🌱 Ukulawula isimo sezulu sendlu yengilazi Imodeli ephilayo

Isisekelo — imodeli engemuva kwezinombolo

Wonke ubudlelwano isilingisi esibusebenzisayo, nomthombo wabo. Izinto ezihlala zingashintshi ezimakwe njengokuthathelwa yizilinganiso zesibonelo.

Izinga lokushisa lomoya lilandela ibhalansi yamandla: ilanga lingena, ukushisa kuphuma ngesembozo nangomoya wokungenisa, ukushisa okusetshenziselwa ukuhwamuka kwamanzi, kanye nokufudumeza.

C·dT/dt = τ·I·(1 − 0.6·0.75·screen) − λ·(E_crop + E_fog) + Q_heat + (U·Ac/Af + ρc_p·Q_v)·(T_out − T) + G_soil·(T_soil − T)[1]Umcabango: usayizi wendlu yengilazi, umthamo wokushisa, amafasitela ophahleni, isikrini, inkungu nama-coefficient ezitshalo ayizinani zokufanekisa zendlu yengilazi yesimanje; i-physics ithatha umoya njengevolumu eyodwa exubene kahle. Izindawo zangempela zilinganisa njalo uhlobo ngalunye lwezinto ezingashintshi.

Ukulahlekelwa ukushisa ngesembozo kungu-U × indawo × umehluko wokushisa; isikrini esivaliwe sehlisa u-U, isibhakabhaka esicacile ebusuku siwukhuphula.

U = 6.2 − (6.2 − 4.0)·screen W/m²K (single glass → with thermal blanket); ×(1 + 0.25·clear sky) at night[1]Umcabango: usayizi wendlu yengilazi, umthamo wokushisa, amafasitela ophahleni, isikrini, inkungu nama-coefficient ezitshalo ayizinani zokufanekisa zendlu yengilazi yesimanje; i-physics ithatha umoya njengevolumu eyodwa exubene kahle. Izindawo zangempela zilinganisa njalo uhlobo ngalunye lwezinto ezingashintshi.

Ukungenisa umoya kungukuvuza kanye nokugeleza okuqhutshwa umoya ngamafasitela avuliwe.

Q_v = (N·H/3600 + vent·C_w·max(1, u_wind))·(1 − 0.4·screen), N = 0.75 h⁻¹[1][4]Umcabango: usayizi wendlu yengilazi, umthamo wokushisa, amafasitela ophahleni, isikrini, inkungu nama-coefficient ezitshalo ayizinani zokufanekisa zendlu yengilazi yesimanje; i-physics ithatha umoya njengevolumu eyodwa exubene kahle. Izindawo zangempela zilinganisa njalo uhlobo ngalunye lwezinto ezingashintshi.

Ingcindezi yomhwamuko ogcwele ikhuphuka kakhulu ngezinga lokushisa; i-VPD ukuthi umoya ukude kangakanani nokugcwala.

e_s(T) = 0.6108·exp(17.27·T / (T + 237.3)) kPa; VPD = e_s(T) − e_a; RH = e_a / e_s(T)[2]

Ibhalansi yomhwamuko wamanzi: i-transpiration nenkungu kwengeza umswakama, ukungenisa umoya nokufingqa engilazini ebandayo kuwususa.

H·dχ/dt = E_crop + E_fog − Q_v·(χ − χ_out) − k_c·(Ac/Af)·(1 − 0.7·screen)·max(0, e_a − e_s(T_cover)), χ = e·M_w/(R·T)[6][2]Umcabango: usayizi wendlu yengilazi, umthamo wokushisa, amafasitela ophahleni, isikrini, inkungu nama-coefficient ezitshalo ayizinani zokufanekisa zendlu yengilazi yesimanje; i-physics ithatha umoya njengevolumu eyodwa exubene kahle. Izindawo zangempela zilinganisa njalo uhlobo ngalunye lwezinto ezingashintshi.

I-transpiration inengxenye evela emisebeni nengxenye eqhutshwa umoya owomile (i-VPD).

E_crop = A·(1 − e^(−k·LAI))·I_in/λ + B·LAI·VPD (A 0.45, k 0.64, LAI 3, B 0.02 kg/m²·h·kPa by day)[3]Umcabango: usayizi wendlu yengilazi, umthamo wokushisa, amafasitela ophahleni, isikrini, inkungu nama-coefficient ezitshalo ayizinani zokufanekisa zendlu yengilazi yesimanje; i-physics ithatha umoya njengevolumu eyodwa exubene kahle. Izindawo zangempela zilinganisa njalo uhlobo ngalunye lwezinto ezingashintshi.

Inkungu ipholisa kuphela kuze kube lapho ihwamuka: cishe i-2.45 MJ ngelitha, okuningi emoyeni owomile kunasemoyeni onomswakama.

E_fog = fog·0.4 kg/m²·h × min(1, VPD/0.8); each evaporated kg removes λ = 2.45 MJ of sensible heat; the rest wets leaves[1][2]Umcabango: usayizi wendlu yengilazi, umthamo wokushisa, amafasitela ophahleni, isikrini, inkungu nama-coefficient ezitshalo ayizinani zokufanekisa zendlu yengilazi yesimanje; i-physics ithatha umoya njengevolumu eyodwa exubene kahle. Izindawo zangempela zilinganisa njalo uhlobo ngalunye lwezinto ezingashintshi.

Ibhalansi ye-CO₂: ukufakwa kungena, ukungenisa umoya nokumunywa isitshalo kuphuma.

