Method for agricultural-photovoltaic complementary rainwater harvesting and automatic irrigation on a tableland

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 water content of the tableland and creating a model for the daily water demand Q1 of the tableland crop; S2. Setting a minimum alarm value P1 and a maximum alarm value P2 of the soil water content of the tableland. When the soil water content of the tableland is lower than the minimum alarm value P1, the spray pipe starts spraying, and when the soil water content of the tableland reaches the maximum alarm value P2, the spray pipe stops spraying; S3.Monitoring the water level in the water collection tank and setting a first alarm level H1 and a second alarm level H2. When the water level is lower than H1, the water body is supplied to the water collection tank. When the water level is at H2, the water supply assembly stops supplying the water body to the water collection tank. The method for agricultural-photovoltaic complementary rainwater harvesting and automatic irrigation on a tableland of the present invention can use rainwater to automatically irrigate the tableland, ensure normal crop yield, and achieve 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 harvesting and automatic irrigation on a tableland and. Background technology

[0002] Photovoltaic power generation is a new-generation method that utilizes inexhaustible solar energy to convert it into electricity for industrial use, agricultural production, and daily life. It can maximize energy conservation and emission reduction and is an important part of a low-carbon lifestyle. Current photovoltaic power generation uses flat photovoltaic panels to capture solar energy and convert it into electrical energy for external use. The larger the area, the higher the power generation efficiency, which inevitably requires a large amount of land resources. Our country is a large agricultural country with vast agricultural areas, and some crops do not receive too much sunlight.For this reason, a "complementary agricultural photovoltaic system" has emerged, organically combining agricultural planting with photovoltaic power generation. It can not only utilize vast rural cultivated areas for photovoltaic power generation, thus supplying electricity to the outside world for industrial, agricultural production, and domestic use, but also ensure the normal growth of crops, ecological mutual feedback, and win-win benefits, and promote the development of agriculture and the photovoltaic industry.

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

[0004] The present invention aims to at least partially solve one of the technical problems in the prior art.

[0005] To this end, embodiments of the present invention provide a method for agricultural-photovoltaic complementary rainwater harvesting and automatic irrigation on a tableland. This method for agricultural-photovoltaic complementary rainwater harvesting and automatic irrigation on a tableland can effectively consider 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 true win-win complementarity between agriculture and the photovoltaic industry.

[0006] The method for agricultural-photovoltaic complementary rainwater harvesting and automatic irrigation on a tableland according to the embodiment of the present invention is based on a system for agricultural-photovoltaic complementary rainwater harvesting and automatic irrigation on a tableland, and the system comprises a bracket, a water collection assembly, a spray assembly, a water supply assembly, and a control device, wherein a plurality of the brackets are arranged in a step-like manner on a plurality of tableland levels and are each provided with inclined photovoltaic modules, and the water collection assembly comprises a plurality of water collection tanks corresponding to the brackets and arranged on the higher tableland level, as well as water collection basins arranged on the bracket, 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 at the corresponding tableland level, wherein the water collection basins are designed to direct the collected rainwater to the corresponding water collection tanks or the water supply assembly, wherein the spray assembly comprises a spray pipe and a valve body, wherein the spray pipe is connected to the water collection tank arranged at a higher tableland level and the valve body is provided in the spray pipe and is designed to control the circulation and blocking of the water body in the spray pipe, wherein the water supply assembly is designed to supply water to a plurality of the water collection tanks when the rainwater in the water collection tanks is insufficient for the spraying process, wherein the control device is communicatively connected to the valve body and is designed to control the operation of the valve body,to realize 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 demand Q1 of the tableland culture; S2. Setting a minimum alarm value P1 and a maximum alarm value P2 of the soil water content of the tableland, and when the soil water content of the tableland is lower than the minimum alarm value P1, the controller drives the valve body to open so that the spray pipe starts spraying, and when the soil water content of the tableland reaches the maximum alarm value P2, the controller drives the valve body to close to stop the spraying of the spray pipe; 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.

