Download presentation

Presentation is loading. Please wait.

Published byKyra Glasco Modified about 1 year ago

1
1 Design Irrigation System II Asher Azenkot

2
2 Local Head Losses The local head loss due to a local disturbance in water flow is proportional to the head velocity. K - Coefficient

3
3 Hydraulic Valve Local Head Loss

4
4 Filter Local Head Loss

5
5 Metzer drip line Water flow velocity reduced gradually along the lateral pipe

6
6 Local head loss in “ head connector ” m 3 /h m

7
7 Local head loss Flow rate Local head loss m

8
8 Example:Example: A 12" valve (K = 2.5) is installed in 1,250 meters long pipe (12 ” and C = 130). What is the total head loss due to the valve and the pipe when the water flow rate is = 100, 200 and 400 m 3 /h. The pipe cross section area is:

9
9 Continue:Continue:

10
10 Continue:Continue: If an 8" valve is replaced the 12", what will be the new total head loss?

11
11 Lateral Pipes Lateral pipe is abide by: 1. A same size of pipe, 2. even distance between outlets, 3. a same outlet (sprinkler or emitter) flow rate. A lateral pipe is characterized by a continuous decline in water discharge along the pipe. The flow rate starts at Q u (m 3 /h) at the upstream end and ends up with a q 1 (m 3 /h) downstream. (Lateral pipe is abide by: 1. A same size of pipe, 2. even distance between outlets, 3. a same outlet (sprinkler or emitter) flow rate. The calculation of the head loss is done in two steps: The head loss is calculated by assuming the pipe is plain The outcome is multiplied by the coefficient F SlSl D 95 m Q u = n*q q 2q3q

12
12 Coefficient F 1. F 1 to be used when the distance from the lateral inlet to the first outlet is Sl meters. 2. F 2 to be used when the first outlet is near the lateral inlet. 3. F 3 to be used when the distance from the lateral inlet to the first outlet is Sl/2 meters.

13
13 Characteristics of a Lateral pipe The sprinkler pressure along the lateral pipe decline faster along the first 40% of the length than afterwards (figure 2). The sprinkler flow rate along the lateral pipe declines faster along the first 40% of the length (figure 1). The location of the sprinkler (or emitter) with the average pressure and flow rate is 40% away from the lateral’s inlet. Three quarter of the lateral head loss takes place along the first two fifth sections (40%).

14
14 Fig. 1: Flow rate reduction in a plain pipe and in a lateral with sprinklers.

15
15 Fig. 2: Head loss and percent of head loss

16
16

17
17

18
18

19
19 Head loss Calculation Along lateral Select a suitable sprinkler or emitter with a required H s, q s and s l from a catalogue (figure 3). The number of sprinklers (n) along the lateral is determined by (L/s l ). The discharge rate at the lateral inlet is determined by (Q u = n x q s ). The lateral diameter (D) should comply with maximum head loss of 20%. The head loss along a lateral (Q u, q, D and L) is computed by: o Assuming the lateral pipe is plain and. o The outcome is multiplied by F factor.

20
20 Fig. 3 - Naan 233

21
21 Head loss in drip lateral pipe òA modified Hazen-Williams head loss equation: H L = head loss along a lateral drip line L = lateral length (m) D = internal diameter (m) N = number of emitters q = average emitter flow rate (m 3 /h) C = Hazen-Williams coefficient (130 - 120 for polyethylene pipe with ID < 16 mm) F = 0.37 for more than 20 emitters

22
22 Hydro P.C. & Hydro P.C.N.D - 1.2* L/H MAXIMUM RECOMMENDED DRIPLINE LENGTH (m) PIPE DIAMETER -16/13.8 (OD/ID)

23
23 Number Of Mamkad spinklers

24
24 Mamkad mini-sprinkler nozzles

25
25 Example:Example: A flat field, 360 x 360 m, is irrigated with a hand moved aluminum lateral pipe (C = 140). The water source to the lateral pipe is from a sub-main, which crosses the center of the field. The selected sprinklers are Naan 233/92 with a nozzle size of 4.5 mm, pressure of 25 m (h s ) and flow rate (q s ) of 1.44 m 3 /hr. The space between the sprinklers is 12 meters apart, and the location of the first sprinkler is 6 meters away from lateral inlet. The riser height is 0.8 m and diameter of 3/4".

