CN207597361U - A kind of special-shaped guiding device for flood discharging groove of turning - Google Patents

Abstract

A special-shaped diversion device for a turning flood trough belongs to the technical field of drainage buildings, comprising a turning chute and a special-shaped diversion structure laid in parallel on the ridge of the chute, according to the deflection of the upstream flow at the outlet of the chute The moving direction, flow velocity, flow state, and the spacing of the special-shaped diversion structure at the outlet of the chute are arranged. The special-shaped diversion structure includes three parts: a semi-elliptical cylindrical pier, a middle pier, and a broken-line pier, and the three are integrated into one structure; the semi-elliptic cylindrical pier is distributed in front of the raised ridge, and its side view is a right-angled trapezoid; The piers are distributed on the ridge, and they are in the same direction as the longitudinal axis of the turning chute; the middle piers are the connecting section of the two. The pier body of the utility model is simple in design and easy in engineering construction. The force of the pier head is simple, the pier body fits the chute and the ridge, and the pier body structure is stable. While ensuring that the discharged water flows into the downstream evenly and smoothly, the energy of the discharged water is dispersed to minimize the damage to the downstream riverbed and bank slope, thereby reducing the downstream protection work and bringing greater economic benefits.

Description

A special-shaped diversion device for a turning flood discharge trough

technical field

The utility model belongs to the technical field of drainage buildings and provides a special-shaped diversion device for a turning flood discharge trough. The special-shaped diversion structure can be used for diversion and energy dissipation in a turning flood discharge trough, and can improve the flow state of downstream water flow and ensure the power plant of a hydropower station. , drainage structures and other water conservancy facilities are safe.

Background technique

In the prior art, there are mainly two types of body designs for diversion facilities: streamlined and broken-line. However, the existing diversion facilities have significant shortcomings in practical applications: 1) The functions and application fields are single, not It has energy dissipation effect, and the diversion and energy dissipation effect of the turning chute is poor; 2) The force on the pier head is complex, which may easily cause the vibration of the pier body structure; The construction cost is high; 4) The range of applicable flow and flow velocity is small, which restricts the management and operation of the reservoir; 5) The body shape of the pier is too complicated, which is not convenient for the actual construction of the project.

Utility model content

Aiming at the problems existing in the prior art, the utility model provides a special-shaped diversion pier structure with simple design and stress, reasonable structure, and can be applied to the turning spillway. This structure has the functions of guiding water flow and eliminating residual energy. While ensuring that the discharged water flows smoothly into the main channel and improving the phenomenon of oblique flow backflow downstream, it uses its unique shape characteristics to eliminate residual energy through the protruding effect and protect the riverbed and bank slope.

In order to achieve the above purpose, the technical proposal of the present utility model is: affected by many factors such as terrain constraints and technical level, there is a certain deviation angle between some reservoir chute sections and the main channel axis. In order to realize the smooth connection between the discharge water flow and the main channel, the chute section in between is usually set as a turning chute on the plane. There is such a problem in the turning chute: Affected by the turning radius of the turning section of the chute, if the turning radius of the bend is too small, the water flow will turn too sharply, which will easily cause the water surface of the concave bank in the turning section of the chute to be high, and the height of the side wall does not meet the specification requirements , and cause erosion damage to the downstream riverbed and bank slope.

A special-shaped diversion device for a turning flood discharge chute, which includes a turning chute section and a plurality of special-shaped diversion structures of the same structure. The special-shaped diversion structure is laid in parallel on the outlet section of the discharge chute, extending from the front of the sill to the deflector The end of the nose sill. Special-shaped diversion structure According to the offset direction, flow velocity and flow state of the upstream flow at the outlet of the chute, the distance between the special-shaped diversion structure at the outlet of the chute is designed, specifically: the diversion pier and the chute distributed on both sides The distance between the side walls is narrow to ensure that the water flow is concentrated in the middle of the chute and discharged into the main channel.

The special-shaped diversion structure includes three parts: a semi-elliptical cylindrical pier, a middle pier, and a zigzag pier, and the three are integrated into one structure; On the raised ridge, the middle pier is located between the semi-elliptic cylindrical pier and the zigzag pier as the connection between the two. The broken-line pier includes two parts, namely a part of the pier before the nose sill and a part above the nose sill.

