Disclosure of Invention
Aiming at the problems in the background art, the invention provides a method for realizing accurate variable irrigation and fertilization of a circular sprinkler, which is characterized by comprising the following steps:
step 1) dividing a plot into a plurality of large management areas and small management areas according to irrigation and fertilization demands in the whole management plot provided by an irrigation and fertilization prescription diagram, and calculating the area of each management area according to an angle and a radius;
step 2) dividing each large management area and each small management area into different irrigation and fertilization grades;
step 3) calculating the total fertilizing amount of the management plots according to the area and the fertilizing amount of each management area;
step 4) calculating the total volume of the prepared fertilizer and the concentration of the fertilizer mother liquor according to the selected fertilizer type and the corresponding fertilizer solubility;
step 5) taking a central fulcrum shaft of the circular sprinkler as a center, dividing a management plot into a plurality of fan-shaped spraying areas, and if a single irrigation and fertilization prescription is adopted in each fan-shaped spraying area, enabling the fan-shaped spraying area to be a large management area and entering 51; if different fertigation prescriptions are adopted in the sector spraying area, dividing a plurality of small management areas according to the fertigation prescriptions, and entering 52;
step 51) setting the irrigation depth of the sector spraying area and the duty ratio of a nozzle electromagnetic valve to obtain the set value of a percentage timer of the circular sprinkler and the working flow of a fertilizer injection pump;
step 52) setting the spray head solenoid valve duty ratio of the small management area with the largest fertilizing amount and the watering depth of the small management area with the smallest fertilizing amount in the fan-shaped spraying area, and obtaining the watering depth of the small management area with the largest fertilizing amount and the spray head solenoid valve duty ratio of the small management area with the smallest fertilizing amount; then, sequentially obtaining the irrigation depth and the duty ratio of the nozzle electromagnetic valve of other small management areas in the sector spraying area; finally, the set value of a percentage timer of the circular sprinkler in the sector spraying area and the working flow of the fertilizer injection pump are obtained;
and 6) subtracting the spraying water and fertilizer liquid depth from the designed water filling depth of each management area, and calculating to obtain the residual clear water filling depth to obtain the set value of the percentage timer of the circular sprinkler and the duty ratio of the electromagnetic valve of the sprinkler. Entering a sector spraying area consisting of a large management area 61; a fan-shaped spray area, consisting of a plurality of small managed areas, enters 62;
step 61) calculating the irrigation depth of the fan-shaped spraying area; obtaining the duty ratio of the electromagnetic valve of the spray head and the set value of the percentage timer of the circular sprinkler;
step 62) calculating the irrigation depth of each small management area of the sector spraying area; setting the duty ratio of the spray head electromagnetic valve of the small management area with the largest irrigation depth, and obtaining the duty ratios of the spray head electromagnetic valves of other small management areas; and finally, obtaining the set value of the percentage timer of the circular sprinkler in the sector spraying area.
The land parcel dividing mode is as follows: according to the irrigation and fertilization prescription information, a central fulcrum shaft of the circular sprinkler is taken as a center, a plurality of fan-shaped sprinkling areas with different angles are divided along the circumferential direction, and then the fan-shaped sprinkling areas are divided into different small management areas according to the difference of irrigation and fertilization amount and the number of groups of sprinklers of the circular sprinkler; if the irrigation quantity and the fertilizing quantity in a certain fan-shaped spraying area are not different, the fan-shaped spraying area is a large management area and is not divided into small management areas; the management plot is composed of all the large management areas and the small management areas.
In the step 3:
Fsum=F1×Aa1+F2×Aa2+...+Fn×Aan
wherein, FsumFertilizing the total mass of the management plot; f1、F2…FnThe fertilizing amount per unit area is the fertilizing amount of the 1 st-n grade fertilizing grade; a. thea1、Aa2…AanRespectively the fertilizing amount per unit area is F1、F2…FnThe area of the corresponding land; n is the number of prescriptions of the fertilization grade.
