Sunlight greenhouse microclimate three-dimensional simulation method and system considering ridge direction

Abstract

The invention provides a sunlight greenhouse microclimate three-dimensional simulation method and system considering the ridge direction, and the method comprises the steps: building a greenhouse geometric model according to the geometric structure parameters of a sunlight greenhouse and the size of a crop canopy, the geometric structure parameter structure comprises the size of the sunlight greenhouse and the ridge width, the ridge length and the ridge spacing for crop planting in the sunlight greenhouse; performing analogue simulation according to the internal and external environmental factors of the greenhouse geometric model and the respective spatial and temporal distribution characteristics of the internal and external geometric structures to obtain a three-dimensional model of the greenhouse environment; wherein the internal and external environment factors comprise illumination intensity, humidity, temperature, air velocity and flow direction corresponding to the external space and the internal space of the greenhouse geometric model. According to the method, the accuracy of greenhouse microclimate environment simulation is improved, and then the efficiency of the crop growth state in the greenhouse cultivation mode is improved.

Description

Technical Field

[0001] The present invention relates to the field of facility agricultural production, and in particular to a three-dimensional simulation method and system for microclimate in a solar greenhouse taking ridge orientation into consideration. Background Art

[0002] Protected agriculture is a form of agricultural production that uses protected farming methods and is expected to become a beneficial measure to cope with the escalating global food demand caused by population growth. The transition from traditional planting patterns to cultivation patterns in solar greenhouses can provide a longer distance for each planting ridge and improve the efficiency of mechanized operations such as ridge forming, film covering, sowing, planting and harvesting.

[0003] 3D simulation technology is widely used in the optimal design of agricultural buildings, such as greenhouses and livestock and poultry houses. 3D simulation technology can visualize the differences in microclimate parameters caused by changes in planting ridge orientation to evaluate whether the new planting pattern has a positive or negative impact on the production environment.

[0004] In the related technologies, the simulation of the greenhouse's architectural structure through fluid mechanics methods cannot reflect the changing characteristics of the greenhouse model in the real environment. When the greenhouse environment is simulated through deep learning methods, it relies on a large data collection base for modeling. For new planting modes that have not yet been promoted on a large scale, it is difficult to obtain a large amount of data. In addition, traditional thermal balance modeling methods assume that the spatial distribution of microclimate elements in the greenhouse is uniform, ignoring the planting management method and the impact of the building structure on the spatial distribution, resulting in inaccurate greenhouse environment simulation results, affecting the monitoring of crop growth status under the greenhouse cultivation mode. Summary of the invention

[0005] The present invention provides a three-dimensional simulation method and system for the microclimate of a solar greenhouse taking ridge orientation into consideration, so as to solve the defect that the greenhouse environment simulation method in the prior art cannot effectively reflect the changing characteristics of the greenhouse model in the real environment, resulting in inaccurate greenhouse environment simulation results, thereby improving the accuracy of greenhouse microclimate environment simulation.

[0006] The present invention provides a three-dimensional simulation method of a solar greenhouse microclimate taking ridge orientation into consideration, comprising: Constructing a greenhouse geometric model according to geometric structural parameters of the solar greenhouse and crop canopy dimensions, wherein the geometric structural parameter structure includes the dimensions of the solar greenhouse and ridge width, ridge length and ridge spacing for crop planting in the solar greenhouse; A three-dimensional model of the greenhouse environment is obtained by performing simulation based on the internal and external environmental factors of the greenhouse geometric model and the respective spatiotemporal distribution characteristics of the internal and external geometric structures; wherein the internal and external environmental factors include the light intensity, humidity, temperature, air flow rate and flow direction corresponding to the external space and internal space of the greenhouse geometric model respectively.

[0007] According to a three-dimensional simulation method of a solar greenhouse microclimate considering ridge orientation provided by the present invention, the simulation is performed according to the internal and external environmental factors of the greenhouse geometric model and the temporal and spatial distribution characteristics of the internal and external geometric structures to obtain a three-dimensional model of the greenhouse environment, including: Solving the time-averaged continuity equation, the Reynolds time-averaged equation, the time-averaged energy equation and the time-averaged component transport equation in the calculation domain of the internal and external spaces of the greenhouse geometric model to obtain target parameters, and constructing a standard k-ε turbulence model based on the target parameters and multiple equations that react to turbulent characteristics; the target parameters include pressure parameters, temperature parameters and water vapor concentration parameters; Calculate the net radiation of the crop canopy based on the radiation heat transfer coefficient, the thermodynamic average temperature of the wall and crop leaves of the solar greenhouse, and the effective radiation area; The sensible heat exchange between the crop canopy and the environment is determined based on the leaf temperature of the crop, the air temperature and the aerodynamic resistance; the latent heat exchange between the crop canopy and the environment is determined based on the leaf temperature, the saturated water vapor pressure at the leaf temperature, the water vapor partial pressure in the air, the leaf stomatal resistance and the aerodynamic resistance, and a transient steady-state equilibrium model between the crop and the environment is established based on the net radiation of the crop canopy, the sensible heat exchange and the latent heat exchange; Determine the leaf dew condensation rate of the crop canopy according to the saturated water vapor pressure at the leaf temperature, the water vapor partial pressure in the air, and the water vapor conductivity of the leaf boundary layer; determine the water vapor liquefaction rate according to the empirical constant, dew point temperature, air density and air temperature; Determine the energy source term in the air according to the blade condensation rate, the water vapor liquefaction rate, the heat of water evaporation and the sensible heat exchange amount; determine the water vapor source term in the air according to the blade condensation rate, the water vapor liquefaction rate and the latent heat exchange amount; The greenhouse geometric model is simulated by fluid dynamics CFD simulation according to the standard k-ε turbulence model, the transient equilibrium model, the energy source term in the air and the water vapor source term in the air to obtain a three-dimensional model of the greenhouse environment.