[0007] The method for agricultural-photovoltaic complementary rainwater harvesting and automatic irrigation on a tableland according to the embodiment of the present invention can effectively consider the natural rainfall required for plant growth and the ambient humidity required by shade-loving plants in completing photovoltaic power generation, ensure normal crop yields, and achieve true win-win complementarity between agriculture and the photovoltaic industry.

[0008] In some examples, the daily water requirement Q1 of the tableland culture satisfies 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 utilization coefficient of the piping system and η pis a field spray water utilization coefficient.

[0009] In some embodiments, the gravity flow pipeline flow model is set up and the maximum flow rate Q max of the pipeline and the minimum alarm value P1 of the soil water content on the tableland must meet the following formula: P1⋅Z+Qmax≥Q1; where Z is the volume of soil rooted by the crop in the corresponding tableland plain.

[0010] In some embodiments, the maximum flow rate Qmax of the pipeline is determined based on the gravity flow pipeline flow model by the following formula: Qmax=v×A; ν=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 filling ratio.

[0011] In some embodiments, the maximum value of the flow rate of the pipeline is calculated from the maximum value of the opening stroke, and the flow rate of the pipeline and the opening stroke of the valve satisfy the following formula: L=Lmax⋅ƒ−1(QQmax); where L is the opening stroke and Q is the real-time flow rate of the pipeline.

[0012] In some implementation examples, the minimum alarm value P1 of the soil water content on the tableland satisfies the following formula: P1⋅Z+Q2≥Q1; Q2=PT(1−dec); where Q2 is the maximum allowable daily irrigation water quantity, P is the allowable irrigation intensity of the soil, T is the daily irrigation time and dec is the allowable value for reducing the irrigation intensity on the slope.

[0013] In some embodiments, in S1, the tableland is provided with a soil moisture meter, wherein the soil moisture meter is used for real-time measurement of the soil water content of the tableland, and the soil moisture meter is communicatively connected to the control device to transmit information about the soil water content of the tableland measured by the soil moisture meter to the control device.

[0014] In some embodiments, a water level sensor is provided in the water collection tank in S3, wherein the water level sensor is communicatively connected to the control unit to transmit information about the water level in the water tank to the control unit.

[0015] In some embodiments, a plurality of diversion pipes are provided, wherein the diversion pipes are arranged between the water collection tanks on two adjacent tableland levels, wherein the plurality of diversion pipes are designed to connect the plurality of 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.

[0016] 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 projects 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 corresponding support into the water reservoir. Figures Fig. 1 is a schematic structural diagram of the rainwater harvesting and automatic irrigation system in the method of agricultural photovoltaic complementary rainwater harvesting and automatic irrigation on a tableland according to the embodiment of the present invention. Reference symbols in the figures:

[0017] 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

[0018] The exemplary embodiments of the present invention are described in detail below. Examples of the exemplary embodiments are illustrated in the accompanying drawings. The exemplary embodiments described below with reference to the accompanying drawings are exemplary and serve to explain the present invention and are not to be understood as limiting the present invention.

[0019] As in Fig. 1, the method for agricultural-photovoltaic complementary rainwater harvesting and automatic irrigation on a tableland according to the embodiment of the present invention is based on a system for agricultural-photovoltaic complementary rainwater harvesting and automatic irrigation on a tableland, and the system comprises a bracket 1, a water collection assembly 2, a spray assembly 3, a water supply assembly 4, and a control device. A plurality of the brackets 1 are arranged in a step-like manner on a plurality of tableland levels and are each provided with inclined photovoltaic modules 5. The water collection assembly 2 comprises a plurality of water collection tanks 21 corresponding to the brackets 1 and arranged on the higher tableland level, as well as water collection basins 22 arranged on the bracket 1. 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 tableland level, wherein the water collection basins 22 are designed 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 on a higher tableland level and the valve body 32 is provided in the spray pipe and is designed to control the circulation and blocking of the water body in the spray pipe, wherein the water supply assembly 4 is designed to supply water to a plurality of the water collection tanks 21 when the rainwater in the water collection tanks 21 is insufficient for the spraying process,wherein the control device 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.,

[0020] The method for agricultural photovoltaic complementary rainwater harvesting and automatic irrigation on a tableland 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 tableland level. When irrigation is required, the rainwater in the water collection tank 21 is used for spraying. When the rainwater in the water collection tank 21 is insufficient for spraying, the water supply assembly 4 supplies water to multiple water collection tanks 21 to ensure the rainwater irrigation effect on the tableland.

