CN112840887B - Light supplementing method for crop phytotron - 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

Light supplementing method for crop phytotron

Technical Field

The invention relates to a light supplementing method for a crop artificial climate chamber, and belongs to the technical field of crop artificial cultivation.

Background

In recent years, extreme weather has frequently occurred in which high-temperature heat damage has a serious influence on rice production, and therefore, a crop phytotron for identifying the heat resistance of rice is one of essential facilities for rice breeding.

Different rice varieties have different sensitivities to high temperature, and the difference of floral organs and physiological characteristics between heat-resistant varieties and heat-intolerant varieties is obvious; screening and identifying heat-resistant rice varieties have important significance for guaranteeing grain safety; therefore, the construction of a rice artificial cultivation laboratory which meets the requirement of rice heat resistance identification, namely the construction of a rice heat resistance identification crop artificial climate chamber, is urgently needed.

The rice heat resistance appraisal crops climatic chamber is generally a glass experiment room, the glass experiment room needs to simulate natural high temperature severe conditions, has strict requirements on illumination, temperature, humidity and ventilation, needs to be provided with refrigeration/heat pump equipment and an air circulation system to adjust the heat in the glass experiment room, and controls proper temperature and humidity; solar radiation is a main and unstable heat source of a glass laboratory, has great influence on the heat load of a refrigeration/heat pump and the indoor temperature regulation and control precision, and directly influences the growth, flowering and fructification of crops; the temperature regulation and control of the crop phytotron needs energy consumption, particularly the temperature regulation and control in a solarized glass room laboratory needs theoretical guidance of thermal analysis, and practical conditions such as energy conservation and the like are also considered.

At present, theoretical guidance is lacked in light and heat analysis of a crop phytotron, energy analysis of the crop phytotron should comprise heat balance analysis and photosynthesis balance analysis, but an analysis article which gives consideration to both light and heat is lacked at present; the reason for this may be that crop growers in the rural communities lack knowledge in the thermophysical field, and those skilled in the thermophysical field do not know the status of the crop phytotron; thermal technicians only adopt an energy balance analysis method of a room air conditioner, and cannot correctly analyze the energy balance condition of the crop phytotron.

One of the energy-saving regulation and control means for influencing the heat load of the crop phytotron by solar radiation is to adopt a sun-shading measure, and when the sunlight is strong, the sun incidence area is reduced by a shading net, so that the measure is effective in energy conservation; however, the photosynthesis energy of the crops is reduced after shading, and the flowering and the fruit setting of the crops are influenced; how to perform thermal analysis with shading, how to design a shading system, how reasonable shading degree is, and theoretical analysis guidance is lacked.

Recently, many studies have been made on the artificial light source to promote growth thereof instead of the natural light source, and there are documents which describe that red light having a wavelength of 620nm to 750nm, chlorophyll can absorb 75% to 85%, and the red light having a wavelength of this band has a promoting effect on germination, flowering, fruiting, synthesis of chlorophyll, light action and the like of plants; blue-violet light with the wavelength of 420nm to 500nm, chlorophyll can absorb more than 90 percent, is a wave band with strong plant growth and photosynthesis, and can promote the growth of crop roots, reduce growing points and thicken leaves and stems; the crops are strong, and the disease resistance is obviously enhanced; and the new light sources that produce these spectra are LED light sources.

The light source of the LED lamp can be used as a supplementary light source for identifying the crop phytotron for the heat resistance of rice. However, at present, natural light regulation and compensation light regulation both stay on the basis of experience, and no system theoretical calculation exists; the quantitative relation guidance of natural light adjustment and compensation light is lacked, the intelligent energy-saving matching control of the natural light adjustment and the compensation light is difficult to realize, and the difficulty is brought to the accurate control of the temperature and the humidity of a crop artificial climate chamber of crops.

Disclosure of Invention

In order to solve one of the technical problems, the present disclosure provides a light supplement method for a crop phytotron.

According to one aspect of the disclosure, a light supplement method for a crop phytotron is provided, which includes:

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 of the crop artificial climate chamber in unit time is as follows:

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 is the indoor air heat capacity in the crop phytotron, the crop bed plant heat capacity and the root soil heat capacity, the heat absorption is negative, and the heat release is positive.

