Water supply and sewerage of a 12-storey residential building Coursework

Contents

CONTENTS

Introduction

1. Installation of internal water supply and sewerage systems

1.1 Description of the internal cold water supply system

1.2. Description of internal hot water supply system

1.3. Description of the sewage system

2. Determination of estimated water flow rates

2.1. Determination of total water flow rates

2.1.1. Determination of maximum water flow rate per second

2.1.2. Determination of maximum hourly water flow rate

2.1.3. Determination of maximum daily water flow rate

2.2. Determination of water consumption for cold water supply

2.2.1. Determination of maximum water flow rate per second

2.2.2. Determination of maximum hourly water flow rate

2.2.3. Determination of maximum daily water flow rate

2.3. Determination of water consumption for hot water supply

2.3.1. Determination of maximum water flow rate per second

2.3.2. Determination of maximum hourly water flow rate

2.3.3. Determination of maximum daily water flow rate

3. Design of internal cold water supply system of the building

3.1. Approximate determination of required head value

3.2. Hydraulic calculation of internal water supply network

3.3. Determination of the required head in the external water supply network

3.3.1. Determination of geometric height of water supply

3.3.2. Water meter selection

4. Design of the building internal hot water supply system

4.1. Hydraulic calculation of internal water supply network

4.1.1. Feed Piping Calculation

4.1.2. Required head in hot water supply system

4.1.3.Addition of capacitive water heater

4.1.4. Circulation Piping Calculation

Conclusion

List of literature

Introduction

The purpose of the course work on the sanitary equipment of the building is to summarize and consolidate the knowledge of the theoretical course, as well as acquire skills for independently solving problems related to the design of internal water supply and sewerage of this building (residential building).

The task of the course work is as follows: according to this plan, a 2-entrance twelve-storey residential building should be calculated and, based on the results of the calculations, internal cold and hot water supply systems, as well as internal sewage systems should be designed.

Course work consists of a graphic part and a calculation and explanatory note.

The graphic part includes:

1) typical floor plan of the building (M 1:100);

2) basement plan (M 1:100);

3) axonometric diagram of internal water supply (M 1:100);

4) axonometric diagram of internal sewerage system (M 1:100);

5) equipment of one sanitary-technical unit (M 1:20);

6) site plot plan with communications (M 1:200);

7) the profile of the yard sewer network (M 1:200).

Installation of internal water supply and sewerage systems

A water supply system of a building or an individual object is a set of devices that provide for the receipt of water from the external water supply and its supply under pressure to water discharge devices located inside the building or object. The cold water supply system, commonly referred to as internal water supply, consists of the following devices:

• Input (one or more)

• water metering unit (one or more);

• mains of mains, distribution pipelines and connections to water discharge devices, valves.

In some cases, the system includes installations for increasing the head, as well as installations for additional treatment of water (softening, discoloration, deiron, etc.).

Water supply systems (water pipelines) are classified by a number of characteristics.

1) According to the type of serviced facility, water supply systems are divided into urban, village, industrial, agricultural, railway, etc.

2) By purpose, water supply systems are divided into domestic, industrial, fire protection systems. Drinking water supply systems are designed to supply water to the economic and drinking needs of the population and employees of enterprises. The installation of drinking water supply is mandatory in all residential and public buildings built in sewage areas, as well as in buildings with a local sewage system. Production water supply systems supplying water to process shops can consist of several water pipelines providing water supply of different quality that meets technological requirements. Fire-fighting water supply systems are designed to extinguish fire or prevent its spread.

3) According to the water supply method, gravity water pipes (gravity) and water pipes with mechanical water supply (using pumps) are distinguished.

4) According to the type of natural sources used, there are water pipelines that take water from surface sources - rivers, reservoirs, lakes, seas, and water pipelines that take water from underground sources (artesian, spring). There are also mixed-feed water pipelines.

5) According to the method of using water, systems come with direct-flow water supply, with recycled water supply and with repeated water supply.

Water supply systems can serve both one facility (city, industrial enterprise) and several facilities. In the latter case, these systems are called group systems. A water supply system serving several large facilities located at a considerable distance from each other is called a district water supply system or district water supply. Small water supply systems serving a single building or a small group of compactly located buildings from a nearby source are usually called local water supply systems.

