CN109496804B - Negative pressure irrigation system and irrigation method thereof - Google Patents
Negative pressure irrigation system and irrigation method thereof Download PDFInfo
- Publication number
- CN109496804B CN109496804B CN201811530066.6A CN201811530066A CN109496804B CN 109496804 B CN109496804 B CN 109496804B CN 201811530066 A CN201811530066 A CN 201811530066A CN 109496804 B CN109496804 B CN 109496804B
- Authority
- CN
- China
- Prior art keywords
- water
- air
- irrigation
- negative pressure
- liquid level
- 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
Images
Classifications
-
- A—HUMAN NECESSITIES
- A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
- A01G—HORTICULTURE; CULTIVATION OF VEGETABLES, FLOWERS, RICE, FRUIT, VINES, HOPS OR SEAWEED; FORESTRY; WATERING
- A01G25/00—Watering gardens, fields, sports grounds or the like
- A01G25/16—Control of watering
Abstract
The invention discloses a negative pressure irrigation system and an irrigation method thereof.A water tank is filled with water to an initial set liquid level through a water supplementing device, air in the air tank forms pressure difference through a vacuum pump, an electromagnetic control water valve controls an irrigation device to start water supply, a negative pressure value in the negative pressure irrigation device is monitored in real time through an air pressure sensor, and an electromagnetic control air valve and the vacuum pump control the pressure value in the air tank, so that the pressure value is maintained in a reasonable variation range. The liquid level of the water tank is monitored by the liquid level float switch, and when the water level drops to trigger the liquid level float switch, the water supplementing device is started to inject water into the water tank to the initially set liquid level, so that the water level and the air pressure are in the set range. The invention can calculate the irrigation quantity through the rotating number of turns of the peristaltic pump, the air pressure sensor records the pressure value inside and outside the device in real time, and the negative pressure value of the negative pressure generating device is maintained in a set range through the control of the vacuum pump and the electromagnetic control air valve, thereby improving the irrigation control precision and the automation degree.
Description
Technical Field
The invention belongs to the negative pressure irrigation technology, and particularly relates to a negative pressure irrigation system and an irrigation method thereof.
Background
In the agricultural production in dry, early and semi-arid areas in the north, small water sources such as various water cellars, pools, dams and the like are frequently built, and as the water level of the water sources is often lower than the crop planting surface, when the traditional water-saving irrigation technology is used, the problem of small or miniature water lifting and pressurizing equipment is also solved, so that the cost and the investment of an irrigation system are undoubtedly increased; in addition, in remote underdeveloped areas, the shortage of power and energy also restricts the popularization and application of the existing water-saving irrigation technology. Therefore, a new type of negative pressure automatic supply irrigation system is proposed to better solve the agricultural water problems in these areas. The basic principle is that water always flows from high water potential to low water potential, and a certain instrument is matched to automatically supplement the water consumed by crops in the rhizosphere soil.
Objects in nature all have energy, and a general tendency is to move or transform spontaneously from a high-energy state to a low-energy state, eventually reaching a state of energy equilibrium. Classical physics holds that any object has energy that consists of kinetic and potential energy. The kinetic energy is generally negligible due to the slow migration of water in the soil pores. Therefore, the soil-water potential, which is the potential energy of soil moisture, becomes very important in determining the energy state and movement of soil moisture.
According to the explanation of the thermodynamic basis of soil-water potential, the total soil-water potential of soil water at a certain point in soil is the sum of five soil-water potentials:
Ψ＝Ψg+Ψp+Ψm+Ψs+ΨT (1)
in analyzing soil moisture movement in the field, solute potential and temperature potential are usually not considered. The water potential is expressed as the water potential of the soil water per unit weight, and is generally referred to as a water head.
For unsaturated soil water, the potential Ψ is due to the soil pressurep0, so that the total soil-water potential Ψ is determined by the matrix potential ΨmAnd the gravitational potential ΨgComposition, i.e. total soil water potential per unit weight:
Ψ＝Ψm+Ψg＝Ψm+z (2)
similarly, when represented by the head, the total head in the above formula is represented by the negative head h ═ ΨmAnd a positional head.
To theoretically analyze the energy basis for the operation of a negative pressure irrigation system, an irrigation system as shown in fig. 1 was constructed. It can be seen that the overall irrigation system comprises an emitter 4, a water source 1 and a water conduit 2 connecting the two. H is the elevation difference between the water source and the emitter. In the irrigation system shown in fig. 1, the coordinate system shown in the figure is established with the emitter 4 as the origin, and the Z-axis orientation is positive, and when H <0, i.e. the water source is lower than the emitter, it is called "negative pressure" irrigation.
