Cool air pipeline cavity structure
By adding a baffle in the front cavity of the pre-rotating nozzle before the cold passage of the aircraft engine turbine, the entry of sand ash particles is solved, and the blade wear and heat transfer performance caused by sand ash particles is achieved, and the effect of extending the blade service life and improving the turbine heat transfer performance is achieved.
Patent Information
- Application Number
- CN202510085420.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-20
- Publication Date
- 2025-04-25
AI Technical Summary
In aircraft engines operating in harsh environments, sand ash particles enter the cold channel inside the turbine, resulting in blade wear and heat transfer performance, affecting the service life of the engine.
Different numbers and structures of baffles are added to the front cavity of the pre-rotating nozzle before the internal cooling channel of the turbine to block the sand ash particles and make them deposited on the baffles, thereby reducing the deposition of particles entering the turbine blades.
The baffle structure significantly increases the deposition of sand ash particles in the front cavity, reduces the deposition of particles on the turbine blades, extends the service life of the blades, and improves the heat transfer performance of the turbine.
Smart Images
Figure CN119878374A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of pre-swirl nozzles for aircraft engines, and in particular relates to a cold air pipeline cavity structure. Background Art
[0002] When aircraft engines are operated for a long time in harsh environments such as dust, haze, etc., a large amount of sand and ash particles will enter the engine, causing the compressor blades to wear and reduce their aerodynamic performance. At the same time, sand and ash particles will be deposited in the cooling channel inside the turbine, affecting the heat transfer performance of the blades, reducing the service life of the blades, and having a serious impact on the turbine components. After the high-pressure cooling air passes through the pipeline cavity, the pre-swirl nozzle changes the rotation direction of the airflow, and enters the turbine cavity through the pre-swirl cavity to reduce the impact effect on the turbine. The current experimental research mainly focuses on the deposition characteristics of particles on the inner and outer surfaces of turbine blades, while the deposition rate of sand and ash particles in the inner cooling channel of the cold air cavity is relatively low, so that most of the sand and ash particles enter the internal blades of the turbine, affecting the heat transfer efficiency of the turbine and reducing the service life of the turbine.
[0003] The current turbine blades do not have effective measures to suppress the internal dust deposition, and the dust deposition problem is becoming increasingly prominent. Therefore, a structure is needed to reduce the particle deposition on the turbine blades and improve the heat transfer performance of the turbine blades.
[0004] The present invention adds baffles of different numbers and structures at the channel of the front cavity of the pre-swirl nozzle before the turbine inner cooling channel to block sand and ash particles as much as possible and deposit them on the baffles, thereby reducing the deposition of particles entering the turbine blades and improving the heat transfer performance of the turbine blades. Summary of the invention
[0005] The present invention aims to provide a cold air pipeline cavity structure, by adding different numbers of baffles at the channel of the front cavity of the pre-swirl nozzle before the cooling channel in the turbine, the sand and ash particles are blocked as much as possible and deposited on the baffles, thereby reducing the deposition of particles entering the turbine blades and improving the heat transfer performance of the turbine blades.
[0006] To achieve the above-mentioned object, the present invention adopts the following specific technical solutions: a cold air pipeline cavity structure, including a front cavity, a pre-swirl nozzle, a pre-swirl nozzle rear cavity and a baffle;
[0007] One end of the front cavity is connected to the cold air pipeline, and the other end is provided with a pre-swirl nozzle, and the interior of the front cavity is a cavity structure;
[0008] The pre-swirl nozzle is installed between the front cavity and the rear cavity of the pre-swirl nozzle, and the pre-swirl nozzle is a curved blade structure;
[0009] The rear cavity of the pre-swirl nozzle is a cylindrical cavity structure, one end of which is connected to the pre-swirl nozzle;
[0010] The baffle is in the shape of a flat plate and is vertically installed in the front cavity to block sand and ash particles from settling.
[0011] Furthermore, an impact hole is provided on the air inlet end of the front cavity; the air flow enters the front cavity through the impact hole.
[0012] Furthermore, a guide groove is provided inside the pre-swirl nozzle, the air inlet end of the guide groove is connected to the front cavity, and the air outlet end of the guide groove is connected to the rear cavity of the pre-swirl nozzle, which converts the axially flowing cold air into a rotating airflow, reducing the impact on the turbine.
[0013] Furthermore, the baffle includes a first baffle, which is arranged on a side of the cavity of the front cavity away from the impact hole; the first baffle is detachably fixed on the inner wall of the front cavity; and the radius of the first baffle is 186 mm.