In the step 4:
wherein V is the total volume of the prepared fertilizer; s is the solubility of the fertilizer; ρ is the density of water; c0The mass concentration of the prepared fertilizer mother liquor is shown.
The step 51 comprises:
511) setting the irrigation depth of the fan-shaped spraying area to be HiAnd the duty ratio of the nozzle electromagnetic valve is PWMiTo obtain the set value of the percentage timer of the circular sprinkler
Wherein H0The water filling depth is set when the set value of the percentage timer of the circular sprinkler is 100% and the duty ratio of the electromagnetic valve of the spray head is 100%;
512) calculating the mass concentration of the sprayed water and fertilizer liquid
Wherein, FiFertilizing amount per unit area of the fan-shaped spraying area; a. theiIs the area of the fan-shaped spraying area;
513) setting machine-entering flow Q of sprinkler in fan-shaped spraying areai;
514) Working flow required by the fertilizer injection pump in the fan-shaped spraying area is obtained
Wherein, C0The mass concentration of the prepared fertilizer mother liquor is obtained;
the PWMi100 percent of the total weight of the alloy, and H is less than or equal to 5mmi≤HsumIn which H issumThe designed irrigation depth is provided for the irrigation and fertilization prescription chart.
Said step 52 comprises:
step 521) in the sector spraying area, setting the solenoid valve duty ratio of the small management area with the maximum fertilizing amount and the irrigation depth of the small management area with the minimum fertilizing amount, and obtaining the irrigation depth of the small management area with the maximum fertilizing amount and the solenoid valve duty ratio of the small management area with the minimum fertilizing amount, wherein:
setting the duty ratio PWM of the electromagnetic valve of the spray head in the small management area with the maximum fertilizing amount in the fan-shaped spraying areaj-maxTo obtain the duty ratio of the electromagnetic valve of the nozzle in the small management area with the minimum fertilizing amount
Wherein Fj-max、Fj-minRespectively the maximum and minimum fertilizing amount per unit area in all small management areas in the fan-shaped spraying area;
setting the irrigation depth of the small management area with the minimum fertilizing amount to be Hj-minTo obtain the irrigation depth of the small management area with the maximum fertilizing amount
Step 522) obtaining the duty ratio of the nozzle electromagnetic valve of other small management areas of the sector spraying area
Wherein Fj-elseThe fertilizing amount per unit area of any small management area except the maximum and minimum fertilizing amount small management areas;
obtaining the irrigation depth of other small management areas in the sector spraying area
Step 523) get the percentage timer set value for the sector spray area
Wherein PWMjkDuty ratio of solenoid valve for any small management area in the sector spraying area, HjkThe irrigation depth of any small management area;
step 524) obtaining the mass concentration of the sprayed water and fertilizer liquid in the fan-shaped spraying area
FjkFertilizing amount per unit area of any small management area, SjkThe area of any small management area, N is the number of small management areas divided in the fan-shaped spraying area, and rho is the density of water;
step 525) setting the machine-entering flow Q of the sprinkler in the fan-shaped sprinkling areaj;
Step 526) obtaining the flow rate of the fertilizer injection pump in the sector spraying area;
wherein, C0The mass concentration of the prepared fertilizer mother liquor is obtained;
the PWMj-max100 percent, wherein H is more than or equal to 5mmj-min≤HsumIn which H issumThe designed irrigation depth is provided for the irrigation and fertilization prescription chart.
