• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    Bar profile for a rake of a hydropower plant, comprising a rounded head (3) and a subsequent section (5) of rectangular cross-section, wherein the portion (5) having a rectangular cross-section at the rear end in the flow direction has a region (4) of reduced thickness , characterized in that the region (4) is formed asymmetrically with reduced thickness.
    公开号:CH710920A2
    申请号:CH00319/16
    申请日:2016-03-11
    公开日:2016-09-30
    发明作者:Rupprecht Albert
    申请人:KWT Hydro Anlagenbau GmbH；
    IPC主号:
    专利说明:

    The invention relates to a bar profile for a rake of a hydropower plant and a rake for a hydropower plant.
    Rakes are installed in hydroelectric plants before the inlet of the turbines to prevent Geschwemmsel and / or fish get into the turbine. They consist of a large number of mutually parallel rod profiles. Previously, these bar profiles were simple rectangles. Because these rectangles have relatively sharp edges, they have a relatively high flow resistance and injure fish swimming against these bar profiles.
    There is another bar profile, which is referred to below as SIPA profile, which has a rounded head and a subsequent rectangular section. This SIPA bar profile represents a significant improvement over the rectangular bar profile.
    From 207 326 a computer system is known, the bar profiles have a rectangular cross-section. The bar profiles are rounded in the flow direction at the front and is formed at its rear end in the flow direction as an isosceles triangle.
    From DE 3,715,020 C2 a fine mesh with a double screen for wastewater is known. A first group of rake bars has an approximately trapezoidal head sn followed by a rectangular cross-sectional area whose thickness is reduced relative to the trapezoidal head. Between these rod profiles more rods are used with circular cross-sections.
    From DE 1 911 979 a two-part bar profile is known. The rear end portion of this bar profile is trapezoidal and is firmly connected to the computational grid or its support structure. At the front part of the rod profile is pushed over a dovetail-like connection to the rear part. This allows the front part of the bar profile easily be replaced in the event of damage without draining the congestion or take the hydropower plant out of service.
    The invention has for its object to provide an improved bar profile, which represents a significant improvement over the SIPA bar profile in terms of risk of injury of fish and Strömungswiderstad. At the same time, the production costs of the rod profile according to the invention should be equal to or only insignificantly higher than those of the SIPA rod profile. In addition, oscillations of the computing bars should be largely suppressed.
    This object is achieved according to the invention in a bar profile for a rake of a hydropower plant comprising a rounded head and a subsequent section with a rectangular cross-section characterized in that the portion having a rectangular cross section at the rear end in the flow direction has an asymmetric region with reduced thickness. This region of reduced thickness may be formed as an asymmetrical trapezoid, as an isosceles or unequal triangle or as a multi-stepped rectangle. The asymmetrical design prevents the formation of vibrations of the rake bar particularly effectively prevented. When the rake bars vibrate, fatigue life is reduced and unwanted noise can be generated.
    By reducing the thickness of the rectangular section section at the rear end, the separation vortices (Karman's vortex street) are reduced, and as a result, the vibration excitation on the screen bar is significantly reduced. The negative effects of the vibrations are thus also reduced.
    If the inventive rod profile is flowed obliquely, the inventive design of the rear end of the bar profile is particularly advantageous.
    It has proved to be advantageous if the maximum thickness of the head is at least 15% of an overall length of the rod profile spaced from the top of the bar profile. Thus, the thickest point of the bar profile over the SIPA bar profile is moved further to the rear and as a result, the tip of the inventive bar profile is rounder and less dangerous for the fish. In addition, the flow resistance improves further.
    It has proved to be advantageous if the section of rectangular cross-section occupies less than 60% of the total length of the bar profile. This also further improves the flow resistance of the inventive bar profile compared to a SIPA bar profile.
    A further significant improvement of the flow resistance is achieved when the transition between the head and the section of rectangular cross-section is rounded with a large radius. The radius in the region of the transition should be greater than 15%, preferably greater than 30% and particularly preferably greater than 50% of the total length of the bar profile.
    Further advantages and advantageous embodiments of the invention are the following drawings, the description and the claims can be removed. All of the features disclosed in the drawing, the description and the claims can be essential to the invention both individually and in any combination with one another.
    drawing
    [0015] FIG.<Tb> FIG. 1 <SEP> a schematic representation of a rake with rod profiles according to the invention,<Tb> FIG. 2 <SEP> different angle of attack of the rake,<Tb> FIG. 3a <SEP> an embodiment of a rod profile according to the invention,<Tb> FIG. 3b and 3c <SEP> different embodiments of the rear end of a bar profile according to the invention,<Tb> FIG. 4 <SEP> the flow losses of different bar profiles in comparison and<Tb> FIG. 5 <SEP> a comparison of the inventive rod profile with the SIPA rod profile.
