CN204199254U - A kind of device improving large reservoir layering water at low temperature - Google Patents

Abstract

The utility model discloses a kind of device improving large reservoir layering water at low temperature.In order to the problem that the low-temperature discharge water temperature improving built power station is low, the device of described raising large reservoir layering water at low temperature, comprise the water temperature primarily of water proof net composition be arranged in reservoir and control curtain, this water temperature of vertical layout controls curtain and is arranged on 600m ~ 1500m before reservoir dam, and perpendicular to the intake bearing of trend sluiced before dam; The top that described water temperature controls curtain is positioned at reservoir and jumps below warm layer, the bottom that this water temperature controls curtain is fixed on bottom reservoir, make reservoir surface water control curtain top with the warm layer water that jumps through water temperature and enter intake, the water at low temperature bottom reservoir is controlled curtain gear at intake place by water temperature.The utility model do not affect power station run present situation prerequisite under, the temperature that sluices under can effectively promoting Built hydropower station reaches 3 DEG C-5 DEG C.

Description

A kind of device improving large reservoir layering water at low temperature

Technical field

The utility model relates to a kind of device improving large reservoir layering water at low temperature, belongs to Hydraulic and Hydro-Power Engineering technical field.

Background technology

The large storehouse of high dam, the deep water storehouse that particularly some adjusting functions are good, its reservoir capacity is large, flow velocity delays, at the end of spring and the beginning of summer, there is obvious layering in the vertical temperature of water body, in profundal zone, water temperature is low, and little by temperature influence of change, the temperature that sluices under causing reservoir, lower than natural river course water temperature, has a negative impact to downstream crops and fish.Along with Chinese society economic development, ecological environment problem is more and more paid attention to, for avoiding the adverse effect of reservoir low-temperature discharge, the water temperature sluiced under starting to consider to improve power station.At present Stoplog gate stratified pumping method is mainly contained to the administering method of power station low-temperature discharge.

Stoplog gate stratified pumping method is appropriate location, the upstream newly-built Stoplog gate stratified pumping formula water inlet of the former water inlet in power station, and select to enable certain layer of newly-built water inlet according to reservoir level, former inlet gate is closed, and can reach the object of stratified pumping like this.But build Stoplog gate and need synchronization implementation during power plant construction, for various reasons China exist much run exist water at low temperature, not yet take the large storehouse of the high dam of control measures.This type of reservoir cannot adopt Stoplog gate scheme to carry out water at low temperature regulation.

Utility model content

In order to solve the confinement problems that above-mentioned existing power station low-temperature discharge administering method exists, the utility model aims to provide a kind of device improving large reservoir layering water at low temperature, this device do not affect power station run present situation prerequisite under, the temperature that sluices under can effectively promoting Built hydropower station reaches 3 DEG C-5 DEG C.

To achieve these goals, the technical scheme that the utility model adopts is:

A kind of device improving large reservoir layering water at low temperature, comprise the water temperature primarily of water proof net composition be arranged in reservoir and control curtain, this water temperature of vertical layout controls curtain and is arranged on 600m ~ 1500m before reservoir dam, and perpendicular to the intake bearing of trend sluiced before dam; The top that described water temperature controls curtain is positioned at reservoir and jumps below warm layer, the bottom that this water temperature controls curtain is fixed on bottom reservoir, reservoir is positioned at jump the superficial water on warm layer and the warm layer water that jumps controls curtain top through water temperature and enters intake, the water at low temperature bottom reservoir is controlled curtain by water temperature and keeps off at intake place.

Be below the technical scheme of further improvement of the utility model:

Conveniently fix water proof net, as a kind of concrete form of structure, the top of described water proof net is provided with exaggerated, and the bottom of water proof net is provided with infraclass, and the two side ends of water proof net is fixed on the slope wall of reservoir.

Preferably, the top of described water temperature control curtain is positioned at 20m ~ 40m under reservoir water face.

The slope wall of described reservoir is equipped with guide rail, and the two side ends of described water proof net is equipped with and multiplely along the movable loop of slide, the bank slope of reservoir can be provided with the hoist engine that movable loop can be driven along slide.Further, described guide rail is stainless steel cable.Thus, the top of water proof net can be adjusted to different elevations at Different water period by hoist engine.

Many vertical manropes are connected with, to improve the bearing strength of water proof net between described exaggerated and infraclass.

Preferably, the mesh of described water proof net is diamond hole or hexagonal hole, and the horizontal hanging ratio u1 of water proof net is less than 0.707.