The entire irrigation system is now analyzed for energy. In the emitter, water is saturated, and the total water potential of the water per unit weight in the emitter is determined by the substrate potential Ψ, as can be seen from equation 1, without considering the atmospheric pressure, solute potential, and temperature potentialmAnd the gravitational potential ΨgConsisting of pressure heads h ═ ΨmAnd a position water head z, wherein the position water head z is zero when the emitter is taken as a reference plane, so that the total water potential of the unit weight water in the emitter is as follows:
if the soil water is not saturated outside the irrigation emitter, the total soil water potential psi of the unit weight water can be determined from the formula 2outFrom the stroma potential ΨmAnd the gravitational potential ΨgThe water irrigation device is taken as a reference plane, and the position water head z is zero, so that the total soil-water potential of the soil water outside the water irrigation device in unit weight is as follows:
Ψout＝Ψm+Ψg＝Ψmo+z＝Ψmo
Ψmois the matrix potential of soil water at the external contact position of the irrigator.
According to Darcy's law, the only principle followed by water flow is that water moves from a high total water potential to a low total water potential, so that to cause water to flow from a water source into soil outside the emitter from the inside of the emitter, the total water inside the emitter must be higher than the total water potential outside the emitter, that is, the total water potential inside and outside the emitter must satisfy the following basic conditions:
Ψin>Ψouti.e. H>Ψmo
When H is present<And when 0, irrigation needs to be carried out under negative pressure, and the position of a water source is lower than that of an emitter. Obviously, irrigation is not possible with saturated soils, although saturated soils generally do not require irrigation. For unsaturated soil, the soil matrix potential is also negative, and if negative pressure irrigation is feasible, it is necessary to see if the water potential H in the emitter is greater than the water potential psi at the contact position outside the emittermo. The water potential H in the douche is limited by the vacuum suction height of the water column, the theoretical minimum value is about-10.33 m, namely the value range of H is-10.33 m-0 m, and actually, the value range of H is smaller due to the complete sealing problem. Under normal conditions, the water content of the soil to be irrigated is generally between the wilting coefficient and the field water capacity and corresponds to the soil water matrix potential rangeThe volume is about 0.15bar to 0.33bar, and is about-150 m to-3.3 m expressed by a water column. From the value ranges of the two, although the water potential in the emitter is H negative, when the soil water content is low (needing irrigation), the soil water matrix potential psi outside the emittermoThe height of the water source is adjusted to change the height difference H between the douche and the water source, namely the water potential H in the douche is adjusted, so that the total water potential H in the douche can be always larger than the total soil water potential psi outside the douchemoAnd irrigation is achieved. At this time, the operating pressure head at the emitter is negative. This is why the irrigation mode in this case is called negative pressure irrigation. Difference of water potential (H-psi) between inside and outside of the douchemo) The water in the negative pressure irrigation system is the only driving force for the water to enter the soil from the water source through the douche.
In summary, from the energy point of view, the negative pressure action head H is within a certain range, that is, the water source elevation is lower than the emitter elevation but not exceeding a certain range, and negative pressure irrigation is completely feasible.
Therefore, the constant negative pressure irrigation device widely applied to farmland irrigation is provided, and the constant irrigation water head is maintained through the peristaltic pump and the electromagnetic valve, so that the purposes of continuously supplying water and improving the utilization rate of water are achieved.
At present, the research on negative pressure irrigation at home and abroad is less. The existing negative pressure irrigation test device comprises two types, wherein one type is negative pressure irrigation formed by controlling the height difference between the liquid level of the Malpighian bottle and an irrigation emitter, and the other type is negative pressure formed by a U-shaped pipe and a negative pressure adjusting device, and the defect that the irrigation quantity and the negative pressure value cannot be accurately monitored in real time.
Disclosure of Invention
The purpose of the invention is as follows: in order to overcome the defects in the prior art, the invention aims to provide a negative pressure irrigation system, and further aims to provide a constant negative pressure irrigation method based on the system.
The technical scheme is as follows: the utility model provides a negative pressure irrigation system, includes irrigation equipment, outlet pipe, electromagnetic control water valve, blast pipe, gas tightness valve, water tank, gas tank, liquid level float switch, baroceptor, negative pressure generating device, solenoid electric pneumatic valve, baffle, gas passage, moisturizing device, inlet tube, moisturizing case and singlechip, water tank and gas tank pass through the baffle and keep apart, and leave gas passage on the baffle, the water tank passes through inlet tube and moisturizing device, links to each other with the irrigation equipment watertight through the outlet pipe, gas tank and the airtight intercommunication of negative pressure generating device and solenoid electric pneumatic valve, be equipped with liquid level float switch in the water tank, be equipped with baroceptor in the gas tank, electromagnetic control water valve, liquid level float switch, negative pressure generating device, solenoid electric pneumatic valve, baroceptor, moisturizing device all are connected with the singlechip.
