Simplified Numerical Modeling of Energy Distribution in a Chinese Solar Greenhouse

Abstract

Abstract.Solar greenhouses are widely used in northeast China to grow vegetables in winter. The energy consumption and distribution were determined in field experiments using a solar greenhouse in northeast China by monitoring the environmental factors inside and outside. Each surface inside greenhouse irradiated with incoming solar radiation was calculated. The greenhouse temperature including the front roof, north roof, north wall, canopy, and soil was calculated based on daily meteorological variables forecast by simulation modeling of each part and comparing with the results obtained using individual meteorological data under greenhouse conditions. Chinese greenhouse day and night energy consumption was calculated and compared. During the coldest days, the conduction energy reached 45% by day and 54% at night. The front roof accounted for the conduction energy loss (day: 54%, night: 68%). When the indoor temperature of the greenhouse was maintained above 15°C, the best time for greenhouse heating was around 5 a.m. and total coal consumption in three months was approximately 5.1 t. Results show that this numerical model simulated the various paths of greenhouse energy flow and heating processes. We estimated the specific daily coal consumption to define a comprehensive heating strategy. Keywords: Chinese greenhouse, Energy balance, Energy calculation model, Energy consumption analysis.