    Description of the embodiments:
    In Fig. 1, a plurality of inventive rod profiles 1 are shown side by side and arranged parallel to each other. Several such parallel bar profiles 1 form a rake. Such rakes may comprise 50 or more such bar profiles 1 and cover an area of more than 10 m 2.
    Since such rakes are well known to those skilled in the art, a detailed description is omitted. In connection with the invention, it should merely be pointed out that water flows through the rake shown in FIG. 1 from left to right. This is indicated by an arrow with the flow direction "X".
    An important variable for the design of a rake is the inside width LW, which marks the minimum distance between two adjacent bar profiles 1. A clear width of 15 mm represents a good compromise between the protection of fish on the one hand and the flow losses of the rake on the other. Therefore, a clear width of 15 mm is usually applied for in new construction of rake cleaners and also approved by the competent authorities.
    The flow direction X shown in Fig. 1 is not always exactly parallel to a longitudinal extension of the bar profiles in practice, but sometimes the bar profiles 1 are also flowed obliquely. This situation is shown in FIG. 2. 2, three arrows are indicated, which extend at an angle of 0 °, 15 ° and 30 ° to the longitudinal extension of the bar profiles 1. These three arrows should represent the flow directions X. With the oblique flow, the flow resistance of the rake increases. Therefore, an oblique flow is undesirable, but can not always be avoided. Rather, it is endeavored to realize a flow angle of 0 °.
    In Fig. 3, an embodiment of an inventive rod profile 1 is shown enlarged. The flow direction X is also indicated in Fig. 3 by an arrow. The rod profile 1 according to the invention has an overall length L from the tip to the rear end. In Fig. 3, the tip of the bar profile 1 is located on the left edge of the sheet and the rear end of the bar profile 1 is located on the right sheet edge.
    The inventive rod profile 1 has in the flow direction at its front end a head 3 and then a section 5 with a rectangular cross-section. The head 3 of the bar profile is designed as a symmetrical rounded profile. The head has a region with a maximum thickness D that is spaced from the tip S by a dimension 7.
    However, it is also possible that the maximum thickness of the head 3 more than 15% of the total length L of the bar profile 1 spaced from the top S arranged is. Values between 15% and 20% have proven particularly suitable.
    The head 3 of the inventive rod profile 1 then decreases in the flow direction again and goes with a radius R in the section with a rectangular cross section 5 over. The radius R is shown in FIG. 3a. He should be as big as possible. In particular, it is advisable if the radius of curvature R in the region of the transition is greater than 15%, preferably greater than 30% and particularly preferably greater than 50% of the total length L of the bar profile 1. Then, detachments of the flow in the transition between the head 3 and the section 5 having a rectangular cross section are effectively avoided, and as a result, the flow resistance of the bar profile 1 according to the invention decreases.
    In Fig. 3a, an embodiment of the inventive rod profile 1 is shown, in which the rear end of the bar profile 1 is formed as a trapezoid. In this area, of course, the cross section of the bar profile 1 is not rectangular, but just, for example, trapezoidal.
    In Figs. 3b and 3c further alternative and exemplary embodiments of the rear end of the bar profile 1 are shown schematically. In Fig. 3b, the rear end is formed as an equilateral triangle. However, it may be a non-equilateral triangle (not shown).
    In Fig. 3c, the rear end of the bar profile 1 is formed as a stepped rectangle.
    All three embodiments shown lead to a significant reduction of turbulence at the rear end of the bar profile and thereby reduce the vibration excitation on the inventive bar profile 1 considerably. The advantages of the inventive design of the bar profile 1 are particularly great when the bar profile 1 is flowing obliquely.
    In a specific embodiment, the bar profile 1 may have a length L of 60 mm and a maximum thickness D in the region of the head 3 of 8 mm.
    The region of rectangular cross-section 5, which in the context of the invention also comprises the triangular, trapezoidal or stepped rear end of the bar profile 1, can be about 35 mm long, over a length of about 27 a rectangular cross-section actually exists is and the rear end with the trapezoidal flattening then has a length of about 7 to 8 mm.
    The thickness of the section 5 with a rectangular cross-section is about 5 mm in this embodiment. At the rearmost end, the bar profile has a thickness of only about 2 mm. Of course, it is possible to let the bar profile 1 run more sharply at the rear end. As a result, the vibration excitations are reduced again. However, this makes the back end less sturdy.
    4, the flow losses of a rake are shown once with a rod with a rectangular profile, with the so-called SIPA rod profile and with an inventive bar profile in a diagram. In the simulation, an infinitely wide rake was assumed, so that edge effects do not occur.
    The line 9 represents the flow losses in centimeters of water column [cm WS] of a conventional rectangular profile as a function of the angle of attack, at a flow velocity of 0.5 m / s and a clear width of 15 mm.