In order to firm water proof net better, described water proof net top is connected with float, and water proof sieve bottom is connected with weight, and weight is preferably concrete and throws pier.

The nettle of described water proof net is Di Nima rope.

The permeability rate of described water proof net is not more than 0.2Lu.

Thus, lay the water temperature with certain permeability rate perpendicular to water (flow) direction in the thermostat layer of the utility model certain distance before reservoir dam and control curtain, make reservoir surface water control curtain top with the warm layer water that jumps through water temperature and enter intake, the water at low temperature bottom reservoir is controlled curtain gear at intake place by water temperature.

Above structure, water temperature of the present utility model controls scene plot layer water-fetching method and is fixed on the bottom by bottom the curtain be made by macromolecular material, top is placed in underwater certain position by stationary rope, the water that skin temperature is higher enters intake through curtain top, bottom water at low temperature at intake place, is reached the object of getting top layer warm water by curtain gear thus.Specifically, it is the certain depth (being generally positioned at thermostat layer) the flexible curtain with certain permeability rate being blocked certain distance before dam, control curtain by water temperature and control the ratio that water at low temperature enters the advance mouth of a river, dam, and the superficial water close with downstream natural river course water temperature and the warm layer water that jumps are not stopped, break the water temperature delamination structure after water temperature control curtain, promote dam advance outlet water temperature.

Compared with prior art, the beneficial effects of the utility model are: the utility model breaches the limitation of traditional power station low-temperature discharge administering method, power station generated energy can also be ensured while improving water temperature, its structure are simple, engineering quantity is little, short construction period, be applicable to Built hydropower station engineering, there is significant economic benefit and social benefit, dam advance outlet water temperature 3 ~ 5 DEG C can be improved, effectively improve the problem that the low-temperature discharge water temperature in built power station is low.

Accompanying drawing explanation

Fig. 1 is the structure principle chart of the utility model embodiment;

Fig. 2 is the structural representation of a kind of mesh of the utility model water proof net.

In the drawings

1-water proof net; 2-is exaggerated; 3-infraclass; 4-guide rail; 5-movable loop;

6-hoist engine; 7-float; 8-weight; 9-indulges manrope; 10-anchor pole.

Detailed description of the invention

Below for certain large reservoir domestic, by reference to the accompanying drawings the utility model is further elaborated.

This programme utility model effectively reduces the impact of water at low temperature on downstream aquatic ecological, in 4 ~ July, as far as possible by the water at low temperature interception of 40m ~ 70m under water, under reservoir surface is put into dam under water, reduces water at low temperature and enters intake flow before dam.Suspension cable suitably regulates according to the change of water level, water proof net generally adopts high performance material as barrier material, owing to being subject to the effect of water, suspension cable and water proof net form parabola in water (flow) direction, need the analysis of flowing pressure and the hydrostatic pressure be subject in conjunction with water proof net specifically stressed.

In the feasibility of analysis project and the basis of validity, consider ensure engineering safety and run convenience, will consider during schematic design following some:

A) engineering safety guarantee

This engineering distance water inlet air line distance is about 1000m, and accident can run jeopardizing power station and shipping safety.Following 5 aspects are considered during design.

1) power station minimum flood discharge flow 4870m is considered ³(wherein flow 870m is completely sent out in power station to/s ³/ s, flood spillway minimum safe letdown flow 4000m ³the total storage outflow of/s) time substantially there is not water at low temperature problem, with power station minimum flood discharge flow 4870m in parameter choose process ³flow velocity 0.21m/s in/s situation is that design discharge carries out calculating the resistance of water proof net to ensure that water proof net can bear the impact of current before power station operation reaches minimum flood discharge flow.

2) mesh sheet top edge considers that the high strength netting twine of employing 4 times of safety stocks is sewed up, and its excess-three limit is pressed flow velocity load and adopted equal strength netting twine to sew up, and etting is once overload, and three side seams close self falling, start etting overcurrent.

3) during the flood discharge of power station, for avoiding current to bring enormous impact to cause security incident, water proof net being positioned over certain elevation bottom reservoir and making not by flood influence, and ensure smooth water excessively.Meanwhile, for ensureing to be mentioned by the throwing pier sunk to the bottom after flood passage, as far as possible selecting sand clay substrate, considering the gentle gradient of two sides side slope on selected section simultaneously, bottom of the reservior is smooth, under water without obstructions such as stub, toft, massifs.

4) owing to there being shipping harbour before reservoir dam, need to arrange channel marking and signal near water proof net.

5) for keeping water proof net to stablize on vertical, under needing to consider flood discharge operating mode in the throwing pier design in bottom, mesh sheet all can be sunken to the measure of bottom of the reservior.

