Centripetal turbine with adjustable air inlet degree

Abstract

The invention relates to the field of energy system components, in particular to an air inflow adjustable centripetal turbine which comprises a nozzle ring, the nozzle ring comprises a plurality of nozzle blades arranged at intervals in the circumferential direction, and a nozzle blade channel is formed between every two adjacent nozzle blades; the impeller comprises a wheel disc and impeller blades arranged at intervals in the circumferential direction of the surface of the wheel disc; the number of the air inlet degree adjusting devices is the same as that of the nozzle blade channels, and each air inlet degree adjusting device comprises a blocking sliding block and a linear displacement mechanism; the whole blocking sliding blocks are circumferentially distributed at the positions corresponding to the nozzle blade channels one to one, and each blocking sliding block is independently driven by the corresponding linear displacement mechanism to be pushed into or pulled out of the corresponding nozzle blade channel. According to the method, on the premise that the internal flow field structure of the turbine is changed as little as possible, the turbine flow can be adjusted, the optimal air inlet degree is matched for all operation working conditions, and therefore the operation efficiency and reliability of the turbine and the system under all working conditions are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of energy system components, and particularly to a centripetal turbine with adjustable intake degree. Background Art

[0002] As a core component of a supercritical carbon dioxide (S-CO2) energy storage system, the centripetal turbine has the advantage of high energy conversion efficiency due to the characteristics of the S-CO2 working medium with high density and low viscosity. However, it also brings significant technical challenges: affected by the working medium characteristics, centripetal turbines generally have the characteristics of small size and extremely high rotational speed, which not only greatly increases the machining difficulty of the shafting and bearings of the centripetal turbine, but also exacerbates the secondary flow loss inside the centripetal turbine, severely restricting the machining 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 centripetal turbine but also appropriately increase the physical size of the centripetal turbine, thereby effectively reducing the secondary flow loss and improving the basic operation efficiency of the centripetal turbine.

[0003] However, the application scenarios of the S-CO2 energy storage system have extremely strong diversity (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 centripetal 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 centripetal turbine according to the flow rate and pressure requirements of different operating conditions, and then change the aerodynamic performance of the centripetal turbine to ensure that the centripetal 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 medium in the non-intake area of the impeller is prone to reverse flow and return to the opened nozzle blade channels. This reflux phenomenon not only causes huge additional flow losses, resulting in a significant decrease in the efficiency of the centripetal turbine; more seriously, the reflux working medium will experience a sudden pressure drop in the nozzle blade channels, thereby triggering the phase change of the working medium and destroying the stability of the internal flow field of the centripetal turbine, seriously affecting the operation reliability and service life of the centripetal turbine. Summary of the Invention

[0005] The present invention aims to provide a centripetal 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 centripetal turbines with wide operating conditions, high efficiency, and high reliability.

[0006] To achieve the above objectives, the technical solution created by this invention is implemented as follows: A centrifugal turbine with adjustable intake angle, 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 impeller includes a disk and impeller blades arranged circumferentially along the surface of the disk. The number of air intake adjustment devices is the same as the number of nozzle blade channels. Each air intake adjustment device includes a blocking slider and a linear displacement mechanism. The blocking sliders are circumferentially distributed in positions that correspond one-to-one with the nozzle blade channels. Each blocking slider is independently driven by the corresponding linear displacement mechanism to push into or pull out of the nozzle blade channel.

[0007] Furthermore, the first side profile of the blocking slider is the same as and completely fits the suction side profile of the corresponding nozzle blade; the second side profile of the blocking slider is the same as and completely fits the pressure side profile of the corresponding nozzle blade; the third side profile of the blocking slider is the same as the inlet edge profile of the nozzle ring and is flush with the inlet end of the corresponding nozzle blade; and the fourth side profile of the blocking slider is the same as the outlet edge profile of the nozzle ring and is flush with the outlet end of the corresponding nozzle blade.

[0008] Furthermore, based on the operating conditions of the centripetal turbine, the nozzle blade channel to be blocked is determined, and the linear displacement mechanism pushes the corresponding blocking slider into the determined nozzle blade channel.

[0009] Furthermore, the centripetal turbine uses supercritical carbon dioxide as the working fluid.

