CN112840887B - The supplementary light method for the artificial climate chamber of crops - Google Patents

Abstract

The present disclosure provides a light supplement method for a crop phytotron, which includes: establishing an energy equation of a crop artificial climate chamber, and adjusting illumination irradiated into the crop artificial climate chamber according to the energy equation so that the illuminated photosynthesis spectral energy of a crop bed inside the crop artificial climate chamber is the same as the illuminated photosynthesis spectral energy of an outdoor crop bed, and the inside of the crop artificial climate chamber is within a preset temperature; wherein, the energy equation of the crop artificial climate chamber in unit time is as follows:

Description

The supplementary light method for the artificial climate chamber of crops

technical field

The disclosure relates to a method for supplementing light in an artificial climate chamber for crops, belonging to the technical field of artificial cultivation of crops.

Background technique

In recent years, extreme weather has frequently occurred, and high temperature heat damage has seriously affected rice production. Therefore, an artificial climate chamber for identifying heat resistance of rice is one of the necessary facilities for rice breeding.

Different rice varieties have different sensitivity to high temperature, and there are significant differences in floral organs and physiological characteristics between heat-resistant and heat-labile varieties. Screening and identification of heat-tolerant rice varieties is of great significance to ensure food security; therefore, it is urgent to construct rice plants that meet the needs of heat resistance. The artificial cultivation laboratory of rice for the needs of sex identification, that is, the construction of an artificial climate room for rice heat resistance identification crops.

The artificial climate room for rice heat resistance identification is generally a glass laboratory room. The glass laboratory room must simulate the harsh conditions of natural high temperature and have strict requirements on light, temperature, humidity and ventilation. It needs to install refrigeration/heat pump equipment and air circulation system. The heat in the glass laboratory room is adjusted to control the appropriate temperature and humidity; solar radiation is the main and unstable heat source of the glass laboratory room, which has a great impact on the heat load of the refrigeration/heat pump and the indoor temperature regulation accuracy, and directly It affects the growth, flowering and fruiting of crops; the temperature regulation of the artificial climate chamber of crops requires energy consumption, especially the temperature regulation in the sun-dried glass room laboratory, which requires theoretical guidance of thermal analysis, and also considers practical conditions such as energy saving.

At present, the light and heat analysis of crop artificial climate chamber lacks theoretical guidance. The energy analysis of crop artificial climate chamber should include heat balance analysis and photosynthesis balance analysis, but there is currently a lack of analysis articles that take into account both light and heat; the reason may be that the Academy of Agricultural Sciences Crop cultivators lack the knowledge in the field of thermophysics, and technicians in the field of thermophysics do not understand the condition of the artificial climate chamber of crops; thermal technicians only use the energy balance analysis method of the room air conditioner, and they cannot correctly analyze the energy balance of the artificial climate chamber of crops Happening.

One of the energy-saving control methods for the effect of solar radiation on the heat load of the artificial climate chamber of crops is to use shading measures. When the sun is strong, use shading nets to reduce the area of solar incidence. This measure is effective for energy saving; however, the photosynthetic energy of crops after shading The reduction will affect the flowering and fruiting of crops; how to conduct thermal analysis with shading, how to design the shading system, how to design the shading degree, and the lack of theoretical analysis guidance.

Recently, many studies have been carried out on artificial light sources instead of natural light sources to promote growth. Some literatures introduce red light with a wavelength of 620nm-750nm, and chlorophyll can absorb 75%-85%. ) germination, flowering, fruiting, the synthesis of plant chlorophyll, and the effect of light and other functions are promoted; the blue-violet light with a wavelength of 420nm--500nm, chlorophyll can absorb more than 90%, which is a strong band for plant growth and photosynthesis. It can promote the development of crop roots, reduce the growth point, and thicken the leaves and stems; make the crops strong and significantly enhance disease resistance; and the new light source that produces these spectrums is the LED light source.

The light source of the LED lamp can be used as a supplementary light source for the artificial climate chamber of rice heat resistance identification crops. However, at present, both natural light adjustment and compensation light control are based on experience, and there is no systematic theoretical calculation; lack of guidance on the quantitative relationship between natural light adjustment and compensation light, it is difficult to achieve intelligent energy-saving matching control of natural light adjustment and compensation light, and it is also beneficial to crops. The precise control of temperature and humidity in the artificial climate chamber brings difficulties.

SUMMARY OF THE INVENTION

In order to solve one of the above technical problems, the present disclosure provides a method for supplementing light in an artificial climate chamber for crops.

According to one aspect of the present disclosure, there is provided a method for supplementing light in an artificial climate chamber for crops, comprising:

Establish the energy equation of the artificial climate chamber for crops,

According to the energy equation, the light irradiated into the crop artificial climate chamber is adjusted so that the photosynthetic spectral energy of the crop bed inside the crop artificial climate chamber is the same as the photosynthetic spectral energy of the outdoor crop bed, and the said The interior of the crop artificial climate chamber is within the preset temperature;

Wherein, the unit time energy equation of the crop artificial climate chamber is:

为空调机循环风送给农作物人工气候室冷量或热量，当输入热量时为正号，输入冷量时为负号；±Q_m为农作物人工气候室内的室内空气热容、作物床植株热容和根系土壤的热容吸热或放热量，吸热为负号，放热为正号。In the described energy equation, the positive sign is the energy input, the negative sign is the energy consumption, and the unit is W; Q ₁ is the solar energy input into the artificial climate room for crops; Q ₂ is the electric energy consumed by the compensation light; Q ₃ is The electric energy consumed by the additional fan for uniform air flow in the artificial climate of crops; Q ₄ is the heat transfer from the glass cover to the room; Q _p1 and Q _p2 are the sunlight absorbed by the crop bed and the photosynthetic energy in the compensation light; Q _ρ is radiant energy reflected from the crop bed outdoors;

The circulating air of the air conditioner sends the cooling or heat to the artificial climate room for crops. When the heat input is positive, it is negative when the cooling is input; ±Q _m is the indoor air heat capacity in the artificial climate room for the crops, and the heat of the crop bed plants. The heat capacity of the root soil is endothermic or exothermic, the endothermic is negative, and the exothermic is positive.

According to the method for supplementing light in an artificial climate room for crops according to an embodiment of the present disclosure, when the artificial climate room for crops is not blocked:

Q ₁ =G _{in, θ} A ₀ =G _{out, θ} τA ₀ =(G _b cosθ+G _d )τA ₀

Among them, G _{in, θ} and G _{out, θ} are the solar radiation intensity on the horizontal plane inside and outside the crop artificial climate chamber respectively, the unit is W/m ² , θ is the zenith angle of sunlight; τ is the average transmittance of the glass light rate; A ₀ is the area of the crop bed in the artificial climate chamber of crops, in m ² ; G _b is the direct solar radiation intensity; G _d is the scattered solar radiation intensity; take G _b /G _d =6/4.

