Methods for agricultural-photovoltaic complementary rainwater use and automatic irrigation on a plateau

Abstract

The present invention discloses a method for agricultural-photovoltaic complementary rainwater harvesting and automatic irrigation on a tableland and relates to the technical field of photovoltaic power generation. The method for agricultural-photovoltaic complementary rainwater harvesting and automatic irrigation on a tableland of the present invention comprises the following steps: S1. Monitoring the soil moisture content of the tableland and creating a model for the daily water requirement Q1 of the tableland crop; S2. Setting a minimum alarm value P1 and a maximum alarm value P2 for the soil moisture content of the tableland, and when the soil moisture content of the tableland is lower than the minimum alarm value P1, the spray pipe starts spraying, and when the soil moisture content of the tableland reaches the maximum alarm value P2, the spray pipe stops spraying; S3.The system monitors the water level in the water collection tank and sets a first alarm level H1 and a second alarm level H2. When the water level is lower than H1, water is supplied to the water collection tank, and when the water level reaches H2, the water supply assembly stops supplying water to the water collection tank. The agricultural-photovoltaic complementary rainwater harvesting and automatic irrigation method for a tableland, as described in the present invention, can utilize rainwater to automatically irrigate the tableland, ensure a normal crop yield, and achieve a win-win complementarity between agriculture and the photovoltaic industry.

Description

Technical area

[0001] The present invention relates to the technical field of photovoltaic power generation and in particular to a method for agricultural-photovoltaic complementary rainwater use and automatic irrigation on a plateau and. Background technology

[0002] Photovoltaic power generation is a next-generation method that harnesses inexhaustible solar energy to convert it into electricity for industrial and agricultural production, as well as for everyday life. It can maximize energy savings and emission reduction and is a crucial component of a low-carbon lifestyle. Current photovoltaic power generation uses flat-panel photovoltaic panels to capture solar energy and convert it into electrical energy for external use. The larger the surface area, the higher the efficiency of power generation, which inevitably requires large amounts of land resources. Our country is a vast agricultural land with enormous acreage, and some crops do not receive sufficient sunlight.For this reason, a "complementary agricultural-photovoltaic" approach to photovoltaic power generation has emerged, organically combining agricultural cropping with photovoltaic power generation. This approach not only utilizes vast rural arable land for photovoltaic power generation, supplying electricity for industrial, agricultural, and domestic use, but also ensures the healthy growth of crops, ecological feedback loops, win-win benefits, and promotes the development of both agriculture and the photovoltaic industry.

[0003] In related technologies, the agricultural-photovoltaic complementary planting model on a plateau cannot effectively account for the natural rainfall required for plant growth and the ambient humidity required by shade-loving plants when photovoltaic power generation is completed, which affects normal crop yields and makes it difficult to achieve a true win-win complementarity between agriculture and the photovoltaic industry.

[0004] From the publication DE 10 2013 101 313 A1, a support structure for supporting photovoltaic modules and for collecting rainwater is also known. Contents of the invention

[0005] The present invention aims to solve at least part of one of the technical problems in the prior art.

[0006] To this end, embodiments of the present invention provide a method for agricultural-photovoltaic complementary rainwater harvesting and automatic irrigation on a plateau. This method for agricultural-photovoltaic complementary rainwater harvesting and automatic irrigation on a plateau can effectively take into account the natural rainfall required for plant growth and the ambient humidity required by shade-loving plants when completing photovoltaic power generation, ensuring normal crop yields and achieving a true win-win complementarity between agriculture and the photovoltaic industry.

[0007] The method for agricultural-photovoltaic complementary rainwater harvesting and automatic irrigation on a plateau according to the embodiment of the present invention is based on a system for agricultural-photovoltaic complementary rainwater harvesting and automatic irrigation on a plateau, and the system comprises a support, a water collection assembly, a spray assembly, a water supply assembly, and a control unit, wherein several of the support structures are arranged in a stepped fashion on several plateau levels and are each provided with inclined photovoltaic modules, and the water collection assembly comprises several water collection tanks corresponding to the support structures and arranged on the higher plateau level, as well as water collection basins arranged on the support structure, wherein the water collection basins located on the lowest level are connected to the water supply assembly.while the other water collection basins are connected to the water collection tanks on the corresponding table level, the water collection basins being configured to direct the collected rainwater to the corresponding water collection tanks or the water supply assembly, the spray assembly comprising a spray pipe and a valve body, the spray pipe being connected to the water collection tank located on a higher table level, and the valve body being provided in the spray pipe and configured to control the circulation and blocking of the water body in the spray pipe, the water supply assembly being configured to supply water to several of the water collection tanks when the rainwater in the water collection tanks is insufficient for the spraying process, the control unit being communicatively connected to the valve body and configured to control the operation of the valve body,to achieve the circulation and blocking of the water body in the spray pipe; The procedure includes the following steps: S1. Monitoring the soil water content of the tableland and creating a model for the daily water requirement Q1 of the tableland crop; S2. Setting a minimum alarm value P1 and a maximum alarm value P2 for the soil moisture content of the tableland, and when the soil moisture content of the tableland is lower than the minimum alarm value P1, the control unit drives the valve body to open so that the spray tube begins spraying, and when the soil moisture content of the tableland reaches the maximum alarm value P2, the control unit drives the valve body to close to stop the spray tube from spraying; S3. Monitoring the water level in the water collection tank and setting a first alarm level H1 and a second alarm level H2, and when the water level is lower than the first alarm level H1, the water body is supplied to the water collection tank by the water supply assembly, and when the water level is at the second alarm level H2, the water supply assembly stops supplying the water body to the water collection tank.