In cases where certain parts of the territory have a significant difference in elevations, zone water supply systems are arranged. With such terrain in the network for highly located sections, pumps shall maintain a high pressure which is unacceptable in the network for low located sections. In this regard, the water supply network is divided into zones, for each of which the required head is installed.

When designing the water supply system of any facility, first of all, it must be determined how much water and what quality is required to be supplied to this facility. To solve this problem, it is necessary to more fully take into account all categories of possible consumers and establish their requirements for the amount and quality of water supplied.

Water is consumed by various consumers for a wide variety of needs. However, most uses of water in the national economy can be reduced to the following main categories:

1. the economic and drinking needs of people (residents of settlements and workers during their stay in production);

2. production needs related to the use of water in the processes of various industries and other technological needs;

3. water costs associated with ensuring the improvement of settlements and industrial enterprises: watering and washing streets and squares, watering green spaces, lawns, etc.;

4. water consumption for fire extinguishing.

The requirements for the quantity and quality of water used by certain categories of consumers are very different. High sanitary requirements are imposed on water used for household and drinking purposes. The required quality of water used for the needs of various industries is determined by the nature of the technological processes and is very diverse. Finally, the quality of water used for irrigation of driveways and green spaces, as well as for fire extinguishing needs, is practically not required.

1.1. Description of the internal cold water supply system

An internal water supply system is a system of pipelines and devices that provides water supply to sanitary devices, fire cranes and technological equipment, serving one building or group of buildings and structures and having a common water measuring device from the water supply network of a settlement or industrial enterprise.

The system of internal domestic and drinking water supply includes: inlet, water metering unit, network of main pipelines, risers, supply to water disassembly devices, water disassembly, mixing, shutoff and control valves.

Commissioning - pipeline from the external water supply network to the internal water supply network (to the water metering unit or shutoff valves located inside the building). Usually one input is made in buildings. The exception is the following cases: residential buildings with a height of more than 12 floors or with a number of apartments more than 400; availability of internal fire-fighting water supply with more than 12 fire cranes.

It is advisable to enter the building where the largest number of water discharge points are located. At the point of connection of the inlet to the external water supply network, a well with a diameter of at least 700 mm is arranged, in which shutoff valves are placed to turn off the inlet.

For the injection device, cast-iron bell pipes with a diameter of 50, 100 mm or more, electric welded steel with anti-corrosion bitumen insulation (with a diameter of at least 50 mm) and, in some cases, plastic polyethylene and other pipes allowed for use by the State Committee for Sanitary Supervision of Russia are used.

The depth of the bushing pipes depends on the depth of the external water supply network, that is, the bushings are placed below the freezing depth 0.5 m to the bottom of the pipe. The minimum depth of entry laying (in the absence of ground freezing) is 1 m. For emptying, the entry is laid with a slope of 0.005 m/m towards the external water supply network.

The bushing can be connected to the external water pipe network by a saddle, tie-in or welding of its pipe or tee, or by connecting parts installed on the external water pipe pipeline during its laying.

The water metering unit consists of a device for measuring the amount of consumed water, shutoff valves, a control valve, a pressure gauge, connecting shaped parts and branch pipes made of water-supply steel pipes.

There are simple water metering units (without a bypass line) and with a bypass line. The bypass line at the cold water meter is mandatory if there is one input to the building, as well as in cases where the meter does not provide for the calculated water flow rate for internal fire extinguishing. The bypass line is calculated for the maximum (taking into account fire-fighting) water flow rate. On the bypass line, it is necessary to provide for the installation of the gate valve, sealed at normal time in the closed position.

A water metering unit with a bypass line is used in the presence of one input, as well as if the device for measuring the amount of water consumed is not designed to pass the fire flow. In the latter case, an electric valve is arranged on the bypass line, which is opened automatically when the fire pump is started.

The water metering unit is located in a warm and dry non-residential room, in a place easily accessible for inspection near the outer wall at the entrance to the building. In order to avoid excessive head losses, water metering units are assembled from as few taps and shaped parts as possible, installing measuring devices in the forward section, and not on the bypass.

Shut-off valves can include: plug through valves, gate valves, shut-off valves, automatically closing valves designed to cover individual sections of the network, etc.

Shut-off valves are installed before and after the measuring device in order to be able to replace it or check the correctness of its readings, as well as to disconnect the internal water supply network from input and emptying.

