Coursework assignment
The degree of fire resistance of the building of the production building II.
The width of buildings is up to 60 m.
The area of the enterprise is up to 150 hectares.
Building volume:
I production building 100 thousand m 3
II production building up to 200 thousand m 3
Number of work shifts 3.
The number of workers per shift is 600 people.
Water consumption for production needs is 700 m 3 / cm.
The number of workers per shift taking a shower is 80%.
Baseline data for the settlement
The number of inhabitants in the settlement is 21 thousand people.
The number of storeys of the building is 5.
The degree of improvement of residential areas: internal water supply, sewerage and centralized hot water supply
Public building type: factory-kitchen (type "b") with a volume of up to 2500m 3 Meter of 5000 dishes.
Material of pipes of the main sections of the water supply network and water pipelines: cast iron with a polymer coating applied by centrifugation.
The length of the water pipelines from НСII to the water tower is 700 m.
1. Determination of water consumers and calculation of the required water consumption for household, drinking, production and fire needs of the village and enterprises
1.1 Definition of water users
The combined household drinking and fire-fighting water supply must provide water consumption for household and drinking needs of the village, household and drinking needs of the enterprise, household and household needs public buildings, production needs of the enterprise, extinguishing possible fires in the village and at the enterprise.
1.2 Calculation of the required water consumption for household and drinking and industrial needs
Water consumption rates for household and drinking needs for settlements are determined according to SNiP 2.04.02-84, clause 2.1, table 1, note 4 and depend on the degree of improvement of residential areas. The water consumption rate for one person is taken as 300 l / day.
Estimated (average for the year) daily water consumption, m 3 / day for household and drinking needs
q - specific water consumption per inhabitant, taken according to table 1 of SNiP 2.04-84; N w - the estimated number of inhabitants.
, m 3 / day
The daily consumption, taking into account water consumption for the needs of the industry providing the population with food, and unaccounted for, increases by 10-20% (clause 2.1, note 4).
Estimated water consumption per day of the highest water consumption
К сm.max - coefficient of daily irregularity of water consumption;
K sum.max - takes into account the lifestyle of the population, the operating mode of the enterprise, the degree of improvement of buildings, the change in water consumption by seasons and days of the week.
For a building equipped with an internal water supply, sewerage and centralized hot water supply, we take K sum.max = 1.1.
Estimated hourly maximum water flow
K h.max - coefficient of hourly irregularity of water consumption;
where a max is a coefficient that takes into account the degree of improvement of buildings, the operating mode of enterprises and other local conditions, is adopted in accordance with clause 2.2.
b max - the coefficient taking into account the number of inhabitants in the settlement is taken according to Table 2, clause 2.2.
, m 3 / day
Water consumption for household and drinking needs in public buildings
q public building - the rate of water consumption by consumers per day for a public building is adopted in accordance with Appendix 3;
N total zd - the number of meters.
Water consumption for household and drinking needs of a kitchen factory
m 3 / day
Total water consumption in the village.
M 3 / day
Industrial enterprise.
In accordance with clause 2.4. , Appendix 3 and according to the assignment, we accept the water consumption rate for household and drinking needs per person per shift 
Water consumption per shift
N cm - the number of workers per shift.
m 3 / cm
Daily water consumption
where
n cm - the number of shifts.
m 3 / day
Number of shower nets
where N cm is the number of workers taking a shower.
PC.
Water consumption per shift
0.5 m 3 / h - the rate of water consumption per one shower net (Appendix 3);
Daily water consumption per shower
where n cm is the number of shifts; n cm = 3.
m 3 / day
Water consumption for the production needs of the enterprise according to the assignment of m3 / cm, which is distributed evenly over the hours of the shift (an eight-hour shift with a one-hour lunch break, during which production does not stop). Eight hour shift work accepted
Hourly water consumption
m 3 / h
Daily water consumption for production needs
Thus, the estimated daily water consumption for the enterprise will be
The total water consumption per day for the village and the enterprise is
In the village and the enterprise, the greatest water consumption occurs from 8 to 9 hours, at this time 574.3 m 3 / h or
l / s
For the enterprise, the estimated expense
l / s
Estimated consumption of a public building (hospital).
l / s
The village spends
We build a schedule of water consumption of the combined water supply system by hours of the day (Fig. 1).
Fig. 1 - Determination of the estimated water consumption for fire extinguishing
Estimated water consumption for external fire extinguishing in settlements and at an industrial enterprise is determined according to SNiP 2.04.02-84, clauses 2.12-2.23, and for internal fire extinguishing according to SNiP 2.04.01-85, clauses 6.1-6.6.
Since the water supply system in the village is designed as a united one, according to SNiP 2.04.02-84, clause 2.23, with a population of 21,000 people, we accept 1 fire. With a five-story building, the water consumption is 15 l / s per fire.
Water consumption for internal fire extinguishing in the village in the presence of a kitchen factory with a volume of up to 2500 m 3, according to SNiP 2.04.01-85, item 61, table 1, we take 1 jet with a capacity of 2.5 l / s
According to SNiP 2.04.02-84, clause 2.22, we accept one fire at the enterprise, because the area of the enterprise is up to 150 hectares.
According to clause 2.14, table 8, note 1, the estimated water consumption for the building is taken
According to SNiP 2.04.01-85, clause 61, table 2, the estimated consumption for internal fire extinguishing in an industrial building is taken at the rate of 2 jets of 5 l / s each:
l / s
2. Hydraulic calculation of the water supply network
Total water consumption per hour of maximum water consumption, i.e. from 8-9 hours, is 159.53 l / s, including the concentrated consumption of the enterprise is 34.83 l / s, and the concentrated consumption of a public building is 0.58 l / s.
Figure 2 - Design diagram of the water supply network.
1.Determine the uniformly distributed flow rate:
2. Determine the specific consumption:
l / s
where is the length of the section;
m is the number of sites;
j - section number.
3. Define path selections:
The results are shown in Table 1.