[0021] Optionally, the valve body 32 is a flow valve. It should be noted that it is sufficient for the valve body 32 to fulfill signal-controlled closing and opening functions, and there are no restrictions regarding the specific application of the valve body 32.

[0022] Based on the above-mentioned system for agricultural photovoltaic complementary rainwater harvesting and automatic irrigation on a tableland, the method for supplementary rainwater harvesting 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 demand Q1 of the tableland culture; S2. Setting a minimum alarm value P1 and a maximum alarm value P2 of the soil water content of the tableland, and when the soil water content of the tableland is lower than the minimum alarm value P1, the controller drives the valve body 32 to open so that the spray pipe 31 starts spraying, and when the soil water content of the tableland reaches the maximum alarm value P2, the controller drives the valve body 32 to close to stop the spraying of the spray pipe 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.

[0023] When the method for agricultural photovoltaic complementary rainwater harvesting and automatic irrigation on a tableland according to the embodiment of the present invention is implemented, the soil moisture content of the tableland is monitored, and the minimum alarm value P1 and the maximum alarm value P2 are set to realize automatic irrigation of the tableland and ensure the soil moisture needs of the tableland. Rainwater harvesting and irrigation are realized through the arrangement of the water collection tank 21 and the water supply assembly 4, and during irrigation, the water body in the water collection tank 21 is automatically refilled to ensure the irrigation needs of the tableland.

[0024] The method for agricultural-photovoltaic complementary rainwater harvesting and automatic irrigation on a tableland according to the embodiment of the present invention can effectively consider the natural rainfall required for plant growth and the ambient humidity required by shade-loving plants in completing photovoltaic power generation, and the irrigation efficiency is high, thereby ensuring normal crop yield and achieving win-win complementarity between agriculture and the photovoltaic industry.

[0025] It should be noted that according to the GBT50085-2007 Irrigation Engineering Technical Specifications, there are upper and lower limits for the suitable soil moisture content for crops. The highest alarm value P2 is not greater than the upper limit of suitable soil moisture content, and the lowest alarm value P1 is not less than the lower limit of suitable soil moisture content. Generally, the relative moisture content of the soil is 50-70%. Different crops have different soil moisture requirements, and the specific values ​​of the highest and lowest alarm values ​​depend on the crop.

[0026] In some examples, the daily water requirement of crops Q1=KS⋅KC⋅ET0ηc⋅ηp, where K S a soil moisture stress factor, K Cis a total plant coefficient and ET0 is a reference plant evapotranspiration, calculated according to the Penman-Monteith formula, η c a water utilization coefficient of the piping system and η p is a field spray water utilization coefficient.

[0027] Evapotranspiration is the maximum loss of water from the surface. It is the flow of water vapor under the combined effects of climate, soil, and vegetation and can be considered the water demand of crops. Daily water requirements are calculated using the formula ET 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 accurate calculation of daily water requirements.

[0028] 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 can be selected depending on the climatic conditions 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 p 0.7-0.8.

[0029] In some embodiments, the gravity flow pipeline flow model is set up and the maximum flow rate Q max of the pipeline, where the maximum flow rate Q max P1·Z+Q max ≥Q1, and the minimum alarm value P1 for the soil moisture content of the tableland is determined by the maximum flow rate Q maxof the pipeline is revised, where Z is the volume of soil rooted by the crop in the corresponding tableland level.

