Water pump turbine runner blade suitable for rapid transition process

Abstract

The application discloses a water pump water turbine runner blade suitable for a quick transition process, which comprises a plurality of long blades (1), a plurality of short blades (2) and a plurality of gradually-changing airfoil trailing edges (3). The long blades (1) and the short blades (2) are installed in the runner. A plurality of the long blades (1) are arranged equidistantly along the axis of the runner lower ring in a circumferential direction. One end of the long blade (1) and one end of the short blade (2) are connected with the inner wall of the runner lower ring. There is a spacing between the other end of the long blade (1) and the other end of the short blade (2) and the axis of the runner lower ring. The gradually-changing airfoil trailing edge (3) is arranged at the trailing edge of the long blade (1). In the application, the gradually-changing airfoil trailing edge of the long blade optimizes the flow state of the water flow entering the runner in the quick transition process of the water pump water turbine, and can effectively reduce the pressure pulsation amplitude in the quick transition process of the unit.

Description

TECHNICAL FIELD

[0001] The present application relates to a kind of water pump water turbine runner blade suitable for fast transition process, belong to water pump water turbine technical field. BACKGROUND

[0002] Water pump water turbine is a kind of reversible hydraulic machinery, can pump water and can generate electricity, is widely used in pumped storage power station.In pumped storage power station, switching speed is fast, has strong peak shaving and frequency modulation performance, makes it become one of the core nodes of power grid regulation.

[0003] Pumped storage power station as the regulation core in power system, one of its key equipment is water pump water turbine.With the proportion of intermittent renewable energy, such as wind energy, photovoltaic power generation in power grid, it causes greater impact on power grid stability, to realize network frequency regulation, power grid load leveling function, pumped storage power station water pump water turbine unit will experience fast and frequent load change, start-stop machine and other transition processes, so that water pump water turbine unit will frequently switch operating condition to regulate power grid parameters.When water pump water turbine unit is in fast switching operating condition, strong water instability phenomenon in fast transition process can cause strong vibration of unit and water conveying pipeline system, and seriously threaten the safe operation of unit and even power station.

[0004] Runner is the most important flow component of water pump water turbine, has irreplaceable role in water pump water turbine, guides water flow movement while also bearing alternating stress load, is the most important in studying water pump water turbine internal flow field flow, optimizing water pump water turbine design, has important influence on the hydraulic performance of water pump water turbine. SUMMARY

[0005] The technical problem to be solved by the present application is to overcome the defects of the prior art, and to provide a water pump water turbine runner blade suitable for fast transition process, the gradual change airfoil trailing edge of the long blade in the present application optimizes the flow pattern of the water flow entering the runner during the fast transition process of the water pump water turbine, which can effectively reduce the pressure fluctuation amplitude during the fast transition process of the unit.

[0006] Preferably, the present application provides a water pump water turbine runner blade suitable for fast transition process, comprising a plurality of long blades, a plurality of short blades and a plurality of gradual change airfoil trailing edges, the long blades and the short blades are installed in the runner, a plurality of the long blades are arranged equidistantly along the axis of the runner lower ring, one end of the long blade and one end of the short blade are connected with the inner wall of the runner lower ring, the other end of the long blade and the other end of the short blade exist spacing between the axis of the runner lower ring, the gradual change airfoil trailing edge is arranged at the trailing edge of the long blade.

[0007] Preferably, the long blade gradually increases in thickness from the top cover of the runner to the lower ring of the runner.

[0008] Preferably, the long blade gradually increases in thickness from the top cover of the runner to the lower ring of the runner.

[0009] Preferably, the long blade gradually increases in thickness from the top cover of the runner to the lower ring of the runner.

[0010] Preferably, the long blade gradually increases in thickness from the top cover of the runner to the lower ring of the runner.

[0011] The present application has the following beneficial effects:

[0012] 1. The long blade gradually increases in thickness from the top cover of the runner to the lower ring of the runner, which optimizes the flow pattern of the water flow entering the runner during the rapid transition process of the pump-turbine, and effectively reduces the pressure fluctuation amplitude during the rapid transition process of the unit.

[0013] 2. The long blade gradually increases in thickness from the top cover of the runner to the lower ring of the runner, which changes the runner inflow conditions in the pump mode and the runner outflow conditions in the turbine mode of the pump-turbine, and alleviates the vortex phenomenon during the rapid transition process of the pump-turbine.

[0014] 3. The long blade gradually increases in thickness from the top cover of the runner to the lower ring of the runner, which effectively ensures the flow conditions of the water flow in the runner.

[0015] 4. The long blade gradually increases in thickness from the top cover of the runner to the lower ring of the runner, which reduces the influence of the gradually increasing tail edge on the operating characteristics of the unit in the normal operating mode, and ensures the efficiency of the unit in the normal operating state. BRIEF DESCRIPTION OF DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of the present application, the following will briefly introduce the drawings needed in the embodiments. Obviously, for those skilled in the art, other drawings can also be obtained without creative labor based on these drawings.