[0014] Furthermore, the baffle includes a first baffle and a second baffle, the first baffle and the second baffle are located in the cavity of the front cavity on a side away from the impact hole; the second baffle is arranged on a side of the first baffle away from the impact hole; the radius of the second baffle is 188 mm.
[0015] Furthermore, the baffle includes a first baffle, a second baffle and a third baffle. The first baffle and the second baffle are arranged on the side of the cavity of the front cavity away from the impact hole, and the third baffle is arranged in the cavity of the front cavity and on the same side as the impact hole, and is fixed to the inner wall of the front cavity in a detachable manner; the radius of the third baffle is 200 mm.
[0016] The present invention can achieve the following technical effects:
[0017] The present invention sets a baffle structure in the front cavity before the pre-swirl nozzle, which can significantly increase the deposition of particles in the front cavity. After the particles are deposited at the baffle, the number of particles entering the turbine blades is reduced, thereby reducing the wear and deposition of the blades and extending the service life of the blades.
[0018] After the baffle is provided, the present invention can change the flow direction of the airflow and reduce the deposition of particles on the blades by changing the flow complexity of the airflow and increasing the resistance in the process.
[0019] The present invention arranges the baffle plate at the detachable structure. Such a design facilitates the easy removal of the baffle plate after the experiment is finished or when the engine is maintained, and the deposited sand and ash particles are cleaned, thereby ensuring the continuous and effective operation of the device. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Figure 1 It is the overall structural diagram of the cold air pipeline cavity structure of the present invention;
[0021] Figure 2 It is a partial structural diagram of the cold air pipeline cavity structure of the present invention;
[0022] Figure 3 It is a cross-sectional view of a partial structural diagram of the cold air pipeline cavity structure of the present invention;
[0023] Figure 4 A perspective view of a partial structural diagram of a cold air pipeline cavity structure of the present invention;
[0024] Figure 5 It is a structural diagram of the first embodiment of the present invention;
[0025] Figure 6 is a structural diagram of a second embodiment of the present invention;
[0026] Figure 7 It is a structural diagram of the third embodiment of the present invention.
[0027] In the figure: 1. first baffle; 2. second baffle; 3. third baffle; 4. front cavity; 5. pre-swirl nozzle; 6. rear cavity of pre-swirl nozzle; 7. impact hole. DETAILED DESCRIPTION
[0028] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and do not constitute a limitation of the present invention.
[0029] refer to Figure 1-4 , a cold air pipeline cavity structure, comprising a front cavity (4), a pre-swirl nozzle (5), a pre-swirl nozzle rear cavity (6) and a baffle;
[0030] One end of the front cavity (4) is connected to the cold air pipeline, and the other end is provided with a pre-swirl nozzle (5). The interior of the front cavity (4) is a cavity structure. The front cavity (4) provides a path for the transmission of cold air and is the starting link for the cold air to enter the subsequent structure. The airflow state inside the front cavity will affect the movement trajectory of the subsequent sand and ash particles.
[0031] The pre-swirl nozzle (5) is installed between the front cavity (4) and the pre-swirl nozzle rear cavity (6). The pre-swirl nozzle (5) is a curved blade structure and is used to change the direction of the airflow so that the airflow enters the turbine cavity at a suitable angle and in a rotating state, thereby reducing the impact effect on the turbine and ensuring stable and efficient operation of the turbine.
[0032] The pre-swirl nozzle rear cavity (6) is a cylindrical cavity structure, one end of which is connected to the pre-swirl nozzle (5) and the other end is connected to the turbine cavity, and accommodates and transmits airflow;
[0033] The baffle is in the form of a flat plate and is vertically mounted in the front cavity (4) to block sand and ash particles from settling. Through the synergistic effect of the above components, the deposition of sand and ash particles entering the turbine blades is reduced, thereby protecting the turbine blades.
[0034] Furthermore, an impact hole (7) is provided on the air inlet end of the front cavity (4); the airflow enters the front cavity (4) through the impact hole (7).
[0035] Furthermore, a guide groove is provided inside the pre-swirl nozzle (5), the air inlet end of the guide groove is closely connected to the front cavity (4), and the air outlet end is connected to the rear cavity (6) of the pre-swirl nozzle, so as to convert the axially flowing cold air into a rotating airflow, reduce the impact on the turbine, and improve the working efficiency of the turbine.
[0036] Furthermore, the baffle plate comprises a first baffle plate (1), which is arranged on a side of the cavity of the front cavity (4) away from the impact hole (7); the first baffle plate (1) is detachably fixed on the inner wall of the front cavity (4); the radius of the first baffle plate (1) is 186 mm, and the length-to-width ratio is between 1.5 and 2.0.