26
26 Answer:Answer: lateral 360 m Submain The number of sprinklers on the lateral is The length of the lateral (l) is l = (14 sprinkler x 12 m apart) + 6 m = 174 meters

27
27 ContinueContinue The inlet flow rate of the lateral is Q u = 15 (sprinklers) x 1.44 m 3 /h = 21.6 m 3 /h The maximum allowed head loss (20%) throughout the field is For a plain 2" aluminum pipe - the hydraulic gradient out of Hazen Williams is: J = 188.9 ‰

28
28 The head loss in a 2" (plain) aluminum pipe is as follows: The F factor for 15 sprinklers is F 15 = 0.363 For a 3" aluminum pipe - the hydraulic gradient out of a table or ruler is: J = 26.2 ‰ Continue:Continue:

29
29 The head loss in a 3" (plain) aluminum pipe is as follows: The F factor for 15 sprinklers is F 15 = 0.363 The difference 5 - 1.66 = 3.34 meters head loss which will be used as the head loss for the sub- main pipe. Continue:Continue:

30
30 A Lateral Inlet Pressure SlSl D Q u = n*q 2q3q P = ?

31
31 A Lateral Inlet Pressure The pressure head at the lateral inlet (h u ) is determined by: h u - lateral inlet pressure head h s - pressure head of selected sprinkler h f - head loss along lateral riser – the length (height) of the riser - local head loss (incurred between laleral pipe and sprinkler)

32
32 Local head loss Flow rate Local head loss m

33
33 Example:Example: Following the previous example, what is the inlet pressure? h f = 1.66 meters riser height = 0.8 meters h s = 25 meters

34
34 Inlet pressure in case of a Lateral pipe Laid out on a Slop The inlet pressure of a lateral pipe which laid out along a slope is as follows: h u - the lateral inlet pressure h s - pressure head of selected sprinkler h f - head loss along lateral riser - riser height - adjustment for an upward slope - adjustment for an downward slope

35
35 Example:Example: Following the previous example, but this time with: a. 2% downward slope, or b. 2% upward slope. The difference elevation between the two ends is as follows: a. 2% downward slope

36
36 Cont.Cont. The pressure by the last sprinkler is as follows: The head loss between lateral inlet and last sprinkler is:

37
37 Cont.Cont. 360 m Sub-main 27.12m 25.3m 20%=5m 28.5 – 25.3 m = 3.2 m is taken place along the sub-main pipe. Therefore, the pressure at the head of the field is 28.5 m. P=30.3m P=28.5m Δh f =3.2m

38
38 Continue:Continue: b. 2% upward slope The total head loss throughout the lateral pipe is: 5.14 meters are just the permitted 20% head loss. Therefore, nothing is left for the sub-main. In this case, pressure regulators should be installed in every lateral inlets or selecting a wider pipe.

39
39 Maximum Permitted Head loss

40
40 s Distribution of water and pressure

41
41 In order to maintain up to 10% difference in flow rate between sprinklers or emitter within a sub-plot, then the pressure difference inside the plot should be less than 20%. Q - flow rate C – coefficient, which depends on a nozzle type A - cross section area of a nozzle H - pressure head X - exponent which depends on the flow pattern. or “ The 20% rule ”

42
42 Pressure Vs. Flow Liter/hr Pressure m

43
43 O-tif Flow rate Vs. Pressure Brown2lph Black4lph Green8lph Purple16lph

44
44 3/8" Rondo Nozzles - Flow rate Vs. Pressure

45
45 Supertif - flow rate Vs. Pressure

46
46 Ram & Agriplas Flow rate Vs Pressure

47
47 Flow rate Vs Pressure

48
48 Temperature Vs CV (tapes drip-line)

49
49 What is the expected difference discharge between the two ends of a lateral sprinkler? When the hydraulic gradient along a lateral pipe is 20%. The flow rate of a sprinkler is as follows: Example:Example:

50
50 Two identical sprinklers have a same coefficient: The difference in flow rate between the two ends is 10% (within 20% rule), once the exponent is 0.5. Continue:Continue:

51
51 TUFFTIF Dripper Flow Rate Table Q=LPH H=m. %DH - MAXIMUM ALLOWABLE HEAD LOSS DIFFERENCE. ALONG A LATERAL (AS PERCENT OF THE WORKING PRESSURE. TO KEEP FLOW RATE DIFFERENCEC ≤ 10% OF WORKING FLOW RATE.