According to the method for supplementing light in an artificial climate room for crops according to an embodiment of the present disclosure, when the artificial climate room for crops uses a ceiling shading net: Q ₁ is denoted as Q _{1, π} ,

Q _{1, π} = [G _{out, θ, b} (1-π _b )+G _d (1-πF ₂₁ )]τA ₀ (4)

Among them, G _{out, θ, b} is the direct solar radiant energy with the sun incident angle θ when there is no shading; π _b is the share of the direct radiant energy reduced by the shading net, which is equal to the proportion of the direct sunlight irradiated area of the crop bed blocked by the shading net and the The product of the shading degree π of the shading net; when the parallel height of the shading net roof and the crop bed is Z, the width of the crop bed is x _b , and the width of the shading net is x _z , from the left end of the shading net roof to the right end of the crop bed The light _La When the zenith angle is θ _a , when the zenith angle of the light L _b from the left end of the shading net roof to the left end of the crop bed is θ _b ;

There is no effect when θ≥θ _a ,

π _b = 0 (θ≥θ _a ) (5a)

When θ < θ _a , as θ continues to decrease, the shadow area of the shading net appears on the crop bed, and the width of the shadow produced by the light La with _a zenith angle of θ on the crop bed is represented by x _π ,

x _π =Z tanθ _a -Z tanθ = x _a -x _θ

x _a = Z tan θ _a , x _θ = Z tan θ , x _b = Z tan θ _b ;

When θ _b > θ

π _b = π (5c)

The πF ₂₁ in the scattered radiation energy G _d (1-πF ₂₁ ) of the formula (4) is the share of the shading net in the hemispherical space radiation, and the F ₂₁ visual coefficient is the intercepted by the crop bed plane from the shading net ceiling surface. radiation share;

According to the different height of the sun and the different zenith angle θ, choose formula (5a) or (5b) or (5c) and substitute it into formula (4) to calculate the solar radiation energy Q _{1, π} that enters the artificial climate chamber of crops when there is shading;

When θ=0,

Q _{1, π, θ=0} = [G _{out, θ, b} (1−π)+G _d (1−πF ₂₁ )]τA ₀ (θ=0) (4a).

红外辐射反射膜的对波长λ≥780nm的红外光辐射遮光度为π_h＝0.9，波长λ≥780nm的红外光辐射能在太阳全辐射能中所占的份额为

According to the method for supplementing light in an artificial climate chamber for crops according to an embodiment of the present disclosure, when the infrared reflective translucent film laid on the top glass of the artificial climate chamber for crops is used, Q ₁ is recorded as Q _{1, πp} , the shading degree of visible light is π _p = 0.1, the share of visible light energy in the total solar radiation energy is

The shading degree of infrared radiation reflection film to infrared light radiation with wavelength λ≥780nm is π _h = 0.9, and the share of infrared light radiation energy with wavelength λ≥780nm in the total solar radiation energy is

When the top infrared reflective translucent film is used, the direct solar radiation energy and scattered radiant energy are decomposed into visible light and infrared radiation, and different shading rates π _p and π _h are used respectively. When the infrared reflective translucent film is used, entering The solar radiation energy of the crop artificial laboratory is:

Formula (6) is arranged according to the visible light part and the infrared radiation, we get:

When θ=0 at noon, cosθ=1, denote π _{b, p} = π _p , π _{b, h} = π _h , so formula (7) is transformed into (7a) or (7b):

Among them, the entering energy of visible light is:

The incoming energy of solar infrared radiation is:

Compared with the no-shading scheme, the difference in solar energy entering the room is:

In formula (9), the amount of visible light reduction is:

Far-infrared radiant energy reduction:

Compared with the shading net scheme, the difference in solar radiation energy entering the room is:

The visible light partial amount of the shading net scheme is:

After deducting the green light share, the partial amount of crop photosynthesis radiant energy in the shading net scheme is:

To reduce the electric power of the fill light is:

ΔP _{2, π-ρ} = ΔQ _{π, VL} /η _d (16)

But far-infrared radiant energy increases by:

The increase of green radiant energy than the shading net is:

Calculated according to the COP of the performance coefficient of the air conditioner, the scheme of infrared reflective shading film saves electric power compared with the scheme of shading net as follows:

ΔP _2,π−p =ΔP _2,π− ρ−(ΔQπ _,IR −ΔQπ _,ρ )/COP (19).

According to the method for supplementing light in an artificial climate chamber for crops according to an embodiment of the present disclosure, the photosynthetic energy Q _p1 absorbed by the crops in the crop bed from sunlight is:

为太阳光中可被植物吸收的光合作用的能量份额，α_p为植物的对光合作用光谱辐射能的吸收率，ξ为光合作用从光能变成化学能的效率；Among them, note

is the energy share of photosynthesis that can be absorbed by plants in sunlight, α _p is the absorption rate of photosynthesis spectral radiant energy by plants, and ξ is the efficiency of photosynthesis from light energy to chemical energy;

At noon, without shade:

When using shade nets:

When using IR reflective shading film:

According to the method for supplementing light in an artificial climate chamber for crops according to an embodiment of the present disclosure, the photosynthesis spectral energy Q _p2 in the compensation light of the energy equation is the energy difference between the outdoor and indoor visible light spectral bands, and when there is no shading:

The power of the fill light is:

Wherein, η _d is the electro-optical conversion efficiency of the compensation light lamp;

When there is no shading and θ=0 at noon, the energy Q _{2 of the compensation light, θ=0} , the photosynthetic energy absorbed by the crop is recorded as Q _{p2, θ=0} ;

When using the ceiling shading net θ=0, Q1 is calculated using Q _{1, π} of formula (4), Q ₂ is denoted as Q _{2, π} , and Q _p2 is denoted as Q _{p2, π} , then:

和被农作物吸收的能量

When using infrared reflective shading film, and the compensation optical power at noon

and energy absorbed by crops

Among them, Q _{out, 0} is 100.

According to the method for supplementing light in an artificial climate room for crops according to an embodiment of the present disclosure, the radiant energy Q _ρ reflected by the artificial climate room for crops is:

in,

When there is no shading θ=0, the green light reflection amount is denoted as Q _{ρ, θ=0} ;

When the top layer adopts a shading net to shield the light and θ=0, the green light reflection amount when the shading degree of the shading net is π=0.6 is denoted as Q _{ρ, θ=0, π=0.6} ;

When the infrared reflective shading film is used, the visible light shading degree is π _p = 0.1, the infrared shading degree is π _{p, h} , the green light reflection amount when θ = 0 is denoted as Q _{ρ, θ = 0, π = 0.1} ,

where at is 0.6, a _{d is} 0.4, and G _out =G _b +G _{d .}

According to the method for supplementing light in an artificial climate room for crops according to an embodiment of the present disclosure, Q4 in the energy equation is the heat transfer amount of the glass cover to the room:

In the daytime:

Q ₄ =0.5G _out (1-τ-ρ)A ₀ =0.5(G _b cosθ+G _d )αA ₀ (26)

When the noon sun zenith angle θ=0°,

Q ₄ =0.5(G _b +G _d )(1-τ)A ₀ =0.5G _out (1-τ-ρ)A ₀ (26a)

There is no solar radiation at night, then

Q ₄ =KA(T _g1 -T)=KA(T _out -T _g2 ) (27)

In the formula, K is the average heat transfer coefficient of the glass wall to the air, A is the glass wall area of the glass room, T _g1 and T _g2 are the indoor and outer glass temperatures, respectively, and T and T _out are the indoor and outdoor air temperatures, respectively.

