Abstract:

In view of the severe winter smog weather in the central and southern parts of Hebei Province and the solar greenhouse cannot fully utilize its proper thermal insulation function, the three-span solar greenhouse was designed and built. To verify its performance, the MATLAB software was used to fit the two-dimensional temperature field and image drawing of the three-span solar greenhouse. The results showed that the temperature of the three-span solar greenhouse at 00:23 was March 8> March 9> March 10. The temperature at 06:23 was the minimum of the three-span solar greenhouse of the day. The minimum temperature in three days was at 06:23 on March 10. The maximum temperature of the greenhouse was at 12:23 on March 8 of cloudy to overcast. The maximum temperature of the greenhouse was at 14:23 on March 9 of overcast to sunny. The maximum temperature of the greenhouse was from 12:23 to 14:23 on March 10 of sunny. The maximum temperature in the 3-day could reach 30℃. The temperature dropped faster from 16:23. From 9:23 to 10:23 on March 8 of cloudy to overcast and March 9 of overcast to sunny, the temperature rose from the upper middle of the north, middle and south of the greenhouse in turn and began to cool down from the lower part of the greenhouse at 16:23. From 09:23 to 10:23 on March 10 of sunny, the temperature rose from the upper middle of the south, middle and north of the greenhouse in turn and began to cool down from the lower part of the north, middle and south the greenhouse in turn at 16:23. The middle and lower part of the north side of the north of the greenhouse had the highest or lowest point of temperature. From March 8 to 10, 09:23 and 18:23 (15 to 20℃), 08:23 and 20:23 (10 to 15℃), the greenhouse temperature was basically the same. The soil temperature of the middle greenhouse was 22℃, the highest on the same day. The soil temperature of the north greenhouse was the lowest during the day. The soil temperature of the south greenhouse was the lowest during the night. The lowest soil temperature of the south greenhouse was 13℃. Light intensity was March 9< March 8< March 10. The thermophilic fruits and vegetables could be planted in the three-span solar greenhouse in mid-February, 25-30 days earlier than the single-film plastic greenhouse, while avoiding the high frequency of winter low temperature, cloudy and smoggy weather. The three-span solar greenhouse has obvious advantages.

Key words: three-span solar greenhouse, temperature field, distribution, MATLAB software, thermal environment simulation