According to the light supplement method for the crop phytotron, when the crop phytotron is not shielded:

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。

According to the light supplement method for the crop phytotron, when a ceiling shading net is used in the crop phytotron, the method comprises the following steps: q₁Is recorded as Q_1，π，

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

Wherein G is_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 shading the net in the hemispherical spaceFraction in interstitial radiation, 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)。

according to the light supplement method for the crop phytotron, Q is an infrared reflection semitransparent film laid on top glass of the crop phytotron₁Is recorded as Q_1，πpThe degree of light shielding 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):

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)。

according to the light supplement method for the crop phytotron, the crop on the crop bed absorbs the photosynthetic energy Q from the 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:

according to the light supplement method for the crop phytotron, the spectral energy Q of photosynthesis in the compensation light of the 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_dTo compensate the electro-optic conversion efficiency of the lamp;

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 shade net θ is 0, Q1 is Q of formula (4)_1，πCalculation, Q₂Is recorded as Q_2，π，Q_p2Is recorded as Q_p2，πAnd then:

compensating optical power at noon when using infrared reflection shading film

And energy absorbed by the crop

Wherein Q is_out，0100 is taken.

According to the light supplementing method for the crop phytotron, the radiation energy Q reflected by the crop phytotron_ρComprises the following steps:

wherein the content of the first and second substances,

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。

According to the light supplement method for the crop phytotron, disclosed by the embodiment of the disclosure, Q4 in the energy equation is the heat transfer amount of the glass cover to the indoor:

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_outRespectively, indoor and outdoor air temperatures.

According to the light supplement method for the crop phytotron, the heat capacity of the crop phytotron absorbs or releases heat Q_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;

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。

According to the light supplementing method for the crop phytotron, the air conditioner circulates air to supply cold energy or the cold energy +/-Q of the crop phytotron_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; c. C_aIs the specific heat of air; 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.

Drawings

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

Fig. 1 is a schematic flow diagram of a method for supplementing light to a crop phytotron according to an embodiment of the present disclosure.

Fig. 2 is a schematic diagram of a crop phytotron according to an embodiment of the present disclosure.

Fig. 3 is a schematic view of a crop phytotron with a light screen on the top layer according to an embodiment of the present disclosure.

FIG. 4 is a view factor of aligned parallel rectangles according to one embodiment of the present disclosure.

The reference numbers in the figures are in particular:

1 bottom layer

2 surrounding wall

3 Top layer

4 shading net

5 compensating light lamp

6 blower

7 roller

8 heat exchanger

Detailed Description

The present disclosure will be described in further detail with reference to the drawings and embodiments. It is to be understood that the specific embodiments described herein are for purposes of illustration only and are not to be construed as limitations of the present disclosure. It should be further noted that, for the convenience of description, only the portions relevant to the present disclosure are shown in the drawings.

It should be noted that the embodiments and features of the embodiments in the present disclosure may be combined with each other without conflict. Technical solutions of the present disclosure will be described in detail below with reference to the accompanying drawings in conjunction with embodiments.

Unless otherwise indicated, the illustrated exemplary embodiments/examples are to be understood as providing exemplary features of various details of some ways in which the technical concepts of the present disclosure may be practiced. Accordingly, unless otherwise indicated, features of the various 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 shading in the drawings is generally used to clarify the boundaries between adjacent components. As such, unless otherwise noted, the presence or absence of cross-hatching or shading does not convey or indicate any preference or requirement for a particular material, material property, size, proportion, commonality between the illustrated components and/or any other characteristic, attribute, property, etc., of a component. Further, in the drawings, the size and relative sizes of components may be exaggerated for clarity and/or descriptive purposes. While example embodiments may be practiced differently, the specific process sequence may be performed in a different order than that described. For example, two processes described consecutively may be performed substantially simultaneously or in reverse order to that described. In addition, like reference numerals denote like parts.

When an element is referred to as being "on" or "on," "connected to" or "coupled to" another element, it can be directly on, connected or coupled to the other element or intervening elements 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. For purposes of this disclosure, the term "connected" may refer to physically, electrically, etc., and may or may not have intermediate components.