According to the method for supplementing light in an artificial climate room for crops according to an embodiment of the present disclosure, the heat capacity of the artificial climate room for crops absorbs heat or releases heat Q _m :

Q _m =M _a c _a dT _a /dt+M _f c _f dT _f /dt+M _s c _s dT _s /dt (28)

In the _formula , _{Ma , M f , and Ms s} are the quality of the air, crop bed _straw , and plant root soil of the crop bed, _respectively . The capacity is the heat sink of the artificial climate chamber of crops, and its temperature change is not sensitive. When the soil temperature of the plant root reaches the set value, the temperature control only needs to keep the heat capacity fluctuation terms of the air and the crop bed plants; dT _a /dt, dT _f / dt and dT _s /dt are the rate of change of the average indoor air temperature, the average temperature of the crop bed straw, and the average temperature of the plant root soil in the crop bed;

When the indoor air temperature control of the artificial climate room for crops requires a fluctuation of 1°C within 30 minutes, the heat capacity of the plant and the air is basically the same, and Q _m is obtained by the following formula:

Q _m =(M _af c _af )dT _a /dt (29)

where M _af c _af = M _a c _a + M _f c _f .

According to the method for supplementing light in an artificial climate room for crops according to an embodiment of the present disclosure, the circulating air of the air conditioner is sent to the artificial climate room for crops with cooling capacity or cooling capacity ±Q _k :

±Q _k =m _a c _a (t _h -t _c )=Q ₁ +Q ₂ +Q ₃ +Q ₄ -Q _p1 -Q _p2 -Q _ρ ±Q _m (30)

Among them, m _a is the mass flow rate of the circulating air, kg/s; c _a is the air specific heat; t _h is the return air temperature or the return air from the crop artificial climate chamber before the circulating air-conditioning air enters the heat exchanger. The air temperature mixed with the fresh air, the return air outlet is arranged near the ground of the crop bed in the crop artificial climate chamber; t _c is the temperature of the circulating air-conditioning air before the air supply port enters the crop artificial climate chamber, and the air supply port is arranged above the crop artificial climate chamber near the top;

When th _h > t _c , send cold air, when _th < t _c , send hot air.

Description of drawings

The accompanying drawings illustrate exemplary embodiments of the present disclosure and, together with the description, serve to explain the principles of the present disclosure, are included to provide a further understanding of the disclosure, and are incorporated in and constitute the present specification part of the manual.

FIG. 1 is a schematic flowchart of a method for supplementing light in an artificial climate chamber for crops according to an embodiment of the present disclosure.

FIG. 2 is a schematic structural diagram of an artificial climate chamber for crops according to an embodiment of the present disclosure.

3 is a schematic structural diagram of a top layer of an artificial climate chamber for crops using a shading net according to an embodiment of the present disclosure.

FIG. 4 is a viewing angle coefficient of an aligned parallel rectangle according to one embodiment of the present disclosure.

The reference signs in the figure are:

1 bottom layer

2 surrounding walls

3 top layers

4 Shading net

5 Compensation light

6 Fans

7 rollers

8 heat exchanger

Detailed ways

The present disclosure will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the related content, but not to limit the present disclosure. In addition, it should be noted that, for the convenience of description, only the parts related to the present disclosure are shown in the drawings.

It should be noted that the embodiments of the present disclosure and the features of the embodiments may be combined with each other unless there is conflict. The technical solutions of the present disclosure will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments.

Unless otherwise stated, the illustrated exemplary embodiments/embodiments are to be understood as exemplary features providing various details of some ways in which the technical concept of the present disclosure may be implemented in practice. Therefore, unless otherwise stated, the features of various embodiments/embodiments may be additionally combined, separated, interchanged and/or rearranged without departing from the technical concept of the present disclosure.

The use of cross-hatching and/or hatching in the drawings is generally used to clarify boundaries between adjacent components. As such, unless stated, the presence or absence of cross-hatching or shading does not convey or represent any particular material, material properties, dimensions, proportions, commonalities between the illustrated components and/or any other characteristics of the components, any preferences or requirements for attributes, properties, etc. Furthermore, in the drawings, the size and relative sizes of components may be exaggerated for clarity and/or descriptive purposes. When example embodiments may be implemented differently, the specific process sequence may be performed in a different order than described. For example, two consecutively described processes may be performed substantially concurrently or in the reverse order of that described. In addition, the same reference numerals denote the same components.

When an element is referred to as being "on" or "over", "connected to" or "coupled to" another element, the element can be directly on, directly connected to, the other element Either directly coupled to the other component, or intermediate components may be present. However, when an element is referred to as being "directly on," "directly connected to," or "directly coupled to" another element, there are no intervening elements present. To this end, the term "connected" may refer to a physical connection, electrical connection, etc., with or without intervening components.

For descriptive purposes, the present disclosure may use words such as "under", "under", "under", "under", "under" Spatially relative terms such as "above," "on," "above," "higher," and "side (eg, as in "sidewall"), etc. , thereby describing the relationship of one element to another (other) element as shown in the figures. In addition to the orientation depicted in the figures, spatially relative terms are intended to encompass different orientations of the device in use, operation, and/or manufacture. For example, if the device in the figures is turned over, elements described as "below" or "beneath" other elements or features would then be oriented "above" the other elements or features. Thus, the exemplary term "below" can encompass both an orientation of "above" and "below." In addition, the device may be otherwise oriented (eg, rotated 90 degrees or at other orientations) and, as such, the spatially relative descriptors used herein should be interpreted accordingly.

The terminology used herein is for the purpose of describing particular embodiments and is not intended to be limiting. As used herein, the singular forms "a" and "the" are intended to include the plural forms as well, unless the context clearly dictates otherwise. Furthermore, when the terms "comprising" and/or "comprising" and their variants are used in this specification, it is indicated that the stated features, integers, steps, operations, parts, components and/or groups thereof are present, but not excluded One or more other features, integers, steps, operations, parts, components and/or groups thereof are present or additional. Note also that, as used herein, the terms "substantially," "approximately," and other similar terms are used as terms of approximation and not as terms of degree, as they are used to explain what one of ordinary skill in the art would recognize Inherent deviations from measured, calculated and/or provided values.

FIG. 1 is a schematic flowchart of a method for supplementing light in an artificial climate chamber for crops according to an embodiment of the present disclosure.

As shown in Figure 1, the supplementary light method for the artificial climate chamber of crops includes:

Establish the energy equation of the artificial climate chamber for crops,

According to the energy equation, the light irradiated into the crop artificial climate chamber is adjusted so that the photosynthetic spectral energy of the crop bed inside the crop artificial climate chamber is the same as the photosynthetic spectral energy of the outdoor crop bed, and the said The interior of the crop artificial climate chamber is within the preset temperature;

Wherein, the unit time energy equation of the crop artificial climate chamber is:

±Q_k为空调机循环风送给农作物人工气候室冷量或冷量，当输入热量时为正号，输入冷量时为负号；±Q_m为农作物人工气候室内的室内空气热容、作物床植株热容和根系土壤的热容吸热或放热量，吸热为负号，放热为正号。In the described energy equation, the positive sign is the energy input, the negative sign is the energy consumption, and the unit is W; Q ₁ is the solar energy input into the artificial climate room for crops, including direct sunlight and heat dissipation solar energy; Q ₂ is the compensation light lamp Electric energy consumed; Q ₃ is the electric energy consumed by the additional fan for uniform air flow in the artificial climate of crops; Q ₄ is the heat transfer from the glass cover to the room; Q _p1 and Q _p2 are the sunlight absorbed by the crop bed and the compensation light Q _ρ is the radiant energy reflected from the crop bed to the outdoors, mainly green light energy,

±Q _k is the cooling or cooling capacity of the circulating air from the air conditioner to the artificial climate room for crops, positive sign when heat is input, and negative when cooling is input; ±Q _m is the heat capacity of indoor air in the artificial climate room for crops, The heat capacity of the crop bed plant and the root soil heat capacity is either endothermic or exothermic, with a negative sign for heat absorption and a positive sign for exothermic heat.

