Design of coastal river water intake with machine water

Contents

1. Select water intake location

2. Process diagram of water intake

Supply channel

Forebay

Water intake arrangement

Retention and fish protection devices

3. Pump Station Design

Design of pump station

Pump station equipment

Hydromechanical equipment

In-station communications

Suction and pressure piping,

Piping valves

Auxiliary equipment

4. Operation of water intake

List of literature

Introduction

Water intake is a structure through which water flows from a water source to a pumping station. This structure shall ensure reliable water intake from the source in accordance with the water supply schedule of the pump station. The structure and equipment of the structure should provide not only its reliable and convenient operation, but also the possibility of inspections and repairs. The influence of the structure on the hydraulic mode of the water source should be minimal.

Water intake facilities shall ensure uninterrupted supply of water of the best quality possible to the consumer. The solution to this problem is achieved by the correct choice of their location (plan and depth), type and design.

The location of the structure in the plan should be chosen as close as possible to the consumer, on a stable section of the reservoir, in the area of ​ ​ the least pollution of the reservoir (on rivers above settlements, industrial enterprises and wastewater collection sites), outside the areas of ice congestion and intensive bottom sediment traffic.

The operating conditions of water intake structures on reservoirs, lakes and seas differ sharply from the operating conditions of structures on rivers. Significant complications are created here by unrest and current arising on large waters. Currents carry sediments, ice, plankton, algae and can cause erosion and displacement of the coast. Therefore, the places beyond the water should be carried outside the zones of water flow. The excitement causes the need to deepen the place of water intake .

If there are depths near the shore that ensure the required water intake conditions, and with a fairly steep shore, coastal-type water intakes are used. They are located on the slope of the bank with the reception of water directly from the river bed. The lifting pumps I may be located in a separate pump station building or in the water intake itself. Therefore, two types of coastal-type water intakes are distinguished - separate and combined.

Separate water intake of coastal type is a supply channel, an advance chamber, a pumping station. Inlet part is provided with grids to prevent ingress of coarse debris and foreign objects into water intake.

The arrangement of the pumping station in a separate building may be due to the nature of the topography of the shore and the degree of its flooding by flood waters.

The sizes of a water intake, its basic elements and the equipment (the bringing channel, the forebay, grids, lattices, pipes, etc.) determine partially by hydraulic calculation and partially by reasons of constructive and operational character.

We design a river water intake of the coastal type with a machine water lift.

Select water intake location

We choose the location of the structure in the plan as close as possible to the consumer (in this case, a settlement), on a stable section of the river in the area of ​ ​ the least pollution, above the settlement, industrial enterprises and wastewater collection sites, outside the areas of ice congestion and intensive bottom sediment traffic.

We accept water intake structure of category 1, separate type providing uninterrupted selection of design water flow rate. They include all types of inshore non-flooded structures, the water intake windows of which are always available for maintenance and cleaning of their holding grids.

The high-altitude location is as follows:

- elevation UMV = 156.00 m;

- HVAC elevation = 156.50 m;

- elevation of inlet part of supply channel (bottom) = 154.00 m;

- elevation of the bottom of the advance chamber = 153.20 m;

- ground elevation (at the pumping station on the water intake side) = 158.00 m.

Retention and fish protection devices

With a large amount of sorrow in the water source (it is observed on the river during the flood period), the grates can be arranged vertically or obliquely, at an angle of 70... 80 ° to the horizon. When grids are installed, the dimensions of the water intake increase. This is usually the case when the water level fluctuations in the source for the small and medium feed pump stations are small. When installing the holding grids vertically, the slots are sometimes combined with the slots of the repair gates, which reduces the size and cost of the structure. To reduce the height of repair gates and grids, intake walls are arranged.

The area of the holding grid is determined by the permissible water flow rates when approaching it. With manual cleaning v < 1.8 m/s, mechanical in a slightly disassembled watercourse v < 2.5 m/s, in a highly disassembled < 1 m/s (average 1.0... 1.8 m/s).

In our case, during operation of the pump station, the approach speed to the advance chamber v = 1 m/s will be observed (see item 2.1.), Therefore, manual cleaning of the holding grids is enough.

Fish protection devices for preventing fish from entering the water intake openings in this case can be used in two types:

- floating dump in combination with air-bubble curtain, which fence the water intake structure from the watercourse and prevent fish from entering the structure;

- mesh conical single-band fish barrier shall be installed in each water receiving chamber with flushing device and fish drain.

