Underground drip irrigation emitter outflow and blockage in-situ real-time monitoring equipment and method

Abstract

The invention discloses in-situ real-time monitoring equipment and an in-situ real-time monitoring method for water dropper outflow and blockage of underground drip irrigation, and relates to the field of agricultural drip irrigation. The automatic heating optical fiber distributed temperature sensor system comprises a distributed temperature sensor DTS, a thermal pulse subsystem HPS, a composite optical cable, an electrical control cabinet, an upper computer and a power supply voltage stabilizer, the power supply voltage stabilizer is connected with the electrical control cabinet, and the electrical control cabinet is connected with the upper computer, the distributed temperature sensor DTS and the thermal pulse subsystem HPS. A signal port of the DTS is connected with an optical fiber in the composite optical cable, the HPS is connected with a cable in the composite optical cable, and the composite optical cable and the drip irrigation pipe are arranged under the ground together. The problem that the blocking degree and the blocking position of the underground drip irrigation dripper cannot be accurately judged through an existing method is solved.

Description

Technical Field

[0001] The invention relates to the field of agricultural drip irrigation, and in particular to an in-situ real-time monitoring device and method for outflow and blockage of underground drip irrigation drippers. Background Art

[0002] The underground drip irrigation system is an efficient, energy-saving and environmentally friendly irrigation method that can increase crop yield and quality while reducing irrigation costs and environmental impact. However, dripper blockage in underground drip irrigation systems is a common but difficult to detect problem. Because drippers are usually buried in the soil at a certain depth below the surface, it is difficult to detect if the dripper is blocked during use, resulting in a decrease in flow. Even if there is no flow at all, it is difficult to detect in time. Unless a comprehensive inspection of the system is carried out or there is obvious abnormal plant growth, it is difficult to determine the extent and exact location of the blockage.

[0003] At present, common methods for detecting underground drip irrigation blockage include flow meter monitoring and pressure gauge monitoring. The flow meter installed in the drip irrigation pipe can monitor the speed and flow of water flow. When the flow of a certain pipe is significantly reduced, it may indicate that the pipe is blocked. Another method is to monitor the pressure changes in the drip irrigation system pipe through a pressure gauge. When the pressure of a certain section of the pipe increases or decreases abnormally, it may indicate that there is a blockage or leakage in the pipe. However, these methods are difficult to reflect in time when the blockage is mild. More importantly, these methods cannot accurately determine the location of the blockage. Summary of the invention

[0004] In view of the above-mentioned deficiencies in the prior art, the present invention provides an in-situ real-time monitoring device and method for outflow and blockage of underground drip irrigation drippers, which solves the problem that the prior method cannot accurately determine the blockage degree and blockage position of underground drip irrigation drippers.

[0005] In order to achieve the above-mentioned invention object, the technical solution adopted by the present invention is: an in-situ real-time monitoring device for outflow and blockage of underground drip irrigation drippers, including an automatic heating optical fiber distributed temperature sensor system, the automatic heating optical fiber distributed temperature sensor system includes a distributed temperature sensor DTS, a heat pulse subsystem HPS, a composite optical cable, an electrical control cabinet, a host computer and a power regulator, the power regulator is connected to the electrical control cabinet, the electrical control cabinet is respectively connected to the host computer, the distributed temperature sensor DTS and the heat pulse subsystem HPS, the signal port of the distributed temperature sensor DTS is connected to the optical fiber in the composite optical cable, the heat pulse subsystem HPS is connected to the cable in the composite optical cable, and the composite optical cable is laid below the surface together with the drip irrigation pipe;

[0006] The power regulator provides stable power to the system;

[0007] The electrical control cabinet provides power to the host computer, distributed temperature sensor DTS and heat pulse subsystem HPS, and realizes automatic control;

[0008] The host computer is used for the user to set the sampling time interval and the spatial spacing of the sampling points according to the needs;

[0009] The distributed temperature sensor DTS is used to continuously monitor the temperature response status of all positions of the composite optical cable;

[0010] The heat pulse subsystem HPS is used to connect and heat the cables in the composite optical cable and provide heat pulses for the cables.