[0010] Compared with the prior art, the present invention can achieve the following beneficial effects: (1) Highly efficient and precise intake adjustment capability Driven by an independently controlled linear displacement mechanism, the blocking slider can be precisely controlled to open or close any nozzle blade channel according to actual working conditions, achieving stepless, wide-range adjustment of air intake from 0% to 100%.

[0011] (2) Effectively suppresses working fluid reflux and phase change phenomena When the blocking slider is in the closed nozzle blade channel, its profile fits perfectly with the nozzle blade and the ring body boundary, forming a good aerodynamic seal. This fundamentally blocks the return path of the working medium in the non-inlet area of ​​the impeller to the nozzle blade channel, significantly reducing additional flow losses and effectively avoiding the S-CO2 working medium phase change problem caused by sudden pressure drop.

[0012] (3) Optimize the flow field structure under partial air intake This invention achieves partial air intake while maximizing the integrity and stability of the internal flow field of the radial turbine. By selecting the optimal combination of channel closures, the impact on the inlet flow field of the moving blades can be reduced, eddies and separation phenomena can be suppressed, and the performance of the radial turbine under low flow conditions can be significantly improved.

[0013] (4) Adaptive wide operating conditions and high-efficiency operation Based on the adjustment criteria established through previous simulations, the centripetal turbine can automatically select the most efficient intake strategy according to real-time operating conditions, achieving adaptive adjustment of the intake degree. This mechanism significantly expands the efficient operating range of the centripetal turbine, improving its overall performance and system reliability under varying operating conditions.

[0014] (5) Simple structure and flexible control This invention requires no change to the nozzle blade profile or installation angle, resulting in a compact structure and easy modification. Each nozzle blade channel is independently controlled, offering high flexibility and scalability, making it suitable for various types of radial turbines. Attached Figure Description

[0015] 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 process of the radial turbine with adjustable intake as described in the embodiment of the present invention.

[0016] 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 air adjustment device 3, Blocking slider 31, and Linear displacement mechanism 32. Detailed Implementation

[0017] 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.

[0018] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0019] 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.

[0020] 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 fixed 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.

[0021] The invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0022] like Figure 1 As shown in the figure, an embodiment of the present invention provides a centrifugal turbine with adjustable air intake, including a nozzle ring 1, an impeller 2 and an air intake adjustment device 3. The nozzle ring 1 is sleeved on the radial outer side of the impeller 2, and the air intake adjustment device 3 is used to adjust the air intake of the centrifugal turbine.

[0023] The nozzle ring 1 includes a plurality of nozzle blades 11 arranged circumferentially, and a nozzle blade channel 12 is formed between two adjacent nozzle blades 11.

[0024] 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.

[0025] The number of intake adjustment devices 3 is the same as the number of nozzle blade channels 12. Each intake adjustment device 3 includes a blocking slider 31 and a linear displacement mechanism 32. The blocking sliders 31 are distributed circumferentially in positions corresponding to the nozzle blade channels 12. Each blocking slider 31 is connected to a corresponding linear displacement mechanism 32, and each blocking slider 31 is independently driven and controlled by the corresponding linear displacement mechanism 32.

[0026] The first side profile of the blocking slider 31 is the same as and completely fits the suction side profile of the corresponding nozzle blade 11. The second side profile of the blocking slider 31 is the same as and completely fits the pressure side profile of the corresponding nozzle blade 11. The third side profile of the blocking slider 31 is the same as the inlet edge profile of the nozzle ring 1 and is flush with the inlet end of the corresponding nozzle blade 11. The fourth side profile of the blocking slider 31 is the same as the outlet edge profile of the nozzle ring 1 and is flush with the outlet end of the corresponding nozzle blade 11.

[0027] The blocking slider 31 has a non-working position and a working position. When the blocking slider 31 is in the non-working position, the blocking slider 31 does not block the nozzle blade channel 12, so that the nozzle blade channel 12 remains unobstructed and does not affect the internal flow field structure of the centripetal turbine. When the blocking slider 31 is in the working position, the linear displacement mechanism 32 drives the blocking slider 31 to fully extend into the corresponding nozzle blade channel 12 to block the nozzle blade channel 12.