[0008] According to a three-dimensional simulation method of a solar greenhouse microclimate considering ridge orientation provided by the present invention, the net radiation of the crop canopy is calculated based on the radiation heat transfer coefficient, the thermodynamic average temperature corresponding to the wall and crop leaves of the solar greenhouse, and the effective radiation area, including: Calculate multiple radiation amounts according to the following formula: ; Among them, T NW 、T EW 、T WW 、T G 、TL 、T R are the thermodynamic average temperatures of the back wall, east wall, west wall, ground, blade surface, and front roof calculated within each 30-second step, K; T S is the average sky temperature measured by the sensor every hour, K; S NW , S EW , S WW , S G , S LS , S LR are the effective radiation areas of the back wall, east wall, west wall, ground, canopy to the sky, and canopy to the front roof; τ L is the long-wave radiation transmittance of the front roof; τ S A is the short-wave radiation transmittance of the front roof; bc is the absorption rate of crop canopy to shortwave radiation; r c1 is the first reflectivity of the lower blade to shortwave radiation; r c2 is the second reflectivity of the lower leaves to shortwave radiation; is the outdoor solar radiation intensity; The net radiation corresponding to the multiple radiation amounts is calculated according to the following formula: ; Among them, R SO is the total solar radiation absorbed by the crop canopy area per second; R NW is the net radiation emitted by the back wall to the crop canopy area per second; R EW is the net radiation emitted by the east wall to the crop canopy area per second; R WW is the net radiation emitted by the west wall to the crop canopy area per second; R GL is the net radiation from the ground to the leaves per second; R LS is the net radiation emitted by the crop canopy area to the sky per second; R LR V is the net radiation emitted by the crop canopy area to the front roof per second; C is the volume of the crop canopy, V C Determined based on the product of ridge width, ridge length, plant height and number of ridges.

[0009] According to a three-dimensional simulation method of a solar greenhouse microclimate taking ridge orientation into consideration provided by the present invention, the standard k-ε turbulence model is determined based on a turbulent kinetic energy equation and a turbulent dissipation rate equation; The turbulent kinetic energy equation is expressed by the following formula: ; The turbulent dissipation rate equation is expressed by the following formula: ; Where k is the turbulent kinetic energy; σk is the Prandtl number of k; ε is the turbulent kinetic energy dissipation rate; S k is the source term of the turbulent kinetic energy equation; σ ε is the Prandtl number of ε; C ε1 , C ε2 , C ε3 is the empirical constant; S ε is the source term of the turbulent kinetic energy dissipation rate equation; .

[0010] According to a three-dimensional simulation method of a solar greenhouse microclimate taking ridge orientation into consideration provided by the present invention, the leaf condensation rate of the crop canopy is determined according to the saturated water vapor pressure at the leaf temperature, the water vapor partial pressure in the air, and the water vapor conductivity of the leaf boundary layer, including: ; in, is the condensation rate of the blade; is the leaf area density, is the air density, p is the atmospheric pressure, g h is the water vapor conductivity of the leaf boundary layer; P vsat (T L ) is the saturated water vapor pressure at leaf temperature; P vair( T a ) is the partial pressure of water vapor in air; wherein, the g h Determined based on the Lewis number and aerodynamic drag.

[0011] According to a three-dimensional simulation method of a solar greenhouse microclimate taking ridge orientation into consideration provided by the present invention, the greenhouse geometric model is constructed according to the geometric structural parameters of the solar greenhouse and the crop canopy size, comprising: A 1:1 scale greenhouse geometric model is established using drawing software according to the geometric structural parameters of the solar greenhouse and the crop canopy size; the drawing software includes CAD or IECM.

[0012] The present invention also provides a three-dimensional simulation system for microclimate in a solar greenhouse taking ridge orientation into consideration, comprising: A first simulation unit is used to construct a greenhouse geometry model according to geometric structure parameters of the solar greenhouse and crop canopy dimensions, wherein the geometric structure parameter structure includes the dimensions of the solar greenhouse and ridge width, ridge length and ridge spacing for crop planting in the solar greenhouse; The second simulation unit is used to simulate the internal and external environmental factors of the greenhouse geometric model and the temporal and spatial distribution characteristics of the internal and external geometric structures to obtain a three-dimensional model of the greenhouse environment; wherein the internal and external environmental factors include the light intensity, humidity, temperature, air flow rate and flow direction corresponding to the external space and internal space of the greenhouse geometric model respectively.

[0013] The present invention also provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements any of the above-described three-dimensional simulation methods for the microclimate of a solar greenhouse taking into account the ridge orientation.

[0014] The present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, the three-dimensional simulation method of the microclimate of a solar greenhouse taking into account the ridge orientation as described in any of the above methods is implemented.

[0015] The present invention also provides a computer program product, including a computer program, which, when executed by a processor, implements any of the above-mentioned three-dimensional simulation methods for microclimate in a solar greenhouse taking ridge orientation into consideration.