We accept the first option as simpler, since in this case we need:

- make a floating spare - pontoons with panels vertically fixed on them, immersed in water for 1 m;

- install two compressors and lay along the bottom of the river along the water intake structure two air ducts from steel galvanized pipes with holes drilled in them for air discharge.

The total length of the air-bubble curtain is at least 50 m; The length of the spare is 40 m. Zapan is installed so that air bubbles reach the water surface immediately before the vertical spare shield, taking into account the translational flow rates to the water intake holes of the pumping station and the average bubble lifting rates equal to 0.4... 0.6 m/s. Zapan is located at a distance of at least 3 m from the water intake. It is recommended to accept: the diameter of the hole in the air outlet duct d = 0.3... 0.8 mm; initial air bubble exit rate v = 2... 4 m/s; number of rows of holes from 3 to 6.

Pump Station Design

Pump stations are rather difficult complex of the mechanical equipment and power stations (electric motors, power transformers, switchgears), pipelines, fittings, instrumentations and the automation equipment.

Design of pump station

In this project, consider a pump station, which is located in the general water supply scheme, refers to lifting pump stations I (designed to supply water from a water supply source to treatment facilities). If water purification is not required, the lifting pump stations I serve to supply water to the tanks or water tower.

In some water supply systems (most often small), the lifting pump station I may be the only one in this system, then it is called a pumping station.

This pump station is a pump station of a semi-deep (chamber) type with the installation of horizontal centrifugal pumps with a double-sided inlet (type D) in it.

The ground part of the pump station building is full-assembly, of typical railway plates and blocks.

Dimensions of pump station building:

- 20 m long;

- width 6 m;

- height of the above-ground part is 4.8 m;

- auxiliary room length 3.50 m.

Elevations:

- pit bottom 156.14 m;

- chamber bottom 154.70 m;

- pump station floor 156.30 m;

- elevation of foundation slab 154.70 m;

- pump axis elevation 157.36 m;

- roof (pediment) 162.80 m.

Auxiliary equipment

It includes:

1). Vacuum system.

2). Technical water supply system.

3). Oil supply system.

4). Compressed air supply system.

5). Mechanical equipment.

6). Equipment for economic and technical needs of the station.

The engine room shall have the following auxiliary equipment:

- vacuum pumps for filling the main pumps;

- drain pumps for removal of ground water leaking through walls from buried pumping stations;

- lifting and transportation mechanisms for installation and dismantling of equipment.

Vacuum system

Water filling of pumps installed above the source level can be performed by means of vacuum pumps, ejectors, by method of automatic suction, by means of suction pipes with raised elbow or tank-accumulators. Pumps are filled with rotary vacuum pumps at pump stations of any capacity. In case of frequent starts (several times a day), it is recommended to use vacuum boilers in vacuum systems, which provide a constant bay of pumps with water and their readiness for launch. It is advisable to fill the pumps with water-air ejectors at a relatively low suction height (2... 2.5 m). Water from pressure pipelines or from a special high-pressure pump can be used to supply ejectors.

At pump stations, where there is a constant operation of one unit, the so-called auto suction method can be used. In this case, the suction pipe of the operating pump is connected to the suction pipe of the non-operating pump, creating the necessary vacuum in it.

Technical water supply system

The need for technically clean water for cooling and lubrication of the pump station process equipment is accepted according to the equipment manufacturers.

Service water supply systems usually consist of water intake devices, filters and sumps, pumps, pipelines, shut-off valves and instrumentation.

Oil supply system

At pumping stations, as a rule, several brands of oils are used, including turbine and transformer. Oil line, oil pump and tank systems shall be separate for each oil grade.

The volume of oil-filled equipment and equipment is accepted according to the data of the manufacturers of the equipment, taking into account the presence of oil losses, which in centrifugal pumps reach 4... 10% of total system capacity per year. The service life of oil in the control system 12... 15 thousand hours, in the lubrication system of sliding bearings 500... 1000 hours, in rolling bearings 9 thousand hours.

Pump stations with oil systems shall have two operating tanks (or one two-section) for clean and used oil, oil pumps, oil pipelines, oil cleaning equipment, spare tanks for clean and used oil storage. The volume of operating tanks for clean and used oil shall be not less than 110% of the largest volume of oil in the oil-filled unit plus 15 day oil flow rate for addition (loss) of all operating units, if there are oil storage tanks at the station, or make a three-month flow rate if oil storage tanks are not provided at the station.