Shut-off valves are installed in the following places: at the base of risers of the Domestic drinking network in buildings with more than two floors, on all branches from main pipelines, on the ring main network, at the base of fire risers, on which five or more fire cranes; on branches to each apartment; on connections to flushing sewers; on connections to heating devices; in front of special-purpose devices and devices; on branches supplying more than three water-collecting devices.

The control and drain valve is used to lower water from the internal water supply network, monitor the pressure ﴾ the located head of the ﴿, check the correct readings of the measuring device and detect water leakage in the system.

To measure the amount of water, high-speed impeller and turbine meters are installed at the inlets of the internal water supply. When selecting a water meter, its hydrometric characteristics, as well as permissible head losses and installation conditions are taken into account.

When the guarantee head in the external water supply is lower than the required for the building, booster pump units are used. Pumps are connected to mains after water metering unit. Pumping units are placed in dry and warm insulated room. It is not allowed to place household pumping units under residential apartments.

When choosing a water supply system depending on the purpose of the facility, technological, fire, sanitary and hygienic requirements, as well as technical and economic considerations should be taken into account. For example, residential and public buildings can be equipped with a combined domestic and drinking water supply with drinking-quality water supply. Combining all water pipelines of the same quality and under the same head into one system leads to a decrease in construction and operating costs.

For normal operation of the internal water pipeline at the entrance to the building, the required head must be created, which provides the standard water flow to the highest (dictating) water disassembly device and covers the head loss to overcome the resistances along the water path. The head in the external water line at the inlet connection point may be greater than, equal to, or less than the head required for the internal water line. The minimum head in the external water supply at the connection point of the inlet is called warranty (NG). In case of periodic or constant lack of head in the external water supply system up to the required for the building, pressure boosting units are used: pumps (constantly or periodically operating), water tanks, pneumatic devices.

Depending on the head supply, the following water supply systems are distinguished:

1. System operating under the pressure in the external water supply. It is used when the guarantee head in the external water supply at the point of connection of the inlet is constantly greater than or equal to the head required for the normal operation of all water discharge devices (Ntr≤Ng). Such a system is the simplest and most common.

2. System with water tank without booster pump unit. It is used when the warranty head in the external water supply during the hours of greatest water consumption is lower than the required for the building, and at other hours of the day - higher than the required. During the hours of insufficient head, consumers are provided with water from the water tank accumulating it during the hours of excess head.

Z. System with booster pump unit without water tank. It is used when the water consumption mode in the building is uniform, and the head in the external water supply is constantly or periodically lower than the one required for the building.

4. System with water tank and booster pump unit. It is used in case of insufficient warranty head in the external water supply and in case of uneven consumption of water in the building during the day.

The water tank receiving the excess water or making up for its disadvantage in the operation of the network is included in the system as a control vessel to increase the efficiency of the booster pump unit. In the presence of a tank, booster pumps are usually automated.

In some cases, instead of a water tank, a pneumatic installation is used, consisting of water and air tanks or one air tank equipped with special equipment (compressors, valves, pressure gauges, etc.). Such a water supply system is called a system with booster pumps and a pneumatic installation.

In multi-storey buildings, zone water supply systems are designed. The lower zone will operate under the pressure of the external water supply, and the upper - from booster pumps. The height of the zone is determined by the maximum permissible hydrostatic head at the lowest point in the network.

When choosing a building water supply system, consideration should be given to its technical and economic feasibility, technological requirements and ensuring the reliability and uninterrupted supply of water to consumers.

The networks of internal water pipelines consist of main and distribution pipelines, as well as connections to water disassembly devices.

Depending on the mode of water consumption and the purpose of the building, as well as on technological and fire protection requirements, the networks are dead end, ring, combined, zone, and on the location of main pipelines - with lower and upper wiring.

Ring networks are used in buildings if it is necessary to ensure reliable and uninterrupted supply of water to consumers. Ring networks are connected to the external water supply by several inputs, so that in case of disconnection of one of them, water supply to the building does not stop.

Dead end networks are used mainly in buildings where a break in water supply is allowed in case of failure of a part or the entire water supply network. These can be residential, administrative, and sometimes production buildings.

Combined networks, consisting of ring and dead end main pipelines, are used in large buildings with a large spread of water disassembly devices.

Zone networks are several networks in the same building, connected to each other or separate. Networks of individual zones can have independent inputs and installations to increase the head. In individual buildings (high-rise), a multi-zone network can be used. In the lower point of the network (at the reinforcement) of each zone, in order to ensure its strength, the hydrostatic head should not exceed 60 m.

