Primary Report of the Experimental Research on Cooling Measures in Solar Greenhouse During Summer

In view of the need of cooling in solar greenhouse during summer, the contrast experiments of four kinds of cooling measures of natural ventilation, sun-shading net under natural ventilation, micro-spray irrigation cooling system under natural ventilation, and joint use of sun-shading net and micro-spray irrigation cooling system under natural ventilation were carried out respectively. The effects of the four kinds of cooling measures on air temperature, relative humidity, soil temperature at 10 cm in depth in greenhouse were measured and discussed. The results show that air temperature decreased 2.2℃ at most and 1.6℃ on an average, soil temperature at 10 cm in depth decreased 3.8℃ on an average of daytime and decreased 4.5℃ at most in greenhouse under the sun-shading net and natural ventilation condition. The air temperature decreased 3.2℃ at most and decreased 2.4℃ on an average, soil temperature at 10 cm in depth decreased 2.0℃ at most and decreased 0.9℃ on an average in greenhouse with the micro-spray irrigation cooling system and natural ventilation condition. The air temperature decreased 5.4℃ at most and 4.4℃ on an average in greenhouse with the joint use of sun-shading net and micro-spray irrigation cooling temperature system under natural ventilation condition. The air temperature inside the greenhouse was 1.9℃ higher at most, but only 0.7℃ higher on an average than that outside the greenhouse, approaching the air temperature outside greenhouse basically. The air temperature inside the greenhouse under natural ventilation condition was 7.2℃ higher at most and 5.1℃ higher on an average than that outside the greenhouse. It is clear that the cooling measure of the joint use of sun-shading net and micro-spray irrigation cooling system under natural ventilation cooling temperature is the optimum.