[0008] The method for agricultural-photovoltaic complementary rainwater use and automatic irrigation on a plateau according to the embodiment of the present invention can, in completing the photovoltaic power generation, effectively take into account the natural amount of precipitation required for plant growth and the ambient humidity required by shade-loving plants, ensuring normal crop yields and achieving a true win-win complementarity between agriculture and the photovoltaic industry.

[0009] In some embodiments, the daily water requirement Q1 of tableland cultivation fulfills the following formula: Q1=KS⋅KC⋅ET0ηc⋅ηp; where K S a soil moisture stress factor, K C a total plant coefficient, ET0, a reference plant evapotranspiration, η c a water usage coefficient of the piping system and η pa field spray water utilization coefficient.

[0010] In some embodiments, the gravity flow pipeline flow model is set up and the maximum flow rate Q is determined. max the pipeline is calculated and the minimum alarm value P1 of the soil water content on the plateau must satisfy the following formula: P1⋅Z+Qmax≥Q1; where Z is the volume of soil penetrated by the crop's roots in the corresponding tableland plain.

[0011] In some embodiments, the maximum flow rate Qmax of the pipeline is determined based on the gravity flow pipeline flow model using the following formula: Qmax=v×A; v=1n⋅R23⋅I12; R=d2(1−sin 2φ2φ); φ=arccos(1−2α); A=φ−sinφ⋅cosφ4⋅d2; where v is the flow velocity of the water body in the gravity flow pipe, A is the flow cross-sectional area of ​​the pipeline, n is the roughness coefficient of the pipeline, R is the hydraulic radius, I is the gradient of the gravity flow pipeline, d is the inner diameter of the pipeline, φ is the filling angle and α is the degree of filling.

[0012] In some embodiments, the maximum value of the pipeline flow rate is calculated from the maximum value of the opening stroke, and the pipeline flow rate and the valve opening stroke satisfy the following formula: L=Lmax⋅f−1(QQmax); where L is the opening stroke and Q is the real-time flow rate of the pipeline.

[0013] In some embodiments, the minimum alarm value P1 of the soil water content on the plateau satisfies the following formula: P1⋅Z+Q2≥Q1; Q2=PT(1−dec); where Q2 is the maximum permissible daily irrigation water quantity, P is the permissible irrigation intensity of the soil, T is the daily irrigation time, and dec is the permissible value for reducing the irrigation intensity on the slope.

[0014] In some embodiments, the tableland in S1 is provided with a soil moisture meter, wherein the soil moisture meter is used to measure the soil water content of the tableland in real time and the soil moisture meter is connected to the control unit for communication purposes in order to transmit information about the soil water content of the tableland measured by the soil moisture meter to the control unit.

[0015] In some embodiments, a water level sensor is provided in the water collection tank in S3, wherein the water level sensor is connected to the control unit for communication purposes in order to transmit information about the water level in the water tank to the control unit.

[0016] In some embodiments, several diversion pipes are provided, wherein the diversion pipes are arranged between the water collection tanks on two adjacent tableland levels, wherein the several diversion pipes are designed to connect the several water collection tanks one after the other, and wherein the connection point of the diversion pipes to the water collection tanks located on a higher tableland level is below the second alarm level.

