Let's divide water consumers into two categories: one category consumes water periodically, the other - for a long time.

The first category includes taps that consume water for a maximum of 10 minutes, such as washbasins, kitchen sinks, toilets, etc. hallmark This category is that water never flows from all taps at the same time. A family of two, for example, can usually use no more than two taps at a time, no matter how many there are in the house.

Moreover, washing and dishwashers take water periodically, depending on installed program. Therefore, it is obvious that choosing a pump with a very high performance is not economically advantageous in terms of cost, since it will not be used to its full capacity.

The table on the next page shows the normal water flow for various types consumers with occasional use. Normal flow is the average water consumption at sufficient pump pressure, typically 10 meters.

Fig.91 Water supply of buildings

Fig.92 Various applications of water

The total normal consumption is:

1.1 l / s (cold water) + 1 l / s (hot water) \u003d 2.1 l / s, which corresponds to 7.56 m 3 / h.

Fig.93 Diagram showing the possible maximum water flow

Possible maximum water flow

Such a flow rate does not actually occur in practice, and it is calculated as the maximum flow rate that theoretically can occur.

The draw point with the highest normal flow determines which characteristic (1, 2, 3 or 4) to use. If the largest normal flow in the house is in the bath (0.3 l/s), then characteristic no. 3 should be applied.

On the X axis from point 2.1, draw a vertical line up to the intersection with the characteristic curve No. 3. Next, draw a horizontal line from the intersection point until it intersects with the vertical Y axis

For this example, according to the diagram, the normal highest flow rate would be 0.57 l/s, which corresponds to 2.05 m 3 /h for all draw-off points of periodic use (category 1).

Prolonged use

After calculating the possible maximum flow of category 1 consumers, the normal consumption of category 2 consumers is added.

To work centrifugal pump When pumping water, several factors influence:

• Suction lift (from water surface to pump)
• Friction loss in suction pipe and valve
• Height from pump to highest draw-off point
• Friction loss in pressure pipeline(depending on performance)
• Required minimum pressure in taps (depending on fittings)

Fig.94 Actual pump head

When calculating the actual pump head, the value of the maximum water consumption must be used, in this case 0.97 l/s (3.49 m 3 /h).

Fig.95 Head loss in suction and check valves type BVF and MVF.

Fig.96 Pressure loss in hot-dip galvanized steel pipes with deposits

Friction loss diagrams

This table and diagrams for calculating friction losses in straight runs and runs such as valves, elbows, etc. are not necessarily identical to those you use in your calculations, but the principles are the same. You can use whichever option suits you best.

In practice, 80% of the pumps sold are installed to replace old ones that have worked out their useful life. When selecting a pump for replacement, system parameters such as age of pipes, type check valve in the well, the type of water taps in the house and the level of rust and sludge deposits in the pipes. Therefore, it is necessary to anticipate these factors for more exact definition friction coefficients.

First, you must find out the type of pump that was previously in this installation. Based on the information received, you will be able to determine the type of new pump.

If there is not enough information on the old pump, you should find out from what depth the pump should pump water (for example, 6.05 m) and what is the distance from the pump to the top draw-off point (in the example, 21.5 m). Then add 10 meters corresponding to the required pressure in top point drawdown. After that, we determine the total head: 6.05 + 21.5 + 10 = 37.55 meters, approximately 30%, equal to 11.26 meters, must be added to this value, the margin for friction losses in the suction valve, pipeline, connections, etc. d.

Thus, the actual pump head will be: 37.55 + 11.26 = 48.81 meters.

The annual average daily water consumption, m 3 / day, is determined by the formula

Because for area A, the degree of sanitary equipment of buildings is 5, then the daily rate of water consumption for this area is equal to 180 l / day, and for area B, the degree of sanitary equipment of buildings is 6, therefore, the daily rate of water consumption for this area is equal to 210 l/day

1.2.2 Determining the design water flow

The estimated water consumption per day of the highest water consumption, m 3 / day, is determined by the formula

Taking into account all of the above, we get

The estimated water consumption per day of the lowest water consumption, m 3 / day, is determined by the formula

Taking into account all of the above, we get

1.2.3 Determination of the calculated hourly water consumption

The maximum and minimum calculated hourly water consumption, m 3 / h and, m 3 / h are determined by the formulas

,

,

Coefficients of hourly unevenness per hour. max., per hour min. are determined by the formulas

SNiP 2.04.01-85*

Building regulations

Internal plumbing and sewerage of buildings.

