CN109711017B - Micro-irrigation capillary pipe length hydraulic design method based on flow deviation coefficient - Google Patents
Micro-irrigation capillary pipe length hydraulic design method based on flow deviation coefficient Download PDFInfo
- Publication number
- CN109711017B CN109711017B CN201811536312.9A CN201811536312A CN109711017B CN 109711017 B CN109711017 B CN 109711017B CN 201811536312 A CN201811536312 A CN 201811536312A CN 109711017 B CN109711017 B CN 109711017B
- Authority
- CN
- China
- Prior art keywords
- capillary
- design
- length
- flow
- micro
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 238000003973 irrigation Methods 0.000 title claims abstract description 105
- 238000000034 method Methods 0.000 title claims abstract description 39
- 238000004364 calculation method Methods 0.000 claims abstract description 27
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 20
- 230000002457 bidirectional effect Effects 0.000 claims description 25
- 230000002411 adverse Effects 0.000 claims description 13
- 230000002262 irrigation Effects 0.000 claims description 13
- 238000012938 design process Methods 0.000 claims description 10
- 238000012876 topography Methods 0.000 claims 2
- 238000010586 diagram Methods 0.000 description 6
- 230000014509 gene expression Effects 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000003908 quality control method Methods 0.000 description 1
Images
Landscapes
- Control Of Metal Rolling (AREA)
- Complex Calculations (AREA)
Abstract
The invention discloses a flow deviation coefficient-based hydraulic design method for the length of a micro-irrigation capillary tube, which comprises the following steps: constructing a capillary tube length design parameter based on a flow deviation coefficient according to the capillary tube slope-drop ratio and the flow index; and determining a calculation formula of the micro-irrigation capillary tube length according to the pipe network arrangement form, and calculating to obtain the capillary tube length based on the obtained capillary tube length design parameters based on the flow deviation coefficient. On the premise of giving a design standard and other design indexes of the flow deviation coefficient, the method can simply and conveniently calculate the number of the pipe lengths and specific numerical values meeting the flow deviation coefficient, determine a proper arrangement form of the capillary, and calculate the working water head at the inlet of the capillary. The invention can improve the design efficiency of the length of the micro-irrigation capillary tube; by considering a proper capillary arrangement form, the design pipe length of the capillary is optimized, and the system investment is reduced.
Description
Technical Field
The invention belongs to the technical field of micro-irrigation capillary tube design, and particularly relates to a flow deviation coefficient-based micro-irrigation capillary tube length hydraulic design method.
Background
When the working water head of the inlet of the micro-irrigation capillary is unknown, designing the capillary length meeting the standards of design flow and irrigation uniformity of an irrigation emitter is one of common hydraulic design tasks. Meanwhile, the investment can be saved and the irrigation quality can be improved by selecting a proper capillary arrangement form. The flow deviation coefficient is one of the commonly used irrigation uniformity design indexes in China.
At present, the method for designing the capillary length of micro irrigation is to solve the capillary length by means of the traditional trial algorithms such as Newton iteration method, dichotomy method, golden section method and the like on the basis of the known capillary length, design flow and other related design parameters of an irrigation emitter, and 1 or more calculated values of the capillary length may exist for the same design flow and flow deviation coefficient design standard of the irrigation emitter; it has the problems that: only 1 calculated value can be obtained by using the traditional trial algorithm, the method cannot be applied to the situation of solving a plurality of calculated values, and the calculation method is complex; furthermore, the design process cannot take into account a suitable arrangement of the capillaries.
Disclosure of Invention
The invention aims to provide a micro-irrigation capillary tube length hydraulic design method based on a flow deviation coefficient so as to solve the existing technical problems. The invention can simplify the hydraulic design process of the capillary tube length and improve the design efficiency.
In order to achieve the purpose, the invention adopts the following technical scheme:
a micro-irrigation capillary tube length hydraulic design method based on a flow deviation coefficient comprises the following steps:
constructing a capillary tube length design parameter based on a flow deviation coefficient according to the capillary tube slope-drop ratio and the flow index; and determining a calculation formula of the micro-irrigation capillary tube length according to the pipe network arrangement form, and calculating to obtain the capillary tube length based on the obtained capillary tube length design parameters based on the flow deviation coefficient.
Further, a calculation formula for constructing the capillary tube length design parameter based on the flow deviation coefficient is as follows:
in the formula: w LCV Designing parameters for the capillary tube length based on the flow deviation coefficient; j is the slope-to-fall ratio of the capillary; m is a flow index; lambda [ alpha ] CV Designing parameters for the capillary flow deviation coefficient based on a suitable arrangement form; x is the flow state index of the irrigator; p is a terrain grade type identifier: in the case of a reverse slope, p is-1, in the case of a flat slope, p is 0, and in the case of a forward slope, p is 1; s. the 0 Is the grade of the terrain; m L Calculating parameters for the capillary length; c Vq(h) Only considering the flow deviation coefficient of hydraulic deviation for the micro-irrigation capillary; h is a total of d For the operating head of the emitter, unit: m; Δ H S The height difference of the ground shape of the inlet and the tail end of the capillary is shown as the following unit: m; Δ H F The total friction loss of the capillary is unit: m; l is the length of the micro-irrigation capillary tube, unit: m; f s Total head loss expansion factor of capillary for local head loss of irrigator, F s 1.10-1.20; q is total flow of the capillary inlet, and the unit is as follows: l/h; n is the number of micro-irrigation capillary douches; s e Is the emitter spacing, unit: m; q. q.s d Design flow for emitter, unit: l/h; d is the inner diameter of the capillary, unit: mm; k is the friction coefficient; b is a pipe diameter index; c. C 1 、c 2 To calculate the parameters; values of the design parameters m, K and b are obtained by referring to micro-irrigation engineering design Specification GB/T50485-.
