| The solar greenhouse has the dominant position in the facility agriculture in our country, and the research on the sunlight greenhouse will promote the development of the facility agriculture in our country. According to the analysis of the heat in the solar greenhouse, of this study focused on the large thick wall in solar greenhouse wall, ground and roof temperature change were analyzed, changes under different weather conditions in the experiment, diurnal variation of different structural temperature in greenhouse, and winter temperature variation were detailed analysis, and the simulation of the mathematical model of the wall, the ground temperature change, more scientific calculation at different levels of a wall or ground temperature, through the law of temperature change, to understand the transformation relationship between the internal heat of the sunlight greenhouse and each part of the greenhouse heat preservation effect, and analysis of greenhouse energy loss and the heat distribution. Finally, the temperature change of different greenhouse is compared and analyzed. Specific conclusions are as follows:1. The temperature change of the wall in the greenhouse is the biggest. The temperature of the wall was gradually decreased and the minimum temperature increased gradually, and the average temperature of the soil was gradually increased. The temperature of the wall in the deeper layers of the wall temperature reaches the maximum time of the wall temperature of the upper wall is always lagging behind. Thick wall sunlight greenhouse mainly from the 5-30cm deep wall to play the role of insulation. The temperature of the wall was affected by the intensity of the light, and the temperature of the 0-30cm was influenced by the temperature of the 30cm.2. The temperature change of the surface of the greenhouse is the largest. The maximum temperature decreases gradually, and the lowest temperature increases gradually, and tends to the average temperature of the soil layer. The deeper the surface temperature of the ground temperature reaches the maximum of the time than the upper layer of the ground temperature reaches the extreme time always has the hysteresis. The greenhouse is mainly composed of the 5-30cm deep ground, and the main heat preservation effect is obvious.. The change of surface temperature is mainly influenced by the intensity of light.3. The temperature of the inner surface of the 5cm in the greenhouse is the largest and the roof is outside, the temperature is close to the outdoor temperature. The roof is somewhat isolated from the effect of temperature and heat conduction outside the house. The change of roof temperature is mainly influenced by the intensity of light. The temperature of the inner roof is always higher than the outdoor temperature, and there is a function of cooling for the greenhouse in 1. The greenhouse needs to strengthen the treatment of the roof, improve the roof of the greenhouse heat preservation performance.4. The value of wall, ground and air three heat change with the formula said:wall heat change △Q1=C1m1△t1, and heat changes in the ground△Q2=C2m2△t2. m=p·V, along with the change of wall thickness or the depth of the ground surface, AT and V is a function of variables. The distribution of △Q2:△Q1, that wall, ground heat ratio. The heat dissipation rate of the solar greenhouse system should be evaluated by the heat loss rate.. After calculation, △Q2>△Q1, so in the greenhouse structure, in the face of the insulation effect of greenhouse is greater than the wall. And △T1>△T2 and wall temperature variation amplitude greater than the ground temperature variation and greenhouse planting plant leaves of occlusion in the ground to receive the sun light is small, and because of the winter sun altitude angle lead to ground receiving radiation less than wall. Moreover, the surface soil moisture content is higher, which causes the difference of the ground temperature difference and the temperature heat conduction of the ground surface is not obvious. But the ground heat storage is greater than the wall, is mainly due to the high specific heat, high density of ground water..5. Large solar greenhouse, the night out heat dissipation area, heat dissipation rate, heat dissipation, the thickness of the wall heat release the speed of the indoor heat loss, indoor temperature drop fast. The greenhouse is not the bigger the insulation performance is better. The heat preservation performance of the composite wall solar greenhouse is better than that of the thick wall, and the heat capacity of the composite is higher than that of the soil, and it provides more heat for the indoor.. When encountering extremely cold weather, the thick earth wall can supply the internal heat continuously, the thicker the wall can display its heat preservation superiority. |
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