[0017] In some embodiments, a drain pipe is provided, wherein the water supply assembly comprises a water reservoir and a conveying pipe, wherein the drain pipe is connected to the water collection tank located on the lowest tableland level at a position above the second alarm level, wherein the other end of the drain pipe is connected to the water reservoir, wherein one end of the conveying pipe is connected to the water reservoir, and the other end of the conveying pipe extends into the water collection tank located on the highest tableland level and is configured to convey a body of water into the water collection tank located on the highest tableland level, and the water collection tank located on the lowest tableland level is connected to the water reservoir and is configured to convey rainwater collected on a suitable support into the water reservoir. Figures Fig. Figure 1 is a schematic structure diagram of the rainwater harvesting and automatic irrigation system within the framework of the method for agricultural-photovoltaic complementary rainwater harvesting and automatic irrigation on a plateau according to the embodiment of the present invention.

[0018] Reference symbols in the figures: Bracket 1; Water collection assembly 2; Water collection tank 21; Water collection basin 22; Drainage pipe 23; Spray assembly 3; spray tube 31; valve body 32; Water supply assembly 4; pump body 41; water reservoir 42; delivery pipe 43; Photovoltaic modules 5; Diversion pipe 6; Drain pipe 7. Specific embodiments

[0019] The embodiments of the present invention are described in detail below; examples of these embodiments are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and serve to explain the present invention; they are not to be understood as limiting the present invention.

[0020] As in Fig. As shown in Figure 1, the method for agricultural-photovoltaic complementary rainwater harvesting and automatic irrigation on a plateau according to the embodiment of the present invention is based on a system for agricultural-photovoltaic complementary rainwater harvesting and automatic irrigation on a plateau, and the system comprises a support 1, a water collection assembly 2, a spray assembly 3, a water supply assembly 4 and a control unit, wherein several of the support 1 are arranged in a stepped fashion on several plateau levels and are each provided with inclined photovoltaic modules 5, and the water collection assembly 2 comprises several water collection tanks 21, corresponding to the support 1 and arranged on the higher plateau level, as well as water collection basins 22 arranged on the support 1.wherein the water collection basins 22 located at the lowest level are connected to the water supply assembly 4, while the other water collection basins 22 are connected to the water collection tanks 21 at the corresponding table level, wherein the water collection basins 22 are configured to direct the collected rainwater to the corresponding water collection tanks 21 or the water supply assembly 4, wherein the spray assembly 3 comprises a spray pipe 31 and a valve body 32, wherein the spray pipe 31 is connected to the water collection tank 21 arranged at a higher table level, and the valve body 32 is provided in the spray pipe and is configured to control the circulation and block the water body in the spray pipe, wherein the water supply assembly 4 is configured to supply water to several of the water collection tanks 21 when the rainwater in the water collection tanks 21 is insufficient for the spraying process,wherein the control unit is communicatively connected to the valve body 32 and is designed to control the operation of the valve body 32 in order to realize the circulation and blocking of the water body in the spray tube 31 and thereby control the spraying process of the spray assembly 3.

[0021] The method for agricultural-photovoltaic complementary rainwater harvesting and automatic irrigation on a plateau according to the embodiment of the present invention provides a water collection basin 22 on the support 1 for collecting rainwater from the corresponding photovoltaic module 5 into the water collection tank 21 or the water supply assembly 4 on the corresponding plateau level. When irrigation is required, the rainwater in the water collection tank 21 is used for spraying. If the rainwater in the water collection tank 21 is insufficient for the spraying process, the water supply assembly 4 supplies water to several water collection tanks 21 to ensure the rainwater irrigation effect on the plateau.

[0022] Optionally, the valve body 32 can be a flow-through valve. It should be noted that it is sufficient for the valve body 32 to perform signal-controlled opening and closing; there are no restrictions regarding the specific application of the valve body 32.

[0023] Based on the above-mentioned system for agricultural-photovoltaic complementary rainwater harvesting and automatic irrigation on a tableland, the method for supplementary rainwater collection and automatic irrigation on the tableland for light agricultural purposes according to the embodiment of the present invention comprises the following steps: S1. Monitoring the soil water content of the tableland and creating a model for the daily water requirement Q1 of the tableland crop; S2. Setting a minimum alarm value P1 and a maximum alarm value P2 for the soil moisture content of the tableland, and when the soil moisture content of the tableland is lower than the minimum alarm value P1, the control unit drives the valve body 32 to open so that the spray tube 31 begins the spraying process, and when the soil moisture content of the tableland reaches the maximum alarm value P2, the control unit drives the valve body 32 to close to end the spraying process of the spray tube 31; S3. Monitoring the water level in the water collection tank 21 and setting a first alarm level H1 and a second alarm level H2, and when the water level is lower than the first alarm level H1, the water body is supplied to the water collection tank 21 by the water supply assembly 4, and when the water level is at the second alarm level H2, the water supply assembly 4 stops supplying the water body to the water collection tank 21.