The semi-elliptic cylindrical pier is consistent with the incoming flow direction, and its side view is a right-angled trapezoid. The central pier is connected with the semi-elliptic cylindrical pier, the axes of both are parallel to the longitudinal axis of the discharge chute, and its side view is a right-angled trapezoid. The broken-line pier is a structure of equal height and thickness, and the bent angle is the corner of the turning chute, and the pier is in the same direction as the longitudinal axis of the turning chute. The height of the semi-elliptic cylindrical pier increases linearly from H1 to H2, and the length of the horizontal axis is equal to the thickness of the middle pier; the height of the middle pier increases linearly from H2 to H2; the height of the broken-line pier is H3; H1, H2, The value principle of H3 is: H1 is taken as twice the depth of the incoming water, and increases linearly to H2 with a slope of 0.5, and H2 increases linearly to H3 with a slope of 0.5.

The working process of the utility model: when the spillway discharges the flood, the water flow pours down along the spillway trough 1, and when it reaches the diversion structure, it passes through the semi-elliptical cylinder in the same direction as the incoming flow, combined with the laying distance of the pier body plane, the discharged water flow is Divided into 4 parts. Among them, the semi-ellipse helps to reduce the impact stress of the incoming flow, and the change in the height of the middle pier can guide the water flow according to the situation. The huge fan-shaped jet tongue increases the contact surface between the air and the water flow, effectively using the chute The longitudinal space of the outlet significantly enhances the energy dissipation in the air. The water tongue falls into the downstream channel and fully mixes with the water body, causing the cascade transmission and dissipation of water energy, which greatly weakens the high-speed water energy. The front part of the zigzag pier ridge is divided into a cuboid with a height of H2, which plays a good buffering role, reduces the jetting water flow hitting the pier body on the ridge, and avoids the phenomenon of instability due to excessive water pressure. The axis of the pier body on the ridge is parallel to the axis of the ridge and the main channel, so that the high-speed concentrated water flow can be smoothly connected with the water flow in the downstream channel and smoothly enter the main channel. At the same time, combined with the energy dissipation effect of the nose sill, it can ensure that the downstream riverbed, bank slope and buildings are not damaged by erosion, and effectively solve the problem of energy dissipation and anti-scour downstream of the discharge structure.

The beneficial effects of the diversion structure of the utility model are: 1) The design of the pier body is simple and convenient for engineering construction. 2) The force on the pier head is simple, the pier body fits the chute and the sill, and the pier body structure is stable. 3) While using the diversion structure to divert the discharged water flow and improve the oblique flow, backflow and washing phenomenon of the downstream riverbed, the projecting effect of the special-shaped pier allows the discharged water flow to diverge horizontally before flowing through the ridge. Longitudinal diffusion greatly eliminates the residual energy of the water flow. Even if part of the residual energy of the water flow dissipates in the air, the other part is eliminated by the violent turbulence of the water flow after the water tongue falls into the downstream channel; thus ensuring the smooth flow of the discharged water into the downstream while dispersing the discharged water. The kinetic energy of the water flow minimizes the damage to the downstream riverbed and bank slope, thereby reducing the downstream protection work and bringing greater economic benefits.

Description of drawings

Figure 1(a) is a schematic diagram of the position of the pressure measuring points of the piers in the front section of the deflected nose sill;

Figure 1(b) is a schematic diagram of the position of the pressure measuring point of the pier body placed on the upper part of the deflected nose sill;

Figure 2 is the contour map of the scour pit downstream of the combined discharge of the surface hole and bottom hole at a check water level of 674.38m;

Fig. 3 is a schematic diagram of the diversion structure of the utility model located at the outlet section of the chute;

Fig. 4 is the enlarged schematic view of the diversion structure provided by the utility model;

Fig. 5 is a side view of the right bank of the diversion structure;

Figure 6 is a top view of the diversion structure;

In the figure: 1 turning chute; 2 special-shaped diversion structure; 3 side wall of turning chute; 21 semi-elliptic cylindrical pier; 22 middle pier; ; 232 parts of pier above the nose sill.

Detailed ways

The utility model will be further described below in conjunction with the embodiments with reference to the accompanying drawings.