Further, for a flat slope terrain, the micro-irrigation capillary tubes are arranged in a two-way mode, and the calculation formula of the tube length is as follows:
in the formula: l is micro-bushTube length, unit: m; [ C ] Vq(h) ]Designing a standard for the flow deviation coefficient; m is a flow index; m is a group of L Calculating parameters for the capillary length; h is d For the operating head of the emitter, unit: m; x is the emitter flow state index; d is the inner diameter of the capillary tube in unit: mm; b is a pipe diameter index; s is e Is the emitter spacing, unit: m; f s Total head loss expansion factor of capillary for local head loss of irrigator, F s 1.10 to 1.20; k is the friction coefficient; q. q.s d Design flow for emitter, unit: l/h.
Furthermore, for the micro-irrigation capillary tube which is limited by the terrain and can be arranged in a single-way adverse slope manner:
when the flow index m is 1.75, the condition that the length of the micro-irrigation capillary tube based on the flow deviation coefficient has a design value is as follows: 0<[W LCV ]Less than or equal to 1.767; when the flow index m is 1.69, the condition that the length of the micro-irrigation capillary tube based on the flow deviation coefficient has a design value is as follows: 0<[W LCV ]Less than or equal to 1.762; when the flow index m is 1.00, the condition that the length of the micro-irrigation capillary tube based on the flow deviation coefficient has a design value is as follows: 0<[W LCV ]≤1.718；
Wherein [ W ] LCV ]The method is a micro-irrigation capillary tube length design parameter based on a flow deviation coefficient design standard.
Further, for the micro-irrigation capillary tube arranged in two directions:
when the flow index m is 1.75, the condition that the length of the micro-irrigation capillary tube based on the flow deviation coefficient has a design value is as follows: w is more than or equal to 0 LCV ]Less than or equal to 10.929; when the flow index m is 1.69, the condition that the length of the micro-irrigation capillary tube based on the flow deviation coefficient has a design value is as follows: w is more than or equal to 0 LCV ]Less than or equal to 11.176; when the flow index m is 1.00, the condition that the length of the micro-irrigation capillary tube based on the flow deviation coefficient has a design value is as follows: w is not more than 0 LCV ]Less than or equal to 16.092; wherein [ W ] LCV ]The method is a micro-irrigation capillary tube length design parameter based on a flow deviation coefficient design standard.
Further, for the one-way adverse slope capillary, the slope-to-fall ratio J of the capillary has the calculation formula:
when the flow index m is 1.75,
J＝0.0841[W LCV ] 4 -0.3658[W LCV ] 3 +0.5543[W LCV ] 2 -0.8507[W LCV ]-0.0254；
when the flow index m is 1.69,
J＝0.0899[W LCV ] 4 -0.3886[W LCV ] 3 +0.59[W LCV ] 2 -0.8744[W LCV ]-0.0266；
when the flow index m is 1.00,
further, for different flow indexes m, the value range of the micro-irrigation bidirectional capillary design pipe length based on the flow deviation coefficient meets the following requirements:
table 1, when m is 1.75, the flow deviation coefficient-based pipe length value range of the micro-irrigation bidirectional capillary design
Table 2. length range of micro-irrigation bidirectional capillary design pipe based on flow deviation coefficient when m is 1.69
Table 3. length range of micro-irrigation bidirectional capillary design pipe based on flow deviation coefficient when m is 1.00
Wherein, table 1 to table 3 are the values of the length of the micro-irrigation bidirectional capillary designed based on the flow deviation coefficient when m is 1.75, m is 1.69 and m is 1.00 in sequence.
Further, the calculated value J of the slope-to-fall ratio of the micro-irrigation bidirectional capillary in tables 1 to 3 1 The calculation formulas of (A) and (B) are respectively as follows:
when the flow index m is 1.75,
when the flow index m is 1.69,
when the flow index m is 1.00,
micro-irrigation bidirectional capillary slope-drop ratio calculation value J in tables 1 and 2 2 The calculation formula of (2) is as follows:
further, the micro-irrigation capillary tube length hydraulic design process based on the flow deviation coefficient comprises the following steps:
step 1: according to a known design parameter q d K and x, calculating the designed working head h of the irrigation emitter d ；
Step 2: when the diameter D of the capillary is more than 8mm, the flow index m is 1.75, the diameter index b is 4.75, and the friction coefficient K is 0.505;
and 3, step 3: according to known design parameters m, D, s e 、F s K and q d Calculating design parameters of tube length
According to known design parameters x, S 0 、m、M L 、[C Vq(h) ]And h d Calculating the parameter [ W ] using the formula (1) LCV ]；
Wherein,
and 4, step 4: when p is 0, the capillary is arranged bidirectionally according to the known parameters x, M L 、[C Vq(h) ]、h d M, calculating the pipe length L by using the formula (2), and selecting a capillary pipe with the length not exceeding L to design the pipe length by comprehensively considering the terrain condition; according to a known parameter h d 、M L L and m, calculating the working water head h of the capillary inlet 0 ＝h d +(m+1)(0.5L) m+1 /[(m+2)M L ]；
Wherein,
and 5: when p is equal to-1, the capillary is arranged in a one-way reverse slope mode according to a known parameter [ W LCV ]And m, calculating a gradient ratio J by using the formulas (3) to (5), according to a known parameter S 0 、M L M and J, calculating the tube length L [ (-S) 0 M L )/J] 1/m Selecting a capillary tube design tube length with the length not more than L in consideration of the terrain condition; according to a known parameter h d 、M L 、L、S 0 And m, calculating the working water head h of the capillary inlet 0 ＝h d +(m+1)L m+1 /[(m+2)M L ]+0.5S 0 L；
Wherein,
when the flow index m is 1.75,
J＝0.0841[W LCV ] 4 -0.3658[W LCV ] 3 +0.5543[W LCV ] 2 -0.8507[W LCV ]-0.0254 (3)；
when the flow index m is 1.69,
J＝0.0899[W LCV ] 4 -0.3886[W LCV ] 3 +0.59[W LCV ] 2 -0.8744[W LCV ]-0.0266 (4)；
when the flow index m is 1.00,
step 6: when p is 1, the capillary is arranged bidirectionally, according to a known parameter [ W ] LCV ]And m, calculating a slope-to-fall ratio J using equations (6) to (8), based on the known parameter S 0 、M L M and J, calculating the tube length L ═ S 0 M L )/J] 1/m Selecting a capillary tube design tube length with the length not more than L by comprehensively considering the terrain conditions; according to a known parameter S 0 、M L M and L, calculating a gradient ratio parameter J ═ S 0 M L /L m (ii) a Calculating the optimal branch pipe position parameter R according to the parameters m and J L ＝0.0636J 2 -0.4347J +0.5, when m is 1.69, calculate R L ＝0.0582J 2 -0.4286J +0.5, when m is 1.00, calculate R L -3/8J + 1/2; according to a known parameter h d 、R L 、M L L and m, calculating the working water head h of the capillary inlet 0 ＝h d +(m+1)(LR L ) m+1 /[(m+2)M L ]+0.5S 0 LR L ；