[0024] When a method for agricultural-photovoltaic complementary rainwater harvesting and automatic irrigation on a plateau according to the embodiment of the present invention is used, the soil moisture content of the plateau is monitored, and the minimum alarm value P1 and the maximum alarm value P2 are set to implement automatic irrigation of the plateau and ensure the soil moisture requirements of the plateau are met. Rainwater collection and irrigation are achieved through the arrangement of the water collection tank 21 and the water supply assembly 4, and during irrigation, the water level in the water collection tank 21 is automatically replenished to ensure the irrigation requirements of the plateau are met.

[0025] The method for agricultural-photovoltaic complementary rainwater use and automatic irrigation on a plateau according to the embodiment of the present invention can effectively take into account the natural amount of precipitation required for plant growth and the ambient humidity required by shade-loving plants when completing photovoltaic power generation, and the irrigation efficiency is high, thereby ensuring a normal crop yield and achieving a win-win complementarity between agriculture and the photovoltaic industry.

[0026] It should be noted that, according to the technical specifications for irrigation technology GBT50085-2007, there is an upper and a lower limit for the suitable soil moisture content for crops. The highest alarm value, P2, is not greater than the upper limit of a suitable soil moisture content, and the lowest alarm value, P1, is not less than the lower limit of a suitable soil moisture content. Generally, the relative moisture content of the soil is 50–70%. Different crops have different requirements for soil moisture content, and the specific values ​​of the highest and lowest alarm values ​​depend on the crop.

[0027] In some examples, the daily water requirement of crops Q1=KS⋅KC⋅ET0ηc⋅ηp, where K S a soil moisture stress factor, K Cwhere η is a total plant coefficient and ET0 is a reference plant evapotranspiration calculated according to the Penman-Monteith formula. c a water usage coefficient of the piping system and η p a field spray water utilization coefficient.

[0028] Evapotranspiration refers to the maximum water loss from the surface. It is the water vapor flux resulting from the combined effects of climate, soil, and vegetation, and can be considered the water requirement of cultivated plants. The daily water requirement is calculated using the ET formula recommended by the FAO. C =K C ·ET0 in combination with the soil moisture stress factor K S , the comprehensive harvest coefficient K C , the water utilization coefficient of the piping system η c and the field spray water utilization coefficient η p revised to ensure an accurate calculation of daily water requirements.

[0029] According to the technical specifications for irrigation technology GBT50085-2007, the water utilization coefficient of the piping system η c between 0.95 and 0.98, and the field spray water utilization coefficient η p Depending on climatic conditions, it can be selected within the following range: if the wind speed is below 3.4 m / s, the η p 0.8-0.9, and when the wind speed is between 3.5 and 5.4 m / s, the η is p 0.7-0.8.

[0030] In some embodiments, the gravity flow pipeline flow model is set up and the maximum flow rate Q is determined. max the pipeline is calculated, where the maximum flow rate Q max P1·Z+Q max ≥Q1 should be met, and the minimum alarm value P1 for the soil moisture content of the tableland is determined by the maximum flow rate Q maxthe pipeline is revised, where Z is the volume of soil penetrated by the crop's roots in the corresponding tableland plain.

[0031] The maximum flow rate Q max The pipeline flow rate is calculated, and the minimum alarm value P1 for the soil moisture content of the tableland is revised once the daily water requirement Q1 of the tableland crops has been determined. It should be ensured that, after the spraying process reaches the maximum flow rate of the pipeline and the water requirement of the tableland crops has been met, the soil moisture content of the tableland is higher than the lower limit of the suitable soil moisture content, thus ensuring normal crop production.

[0032] In some embodiments, the water flow in the gravity flow pipeline is in the gravity flow pipeline flow model. v=1n⋅R23⋅I12, where n is the pipe roughness coefficient, I is the inclination of the gravity flow pipeline, and R is the hydraulic radius. The filling angle φ = arccos(1 - 2α) can be determined from the degree of filling α of the pipe and the hydraulic radius. R=d2(1−sin 2φ2φ) can be determined using the filling angle φ, where d is the inner diameter of the pipe and the flow cross-sectional area A=φ−sinφ⋅cosφ4⋅d2 The maximum flow rate of the pipeline is: According to the maximum design fill level, the flow cross-sectional area and the flow velocity of the pipeline, the maximum flow rate of the pipeline Q is: max =v×A.

[0033] The gravity flow pipeline model is used to calculate the flow velocity in the pipeline. In an irrigation system, the pipe wall roughness coefficient n and the gradient of the gravity flow pipeline I are fixed values. Therefore, the only factor that actually influences the flow velocity is the hydraulic radius R. The maximum fill level of the pipeline is fixed during installation, and the maximum design fill level for gravity pipelines of varying diameters is less than 0.75, as specified in the pipe manufacturing specifications. Based on the fill level α of the pipeline, the hydraulic radius R and the maximum flow rate Q can be determined. max the pipeline is determined, thus ensuring an accurate value for the maximum flow rate.