B) convenience guarantee is run

1) for ensureing that water proof net is in the lifting of run duration according to different water level, ensures and water proof net can be mentioned to design altitude after flood passage, need to consider the automatic lifting facilities such as hoist engine in the drag-line Platform Designing of two sides simultaneously.

2) according to the pollutant characteristic of the present embodiment and other reservoirs domestic, dirt thickness remains on below the water surface to water surface 1.5m.Because the online guiding principle of water proof is generally positioned at underwater 30m, substantially do not have the appearance of dirt and large obstacle.But on netting twine, have attached growth of microorganisms, along with the accumulation of running time, can mesh be blocked, need to consider to smear at netting twine to prevent the non-toxic coatings of attached growth of microorganisms or add Related Component in twisted-pair production process for this reason.

3) for convenience of the lifting of water proof net under different water level situation and before and after flood discharge, need to arrange guide rod along water proof net section both sides.Guide rod more can the location of water proof net in lifting process.

1, the route selection of water proof net is arranged

The layout section selection of water proof net needs to consider the stressed many factors such as even as far as possible of curtain difficulty of construction, economical rationality, curtain.Need to select in river course relative narrower, two sides, river course and flooded area are area, gentle slope and the good region of geological conditions as far as possible, avoid regions of turbulent flow for this reason.In addition, consider that, in the running of power station, near water inlet, the disturbing influence of water body, needs away from water inlet.First plan before dam 1000m landform comparatively stenosis arrange permeable efficiency be 10% water proof net water body intercept.Water proof net adopts top suspension cable to fix, and pier scheme thrown by bottom lifting concrete, both sides adopt steel cable rail fixed form, and its centre suspension cord arranges that elevation is below normal pool level 30m, i.e. 445m elevation; Water proof end off the net is arranged on below foundation plane elevation 10m, i.e. 395m elevation.

2, water proof net calculates

2.1 water proof web area

The online infraclass length of water proof should be able to block the maximum span of block section, because water proof net will inevitably present parabolic shape under the effect being subject to impact of water in length and short transverse, thus the length of block and height than the width of section and height dimension large.The exaggerated length of general block is that the length of the maximum outreach of block section adds 5% of maximum outreach length, i.e. L _{on 0}for 337m; Infraclass length is that maximum base line length adds 5% of maximum base line length, i.e. L _{0 time}for 219m; Net height is that actual height adds 5% of actual height, i.e. 53m.

2.2 water proof net mesh sheet specifications

Water proof net mesh sheet is made up of etting, hoddy, and etting is the major part of water proof net, plays and intercepts water effect, and hoddy is specially with the etting of thick line establishment in order to strengthen edge strength.

2.2.1 water proof net mesh size and sealike colour

Understand from the establishment of market net, be rhombus net and hexagon net at present, rhombus net is in the majority.In the design adopt mesh to be rhombus net, water proof net signal as shown in Figure 2.Suppose that the permeability rate of water proof net is equal with mesh void content, when water proof net permeability rate is (Z) 10%, that is:

S _single-mesh(single-mesh area)/S _{single mesh}(single mesh area)=1/10, wherein S _{single mesh}=S _{1/2 netting twine}(area that the netting twine (radius is wide) forming single mesh surrounds).

S _single-mesh=e ²× sin α (2.2-1)

S _{single mesh}=a ²× sin α=(e+d/sin α) ²× sin α (2.2-2)

Wherein e-half inner diameter of mesh;

A-bar size (in mesh two adjacent bonds or tie point center between distance when order pin fully stretches and do not extend);

D-sealike colour;

α-be the vertical angle of netting twine;

Stressed according to netting twine, under guarantee net intensity prerequisite, look into associated materials performance, preliminary plan selects the woven polyethylene rope of diameter 20mm as netting twine, and brute force that it is disrumpent feelings is 4.3ts, and weight is 20kg/100m.To extrapolate inner diameter of mesh size 2e be thus 18.66mm, size of mesh 2a is 59.00mm.

Water proof net mesh sheet in use needs the mesh being realized water proof net by mesh sheet sheepshank open in water and obtain certain shape, and it is stressed most suitable that mesh is made when suitable corner angle.Sheepshank, is shortened the closed length after mesh sheet stretches, and to be fixed on uniformly on rete cord, to make the activities of mesh flare up definite shape.Mesh sheet sheepshank degree represents with hanging ratio, and hanging ratio is designated as u in the horizontal direction ₁, vertical direction hanging ratio is designated as u ₂.

u ₁＝sin(α/2) (2.2-3)

u ₂＝cos(α/2) (2.2-4)

The selection of hanging ratio should make that the utilization rate of mesh sheet is large, material is economized, and makes stressed to be minimumly advisable, but u ₁too large, the tension force of netting twine is large, easily disrumpent feelings, general selection level hanging ratio u ₁should 0.707 be less than.The horizontal hanging ratio of preliminary plan anthology project is 0.66, then vertical hanging ratio is 0.75, α is 82.6 °.

