Experimental Study On The Solar-assisted Heating System In Ecological Greenhouse Under Different Heat Dissipation Modes

The temperature control of the solar greenhouse is very important in production,and plays a key role in the safe wintering of crops in the greenhouse and annual production.In order to study the effect of the solar greenhouse auxiliary heating system on greenhouse air temperature and ground temperature under different heat dissipation methods,in this thesis the warming effect of greenhouse temperature and ground temperature was analyzed through the comparative test with the wall heat dissipation method,the ground heat dissipation method,the wall and ground heat dissipation method respectively.The result shows:(1)Compared with the control area,with the wall heat dissipation method,the average daily temperature in the test area is increased by 3.5? under sunny conditions,and the average daily ground temperature is increased by 1.2,0.9,0.5 ? at 10,30,and 50 cm underground.With the ground cooling method,the average daily temperature increases by 0.9? and the average daily ground temperature at 10,30,and 50 cm underground increases by 2.4,3.2,and 2.8?.The average daily temperature increases by 2? with the wall and ground heat dissipation method,and the average daily ground temperature at 10,30,and 50 cm underground increases by 2,2.6,1.8?.(2)Under cloudy and snowy conditions,compared with the control area,with the wall heat dissipation method the average daily temperature in the test area is increased by 1.6?,and the average daily ground temperature at 10,30,and 50 cm underground is increased by 0.6,0.4,and 0.3 ?.The average daily temperature increases by 0.5 ? under the ground heat dissipation method,and the average daily ground temperature increases by 1.7,2.3,and 1.8 ? at 10,30,and 50 cm underground.The average daily temperature increases by 1.1 ? with the wall and ground heat dissipation method,and at 10,30,and 50 cm underground the average daily ground temperature increased by 1.2,1.6,1.3?.(3)Compared with the heating effect of the solar-assisted heating system on the greenhouse under sunny conditions and cloudy(or snowy)conditions,the average daily temperature with the wall heat dissipation method is increased by 1.9 ?,and the average daily ground temperature at 10,30,50 cm underground is increased by 0.6,0.5,and 0.2 ?.The average daily temperature is increased by 0.4 ? with the ground heat dissipation method,and the average daily ground temperature is increased by 0.7,0.9,and 1? at 10,30,and 50 cm underground.With the wall and ground heat dissipation method the average daily temperature will increase by more than 0.9 ?,and the average daily ground temperature at 10,30,and 50 cm underground will increase by 0.8,1.6,and 0.5 ?.It can be concluded from the above conclusions that the wall cooling mode has obvious advantages in the heating effect of greenhouse temperature,and the ground cooling mode has the best heating effect on greenhouse ground temperature,the solar-assisted heating system's heating effect on the greenhouse is significantly affected by external weather conditions.