Furthermore, the water filling device is connected with a water outlet pipe and an exhaust pipe, an air tightness valve is arranged on the exhaust pipe, a ball valve switch is arranged on the water outlet pipe, and the ball valve switch is used for controlling the water filling device.
Preferably, an electromagnetic control water valve is arranged on the water outlet pipe and is connected with the single chip microcomputer, and when the initial liquid level and the negative pressure value of the device or the negative pressure value in continuous working are in a preset state, the electromagnetic control valve is started to be started, so that the device is ensured to operate in a preset working environment all the time;
preferably, the watering device is a water-permeable and air-impermeable pottery clay irrigator or a fiber irrigator;
preferably, the water replenishing device is a peristaltic pump, power is provided by a stepping motor, an alternating current motor and a direct current motor, and the peristaltic pump is communicated with the water replenishing tank and the negative pressure irrigation device through a water inlet pipe;
preferably, the pipe orifice of the water inlet pipe is arranged at the bottom of the water tank;
preferably, the negative pressure generating device is a vacuum pump, and the vacuum pump is connected with the air box in an airtight manner through an air exhaust hole;
preferably, the float switch is arranged above a preset liquid level, and the height is set according to the size of the float switch;
preferably, the water tank and the gas tank are separated by a partition plate, and a serrated gas channel is arranged at the upper part of the partition plate.
A constant negative pressure irrigation method is mainly divided into an initialization stage and a maintenance operation stage. Firstly, setting the pressure difference range and the ending condition of the device, and reading the on-off state of the liquid level floating ball by the singlechip. In the starting state, the peristaltic pump supplies water, and the running steps of the peristaltic pump are recorded; when the system is in a closed state, the peristaltic pump stops running, the pressure sensor monitors the pressure value and judges whether the pressure difference reaches a preset range, if the pressure difference does not reach the preset range, the vacuum pump extracts air, if the pressure difference reaches the preset range, the electromagnetic control water valve is opened, the irrigator pours water, and the system starts to continuously supply water. The air pressure sensor monitors the negative pressure value inside and outside the negative pressure irrigation device in real time, when the pressure value is higher than a preset range, the electromagnetic control air valve is started to deflate, and when the pressure value is lower than the preset pressure range, the vacuum pump is started to evacuate until the pressure value reaches the initial preset pressure value; monitoring the liquid level of the water tank through a liquid float switch, starting a water supplementing device when the water level is reduced to a preset water level, injecting water into the water tank to the initially set liquid level, recording the operation steps of the peristaltic pump, judging whether the peristaltic pump reaches the preset operation steps, and if not, continuously monitoring the pressure value and the water level state; if the preset steps are reached, the single chip microcomputer sends an instruction, the electromagnetic control water valve is closed, and water filling is stopped.
Further, the irrigation quantity of the irrigation device is calculated according to the rotation number of turns of the peristaltic pump, and the peristaltic pump is used for reflecting the irrigation quantity; the pressure sensor monitors and records the pressure value of the device in real time, and the negative pressure value of the device is maintained in a set constant range through the vacuum pump and the electromagnetic control air valve.
Has the advantages that: according to the negative pressure irrigation system, the negative pressure value of the device can be automatically monitored through the negative pressure adjusting device, automatic adjustment and control are realized, and the irrigation effect is better compared with that of the conventional device; the irrigation method provided by the invention solves the problem of insufficient real-time monitoring of irrigation and improves the irrigation effect.
Drawings
FIG. 1 is a schematic view of the principle of negative pressure irrigation;
FIG. 2 is a schematic structural view of the constant negative pressure irrigation device of the present invention;
fig. 3 is a schematic flow chart of the constant negative pressure irrigation method of the invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in further detail with reference to the accompanying drawings and specific embodiments.
Objects in nature all have energy, and a general tendency is to move or transform spontaneously from a high-energy state to a low-energy state, eventually reaching a state of energy equilibrium. To make water flow from the water source into the soil outside the emitter from the inside of the emitter, the total water level inside the emitter must be higher than the total water level outside the emitter, and the difference between the water levels inside and outside the emitter (H-psi)mo) The water in the negative pressure irrigation system is the only driving force for the water to enter the soil from the water source through the douche.