[0011] In addition, the present invention also adopts a technical solution: an in-situ real-time monitoring method for outflow and blockage of underground drip irrigation drippers, comprising the following steps:

[0012] S1: Monitor based on the automatic heating optical fiber distributed temperature sensor system and draw a comparison chart of the wetting front time of typical measuring points;

[0013] S2: extracting the wetting front moment of the optical fiber measuring point according to the continuous sampling value of the optical fiber measuring point;

[0014] S3: According to the comparison chart of the wetting front moment of the optical fiber measuring point and the wetting front moment of the typical measuring point, the blockage degree and blockage position of the dripper are determined, and the in-situ real-time monitoring of the outflow and blockage of the underground drip irrigation dripper is completed.

[0015] Furthermore, drawing the comparison diagram of the wetting front time of the measuring point in S1 includes the following sub-steps:

[0016] S1-1: establishing a correspondence between the positions of typical measuring points of the optical fiber and the positions of the drippers, and performing a cycle along the optical fiber with the correspondence as one group;

[0017] S1-2: Based on the established corresponding relationship, calculate the reasonable variation range of the wetting front moment of the typical measuring point when the dripper is not blocked, and draw a reasonable variation range diagram of the wetting front moment of the typical measuring point when there is no blockage;

[0018] S1-3: According to the change of dripper flow, the blockage is divided into complete blockage, 75% blockage, 50% blockage and 25% blockage, and based on the in-situ soil experiment, the reasonable change range of the wetting front moment of the typical measuring point at different blockage degrees is calculated, and at the same time, a reasonable change range diagram of the wetting front moment of the typical measuring point at different blockage degrees is drawn to realize the drawing of the comparison diagram of the wetting front moment of the measuring point.

[0019] Furthermore, the method for extracting the wetting front moment of the optical fiber measuring point in S2 is: before the start of irrigation, turn on the in-situ real-time monitoring equipment to perform optical fiber measurement, and use the time corresponding to the first inflection point in the continuous soil moisture curve in a period of time before and after irrigation as the wetting front moment of the optical fiber measuring point.

[0020] Furthermore, judging the blockage degree of the dripper in S3 includes the following sub-steps:

[0021] A1: Draw a continuous waveform diagram based on the wetting front moment of the optical fiber measurement point;

[0022] A2: Compare the continuous waveform diagram with the reasonable variation range diagram of the wetting front moment of the typical measuring point when there is no blockage, and determine the typical measuring point position corresponding to the actual measuring point of the optical fiber;

[0023] A3: Based on the typical measuring point position corresponding to the actual measuring point of the optical fiber, the wetting front moment of the optical fiber measuring point is compared with the reasonable variation range diagram of the wetting front moment of the typical measuring point at different blockage degrees, and the blockage degree of the dripper at the current position is determined according to the position of the wetting front moment of the optical fiber measuring point in the reasonable variation range diagram of the wetting front moment of the typical measuring point at different blockage degrees.

[0024] Furthermore, determining the dripper blockage position in S3 includes the following sub-steps:

[0025] B1: Get the number of measuring points between the blocking measuring point and the positioning point on the optical fiber;

[0026] B2: Multiply the number of measuring points by the distance between measuring points to obtain the actual distance between the positioning point and the blocked measuring point;

[0027] B3: The actual distance between the positioning point and the blockage measuring point is taken as the blockage position of the dripper.

[0028] The beneficial effect of the present invention is that the present invention uses distributed optical fiber temperature measurement technology (DTS) to accurately detect the blockage degree and position of underground drip irrigation drippers. Compared with traditional methods, this method can monitor the outflow status of underground drip irrigation systems in real time, solve the problem that underground drip irrigation blocked drippers cannot be found and accurately located in time, help managers quickly and accurately find blocked drippers and replace them, reduce the maintenance cost of drip irrigation systems, and extend the service life of drip irrigation systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 Schematic diagram of the in-situ real-time monitoring equipment for underground drip irrigation emitter outflow and blockage.

[0030] Figure 2 Flow chart of the in-situ real-time monitoring method for underground drip irrigation emitter outflow and blockage.

[0031] Figure 3 This is a schematic diagram of the correspondence between typical optical fiber measurement points and the positions of drip irrigation pipe drippers.

[0032] Figure 4 This is a curve diagram of the reasonable variation range of the wetting front moment at a typical measuring point when the dripper is not blocked.

[0033] Figure 5 This is a curve diagram of the wetting front variation range of typical measuring points when the dripper is blocked to different degrees.

[0034] Figure 6 A schematic diagram of determining the wetting front moment of each measuring point based on the continuous sampling values ​​of the optical fiber measuring point.