Systems of internal cold and hot water supply

3. Determination of the estimated water consumption in water supply and sewerage systems and heat for the needs of hot water supply

3.1. Systems of cold, hot water supply and sewerage must provide water supply and discharge Wastewater(flow rate) corresponding to the estimated number of water consumers or installed sanitary appliances.

3.2. Secondary water consumption, l / s, water fittings (device),

assigned to one device, it is necessary to determine:

a separate device - according to mandatory Appendix 2;

various devices serving the same water consumers in the section of the dead-end network - in accordance with the mandatory Appendix 3;

various devices serving different water consumers - according to the formula

(1)

The probability of operation of sanitary appliances, determined for each group of water consumers in accordance with clause 3.4;

Secondary water consumption (total, hot, cold), l / s, by water fittings (device), taken in accordance with mandatory Appendix 3, for each group of water consumers.

Notes: 1. When constructing a ring network, the water flow should be determined for the network as a whole and taken the same for all.

2. In residential and public buildings and structures for which there is no information on water consumption and technical specifications sanitary appliances, it is allowed to accept:

3.3. Maximum second consumption water in the calculated section of the l / s network should be determined by the formula

Secondary water consumption, the value of which should be determined in accordance with clause 3.2;

The coefficient determined according to the recommended annex 4, depending on total number devices N on the calculated section of the network and the probability of their action P, calculated according to clause 3.4. At the same time, Table 1 of the recommended appendix 4 should be guided by P > 0.1 and N<= 200; при других значениях Р и N

coefficient should be taken from Table. 2 recommended applications 4 .

With known calculated values ​​P, N and values ​​q(0) = 0.1; 0.14; 0.2; 0.3 l / s to calculate the maximum second water flow, it is allowed to use nomograms 1-4 of the recommended appendix 4.

Notes: 1. The water flow at the end sections of the network should be taken according to the calculation, but not less than the maximum second water flow by one of the installed sanitary appliances.

3. Water consumption for technological needs of industrial enterprises should be determined as the sum of water consumption by technological equipment, provided that the operation of the equipment coincides in time.

3. For auxiliary buildings of industrial enterprises, the value q can be determined as the sum of water consumption for domestic needs according to the formula (2) and shower needs - by the number of installed shower nets according to the mandatory application 2.

3.4. The probability of the action of sanitary appliances in the network sections should be determined by the formulas:

a) with the same water consumers in the building (buildings) or structure (structures) without taking into account changes in the U / N ratio

(3)

b) with different groups of water consumers in the building (buildings) or structure (structures) for various purposes

Notes: 1. In the absence of data on the number of sanitary appliances in buildings or structures, the value of P can be determined by formulas (3) and (4), assuming N = 0.

2. With several groups of water consumers, for which the periods of the highest water consumption will not coincide in time of day, the probability of operation of devices for the system as a whole can be calculated using formulas (3) and (4) taking into account the reduction factors determined during the operation of similar systems.

3.5. The maximum second flow rate of wastewater, l / s, should be determined:

a) with a total maximum second water flow in cold and hot water supply networks serving a group of devices, according to the formula

b) in other cases

3.6. The hourly water consumption of a sanitary appliance should be determined: , l/h,

a) with the same water consumers in the building (buildings) or structure (structures) in accordance with the mandatory Appendix 3;

b) with different water consumers in the building (buildings) or structure (structures) - according to the formula

(6)

Note. In residential and public buildings (structures) for which there is no information on the number and technical characteristics of sanitary appliances, it is allowed to accept:

3.7. The probability of using sanitary appliances for the system as a whole should be determined by the formula

3.8. Maximum hourly water consumption cubic m/h should be determined by the formula

(8)

At the same time, Table 1 recommended application 4 should be guided at > 0.1 and N<=200, при других значениях и N коэффициент следует принимать по табл. 2 рекомендуемого приложения 4 .

Note. For auxiliary buildings of industrial enterprises, the value can be determined as the sum of water consumption for the use of showers and household and drinking needs, taken according to mandatory Appendix 3 according to the number of water consumers in the most numerous shift.

3.9. The average hourly water consumption, cubic m / h, for the period (day, shift) of maximum water consumption T, h, should be determined by the formula

3.10. When designing direct water intake from the pipelines of the heating network for the needs of hot water supply, the average temperature of hot water in the water risers should be maintained at 65 ° C, and the hot water consumption rates should be taken in accordance with the mandatory Appendix 3 with a coefficient of 0.85, while the total amount of water consumed should not be changed .

