Tube properties measuring method and tube properties measuring device for measuring properties of tube for drip irrigation

Abstract

To provide a tube properties measuring method capable of easily measuring properties of a tube for drip irrigation.SOLUTION: A tube properties measuring method executes a properties measuring step of measuring the flow rate Q1 and pressure P1 of water at an upper end 1a of a tube for drip irrigation 1 having a plurality of holes while injecting water into the tube for drip irrigation 1, executes an adjusting step of adjusting the flow rate Q2 and pressure P2 of water at a lower end 1b of the tube for drip irrigation 1 such that the flow rate Q2 and pressure P2 of water at the lower end 1b of the tube for drip irrigation 1 match the measured values of the flow rate Q1 and pressure P1 of water at the upper end 1a of the tube for drip irrigation 1, which have been obtained in the properties measuring step, and repeats the properties measuring step and the adjusting step.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a method and an apparatus for measuring the characteristics of drip irrigation tubes used in drip irrigation for watering soil in fields, agricultural land, and the like. [Background technology]

[0002] Drip irrigation is one of the irrigation methods that has been traditionally used as an efficient irrigation method. In other words, drip irrigation is a technology in which water flows through drip irrigation tubes placed in the soil of fields and agricultural land, and the water is applied to the soil through multiple holes formed in the drip irrigation tubes. Drip irrigation can minimize the amount of water used and the energy used (electricity and fuel for pumps).

[0003] Drip irrigation tubes, like normal hoses, experience pressure loss when water flows through them. In addition, because water is sprayed from many holes in the drip irrigation tube, the flow rate of water flowing through the tube decreases as the water moves downstream. In order to minimize the amount of water and energy used in drip irrigation, it is important to measure such characteristics of the drip irrigation tube, i.e., the pressure loss of water in the drip irrigation tube, the flow rate of water injected into the drip irrigation tube, and the flow rate of water discharged from the drip irrigation tube. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2020-43773 A [Patent Document 2] International Publication No. 2021 / 100607 Summary of the Invention [Problem to be solved by the invention]

[0005] However, since drip irrigation tubing is typically several hundred meters long, it is not easy to measure the complex characteristics of drip irrigation tubing.

[0006] Therefore, the present patent provides a tube characteristic measuring method and a tube characteristic measuring device that can easily measure the characteristics of drip irrigation tubes. [Means for solving the problem]

[0007] In one aspect, there is provided a tube characteristic measurement method for measuring characteristics of a drip irrigation tube, the method comprising: performing a characteristic measurement step of measuring the water flow rate and pressure at an upper end of the drip irrigation tube while injecting water into a drip irrigation tube having a plurality of holes; performing an adjustment step of adjusting the water flow rate and pressure at the lower end of the drip irrigation tube so that the water flow rate and pressure at the lower end of the drip irrigation tube match the measured values ​​of the water flow rate and pressure at the upper end of the drip irrigation tube obtained in the characteristic measurement step; and repeating the characteristic measurement step and the adjustment step.

[0008] In one aspect, in the adjusting step, the flow rate and pressure of water at the lower end of the drip irrigation tube are adjusted by a downstream flow control valve with a flow meter provided at the lower end of the drip irrigation tube and a pressure regulator for adjusting the pressure of water injected into the drip irrigation tube. In one aspect, the characteristic measuring step includes measuring water pressure at a midpoint between the upper end and the lower end of the drip irrigation tube. In one embodiment, a temperature measuring step is performed before the characteristic measuring step, to measure the temperature of the water injected into the drip irrigation tube.

[0009] In one aspect, a tube characteristics measuring device is provided for measuring characteristics of a drip irrigation tube, the tube characteristics measuring device comprising: an upstream flow control valve with a flowmeter connected to an upper end of the drip irrigation tube; an upstream pressure measuring device connected to the upper end of the drip irrigation tube; a downstream flow control valve with a flowmeter connected to the lower end of the drip irrigation tube; a downstream pressure measuring device connected to the lower end of the drip irrigation tube; and a pressure regulator connected to the upper end of the drip irrigation tube via the upstream flow control valve with flowmeter and for adjusting the pressure of water injected into the drip irrigation tube.