[0035] Figure 7 This is a curve diagram of the wetting front time at consecutive measuring points on the optical fiber.

[0036] Figure 8 This is a comparison chart of the wetting peak moments at typical measurement points of the actual optical fiber. DETAILED DESCRIPTION

[0037] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0038] Embodiment 1, as Figure 1 As shown, an in-situ real-time monitoring device for outflow and blockage of underground drip irrigation drippers includes an automatic heating optical fiber distributed temperature sensor system, the automatic heating optical fiber distributed temperature sensor system includes a distributed temperature sensor DTS, a heat pulse subsystem HPS, a composite optical cable, an electrical control cabinet, a host computer and a power regulator, the power regulator is connected to the electrical control cabinet, the electrical control cabinet is respectively connected to the host computer, the distributed temperature sensor DTS and the heat pulse subsystem HPS, the signal port of the distributed temperature sensor DTS is connected to the optical fiber in the composite optical cable, the heat pulse subsystem HPS is connected to the cable in the composite optical cable, and the composite optical cable is laid below the surface together with the drip irrigation pipe;

[0039] The power regulator provides a stable power supply for the system. Before the power supply is connected to the active heating optical fiber distributed temperature sensor system, the power regulator is required to ensure that the input voltage is constant during the detection process, with a rated power of 8000W and a rated voltage of 250V;

[0040] The electrical control cabinet provides power to the host computer, distributed temperature sensor DTS and heat pulse subsystem HPS, and realizes automatic control;

[0041] The host computer is used for the user to set the sampling time interval and the spatial spacing of the sampling points according to the needs;

[0042] The distributed temperature sensor DTS is used to continuously monitor the temperature response status of all positions of the composite optical cable, including a host computer, and the user can set the time interval of the programmed monitoring sampling and the spatial spacing of the sampling points through software as needed. In this method, the DTS spatial sampling spacing is set to 0.25m and the time sampling interval is set to 30s.

[0043] The heat pulse subsystem HPS is used to connect and heat the cables in the composite optical cable and provide heat pulses for the cables.

[0044] Embodiment 2, as Figure 2 As shown, an in-situ real-time monitoring method for outflow and blockage of underground drip irrigation drippers includes the following steps:

[0045] S1: Monitor based on the automatic heating optical fiber distributed temperature sensor system and draw a comparison chart of the wetting front time of typical measuring points;

[0046] S2: extracting the wetting front moment of the optical fiber measuring point according to the continuous sampling value of the optical fiber measuring point;

[0047] S3: According to the comparison chart of the wetting front moment of the optical fiber measuring point and the wetting front moment of the typical measuring point, the blockage degree and blockage position of the dripper are determined, and the in-situ real-time monitoring of the outflow and blockage of the underground drip irrigation dripper is completed.

[0048] Drawing the comparison diagram of the wetting front time of the measuring point in S1 includes the following steps:

[0049] S1-1: establishing a correspondence between the positions of typical measuring points of the optical fiber and the positions of the drippers, and performing a cycle along the optical fiber with the correspondence as one group;

[0050] There is a fixed rule for the horizontal correspondence between the optical fiber measurement point position and the dripper position. Take the dripper spacing of 30cm as an example: because the optical fiber sampling spacing is 0.25m, there are 6 continuous measurement points on the optical fiber to monitor the outflow conditions of the 5 drippers above it, such as Figure 3 As shown, the correspondence between other measuring points and the dripper positions is a cyclic repetition of these six typical measuring points. Figure 3 The measuring point A on the middle optical fiber is located directly below the No. 1 dripper. However, in actual field installation, the measuring point A may be located anywhere between the No. 1 and No. 2 drippers. When the measuring point A moves to below the No. 2 dripper, the No. 2 dripper can be renumbered as the No. 1 dripper, and the positional relationship between the 6 consecutive measuring points and the 5 drippers is restored to Figure 2 The state shown, therefore, the corresponding relationship between the optical fiber and the dripper position is "6 optical fiber measuring points corresponding to 5 drippers" as a group and continuously circulates along the optical fiber;

[0051] S1-2: Based on the established corresponding relationship, calculate the reasonable variation range of the wetting front moment of the typical measuring point when the dripper is not blocked, and draw a reasonable variation range diagram of the wetting front moment of the typical measuring point when there is no blockage;

