Research Of Estimation Model For Temporal And Spatial Distribution Of Environmental Elements In Solar Greenhouse

?Object?The objective of this research was to describe the spatial and temporal variation in the microclimate of solar greenhouses so that horticultural crops can be managed according to the greenhouse environment.It was to provide theoretical basis for the design,construction,environmental regulation and crop management of the solar system.Specifically,the study investigated the effect of fog on solar greenhouses in Beijing and Tianjin.The horticultural crop was cucumber.The meteorological variables included solar radiation,temperature,humidity and ventilation.The spatial and temporal variation in the greenhouse microclimate was analyzed using the principle of energy balance.The research provides a basis for improving vegetable production in solar greenhouses.This paper was based on the solar greenhouse was suffered from poor sunshine study of disaster prevention and reduction of disaster warning,for future solar greenhouse indoor crop management services.It was to provide the theoretical basis for solar greenhouse cultivation completed the prevention work in the future.?Methods?This "Beijing" research mini 2 of cucumber varieties was as experimental material.The test decorated of Davis Vantage Pro&Plus weather stations in sunlight greenhouse,measuring outside the greenhouse air temperature,air humidity,soil temperature and soil moisture.The second generation solar greenhouse was a representative of greenhouse in Beijing.The research deployed micro climate monitoring sensors.The span(Y)was 7.01 m;length(X)was 50.01 m.The vertical axis was Y = 1.568 m,Y = 3.578 m and Y = 5.350 m,the horizontal axis was X =5.070 m,X = 19.793 m and X = 45.533 m,respectively.The different height was Z =0.51 m,Z = 1.01 m and Z = 1.51 m.The experiment was seted up 27 points,including temperature,humidity and radiation measurement.There were many instruments.For example,sensor of UX100-003(Onset Computer Corp,USA),infrared temperature Instrument of SI-111(American Apogee Instrument Corp),net radiation measuring instrument FNP–2,Skyworth to science and technology development co.,LTD.(Beijing,China)and solar total radiation sensor S-LIB(Onset Computer Corp,USA).They detected air temperature,air humidity,value of solar total radiation,value of net radiation and leaf temperature inside the greenhouse.There was a sensor UX100-003 in central place of greenhouse.It measured inside and outside surface temperature of the back wall and transparent cover material.There was a thermocouple TC6-K(Netherlands Hukseflux Thermal Sensors Corp),measuring soil temperature and humidity of the underground soil 2.01 cm.The data was recorded intervals for 5 min,unloading 1 times a week.?Results?1)This article major considered these,including the variation rule of different time,different temporal distribution of the direct radiation,scatter radiation,transparent cover material of haze and cloud cover.They effected on direct radiation and scattering problems.And we researched a simple optical radiation calculation model of the sunlight greenhouse.The solar radiation of solar greenhouse was lower in sunny day and poor sunshine.The solar radiation of solar greenhouse was in175W·m-2·s-1to 255W·m-2·s-1in poor sunshine of winter.Between the simulated values and measured values,the correlation coefficient of sunny day(R2=0.9717,RMSE=2.0849,RE=0.0023,AE=0.1036)was higher than that in the situation of poor sunshine(R2=0.9945,RMSE=2.5766,RE=0.0010,AE=0.0935).The solar radiation of solar greenhouse on the horizontal gradient type was "M" and was higher than the south from the north to the south to the north.2)The research was used the principle of energy balance,constructed the greenhouse temperature model.The temperature(December 25 thand 26th)of the measured and simulated values was consistent in poor sunshine.But when it was from(December 27th)the third day 3:00,temperature measured value was lower than the simulated values.Temperature was lower than temperature of cucumber the normal growth.According to temperature horizontal distribution of solar greenhouse in poor sunshine(January 16th),different canopy height temperature distribution variation was less than 1?.Temperature of the highest position for the canopy was in central of sunlight greenhouse,south and north temperature was low.The distribution of temperature of vertical direction in sunlight greenhouse,temperature of the upper canopy and central was higher in poor sunshine.Temperature difference of the top(about 20 m from east frontispiece)was about 2?.The lowest canopy temperature was below of greenhouse.3)The research was used the dynamic balance humidity,constructed the greenhouse humidity model.The humidity of the cucumber greenhouse under the spatial distribution was different.According to humidity horizontal distribution of solar greenhouse on poor sunshine(January 16th),eastern canopy height humidity distribution variation was less than 10%.Air relative humidity of the canopy bottom was generally low.It has a high humidity area in canopy the middle and lower,at 86%.According to humidity vertical distribution of solar greenhouse on poor sunshine,location canopy the highest humidity was north and south of greenhouse,at 80%.The below canopy humidity was higher than central and upper of greenhouse,humidity vertical distribution was 20%.4)Building diurnal ventilated temporal estimation model about cucumber indoor solar greenhouse in the winter.Using the December 2015 to February 2016 of the outsidethe solar greenhouse near the ground solar radiation,moisture content and moisture content as driving factor in solar greenhouse.We prevented of indoor temperature was too low because of ventilation in the winter.When the humidity outdoor was 15 degrees below 0 to 15 degrees,winter maximum ventilation rate should be less than0.01m2·m-3·s-1.The best ventilation rate should be under 1 times per minute([agriculture standard]-NYT 1451-2007 solar greenhouse ventilation design specification).It could determine the ventilation time.Ventilation rate of the data of solar greenhouse was at the February 8th,14 th and 15 th,2016.(Ventilation rate is greater than 0.03).Ventilation time was 48.12 seconds at 8th,ventilation time was60.35 seconds at 14 th and ventilation time was 1.75 minutes at 15 th in poor sunshine.?Conclusion?This paper was based on the solar greenhouse was suffer from poor sunshine study of disaster prevention and reduction of disaster warning,for solar greenhouse cultivation completed the prevention work in the future.And did corresponding prepare before the arrival of the outside world meteorological disaster,made it crops of solar greenhouse did not affect very small or not.The principle of energy balance was used to simulate the distribution in different height of the solar radiation,temperature and humidity of solar greenhouse.The study could accurately intuitive understood distribution inside the solar greenhouse environment,and the necessary ventilation rate model could predict ventilation time of solar greenhouse.And it could prevent the happening of the high humidity of solar greenhouse in temporal.