Wherein,
when the flow index m is 1.75,
when the flow index m is 1.69,
when the flow index m is 1.00,
and 7: when the inner diameter D of the capillary<When the diameter of the tube is 8mm, assuming that m is 1.69, b is 4.69 and K is 0.505, the tube length L is designed by repeating the steps 3 to 6, and the reynolds number Re is calculated to be Lq d /(900πDs e ν T ) (ii) a If Re>2320, the design result meets the value requirement of flow index m in "micro-irrigation engineering technical Specification"; and if Re is less than or equal to 2320, m is 1.00, b is 4.00, and K is 1.75, and the steps 3 to 6 are repeated to design the tube length L.
Further, the method also comprises the following steps: drawing a relation graph of corresponding slope-drop ratios and pipe length design parameters under different flow indexes, and judging the number of the designed pipe lengths meeting the flow deviation coefficient.
Compared with the prior art, the invention has the following beneficial effects:
the micro-irrigation capillary tube length hydraulic design method based on the flow deviation coefficient can be used for the micro-irrigation capillary tube length hydraulic design process, and can improve the design efficiency of the micro-irrigation capillary tube length; by considering a proper capillary arrangement form, the design length of the capillary can be optimized, and the cost investment is reduced.
Drawings
FIG. 1 shows a design parameter W of a pipe length of a one-way adverse slope capillary based on a flow deviation coefficient LCV A schematic diagram of the relationship with the gradient ratio J, wherein the flow index m is 1.75;
FIG. 2 is a design parameter W of the length of a one-way adverse slope capillary tube based on a flow deviation coefficient LCV A schematic diagram of the relationship with the gradient ratio J, wherein the flow index m is 1.69;
FIG. 3 is a design parameter W of the length of a one-way adverse slope capillary tube based on a flow deviation coefficient LCV A schematic diagram of the relation with the gradient ratio J, wherein the flow index m is 1.00;
FIG. 4 is a design parameter W of the length of a bidirectional capillary tube based on a flow deviation coefficient LCV A schematic diagram of the relationship with the gradient ratio J, wherein the flow index m is 1.75;
FIG. 5 is a design parameter W of the length of a bidirectional capillary tube based on a flow deviation coefficient LCV A schematic diagram of the relationship with the gradient ratio J, wherein the flow index m is 1.69;
FIG. 6 is a design parameter W of the length of a bidirectional capillary tube based on a flow deviation coefficient LCV A schematic diagram of the relation with the gradient ratio J, wherein the flow index m is 1.00;
FIG. 7 shows a flow deviation coefficient based design case I in an embodiment of the present inventionDesign parameter W of capillary length LCV The relation with the slope-drop ratio J is shown schematically;
FIG. 8 shows the design parameters W of the capillary tube length based on the flow deviation coefficient for the design condition II in the embodiment of the present invention LCV And the relation with the slope-drop ratio J is shown schematically.
Detailed Description
The invention is described in further detail below with reference to the figures and specific examples. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.
The invention relates to a micro-irrigation capillary tube length hydraulic design method based on a flow deviation coefficient, which comprises the steps of firstly, constructing capillary tube length design parameters based on the flow deviation coefficient, further providing a simple calculation formula of the capillary tube length under each pipe network arrangement form, and drawing a relation graph of corresponding slope-drop ratios and the tube length design parameters under different flow indexes; on the basis, a micro-irrigation capillary tube length hydraulic design process based on a flow deviation coefficient is provided: knowing the design flow deviation coefficient of the micro-irrigation capillary, the diameter of the capillary and other design variables, calculating the length of the capillary and the working water head at the inlet, and determining the appropriate arrangement form of the capillary and the optimal branch position.
Specifically, the calculation formula of the design parameter of the micro-irrigation capillary tube length based on the flow deviation coefficient is as follows:
in the formula: w LCV Designing parameters for the capillary tube length based on the flow deviation coefficient; j is slope-to-fall ratio of capillary, and J is delta H S /ΔH F (ii) a m is a flow index; lambda CV Designing parameters for micro-irrigation capillary flow deviation coefficients based on a suitable arrangement form; x is the emitter flow state index; p is a terrain grade type identifier: in the case of a reverse slope, p is-1, in the case of a flat slope, p is 0, and in the case of a forward slope, p is 1; s. the 0 Is the grade of the terrain; m L The parameters are calculated for the length of the capillary,
C Vq(h) only considering the flow deviation coefficient of hydraulic deviation for the micro-irrigation capillary; h is d For the operating head of the emitter, unit: m; Δ H S Is the topographic height difference between the inlet and the tail end of the capillary tube, Delta H S ＝pS 0 L, unit: m; l is the length of the micro-irrigation capillary tube, unit: m; Δ H F Δ H is the total friction loss of the capillary F ＝F s KQ m /[(m+1)D b ]L, unit: m; f s To account for the capillary total head loss expansion coefficient of emitter local head loss, usually F s 1.10-1.20; q is total flow of the inlet of the capillary, and Q is N.q d The unit: l/h; n is the number of micro-irrigation capillary douches, and N is L/s for bidirectional capillary e +1, for unidirectional capillary N ═ L/s e ；s e Is the emitter spacing, unit: m; q. q.s d Design flow for emitter, unit: l/h; d is the inner diameter of the capillary, unit: mm; k is the friction coefficient; b is a pipe diameter index; the values of the design parameters m, K and b can be referred to the micro-irrigation engineering design Specification (GB/T50485-.