[0052] The outflow from the dripper continuously wets the soil in the soil, and the edge of the wet body is called the wetting front. Generally speaking, the larger the dripper flow rate, the faster the wetting front advances. That is, the larger the dripper flow rate, the earlier the wetting front reaches the location where the optical fiber is buried and is detected by the DTS system. The time point when the wetting front reaches the optical fiber and is detected by the DTS system is called the "wetting front moment". It can be seen that the dripper flow rate is inversely proportional to the wetting front moment, that is, the larger the dripper flow rate, the smaller the wetting front moment. The wetting front advancement process in the soil can be simply expressed as y=kx+b, where y is the distance traveled by the wetting peak, in cm, and x is the time, in min. The k value can be measured by simple experiments in the early stage. According to the above principle, the wetting peak moment of the A~F measuring points on the optical fiber when the dripper is not blocked can be calculated. From the above content, it can be seen that when installed in the field, the A measuring point may be located at any position between the No. 1 and No. 2 drippers (the B measuring point may be located at any position between the No. 2 and No. 3 drippers, and so on...), so the wetting front time of the optical fiber measuring point is an interval value: Figure 3 Take the measuring point A in the figure as an example. When the measuring point A is located just below the dripper No. 1, the distance between the measuring point and the dripper is the smallest, which is 5 cm. At this time, the wetting front moment of the measuring point is the smallest, which is (5-b) / k. When A moves to the right to just below the midpoint of the line connecting dripper No. 1 and dripper No. 2, its wetting front moment is the largest, which is ((52+152)1 / 2-b) / k, which is about (7.07-b) / k. When the measuring point A continues to move to the right, the distance to dripper No. 2 becomes closer and closer, and its wetting front moment gradually decreases. Because the change is symmetrical, only the minimum and maximum values ​​of the wetting front moment of the measuring point A need to be calculated. This range is the reasonable variation range of the wetting front moment of the measuring point A. In field practice, when the wetting front moment of the measuring point A is within this range, it can be considered that dripper No. 1 is not blocked. The same is true for other measuring points and drippers. The reasonable variation range of their wetting front moments is calculated respectively, and the reasonable variation range of the wetting front moment of the typical measuring point is plotted as shown in the figure. Figure 4 As shown. Figure 4 In the diagram, each typical measuring point has a red point and a pink point in the longitudinal direction. The longitudinal range between the two points is the reasonable variation range of the measuring point. Within this range, it can be considered that the dripper is not blocked. Figure 4 The middle red or pink dots, the AF typical measurement points form a waveform;

[0053] S1-3: According to the change of dripper flow, the blockage is divided into complete blockage, 75% blockage, 50% blockage and 25% blockage, and based on the in-situ soil experiment, the reasonable change range of the wetting front moment of the typical measuring point at different blockage degrees is calculated, and at the same time, a reasonable change range diagram of the wetting front moment of the typical measuring point at different blockage degrees is drawn to realize the drawing of the comparison diagram of the wetting front moment of the measuring point.

[0054] According to the change of dripper flow, the blockage can be divided into four situations: "complete blockage", "75% blockage", "50% blockage" and "25% blockage". When different degrees of blockage occur, soil in-situ experiments can be carried out to obtain different k and b values ​​in the expression y=kx+b of the wetting front advancement process under different blockage conditions. The same principle as in step S1-2 can be used to calculate the range of wetting front changes (i.e. upper and lower limits) at typical measuring points when different degrees of blockage occur, and the graph can be drawn as follows: Figure 5 In field practice, the wetting front time of the optical fiber measuring point is compared with Figure 5 By comparing, you can determine whether the dripper is blocked and the degree of blockage. You can also simply draw a table of the upper and lower limits of the wetting front time of typical optical fiber measurement points at different degrees of blockage, which is more convenient for comparison in practice.

[0055] from Figure 3 It can be seen that among the six typical measuring points on the optical fiber, one measuring point is located in the middle of the two drippers in the vertical direction (i.e. Figure 3 There is no critical range of wetting front moments at the D measuring point in the figure, that is Figure 5 This is because when the No. 3 or No. 4 dripper above this measuring point is blocked, the wetting front of the other dripper can always reach this measuring point on time, but the adjacent C and E measuring points are affected first, and the wetting front time is delayed. Therefore, the role of the D measuring point in the process of identifying the dripper blockage can be ignored, and there is no need to calculate the critical value of its wetting front time.