[0016] The present invention provides a three-dimensional simulation method and system for the microclimate of a solar greenhouse taking ridge orientation into consideration. The greenhouse geometric model is constructed through the geometric structural parameters of the solar greenhouse and the size of the crop canopy. The internal and external environmental factors of the greenhouse geometric model and the temporal and spatial distribution characteristics of the internal and external geometric structures are simulated to obtain a three-dimensional model of the greenhouse environment, thereby improving the accuracy of greenhouse microclimate environment simulation and further improving the efficiency of the crop growth status under the cultivation mode in the greenhouse. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 It is a schematic flow chart of the three-dimensional simulation method of the microclimate of a solar greenhouse taking ridge orientation into consideration provided by the present invention.

[0019] Figure 2 It is a schematic diagram of the geometric model of east-west and north-south ridge planting in a solar greenhouse provided by the present invention.

[0020] Figure 3 This is a schematic diagram of the effective radiation area provided by the present invention taking the north-south cultivation as an example; Figure 4 It is a structural schematic diagram of a three-dimensional simulation system for microclimate in a solar greenhouse taking ridge orientation into consideration provided by the present invention.

[0021] Figure 5 It is a structural schematic diagram of the electronic device provided by the present invention. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] Combine the following Figure 1-Figure 3 The present invention describes a three-dimensional simulation method and system for the microclimate of a solar greenhouse taking ridge orientation into consideration.

[0024] Figure 1 : is a schematic flow chart of a three-dimensional simulation method of a solar greenhouse microclimate taking ridge orientation into consideration provided by the present invention, such as Figure 1 As shown, the three-dimensional simulation method of the microclimate of the solar greenhouse considering the ridge direction includes the following steps: Step 110: construct a greenhouse geometric model according to the geometric structural parameters of the solar greenhouse and the crop canopy size. The geometric structural parameters include the size of the solar greenhouse and the ridge width, ridge length and ridge spacing for crop planting in the solar greenhouse.

[0025] In this step, the dimensions of the greenhouse include but are not limited to the length, width, height and volume of the greenhouse.

[0026] In this embodiment, constructing a greenhouse geometric model according to the geometric structural parameters of the solar greenhouse and the crop canopy size includes: using drawing software to establish a 1:1 scale greenhouse geometric model according to the geometric structural parameters of the solar greenhouse and the crop canopy size; the drawing software includes CAD or IECM.

[0027] Figure 2 The geometric model diagram of the east-west and north-south ridge planting in the solar greenhouse provided by the present invention is shown in FIG. Figure 2 In the embodiment shown, the crop canopy includes an east-west canopy and a north-south canopy; wherein the solar greenhouse is 79.2 m long, 8 m wide, and 2.92 m high; and the ridge spacing is 0.6 m.

[0028] Step 120, simulate the internal and external environmental factors of the greenhouse geometric model and the temporal and spatial distribution characteristics of the internal and external geometric structures to obtain a three-dimensional model of the greenhouse environment; wherein the internal and external environmental factors include the light intensity, humidity, temperature, air velocity and flow direction corresponding to the external space and internal space of the greenhouse geometric model respectively.

[0029] In this step, CFD (Computational Fluid Dynamics) can be used to establish a three-dimensional simulation model of the spatiotemporal distribution of the microclimate in the solar greenhouse to simulate the indoor lighting, air temperature, humidity, gas flow rate and direction under different cultivation ridges, thereby providing an assessment reference for yield and disease risk for the promotion of the new east-west planting pattern.

[0030] In this embodiment, a crop-environment interaction model in a solar greenhouse based on computational fluid dynamics, that is, a three-dimensional model of the greenhouse environment, is constructed to simulate indoor lighting, air temperature, humidity, gas flow rate and direction under different cultivation ridges; thereby performing a significance analysis of the differences and providing an evaluation basis for yield and disease risk for the promotion of the new east-west planting pattern.

[0031] In this embodiment, pressure parameters, temperature parameters, and water vapor concentration parameters can be calculated in the calculation domain of the internal and external spaces of the greenhouse geometric model, and a corresponding turbulence model can be constructed to calculate the net radiation of the crop canopy; thereby, the sensible heat exchange and latent heat exchange between the crop canopy and the environment are calculated, and a transient steady-state equilibrium model between the crop and the environment is established based on the net radiation, sensible heat exchange, and latent heat exchange of the crop canopy; then, the energy source term in the air is calculated based on the leaf condensation rate and water vapor liquefaction rate, water evaporation heat, and sensible heat exchange of the crop canopy; the water vapor source term in the air is calculated based on the leaf condensation rate, water vapor liquefaction rate, and latent heat exchange; finally, the greenhouse geometric model is simulated based on the above parameters to obtain a corresponding three-dimensional model of the greenhouse environment.

[0032] The three-dimensional simulation method of the microclimate of a solar greenhouse taking ridge orientation into consideration provided in an embodiment of the present invention constructs a greenhouse geometric model through the geometric structural parameters of the solar greenhouse and the size of the crop canopy; the internal and external environmental factors of the greenhouse geometric model and the respective spatiotemporal distribution characteristics of the internal and external geometric structures are simulated to obtain a three-dimensional model of the greenhouse environment, thereby improving the accuracy of greenhouse microclimate environment simulation and further improving the efficiency of the crop growth status under the cultivation mode in the greenhouse.

