新型大跨度非对称塑料大棚内冬季温光变化特征研究

Winter temperature and sunlight variation characteristics in large-span asymmetric plastic greenhouses

【目的】研究大跨度非对称塑料大棚内冬季温光变化特征,为新型棚体的开发与设计提供思路。【方法】根据跨度和覆盖层数不同,选取5座大棚,分别为17m单层(17-1)、17m双层(17-2)、18m单层(18-1)、18m双层(18-2)和20m单层(20-1),并以塑料拱棚和日光温室为对照,对大棚进行连续气温监测及典型晴天、阴天、雪天条件下气温、土壤温度(20cm深)和光照环境的监测与比较。【结果】①2017-12-01至2018-01-31,18-1、18-2、17-1、17-2、20-1温室冬季平均最低气温分别为4.1,4.9,-1.9,0,-1.8℃,平均最高气温分别为31.7,27.8,32.6,31.9,33.9℃。②典型晴天条件下,18-1、18-2、17-1、17-2、20-1温室最低气温分别为4.4,5.0,-3.4,-2.6,-3.1℃,较室外分别高11.6,12.2,3.8,4.6,4.1℃,较塑料拱棚分别高10.5,11.1,2.7,3.5,3.0℃,较日光温室分别低6.3,5.7,14.1,13.3,13.8℃;典型阴天条件下,最低气温分别为6.3,7.5,1.0,1.6,1.7℃,较室外分别高8.4,9.6,3.1,3.7,3.8℃,较塑料拱棚分别高7.7,8.9,2.4,3.0,3.1℃,较日光温室分别低5.4,4.2,10.7,10.1,10.0℃;典型雪天条件下,最低气温分别为4.9,6.0,-2.7,-1.0,-1.4℃,较室外分别高10.7,11.8,3.1,4.8,4.4℃,较塑料拱棚分别高10.0,11.1,2.4,4.1,3.7℃,较日光温室分别低5.0,3.9,12.6,10.9,11.3℃。典型晴天条件下,18-1、18-2、17-1、17-2、20-1温室20cm深处土壤平均温度分别为12.2,12.3,10.0,11.1,9.6℃,较塑料拱棚分别高6.0,6.1,3.8,4.9,3.4℃;典型阴天条件下,土壤平均温度分别为11.9,12.1,9.5,10.6,9.6℃,较塑料拱棚分别高5.8,6.0,3.4,4.5,3.5℃;典型雪天条件下,土壤平均温度分别为11.2,11.4,9.9,10.5,9.5℃,较塑料拱棚分别高5.4,5.6,4.1,4.7,3.7℃。③对大棚内南北方向气温和光照分布进行比较可知,各试验温室内气温以中部最高,南北次之,分布差异大小排列为17-1温室>18-1温室>20-1温室>18-2温室>17-2温室;各试验温室南部光照最好,中部略低于南部,北部最差,透光率大小排序为18-1温室>18-2温室>20-1温室>17-1温室>17-2温室。【结论】综合考虑温光环境性能可知,18-2温室大棚的保温性能较好,平均最低气温和土壤平均温度高,无极端低温和高温情况,且南北方向气温、光照分布差异小,透光率高,更适合推广应用。

【Objective】 A new large-span asymmetric plastic greenhouse was designed and built to provide corresponding ideas for the development and design of new shed.【Method】 According to the span size and number of covering layers,five tested greenhouses including 17 m span single-layer plastic greenhouse (17-1),17 m span double-layer plastic greenhouse (17-2),18 m span single-layer plastic greenhouse (18-1),18 m span double-layer plastic greenhouse (18-2),and 20 m span single-layer plastic greenhouse (20-1) were selected. Continuous temperature monitoring and comparison of temperature,soil temperature and illumination environment under typical sunny,cloudy and snowy days were carried out in the experimental greenhouses with the traditional arch plastic greenhouse and the Chinese solar greenhouse (CSG) as the control.【Result】① From December 01,2017 to January 31,2018,the average minimum temperatures in the winter of 18-1,18-2,17-1,17-2, and 20-1 were 4.1,4.9,-1.9,0,and -1.8 ℃,and the average maximum temperatures were 31.7,27.8,32.6,31.9,and 33.9 ℃ respectively.② Under typical sunny conditions,the minimum temperatures of 18-1,18-2,17-1,17-2 and 20-1 were 4.4,5.0,-3.4,-2.6, and -3.1 ℃,and they were 11.6, 12.2, 3.8,4.6,and 4.1 ℃ higher than outside,10.5,11.1,2.7,3.5,and 3.0 ℃ higher than arch plastic greenhouse and 6.3, 5.7, 14.1, 13.3, and 13.8 ℃ lower than solar greenhouse. Under typical cloudy conditions,the minimum temperatures were 6.3,7.5,1.0,1.6,and 1.7 ℃,which were 8.4,9.6,3.1,3.7,and 3.8 ℃ higher than outdoor temperatures, 7.7,8.9,2.4,3.0,and 3.1 ℃ higher than arch plastic greenhouse,and 5.4,4.2,10.7,10.1, and 10.0 ℃ lower than solar greenhouse, respectively. Under typical snow conditions,the minimum temperatures were 4.9,6.0,-2.7,-1.0, and -1.4 ℃,which were 10.7,11.8,3.1,4.8,and 4.4 ℃ higher than outdoor temperatures,10.0,11.1,2.4,4.1,and 3.7 ℃ higher than arch plastic greenhouse,and 5.0,3.9,12.6,10.9,and 11.3 ℃ lower than solar greenhouse, respectively. Under typical sunny conditions, the average soil temperatures of 18-1,18-2,17-1,17-2,and 20-1 were 12.2,12.3,10.0,11.1,and 9.6 ℃,which were 6.0,6.1,3.8,4.9,and 3.4 ℃ higher than arch plastic greenhouse.Under typical snowy conditions,the average soil temperatures were 11.9,12.1, 9.5, 10.6,and 9.6 ℃,which were 5.8,6.0,3.4,4.5, and 3.5 ℃ higher than arch plastic greenhouse. Under typical cloudy conditions,the average soil temperatures were 11.2,11.4, 9.9, 10.5,and 9.5 ℃,which were 5.4,5.6,4.1,4.7,and 3.7 ℃ higher than arch plastic greenhouse.③ Comparison of temperature and light distribution between the north and south of the experimental greenhouse showed that the temperature in each test greenhouse was the highest in the middle,followed by the south and the north.The temperature distribution in the greenhouses was in the order of 17-1>18-1>20-1>18-2>17-2.The experimental greenhouses had the best light in the south, slightly lower in the middle and the worst in the north.The light transmittance was in the order of 18-1>18-2>20-1>17-1>17-2.【Conclusion】 Comprehensively considering thermal and light environment,18 m double-layer asymmetric greenhouse had good thermal insulation performance,minimum average temperature and high average soil temperature without extreme low and high temperature.The north and south temperature and light distribution had small difference,the transmission rate was high,and it was more suitable for promotion and application.