Radial flow type turbine with adjustable air inlet degree

Abstract

The invention relates to the field of turbines, in particular to a radial flow type turbine with adjustable air inflow degree, which comprises a nozzle ring, the nozzle ring comprises a plurality of nozzle blades which are arranged at intervals in the circumferential direction, and a nozzle blade channel is formed between every two adjacent nozzle blades; the impeller is arranged on the radial inner side of the nozzle ring, and a gap between the impeller and the nozzle ring serves as an annular track; the impeller comprises a wheel disc and impeller blades arranged at intervals in the circumferential direction of the surface of the wheel disc. The air inlet degree adjusting device comprises at least one air inlet baffle and at least one driving mechanism which are the same in number, and each air inlet baffle is driven by the corresponding driving mechanism to move in the circumferential direction and the axial direction along the annular track so as to shield the nozzle blade channel. According to the method, on the premise that the internal flow field structure of the turbine is not changed as far as possible, the turbine flow can be adjusted, the optimal air inlet degree is matched for all operation working conditions, and therefore the full-working-condition operation efficiency and reliability of the turbine and a system are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of turbines, and in particular to a radial turbine with adjustable intake degree. Background Art

[0002] As a core component of a supercritical carbon dioxide (S-CO2) energy storage system, the radial turbine has the advantage of high energy conversion efficiency due to the characteristics of the S-CO2 working fluid with high density and low viscosity. However, it also brings significant technical challenges: affected by the working fluid characteristics, radial turbines generally have the characteristics of small size and extremely high rotational speed, which not only greatly increases the processing difficulty of the shafting and bearings of the radial turbine, but also exacerbates the secondary flow loss inside the radial turbine, seriously restricting the processing feasibility and operation stability of the system. To solve this problem, the industry generally adopts the partial admission technology. By reasonably distributing the intake area, it can not only avoid the excessive rotational speed of the radial turbine, but also appropriately increase the physical size of the radial turbine, thereby effectively reducing the secondary flow loss and improving the basic operation efficiency of the radial turbine.

[0003] However, the application scenarios of the S-CO2 energy storage system are highly diverse (such as peak shaving and valley filling, renewable energy supporting energy storage, etc.), and the system itself has the operating characteristic of load fluctuation, which makes the radial turbine need to operate under conditions deviating from the design conditions for a long time. Therefore, the traditional fixed-mode partial admission technology can no longer meet the requirements, and the adjustable partial admission technology has emerged. Its goal is to dynamically adjust the intake air volume of the radial turbine according to the flow rate and pressure requirements of different operating conditions, and then change the aerodynamic performance of the radial turbine to ensure that the radial turbine can still maintain a high energy conversion efficiency during variable-condition operation.

[0004] The current mainstream partial admission adjustment methods mainly achieve the opening and closing control of the nozzle blade channels by blocking or valve closing at the nozzle inlet to adjust the intake area range. However, this type of method has significant technical defects: when some nozzle blade channels are closed to form a non-intake area, the working fluid in the non-intake area of the impeller is prone to reverse flow and flow back into the nozzle blade channels. This reflux phenomenon not only causes huge additional flow losses, resulting in a significant decrease in the efficiency of the radial turbine; more seriously, the reflux working fluid will experience a sudden pressure drop in the nozzle blade channels, which will then cause the phase change of the working fluid,破坏 the stability of the internal flow field of the radial turbine, and seriously affect the operation reliability and service life of the radial turbine. Summary of the Invention

[0005] The present invention aims to provide a radial turbine with adjustable intake to solve the problem that some existing intake regulation technologies are unable to achieve a balance between dynamically adjusting the intake and maintaining flow field stability and avoiding additional losses, and thus cannot meet the S-CO2 energy storage system's requirements for wide operating conditions, high efficiency and high reliability of radial turbines.

[0006] To achieve the above objectives, the technical solution created by this invention is implemented as follows: An adjustable intake radial-flow turbine, comprising: The nozzle ring includes a plurality of nozzle blades arranged circumferentially spaced apart, with a nozzle blade channel formed between two adjacent nozzle blades; An impeller is disposed radially inside the nozzle ring, and the gap between the impeller and the nozzle ring serves as an annular track; the impeller includes a disk and impeller blades arranged circumferentially along the surface of the disk; An air intake adjustment device includes an equal number of air intake baffles and drive mechanisms, with at least one air intake baffle and drive mechanism. Each air intake baffle moves circumferentially and axially along a circular track under the drive of its corresponding drive mechanism to block the nozzle blade channel.

[0007] Furthermore, the intake baffle includes a thick section and a thin section. The thin section of the intake baffle is connected to the drive mechanism. The height of the thick section of the intake baffle is the same as the height of the nozzle blade, and the length of the thick section of the intake baffle is the same as the length of the nozzle blade channel. When the intake baffle blocks the nozzle blade channel, the thick section of the intake baffle is in contact with the nozzle blade.

