperature limit and flow rate matching of the main flow and secondary flow, and the temperature regulation range during a single test is narrow, which is difficult to meet the wider intake condition simulation requirements of modern advanced engines.

[0004] Therefore, how to design a mixer that can simultaneously achieve a wide temperature adjustment range and high mixing uniformity, while also being compact, reliable, and adaptable to thermal stress environments with large temperature differences, has become a pressing technical problem to be solved in this field. Summary of the Invention

[0005] This invention provides a multi-stage high and low temperature gas mixer based on a Y-shaped partition structure to solve the technical problems in the prior art of simultaneously achieving wide temperature range regulation and high uniformity mixing, as well as the technical problem of thermal stress concentration in the structure under large temperature difference conditions.

[0006] On one hand, the present invention provides a multi-stage high and low temperature gas mixer based on a Y-shaped partition structure, comprising: at least two stages of mixing units connected sequentially along the gas flow direction, and a mixing gas outlet cylinder and a mixing gas inlet located downstream of the at least two stages of mixing units; Each of the at least two mixing units includes: a secondary flow cavity cone, a main flow diffusion section cone coaxially disposed inside the secondary flow cavity cone, and a secondary flow port for introducing secondary flow opened on the secondary flow cavity cone; the main flow diffusion section cone has mixing holes opened on its wall. Adjacent mixing units are connected by a Y-shaped partition structure; the Y-shaped partition structure includes a first conical section facing upstream of the airflow, a second conical section facing downstream of the airflow, a root partition connecting the first and second conical sections, and an inner conical ring located inside the second conical section; The secondary flow cavity cone of the upstream mixing unit is connected to the first cone section of the Y-shaped partition structure, and the secondary flow cavity cone of the downstream mixing unit is connected to the second cone section of the Y-shaped partition structure. Axial gaps are reserved between the end of the mainstream diffusion section cone of the upstream mixing unit and the inner cone ring, and between the beginning of the mainstream diffusion section cone of the downstream mixing unit and the inner cone ring, to compensate for the thermal expansion of the structure.

[0007] According to the present invention, a multi-stage high and low temperature gas mixer based on a Y-type partition structure is provided, wherein the at least two-stage mixing unit includes a first-stage mixing unit and a second-stage mixing unit; The first-stage mixing unit includes: a secondary flow I cavity cone, a main flow diffusion section cone I coaxially disposed inside the secondary flow I cavity cone, and a secondary flow I inlet; The second-stage mixing unit includes: a secondary flow II cavity cone, a main flow diffusion section cone II coaxially disposed inside the secondary flow II cavity cone, and a secondary flow II inlet; The Y-shaped partition structure connects the secondary flow I cavity cone and the secondary flow II cavity cone.

[0008] According to the present invention, a multi-stage high and low temperature gas mixer based on a Y-shaped partition structure is provided, wherein the width of the axial gap is 2~5mm.

[0009] According to the present invention, a multi-stage high and low temperature gas mixer based on a Y-shaped partition structure is provided, wherein the root partition of the Y-shaped partition structure is the only physical connector connecting its first conical part and second conical part, so that the structural load is transferred between the first conical part and the second conical part through the root partition.

[0010] According to the present invention, a multi-stage high and low temperature gas mixer based on a Y-shaped partition structure is provided, wherein the secondary flow cavity cone, the Y-shaped partition structure, and the mixed gas outlet cylinder together constitute the continuous pressure-bearing shell of the mixer; the main flow diffusion section cone is suspended in the pressure-bearing shell and is not rigidly fixed to the pressure-bearing shell.

[0011] According to the present invention, a multi-stage high and low temperature gas mixer based on a Y-shaped partition structure further includes a mainstream port located at the upstream side, which is connected to the mainstream diffusion section cone of the upstream mixing unit.

[0012] According to the present invention, a multi-stage high and low temperature gas mixer based on a Y-shaped partition structure is provided, wherein the number of the at least two-stage mixing units is three or more, and adjacent mixing units are connected by the Y-shaped partition structure.