[0030] The maximum flow rate Q max The pipeline is calculated, and the minimum alarm value P1 of the soil moisture content of the tableland is revised when the daily water demand Q1 of the tableland crops is determined. It should be ensured that after the spraying process reaches the maximum flow rate of the pipeline and the water demand of the tableland crops is consumed, the soil moisture content of the tableland is greater than the lower limit of the suitable soil moisture content, thus ensuring normal crop production.

[0031] In some embodiments, the water flow in the gravity flow pipeline in the gravity flow pipeline flow model is ν=1n⋅R23⋅I12, where n is the pipe roughness coefficient, I is the slope of the gravity flow pipeline and R is the hydraulic radius. The filling angle φ=arccos(1-2α) can be calculated from the filling degree 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 of the pipeline is: According to the maximum design filling level, the flow cross-sectional area and the flow velocity of the pipeline, the maximum flow rate of the pipeline Q max =v×A.

[0032] The gravity flow pipeline model is used to calculate the flow velocity in the pipeline. In the irrigation system, the pipe wall roughness coefficient n and the slope of the gravity flow pipeline I are fixed values, so the only factor that actually affects the flow velocity is the hydraulic radius R. The maximum filling ratio of the pipeline has become a fixed value during pipeline design, and the maximum design filling ratio of gravity pipelines of different diameters is less than 0.75 in the production specifications for processing the pipes. According to the filling ratio α of the pipeline, the hydraulic radius R and the maximum flow rate Q can be determined. max of the pipeline, ensuring an accurate value of the maximum flow rate.

[0033] In some embodiments, the relationship between flow rate and valve opening is determined based on the flow characteristics of the valve, L=Lmax⋅ƒ−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.

[0034] Generally, the maximum opening of the valve must be approximately 90% and cannot be too small, otherwise the adjustable ratio will be reduced and the valve diameter will become too large, which will affect the control performance and become uneconomical; the minimum opening should not be less than 10%, otherwise the water body will further corrode the valve core and valve seat, easily damaging the valve core, leading to deterioration of the properties and even adjustment errors. The flow characteristics of valves are mainly linear, logarithmic, parabolic, and fast-opening. Depending on the flow characteristics of the valve, the relationship between flow rate and valve opening is determined. L=Lmax⋅ƒ−1(QQmax) and the maximum flow rate Q maxthe pipeline is revised by the opening stroke of the valve in order to achieve the set irrigation volume requirement within the set time.

[0035] In some embodiments, the daily maximum allowable 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 is revised by the daily maximum allowable irrigation water quantity Q2, where P is the allowable irrigation intensity of the soil, T is the daily irrigation time and dec is the allowable value for reducing the irrigation intensity on the slope.

[0036] According to the GBT50085-2007 Irrigation Engineering Technical Specifications, the planned irrigation intensity of the fixed irrigation system shall not exceed the allowable irrigation intensity of the soil, and the planned daily irrigation time for fixed pipes and crops should be 12 to 20 hours. The allowable irrigation intensity for different soil types should be determined according to the "Table of Allowable Irrigation Intensity for Different Soil Types" in GBT50085-2007 Irrigation Engineering Technical Specifications. If the soil slope exceeds 5%, the allowable irrigation intensity should be reduced according to the "Table of Reduced Irrigation Intensity on Slopes" in GBT50085-2007 Irrigation Engineering Technical Specifications.

[0037] By calculating the maximum allowable daily irrigation water quantity Q2 and combining the daily water requirement Q1 of crops, the minimum alarm value P1 of the soil moisture content of the tableland is revised and it is ensured that the daily water requirement of crops is met under the requirement of the maximum allowable daily irrigation water quantity Q2 to ensure the normal yield of crops.

[0038] In some embodiments, in S1, the tableland is provided with a soil moisture meter, the soil moisture meter is used for real-time measurement of the soil water content of the tableland, and the soil moisture meter is communicatively connected to the control device to transmit information about the soil water content of the tableland measured by the soil moisture meter to the control device.

