CN204803853U - Undergauge dissipation structure in pressure tunnel hole - Google Patents

Abstract

The utility model relates to an undergauge dissipation structure in pressure tunnel hole. The utility model aims at providing a simple structure, construction convenience, the lower undergauge dissipation structure in pressure tunnel hole of construction investment to improve the hydraulics condition, directly reduce pressure tunnel's the export flood peak and the velocity of flow. The utility model provides a: an undergauge dissipation structure in pressure tunnel hole, this pressure tunnel has upstream side pressure tunnel, downstream side pressure tunnel, and establish the export arc door and the energy dissipater in the pressure tunnel exit of downriver inclining, be equipped with undergauge section and flaring section between upstream side pressure tunnel and the downstream side pressure tunnel in proper order, the undergauge section physically comprises the concrete shutoff of arranging in pressure tunnel the endotheca steel lining and fill between this steel lining and pressure tunnel inner wall, its upstream side abrupt change of cross section of the undergauge section that forms is reduced, the flaring section is formed by the section diffusion that the gradual change of the section of undergauge section is downstream side pressure tunnel. The utility model is suitable for a hydraulic and hydroelectric engineering.

Description

Undergauge energy-dissipating structure in pressurized tunnel hole

Technical field

The utility model relates to undergauge energy-dissipating structure in a kind of pressurized tunnel hole.Be applicable to Hydraulic and Hydro-Power Engineering.

Background technology

Pressurized tunnel barrel generally bears middle high water head, the lower sluicing stream of outlet is a kind of high energy torrent, and downstream river course mostly is unhurried current, and the energy (namely than energy) that the former Unit Weight water body has is more much bigger than the latter, have obvious damage capability to underwater bed, formation is washed away.For preventing degradation riverbed, causing the destruction of downstream bank slope, selecting suitable energy dissipating measure, to reduce head and the flow velocity of pressurized tunnel outlet, improve HYDRODYNAMIC CONDITION RELATING TO, thus ensure building safety.In engineering, the normal energy dissipating measure adopted roughly has: underflow type, choose streaming, surface current formula, these three kinds of Energy Dissipation Modes all consider the energy dissipation below spillway of pressurized tunnel, and also should according to topographic and geologic, waterpower and service condition during practical engineering application, the engineering measure taking other suitable of suiting measures to local conditions.

Summary of the invention

The technical problems to be solved in the utility model is: for above-mentioned Problems existing, there is provided that a kind of structure is simple, undergauge energy-dissipating structure in pressurized tunnel hole that easy construction, construction investment are lower, to improve HYDRODYNAMIC CONDITION RELATING TO, directly reduce exit head and the flow velocity of pressurized tunnel.

The technical scheme that the utility model adopts is: undergauge energy-dissipating structure in a kind of pressurized tunnel hole, this pressurized tunnel has upstream side pressurized tunnel, downstream pressurized tunnel, and be located at outlet arc door and the energy dissipater in pressurized tunnel exit, downstream, it is characterized in that: between described upstream side pressurized tunnel and downstream pressurized tunnel, be provided with undergauge section and divergent segment successively, described undergauge section is formed by being arranged in inner sleeve steel lining and the concrete occluding body be filled between this steel lining and pressurized tunnel inwall in pressurized tunnel, its upstream side abrupt change of cross section of the undergauge section formed reduces, the section that described divergent segment is downstream pressurized tunnel by the section gradient of undergauge section spreads and forms.

Footpath, the hole d of described undergauge section is 1/2 ~ 2/3 times of pressurized tunnel hole footpath D.

The angle of flare of described divergent segment is taken as 10 ~ 20 °.

The beneficial effects of the utility model are: the utility model structure is simple, easy construction, engineering drop into lower, and shown by elevation computation, the utility model, by undergauge section consumed energy, improves the HYDRODYNAMIC CONDITION RELATING TO in downstream; By the undergauge section ruggedized construction form of concrete occluding body, inner sleeve steel lining, above largely can strengthen structure stress condition, and increase the planeness of structure, avoid occurring the cavitation phenomenon under high-velocity flow.

Accompanying drawing explanation

Fig. 1 is structural representation of the present utility model.

Fig. 2 is the sectional view of upstream side of the present utility model, downstream pressurized tunnel section.

Fig. 3 is the sectional view of undergauge section of the present utility model.