[0056] The method for extracting the wetting front moment of the optical fiber measuring point in S2 is: before the start of irrigation, turn on the in-situ real-time monitoring equipment to perform optical fiber measurement, and use the time corresponding to the first inflection point in the continuous soil moisture content curve within a period of time before and after irrigation as the wetting front moment of the optical fiber measuring point.

[0057] In this embodiment, the DTS time sampling interval is set to 30s, that is, the data result of each measurement point on the optical fiber is the continuous soil temperature value at intervals of 30s. There is a certain empirical relationship between the change in soil temperature and soil moisture content during the test period. The soil moisture content can be calculated using this relationship. The equipment is turned on 10 minutes before the start of irrigation to perform optical fiber measurement and data calculation. Continuous soil moisture content data (sampling interval is 30s) for a period of time before and after irrigation can be obtained. Figure 6As shown in Figure 1, it is easy to distinguish the low moisture content interval before irrigation, the moisture content increase interval after irrigation, and the stable moisture content interval. The time corresponding to the first inflection point of the curve is the time of the wet front detected at the measuring point.

[0058] Determining the blockage degree of the dripper in S3 includes the following steps:

[0059] A1: Draw a continuous waveform diagram based on the wetting front moment of the optical fiber measurement point;

[0060] A2: Compare the continuous waveform diagram with the reasonable variation range diagram of the wetting front moment of the typical measuring point when there is no blockage, and determine the typical measuring point position corresponding to the actual measuring point of the optical fiber;

[0061] A3: Based on the typical measuring point position corresponding to the actual measuring point of the optical fiber, the wetting front moment of the optical fiber measuring point is compared with the reasonable variation range diagram of the wetting front moment of the typical measuring point at different blockage degrees, and the blockage degree of the dripper at the current position is determined according to the position of the wetting front moment of the optical fiber measuring point in the reasonable variation range diagram of the wetting front moment of the typical measuring point at different blockage degrees.

[0062] In this embodiment, a continuous waveform is formed by extracting the wetting front moments of all continuous measuring points on the optical fiber, such as Figure 7 As shown in the figure, the cyclic characteristics of the measuring point can be seen from the waveform diagram. Figure 4 Compare the red dot position in the image to determine the typical measurement point position corresponding to the actual measurement point of the optical fiber (i.e. the position marked with AF). Note that the waveform of the measured data is not smooth due to measurement errors.

[0063] The wetting front moment of the optical fiber measuring point ( Figure 7 The blue point) and Figure 5 The wetting front time of typical measuring points is compared according to Figure 7 The blue point falls on Figure 5 The position in the image is used to determine the outflow or blockage status of the dripper at that position.

[0064] Determining the dripper blockage position in S3 includes the following steps:

[0065] B1: Get the number of measuring points between the blocking measuring point and the positioning point on the optical fiber;

[0066] B2: Multiply the number of measuring points by the distance between measuring points to obtain the actual distance between the positioning point and the blocked measuring point;

[0067] B3: The actual distance between the positioning point and the blockage measuring point is taken as the blockage position of the dripper.

[0068] In this embodiment, first, the position of the positioning point (usually the ice point) on the optical fiber in the DTS system is known, and then the number of measuring points between the blocking measuring point and the positioning point is determined in the system, and the actual distance between the positioning point and the blocking measuring point is obtained by multiplying the number of measuring points by the distance between the measuring points. At this point, the buried position of the blocking measuring point, that is, the buried position of the blocked dripper, can be determined.

[0069] In one embodiment of the present invention, the application and test research of the method are carried out in the solar greenhouse of Shandong Shouguang Lusheng Agricultural Science and Technology Development Co., Ltd. Select a drip irrigation pipe with a flow rate of 4.0L / h (with 23-25 ​​drippers) and bury it at a depth of 20cm. Select 15 continuous drippers in the center of the drip irrigation pipe as test samples, and the remaining drippers are scattered at both ends of the planting ridge as "protection rows". The 15 drippers are evenly divided into 3 groups, and one dripper in each group is selected as a "blocked" dripper for the following treatment: the dripper is cut off and replaced with a blind pipe, which is treated as "completely blocked", and the dripper is cut off and replaced with 3.0L / h, 2.0L / h, and 1.0L / h drippers, respectively, as 25%, 50%, and 75% blocked. Each treatment has 1 drip irrigation pipe and 1 planting ridge. The optical fiber is buried below the drip irrigation pipe at a distance of 5cm from the drip irrigation pipe.