52
52 Tufftif performance chart

53
53 A polyethylene lateral pipe, grade 4, has 10 micro-sprinklers at 10 meters apart, while the first is only one half way. The flow rate of the selected sprinkler is q s = 120 l/h at h s = 20 meters. The riser ’ s height is 0.15 meter (can be ignored). What is the required pipe for the lateral pipe? 10 m q s =120l/h h s =20m D = ? mm 0.15 m 95 m Q=1.2m 3 /h Example for a micro sprinklers

54
54 Continue:Continue: n = 10 micro-sprinklers length (L) = (9 sprinkler x 10 m) + 5 m = 95 meters F 10 = 0.384

55
55 The maximum allowable in the field is as follows: For a 20 mm polyethylene pipe grade 4 (ID 16.6 mm), the hydraulic gradient found out of a slide ruler or monograph Q = 1.2 m 3 /h is J = 18.5%. 6.74 meters is exceeding the allowable 4 meters (20%) Continue:Continue:

56
56 The hydraulic gradient for a 25 mm P.E. pipe (ID 21.2 mm) and Q = 1.2 m 3 /h is J = 5.8%. The head loss of 2.1 meters is less than the allowable 4 m (20%). The maximum allowed head loss along the manifold is 4 m - 2.1 m = 1.9 meters. Continue:Continue:

57
57 Continue:Continue: The required pressure by the lateral inlet pipe is as follows:

58
58 Design an Irrigation System Option 1 - The rule of 20% is applied to all the outlets (either sprinklers or drips) on the same subplot. Any excess pressure over 20% between the subplots is controlled by flow pressure regulators. P=< 20%

59
59 Lay out of drip line without pressure regulator

60
60 Drip line inlet without pressure regulator

61
61 Design an Irrigation System Option 2 - The rule of 20% is applied to a single lateral, and pressure regulators control the pressure difference between the laterals. P =< 20%

62
62 Inlet with pressure regulator

63
63 Design an Irrigation System Option 3 - The difference pressure along a lateral pipe exceeds the 20% head loss by any desired amount, and the excess pressure should be reduced by pressure or flow regulators in each emitters or sprinklers. P > 20%

64
64 Example:Example: Ten micro-sprinklers are installed along a plastic lateral pipe (grade 4) at 10 m (32.8 ft) apart (the first sprinkler is 5 meters). The flow rate of the selected sprinkler is q s = 120 l/h (0.5 GPM), at a pressure of h s = 20 meters. The riser height is 0.15 m (which can be ignored). What is the appropriate lateral pipe diameter, if the field is designed and abided by options 1, 2 and 3? n = 10, L = 95 mF 10 =0.384

65
65 Option 1: For 20 mm - The hydraulic gradient For a 20 mm P.E. pipe and Q = 1.2 m 3 /h is J = 18.5%. 6.72 meters exceed the allowable 4 meters (20%) Continue:Continue:

66
66 Continue:Continue: For 25 mm - The hydraulic gradient For a 25 mm P.E. pipe and Q = 1.2 m 3 /h is J = 5.8%. The head loss difference 4 - 2.11 = 1.89 m, which is available for the manifold head loss. The inlet lateral pressure is:

67
67 Continue:Continue: Option 2: If the allowable pressure variation along the lateral pipe is 4 meters, then 25 mm P.E. pipe is too much and 20 mm pipe too small. Therefore, a combination of the two pipes can be used. The design procedure for the combined lateral pipe is: Try first D = 25 mm along 35 meters (n = 4) and D = 20 mm along 60 meters (n = 6)

68
68 Compute the head loss for a pipe D = 25, L = 95 m, n = 10 and Q = 1.2 m 3 /h (from previous calculation which it was found 2.11 m) Compute the head loss for D = 25, L = 60 m, n = 6 and F 6 = 0.458 Continue:Continue:

69
69 Continue:Continue: From a table or a slide ruler - the hydraulic gradient for D = 25 mm and Q = 0.72 is J = 2.4%. The head loss for D = 25 mm and 35 meter long with four sprinklers is 2.11 m - 0.64 = 1.47 meter L = 60 m h = 0.64 L = 95 m h = 2.11 mm L = 35 m h = h 95 – h 60

70
70 Continue:Continue: Compute the head loss in D = 20 mm, L = 60 meters, n = 6 and F 6 = 0.458 and From tables or a slide ruler the hydraulic gradient for D = 20 mm and Q = 0.72 is J = 7.6%.

71
71 Continue:Continue: The total head loss along the combined 25 and 20 mm lateral is as follows: Since 3.5 m is too less than 4.0 meters. Therefore, it is possible to try a shorter 25 mm pipe with a length of 25 m and n = 3 and a longer 20 mm diameter pipe along 70 m and n = 7. The previous procedure should be repeated. The new head loss is 4.5 meters, which exceeds the limit of 4 meters - (20% rule).