[0033] Furthermore, according to the internal and external environmental factors of the greenhouse geometric model and the respective time-space distribution characteristics of the internal and external geometric structures, a simulation is performed to obtain a three-dimensional model of the greenhouse environment, including: solving the time-averaged continuity equation, the Reynolds time-averaged equation, the time-averaged energy equation and the time-averaged component transport equation in the internal and external space calculation domain of the greenhouse geometric model to obtain the target parameters, and constructing a standard k-ε turbulence model according to the target parameters and multiple equations that react to turbulent characteristics; the target parameters include pressure parameters, temperature parameters, and water vapor concentration parameters; the net radiation of the crop canopy is calculated according to the radiation heat transfer coefficient, the thermodynamic average temperature corresponding to the wall and crop leaves of the solar greenhouse, and the effective radiation area; The sensible heat exchange between the crop canopy and the environment is determined according to the leaf temperature, air temperature and aerodynamic resistance of the crop; the latent heat exchange between the crop canopy and the environment is determined according to the leaf temperature, saturated water vapor pressure at leaf temperature, water vapor partial pressure in the air, leaf stomatal resistance and aerodynamic resistance, and a transient steady-state equilibrium model between the crop and the environment is established according to the net radiation, sensible heat exchange and latent heat exchange of the crop canopy; the leaf condensation rate of the crop canopy is determined according to the saturated water vapor pressure at leaf temperature, water vapor partial pressure in the air and water vapor conductivity of the leaf boundary layer; the water vapor liquefaction rate is determined according to empirical constants, dew point temperature, air density and air temperature; the energy source term in the air is determined according to the leaf condensation rate, water vapor liquefaction rate, water evaporation heat and sensible heat exchange; the water vapor source term in the air is determined according to the leaf condensation rate, water vapor liquefaction rate and latent heat exchange; the greenhouse geometric model is simulated by fluid dynamics CFD simulation according to the standard k-ε turbulence model, transient steady-state equilibrium model, energy source term in the air and water vapor source term in the air to obtain a three-dimensional model of the greenhouse environment.

[0034] In this embodiment, the finite volume method is used to solve the following partial differential equation in the calculation domain of the greenhouse internal and external space:

[0035] (1) Time-averaged continuity equation

[0036] ; (2) Reynolds time-averaged Navier-Stokes equation: ; (3) Time-averaged energy equation: ; (4) Time-averaged component transport equation: ; Where ρ is the air density in kg m -3 ; t is time, unit is s; x i is the coordinate component in the i direction, in m; x j is the j-direction coordinate component, in m; ui is the velocity component in the i direction, in ms -1 ;u j is the velocity component in the j direction, in ms -1 ; σ ij is the stress tensor component, in kg m -1 s -2 ; μ is the dynamic viscosity, unit is kg m -1 s -1 ; g i is the gravitational acceleration component in direction i, in ms -2 ; S m The momentum drop caused by the drag effect of the crop area on the fluid, in kgm -2 s -2 ; U is wind speed, unit is ms -1 ; T is the air temperature, in K; λ f is the thermal conductivity of air, in W m -1 K -1 ; C P is the specific heat capacity of air, in J kg -1 K -1 ;μ t is the turbulent viscosity, in kg m -1 s -1 ; S r is the DO radiation source term, in W m -3 ; S t is the heat source term, in W m -3 ; C w is the volume concentration of water vapor component, in kg kg -1 ;D w is the diffusion rate of the water vapor component, in m 2 s -1 Sc t is the turbulent Schmidt number (dimensionless, value 0.7); S w is the source term of the water vapor component, in kgm -3 s -1 .

[0037] In this embodiment, the semi-implicit method of coordinated pressure coupled equations (SIMPLEC) can be used to solve the equations corresponding to (1)-(4) above, that is, in each grid, there are momentum equations in the three directions of x, y, and z and velocity vector unknowns U, V, and W in the three directions of x, y, and z; a continuity equation and an unknown pressure P (the continuity equation with the unknown being density is discretized into a discrete equation for the pressure correction value P'); an energy equation and an unknown temperature T, a component transport equation and a water vapor volume concentration C W; At the same time, two equations reflecting the turbulence characteristics and two unknowns k and ε are added. Without considering the source term, the above set of equations is closed. Compared with other turbulence models, the standard k-ε turbulence model is more suitable for use in greenhouse environment flow fields.

[0038] Specifically, the standard k-ε turbulence model is determined based on the turbulence kinetic energy equation and the turbulence dissipation rate equation; The turbulent kinetic energy equation is expressed as follows: ; The turbulent dissipation rate equation is expressed as follows: ; Where k is the turbulent kinetic energy, in m 2 s -2 ; σ k is the Prandtl number of k, which can be 1; ε is the turbulent kinetic energy dissipation rate, in m 2 s -3 ; S k is the source term of the turbulent kinetic energy equation, in kg m -1 s -3 ; σ ε is the Prandtl number of ε, which can be 1.3; C ε1 , C ε2 , C ε3 is an empirical constant, and its value can be (1.44, 1.92, 1); S ε is the source term of the turbulent kinetic energy dissipation rate equation, in kg m -1 s -3 ; is the absolute value of the component of fluid velocity in the i direction; is the turbulent viscosity; is the component of fluid velocity in the j direction.