[0034] In some embodiments, the relationship between flow rate and valve opening is determined based on the flow characteristics of the valve. L=Lmax⋅f⋅−1(QQmax), where L is the opening stroke and Q is the real-time flow rate of the pipeline, and the maximum flow rate Qmax of the pipeline is revised by the opening stroke L.

[0035] Generally, the maximum valve opening should be around 90% and must not be too small, otherwise the adjustable ratio will be reduced and the valve diameter will become too large, impairing control performance and making it uneconomical. The minimum opening should not be less than 10%, otherwise the water body will exert even greater pressure on the valve core and seat, easily damaging the valve core and leading to a deterioration of its properties and even adjustment errors. Valve flow characteristics are primarily linear, logarithmic, parabolic, and fast-opening. The relationship between flow rate and valve opening is determined based on the valve's flow characteristics. L=Lmax⋅f⋅−1(QQmax), and the maximum flow rate Q maxThe pipe is revised by the opening stroke of the valve in order to achieve the set irrigation volume requirement within the set time.

[0036] In some embodiments, the maximum daily permissible irrigation water quantity Q2 = PT (1-dec), P1·Z+Q2≥Q1 and the minimum alarm value P1 for the soil moisture content of the tableland are revised by the maximum daily permissible irrigation water quantity Q2, where P is the permissible irrigation intensity of the soil, T is the daily irrigation time and dec is the permissible value for the reduction of irrigation intensity on the slope.

[0037] According to the Technical Specifications for Irrigation Technology GBT50085-2007, the planned irrigation intensity of the fixed irrigation system must not exceed the permissible irrigation intensity of the soil, with a planned daily irrigation time of 12 to 20 hours for fixed pipes and crops. The permissible irrigation intensity for different soil types should be determined using the "Table of Permissible Irrigation Intensities for Different Soil Types" in GBT50085-2007 Technical Specifications for Irrigation Technology; if the soil slope exceeds 5%, the permissible irrigation intensity should be reduced according to the "Table of Reduced Values ​​for Permissible Irrigation Intensities on Slopes" in GBT50085-2007 Technical Specifications for Irrigation Technology.

[0038] By calculating the maximum permissible daily irrigation water quantity Q2 and combining it with the daily water requirement Q1 of the crops, the minimum alarm value P1 of the soil moisture content of the tableland is revised, ensuring that the daily water requirement of the crops is met below the requirement of the maximum permissible daily irrigation water quantity Q2 to guarantee the normal yield of the crops.

[0039] In some embodiments, the tableland in S1 is equipped with a soil moisture meter, the soil moisture meter is used to measure the soil water content of the tableland in real time, and the soil moisture meter is connected to the control unit for communication purposes in order to transmit information about the soil water content of the tableland measured by the soil moisture meter to the control unit.

[0040] Installing a soil moisture meter makes it easier to monitor the soil moisture content and the measurement more accurate.

[0041] Optionally, the soil moisture meter has a pin-type soil moisture sensor or a soil moisture and temperature monitor.

[0042] Optionally, several soil moisture meters are provided at each plateau level. The average soil moisture content measured by several soil moisture meters is considered the soil moisture content of the corresponding plateau, thus facilitating accurate monitoring of the plateau soil.

[0043] Optionally, the control unit is equipped with a processing module, the processing module being designed to compare the soil moisture content with the lowest alarm value P1 or the highest alarm value P2, and if the soil moisture content of the tableland is lower than the minimum alarm value P1, the control unit drives the valve body 32 to open so that the spray tube 31 begins the spraying process, and if the soil moisture content of the tableland reaches the maximum alarm value P2, the control unit drives the valve body 32 to close in order to end the spraying process of the spray tube 31.

[0044] In some embodiments, a water level sensor is provided in the water collection tank 21 in S3, wherein the water level sensor is connected to the control unit by means of communication in order to transmit information about the water level in the water tank to the control unit.

[0045] By installing a water level sensor, it is convenient to monitor the water level in the water collection tank 21 and to replenish the moisture in the water collection tank 21 in a timely manner to ensure the water supply required for plant growth and the ambient humidity required for shade-loving plants, thus ensuring high irrigation efficiency and a normal crop yield.

[0046] Optionally, the control unit is equipped with a processing module, wherein the processing module is designed to compare the water level in the water collection tank 21 with the first alarm level H1 or the second alarm level H2, and if the water level is lower than the first alarm level H1, the control unit controls the pump body 41 to deliver the water body to the water collection tank 21, and if the water level is at the second alarm level H2, the control unit controls the pump body 41 to stop the delivery of the water body to the water collection tank 21.