For the flat slope terrain, the calculation formula of the length of the micro-irrigation capillary tube is as follows:
in the formula: l is the length of the micro-irrigation capillary tube in unit: m; [ C ] Vq(h) ]Designing a standard for the flow deviation coefficient; m is a flow index; m L Calculating parameters for the capillary length; h is a total of d For the emitter operating head, unit: m; x is the flow state index of the irrigator; d is the inner diameter of the capillary, unit: mm; b is a pipe diameter index; s is e Is the emitter spacing, unit: m; f s Total head loss expansion factor of capillary for local head loss of irrigator, F s 1.10-1.20; k is the friction coefficient; q. q.s d Design flow for emitter, unit: l/h.
Referring to fig. 1 to 3 of the drawings,for micro-irrigation capillary tubes which are limited by terrain and can be arranged in a one-way reverse slope only, corresponding slope-to-fall ratio J and tube length design parameters W under different flow indexes LCV The relationship (2) of (c). For a flow index m of 1.75, 1.69 or 1.00, the conditions for the existence of the design value of the micro-irrigation capillary tube length based on the flow deviation coefficient are as follows: 0<[W LCV ]≤1.767、0<[W LCV ]Less than or equal to 1.762 or 0<[W LCV ]1.718, for a given emitter design flow q d Sum flow deviation factor design criteria [ C Vq(h) ]The slope-drop ratio J has a unique calculated value, and the capillary tube length also has a unique calculated value.
For the one-way adverse slope capillary, the calculation formula of the slope-to-fall ratio parameter J is as follows:
when the flow index m is 1.75,
J＝0.0841[W LCV ] 4 -0.3658[W LCV ] 3 +0.5543[W LCV ] 2 -0.8507[W LCV ]-0.0254 (3)
when the flow index m is 1.69,
J＝0.0899[W LCV ] 4 -0.3886[W LCV ] 3 +0.59[W LCV ] 2 -0.8744[W LCV ]-0.0266 (4)
when the flow index m is 1.00,
referring to fig. 4 to 6, for the micro-irrigation capillary tubes arranged in two directions, the corresponding slope-to-fall ratio J and the tube length design parameter W under different flow indexes LCV The relationship (2) of (c). For a flow index m of 1.75, 1.69 or 1.00, the conditions for the existence of the design value of the length of the micro-irrigation capillary tube based on the flow deviation coefficient are as follows: w is not more than 0 LCV ]≤10.929、0≤[W LCV ]Less than or equal to 11.176 or less than or equal to 0 [ W ≦ W LCV ]Less than or equal to 16.092. For a given emitter design flow q d Sum flow deviation factor design criteria [ C Vq(h) ]The slope-to-fall ratio J has 1 or 2 calculated values, and the capillary length is 1 or 2 calculated values.
For different flow indexes m, the value ranges of the lengths of the micro-irrigation bidirectional capillary design pipes based on the flow deviation coefficient are respectively as follows:
table 1. micro-irrigation bidirectional capillary design pipe length value range based on flow deviation coefficient (m is 1.75)
Table 2. micro-irrigation bidirectional capillary design pipe length value range based on flow deviation coefficient (m is 1.69)
Table 3. micro-irrigation bidirectional capillary design pipe length value range based on flow deviation coefficient (m is 1.00)
Micro-irrigation bidirectional capillary slope-drop ratio calculation value J in tables 1-3 1 The calculation formulas of (A) and (B) are respectively as follows:
when the flow index m is 1.75,
when the flow index m is 1.69,
when the flow index m is 1.00,
table 1-2 shows the calculated value J of slope-to-fall ratio of micro-irrigation bidirectional capillary 2 The calculation formula of (2) is as follows:
the design process specifically comprises the following steps: the deviation coefficient of the design flow of the micro-irrigation capillary is known Vq(h) ]The design steps of the pipe diameter D and other design variables, the length of the capillary pipe, the suitable arrangement form, the best branch pipe position and the working water head at the capillary inlet are determined:
step 1: according to known design parameters q d K and x, calculating the designed working head h of the irrigation emitter d ；
And 2, step: when the pipe diameter D is more than 8mm, the flow index m is 1.75, the pipe diameter index b is 4.75, and the friction coefficient K is 0.505;
and step 3: according to known design parameters m, D, s e 、F s K and q d Calculating design parameters of tube length
According to known design parameters x, S 0 、m、M L 、[C Vq(h) ]And h d Calculating the parameter [ W ] using the formula (1) LCV ]；
And 4, step 4: when p is 0, the capillary is arranged bidirectionally, according to the known parameters x, M L 、[C Vq(h) ]、h d And m, calculating the pipe length L by using the formula (2), and selecting a capillary pipe with the length not more than L by comprehensively considering the terrain condition to design the pipe length; according to a known parameter h d 、M L L and m, calculating the working water head h of the capillary inlet 0 ＝h d +(m+1)(0.5L) m+1 /[(m+2)M L ]；
And 5: when p is equal to-1, the capillary is arranged in a one-way reverse slope mode according to a known parameter [ W LCV ]And m, calculating a gradient ratio J by using the expressions (3) to (5), and calculating the gradient ratio J according to the known parameter S 0 、M L M and J, calculating the tube length L [ (-S) 0 M L )/J] 1/m Selecting a capillary tube design tube length with the length not more than L by comprehensively considering the terrain conditions; according to a known parameter h d 、M L 、L、S 0 And m, calculating the working water head h of the capillary inlet 0 ＝h d +(m+1)L m+1 /[(m+2)M L ]+0.5S 0 L；
