headwork

UNIVERSIDAD NACIONAL PEDRO RUIZ GALLOESCUELA PROFESIONAL DE INGENIERIA CIVIL

HEADWORKS:

It is called work of taking the set of structures that are built with the purpose of removing the water in a controlled manner and be able to use it with the purpose for which it was projected its use.

CLASSES OF HEADWORKS:

There are works of Socket for power generation, construction of irrigation intake , intake works for provision of drinking water , the work of Jack For Current diversion

FUNCTIONS OF A INTAKE WORKS

The works of jack for water supplies are used in dams to control, regulate and derive the spending toward driving.

The works of jack can also operate as regulators, to provide an outlet for waters temporarily stored in the space for flood control, or to dislodge with anticipation to the arrival of avenues.

OBJECTIVES OF A WORK OF TAKES

INTAKE WORKS FOR POWER GENERATION: The discharge is to the river, and the entry of the water should be as high as possible to take advantage of the height of the drop.

INTAKE FOR FORWARDING: If during the construction of the different structures

that make up the dam, is going to be used the intake works as a work of diversion, we will have to project a kind of socket with its ducts or tunnels to a level, as low as possible, to easily achieve the diversion of the river.

JACK WORKS IN DOWNLOAD: In the case of, that the work of jack you intend to use as drainage for the rapid draining of the glass, it will be necessary to place its ducts or tunnels to a level as low as possible and with sections designed to drain at a time that s convenient the beaker

INTAKE WORKS IN STORAGE DAMS:

The dams have with various works that ensure its efficient operation under various circumstances: curtain, intake works and work of leave. The water that flows through the channel of a river is caught and stored by means of the curtain, and its utilization is carried out through a work of takes.Among the elements that can be presented are:

Input Structure ,ducts,

Mechanisms of regulation and emergencies with its operation Team ,

Devices for energy dissipation.

DESCRIPTION OF THE CAPABILITIES OF USE

N. A. M. E: relates to the maximum level that reach the waters of a stream under conditions of maximum flow occurred in rainy season high-return period in which houses the collection

N. A. M. OR:Known as N. A. N. (Normal water level) and is defined by the level of the high ridge.


N. A. min: minimum water level of operation in the body of water and place the catchment, corresponds to the volume destined to the blockages.

Cr: Capacity for flood control, this is understood as the volume stored between the NAME and the NAMO

C. U: directly exploitable volume of the dam

SELECTION OF ELEMENTS OF WORK OF OUTPUT:

The design of a work output is influenced by many conditions relating to the hydraulic requirements, adaptability to the site, to the interrelationship of the output and the procedure of construction, and to other units within the development. Topography - geology.

Depending on the position of the control device, the duct or tunnel can be free flowing, flowing under the pressure of a part of its length, or flowing under pressure in its entire length. Incorporation can be organized to draw water from the bottom of the tank, or the entry of the side rails can be placed at any level within the tank top, Dispelling devices can be used in the rear end of the passage.

OUTPUT ELEMENTS IN WORKS OF TAKES

1. Tunnels:Due to its inherent advantages, an exit tunnel is preferable in works of abutment and the conditions that will allow its foundation and is cheaper than other types of output. A tunnel is not in direct contact with the dam embankment and, therefore, provides a much safer and more durable available that can be achieved with a cover of ducts.

2. CUT AND COVER THE LINES: If a closed passage that must be provided and the foundation conditions are not suitable for a tunnel, or if the size required for the navigation is too small to justify the minimum size tunnel, a cut-and-duct cover must be used. Due to this kind of conduit or passes through the dam, conservative and safe the designs must be used.

3. CONTROL DEVICES:The use of special devices that involve expensive design and manufacturing costs should be avoided. Cast Iron sliding doors, which can be used for the control and protection doors, are available for both the rectangular and circular openings. However, installations require greater disenosde special doors. The control gate of a output operates can be placed at the upper end of the passage, at an intermediate point in its entire length, or at the bottom end of the structure. Where the flow of a control gate is released directly into the open free download, only the part of the duct before the door is under pressure. In the event of a control or needle valve is placed at the bottom end of the structure, the full internal pressure should be considered in the design of the tunnel or tube. If the controls are located at some intermediate point in the high pressure line, doors, sliding doors, doors and radial can be used.

4. 4. INTAKE STRUCTURES: a structure of admission can accommodate control devices. Intake structures may appear in many forms. The type of structure of admission should be based on several


factors: the functions that should serve, the range of tank that should work, the performance should handle, the frequency of use of the tank, depending on the need for the frequency of cleaning of the protective grilles, the tank action of the waves that could affect the stability, and other similar considerations. The need for a protective grilles in output works depends on the size of the sluice or conduit, the type of control device used, the use of water, the need to trash except for the small of the output, and other factors. These factors determine the type of protective grille, and the size of the openings.