[0047] In some embodiments, as in Fig. Figure 1 shows several diversion pipes 6 provided, wherein the diversion pipes 6 are arranged between the water collection tanks 21 on two adjacent tableland levels, wherein the several diversion pipes 6 are designed to connect the several water collection tanks 21 one after the other, and wherein the connection point of the diversion pipes 6 to the water collection tanks 21 located on a higher tableland level is below the second alarm level.

[0048] A diversion pipe 6 is provided between each pair of adjacent water collection tanks 21, and the connection point of the diversion pipe 6 to the water collection tank located on a higher level below the two water collection tanks 21 is below the second alarm level. When rainwater is collected or water is supplied to the water collection tank 21, and the water level in the upper water collection tank 21 reaches the connection point of the diversion pipe 6 to the water collection tank 21, the water flows through the diversion pipe 6 into the lower water collection tank 21. The connection between two adjacent water collection tanks 21 is achieved by multiple diversion pipes 6, which facilitates monitoring of the water level in the water collection tanks 21 on each level and ensures a balanced water storage level in each tank.Simultaneously, when water is being supplied to the water collection tanks 21 by the water supply assembly 4, the water collection tank 21 located on the lowest level of the tableland is not connected to the diversion pipe 6. When the water level reaches the second alarm line, the supply of water to the water collection tank 21 is stopped.

[0049] In some embodiments, as in Fig.Figure 1 shows a drain pipe 7, wherein the water supply assembly 4 comprises a water reservoir 42 and a conveying pipe 43, the drain pipe 7 being connected to the water collection tank 21 located at the lowest tableland level at a position above the second alarm level, the other end of the drain pipe 7 being connected to the water reservoir 42, one end of the conveying pipe 43 being connected to the water reservoir 42, and the other end of the conveying pipe 43 extending into the water collection tank 21 located at the highest tableland level and being configured to convey a body of water into the water collection tank 21 located at the highest tableland level, and the water collection tank 21 located at the lowest tableland level being connected to the water reservoir 42 and being configured to convey rainwater collected on a suitable support into the water reservoir.

[0050] Due to the arrangement of the drainpipe 7, when rainwater is collected on rainy days, the water flows from top to bottom through the diversion pipes 6 into the water collection tank 21 located at the lowest level of the tableland, after the water level in the water collection tank 21 reaches the connection point of the diversion pipes 6 to the water collection tank 21. Once the water level in the water collection tank 21 at the lowest level of the tableland reaches the second alarm level, the rainwater is collected via the drainpipe in the tank to ensure rainwater collection.At the same time, the water body is delivered directly to the water collection tank 21 located on the highest tableland level via the delivery pipe 43, and the water body in the several water collection tanks 21 is filled one after the other from top to bottom via the diversion pipes 6, thereby reducing the number of water supply lines and ensuring that the water level in each water collection tank 21 is on the water level control line when the water delivery to the water collection tanks 21 is complete, which facilitates the filling of the water body in the water collection tank 21 and the control of the water level in the water collection tank 21.

[0051] Optionally, the volume of the water reservoir 42 is more than five times the volume of the water collection tank 21.

[0052] Optionally, the other end of the drain pipe 7 extends into the water reservoir 42.

[0053] Optionally, one end of the conveying pipe 43 is connected to the pump body 41.

[0054] Optionally, the water supply assembly 4 includes a pump body 41 for supplying water to the water collection tank 21, the pump body 41 is located in the water reservoir 42 and the control unit is connected to the pump body 41 by means of communication in order to control the water pumping operation of the pump body 41.

[0055] Optionally, the water supply assembly 4 can extract groundwater or surface water to supply water to the water reservoir 42. When feeding water into the multiple water collection tanks 21, the water supply assembly 4 preferably extracts water from the water reservoir 42.

[0056] Optionally, a drainage pipe 23 is connected between the water collection basin 22 and the water collection tank 21, and the drainage pipe 23 is designed to supply rainwater in the water collection basin 22 to the water collection tank 21.

[0057] In describing the present invention, it is necessary to point out that any azimuth or positional relationship referred to in terms such as "center," "longitudinal," "transverse," "length," "width," "thickness," "top," "bottom," "front," "back," "left," "right," "vertical," "horizontal," "top," "bottom," "inside," "outside," "clockwise," "counterclockwise," "axial," "radial," "circumferential direction," and the like, is based on the drawing. These terms are intended to facilitate and simplify the description of the present invention, rather than indicating or implying that the device or component in question must have a specific orientation, be designed, or be operated in a particular orientation. Therefore, they should not be construed as limiting the present invention.