And 6: when p is 1, the capillary is arranged bidirectionally, according to a known parameter [ W ] LCV ]And m, calculating a gradient ratio J by using the expressions (6) to (8), and calculating the gradient ratio J according to the known parameter S 0 、M L M and J, calculating the tube length L ═ S 0 M L )/J] 1/m Selecting a capillary tube design tube length with the length not more than L by comprehensively considering the terrain conditions; according to a known parameter S 0 、M L M and L, calculating a gradient ratio parameter J ═ S 0 M L /L m (ii) a Calculating the optimal branch pipe position parameter R according to the parameters m and J L ＝0.0636J 2 -0.4347J +0.5, when m is 1.69, calculate R L ＝0.0582J 2 -0.4286J +0.5, when m is 1.00, calculate R L -3/8J + 1/2; according to a known parameter h d 、R L 、M L L and m, calculating the working water head h of the capillary inlet 0 ＝h d +(m+1)(LR L ) m+1 /[(m+2)M L ]+0.5S 0 LR L 。
And 7: when the inner diameter D of the capillary<When 8mm is used, assuming that m is 1.69, b is 4.69 and K is 0.505, the design tube length L is repeated from step 3 to step 6, and the reynolds number Re is calculated to Lq d /(900πDs e ν T ). If Re>2320, the design result meets the value requirement of flow index m in "micro-irrigation engineering technical specification" (national quality control administration 2009); if Re is 2320 or less, then m is 1.00, b is 4.00, and K is 1.75, and steps 3 to 6 are repeated.
Examples
The known data are: the diameter D of the capillary is 16mm, and the distance s between the douches e 0.3m, local head loss expansion coefficient F s 1.10, the pressure and flow relation of the irrigation device is that q is 0.717h 0.598 Design flow q of emitter d 2.7L/h, terrain slope S 0 0.01, flow deviation coefficient design criteria [ C [ ] Vq(h) ]＝0.10。
Case I: when the terrain gradient type p is equal to-1, calculating the design pipe length L and the inlet working water head h of the one-way adverse slope capillary 0 . The specific design process is as follows:
1) calculating designed working head h of irrigator d
2) Calculating a design parameter M of tube length L
3) Calculating the design parameter [ W ] of the tube length LCV ]
According to fig. 7, the ramp-down ratio has only a unique design value, and therefore the capillary has only a unique design value.
4) Calculating a slope-to-fall ratio parameter J
J＝0.0841[W LCV ] 4 -0.3658[W LCV ] 3 +0.5543[W LCV ] 2 -0.8507[W LCV ]-0.0254
＝0.0841×0.716 4 -0.3658×0.716 3 +0.5543×0.716 2 -0.8507×0.716-0.0254
＝-0.463
5) Calculating the length L of the capillary tube
6) Calculating working water head h of capillary inlet 0
In order to further compare and verify the design results of the disclosed method, the present invention also calculated the design results of the Valiantzas method (1998) which is a traditional representative method: calculated tube length L ═90m, working head h at the inlet of the capillary 0 12.81 m. The relative deviation between the design result of the invention and the design result of the Valiantzas method is within 5%. Therefore, the results of the method of the present invention have sufficient design accuracy; meanwhile, compared with a Valiantzas method which needs to be solved by means of an iterative method, the method is simple and easy to implement in the calculation process, and can improve the design efficiency.
Case II: when the terrain gradient type p is equal to 1, calculating the design pipe length L of the bidirectional capillary pipe and the inlet working water head h 0 Optimum inlet position parameter R L And the length L of capillary tube in the adverse slope section up . The specific design process is as follows:
1) calculating designed working head h of irrigator d
2) Calculating a design parameter M of tube length L
3) Calculating the design parameter [ W ] of the tube length LCV ]
According to table 1 and fig. 8, the ramp down ratio has only a unique design value, and therefore the capillary has only a unique design value.
4) Calculating a slope-to-fall ratio parameter J
J＝0.1328[W LCV ] 0.6317 ＝0.1328×0.716 0.6317 ＝0.108
5) Calculating the length L of the capillary
6) Calculating the optimal design parameter R of branch pipe position L
R L ＝0.0637J 2 -0.4347J+0.5
＝0.0637×0.108 2 -0.4347×0.108+0.5
＝0.454
7) Calculating the number N of capillary douches at the adverse slope section up
8) Calculating the length L of the capillary at the adverse slope section up
L up ＝(N up -1+u)s e ＝(297-1+0.5)×0.3＝88.95(m)
10) Calculating working water head h at capillary inlet 0
To further compare and validate the design results of the disclosed method, the present invention also calculated the design results of the traditional representative method, Keller method (1990): the calculated length L of the pipe is 195.9m, and the length L of the capillary pipe at the adverse slope section up 88.95m, working water head h at the inlet of the capillary 0 13.14 m. The relative deviation between the design result of the invention and the design result of the Keller method is within 0.3 percent. Therefore, the results of the method of the present invention have sufficient design accuracy; meanwhile, compared with a Keller method which needs to be solved by means of a trial algorithm, the method is simple and easy in calculation process, and design efficiency can be improved.