[0070] DTS sampling was started 5 minutes before watering, with the sampling interval set to 30 seconds and the sampling interval set to 0.25 meters. Watering lasted for 2 hours and sampling continued until the end of watering. The moisture data at each measuring point on the optical fiber increased with time and finally stabilized. The time when the wet peak arrived at each measuring point was extracted and recorded, which was recorded as the wet front moment.

[0071] In the early stage, after point source infiltration tests and experiments with drippers of different flow rates, different k and b values ​​were obtained for four conditions of dripper flow: "complete blockage", "75% blockage", "50% blockage" and "25% blockage". The upper and lower limits of the wetting front moments of the six typical measuring points A-F under the four degrees of blockage were obtained by calculation, as shown in Table 1.

[0072] Table 1 Upper and lower limits of the wetting front time at six typical measuring points of AF under four levels of blockage (min)

[0073]

[0074] From Table 1, we can see that there is no critical range of wetting front moment at measuring point D. Figure 5 The critical value of the moment when there is no wetting front at the D measuring point in the figure is consistent.

[0075] The measurement results of all processed optical fibers in the experiment were processed to obtain the wet front time values ​​of typical measuring points corresponding to different degrees of blockage at different buried distances, and then plotted. Figure 8From the figure, we can see that all the processed optical fiber measurement results have three groups of typical measurement point values, namely group 1, group 2, and group 3. These are the three groups set up in the experiment. The three groups of typical measurement point results form a consistent waveform, and the measurement point corresponding to the peak is Figure 3 and Figure 5 Point D in the figure can be used to label other measuring points in turn to form horizontal axis labels. The pink covered area is the reasonable range of the wetting front time of the measuring point when the dripper is not blocked, that is, the measuring point whose value is within the pink area has no blockage in the corresponding dripper.

[0076] Will Figure 8 By comparing all the fiber measurement results with the critical values ​​of the wetting front moment in Table 1, it can be seen that the blocked drippers were accurately detected in all three groups of the four blockage levels, that is, the detection rate of blocked drippers was 100%. For example, in the complete blockage treatment (a in the figure), in the three repeated groups, the wetting front moments of the blocked drippers in Group 1 and Group 3 (blue A measurement point, gray B measurement point, and orange C measurement point) were 47.21, 40.88, and 32.96, respectively. By comparing the upper and lower limits of the A measurement point, B measurement point, and C measurement point in Table 1, it can be seen that these three measurement points were accurately judged as "completely blocked."

[0077] However, in the other three degrees of blockage, there is a certain error in the determination of the blockage degree of the dripper. For example, in the 75% blockage treatment, the gray C measuring point of group 3 actually measured the wetting front time of 37.21. According to the upper and lower limits of the C measuring point in Table 1, it should be judged as "completely blocked", but in the actual test design, the dripper is 75% blocked, and this method misjudges its blockage degree more seriously. This is because the spatial heterogeneity of the soil means that the soil is not an ideal uniform material, and the infiltration of water and the advancement of the wetting front are not uniform and consistent. This will cause the wetting front time of a certain measuring point to be advanced or delayed to a certain extent, resulting in errors in the determination results. However, the errors in the determination of the blockage degree of the present invention are all within an acceptable range, that is, the blockage degree is judged to be slightly mild or severe, and there will be no misjudgment. Therefore, the present invention has been verified in practice and is a reliable method.

[0078] Those skilled in the art will appreciate that the embodiments described herein are intended to help readers understand the principles of the present invention, and should be understood that the protection scope of the present invention is not limited to such specific statements and embodiments. Those skilled in the art can make various other specific variations and combinations that do not deviate from the essence of the present invention based on the technical revelations disclosed by the present invention, and these variations and combinations are still within the protection scope of the invention.