[0058] Furthermore, the terms “first” and “second” are used for descriptive purposes only and should not be understood as indicating or suggesting a relative meaning or implicitly specifying the set of the technical features mentioned. Therefore, features defined as “first” and “second” may explicitly or implicitly include at least one of these features. In the description of the present invention, “several” means two or more than two, unless expressly and specifically limited otherwise.

[0059] In the present invention, it is necessary to point out that the terms "install," "connect," "link," and "fasten" are to be understood in a broad sense unless expressly stated otherwise or limited. For example, it may be a permanent connection, a detachable connection, or a connection in one piece; it may be a mechanical connection, an electrical connection, or a communication; it may be a direct connection or an indirect connection via an intermediate medium; and it may be a connection within the two elements or an interaction between the two elements. For general technical personnel in this field, the specific meaning of the above terms in the present invention may be understood according to the specific circumstances.

[0060] In the present invention, it means that, unless expressly defined otherwise, if a first feature is "above" or "below" with respect to the second feature, the first feature and the second feature are in direct contact, or they may be in indirect contact via an intermediate medium. Furthermore, it means that if the first feature is "on," "above," or "above" with respect to the second feature, the first feature is directly above or diagonally above the second feature, or simply that the horizontal height of the first feature is greater than the horizontal height of the second feature. It means that if the first feature is "below," "under," or "below" with respect to the second feature, the first feature is directly below or diagonally below the second feature, or simply that the horizontal height of the first feature is less than the horizontal height of the second feature.

[0061] In the description of this specification, reference to the terms “an embodiment”, “some embodiments”, “example”, “specific example”, or “some examples”, or the like, means that certain features, structures, materials, or properties associated with the embodiment or example are included in at least one embodiment or example of the invention. In this description, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the described specific features, structures, materials, or properties may be combined in any suitable manner in one or more embodiments or examples.Furthermore, technical personnel may combine and mix different embodiments or examples and features of different embodiments or examples described in this description, provided they do not contradict each other.

[0062] Although exemplary embodiments of the present invention have been shown and described, it is understood that the above-mentioned exemplary embodiments are merely examples and should not be interpreted as limitations of the present invention. General technical personnel may make changes, modifications, substitutions, and variations to the exemplary embodiments described above within the scope of the present invention.