The step 61 comprises:
step 611) in the fan-shaped spraying area, subtracting the irrigation depth when water and fertilizer liquid are sprayed from the total irrigation depth designed according to the irrigation prescription map to obtain the irrigation depth of the large management area for spraying clear water
Hu=Hsum-Hi
Wherein HsumTotal irrigation depth, HiThe irrigation depth of the large management area when water and fertilizer liquid are sprayed is obtained;
step 612) setting the duty ratio of the nozzle electromagnetic valve of the sector spraying area to PWMuTo obtain the set value of the percentage timer of the circular sprinkler
The step 62 includes:
step 621) in the fan-shaped spraying area, subtracting the irrigation depth when spraying the water and fertilizer liquid from the irrigation depth of the fertigation prescription chart to obtain the irrigation depth of the clear water sprayed in each small management area
Hv=Hsum-Hj
Step 622) setting the duty ratio PWM of the spray head electromagnetic valve of the small management area with the maximum irrigation depthv-max(in order to improve the working efficiency and save energy, the duty ratio of the solenoid valve is recommended to be set to be 100%), and the duty ratios of the spray head solenoid valves of other small management areas are calculated
Wherein Hv-maxFor the maximum depth of irrigation in each community, Hv-elseThe irrigation depth of any other small management area;
step 623) calculating the set value of the percentage timer of the circular sprinkler in the sector spraying area;
wherein, PWMvkSolenoid duty cycle for any one of the subdivisions in the sector spray area,HvkThe irrigation depth of any small management area.
The invention has the beneficial effects that:
1. the method is characterized in that the calculation of each operation parameter of the accurate irrigation and fertilization of the circular sprinkler is carried out according to the crop irrigation and fertilization prescription chart, so that the preparation is made for realizing the accurate water and fertilizer application, and the aims of saving water, losing weight and improving the fertilizer utilization rate can be achieved.
2. The set value of a percentage timer of the circular sprinkler, the duty ratio of a sprinkler electromagnetic valve and the working flow of a fertilizer injection pump are comprehensively considered and changed to carry out accurate regulation and control of variable irrigation and fertilization, and the differentiated requirements of specific areas in a management plot on irrigation and fertilization are met.
Detailed Description
The present invention will be described in further detail with reference to the accompanying drawings.
Embodiment 1 of the present invention shown in fig. 1 includes:
1) dividing the plot into a plurality of large management areas and small management areas according to the irrigation and fertilization demand in the whole management plot provided by an irrigation and fertilization prescription diagram, and calculating the area of each management area according to the angle and the radius;
the management area is divided into the following modes: according to the irrigation and fertilization prescription information, a central fulcrum shaft of the circular sprinkler is taken as a center, a plurality of fan-shaped sprinkling areas with different angles are divided along the circumferential direction, and then the fan-shaped sprinkling areas are divided into different small management areas according to the difference of irrigation and fertilization amount and the number of groups of sprinklers of the circular sprinkler; if the irrigation quantity and the fertilizing quantity in a certain fan-shaped spraying area are not different, the fan-shaped spraying area is a large management area and is not divided into small management areas; all the large management areas and the small management areas jointly form a management plot;
the total irrigation depth H is provided in the irrigation and fertilization prescription chartsum。
2) Dividing each large management area and each small management area into different irrigation and fertilization grades;
specifically, the division standard is a near principle or a natural break point classification method, and the division standard is divided into n levels of irrigation and fertilization levels.
3) Calculating the total fertilization of the plot according to the area of each management area and the fertilization amount per unit area of each management area, specifically comprising the following steps:
Fsum=F1×Aa1+F2×Aa2+…+Fn×Aan
wherein, FsumFertilizing the total mass of the management plot in kg; f1、F2…FnThe fertilizing amount per unit area of the 1 st to n-th grade fertilizing grade is kg/hm2;Aa1、Aa2…AanRespectively the fertilizing amount per unit area is F1、F2…FnArea of the corresponding land mass hm2(ii) a n is the number of prescriptions of the fertilization grade.
4) Calculating the total fertilizer preparation volume and the concentration of fertilizer mother liquor according to the selected fertilizer type and the fertilizer solubility;
wherein V is the total volume of the fertilizer preparation, m3(ii) a S is the solubility of the fertilizer, g/100 g; rho is the density of water, kg/m3;C0The mass concentration of the prepared fertilizer mother liquor is shown.