[0010] In one aspect, the tube characteristic measuring device further comprises an intermediate pressure measuring device that measures water pressure at a midpoint between the upper and lower ends of the drip irrigation tube. In one aspect, the pressure regulator includes a buffer tank connected to the upper end of the drip irrigation tube via the upstream flow control valve with flow meter, an internal tank pressure measuring device that measures the water pressure in the buffer tank, and a flow control discharge valve connected to the buffer tank, the flow control discharge valve being configured to be adjustable in opening degree. In one embodiment, the pressure regulator further includes a temperature measuring device that measures the temperature of the water in the buffer tank. Effect of the Invention

[0011] By repeating the characteristic measuring process and the adjustment process, it is possible to measure the characteristics of a drip irrigation tube of a desired length using a drip irrigation tube that is shorter than the drip irrigation tube that will actually be used in the field. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is a schematic diagram showing one embodiment of a tube characteristic measuring device for measuring the characteristics of a drip irrigation tube. [Diagram 2] 1 is a flow chart illustrating an embodiment of a tube characteristic measurement method for measuring a characteristic of a drip irrigation tube. [Diagram 3] 10 is a schematic diagram showing another embodiment of a tube characteristic measuring device for measuring the characteristics of a drip irrigation tube. FIG. [Figure 4] 13 is a schematic diagram showing yet another embodiment of a tube characteristic measuring device for measuring the characteristics of a drip irrigation tube. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram showing one embodiment of a tube characteristic measuring device for measuring the characteristics of a drip irrigation tube. As shown in FIG. 1, this tube characteristic measuring device includes an upstream flow control valve 3 with a flow meter connected to the upper end 1a of a drip irrigation tube 1, an upstream pressure measuring device 5 connected to the upper end 1a of the drip irrigation tube 1, a downstream flow control valve 7 with a flow meter connected to the lower end 1b of the drip irrigation tube 1, and a downstream pressure measuring device 9 connected to the lower end 1b of the drip irrigation tube 1. Each of the upstream flow control valve 3 with a flow meter and the downstream flow control valve 7 with a flow meter has both a function of measuring the flow rate of water and a function of adjusting the flow rate of water. In one embodiment, each of the upstream flow control valve 3 with a flow meter and the downstream flow control valve 7 with a flow meter may be a combination of a flow meter and a flow control valve connected in series.

[0014] The drip irrigation tube 1 has a plurality of holes (not shown) through which water flowing therethrough is released. The length L of the drip irrigation tube 1 incorporated in the tube characteristic measuring device is shorter than that of a drip irrigation tube actually used for drip irrigation to water soil in fields and farmland. Usually, a drip irrigation tube actually used for drip irrigation has a length of 100 m or more, but the length L of the drip irrigation tube 1 of the embodiment shown in FIG. 1 is shorter than 100 m. In one example, the length L of the drip irrigation tube 1 is within a range of 10 m to 50 m. In another example, the length L of the drip irrigation tube 1 is within a range of 20 m to 30 m.

[0015] The tube characteristic measuring device shown in FIG. 1 further includes a pressure regulator 12 for adjusting the pressure of water injected into the drip irrigation tube 1, and a water injection valve 14 arranged between the pressure regulator 12 and the upstream flow control valve 3 with a flow meter. The water injection valve 14 is an on-off valve connected to both the pressure regulator 12 and the upstream flow control valve 3 with a flow meter. The water injection valve 14 does not need to have a flow control function, but in one embodiment, it may have a flow control function. The pressure regulator 12 is connected to a water supply line 15 extending from a water source 100. Examples of the water source 100 include a waterworks and a pump. The pressure regulator 12 is connected to the upstream flow control valve 3 with a flow meter via the water injection valve 14, and the upstream flow control valve 3 with a flow meter is connected to the upper end 1a of the drip irrigation tube 1. Therefore, the pressure regulator 12 is connected to the upper end 1a of the drip irrigation tube 1 via the water injection valve 14 and the upstream flow control valve 3 with a flow meter. The upstream pressure measuring device 5 and the downstream pressure measuring device 9 can be pressure sensors.

