Partition plate for centripetal impeller and turbine

Abstract

The invention relates to the technical field of turbines, and discloses a partition plate for a centripetal impeller and a turbine, the partition plate and the wheel back of the centripetal impeller are arranged at intervals to form a sealing flow channel suitable for sealing gas flowing, the partition plate for the centripetal impeller comprises a flow guide structure, and the flow guide structure is arranged on the side, facing the sealing flow channel, of the partition plate; the flow guide structure comprises at least one flow guide channel, the flow guide channel comprises a fluid inlet and a fluid outlet, and the fluid inlet is communicated with the inlet of the sealing flow channel; according to the invention, the flow guide channel extending in an arc shape is arranged on one side, facing the sealing flow channel, of the partition plate, so that optimized sealing airflow can more uniformly flush a high-heat load area on the back of the wheel, and the convective heat exchange effect is enhanced; the problems of thermal stress concentration and the like caused by leakage flow high-speed impact, flow separation and the like are solved, so that the thermal environment of a rotor wheel disc is improved, and the service life of a turbine rotor is prolonged.

Description

Technical Field

[0001] This invention relates to the field of turbine technology, and more specifically to a diaphragm and turbine for a centripetal impeller. Background Technology

[0002] As a key energy conversion component in small gas turbines, turbochargers, and aerospace auxiliary power units, the aerodynamic performance and structural reliability of radial turbines directly affect the overall efficiency and service life of the machine. Based on the impeller structure, radial turbines can be divided into three types: closed, semi-open, and open. Among them, semi-open radial turbines, due to the elimination of the front cover plate, have certain advantages in reducing rotor weight, simplifying manufacturing processes, and improving structural strength, and are therefore widely used in high-speed, small-size turbine systems.

[0003] However, due to the semi-open structure including the rotor back clearance, some of the mainstream gas in the channel, driven by the pressure difference between the pressure and suction surfaces, directly leaks from the high-pressure side, bypassing the blade's working area, and through the back clearance to the low-pressure side. Furthermore, the leaked flow undergoes complex flow processes such as separation and jetting, resulting in a high heat transfer coefficient in localized areas, forming a high-heat-load zone. This uneven and intense thermal load easily induces thermal fatigue damage to the rotor disc, shortening the turbine rotor's service life. Summary of the Invention

[0004] In view of this, the present invention provides a baffle and turbine for a centripetal impeller to solve the problem that the existence of the back gap causes some of the mainstream gas in the channel to bypass the working area of ​​the blades directly from the high-pressure side and leak to the low-pressure side through the back gap under the pressure difference between the pressure surface and the suction surface. Furthermore, the leakage flow undergoes complex flow processes such as separation and jetting, resulting in a high heat transfer coefficient in local areas and forming a high heat load zone.

[0005] In a first aspect, the present invention provides a baffle for a centripetal impeller, the baffle being spaced apart from the back of the centripetal impeller to form a sealing flow channel suitable for sealing gas flow. The baffle for the centripetal impeller includes a flow guiding structure disposed on the side of the baffle facing the sealing flow channel; and the flow guiding structure includes at least one flow guiding channel, the flow guiding channel including a fluid inlet and a fluid outlet, the fluid inlet communicating with the inlet of the sealing flow channel; the flow guiding channel extends in an arc shape from the fluid inlet to the fluid outlet.

[0006] Beneficial effects: By setting an arc-shaped guide channel on the side of the baffle facing the sealing channel, and with the fluid inlet of the guide channel connected to the inlet of the sealing channel, it is ensured that the sealing gas entering the sealing channel can enter the guide channel in a timely manner. The arc-shaped guide channel actively guides the flow path of the sealing gas, allowing it to flow orderly along a smooth trajectory that conforms to the curvature of the wheel back. This avoids the turbulence, backflow, or local dead zones caused by inertia or pressure difference in traditional unguided structures, thereby improving the uniformity and adhesion of the sealing gas in the wheel back area. It also enhances the momentum retention and penetration depth of the sealing gas, effectively suppressing the direct leakage of high-temperature working fluid through the wheel back gap, reducing ineffective working fluid loss and mixing loss. The optimized sealing airflow can more evenly flush the high heat load area of ​​the wheel back, enhance the convective heat transfer effect, and solve problems such as thermal stress concentration caused by high-speed impact and flow separation of the leakage flow, thereby improving the thermal environment of the rotor disc and extending the life of the turbine rotor.

