Effects of orientation and structure on solar radiation interception in Chinese solar greenhouse

Abstract

In order to further improve the utilization of solar energy in Chinese Solar Greenhouse (CSG), this paper systematically studied the effects of orientation and structure on solar radiation interception in CSG. A solar radiation model has been developed based on the previous research, which taking solar motion law, meteorological data, and optical properties of materials into consideration. The established model was used to optimize the orientation and structure of CSG. The analysis of structure considered two major structural parameters, which are the ridge height and the horizontal projection of the rear roof. Moreover, the widely used Liao-Shen type Chinese solar greenhouse (CSG-LS) has been taken as the prototype in the present research, and the measured data of the typical clear day was used for the model validation. The results showed that the ridge height has a remarkable influence on the solar energy captured by CSG-LS. Compared with the optimization of a single factor, the comprehensive optimization of orientation and structure can increase the solar radiation interception of the rear wall by 3.95%. Considering the limiting factor of heat storage-release capacity and the shading effect on the greenhouse structure, the optimal lighting construction of the CSG-LS (with a span of 9.0 m) was specified as 7~9° from south to west of azimuth angle, 4.5~4.7 m ridge height, and 1.4~1.6 m horizontal projection of the rear roof at 42°N latitude. The proposed solar radiation model can provide scientific guidance for the CSG-LS construction in different areas.

Determination of the Optimal Orientation of Chinese Solar Greenhouses Using 3D Light Environment Simulations

“…Previous studies on the optical properties of the lighting roof have achieved remarkable outcomes and recommended that the diffuse light plastic films can improve the homogeneity of the canopy light distribution and increase crop production [14,36]. However, only a few studies have investigated the effect of greenhouse orientation on light interception [16]. To determine the influence of greenhouse orientation on solar radiation interception by lighting roof, the widely used CSG of the Liao-Shen type was used.…”

“…Previous studies on light optimization of CSG have mainly focused on greenhouse structures [11][12][13] and optical properties of plastic films [14,15], while the orientation of the CSGs has not been considered. Due to the lack of theoretical information for greenhouse construction, the orientation of the CSGs is usually determined by either experience or simply following the local topography [16].…”

Fabrication and performance evaluation of vertical farming structures

“…This is due to the direction of solar radiation. Xu et al (2020) stated that the careful orientation of structure could increase the interception of solar radiation on the rear side by 3.95 %.…”

Sensitivity of solar greenhouse envelopes to the thermal disfigurements and optimal selection of the thermal insulation quilt

“…In Equation (12), the ratio of thickness of PO film or thermal insulation quilt to its thermal conductivity is thermal resistance R, which is merely depended on the properties of themselves. The…”

“…The above research provides a certain technical reference for the selection of thermal insulation quilt in solar greenhouse. However, the proportion of the front roof area of the solar greenhouse varied with the structure of greenhouse [12] , which will lead to heat loss through the front roof was different. Moreover, crop demand determines the lowest indoor temperature which can guarantee the growth of the crop.…”