Detailed description of the invention

As shown in Figure 1, Figure 2, Figure 3 shows, the present embodiment is undergauge energy-dissipating structure in a kind of pressurized tunnel hole, this pressurized tunnel comprises the upstream side pressurized tunnel 1, undergauge section 2, the divergent segment 3 that connect successively, and downstream pressurized tunnel 4, downstream pressurized tunnel 4 exit is provided with outlet arc door and energy dissipater 5.Wherein, the section of undergauge section 2 for reduce suddenly, then adopts divergent segment 3 to be connected with downstream pressurized tunnel 4; Undergauge section adopts the ruggedized construction form of concrete occluding body 21, inner sleeve steel lining 22, can avoid cavitation erosion.

In the present embodiment, upstream side pressurized tunnel 1 is identical with footpath, the hole D of downstream pressurized tunnel 4, footpath, the hole d of undergauge section 2 is taken as D/2 ~ 2D/3, and divergent segment 3 is the circular cross section being faded to diameter D by the circular cross section of diameter d, and angle of flare is taken as 10 ~ 20 ° (this routine angle of flare is 10 °); Form energy-dissipating structure by the undergauge section 2 of sudden contraction area, divergent segment 3 improves the HYDRODYNAMIC CONDITION RELATING TO in undergauge section downstream.Cross-sectional area due to pressurized tunnel is 2.25 ~ 4 times of undergauge section 2, and therefore the flow velocity of undergauge section is 2.25 ~ 4 times of pressurized tunnel section, can reach 15 ~ 40m/s, and high-velocity flow will cause the cavitation erosion of undergauge section 2 part concrete structure; Adopt inner sleeve steel lining 22 in undergauge section 2, and between inner sleeve steel lining and pressurized tunnel inwall fill concrete occluding body 21, effectively strengthen the structure of undergauge section, improve structural strength, increase structure planeness, avoid occurring cavitation phenomenon.

The energy dissipating principle of the present embodiment: in pressurized tunnel hole, current enter undergauge section 2 by aperture and form high-velocity flow, and high-velocity flow is connected with downstream pressurized tunnel 4 by divergent segment 3 again, and current return to normal flow.Flow velocity now, because of the energy dissipating through undergauge section 2, be less than the flow velocity in original pressurized tunnel hole, and artesian head is also less than the head of import.Engineering also can adopt multistage undergauge and flaring, eliminate energy, reduce exit head and flow velocity.

Undergauge section 2 import causes local head loss Δ H can adopt formulae discovery, for d value D/2:

$\mathrm{\ΔH}=\mathrm{\ξ}\frac{{v_1}^2}{2g}=0.375\×\frac{{\left(4v_0\right)}^2}{2g}=6\frac{{v_0}^2}{2g}$

Wherein:

v ₁＝4v ₀，m/s；

$\mathrm{\ξ}=0.5\×(1-\frac{A_2}{A_1})=0.375;$

A ₁--admission section area, m ²;

A ₂-undergauge section cross-sectional area, m ².

The flow velocity of general pressurized tunnel is at 5 ~ 15m/s, and can try to achieve local losses with above formula can reach 7.7 ~ 68.9m, as pressurized tunnel bear in water head at 60 ~ 150m, can effectively reduce exit head 13% ~ 46%.

Above-mentioned explanation is not limitation of the utility model; the utility model is also not limited to above-mentioned citing, those skilled in the art, in scope of the present utility model; the change made, change add or replace, all should belong to protection domain of the present utility model.

Claims (3)

1. undergauge energy-dissipating structure in a pressurized tunnel hole, this pressurized tunnel has upstream side pressurized tunnel (1), downstream pressurized tunnel (4), and be located at outlet arc door and the energy dissipater (5) in pressurized tunnel exit, downstream, it is characterized in that: between described upstream side pressurized tunnel (1) and downstream pressurized tunnel (4), be provided with undergauge section (2) and divergent segment (3) successively, described undergauge section (2) is made up of the inner sleeve steel lining (22) be arranged in pressurized tunnel and the concrete occluding body (21) be filled between this steel lining and pressurized tunnel inwall, its upstream side abrupt change of cross section of undergauge section (2) formed reduces, the section that described divergent segment (3) is downstream pressurized tunnel (4) by the section gradient of undergauge section (2) spreads and forms.

2. undergauge energy-dissipating structure in a kind of pressurized tunnel hole according to claim 1, is characterized in that: footpath, the hole d of described undergauge section (2) is 1/2 ~ 2/3 times of pressurized tunnel hole footpath D.

3. undergauge energy-dissipating structure in a kind of pressurized tunnel hole according to claim 1, is characterized in that: the angle of flare of described divergent segment (3) is taken as 10 ~ 20 °.