When the crop artificial climate chamber reaches the equilibrium state, it is mainly the heat required by the temperature fluctuation of the air heat capacity of the crop artificial climate chamber.

FIG. 2 is a schematic structural diagram of an artificial climate chamber for crops according to an embodiment of the present disclosure.

The crop artificial climate chamber of the present disclosure is modeled as a rectangular glass room, with a width of 6±0.1m from east to west, a depth of 4±0.1m from north to south, and a height of 3m. The bottom layer 1 is a crop bed, and the surrounding walls 2 and the top layer 3 are double layers Insulating glass partition, the top layer of the glass slope is high in the north and low in the south; equipped with a cooling and heating system and an air circulation system, the indoor air circulates through the heat exchanger 8 to obtain cold or heat, and the heat exchanger 8 is used for refrigeration when the refrigerant is used as a refrigeration cycle. The evaporator of the machine, or the condenser when the refrigeration working medium is used as a heat pump cycle; the circulating air duct is equipped with a new air outlet at the return air outlet, and an air outlet is opened on the glass wall opposite the return air outlet. There is a shutter regulating valve; a sunshade net 4 with a light transmittance π of 60% is arranged on the top of the glass room; Measuring heads for temperature, humidity, outdoor temperature, air circulation loop supply and return air temperature, indoor and outdoor solar irradiance meters and signal collection and processing control systems; the center of the artificial climate room is equipped with a fan 6 for air uniformity.

能被植物吸收的光合作用的能量份额为

In the present disclosure, by analyzing the quality characteristics of spectral energy, it is determined that the spectrum of photosynthesis and compensation light of crops is the radiant energy of visible light except green light, mainly blue-violet light (380-420nm) and blue light (420-450nm) , supplemented by red light (605-670nm); solar radiation visible light (380-780nm) accounts for 47.29% of solar radiation energy, deducting green light (500-560nm)

The share of photosynthetic energy that can be absorbed by plants is

In the energy equation, the electrical power consumed to adjust the temperature of the climate chamber for crops is:

P=Q ₂ +Q ₃ +Q _k /COP (2)

Among them, COP is the coefficient of performance of the cooling/heating and air circulation energy regulation system;

The indoor air temperature and humidity in the crop artificial climate room are controlled by the circulating air system of the air conditioner to control the temperature and humidity of the inlet air sent into the room. The circulating air circuit is equipped with a heat exchanger in front of the air inlet to adjust the inlet air temperature; The return air is equipped with a fresh air adjustment port.

Before the solar radiation penetrates the glass wall and glass roof and enters the artificial climate chamber of crops, there is a part of the radiant energy G _{out, ρ} is reflected by the glass, part of G _{out, α} is absorbed by the glass, and the rest enters the artificial climate chamber of crops (glass test room) , this part of the energy is recorded as Q ₁ .

When the crop artificial climate chamber is not shaded:

Q ₁ =G _{in, θ} A ₀ =G _{out, θ} τA ₀ =(G _b cosθ+G _d )τA ₀ (3)

Among them, G _{in, θ} and G _{out, θ} are the solar radiation intensity on the horizontal plane inside and outside the artificial climate chamber of crops, respectively, the unit is W/m ² . value, the subscript in represents indoor, out represents outdoor, θ represents the zenith angle of sunlight; τ is the average transmittance of glass, and the relationship between the transmittance τ of glass, reflectivity ρ and absorption rate α is τ +ρ+α=1, generally τ=0.85, ρ=0.1, α=0.05; A ₀ is the area of the crop bed of the crop artificial climate chamber, the unit is m ² , in this disclosure, it is 4×25m ² =100m ² ; G _b is the direct solar radiation intensity, which is measured with a direct solar radiation meter; G _d is the scattered solar radiation intensity, which is the difference between the measured value of the total solar radiation meter minus the measured value of the direct solar radiation meter; the direct solar radiation intensity is irradiated at The radiant energy of the crop bed on the horizontal plane is calculated by G _b cos θ, where θ is the angle between the incoming solar ray and the normal to the horizontal plane, called the zenith angle; for the horizontal plane, the scattered radiation comes from the hemisphere of the sky; the intensity of direct solar radiation The proportional share of the radiation intensity of the scattered sun is related to the gray level of the cloud layer in the sky, which can be obtained from special data such as solar energy utilization, or obtained by measurement methods; as an example analysis, take G _b /G _d =6/4 , G _b =0.6G _out , G _d =0.4G _out , G _out =1.0kW; θ=0 is noon, and the total solar radiation intensity at noon can be represented by G _{out, θ=0} =G _out ; When θ=0 at noon, the solar radiation intensity G _{out received by the horizontal plane, 0} =G _out =1.0W/m ² . The solar radiation intensity is G ₀ =1368W/m ² outside the atmosphere. It is called the solar radiation constant. The actual solar radiation intensity is related to the thickness of the sunlight passing through the atmosphere, and the concentration of water vapor and carbon dioxide contained in the atmosphere. The total solar irradiance meter installed above the indoor crop bed and on the outdoor glass roof horizontal frame measures the solar irradiance G _{in, θ} and G _{out, θ} on the indoor crop bed and outdoors.

Q _{1, θ=0} =G _in A ₀ =G _out (at _cosθ +ad ) _{τA 0} =1×(0.6+0.4)×0.85×100=85kW;

Q _{1, θ=30°} =G _out (at cos 75°+ad )τA ₀ =1×( _0.6cos 30°+0.4)×0.85×100= _78.2kW ;

Q _{1, θ=75°} =G _out (at cos 75°+ad )τA ₀ =1×( _0.6cos 75°+0.4)×0.85×100= _49.5kW ;

That is, at noon, the crop beds receive the greatest amount of solar radiation.

