CN104074178B - Cell-type surge-chamber in a kind of impedance - Google Patents

Abstract

The invention discloses cell-type surge-chamber in a kind of impedance。In order to effectively reduce surge chamber vertical shaft height, reducing difficulty of construction, reduce investment outlay, in described impedance, cell-type surge-chamber includes the surge chamber vertical shaft and the working tunnel that are connected by impedance hole with pressure diversion road；Described surge chamber vertical shaft connects with working tunnel, is provided with occluding body in this working tunnel, doubles as the floor elevation Z at the described working tunnel occluding body place of room on surge-chamber_sLower than top surge elevation Z in surge chamber vertical shaft_max。Working tunnel, from the viewpoint of utilizing surge-chamber top working tunnel volume, is also served as room on surge-chamber by the present invention, thus greatly reducing the height of surge chamber vertical shaft, saves investment。

Description

Cell-type surge-chamber in a kind of impedance

Technical field

The present invention relates to cell-type surge-chamber in a kind of impedance, be mainly used in the full underground surge-chamber in water channeling type exploitation power station。

Background technology

For meeting regulation assurance calculation requirement in long water channeling type exploitation power station, generally it is both needed to arrange surge-chamber, throttled surge chamber have simple in construction, volume little, properly functioning time bottom the advantages such as the loss of flood peak is little, water-level fluctuation amplitude is little, ripple attenuation is very fast, thus be used widely。Under normal circumstances, the bore that the unexpected removal of load room of unit produces all is held by surge chamber vertical shaft volume, causes that shaft height is too high, invest big phenomenon。

From the viewpoint of construction method and construction speed, surge-chamber work progress is both needed to lay working tunnel。

Summary of the invention

In order to effectively reduce surge chamber vertical shaft height, reduce difficulty of construction, reduce investment outlay, it is desirable to provide cell-type surge-chamber in a kind of impedance, this surge-chamber is from the viewpoint of utilizing surge-chamber top working tunnel volume, working tunnel being also served as room on surge-chamber, thus greatly reducing the height of surge chamber vertical shaft, saving investment。

To achieve these goals, the technical solution adopted in the present invention is:

Cell-type surge-chamber in a kind of impedance, including the surge chamber vertical shaft connected with pressure diversion road by impedance hole and working tunnel；It is structurally characterized in that, and described surge chamber vertical shaft connects with working tunnel, is provided with occluding body in this working tunnel；Double as the described working tunnel occluding body place floor elevation Z of room on surge-chamber_sLower than top surge elevation Z in surge chamber vertical shaft_max；Top surge elevation Z in described surge chamber vertical shaft_maxDetermined by equation below:

${\mathrm{\λ}}^{\′}=\frac{2gA(h_{w0}+h_{c0})}{{\mathrm{LA}}_1{v}_0^2}$

1), as λ ' h_c0During < 1:

(1+λ′|Z_a|)-ln(1+λ′|Z_a|)=(1+ λ ' h_w0)-ln(1-λ′h_c0)

2), as λ ' h_c0During > 1:

(λ′|Z_a|-1)+ln(λ′|Z_a|-1)=ln (λ ' h_c0-1)-(λ′h_w0+1)

$Z_{max}=\frac{Z_{a}A-(H-Z_s)L_{s}B}{{\mathrm{BL}}_S+A}$

In various above: Z_maxSurge-chamber top surge during room on-band；

Z_a-without upper room time surge-chamber top surge；

Z_s-upper occluding body place, room floor elevation；

B-upper room width；

The reservoir level elevation that H-top surge design condition is corresponding；

L_s-upper room effective length；

L-pressure diversion road length；

A-surge chamber vertical shaft basal area；

A₁-pressure diversion road cross-sectional area；

h_w0-flow is Q₀Time, the difference of upstream reservoir level and surge-chamber water level；

h_c0The loss of flood peak value in-impedance hole；

The Q-flow by impedance hole；

v₀-corresponding to Q₀Time pressure diversion road flow velocity；

Q₀Flow is quoted in the generating that-top surge design condition is corresponding；

S-impedance hole area；

-impedance hole discharge coefficient；

G-acceleration of gravity。

The present invention takes into full account working tunnel occluding body place floor elevation and Surge in Surge Chamber elevation relation when design, makes working tunnel occluding body place floor elevation lower than top surge；By surge-chamber top working tunnel faces end head plugging after surge-chamber completion, also serving as room on surge-chamber, together hold produced bore during load rejection with vertical shaft, occluding body cope level should have the ventilation space of 0.5～0.8m from working tunnel cope level。So being possible not only to reduce shaft height, also effectively make use of working tunnel, owing to a hole floor elevation reduces, the road therefore leading to working tunnel also will shorten。