5. 5. ELEMENTS OF DISSIPATION OF ENERGY:

6. The discharge of an electrical outlet, either a gate valve, conduit or free flow, will be released at high speed, usually in a nearly horizontal direction. If the erosion resistant rock exists at a shallow depth, the flow can be discharged directly into the river. Otherwise, should be directed to the tip of the dam of a deflector. Where erosion is reduced to the minimum necessary , the fall can be excavated basin and lined with riprap or concrete is when you need it most energy sinks. The hydraulic jump basin is most often used for power dissipation of the discharges from the works of output. However, the flow can be seen from the output in the form of a free jet, as is the case of the pressure control valve of ducts, should be oriented to the transition to the basin floor so are distributed evenly before entering the basin. Otherwise, the power dissipation will not get.

7. INPUT AND OUTPUT OF THE CHANNEL: a channel input and an output channel are often needed for a tunnel or cut lines and cover design. An input channel may be

needed to express deviation flows to a conduit or in a recess for the water supply to the output of admission deposited works under. And an output channel may be required to transmit the discharges from the end of the exit to the downstream or to a channel.

INTAKE FOR IRRIGATION

OF THE TYPE OF RIO additions: They are the ones that extract water from the river entries continues without any appreciable storage before the diversion . A typical diagram of admission to comply with special characteristics, such as steep slopes, high peaks and short duration flood flows and high sediment loads, shown in Figure

THE TYPE OF TANK INLET: Where the outflows is provided for the irrigation of storage built for this purpose. Depending on the head, this is a category of low: Low Level (up to 15 m), Medium Level (15 to 30 m), yNivel high (above 30 m).

Admission to concrete or masonry dams: In the case of concrete dams, intake structure may be located at the tip when operating head is low or in the body of the dam.

Intake of earth dams: When the reservoir is formed by an embankment dam, irrigation is tunnel beneath it or in the foundation. The intake structure for this type of situations will be a leaning tower of admission or type of consumption.. measures as the provision of steel coatings and adequate drainage after the core, the provisions of the joints for differential settlements when not founded


on the rock should be considered in the case of conduits are always under the earth dams.

Tickets directly from the tank by buttresses: In this case, the prey is separated from the structure of admission. The dam can be of any material (concrete, dirt, etc. ), but the consumption is built by the classification the left or the right buttresses and outlet tubes through the surrounding hills.

MAKING STRUCTURES WATER WATER SURFACE AND SUB SURFACE

Content:

1. Introduction 2. Types 3. Control of Water Quality1. Introduction

A reservoir is constructed to store water as required. The stored water is removed from the tank in order to use the power of water or water itself. In this chapter, the withdrawal of water from a reservoir is described and the relationship between removal, reservoir environment, and the role of the intake structure is described.

To improve the efficiency of annual use, even in reservoirs of hydropower generation. The water can be supplied to the river downstream, using the stored water in the tank, in order to provide ecological benefits during dry periods.

There is a difference between the deposit and withdrawal of a direct removal of a river or ground water. The water stream storage affects the quality of water

reservoir and the flow rate and the quality of the river water channel below.

2. Types

In temperate and subtropical regions, river water low temperature flowing in autumn and winter is stored in the lower layer of the shell. The solar radiation at the surface of the deposit intensified in early spring, and the water surface heated. The temperature of the water stored in the upper layer of the tank is further increased by the inflow, because its temperature also rises at this time. The thermal stratification, stabilization of the upper and lower layers, therefore, occurs in summer. The quality of water, dissolved oxygen and nutrients, and distribution of suspended matter, depends on this stratification.

1) The intake surface

An intake surface is used to take water from the surface of the tank when it is comparatively light. Obviously, the withdrawal must follow fluctuations in the tank level. It is necessary to prevent contamination of the lower layers to make efficiently the water surface. hydraulic test is performed to determine the distribution of the approach speed and depth of the water removed.

2) subsurface Consumption (Intake submerged)

Whatever the level of water in the tank, an intake subsoil takes water from a low level in the tank. The intake will have a simple, because this system can set the level of intake. The water temperature of the water is usually low, and contains little phytoplankton.


3) The intake of multiple levels (Selective Removal)

Selective removal is carried out in an optional position to take the desired water quality. The shape of the density stratification is positively controlled by this system in order to effectively use the stratification in the tank. The shape of the installation is similar to the intake surface, but there is some difference in the top of the installation. Sometimes, the intake is in the middle layer, when the upper and lower layers are prone to contamination

3. Control Water Quality

Water quality problems in relation to water temperature, muddy water, eutrophication, etc. are particularly likely to occur in reservoirs including natural lakes. Control of water quality is an important consideration in the withdrawal of deposits and the various facilities described in this section are used to provide this control.

Problems of water quality include those caused by the quality of water discharged into the river downstream. This effect can be mitigated by choosing the most appropriate level of consumption. Changes in water quality attributable to storage tap water can impair or limit the use of water. This can be reduced by controlling the change in the quality of water in the tank.

Such water quality problems are the result of processes operating in the environment of container, such as water stratification. Efforts are therefore, made to keep the water quality by reducing stratification. The methods available to

control stratification include reducing thermocline selective uptake, and destruction of the thermocline by circulating water.

