分级相变储放热系统在日光温室中的应用效果

APPLICATION EFFECT OF GRADED PHASE-CHANGE HEAT STORAGE AND RELEASE SYSTEM IN SOLAR GREENHOUSE

针对北方日光温室夜间室内低温问题,该文以收集利用温室内白天富余太阳能为目标,在理论分析相变材料特性的基础上,开发基于管材封装方式的两级相变储放热系统,并通过对比试验,在北京地区的日光温室中开展冬季应用效果试验。结果表明,所开发系统对冬季室内空气温度和土壤温度均有良好的增温效果。其中,空气温度方面,在试验周期内,试验温室夜间(17:00—次日08:00期间)平均室内气温比对照温室平均提高1.0℃,最低气温平均提高1.2℃;在晴天、多云不同天气条件下,试验温室的夜间平均气温分别提高1.3、1.2℃,最低气温分别提高1.5、1.7℃;在两天一夜未盖保温被的阴雪天气条件下,试验温室的室内气温全程高于对照温室,最大温差仍有1.9℃。在土壤温度方面,晴天和多云天气下,试验温室10和15 cm处的土壤温度平均提高0.6和0.8℃,研究表明所开发系统具有良好的持续储放热能力,能改善日光温室的冬季热环境。

Aiming at the problem of low temperature at night in the northern solar greenhouse,the paper aimed to collect and utilize surplus solar energy in the greenhouse during the day,on the basis of theoretical analysis of the characteristics of phase change materials,the two-stage phase change heat storage and release system based on the tube packaging method was developed,and the winter application effect test was carried out in the solar greenhouse in Beijing through comparative experiments.The results showed that the designed system had good warming effect on indoor air temperature and soil temperature in winter.In terms of indoor air temperature,during the test cycle,the average indoort emperature during night(from 17:00 to 08:00 in the next day)of the experimental greenhouse was 1.0℃higher than that of the comparative greenhouse,and the average minimum temperature of the experimental greenhouse was increased by 1.2℃.Under sunny and cloudy weather conditions,the average indoor temperature during night of the experimental greenhouse was increasedby 1.3℃,1.2℃,respectively,the minimum temperature of the experimental greenhouse was 1.5℃,1.7℃ higher than that of the comparative greenhouse.Under the condition of snowy weather without heat preservation quilt for two days and one night,the indoor temperature of the test greenhouse was higher than that of the control greenhouse,the maximum temperature difference was 1.9℃.In addition,the average soil temperature at 10 cm and 15 cm of the experimental greenhouse was increased by 0.6-0.8℃ on sunny and cloudy days.The findings show that the system has aprosperous heat storage and release capacity,which can improve the thermal environment of solar greenhouse.