[0039] In this embodiment, the energy, momentum and component transport source term equations in the crop canopy computational domain are written in C language to truly describe the crop canopy-microenvironment equilibrium system. The entire calculation process is transient, with a time step of 30 seconds and 20 iterations in each time step. The equation is as follows,

[0040] ; ; ; Among them, S m is the momentum drop of the fluid in all directions in the crop area; C d is the drag coefficient, the value is 0.32; LAD is the leaf area density, the unit is m -1, LAD=LAI / H, LAI is the leaf area index, H is the plant height, the unit is m; S ε is the source term of the turbulent kinetic energy dissipation rate equation, in kg m -1 s -3 ; S k is the source term of the turbulent kinetic energy equation, in kg m -1 s -3 .

[0041] It should be noted that there is a temporary steady-state equilibrium between crops and the environment, so there is an energy balance, which is expressed by the following formula: ; Among them, R n is the net radiation received by the canopy per unit volume, in W m -3 ; S s is the sensible heat exchange per unit volume between the crop canopy and the environment, in W m -3 ; S tr is the amount of latent heat exchange per unit volume between the crop canopy and the environment (i.e. transpiration, which only exists during the day), in W m -3 .

[0042] Furthermore, the net radiation corresponding to the multiple radiation amounts is calculated according to the following formula: ; Among them, R SO is the total solar radiation absorbed by the crop canopy area per second; R NW is the net radiation emitted by the back wall to the crop canopy area per second; R EW is the net radiation emitted by the east wall to the crop canopy area per second; R WW is the net radiation emitted by the west wall to the crop canopy area per second; R GL is the net radiation from the ground to the leaves per second; R LS is the net radiation emitted by the crop canopy area to the sky per second; R LR V is the net radiation emitted by the crop canopy area to the front roof per second; C is the volume of the crop canopy, V C Determined based on the product of ridge width, ridge length, plant height and number of ridges.

[0043] In this embodiment, multiple radiation amounts can be obtained by the following method: Specifically, the net radiation of the crop canopy is calculated based on the radiation heat transfer coefficient, the thermodynamic average temperature of the greenhouse wall and crop leaves, and the effective radiation area: Calculate multiple radiation amounts according to the following formula: ; Figure 3 Schematic diagram of effective radiation area provided by the present invention taking north-south cultivation as an example. Figure 3 In the embodiment shown, T NW , T EW 、T WW , T G , T L , T R are the thermodynamic average temperatures of the back wall, east wall, west wall, ground, blade surface, and front roof calculated in every 30-second step, in K; T S is the average sky temperature measured by the sensor every hour, in K; S NW , S EW , S WW , S G , S LS , S LR are the effective radiation areas of the back wall, east wall, west wall, ground, canopy to the sky, and canopy to the front roof; τ L is the long-wave radiation transmittance of the front roof; τ S A is the short-wave radiation transmittance of the front roof; bc is the absorption rate of crop canopy to shortwave radiation; r c1 is the first reflectivity of the lower blade to shortwave radiation; r c2 is the second reflectivity of the lower leaves to shortwave radiation; is the solar radiation intensity.

[0044] In this embodiment, the radiation heat transfer coefficient is obtained by the following steps: According to Stefan Boltzmann's law: the radiation power per unit area of ​​a black body surface is proportional to the fourth power of its absolute temperature T, which can be specifically expressed by the following formula.

[0045] ; Among them, E b is the radiation power emitted by the black body surface, in W m -2 ; б is the Stefan Boltzmann constant, which is 5.67×10 -8 W m -2 k -4 ; T is the thermodynamic temperature, unit is K; the radiation force emitted per unit area of ​​the gray body surface is E b With its emissivity The product of .

[0046] The net radiation heat transfer coefficient between two gray body surfaces is defined by: ; Therefore, the radiation heat transfer coefficient of the north, east and west walls to the blades is: ; The radiation heat transfer coefficient of the ground to the blade is: ; The radiation heat transfer coefficient of the blade to the sky is: ; The radiation heat transfer coefficient of the blade to the front roof is: .

[0047] in, is the gray body emissivity of the wall; Gray body emissivity of the blade; is the gray body emissivity of the ground; is the gray body emissivity of the sky; is the gray body emissivity of the front roof.

[0048] In this embodiment, not all radiation emitted by the radiator is absorbed by the receptor, so an approximate calculation is made by defining the effective radiation area; ignoring the reflected radiation, assuming that the direction of all radiation is directional emission perpendicular to the radiation surface rather than diffuse emission, the crop area is subject to radiation emitted by the back wall with an area of ​​ridge width * plant height * number of ridges, radiation emitted by the ground with an area of ​​ridge width * ridge length * number of ridges, and radiation emitted by a single side wall with an area of ​​plant height * ridge length; the radiation emitted by the crop area to the front roof and the sky is ridge width * number of ridges * front roof width.

[0049] Sensible heat exchange between crop canopy and environment S s Defined by the following formula,

[0050] ; Among them, r a is the aerodynamic drag, in sm -1 ; T L is the leaf temperature in K.

[0051] In this embodiment, the aerodynamic drag in low-speed airflow is defined by the following equation: ; Where l is the characteristic length of the blade; u is the instantaneous wind speed, in ms -1 ; Latent heat exchange between crop canopy and environment S tr That is, during the day, the crop canopy per unit volume releases water vapor heat through transpiration every second.