[0007] In one optional embodiment, the flow guiding structure includes a first flow guiding portion and a second flow guiding portion, wherein the first flow guiding portion and the second flow guiding portion are arranged at circumferential intervals along the partition to form the flow guiding channel.

[0008] Beneficial effects: The flow guiding structure forms an arc-shaped flow guiding channel with a clear boundary by setting the first flow guiding part and the second flow guiding part at circumferential intervals on the partition, which effectively constrains and guides the sealing gas to flow along a predetermined path.

[0009] In one alternative embodiment, the extension length of the first guide portion is greater than the extension length of the second guide portion, and in the radial direction of the partition, the end of the second guide portion is located inside the end of the first guide portion.

[0010] Beneficial effects: By making the extension length of the first guide section greater than that of the second guide section, and in the radial direction of the partition, the end of the second guide section is located inside the end of the first guide section, the sealing gas is biased towards the shorter second guide section when it flows out of the guide channel, which effectively controls the flow direction of the sealing gas in the wheel back gap and improves the utilization efficiency of the sealing gas.

[0011] In one alternative embodiment, the starting ends of the first guide portion and the second guide portion are aligned radially with each other on the partition.

[0012] Beneficial effects: Aligning the starting ends of the first and second guide sections radially along the partition ensures that the sealing gas enters the guide channel uniformly and synchronously from the fluid inlet, avoiding airflow deflection, local acceleration, or vortex generation caused by inlet misalignment. The regularity of the inlet cross-section helps to form a stable and symmetrical initial flow field, improving the guiding efficiency and controllability of the guide channel for the sealing airflow.

[0013] In one alternative embodiment, the first guide portion includes a first arcuate protrusion.

[0014] Beneficial effects: Since the first guide section includes the first arc-shaped protrusion, the curved surface structure of the first arc-shaped protrusion reduces the local flow loss and separation risk of the airflow during the turning or acceleration process, and makes the airflow adhere more closely to the wall surface, thereby improving the smoothness and efficiency of the guide.

[0015] In one alternative embodiment, the second guide portion includes a second arcuate protrusion.

[0016] Beneficial effects: Since the second guide section includes a second arc-shaped protrusion, the curved surface structure of the second arc-shaped protrusion reduces the local flow loss and separation risk of airflow during turning or acceleration, allowing the airflow to adhere more closely to the wall surface, thereby improving the smoothness and efficiency of the guide.

[0017] In one alternative implementation, the guide channel gradually narrows along the flow direction of the sealing gas.

[0018] Beneficial effects: Along the flow direction of the sealing gas, the guide channel gradually narrows, effectively accelerating the flow velocity of the sealing gas. This not only suppresses the reverse leakage of the high-temperature working fluid from the main channel to the wheel back cavity, improving sealing efficiency, but also helps to enhance convective heat transfer on the wheel back surface, improve local temperature distribution, and reduce the risk of thermal stress concentration. Furthermore, the gradually narrowing guide channel can reduce flow separation and eddy generation, making the flow of the sealing gas more stable and orderly.

[0019] In one optional embodiment, the flow guiding structure further includes a third flow guiding portion that extends circumferentially along the partition; and in the radial direction of the partition, the third flow guiding portion is located on the side of the fluid outlet opposite to the fluid inlet and is spaced apart from the fluid outlet.

[0020] Beneficial effects: By adding a third guide section extending circumferentially along the baffle and arranged radially at intervals on the radially outer side of the fluid outlet, the sealing gas discharged through the guide channel can be regulated and guided for a secondary purpose, avoiding direct diffusion and turbulence after the airflow is discharged, and maintaining the circumferential flow trend of the airflow; at the same time, the radially spaced layout will not hinder the smooth discharge of the airflow, and can also form a buffer zone between the fluid outlet and the third guide section; in addition, the gas guided by the second step can form a continuous and stable circumferential gas film between the impeller back and the baffle, effectively preventing the sealing gas flowing out of the fluid outlet from diffusing outward excessively or mixing with the high-temperature working gas.

[0021] In one alternative embodiment, the third guide portion includes a third arcuate protrusion.

[0022] Beneficial effects: Because the third guide section includes a third arc-shaped protrusion, it can more smoothly guide the sealing gas to flow circumferentially, reducing flow separation, vortex, or local impact losses caused by structural abrupt changes. Furthermore, as an aerodynamic barrier located radially outside the fluid outlet, the third arc-shaped protrusion not only effectively constrains the diffusion path of the sealing airflow, preventing premature mixing with high-temperature working fluid, but also promotes airflow adhesion to the wheel back surface through its curved shape, enhancing the uniformity and stability of the cooling film coverage.