72
72 Continue:Continue: The lateral inlet pressure requirement is as follows:

73
73 Continue:Continue: Option 3: The lateral pipe is design either with flow or pressure regulators in every - sprinkler. The laterals diameter can be reduced to 20 mm or even further to 16 mm. In case of 20 mm diameter pipe, the head loss is 6.72 meters (see Option 1). Therefore, the pressure requirement at the last lateral inlet is: The lateral inlet pressure - the entire head loss is added to the required sprinkler pressure.

74
74 Example:Example: A manifold was installed along the center of a rectangular field (100 x 100 m). The lateral pipes were hooked up to the two sides of the manifold pipe. The difference in elevation between the center and the end of the field is 2 meters (either positive or negative). Each lateral pipe has eight 120 l/hr micro-sprinklers at 6 meters apart and the pressure (h s ) is 25 meters. What is the required diameter of the lateral pipess, if the system is designed and abides by option 1?

75
75 The lateral's head loss along the two sides of the manifold should be close enough (in away that the total head loss due to the difference in elevation and friction on both sides of the manifold should be almost the same). 100 m 6m 4% slope Answer:Answer:

76
76 Continue:Continue: For a 20 mm (ID = 16.6 mm) lateral pipe on the two sides: n = 8F 8 = 0.394 L = (7 sprinklers x 6 m) + 3 m = 45 m The maximum head loss between the sprinklers throughout the field is:

77
77 The hydraulic gradient for Q = 0.96 m 3 /hr and D = 20 mm (ID = 16.6 mm) is J = 12.5% The inlet pressure on the downward slope lateral is: Continue:Continue:

78
78 The pressure by the last sprinkler is The pressure difference between the two ends is Continue:Continue:

79
79 The inlet pressure by the lateral upward is: The pressure by the last sprinkler is The head loss along the upward lateral is 27.65 m - 23.4 m = 4.25 m, which is less than 5 m - 20% rule Continue:Continue:

80
80 The pressure requirement for the upward laterals inlet is 27.65 m and for downward laterals inlet is only 25.6 m. The head loss along the upward laterals is 4.25 m, almost all the permitted 20% (5 m). Therefore either: the upward lateral will be increased to 25 mm or more, the manifold can be reallocated to a higher position. (or pressure regulators should be installed by the lateral inlets,) Continue:Continue:

81
81 Continue:Continue: When 20 mm lateral pipes are in used, the values of h u for both sides of the manifold vary by 27.65 - 25.6 = 2.05 m. To avoid this difference (h u ) in the pressure, the upward 20 mm laterals can be replaced by 25 mm. The inlet pressure (h u ) for 25 mm is 26.5 m. Therefore, the the difference inlet pressure for both sides of the manifold will be less, only 26.5 - 25.7 = 0.8 m. Less expensive alternative is by reallocating the manifold away from the center of the field to a higher point. That way, 6 sprinklers will be on the upward side and 10 sprinklers on the downward laterals.

82
82 D = 20 mmn = 10L = (9 sprinkler x 6 m) + 3 m = 57 m Q = 1.2 m 3 /hrF 10 = 0.384 J = 18.5% Downward laterals: Continue:Continue:

83
83 The difference elevation is as follows: The pressure at the lateral inlet is as follows: Continue:Continue:

84
84 The pressure head by the last lateral sprinkler is The head loss along the downward lateral is Continue:Continue:

85
85 Upward laterals: n = 6 F 6 = 0.405 L = (5 sprinklers x 6) + 3 = 33 m Q = 0.72 m 3 /hr D=20 mm (ID=16.6mm) J = 7.6% The elevation difference is for a slope of 4% is: Continue:Continue:

86
86 The pressure head at the lateral inlet is: The pressure head at the last lateral sprinkler is Continue:Continue:

87
87 The head loss along the upward lateral is The values of h u for both sides are 27.1 m and 26.51 m which is practically the same. The maximum head loss is 2.3 m, so 2.7 meters are available as a head loss for the manifold. Continue:Continue:

88
88 The manifold is a pipe with multiple outlets with the same space between the outlets, therefore the manifold is designed the same way as a lateral. Design of a manifold pipe

89
89 A fruit tree plot (96 x 96 m) is designed for irrigation with a solid set system. A manifold is laid throughout the center of the field. The whole plot is irrigated simultaneously. The flow rate of the selected micro-sprinkler is q s = 0.11 m 3 /hr at a pressure (h s ) of 2.0 atmosphere. The space between the micro-sprinklers along the lateral is 8 meters (26.24 ft.) and between the laterals is 6 meters (19.68 ft.). What is the required diameter of the pipes? (The local head loss is 10% of the total head loss and is taken in account). Example:Example:

90
90 96 m manifold lateral 8m8m Answer:Answer: 6 m q s =.11m 3 /h P s =20m

91
91 The maximum allowable pressure head variation is The number of micro-sprinkler on every lateral is Continue:Continue:

92
92 F 6 = 0.405 L = (5 sprinklers x 8 m) + 4 m = 44 m Q = 0.11 m 3 /hr x 6 sprinklers = 0.66 m 3 /hr For 16 mm P.E. lateral pipe (ID = 12.8 mm) The hydraulic gradient for 16 mm P.E. pipe (ID=12.8mm) and Q = 0.66 m 3 /hr is J = 22.3% Continue:Continue:

93
93 The head loss along 16 mm lateral pipe (including 10% local head loss) is as follows: 4.36 m head loss exceeds the allowable 4 meter (20%). So we have to try the head loss for 20 mm P.E. lateral pipe. Continue:Continue:

94
94 The hydraulic gradient for 20 mm P.E. pipe (ID = 16mm) and Q = 0.66 m 3 /hr is J = 6.5% The head loss in 20-mm lateral pipe (including 10 local head loss) is Continue:Continue:

95
95 1.3 m head loss is less than 4 m (20%) and can be selected as a lateral. The lateral inlet pressure is: The water pressure at the last micro-sprinkler on the lateral pipe is, as follows: Continue:Continue:

96
96 Manifold Design: The number of laterals is F 32 = 0.376L = (31 laterals x 6 m) + 3 = 93 m Q = 32 x 0.66 = 21.1 m 3 /hr Continue:Continue:

97
97 The hydraulic gradient for 63 mm P.E. pipe (ID = 58.2 mm) and Q = 21.1 m 3 /hr is J = 7.2% The head loss in 63 mm P.E. pipe (including 10% local head loss) is as follows: Continue:Continue:

98
98 The pressure by the manifold inlet is as follows: The pressure by the last lateral inlet is as follows: The maximum pressure in the entire plot is at the first lateral inlet 23.07 meters (2.3 atmosphere) Continue:Continue:

99
99 Continue:Continue: The minimum pressure throughout the system is at the last sprinkler on the last lateral, which is as follows: 20.31 - 1.3 = 19.01 m The pressure difference between the first and last sprinkler is as follows: 23.07 - 19.01 = 4.06 m (i.e. just above 4 meters (20%))

100
100 s Distribution of water and pressure

101
101 h average q average main pipe manifold p max. p min <20% q max q min <10% lateral Distribution of water and pressure

102
102 Designing of Irrigation System Considerations: soil, topography, water supply and quality, kind of crops, climate. o Soil – infiltration rate, field capacity, (the lighter the soil is - a higher advantage to drip system). המטרה המטרה o Topography – the steeper the terrain - a higher advantage to drip system. o Water supply – availability (time), pressure and quantity o Water quality – salinity (chlorine, SAR, B, heavy metal or any other toxic), hardness, Fe, Mn, total suspended material and type. o Crop – as the root system shallower a higher advantage to micro irrigation system (closing spacing). o Price – as the expected income is relative higher - a better water distribution system is an advantage. o Crop – Layout of the crop and type. o Climate – evaporation, wind pattern, crop protection (high or low temperature)

103
103 Continue:Continue: Farm schedule. o Working time. o Crop related activity – such as chemical application, harvesting, weeds control and so on. Water application: o Estimate water application depth at each irrigation cycle. o Determine the peak period of daily water consumption. o Determine the frequency of water supply.

104
104 Continue:Continue: Irrigation system: o Consider several alternative types of irrigation systems. o Determine the sprinklers or emitters spacing, discharge, nozzle sizes, water pressure. המטרה טפטוף המטרה טפטוף o Determine the minimum number of sprinklers or emitters (or a size of subplot) which must be operated simultaneously.

105
105 Continue:Continue: Irrigation layout: o Divide the field into sub-plots according to the crops, availability of water and number of shifts (in one complete irrigation cycle). o Determine the best layout of main and laterals. o Determine the required lateral size. o Determine the size of a main pipe. o Select a pump.

106
106 ContinueContinue Prepare plans, schedules, and instructions for a proper layout and operation. Prepare a schematic diagram for each set of sub- mains or manifolds which can operate simultaneously. Prepare a diagram to show the discharge, pressure requirement, elevation and pipe length. Select appropriate pipes, starting at the downstream end and ending up by the water source.