[0052] ; Among them, γ is the enthalpy constant; P vsat (T L ) is the saturated water vapor pressure at leaf temperature, in Pa; Pvair( T a ) is the partial pressure of water vapor in the air, in Pa; r s Stomatal resistance in sm related to irrigation conditions and microclimate -1 The following formula is for solar radiation intensity between 0 and 150 W m -2 The expression of leaf pore resistance within the range is: ; Among them, rg, rh, τ are dimensionless parameters,

[0053] ; Among them, R g (y) is the solar radiation intensity at height y, in W m -2 ; y is the height, unit is m; H is the plant height, value is 1.5m; RH is the relative humidity, unit is %; t c is the air temperature in degrees Celsius, the unit is ℃; K c is the radiation attenuation coefficient.

[0054] In this embodiment, the blade condensation rate is determined by the following steps: The leaf condensation rate of the crop canopy is determined based on the saturated water vapor pressure at leaf temperature, the water vapor partial pressure in the air, and the water vapor conductivity of the leaf boundary layer, including: ; in, is the leaf condensation rate; is the leaf area density, is the air density, p is the atmospheric pressure, g h is the water vapor conductivity of the leaf boundary layer; P vsat (T L ) is the saturated water vapor pressure at leaf temperature; P vair( T a ) is the partial pressure of water vapor in air; where g h Determined based on the Lewis number and aerodynamic drag.

[0055] In this embodiment, a closed nonlinear equation group is first established, the initial leaf temperature of the equation group is set to the same value as the air temperature, and the equation group is solved by an iterative method, the time step is set to 30 seconds, and 20 iterations are set in each time step; thereafter, the condensation rate on the leaves can be calculated using the above formula.

[0056] g h is the Lewis number N Le and aerodynamic drag r a Related variables [84, 85] ,

[0057] ; Among them, N Le is the Lewis number, a dimensionless quantity, is the thermal diffusivity of air, in m 2 s -1 ;D w is the water vapor diffusion rate, in m 2 s -1 ; T b is the leaf boundary layer temperature, in K. In addition, when the indoor air water vapor is close to saturation, the water vapor in the air will liquefy, and the phase change of water vapor in the air is quantified using the following formula,

[0058] ; In the formula, m al is the liquefaction rate of water vapor in air, in kg m -3 s -2 ; C cds It is an empirical constant, which can be taken as 0.1, and the unit is m -1 ; Y is the mass fraction of water vapor; T dew is the dew point temperature in K.

[0059] ; Finally, all modeling parameters within the crop area are determined.

[0060] In this example, the energy source term per cubic meter of air (unit: W m -3 )for:

[0061] Where ϖ is the heat of evaporation of water, which is 2.45×10 6 J kg -1； The water vapor source term per cubic meter of air (in kg m -3 s -1 )for: ; In this embodiment, the three-dimensional simulation method of the solar greenhouse can be used to perform differentiated simulations on microclimate factors such as indoor temperature, wind speed, etc. under the influence of different planting ridge directions, which can provide a reference for the promotion of new planting methods.

[0062] The three-dimensional simulation method of the microclimate of a solar greenhouse taking ridge orientation into consideration provided in an embodiment of the present invention can be used to simulate a real production environment by combining the influence of the crop canopy on the indoor air flow distribution, the sensible / latent heat transfer between the crop canopy and the surrounding environment, and the simulation method of leaf temperature based on thermal balance, thereby improving the accuracy of greenhouse environment simulation.

[0063] The three-dimensional simulation system of the microclimate of a solar greenhouse considering the ridge orientation provided by the present invention is described below. The three-dimensional simulation system of the microclimate of a solar greenhouse considering the ridge orientation described below and the three-dimensional simulation method of the microclimate of a solar greenhouse considering the ridge orientation described above can be referenced to each other.

[0064] Figure 4 Schematic diagram of the structure of the three-dimensional simulation system of the microclimate of the solar greenhouse considering the ridge direction provided by the present invention. Figure 4 As shown, the three-dimensional simulation system of the microclimate of the solar greenhouse considering the ridge direction includes a first simulation unit 410 and a second simulation unit 420.

[0065] A first simulation unit 410 is used to construct a greenhouse geometry model according to the geometric structure parameters of the solar greenhouse and the crop canopy size, wherein the geometric structure parameters include the size of the solar greenhouse and the ridge width, ridge length and ridge spacing for crop planting in the solar greenhouse; The second simulation unit 420 is used to simulate the internal and external environmental factors of the greenhouse geometric model and the temporal and spatial distribution characteristics of the internal and external geometric structures to obtain a three-dimensional model of the greenhouse environment; wherein the internal and external environmental factors include the light intensity, humidity, temperature, air flow rate and flow direction corresponding to the external space and internal space of the greenhouse geometric model respectively.

[0066] The three-dimensional simulation system of the microclimate of a solar greenhouse taking ridge orientation into consideration provided in an embodiment of the present invention constructs a greenhouse geometric model through the geometric structural parameters of the solar greenhouse and the size of the crop canopy; the three-dimensional model of the greenhouse environment is obtained by simulating the internal and external environmental factors of the greenhouse geometric model and the respective spatiotemporal distribution characteristics of the internal and external geometric structures, thereby improving the accuracy of the simulation of the greenhouse microclimate environment and further improving the efficiency of the crop growth status under the cultivation mode in the greenhouse.