The diagram of the internal water supply network is selected taking into account the placement of water collection devices in the plans of each floor, water supply and consumption modes, reliability of water supply to consumers, as well as technical and economic feasibility. Special attention in the design is paid to the rational placement of sanitary devices in the building. For example, sanitary units and water collection valves are grouped in floor by floor, placing them above each other, pipelines are laid along the shortest distance.

1.2. Description of internal hot water supply system

The hot water supply system is a system of devices and pipelines designed to heat water to the design temperature and supply consumers with the required flow and head, provided that reliable and uninterrupted operation.

According to the range of operation, hot water systems are divided into centralized and local.

Local systems are arranged for one or a group of small buildings where water is heated directly by consumers. Local hot water systems include:

• with gas water heaters;

• with wood hot water columns;

• with electric water heaters.

In centralized hot water supply systems, water is prepared for a number of consumers in one place and transported through pipes to consumption points. Water in them can be heated in a closed or open scheme:

• When the scheme is closed, hot water is prepared by heating cold water in water heaters or in hot water boilers of high thermal power;

• when the scheme is open, hot water is obtained by mixing water taken from the district heating network of the CHPP with cold tap water.

In this course work, a hot water supply system of a residential building is being developed, connected to a closed thermal network through a water heater.

In order to maintain the desired temperature of hot water, continuous circulation of hot water is usually provided.

Hot water supply systems can be with natural and forced circulation of hot water.

Hot water supply systems with natural circulation are designed with both lower and upper routing of main pipelines. Hot water supply systems with forced circulation are designed with lower routing of main pipelines, except when in buildings the centralized hot water supply system is divided into zones vertically.

Main pipelines of the hot water supply system are laid under the basement ceiling on brackets along the internal walls. Lines shall be insulated by thermal insulation. When designing pipelines of hot water supply systems, it is necessary to provide for the possibility of compensation of temperature extensions of pipes. To provide air discharge and water lowering, pipelines are laid with slope of at least 0.002 towards heat point. Air exhaust devices are installed at the upper points of hot water supply pipelines. It is allowed to exhaust air through water discharge valves located in the upper floors. Drain devices shall be provided at the lower points of the system pipelines. Hot water pipelines shall be laid in places accessible for repair and inspection. Hidden laying of pipelines to water collecting devices behind the lining, in walls and floors is possible. Hot water system risers are laid in bathrooms and toilets. To supply hot water in the apartment, a mixer at the bath and a mixer at the wash are installed. The bathrooms are equipped with permanently heated towels.

Shut-off valves in hot water supply systems shall be installed at the following points: on all branches from main pipelines; at the bases of falling and circulating risers, in buildings 3 floors or more high; on branches to each apartment; towel dryers.

To prevent hot water from entering the cold water supply network and cold water to the hot water supply network, it is mandatory to install check valves on the cold water line to the water heater, as well as on the circulation pipeline before connecting it to the water heater.

When selecting a hot water supply system, the same requirements as when selecting a cold water supply system are taken into account. The difference of the hot water supply system is that devices for hot water preparation, circulation pipelines for maintaining the required temperature of hot water, circulation pumps are additionally included.

The hot water supply network consists of horizontal supply lines and vertical distribution pipelines - risers, from which apartment wiring is arranged. Risers are laid as close as possible to water discharge devices.

The hot water supply network is with the lower and upper wiring of the supply lines, it is dead end and looped.

Simple (dead end) hot water supply networks are used in small low-rise buildings with short risers, as well as in domestic premises of industrial buildings and in buildings with long and more or less stable consumption of hot water.

Diagrams of hot water supply networks with circulation pipeline are used in all cases when uneven and short-term water extraction is possible.

1.3. Description of the sewage system

Depending on the nature of the pollution of the waste water discharged, household, industrial, combined and rain (internal drains ﴿ systems are distinguished.

• Domestic sewage system is designed to drain domestic wastewater from washes, baths, showers and other sanitary devices.

• The production sewage system is designed to drain the production waste water. Depending on the type and concentration of industrial wastewater contaminants, they can be discharged via one or more internal networks.

• The combined sewerage system is designed for the joint discharge of domestic and industrial wastewater into the intra-quarter sewerage network and further into the external sewerage system.

