Calculation and design of a water intake structure from a surface source

Course work on the subject "Water intake structures from surface sources" on the topic Calculation and design of a water intake structure from a surface source.

INTRODUCTION 

Water intake is the first link in a complex water supply system that provides power to all water consumers. Occupying a leading position in the system, the water intake has a decisive role in its functioning. A modern water intake for water supply of a large city is a complex complex of engineering structures equipped with energy and mechanical equipment, an automatic and telemechanical control system. Such a water intake should work smoothly under any conditions of water intake, which vary significantly depending on the seasons of the year.

Surface sources of water supply for domestic and drinking water use and industrial purposes are rivers, reservoirs, lakes and seas. The type of source determines the type of water intake structure, and the purpose of water use is its purpose. When choosing a source of water supply, the requirements for the composition and properties of water from surface sources used for drinking water supply, the compliance of water quality with consumer requirements, the conditions for water intake, as well as technical and economic indicators that determine the effectiveness of the decision are taken into account.

The quality of water in the river is assessed at a distance of at least 1 km upstream from the intended water intake unit, and at a distance of 1 km in both directions from the water intake on non-flowing reservoirs and reservoirs. The type of water intake is greatly influenced by the natural conditions of the water supply source: the amount of suspended solids, the engineering and geological characteristics of the shore and bottom of the reservoir, the presence of circulating water currents, the shape of the channel in cross-section and the steepness of the coast, the presence of sludge and ice in the stream, as well as the presence of timber rafting and navigation.

When choosing the location and type of water intake facilities, the possibility of changing the flow regime and water levels in the river in connection with the construction of dams and other measures in accordance with the scheme of integrated use of the river is taken into account. The location, type and scheme of the water intake structure in a navigable or timber rafting river shall be agreed with the organization responsible for the operation of transport. Placement of water intakes at the foot of hills and steep slopes in seismic areas is prohibited. In reservoirs and lakes, water intakes are located in places sheltered from waves, and outside the zone of turbidity of water during waves. It is recommended to take water from rivers at depths not less than three times the height of the wave. The depth is measured from the calculated minimum water horizon at the source. 

On the seas and in large lakes, water intakes are placed in bays fenced with water areas, or outside the surf zone. In the northern regions, water intakes are located on river sections with constant surface or underflow runoff and with a stable zone of melted soils. Under very severe natural conditions, water intakes are placed in two separate sections of the source at such a distance from each other, at which a simultaneous interruption of water supply is excluded.

When designing river water intakes, hydraulic calculations determine the area of the entrance windows in the head or on the front wall of the coastal well, the area of the access windows of the coastal (water intake-mesh) well, covered with flat grids (or the working area of tape rotating grids); diameters of gravity lines and pipelines for supplying wash water to these lines; the required height of the shore (water intake-mesh) well.