3.11. The maximum hourly wastewater flow rate should be taken equal to the estimated flow rates determined in accordance with clause 3.8.

3.12. The daily water consumption should be determined by summing up the water consumption by all consumers, taking into account the water consumption for irrigation. The daily consumption of wastewater must be taken equal to water consumption, excluding the consumption of water for irrigation.

3.13. Heat flow, kW, for the period (day, shift) of maximum water consumption for the needs of hot water supply (taking into account heat losses) should be calculated using the formulas:

a) during the average hour

b) during the hour of maximum consumption

The process of formation of the minimum runoff on large, medium and small rivers has a number of features, therefore, the methods for determining the estimated minimum flow rates for small rivers differ from the calculation of large and medium ones.

Large, medium and small include rivers with a catchment area of ​​more than 75,000 km 2, from 75,000 to 10,000 and less than 10,000 km 2, respectively.

Estimated minimum water flow (m 3 / s):

Q p \u003d Q 80% ʎ p , (123)

where Q 80% is the minimum 30-day (average monthly) flow rate (m 3 /s) with an annual probability of exceeding p=80%; ʎ p - transition coefficient from the minimum flow rate with 80% security to the flow rate with another security; determined according to the table given in SP 33-101-2003.

For large and medium rivers, the minimum 30-day flow (m 3 / s):

Q 80% \u003d 10 -3 q 80% F, (124)

where q 80% - minimum 30-day runoff module with an annual probability of exceeding 80%, l / (s km 2); F - catchment area, km 2.

The minimum 30-day modulus of water runoff with a probability of 80% for the summer-autumn and winter periods is found by analogous rivers or by maps SP 33-101-2003 for the center of gravity of the estimated basin by interpolation between runoff isolines.

For small rivers with a catchment area smaller than indicated in table 17. 4. 1, but not less than 20 km 2 for humid areas and 50 km 2 for areas of insufficient moisture, the minimum 30-day flow rate of 80% of the security is determined by the empirical formula (m 3 /with):

Q 80% \u003d 10 -3 a (F + f 0) n (125)

where a, f 0 , n - parameters determined depending on the geographical areas according to the table SP 33-101-2003; F- river catchment area, km 2.

Table 7. The largest areas (km 2) of the catchment area of ​​small rivers

Questions for self-control

1. Determination of the estimated minimum water flow rates in the presence of hydrometric data.

2. Determination of the estimated minimum water flow rates in the absence of hydrometric data.

Bibliography

Main

1. Mikhailov, V. N.

2. Bondarenko, Yu. V.

Additional

1. SP 11-103-97.

2. SP 33-101-2003.

3. GOST 19179-73

4. Bondarenko, Yu. V.

5. Databases, information and reference and search systems:

http://elibrary.sgau.ru/;

REFERENCES

1. Kozhemyachenko, I. V. Hydrometry. [Text]: studies. allowance / I. V. Kozhemyachenko, Yu. V. Bondarenko, O. V. Gutsol, O. N. Zhikhareva. - FGOU VPO "Saratov State Agrarian University"; Saratov, 2010. - 160 p. - ISBN978-5-7011-0603-9.

2. Kozhemyachenko, I. V. Hydrometry. [Text]: method. allowance for laboratory work / I. V. Kozhemyachenko, S. V. Zheludkova. - FGOU VPO "Saratov State Agrarian University"; Saratov, 2009. - 61 p.

3. Zakharovskaya, N. N. Meteorology and climatology [Text] / N. N. Zakharovskaya, V. V. Ilyinich. - M.: Kolos, 2005. - 127 p. - ISBN5-9532-0136-2.

4. Bondarenko, Yu. V. Climatology, meteorology and hydrology. [Text]: studies. allowance / Bondarenko Yu. V., Afonin V. V., Zheludkova S. V. - FGOU VPO "Saratov State Agrarian University"; Saratov, 2010 - 183 p.

5. Mikhailov, V. N. Hydrology. [Text]: studies. for universities / V. N. Mikhailov, A. D. Dobrovolsky, S. A. Dobrolyubov. - 3rd ed., erased. - M .: Higher. school, 2008. - 463 p. - ISBN978-5-06-005815-4.

6. Zheludkova, S. V. Meteorology and climatology. [Text]: method. instructions for settlement and graphic work. / S. V. Zheludkova, D. S. Mayorova. - FGOU VPO "Saratov State Agrarian University"; Saratov, 2010. - 68 p.

