温室大棚压膜绳的性能特点
温度条件
Temperature condition
塑料薄膜具有保温性。覆盖薄膜后,大棚内的浊度将随着外界气温的升高而升高,随着外界气温下降而下降。并存在着明显的季节变化和较大的昼夜温差。越是低温期温差越大。一般在寒季大棚内日
增温可达3-6℃,阴天或夜间增温能力仅1-2℃。春暖时节棚内和露地的温差逐渐加大,增温可达6-15℃。外界气温升高时,棚肉增温相对加大,最高可达20℃以上,因此大棚内存在着高温及冰冻危害,需进行人工调整。在高温季节棚内可产生50℃以上的高温。进行全棚通风,棚外覆盖草帘或搭成"凉棚",可比露地气温低1-2℃。冬季晴天时,夜间最低温度可比露地高1-3℃,阴天时几科与露地相同。因此大棚的主要生产季节为春、夏、秋季。通过保温及通风降温可使棚温保持在15-30℃的生长适温。
Plastic film has thermal insulation. After covering the thin film,
turbidity in the greenhouse will increase with the increase of ambient
air temperature, and decrease with the decrease of ambient temperature.
There is obvious seasonal variation and large diurnal temperature
difference. The greater the temperature difference is at the lower
temperature. Generally, the daily temperature increase is 3-6 degrees in
the cold season, and it is only 1-2 degrees in cloudy or nocturnal
temperature. The spring season and in the greenhouse temperature
gradually increased, increasing temperature can reach 6-15 deg. When the
external temperature rises, the temperature of the shed meat increases
relatively, and the highest temperature can reach above 20 degrees.
Therefore, there is high temperature and freezing hazard in the
greenhouse, which needs artificial adjustment. In the season of high
temperature shed can generate high temperature above 50 DEG C. The whole
roof ventilation, shed covered straws or a "shelter", can than that of
low temperature 1-2 DEG C. On a sunny day in winter, the lowest
temperature is higher than that of the night can be 1-3 degrees, cloudy
when several in the same. Therefore, the main production season of the
greenhouse is spring, summer and autumn. Through the thermal insulation
and ventilation and cooling, the temperature of the shed can be kept at
15-30 C.