膨润土基有机复合相变材料性能研究

发布时间：2018-06-30 21:42

  本文选题：储能 + 复合相变材料　； 参考：《苏州科技大学》2017年硕士论文

【摘要】：随着经济快速发展,能源的消耗量越来越大,带来的环境问题也越来越大。据统计,我国建筑能耗占社会总能耗的40%以上,采暖和空调占比达50%左右,建筑节能已成为社会关注的焦点。相变储能以潜热方式储存能量,具有储能密度大、储能温度变化小等优点,被广泛应用于能量存储、余热回收、太阳能利用、建筑节能等领域。相变材料与建筑围护结构相结合,有助于改善室内热环境,降低室内温度峰值,减少空调能耗。储能技术是一种提高能源利用率,清洁无污染的节能技术,有利于解决能源供应与需求在时间和空间上不匹配的矛盾,在建筑节能中具有广阔的应用前景。将十四酸(MA)、十六醇(HD)和十二酸(LA)、聚乙二醇1000(PEG)进行二元共混复合,通过步冷曲线法得到低共晶质量配比分别为48:52和28:72,其低共晶温度分别为35.3℃、32.1℃。通过酸、醇复合,克服了脂肪醇多次相变的缺点。利用T-history获得有机复合相变材料相变潜热分别为230.3kJ/kg和125.2kJ/kg,其固态有效导热系数分别为0.25W/(m·K)和0.19W/(m·K)。对两组有机复合相变材料进行热稳定性实验,300次热循环实验表明,48%MA+52%HD复合相变材料降温曲线变化不大,其结晶温度变化在0.2℃以内,28%LA+72%PEG复合相变材料经100次热循环后,结晶温度下降了2.0℃,热稳定性较差。采用“熔融插层法”,制备膨润土基有机复合相变材料,解决二元有机复合相变材料液相渗漏的问题。利用十六烷基三甲基溴化铵对钙基膨润土进行改性,增大了膨润土的纳米层间距离,降低了层间极性,提高亲油性,有利于有机大分子进入层间。利用扩散-渗出圈法确定了有机复合相变材料和改性膨润土的最佳质量复配比为5:5,并通过SEM、FT-IR、DSC等技术手段表征了复合情况,经200次热循环实验表明,实验样品的最大质量损失率为0.12%,表面没发生泄露、渗出、挥发等现象,复合稳定性良好。制备了相变材料含量为0%、3%、6%、9%的储能墙板,模拟夏季室外温度变化,测试了4种墙板的温度响应。随着相变材料含量的增加,储能墙板的温度调节能力越明显。相变材料含量为6%的储能墙板在高温段的平均温度比普通墙板降低了3.0℃,有效降低了墙板表面温度响应峰值,降低了峰值负荷,实现能量转移。利用Matlab模拟墙板内部传热过程,展示了墙板内部各节点不同时刻的温度分布。
[Abstract]:With the rapid development of economy, the consumption of energy is increasing and the environmental problems are becoming more and more serious. According to statistics, building energy consumption in China accounts for more than 40% of the total energy consumption, heating and air conditioning accounts for about 50% of Prida, building energy saving has become the focus of social attention. Phase change energy storage is widely used in energy storage, waste heat recovery, solar energy utilization, building energy saving and so on. The combination of phase change material and building envelope will help to improve the indoor thermal environment, reduce the peak indoor temperature and reduce the energy consumption of air conditioning. Energy storage technology is a kind of energy saving technology which can improve energy efficiency, clean and no pollution. It is helpful to solve the contradiction between energy supply and demand in time and space, and has a broad application prospect in building energy conservation. Tetradecanoic acid (MA), hexadecanol (HD), dodecanoic acid (LA) and polyethylene glycol 1000 (PEG) were mixed in binary blends. The low eutectic mass ratios were 48:52 and 28: 72, respectively, and the low eutectic temperatures were 35.3 鈩，

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