[0016] The pressure regulator 12 includes a buffer tank 20 connected to the upper end 1a of the drip irrigation tube 1 via the water injection valve 14 and the upstream flow rate control valve 3 with a flow meter, a tank pressure measuring device 21 for measuring the water pressure in the buffer tank 20, and a flow rate control discharge valve 25 connected to the buffer tank 20. A pressure sensor or a Bourdon tube pressure gauge can be used for the tank pressure measuring device 21. The flow rate control discharge valve 25 is configured so that its opening degree can be adjusted. The flow rate control discharge valve 25 is attached to a drain line 26 connected to the bottom of the buffer tank 20. The drain line 26 extends to a water tank (not shown). Alternatively, the drain line 26 may extend to a drain outlet (not shown).

[0017] The water supply line 15 is connected to the buffer tank 20. Thus, water is supplied from the water source 100 through the water supply line 15 into the buffer tank 20 of the pressure regulator 12. The buffer tank 20 has a certain capacity and has a function of stabilizing the pressure of the water injected into the drip irrigation tube 1. The water is temporarily stored in the buffer tank 20. The tube characteristic measuring device shown in FIG. 1 includes a water supply valve 28 attached to the water supply line 15. When the water supply valve 28 is opened, the water from the water source 100 flows into the buffer tank 20 through the water supply line 15, and when the water supply valve 28 is closed, the supply of water into the buffer tank 20 is stopped.

[0018] With water supply valve 28 open, the pressure of the water in buffer tank 20 can be adjusted by adjusting the opening of flow rate regulating discharge valve 25. More specifically, increasing the opening of flow rate regulating discharge valve 25 reduces the pressure of the water in buffer tank 20, and decreasing the opening of flow rate regulating discharge valve 25 increases the pressure of the water in buffer tank 20. The pressure of the water injected into drip irrigation tube 1 depends on the pressure of the water in buffer tank 20. Therefore, by operating flow rate regulating discharge valve 25, the pressure of the water injected into drip irrigation tube 1 can be adjusted.

[0019] The water, the pressure of which is adjusted by the pressure regulator 12, flows into the drip irrigation tube 1 through the water injection valve 14 and the upstream flow control valve with flowmeter 3. The water pressure in the pressure regulator 12, i.e., the water pressure in the buffer tank 20, is adjusted so that it is equal to or lower than the allowable pressure of the drip irrigation tube 1 connected downstream.

[0020] The pressure regulator 12 further includes a temperature measuring device 30 that measures the temperature of the water in the buffer tank 20. The temperature measuring device 30 may be a temperature sensor. In one embodiment, the pressure of the water in the buffer tank 20 may be fine-tuned based on the temperature of the water in the buffer tank 20.

[0021] The tube characteristic measuring device of this embodiment further includes a plurality of intermediate pressure measuring devices 35 for measuring water pressure P at a plurality of intermediate points 1c between the upper end 1a and the lower end 1b of the drip irrigation tube 1. The intermediate pressure measuring devices 35 are connected to the drip irrigation tube 1 at positions between the upper end 1a and the lower end 1b of the drip irrigation tube 1. The number of intermediate pressure measuring devices 35 is not limited to this embodiment. In one embodiment, only one intermediate pressure measuring device 35 may be provided at one intermediate point 1c. In other embodiments, the intermediate pressure measuring device 35 may not be provided.

[0022] Next, one embodiment of a tube characteristic measuring method for measuring the characteristics of drip irrigation tube 1 using the tube characteristic measuring device shown in FIG. 1 will be described with reference to the flowchart of FIG.

[0023] In step 1, with the water injection valve 14 closed, the water supply valve 28 is opened to supply water from the water source 100 through the water supply line 15 into the buffer tank 20 of the pressure regulator 12, filling the buffer tank 20 with water. At this time, the flow rate control discharge valve 25 may be opened slightly. After the buffer tank 20 is filled with water, the water supply valve 28 is opened and the opening degree of the flow rate control discharge valve 25 is adjusted to adjust the water pressure in the buffer tank 20. The water pressure in the buffer tank 20 at this time is equal to or lower than the allowable pressure of the drip irrigation tube 1. The temperature of the water in the buffer tank 20 is measured by the temperature measuring device 30.

[0024] In step 2, the water injection valve 14 is opened and water is injected from the pressure regulator 12 through the water injection valve 14 and the upstream flow control valve 3 with a flow meter into the drip irrigation tube 1.