At the initial stage of negative pressure irrigation, the water content of the soil is lower, the matrix potential of the soil water is also lower, the flux is larger, namely the water quantity entering the unit soil from the irrigator in unit time is larger. Along with the continuous going on of negative pressure irrigation, the moisture content of soil constantly increases, and soil water matric potential also increases, and the flux will correspondingly diminish, and until the irrigation emitter contact department soil water matric potential no longer increases, soil water matric potential equals with the negative pressure working head of irrigation emitter, and the flux is zero, and the irrigation will stop. At this time, the water content of the soil is the maximum water content that can be achieved by the soil under the negative pressure acting head H (height difference). With the water consumption of crops (including crop transpiration and evaporation on the soil surface), the water content of the soil is reduced, the soil matrix potential is reduced, when the water content is lower than a negative pressure action water head, negative pressure irrigation is continued, the crops consume much water, and the soil absorbs the same water amount from a water source by using the soil water matrix potential (suction) through a negative pressure irrigation system. The negative pressure irrigation speed is equivalent to the water consumption speed of crops, and the water required by the crops can be automatically supplied at any time. The negative pressure irrigation system has a self-regulation function, and can automatically regulate the irrigation speed and the irrigation quantity according to the soil moisture content, so that the conditions of high and low soil moisture content of other irrigation systems are changed, and the soil moisture content is basically kept in a balanced trend. Moreover, the stable water content near the soil irrigator under negative pressure irrigation can be adjusted by adjusting the height difference H, so that the water content is kept in a range suitable for the growth of crops.
Therefore, the constant negative pressure irrigation device widely applied to farmland irrigation maintains the constancy of the irrigation water head through the peristaltic pump and the electromagnetic valve, thereby achieving the purposes of continuously supplying water, improving the utilization rate of water and realizing the irrigation control through water shortage and regulation.
Example 1
As shown in fig. 1, a schematic diagram of a negative pressure irrigation principle is shown, a water source 1 reaches an emitter 4 through a water pipe 2, and the emitter 4 is arranged in a soil section 3 and is arranged inside soil.
The negative pressure irrigation device provided by the invention comprises a water tank 21, an air tank 22, a negative pressure generating device 25, a watering device 11, a water supplementing device 31 and a single chip microcomputer 51, wherein the water tank 21 and the air tank 22 are both closed containers, the liquid level of the water tank 21 is set according to specific requirements, and the air tank 22 is a negative pressure generating and regulating place. According to the requirement, the negative pressure generating device 25 is a vacuum pump, and the vacuum pump extracts air through an air extracting hole on the air box 22, so that the pressure value of the air box 22 reaches a preset value; the water tank 21 and the air tank 22 are separated by a partition plate 27, so that the liquid and the air tank 22 are isolated, and the transverse deformation resistance of a negative pressure generation place can be increased; the upper part of the clapboard 27 adopts a sawtooth shape and is used as a gas channel 28 to balance the pressure values of the two chambers above the liquid level of the water tank 21; the atmospheric pressure outside the air box 22 changes in time, so that air pressure sensors 24 are arranged inside and outside the device or the air box 22, and the negative pressure value inside the device is adjusted in real time according to the fluctuation of the atmospheric pressure outside the device; the actual pressure value of the gas tank 22 is affected by the temperature, the gas volume, etc., and is difficult to maintain at a constant value, so that the actual pressure value should be allowed to fluctuate within the actual requirement or reasonable range of the preset pressure value.
Before negative pressure is pumped, proper irrigation water is injected into the water tank 21 according to the water demand of crops, when the irrigation water infiltrates, the water level in the water tank 21 is lowered, so that the pressure value of the air tank 22 is reduced, the volume ratio of the air volume to the water is required to be as large as possible, and the air pressure change caused by the unit infiltration water amount is within an error allowable range; the water tank 21 is connected with the water supplementing device 31 and the irrigation device 11 in a watertight way through pipelines, and the air tank 22 is connected with the negative pressure generating device 25 and the electromagnetic control air valve 26 in an airtight way through pipelines; an air pressure sensor 24 is arranged inside and outside the air tank 22, a liquid level float switch 23 is arranged in the water tank 21, and the irrigation device 11, the electromagnetic control water valve 13, the liquid level float switch 23, the negative pressure generation device 25, the electromagnetic control air valve 26, the air pressure sensor 24 and the water replenishing device 31 are all connected with the single chip microcomputer 51; the negative pressure generating device is a vacuum pump.
In the invention, the irrigation device 11 is a water-permeable and air-impermeable pottery clay irrigator or a fiber irrigator which is connected with a negative pressure generating device 25 through a water outlet pipe 12, an electromagnetic control water valve 13 is arranged on the water outlet pipe 12 so as to control the on-off of the irrigation device 11, an exhaust pipe 14 is arranged on the irrigator, and an air-tight valve 15 is arranged on the exhaust pipe 14.