To sum up, the invention provides a flow deviation coefficient-based hydraulic design method for the length of a micro-irrigation capillary tube, which comprises the following steps: firstly, constructing a capillary pipe length design parameter based on a flow deviation coefficient, further providing a simple capillary pipe length calculation formula in each pipe network arrangement form, and visually judging the number of the designed capillary pipes meeting the flow deviation coefficient by drawing a relation graph of corresponding slope-drop ratios and the pipe length design parameter under different flow indexes; on the basis, a flow deviation coefficient-based hydraulic design process for the length of the micro-irrigation capillary tube is provided: knowing the design flow deviation coefficient of the micro-irrigation capillary, the diameter of the capillary and other design variables, calculating the length of the capillary and the working water head at the inlet, and determining the appropriate arrangement form of the capillary. The invention is based on an energy profile method, and takes a flow deviation coefficient as an irrigation uniformity index, constructs a micro-irrigation capillary tube length hydraulic analysis model considering a suitable arrangement form, and comprises the following steps: and (3) a capillary tube length design parameter and a capillary tube length calculation formula. The invention can simply and conveniently calculate the number of the pipe lengths and the specific numerical values meeting the flow deviation coefficient, determine the appropriate arrangement form of the capillary and calculate the working water head at the inlet of the capillary on the premise of giving the design standard of the flow deviation coefficient and other design indexes. The invention provides a novel micro-irrigation capillary tube length design method based on the flow deviation coefficient, which is simple, convenient and feasible and can improve the design efficiency of micro-irrigation engineering.
The above description is only an example of the present invention, and is not intended to limit the present invention. The invention is susceptible to various modifications and alternative forms. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (2)
1. A micro-irrigation capillary tube length hydraulic design method based on flow deviation coefficients is characterized by comprising the following steps:
constructing a capillary tube length design parameter based on a flow deviation coefficient according to the capillary tube slope-drop ratio and the flow index; determining a calculation formula of the micro-irrigation capillary tube length according to a pipe network arrangement form, and calculating to obtain the capillary tube length based on the obtained capillary tube length design parameters based on the flow deviation coefficient;
the calculation formula for constructing the capillary tube length design parameter based on the flow deviation coefficient is as follows:
in the formula: w is a group of LCV Designing parameters for the capillary tube length based on the flow deviation coefficient; j is the slope-to-fall ratio of the capillary; m is a flow index; lambda [ alpha ] CV Designing parameters for the capillary flow deviation coefficient based on a suitable arrangement form; x is the emitter flow state index; p is a terrain grade type identifier: in the case of a reverse slope, p is-1, in the case of a flat slope, p is 0, and in the case of a forward slope, p is 1; s. the 0 Is the grade of the terrain; m L Calculating parameters for the capillary length; c Vq(h) Only considering the flow deviation coefficient of hydraulic deviation for the micro-irrigation capillary; h is a total of d For the operating head of the emitter, unit: m; Δ H S The height difference of the ground shape of the inlet and the tail end of the capillary is shown as the following unit: m; Δ H F The total friction loss of the capillary is unit: m; l is the length of the micro-irrigation capillary tube in unit: m; f s To take into account the local head loss of the emitterExpansion coefficient of total head loss of lost capillary, F s 1.10-1.20; q is total flow of the capillary inlet, and the unit is as follows: l/h; n is the number of micro-irrigation capillary douches; s e Is the emitter spacing, unit: m; q. q.s d Design flow for emitter, unit: l/h; d is the inner diameter of the capillary tube in unit: mm; k is the friction coefficient; b is a pipe diameter index; c. C 1 、c 2 To calculate the parameters;
wherein, for the flat slope topography, the micro-irrigation capillary tube is arranged in two directions, and the calculation formula of the tube length is as follows:
in the formula: l is the length of the micro-irrigation capillary tube, unit: m; [ C ] Vq(h) ]Designing a standard for the flow deviation coefficient; m is a flow index; m L Calculating parameters for the capillary length; h is d For the operating head of the emitter, unit: m; x is the emitter flow state index; d is the inner diameter of the capillary, unit: mm; b is a pipe diameter index; s e Is the emitter spacing, unit: m; f s Total head loss expansion factor of capillary for local head loss of irrigator, F s 1.10 to 1.20; k is the friction coefficient; q. q.s d Design flow for emitter, unit: l/h;
wherein, to the micro-irrigation capillary that can only one-way adverse slope arrange by the restriction of topography: when the flow index m is 1.75, the condition that the length of the micro-irrigation capillary tube based on the flow deviation coefficient has a design value is as follows: 0<[W LCV ]Less than or equal to 1.767; when the flow index m is 1.69, the condition that the length of the micro-irrigation capillary tube based on the flow deviation coefficient has a design value is as follows: 0<[W LCV ]Less than or equal to 1.762; when the flow index m is 1.00, the condition that the length of the micro-irrigation capillary tube based on the flow deviation coefficient has a design value is as follows: 0<[W LCV ]Less than or equal to 1.718; wherein [ W ] LCV ]Design criteria for micro-flow based on flow deviation coefficientsDesigning parameters of the length of the capillary irrigation pipe;