[0008] Furthermore, the annular track has a baffle shaft displacement opening, the width of which is greater than the width of the annular track, and the thicker section of the intake baffle moves axially from the baffle shaft displacement opening.

[0009] Furthermore, the air intake baffle is an arc-shaped baffle.

[0010] Furthermore, the arc length of the intake baffle is an integer multiple of the arc length of the nozzle blade channel outlet end.

[0011] Furthermore, radial turbines use supercritical carbon dioxide as the working fluid.

[0012] Compared with the prior art, the present invention can achieve the following beneficial effects: (1) Achieve precise flow field control and improve turbine efficiency This invention achieves active control of the flow field within the nozzle blade channel by incorporating an inner and outer ring baffle structure that can move and rotate axially, without altering the nozzle blade profile and installation angle. This structure effectively adjusts the intake of the radial-flow turbine, avoiding the additional flow losses caused by the backflow of working fluid from the non-intake zone to the nozzle blade channel in traditional partial intake methods, and significantly improving the operating efficiency of the radial-flow turbine under varying operating conditions.

[0013] (2) Improve performance under low flow conditions and broaden the range of high-efficiency operation. By coordinating the adjustment of the inner and outer ring baffles, the intake area can be flexibly controlled, reducing the disturbance of some intake air to the internal flow field structure of the impeller, significantly improving the phenomenon of turbine performance deterioration under low flow conditions, thereby broadening the efficient and stable operating range of the turbine. Attached Figure Description

[0014] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments and descriptions of the invention are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings: Figure 1 A schematic diagram of the flow rate of the radial turbine with adjustable air intake as described in the embodiment of the present invention.

[0015] Explanation of reference numerals in the attached drawings: Nozzle ring 1, Nozzle blade 11, Nozzle blade channel 12, Impeller 2, Wheel disk 21, Impeller blade 22, Inlet baffle 31, Annular track 32, Drive mechanism 33, Baffle shaft shifting port 34. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and do not constitute a limitation thereof.

[0017] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0018] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0019] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0020] The invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0021] like Figure 1 As shown in the figure, an embodiment of the present invention provides a radial flow turbine with adjustable air intake, including a nozzle ring 1, an impeller 2, and an air intake adjustment device. The nozzle ring 1 is sleeved on the radial outer side of the impeller 2, and a part of the air intake adjustment device is located on the nozzle ring 1, and the other part is located between the nozzle ring 1 and the impeller 2.

[0022] The nozzle ring 1 includes a plurality of nozzle blades 11 arranged circumferentially on the surface of the nozzle ring 1, and a nozzle blade channel 12 is formed between two adjacent nozzle blades 11.

[0023] Impeller 2 includes a disk 21 and impeller blades 22, the impeller blades 22 being arranged circumferentially on the surface of disk 21. Impeller 2 is used to receive supercritical carbon dioxide working fluid flowing out through nozzle blade channel 12.

[0024] The intake adjustment device includes an intake baffle 31, an annular track 32, and a drive mechanism 33. The annular track 32 is formed by the gap between the nozzle ring 1 and the impeller 2. There is at least one intake baffle 31. The number of drive mechanisms 33 is the same as the number of intake baffles 31. Each intake baffle 31 is driven independently by its corresponding drive mechanism 33. Under the drive of the drive mechanism 33, the intake baffle 31 can move circumferentially and axially along the annular track 32, thereby realizing independent adjustment of each intake baffle 31. When the radial turbine is in operation, multiple intake baffles 31 can block the nozzle blade channels 12 at different positions.

[0025] When the intake baffle 31 blocks the nozzle blade channel 12, the intake baffle 31 is in contact with the nozzle blade 11. To ensure the blocking effect of the intake baffle 31, the intake baffle 31 adopts an arc-shaped baffle with a stepped cross-section. That is, the intake baffle 31 has an arc-shaped two-section structure, specifically including an arc-shaped thick section and an arc-shaped thin section. The height of the arc-shaped thick section of the intake baffle 31 is the same as the height of the nozzle blade 11, and the arc length of the arc-shaped thick section of the intake baffle 31 is the same as the arc length of the outlet end of the nozzle blade channel 12. The curved section of the intake baffle 31 is located within the annular track 32 and is connected to the drive mechanism 33. When the drive mechanism 33 drives the curved section of the intake baffle 31 to move to a designated position within the annular track 32, the curved section of the intake baffle 31 fits against the two adjacent nozzle blades 11 to block the nozzle blade channel 12.

[0026] The arc length of the thicker arc section of the intake baffle 31 can also be an integer multiple of the arc length of the nozzle blade channel 12 outlet end. This allows one intake baffle 31 to simultaneously block multiple nozzle blade channels 12.