In the invention, the water replenishing device 31 is a peristaltic pump, a liquid level float switch 23 is arranged in the water tank 21 and is arranged above a preset liquid level for detecting the liquid level change of the water tank 21, the installation height is specifically set according to the size of the liquid level float switch 23, when the liquid level of the water tank 21 is reduced to the preset water level, a float ball leaves a contact, the peristaltic pump is started, and water is supplied to the water tank 21; installing an air pressure sensor 24 inside and outside the air tank 22, monitoring the negative pressure value of the device in real time, starting an electromagnetic control air valve 26 to charge air into the air tank 22 when the pressure value is higher than the reasonable fluctuation range of the preset pressure value, and starting a vacuum pump 25 to pump air from the air tank 22 when the pressure value is lower than the reasonable fluctuation range of the preset pressure value, so that the pressure value reaches the initial preset pressure value; the preset water level of the liquid level drop of the water tank 21 is determined according to the preset pressure variation range, the water level drop value allowed by the reasonable pressure variation range can be calculated according to the ideal gas law, and when the water level drops to the preset water level, the peristaltic pump can be started to inject water into the water tank 21 to the initially set liquid level; the peristaltic pump is connected with the water replenishing tank 41 through the water inlet pipe 32, the pressure value in the air tank 22 is increased in the process that the peristaltic pump fills water into the water tank 21, and after the pressure value exceeds a reasonable variation range of the pressure value, the electromagnetic control air valve 26 is started to adjust the pressure value to an initial set pressure value; the water inlet pipe 32 should be disposed at the bottom of the water tank 21 to prevent the level float switch 23 from being triggered by the fluctuation of the water level due to the amount of water filled when the water pump is operated.
When the peristaltic pump is driven by a stepping motor, the water quantity pumped by the peristaltic pump driven by the stepping motor is positively correlated with the rotating steps of the stepping motor, and the water filling quantity of the water filling device 11 can be calculated according to the rotating steps of the peristaltic pump; when the peristaltic pump is driven by alternating current and direct current motors, the water filling amount of the water filling device 11 can be calculated according to the power supply time of the peristaltic pump because the water amount pumped by the peristaltic pump driven by the two motors under constant power supply is positively correlated with the power supply time.
The air pressure sensor 24 can record the pressure value inside and outside the device in real time and adjust the air pressure inside the device according to the change of the air pressure difference, so that the air pressure inside the device and the air pressure difference outside the device are always kept in a set range.
The system provided by the invention comprises the use of electronic devices, including an electromagnetic control water valve 13, an electromagnetic control air valve 26, an air pressure sensor 24, a water supplementing device 31, a liquid level float switch 23 and a single chip microcomputer 51, wherein the single chip microcomputer 51 and the necessary components thereof are conventional technologies in the field according to the scheme, and are not described herein.
As shown in FIG. 3, the invention discloses a constant negative pressure irrigation method, which comprises the following steps:
(1) the pressure difference range and the ending condition of the device are set, in the embodiment, the total rotating step number of the peristaltic pump driven by the stepping motor reaches a set value to serve as the ending operation condition.
(2) The singlechip 51 reads the on-off state of the liquid level float 23. In the starting state, the peristaltic pump 31 is used for replenishing water, and the running steps of the peristaltic pump 31 are recorded; when the system is in a closed state, the peristaltic pump 31 stops running, the pressure sensor 24 monitors the pressure value and judges whether the pressure difference reaches a preset range or not, if the pressure difference does not reach the preset range, the vacuum pump 25 pumps air, if the pressure difference reaches the preset range, the electromagnetic control water valve 13 is opened, the douche 11 douches water, and the system starts to continuously supply water.
(3) The air pressure sensor 24 monitors the negative pressure value inside and outside the negative pressure irrigation device in real time, when the pressure value is higher than a preset range, the electromagnetic control air valve 26 is started to deflate, and when the pressure value is lower than the preset pressure range, the vacuum pump 25 is started to pump air until the pressure value reaches the initial preset pressure value; monitoring the liquid level of the water tank 21 through a liquid float switch 23, starting a water supplementing device 31 when the water level is reduced to a preset water level, injecting water into the water tank 21 to the initially set liquid level, recording the operation steps of the peristaltic pump, judging whether the peristaltic pump reaches the preset operation steps, and if so, continuously monitoring the pressure value and the water level state; if the preset number of steps is reached, the device stops watering.