[0067] Figure 5 An example of a physical structure diagram of an electronic device is shown in FIG. Figure 5As shown, the electronic device may include: a processor 510, a communication interface 520, a memory 530 and a communication bus 540, wherein the processor 510, the communication interface 520 and the memory 530 communicate with each other through the communication bus 540. The processor 510 may call the logic instructions in the memory 530 to execute a three-dimensional simulation method of a solar greenhouse microclimate considering ridge direction, the method comprising: constructing a greenhouse geometric model according to the geometric structure parameters of the solar greenhouse and the crop canopy size, the geometric structure parameter structure including the size of the solar greenhouse and the ridge width, ridge length and ridge spacing for crop planting in the solar greenhouse; performing simulation according to the internal and external environmental factors of the greenhouse geometric model and the temporal and spatial distribution characteristics of the internal and external geometric structures, and obtaining a three-dimensional model of the greenhouse environment; wherein the internal and external environmental factors include the light intensity, humidity, temperature, air velocity and flow direction corresponding to the external space and the internal space of the greenhouse geometric model respectively.

[0068] In addition, the logic instructions in the above-mentioned memory 530 can be implemented in the form of a software functional unit and can be stored in a computer-readable storage medium when it is sold or used as an independent product. Based on such an understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc. Various media that can store program codes.

[0069] On the other hand, the present invention also provides a computer program product, which includes a computer program, which can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer can execute the three-dimensional simulation method of the microclimate of a solar greenhouse taking into account the ridge direction provided by the above-mentioned methods, the method including: constructing a greenhouse geometric model according to the geometric structure parameters and crop canopy dimensions of the solar greenhouse, the geometric structure parameter structure including the dimensions of the solar greenhouse and the ridge width, ridge length and ridge spacing used for crop planting in the solar greenhouse; performing simulation according to the internal and external environmental factors of the greenhouse geometric model and the respective spatiotemporal distribution characteristics of the internal and external geometric structures to obtain a three-dimensional model of the greenhouse environment; wherein the internal and external environmental factors include the light intensity, humidity, temperature, air velocity and flow direction corresponding to the external space and internal space of the greenhouse geometric model, respectively.

[0070] On the other hand, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, is implemented to execute the three-dimensional simulation method of the microclimate of a solar greenhouse taking into account the ridge direction provided by the above-mentioned methods, the method comprising: constructing a greenhouse geometric model according to the geometric structural parameters and crop canopy dimensions of the solar greenhouse, the geometric structural parameter structure including the dimensions of the solar greenhouse and the ridge width, ridge length and ridge spacing used for crop planting in the solar greenhouse; performing simulation according to the internal and external environmental factors of the greenhouse geometric model and the respective spatiotemporal distribution characteristics of the internal and external geometric structures to obtain a three-dimensional model of the greenhouse environment; wherein the internal and external environmental factors include the light intensity, humidity, temperature, air velocity and flow direction corresponding to the external space and internal space of the greenhouse geometric model, respectively.

[0071] The device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Ordinary technicians in this field can understand and implement it without paying creative labor.

[0072] Through the description of the above implementation methods, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a necessary general hardware platform, and of course, can also be implemented by hardware. Based on this understanding, the above technical solution is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0073] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A three-dimensional simulation method of microclimate in a solar greenhouse considering ridge orientation, characterized in that: include: Constructing a greenhouse geometric model according to geometric structural parameters of the solar greenhouse and crop canopy dimensions, wherein the geometric structural parameter structure includes the dimensions of the solar greenhouse and ridge width, ridge length and ridge spacing for crop planting in the solar greenhouse; A three-dimensional model of the greenhouse environment is obtained by performing simulation based on the internal and external environmental factors of the greenhouse geometric model and the respective spatiotemporal distribution characteristics of the internal and external geometric structures; wherein the internal and external environmental factors include the light intensity, humidity, temperature, air flow rate and flow direction corresponding to the external space and internal space of the greenhouse geometric model respectively.

2. The three-dimensional simulation method of the microclimate of a solar greenhouse considering ridge orientation according to claim 1, characterized in that: The simulation is performed based on the internal and external environmental factors of the greenhouse geometric model and the temporal and spatial distribution characteristics of the internal and external geometric structures to obtain a three-dimensional model of the greenhouse environment, including: Solving the time-averaged continuity equation, the Reynolds time-averaged equation, the time-averaged energy equation and the time-averaged component transport equation in the calculation domain of the internal and external spaces of the greenhouse geometric model to obtain target parameters, and constructing a standard k-ε turbulence model based on the target parameters and multiple equations that react to turbulent characteristics; the target parameters include pressure parameters, temperature parameters and water vapor concentration parameters; Calculate the net radiation of the crop canopy based on the radiation heat transfer coefficient, the thermodynamic average temperature of the wall and crop leaves of the solar greenhouse, and the effective radiation area; The sensible heat exchange between the crop canopy and the environment is determined based on the leaf temperature of the crop, the air temperature and the aerodynamic resistance; the latent heat exchange between the crop canopy and the environment is determined based on the leaf temperature, the saturated water vapor pressure at the leaf temperature, the water vapor partial pressure in the air, the leaf stomatal resistance and the aerodynamic resistance, and a transient steady-state equilibrium model between the crop and the environment is established based on the net radiation of the crop canopy, the sensible heat exchange and the latent heat exchange; Determine the leaf dew condensation rate of the crop canopy according to the saturated water vapor pressure at the leaf temperature, the water vapor partial pressure in the air, and the water vapor conductivity of the leaf boundary layer; determine the water vapor liquefaction rate according to the empirical constant, dew point temperature, air density and air temperature; Determine the energy source term in the air according to the blade condensation rate, the water vapor liquefaction rate, the heat of water evaporation and the sensible heat exchange amount; determine the water vapor source term in the air according to the blade condensation rate, the water vapor liquefaction rate and the latent heat exchange amount; The greenhouse geometric model is simulated by fluid dynamics CFD simulation according to the standard k-ε turbulence model, the transient equilibrium model, the energy source term in the air and the water vapor source term in the air to obtain a three-dimensional model of the greenhouse environment.