1) The work Outlet 2) Installation selective Retirement 3) Water Curtain Quality Control 4) Circulation

The technique circulation all layers destroys the thermocline, and the whole mixture reservoir. When this happens, the lower layer is supplied with oxygen, and the bottom layer of cold water with surface water is mixed. This avoids the problem of cold water, and also disperses phytoplankton. Control flow phenomena using current density is also an effective way to solve various problems of water quality in reservoirs. In this case, the thermocline is maintained, and the method movement of the entire layer and not suitable.

DESIGN OF HYDRAULIC STRUCTURES INTRODUCTION

Any hydraulic structure that supplies water to the intake channel is called a main word.

Frame can be: 1. Headwork storage. 2. Headwork Diversion.

A headwork storage involves building a dam on the river. It stores water during the period of oversupply and released when the demand exceeds the available supply.A headwork deviation serves to deflect the supply necessary for the river channel.


a. A diversion works head is a built across a river in order to raise the water level in the river so it can be diverted to the channel structure.

b. diversion headworks are generally constructed in perennial rivers that have adequate flow throughout the year and, therefore, no need for a storage tank.

c. A head diversion works differs from a work storage or dam. A dam built on the river to create a storage tank. The works of storage for storing water in a non-perennial river or is require river with inadequate flow throughout the year.

d. On the other hand, in the works of a head of diversion, there is very little storage, if any.

e. If storage in the upstream of a diversion works head is significant, it is called a storage dam.

f. A diversion headworks builds on the downstream of a dam to divert water released from the u / s dam channels is called a garbage collection.

g. In general, the dam is built on the rock or mountain range of the river, where the conditions are right for a dam and a catchment dam is built near the commanded in the stretch of river alluvial area.

Features a fun Headworks

The water level rises in the upstream side.

Water supply is regulated channels.

Sediment inputs is controlled channels

A small pond (no reservoir) in its upward and provides some is created.

Helps control the vagaries of the river.

List of components

Alluvium Undersluicespared Divide ladder Regulator head Channel Excluder Work training (marginal and guide banks dikes)


GATES

A gate is a mechanism of control and emergency, which are designed for maximum load; consists of a movable, flat or curved plate, which permits adjusting the height up hole is discovered that, while controlling the discharge produced.

The gates are used to control spending, with peculiarities in its operation and parts thereof; by design are classified into different types, following are some of them:

Sliding gates

Rolling Gates

Radial Gates

DROPS

Friction Head Loss (h f)

The friction losses are due to fluid friction with the walls of the duct.

h f=

f∗LD

∗V 2

2gformula dedarcy

h f=n2∗L∗V 2

R43

formuladeManning

Loss in the changes of direction (h b)

Occur when there is a change in the circulation flow between the inlet and the outlet section and control mechanisms due to changing flow speeds, producing separation zones on the inner side of the curve and increases pressure on the outside, with spiral movement extending over distances up to 50 times the diameter or height of the duct.

Kb=C c∗θ

0

900

Pressure Drop for Enlargement (h ex)

In calculating losses expansion equation (8.5), where the coefficient Ka depends on the abruptness of enlargement and to obtain its value equation (8.6) and the values of Table 8.1 is used is used. The minimum load loss has to spread angle θ = 8; for θ = 50 the abrupt enlargement is as reliable as gradual.

hex=Ka(V 12−V 2

2

2g )(8.5)

θ=arc tan √gD2V

(8.6)


Pressure Drop by Reduction (h c)

In reducing load losses reduction of such a phenomenon occurs when the expansion and seeks also be gradual; losses are smaller than the expansion coefficient Kr and the angle θ depends on the contraction.

hc=K r(V 22−V 1

2

2g )Pressure Drop in Output (h v2)

The losses in the output is a function of the velocity and shape of departure; losses are calculated using equation (8.8). When the output is open, the output coefficient Ks is equal to one and if you want to recover part of the velocity divergent forms should be used. If the output is drowned, take into account equation (8.9)

hv2=K s( V 2

2g )(8.8)

hv2=K s( (V−V c)2

2 g )(8.9)

Pressure Drop for Grids (h t)

Is important to consider, in the case of the grids comprised of slabs, in which the separation between these is small, this structure losses generated.

ht=β∗( SB )43∗sen

γ∗vo2

2g

Type RejaRectangular section 2.42With rounded edges 1.83

With the extreme end thinned 1.63

Circular cross-section 1.79

Loss of load per entry (h e)

k e=( 12C2 −1)

LOCATION OF DECISION REGARDING THE LEVELS OF RESERVOIR

1) They must be sufficiently below the minimum operating level that is sufficient burden for the minimum flow operation, either may or may not coincide with the corresponding capacity dead volume level.

2) Given that it is common to reserve a dead storage, decision should be above this level enough to ensure a certain quality of water is removed.

They should note that tickets should be placed at points in the vessel where algae can accumulate or where prevailing


winds trash and floating objects in general

headwork

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