2.2.2 netting twine consumption

Water proof net mesh number is calculated according to the permeability rate under tension:

N=S _{mesh sheet}× Z/S _single-mesh(2.2-5)

Wherein S _{mesh sheet}-mesh sheet area

N-mesh number;

Z-permeability rate;

Permeability rate is 10% net, and discharge area is 1643m ², mesh number is 17078551 orders.For single mesh, with line amount be four sidelines and four anastomoses use line amount, wherein every 2 meshes share a sideline, and every four meshes share an anastomose.Obtain formula thus:

G＝4g _LN(a/2+cd/4)/10 ⁸(2.2-6)

In formula: G-mesh sheet is with line amount (kg);

A-order pin (mesh) long (mm);

C-anastomose consumption coefficient; Fast knot C gets 14, wears fast knot C and gets 16, and the two fast knot C of single line gets 24, and two-wire fast knot C gets 36, and knotless net C gets 8.

D-sealike colour (mm);

G _l-netting twine unit hundred meters of length weight (g/100m).

Use line amount for what ensure block mesh sheet, consider the impact of water impact and loss, during design, 10% should be added on the basis of calculated value.

Knotless net is a kind of collar serif net using professed machine to knit out, it overcomes the feature of knotting to a great extent, such as reduce the strength loss of net and the resistance of water and decrease the use amount of line, also avoid the loose problem of mesh after net breakage.This project is intended selecting knotless net.Calculate water proof net mesh sheet weight 822845kg thus.

3, water proof net force analysis

The drag overall of water proof net is that etting, suspension cable and float resistance are added, and adds the drag overall that the factors 10% such as other object resistance are block.

3.1 mesh sheet resistances

Water proof net is subject to the impact of current in water, the active force suffered by it, except deadweight, topmost stressed be the resistance of water.The approximate netting twine composition mesh sheet is equal to cylinder, tubercle equivalent spherical.

R _{mesh sheet}=K ₀× K ₁× S _{netting twine}× V ²(5-1)

Wherein R _{mesh sheet}-mesh sheet resistance

K ₀-cylinder resistance coefficient, reynolds number Re is 10 ²~ 2 × 10 ²in scope, K ₀=62; Reynolds number Re is 2 × 10 ²~ 2 × 10 ⁵in scope, K ₀=55;

K ₁-difference coefficient, under netting twine resistance ratios similarity condition, cylinder resistance increases 10% ~ 25%, and for synthetic fibers, when low speed, (reynolds number Re is 10 ²~ 2 × 10 ²in scope) get 1.2, when high speed, (reynolds number Re is 2 × 10 ²~ 2 × 10 ⁵in scope) get 1.12;

Flow velocity before V-net, flow velocity after approximate consideration water proof net reduction section.

Because water proof net permeability rate is 10%, then netting twine area is 14790m ²; Cross-sectional flow considers power station minimum flood discharge flow 4870m ³net front flow velocity 0.45m/s, now K during/s ₀get 62, K ₁get 1.2.Then, R _{mesh sheet}for 199784kg.

3.2 suspension cable resistances

Owing to considering to need curtain to be hung different elevation at Different water period, suspension cable length is needed to have certain adjustable extent.Diameter is about 12 strands of Di Nima ropes (by the fine UHMWPE material of ultra-high molecular weight polyethylene) of 96mm, and UHMWPE gives the functional performance of its excellence, and belongs to thermoplastic engineering plastic that is moderate, function admirable.It has almost concentrated the advantage of various plastics, comprehensive functions such as having common polythene and unrivaled wear-resisting, the resistance to punching of other engineering plastics, self-lubricating, corrosion-resistant, water suction impact energy, low temperature resistant, disinfecting, not easily adhere to, not easily absorb water, density is less.Consult relevant parameter data, this cord break pulling force is 500t, and line density is 4450g/m, and this type of is applied more and more widely at present, if Jiangyin is greatly across elementary unwrapping wire and secondary traction.Because this rope has better suppleness, shrinkage is strong, is convenient to receive net to bottom during flood passage.Consider the top rete cord stressing conditions during operating maintenance, top suspension cable is adopted 12 strands of Di Nima ropes of two 96mm.Suspension cable weight is respectively 3234kg, 1819kg up and down as calculated.