Table 1 - Travel costs
| Lot number | Section length, m | Track selection, l / s |
| 1-2 | 1000 | 12,412 |
| 2-3 | 1500 | 18,618 |
| 3-4 | 1000 | 12,412 |
| 4-5 | 1500 | 18,618 |
| 5-6 | 1500 | 18,618 |
| 6-7 | 500 | 6,206 |
| 7-1 | 1000 | 12,412 |
| 7-4 | 2000 | 24,824 |
| 10000 | 124,12 |
4. Determine the nodal costs:
,
where is the sum of track selections in the sections adjacent to this node;
Table 2 - Nodal costs
5. Add lumped costs to the nodal costs. The lumped consumption of the enterprise is added to the nodal consumption at point 5, and the lumped consumption of a public building is added at point 3.
Then q 3 = 15.515 + 0.58 = 16.095 l / s, q 5 = 18.618 + 34.83 = 53.448 l / s
The values of the nodal costs are shown in Fig. 3 with lumped costs
Figure 3 - Design diagram of the water supply network with nodal costs.
6. Let's carry out a preliminary distribution of water flow rates across the network sections. We will do this first for the water supply network at maximum economic and industrial water consumption (without fire).
The dictating point is point 5. We have previously outlined the direction of water movement from point 1 to point 5 (the direction is shown in Fig. 3). water flows can approach point 5 in three directions: the first 1-2-3-4-5, the second –1-7-4-5, the third –1-7-6-5. For node 1, the relation must be satisfied 
... Values l / s and 
.
, .
The result will be:
Checking l / s.
In the event of a fire, the water supply network must ensure the supply of water for fire extinguishing at the maximum hourly consumption of water for other needs, with the exception of costs at an industrial enterprise for a shower, watering the territory, etc. (clause 2.21), if these costs are included in the flow rate at the hour of maximum water consumption. For the water supply network shown in Fig. 2, the water consumption for fire extinguishing should be added to the nodal flow at point 5, where water is taken to an industrial enterprise and which is the most distant from the point of entry (from point 1), i.e.
Water supply network diagram with pre-allocated costs in usual time shown in Fig. 4.
Figure 4 - Calculation diagram of the water supply network with pre-allocated costs for economic and industrial water consumption
In the event of a fire, the water supply network must provide water supply for fire extinguishing at the maximum hourly water consumption for other needs, with the exception of expenses at an industrial enterprise for a shower, watering the territory, etc. (Clause 2.21 SNiP 2.04.02-84), if these costs are included in the hour of maximum water consumption.
Hydraulic calculation of the network in case of fire.
Since, then the nodal costs during a fire will be different than at the hour of maximum water consumption without a fire, we will determine the nodal costs as we thought without a fire
For node 1, the relation must be satisfied ... Values l / s and 
l / s are known, but also unknown. We set arbitrarily one of these values. Take l / s, for example. Then,
For point 7, the following relationship must be observed
.
The l / s and l / s values are known and not known. We set arbitrarily one of these quantities and take, for example, l / s. Then,
Water consumption in other areas can be determined from the following ratios:
, .
The result will be:
Checking l / s.
Figure 5 - Calculation diagram of the water supply network with nodal and pre-allocated costs in case of fire.
7. Determine the pipe diameters of the network sections.
For cast iron pipes.
According to the economic factor and the pre-distributed water consumption over the network sections in case of a fire, according to table 3 cast iron pipes GOST 9583-75 and GOST 21053-75, we determine the pipe diameters of the sections of the water supply network:
Linking the water supply network with the maximum economic and industrial water consumption.
Tying is carried out as long as ∆h ≤ 0.5 m
∆q ’= ∆h / 2∑ (h / q)
For section 4–7, which is common for both rings, two corrections are introduced - from the first ring and from the second. The sign of the correction flow rate when transferring from one ring to another should be kept.
Determination of pressure losses at maximum industrial and industrial water consumption.
where , 
, 
The pressure losses in the network at the maximum economic and industrial water consumption are: h c = 10.9596 m.
Determination of pressure losses at maximum industrial water consumption and fire.
Water flows from point 1 to point 5 (dictating point), as seen in the directions of the arrows, can go in 3 directions: the first - 1-2-3-4-5, the second - 1-7-4-5
Water flows from point 1 to point 5 (dictating point), as seen in the directions of the arrows, can go in 3 directions: the first - 1-2-3-4-5, the second - 1-7-4-5, the third - 1-7-6-5. The average head loss in the network can be determined by the formula
where , ,
The pressure loss in the network at maximum economic and industrial water consumption (without the cost of a shower at the enterprise) and in case of fire is
h 1 = 2.715 + 6.2313 + 6.6521 + 11.9979 = 27.5927 m
h 2 = 2.5818 + 12.8434 + 11.9970 = 27.4722 m
h 3 = 2.5818 + 3.6455 + 21.1979 = 27.4234 m
3. Determination of the operating mode of the NS- II
The choice of the operating mode of the second lift pumping station is determined by the water consumption schedule. In those hours when the supply of HC-II is greater than the water consumption of the village, excess water enters the tank of the water tower, and at hours when the supply is less than the water consumption of the village, the lack of water comes from the tank of the water tower. To ensure the minimum capacity of the tank, the schedule for pumping water is sought to be closer to the schedule for water consumption. However, frequent switching on and off of pumps complicates the operation of the pumping station and adversely affects the electrical control equipment of the pumping units. Installation large group pumps with a low flow leads to an increase in the HC-II area and the efficiency of pumps with a low flow is lower than with a larger one. Therefore, a two or three-stage mode of operation of the HC-II is adopted.
In any operating mode of the NS-II, the pump supply must fully (100%) the water consumption of the village. We accept a two-stage operation mode НС-II with each pump supplying 2.5% per hour of daily water consumption. Then one pump per day will supply 2.5 * 24 = 60% of the daily water consumption. The second pump should supply 100-60 = 40% of the daily water consumption and it should be turned on for 40 / 2.5 = 16 hours.