107
107 Combination of pipes The total head loss along 300 meters PVC (grade 6) pipe is 15 m, with a flow rate of 180 m 3 /h. Which size of pipes are required? 300 m h=15m Q=180 m 3 /h

108
108 AnswerAnswer The hydraulic gradient for 160 mm (ID 150.2 mm) is: 3.4% Therefore, the head loss for 300 m long pipe is: 10.2 m (too big pipe) The hydraulic gradient for 140 mm (ID 131.4 mm) is: 6.4% Therefore, the head loss for 300 m long pipe is: 19.2 m (too small pipe). Therefore, a combination of the two can make it.

109
109 Cont.Cont. 300 m Q=150 m 3 /h L300-L 140 m 160 mm PVC pipe + 160 m 140 mm PVC pipe

110
110 Example:Example: A flat field with two plots, each plot is divided into six subplots. The selected system for this field is drip irrigation. The flow rate in each subplot is 21 m 3 /hr and the pressure requirement to the sub- main inlets is 25 meters. The interval of water supply is every three days and only one shift a day. Therefore, two subplots in each plot must be irrigated simultaneously. The main pipes are made of PVC (C = 150) and are buried 0.6 meters deep. The local head losses is up to 10% of the longitudinal head losses. The pump pressure is 50 meters and with a flow rate of 84m 3 /h (local head loss due primary filter and others pump attached accessories is 10m).

111
111 1 35 Continue:Continue: 1 ’ 3 ’ 5 ’ C BA 2 46 C ’ B ’ A ’ 2 ’ 4 ’ 6 96m 50m 250m D E 120m F Pump Q=84m 3 /h 96m 50m

112
112 Pressure requirement Q u =21m 3 H u =25 m Q u =84m 3 H u =40m

113
113 Continue:Continue: The sequence of water application is as follows: First day - 1, 5, 1' and 5' plots Second day - 2, 6, 2' and 6' plots Third day- 3, 4, 3' and 4' plots

114
114 The diagram for the first and second day of water supply is: Continue:Continue: 1 35 1 ’ 3 ’ 5 ’ C BA 2 46 C ’ B ’ A ’ 2 ’ 4 ’ 6 L=192L=50m 250m D E 120m 2Q=42m 3 /h Q=21m 3 /h L=192mL=50m h u =25.6m 2Q=42m 3 /h Q=21m 3 /h F Pump (Q=84m 3 /H= 50m)

115
115 The diagram for the third day of water supply is: Continue:Continue: 1 35 1 ’ 3 ’ 5 ’ C BA 2 46 C ’ B ’ A ’ 2 ’ 4 ’ 6 L=146m 250m D E 120m F Pump (Q=84m 3 /h, 40m) 2Q=42m 3 /h Q=0m 3 /h L=146m h u =25.6m 2Q=42m 3 /h Q=0m 3 /h

116
116 Main pipes ’ diagram for first and second day F E 120 m 84 m 3 /h D C 300 m 42 m 3 /h A 192m 21m 3 /h

117
117 Main pipes ’ diagram for third day (Case 2) F E 120 m 84 m 3 /h D B 396 m 42 m 3 /h

118
118 Continue:Continue: The following table presents the the head loss (including 10%) for local head loss for selected pipe:

119
119 Continue:Continue: Case 1: Design system for the first and second day. hu - 25.6 m (including the depth of the main pipe 0.6 m) pump pressure - 40 m Total head loss = 40 - 25.6 = 14.4 m Head loss for the selected pipe: A-C 192m Q = 21 m 3 /hr 3" pipe = 4.5 m C-D 50mQ = 42 m 3 /hr 4" pipe = 1m D-E 250mQ = 42 m 3 /hr 4" pipe = 5.2 m The pressure by E is : 25.6 + 4.5 + 1.0 + 5.2 = 36.3 m. The head loss available for E-F = 40 – 36.3 = 3.7 m

120
120 Pressure diagram for case 1 A C D E F 25.6m 30.1m 31.1m 36.3m 40m 3” 192m4” 50m 4”250m

121
121 Continue:Continue: For E - F (pump) section: 4" pipe is too small (8.8 m head loss, 6.7%), on the other hand 5" pipe is too much (3 m head loss, 2.3%). Therefore, a combination of the two is selected for E-F section. L (4") = 13.7 m L (5 “ ) = 120 – 13.7 = 106.3 m