• Internal drains are designed to drain rain and meltwater from the roofs of buildings.

The internal sewerage system consists of the following elements: waste water receivers, a network of pipelines ﴾ drain lines, risers, headers, ﴿ outlets and local plants for pumping or pre-treatment of waste water. Internal sewage systems are equipped with ventilation devices ﴾ ventilation pipelines ﴿, for cleaning in case of clogging ﴾ revisions, cleaning ﴿ and for protection of premises from ingress of harmful and bad-smelling gases from the sewage network.

Waste water can also be discharged via open or closed channels and trays in accordance with sanitary requirements. Waste water is usually drained by gravity into the intraquartal sewage network. If the territory of a production or public facility has borders, then sewage flows first to the courtyard network, and then to the external sewage network of the settlement.

To ensure reliable and uninterrupted operation of the internal sewerage network, audits and cleaning are installed on it. On risers, revisions are installed at least three floors later, and in addition, as a rule, in the upper and lower floors and above indents. On horizontal sections of the inspection or cleaning network, they are installed on turns, as well as along the length of pipelines at a distance of 6 to 25 m from each other, depending on the diameters of the pipelines and the nature of sewage pollution.

The internal sewage network, consisting of branch pipelines from instruments ﴾ sewage receivers ﴿, from risers, headers (horizontal pipelines combining several risers ﴿, exhaust pipes, outlets and intra-quarter network, is laid in compliance with the following rules:

Drain pipelines are laid on walls above the floor, and sometimes under the ceiling of a lower non-residential or public room in the form of suspension lines or in an inter-floor floor, if the structure and thickness of it allow this to be done. In case of increased requirements for rooms finishing, suspended pipelines are masked by means of arrangement of set ceilings and boxes.

The sewer struts transporting sewage from by-pass lines in the lower part of the building place near receivers of sewage v toilets, kitchens ﴿. Drain receivers are connected to pipes with installation of hydraulic gates ﴾ siphons ﴿ between them. Receivers are placed on floors of building above each other in order to reduce total number of risers.

Along the entire height, the sewage risers shall have the same diameter, not less than the largest diameter of the discharge of the sewage receptacles connected to them. Risers are placed openly - near walls and partitions ﴾ closer to the corner ﴿ or hidden - in mounting shafts, blocks.

Discharges discharging waste water from risers outside the building into the intra-quarter sewage network are laid with provision of smooth connections to risers ﴾ two branches along 1350 or elongated branches ﴿. Pipelines laid in cold rooms are insulated.

On the branch lines from the sewage receivers located in the basements below the elevation of the hatch of the nearest inspection well, gate valves are necessarily installed to prevent the discharge of sewage liquid into the room during clogging of the intra-quarter sewage network.

The intra-quarter network of the organization is laid parallel to the external walls of the building, along the shortest path to the street collector, with the smallest depth of pipe laying according to the rules for the arrangement of external sewage networks. The depth of the intra-quarter network is determined by the elevation of the most buried ﴾ dictating ﴿ of release from the building. The dictator will be an outlet that receives drains from receivers installed in the basement. The diameter of the pipes of the intra-quarter network is usually taken at least 150-200 mm. Calculation of intra-quarter networks is carried out according to the norms and rules of internal sewage system design.

For ventilation of internal sewage networks, exhaust pipes are installed, which are a continuation of sewage risers. The exhaust pipes are brought out 0.5 m higher than the non-operated roof of the building and not less than 3 m higher than the flat operated roof. Ventilation of sewage networks is necessary to remove gases from them with harmful components.

The effluent, when falling down the riser, captures the air through the exhaust. If the amount of air entering the riser is less than the required amount, a vacuum occurs which causes the hydraulic gates at the wastewater receptacles to fail. This phenomenon is observed when the flow rate of effluents exceeds the permissible one. In the absence of effluent or small ﴾ 0.05-0.3 l/s ﴿ waste water flow, contaminated air and gases rise along the downcomer and through its exhaust part exit into the atmosphere.

Diameter of exhaust pipes is taken equal to diameter of sewage riser. Exhaust sections of sewage risers are made of asbestos cement or cast iron pipes, attaching them to risers below the riser floor. It is allowed to install one exhaust pipe on several sewage risers.