In accordance with the water consumption schedule, it is proposed to turn on the second pump at 5 o'clock and turn off at 21. This mode is shown by a dotted line.
To determine the regulating capacity of the water tower tank, we will compile table 3.
Table 3 - Water consumption and pump operation mode
| Times of Day | Hourly water consumption | Option 1 | Option 2 | ||||||
| Pump feed | Tank entry | Tank flow | Remaining in the tank | Pump feed | Tank entry | Tank flow | Remaining in the tank | ||
| 0-1 | 2,820 | 2,5 | 0 | 0,32 | -0,32 | 3 | 0,18 | 0 | 0,18 |
| 1-2 | 2,530 | 2,5 | 0 | 0,03 | -0,35 | 3 | 0,47 | 0 | 0,65 |
| 2-3 | 2,330 | 2,5 | 0,17 | 0 | -0,18 | 3 | 0,67 | 0 | 1,32 |
| 3-4 | 2,370 | 2,5 | 0,13 | 0 | -0,05 | 3 | 0,63 | 0 | 1,95 |
| 4-5 | 3,120 | 2,5 | 0 | 0,62 | -0,67 | 3 | 0 | 0,12 | 1,83 |
| 5-6 | 3,800 | 2,5 | 0 | 1,3 | -1,97 | 3 | 0 | 0,8 | 1,03 |
| 6-7 | 4,370 | 5 | 0,63 | 0 | -1,34 | 3 | 0 | 1,37 | -0,34 |
| 7-8 | 4,980 | 5 | 0,02 | 0 | -1,32 | 3 | 0 | 1,98 | -2,32 |
| 8-9 | 5,730 | 5 | 0 | 0,73 | -2,05 | 6 | 0,27 | 0 | -2,05 |
| 9-10 | 5,560 | 5 | 0 | 0,56 | -2,61 | 6 | 0,44 | 0 | -1,61 |
| 10-11 | 5,370 | 5 | 0 | 0,37 | -2,98 | 6 | 0,63 | 0 | -0,98 |
| 11-12 | 5,290 | 5 | 0 | 0,29 | -3,27 | 6 | 0,71 | 0 | -0,27 |
| 12-13 | 4,620 | 5 | 0,38 | 0 | -2,89 | 6 | 1,38 | 0 | 1,11 |
| 13-14 | 4,570 | 5 | 0,43 | 0 | -2,46 | 6 | 1,43 | 0 | 2,54 |
| 14-15 | 4,800 | 5 | 0,2 | 0 | -2,26 | 6 | 1,2 | 0 | 3,74 |
| 15-16 | 4,980 | 5 | 0,02 | 0 | -2,24 | 6 | 1,02 | 0 | 4,76 |
| 16-17 | 5,470 | 5 | 0 | 0,47 | -2,71 | 6 | 0,53 | 0 | 5,29 |
| 17-18 | 4,790 | 5 | 0,21 | 0 | -2,5 | 4 | 0 | 0,79 | 4,5 |
| 18-19 | 4,640 | 5 | 0,36 | 0 | -2,14 | 3 | 0 | 1,64 | 2,86 |
| 19-20 | 4,370 | 5 | 0,63 | 0 | -1,51 | 3 | 0 | 1,37 | 1,49 |
| 20-21 | 4,160 | 5 | 0,84 | 0 | -0,67 | 3 | 0 | 1,16 | 0,33 |
| 21-22 | 3,720 | 5 | 1,28 | 0 | 0,61 | 3 | 0 | 0,72 | -0,39 |
| 22-23 | 3,110 | 2,5 | 0 | 0,61 | 0,00 | 3 | 0 | 0,11 | -0,5 |
| 23-24 | 2,520 | 2,5 | 0 | 0,02 | -0,02 | 3 | 0,48 | 0 | -0,02 |
| V tank = | 3,88 | V tank = | 7,61 | ||||||
Column 1 contains hourly intervals, and in column 2 hourly water consumption in% of daily water consumption in accordance with column 11 of Table 1. Column 3 pump delivery in accordance with the proposed operating mode of the HC-II.
If the pump supply is higher than the water consumption of the village, then the difference between these values is recorded in column 4 (flow to the tank), and if it is lower, in column 5 (tank flow).
The remainder of the water in the tank (column 6) by the end of a certain interval is determined as the algebraic sum of two columns 4 and 5 (positive when entering the tank and negative when discharging from it).
The regulating capacity of the tank will be equal to the sum of the absolute values of the largest positive and the smallest negative values of column 6. In the example considered, the capacity of the tower tank turned out to be equal to 3.88% of the daily water consumption.
Let's try to analyze another mode of operation of the NS-II. By setting the pump flow at 3% of the daily water consumption of each pump. One pump in 24 hours will deliver 24 * 3 = 72% of the daily flow. The other will have 28% and should work 28/3 = 9.33 hours. The second pump must be turned on from 8 to 17 hours 20 minutes. This mode of operation of the HC-II is shown on the graph with a dash-dotted line. The regulating capacity of the tank is
7.61%, i.e. in this mode, the tank capacity will be larger. We choose the first option with a pump delivery rate of 2.5% of the daily rate.
4. Hydraulic calculation of water pipelines
The purpose of the hydraulic calculation of water pipelines is to determine the head loss when the estimated water flow is passed. Water pipelines, like the water supply network, are calculated for two modes of operation, for the passage of household and drinking and production costs in accordance with the operating mode of the NS-II and for the passage of maximum household, drinking, production and fire costs, taking into account the requirements of clause 2.21 of SNiP 2.04. 02-84. The method for determining the diameter of water pipes is the same as for the diameters of pipes in the water supply network.
In this course project it is given that the water conduits are made of asbestos-cement pipes, the distance from NS-II to the water tower is m.