In level, resistance is identical with etting with the angle of attack of rope due to current, therefore should by the vertical resistance formulae discovery of rope, that is:

R _{guiding principle}=K ₂× L × d × V ²(3-2)

In formula: R _rope-suspension cable resistance (kg);

K ₂-suspension cable resistance coefficient; (during L/S=0.95, K ₂k when being 70, L/S=0.9 ₂be 65)

L-suspension cable projected length (m);

D-suspension cable diameter (m);

V-water velocity (m/s).

R _exaggerated=870kg, R _infraclass=435kg

3.3 floating weight and associated resistive

A) floating weight calculates

The weight of water proof net in water can calculate with following formula:

G _water=G ₁q ₁+ G ₂q ₂(3-3)

In formula: G ₁-etting gross weight (kg)

G ₂-suspension cable gross weight (kg)

Q ₁-web pre fetching sedimentation rate

Q ₂-suspension cable material sedimentation rate

Wherein poly sedimentation rate is-0.0526, and polyamide fibre line is 0.1228, and it is 0.0566 that the mixing of second dimension is twisted thread, and hawser is 0.866.

The weight of water proof net in water is-43462kg as calculated, and namely water proof net is buoyancy in water.

Water proof net is similar parabolic shape under flow action on vertical, causes exaggerated to pressing down T _pressure, the active force T that infraclass is upwards carried _carry, be approximately according to parabolical Horizontal Tension:

In formula: R _etting-etting resistance (for mesh sheet resistance and suspension cable resistance sum)

H-depth of water

F _archthe sag of-mesh sheet in water (camber)

The mesh sheet height (chord length) of H-water proof net

According to above-mentioned calculating, mesh sheet resistance 199784kg, upper infraclass resistance 870kg, then the resistance of water proof etting is 200654kg.Due to the ratio 0.95 of the depth of water and net height, then H/h=1.05.So T _pressure=T _carry=183171kg.

Because water proof net adopts polythene material, water proof net is greater than gravity at buoyancy, is 43462kg, shows as T to buoyancy _pressurefor 139704kg, T _carryfor 226633kg.For upper and lower guiding principle can be made substantially to keep level, ensure water proof net effect, need exaggerated increase buoyancy, infraclass increases settling capacity.Need to arrange float at the water surface, infraclass arranges weight for this reason, and wherein the cylindrical foam plastic float of diameter 500mm, long 800mm selected by float, and its holding power is 150kg, needs 930 altogether, is mainly arranged within the scope of the middle each 100m in both sides in river course; Weight adopts concrete casting to build up throwing pier, and throw pier and be made up of two parts, the first half is cone, the latter half cylinder, consider that need the weight increasing weight, considering that 1.1 multiplying factors obtain weight settling capacity is 249100kg in order also can reduce after the network of rivers in water level reduction.According to suspension cable length, every 3m arranges a throwing pier, and water proof net arranges 70, each throwing pier 1.95m ³.Meanwhile, for ensureing mesh sheet uniform stressed under weight effect, need vertically arranging vertical manrope, every 3m arranges one, arranges 73 altogether, the long 60m of every root, employing diameter is Di Nima rope (line density is 75g/m) ultimate strength of 12mm is 10t, and gross weight is 329kg.

B) float resistance

R _{ball float}=mK _{ball float}l _floatingd _floatingv ²(3-5)

Wherein m-ball float number

K _{ball float}-ball float resistance coefficient is 55 when current are vertical with float

R _{ball float}=4143kg

Weight basic setup is in hydrostatic region, bottom, and its resistance to water-flow can be ignored.

3.4 water proof net drag overalls

The drag overall of water proof net is that etting, suspension cable and float resistance are added, and adds the drag overall that the factors 10% such as other object resistance are block.By water proof net drag overall R _alwaysfor 225110kg.

Infraclass tension force on 3.5

Upper infraclass bears the resistance of whole water proof net, and two sides shore pier in the same horizontal line, can regard suspension point parabola in the same horizontal line as, and upper infraclass tension force is equal.

Circumferential tension (T) on the suspension point of two ends.

$T=\sqrt{T_0^2+{\left(\frac{Q}{2}\right)}^2}---(3-6)$

T ₀＝QL/8f (3-7)

In formula: Q-cable tension is at the component of water (flow) direction, and its value is the half (kg) of net resistance;

T ₀-cable tension component in vertical direction (kg);

Circumferential tension when T-suspension cable is symmetrical on two suspension points.