5) Dividing a management land block into a plurality of fan-shaped spraying areas by taking a central fulcrum shaft of the circular sprinkler as a center, and if a single fertigation prescription is adopted in the fan-shaped spraying areas, taking the fan-shaped spraying areas as large management areas and entering 51); if different fertigation prescriptions are adopted in the sector spraying area, dividing a plurality of small management areas according to the fertigation prescriptions, and entering 52); 51) setting the irrigation depth of the fan-shaped spraying area and the duty ratio of a nozzle electromagnetic valve, and calculating the set value of a percentage timer of the circular spraying machine and the power frequency of a fertilizer injection pump, specifically:
51) setting the irrigation depth of the fan-shaped spraying area and the duty ratio of a spray head electromagnetic valve to obtain the set value of a percentage timer of the circular spraying machine and the working flow of a fertilizer injection pump;
511) setting the irrigation depth of the fan-shaped spraying area to be HiMm (considering that the irrigation depth is less than 5mm, the irrigation depth is recommended to be set to be more than or equal to 5mm) and the duty ratio of the nozzle electromagnetic valve is PWMi(in order to improve the working efficiency and save energy, the duty ratio of the electromagnetic valve is recommended to be set to be 100%), and the set value of the percentage timer of the circular sprinkler is obtained
Wherein H0When the set value of a percentage timer of the circular sprinkler is 100% and the duty ratio of a spray head electromagnetic valve is 100%, the circular sprinkler is in the water filling depth of the fan-shaped sprinkling area, which is mm; in the present embodiment, PWMiThe flow rate of the sprinkler is 100 percent, and the sprinkler has high traveling speed under the duty ratio of the electromagnetic valve;
512) calculating the mass concentration of the sprayed water and fertilizer liquid
Wherein, FiThe fertilizer application amount per unit area of the fan-shaped spraying area is kg/hm2;AiIs the area of the fan-shaped spraying area hm2;
513) Setting machine-entering flow Q of sprinkler in fan-shaped spraying areai,m3/h;
514) Obtaining the working flow m required by the fertilizer injection pump in the fan-shaped spraying area3/h
515) The fertilizer injection pump preferentially recommends using a plunger pump, and when the plunger stroke is fixed, the power supply frequency, Hz of the motor is obtained
fi=r+s×P+t×qi
Wherein r, s and t are coefficients; and P is the pressure of the circular sprinkler in the machine, and is MPa.
In this example, r is-1.082, s is 3.520, and t is 165 for a plunger pump with a rated flow rate of 300L/h.
52) Setting the duty ratio of a spray head electromagnetic valve of the small management area with the largest fertilizing amount and the irrigation depth of the small management area with the smallest fertilizing amount in the fan-shaped spraying area, and obtaining the irrigation depth of the small management area with the largest fertilizing amount and the duty ratio of the spray head electromagnetic valve of the small management area with the smallest fertilizing amount; then, sequentially obtaining the irrigation depth and the duty ratio of the nozzle electromagnetic valve of other small management areas in the sector spraying area; finally, the set value of a percentage timer of the circular sprinkler in the sector spraying area and the working flow of the fertilizer injection pump are obtained;
521) in the sector spraying area, the electromagnetic valve duty ratio of the small management area with the largest fertilizing amount and the irrigation depth of the small management area with the smallest fertilizing amount are set, and the irrigation depth of the small management area with the largest fertilizing amount and the electromagnetic valve duty ratio of the small management area with the smallest fertilizing amount are obtained.
The specific steps in this step are:
5221) setting the duty ratio PWM of the electromagnetic valve of the spray head in the small management area with the maximum fertilizing amount in the fan-shaped spraying areaj-max(in order to improve the working efficiency and save energy, the duty ratio of the electromagnetic valve is recommended to be set to be 100 percent), and the duty ratio of the electromagnetic valve of the spray head of the small management area with the minimum fertilizing amount is obtained
Wherein Fj-max、Fj-minThe maximum and minimum fertilizing amount per unit area in all small management areas in the sector spraying area are respectively.