[0023] Secondly, the present invention also provides a turbine, including the aforementioned baffle for a centripetal impeller. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the specific embodiments or related technologies of the present invention, the drawings used in the description of the specific embodiments or related technologies will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0025] Figure 1 This is a partial structural cross-sectional view of a turbine according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the partition structure according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the control curve of the flow guiding structure according to an embodiment of the present invention; Figure 4 This is a schematic diagram of the temperature distribution on the surface of the partition plate according to an embodiment of the present invention; Figure 5 This is a schematic diagram of the temperature distribution on the surface of a partition in a traditional structure. Figure 6 This is a schematic diagram of the temperature distribution on the back surface of the wheel according to an embodiment of the present invention; Figure 7 This is a schematic diagram of the temperature distribution on the back surface of a wheel in a traditional structure. Figure 8 This is a schematic diagram of the streamline distribution on the wheel back of an embodiment of the present invention; Figure 9 This is a schematic diagram of the streamline distribution on the wheel back in a traditional structure.

[0026] Explanation of reference numerals in the attached figures: 1. Partition; 2. Centripetal impeller; 3. Seal off the flow channel; 41. Flow guiding channel; 411. Fluid inlet; 412. Fluid outlet; 42. First flow guiding section; 43. Second flow guiding section; 44. Third flow guiding section; 5. Guide vane. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] The following is combined Figures 1 to 9 The following describes embodiments of the present invention.

[0029] According to an embodiment of the present invention, in one aspect, a baffle 1 for a centripetal impeller 2 is provided. The baffle 1 is spaced apart from the back of the centripetal impeller 2 to form a sealing flow channel 3 suitable for sealing gas flow. The baffle 1 for the centripetal impeller 2 includes a flow guiding structure, which is disposed on the side of the baffle 1 facing the sealing flow channel 3. The flow guiding structure includes at least one flow guiding channel 41, which includes a fluid inlet 411 and a fluid outlet 412. The fluid inlet 411 communicates with the inlet of the sealing flow channel 3. The flow guiding channel 41 extends in an arc shape from the fluid inlet 411 to the fluid outlet 412.

[0030] In the above embodiment, by providing an arc-shaped guide channel 41 on the side of the partition 1 facing the sealing channel 3, and the fluid inlet 411 of the guide channel 41 being connected to the inlet of the sealing channel 3, it is ensured that the sealing gas entering the sealing channel 3 can enter the guide channel 41 in a timely manner. Furthermore, the arc-shaped guide channel 41 actively guides the flow path of the sealing gas, allowing it to flow orderly along a smooth trajectory conforming to the curvature of the wheel back. This avoids the turbulence, backflow, or local dead zones caused by inertia or pressure difference in the sealing gas in traditional unguided structures, thereby improving the uniformity and adhesion of the sealing gas in the wheel back area. It also enhances the momentum retention and penetration depth of the sealing gas, effectively suppressing the direct leakage of high-temperature working fluid through the wheel back gap, reducing ineffective working fluid loss and mixing loss. The optimized sealing airflow can more evenly scour the high heat load area of ​​the wheel back, enhance the convective heat transfer effect, and solve problems such as thermal stress concentration caused by high-speed impact and flow separation of the leakage flow, thereby improving the thermal environment of the rotor disc and extending the life of the turbine rotor.

[0031] In specific embodiments, the baffle 1 structure of the centripetal impeller 2 is typically composed of multiple baffle units spliced ​​together circumferentially to form a complete annular structure. This embodiment shows the structure of a single baffle 1, which is used to form part of the complete annular structure. The single baffle 1 integrates features such as flow guiding structures and can work in conjunction with other baffle units to form a complete sealed flow channel system.

[0032] Specifically, the number of baffle units that make up the baffle structure of the centripetal impeller 2 can be set according to actual design requirements. For example, seven, eight or other numbers can be used to adapt to different aerodynamic layouts, manufacturing processes or assembly requirements. This embodiment does not limit this.

[0033] In one embodiment, such as Figure 2 As shown, the flow guiding structure includes a first flow guiding part 42 and a second flow guiding part 43, and the first flow guiding part 42 and the second flow guiding part 43 are arranged at intervals along the circumference of the partition 1 to form the flow guiding channel 41.