Claims

1. An in-situ real-time monitoring device for outflow and blockage of underground drip irrigation drippers, characterized in that: It comprises an automatic heating optical fiber distributed temperature sensor system, which comprises a distributed temperature sensor DTS, a heat pulse subsystem HPS, a composite optical cable, an electrical control cabinet, a host computer and a power regulator, wherein the power regulator is connected to the electrical control cabinet, and the electrical control cabinet is respectively connected to the host computer, the distributed temperature sensor DTS and the heat pulse subsystem HPS, the signal port of the distributed temperature sensor DTS is connected to the optical fiber in the composite optical cable, the heat pulse subsystem HPS is connected to the cable in the composite optical cable, and the composite optical cable is laid below the ground surface together with the drip irrigation pipe; The power regulator provides stable power to the system; The electrical control cabinet provides power to the host computer, distributed temperature sensor DTS and heat pulse subsystem HPS, and realizes automatic control; The host computer is used for the user to set the sampling time interval and the spatial spacing of the sampling points according to the needs; The distributed temperature sensor DTS is used to continuously monitor the temperature response status of all positions of the composite optical cable; The heat pulse subsystem HPS is used to connect and heat the cables in the composite optical cable and provide heat pulses for the cables.

2. An in-situ real-time monitoring method for outflow and blockage of underground drip irrigation drippers, characterized in that: The following steps are involved: S1: Monitor based on the automatic heating optical fiber distributed temperature sensor system and draw a comparison chart of the wetting front time of typical measuring points; S2: extracting the wetting front moment of the optical fiber measuring point according to the continuous sampling value of the optical fiber measuring point; S3: According to the comparison chart of the wetting front moment of the optical fiber measuring point and the wetting front moment of the typical measuring point, the blockage degree and blockage position of the dripper are determined, and the in-situ real-time monitoring of the outflow and blockage of the underground drip irrigation dripper is completed.

3. The in-situ real-time monitoring method for outflow and blockage of underground drip irrigation drippers according to claim 2, characterized in that: Drawing the comparison diagram of the wetting front time of the measuring point in S1 includes the following steps: S1-1: establishing a correspondence between the positions of typical measuring points of the optical fiber and the positions of the drippers, and performing a cycle along the optical fiber with the correspondence as one group; S1-2: Based on the established corresponding relationship, calculate the reasonable variation range of the wetting front moment of the typical measuring point when the dripper is not blocked, and draw a reasonable variation range diagram of the wetting front moment of the typical measuring point when there is no blockage; S1-3: According to the change of dripper flow, the blockage is divided into complete blockage, 75% blockage, 50% blockage and 25% blockage, and based on the in-situ soil experiment, the reasonable change range of the wetting front moment of the typical measuring point at different blockage degrees is calculated, and at the same time, a reasonable change range diagram of the wetting front moment of the typical measuring point at different blockage degrees is drawn to realize the drawing of the comparison diagram of the wetting front moment of the measuring point.

4. The in-situ real-time monitoring method for outflow and blockage of underground drip irrigation drippers according to claim 2, characterized in that: The method for extracting the wetting front moment of the optical fiber measuring point in S2 is: before the start of irrigation, turn on the in-situ real-time monitoring equipment to perform optical fiber measurement, and use the time corresponding to the first inflection point in the continuous soil moisture content curve within a period of time before and after irrigation as the wetting front moment of the optical fiber measuring point.

5. The in-situ real-time monitoring method for outflow and blockage of underground drip irrigation drippers according to claim 3, characterized in that: Determining the blockage degree of the dripper in S3 includes the following steps: A1: Draw a continuous waveform diagram based on the wetting front moment of the optical fiber measurement point; A2: Compare the continuous waveform diagram with the reasonable variation range diagram of the wetting front moment of the typical measuring point when there is no blockage, and determine the typical measuring point position corresponding to the actual measuring point of the optical fiber; A3: Based on the typical measuring point position corresponding to the actual measuring point of the optical fiber, the wetting front moment of the optical fiber measuring point is compared with the reasonable variation range diagram of the wetting front moment of the typical measuring point at different blockage degrees, and the blockage degree of the dripper at the current position is determined according to the position of the wetting front moment of the optical fiber measuring point in the reasonable variation range diagram of the wetting front moment of the typical measuring point at different blockage degrees.

6. The in-situ real-time monitoring method for outflow and blockage of underground drip irrigation drippers according to claim 2, characterized in that: Determining the dripper blockage position in S3 includes the following steps: B1: Get the number of measuring points between the blocking measuring point and the positioning point on the optical fiber; B2: Multiply the number of measuring points by the distance between measuring points to obtain the actual distance between the positioning point and the blocked measuring point; B3: The actual distance between the positioning point and the blockage measuring point is taken as the blockage position of the dripper.

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