Example 2
The implementation steps of the invention are as follows:
(1) the device is provided with a water tank 21, an air tank 22, a negative pressure generating device 25, a water filling device 11, a negative pressure adjusting device, a water supplementing device 31 and a single chip microcomputer 51, wherein an air channel 28 is reserved between the water tank 21 and the air tank 22, the water tank 21 is connected with the water supplementing device 31 and the water filling device 11 in a watertight manner through pipelines, the air tank 22 is connected with the negative pressure generating device 25 and an electromagnetic control air valve 26 in a gastight manner through pipelines, a liquid level float switch 23 is arranged in the water tank 21, an air pressure sensor 24 is arranged inside and outside the air tank 22, and the water filling device 11, the electromagnetic control water valve 13, the liquid level float switch 23, the negative pressure generating device 25, the electromagnetic control air valve 26, the air pressure sensor 24 and the water filling device 31 are all connected with the single chip microcomputer 51.
(2) And (3) injecting water into the water tank 21, pumping air by using a vacuum pump, and monitoring whether the pressure value reaches a preset value by using the pressure sensor 24 until the pressure in the air tank 22 reaches an initial negative pressure value.
In this step, before the negative pressure is pumped, a proper amount of irrigation water is injected into the water tank 21 according to the water demand of crops, and when the irrigation water infiltrates, the water level in the water tank 21 is lowered to cause the pressure value of the air tank 22 to be reduced, so that the volume ratio of the air volume to the water is required to be as large as possible, and the air pressure change caused by the unit infiltration water amount is within the error allowable range.
Because the actual atmospheric pressure changes with time, and the negative pressure value in the device is the difference value between the actual atmospheric pressure and the air pressure value in the device, the air pressure in the device needs to be adjusted when the actual atmospheric pressure changes, therefore, pressure sensors 24 are arranged inside and outside the device, the air pressure value is monitored in real time, and the difference value between the internal pressure and the external pressure of the device is adjusted through the vacuum pump 25 and the electromagnetic control air valve 26.
Since the actual pressure value of the gas tank 22 is affected by the temperature, the gas volume, etc., and is difficult to maintain at a constant value, the actual pressure value should be allowed to fluctuate within a reasonable range of the preset pressure value.
(3) Opening an electromagnetic control water valve of a water outlet pipe;
(4) the system starts to operate, and the irrigation device 11 continuously supplies water;
(5) the air pressure sensor 24 monitors the internal and external negative pressure values of the device in real time, when the pressure value is higher than a preset range, the electromagnetic control air valve 26 is started to deflate, and when the pressure value is lower than the preset pressure range, the vacuum pump 25 is started to pump air until the pressure value reaches the initial preset pressure value;
in this step, the preset water level of the liquid level of the water tank 21 is determined according to the preset pressure variation range, the water level reduction value allowed by the reasonable pressure variation range can be calculated according to the ideal gas law, and when the water level is reduced to the preset water level, the peristaltic pump can be started to inject water into the water tank 21 to the initially set liquid level.
(6) The liquid level of the water tank 21 is monitored by a liquid level float switch 23, and when the water level is reduced to a preset water level, the peristaltic pump is started to inject water into the water tank 21 to the initially set liquid level.
In this step, the liquid level float switch 23 is disposed above a predetermined liquid level to detect a change in the liquid level of the water tank 21, and the height is specifically set according to the size of the liquid level float switch 23.
When the liquid level reaches an initial value, the pressure sensor 24 monitors the pressure value in the air tank 22, the step (5) is started, when the liquid level and the pressure reach the initial values, the system operates normally, water is continuously supplied in the initial state, and the steps (5) and (6) can be started in the subsequent state.
