日光温室论文外挂型相变材料日光温室的蓄热效果研究.docVIP

日光温室论文：外挂型相变材料日光温室的蓄热效果研究 【中文摘要】在我国北方大部分地区,日光温室夜间的温度往往不能满足温室内作物的生长需要,因此夜间需要向温室内提供额外的热量以维持温室的正常生产。传统的供热方式如煤炭供热等具有能耗大,污染严重等缺点。在能源越来越紧张,环境污染日益严重的今天,这些方法均不可取。因此在低碳经济形式下应选择清洁有效的方式为温室供暖。我国的太阳能资源十分丰富,西北地区尤为明显。许多日光温室在白天蓄积的热量远远超过植物所需的热量,因此,本文将相变材料应用在日光温室中,可以将温室在白天多余能量储存起来,在夜晚温度低的时候释放,起到对热量“削峰填谷”的作用。这样既解决了温室的夜间的能量短缺问题,又使温室白天的温度不至于过高而给植物带来损伤。本文筛选出适合日光温室应用的相变材料CaCl2·6H2O,并采用工业级无水CaCl2大量制备了CaCl2·6H2O后将其外挂在普通砖墙温室的后墙内表面制成外挂型相变材料温室,测试并分析了其蓄热效果。同时对课题组原有的内渗型相变材料温室的蓄热效果进行测试分析。最后,对比了外挂型相变材料温室和内渗型相变材料温室的蓄热效果,对其应用效果进行综合评价。研究结果表明:（1）纯物质相变材料CaCl2·6H2O符合温室中相变材料的应用要求,是较为理想的材料。（2）通过对安装CaCl2·6H2O前后温室内空气总对流换热量和热量减少量分析得知,安装CaCl2·6H2O前,温室内空气总对流换热量和热量减少量基本相等。安装CaCl2·6H2O后,温室各内表面与温室内空气总对流换热量为-6450.91kJ,热量减少量为-1506.33kJ,CaCl2·6H2O向其中放热量为4944.58kJ。CaCl2·6H2O的相变效率为67.53%。(3通过对内渗型相变材料温室蓄热效果的研究表明,内渗型相变材料温室蓄热效果良好,晴天夜间的室内平均温度比普通温室高0.9℃,阴天高0.3℃。无论晴天阴天,内渗型有机相变材料温室的墙体温度均高于普通温室,晴天墙体的温度较普通温室平均高1.6℃,阴天平均高0.6℃。（4）通过对外挂相变材料温室和内渗相变材料温室的蓄热效果对比得出:内渗型温室的蓄热效果优于外挂型温室,晴天内渗型的室内温度较外挂型温室夜间平均高0.2℃,阴天高0.3℃。而内渗型温室后墙内表面温度也一直高于外挂型温室,晴天时候平均高1.1℃,阴天平均高0.5℃。 【英文摘要】In the most part of northern china, the temperature in the greenhouse at night is often lower than it is required by crops growing. Therefore, extra heat should be provided to raise it for the greenhouse normal production. The traditional heating methods using coal are polluted and consume precious energy. Nowadays, the energy became less and the environment is increasingly seriously contaminated, so these methods should be instead by some clean and effective ways to heat the greenhouse.Our country抯 solar energy resource is extremely rich, especially in the northwest part of it. The amount of heat which was accumulated by many greenhouses far exceeds its need at night. According to this, we use the phase change material in greenhouse, which can move excess energy accumulated by the greenhouse in the daytime to the night to protect the plant in the daytime from the high temperature and ease the shortage of heat in the greenhouse in night.The text use CaCl2?H2O as phase c