wherein, for the micro-irrigation capillary tube arranged in two directions: when the flow index m is 1.75, the condition that the length of the micro-irrigation capillary tube based on the flow deviation coefficient has a design value is as follows: w is not more than 0 LCV ]Less than or equal to 10.929; when the flow index m is 1.69, the condition that the length of the micro-irrigation capillary tube based on the flow deviation coefficient has a design value is as follows: w is not more than 0 LCV ]Less than or equal to 11.176; when the flow index m is 1.00, the condition that the length of the micro-irrigation capillary tube based on the flow deviation coefficient has a design value is as follows: w is not more than 0 LCV ]Less than or equal to 16.092; wherein [ W ] LCV ]Designing parameters for the length of the micro-irrigation capillary tube based on the flow deviation coefficient design standard;
for the one-way adverse slope capillary, the slope-to-fall ratio J of the capillary is calculated by the following formula:
when the flow index m is 1.75,
J＝0.0841[W LCV ] 4 -0.3658[W LCV ] 3 +0.5543[W LCV ] 2 -0.8507[W LCV ]-0.0254；
when the flow index m is 1.69,
J＝0.0899[W LCV ] 4 -0.3886[W LCV ] 3 +0.59[W LCV ] 2 -0.8744[W LCV ]-0.0266；
when the flow index m is 1.00,
for different flow indexes m, the long value range of the micro-irrigation bidirectional capillary design pipe based on the flow deviation coefficient meets the following requirements:
table 1, when m is 1.75, the value range of the length of the micro-irrigation bidirectional capillary designed pipe based on the flow deviation coefficient
Table 2. length range of micro-irrigation bidirectional capillary design pipe based on flow deviation coefficient when m is 1.69
Table 3. length range of micro-irrigation bidirectional capillary design pipe based on flow deviation coefficient when m is 1.00
Wherein, table 1 to table 3 are sequentially the values of the micro-irrigation bidirectional capillary design pipe length range based on the flow deviation coefficient when m is 1.75, m is 1.69 and m is 1.00;
micro-irrigation bidirectional capillary slope-drop ratio calculation value J in tables 1 to 3 1 The calculation formulas of (A) and (B) are respectively as follows:
when the flow index m is 1.75,
when the flow index m is 1.69,
when the flow index m is 1.00,
micro-irrigation bidirectional capillary slope-drop ratio calculation value J in tables 1 and 2 2 The calculation formula of (2) is as follows:
the micro-irrigation capillary tube length hydraulic design process based on the flow deviation coefficient comprises the following steps:
step 1: according to known design parameters q d K and x, calculating the designed working head h of the irrigation emitter d ；
Step 2: when the diameter D of the capillary is more than 8mm, the flow index m is 1.75, the diameter index b is 4.75, and the friction coefficient K is 0.505;
and step 3: according to known design parameters m, D, s e 、F s K and q d Calculating the design parameter M of the tube length L ＝(m+1)D b s e m /(F s Kq d m ) (ii) a According to known design parameters x, S 0 、m、M L 、[C Vq(h) ]And h d Calculating the parameter [ W ] using the formula (1) LCV ]；
And 4, step 4: when p is 0, the capillary is arranged bidirectionally according to the known parameters x, M L 、[C Vq(h) ]、h d And m, calculating the pipe length L by using the formula (2), and selecting a capillary pipe with the length not more than L by comprehensively considering the terrain condition to design the pipe length; according to a known parameter h d 、M L L and m, calculating working water head h of capillary inlet 0 ＝h d +(m+1)(0.5L) m+1 /[(m+2)M L ]；
And 5: when p is equal to-1, the capillary is arranged in a one-way reverse slope mode according to a known parameter [ W LCV ]And m, calculating a slope-to-fall ratio J using the equations (3) to (5), based on the known parameter S 0 、M L M and J, calculating the tube length L [ (-S) 0 M L )/J] 1/m Selecting a capillary tube with the length not more than L according to the terrain condition to design the tube length; according to a known parameter h d 、M L 、L、S 0 And m, calculating the working water head h of the capillary inlet 0 ＝h d +(m+1)L m+1 /[(m+2)M L ]+0.5S 0 L；
Wherein, when the flow index m is 1.75,
J＝0.0841[W LCV ] 4 -0.3658[W LCV ] 3 +0.5543[W LCV ] 2 -0.8507[W LCV ]-0.0254 (3)；
when the flow index m is 1.69,
J＝0.0899[W LCV ] 4 -0.3886[W LCV ] 3 +0.59[W LCV ] 2 -0.8744[W LCV ]-0.0266 (4)；
when the flow index m is 1.00,
step 6: when p is 1, the capillary is arranged bidirectionally, according to a known parameter [ W ] LCV ]And m, calculating a slope-to-fall ratio J using equations (6) to (8), based on the known parameter S 0 、M L M and J, calculating the tube length L ═ S 0 M L )/J] 1/m Selecting a capillary tube design tube length with the length not more than L by comprehensively considering the terrain conditions; according to a known parameter S 0 、M L M and L, calculating a gradient ratio parameter J ═ S 0 M L /L m (ii) a Calculating the optimal branch pipe position parameter R according to the parameters m and J L ＝0.0636J 2 -0.4347J +0.5, when m is 1.69, calculate R L ＝0.0582J 2 -0.4286J +0.5, when m is 1.00, calculate R L -3/8J + 1/2; according to a known parameter h d 、R L 、M L L and m, calculating the working water head h of the capillary inlet 0 ＝h d +(m+1)(LR L ) m+1 /[(m+2)M L ]+0.5S 0 LR L ；
Wherein, when the flow index m is 1.75,
when the flow index m is 1.69,
when the flow index m is 1.00,
and 7: when the inner diameter D of the capillary<When 8mm is used, assuming that m is 1.69, b is 4.69 and K is 0.505, repeating steps 3 to 6 to design the tube length L, and calculating the reynolds number Re is Lq d /(900πDs e ν T ) (ii) a If Re>2320, the design result meets the value requirement of the preset flow index m; if Re ≦ 2320, m ≦ 1.00, b ≦ 4.00, and K ≦ 1.75, and step 3 to step 6 are repeated to design the tube length L.