Considering that the project adopted an uneven operating mode of the NS-II with maximum feed pumps P = 2.5 + 2.5 = 5% per hour of daily water consumption, the water consumption that will pass through the water pipelines will be equal to:
Since the water conduits should be laid in at least two lines, the water consumption for one water conduit is:
l / s
From Appendix II of the guidelines, we determine the diameter of the water conduits: d = 0.280 m., D p = 0.229 m.
The water velocity in the conduit is determined from the expression:
At a flow rate of Q water = 69.63 l / s, the speed of water movement in a water conduit with a calculated diameter of 0.229 m. will be equal to:
m / s
The head loss in the water pipe is determined by the formula:
h water = 0.012 700 = 8.4 m
The total water consumption under fire extinguishing conditions is
l / s
The water consumption in one line of water pipes under fire extinguishing conditions will be equal to:
In this case, the speed of movement of water in the pipeline will be equal to:
m / s
h water = 0.028 700 = 19.6 m
The head loss in the water lines at (h water, h water fire) will be taken into account when determining the required pressure of utility and fire pumps.
5. Calculation of the water tower
The water tower is designed to regulate the unevenness of water consumption, store an inviolable fire-fighting supply of water and create the required pressure in the water supply network.
5.1 Determining the height of the water tower
The height of the water tower is determined by the formula:
where 1.1 is a coefficient that takes into account pressure losses in local resistances (clause 4, Appendix 10);
h c - pressure loss of the water supply network during its operation at normal times;
Z AT, Z V.B. - geodetic marks, respectively, at the dictating point and at the location of the tower. The minimum head H sv at the dictating point of the network at the maximum household and drinking water consumption at the entrance to the building in accordance with clause 2.26 of SNiP 2.04.02-84 should be equal to:
where n is the number of floors
5.2 Determination of the tank capacity of the water tower
The capacity of the water tower tank must be equal (clause 9.1. SNiP 2.04.02-84).
where W speech is the regulating capacity of the tank;
W N.Z. - the volume of an inviolable water supply, the value of which is determined in accordance with clause 9.5 of SNiP 2.04.02-84 from the expression:
where is the water supply required for a 10-minute duration of extinguishing one external and one internal fire;
Water supply for 10 minutes, determined by the maximum water consumption for household and drinking and industrial needs.
The regulating volume of water in tanks (reservoirs, tanks, water towers) should be determined on the basis of the water intake and withdrawal schedules, and in their absence, according to the formula given in clause 9.2. SNiP 2.04.02-84. In this course work, the schedule of water consumption is determined and the operating mode of the NS-II is proposed, for which the regulating volume of the tank of the water tower was K = 3.88 of the daily water consumption in the village (section 4)
where 
m 3 / day.
Since the largest estimated water consumption is required to extinguish one fire at the enterprise, then
m 3
In this way
By annex III methodological instructions, we accept a typical water tower 32.5 m high with a tank with a capacity of W B = 800 m 3.
Knowing the capacity of the tank, we determine its diameter and height
m
6. Calculation of clean water reservoirs
Clean water reservoirs are designed to regulate the uneven operation of the pumping station of I and II rises and to store an inviolable supply of water for the entire period of fire extinguishing.
The regulating capacity of clean water reservoirs can be determined based on an analysis of the operation of pumping stations of I and II rises.
The operating mode of the HC-I is usually assumed to be uniform, since this mode is most favorable for the HC-I equipment and water treatment facilities. At the same time, NS-I, as well as NS-II, must supply 100% of the daily water consumption in the village. Consequently, the hourly water supply НС-I will be 100/24 = 4.167% of the daily water consumption in the village. The NS-II operating mode is given in section 3.
Fig. 7. - Operating mode NS-I and NS-II
To determine W reg. we will use the graphic-analytical method. To do this, we will combine the work schedules of NS-I and NS-II (Fig. 8). The regulating volume as a percentage of the daily water consumption is equal to the area “a” or the sum of areas equal to it “b”.
W reg = (5-4.167) * 16 = 13.33% or
W reg = (4.167-2.5) * 6 + (4.167-2.5) * 2 = 13.33%
The daily water consumption is 10026.85 m 3 and the regulating volume of the clean water tank will be equal to:
An inviolable supply of water W n.z. in accordance with clause 9.4. SNiP 2.04.02.-84 is determined from the conditions for providing fire extinguishing from external hydrants and internal fire hydrants (clauses 2.12.-2.17., 2.20., 2.22.-2.24. SNiP 2.04.02.-84 and pp. 2.12.-2.17., 2.20., 2.22.-2.24. 6.1.-6.4. SNiP 2.04.01.-85), as well as special means fire extinguishing (sprinklers, drenchers and others that do not have their own tanks) in accordance with clause 2.18. and 2.19. SNiP 2.04.02.-84 and ensuring maximum drinking and industrial needs, for the entire period of fire extinguishing, taking into account the requirements of clause 2.21.
In this way:
When determining the volume of an inviolable supply of water in tanks, it is allowed to take into account their replenishment with water during extinguishing a fire, if the water supply to the tanks is carried out by water supply systems of I and II categories according to the degree of water supply, i.e.:
where t t = 3 hours - the estimated duration of extinguishing the fire (clause 2.24 SNiP 2.04.02.-84).
When determining the Q of the settlement, the water consumption for irrigating the territory, taking a shower, washing floors and washing is not taken into account technological equipment at an industrial enterprise.
In this example, Q ¢ settlement pr -Q shower = 764.96-0 = 764.96 m 3 / h
Q ¢ settlement pr = 764.96 m 3 / h or 212.49 l / s.
W n.z.x-n = Q ¢ pos.pr . t t = 764.96 . 3 = 2294.88 m 3.
During extinguishing the fire, the HC-I pumps supply 4.167% of the daily consumption per hour, and during the time t t will be supplied
Thus, the volume of the emergency water supply will be equal to:
Total volume of clean water tanks
According to clause 9.21. SNiP 2.04.02-84, the total number of tanks should be at the same elevations, when one tank is turned off, at least 50% of the NZ should be stored in the rest, and the equipment of the tanks should provide the ability to turn on and empty each tank. We accept two standard tanks with a volume of 1600m 3 (Appendix IV of the guidelines).