7. Bondarenko, Yu. V. Meteorological observations (Organization, production, analysis). [Text]: studies. allowance / Bondarenko Yu. V., Zheludkova S. V., Levitskaya N. G., Kiseleva Yu. Yu. - Saratov.: Publishing Center "Nauka", 2012. - 61 p.

8. Bondarenko, Yu. V. Methods of field hydrological and meteorological studies. [Text]: studies. allowance / Yu. V. Bondarenko. - 2nd ed. add. and Spanish - Saratov.: Publishing Center "Nauka", 2011. - 202 p. - ISBN 978-5-9999-0885-8.

9. Levitskaya N. G. Fundamentals of agrometeorology. [Text]: studies. allowance. / N. G. Levitskaya, Yu. V. Bondarenko. - Saratov.: Saratov source, 2012. - 150 p. - ISBN978-5-91879-163-9.

10. SNiP 23-01-99. Building climatology [Text]. – M.: Gosstroy RF, 1999.

11. SP 11-103-97. Engineering and hydrometeorological surveys for construction [Text]. - M .: Gosstroy RF, 1997

12. SP 33-101-2003. Determination of the main hydrological characteristics [Text]. – M.: Gosstroy RF, 2004

13. GOST 19179-73. Land hydrology. Terms and definitions [Text]. - M .: Gosstandart of the USSR, 1988

14. Khromov, S. P. Meteorology and climatology [Text] / Khromov S.P., Petrosyants M.A. - 6th ed., revised. and additional - M.: MGU, 2004. - 582 p. - ISBN 5-211-04847-4. - ISBN 5-9532-0267-9.

15. Databases, information and reference and search systems:

SSAU Electronic Library - http://library.sgau.ru;

Scientific electronic library - http://elibrary.sgau.ru/;

Electronic data of Roshydromet: http://meteorf.ru;

Electronic data of the State Hydrological Institute - http://www.hydrology.ru.

Page 1

Probability of instrument action:

qс hr,u - water consumption by one consumer per hour of the highest water consumption, is taken in accordance with Appendix 3 of SNiP 2.04.01-85. (qс hr,u = 5.6)

q0 - total water consumption, l / s, sanitary fixture

(reinforcement). accepted according to Appendix 2 of SNiP 2.04.01-85.

U is the number of consumers in the building.

N is the total number of devices serving consumers.

Secondary consumption of water and risers in the design area:

q0 - second water consumption of a sink with a mixer

α - coefficient determined in accordance with Appendix No. 4, depending on the total number of devices N in the calculated section of the network and the probability of their action Р

All calculated data, as well as the calculated values ​​of pressure losses in the calculated sections, are entered in table 3:

Example (for plot 0-1) ;

PN=0.04, then a=0.256; q=5*0.18*0.256=0.23;

Corresponding to this flow rate is a pipe dia. equal to 15mm; V=1.18; i=0.36; Li=0.108

R results

Calculation of the internal cold water supply network

Probability of using sanitary appliances

= = 0,034105

Maximum hourly consumption:

qhr =0.005 q0,hr ahr = 0.005*190*1.437 = 1.36515m3/h

where, q0,hr - the maximum hourly consumption of plumbing fixtures, taken in accordance with the mandatory Appendix 3. ahr - the coefficient should be taken from Table. 2 applications №4.

Daily water consumption

8.25 m3/day

consumption rate of cold water, l, by the consumer per day (shift) of the highest water consumption,

Ui - the number of water consumers of the billing house.

Water meter selection

A water metering unit is installed at the inlet of this projected water supply building to account for the building's water consumption. Water meters are installed at the inlets of the cold and hot water supply pipeline.

Average hourly water consumption for the period (day) of maximum water consumption:

0.446875 m3/h

where K is the coefficient of daily unevenness, (K = 1.1 - 1.3)

T- estimated time, h, water consumption (day, shift)

Pressure loss in meters at the estimated second flow of water

h \u003d S q2 \u003d 1.3 * 0.692 \u003d 0.61893 m.

S - hydraulic resistance of the meter, taken according to the table in Appendix 2. (for Ø 32 S = 1.3)

Determination of the required pressure

In order to determine the required pressure in the internal water supply network of the building, the geometric height of the water supply, all possible pressure losses, as well as the operating pressure at the dictating draw-off point are taken into account.

where - the geometric height of the water supply from the axis of the pump to the calculated sanitary - technical device, m;