For descriptive purposes, the present disclosure may use spatially relative terms such as "below," in.. below, "" above, "" upper, "" above, "" higher, "and" side (e.g., as in "side walls") to describe one component's relationship to another (other) component as illustrated in the figures. Spatially relative terms are intended to encompass different orientations of the device in use, operation, and/or manufacture in addition to the orientation depicted in the figures. 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". Further, the devices may be otherwise positioned (e.g., rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein 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", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. Furthermore, when the terms "comprises" and/or "comprising" and variations thereof are used in this specification, the presence of stated features, integers, steps, operations, elements, components and/or groups thereof are stated but does not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and/or groups thereof. It is also noted that, as used herein, the terms "substantially," "about," and other similar terms are used as approximate terms and not as degree terms, and as such, are used to interpret inherent deviations in measured values, calculated values, and/or provided values that would be recognized by one of ordinary skill in the art.

Fig. 1 is a schematic flow diagram of a method for supplementing light to a crop phytotron according to an embodiment of the present disclosure.

The method for supplementing light in a crop phytotron as shown in fig. 1 comprises 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 of the crop artificial climate chamber in unit time is as follows:

in the energy equation, the positive sign is energy input, the negative sign is energy consumption, and the unit is W; q₁The energy of the sun input into the artificial climate chamber of the crops comprises direct radiation and heat dissipation solar energy; 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_p2For agricultureThe photosynthesis energy in the sunlight and the compensating light absorbed by the crop bed is converted into glucose or hydrocarbon oxygen organic matters of starch or plant fibers; q_ρIs the radiation energy reflected to the outside by the crop bed, mainly the energy of green light,

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

When the crop phytotron reaches an equilibrium state, the heat required by the temperature fluctuation of the air heat capacity of the crop phytotron is mainly used.

Fig. 2 is a schematic diagram of a crop phytotron according to an embodiment of the present disclosure.

The crop phytotron disclosed by the invention is characterized in that a model is a rectangular glass house, the width of the glass house is 6 +/-0.1 m in the east-west direction, the depth of the glass house is 4 +/-0.1 m in the north-south direction, the height of the glass house is 3m, the bottom layer 1 is a crop bed, the surrounding walls 2 and the top layer 3 are double-layer hollow glass interlayers, and the top layer of a glass slope is north-high and south-low; the system is provided with a refrigeration and heat supply system and an air circulation system, indoor air circulates through a heat exchanger 8 to obtain cold or heat, and the heat exchanger 8 is an evaporator of a refrigerator when a refrigeration working medium is used as refrigeration circulation or a condenser when the refrigeration working medium is used as heat pump circulation; the circulating air duct is additionally provided with a fresh air inlet at the air return inlet, an air outlet is formed in the opposite glass wall of the air return inlet, and brake pad regulating valves are arranged in the fresh air inlet and the air outlet pipeline; a sunshade net 4 with 60 percent of light transmittance pi is arranged above the top layer of the glass house; the sunshade net is rolled up by the roller 7 when not used; the indoor solar energy artificial climate system is provided with an LED compensation light lamp 5, a measuring head for measuring the temperature, the humidity, the outdoor temperature and the air supply and return temperature of an air circulation loop in the artificial climate chamber, an indoor and outdoor solar full-irradiation intensity instrument and a signal collecting, processing and controlling system; the middle part in the artificial climate chamber is provided with a fan 6 for homogenizing air flow.

In this disclosure, byAnalyzing the quality characteristics of the spectral energy, and determining that the spectrum of the crop photosynthesis and the compensation light is the radiation energy except the green light in the visible light, the blue-violet light (380-; the proportion of the solar radiation visible light (380-780nm) in the solar radiation energy is 47.29%, the proportion of the green light (500-560nm) is subtracted

The photosynthetic energy share which can be absorbed by the plant is

In the energy equation, the electrical power consumed to regulate the crop phytotron temperature:

P＝Q₂+Q₃+Q_k/COP (2)

wherein COP is the coefficient of performance of the refrigeration/heating and air cycle energy conditioning system;

the indoor air temperature and humidity in the crop artificial climate chamber are controlled by an air conditioner circulating air system to finish the adjustment of the temperature and humidity of the inlet air sent into the room, and a heat exchanger is arranged in front of an air inlet of a circulating air loop to adjust the temperature of the inlet air; the return air of the circulating air loop is provided with a fresh air regulating port.