[0025] In step 3, an initial setting process is performed to adjust the water flow rate Q2 and pressure P2 at the lower end 1b of the drip irrigation tube 1 so that the water flow rate Q2 and pressure P2 at the lower end 1b of the drip irrigation tube 1 become the predetermined terminal flow rate and terminal pressure while injecting water into the drip irrigation tube 1. The terminal flow rate is a flow rate equivalent to the terminal flow rate of the drip irrigation tube actually used for drip irrigation, and in one example, the terminal flow rate is 0. The terminal pressure is a pressure equivalent to the terminal pressure of the drip irrigation tube actually used for drip irrigation, and is determined based on the length of the drip irrigation tube actually used for drip irrigation, the supply water pressure, and the like. The water flow rate Q2 and pressure P2 at the lower end 1b of the drip irrigation tube 1 are measured by the downstream flow rate control valve 7 with a flow meter and the downstream pressure measuring device 9, respectively. The water flow rate Q2 and pressure P2 at the lower end 1b of the drip irrigation tube 1 can be adjusted by operating the downstream flow rate control valve 7 with a flow meter and the flow rate control discharge valve 25 of the pressure regulator 12.

[0026] In step 4, a characteristic measuring step is carried out to measure the water flow rate Q1 and pressure P1 at the upper end 1a of the drip irrigation tube 1 while injecting water into the drip irrigation tube 1. The water flow rate Q1 and pressure P1 at the upper end 1a of the drip irrigation tube 1 are measured by the upstream flow control valve 3 with flowmeter and the upstream pressure measuring device 5, respectively. In this characteristic measuring step of step 4, the water pressure P at the midpoint 1c between the upper end 1a and the lower end 1b of the drip irrigation tube 1 may be measured by the intermediate pressure measuring device 35.

[0027] In step 5, an adjustment step is carried out to adjust the water flow rate Q2 and pressure P2 at the lower end 1b of the drip irrigation tube 1 so that the water flow rate Q2 and pressure P2 at the lower end 1b of the drip irrigation tube 1 match the measured values ​​of the water flow rate Q1 and pressure P1 at the upper end 1a of the drip irrigation tube 1 obtained in the characteristic measurement step in step 4 above. The water flow rate Q2 and pressure P2 at the lower end 1b of the drip irrigation tube 1 can be adjusted by operating the downstream flow rate adjustment valve 7 with flowmeter and the flow rate adjustment discharge valve 25 of the pressure regulator 12.

[0028] In step 6, the characteristic measuring process in step 4 and the adjustment process in step 5 are repeated a predetermined number of times. This predetermined number of times is determined based on the length of the drip irrigation tube actually used for drip irrigation and the length L of the drip irrigation tube 1 in the tube characteristic measuring device shown in FIG.

[0029] In step 7, after the characteristic measurement process of step 4 and the adjustment process of step 5 are repeated a predetermined number of times, a final measurement process is performed to measure the water flow rate Q1 and pressure P1 at the upper end 1a of the drip irrigation tube 1.

[0030] The characteristic measuring step of step 4 above is a step of constructing a state simulating a portion of a long drip irrigation tube actually used for drip irrigation. The adjustment step of step 5 above is a step of constructing a state simulating a portion upstream of the portion of the drip irrigation tube simulated in the characteristic measuring step of step 4 above. By repeating the characteristic measuring step of step 4 above and the adjustment step of step 5 above, the overall characteristics of a long drip irrigation tube actually used can be measured. Specific examples of the overall characteristics of a drip irrigation tube include the flow rate that can be injected into the drip irrigation tube, the pressure loss of the drip irrigation tube, and the total flow rate of water released from multiple holes in the drip irrigation tube.

[0031] In one embodiment, as shown in Fig. 3, the pressure at the intermediate point 1c of the drip irrigation tube 1 may be measured by a downstream pressure measuring device 9. In the embodiment shown in Fig. 3, the downstream pressure measuring device 9 is connected to the lower end 1b and the intermediate points 1c of the drip irrigation tube 1 by a plurality of branch pipes 41. A plurality of on-off valves 42 are respectively attached to the plurality of branch pipes 41. By opening only one of these on-off valves 42, the downstream pressure measuring device 9 can measure the pressure at the lower end 1b of the drip irrigation tube 1 and any one of the intermediate points 1c.