[0013] On the other hand, the present invention provides a method for gas mixing using a multi-stage high and low temperature gas mixer based on a Y-type partition structure, characterized by comprising the following steps: A stream of mainstream gas is introduced into the upstream mainstream diffusion section cone through the mainstream pipe opening; At least two secondary gases with temperatures different from the mainstream gas are introduced into the corresponding secondary flow chamber cone through their respective secondary flow ports. When each secondary gas flows through the corresponding secondary cavity cone, it passes through the mixing holes on the wall of the corresponding main diffuser cone and merges into the main gas flowing through the main diffuser cone in multiple stages and sequentially for mixing. The homogeneous mixed gas formed after multi-stage mixing is output through the mixing gas port.

[0014] According to the present invention, a method for gas mixing using a multi-stage high and low temperature gas mixer based on a Y-shaped partition structure is provided. When the gas temperatures in adjacent secondary flow chamber cones are different, the root partition and inner cone ring of the Y-shaped partition structure can undergo thermal deformation, and the axial gap provides compensation space for the relative thermal expansion between the connected main flow diffuser cone and the inner cone ring.

[0015] According to the present invention, a method for gas mixing using a multi-stage high and low temperature gas mixer based on a Y-type partition structure is provided. The at least two secondary gas streams include at least one high temperature gas and at least one low temperature gas. By independently adjusting the flow rate of each secondary gas stream, a wide range of temperature adjustment of the mixed gas output from the mixing gas outlet can be achieved.

[0016] The multi-stage high and low temperature gas mixer based on a Y-type partition structure provided by this invention has the following advantages compared with the prior art: (1) The multi-stage high and low temperature gas mixer based on the Y-type partition structure provided by the present invention allows the mainstream and multiple secondary streams of different temperatures to be mixed in stages and step by step by adopting at least two stages of scalable mixing units in series. This multi-stage mixing mechanism not only significantly broadens the overall temperature regulation range of the outlet gas, but also effectively improves the uniformity of gas flow temperature through multi-stage mixing, overcoming the contradiction that a single mixing stage cannot simultaneously achieve "wide range" and "high uniformity".

[0017] (2) The multi-stage high and low temperature gas mixer based on the Y-shaped partition structure provided by this invention connects adjacent mixing units through an original Y-shaped partition structure. This structure minimizes the direct contact area between the pressurized secondary flow cavities (limited to the root partition), greatly limiting the heat conduction area caused by large temperature differences; at the same time, it reserves an axial thermal expansion gap for the internal mainstream diffusion section cone and allows the Y-shaped structure itself to deform freely by heat. This design allows the equipment to effectively release thermal stress without relying on external expansion joints while maintaining the overall rigid pressure-bearing structure, avoiding stress concentration, thus achieving both compact structure and high reliability.

[0018] (3) The multi-stage high and low temperature gas mixer based on the Y-type partition structure provided by the present invention, through the modular design concept, allows the number of mixing units to be flexibly expanded according to actual needs. By simply adding mixing units and Y-type partition structures, it is possible to mix more airflows with greater temperature differences, further improving the system's temperature regulation capability and mixing uniformity potential, while maintaining the uniformity and maintainability of the structural design. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the structure of the multi-stage high and low temperature gas mixer based on the Y-type partition structure provided by the present invention; Figure 2 This is a partially enlarged view of the Y-type partition structure of the multi-stage high and low temperature gas mixer based on the Y-type partition structure provided by the present invention; Figure 3 This is an extended schematic diagram of the multi-stage high and low temperature gas mixer based on the Y-shaped partition structure provided by the present invention.

[0021] Figure label: 1. Mainstream inlet; 2. Secondary flow I cavity cone; 3. Mainstream diffuser section cone I; 4. Secondary flow I inlet; 5. Y-shaped partition structure; 6. Secondary flow II inlet; 7. Mainstream diffuser section cone II; 8. Secondary flow II cavity cone; 9. Mixed gas outlet cylinder; 10. Mixed gas inlet; 51. First cone section; 52. Second cone section; 53. Root baffle; 54. Inner cone ring. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0023] The following is combined Figures 1-3 The present invention describes a multi-stage high and low temperature gas mixer based on a Y-shaped partition structure.

[0024] Figure 1 This is a schematic diagram of the structure of the multi-stage high and low temperature gas mixer based on the Y-shaped partition structure provided by the present invention.