When the crop artificial climate chamber is shaded by the roof shading net, Q ₁ is denoted as Q _{1, π} , (indicated by adding π in the subscript), the irradiated solar radiation energy on the crop bed includes direct radiation energy and scattered radiation energy. The calculation formula is:

Q _{1, π} = [G _{out, θ, b} (1-π _b )+G _d (1-πF ₂₁ )]τA ₀ (4)

Among them, G _{out, θ, b} is the direct radiant energy of the sun incident angle θ when there is no shading, π _b is the direct radiant energy share reduced by the shading net, and is the product of the area share of the crop bed blocked by the shading net and the shading degree , the specific parameters should be calculated according to the geometric position and size of the shading net; for example: the height of the ceiling of the shading net parallel to the crop bed is Z, the width of the crop bed is x _b , and the width of the shading net is x _z , refer to Figure 3, from the ceiling of the shading net The zenith angle of the light L _a from the left end to the right end of the crop bed is θ _a , and the zenith angle of the light L _b from the left end of the shading net roof to the crop bed is θ _b . When θ < θ _a , the shading net is directed toward The interception of the sun has the effect of reducing the direct solar radiation. When θ≥θ _a , the direct solar radiation is not affected by the shading net, because the sun height is low; when θ < θ _a , as θ continues to decrease, the sun height increases. The shadow area of the shading net appears on the bed, and the shadow width x _π produced by the light L _a with the zenith angle θ on the crop bed is expressed as,

x _π =Z tan θ _a -Z tan θ = x _a -x _θ ;

x _a = Z tan θ _a , x _θ = Z tan θ , x _b = Z tan θ _b ;

G _{out, θ, b} (1-π _b )=G _{out, b} (θ≥θ _a )π _b =0 (5a)

G _{out, θ, b} (1-π _b )=G _{out, b} (1-π) (θ _b >θ, θ=0) π _b =π (5c)

The πF ₂₁ of the scattered radiation energy G _d (1-πF ₂₁ ) is the share of the shading net in the hemispherical space radiation, and the F ₂₁ viewing angle coefficient is the radiation share from the roof surface of the shading net intercepted by the crop bed plane;

Therefore, according to the different height of the sun and the different zenith angle θ, choose formula (5a) or (5b) or (5c) and substitute it into formula (4) to calculate the solar radiation energy Q _{1, π} that enters the artificial climate chamber of crops when there is shading ;

When θ=0,

Q _{1, π, θ=0} = [G _b (1-π)+G _d (1-πF ₂₁ )]τA ₀ (4a)

The area of the crop bed is x = x _b = 12.5m, y = 8m, Z = 3.5m, x _z = 13.5m, x _a = 13m, according to x/Z = 3.57, y/z = 2.29 F from Figure 2 ₁₂ = 0.52, let π = 0.6, after adopting shading measures, when θ = 0 at noon, the energy of the sun input into the glass laboratory room per unit time input to the sun energy in the glass laboratory room is:

Q _{1, θ=0, π} =G _in A ₀ =[0.6(1-0.6)+0.4(1-0.6×0.52)]×0.85×100=43.8kW;

When θ=30°,

When θ=75°, Q _{1, θ=75°} =84.7kW, no need to block.

Q1 calculation when using infrared reflective translucent film, _denoted as

红外辐射反射膜的对波长λ≥780nm的光谱辐射遮光度为π_h＝0.9，占太阳辐射的份额

东西南北四围玻璃无遮拦；采用红外反射半透明膜时，式(4)的太阳直射辐射能和散射辐射能，应当分解为可见光和红外辐射两部分能量，并分别使用不同的遮光率π_p和π_h，则式(4)转化为使用红外反射半透明膜时进入作物人工实验室的太阳辐射能为：When using the infrared reflective translucent film laid on the top glass of the crop artificial climate chamber, the shading degree of visible light is π _p = 0.1, which accounts for the share of solar radiation

The shading degree of the infrared radiation reflective film to the spectral radiation of wavelength λ≥780nm is π _h = 0.9, accounting for the share of solar radiation

The glass around the east, west, north and south is unobstructed; when infrared reflective translucent film is used, the direct solar radiation energy and scattered radiation energy of formula (4) should be decomposed into two parts of visible light and infrared radiation, and different shading rates π _p and π _h , then the formula (4) is transformed into the solar radiation energy entering the artificial laboratory of crops when the infrared reflective translucent film is used as:

Organized into two parts, visible light and infrared radiation, the calculation formula is

The first term on the right side of the equal sign of formula (7) is the visible light part, and the second term is the infrared radiation part;

At noon θ=0, π _{b, p} = π _p , π _{b, h} = π _h , so formula (7) becomes (7a) or (7b)

Among them, the entering energy of visible light is

The incoming energy of solar infrared radiation is

Compared with the no shading scheme, the air-conditioning cooling capacity is saved by

Among them, the visible light reduction is only

Mainly the reduction of far-infrared radiant energy, namely

Compared with the shading net scheme, the difference in the amount of solar radiation entering the room is as follows:

In formula (13), the partial amount of visible light in the shading net scheme is:

After deducting the green light share, the partial amount of crop photosynthesis radiant energy in the shading net scheme is:

Therefore, compared with the shading net scheme, the scheme of using the infrared reflective shading film:

Reduce the power of the compensation light:

ΔQ _{π, VL} = 0.3924 × 16.24/0.4729 = 13.47kW (15a)

To reduce the electric power of the fill light is:

ΔP _{2, π-ρ} = ΔQ _{π, VL} /η _d = 13.47/0.85 = 15.8kW (16)

Increase far-infrared radiant energy:

The radiant energy of green light is more than that of the shading net:

Calculated according to the coefficient of performance of the air conditioner COP=3.2, the scheme of infrared reflection shading film saves electric power compared with the scheme of shading net as follows:

ΔP _2,π-p =ΔP _2,π- ρ-(ΔQπ _,IR -ΔQπ _,ρ )/COP=15.8-(10.86-1.66)/3.2=12.9kW (19)

Q _p1 is the energy absorbed by the crops in the crop bed from sunlight, and α _p is the photosynthesis spectral radiant energy absorption rate of the plant, then the photosynthetic energy absorbed by the crop bed is

为太阳光中被植物吸收的光合作用的能量份额，

α_p为植物的光合作用光谱辐射能吸收率，ξ为光合作用从光能变成化学能的效率；由于植物的光合作用是光量子作用，是辐射能中的可做功的有效能起作用，光量子有效能占有率ξ与波长的关系为in,

is the share of photosynthetic energy absorbed by plants in sunlight,

α _p is the spectral radiant energy absorption rate of the photosynthesis of plants, ξ is the efficiency of photosynthesis from light energy to chemical energy; because the photosynthesis of plants is the action of photons, it is the effective energy that can do work in the radiant energy, and the photons The relationship between the effective energy occupancy rate ξ and the wavelength is

In the formula, c ₃ is the spectral characteristic temperature equation constant, c ₃ =λT _λ =5.33016×10 ^-3 m·K; when the ambient temperature T ₀ =298K, it is calculated that ξ=0.9787 for blue-violet light, ξ= ξ= for blue light 0.976-0.9748, ξ=0.964-0.9625 of red light; for plants, blue-violet light, blue light and red light can be received by the chlorophyll of plants, and the functions contained in the light quantum energy can ensure photosynthesis at room temperature The energy conversion efficiency of the core complex to produce glucose is between 0.93-0.92; formula (8) calculates the ideal photosynthesis efficiency, that is, the highest efficiency; the actual photosynthesis efficiency is also very high, and the blue light photosynthesis efficiency exceeds 90%, The photosynthetic efficiency of red light reaches 75-85%; the photosynthetic spectral radiant energy absorption rate α _p of plants is related to the conditions of crop growth, the size of the plant, the light-receiving area of green leaves and other factors. Large-scale experiments have reported the efficiency of crop photosynthesis About 0.3-0.4; crop spectral energy absorption rate should be done more experimental research and statistical summary, in this embodiment, it is recommended to take α _p ξ = 0.35;

At noon, Q _p1 when there is no shading, denoted as Q _{p1, θ=0}

When using shade nets:

When using infrared reflective shading film,

蓝光的

阳红光的

蓝紫光+蓝光与红光的占比为8.12/8.055；所以，补偿光的蓝光(包括蓝紫光)的功率与红光的功率配比为The principle of the non-reduction of the spectral energy of the photosynthesis of the crop bed, the principle of designing matching compensation light and regulating the compensation light, is embodied as the compensation light is emitted by the LRD lamp to emit blue light (including blue-violet light) and red light; according to The radiant energy share of blue light (including blue-violet light) and red light in sunlight, blue-violet light

Blu-ray

sunny

The ratio of blue-violet light + blue light to red light is 8.12/8.055; therefore, the ratio of the power of blue light (including blue-violet light) of the compensation light to the power of red light is

Compensation light quantity Q _p2 , compensation light quantity absorbed by plants Q _p2,α , calculation of fill light power Q ₂ :

The photosynthesis spectral energy _Q2 produced by the compensation light of the energy equation (1) is the energy difference between the outdoor and indoor visible light spectrum:

η _d is the electro-optical conversion rate of the compensation light, in this example η _d = 0.80;

Compensation optical power quantity Q _{2, θ=0} and absorbed Q _{p2, θ=0} at noon without shading:

Q _p2 =η _d Q ₂ αξ=0.85×6.94×0.35=2.07 (23a)

Compensation optical power Q _{2, π, θ=0} and absorbed Q _{p2, π, θ=0} at noon when the shading net is shading:

When a shading net is used, and the power of the fill light Q2 _{, π, θ=0} at noon and the energy Q _{p2, π, θ=0} absorbed by the crops are:

Q _{p2, π, θ=0} = η _d Q _{2, π, θ=0} αξ=0.85×26.1×0.35=7.77kW (23b)

阳被农作物吸收的能量

When using infrared reflective shading film, and the compensation optical power at noon

Yang energy absorbed by crops

Q _ρ is the radiant energy reflected by the artificial climate chamber of crops, and the green light is mainly reflected,

When there is no shading θ=0, the green light reflection amount is denoted as Q _{ρ, θ=0} ;

When the shading net is used for shading, and θ=0, the green light reflection amount when the shading degree π=0.6 is denoted as Q _{ρ, θ=0, π=0.6} ;

When the infrared reflective film is used for shading, the visible light shading degree is π _p = 0.1, the infrared shading degree is π _ph = 0.85, and the green light reflection amount when θ = 0 is denoted as Q _{ρ, θ = 0, π = 0.1} ,

Q ₄ is the heat transfer from the glass cover to the room. In the daytime, Q ₄ is equal to the solar radiation energy Q _{out absorbed by the glass of the glass room, α} = Q _out α, minus the heat released by the glass to the outdoor Q _4,out , engineering calculation It is allowed to assume that Q _{4 , out} = Q ₄ ; the solar radiation energy absorbed by the glass cover is equal to the outdoor solar radiation energy, after deducting the solar radiation energy Q _{out reflected by the glass, ρ} = Q _out ρ and the solar radiation energy entering the room _Qin , Q _in =G _out (1-τ-ρ)A ₀ , so in the daytime heat is generated due to the absorption of solar radiation, and the heat transferred to the artificial climate room for crops is calculated according to the equation as,

Q ₄ =0.5G _out (1-τ-ρ)A ₀ =0.5(G _b cosθ+G _d )αA _o (26)

When noon θ = 0,

Q ₄ =0.5×(0.6+0.4)×0.05×100=2.5kW (26a)

When θ=75° in the morning

Q ₄ =0.5×1000×(0.6cos 75°+0.4)×0.05×100=1.39kW (26b)

There is no solar radiation at night, then

Q ₄ =KA(T _g1 -T)=KA(T _out -T _g2 ) (27)

In the formula, K is the average heat transfer coefficient of the glass wall to the air, A is the glass wall area of the glass room, T _g1 and T _g2 are the indoor and outer glass temperatures, respectively, and T and T _out are the indoor and outdoor air temperatures, respectively.

Q _m is the heat capacity and heat absorption term of the temperature fluctuation of the artificial climate room for crops,

Q _m =M _a c _a dT _a /dt+M _f c _f dT _f /dt+M _s c _s dT _s /dt (28)

In the formula, _Ma , _Mf , and _Ms are the quality of the air, crop bed straw, and plant root soil in the crop artificial climate room, respectively, _ca , _cf , and _cs are the air in the crop artificial climate room, The specific heat of crop bed straw and plant root soil in crop bed, M _a ≈ M _f ＜<M _s , so the heat capacity of M _s c _s is the heat sink of the artificial climate chamber of crops, which is not sensitive to temperature changes. After the soil temperature reaches the set value, the temperature control only needs to keep the heat capacity fluctuation terms of the air and the crop bed plant; The artificial climate chamber for crops, the soil layer quality M ₁ =1300kg/m ³ ×0.4m×100m ² =52000kg, the specific heat capacity of the water-bearing soil c ₁ =3.5kJ/(kg·K), the heat capacity of the soil is M ₁ c ₁ = 182000kJ/K;

The mass of the crop layer M ₂ =5kg/m ³ ×0.5×100m ³ =250kg, the specific heat capacity of the wet crop c ₂ =2.5kJ/(kg·K), M ₂ c ₂ =625kJ/K;

Mass of air layer M ₃ =1.3kg/m ³ ×3×100m ³ =390kg, specific heat capacity of air c ₃ =1.1kJ/(kg·K), M ₃ c ₃ =429kJ/K

Therefore, the heat capacity of air and crop bed only accounts for 0.58% of the total heat capacity, while the heat capacity of the plant root soil layer accounts for 99.4% of the total heat capacity.

When the indoor air temperature control of the artificial climate room for crops requires a fluctuation of 1°C within 30 minutes, the heat capacity of the plant and the air is basically the same, and Q _m is calculated by the simplified formula

Q _m =(M _af c _af )dT _a /dt (29)

where M _af c _af =M _a c _a +M _f c _f ;

If the indoor air temperature fluctuates by 1 degree in 5 minutes, then:

Q _m =M _f c _f dT _f /dt=(429+625)×1/1800=0.41kW (29a)

Therefore, when the crop artificial climate chamber enters into precise temperature regulation, Q _m can be neglected.

The energy balance of the crop artificial climate chamber is completed by the refrigeration and heating system and the air circulation system; the refrigeration and heating system uses the evaporator of the compression refrigerator and the circulating air circulating in the crop artificial climate chamber to exchange. Heat, provide cooling to the crop artificial climate chamber, balance the excess heat of solar radiation entering the crop artificial climate chamber, and keep the indoor air temperature within the allowable fluctuation range of the design temperature; at night, the crop artificial climate chamber dissipates heat to the outside, and the indoor temperature is In the downward trend, the refrigerant circulates in reverse, the refrigerator operates as a heat pump, and the evaporator of the refrigerator becomes a condenser to provide heat to the circulating air; note, m _a is the mass flow of the circulating air, kg/s; c _a is the specific heat of air; t _h is the air temperature of the air return outlet of the circulating air conditioning air in the artificial climate chamber of crops, and the return air outlet is arranged near the ground of the crop bed in the artificial climate chamber of crops; t _c is the cold air (or hot air) of the air supply air of the circulating air conditioning air temperature, the air supply port is arranged above the artificial climate chamber of crops and close to the top surface; according to the energy equation, the calculation formula of Q _k is:

The calculation formula of the cooling capacity Q _k provided by the air conditioner adjusting the room temperature of the artificial climate of crops is:

±Q _k =m _a c _a (t _h -t _c )=Q ₁ +Q ₂ +Q ₃ +Q ₄ -Q _p1 -Q _p2 -Q _ρ ±Q _m (30)

Among them, m _a is the mass flow rate of the circulating air circulating in the crop artificial climate chamber and the evaporator of the air conditioner, kg/s; c _a is the air specific heat, th _h is the air temperature of the circulating air-conditioning air return port of the crop artificial climate chamber, The return air outlet is arranged near the ground of the crop bed in the crop artificial climate chamber, t _c is the cold air temperature of the circulating air-conditioning air supply outlet, and the air supply outlet is arranged above the crop artificial climate chamber and close to the top surface;

When t _h >t _c , supply cold air, when t _h <t _c , supply hot air, and when t _h =t _c , no air is supplied;

No shade, and at noon,

Q _{k, θ=0} =85+6.94+1+2.5-11.7-2.07-6.84+0.41=75.24kW (30a)

When using a shading net to block light, and at noon

Q _{k, π, θ=0} = 43.8+26.1+1+2.5-6.01-7.77-3.96+0.41=56.07kW (30b)

When using infrared reflective film to block light, and at noon

Calculation result summary table

Q₁ Q_p1 Q_p2,α Q₂ Q₃ Q_ρ Q₄ Q_m Q_k no shading 85 -11.7 -2.07 6.94 1.0 -6.84 2.5 0.41 75.24 shading net 43.8 -6.01 -7.77 26.1 1.0 -3.96 2.5 0.41 56.07 shading film 49.2 -10.7 -3.00 10.1 1.0 -6.04 2.5 0.41 43.47

6H ₂ O+6CO ₂ +(Light energy 2870kJ)→C ₆ H ₁₂ O ₆ (180g)+6O ₂ (31a)

E _P +xE(H ₂ O)+yE(CO ₂ )=jE(C _m H _n O _k )+iE(O ₂ ) (32)

Outdoor sunshine energy Q _{out, D} = Q _{out, 0, day} A ₀ =0.60×3600×8×100=1728000KJ;

Daily grams of glucose

In the description of this specification, references to the terms "one embodiment/mode", "some embodiments/modes", "example", "specific example", or "some examples", etc. are intended to be combined with the description of the embodiment/mode A particular feature, structure, material, or characteristic described by way of example or example is included in at least one embodiment/mode or example of the present application. In this specification, schematic representations of the above terms are not necessarily directed to the same embodiment/mode or example. Furthermore, the particular features, structures, materials or characteristics described may be combined in any suitable manner in any one or more embodiments/means or examples. Furthermore, those skilled in the art may combine and combine the different embodiments/modes or examples described in this specification and the features of the different embodiments/modes or examples without conflicting each other.

In addition, the terms "first" and "second" are only used for descriptive purposes, and should not be construed as indicating or implying relative importance or implying the number of indicated technical features. Thus, a feature delimited with "first", "second" may expressly or implicitly include at least one of that feature. In the description of the present application, "plurality" means at least two, such as two, three, etc., unless expressly and specifically defined otherwise.

It should be understood by those skilled in the art that the above embodiments are only for clearly illustrating the present disclosure, but not for limiting the scope of the present disclosure. For those skilled in the art, other changes or modifications may also be made on the basis of the above disclosure, and these changes or modifications are still within the scope of the present disclosure.

Claims (1)

1. A light supplementing method for a crop phytotron is characterized by comprising the following steps:

establishing an energy equation of the crop phytotron,

adjusting illumination irradiated into the crop phytotron according to the energy equation to enable the illuminated photosynthesis spectral energy of the crop bed in the crop phytotron to be the same as that of the crop bed outside, and enable the interior of the crop phytotron to be within a preset temperature;

wherein the energy equation is:

in the energy equation, the positive sign is energy input, the negative sign is energy consumption, and the unit is W; q₁Is the solar energy input into the crop phytotron; q₂To compensate for the amount of power consumed by the lamp; q₃The electric energy consumed by an additional fan for homogenizing the air flow in the crop artificial climate chamber; q₄The heat transfer quantity of the glass cover to the indoor is obtained; q_p1、Q_p2The photosynthesis energy in the sunlight and the compensating light absorbed by the crop bed; q_ρIs the radiation energy reflected by the crop bed to the outside;

the method comprises the steps that cold or heat is supplied to a crop artificial climate chamber for circulating air of an air conditioner, the heat is positive when the heat is input, and the cold is negative when the cold is input; +/-Q_mThe heat absorption or heat release quantity of indoor air heat capacity, crop bed plant heat capacity and root soil heat capacity in the crop artificial climate chamber is negative, and the heat release is positive;

when the crop phytotron is not sheltered:

Q₁＝G_in,θA₀＝G_out,θτA₀＝(G_bcosθ+G_d)τA₀

wherein G is_in,θAnd G_out,θThe intensity of the solar radiation on the horizontal planes inside and outside the crop phytotron respectively is W/m²And theta represents the zenith angle of the solar rays; τ is the average light transmittance of the glass; a. the₀The area of the crop bed in the crop phytotron is m²；G_bIs the intensity of direct solar radiation; g_dIs the intensity of scattered solar radiation; get G_b/G_d＝6/4；

When the crop phytotron uses a ceiling shading net: q₁Is recorded as Q_1,π，

Q_1,π＝[G_out,θ,b(1-π_b)+G_d(1-πF₂₁)]τA₀ (4)

Wherein，G_out,θ,bThe solar direct radiation energy with the solar incident angle theta is obtained when no shading exists; pi_bThe fraction of the direct radiation energy reduced by the shading net is equal to the product of the fraction of the direct solar irradiation area of the crop bed shielded by the shading net and the shading degree pi of the shading net; when the parallel height of the shading net ceiling and the crop bed is Z, the crop bed width is x_bThe width of the shading net is x_zLight L emitted from the left end of the shading net ceiling to the right end of the crop bed_aHas a zenith angle of theta_aLight L emitted from the left end of the shading net ceiling to the left end of the crop bed_bHas a zenith angle of theta_bWhen the current is over;

when theta is more than or equal to theta_aWhen the method is not used, the effect is not achieved,

π_b＝0(θ≥θ_a) (5a)

when theta < theta_aThen, as theta continues to decrease, the shadow area of the shading net appears on the crop bed, and the light L with the zenith angle of theta_aThe width of the shadow produced on the crop bed is measured in x_πIt is shown that,

x_π＝Z tanθ_a-Z tanθ＝x_a-x_θ

x_a＝Z tanθ_a，x_θ＝Z tanθ，x_b＝Z tanθ_b；

when theta is_bAfter > theta

π_b＝π (5c)

Scattered radiant energy G of formula (4)_d(1-πF₂₁) Of (ii) pi F₂₁For the proportion of the shading screen in the radiation of the hemisphere, F₂₁The visual coefficient is the radiation fraction intercepted by the plane of the crop bed from the ceiling surface of the shading net;

according to different sun heights and different zenith angles theta, the formula (5a), (5b) or (5c) is selected to be substituted into the formula (4), and the solar radiation energy Q entering the crop phytotron under the condition of shading is calculated_1,π；