3. The three-dimensional simulation method of the microclimate of a solar greenhouse considering ridge orientation according to claim 2, characterized in that: The net radiation amount of the crop canopy is calculated according to the radiation heat transfer coefficient, the thermodynamic average temperature corresponding to the wall of the solar greenhouse and the crop leaves, and the effective radiation area, including: Calculate multiple radiation amounts according to the following formula: ； Among them, T NW , T EW , T WW , T G , T L , T R are the thermodynamic average temperatures of the rear wall, east wall, west wall, ground, blade surface, and front roof calculated within each 30-second step; T S is the average sky temperature measured by the sensor every hour; S NW , S EW , S WW , S G , S LS , S LR are the effective radiation areas of the back wall, east wall, west wall, ground, canopy to the sky, and canopy to the front roof; τ L is the long-wave radiation transmittance of the front roof; τ S A is the short-wave radiation transmittance of the front roof; bc is the absorption rate of crop canopy to shortwave radiation; r c1 is the first reflectivity of the lower blade to shortwave radiation; r c2 is the second reflectivity of the lower leaves to shortwave radiation; is the outdoor solar radiation intensity; is the gray body emissivity of the wall; Gray body emissivity of the blade; is the gray body emissivity of the ground; is the gray body emissivity of the sky; is the gray body emissivity of the front roof; The net radiation corresponding to the multiple radiation amounts is calculated according to the following formula: ； Among them, R SO is the total solar radiation absorbed by the crop canopy area per second; R NW is the net radiation emitted by the back wall to the crop canopy area per second; R EW is the net radiation emitted by the east wall to the crop canopy area per second; R WW is the net radiation emitted by the west wall to the crop canopy area per second; R GL is the net radiation from the ground to the leaves per second; R LS is the net radiation emitted by the crop canopy area to the sky per second; R LR V is the net radiation emitted by the crop canopy area to the front roof per second; C is the volume of the crop canopy, V C Determined based on the product of ridge width, ridge length, plant height and number of ridges.

4. The three-dimensional simulation method of microclimate in a solar greenhouse considering ridge orientation according to claim 2, characterized in that: The standard k-ε turbulence model is determined based on the turbulence kinetic energy equation and the turbulence dissipation rate equation; The turbulent kinetic energy equation is expressed by the following formula: ； The turbulent dissipation rate equation is expressed by the following formula: ； Where k is the turbulent kinetic energy; σ k is the Prandtl number of k; ε is the turbulent kinetic energy dissipation rate; S k is the source term of the turbulent kinetic energy equation; σ ε is the Prandtl number of ε; C ε1 , C ε2 , C ε3 is the empirical constant; S ε is the source term of the turbulent kinetic energy dissipation rate equation; is the absolute value of the component of fluid velocity in the i direction; is the turbulent viscosity; is the component of fluid velocity in the j direction.

5. The three-dimensional simulation method of microclimate in a solar greenhouse considering ridge orientation according to claim 2, characterized in that: The method of determining the leaf condensation rate of the crop canopy according to the saturated water vapor pressure at the leaf temperature, the water vapor partial pressure in the air, and the water vapor conductivity of the leaf boundary layer comprises: ； in, is the condensation rate of the blade; is the leaf area density, is the air density, p is the atmospheric pressure, g h is the water vapor conductivity of the leaf boundary layer; P vsat (T L ) is the saturated water vapor pressure at leaf temperature; P vair( T a ) is the partial pressure of water vapor in air; wherein, the g h Determined based on Lewis number and aerodynamic drag.

6. The three-dimensional simulation method of microclimate in a solar greenhouse considering ridge orientation according to claim 1, characterized in that: The method of constructing a greenhouse geometric model according to the geometric structural parameters of the solar greenhouse and the crop canopy size includes: A 1:1 scale greenhouse geometric model is established using drawing software according to the geometric structural parameters of the solar greenhouse and the crop canopy size; the drawing software includes CAD or IECM.

7. A three-dimensional simulation system for microclimate in a solar greenhouse taking ridge orientation into consideration, characterized in that: include: A first simulation unit is used to construct a greenhouse geometry model according to geometric structure parameters of the solar greenhouse and crop canopy dimensions, wherein the geometric structure parameter structure includes the dimensions of the solar greenhouse and ridge width, ridge length and ridge spacing for crop planting in the solar greenhouse; The second simulation unit is used to simulate the internal and external environmental factors of the greenhouse geometric model and the temporal and spatial distribution characteristics of the internal and external geometric structures to obtain a three-dimensional model of the greenhouse environment; wherein the internal and external environmental factors include the light intensity, humidity, temperature, air flow rate and flow direction corresponding to the external space and internal space of the greenhouse geometric model respectively.

8. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the computer program, the three-dimensional simulation method of the microclimate of the solar greenhouse taking into account the ridge orientation as described in any one of claims 1 to 6 is implemented.

9. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the three-dimensional simulation method of the microclimate of a solar greenhouse taking into account the ridge orientation as described in any one of claims 1 to 6 is implemented.

10. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the three-dimensional simulation method of the microclimate of a solar greenhouse taking into account the ridge orientation as described in any one of claims 1 to 6 is implemented.

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