[0017] Figure 1 is a structural diagram of some embodiments of the present application;

[0018] Figure 2 is a structural diagram of the long blade gradually increasing in thickness from the top cover of the runner to the lower ring of the runner in some embodiments of the present application;

[0019] Figure 3 is a structural diagram of the long blade gradually increasing in thickness from the top cover of the runner to the lower ring of the runner in some embodiments of the present application;

[0020] Figure 4 is a pressure fluctuation time domain diagram before and after the optimization of the runner design in some embodiments of the present application.

[0021] Significance of reference signs, 1 - long blade; 2 - short blade; 3 - gradually changing airfoil trailing edge; 4 - gradually changing airfoil trailing edge top; 5 - gradually changing airfoil trailing edge bottom. DETAILED DESCRIPTION

[0022] For the convenience of the technical solutions of the application, the following first explains some concepts related to the present application.

[0023] It should be noted that if there is a directional indication (such as up, down, left, right, front, back,...) in the embodiments of the present application, it is only used to explain the relative positional relationship and movement between the components in a certain posture, and if the specific posture changes, the directional indication will also change accordingly.

[0024] In addition, if the description of "first" and "second" and the like is involved in the present application, it is only for description purposes, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" can be explicitly or implicitly included at least one of the features. In addition, the technical solutions of each embodiment can be combined with each other, but it must be based on the realization of ordinary skilled in the art, when the combination of technical solutions appears contradictory or cannot be realized, it should be considered that the combination of technical solutions does not exist, also not within the scope of protection required by the present application.

[0025] Reference Figure 1 The present application provides a water pump water turbine runner blade suitable for rapid transition process, comprising a plurality of long blades 1, a plurality of short blades 2 and a plurality of gradually changing airfoil trailing edges 3, the long blades 1 and the short blades 2 are installed in the runner, a plurality of long blades 1 are arranged equidistantly along the axis of the runner lower ring, one end of the long blade 1 and one end of the short blade 2 are connected with the inner wall of the runner lower ring, the other end of the long blade 1 and the other end of the short blade 2 exist a distance between the axis of the runner lower ring, the gradually changing airfoil trailing edge 3 is arranged at the trailing edge of the long blade 1.

[0026] In the embodiments of the present application, the gradually changing airfoil trailing edge thickness of the long blade 1 gradually increases from the top cover of the runner to the lower direction of the runner.

[0027] In the embodiments of the present application, the trailing edge gradually changing part of the long blade 1 only accounts for 10% of the entire chord length of the long blade 1.

[0028] In the embodiments of the present application, the number of the gradually changing airfoil trailing edge 3 arranged on each long blade 1 is 1.

[0029] In the embodiments of the present application, the thickness of the trailing edge of the airfoil of the short blade 2 is the same from the top cover of the runner to the lower direction of the runner. As shown in Figure 4 After the runner blade optimized by the present application is used, the pressure fluctuation amplitude of the pump-turbine rapid transition process is significantly reduced.

[0030] Each of the embodiments in the specification is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment mainly explains the difference from other embodiments.

[0031] Other embodiments of the present application will be apparent to those skilled in the art from consideration of the specification and practice of the application disclosed herein. This application is intended to cover any variations, uses or adaptations of the application following, in general, the principles of the application and including such departures from the present disclosure as come within known or customary practice in the art to which the application pertains. The specification and examples are to be regarded as illustrative only, and the true scope and spirit of the application is indicated by the following claims.

[0032] Finally, it should be pointed out that: first, in the description of the present application, it should be pointed out that unless otherwise specified and limited, the terms "installation", "connection", "connection", "fitting" should be understood broadly, which can be mechanical connection or electrical connection, or the communication between two elements, or direct connection, "up", "down", "left", "right" and the like are only used to indicate the relative positional relationship, when the absolute position of the described object changes, the relative positional relationship may change;

[0033] Secondly: the present application discloses the structure involved in the embodiments of the present application, and other structures can refer to the usual design; the above specific embodiments further explain the purpose, technical scheme and beneficial effects of the present application, and it should be understood that the above is only the specific embodiment of the present application, and is not used to limit the protection scope of the present application, any modification, equivalent replacement, improvement, etc. made on the basis of the technical scheme of the present application should be included in the protection scope of the present application.

Claims

1. A runner blade for a pump-turbine suitable for fast transient processes, characterized in that The turbine blade comprises a plurality of long blades (1), a plurality of short blades (2) and a plurality of gradually-changing airfoil trailing edges (3), the long blades (1) and the short blades (2) are installed in the runner, a plurality of the long blades (1) are arranged equidistantly along the axis of the lower ring of the runner, one end of the long blades (1) and one end of the short blades (2) are connected with the inner wall of the lower ring of the runner, the other end of the long blades (1) and the other end of the short blades (2) are spaced apart from the axis of the lower ring of the runner, and the gradually-changing airfoil trailing edge (3) is arranged at the trailing edge of the long blade (1). The gradually-changing airfoil trailing edge thickness of the long blade (1) gradually increases from the top cover of the runner to the lower ring of the runner. The gradually-changing trailing edge portion of the long blade (1) accounts for only 10% of the entire chord length of the long blade (1). The airfoil trailing edge thickness of the short blade (2) is the same from the top cover of the runner to the lower ring of the runner.

2. A pump turbine runner blade suitable for rapid transient processes according to claim 1, characterized in that The number of the gradually-changing airfoil trailing edges (3) arranged on each long blade (1) is one.

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