When the value of theta is equal to 0,

Q_1,π,θ＝0＝[G_out,θ,b(1-π)+G_d(1-πF₂₁)]τA₀(θ＝0) (4a)；

when an infrared-reflecting translucent film laid on top glass of a crop phytotron is used, Q₁Is marked as

The light-shielding degree of visible light is pi_pThe share of visible light energy in the solar full radiant energy is 0.1

The infrared radiation reflecting film has a pi infrared radiation shielding degree of not less than 780nm in wavelength lambda_hThe infrared radiation energy with the wavelength lambda more than or equal to 780nm accounts for the total solar radiation energy of 0.9

When the top infrared reflection semitransparent film is adopted, the direct solar radiation energy and the scattered radiation energy are decomposed into two parts of energy of visible light and infrared radiation, and different shading rates pi are respectively used_pAnd pi_hWhen the infrared reflection semitransparent film is used, the solar radiation energy entering a crop artificial laboratory is as follows:

the formula (6) is finished according to visible light parts and infrared radiation to obtain:

when θ is equal to 0, cos θ is equal to 1, and pi is written_b,p＝π_p，π_b,h＝π_hTherefore, formula (7) is defined as (7a) or (7 b):

or

The indoor energy of the visible light is as follows:

the indoor energy of solar infrared radiation is as follows:

compared with the non-shading scheme, the difference value of the solar energy entering the room is as follows:

in formula (9), the visible light reduction is:

reduction of far infrared radiation energy:

compared with the shading net scheme, the difference value of the indoor solar radiation energy is as follows:

the visible light bias for the shading net scheme is a small amount:

after deducting the green light share, the crop photosynthesis radiant energy of the shading net scheme is a little:

the electric power of the light supplement lamp is reduced as follows:

ΔP_2,π-ρ＝ΔQ_π,VL/η_d (16)

however, the far infrared radiation energy increment is as follows:

the green light radiant energy is increased by the following amount compared with the shading net:

according to the COP calculation of the air conditioner performance coefficient, the electric power saving of the scheme of the infrared reflection shading film compared with the scheme of the shading net is as follows:

ΔP_2,π-p＝ΔP_2,π-ρ-(ΔQ_π,IR-ΔQ_π,ρ)/COP (19)；

photosynthetic energy Q absorbed by crops of crop beds from sunlight_p1Comprises the following steps:

wherein, note

The photosynthetic energy share of sunlight, alpha, which can be absorbed by plants_pThe absorption rate of the plant to the photosynthetic spectrum radiant energy, and xi is the efficiency of photosynthesis to change from light energy to chemical energy;

at noon, when no shade is present:

when the shading net is used:

when an infrared reflection light-shielding film is used:

photosynthetic spectral energy Q in compensating light of energy equation_p2The energy difference of the visible light spectrum sections of the outdoor and the internal is shown, and when no shading exists:

the power of the light supplement lamp is as follows:

wherein eta is_dFor compensating light lampsThe electro-optic conversion efficiency of (a);

energy Q of compensating lamp when no shading exists and theta is 0 at noon_2,θ＝0And the photosynthetic energy absorbed by the crop is recorded as Q_p2,θ＝0；

When the ceiling shading net theta is 0, Q₁Q using formula (4)_1,πCalculation, Q₂Is recorded as Q_2,π,Q_p2Is recorded as Q_p2,πAnd then:

Q_p2,π＝(G_out,θ,bπ_b+G_dπF₂₁)τA₀ (23b)

compensating optical power at noon when using infrared reflection shading film

And energy absorbed by the crop

Wherein Q is_out,0Taking 100;

radiation energy Q reflected by crop phytotron_ρComprises the following steps:

wherein,

the amount of green light reflected when the light-shielding-free θ is 0 is denoted as Q_ρ,θ＝0；

When the top layer is shielded by the shading net and theta is 0, the green light reflection amount when the shading degree pi of the shading net is 0.6 is marked as Q_{ρ,θ＝0,π＝0.6}；

When an infrared reflection light-shielding film is used, the degree of shielding visible light is pi_p0.1, infrared opacity pi_p,hThe amount of green light reflected when θ is 0 is denoted as Q_{ρ,θ＝0,π＝0.1}，

Wherein a is_tTake 0.6, a_dTake 0.4, G_out＝G_b+G_d；

Q in the energy equation₄The heat transfer amount of the glass cover to the indoor is as follows:

in the daytime:

Q₄＝0.5G_out(1-τ-ρ)A₀＝0.5(G_bcosθ+G_d)αA₀(26) when the solar zenith angle theta is 0 deg.,

Q₄＝0.5(G_b+G_d)(1-τ)A₀＝0.5G_out(1-τ-ρ)A₀ (26a)

at night, no solar radiation exists

Q₄＝KA(T_g1-T)＝KA(T_out-T_g2) (27)

Wherein K is the average heat transfer coefficient of the glass wall to air, A is the glass wall area of the glass room, and T_g1、T_g2Respectively, indoor and outdoor glass temperatures, T, T_outIndoor and outdoor air temperatures, respectively;

heat capacity heat absorption or heat release Q of crop phytotron_m：

Q_m＝M_ac_adT_a/dt+M_fc_fdT_f/dt+M_sc_sdT_s/dt (28)

M in the formula_a、M_f、M_sRespectively the quality of the air in the crop phytotron, the crop bed straw and the plant root soil of the crop bed, M_a≈M_f＜＜M_sSo that M_sc_sThe heat capacity of the crop phytotron is heat sink, the temperature change is insensitive, and when the temperature of the soil of the plant root system reaches a set value, the temperature control only needs to keep the heat capacity fluctuation items of the air and the plant of the crop bed; dT_a/dt、dT_f/dt、dT_sThe dt is the change rate of the average air temperature of the indoor air, the average temperature of the straws of the crop bed and the average temperature of the soil of the plant root system of the crop bed respectively; c. C_a、c_f、c_sThe specific heat of the air in the crop artificial climate chamber, the crop bed straws and the plant root soil of the crop bed respectively;

when the indoor air temperature of the crop phytotron is controlled to be allowed to fluctuate by 1 ℃ within 30 minutes, the heat capacities of plants and air are basically the same, and Q_mObtained by the following formula:

Q_m＝(M_afc_af)dT_a/dt (29)

wherein M is_afc_af＝M_ac_a+M_fc_f；

Cold quantity or cold quantity +/-Q of crop artificial climate chamber fed by circulating air of air conditioner_k：

±Q_k＝m_ac_a(t_h-t_c)＝Q₁+Q₂+Q₃+Q₄-Q_p1-Q_p2-Q_ρ±Q_m(30)

Wherein m is_aThe mass flow of the circulating air is kg/s; t is t_hThe return air temperature from the crop artificial climate chamber or the air temperature of the mixture of the return air and the fresh air before the circulating air-conditioning air of the crop artificial climate chamber enters the heat exchanger is arranged at the part, close to the ground, of the crop bed of the crop artificial climate chamber; t is t_cThe air supply outlet is arranged above the crop artificial climate chamber and close to the top surface for circulating air-conditioning air temperature before the air supply outlet enters the crop artificial climate chamber;

when t is_h＞t_cCold air supply, when t_h＜t_cAnd (5) feeding hot air.

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