    The line 11 represents the flow losses of a rake with a SIPA profile, while the flow losses of the inventive rod profile are represented by the line 13.
    By comparing the lines 9 and 11 it is clear that the SIPA profile already represents a considerable improvement compared to the rectangular profile. If one compares this SIPA profile with the bar profile according to the invention, it becomes clear that the profile according to the invention (see line 13) always has a significantly low flow loss, both with an angle of incidence of 0 ° and angle of incidence of 30 °, than the SIPA -Profile.
    If you take now the SIPA profile as a reference and sets its flow losses equal to 1, you can compare the inventive rod profile 1 well with this SIPA reference. This comparison is shown in FIG. 5. The comparison shows that the rod profile 1 according to the invention causes only about 83% of the losses of the SIPA profile with an angle of incidence of 0 ° and a clear width of 10 mm. The value for a clear width of 15 mm (see the line 17 in FIG. 5) is almost identical at the angle of incidence 0 °.
    This means nothing else than that both the clear width of 10 mm and a clear width of 15 mm, the inventive rod profile 1 has flow losses, which have only about 83% of the flow losses of a equipped with a SIPA rake ,
    The more obliquely the flow or the greater the angle of attack, the greater are the advantages of the inventive bar profile compared with the SIPA profile. With an angle of incidence of 30 °, the bar profile according to the invention has more than 20% less flow losses than the SIPA profile with a clear width of 10 mm. With a clear width of 15 mm, the advantages of the inventive SIPA profile are even greater than 30%.
    Due to the reduced flow losses increases the annual work of a hydropower plant, which has a rake, which is equipped with a novel bar profile. Even if it is only one or two centimeters usable height of fall, this can lead to an increase in annual work of 0.3 to 0.5% for hydropower plants with a drop of, for example, 2 m. Because the rod profile 1 according to the invention can be manufactured at the same cost as the SIPA profile, the economic efficiency of a hydropower plant equipped with the rod profile 1 according to the invention is appreciably increased.
    权利要求:
    Claims (8)
    [1]
    1. bar profile for a rake of a hydropower plant comprising a rounded head (3) and a subsequent section (5) of rectangular cross-section, wherein the portion (5) having a rectangular cross-section at the rear end in the flow direction has a region (4) of reduced thickness , characterized in that the region (4) is formed asymmetrically with reduced thickness.
    [2]
    2. bar profile according to claim 1, characterized in that the region (4) is formed with a reduced thickness as a triangle, trapezoid or stepped rectangle.
    [3]
    3. bar profile according to one of the preceding claims, characterized in that a maximum thickness (D) of the head (3) at least 15% of an overall length (L) of the bar profile () from a tip (S) spaced (7).
    [4]
    4. Rod profile according to one of the preceding claims, characterized in that the section (5) with a rectangular cross-section less than 60% of the total length (L) of the bar profile (1) occupies.
    [5]
    5. Rod profile according to one of the preceding claims, characterized in that a transition between the head (3) and that of the section (5) is rounded with a rectangular cross-section, and that a radius (R) in the region of the transition greater than 15%, preferably greater than 30%, and more preferably greater than 50% of the total length (L) of the bar profile (1).
    [6]
    6. Rod profile according to one of the preceding claims, characterized in that a ratio of the maximum thickness (D) of the head (3) to the thickness of the portion (5) having a rectangular cross section is about 1.5 to 1.7.
    [7]
    7. Bar profile according to one of the preceding claims, characterized in that it is symmetrical with the exception of the region (4) with reduced thickness.
    [8]
    8. rake for a hydropower plant comprising a plurality of mutually parallel bar profiles, characterized in that it comprises bar profiles (1) according to one of the preceding claims.
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    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    AT207326B|1958-08-18|1960-01-25|Rheinstahl Union Brueckenbau|Computer system with exchangeable, guided computer panels for tunnel inlets, especially for turbine inlets|
    DE1911979U|1962-02-07|1965-03-11|Hugo Bauer|HOLLOW PROFILE RULER WITH INTERCHANGEABLE NOSES.|
    DE3715020C2|1987-05-06|1996-08-29|Geiger Maschf Helmut|Fine screen with a double screen grate for waste water|
    AT508365B1|2009-07-02|2011-01-15|Mahr Gernot|STAB RAKES|
    CH710671B1|2015-01-29|2020-11-13|Gustav Barbueda|Computer system for the removal of solid debris from a flowing body of water.|
    法律状态:
    2019-01-31| PK| Correction|Free format text: BERICHTIGUNG ERFINDER |
    优先权:
    申请号 | 申请日 | 专利标题
    DE102015204911.6A|DE102015204911A1|2015-03-18|2015-03-18|Bar profile for a rake cleaner|
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