[0025] like Figure 1 As shown, the multi-stage high and low temperature gas mixer based on a Y-shaped partition structure provided by this invention is characterized by a design that combines modular multi-stage mixing units with a unique Y-shaped partition structure. Along the airflow direction (e.g.) Figure 1 (From left to right in the middle) The mixer mainly includes: the main flow port 1 located at the uppermost position for introducing the main flow, at least two mixing units connected in series, and the mixing gas outlet cylinder 9 and mixing gas port 10 located at the lowermost position for outputting the final uniformly mixed gas.

[0026] In this invention, each blending unit follows similar structural principles. Figure 1 The two-stage embodiment shown includes a first-stage mixing unit and a second-stage mixing unit. The first-stage mixing unit mainly consists of a secondary flow I cavity cone 2, a main flow diffuser cone 3, and a secondary flow I port 4. The main flow diffuser cone 3 is coaxially disposed inside the secondary flow I cavity cone 2, forming an annular secondary flow I cavity. The secondary flow I port 4 is welded or flanged to the side wall of the secondary flow I cavity cone 2, used to introduce a secondary flow (e.g., low-temperature gas) into the annular cavity. A large number of mixing holes are uniformly opened on the wall of the main flow diffuser cone 3, used to allow the secondary flow gas to penetrate into the main flow channel. Similarly, the second-stage mixing unit consists of a secondary flow II cavity cone 8, a main flow diffuser cone II 7, and a secondary flow II port 6, and its structure is symmetrical or similar to that of the first-stage unit, used to introduce another secondary flow at a different temperature (e.g., high-temperature gas).

[0027] In this invention, the two-stage mixing units are not directly connected, but are connected through a Y-shaped partition structure 5. Specifically, the right end (downstream end) of the secondary flow I cavity cone 2 is connected to the left end of the Y-shaped partition structure 5, and the left end (upstream end) of the secondary flow II cavity cone 8 is connected to the right end of the Y-shaped partition structure 5, thereby achieving structural isolation and series connection of the two pressure-bearing cavities.

[0028] Figure 2 This is a partially enlarged view of the Y-shaped partition structure of the multi-stage high and low temperature gas mixer based on the Y-shaped partition structure provided by the present invention.

[0029] like Figure 2 As shown, the Y-shaped partition structure 5 is its core innovation. It is not a simple connector, but a composite structure with a specific geometry and functional partitions. In this invention, the Y-shaped partition structure 5 includes four main parts: a first conical section 51 facing the upstream side of the airflow, a second conical section 52 facing the downstream side of the airflow, a root partition 53 connecting the first conical section 51 and the second conical section 52, and an inner conical ring 54 fixed to the inner side of the starting end (left end) of the second conical section 52.

[0030] In a key design aspect of this invention, the root partition 53 is the only physical connector linking the first conical section 51 and the second conical section 52. This means that, apart from the area of ​​the root partition 53, the remaining portions of the first and second conical sections 51 and 52 are structurally separated, with a gap in between (i.e., a Y-shaped "fork" region). This design significantly reduces the contact area between the high-temperature side (e.g., the second-stage cavity) and the low-temperature side (e.g., the first-stage cavity) through direct metal-to-metal heat transfer, confining temperature gradient changes and corresponding thermal stress concentration areas to the small area of ​​the root partition 53.

[0031] Furthermore, the right end of the upstream (first stage) mainstream diffuser cone I3 and the left end of the downstream (second stage) mainstream diffuser cone II7 are both arranged opposite to the inner cone ring 54 of the Y-shaped partition structure 5, with a narrow axial gap reserved between them. Figure 2 The "reserved gap" is clearly shown in the text. In embodiments of the present invention, the width of this axial gap is preferably 2-5 mm, for example, 3 mm. This gap is not an assembly error, but an intentionally reserved gap for thermal expansion compensation. When the temperature difference of the gas flowing in two adjacent stages is large, the various cylindrical structures connected to it will undergo different degrees of thermal expansion. The reserved axial gap provides space for the relative elongation or contraction between the main diffuser section cone (3,7) and the fixed inner cone ring 54, avoiding the huge structural stress caused by limited thermal expansion, and ensuring the long-term safe operation of the equipment under wide temperature difference conditions.

