The relationship between the use of thermal insulation quilts in vegetable greenhouses and the incidence of sunlight

The angle and shape of the lighting roof for the insulation of vegetable greenhouses The lighting roof is also called the front roof, and its function is lighting and insulation. The angle of the lighting roof is the angle between the lighting and the ground. It is necessary to maintain the corresponding angle of the lighting roof, so that the incident angle formed by the lighting roof and the sunlight is as small as possible. At this stage of greenhouse planting, greenhouse insulation quilts are selected to achieve the stability of the temperature in the greenhouse. However, it should be noted that the greenhouse uses the radiant heat generated by the sun to make the temperature in the greenhouse increase. In addition, the heat generated in the greenhouse cannot be carried out by the wind, which is very likely to generate high temperature and penetrate from the soil surface into the ground. . In addition, the temperature in the front and rear and left and right directions of the greenhouse is often very uneven, so that the temperature in the greenhouse is not coordinated, resulting in a temperature difference. If farmers do not pay attention, it will affect the growth of crops and affect the yield of crops. It is necessary to use all anti-corrosion and anti-aging materials in use, and it must not lose hair during use, and can absorb the dust on the greenhouse film, so that the greenhouse film can always be kept clean and bright, and the amount of lighting in the greenhouse is improved, especially in winter. The lighting time is short, and the sunlight is very valuable. After increasing the amount of light, the advantages can be greatly improved compared with the use of curtains, no need for people to clean, and the damage to the greenhouse film is reduced. So what is the relationship between the correct use of vegetable greenhouse insulation and the incidence of sunlight in winter and summer? Now let's introduce it to you. At least after reading this article, the wrong use rate of the vegetable greenhouse insulation quilt will be reduced to a lower level. Ten centimeters, the nylon rope under the insulation blanket is fixed on the iron rod of the greenhouse, and the upper end is fixed on the steel wire. : 1. Of course, the incident angle is equal to 0 degrees, and it is ideal when the sunlight is perpendicular to the lighting roof, because the reflectivity of the lighting roof to the sunlight is equal to 0 at this time, and almost all the sunlight hitting the lighting surface can penetrate into the greenhouse. 2. The height angle of the sun in winter is very small. To make the lighting surface perpendicular to the sun, the lighting surface needs to be very steep. For example, in Beijing, the angle between the lighting surface and the ground must reach more than 60 degrees, so the north wall needs to be quite high. 3. The position of the sun moves all the time, and the lighting surface of the solar greenhouse is generally a curved surface, and the sunlight incident angle of each point on the lighting surface at the same time is also different, so it is necessary to make all points on the lighting surface at all times. It is obviously impossible to be perpendicular to the rays of the sun. 4. In winter, under the conditions of light wind at night on a clear day, there may be a temperature inversion phenomenon in which the temperature inside the greenhouse is 2-3°C lower than the temperature outside the greenhouse. Therefore, when the temperature outside the shed is significantly lower than that inside the shed, our greenhouse insulation can be used to maintain the temperature unchanged. In addition, the surface of the film on both sides of the greenhouse also transfers heat to the outside to cool down, so that the marginal ground of the greenhouse forms a low temperature zone. Therefore, in winter and spring, adding a skirt film with a height of about meters on both sides of the plastic greenhouse can increase the marginal ground temperature. This is especially effective for growing seedlings in greenhouses and extra-early-maturing cultivation in winter. But why does the temperature inversion occur? The main reason for the temperature inversion is that the soil surface and crop bodies heated during the day radiate heat through the mulch at night, and this activity is very intense at night with clear winds, which leads to the phenomenon of temperature inversion. At the same time, under the action of prestige, the air outside the greenhouse can supplement the heat, while the effect of prestige in the greenhouse is useless, so that there is no heat supplement in the greenhouse. Therefore, the temperature inside the greenhouse is lower than the temperature outside the greenhouse. The same problem will also occur in medium and small greenhouses. When this happens, the greenhouse thermal insulation quilt will play a very good role in thermal insulation.