Temperature variations inside Chinese solar greenhouses with external climatic conditions and enclosure materials

Abstract

Chinese solar greenhouses enable the extension of the crop growing season in the cold climate in Northern China with little or no additional heating. The temporal variations of the air temperatures inside solar greenhouses located at three cities in North, Northeast and Northwest China were predicted by CFD simulations of the greenhouse systems using typical meteorological data. The predicted temperatures based on the meteorological data in Shenyang are quite similar to the measured temperatures. The results also show that the external air temperatures and solar radiation fluxes play more important roles for the inside temperatures as indicated by the highest inner temperature in the morning on Feb. 18 and from 10:00 to 14:00 on Feb. 19 in Beijing and by the predicted temperatures inside the greenhouse being higher in Lanzhou than those in Shenyang and Beijing during most of the day. The average daily temperature inside the greenhouse in Lanzhou was nearly 3.5