H·dC/dt = dose − Q_v·(C − C_out) − P_net; dosing ≈ 5.5 g/m²·h holds ≈ 1000 ppm at 1 air change per hour[1]

I-photosynthesis iphendula ekukhanyeni, ku-CO₂, ezingeni lokushisa nakwi-VPD; impendulo ye-CO₂ ilandela umthetho ophumelelayo okushicilelwe wezitshalo zezithelo zendlu yengilazi.

P = P_ref·(1 − e^(−I_in/300))·exp(150/400 − 150/C)·f(T: 1 at 17–27 °C)·f(VPD) (from the CO₂ rule dP/P = 1.5 %·(1000/C)² per 100 ppm)[5][7]Umcabango: usayizi wendlu yengilazi, umthamo wokushisa, amafasitela ophahleni, isikrini, inkungu nama-coefficient ezitshalo ayizinani zokufanekisa zendlu yengilazi yesimanje; i-physics ithatha umoya njengevolumu eyodwa exubene kahle. Izindawo zangempela zilinganisa njalo uhlobo ngalunye lwezinto ezingashintshi.

Izibali zokucindezeleka kwesitshalo: amahora ashisa kakhulu, abanda kakhulu, noma anomswakama owanele isikhunta esimpunga.

heat hours: T > 35 °C · cold hours: T < 10 °C · disease-risk hours: RH ≥ 90 % or wet leaves · GDD = Σ max(0, T − 10)·Δt[1][7][8][10]

Isimo sezulu sangaphandle: ijika lezinga lokushisa langaphandle losuku, indawo yamazolo engashintshi, ilanga elinciphiswe amafu, amafu nomoya okuguquguqukayo ngokungahleliwe.

T_out = T̄ + A·cos(2π(h − 15)/24); e_out = e_s(T_dew); I = I_clear·(1 − 0.75·N^3.4); cloud N and wind fluctuate (normal, seeded)[9][2]Umcabango: usayizi wendlu yengilazi, umthamo wokushisa, amafasitela ophahleni, isikrini, inkungu nama-coefficient ezitshalo ayizinani zokufanekisa zendlu yengilazi yesimanje; i-physics ithatha umoya njengevolumu eyodwa exubene kahle. Izindawo zangempela zilinganisa njalo uhlobo ngalunye lwezinto ezingashintshi.

Ezinye izinto ezingashintshi ezisetshenziswa imodeli.

height 4.5 m · cover/floor 1.2 · τ 0.8 · heat capacity 30 kJ/m²K · heating ≤ 180 W/m² · screen blocks 60 % of light (75 % of that as heat) and 40 % of air exchange, and hides 70 % of the cold glass (condensation) · vents 0.016 m³/s·m² per m/s wind · soil 2 W/m²K · fog ≤ 0.4 L/m²·h · CO₂ ≤ 8 g/m²·h · P_ref 4 g CO₂/m²·h · condensation 1.9·10⁻⁸ kg/m²·s·PaUmcabango: usayizi wendlu yengilazi, umthamo wokushisa, amafasitela ophahleni, isikrini, inkungu nama-coefficient ezitshalo ayizinani zokufanekisa zendlu yengilazi yesimanje; i-physics ithatha umoya njengevolumu eyodwa exubene kahle. Izindawo zangempela zilinganisa njalo uhlobo ngalunye lwezinto ezingashintshi.

Ukungahleliwe: i-generator ye-mulberry32 enembewu; ukusabalalisa okusetshenzisiwe — uniform, exponential (inverse CDF), normal (Box–Muller), Poisson (Knuth). Imbewu iyabonisa futhi ingabelwana.

Imithombo

1. ANSI/ASAE EP406.4 JAN2003 (R2008) — Heating, Ventilating and Cooling Greenhouses (eq. 1–4, Table 1 U-values, Table 2 infiltration: new glass or fiberglass 0.50–1.0 h⁻¹, §5.8.5 CO₂ injection, §7.1.3 temperature limits); since withdrawn, available from ASABE as a historical document — American Society of Agricultural and Biological Engineers, 2003
2. R. G. Allen, L. S. Pereira, D. Raes, M. Smith — Crop evapotranspiration, FAO Irrigation and Drainage Paper 56 (eq. 11 saturation vapour pressure, eq. 14 dew point, λ = 2.45 MJ/kg) — FAO, Rome, 1998
3. M. Baille, A. Baille, J. C. Laury — A simplified model for predicting evapotranspiration rate of nine ornamental species vs. climate factors and leaf area — Scientia Horticulturae 59:217–232, 1994
4. T. Boulard, A. Baille — Modelling of air exchange rate in a greenhouse equipped with continuous roof vents — Journal of Agricultural Engineering Research 61(1):37–48, 1995
5. E. M. Nederhoff — Effects of CO₂ concentration on photosynthesis, transpiration and production of greenhouse fruit vegetable crops (PhD thesis; CO₂ rule) — Wageningen Agricultural University, 1994
6. B. H. E. Vanthoor, C. Stanghellini, E. J. van Henten, P. H. B. de Visser — A methodology for model-based greenhouse design: Part 1, a greenhouse climate model for a broad range of designs and climates — Biosystems Engineering 110:363–377, 2011
7. R. R. Shamshiri et al. — Review of optimum temperature, humidity, and vapour pressure deficit for microclimate evaluation and control in greenhouse cultivation of tomato: a review — International Agrophysics 32:287–302, 2018
8. Identifying and Managing Three Major Disease Threats in Greenhouse Tomatoes: Leaf Mold, Gray Mold, and Bacterial Wilt (SPES-820) — Virginia Cooperative Extension
9. F. Kasten, G. Czeplak — Solar and terrestrial radiation dependent on the amount and type of cloud — Solar Energy 24:177–189, 1980
10. G. S. McMaster, W. W. Wilhelm — Growing degree-days: one equation, two interpretations — Agricultural and Forest Meteorology 87:291–300, 1997