Claims

[1] Method for agricultural-photovoltaic complementary rainwater harvesting and automatic irrigation on a tableland, the method being based on a system for agricultural-photovoltaic complementary rainwater harvesting and automatic irrigation on a tableland and the system comprising a support (1), a water collection assembly (2), a sprinkler assembly (3), a water supply assembly (4) and a control unit, wherein several of the supports (1) are arranged in a stepped fashion on several tableland levels and each is provided with inclined photovoltaic modules (5), and the water collection assembly (2) comprises several water collection tanks (21) corresponding to the supports (1) and arranged on the higher tableland level, as well as water collection basins (22) arranged on the support (1), wherein the water collection basins (22) located on the lowest level are connected to the water supply assembly (4),while the other water collection basins (22) are connected to the water collection tanks (21) on the corresponding table level, the water collection basins (22) being configured to direct the collected rainwater to the corresponding water collection tanks (21) or the water supply assembly (4), the spray assembly (3) comprising a spray pipe (31) and a valve body (32), the spray pipe (31) being connected to the water collection tank (21) arranged on a higher table level, and the valve body (32) being provided in the spray pipe (31), the water supply assembly (4) being configured to supply water to several of the water collection tanks (21) when the rainwater in the water collection tanks (21) is insufficient for the spraying process, the control unit being communicatively connected to the valve body (32) and configured to control the operation of the valve body (32),to achieve the circulation and blocking of the water in the spray tube (31); , characterized by that the procedure includes the following steps: S1. Monitoring the soil water content of the tableland and creating a model for the daily water requirement Q1 of the tableland crop; S2. Setting a minimum alarm value (P1) and a maximum alarm value (P2) of the soil moisture content of the tableland, and when the soil moisture content of the tableland is lower than the minimum alarm value (P1), the control unit drives the valve body (32) to open so that the spray tube (31) begins the spraying process, and when the soil moisture content of the tableland reaches the maximum alarm value (P2), the control unit drives the valve body (32) to close in order to stop the spraying process of the spray tube (31); S3. Monitoring the water level in the water collection tank (21) and setting a first alarm level (H1) and a second alarm level (H2), and when the water level is lower than the first alarm level (H1), the water body is supplied to the water collection tank (21) by the water supply assembly (4), and when the water level is at the second alarm level (H2), the water supply assembly (4) stops supplying the water body to the water collection tank (21). [2] Method for agricultural-photovoltaic complementary rainwater use and automatic irrigation on a tableland according to claim 1, characterized by , that the daily water requirement Q1 of the tableland crop fulfills the following formula: Q1=KS⋅KC⋅ET0ηc⋅ηp; where K S a soil moisture stress factor, K C a total plant coefficient, ET0; a reference plant evapotranspiration, η ca water usage coefficient of the piping system and η p a field spray water utilization coefficient. [3] Method for agricultural-photovoltaic complementary rainwater use and automatic irrigation on a tableland according to claim 2, characterized by , that the gravity flow pipeline flow model was set up and the maximum flow rate Q max the pipeline is calculated and the minimum alarm value (P1) of the soil water content on the plateau must satisfy the following formula: P1−Z+Qmax≥Q1; where Z is the volume of soil penetrated by the crop's roots in the corresponding tableland plain. [4] Method for agricultural-photovoltaic complementary rainwater use and automatic irrigation on a tableland according to claim 3, characterized by that the maximum flow rate Q maxThe pipeline is determined based on the gravity flow pipeline flow model using the following formula: Qmax=v×A; v=1n⋅R23⋅I12; R=d2(1−sin 2φ2φ); φ=arccos(1−2α); A=φ−sinφ⋅cosφ4⋅d2; where v is the flow velocity of the water body in the gravity flow pipeline, A is the flow cross-sectional area of ​​the pipeline, n is the roughness coefficient of the pipeline, R is the hydraulic radius, I is the gradient of the gravity flow pipeline, d is the inner diameter of the pipeline, φ is the filling angle and α is the degree of filling. [5] Method for agricultural-photovoltaic complementary rainwater use and automatic irrigation on a tableland according to claim 4, characterized by, that the maximum value of the pipeline flow rate is calculated from the maximum value of the opening stroke, and that the pipeline flow rate and the valve opening stroke satisfy the following formula: L=Lmax⋅f⋅−1(QQmax); where L is the opening stroke and Q is the real-time flow rate of the pipeline. [6] Method for agricultural-photovoltaic complementary rainwater use and automatic irrigation on a tableland according to claim 3, characterized by , that the minimum alarm value P1 of the soil water content on the plateau satisfies the following formula: P1−Z+Q2≥Q1; Q2=PT(1−dec); where Q2 is the maximum permissible daily irrigation water quantity, P is the permissible irrigation intensity of the soil, T is the daily irrigation time, and dec is the permissible value for reducing the irrigation intensity on the slope. [7] Method for agricultural-photovoltaic complementary rainwater use and automatic irrigation on a tableland according to claim 1, characterized by , that in S1 the tableland is equipped with a soil moisture meter, wherein the soil moisture meter is used to measure the soil water content of the tableland in real time and the soil moisture meter is connected to the control unit for communication purposes in order to transmit information about the soil water content of the tableland measured by the soil moisture meter to the control unit. [8] Method for agricultural-photovoltaic complementary rainwater use and automatic irrigation on a tableland according to claim 1, characterized by, that in S3 a water level sensor is provided in the water collection tank (21), wherein the water level sensor is connected to the control unit by means of communication in order to transmit information about the water level in the water collection tank (21) to the control unit. [9] Method for agricultural-photovoltaic complementary rainwater use and automatic irrigation on a tableland according to claim 1, characterized by , that several diversion pipes (6) are provided, wherein the diversion pipes (6) are arranged between the water collection tanks (21) on two adjacent tableland levels, wherein the several diversion pipes (6) are designed to connect the several water collection tanks (21) one after the other, and wherein the connection point of the diversion pipes (6) to the water collection tank (21) located on a higher tableland level is below the second alarm level (H2). [10] Method for agricultural-photovoltaic complementary rainwater use and automatic irrigation on a tableland according to claim 9, characterized by, that a drain pipe (7) is provided, wherein the water supply assembly (4) comprises a water reservoir (42) and a delivery pipe (43), the drain pipe (7) being connected to the water collection tank (21) located at the lowest table level at a position above the second alarm level (H2), the other end of the drain pipe (7) being connected to the water reservoir (42), one end of the delivery pipe (43) being connected to the water reservoir (42), and the other end of the delivery pipe (43) extending into the water collection tank (21) located at the highest table level and being configured to convey a body of water into the water collection tank (21) located at the highest table level, and the water collection tank (21) located at the lowest table level being connected to the water reservoir (42) and being configured to convey rainwater collected on a corresponding support (1) into the Water reservoir (42) is formed.

Images