[0028] When the blocking slider 31 closes the nozzle blade channel 12, its profile is completely in contact with the nozzle blade 11 and the ring body boundary, forming a good pneumatic seal. This fundamentally blocks the return path of the working medium in the non-inlet area of ​​the impeller 2 to the nozzle blade channel 12, significantly reducing additional flow losses and effectively avoiding the S-CO2 working medium phase change problem caused by sudden pressure drop.

[0029] Since each blocking slider 31 is independently driven and controlled, the blocking of the nozzle blade channel 12 can be arbitrarily selected. By precisely controlling the opening and closing of each nozzle blade channel 12, the intake adjustment range covers 0 (fully blocked) to 1 (fully intake), achieving stepless and wide-range adjustment of the intake from 0% to 100%. At the maximum intake (intake = 1), the blocking slider 31 will not affect the internal flow field structure of the radial turbine; when the intake is less than 1, the profile of the blocking slider 31 completely fits the boundary profile of the nozzle blade channel 12 and will not affect the flow characteristics within other nozzle blade channels 12.

[0030] Based on the actual operating conditions of the centripetal turbine, the nozzle blade channel 12 that needs to be blocked is selected. The blocking combination method is different for different actual operating conditions. The combination principle is to maximize the aerodynamic efficiency of the centripetal turbine under the current operating conditions. This controls the corresponding linear displacement mechanism 32 to drive the blocking slider 31 into the corresponding nozzle blade channel 12, thereby achieving the optimal air distribution of the centripetal turbine while adjusting the air intake.

[0031] This invention achieves partial air intake while maximizing the integrity and stability of the internal flow field of the radial turbine. By selecting the optimal combination of channel closures, the impact on the inlet flow field of the moving blades can be reduced, eddies and separation phenomena can be suppressed, and the performance of the radial turbine under low flow conditions can be significantly improved.

[0032] Based on the adjustment criteria of the blocking slider 31, this invention achieves the most efficient blocking method under the current operating conditions by selecting the optimal channel closing combination. This reduces the impact on the flow field at the blade inlet, suppresses eddies and separation phenomena, and significantly improves the performance of the centripetal turbine under low flow conditions.

[0033] Based on the adjustment criteria established through previous simulations, the centripetal turbine can automatically select the most efficient intake strategy according to real-time operating conditions, achieving adaptive adjustment of the intake degree. This mechanism significantly expands the efficient operating range of the centripetal turbine, improving its overall performance and system reliability under varying operating conditions.

[0034] This invention requires no change to the blade profile or installation angle of the nozzle blades 11, resulting in a compact structure and easy modification. Each nozzle blade channel is independently controlled, offering high flexibility and scalability, making it suitable for various types of radial turbines.

[0035] 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.

[0036] 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 air intake, characterized in that, include: 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 impeller includes a disk and impeller blades arranged circumferentially along the surface of the disk. The number of air intake adjustment devices is the same as the number of nozzle blade channels. Each air intake adjustment device includes a blocking slider and a linear displacement mechanism. The blocking sliders are circumferentially distributed in positions that correspond one-to-one with the nozzle blade channels. Each blocking slider is independently driven by the corresponding linear displacement mechanism to push into or pull out of the nozzle blade channel.

2. The radial turbine with adjustable air intake according to claim 1, characterized in that, The first side profile of the blocking slider is the same as and completely fits the suction side profile of the corresponding nozzle blade. The second side profile of the blocking slider is the same as and completely fits the pressure side profile of the corresponding nozzle blade. The third side profile of the blocking slider is the same as the inlet edge profile of the nozzle ring and is flush with the inlet end of the corresponding nozzle blade. The fourth side profile of the blocking slider is the same as the outlet edge profile of the nozzle ring and is flush with the outlet end of the corresponding nozzle blade.

3. The radial turbine with adjustable air intake according to claim 1, characterized in that, The nozzle blade channel to be blocked is determined based on the operating conditions of the centrifugal turbine, and the linear displacement mechanism pushes the corresponding blocking slider into the determined nozzle blade channel.

4. The radial turbine with adjustable air intake according to claim 1, characterized in that, Centripetal turbines use supercritical carbon dioxide as the working fluid.

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