5222) Setting minimum fertilizing amountThe irrigation depth of the small management area is Hj-min(preferably considering irrigation depth more than or equal to 5mm, otherwise ineffective irrigation), obtaining irrigation depth of the small management area with maximum fertilizing amount
In the present embodiment, PWMj-maxThe flow rate of the sprinkler is 100 percent, and the sprinkler has high traveling speed under the duty ratio of the electromagnetic valve;
522) calculating a percentage timer set point for the fan spray zone
Wherein, PWMjkDuty ratio of solenoid valve for any small management area in the sector spraying area, HjkThe irrigation depth of any small management area;
523) obtaining the mass concentration of the sprayed water and fertilizer liquid in the fan-shaped spraying area
Wherein, FjkFertilizing amount per unit area of any small management area, SjkThe area of any small management area, and N is the number of small management areas divided in the fan-shaped spraying area;
524) setting the flow Q of the sprinkler in the fan-shaped sprinkling areaj,m3/h;
525) Obtaining the flow rate of a fertilizer injection pump in the sector spraying area;
step 527) the fertilizer injection pump preferentially recommends using a plunger pump, and when the stroke of the plunger is constant, the power supply frequency of the motor is obtained
fi=r+s×P+t×qj
Wherein r, s and t are coefficients; and P is the pressure of the circular sprinkler in the machine, and is MPa.
In this example, r is-1.082, s is 3.520, and t is 165 for a plunger pump with a rated flow rate of 300L/h.
6) And (4) subtracting the sprayed water and fertilizer liquid depth from the designed water filling depth of each management area, and calculating to obtain the residual clear water filling depth to obtain the set value of the percentage timer of the circular sprinkler and the duty ratio of the electromagnetic valve of the sprinkler. A sector spraying area consisting of a large management area, entering 61); a fan-shaped spray area consisting of a plurality of small management areas, entering 62);
step 61) calculating the irrigation depth of the fan-shaped spraying area; obtaining the duty ratio of the electromagnetic valve of the spray head and the set value of the percentage timer of the circular sprinkler, specifically:
step 611) in the fan-shaped spraying area, subtracting the irrigation depth when water and fertilizer liquid are sprayed from the total irrigation depth designed according to the irrigation prescription map to obtain the irrigation depth H of the large management area for spraying clear wateru
Hu=Hsum-Hi
Wherein HsumTotal irrigation depth, HiThe irrigation depth of the large management area is increased when water and fertilizer liquid are sprayed.
Step 612) setting the duty ratio of the nozzle electromagnetic valve of the sector spraying area to PWMu(in order to improve the working efficiency and save energy, the duty ratio of the electromagnetic valve is recommended to be set to be 100%), and the set value of the percentage timer of the circular sprinkler is obtained
In the present embodiment, PWMuThe duty ratio of the electromagnetic valve is 100 percent, and the traveling speed of the sprinkler is high.
Step 62) calculating the irrigation depth of each small management area of the sector spraying area; setting the duty ratio of the spray head electromagnetic valve of the small management area with the largest irrigation depth, and obtaining the duty ratios of the spray head electromagnetic valves of other small management areas; finally, the set value of the percentage timer of the circular sprinkler in the sector spraying area is obtained, specifically:
step 621) in the fan-shaped spraying area, subtracting the irrigation depth when spraying the water and fertilizer liquid from the irrigation depth designed according to the irrigation prescription map to obtain the irrigation depth of spraying clear water in each small management area
Hv=Hsum-Hj
Step 622) setting the duty ratio PWM of the spray head electromagnetic valve of the small management area with the maximum irrigation depthv-maxCalculating the duty ratio of the nozzle electromagnetic valves of other small management areas;
wherein Hv-maxThe maximum irrigation depth in each small management area is mm; hv-elseThe irrigation depth of any other small management area is mm;
in the present embodiment, PWMv-maxThe duty ratio of the electromagnetic valve is 100 percent, and the traveling speed of the sprinkler is high.
Step 623) calculate the sector spray area circular sprinkler percentage timer set value.