A special-shaped diversion device for a turning flood trough, comprising a turning chute section 1 and three special-shaped diversion structures 2 of the same structure, the special-shaped diversion structures 2 are laid in parallel on the outlet section of the chute, and extend from the front of the sill To the end of the nasal ridge. The special-shaped diversion structure 2 includes three parts: a semi-elliptical cylindrical pier 21, a middle pier 22, and a broken-line pier 23. The three are integrated into one structure; the semi-elliptic cylindrical pier 21 is distributed in front of the bridge, and The linear piers 23 are distributed on the raised ridge, and the middle piers 22 are located between the semi-elliptic cylindrical piers and the zigzag piers as the connecting section of the two. The broken-line pier 23 includes two parts, respectively a part of the pier 231 located in front of the flow-deflecting nose sill, and a part of the pier 232 located above the flow-deflecting nose sill.

As shown in Figure 3, the utility model includes three diversion structures placed in the outlet section of the chute and laid in parallel according to the spacing of 2:2.5:2.5:1. The bottom of the diversion device is closely connected with the outlet section of the chute, and extends from the front of the sill to the end of the sill.

As shown in Figure 4, the diversion structure of the utility model is divided into two parts according to the relative position to the ridge: the pier body in front of the ridge is divided into two parts: a semi-elliptical pier body and a right-angled trapezoidal pier body. The height of the semi-elliptical pier increases linearly from H1 to H2 with a slope of 0.5, and the horizontal axis is equal to the thickness L1 of the cuboid pier; the height of the right-angled trapezoidal pier increases linearly from H2 to H3 with a slope of 0.5. The pier on the ridge is a rectangular broken-line pier in the side view. Its height is H3 and its thickness is L1.

In the experiment, the designer observed that: when the water level is 674.38m and the flow rate reaches 1357.79m ³ /s, according to the position and size of the three diversion and impact piers mentioned above, the actual measurement of the three diversion and diversion impact piers The pressure values are listed in Table 1. The positions of the pressure measuring points are shown in Figure 1(a) and Figure 1(b). Pressure sensors are installed at the positions of the pressure measuring points. It is divided into three parts: upper, middle and lower. Each part is evenly set with two pressure measuring points according to the horizontal distance. A total of twelve pressure measuring points are set for the whole special-shaped diversion pier to accurately measure the water pressure on the pier body.

Table 1. Measured values of point pressure in diversion structure

According to the geological profile at the project dam site and the distribution of various rock and soil layers, model sand materials are laid in layers to conduct model test research on the moving bed section, and the downstream channel is simulated. It can be seen from Figure 2 and Table 1 that the pressure on the diversion structure and the shape of the downstream flushing pit all meet the design requirements.

Claims (2)

1. A special-shaped diversion device for turning flood troughs, characterized in that, the special-shaped diversion device comprises a turning chute section and a plurality of special-shaped diversion structures of the same structure, and the special-shaped diversion structures are laid in parallel on The outlet section of the chute extends from the front of the sill to the end of the nose sill; the special-shaped diversion structure is designed at the outlet of the chute according to the offset direction, flow velocity, and flow state of the upstream flow at the outlet of the chute Pitch; The special-shaped diversion structure includes three parts: a semi-elliptical cylindrical pier, a middle pier, and a zigzag pier, and the three are integrated into one structure; On the raised ridge, the middle pier is located between the semi-elliptical cylindrical pier and the broken-line pier as the connecting section between the two; the semi-elliptic cylindrical pier is consistent with the direction of the incoming flow, and its side view is a right-angled trapezoid; The central pier is connected with the semi-elliptical cylindrical pier, the axes of both are parallel to the longitudinal axis of the discharge chute, and its side view is a right-angled trapezoid; The longitudinal axis of the turning chute is in the same direction; The height of the semi-elliptical cylindrical pier increases linearly from H1 to H2, and the length of the horizontal axis is equal to the thickness of the middle pier; the height of the middle pier increases linearly from H2 to H2; the height of the zigzag pier is H3. 2. A special-shaped diversion device for a turning flood discharge trough according to claim 1, wherein said H1 is twice the depth of the incoming water, and increases linearly to H2 with a slope of 0.5, and H2 is less than A slope of 0.5 increases linearly up to H3.