Experimental study on temperature increasing in solar greenhouse with underground pebble bed thermal storage.

A demonstrative solar greenhouse with underground pebble bed thermal storage was established and compared with a control case greenhouse.The experimental result shows that the thermal storage power of pebble bed system is more than that of buried pipe system with the former 94 W/m2 and the latter 76 W/m2.The lowest night temperature of the solar greenhouse with thermal storage is 5～8 ℃,which is higher than that of the greenhouse without thermal storage,and the diurnal amplitude in the solar greenhouse is decreased.The solar greenhouse facilitates the thermophilic crops to live through the winter.