7. Selection of pumps for the pumping station of the second lift
From the calculation it follows that the NS-II operates in an uneven mode with the installation of two main household pumps in it, the flow of which will be equal to:
The required head of household pumps is determined by the formula:
where h water is the pressure loss in the conduits, m;
H N.B. - the height of the water tower, m;
Z V.B. and Z N.C. - geodetic marks, respectively, of the place of installation of the tower and NS-II;
1.1 is a coefficient that takes into account pressure losses due to local resistances (clause 4, appendix 10).
The pump head during operation during a fire is determined by the formula:
where h vod.pozh and h s.pozh - respectively, the loss of pressure in the water conduits and the water supply network during fire extinguishing, m;
H sv - free head of a hydrant located at a dictating point, m. For water pipes low pressure H sv = 10m;
Z АТ - geodetic mark at the dictating point, m.
We build a pumping station on the principle of low pressure. During normal times, one or a group of utility pumps is in operation. In the event of a fire, an additional pump is switched on with the same pressure as the household pumps and provides the supply of water for fire extinguishing. The design of the switching chamber depends on the type of pumping station (Fig. 9).
The selection of brands of pumps can be performed according to the consolidated graph of the Q-H fields (Appendix XI and XII). On the graph, the abscissa shows the pump flow, the ordinate shows the pressure, and for each brand of pumps the fields are shown within which these values can change. The fields are formed as follows. Upper and lower bounds Are, respectively, characteristics
Q-H for a given pump brand with the largest and smallest impeller diameters of the series produced. The lateral boundaries of the fields limit the area of optimal pump operation, i.e. area corresponding maximum values coefficient useful action... When choosing a pump brand, it is necessary to take into account that the calculated values of the pump flow and head must lie within its Q-H field.
The proposed pumping unit must ensure the minimum amount of excess heads developed by the pumps in all operating modes, through the use of regulating tanks, speed control, changing the number and type of pumps, replacing impellers in accordance with changes in their operating conditions during the design period (p. 7.2 SNiP 2.04.02-84).
The calculated values of the flow and head, the accepted brands and number of pumps, the category of the pumping station are given in table 4.
Table 4 - Calculated values of flow and head, accepted brands and number of pumps, category of pumping station
Bibliography:
1. SNiP 2.04.02-84 “Water supply. External networks and facilities ”. - M .: Stroyizdat, 1985.
2. SNiP 2.04.01-85 “Internal water supply and sewerage systems of buildings”. - M .: Stroyizdat, 1986.
3. Shevelev F.A., Shevelev A.F. "Tables for hydraulic calculation of water pipes." / Reference manual. - M .: Stroyizdat, 1984.
4. Lobachev P.V. “Pumps and pumping stations”, - M .: Stroyizdat, 1983.
The main types of water consumption are: household and drinking water consumption by residents of settlements; water consumption of industrial enterprises; water consumption associated with landscaping (watering streets, green spaces, etc.); use of water for fire extinguishing; own needs of the water supply system.
Domestic and drinking water consumption. The norms of household and drinking water consumption in settlements are adopted according to SNiP 2.04.02 - 84 (Table 1.1).
For areas with buildings with water use from standpipes, the specific average daily (per year) water consumption per inhabitant should be taken as 30 ... 50 l / day.
Specific water consumption includes water consumption for household, drinking and household needs in public buildings, excluding water consumption for holiday homes, sanatorium and tourist complexes and health camps.
The choice of specific water consumption within the limits indicated in table. 1.1, should be made depending on climatic conditions, the capacity of the water supply source and water quality, the degree of improvement, the number of storeys of buildings and local conditions.
The amount of water for the needs of industry, providing the population with food, and unaccounted costs, with appropriate justification, may be taken additionally in the amount of 10 ... 20% of the total water consumption for household and drinking needs of the settlement.
Specific water consumption in settlements with a population of more than 1 million people may be increased if justified in each a separate case and in agreement with the state supervision authorities.
The average daily (for the year) volume of water consumption, m 3 / day, for household and drinking needs is determined by the formula
where q W1 is the rate of specific water consumption, l / (day ith the degree of sanitary and technical improvement of residential buildings and taken according to table. 1.1; Ni - the estimated number of residents living in residential areas with the i-th degree of improvement, at the end of the considered construction phase.
The estimated number of inhabitants can be determined by the formula
where Rj - j-th population density, people / ha; Fij, - the area of the residential area with the i-th degree of sanitary-technical improvement of buildings and the j-th population density, hectares.
For the correct calculation of water supply systems, it is necessary to know the sequence of their development and the corresponding water consumption. The increase in water consumption during the development of the system is due to an increase in the population and an increase in the degree of sanitary and technical improvement of buildings. Water consumption growth is accounted for by determining the estimated water consumption at the end of the corresponding development stage.
Water consumption for household and drinking needs of the settlement is uneven throughout the year. There are fluctuations in daily consumption: seasonal, associated with changes in temperature and humidity in separate times of the year, a also weekly and daily, due to the peculiarities of water consumption on different days of the week (weekdays, weekends, pre-holidays and holidays). Water supply systems should be designed to pass the maximum daily water consumption, m 3 / day, equal to
where Ksut max = 1.1 ... 1.3 is the maximum coefficient of daily irregularity of water consumption, taking into account the lifestyle of the population, the mode of operation of enterprises, the degree of improvement of buildings, the change in water consumption by seasons and days of the week, Qdaym is the calculated (average for the year) daily water consumption, m 3 / day, determined by the formula (1.1).
In some cases, it is required to check the operation of the water supply system at a minimum daily water consumption, m 3 / day, determined by the formula
where TOdaysmin= 0.7 ... 0.9 is the minimum coefficient of daily irregularity of water consumption.