The ventilation riser is connected to the sewage riser at its lowest and highest points, as well as through the height of the building through the floor by means of bridges with a slope of at least 0.02 towards the sewage riser. The diameter of the ventilation riser is taken one standard size smaller than the diameter of the sewage riser, for example 40, 70, 100 mm or 50, 100, 150 mm. If the diameter of the ventilation riser is taken equal to the diameter of the sewage riser, then the risers are connected to each other on each floor by passages. Such a sewage system is called double-tube.

The transfer of wastewater from the internal sewerage network to the external sewerage network is necessary when the wastewater receivers are located below the pipe level of the external sewerage network.

Waste water is directed to tanks located, as a rule, outside the building or in exceptional cases inside the building. In a tank equipped with a plenum ventilation device and a level alarm, grids should be installed to deter large contaminants and a device for agitating the sediment, as well as a pit for accommodating the suction valve of the water lift. Tanks are made of concrete, reinforced concrete or brick with reliable waterproofing. Waste water is pumped from reservoirs by water lifters to external network.

Determination of estimated water flow rates

Source Data

1. In accordance with the standard floor plan, we determine the number of apartments in the building nkv = 72.

2. Depending on the degree of improvement of the building, we choose water collection devices in accordance with [1, Appendix 2]: a bath with a mixer (including one common to the bath and washbasin) with a length of 1,500 to 1,700 mm, equipped with a shower, a wash with a mixer, a toilet with a flush barrel.

2.1.Define total water flow rates

2.1.1.Define Maximum Second Water Flow

The maximum second flow rate of water is determined by the formula:

2.1.2.Determination of maximum hourly water flow rate

The maximum second flow rate of water is determined by the formula:

Design of internal cold water supply heating system of the building

3.1.Inter determination of required head value

The required head is the head, ensuring uninterrupted supply of water to all points of the internal water supply.

The estimated value of the required head at the point of connection of the input to the external water supply network is determined by the formula:

3.2.Hydraulic calculation of internal water supply network

The purpose of the hydraulic calculation is to determine the most economical diameters of pipelines for passing the estimated water flow rates, as well as the conditions that ensure the supply of water to all consumers in the required amount and with the least head losses.

The calculation is done in tabular form in the following sequence.

In the first column of the table, we enter the number of the calculated area 12, 2-3, etc., in accordance with the axonometric diagram.

In the second, the length of the calculated sections is recorded. Horizontal parcel lengths are defined by plan. Length of calculated sections on riser is determined based on height above floor of points of connection to riser. So, for example, the distance from the floor to the wash is taken equal to 1.2 m. The length of the section 1-2 is

Columns 3, 4 and 5 record the number of instruments in each area. Graph 6 is equal to the sum of graphs 3, 4 and 5.

The value of the rated water flow rate by the water disassembly device is taken equal to [1, Appendix 2] and we enter its value in column 7. In the first design area there is a wash with a mixer, therefore qo = 0.09 l/s.

The number of inhabitants is entered in column 8.

The value of probability of instrument action is determined by formula (10) and entered in column 9

We find the product N∙P and the value is entered into column 10, and then by interpolation we determine the coefficient α according to [1, appendix 4, table 2], column 11.

The maximum second water flow rate in the design area is determined by

The diameter of the pipeline of the design section (column 13) and the water flow rate (column 14) are assumed according to [2, appendix 4], based on the most economical water flow rates of 0.91.2 m/s.

d = 15 mm; υ=0.7 m/s

Column 15 records the head losses in the design area i • 1000 determined by [2, attachment 4] at the water flow rate in the design area and the selected pipeline diameter.

Column 16 shows the head loss over the entire length, i.e. the product of the length of the design section l and the head loss per unit length i • 1000:

3.3. Determination of the required head in the external pipe network

The required head in the external water supply network at the point of connection of the inlet is determined by the following formula:

3.3.1. Determination of geometric height of water supply

Define the absolute elevation of the input axis:

We determine the absolute mark of the dictating device:

We determine the geometric height of water supply by the formula:

3.3.2. Water meter selection

The meter for measuring the amount of water installed at the inlet of the internal water supply shall be selected so that the average hourly flow rate of water (nominal) allowed during the long-term operation of the meter is more than 4% of the maximum daily flow rate of water, that is, the ratio:

The gauge of the meter is determined as per [2, Annex 5] to pass the calculated maximum second water flow rate.