[0034] In the above embodiment, the flow guiding structure forms an arc-shaped flow guiding channel 41 with a clear boundary by circumferentially spaced first flow guiding part 42 and second flow guiding part 43 on the partition 1, which effectively constrains and guides the sealing gas to flow along a predetermined path.

[0035] In one embodiment, such as Figure 2 As shown, the extension length of the first guide portion 42 is greater than the extension length of the second guide portion 43, and in the radial direction of the partition 1, the end of the second guide portion 43 is located inside the end of the first guide portion 42.

[0036] In the above embodiment, by making the extension length of the first guide section 42 greater than the extension length of the second guide section 43, and in the radial direction of the partition 1, the end of the second guide section 43 is located inside the end of the first guide section 42, so that the sealing gas is biased to the shorter second guide section 43 side when it flows out of the guide channel 41, the flow direction of the sealing gas in the wheel back gap is effectively controlled, and the utilization efficiency of the sealing gas is improved.

[0037] In one embodiment, the starting ends of the first guide portion 42 and the second guide portion 43 are aligned radially on the partition 1.

[0038] In the above embodiments, aligning the starting ends of the first guide section 42 and the second guide section 43 radially with the partition 1 ensures that the sealing gas enters the guide channel 41 uniformly and synchronously from the fluid inlet 411, avoiding airflow deflection, local acceleration, or vortex generation caused by inlet misalignment. The regularity of the inlet cross-section helps to form a stable and symmetrical initial flow field, improving the guiding efficiency and controllability of the guide channel 41 for the sealing airflow.

[0039] In one embodiment, the first guide portion 42 includes a first arcuate protrusion.

[0040] In the above embodiments, since the first guide portion 42 includes a first arc-shaped protrusion, the curved surface structure of the first arc-shaped protrusion reduces the local flow loss and separation risk of the airflow during the turning or acceleration process, making the airflow adhere more closely to the wall surface, thereby improving the smoothness and efficiency of the guide.

[0041] In one embodiment, the second guide portion 43 includes a second arcuate protrusion.

[0042] In the above embodiments, since the second guide portion 43 includes a second arc-shaped protrusion, the curved surface structure of the second arc-shaped protrusion reduces the local flow loss and separation risk of the airflow during the turning or acceleration process, making the airflow adhere more closely to the wall surface, thereby improving the smoothness and efficiency of the guide.

[0043] In one embodiment, the flow channel 41 gradually narrows along the flow direction of the sealing gas.

[0044] In the above embodiment, the guide channel 41 gradually narrows along the flow direction of the sealing gas, which can effectively accelerate the flow velocity of the sealing gas. This not only suppresses the reverse leakage of the high-temperature working fluid from the main channel to the wheel back cavity, improving sealing efficiency, but also helps to enhance convective heat transfer on the wheel back surface, improve local temperature distribution, and reduce the risk of thermal stress concentration. In addition, the gradually narrowing guide channel 41 can also reduce flow separation and eddy generation, making the flow of the sealing gas more stable and orderly.

[0045] In one embodiment, the flow guiding structure further includes a third flow guiding section 44, which extends circumferentially along the partition 1; and in the radial direction of the partition 1, the third flow guiding section 44 is located on the side of the fluid outlet 412 opposite to the fluid inlet 411, and is spaced apart from the fluid outlet 412.

[0046] In the above embodiment, by adding a third guide section 44 extending circumferentially along the partition 1 and arranged radially at intervals on the radially outer side of the fluid outlet 412, the sealing gas discharged through the guide channel 41 can be guided and regulated for a secondary purpose, avoiding direct diffusion and turbulence after the airflow is discharged, and maintaining the circumferential flow trend of the airflow; at the same time, the radially spaced layout will not hinder the smooth discharge of the airflow, and can also form a buffer area between the fluid outlet 412 and the third guide section 44; in addition, the gas guided by the secondary purpose can form a continuous and stable circumferential gas film between the impeller back and the partition 1, effectively preventing the sealing gas flowing out of the fluid outlet 412 from excessively diffusing outward or mixing with the high-temperature working gas.

[0047] In one embodiment, the third guide portion 44 includes a third arcuate protrusion.