[0032] In another embodiment, as shown in Fig. 4, the pressure at the intermediate point 1c of the drip irrigation tube 1 may be measured by the upstream pressure measuring device 5. In the embodiment shown in Fig. 4, the upstream pressure measuring device 5 is connected to the upper end 1a and the intermediate points 1c of the drip irrigation tube 1 by a plurality of branch pipes 41. A plurality of on-off valves 42 are attached to each of the plurality of branch pipes 41. By opening only one of these on-off valves 42, the upstream pressure measuring device 5 can measure the pressure at the upper end 1a of the drip irrigation tube 1 and any one of the intermediate points 1c.

[0033] The above-described embodiments have been described for the purpose of enabling a person having ordinary skill in the art to practice the present invention. Various modifications of the above-described embodiments are naturally possible for a person skilled in the art, and the technical idea of ​​the present invention can be applied to other embodiments. Therefore, the present invention is not limited to the described embodiments, but is to be interpreted in the broadest scope according to the technical idea defined by the claims. [Explanation of symbols]

[0034] 1 Drip irrigation tube 3. Upstream flow control valve with flow meter 5. Upstream pressure measuring device 7. Downstream flow control valve with flow meter 9. Downstream pressure measuring device 12 Pressure regulator 14 Water injection valve 15 Water Supply Line 20 Buffer Tank 21 Tank pressure measuring device 25 Flow control discharge valve 26 Drain line 28 Water supply valve 30 Temperature measuring device 35 Intermediate pressure measuring device 41 Branch Pipe 42 On-off valve 100 water source

Claims

1. A method for measuring characteristics of a tube for drip irrigation, comprising: performing a characteristic measuring step of measuring the flow rate and pressure of water at an upper end of a drip irrigation tube having a plurality of holes while injecting water into the drip irrigation tube; performing an adjustment step of adjusting the water flow rate and pressure at the lower end of the drip irrigation tube so that the water flow rate and pressure at the lower end of the drip irrigation tube correspond to the measured values ​​of the water flow rate and pressure at the upper end of the drip irrigation tube obtained in the characteristic measurement step; The tube characteristic measuring method further comprises repeating the characteristic measuring step and the adjustment step.

2. 2. The tube characteristic measuring method according to claim 1, wherein in the adjusting step, the flow rate and pressure of the water at the lower end of the drip irrigation tube are adjusted by a downstream flow control valve with a flow meter provided at the lower end of the drip irrigation tube and a pressure regulator for adjusting the pressure of the water injected into the drip irrigation tube.

3. 2. The tube characteristic measuring method according to claim 1, wherein the characteristic measuring step measures water pressure at a midpoint between the upper end and the lower end of the drip irrigation tube.

4. 2. The tube characteristic measuring method according to claim 1, further comprising the step of: measuring a temperature of water injected into the drip irrigation tube before the characteristic measuring step.

5. A tube characteristic measuring device for measuring characteristics of a drip irrigation tube, An upstream flow control valve with a flow meter connected to the upper end of the drip irrigation tube; an upstream pressure measuring device connected to the upper end of the drip irrigation tube; A downstream flow control valve with a flow meter connected to the lower end of the drip irrigation tube; a downstream pressure measuring device connected to the lower end of the drip irrigation tube; A tube characteristic measuring device comprising a pressure regulator connected to the upper end of the drip irrigation tube via the upstream flow control valve with flow meter and for adjusting the pressure of water injected into the drip irrigation tube.

6. 6. The tube characteristic measurement apparatus of claim 5, further comprising an intermediate pressure measurement device for measuring water pressure at a midpoint between said upper and lower ends of said drip irrigation tube.

7. The pressure regulator is A buffer tank connected to the upper end of the drip irrigation tube via the upstream flow control valve with a flow meter; a tank internal pressure measuring device for measuring the pressure of water in the buffer tank; a flow control discharge valve connected to the buffer tank; 6. The tube characteristic measuring device according to claim 5, wherein the flow rate adjusting discharge valve is configured so that its opening degree is adjustable.

8. 8. The tube characteristic measuring device according to claim 7, wherein the pressure regulator further comprises a temperature measuring device for measuring a temperature of the water in the buffer tank.

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