Claims (7)
1. A constant negative pressure irrigation method adopts a negative pressure irrigation system, wherein the negative pressure irrigation system comprises an irrigation device (11), a water outlet pipe (12), an electromagnetic control water valve (13), an exhaust pipe (14), an air tightness valve (15), a water tank (21), an air tank (22), a liquid level float switch (23), an air pressure sensor (24), a negative pressure generating device (25), an electromagnetic control air valve (26), a partition plate (27), an air channel (28), a water replenishing device (31), a water inlet pipe (32), a water replenishing tank (41) and a single chip microcomputer (51);
the water tank (21) is isolated from the gas tank (22) through a partition plate (27), and a gas channel (28) is reserved on the partition plate (27) and used for balancing pressure values of two chambers above the liquid level of the water tank (21);
the water tank (21) is connected with the water supplementing device (31) through a water inlet pipe (32) and is connected with the irrigation device (11) through a water outlet pipe (12) in a watertight manner, the air tank (22) is communicated with the negative pressure generating device (25) and the electromagnetic control air valve (26) in an airtight manner, the negative pressure generating device (25) is a vacuum pump, and the vacuum pump is connected with the air tank (22) in an airtight manner through an air exhaust hole; before irrigation begins, a vacuum pump is used for pumping negative pressure to the device to form a set negative pressure value, and the vacuum pump and an electromagnetic control air valve (26) are used for pumping air and inflating air in the irrigation process to adjust the negative pressure value of the device;
a liquid level float switch (23) is arranged in the water tank (21) and used for monitoring the liquid level change in the water tank and transmitting a liquid level change signal to the single chip microcomputer so as to control the water supplementing device (31) to supplement water, and meanwhile, the liquid level float switch (23) also controls the liquid level falling range in the water tank;
air pressure sensors (24) are arranged inside and outside the air box (22), and the electromagnetic control water valve (13), the liquid level float switch (23), the negative pressure generating device (25), the electromagnetic control air valve (26), the air pressure sensors (24) and the water supplementing device (31) are connected with the single chip microcomputer (51);
the water supplementing device (31) is a peristaltic pump, and the peristaltic pump is communicated with the water supplementing tank (41) and the water tank (21) through a water inlet pipe (32);
the irrigation method comprises an initialization phase and a maintenance operation phase, and is characterized in that:
(1) setting the pressure difference range and the ending condition of the system and the negative pressure generating device;
(2) starting an initialization stage, reading the state of a liquid level float switch (23) by a singlechip (51), supplementing water by a peristaltic pump in an opening state, and simultaneously recording the operation steps of the peristaltic pump; when the peristaltic pump is in a closed state, the peristaltic pump stops running, the air pressure sensor (24) monitors the pressure value and judges whether the pressure difference reaches a preset range, and if the pressure difference does not reach the preset range, the vacuum pump pumps air; if the water reaches the preset value, the electromagnetic control water valve (13) is opened, the water filling device (11) fills water, the system starts to supply water continuously, and the operation maintaining stage is started;
(3) the air pressure sensor (24) monitors the pressure difference inside and outside the negative pressure irrigation system in real time, when the pressure difference is higher than a preset pressure range, the electromagnetic control air valve (26) is started to deflate, and when the pressure difference is lower than the preset pressure range, the vacuum pump is started to pump air until the pressure value reaches an initial preset pressure value; monitoring the liquid level of the water tank (21) through the liquid level float switch (23), starting the water supplementing device (31) when the state of the liquid level float switch (23) is triggered to change due to the falling of the water level, injecting water into the water tank (21) to the initially set liquid level, recording the running steps of the peristaltic pump, judging whether the peristaltic pump reaches the preset running steps, and if not, continuously monitoring the pressure difference value and the water level state and maintaining the pressure difference and the water level; if the preset steps are reached, the single chip microcomputer (51) sends an instruction, the electromagnetic control water valve (13) is closed, and the water filling is stopped.
2. The constant negative pressure irrigation method as claimed in claim 1, wherein: the irrigation device (11) is connected with a water outlet pipe (12) and an exhaust pipe (14), an electromagnetic control water valve (13) is arranged on the water outlet pipe (12), the electromagnetic control water valve (13) is used for controlling the irrigation device (11) to be opened and closed, when the pressure range and the water level in the system are within an initial preset range, the electromagnetic control water valve (13) is opened, the irrigation device (11) starts to supply water, and an air tightness valve (15) is arranged on the exhaust pipe (14).
3. The constant negative pressure irrigation method as claimed in claim 2, wherein: the irrigation device (11) is a water-permeable and air-impermeable pottery clay irrigator or a fiber irrigator.
4. The constant negative pressure irrigation method as claimed in claim 1, wherein: the nozzle of the water inlet pipe (32) is arranged at the bottom of the water tank (21).
5. The constant negative pressure irrigation method as claimed in claim 1, wherein: the power supply of the peristaltic pump comprises a direct current power supply or an alternating current power supply, and the power supply is driven by a stepping motor, a direct current motor or an alternating current motor.
6. The constant negative pressure irrigation method as claimed in claim 1, wherein: the middle of the water tank (21) is separated from the middle of the air tank (22) by a partition plate (27), a sawtooth-shaped air channel (28) is arranged at the upper part of the partition plate (27), the liquid level float switch (23) is arranged above a preset liquid level, and the height of the liquid level float switch is set according to the size of the liquid level float switch (23).