Wherein, PWMvkDuty ratio of solenoid valve for any small management area in the sector spraying area, HvkThe irrigation depth of any small management area is mm.
Example 2 of the present invention as shown in FIG. 2
1) A first fan-shaped spraying area consisting of a 101 large management area 1, a second fan-shaped spraying area consisting of a 201 small management area 2 and a 202 small management area 3, a third fan-shaped spraying area consisting of a 301 small management area 4 and a 302 small management area 5, a fourth fan-shaped spraying area consisting of a 401 large management area 6 and a fifth fan-shaped spraying area consisting of a 501 large management area 7;
first fan-shaped sprayThe angles of the sprinkling area, the second fan-shaped sprinkling area, the third fan-shaped sprinkling area, the fourth fan-shaped sprinkling area and the fifth fan-shaped sprinkling area are respectively 30 degrees, 60 degrees, 45 degrees, 35 degrees and 10 degrees. The boundary between the small 201 management area 2 and the small 202 management area 3 in the second fan-shaped spraying area is positioned between the spray heads No. 13 and No. 14 (between the first 13 spray heads and the second 1 spray heads), and the total flow rate Q of the first 13 spray headstotal13=4.45m3Total flow Q of the last 15 nozzlestotal15=16.55m3H) distance from the central pivot axis R1About 43 m. The boundary between the small management areas 4 and 302 and the small management area 5 is located between the number 17 and the number 18 (the second span between the number 4 and the number 5) (the first 17 nozzles have total flow rate Q)total17=8.15m3Total flow Q of the last 11 nozzlestotal11=12.85m3H) distance from the center pivot axis R2About 57 m. The effective spraying radius R of the circular sprinkler is 94.2 m; the pressure of the mixture entering the machine is 0.25 MPa; when the percentage setting value of the circular sprinkler is 100% and the duty ratio of the nozzle electromagnetic valve is 100%, the irrigation depth H when the percentage timer of the circular sprinkler is 100% and the duty ratio of the nozzle electromagnetic valve is 100%0Is 2.46 mm; designed irrigation depth H provided by irrigation and fertilization prescription diagramsum=35mm。
Calculating the area of each management area, wherein:
area of 101 large management area:
area of cell 201 management area:
area of 202 cell management area:
area of cell management 301:
302 cell management areaArea of (d):
401 area of large management area:
501 area of large management area:
2) dividing each large management area and each small management area into different irrigation and fertilization grades according to the fertilization amount of the summer corn provided in the figure 2 and irrigation and fertilization demand; the classification method used in this embodiment is a natural break point classification method, and is divided into three fertigation levels according to a standard from high to low, so as to obtain: 101 large management area, 401 large management area with high nitrogen supply level, F3=120kg/hm2(ii) a The 201 small management area and 301 small management area are of medium nitrogen application level, F2=100kg/hm2(ii) a The 202 small management area, 302 small management area and 501 large management area are low nitrogen application level, F1=80kg/hm2。
3) Calculating the total fertilization amount of the land, wherein:
total nitrogen application:
F=F1×(A3+A5+A7)+F2×(A2+A4)+F3×(A1+A6)
=80×(0.3683+0.2208+0.0774)+100×(0.0968+0.1276)+120×(0.2323+0.2710)=136.16kg
selecting the fertilizer type: the nitrogen content FNC of the urea is 46 percent
Total fertilization amount:
selecting urea with solubility S of 25g/100g
4) Calculating the total fertilizer preparation volume and the concentration of the fertilizer mother liquor according to the selected fertilizer type and the fertilizer solubility, specifically:
calculating the volume of the fertilizer mother liquor
Mass concentration of fertilizer mother liquor
5) Dividing each sector spraying area according to the type of the management area, wherein the large management area is a sector spraying area and enters 51); small management areas in the same sector area form a sector spraying area, and the small management areas enter 52); in this embodiment, the first fan-shaped spraying area, the fourth fan-shaped spraying area, and the fifth fan-shaped spraying area enter 51), the second fan-shaped spraying area, and the third fan-shaped spraying area enter 52), and the calculation steps are respectively:
calculating the fertilizing amount to be F3A first fan-shaped spraying area (101 large management area) and a fourth fan-shaped spraying area (401 large management area)
Setting the irrigation depth H of the first fan-shaped spraying area1The irrigation depth H of the fourth fan-shaped spraying area610mm, solenoid valve duty cycle PWM for the first sector spray zone1Duty cycle PWM of solenoid valve in fourth sector spraying area6Percent timer set point, 100%
Mass concentration of sprayed water fertilizer liquid
Plunger type fertilizer injection pump flow
Power frequency of plunger type fertilizer injection pump at 100% stroke
f1=f6=-1.082+3.520P+165q=-1.082+3.520×0.25+165×0.27=44.35Hz
Wherein k is1、k6Set point for percentage timer for circular sprinkler, C1、C6Is sprayed with water fertilizer liquid with mass concentration q1、q6Flow rate of plunger type fertilizer injection pump, f1、f6The power frequency of the plunger type fertilizer injection pump is adopted.