[0032] In this invention, a continuous, sealed, rigid pressure-bearing shell is formed by welding or bolting together the various secondary flow chamber cones (2,8), the Y-shaped partition structure 5 connecting them, and the mixing gas outlet cylinder 9 at the end. This shell bears the entire pressure of the working gas. The main flow diffuser cones I3 and II7, located within this pressure-bearing shell, are "suspended" through gaps or free ends at their two ends. They are not rigidly connected to the external pressure-bearing shell, serving only to guide flow and create mixing holes, and do not bear the main pressure load. This "suspended flow guide cylinder within the shell" design achieves decoupling between the pressure-bearing structure and the thermally deformable structure.

[0033] The working process of the mixer of this invention is as follows: The mainstream gas (such as room temperature air) enters from the mainstream port 1 and flows through the interior of the mainstream diffuser cone I 3. Secondary flow I (such as low temperature nitrogen) enters from the secondary flow I port 4 into the annular cavity between the secondary flow I cavity cone 2 and the mainstream diffuser cone I 3, and under pressure, it passes through the holes on the wall of the mainstream diffuser cone I 3, initially mixing with the mainstream gas. The initially mixed gas flow continues to the right and enters the second stage through the central channel of the Y-shaped partition structure 5 (i.e., the area enclosed by the inner conical ring 54). Secondary flow II (such as high temperature fuel gas) enters from the secondary flow II port 6 into the annular cavity between the secondary flow II cavity cone 8 and the mainstream diffuser cone II 7, and is similarly mixed a second time through the holes on the wall of the mainstream diffuser cone II 7. After two stages of mixing, the gas with a relatively uniform temperature is finally discharged through the mixed gas outlet cylinder 9 and the mixed gas port 10. By independently adjusting the flow ratio of secondary flow I and secondary flow II, the temperature of the outlet gas can be precisely controlled over a wide range.

[0034] Figure 3 This is an extended schematic diagram of the multi-stage high and low temperature gas mixer based on the Y-shaped partition structure provided by the present invention.

[0035] like Figure 3 As shown, the multi-stage high and low temperature gas mixer based on a Y-shaped partition structure provided by this invention has excellent scalability. In the extended version of this invention, the number of mixing units is not limited to two stages, but can be three or more stages. By simply repeating the Y-shaped partition structure 5 described above between every two adjacent mixing units, the step-by-step mixing of more gas streams at different temperatures can be achieved. For example, ultra-low temperature, low temperature, room temperature, and high temperature gases can be introduced sequentially. Through multi-stage fine mixing, an extremely uniform mixed gas stream over a wider temperature range can be obtained, while the structure remains compact, and the thermal stress problem is properly solved through each Y-shaped partition structure.

[0036] This invention also provides a method for gas mixing using a multi-stage high and low temperature gas mixer based on a Y-shaped partition structure, comprising the following steps: introducing a mainstream gas into the upstream mainstream diffuser cone through a mainstream port 1; introducing at least two secondary gases with temperatures different from the mainstream gas into corresponding secondary cavity cones through corresponding secondary ports; causing each of the secondary gases to pass through mixing holes on the wall of the corresponding mainstream diffuser cone as it flows through the corresponding secondary cavity cone, and to merge into the mainstream gas flowing through the mainstream diffuser cone in multiple stages for mixing; and outputting the uniformly mixed gas formed after multi-stage mixing through the mixing gas port 10.

[0037] In this invention, when the gas temperatures inside adjacent secondary flow cavity cones are different, the root baffle and inner cone ring of the Y-shaped partition structure 5 can undergo thermal deformation, and the axial gap provides compensation space for the relative thermal expansion between the connected main flow diffuser cone and the inner cone ring.

[0038] In this invention, the at least two secondary gas streams include at least one high-temperature gas and at least one low-temperature gas. By independently adjusting the flow rate of each secondary gas stream, a wide range of temperature adjustment can be achieved for the mixed gas output from the mixing gas port 10.