Due to 1.05 times that suspension cable length is section length, L/f=6.8, f=47m calculate, and upper and lower suspension cable circumferential tension is 110996kg.Because upper and lower guiding principle two ends are all fixed on same position, but its tension direction is inconsistent, and its angle is θ=54 °, according to

T _close=((T _on+ T _undercos θ) ²+ (T _undersin θ) ²) ^0.5=197796kg, consider that 1.5 times of safety factor are 296694kg, then two sides shore pier must have the ability such as resistance to plucking, antiskid of 300t.

The strength accounting of 3.6 netting twines

Twine strength is adjusted and following formula can be adopted to carry out approximate calculation:

P _{netting twine}=1.65n × a × u ₁[(T ₀ ²+ (R _always/ 2) ²] ^0.5/ L _ettingu ₂(3-8)

Wherein:

P _{netting twine}the breaking strength of-single netting twine

L _etting-netting-length

N-safety factor, 6-12

This project n gets 10, L _ettingget rete cord length 337m, obtain P as calculated _{netting twine}for 311kg, the woven polyethylene rope of this project primary election diameter 20mm is as netting twine, and it is disrumpent feelings, and brute force is 4.3ts, meets the demands.

4, water proof network operation ensures

4.1 hang and draw scheme

According to above-mentioned calculating, two sides need the facility arranging 300t to draw support as hanging of water proof net.Because water proof net needs to adjust up and down to ensure that the online guiding principle of water proof remains on 30m under water according to different water level, need in addition to consider water proof net to be zoomed to bottom reservoir inner lead part to avoid flood to the destruction of water proof net in the flood season.For this reason, the upper infraclass of water proof net can not be fixed, and initial option hoist engine adds assembly pulley scheme.

Because the domestic specification of current hoist engine is 50t to the maximum, be configured to 1.25 times of pulling force according to code requirement two sides drag-line platform hoist engine.Select 50t hoist engine (speed 0.1m/s, motor 90KW), configure 9 sections of ropes (being about 300m altogether), 4 movable pulley, the assembly pulley of 4 fixed pulleys realizes 300t pulling force and ensures that water proof net promotes.Bottom running block, slide rail is set, long 150m is because water proof net is in the skew promoting and can cause because of the effect of current in decentralization process drag rope, for ensureing that its skew can not affect the operation of pulley, a guiding stainless steel annulus being set on bank, rope is through in ring.

The directed facility of 4.2 water proof nets

Because water proof net is carrying out carrying, falling the swing easily occurring water proof net in process under forward effect of water pressure, easily occur that the ropes amplitude of oscillation is excessive, the security of operation of pulley and hoist engine can be affected, the swing of weight may be caused simultaneously, water proof net will be affected stressed, reduce its application life.Need to arrange a stainless steel pull-cord as guide rail at reservoir along water proof net position, two ends adopt anchor pole to be fixed on basement rock, and top elevation is 480m, and more than normal pool level, bottom elevation is 325m elevation, and length is 220m for this reason.The oblique guiding principle of water proof sieve bottom arranges slip collar, and stainless steel hawser is through the collar.

The installation of 5 water proof nets and operation

The mounting technique of water proof net engineering comprises the assembly technology of water proof net itself and two parts installed by water proof net.The former refers to cutting out and sewing up between block etting, and upper and lower guiding principle assembles (sheepshank), the assembling etc. of cover net and deposited net, and the latter refers to the mounting technique when the whole water proof water off the net of assembling is constructed.

5.1 water proof net assembly technologies

5.1.1 the cutting out and sewing up of mesh sheet

Water proof net is made up of etting, suspension cable.Wherein etting is the main body forming water proof net, because netting gear scale is large, considers the facility of processing and transport, often it is divided into after some sections of ettings are knitted respectively and is sewed up.In order to ensure the intensity of water proof net, specifying during stitching, the stitching of all major network clothing, comprising and longitudinally sewing up and laterally sew up, all adopting the mode compiling seam.Compile specification and the size of mesh of seam line, all identical with major network clothing.If the height of adjacent two pieces of ettings is variant, then by the requirement of certain joining ratio, two pieces of ettings must be carried out volume seam equably.

Because the landform of water proof net place reservoir range is irregular status, in order to ensure the water proof effect of water proof net, just require that the infraclass of water proof net is close on the ground on bottom of the reservior and slope, bank both sides, storehouse.Therefore, when configuring etting, should according to the sectional shape of water proof, be positioned at slope become the to be uneven etting in location and cut-out method should be used to be cut into match with the shape of bottom of the reservior.