[0027] The curvature of the arc-shaped segment of the air intake baffle 31 matches the curvature of the annular track 32, ensuring that the arc-shaped segment of the air intake baffle 31 can move circumferentially along the annular track 32.

[0028] There are two purposes for setting the intake baffle 31 in two sections. One purpose is to prevent gaps between the intake baffle 31 and the nozzle blade 11 to avoid air leakage. The other purpose is to minimize the width of the annular track 32 (i.e., the gap between the nozzle ring 1 and the impeller 2).

[0029] The width of the arc-shaped segment of the intake baffle 31 is slightly smaller than the width of the annular track 32. To ensure that the intake baffle 31 can move axially, the annular track 32 has a baffle shaft displacement opening 34. The baffle shaft offset 34 is actually a space reserved in the turbine stage. Specifically, by changing the shape of the nozzle ring 1 and the impeller 2 at a specific position, a space is formed at that specific position. The width of this space is the gap width between the nozzle ring 1 and the impeller 2, and the length of this space is equal to the length of the intake baffle 31, so that the arc-shaped thick section of the intake baffle 31 can enter from the outside of the nozzle ring 1 (the side without nozzle blades 11) to the inside of the nozzle ring 1 (the side with nozzle blades 11).

[0030] When the radial turbine is not in operation, the intake baffle 31 is located outside the nozzle ring 1. When the radial turbine is in operation, the drive mechanism 4 first drives the thick arc section of the intake baffle 31 to move axially through the baffle shaft shift port 34 to the inside of the nozzle ring 1. Then, the drive mechanism 4 drives the thin arc section of the intake baffle 31 to move circumferentially along the annular track 32, so that the thick arc section of the intake baffle 31 blocks the nozzle blade channel 12, preventing the supercritical carbon dioxide working fluid from flowing back into the nozzle blade channel 12 from the non-intake area of ​​the impeller 2, thus avoiding additional flow losses caused by the backflow of the working fluid.

[0031] The drive mechanism 33 adopts a two-dimensional motion mechanism with linear motion and rotation functions, but is not limited to a specific model.

[0032] Each intake baffle 31 can be controlled independently. Through the coordinated adjustment between the intake baffles 31, the intake area can be flexibly controlled, reducing the disturbance of some intake air to the internal flow field structure of the impeller, significantly improving the phenomenon of turbine performance deterioration under low flow conditions, thereby expanding the efficient and stable operating range of the turbine.

[0033] This invention does not require changes to the blade shape or installation angle of the nozzle blades 11, resulting in a compact structure and easy modification. The opening and closing of each nozzle blade channel 12 can be controlled by the cooperation between each intake baffle 31, providing high flexibility and scalability.

[0034] It should be understood that the various forms of processes shown above can be used to reorder, add, or delete steps. For example, the steps described in this invention disclosure can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution disclosed in this invention can be achieved, and this is not limited herein.

[0035] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A radial turbine with adjustable inlet incidence, characterized in that, The application relates to a radial turbine, comprising: a nozzle ring, which comprises a plurality of nozzle vanes arranged at intervals in the circumferential direction, and nozzle vane channels formed between two adjacent nozzle vanes; a impeller arranged at the radially inner side of the nozzle ring, and a gap between the impeller and the nozzle ring serving as an annular track; the impeller comprises a disc and impeller vanes arranged at intervals in the circumferential direction on the surface of the disc; an inlet degree adjusting device, which comprises a same number of inlet baffles and driving mechanisms, and the number of the inlet baffles and the driving mechanisms is at least one; each inlet baffle is driven by a corresponding driving mechanism to move in the circumferential direction and the axial direction along the annular track to shield the nozzle vane channels.

2. The variable-inlet radial turbine according to claim 1, characterized in that, The inlet baffle comprises a thick section and a thin section, the thin section of the inlet baffle is connected with the driving mechanism, the height of the thick section of the inlet baffle is the same as the height of the nozzle vane, the length of the thick section of the inlet baffle is the same as the length of the nozzle vane channel, and the thick section of the inlet baffle is attached to the nozzle vane when the inlet baffle shields the nozzle vane channel.

3. The variable-inlet radial turbine according to claim 2, wherein The annular track is formed with a baffle shaft moving port, the width of the baffle shaft moving port is greater than the width of the annular track, and the thick section of the inlet baffle moves axially from the baffle shaft moving port.

4. The variable-inlet radial turbine according to any one of claims 1 to 3, characterized in that, The inlet baffle is an arc-shaped baffle.

5. The variable-inlet radial turbine according to claim 4, wherein The arc length of the inlet baffle is an integer multiple of the arc length of the outlet end of the nozzle vane channel.

6. The variable-inlet radial turbine according to claim 1, wherein The radial turbine uses supercritical carbon dioxide as a working medium.

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