[0039] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions 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. A multi-stage high and low temperature gas mixer based on a Y-type partition structure, characterized in that, include: At least two mixing units connected in sequence along the airflow direction, and a mixing gas outlet cylinder (9) and a mixing gas inlet (10) located downstream of the at least two mixing units. Each of the at least two mixing units includes: a secondary flow cavity cone, a main flow diffusion section cone coaxially disposed inside the secondary flow cavity cone, and a secondary flow port for introducing secondary flow opened on the secondary flow cavity cone; the main flow diffusion section cone has mixing holes opened on its wall. The two adjacent mixing units are connected by a Y-shaped partition structure (5); the Y-shaped partition structure (5) includes a first cone section (51) facing the upstream side of the airflow, a second cone section (52) facing the downstream side of the airflow, a root partition plate (53) connecting the first cone section and the second cone section, and an inner cone ring (54) located inside the second cone section. The secondary flow cavity cone of the upstream mixing unit is connected to the first cone section (51) of the Y-shaped separation structure (5), and the secondary flow cavity cone of the downstream mixing unit is connected to the second cone section (52) of the Y-shaped separation structure (5). Axial gaps are reserved between the end of the mainstream diffusion section cone of the upstream mixing unit and the inner cone ring (54), and between the beginning of the mainstream diffusion section cone of the downstream mixing unit and the inner cone ring (54) to compensate for the thermal expansion of the structure.

2. The multi-stage high and low temperature gas mixer based on a Y-shaped partition structure according to claim 1, characterized in that, The at least two-stage blending unit includes a first-stage blending unit and a second-stage blending unit; The first-stage mixing unit includes: a secondary flow I cavity cone (2), a main flow diffusion section cone I (3) coaxially disposed inside the secondary flow I cavity cone (2), and a secondary flow I port (4); The second-stage mixing unit includes: a secondary flow II cavity cone (8), a main flow diffusion section cone II (7) coaxially disposed inside the secondary flow II cavity cone (8), and a secondary flow II inlet (6); The Y-shaped partition structure (5) is connected between the secondary flow I cavity cone (2) and the secondary flow II cavity cone (8).

3. The multi-stage high and low temperature gas mixer based on a Y-type partition structure according to claim 1, characterized in that, The width of the axial clearance is 2~5mm.

4. The multi-stage high and low temperature gas mixer based on a Y-type partition structure according to claim 1, characterized in that, The root partition of the Y-shaped partition structure (5) is the only physical connector connecting its first conical part and second conical part, so that the structural load is transferred between the first conical part and the second conical part through the root partition.

5. The multi-stage high and low temperature gas mixer based on a Y-type partition structure according to claim 1, characterized in that, The secondary flow cavity cone, the Y-shaped partition structure (5), and the mixed gas outlet cylinder (9) together constitute the continuous pressure-bearing shell of the mixer; the main flow diffusion section cone is suspended in the pressure-bearing shell and is not rigidly fixed to the pressure-bearing shell.

6. The multi-stage high and low temperature gas mixer based on a Y-type partition structure according to claim 1, characterized in that, It also includes a main flow port (1) located at the upstream side, which is connected to the main flow diffusion section cone of the upstream mixing unit.

7. The multi-stage high and low temperature gas mixer based on a Y-type partition structure according to claim 1, characterized in that, The number of the at least two-level blending units is three or more, and adjacent blending units are connected by a Y-shaped separation structure (5).

8. A method for gas mixing using a multi-stage high- and low-temperature gas mixer based on a Y-shaped partition structure as described in any one of claims 1-7, characterized in that, Includes the following steps: A stream of mainstream gas is introduced into the upstream mainstream diffusion section cone through the mainstream pipe opening (1); At least two secondary gases with temperatures different from the mainstream gas are introduced into the corresponding secondary flow chamber cone through their respective secondary flow ports. When each secondary gas flows through the corresponding secondary cavity cone, it passes through the mixing holes on the wall of the corresponding main diffuser cone and merges into the main gas flowing through the main diffuser cone in multiple stages and sequentially for mixing. The uniform mixed gas formed after multi-stage mixing is output through the mixing gas port (10).

9. The method according to claim 8, characterized in that, When the gas temperatures inside adjacent secondary flow cavity cones are different, the root baffle and inner cone ring of the Y-shaped partition structure (5) can undergo thermal deformation, and the axial gap provides compensation space for the relative thermal expansion between the connected main flow diffuser cone and the inner cone ring.

10. The method according to claim 8, characterized in that, The at least two secondary gas streams include at least one high-temperature gas and at least one low-temperature gas. By independently adjusting the flow rate of each secondary gas stream, a wide range of temperature adjustment can be achieved for the mixed gas output from the mixing gas port (10).

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