Water consumption of industrial enterprises. At industrial enterprises (including agricultural enterprises), water is consumed for the technological needs of production, household and drinking needs of workers, as well as for the use of their shower.
Water consumption rates for technological needs depend on the adopted technological process, the type of water supply system, water quality, etc.
The average volume of water consumption is determined by the types of water used (circulating, make-up) by multiplying the corresponding specific costs for productivity technological process in accepted units of values (1 t, 1000 kW, etc.).
In accordance with SNiP 2.04.01-85, the norms of water consumption for household and drinking needs of workers of industrial enterprises are taken equal for those working in shops with a heat release of more than 84 kJ per 1 m 3 / h (hot shops) qr = 45 liters per shift for one person; for other workshops qX = = 25 l.
The volume of water consumption per shift, m 3 / cm, is determined by the formula
Qx / n = qrnr + qxnx, (1.5)
where Pr, PX - the number of workers, respectively, in shops with a heat release of more than 84 kJ per 1 m 3 / h and in other shops for the shift under consideration.
The water consumption for using the shower is determined based on the hourly water consumption
for one shower net of 500 liters with a shower duration of 45 minutes. In this case, the water consumption for taking a shower after the end of the shift, m 3 / h, is determined by the formula
where N shower- the number of people using the shower in a given shift; a - the number of people per shower.
Water consumption associated with the improvement of urban areas and industrial sites. Water consumption rates for watering green spaces, as well as washing streets of settlements and territories of industrial enterprises are adopted according to SNiP 2.04.02-84, depending on the Type of coverage of the territory, the method of irrigation, the type of plantations, climatic and other local conditions (Table 1.2) ...
The daily volume of water consumption, m 3 / day, for watering streets and green spaces is determined by the formula
where Qpol is the water consumption for irrigation, l / m 2, taken from the table. 1.2; F - area of the territory of the settlement "gross" (including streets, squares, etc.), hectares; a - the share of the irrigated area of the settlement,%.
In the absence of data on areas by type of improvement (green spaces, driveways, etc.), the average daily water consumption for irrigation, m 3 / day, for the irrigation season, can be determined by the formula
where qw n - specific rate of water consumption for irrigation per one inhabitant of the settlement, taken equal to 50 .. 90 l / day per person, depending on climatic conditions, power, water supply source, the degree of improvement of the settlement and other local conditions; N - the estimated number of inhabitants in the village.
Total daily water consumption determined by individual groups of consumers supplied with water by the calculated water supply system.
For a single water supply system serving all listed groups consumers, determine: average daily water consumption, m 3 / day,
maximum daily water consumption, m 3 days,
In formulas (1.9) and (1.10) Qtech is the daily water consumption for the technological needs of industrial enterprises.
Water supply systems rely on the maximum daily water consumption and check for the passage of the calculated fire-fighting consumption.
Use of water for fire extinguishing. In accordance with SNiP 2.04.02-84, the water consumption for external fire extinguishing (per one fire) and the number of simultaneous fires in the settlement for calculating the main (calculated ring) lines of the water supply network should be taken according to table. 1.3.
With zonal water supply, the water consumption for external fire extinguishing and the number of simultaneous fires in each zone should be taken depending on the number of residents living in the zone.
The number of simultaneous fires and water consumption per fire in settlements with more than 1 million inhabitants. a person should be taken in accordance with the requirements of the State Fire Supervision Authorities.
For a group water supply, the number of simultaneous fires is taken depending on the total residents in settlements connected to the water supply.
The consumption of water for external fire extinguishing of housing and industrial buildings for calculating the connecting and distributed lines of the water supply network, as well as the water supply network inside the microdistrict or block should be taken for the building that requires the highest water consumption, according to table. 1.4.
Water consumption for one fire for external fire extinguishing at industrial and agricultural enterprises should be taken for a building that requires the highest water consumption, according to table. 1.5 and 1.6. The estimated number of fires in this case depends on the area they occupy: one fire - with an area of up to 150 hectares, two fires - more than 150 hectares.
The estimated duration of extinguishing a fire is assumed to be 3 hours; for buildings of I and II degrees of fire resistance with fireproof load-bearing structures and insulation with production facilities of categories G and D - 2 hours.
The determination of the total fire-fighting water consumption in a settlement is carried out depending on the location of industrial or agricultural enterprises.
table 1.6 Water consumption rates for external fire extinguishing of industrial buildings with a width of 60 m and more
If the enterprise is located within the city, the estimated number of simultaneous fires (Table 1.3) includes the fires of this enterprise. In this case, the estimated water consumption should include the corresponding water consumption for fire extinguishing at these enterprises, if they are more than those indicated in table. 1.3.
When the enterprise is located outside the settlement, the estimated number of simultaneous fires should be taken:
with the area of the enterprise territory up to 150 hectares and the number of inhabitants in the settlement up to 10 thousand people - one fire (at the enterprise or in the settlement with the highest water consumption); the same, with the number of inhabitants in a settlement over 10 to 25 thousand people - two fires (one at the enterprise and one in the settlement);
with an area of more than 150 hectares and with a population of up to 25 thousand people in a settlement - two fires (two at an enterprise or two in a settlement at the highest expense).
when the number of inhabitants in a settlement is more than 25 thousand people, the water consumption should be determined as the sum of the required higher flow (at the enterprise or in the settlement) and 50% of the required lower flow (at the enterprise or in the settlement).
In all cases, the water consumption for external fire extinguishing in the settlement must be at least the water consumption for fire extinguishing of residential and public buildings, indicated in table. 1.4.
Own needs of the water supply system. The water supply system should be considered as an industrial enterprise that consumes water for the household needs of workers, in technological processes and for fire extinguishing. The largest consumer of water used for own needs in the water supply system is treatment facilities.