A part of radiant energy G is generated before solar radiation penetrates through the glass wall and the glass top to enter the crop phytotron_out，ρIs reflected by the glass and has a part G_out，αAbsorbed by the glass, the rest enters a crop phytotron (glass test room), and the energy of the part is recorded as Q₁。

When the crop phytotron is not sheltered:

Q₁＝G_in，θA₀＝G_out，θτA₀＝(G_bcosθ+G_d)τA₀ (3)

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/m²By being placed indoorsThe lower corner mark in represents indoor, out represents outdoor and theta represents the zenith angle of the solar ray; τ is the average light transmittance of the glass, and the three relations of the light transmittance τ, the reflectance ρ and the absorption α of the glass are τ + ρ + α equal to 1, generally τ equal to 0.85, ρ equal to 0.1, and α equal to 0.05; a. the₀The area of the crop bed in the crop phytotron is m²In this disclosure, 4X 25m²＝100m²；G_bThe intensity of direct solar radiation is measured by a direct solar radiometer; g_dThe scattered solar radiation intensity is the difference obtained by subtracting the measurement value of the direct solar radiometer from the measurement value of the total solar radiometer; g for radiant energy of crop bed irradiated on horizontal plane by direct solar radiation intensity_bcalculating cos theta, wherein theta is an included angle between the incident ray of the sun and the normal line of the horizontal plane and is called a zenith angle; for the horizontal plane, the scattered radiation comes from the illumination of the sky hemisphere; the proportion of the direct solar radiation intensity to the scattered solar radiation intensity is related to the cloud layer gray scale of the sky, and can be obtained by searching from special data such as solar energy utilization and the like or by a measuring method; as an example analysis, take G_b/G_d＝6/4，G_b＝0.6G_out，G_d＝0.4G_out，G_out1.0 kW; theta is 0, and G can be used for the total irradiation intensity of the sun at noon and noon_out，θ＝0＝G_outRepresents; when theta is 0, the intensity G of solar radiation on the horizontal plane_out，0＝G_out＝1.0W/m². Intensity of solar radiation G outside atmosphere₀＝1368W/m²The actual solar radiation intensity is related to the thickness of sunlight passing through the atmosphere and the concentration of water vapor and carbon dioxide contained in the atmosphere, and the solar full-radiation intensity instrument arranged above an indoor crop bed and on a horizontal frame of an outdoor glass roof is used for measuring the indoor crop bed and outdoor solar radiation intensity G_in，θAnd G_out，θ。

Q_1，θ＝0＝G_inA₀＝G_out(a_tcosθ+a_d)τA₀＝1×(0.6+0.4)×0.85×100＝85kW；

Q_{1，θ＝30°}＝G_out(a_tcos 75°+a_d)τA₀＝1×(0.6cos 30°+0.4)×0.85×100＝78.2kW；

Q_{1，θ＝75°}＝G_out(a_tcos 75°+a_d)τA₀＝1×(0.6cos 75°+0.4)×0.85×100＝49.5kW；

That is, at noon, the crop bed receives the greatest amount of solar radiation.

When the crop artificial climate chamber is shielded from light through the ceiling shading net, Q₁Is recorded as Q_1，πThe irradiated solar radiant energy on the crop bed (represented by adding pi in the lower corner mark) comprises direct radiant energy and scattered radiant energy, and the calculation formula is as follows:

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

wherein G is_out，θ，bIs the direct radiant energy of the sun at an angle of incidence theta without shading, pi_bThe direct radiation energy share reduced for the shading net is the product of the area share of the crop bed shaded by the shading net and the shading degree, and the specific parameters are calculated according to the geometric position and the size of the shading net; examples are: the parallel height of the ceiling of the shading net and the crop bed is Z, and the width of the crop bed is x_bThe width of the shading net is x_zReferring to fig. 3, a light ray L is emitted from the left end of the sunshade 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 theta < theta_aThe shading net has the function of reducing direct solar radiation when intercepting direct solar, and theta is more than or equal to theta_aThe direct solar radiation is not influenced by the shading net because of the low solar height; when theta < theta_aThen, as theta is continuously reduced, the height of the sun is increased, the shadow area of the shading net appears on the crop bed, and the light ray L with the zenith angle of theta_aShadow width x produced on crop bed_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；

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)

scattered radiant energy G_d(1-πF₂₁) Of pi F₂₁For the proportion of the shading screen in the radiation of the hemisphere, F₂₁The visual angle coefficient is the radiation fraction from the top surface of the shading net intercepted by the plane of the crop bed;

therefore, according to the difference of the sun height and the zenith angle theta, the formula (5a) or (5b) or (5c) is selected to replace the formula (4), and the solar radiation energy Q entering the crop phytotron under the condition of shading can be calculated_1，π；