It is below the technical scheme of further improvement of the present invention:

In order to ensure ventilation, the top surge elevation Z of described surge chamber vertical shaft_maxIt is 0.8m～1m with the spacing of surge chamber vertical shaft roof。

The cope level at the described working tunnel occluding body place cope level from working tunnel has the ventilation space of 0.5m～0.8m。

The base plate of the described working tunnel doubling as room is 1: 1000～1: 200 relative to the longitudinal gradient gradient in surge chamber vertical shaft direction。

The determination of upper room section is to meet construction requirement for foundation, at the highest bore top surge Z_maxUnder condition, the highest bore top surge water surface should ensure that from upper ceiling portion the safe distance of 0.8～1.0m is in order to ventilate；Upper room base plate is advisable with flat slope relative to the longitudinal gradient in surge-chamber direction；Upper room volume is determined according to working tunnel section, length and the highest bore top surge elevation, and working tunnel section is more big, length is more long, and the amplitude of surge chamber vertical shaft height reduction is more big。

Compared with prior art, the invention has the beneficial effects as follows: present invention is mainly used for the full underground surge-chamber in water channeling type exploitation power station, greatly reduce surge chamber vertical shaft height, save great amount of investment。

Below in conjunction with drawings and Examples, the present invention is further elaborated。

Accompanying drawing explanation

Fig. 1 is the structure principle chart of one embodiment of the invention；

Fig. 2 is cell-type surge-chamber profile in impedance of the present invention。

In the drawings

1-pressure diversion road；2-surge-chamber；3-penstock；4-butterfly valve room；5-working tunnel；6-connects a trunk road；7-surge chamber vertical shaft；8-impedance hole；9-working tunnel occluding body。

Detailed description of the invention

1, basic situation

Southwest China some hydropower station is third medium-sized engineering, and its development task is generating, total installation of generating capacity 90MW。Main structures is mainly made up of concrete gate dam, left bank diversion system and shore type ground power house。

Water diverting structure is arranged in determines Qu He left bank, is made up of water inlet, diversion tunnel, surge-chamber and pressure pipeline etc.。Diversion tunnel is about 14398m from water inlet end to surge-chamber center total length, surge-chamber adopts the cylinder type impedance type of the upper room of band, surge chamber vertical shaft internal diameter 12.5m, impedance hole internal diameter 2.4m, well height 71.34m, top working tunnel is held concurrently room on surge-chamber, and its cross dimensions is 4.5m × 5.0m (wide × high), long 100m。

2, structural design

According to surge-chamber water force achievement, along with on surge-chamber, room floor elevation reduces, surge-chamber top surge reduces accordingly, but upper room floor elevation is too low, and required upper room profile height also can increase accordingly, and engineering cost is bigger。Considering, control within 2.5m by top surge distance floor elevation, finally determine cell-type surge-chamber barrel bore 12.5m in the impedance of full underground, impedance hole internal diameter 2.4m, the long 90m in upper room, wide 4m, floor elevation is 2292.5m。Top surge is 2294.900m, and minimum bore is 2240.570m, surge-chamber cope level 2305.340m, surge-chamber Bottom Altitude 2234.00m, shaft height 71.34m。Than the surge chamber vertical shaft height reduction 9.21m not considering upper room。

3, surge-chamber water force

${\mathrm{\&lambda;}}^{\&prime;}=\frac{2gA(h_{w0}+h_{c0})}{{\mathrm{LA}}_1{v}_0^2}$

As λ ' h_c0During < 1:

(1+λ′|Z_a|)-ln(1+λ′|Z_a|)=(1+ λ ' h_w0)-ln(1-λ′h_c0)

As λ ' h_c0During > 1:

(λ′|Z_a|-1)+ln(λ′|Z_a|-1)=ln (λ ' h_c0-1)-(λ′h_w0+1)

$Z_{max}=\frac{Z_{a}A-(H-Z_s)L_{s}B}{L_{S}B+A}$

In formula:

Z_s=2291.500m；B=4.5m；H=2270.00m；L_s=120.00m；L=14423.445m；A=122.66m²；A₁=24.62m²；H_w0=18.42m；Q=77.8m³/ s；V₀=3.16m/s；Q₀=77.8m³/ s；S=4.522m²；G=9.81m/s²。

${\mathrm{\&lambda;}}^{\&prime;}=\frac{2gA(h_{w0}+h_{c0})}{{\mathrm{LA}}_1{v}_0^2}=0.03$

Because λ ' is h_c0=0.9228 < 1, is calculated as follows:

(1+λ′|Z_a|)-ln(1+λ′|Z_a|)=(1+ λ ' h_w0)-ln(1-λ′h_c0)

Solve Z_a=32.49m。

Above-mentioned parameter is substituted into following formula:

$Z_{max}=\frac{Z_{a}A-(H-Z_s)L_{s}B}{L_S+A}$

Solve Z_max=23.208m

As can be seen from the above data, on band, surge chamber vertical shaft height in room relatively reduces Z without upper room surge chamber vertical shaft height_a-Z_max=32.49-23.208=9.21m。

4, quantities and output investment ratio are relatively

According to conventional impedance formula surge-chamber, this hydraulic power plant surge-chamber vertical shaft internal diameter is 12.5m, vertical shaft height 79.44m。According to cell-type surge-chamber in novel impedance, shaft height can reduce 9.21m, and cubic meter of stone well digs minimizing 2225m³, concrete reduces 627m³, reinforcing bar reduces 97t, reduces investment outlay about 2,000,000 yuan。

The content that above-described embodiment illustrates should be understood to these embodiments only for being illustrated more clearly that the present invention, rather than restriction the scope of the present invention, after having read the present invention, the amendment of the various equivalent form of values of the present invention is all fallen within the application claims limited range by those skilled in the art。

Claims (2)

1. a cell-type surge-chamber in impedance, including the surge chamber vertical shaft (7) connected with pressure diversion road (1) by impedance hole (8) and working tunnel (5)；It is characterized in that, described surge chamber vertical shaft (7) connects with working tunnel (5), is provided with occluding body (9) in this working tunnel (5)；Double as the floor elevation Z at described working tunnel (5) occluding body (9) place of room on surge-chamber_sLower than the interior top surge elevation Z of surge chamber vertical shaft (7)_max；The top surge elevation Z of described surge chamber vertical shaft (7)_maxIt is 0.8m～1m with the spacing of surge chamber vertical shaft (7) roof；The cope level at described working tunnel (5) occluding body (9) the place cope level from working tunnel (5) has the ventilation space of 0.5m～0.8m；The interior top surge elevation Z of surge chamber vertical shaft (7)_maxDetermined by equation below:

${\mathrm{\&lambda;}}^{\&prime;}=\frac{2gA(h_{w0}+h_{c0})}{{\mathrm{LA}}_1{v}_0^2}$

1), as λ ' h_c0During < 1:

(1+λ′|Z_a|)-ln(1+λ′|Z_a|)=(1+ λ ' h_w0)-ln(1-λ′h_c0)

2), as λ ' h_c0During > 1:

(λ′|Z_a|-1)+ln(λ′|Z_a|-1)=ln (λ ' h_c0-1)-(λ′h_w0+1)

$Z_{max}=\frac{Z_{a}A-(H-Z_s)L_{s}B}{{\mathrm{BL}}_S+A}$

In various above: Z_maxSurge-chamber top surge during room on-band；

Z_a-without upper room time surge-chamber top surge；

Z_s-upper occluding body place, room floor elevation；

B-upper room width；

The reservoir level elevation that H-top surge design condition is corresponding；

L_s-upper room effective length；

L-pressure diversion road length；

A-surge chamber vertical shaft basal area；

A₁-pressure diversion road cross-sectional area；

h_w0-flow is Q₀Time, the difference of upstream reservoir level and surge-chamber water level；

h_c0The loss of flood peak value in-impedance hole；

The Q-flow by impedance hole；

v₀-corresponding to Q₀Time pressure diversion road flow velocity；

Q₀Flow is quoted in the generating that-top surge design condition is corresponding；

S-impedance hole area；

-impedance hole discharge coefficient；

G-acceleration of gravity。

2. cell-type surge-chamber in impedance according to claim 1, it is characterised in that the base plate of the described working tunnel (5) doubling as room is 1: 1000～1: 200 relative to the longitudinal gradient gradient in surge chamber vertical shaft (7) direction。