[0037] Furthermore, the baffle comprises a first baffle (1) and a second baffle (2), the first baffle (1) and the second baffle (2) being located in the cavity of the front cavity (4) on a side away from the impact hole (7); the second baffle (2) is arranged on a side of the first baffle (1) away from the impact hole (7); the radius of the second baffle (2) is 188 mm, and the aspect ratio is between 1.5 and 2.0.
[0038] Furthermore, the baffle comprises a first baffle (1), a second baffle (2) and a third baffle (3); the first baffle (1) and the second baffle (2) are arranged in the cavity of the front cavity (4) on a side away from the impact hole (7); the third baffle (3) is arranged in the cavity of the front cavity (4) and on the same side as the impact hole (7), and is fixed to the inner wall of the front cavity (4) in a detachable manner; the radius of the third baffle (3) is 200 mm, and the aspect ratio is between 1.5 and 2.0.
[0039] Embodiment 1: A baffle is set in the cold air cavity pipeline cavity, namely the first baffle (1), with a radius of 186mm and a distance of 27mm from the left end of the front cavity (4). When the cold air carrying particles enters the front cavity (4) from the impact hole (7), without adding a baffle, the airflow will flow downstream along the inner wall of the front cavity (4), and after changing the flow direction through the pre-swirl nozzle 2, it will flow toward the turbine cavity and blades, so that the sand and ash particles are mainly deposited in the turbine cavity. After adding a baffle, the particles carried by the cold air will collide with the baffle on the front cavity (4), thereby changing the original flow direction of the airflow. Compared with the cavity without a baffle, the deposition rate of particles on the inner wall of the front cavity (4) is higher, reducing the deposition of sand and ash particles on the blades. This is because the presence of the first baffle (1) changes the flow field structure of the airflow. When the particles collide with the first baffle (1), the velocity direction changes, and some particles settle in the low-speed area near the first baffle (1), thereby reducing the number of particles entering the turbine blade area.
[0040] Embodiment 2: Two baffles are provided at the target surface of the cold air pipeline, namely, a first baffle (1) and a second baffle (2). The radius of the first baffle (1) is 186 mm, and the distance from the left end of the front cavity (4) is 27 mm; the radius of the second baffle (2) is 188 mm, and the distance from the left end of the front cavity (4) is 38 mm. Compared with the case where only one baffle is provided, after the airflow passes through the baffle, the airflow that is not blocked will continue to carry the particles to flow downstream. Due to the increase in the number of baffles, the deposition rate of the particles on the inner wall of the front cavity (4) is further improved. When the particles pass through the first baffle (1), they are blocked by the second baffle (2), and a part of the particles will be deposited between the two baffles, which increases the deposition amount on the inner wall of the front cavity (4) and reduces the deposition of particles flowing into the downstream blades. Between the two baffles, due to the change in airflow velocity and the multiple collisions between the particles and the baffles, the particles are more likely to be deposited in this area, further reducing the amount of particles entering the turbine blades.
[0041] Embodiment 3: Three baffles are provided at the cold air pipeline cavity, wherein the first baffle (1) and the second baffle (2) are located on the inner wall of the front cavity (4), with radii of 186 mm and 188 mm respectively, and the distances from the left end of the front cavity (4) are 27 mm and 38 mm respectively; the third baffle (3) is provided on the top wall of the front cavity (4), with a radius of 200 mm, and the distance from the left end of the front cavity (4) is 33 mm. After the third baffle (3) is added to the top wall of the front cavity (4), the particles carried by the cold air will change direction after passing through the first baffle (1) and the second baffle (2). A portion of the particles carried by the cold air flows along the top wall of the front cavity (4), and when this portion passes through the third baffle (3), the particles collide with the third baffle (3), and a portion of the particles adhere, resulting in a higher adhesion density at the impact surface of the third baffle (3) than at other positions of the front cavity (4). Compared with the case where two baffles are provided in the front cavity (4), the third baffle (3) provided in the front cavity (4) allows some particles to be deposited on the top wall of the front cavity (4). The three baffles deposit more particles, and the number and quality of particles flowing downstream are greatly reduced. This indicates that under the multiple obstruction effects of the baffles, the deposition of particles inside the front cavity (4) can be effectively enhanced, and the amount of sand and ash particles entering the turbine blades can be reduced.