When the value of theta is equal to 0,

Q_{1，π，θ＝0}＝[G_b(1-π)+G_d(1-πF₂₁)]τA₀ (4a)

the area of the crop bed is x ═ x_b＝12.5m，y＝8m，Z＝3.5m，x_z＝13.5m，x_a13m, 3.57 x/Z, 2.29 y/Z from fig. 2₁₂When the sun energy input into the glass test room per unit time is 0 at noon after the shading measure is taken, the sun energy input into the glass test room is 0.52, pi is 0.6

Q_{1，θ＝0，π}＝G_inA₀＝[0.6(1-0.6)+0.4(1-0.6×0.52)]×0.85×100＝43.8kW；

When the angle theta is equal to 30 degrees,

when theta is 75 DEG, Q_{1，θ＝75°}84.7kW without blocking.

Q when using an infrared reflective translucent film₁Calculate and record as

When an infrared reflection semitransparent film laid on top glass of a crop phytotron is adopted, the shading degree of visible light is pi_p0.1, the share of solar radiation

The infrared radiation reflecting film has a pi light-shielding degree for spectral radiation with wavelength lambda not less than 780nm_h0.9, the share of solar radiation

The glass around east, west, south and north has no barrier; when the infrared reflection semi-transparent film is used, the direct solar radiation energy and the scattered radiation energy of the formula (4) should be decomposed into two energy of visible light and infrared radiation, and different shading rates pi are respectively used_pAnd pi_hThen equation (4) translates to solar radiation energy entering the crop plant laboratory when using an infrared reflective translucent film:

the calculation formula is shown in visible light and infrared radiation

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

when theta is equal to 0, pi_b，p＝π_p，π_b，h＝π_hTherefore, the formula (7) is modified as (7a) or (7b)

Wherein the room energy of visible light is

The indoor energy of the solar infrared radiation is

Compared with the scheme without shading, the method saves the cold energy of the air conditioner

Wherein visible light is reduced only by

Mainly reduction of far infrared radiation energy, i.e.

Compared with the shading net scheme, the infrared reflection shading film has the following difference in the amount of solar radiation transmitted into a room:

in formula (13), the visible light deviation of 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:

thus, compared to the shading net scheme, the scheme using the infrared reflection shading film:

reducing the power of the compensating light:

ΔQ_π，VL＝0.3924×16.24/0.4729＝13.47kW (15a)

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

ΔP_2，π-ρ＝ΔQ_π，VL/η_d＝13.47/0.85＝15.8kW (16)

increasing far infrared radiation energy:

green radiant energy is increased over shade nets:

the electric power saving of the scheme of the infrared reflection shading film compared with the scheme of the shading net is calculated according to the air conditioner performance coefficient COP being 3.2:

ΔP_2，π-p＝ΔP_2，π-ρ-(ΔQ_π，IR-ΔQ_π，ρ)/COP＝15.8-(10.86-1.66)/3.2＝12.9kW (19)

Q_p1the crop in the crop bed absorbs energy from sunlight, and the symbol alpha_pThe absorption rate of the spectral radiant energy of the photosynthesis of the plant is that the photosynthesis energy absorbed by the crop bed is

Wherein the content of the first and second substances,

is the photosynthetic energy share of sunlight absorbed by plants,

α_pthe absorption rate of the spectral radiant energy of the photosynthesis of the plant, and xi is the efficiency of the photosynthesis for changing the light energy into the chemical energy; because the photosynthesis of the plant is the photon effect and the effective energy which can do work in the radiant energy, the relationship between the occupancy rate xi of the photon effective energy and the wavelength is

In the formula, c₃Is the temperature equation constant of the spectral characteristics, c₃＝λT_λ＝5.33016×10^-3m.K; when the ambient temperature T is taken₀298K, calculated as ξ of blue-violet 0.9787, blueXi of light is 0.976-0.9748, xi of red light is 0.964-0.9625; for plants, the blue-violet light, the blue light and the red light can be received by chlorophyll of the plants, and the light quantum energy of the plants can be used for functions, so that the energy conversion efficiency of the kernel complex for generating glucose at room temperature in photosynthesis can be ensured to be between 0.93 and 0.92; the ideal photosynthesis efficiency, i.e., the highest efficiency, is calculated by the formula (8); the actual photosynthesis efficiency is also high, the blue light photosynthesis efficiency exceeds 90%, and the red light photosynthesis efficiency reaches 75-85%; photosynthetic spectral radiant energy absorption rate alpha of plant_pThe photosynthetic efficiency of the crops is reported to be about 0.3-0.4 in large-area experiments, which are related to factors such as the growth condition of the crops, the size of plants, the light receiving area of green leaves and the like; the spectral energy absorption rate of crops should be statistically summarized by more experimental researches, and the embodiment suggests that alpha is taken_pξ＝0.35；