In accordance with SNiP 2.04.02-84, the approximate average daily (per year) water consumption for the auxiliary needs of the clarification and disinfection stations should be taken: when washing water is reused in the amount of 3 ... 4% of the amount of water supplied to consumers; without reuse - 10 ... 14%, for softening stations - 20 ... 30%;
The volume of water consumption for auxiliary needs of the water supply system affects the design productivity, m 3 / day, of water intake and treatment facilities (Fig.1.1)
where
- maximum daily water consumption, m3 / day; α is a coefficient that takes into account the own needs of treatment facilities; for water intake facilities and we take it equal to 1.03 ... 1.04 with re-use of water and 1.1 ... 1.14 without re-use at the clarification and deferrization station, at softening stations 1.2 ... 1.3; for treatment facilities both with and without water reuse 1.10 ... 1.14 at softening and deferrization stations and 1.2 ... 1.3 at softening stations.
Section Contents
The amount of water required for each production facility, as well as the generated waste water, is established by a technological calculation or adopted on the basis of best practices. They can be adopted according to the current departmental technological or consolidated standards. The rates of water consumption for sanitary needs (including its consumption for cleaning floors, watering green spaces, the territory of enterprises) for fire-fighting systems are given in.
The scheme and composition of the equipment of the water supply system essentially depend on the type and type of boiler house (boiler house of a TPP, industrial enterprise or housing and communal services).
Depending on the purpose, the water supply can be:
a) production - to supply production (technical) water to an industrial enterprise and power plants; *
b) household and drinking water - to supply drinking (purified and disinfected) water to employees of enterprises and the population of nearby villages or cities;
c) fire-fighting - to extinguish a fire.
On the industrial enterprises There is no independent fire-fighting water supply system, therefore water for extinguishing a fire is taken from an industrial or utility-drinking water supply system, or from local water bodies, for example, spray pools, cooling ponds for circulating water, etc.
Water used by consumers and discharged from them for reuse or into a body of water is called waste water. All waste water can be divided:
a) on polluted waters, i.e. containing mechanical or chemical impurities. These waters, when reused, as when released into a reservoir, need to be treated;
b) the waters are conditionally clean, not requiring any purification before reuse or before being released into the reservoir.
Domestic waste water and most industrial Wastewater are contaminated.
Conditionally clean, as a rule, includes cooling waters after of various kinds heat exchange and electromechanical equipment.
Part of the water used by industrial and household consumers is irretrievably consumed, that is, there is a loss of water, depending on the processes being serviced, from 5 to 70% or more. The rest of the water flows into the drain. Irretrievably lost, for example, a part of the water (up to several percent), cooled in cooling towers or artificial and natural reservoirs due to its evaporation and droplet entrainment. There is a loss of water with the exhaust ventilation air in showers and. etc.
At TPPs, the total water consumption is mainly determined by the consumption for condensation of steam spent in turbines.
The maximum flow rate of cooling water in the surface condenser of the unit is
G max = D(h – ct) ,
where D- steam consumption at the inlet to the condenser; h- enthalpy of steam, With and t- heat capacity and condensate temperature
In addition, water is used to cool the vapor (see section 4.7.3) of deaerators, air, gases, oil in lubrication systems for bearings of auxiliary mechanisms and oil systems for automatic control of turbine generators. Water is also required to replenish steam and condensate losses both inside the power plant and boiler houses, and at external heat consumers (to replenish condensate losses and feed water boilers, steam converters and evaporators, taking into account the own needs of the chemical department; to feed both closed and open systems heat supply (see); to replenish the losses of cooling water in the circulating water supply systems), as well as to move through the pipes ash and slag to be removed (see section 5). Finally, water is used to meet household and household needs (drinking water, toilets, showers, etc.).
The value of the above water consumption depends on the purpose and type of the power plant or boiler house, the facilities connected to them, the type and amount of fuel burned, the type and capacity of the installed main and auxiliary boiler and turbine equipment, the temperature of the water used for cooling, as well as the operating conditions of the equipment. ...
Approximate data for calculating the total demand of a condensing power plant (CES) in water with a direct-flow water supply system are given in table. 3.1.2. The initial value is taken as the hourly steam consumption for the turbine D, t / h.
Table 3.1.2. Estimated water consumption at IES
| Water flow name | The amount of consumed water |
| For condensation of steam spent in the turbine | (50 - 60)D |
| For cooling the oil of the turbine unit | (2 - 3) D |
| For cooling the bearings of auxiliary mechanisms (mills, fans, smoke exhausters, pumps, etc.) |
(0,1 - 0,5)D |
| Boiler power supply | (0,05 - 0,1)D |
| For hydraulic ash removal | (1,0 - 1,5)D |
| For household needs | Up to 0.1 D |
At combined heat and power plants (CHP), water is required, in addition, to recharge heating networks 0.05 - 0.4 D, and for feeding the boilers. Therefore, the water consumption increases to 0.3 D and more. Consequently, the total water consumption for the condensing power plant (when operating on a direct-flow water supply system) is 55-65 D... For a condensing power plant with a capacity of about 1 million kW, this consumption will be 40 - 50 m 3 / s, which corresponds to the consumption of water, for example, r. Moscow.
With a circulating water supply system, to replenish the loss of water cooling the turbine condensers, depending on the adopted cooling method, only 2 - 3.5 D... The rest of the water discharge will be the same (Table 3.1.2). Thus, the total water consumption for circulating water supply will be 3 - 5.5 D, that is, approximately 12 - 15 times less than with direct-flow water supply.
Home> LecturesWater use classification
Water consumption regulation
Water use is the consumption of water from water bodies or water supply systems (GOST 17.1.1.01-77) Rationing of water consumption is the establishment of a planned measure of water consumption, taking into account its quality, as well as the development and approval of standards for water consumption per unit of planned products and control over their implementation ... The main task of the regulation is to provide technically and economically justified norms of water consumption and wastewater disposal in production and planning in order to achieve the most effective use water resources... In the utilities sector, rationing is carried out on the basis of SNiPs, in industry - on the basis of “ Methodical instructions on the development of norms and standards for water consumption and wastewater disposal, taking into account the quality of consumed and discharged water, as well as taking into account industry methods for enterprises and associations of various industries National economy”. The following are subject to standardization:
- consumption of the total amount of water required to produce a unit of production; consumption of fresh drinking water; consumption of industrial water; consumption of recycled and reused or sequentially used water; the amount of wastewater discharged from consumers (including from production).