Head losses to pass the design water flow rate are determined by the formula:

hsch=S∙q2, m, (23)

where the S-hydraulic resistance of the counter, depending on its gauge, [2, annex 5], m/( l/s) 2;

q-Maximum second water flow rate at the entry into the building is assumed by calculation.

Select a counter with a nominal passage diameter of 40 mm.

The required head in the external water supply network at the point of connection of the inlet:

Compare the required head with the guarantee head in the external water supply.

Since NTP > NG = 45.0 m, we accept the scheme with an booster pump and a water tank.

Design of the building internal hot water supply system

4.1. Hydraulic calculations of the internal water supply network

The objectives of the hydraulic calculation are to determine the required flow rate of hot water, pipe diameters, the required head, the volume of water storage tanks - accumulators, the supply and head of booster and circulation pumps and the selection of water heaters.

4.1.1. Feed Piping Calculation

The diameters of the pipes in the hot water supply network are determined as in the cold water supply network (item 3.2.), taking into account the decrease in their diameter due to scale deposits and overgrowing of the pipes. The calculation is done in tabular form. Head losses in the design areas taking into account pipe overgrowing are determined by the formula:

where i - head losses at the design area, determined as per [2, annex 4], (in the area 1-3 i = 0.19831); l-length of design section, m, (length of section 1-3 l = 3.155 m); KM factor, which takes into account the ratio of head losses on local resistances and friction along the length of pipes, equal to: 0.1 for water-discharge risers without towels; 0.2to supply distribution pipes (in the area of 1-3 km = 0.1).

Total head losses in the feed pipeline of the design direction are defined as the sum of losses for each of the design sections. (htr = 7.615 m)

4.1.2. Required head in hot water supply system

The required head at the point of connection of the hot water supply system to the cold water supply pipeline is determined by the formula:

cold water to the system, to the axis of the highest device, is determined by formula (21), m, hg = 38.045 m;

ΑH-sum of head losses in pipelines of hot water supply system (htr = 11.54 m), including losses in water meter (by formula 23, hsch = 3.19 m), in pipes of water heater (determined by formula (26));

Hsv - free head before the device is determined according to [2, attachment 1], (Hsv = 2m).

4.1.3. Selection of capacitive water heater

Capacitive water heaters in hot water supply systems are designed to equalize the consumption of hot water with a limited capacity of a heat supply source and uniform consumption of hot water in a building or group of buildings. The required heating surface of the capacitive water heaters coils is determined by the formula:

The calculated difference between the average temperatures of the coolant and the heated water is determined by the formula:

4.1.4. Calculation of circulation devices

Hot water circulation is provided to prevent cooling of water at water collection points in hot water supply systems of residential buildings, hospitals and in buildings where it is necessary to maintain a uniform water collection temperature during the day.

The required circulating water flow rate in the pipelines of the hot water supply system risers is determined by formula (34):

received from 5 to 15 ° C depending on the length of the circulation ring.

Diameters of circulation pipelines are selected by one two sizes less than corresponding supply pipelines.

The design head of the circulation pump is calculated based on the condition of ensuring circulation during water discharge in the amount of 15% of the maximum hourly flow rate:

Conclusion

After making the required calculations, they designed the internal water supply of the building, and also calculated and designed the sewage system. They calculated the main costs of hot and cold water, hydraulic calculation of cold, hot water supply and sewage for a residential building, and also calculated circulation pipelines and selected a capacitive water heater.

Based on the results of hydraulic calculations, it was determined that the required head in the external water supply network is more than the free head in the city water supply (50.979 m > 45 m), therefore we accept a scheme with an booster pump and a water tank.

The following drawings are made in the graphic part: the 1st floor plan, the basement plan, the axonometric diagram of the internal water supply, the axonometric diagram of the internal sewage system, the plot plan of the section, the profile of the yard sewerage system, as well as the equipment of the sanitary and technical unit.

List of literature

1. Building codes and regulations: SNiP 2.04.01-85. Internal water supply and sewerage of buildings. - Vved. 01.07.86. - M.: Stroyizdat, 1986. – 56 pages.

2. Khrapova O.V., Internal water supply of buildings and structures. - Educational and methodological manual for the implementation of the course project, Cherepovets: ChSU, 1998.

3. Kalitsun V.N. And others. Hydraulics, water supply and sewerage. - M.: Stroyizdat, 1980 – 287 pages.

4. Abramov N. N. Water supply. - M.: Stroyizdat, 1982. – 436 pages.