Q at noon without shading_p1Is recorded as Q_p1，θ＝0

When the shading net is used:

when an infrared-reflective light-shielding film is used,

the principle of spectral energy non-reduction of the illuminated photosynthesis of the crop bed and the principle of matching compensation light and regulation and control of the compensation light are designed, and the principle is specifically that the compensation light is blue light (including blue-violet light) and red light emitted by an LRD lamp; according to the radiation energy share of blue light (including blue-violet light) and red light in sunlight, the blue-violet light

Of blue light

Of bright red light

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

Amount of compensating light Q_p2Amount of compensating light Q absorbed by plant_p2，αPower Q of light supplement lamp₂The calculation of (2):

photosynthetic spectral energy Q generated by the compensating lamp of energy equation (1)₂Energy difference in the visible spectrum bands outside and inside:

η_dis the electro-optic conversion of the compensating lamp, example eta_d＝0.80；

Non-shading and noon compensating light power quantity Q_2，θ＝0Absorbed Q_p2，θ＝0The calculation of (2):

Q_p2＝η_dQ₂αξ＝0.85×6.94×0.35＝2.07 (23a)

shading net shading and compensating light power Q at noon_{2，π，θ＝0}Absorbed Q_{p2，π，θ＝0}The calculation of (2):

when the shading net is adopted, and the power Q of the light supplement lamp is at noon_{2，π，θ＝0}And energy Q absorbed by the crop_{p2，π，θ＝0}Respectively as follows:

Q_{p2，π，θ＝0}＝η_dQ_{2，π，θ＝0}αξ＝0.85×26.1×0.35＝7.77kW (23b)

compensating optical power at noon when using an infrared reflective light-shielding film

The energy of the sun being absorbed by the crop

Q_ρThe radiant energy reflected by the crop phytotron is mainly reflected by green light,

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

When the light is shielded by the light shielding net, the reflection amount of green light when θ is 0 and the light shielding degree pi is 0.6 is denoted as Q_{ρ，θ＝0，π＝0.6}；

When the infrared reflection film is adopted for shading, the shading degree of visible light is pi_p0.1, infrared opacity pi_phThe amount of green light reflected when θ is 0.85 and Q is denoted as Q_{ρ，θ＝0，π＝0.1}，

Q₄For the heat transfer from the glass cover to the room, during the day, Q₄Solar radiation energy Q equal to the absorption of the glass house_out，α＝Q_outα, minus the heat release Q of the glass to the outside_4，outEngineering calculations allow to assume Q_4，out＝Q₄(ii) a The solar radiation energy absorbed by the glass cover is equal to the outdoor solar radiation energy, and the solar radiation energy Q reflected by the glass is deducted_out，ρ＝Q_outRho and solar radiation energy Q entering the room_in，Q_in＝G_out(1-τ-ρ)A₀Therefore, in the daytime, heat is generated due to the absorption of solar radiation, the heat transferred to the crop phytotron is calculated according to an equation,

Q₄＝0.5G_out(1-τ-ρ)A₀＝0.5(G_bcosθ+G_d)αA_o (26)

when the noon θ is equal to 0,

Q₄＝0.5×(0.6+0.4)×0.05×100＝2.5kW (26a)

when theta is 75 deg. in the morning

Q₄＝0.5×1000×(0.6cos 75°+0.4)×0.05×100＝1.39kW (26b)

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_outRespectively, indoor and outdoor air temperatures.

