Optimal design for solar greenhouses based on canopy height

Abstract

The front roof of the solar greenhouse captures more solar radiation energy, the height of the rear wall exposed to direct sunlight is high and the last row of crop canopy receives direct sunlight throughout the day is the basis for the efficient use of solar thermal resources in solar greenhouses, however, previous studies generally focused on the optimization of individual structural parameters of greenhouses, never considering the greenhouse structure-crop cultivation correlation. Therefore, a model for optimal the design of the structural dimensions of the solar greenhouse based on the canopy height was established, comparing the calculated values with the actual structural dimensions of greenhouse and analyzing their structural stability in Abaqus software. The results showed that: The calculated values of the model and the actual construction parameters are in good agreement and meet the structural stability requirements; Taking the 12 m span of the solar greenhouse in Xi'an area as an example, the difference in solar radiation capture on the winter solstice for greenhouse front roofs of different structures under three canopy height conditions were small, 195.95, 194.76 and 192.44 MJ/m, respectively. Taking the 8 m span solar greenhouse in Harbin area as an example, when the canopy height is reduced from 2.0 m to 0.8 m, the corresponding total cost of solar greenhouse construction can be reduced by 5.24%, of which the wall and skeleton costs are reduced by 12.54% and 5.08%, respectively. This study can provide a reference for the optimization of structural dimensions of the solar greenhouse.