Greenhouse manufacturers explain the principle of glass greenhouse

　Glass greenhouse refers to a greenhouse with hot-dip galvanized steel skeleton and glass as daylighting material. The top and surrounding of the greenhouse are special aluminum profiles. In cultivation facilities, glass greenhouse, as a form with the longest service life, is suitable for use in a variety of regions and various climatic conditions. This kind of greenhouse can realize full-automatic control, with optional supporting facilities, such as external shading system, internal shading system, fan water curtain cooling system, top opening window ventilation system, light supplement system, seedbed seedling raising system, sprinkler system, computer control system, etc.

1. Understand what is the thermal insulation effect of the atmosphere? (the earth's atmosphere is almost transparent to the solar short wave radiation. Most of the solar radiation can be emitted to the ground through the atmosphere to increase the temperature of the ground; the atmosphere is an insulating layer to the ground long wave radiation, which intercepts most of the heat released by the ground radiation in the atmosphere and returns the heat to the ground through the atmospheric inverse radiation. People call this effect of the atmosphere atmospheric thermal insulation effect.) Therefore, the increase of carbon dioxide will strengthen the "greenhouse effect" of the atmosphere. (with the increase of carbon dioxide, the ability of the atmosphere to absorb long wave radiation from the ground is enhanced, and the temperature of the atmosphere is increased; the ability of the atmosphere to reverse radiation is enhanced, and the heat to compensate for the loss of the ground is also increased)

2. How to understand the greenhouse effect of glass greenhouse? The function of heat preservation is similar to that of carbon dioxide glass. The solar short wave radiation can heat the room through the glass and plastic greenhouse, and the ground radiation released after the indoor ground heating is blocked by the glass or plastic greenhouse, reducing the heat loss. At the same time, the glass also prevents the indoor (warm) and outdoor (cold) air from exchanging heat by convection or turbulence, making the temperature in the greenhouse higher than that outside.

3. What are the beneficial effects of greenhouse technology in the north on the light, heat and water conditions of agricultural production? (① make full use of the light in winter; ② increase the temperature in the greenhouse to reduce the impact of low temperature and freezing injury on agriculture in winter, so that crops can be planted in winter; ③ it is conducive to maintaining and regulating the moisture of air and soil in the greenhouse.)

Before the early 20th century, people mistakenly believed that the thermal insulation mechanism of glass greenhouse (flower house without artificial heating) was the same as that of atmosphere, so it was called "greenhouse effect". In 1909, American physicist wood made greenhouse (greenhouse) experiments with rock salt (transparent to long and short wave radiation and will not intercept long wave radiation) and glass (capable of intercepting long wave radiation through short wave radiation). The results showed that the temperature in the two greenhouses was as high as that in the greenhouse. This shows that the heat preservation function of greenhouse mainly lies not in whether it intercepts or absorbs long wave radiation, but in its glass or rock salt wall preventing the heat exchange of indoor (warm) and outdoor (cold) air in the form of convection or turbulence. According to the research, the effect of preventing the indoor and outdoor heat exchange of air is 3-4 times greater than that of atmospheric insulation gas absorbing long wave radiation.