122
122 Case 2 B D E 146m 250m 42 m 3 Hu-25.6 F 42 m 3 Hu-40m

123
123 ContinueContinue Case 2 : Design system for the third day: h u – 25.6 m (including the depth of a main pipe 0.6 m) After pump pressure - 40 m Maximum head loss = 40 – 25.6 = 14.4 m Selected pipes – B-D Q = 42 m 3 /hr 4" pipe = 3 m D-E Q = 42 m 3 /hr 4" pipe = 5.2 m The pressure head by E tee is 26.6+3+5.2=33.8 m. The head loss available for E-F = 40 – 33.8 = 6.2 m

124
124 Case 2 B D E 4” 146m 4” 250m 42 m 3 Hu-25.6 H-28.6m H-33.8m F Hu-40m

125
125 ContinueContinue The pressure in case 2 at point E is 33.8 m which is lower than in case 2 which was 36.3 m (pressure different of 2.5 m).. Therefore, the pipe for DB should be reduced, in a way that the pressure at a point D should be a same as case 1 which is 31.2m. B D E 146m 250m 42 m 3 Hu-25.6 H-31.1m A combination of pipes 3” and 4” for DB section with 5.6 m head loss should be selected.

126
126 ContinueContinue Section DB: the hydraulic gradient for 3” pipe with 42 m 3 is 7.5% and for 4” is 1.9% 3” pipe is = 39.75 m and for 4” is 106.25 m (The actual length should take in account the commercial pipe length)

127
127 Case 2 B D E 4” 250m 42 m 3 Hu-25.6 H-31.2m 3” 4” 39.75 m106.25m In this situation the size of pipes DE and EF are a same as in case 1. In case 2, the required pipes are smaller than case 1 (DB). (The selected pipe in case 1 are too small to maintain the pressure requirement in case 2) 42 m 3

128
128 Pipe diagram for case 1 & 2 A C D E F Hu-25.6m 3” 135.25m 4” 106.75m 4”250m B

129
129 Head loss in case 1 For section A – C (192m 21m 3 /h): 3” 137.4 m - 3.2 m 4” 54.6m - 0.3 m For section C – D (42m 3 /h) 4” 50 m - 1 m For section D – E (42 m 3 /h): 4” 250 m - 5.2 m For section E – F (120m 84m 3 /h): 4” 13.7 m - 1 m 5: 106.3 m - 2.7 m The total head loss from A to F is -13.4 m

130
130 Pressure diagram for case 1 A C D E F 25.6m 3” 137.4m 4” 104.6m 4”250m B H-29.1m H-30.1 H-35.3m H-39m

131
131 Head loss in case 2 For section D – B (1146m 42m 3 /h): 3” 39.75 m - 3.3 m 4” 106.25 m - 2.2 m For section D – E (42 m 3 /h): 4” 250 m - 5.2 m For section E – F (120m 84m 3 /h): 4” 13.7 m - 1 m 5”: 106.3 m - 2.7 m The total head loss from A to F is 14.4 m

132
132 Pressure diagram for case 2 C D E F 25.6m 3” 39.75m 4” 106.25m 4”250m B H-28.9m H-31.1 H-36.3m H-40m צריך להוסיף מפה דומה ל - Case 2

133
133 Diagram for E – A ’ case 2 A C D E F 25.6m 3” 137.4m 4” 104.6m 4”250m B H-28.9m H-31.1 H-36.3m H-40m B’ 25.6m

134
134 The pipe for E – A ’ for case 1 The head loss E – A’: 35.3 – 25.6 = 9.7 m The length of E – C’ is 50 m 42 m 3 /h for 3” pipe the head loss is 4.1 m The length of C’ A’ is 192 m 21m 3 /h the required head loss for this section is: 9.7 – 4.1 = 5.6m The hydraulic gradient for 2” is 15% and for 3” is 2.1% and combination of the two will make it. E C’ A’A’ Q – 21m 3 /h 42m 3 /h H-35.3mH-25.6m 192 m50 m

135
135 ContinueContinue 8.2 m 2” pipe, and 183.8 m 3” pipe. The head loss for E-C’ 3” pipe (42 m 3 /h is 4.1 m. The total head loss for E-A’ is 9.7 m. E C’ A’ Q – 21m 3 /h 42m 3 /h 2” 8.2m 3” 233.8 m The hydraulic gradient for 2” is 15% and for 3” is 2.1% and combination of the two will make it.