7. The constant negative pressure irrigation method as claimed in claim 1, wherein: the irrigation quantity of the irrigation device (11) is calculated according to the rotation steps of the peristaltic pump, air pressure sensors (24) inside and outside the device monitor and record the pressure values inside and outside the device in real time, the pressure difference is further calculated through a single chip microcomputer (51), and the negative pressure value of the device is further maintained within a set constant range through a vacuum pump and an electromagnetic control air valve (26).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811530066.6A CN109496804B (en) | 2018-12-14 | 2018-12-14 | Negative pressure irrigation system and irrigation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811530066.6A CN109496804B (en) | 2018-12-14 | 2018-12-14 | Negative pressure irrigation system and irrigation method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN109496804A CN109496804A (en) | 2019-03-22 |
| CN109496804B true CN109496804B (en) | 2021-09-24 |
Family
ID=65753409
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201811530066.6A Active CN109496804B (en) | 2018-12-14 | 2018-12-14 | Negative pressure irrigation system and irrigation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN109496804B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110208148A (en) * | 2019-07-10 | 2019-09-06 | 中国市政工程华北设计研究总院有限公司 | For studying and testing the integrated system of moisture and salt regime rule in coastal region soil |
| CN111992024B (en) * | 2020-08-26 | 2022-01-28 | 盐城工学院 | Biological trickling filter denitration tower |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005013202A (en) * | 2003-06-27 | 2005-01-20 | Oofuna Denki Kk | Automatic stopping device of paddy field irrigation water |
| CN2870446Y (en) * | 2005-11-17 | 2007-02-21 | 北京农业信息技术研究中心 | Water-supplier with negative head |
| CN103141364A (en) * | 2013-03-28 | 2013-06-12 | 中国农业科学院农业资源与农业区划研究所 | Constant negative pressure irrigation device and constant negative pressure irrigation method |
| CN203884348U (en) * | 2014-02-26 | 2014-10-22 | 湖北工业大学 | Pressure adjustable type underground negative-pressure infiltrating irrigation device |
-
2018
- 2018-12-14 CN CN201811530066.6A patent/CN109496804B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005013202A (en) * | 2003-06-27 | 2005-01-20 | Oofuna Denki Kk | Automatic stopping device of paddy field irrigation water |
| CN2870446Y (en) * | 2005-11-17 | 2007-02-21 | 北京农业信息技术研究中心 | Water-supplier with negative head |
| CN103141364A (en) * | 2013-03-28 | 2013-06-12 | 中国农业科学院农业资源与农业区划研究所 | Constant negative pressure irrigation device and constant negative pressure irrigation method |
| CN203884348U (en) * | 2014-02-26 | 2014-10-22 | 湖北工业大学 | Pressure adjustable type underground negative-pressure infiltrating irrigation device |
Also Published As
| Publication number | Publication date |
|---|---|
| CN109496804A (en) | 2019-03-22 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN109496804B (en) | Negative pressure irrigation system and irrigation method thereof | |
| CN105850662B (en) | A kind of Non-energy-consumption negative pressure regulating system | |
| CN205427579U (en) | Liquid manure integrated device is irrigated to intelligence | |
| CN102160518B (en) | Novel non-pressure irrigation rig | |
| CN103982700B (en) | A kind of passive type field irrigation automaton | |
| CN202222222U (en) | Multistage distributed type constant-pressure irrigation system | |
| KR101356583B1 (en) | Active type irrigation method based on soil potential force and irrigation apparatus thereof | |
| CN110178710A (en) | A kind of irrigation rig and irrigation method based on the response of root region soil water stress | |
| CN2623007Y (en) | Constant negative pressure differentia irrigation device | |
| CN107493789A (en) | A kind of jet-flow aeration oxygen fill system | |
| CN207427797U (en) | A kind of subsurface irrigation device | |
| CN207011395U (en) | A kind of agricultural drip irrigation controller of pressure adjustable | |
| CN202252208U (en) | Waterflow servo valve used for constant pressure | |
| JP2013102710A (en) | Automatic watering device | |
| CN206118679U (en) | Automatic regulation and control system is irrigated to energy -concerving and environment -protective negative pressure | |
| CN107121996B (en) | Constant temperature and humidity control device and control method | |
| CN205658126U (en) | Negative pressure governing system | |
| CN107836322A (en) | The watering device of automatic humidity controlling scope in the case where not consuming the energy | |
| CN201450985U (en) | Negative-pressure pipe-type pressure regulator of infiltrating irrigation device | |
| CN208258410U (en) | Water-fertilizer integral essence amount managing and control system | |
| EP4304332A1 (en) | Hydroponic apparatus | |
| JP4448192B1 (en) | Evaporation automatic irrigation system | |
| CN108789777B (en) | Pressure filling foam device and method for hollow material | |
| CN107432221A (en) | A kind of method of work of distributed automatic spraying arrangement | |
| CN209609462U (en) | One kind being based on Internet of Things intelligent drip-irrigation planting box |
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 |