芒硝基相变储能材料制备及其模拟温室应用研究
发布时间：2018-10-31 16:31
【摘要】：能源与环境是现今世界可持续发展中最受关注的热点问题之一。青藏高原地区太阳光资源丰富,同时一年中大部分时间气候寒冷。温室若夜间不加热难以维持作物生长,传统的加热方式需要消耗大量化石燃料能源,同时产生大量有毒有害温室气体,污染环境。高效节能型温室种植蔬菜在青藏高寒地区推广应用,能有效克服恶劣多变的天气,解决反季节蔬菜生产问题,基本达到当地人们对蔬菜的需求,具有显著的经济和社会效益。因此新能源太阳能存储相变材料在温室环境的调控模式,便成了温室工程技术领域追求的新目标。以芒硝(Na_2SO_4·10H_2O)为主相变材料,采用物理共混法,筛选出合适添加辅助材料组成多元混盐体系,制备出相变温度在10~25℃左右的三种Na_2SO_4·10H_2O基复合相变材料,添加成核剂、防相分层剂、导热剂等对相变材料进行进一步优化。通过热重分析(TG)、T-history曲线、差示扫描量热法(DSC)热常数分析(Hot Disk)等方法表征了相变材料相变温度、相变潜热和导热等性能。然后采用真空吸附法,以膨胀石墨为载体,制备出导热增强型膨胀石墨/复合Na_2SO_4·10H_2O定形相变材料。最终将芒硝基复合相变材料放置于模拟温室中探究相变材料保温性能。结果表明:当Na_2SO_4·10H_2O 86.4%、Na_2CO_3·10H_2O9.6%、NaCl 4%时,相变温度为24.6℃。对其改性添加成核剂硼砂4%,增稠剂羧甲基纤维素钠1.5%,导热剂石墨粉1%时,复合相变材料导热系数为1.0216W/(m·K),材料相变潜热为127kJ/kg,经过300次相变循环,材料仍旧能保持较好的相变性能。最后将此材料在简易模拟温室中试验,当芒硝基相变材料添加量为25、35和45kg时清晨日出前最低温度分别可以提高1、3.6和4.4℃。表明该芒硝基复合相变材料适用于高寒气候环境下简易温室。芒硝基相变储能材料制备方法简单,成本低,环境友好,在高寒地区温室中具有良好的保温性能,还可以与传统温室控温方法结合,在温室保温方面具有广阔应用前景。
[Abstract]:Energy and environment are one of the hot issues in the sustainable development of the world. The Qinghai-Xizang Plateau is rich in solar light and has a cold climate for most of the year. If it is difficult to maintain crop growth in greenhouse without heating at night, the traditional heating methods need to consume a large amount of fossil fuel energy, produce a large number of toxic and harmful greenhouse gases, and pollute the environment at the same time. The popularization and application of high efficiency and energy saving greenhouse planting vegetables in Qinghai-Tibet alpine region can effectively overcome the bad and changeable weather, solve the problem of off-season vegetable production, basically meet the local people's demand for vegetables, and have remarkable economic and social benefits. Therefore, the regulation mode of new energy solar energy storage phase change materials in greenhouse environment has become a new goal in greenhouse engineering field. With Na_2SO_4 10H_2O as the main phase change material and physical blending method, the suitable auxiliary materials were selected to make up the multi-component mixed salt system. Three kinds of Na_2SO_4 10H_2O based composite phase change materials with phase transition temperature of about 10 ~ 25 鈩，
本文编号：2302876
[Abstract]:Energy and environment are one of the hot issues in the sustainable development of the world. The Qinghai-Xizang Plateau is rich in solar light and has a cold climate for most of the year. If it is difficult to maintain crop growth in greenhouse without heating at night, the traditional heating methods need to consume a large amount of fossil fuel energy, produce a large number of toxic and harmful greenhouse gases, and pollute the environment at the same time. The popularization and application of high efficiency and energy saving greenhouse planting vegetables in Qinghai-Tibet alpine region can effectively overcome the bad and changeable weather, solve the problem of off-season vegetable production, basically meet the local people's demand for vegetables, and have remarkable economic and social benefits. Therefore, the regulation mode of new energy solar energy storage phase change materials in greenhouse environment has become a new goal in greenhouse engineering field. With Na_2SO_4 10H_2O as the main phase change material and physical blending method, the suitable auxiliary materials were selected to make up the multi-component mixed salt system. Three kinds of Na_2SO_4 10H_2O based composite phase change materials with phase transition temperature of about 10 ~ 25 鈩，
本文编号：2302876
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