[0039] Setting up a soil moisture meter makes soil moisture content easier to monitor and measurement more accurate.

[0040] Optionally, the soil moisture meter has a pin soil moisture sensor or a soil moisture and temperature monitor.

[0041] Optionally, multiple soil moisture meters are provided at each tableland level. The average soil moisture content measured by multiple soil moisture meters is considered the soil moisture content of the corresponding tableland, facilitating accurate monitoring of the tableland soil.

[0042] Optionally, the control unit is provided with a processing module, wherein the processing module is designed to compare the soil moisture content with the lowest alarm value P1 or the highest alarm value P2, and when the soil water content of the table land is lower than the minimum alarm value P1, the control unit drives the valve body 32 to open so that the spray pipe 31 starts spraying, and when the soil water content of the table land reaches the maximum alarm value P2, the control unit drives the valve body 32 to close to stop the spraying of the spray pipe 31.

[0043] In some embodiments, a water level sensor is provided in the water collection tank 21 in S3, wherein the water level sensor is communicatively connected to the control unit to transmit information about the water level in the water tank to the control unit.

[0044] By arranging a water level sensor, it is convenient to monitor the water level in the water collection tank 21 and replenish the humidity in the water collection tank 21 in time to ensure the water supply required for plant growth and the ambient humidity required for shade-loving plants, whereby the irrigation efficiency is high and a normal crop yield can be ensured.

[0045] Optionally, the control unit is provided with a processing module, wherein the processing module is configured to compare the water level in the water collection tank 21 with the first alarm level H1 or the second alarm level H2, and when the water level is lower than the first alarm level H1, the control unit controls the pump body 41 to deliver the water body into the water collection tank 21, and when 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 into the water collection tank 21.

[0046] In some embodiments, as in Fig. 1, a plurality of 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 plurality of diversion pipes 6 are designed to connect the plurality of 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.

[0047] A diversion pipe 6 is provided between each two adjacent water collection tanks 21, and the connection point of the diversion pipe 6 to the water collection tank located at a higher tableland 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 body enters the lower water collection tank 21 through the diversion pipe 6. The connection of two adjacent ones of the plurality of water collection tanks 21 is achieved by a plurality of diversion pipes 6, which facilitates the control of the water level in the water collection tanks 21 at each tableland level and ensures the balance of water storage in each water tank.At the same time, when the water supply assembly 4 supplies water to the water collection tanks 21, the water collection tank 21 located at the lowest tableland level 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.

[0048] In some embodiments, as in Fig.1, a drain pipe 7 is provided, the water supply assembly 4 comprising a water reservoir 42 and a conveying pipe 43, the drain pipe 7 being connected to the water collection tank 21 located on 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 projecting into the water collection tank 21 located on the highest tableland level and being configured to convey a body of water into the water collection tank 21 located on the highest tableland level, and the water collection tank 21 located on the lowest tableland level being connected to the water reservoir 42 and being configured to convey rainwater collected on a corresponding support into the water reservoir.

[0049] Due to the arrangement of the drain pipe 7, when collecting rainwater 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 tableland level 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. After the water level in the water collection tank 21 located at the lowest tableland level reaches the second alarm level, the rainwater is collected via the drain pipe in the tank to ensure rainwater collection.At the same time, the water body is directly supplied to the water collection tank 21 located on the highest tableland level through the delivery pipe 43, and the water body in the plurality of water collection tanks 21 is replenished one by one from top to bottom through the diversion pipes 6, thereby reducing the number of water delivery pipes 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 completed, which facilitates the replenishing of the water body in the water collection tank 21 and the control of the water level in the water collection tank 21.

[0050] Optionally, the volume of the water reservoir 42 is more than five times the volume of the water collection tank 21.

[0051] Optionally, the other end of the drain pipe 7 extends into the water reservoir 42.

[0052] Optionally, one end of the delivery pipe 43 is connected to the pump body 41.

[0053] Optionally, the water supply assembly 4 includes a pump body 41 for supplying water body to the water collection tank 21, the pump body 41 is located in the water reservoir 42, and the control device is communicatively connected to the pump body 41 to control the water pumping operation of the pump body 41.