Water disposal rationing
Accounting for the quality of consumed and discharged water
Water consumption and sewerage limits and control over the implementation of standards
Participants of the water management complex
Ways to save water in public utilities
Features of municipal water supply
Specific water consumption for household needs
| The degree of improvement of buildings | Specific water consumption per 1 inhabitant, l / day | Irregularity coefficient |
|
| Without plumbing and sewerage | 30 - northern areas 50 - southern areas | ||
| Plumbing, sewerage (without baths) | |||
| Plumbing, sewerage with bathtubs and gas water heaters | |||
| Plumbing, sewerage and centralized hot water supply | |||
- the third feature of the municipal water supply is related to its role in the VHK and its influence on other participants in the VHK. It is especially evident when using surface waters
- one of the main measures is the fight against leaks that occur through leaks in pipes, fittings and sanitary equipment. Only in residential buildings, they account for up to 25% of the volume of water supplied to the population. Large losses - due to damage to water mains, especially during earthworks. Average size - 20%. To reduce them, it is necessary to regulate the water pressure depending on the height of the buildings, the use of perfect shut-off and starting valves, the use of pumping and power equipment with an adjustable speed, etc. the introduction of a separate water supply system for municipal and industrial water supply. This will save water. High Quality for drinking, and for other municipal needs (washing cars, watering streets and green spaces) use water of a lower quality and with less availability, for example, untreated river or cleaned municipal wastewater. The municipal water supply has a low irrecoverable water consumption, i.e. going to most of used water. The widespread introduction of sewerage will increase the amount of wastewater that can be reused for irrigation or industry. This results in an overall water savings. Reducing the norms of communal water supply. This is achieved through the introduction of waterless methods for cleaning urban areas and waste. This will reduce the rates of wastewater disposal, the cost of treating municipal wastewater and, ultimately, to the improvement of reservoirs and watercourses.
When buying a private home, it is imperative to delve into the question of what water supply and sewerage should be in accordance with SNiP, because water consumption is necessary for household, drinking and communal needs of a person. And the Building Codes and Rules just regulate their arrangement.
The rate of water consumption is the maximum allowable amount of water of an appropriate quality that is necessary to meet the needs of people living in a particular dwelling. Water consumption rates are determined by the rules adopted executive bodies authorities.
Water flow dependence
The amount of water consumption depends on the level and quality of people's life. Turning to history, we can notice that in 1890 one inhabitant of the capital used 11 liters of water every day. After 20 years, the Muscovite has already needed 66 liters per day. On the this moment according to SNiP standards, the consumption of water consumed by a resident of Moscow has increased significantly and is about 700 liters per day.
Water consumption directly depends on the climate where a person lives and on the work that he does. Doctors assure us that a person needs to consume up to 2 liters of liquid per day.
Plus, in different climatic conditions, the need for water is different. For example, in southern regions more fluid is required than in the north.
Difference in water consumption
The fluctuation in depends on technology and on the habits of humanity. As we said earlier, the difference in fluid consumption is associated with the climate of a person's residence, but also on working conditions, more precisely on weekends. This affects the annual water consumption specified in SNiP. Daily fluctuations vary from day to day, in general, from sleep and wakefulness. In apartments, the water consumption in winter increases due to central heating, in comparison with private houses or countryside... Partially, according to SNiP, water consumption per week depends on weekends and is 30%, these are always Saturdays and Sundays.
It has been proven that daily fluctuations in water consumption are associated not only with the time of day, but also with the organization of household leisure, in particular, television programs, films, holidays and others. interesting events that take place at home. There is also a colossal difference in the consumption of cold and hot water.
On average, a family living in Russia with two children uses about 7,000 liters of hot water and 10,000 liters of cold water.
Daily water consumption rates
According to the documentation, SNiP water consumption rates are used for drinking and household needs. This includes food preparation, daily hygiene, and much more. And for a private house, a sink is also added vehicle, watering the local area and flower beds, filling the pool and so on. Consider daily norms water consumption SNiP:
- Food preparation - 3 liters;
- Drinking water - up to 2 liters;
- Hand washing (without stopping the water) - up to 8 liters;
- Oral hygiene (without stopping the water) - up to 7 liters;
- Toilet flush - up to 12 liters at a time;
- Taking a shower - 20 liters / minute;
- Taking a bath - 150 liters;
- Washing - up to 100 liters;
- Dishwashing - up to 10 liters at a time.
In total, we get from 300 to 570 liters per day. From the calculation it is clear that the water consumption of SNiP is significantly different from actual indicators... Therefore, it is logical to think about saving water consumption.
Drainage standards in private houses
Wastewater disposal, like water supply, is an essential element of modern comfortable life person.
Living in a private home, the necessary amenities, such as a kitchen and a bathroom, also require the collection of used water, and not just water supply. And the water disposal SNiP for private houses per day per person is given below:
- With plumbing and sewerage (without bath) - 120 liters;
- With plumbing and bathrooms - 225 liters;
- Center. hot water supply - 300 liters;
- Center. hot water supply (building height over 12 meters) - 400 liters.
The daily drainage is uneven for 1 hour, but this difference is usually not taken into account in the calculation of costs, because the drainage takes into account the minimum and maximum coefficients per day, hours with general unevenness. According to the data, we see that the water supply and sanitation of SNiP does not even correspond to targets... For example, if a person lives in a house with running water, sewerage, a bathroom and uses 500 liters of water, while according to the norms, he is obliged to divert only 225 liters.
The calculated norms have long been exceeded by the actual water consumption, therefore, residents of private houses are trying to save money.
With the help of various filtering installations, you can use industrial water for other needs, of course, not drink it, but it is quite suitable for watering and washing a car.