[0048] In the above embodiment, since the third guide section 44 includes a third arc-shaped protrusion, the third arc-shaped protrusion can guide the sealing gas to flow more smoothly along the circumferential direction, reducing flow separation, vortex, or local impact losses caused by structural abrupt changes. Furthermore, the third arc-shaped protrusion, as an aerodynamic barrier located radially outside the fluid outlet 412, not only effectively constrains the diffusion path of the sealing airflow, preventing premature mixing with high-temperature working fluid, but also promotes airflow adhesion to the wheel back surface through its curved shape, enhancing the uniformity and stability of the cooling gas film coverage.

[0049] In a specific implementation, the first guide section 42, the second guide section 43 and the third guide section 44 are integrally formed with the partition plate 1, without the need to add additional complex parts or make significant structural modifications to the centripetal impeller 2 body, thus improving the turbine performance while ensuring the structural stability of the overall device.

[0050] In specific implementations, the arrangement position and quantity of the flow guiding structure on the baffle 1 need to be determined by comprehensive analysis and optimization in conjunction with the actual flow field characteristics of the back region of the centripetal impeller 2, so as to ensure that the sealing airflow can efficiently and uniformly cover the key area according to the expected path, which is applicable to turbines operating under different working conditions.

[0051] In a specific implementation, the number of guiding structures is first determined based on the flow field characteristics, and then, using methods such as... Figure 3 The preset control curve shown is used to optimize and adjust its distribution pattern; then, the height and width dimensions of the guide structure are determined by combining the gap distance between the baffle 1 and the wheel back of the radial impeller 2.

[0052] In a specific implementation, during operation, the high-temperature gaseous working fluid first enters the guide vane 5, where it is accelerated, and then enters the centripetal impeller 2, driving the impeller disk to rotate and perform work. The sources of the high-temperature gaseous working fluid include, but are not limited to, natural gas, compressed air, high-temperature gas from solar collectors, high-temperature gas from heat storage devices, and high-temperature gases from chemical processes.

[0053] According to an embodiment of the present invention, another aspect provides a turbine, including the aforementioned baffle for a centripetal impeller.

[0054] Specifically, the turbine in this embodiment is a gas turbine.

[0055] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended application.

Claims

1. A baffle for a centripetal impeller, wherein the baffle (1) is spaced apart from the back of the centripetal impeller (2) to form a sealing flow channel (3) suitable for sealing gas flow, characterized in that, The baffles used for the centripetal impeller include: A flow guiding structure is provided on the side of the partition (1) facing the sealed flow channel (3); and the flow guiding structure includes at least one flow guiding channel (41), the flow guiding channel (41) includes a fluid inlet (411) and a fluid outlet (412), the fluid inlet (411) is connected to the inlet of the sealed flow channel (3); from the fluid inlet (411) to the fluid outlet (412), the flow guiding channel (41) extends in an arc shape.

2. The partition for a centripetal impeller according to claim 1, characterized in that, The flow guiding structure includes a first flow guiding part (42) and a second flow guiding part (43), and the first flow guiding part (42) and the second flow guiding part (43) are arranged circumferentially to form the flow guiding channel (41).

3. The partition for a centripetal impeller according to claim 2, characterized in that, The extension length of the first guide section (42) is greater than the extension length of the second guide section (43), and in the radial direction of the partition (1), the end of the second guide section (43) is located inside the end of the first guide section (42).

4. The partition for a centripetal impeller according to claim 3, characterized in that, The starting ends of the first guide section (42) and the second guide section (43) are aligned radially on the partition (1).

5. The partition for a centripetal impeller according to claim 2, characterized in that, The first guide portion (42) includes a first arc-shaped protrusion.

6. The partition for a centripetal impeller according to claim 2, characterized in that, The second guide portion (43) includes a second arc-shaped protrusion.

7. The partition plate for a radial impeller according to any one of claims 1 to 6, characterized in that, Along the flow direction of the sealing gas, the guide channel (41) gradually contracts.

8. The partition for a radial impeller according to any one of claims 1 to 6, characterized in that, The flow guiding structure also includes: The third flow guide (44) extends circumferentially along the partition (1); and in the radial direction of the partition (1), the third flow guide (44) is located on the side of the fluid outlet (412) away from the fluid inlet (411) and is spaced apart from the fluid outlet (412).

9. The partition for a centripetal impeller according to claim 8, characterized in that, The third guide section (44) includes a third arc-shaped protrusion.

10. A turbine, characterized in that, Includes the partition for a centripetal impeller as described in any one of claims 1 to 9.

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