5.1.2 upper and lower guiding principle assembling

Hanging ratio is got in the assembling of water proof net etting and upper and lower guiding principle.In order to strengthen the edge strength of water proof host etting, often get upper and lower two order edge orders in netting.During exaggerated assembling, the Di Nima line first getting a diameter 32mm makes upper limb guiding principle through in whole upper limb orders of major network clothing, then press hanging ratio with assembly line etting seam is contracted on suspension cable, ensure that both sides assembly line intensity is less than top rete cord assembling intensity, make under extreme streamflow regime, both sides assembly line ruptures in advance, and top rete cord tension mesh sheet, ensures the cross-section of river.During infraclass assembling, by same hanging ratio, first by lower edge guiding principle through in the whole lower edge mesh of major network clothing, with assembly line joining in infraclass.

5.2 water proof nets are installed

The installation of water proof net comprises drag-line platform construction, the lifting of water proof net, puts net and throw pier location etc.

5.2.1, hoist engine and trimming bank slope are installed

When water proof net etting carries out the class that processes, just by designing requirement, should synchronously cast hoist engine pedestal and pulley track.The weight of hoist engine base is decided by the full payload of whole water proof net engineering in water.Meanwhile, the domatic of two sides and Underwater Slope should be repaired according to certain slope, to ensure water proof net to be put smoothly to bottom of the reservior at run duration by water proof net position.In addition, remove domatic on assorted tree stone riprap, arrange out more smooth domatic section of one wide about 5 meters, be used for ensureing to install to descend water smoothly after the network of rivers.

Carrying out the anchor bolt construction first carrying out upper and lower side when construction fixed by guide rail, then stainless steel hawser is fixed on the anchor pole of bottom.Upper end needs to be fixed after the oblique guiding principle collar of water proof water off the net has assembled again.

5.2.2 water proof net lifts

Because water proof net weighs more than 800 ton, throw pier weight in addition and reach 1100 tons, and reach 320m due to span, its hoisting difficulty is large.For lifting smoothly, consider to be undertaken putting net by the hoist engine of drag-line platform and assembly pulley and both sides stainless steel hawser (guide rail), ship carries out auxiliary enforcement.

1) hawser of one crossing river channel is set at upper end, mesh sheet installation site 480m elevation and pulley is set.Right bank drag-line platform arranges a 500t temporarily and hangs Operating table and pull pulley.

2) mesh sheet of making is placed left bank drag-line platform, the stainless steel hawser fixed bottom is in turn through the stainless steel collar be placed on oblique guiding principle.Exaggerated initiating terminal is connected to left bank hoist engine.

3) the stainless steel hawser fixed bottom right bank is adopted temporary cables (lengthen 500m, make it crossing river channel), and hang in top pulleys through after the stainless steel collar on the right side of water proof net successively.The exaggerated rope of right-hand member is taken advantage of a situation and extends 350m, connect right bank hoist engine.

4) according to network of rivers installation progress, bottom is fallen block and the installation of upper buoy branch.Be aided with net boat successively from left to right just to throw pier and be installed on perpendicular guiding principle, notice that encryption is installed in middle part.

5) strain stainless steel hawser after being in place and be fixed, and slowly adopting hoist engine that water proof net is put in fixing elevation.

5.3 water proof net ancillary facilities

1) because this water proof net size of mesh is only 59mm, though there is not the blocking of river garbage etc. at underwater 30m, netting twine provides the environment of procreation growth can to microorganism and reservoir part planktonic organism etc., and permanent operation can make aperture reduce, and even blocks.When the time comes, water proof net resistance can increase greatly, even threatens the safety of operation.For the biology of microorganism and reservoir can be made not breed on netting twine, consider to carry out specially treated to water proof net in twisted-pair production process.Water proof net surface is applied or is soaked in and has in antimicrobial polyureas or (polyurethane-urea) liquid, after drying after taking-up, make liquid be solidified into one deck high-strength coating in web surface.Fleece coating after this solidification has feature: antimicrobial, and in water, microorganism is difficult in its surface attachment; Fibroreticulate tensile strength can be improved; Can long period of soaking in water, good water resistance.

2) because water proof reticular density is less than water, before flood passage, for guaranteeing, water proof net is placed bottom, will consider that when throwing pier and drawing pendant half throwing pier draws pendant point and is arranged at suspension cable, half is drawn pendant point and is arranged at water proof guiding principle off the net, arranged crosswise.

