Study Of Light And Temperature Environment Performance In Different Type Of Structure Solar Greenhouses

For the current production in solar greenhouse various structure and materials, the construction of standardized low degree, sunken thick walls greenhouse insulation effect is well, but the large area, land utilization is low, horizon solar greenhouse construction costs higher the actual situation most greenhouse poor insulation.This paper selected Shandong Province recent years appears bidirectional greenhouse, different retaining structure solar greenhouse as the research object, light and temperature environmental performance of a comparative study in order to optimize the structure of the solar greenhouse and provide evidence.The main results are as follows:1. Select the same span ratio of bidirectional and unidirectional greenhouse, December to January observations suggest that:(1) Bidirectional solar greenhouse(south side) of the insulation performance is better than unidirectional solar greenhouse: sunken bidirectional solar greenhouse(south side) mild daytime temperatures average night were higher than unidirectional in solar greenhouse0.9 ℃ and 1.8℃, altazimuth bidirectional solar greenhouse(south side) the average daytime temperatures are mild night 0.4℃ and 1.7℃ higher than the unidirectional solar greenhouse;sunny bidirectional solar greenhouse(south side) of the maximum temperature in 12:30~13:00, appears cloudy around 13:30; regardless of sunny and cloudy day, two-way solar greenhouse(south side) are the lowest temperature occurs in the morning before the insulation was opened; Sunny morning south and north after the gas by installing a ventilation fan in horizon greenhouse exchange can improve the north side of the wall temperature, the highest increase of up to 6℃.(2) Unidirectional bidirectional solar greenhouse solar greenhouse space and temperature distribution are uneven, sunny daytime maximum temperature in the horizontal direction to the highest central, northern, followed by the southern lowest, temperature 0.2~ 1.3 ℃, the vertical direction of crop canopy(1.5m) higher than the surface layer temperature,temperature 1.0 ~ 2.0 ℃; minimum temperature at night in the horizontal direction to the highest northern, the central and southern minimum, temperature 0.1~0.6 ℃, the vertical direction in the crop canopy near the ground storey layer(1.5m), the temperature difference between 0.3~0.7℃. Cloudy daytime maximum temperature in the horizontal direction to the highest central, southern, followed by the northern part of the minimum, temperature0.2~0.9 ℃, the vertical direction of crop canopy(1.5m) higher than the temperature of thesurface layer, temperature 0.1~1.7℃; minimum night temperature in the horizontal direction to the northern part of the highest, followed by central and southern minimum, temperature0.2~1.2 ℃, the vertical direction near the ground storey to the crop canopy(1.5m), the temperature difference between 0.1~1.5℃.(3) The order within the crop canopy height in solar greenhouse light intensity in the order of the southern> central> northern horizon compared to bidirectional solar greenhouse,the space under the sunken solar greenhouse light intensity distribution is more uneven.2. Select the same structural parameters of the different retaining structure greenhouse,February observations showed that:(1) The following formula thick insulation properties of walls dug optimal solar greenhouse, solar greenhouse long span shed, followed by polystyrene board heterogeneous composite wall in greenhouse worst. Sunken thick walls greenhouse average night temperatures were higher than mild daytime large span shed sunlight greenhouse 2.8℃ and1.4℃, higher than the polystyrene board heterogeneous composite wall in greenhouse 4.2℃and 2.0℃. Different structural solar greenhouse sunny indoor maximum temperature occurred at about 12:30, cloudy occurred at about 13:00; sunny and cloudy indoor temperatures are the lowest in the morning appeared before insulation was opened.(2) Different retaining structure sunlight greenhouse uneven spatial distribution of temperature, sunny daytime maximum temperature in the horizontal direction to the highest central, southern, followed by the northern part of the minimum, temperature 0.4 ~1.6℃, crop canopy height in the vertical direction(1.5m) above the surface layer, temperature1.0~2.0 ℃; minimum temperature at night in the horizontal direction to the northern part of the highest, followed by central and southern minimum, a difference of 0.1~1.0℃, the vertical direction near the ground storey to the crop canopy(1.5 m), a difference of 0.5~1.0℃; cloudy daytime maximum temperature in the horizontal direction to the highest central, southern,followed by the northern part of the minimum, temperature 0.2~1.2℃, the vertical direction of crop canopy(1.5m) above the ground near layer, temperature 1.0~2.0 ℃; minimum temperature at night in the horizontal direction to the highest northern, the central and southern minimum, temperature 0.1~ 0.7℃, the vertical direction near the ground storey to the crop canopy(1.5m), the temperature difference 0.5~ 0.6℃; dig formula thick walls space Solar greenhouse temperature uniformity better than heterogeneous composite wall and polystyrene board Long span Shed sunlight greenhouse.(3) Lighting performance of different retaining structure of a large span sunlight greenhouse shed solar greenhouse(parabolic) optimum, heterogeneous composite wall polystyrene board sunlight greenhouse(parabolic), followed by sunken thick walls sunlight greenhouse(streamlined) the worst; the light intensity in different parts of the crop canopy height from strong to weak southern, central, northern, wherein the polystyrene board heterogeneous composite wall solar greenhouse sunlight greenhouse sunken thick walls and large-span than the shed space solar greenhouse light intensity distribution is more uniform.