[0054] Optionally, the water supply assembly 4 may extract groundwater or surface water to supply water to the water reservoir 42. When supplying water bodies to the plurality of water collection tanks 21, the water supply assembly 4 preferably extracts water from the water reservoir 42.

[0055] Optionally, a drainage pipe 23 is connected between the water collecting basin 22 and the water collection tank 21, and the drainage pipe 23 is designed to supply rainwater in the water collecting basin 22 to the water collection tank 21.

[0056] In describing the present invention, it is necessary to note that an azimuth or positional relationship referring to 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," and the like, includes the azimuth or positional relationship based on the drawing. They are intended to facilitate and simplify the description of the present invention, rather than indicating or implying that the device or component mentioned must have a particular orientation, be constructed, and operate in a particular orientation. Therefore, they should not be construed as limiting the present invention.

[0057] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply a relative importance or to imply the set of technical features specified. 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, "plural" means two or more than two, unless expressly and specifically limited otherwise.

[0058] In the present invention, it is necessary to point out that the terms "installing," "connecting," "connecting," and "fixing" are to be understood in a broad sense unless expressly stated or limited otherwise. For example, it may be a fixed connection, a detachable connection, or a one-piece connection; it may be a mechanical connection, an electrical connection, or 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 both elements. For general technical personnel in the field, the specific meaning of the above terms in the present invention can be understood depending on the specific circumstances.

[0059] In the present invention, unless expressly defined otherwise, when a first feature is "above" or "below" with respect to the second feature, it means that the first feature and the second feature are in direct contact, or the first feature and the second feature may be in indirect contact via an intermediate medium. Furthermore, it means that when the first feature is "on", "over", and "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 when the first feature is "below", "under", and "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.

[0060] In the description of this specification, reference to the terms "one 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 the present 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.In addition, technical personnel may combine and combine different embodiments or examples and features of different embodiments or examples described in this specification, provided they do not conflict with each other.

[0061] Although the embodiments of the present invention have been shown and described, it should be understood that the above-mentioned embodiments are exemplary and should not be construed as limitations of the present invention. A person of ordinary skill in the art may make changes, modifications, substitutions, and variations to the above-described embodiments within the scope of the present invention. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited non-patent literature

[0000] GBT50085-2007

[0036]

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, a water collection assembly, a sprinkler assembly, a water supply assembly and a control unit, wherein several of the supports are arranged in a stepped fashion on several tableland levels and each is inclined with photovoltaic modules, and the water collection assembly comprises several water collection tanks corresponding to the supports and arranged on the higher tableland level, as well as water collection basins arranged on the support, 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, 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 being configured to control the operation of the valve body in order to achieve the circulation and blocking of the water in the spray pipe; characterized bythat 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. [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 c a water usage coefficient of the piping system and ηp 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 is set up and the maximum flow rate Qmax of the pipeline is calculated and the minimum alarm value P1 of the soil water content on the tableland 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 max The pipeline is determined based on the gravity flow pipeline flow model using the following formula: Qmax=v×A; ν=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⋅ƒ−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, 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. [9] Method for agricultural-photovoltaic complementary rainwater use and automatic irrigation on a tableland according to claim 1, characterized by that 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 tank located on a higher tableland level is below the second alarm level. [10] Method for agricultural-photovoltaic complementary rainwater use and automatic irrigation on a tableland according to claim 9, characterized by, that a drain pipe is provided, wherein the water supply assembly comprises a water reservoir and a delivery pipe, the drain pipe being connected to the water collection tank located on the lowest tableland level at a position above the second alarm level, the other end of the drain pipe being connected to the water reservoir, one end of the delivery pipe being connected to the water reservoir, and the other end of the delivery pipe extending into the water collection tank located on the highest tableland level and being 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 being connected to the water reservoir and being configured to convey rainwater collected on a suitable support into the water reservoir.

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