Q_mIs a heat capacity heat absorption item of air temperature fluctuation of a crop phytotron,

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_sQuality of air in the crop phytotron, crop bed straw, crop bed plant root soil, respectively, c_a、c_f、c_sRespectively the specific heat of the air in the crop phytotron, the crop bed straws 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; for example, the soil of the root system has a large thermal capacity, in a 0.4M deep soil layer, a 0.6M high crop layer, a 3M high crop phytotron, a soil mass M₁＝1300kg/m³×0.4m×100m²52000kg, specific heat capacity of hydrous soil c₁3.5 kJ/(kg. K), the heat capacity of the soil is M₁c₁＝182000kJ/K；

Mass M of the crop layer₂＝5kg/m³×0.5×100m³Specific heat capacity of wet crop c 250kg₂＝2.5kJ/(kg·K)，M₂c₂＝625kJ/K；

Mass M of air layer₃＝1.3kg/m³×3×100m³Specific heat capacity c of air 390kg₃＝1.1kJ/(kg·K)，M₃c₃＝429kJ/K

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

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_mBy calculation of simplified form

Q_m＝(M_afc_af)dT_a/dt (29)

Wherein M is_afc_af＝M_ac_a+M_fc_f；

If the room air temperature fluctuates by 1 degree for 5 minutes:

Q_m＝M_fc_fdT_f/dt＝(429+625)×1/1800＝0.41kW (29a)

therefore, when the crop phytotron enters the precise temperature regulation and control, Q_mCan be ignored.

The energy balance of the crop artificial climate chamber is completed by a refrigeration and heat supply system and an air circulation system; the refrigeration and heat supply system adopts an evaporator of a compression type refrigerator to exchange heat with circulating air circulating in the crop artificial climate chamber, provides cold for the crop artificial climate chamber, balances excessive heat of solar radiation entering the crop artificial climate chamber, and keeps the indoor air temperature within an allowable fluctuation range of the design temperature; when the crop phytotron radiates heat to the outside at night and the indoor air temperature tends to fall, the refrigeration working medium reversely circulates, the refrigerator operates as a heat pump, and an evaporator of the refrigerator becomes a condenser to provide heat for circulating air; note, m_aThe mass flow of the circulating air is kg/s; c. C_aIs the specific heat of air; t is t_hThe air temperature of an air return inlet of a circulating air conditioner in a crop artificial climate chamber is set, and the air return inlet is arranged at a position close to the ground of a crop bed in the crop artificial climate chamber; t is t_cThe temperature of cold air (or hot air) of an air supply outlet of the circulating air conditioner is controlled, and the air supply outlet is arranged above the crop artificial climate chamber and close to the top surface; from the energy equation to Q_kThe calculation formula of (A) is as follows:

air conditioner for adjusting cropsCold quantity Q provided by air temperature of artificial climate chamber_kThe calculation formula of (A) is as follows:

±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 circulating in the crop phytotron and the evaporator of the air conditioner is kg/s; c. C_aIs the specific heat of air, t_hThe air temperature of the air return inlet of the circulating air conditioner in the crop artificial climate chamber is controlled, the air return inlet is arranged at the part close to the ground of a crop bed in the crop artificial climate chamber, t_cThe air supply outlet is arranged above the crop artificial climate chamber and close to the top surface;

when t is_h＞t_cCold air supply, when t_h＜t_cSupply hot air when t_h＝t_cNo air is supplied;

no shading exists, and in the midday,

Q_k，θ＝0＝85+6.94+1+2.5-11.7-2.07-6.84+0.41＝75.24kW (30a)

when the shading net is used for shading 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

Summary of the calculated results

	Q1	Qp1	Qp2，α	Q2	Q3	Qρ	Q4	Qm	Qk
										Without 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
										Light shielding film	49.2	-10.7	-3.00	10.1	1.0	-6.04	2.5	0.41	43.47

6H₂O+6CO₂+ (light energy 2870kJ) → C₆H₁₂O₆(180 g) +6O₂ (31a)

E_P+xE(H₂O)+yE(CO₂)＝jE(C_mH_nO_k)+iE(O₂) (32)

Outdoor sunshine energy Q_out，D＝Q_{out，0，day}A₀＝0.60×3600×8×100＝1728000KJ；

Grams of glucose produced per day

In the description herein, reference to the description of the terms "one embodiment/mode," "some embodiments/modes," "example," "specific example," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment/mode or example is included in at least one embodiment/mode or example of the application. In this specification, the schematic representations of the terms used above are not necessarily intended to be 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/modes or examples. Furthermore, the various embodiments/aspects or examples and features of the various embodiments/aspects or examples described in this specification can be combined and combined by one skilled in the art without conflicting therewith.

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

It will be understood by those skilled in the art that the foregoing embodiments are merely for clarity of illustration of the disclosure and are not intended to limit the scope of the disclosure. Other variations or modifications may occur to those skilled in the art, based on the foregoing disclosure, and 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 content of the first and second substances,

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.

Images