2. The micro-irrigation capillary tube length hydraulic design method based on the flow deviation coefficient as claimed in claim 1, further comprising: drawing a relation graph of corresponding slope-drop ratios and pipe length design parameters under different flow indexes, and judging the number of the designed pipe lengths meeting the flow deviation coefficient.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811536312.9A CN109711017B (en) | 2018-12-14 | 2018-12-14 | Micro-irrigation capillary pipe length hydraulic design method based on flow deviation coefficient |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811536312.9A CN109711017B (en) | 2018-12-14 | 2018-12-14 | Micro-irrigation capillary pipe length hydraulic design method based on flow deviation coefficient |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN109711017A CN109711017A (en) | 2019-05-03 |
| CN109711017B true CN109711017B (en) | 2022-09-27 |
Family
ID=66256579
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201811536312.9A Active CN109711017B (en) | 2018-12-14 | 2018-12-14 | Micro-irrigation capillary pipe length hydraulic design method based on flow deviation coefficient |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN109711017B (en) |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102880757A (en) * | 2012-09-27 | 2013-01-16 | 西北农林科技大学 | Micro-irrigation pressure adjuster design method based on fluid-solid coupling numerical calculation |
| CN103062466A (en) * | 2013-01-11 | 2013-04-24 | 李光永 | Micro-irrigation capillary pipe inlet flow adjuster |
| CN104090997A (en) * | 2014-06-23 | 2014-10-08 | 西北农林科技大学 | Hydraulic design method of bidirectional micro-irrigation capillary |
| CN104719095A (en) * | 2015-03-24 | 2015-06-24 | 国网吉林省电力有限公司电力科学研究院 | Intelligent drip irrigation system based on solar photovoltaic power generation |
| WO2015123916A1 (en) * | 2014-02-19 | 2015-08-27 | 清华大学深圳研究生院 | Method for measuring and scheduling node flow of pipe network based on pressure monitoring |
-
2018
- 2018-12-14 CN CN201811536312.9A patent/CN109711017B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102880757A (en) * | 2012-09-27 | 2013-01-16 | 西北农林科技大学 | Micro-irrigation pressure adjuster design method based on fluid-solid coupling numerical calculation |
| CN103062466A (en) * | 2013-01-11 | 2013-04-24 | 李光永 | Micro-irrigation capillary pipe inlet flow adjuster |
| WO2015123916A1 (en) * | 2014-02-19 | 2015-08-27 | 清华大学深圳研究生院 | Method for measuring and scheduling node flow of pipe network based on pressure monitoring |
| CN104090997A (en) * | 2014-06-23 | 2014-10-08 | 西北农林科技大学 | Hydraulic design method of bidirectional micro-irrigation capillary |
| CN104719095A (en) * | 2015-03-24 | 2015-06-24 | 国网吉林省电力有限公司电力科学研究院 | Intelligent drip irrigation system based on solar photovoltaic power generation |
Also Published As
| Publication number | Publication date |
|---|---|
| CN109711017A (en) | 2019-05-03 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN108332059A (en) | Serve the pressure tap optimization placement method of water supply network booster monitoring | |
| CN110263501B (en) | Simple linkage quantization calculation method for steam pipe network parameters | |
| CN106682287A (en) | Design method of inner and outer duct molded line of turbofan engine | |
| CN107273597B (en) | Design method of water distribution system of natural ventilation cooling tower | |
| CN112163301A (en) | Distributed checking method for water supply network hydraulic model | |
| CN109711017B (en) | Micro-irrigation capillary pipe length hydraulic design method based on flow deviation coefficient | |
| CN204476865U (en) | The serial inclined outlet passage of hydraulic performance excellence | |
| CN104090997B (en) | Hydraulic design method of bidirectional micro-irrigation capillary | |
| Yildirim | Simplified procedure for hydraulic design of small‐diameter plastic pipes | |
| CN109614716A (en) | A kind of micro-inertia device pipe range Hydraulic Design Method based on distribution uniformity coefficient | |
| CN111143954A (en) | Manufacturing method of branched water pipe capable of effectively reducing local head loss | |
| CN110688782A (en) | Long-distance superconducting energy pipeline simulation method considering axial and radial field distribution | |
| CN109726455B (en) | Micro-irrigation capillary pipe diameter hydraulic design method based on Kehler uniformity coefficient | |
| CN109684696A (en) | A kind of micro-inertia device pipe range Hydraulic Design Method based on triumphant Le coefficient of uniformity | |
| CN109711011A (en) | A kind of micro-inertia device caliber Hydraulic Design Method based on flow deviational coefficient | |
| CN109753696A (en) | A kind of micro-inertia device caliber Hydraulic Design Method based on distribution uniformity coefficient | |
| CN214948188U (en) | Mixed gas fills dress busbar | |
| CN104595239B (en) | The serial inclined outlet passage of hydraulic performance excellence and application process thereof | |
| CN207880265U (en) | Discharge pressure and flow equalization system | |
| Theocharis et al. | Design of optimal irrigation networks | |
| CN208168862U (en) | A kind of natural gas wellhead metering throttling integrated apparatus | |
| CN206830965U (en) | Bundle pipes laying structure during highway pipeline construction | |
| CN105160063B (en) | A kind of DRS hydraulic pipeline check method | |
| CN106844984B (en) | A kind of structural optimization method of more well collector-shoe gears and two well collector-shoe gears | |
| CN103301963B (en) | Labyrinth ultra-low-pressure trickle irrigation emitter |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| CP01 | Change in the name or title of a patent holder |
Address after: Beilin District in Shaanxi province Xi'an City friendship road 710054 No. 308 Patentee after: STATE GRID SHAANXI ELECTRIC POWER Research Institute Patentee after: National Network (Xi'an) Environmental Protection Technology Center Co.,Ltd. Patentee after: STATE GRID CORPORATION OF CHINA Patentee after: CHINA THREE GORGES University Patentee after: Hunan City University Address before: Beilin District in Shaanxi province Xi'an City friendship road 710054 No. 308 Patentee before: STATE GRID SHAANXI ELECTRIC POWER Research Institute Patentee before: XI'AN POWER TRANSMISSION AND TRANSFORMATION PROJECT ENVIRONMENTAL IMPACT CONTROL TECHNIQUE CENTER Co.,Ltd. Patentee before: STATE GRID CORPORATION OF CHINA Patentee before: CHINA THREE GORGES University Patentee before: Hunan City University |
|
| CP01 | Change in the name or title of a patent holder |