Compressed air supply system.

Main compressed air consumers: control system (pressure 4 MPa, air is consumed in accordance with the data of the plants - equipment suppliers); pneumatic instrument (pressure 0.3... 0.8 MPa, flow rate of air consumed by various instruments varies from 0.7 to 2.6 m3/min); blowing equipment from dust (pressure 0.3... 0.8 MPa, air flow 1... 3m3/min); air blowing of capsule pumps engines. The compressed air supply system should normally operate automatically. Duct systems are manually switched

Mechanical equipment

Mechanical equipment of pumping stations includes movable structures of gates and holding grids, their embedded parts, grating machines, lifting vehicles, gripping beams, rods, bogies for transporting garbage, etc.

Equipment for economic and technical needs of the station

Domestic drinking system and sewerage system. It is provided in buildings where more than 5 people can be located at the same time. The source of drinking water can be: the nearest water supply, groundwater and, with special justification and coordination with the authorities of the sanitary and epidemiological service, water from canals or from a special body. The use of imported water is allowed.

Recommended water consumption rates at pumping stations are 25 liters per shift per 1 person. Water is supplied to the system of domestic drinking water supply by pneumatic pump units, and in the presence of water towers - by conventional centrifugal pumps.

Internal and external sewage networks are made of plastic, cast iron or asbestos cement pipes. Both open and closed gasket is possible. Inspection wells are made on horizontal sections at a distance of 8... 20 m from each other, on vertical risers - at least after 15 m.

Wastewater at medium pumping stations is discharged into an open channel at 20... 30 m below the water intake for household and drinking water supply conditionally clean water (from the shower and washbasin), and to a special reservoir from where fecal water is exported by machines 1... 2 times a year. The sewerage project is coordinated with the district sanitary and epidemiological station.

Ventilation. It shall ensure conditions for normal operation of maintenance personnel and equipment safety. The simplest natural ventilation system is ventilation of rooms through open windows, but this type of ventilation can be used only for office rooms, warehouses and buildings of pump stations of low capacity.

For pump station premises, where the ratio of air volume, m3, to power losses of electric motors, kW, is less than 12, a forced ventilation system is provided, separate for electric motors and rooms. With a special justification, instead of a separate ventilation system, there is a combined supply and supply system, if 1 kW of lost power accounts for Z... 12m3 of the room volume.

It should be borne in mind that heat in pump station buildings is released from two sources: electrical equipment and solar radiation through enclosing structures. The ventilation system in general consists of air coolers, axial or centrifugal fans, filters, air ducts, shutoff valves, instrumentation.

The air velocity at the outlet of the pipes to the machine rooms shall not exceed 12 m/s.

Heating. As a rule, electric furnaces and electric heaters are used for heating buildings of pumping stations, and in large stations - double heating.

Fire protection systems. The volume of fire protection equipment for internal fire fighting depends on the size of the structures and their purpose.

According to SNiP 2.04.02 - 84 and SNiP 2.04.01 - 85 primary fire protection equipment (fire extinguishers, sandboxes, etc.) equip buildings of pump stations of I and II degree of fire resistance regardless of their volume, III and IV degree of fire resistance at a volume of up to 5000 m3 and buildings for which fire fighting is provided from special tanks or channels, as well as cable structures with a volume of up to 100 m3, in which there are no oil-filled cables.

External fire extinguishing may not be provided for buildings of I and II degree of fire resistance up to 1000 m3.

Design water flow rates for external fire extinguishing shall be taken to be at least 10 l/s at building volume up to 5 thousand m3 and 15 l/s at volume 5... 20 thousand m3. For fire extinguishing inside the building, an additional flow rate of 5 l/s (two jets of 2.5 l/s) is taken into account.

Drainage and drainage systems. During the operation of pump stations, in practice, it was established that for buried buildings of pump stations equipped with pumps with a supply of up to 3 m3/s, combined drainage systems are adopted.

Drainage and drainage systems, as a rule, consist of receiving wells, discharge and pressure pipelines, pumps, shut-off pipeline valves and instrumentation. Drainage system receiving pits are placed on the lowest from-marks of the building in order to provide gravity drainage of water from all rooms.

The drainage system is usually serviced by at least two pumps (one standby), the drainage system by at least two pumps (no standby), and the combined drainage system by at least three pumps (one standby).

Switching on and off of drain system pumps shall be automatic depending on the water level in the drain pit.

Drain and drain system pipelines shall be steel.

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