石蜡体系相变材料北方地区温室大棚控温试验研究
发布时间：2018-03-15 09:38
本文选题：温室大棚 切入点：相变材料 出处：《东北电力大学》2017年硕士论文 论文类型：学位论文
【摘要】：温室大棚的发展缓解了北方冬季蔬菜供应压力,方便了人们的生活,因其经济、实用而得到推广使用,但也存在能源利用率低,环境污染的问题。为了满足作物生长所需的温度,同时达到环保、低碳的目标,温室大棚控温节能研究越来越受到重视。本课题将复合相变材料应用于温室大棚中,达到控制温室温度波动幅度的目的,即利用相变材料在特定温度范围内的热效应,将温室白天多余的热量转移至夜间,起到调节温度的作用。试验材料为自制六水氯化钙和加入不同添加剂的六水氯化钙复合相变材料以及石蜡和不同配比石蜡石墨粉复合相变材料。测量了各材料的相变温度和相变潜热;测试了自制六水氯化钙和加入不同添加剂的六水氯化钙复合相变材料的物理性能;研究了石蜡以及不同配比石蜡石墨粉复合相变材料的储(放)热性能;为研究两种复合相变材料在温室大棚中的实际应用效果,采用模型试验的方法,测试了分别加入两种复合相变材料的温室模型和对比模型的温控性能。其中,两个加入复合相变材料的温室模型为相变材料外挂于墙体内表面,即在蒸压粉煤灰多孔砖温室模型墙体内表面分别外挂用自封袋密封的六水氯化钙复合相变材料和石蜡石墨粉复合相变材料,对比模型为仅采用蒸压粉煤灰多孔砖的温室模型。结果表明:(1)控温试验采用的相变材料为添加1%硼砂和1%羧甲基纤维素钠的六水氯化钙体系和组成为95%的石蜡和5%的石墨粉的石蜡体系。控温试验用的六水氯化钙体系相变潜热为240.1994kJ/kg,相变起始温度为29.7℃,可降低六水氯化钙样品过冷度至1.3℃,提高相变时间至28min;石蜡体系,相变潜热为267.2490kJ/kg,相变起始温度为23.9℃,减少样品30.1%的升温时间,14.4%的降温时间。均符合在温室中应用相变材料的要求。(2)本课题采用建立温室模型的试验方法。夏季控温试验,添加石蜡体系温室模型,与对比温室模型相比,室内温度最大波幅差为13.9℃,后墙内侧温度最大波幅差为11.5℃。不同热工条件温室模型控温试验,添加六水氯化钙体系温室模型和石蜡体系温室模型室内温度波幅比对比模型分别小3.1℃、6.9℃;后墙内侧温度波幅分别小7.6℃、12.3℃。模拟极端气候控温试验,添加六水氯化钙体系温室模型和石蜡体系温室模型室内温度波幅比对比模型分别小5℃、8.1℃;后墙内侧温度波幅分别小3.2℃、3.5℃。综合试验数据可知,添加石蜡体系相变材料的温室模型控温效果最好。
[Abstract]:The development of greenhouse vegetables in winter in North China to ease the supply pressure, to facilitate people's lives, because of its economic, practical and widely used, but also has low energy efficiency and environmental pollution. In order to meet the needs of crop growth temperature, while achieving environmental protection, low carbon, energy research has greenhouse temperature control shed more attention. The composite phase change materials used in the greenhouse, to control greenhouse temperature fluctuations to thermal effect namely the use of phase change materials in a specific temperature range, the greenhouse in excess heat transfer to the night, play a role in regulating temperature. The materials were made of six water chloride calcium and adding different additives in six water calcium chloride composite phase change materials and different ratio of paraffin wax and graphite composite phase change materials. The phase transition temperature of each material and phase change latent heat measurement; measuring The physical properties of self-made six water calcium chloride and adding different additives in six water calcium chloride composite phase change materials; study the different ratio of graphite powder and paraffin wax composite phase change material storage (release) thermal properties; for practical application of two kinds of composite phase change material in the greenhouse, using the method of model test the temperature control performance of the greenhouse model and comparison of two models of composite phase change materials added respectively were tested. Among them, two with composite phase change material model for phase change materials in greenhouse external wall surface, namely in autoclaved fly ash brick wall surface model of greenhouse respectively using external bag sealing water six calcium chloride and paraffin composite phase change material graphite composite phase change materials, compared the model only by steam pressure greenhouse model of fly ash porous brick. The results showed that: (1) phase change material temperature control experiment Paraffin system six calcium chloride water system with 1% borax and 1% sodium carboxymethyl cellulose and is composed of 95% paraffin and 5% graphite powder. The temperature control experiment with six calcium chloride water system of latent heat is 240.1994kJ/kg, phase transition temperature of 29.7 DEG C, six calcium chloride water samples can reduce the degree of supercooling to 1.3 C, to improve the transformation time of 28min; paraffin system, latent heat is 267.2490kJ/kg, phase transition temperature of 23.9 DEG C, reducing sample 30.1% heating time, cooling time. 14.4% are in line with the application of phase change materials in the greenhouse. (2) the test method of building greenhouse model. Summer temperature control test, add paraffin system of greenhouse model, and compared the greenhouse model, the maximum amplitude of the indoor temperature difference of 13.9 degrees, the temperature inside the wall after the maximum amplitude difference of 11.5 DEG. Different thermal conditions of greenhouse temperature control model test, adding six water calcium chloride 浣撶郴娓╁妯″瀷鍜岀煶铚′綋绯绘俯瀹ゆā鍨嬪鍐呮俯搴︽尝骞呮瘮瀵规瘮妯″瀷鍒嗗埆灏，
本文编号：1615465
本文链接：https://www.wllwen.com/shoufeilunwen/zaizhiyanjiusheng/1615465.html
教材专著