[0042] Working principle:
[0043] When the aircraft engine is running, high-pressure cooling air carrying a large amount of sand and ash particles enters from the front cavity (4). The airflow originally flows toward the pre-swirl nozzle (5) along an inherent path, and the sand and ash particles move with the airflow. When no baffle is provided, most of the sand and ash particles will follow the airflow through the pre-swirl nozzle (5) into the turbine cavity and blades, causing sand and ash to deposit on the blades, affecting the heat transfer performance.
[0044] When a baffle is set in the front cavity (4), the baffle is perpendicular to the flow direction of the cold air. The airflow carries particles and hits the baffle, and the direction of particle movement changes. Due to the obstruction of the baffle, the particles lose kinetic energy and their speed decreases. Some particles are directly deposited on the baffle, and some particles change their movement trajectory after colliding with the baffle, increasing the probability of collision with the cavity wall, especially the target surface and the impact surface, so that more particles are deposited in these areas. As the number of baffles increases, the complexity of the airflow increases, and the probability of collision, adhesion and deposition of particles with the wall and baffles is further increased.
[0045] The presence of the baffle changes the flow characteristics of the airflow. On the one hand, it increases the resistance of the airflow during flow, causing changes in the airflow velocity and pressure distribution; on the other hand, it changes the direction of the airflow, causing the airflow to form a complex flow field in the cavity. This complex flow field makes the movement of particles in the cavity more disordered, increases the interaction between particles and the wall and baffles, and promotes the deposition of particles. The total pressure recovery coefficient inside the cavity where the baffle is set does not change much, indicating that while this structure promotes particle deposition, it has little effect on the total airflow pressure and will not excessively affect the overall performance of the engine.
[0046] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.
[0047] Although the embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and cannot be understood as limiting the present invention. Those skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention.
[0048] The above specific implementations of the present invention do not constitute a limitation on the protection scope of the present invention. Any other corresponding changes and modifications made based on the technical concept of the present invention should be included in the protection scope of the claims of the present invention.
Claims
1. A cold air pipeline cavity structure, characterized in that: It comprises a front cavity (4), a pre-swirl nozzle (5), a pre-swirl nozzle rear cavity (6) and a baffle; One end of the front cavity (4) is connected to the cold air pipeline, and the other end is provided with a pre-swirl nozzle (5), and the interior of the front cavity (4) is a cavity structure; The pre-swirl nozzle (5) is installed between the front cavity (4) and the pre-swirl nozzle rear cavity (6), and the pre-swirl nozzle (5) is in the form of a curved blade structure; The pre-swirl nozzle rear cavity (6) is a cylindrical cavity structure and is connected to the pre-swirl nozzle (5); The baffle is in the shape of a flat plate and is vertically installed in the front cavity (4) to block sand and ash particles and allow them to settle.
2. The cold air pipeline cavity structure according to claim 1, characterized in that: An impact hole (7) is provided on the air inlet end of the front cavity (4); airflow enters the front cavity (4) through the impact hole (7).
3. The cold air pipeline cavity structure according to claim 1, characterized in that: The pre-swirl nozzle (5) is provided with a guide groove inside, the air inlet end of the guide groove is connected to the front cavity (4), and the air outlet end of the guide groove is connected to the pre-swirl nozzle rear cavity (6), so as to convert the axially flowing cold air into a rotating airflow, thereby reducing the impact on the turbine.
4. The cold air pipeline cavity structure according to claim 2, characterized in that: The baffle plate comprises a first baffle plate (1), which is arranged on a side of the cavity of the front cavity (4) away from the impact hole (7); the first baffle plate (1) is detachably fixed on the inner wall of the front cavity (4).
5. The cold air pipeline cavity structure according to claim 2, characterized in that: The baffle plate comprises a first baffle plate (1) and a second baffle plate (2), wherein the first baffle plate (1) and the second baffle plate (2) are located in the cavity of the front cavity (4) on a side away from the impact hole (7); and the second baffle plate (2) is arranged on a side of the first baffle plate (1) away from the impact hole (7).
6. The cold air pipeline cavity structure according to claim 2, characterized in that: The baffle plate comprises a first baffle plate (1), a second baffle plate (2) and a third baffle plate (3); the first baffle plate (1) and the second baffle plate (2) are arranged on a side of the cavity of the front cavity (4) away from the impact hole (7); the third baffle plate (3) is arranged in the cavity of the front cavity (4) and on the same side as the impact hole (7); the first baffle plate (1), the second baffle plate (2) and the third baffle plate (3) are detachably fixed on the inner wall of the front cavity (4).