Calculating the fertilizing amount to be F1The fifth sector spray area (501 big management area)
Depth of irrigation H710mm, solenoid valve duty cycle PWM7When 100%, the percentage timer set point
Mass concentration of sprayed water fertilizer liquid
Plunger type fertilizer injection pump flow
Power frequency of plunger type fertilizer injection pump at 100% stroke
f7=-1.082+3.520P+0.165q=-1.082+3.520×0.25+165×0.181=29.50Hz
Calculating the second fan-shaped spraying area with the fertilizing amount of F2201 cell management area and is F1202 cell management area set 201 cell management area electromagnetic valve duty ratio PWM2When the power is 100%, the duty ratio of the solenoid valve in the 202 small management area
Set 202 the irrigation depth H of the management area3Calculating the irrigation depth of a 201-cell management area as 10mm
Calculate percent timer set point
Mass concentration of sprayed water fertilizer liquid
Flow rate of sprinkler
Q2=Qtotal13+Qtotal15×80%=4.45+16.55×80%=17.69m3/h
Plunger type fertilizer injection pump flow
Power frequency of plunger type fertilizer injection pump at 100% stroke
f2=f3=-1.082+3.520P+165q=-1.082+3.520×0.25+165×0.155=25.37Hz
Calculating the third fan-shaped spraying area, wherein the fertilizing amount is F2301 cell management area, F1Electromagnetic valve duty ratio PWM of 302 small management area and 301 small management area4When the power is 100%, the duty ratio of the electromagnetic valve in the 302 small management area
Setting 302 water filling depth H of management district5Calculating the irrigation depth of a 301 small management area as 10mm
Calculate percent timer set point
Mass concentration of sprayed water fertilizer liquid
Flow rate of sprinkler
Q4=Qtotal17+Qtotal11×80%=8.15+12.85×80%=18.43m3/h
Plunger type fertilizer injection pump flow
Power frequency of plunger type fertilizer injection pump at 100% stroke
f4=f5=-1.082+3.520P+165q=-1.082+3.520×0.25+165×0.162=26.53Hz
6) Calculating the irrigation depth and the duty ratio of the electromagnetic valve when each partition is sprayed with clear water
The water filling depth of a 101 large management area, a 401 large management area, a 501 large management area, a 202 small management area and a 302 small management area
H1'=H3'=H5'=H'6=H'7=Hsum-H1=35-10=25mm
Irrigation depth of 201 small management area and 301 small management area
H'2=H'4=Hsum-H2=35-12.5=22.5mm
Obtaining the electromagnetic valve duty ratio of 201 small management area and 301 small management area
Setting the duty ratio of the solenoid valve in a large management area 101, a large management area 401, a large management area 501, a small management area 202 and a small management area 302 to be 100 percent to obtain the set value of the percentage timer of the circular sprinkler