136
136 The pipe for E – B ’ for case 2 The head loss E – B’: 36.3 – 25.6 = 10.7 m The length of E – B’ is 146 m 42 m 3 /h The head loss for 3” is too much 12.1 m and for 4” is too small 3 m A combination of the two will make it, the hydraulic gradient for 3” is 7.5% and for 4” is 1.9%. EB’ 42m3/h 146 m H-36.3mH-25.6m

137
137 The combination pipes for E – B ’ 3” pipe 124.1 m 4” pipe21.9 m

138
138 Diagram for E – A ’ for case 2 A C D E F 25.6m 3” 137.4m 4” 104.6m 4”250m B H-29.1m H-30.1 H-35.3m H-39m A’ 25.6m 2” 8.2m B’ 3” 211.9m 4” 21.9m Since the size of the pipe E-A’ increased, therefore we have to reconsider the pipe size for EA’ in case 1.

139
139 Section E-A ’ case 1 E A’ 25.6m 2” 8.2m C’ 3” 211.9m 4” 21.9m H-35.3m The head loss E – B’: 35.3 – 25.6 = 9.7 m The length of E – C’ is 50 m 42 m 3 /h The head loss for 4” 21.9 m is 0.5 m The head loss for 3” 28. 1 m is 2.3 m The length of C’ – A’ is 192 m 21 m 3 /h The head loss for 3” 183.8 m is 4.3 m The head loss for 2” 8.2 m is 1.4 m The total head loss is 0.5 + 2.3 + 4.3 + 1.4 = 8.5 m Therefore, the length of 2” pipe can be extended a little bit by (to increase the head loss): 9.7 – 8.5 = 1.2 m:

140
140 ContinueContinue The length of B – A is 96 m with 21 m 3 /h The current head loss is: for 3” 183.8 m is -4.3 m for 2” 8.2 m is -1.4 m The total head loss should be increased by 1.2 m 4.3 + 1.4 + 1.2 = 6.9 m The hydraulic gradient for 2” and 21m 3 /h is 15% and for 3” pipe is 2.1% The length of 2” pipe is 17.4 m and 3” pipe is 174.6 m

141
141 Final Diagram for E – A ’ A C D E F 25.6m 3” 137.4m 4” 104.6m 4”250m B H-29.1m H-30.1 H-35.3m H-39m A’ 25.6m 2” 17.4m B’ 3” 202.7m 4” 21.9m C’ To overcome the pressure differences, pressure regulator should be installed by every risers. 4” 5”

142
142

143
143

144
144 To overcome the pressure differences, pressure regulator should be installed by every risers.

145
145 צריך להוסיף את בחינה של גודל צינורות E-A’ עבור case2 אשר נדרש לקטרים אחרים

146
146 Case 2 B D E 250m 42 m 3 Hu-25.6 H-31.2m 3” 4” 41.4 m104.6m

147
147 ContinueContinue The pipe selection for F - A is as follows: A-D 3" 242 meters D-E 4" 250 meters E-F 6" 120 meters

148
148 H u =38m C ’ B ’ A ’ E H u =25.6 ContinueContinue The pipe selection for the section E-A' for case 1 is as follows: 50 m 42m 3 /h 192m 21m 3 /h

149
149 ContinueContinue The head loss is 38.0 - 25.6 = 12.4 m Selection of pipes - A'-C' Q = 21 m 3 /hr 2" pipe = 7.7 m The head loss available for E-C' 38 - 7.7 - 25.6 = 4.7 m

150
150 ContinueContinue 2" pipe is too small (6.5 m), on the other hand 3" pipe is too much (2.4 m). Therefore, a combination of the two pipes is required for E- C' section. The two pipes which required for E- C section are: L = 33 m L(3") = 33 meters and 2" pipe 27 meters

151
151 ContinueContinue The design for the section E-A' for case 2 is as follows: Q EB' = 42 m 3 /hr 2" pipe = 7.7 m The hydraulic gradient for E-B ’ section is 38.0 - 25.6 = 12.4 m A’ B’ C’ E H=38m 146m 42m 3 /h

152
152 ContinueContinue 2" pipe is too small (18.9 m), on the other hand 3" pipe is too much (6.9m) Therefore, a mix of the two is required for F-B', section. L = 95 L (3") = 95 m and 2" pipe 51 m

153
153 The selected pipe for E-B' section will be as in case 2, 95 meters 3" pipe and 51 meters 2" pipe. Pressure regulators on some of the risers should be considered to compensate the total head loss over 20% (including the head loss inside each plot). Continue:Continue:

Similar presentations

© 2017 SlidePlayer.com Inc.

All rights reserved.

Ads by Google