5.4 water proof network operation and maintenance

Water proof network arrangements 1000m before dam, upper end suspension cable determines concrete elevation according to liquid level sensor, carries out landing by pulling of two sides hoist engine, ensures water proof network arrangements 30m below the water surface.Due to the present embodiment Power Plant Design minimum flood discharge flow 4870m ³(wherein flow 870 is completely sent out in power station to/s ³/ s, flood spillway minimum safe letdown flow 4000m ³the total storage outflow of/s), when flood discharge flow is greater than 4870m ³during/s, lower sluicing is released mainly through flood spillway, this at present sluicing body be mainly superficial water, water at low temperature impact less.Therefore be greater than 4870m at amount of water to be discharged ³water proof net is needed to place reservoir bottom, to avoid the water yield to the impact failure of water proof net during/s.

Because water proof net materials water resistance is strong, netting twine shear strength is high, and can not rot in water, and running time is of a specified duration.Need maintenance in case of exceptional circumstances, can according to installation procedure contrary operation.

6 water proof net effects

Ensure security of operation prerequisite under, water proof net scheme effectively can improve low-temperature discharge, by adopt MIKE 3 carry out water temperature simulation learn, water proof net can increase by 3 ~ 5 DEG C to the temperature that sluices under intake.Its effect is relevant to permeability rate, and along with permeability rate constantly reduces, intake water temperature increases gradually, but increasing degree reduces gradually.Wherein can improve temperature when permeability rate is 20% be 3.2 DEG C ~ 4.6 DEG C, and can improve temperature when permeability rate is 10% be 3.5 DEG C ~ 5.2 DEG C, and improving temperature when permeability rate is 5% is 3.8 DEG C ~ 5.3 DEG C.Temperature raising effect after permeability rate is lower than 10% is not obvious especially, and from safe operation angle, main employing permeability rate is the control that 10% water proof net carries out water at low temperature.

The content that above-described embodiment is illustrated should be understood to these embodiments only for being illustrated more clearly in the utility model, and be not used in restriction scope of the present utility model, after having read the utility model, the amendment of those skilled in the art to the various equivalent form of value of the present utility model has all fallen within the application's claims limited range.

Claims (9)

1. one kind is improved the device of large reservoir layering water at low temperature, it is characterized in that, comprise the water temperature primarily of water proof net composition be arranged in reservoir and control curtain, vertical this water temperature of arranging controls curtain and is arranged on 600m ~ 1500m before reservoir dam, and perpendicular to the intake bearing of trend sluiced before dam; The top that described water temperature controls curtain is positioned at reservoir and jumps below warm layer, the bottom that this water temperature controls curtain is fixed on bottom reservoir, reservoir is positioned at jump the superficial water on warm layer and the warm layer water that jumps controls curtain top through water temperature and enters intake, the water at low temperature bottom reservoir is controlled curtain by water temperature and keeps off at intake place.

2. the device of raising large reservoir layering water at low temperature according to claim 1, it is characterized in that, the top of described water proof net is provided with exaggerated, and the bottom of water proof net is provided with infraclass, and the two side ends of water proof net is fixed on the slope wall of reservoir.

3. the device of raising large reservoir layering water at low temperature according to claim 1, is characterized in that, the top that described water temperature controls curtain is positioned at 20m ~ 40m under reservoir water face.

4. the device of raising large reservoir layering water at low temperature according to claim 2, it is characterized in that, the slope wall of described reservoir is equipped with guide rail, the two side ends of described water proof net is equipped with and multiplely along the movable loop of slide, the bank slope of reservoir can be provided with the hoist engine that movable loop can be driven along slide.

5. the device of raising large reservoir layering water at low temperature according to claim 2, is characterized in that, is connected with many vertical manropes between described exaggerated and infraclass.

6. according to the device of the raising large reservoir layering water at low temperature one of claim 1 ~ 5 Suo Shu, it is characterized in that, the mesh of described water proof net is diamond hole or hexagonal hole, and the horizontal hanging ratio u1 of water proof net is less than 0.707.

7. according to the device of the raising large reservoir layering water at low temperature one of claim 1 ~ 5 Suo Shu, it is characterized in that, described water proof net top is connected with float, and water proof sieve bottom is connected with weight.

8. according to the device of the raising large reservoir layering water at low temperature one of claim 1 ~ 5 Suo Shu, it is characterized in that, the nettle of described water proof net is Di Nima rope.

9., according to the device of the raising large reservoir layering water at low temperature one of claim 1 ~ 5 Suo Shu, it is characterized in that, the permeability rate of described water proof net is not more than 0.2Lu.